WO2015079531A1 - Air conditioning apparatus - Google Patents

Abstract

An air conditioning apparatus (100) is provided with, in a heating medium circulation circuit (B), a heating medium transfer apparatus using cooling medium expansion, said heating medium transfer apparatus using expansion power of a heat source-side cooling medium as transfer power of a heating medium.

Description

Air conditioner

The present invention relates to an air conditioner applied to, for example, a building multi air conditioner.

Conventionally, in an air conditioner such as a multi air conditioning system for buildings, for example, a refrigerant is used between an outdoor unit (outdoor unit) that is a heat source unit arranged outside a building and an indoor unit (indoor unit) arranged inside a building. Circulate. And the refrigerant | coolant thermally radiated and absorbed heat, and air-conditioning object space was cooled or heated with the air heated and cooled. As the refrigerant used in such an air conditioner, for example, an HFC (hydrofluorocarbon) refrigerant is often used. In addition, one using a natural refrigerant such as carbon dioxide (CO ₂ ) has been proposed.

Also, in an air conditioner called a chiller, heat or heat is generated by a heat source device arranged outside the building. Then, water, antifreeze, etc. are heated and cooled by a heat exchanger arranged in the heat source machine, and this is transferred to a fan coil unit, a panel heater, etc., which are indoor units, for cooling or heating (for example, Patent Documents) 1).

Also, a waste heat recovery type chiller, which is connected to four water pipes between the heat source unit and the indoor unit, supplies cooled and heated water at the same time, and can freely select cooling or heating in the indoor unit (For example, refer to Patent Document 2).

Also, there is a configuration in which a heat exchanger for the primary refrigerant and the secondary refrigerant is disposed in the vicinity of each indoor unit and the secondary refrigerant is conveyed to the indoor unit (for example, see Patent Document 3).

Also, there is a configuration in which an outdoor unit and a branch unit having a heat exchanger are connected by two pipes and a secondary refrigerant is conveyed to the indoor unit (for example, see Patent Document 4).

Further, in an air conditioner such as a multi air conditioner for buildings, a refrigerant such as water is circulated from the outdoor unit to the repeater and a heat medium such as water is circulated from the repeater to the indoor unit. Some are configured to reduce the conveyance power of the heat medium while circulating (see, for example, Patent Document 5).

Japanese Patent Laying-Open No. 2005-140444 (page 4, FIG. 1, etc.) JP-A-5-280818 (4th, 5th page, FIG. 1 etc.) Japanese Patent Laid-Open No. 2001-289465 (pages 5 to 8, FIG. 1, FIG. 2, etc.) JP 2003-343936 A (Page 5, FIG. 1) WO2010 / 049998 (3rd page, FIG. 1 etc.)

In conventional air conditioners such as multi air conditioners for buildings, since the refrigerant is circulated to the indoor unit, the refrigerant may leak into the room. On the other hand, in the air conditioning apparatus as described in Patent Document 1 and Patent Document 2, the refrigerant does not pass through the indoor unit. However, in the air conditioning apparatus as described in Patent Document 1 and Patent Document 2, it is necessary to heat or cool the heat medium in the heat source unit outside the building and transport it to the indoor unit side. For this reason, the circulation path of a heat medium becomes long. Here, if it is going to convey the heat which carries out the work of predetermined heating or cooling with a heat medium, the amount of energy consumption by conveyance power etc. will become higher than a refrigerant. Therefore, when the circulation path becomes long, the conveyance power becomes very large. From this, it can be seen that energy saving can be achieved in the air conditioner if the circulation of the heat medium can be well controlled.

In the air conditioner as described in Patent Document 2, in order to be able to select cooling or heating for each indoor unit, four pipes must be connected from the outdoor side to the indoor side. It was bad. In the air conditioner described in Patent Document 3, since it is necessary to have a secondary medium circulation means such as a pump for each indoor unit, it is not only an expensive system but also a large noise, which is practical. It was not something. In addition, since the heat exchanger is in the vicinity of the indoor unit, the possibility that the refrigerant leaks in a place close to the room could not be excluded.

In the air conditioner as described in Patent Document 4, since the primary refrigerant after heat exchange flows into the same flow path as the primary refrigerant before heat exchange, a plurality of indoor units are connected. In addition, the maximum capacity of each indoor unit could not be demonstrated, resulting in a wasteful configuration. In addition, since the branch unit and the extension pipe are connected by a total of four pipes of two cooling units and two heating units, as a result, the system in which the outdoor unit and the branch unit are connected by four pipes. The system was similar in construction to that of poor workability.

In the air conditioner described in Patent Document 5, there is no particular problem when a single refrigerant or a pseudo-azeotropic refrigerant is used as the refrigerant. However, when a non-azeotropic refrigerant mixture is used as a refrigerant, when using a refrigerant-heat medium heat exchanger as an evaporator, due to a temperature gradient between the saturated liquid temperature and the saturated gas temperature of the refrigerant, There was a possibility that the heat medium would freeze.

Moreover, in patent document 5, when a heat medium is heated with a refrigerant | coolant, it is conveyed with respect to the indoor unit which performs heating operation among the connected indoor units using a heat medium conveyance means. . Further, when the heat medium is cooled by the refrigerant, the heat medium cooled by the heat medium transport unit is used for the indoor unit that performs the cooling operation among the connected indoor units by using the heat medium transport device. Transport is in progress. Therefore, in performing cooling operation or heating operation using such a refrigerant and a heat medium, the heat medium transport device is necessary as a heat capacity transport means for cooling and a heat capacity transport means for heating. With this operation, the cooling operation or the heating operation can be continued.

On the other hand, when heating or cooling the heat medium using the refrigerant, the refrigerant conveyed to the refrigerant-heat medium heat exchanger needs to be a high temperature high pressure or a low temperature low pressure, and the refrigerant is compressed in the refrigerant circuit, By repeating the expansion, heat exchange between the refrigerant and the heat medium is realized. In this process, when the refrigerant is expanded from the high temperature and high pressure to the low temperature and low pressure, there is expansion energy associated with the expansion of the refrigerant.

For these reasons, in the air conditioner, in order to transport the heated or cooled heat medium to the connected indoor units, external heat is required to drive the heat medium transport apparatus and the heat medium transport apparatus. is there. On the other hand, in the refrigerant circuit, the refrigerant conveyed to the refrigerant-heat medium heat exchanger for heating or cooling the heat medium is repeatedly compressed and expanded at high temperature, high pressure or low temperature and low pressure, and the expansion process However, although expansion energy exists, it has not been utilized as energy and has not fully utilized the energy saving performance as a system.

For this reason, in the air conditioner, if the expansion energy generated when the refrigerant is expanded can be used for the power of the heat medium transport device necessary for transporting the heat medium, energy saving as a system can be achieved. Furthermore, if the number of parts can be reduced by this, it is possible to save space as a system.

The present invention has been made in order to solve the above-described problems. By utilizing the generated expansion energy as power of a heat medium transport device necessary for transporting to a plurality of connected indoor units, the present invention can save energy. It aims at providing the air conditioning apparatus which improved the.

An air conditioner according to the present invention includes a compressor, a heat source side heat exchanger, a plurality of expansion devices, a refrigerant side flow path of a plurality of heat exchangers between heat media, and a plurality of refrigerant flow switching devices that switch a refrigerant circulation path. A refrigerant circulation circuit that circulates the heat source side refrigerant by connecting with a refrigerant pipe, a plurality of use side heat exchangers, and a heat medium side flow path of the plurality of heat exchangers between the heat mediums are connected by a heat medium pipe. A heat medium circulation circuit that circulates the heat medium, and the heat source side refrigerant and the heat medium exchange heat in the heat exchanger between the heat medium, wherein the heat medium circulation circuit includes a plurality of the heat medium circulation circuits. And a heat medium transport device that uses the expansion power of the heat source side refrigerant expanded by the expansion device as the power for transporting the heat medium.

According to the air conditioner of the present invention, the expansion power accompanying expansion of the heat-source-side refrigerant flowing in by the heat medium transport device can be converted into power necessary for heat medium transport, and the heat medium can be transported. Thus, it becomes possible to supply an appropriate heat medium flow rate to a plurality of indoor units, and energy saving can be improved.

It is the schematic which shows the example of installation of the air conditioning apparatus which concerns on embodiment of this invention. It is a schematic circuit block diagram which shows an example of the circuit structure of the air conditioning apparatus which concerns on embodiment of this invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the cooling only operation mode of the air conditioning apparatus which concerns on embodiment of this invention. In the refrigerant circuit in the air harmony device concerning an embodiment of the invention, it is a key map showing expansion energy which can be used with expansion of a heat source side refrigerant. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the heating only operation mode of the air conditioning apparatus which concerns on embodiment of this invention. It is a refrigerant circuit diagram which shows the flow of the refrigerant | coolant at the time of the air conditioning apparatus which concerns on embodiment of this invention in the air conditioning heating mixed operation mode. It is a conceptual diagram which shows notionally the structure of the refrigerant | coolant expansion thermal-medium conveying apparatus mounted in the air conditioning apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram illustrating an installation example of an air conditioner according to an embodiment of the present invention. Based on FIG. 1, the installation example of an air conditioning apparatus is demonstrated. This air conditioner uses a refrigeration cycle (refrigerant circulation circuit A, heat medium circulation circuit B) that circulates refrigerant (heat source side refrigerant, heat medium) so that each indoor unit can be in the cooling mode or the heating mode as an operation mode. You can choose freely. FIG. 1 schematically shows an entire air conditioner connecting a plurality of indoor units 3. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one.

In FIG. 1, the air-conditioning apparatus according to the present embodiment includes an outdoor unit (heat source unit) 1, a plurality of indoor units 3, and one relay interposed between the outdoor unit 1 and the indoor unit 3. And a unit 2. The relay unit 2 performs heat exchange between the heat source side refrigerant and the heat medium. The outdoor unit 1 and the relay unit 2 are connected by a refrigerant pipe 4 that conducts the heat source side refrigerant. The relay unit 2 and the indoor unit 3 are connected by a pipe (heat medium pipe) 5 that conducts the heat medium. The cold or warm heat generated by the outdoor unit 1 is delivered to the indoor unit 3 via the relay unit 2.

The outdoor unit 1 is usually disposed in an outdoor space 6 that is a space (for example, a rooftop) outside a building 9 such as a building, and supplies cold or hot energy to the indoor unit 3 via the relay unit 2. . The indoor unit 3 is disposed at a position where cooling air or heating air can be supplied to the indoor space 7 that is a space (for example, a living room) inside the building 9, and the cooling air is supplied to the indoor space 7 that is the air-conditioning target space. Alternatively, heating air is supplied. The relay unit 2 is configured as a separate housing from the outdoor unit 1 and the indoor unit 3 so as to be installed at a position different from the outdoor space 6 and the indoor space 7. The refrigerant pipe 4 and the pipe 5 are respectively connected to transmit cold heat or hot heat supplied from the outdoor unit 1 to the indoor unit 3.

The operation of the air conditioner according to the embodiment of the present invention will be briefly described. The heat source side refrigerant is conveyed from the outdoor unit 1 to the relay unit 2 through the refrigerant pipe 4. The conveyed heat source side refrigerant exchanges heat with the heat medium in a heat exchanger between heat medium to be described later in the relay unit 2 to heat or cool the heat medium. That is, hot water or cold water is produced by the heat exchanger between heat media. Hot water or cold water produced by the relay unit 2 is transported to the indoor unit 3 through the pipe 5 by a heat medium transport device to be described later, and the indoor unit 3 performs heating operation (operation requiring hot water). It may be in a state) or a cooling operation (an operation state requiring cold water may be used). At this time, the hot water or the cold water is conveyed to the indoor unit 3 selected by the heat medium flow switching flow rate adjusting device described later.

Examples of the heat source side refrigerant include single refrigerants such as R-22, R-134a, and R-32, pseudo-azeotropic mixed refrigerants such as R-410A and R-404A, and non-azeotropic mixed refrigerants such as R-407C. A refrigerant or mixture thereof containing a double bond in the chemical formula and having a relatively low global warming coefficient such as CF ₃ CF═CH ₂ , or a natural refrigerant such as CO ₂ or propane can be used.

On the other hand, as the heat medium, for example, water, antifreeze, a mixture of water and antifreeze, a mixture of water and an additive having a high anticorrosive effect, or the like can be used.

As shown in FIG. 1, in the air conditioner according to the present embodiment, the outdoor unit 1 and the relay unit 2 use two refrigerant pipes 4, and the relay unit 2 and each indoor unit 3 have two. These pipes 5 are connected to each other. Thus, in the air conditioning apparatus according to the present embodiment, by connecting each unit (outdoor unit 1, indoor unit 3, and relay unit 2) using two pipes (refrigerant pipe 4, pipe 5). Construction is easy.

In FIG. 1, the relay unit 2 is installed in a space such as the back of the ceiling (hereinafter simply referred to as a space 8) that is inside the building 9 but is different from the indoor space 7. An example is shown. However, the relay unit 2 may be installed in any place as long as it is outside the ceiling or other than the living space and has some ventilation with the outside. It can also be installed in a space that is ventilated. Further, the relay unit 2 can be installed in the vicinity of the outdoor unit 1. However, it should be noted that if the distance from the relay unit 2 to the indoor unit 3 is too long, the transfer power of the heat medium becomes considerably large, so that the effect of energy saving is reduced.

FIG. 1 shows an example in which the outdoor unit 1 is installed in the outdoor space 6, but the present invention is not limited to this. For example, the outdoor unit 1 may be installed in an enclosed space such as a machine room with a ventilation opening. If the waste heat can be exhausted outside the building 9 by an exhaust duct, the outdoor unit 1 may be installed inside the building 9. It may be installed, or may be installed inside the building 9 when the water-cooled outdoor unit 1 is used. Even if the outdoor unit 1 is installed in such a place, no particular problem occurs.

In FIG. 1, the case where the indoor unit 3 is a ceiling cassette type is shown as an example. However, the present invention is not limited to this, and the indoor unit 3 is directly or directly connected to the indoor space 7 such as a ceiling embedded type or a ceiling suspended type. As long as the air for heating or the air for cooling can be blown out, any kind may be used.

Moreover, about the indoor unit 3 to be connected, even if heating air or cooling air cannot be blown into the indoor space 7, hot water or cold water from the relay unit 2 such as a panel heater or a floor heating device is used. Even if it is a unit aiming at the function of giving a heating effect or a cooling effect to the indoor space 87, no particular problem occurs.

Furthermore, the number of connected outdoor units 1, indoor units 3, and relay units 2 is not limited to the number shown in FIG. 1, but according to the building 9 in which the air conditioner according to the present embodiment is installed. What is necessary is just to determine the number.

When a plurality of relay units 2 are connected to one outdoor unit 1, the plurality of relay units 2 may be installed in a shared space in a building such as a building or in a space such as a ceiling. it can. By doing so, an air-conditioning load can be covered with the heat exchanger between heat media in each relay unit 2. In addition, the indoor unit 3 can be installed at a distance or height within the allowable transfer range of the heat medium transfer device in each relay unit 2, and can be arranged on the entire building such as a building. .

FIG. 2 is a schematic circuit configuration diagram showing an example of a circuit configuration of the air conditioning apparatus according to the present embodiment (hereinafter referred to as the air conditioning apparatus 100). Based on FIG. 2, the structure of the air conditioning apparatus 100, ie, the effect | action of each actuator which comprises the refrigerant circuit, is demonstrated in detail. As shown in FIG. 2, the outdoor unit 1 and the relay unit 2 include a heat exchanger related to heat medium (refrigerant-water heat exchanger) 25 a and a heat exchanger related to heat medium (refrigerant—) provided in the relay unit 2. The refrigerant pipe 4 is connected via a water heat exchanger 25b. In addition, the relay unit 2 and the indoor unit 3 are connected by the pipe 5 via the heat exchanger related to heat medium 25 a, the heat exchanger related to heat medium 25 b, and the heat medium flow switching flow rate adjusting device 40.

[Outdoor unit 1]
In the outdoor unit 1, a compressor 10, a first refrigerant flow switching device 11 such as a four-way valve, a heat source side heat exchanger 12, and an accumulator 19 are connected and connected in series through a refrigerant pipe 4. Yes. The outdoor unit 1 is also provided with a refrigerant connection pipe 4a, a refrigerant connection pipe 4b, a check valve 13a, a check valve 13b, a check valve 13c, and a check valve 13d. Regardless of the operation required by the indoor unit 3, relay connection pipe 4a, refrigerant connection pipe 4b, check valve 13a, check valve 13b, check valve 13c, and check valve 13d are provided. The flow of the heat source side refrigerant flowing into the unit 2 can be in a certain direction.

The compressor 10 sucks the heat source side refrigerant, compresses the heat source side refrigerant, and transfers it to the refrigerant circulation circuit A in a high temperature / high pressure state. Good. The first refrigerant flow switching device 11 is in the refrigerant circulation path that is the flow of the heat source side refrigerant in the heating operation mode (in the heating only operation mode and in the heating main operation mode) and in the cooling operation mode (in the cooling only operation mode and The refrigerant circulation path which is the flow of the heat source side refrigerant in the cooling main operation mode) is switched.

The heat source side heat exchanger 12 functions as an evaporator during heating operation, functions as a condenser (or radiator) during cooling operation, and fluid such as air supplied from a blower such as a fan (not shown) and the heat source side Heat exchange is performed with the refrigerant, and the heat source side refrigerant is vaporized or condensed and liquefied. The accumulator 19 is provided on the suction side of the compressor 10 and stores excess refrigerant due to a difference between the heating operation and the cooling operation, or excess refrigerant with respect to a transient change in operation.

The check valve 13c is provided in the refrigerant pipe 4 between the relay unit 2 and the first refrigerant flow switching device 11, and the heat source side refrigerant is only in a predetermined direction (direction from the relay unit 2 to the outdoor unit 1). It allows flow. The check valve 13a is provided in the refrigerant pipe 4 between the heat source side heat exchanger 12 and the relay unit 2, and flows the heat source side refrigerant only in a predetermined direction (direction from the outdoor unit 1 to the relay unit 2). It is acceptable. The check valve 13d is provided in the refrigerant connection pipe 4a and causes the heat source side refrigerant discharged from the compressor 10 to flow through the relay unit 2 during the heating operation. The check valve 13b is provided in the refrigerant connection pipe 4b, and causes the heat source side refrigerant returned from the relay unit 2 during the heating operation to flow to the suction side of the compressor 10.

In the outdoor unit 1, the refrigerant connection pipe 4 a includes a refrigerant pipe 4 between the first refrigerant flow switching device 11 and the check valve 13 c, and a refrigerant pipe 4 between the check valve 13 a and the relay unit 2. Are connected to each other. In the outdoor unit 1, the refrigerant connection pipe 4b includes a refrigerant pipe 4 between the check valve 13c and the relay unit 2, a refrigerant pipe 4 between the heat source side heat exchanger 12 and the check valve 13a, Are connected. FIG. 2 shows an example in which the refrigerant connection pipe 4a, the refrigerant connection pipe 4b, the check valve 13a, the check valve 13b, the check valve 13c, and the check valve 13d are provided. However, the present invention is not limited to this, and these are not necessarily provided.

[Indoor unit 3]
Each indoor unit 3 is equipped with a use side heat exchanger 35. The use side heat exchanger 35 is connected to the heat medium flow switching flow rate adjusting device 40 of the relay unit 2 through the pipe 5. The use side heat exchanger 35 exchanges heat between air supplied from a blower such as a fan (not shown) and a heat medium, and supplies heating air or cooling air to be supplied to the indoor space 7. Is to generate

FIG. 2 shows an example in which four indoor units 3 are connected to the relay unit 2, which are illustrated as an indoor unit 3 a, an indoor unit 3 b, an indoor unit 3 c, and an indoor unit 3 d from the upper side of the drawing. Yes. In accordance with the indoor unit 3a to the indoor unit 3d, the use side heat exchanger 35 also has a use side heat exchanger 35a, a use side heat exchanger 35b, a use side heat exchanger 35c, and a use side heat exchanger from the upper side of the drawing. It is illustrated as 35d. As in FIG. 1, the number of indoor units 3 connected is not limited to the four shown in FIG.

[Relay unit 2]
The relay unit 2 includes two or more heat exchangers for heat medium 25, two refrigerant expansion heat medium transfer devices 60, two switch devices (switch devices 27, switch devices 29), and two second refrigerants. A flow path switching device 28 and four heat medium flow path switching flow rate adjustment devices 40 are mounted.

The two heat exchangers for heat medium 25 (heat exchanger for heat medium 25a, heat exchanger for heat medium 25b) are provided with a condenser (when the heat is supplied to the indoor unit 3 in the heating operation). When supplying cold heat to the indoor unit 3 that is in the cooling operation as a radiator, it functions as an evaporator, performs heat exchange between the heat-source-side refrigerant and the heat medium, and is generated by the outdoor unit 1 The cold heat or warm heat stored in the side refrigerant is transmitted to the heat medium. The heat exchanger related to heat medium 25a is provided between the refrigerant expansion heat medium transfer device 60a and the second refrigerant flow switching device 28a in the refrigerant circulation circuit A, and cools the heat medium in the cooling / heating mixed operation mode. It is for use. The heat exchanger related to heat medium 25b is provided between the refrigerant expansion heat medium transfer device 60b and the second refrigerant flow switching device 28b in the refrigerant circulation circuit A, and is used in the cooling / heating mixed operation mode. It is used for heating.

In the refrigerant circuit A, the two refrigerant expansion heat medium conveyance devices 60 (the refrigerant expansion heat medium conveyance device 60a and the refrigerant expansion heat medium conveyance device 60b) have functions as throttle devices such as a pressure reducing valve and an expansion valve. The heat source side refrigerant is decompressed and expanded. The refrigerant expansion heat medium transfer device 60a is provided on the upstream side of the heat exchanger related to heat medium 25a in the flow of the heat source side refrigerant during the cooling operation. The refrigerant expansion heat medium transport device 60b is provided on the upstream side of the heat exchanger related to heat medium 25b in the flow of the heat source side refrigerant during the cooling operation.

In the heat medium circulation circuit B, the two refrigerant expansion heat medium transport devices 60 also have a function as a heat medium transport device described later. Therefore, the refrigerant expansion heat medium transport device 60 is preferably configured by integrating the expansion device and the heat medium transport device. However, in the case where power more than the power necessary for transporting the heat medium is obtained by decompression and expansion of the heat source side refrigerant, or when the power necessary for heat medium transport is adjusted, it is omitted in FIG. It is also possible to provide a bypass circuit with an expansion valve or a throttling device for each refrigerant expansion heat transfer device 60. By doing so, the two refrigerant expansion heat medium transfer devices 60 can obtain stable expansion power from the refrigerant circuit A.

Furthermore, the two refrigerant expansion heat medium conveying devices 60 also have a function as a heat source device conveying device that circulates the heat medium conducted through the pipe 5 to the heat medium circulation circuit B. The refrigerant expansion heat medium transfer device 60 a is provided in the pipe 5 between the heat exchanger related to heat medium 25 a and the heat medium flow switching flow rate adjusting device 40. The refrigerant expansion heat medium transport device 60 b is provided in the pipe 5 between the heat exchanger related to heat medium 25 b and the heat medium flow switching flow rate adjusting device 40. The two refrigerant expansion heat medium conveying devices 60 can also be provided with a bypass circuit with an adjustment valve capable of flowing the heat medium in each of the heat medium circulation circuits B, whereby the heat medium circulation circuit B is provided. It is also possible to adjust the flow rate of the circulating heat medium.

Referring to FIG. 7 which is a conceptual diagram of the two refrigerant expansion heat medium transfer devices 60, the following is obtained. FIG. 7 is a conceptual diagram conceptually showing the configuration of the refrigerant expansion heat medium transport device 60 mounted on the air conditioning apparatus 100. In FIG. 7, a part of a general configuration of the refrigerant expansion heat medium transport device 60 is illustrated. Arrows X1 and X2 shown in FIG. 7 indicate the flow of the heat source side refrigerant. Arrows Y1 and Y2 shown in FIG. 7 indicate the flow of the heat medium. Z1 shown in FIG. 7 indicates that both the refrigerant circuit A and the heat medium circuit B are rotating coaxially. An arrow Z2 shown in FIG. 7 indicates conversion and propagation of the refrigerant expansion power into the rotational power.

As shown in FIG. 7, the refrigerant expansion heat medium transfer device 60 has a sealed container 69 in which an internal space is partitioned by a partition plate 65. Of the spaces partitioned by the partition plate 65, the space below the paper surface functions as a refrigerant expansion chamber 60A for expanding the heat source side refrigerant. Of the spaces partitioned by the partition plate 65, the space on the upper side of the drawing functions as a heat medium transfer chamber 60B for circulating the heat medium. The refrigerant expansion chamber 60A communicates with the refrigerant circulation circuit A via a refrigerant inlet 61 serving as an inlet for the heat source side refrigerant and a refrigerant outlet 62 serving as an outlet for the heat source side refrigerant. The heat medium transfer chamber 60B communicates with the heat medium circuit B through a heat medium inlet 63 serving as a heat medium inlet and a heat medium outlet 64 serving as a heat medium outlet.

Further, the refrigerant expansion heat medium transfer device 60 has a shaft 66 that penetrates the central portion of the partition plate 65. The shaft 66 is rotated by power generated when the heat source side refrigerant is expanded in the refrigerant expansion chamber 60A, and the heat medium in the heat medium transfer chamber 60B is transferred to the heat medium circulation circuit B by this rotational force (shown in FIG. 7). Arrows Z1, Z2).

The operation of the refrigerant expansion heat medium transport device 60 will be described.
The high-pressure heat source side refrigerant flows into the refrigerant expansion chamber 60A of the refrigerant expansion heat medium transport device 60 through the refrigerant inlet 61 (arrow X1 shown in FIG. 7). The heat source side refrigerant is squeezed and expanded in the refrigerant expansion chamber 60A. At this time, expansion energy (refrigerant expansion power) is generated. The generated refrigerant expansion power propagates as rotation power to the heat medium transfer chamber 60B connected coaxially via the shaft 66 (arrows Z1 and Z2 shown in FIG. 7). The expanded heat source side refrigerant flows out of the refrigerant expansion heat medium transport device 60 through the refrigerant outlet 62 (arrow X2 shown in FIG. 7).

On the other hand, the heat medium also flows into the heat medium transfer chamber 60B of the refrigerant expansion heat medium transfer device 60 through the heat medium inlet 63 (arrow Y1 shown in FIG. 7), and the shaft is connected coaxially in the heat medium transfer chamber 60B. It flows out of the refrigerant expansion heat transfer device 60 by the rotational power generated by the refrigerant expansion power propagated through 66 (arrow Y2 shown in FIG. 7). The heat medium that has flowed out of the refrigerant expansion heat medium transport device 60 via the heat medium outlet 64 is transported to the use side heat exchanger 35.

In FIG. 7, in the refrigerant expansion heat medium conveying device 60, the expansion power of the heat source side refrigerant is propagated to the heat medium as rotational power and used as heat medium conveyance power. However, the present invention is not limited to this. For example, there is no problem with any structure as long as the structure can use the expansion power from the refrigerant as the heat transfer power of the heat medium, not the rotational power.

The two opening / closing devices (opening / closing device 27, opening / closing device 29) are configured by electromagnetic valves or the like that can be opened and closed by energization, and open / close the refrigerant pipe 4. That is, the opening and closing of the two opening / closing devices is controlled according to the operation mode, and the flow path of the heat source side refrigerant is switched. The opening / closing device 27 is provided in the refrigerant pipe 4 on the inlet side of the heat-source-side refrigerant (the refrigerant pipe 4 located at the lowest level in the drawing among the refrigerant pipes 4 connecting the outdoor unit 1 and the relay unit 2). The opening / closing device 29 is provided in a pipe (bypass pipe 20) connecting the refrigerant pipe 4 on the inlet side of the heat source side refrigerant and the refrigerant pipe 4 on the outlet side. The opening / closing device 27 and the opening / closing device 29 may be any devices that can switch the refrigerant flow path. For example, an electronic expansion valve or the like that can variably control the opening degree may be used.

The two second refrigerant flow switching devices 28 (second refrigerant flow switching device 28a, second refrigerant flow switching device 28b) are constituted by, for example, a four-way valve or the like, and the heat exchanger related to heat medium according to the operation mode. The flow of the heat source side refrigerant is switched so that 25 acts as a condenser or an evaporator. The second refrigerant flow switching device 28a is provided on the downstream side of the heat exchanger related to heat medium 25a in the flow of the heat source side refrigerant during the cooling operation. The second refrigerant flow switching device 28b is provided on the downstream side of the heat exchanger related to heat medium 25b in the flow of the heat source side refrigerant in the cooling only operation mode.

The four heat medium flow path switching flow rate adjusting devices 40 (heat medium flow path switching flow rate adjusting device 40a to heat medium flow path switching flow rate adjusting device 40d) are configured by one drive device, a valve body, and the like. Are switched between the heat exchanger related to heat medium 25a and the heat exchanger related to heat medium 25b, and the flow rate of the heat medium for each branch is adjusted. In other words, the heat medium flow switching device 40 has both a function as a heat medium flow switching device and a function as a heat medium flow control device. Further, the heat medium flow switching flow rate adjusting device 40 is provided with a number (four in this case) corresponding to the number of indoor units 3 installed, and can be connected to each other. It is.

Further, in the heat medium flow switching flow rate adjusting device 40, one of them is connected to the heat exchanger related to heat medium 25a and the other is connected to the heat exchanger related to heat medium 25b. It is also connected to the exchanger 35. In correspondence with the indoor unit 3, the heat medium flow switching flow rate adjustment device 40 a, the heat medium flow switching flow adjustment device 40 b, the heat medium flow switching flow adjustment device 40 c, and the heat medium flow switching flow adjustment from the upper side of the page. Illustrated as device 40d. The switching of the heat medium flow path includes not only complete switching from one to the other but also partial switching from one to the other.

In addition, the four heat medium flow switching flow adjustment devices 40 (heat medium flow switching flow adjustment device 40a to heat medium flow switching flow adjustment device 40d) can also adjust the flow rate, and by adjusting the opening area, The flow rate of the heat medium flowing through the pipe 5 is controlled. One of the heat medium flow switching flow rate adjusting devices 40 is connected to the use side heat exchanger 35 and the other is connected to the heat exchanger related to heat medium 25. That is, the heat medium flow switching flow rate adjusting device 40 adjusts the amount of the heat medium flowing into the indoor unit 3 according to the temperature of the heat medium flowing into the indoor unit 3 and the temperature of the heat medium flowing out, according to the indoor load. The optimum amount of heat medium can be provided to the indoor unit 3.

When the indoor unit 3 does not require a load such as stop or thermo OFF, or when it is desired to shut off the heat medium flow path due to maintenance or the like, the heat medium flow path switching flow rate adjustment device 40 is fully closed. As a result, the supply of the heat medium to the indoor unit 3 can be stopped.

Further, the relay unit 2 is provided with a temperature sensor 55 (temperature sensor 55a, temperature sensor 55b) for detecting the temperature of the heat medium on the outlet side of the heat exchanger 25 between heat mediums. Information (temperature information) detected by the temperature sensor 55 is sent to a control device 50 that performs overall control of the operation of the air conditioner 100, and the driving frequency of the compressor 10, the rotational speed of the blower not shown, and the first refrigerant. This is used for control such as switching of the flow path switching device 11, switching of the second refrigerant flow switching device 28, switching of the flow path of the heat medium, adjustment of the heat medium flow rate of the indoor unit 3, and the like. In addition, although the control apparatus 50 has shown in the example the state mounted in the relay unit 2, it is not limited to this, It mounts so that communication is possible in the outdoor unit 1 or the indoor unit 3, or each unit. You may make it do.

Moreover, the control apparatus 50 is comprised by the microcomputer etc., Based on the detection information in various detection means, and the instruction | indication from a remote control, the drive frequency of the compressor 10, the rotation speed (including ON / OFF) of an air blower, Switching of the first refrigerant flow switching device 11, opening / closing of the switching device, switching of the second refrigerant flow switching device 28, switching of the heat medium flow switching flow rate adjusting device 40, and heat medium flow switching flow rate adjusting device 40 Each actuator is controlled to control each actuator (including drive parts such as a throttle device that accompanies the drive of the refrigerant expansion heat transfer device 60) and execute each operation mode described later.

The pipe 5 that conducts the heat medium is composed of one that is connected to the heat exchanger related to heat medium 25a and one that is connected to the heat exchanger related to heat medium 25b. The pipe 5 is branched (here, four branches each) according to the number of indoor units 3 connected to the relay unit 2. The pipe 5 is connected by a heat medium flow switching flow rate adjusting device 40. By controlling the heat medium flow switching flow rate adjusting device 40, the heat medium from the heat exchanger related to heat medium 25a flows into the use side heat exchanger 35, or the heat medium from the heat exchanger related to heat medium 25b is used as the heat medium. Whether to flow into the use side heat exchanger 35 is determined.

In the air conditioner 100, the compressor 10, the first refrigerant flow switching device 11, the heat source side heat exchanger 12, the switching device 27, the switching device 29, the second refrigerant flow switching device 28, and heat exchange between heat media. The refrigerant flow path, the refrigerant expansion heat medium transport device 60 (refrigerant expansion unit), and the accumulator 19 are connected by the refrigerant pipe 4 to constitute the refrigerant circuit A. In addition, the heat medium flow path of the heat exchanger 25 between heat mediums, the refrigerant expansion heat medium transport device 60 (heat medium transport unit), the heat medium flow path switching flow rate adjustment device 40, and the use side heat exchanger 35 are connected to the piping. 5, the heat medium circulation circuit B is configured. That is, a plurality of use side heat exchangers 35 are connected in parallel to each of the heat exchangers 25 between heat mediums, and the heat medium circulation circuit B has a plurality of systems.

Therefore, in the air conditioner 100, the outdoor unit 1 and the relay unit 2 are connected via the heat exchanger related to heat medium 25a and the heat exchanger related to heat medium 25b provided in the relay unit 2, and the relay unit 2 is connected. And the indoor unit 3 are also connected via the heat exchanger related to heat medium 25a and the heat exchanger related to heat medium 25b. That is, in the air conditioner 100, the heat source side refrigerant circulating in the refrigerant circuit A and the heat medium circulating in the heat medium circuit B exchange heat in the intermediate heat exchanger 25a and the intermediate heat exchanger 25b. It is like that. By using such a configuration, the air conditioner 100 can realize an optimal cooling operation or heating operation according to the indoor load.

[Operation mode]
Next, each operation mode executed by the air conditioner 100 will be described together with an example of the power of the refrigerant expansion heat medium transport device 60 in addition to the flow of the heat source side refrigerant and the heat medium. The air conditioner 100 can perform a cooling operation or a heating operation in the indoor unit 3 based on an instruction from each indoor unit 3. That is, the air conditioning apparatus 100 can perform the same operation for all the indoor units 3 and can perform different operations for each of the indoor units 3.

The operation mode executed by the air conditioner 100 includes a heating only operation mode in which all the driven indoor units 3 execute the heating operation, and a cooling only operation in which all the driven indoor units 3 execute the cooling operation. There are a heating main operation mode in which the heating load is larger than the cooling load in the mode and the mixed cooling and heating operation mode, and a cooling main operation mode in which the cooling load is larger than the heating load in the cooling and heating mixed operation mode.

[Cooling operation mode]
FIG. 3 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 is in the cooling only operation mode. In FIG. 3, the cooling only operation mode will be described by taking as an example a case where a cooling load is generated in all of the use side heat exchangers 35a to 35d. In FIG. 3, the flow direction of the heat source side refrigerant is indicated by solid line arrows, and the flow direction of the heat medium is indicated by broken line arrows.

3, in the cooling only operation mode shown in FIG. 3, in the outdoor unit 1, the first refrigerant flow switching device 11 is switched so that the heat source side refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12.

In the relay unit 2, the refrigerant expansion heat medium conveyance device 60a and the refrigerant expansion heat medium conveyance device 60b are driven to open the heat medium flow switching flow rate adjustment device 40a to the heat medium flow switching flow adjustment device 40d, A heat medium is circulated between each of the heat exchanger 25a and the heat exchanger 25b between the heat medium and the use side heat exchanger 35a to the use side heat exchanger 35d. At this time, the second refrigerant flow switching device 28a and the second refrigerant flow switching device 28b are switched to the cooling side, the opening / closing device 27 is opened, and the opening / closing device 29 is closed.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 passes through the heat source side heat exchanger 12 via the first refrigerant flow switching device 11, and is the air in the outdoor space 6 (hereinafter referred to as outside air). Heat exchange is performed to obtain a high-temperature / high-pressure liquid or two-phase refrigerant, and after passing through the check valve 13a, the refrigerant connection pipe 4a is conducted and flows out of the outdoor unit 1. The high-temperature and high-pressure liquid or two-phase refrigerant that has flowed out of the outdoor unit 1 flows into the relay unit 2 through the refrigerant pipe 4.

The high-temperature / high-pressure liquid or two-phase refrigerant that has flowed into the relay unit 2 passes through the opening / closing device 27, and is branched and expanded by the refrigerant expansion heat medium conveyance device 60a and the refrigerant expansion heat medium conveyance device 60b.・ Low pressure two-phase refrigerant. These two-phase refrigerant flows into the heat exchanger related to heat medium 25a and the heat exchanger related to heat medium 25b, evaporates while absorbing heat from the heat medium circulating in the heat medium circuit B, and becomes a low-temperature gas refrigerant. . The gas refrigerant flowing out of the heat exchanger related to heat medium 25a and the heat exchanger related to heat medium 25b flows out of the relay unit 2 through the second refrigerant flow switching device 28a and the second refrigerant flow switching device 28b, and the refrigerant The pipe 4 is conducted, passes through the check valve 13 c, and is sucked again into the compressor 10 through the first refrigerant flow switching device 11 and the accumulator 19.

At this time, the refrigerant expansion heat medium transport device 60 includes a value obtained by converting the pressure of the heat source side refrigerant flowing between the heat exchanger related to heat medium 25 and the refrigerant expansion heat medium transport device 60 into a saturation temperature, and a heat exchanger related to heat medium. The opening degree is controlled so that the superheat (superheat degree) obtained as a difference from the temperature on the outlet side of 25 is constant. Alternatively, it is possible to adjust by providing a bypass circuit so that the superheat becomes constant. In addition, when the temperature of the intermediate position of the intermediate heat exchanger 25 can be measured, the saturation temperature obtained by converting the temperature at the intermediate position may be used instead. In this case, it is not necessary to install a pressure sensor, and the system can be configured at low cost.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the cooling only operation mode, the heat of the heat medium is transmitted to the heat source side refrigerant in both the heat exchanger related to heat medium 25a and the heat exchanger related to heat medium 25b, and the cooled heat medium is transferred to the refrigerant expansion heat medium transport device 60a and The refrigerant expansion heat medium transport device 60b is pressurized and flows out, and the use side heat exchanger 35a to the use side heat exchanger are passed through the heat medium flow channel switching flow rate adjusting device 40a to the heat medium flow channel switching flow rate adjusting device 40d. Flows into 35d. The heat medium absorbs heat from the indoor air in the use side heat exchanger 35a to the use side heat exchanger 35d, thereby cooling the indoor space 7.

At this time, as the power for transporting the refrigerant expansion heat medium transport device 60, as described above, the expansion power obtained when the heat source side refrigerant flows into the refrigerant expansion heat medium transport device 60 is used. The heat medium is pressurized and discharged.

Then, the heat medium flows out of the use side heat exchanger 35a to the use side heat exchanger 35d and flows again into the heat medium flow path switching flow rate adjustment device 40a to the heat medium flow path switching flow rate adjustment device 40d. At this time, the flow rate of the heat medium becomes a flow rate required to cover the air conditioning load required indoors by the flow rate adjusting action of the heat medium flow path switching flow rate adjusting device 40a to the heat medium flow path switching flow rate adjusting device 40d. It is controlled to flow into the use side heat exchanger 35a to the use side heat exchanger 35d. The heat medium that has flowed out of the heat medium flow path switching flow rate adjusting device 40a to the heat medium flow path switching flow rate adjusting device 40d flows into the heat medium heat exchanger 25a and the heat medium heat exchanger 25b, and passes through the indoor unit 3 to the room. The amount of heat absorbed from the space 7 is transferred to the refrigerant side and again sucked into the refrigerant expansion heat medium transfer device 60a and the refrigerant expansion heat medium transfer device 60b.

In the pipe 5 of the use side heat exchanger 35, the heat medium flows in a direction from the heat medium flow switching flow rate adjusting device 40 to the refrigerant expansion heat medium conveying device 60. The air conditioning load required in the indoor space 7 is the temperature detected by the temperature sensor 55a, or the temperature detected by the temperature sensor 55b and the temperature of the heat medium flowing out from the use side heat exchanger 35. This can be covered by controlling the difference to keep it at the target value. As the outlet temperature of the heat exchanger related to heat medium 25, the temperature of either the temperature sensor 55a or the temperature sensor 55b may be used, or the average temperature thereof may be used.

Next, an example of refrigerant expansion power and heat medium conveyance power recovered from the heat source side refrigerant in the cooling only operation mode will be described with reference to FIG. FIG. 4 is a conceptual diagram illustrating expansion energy that can be used in association with expansion of the heat source side refrigerant in the refrigerant circuit A in the air-conditioning apparatus 100. Specifically, FIG. 4 is a Ph diagram showing the pressure of the heat source side refrigerant and the enthalpy at that time, and the arrows in FIG. 4 are images showing the movement of the heat source side refrigerant in each operation mode. The high-temperature and high-pressure refrigerant pressure during the cooling only operation mode is given by Pc in the figure, and the low-temperature and low-pressure refrigerant pressure during the cooling only operation mode is given by Pe in the figure.

When the pressure, temperature, and refrigerant flow rate of the heat source side refrigerant during the cooling only operation mode are given as follows, the expansion power of the heat source side refrigerant can be calculated.
Pc = 3 [Mpa], Pe = 1 [Mpa], subcool SC = 10 [deg], refrigerant flow rate Gr = 654 [kg / hr].
At this time,
(Enthalpy difference from isentropic change with respect to isoenthalpy change) x refrigerant flow rate = refrigerant expansion power. The refrigerant expansion power in the above example is 0.78 [kW], and this refrigerant expansion power is used as the heat transfer power. It can be used.

In addition, since it is not necessary to flow a heat medium to the use side heat exchanger 35 (including thermo-off) having no heat load, the use side heat exchanger 35 is closed by closing the flow path with the heat medium flow path switching flow rate adjusting device 40. It suffices to prevent the heat medium from flowing. In FIG. 3, the heat medium flows because all of the use side heat exchanger 35a to the use side heat exchanger 35d have a heat load, but when the heat load disappears, the corresponding heat medium flow switching flow rate The adjustment device 40 may be fully closed. Then, when a heat load is generated again, the corresponding heat medium flow switching flow rate adjusting device 40 may be opened to circulate the heat medium. The same applies to other operation modes described below.

[Heating operation mode]
FIG. 5 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 is in the heating only operation mode. In FIG. 5, the heating only operation mode will be described by taking as an example a case where a heating load is generated in all of the use side heat exchanger 35a to the use side heat exchanger 35d. In FIG. 5, the flow direction of the heat source side refrigerant is indicated by solid arrows, and the flow direction of the heat medium is indicated by broken arrows.

In the heating only operation mode shown in FIG. 5, in the outdoor unit 1, the first refrigerant flow switching device 11 is connected to the relay unit without passing the heat source side refrigerant discharged from the compressor 10 through the heat source side heat exchanger 12. Switch to 2

In the relay unit 2, the refrigerant expansion heat medium conveyance device 60a and the refrigerant expansion heat medium conveyance device 60b are driven to open the heat medium flow switching flow rate adjustment device 40a to the heat medium flow switching flow adjustment device 40d, A heat medium is circulated between each of the heat exchanger 25a and the heat exchanger 25b between the heat medium and the use side heat exchanger 35a to the use side heat exchanger 35d. At this time, the second refrigerant flow switching device 28a and the second refrigerant flow switching device 28b are switched to the heating side, the open / close device 27 is closed, and the open / close device 29 is open.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 passes through the first refrigerant flow switching device 11, conducts through the refrigerant connection pipe 4 a, passes through the check valve 13 d, and flows out of the outdoor unit 1. The high-temperature and high-pressure gas refrigerant that has flowed out of the outdoor unit 1 flows into the relay unit 2 through the refrigerant pipe 4. The high-temperature and high-pressure gas refrigerant that has flowed into the relay unit 2 is branched and passes through the second refrigerant flow switching device 28a and the second refrigerant flow switching device 28b, and the heat exchanger related to heat medium 25a and the heat between the heat media. It flows into each of the exchangers 25b.

The high-temperature and high-pressure gas refrigerant flowing into the heat exchanger related to heat medium 25a and the heat exchanger related to heat medium 25b is condensed and liquefied while dissipating heat to the heat medium circulating in the heat medium circuit B, and becomes a high-pressure liquid refrigerant. . The liquid refrigerant that has flowed out of the heat exchanger related to heat medium 25a and the heat exchanger related to heat medium 25b is expanded by the refrigerant expansion heat medium transfer device 60a and the refrigerant expansion heat medium transfer device 60b, and is a low-temperature, low-pressure two-phase refrigerant. It becomes. These two-phase refrigerants merge, flow out of the relay unit 2 through the opening / closing device 29, and flow into the outdoor unit 1 again through the refrigerant pipe 4. The refrigerant that has flowed into the outdoor unit 1 is conducted through the refrigerant connection pipe 4b, passes through the check valve 13b, and flows into the heat source side heat exchanger 12 that functions as an evaporator.

The heat source side refrigerant flowing into the heat source side heat exchanger 12 absorbs heat from the outside air in the heat source side heat exchanger 12 and becomes a low-temperature / low-pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flowing out from the heat source side heat exchanger 12 is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

At this time, the refrigerant expansion heat medium transport device 60 has a value obtained by converting the pressure of the heat source side refrigerant flowing between the heat exchanger related to heat medium 25 and the refrigerant expansion heat medium transport device 60 into a saturation temperature, and heat between the heat media. The opening degree is controlled such that the subcool (degree of supercooling) obtained as a difference from the temperature on the outlet side of the exchanger 25 becomes constant. Alternatively, it is possible to adjust by providing a bypass circuit so that the subcooling is constant. In addition, when the temperature of the intermediate position of the heat exchanger 25 between heat media can be measured, you may use it instead of the saturation temperature which converted the temperature in the intermediate position. In this case, it is not necessary to install a pressure sensor, and the system can be configured at low cost.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the heating only operation mode, the heat of the heat source side refrigerant is transmitted to the heat medium in both the heat exchanger related to heat medium 25a and the heat exchanger 25b, and the heated heat medium is transferred to the refrigerant expansion heat medium transfer device 60a and The inside of the pipe 5 is caused to flow by the refrigerant expansion heat medium transfer device 60b. The heat medium pressurized and discharged by the refrigerant expansion heat medium transfer device 60a and the refrigerant expansion heat medium transfer device 60b is used via the heat medium flow switching flow rate adjustment device 40a to the heat medium flow switching flow adjustment device 40d. It flows into the side heat exchanger 35a to the use side heat exchanger 35d. The indoor space 7 is heated by the heat medium radiating heat to the indoor air by the use side heat exchanger 35a to the use side heat exchanger 35d.

Then, the heat medium flows out of the use side heat exchanger 35a to the use side heat exchanger 35d and flows into the heat medium flow switching flow rate adjusting device 40a to the heat medium flow switching flow adjusting device 40d. At this time, the flow rate of the heat medium is controlled to a flow rate necessary to cover the air conditioning load required indoors by the action of the heat medium flow path switching flow rate adjusting device 40a to the heat medium flow path switching flow rate adjusting device 40d. It flows into the use side heat exchanger 35a to the use side heat exchanger 35d. The heat medium that has flowed out of the heat medium flow path switching flow rate adjusting device 40a to the heat medium flow path switching flow rate adjusting device 40d flows into the heat medium heat exchanger 25a and the heat medium heat exchanger 25b, and passes through the indoor unit 3 to the room. The amount of heat supplied to the space 7 is received from the refrigerant side and again sucked into the refrigerant expansion heat medium transfer device 60a and the refrigerant expansion heat medium transfer device 60b.

At this time, as the power for transporting the refrigerant expansion heat medium transport device 60, as described above, the expansion power obtained when the heat source side refrigerant flows into the refrigerant expansion heat medium transport device 60 is used. The heat medium is pressurized and discharged.

Then, the heat medium flows out of the use side heat exchanger 35a to the use side heat exchanger 35d and flows again into the heat medium flow path switching flow rate adjustment device 40a to the heat medium flow path switching flow rate adjustment device 40d. At this time, the flow rate of the heat medium becomes a flow rate required to cover the air conditioning load required indoors by the flow rate adjusting action of the heat medium flow path switching flow rate adjusting device 40a to the heat medium flow path switching flow rate adjusting device 40d. It is controlled to flow into the use side heat exchanger 35a to the use side heat exchanger 35d. The heat medium that has flowed out of the heat medium flow path switching flow rate adjusting device 40a to the heat medium flow path switching flow rate adjusting device 40d flows into the heat medium heat exchanger 25a and the heat medium heat exchanger 25b, and passes through the indoor unit 3 to the room. The amount of heat supplied to the space 7 is received from the refrigerant side and again sucked into the refrigerant expansion heat medium transfer device 60a and the refrigerant expansion heat medium transfer device 60b.

In the pipe 5 of the use side heat exchanger 35, the heat medium flows in a direction from the heat medium flow switching flow rate adjusting device 40 to the refrigerant expansion heat medium conveying device 60. The air conditioning load required in the indoor space 7 is the temperature detected by the temperature sensor 55a, or the temperature detected by the temperature sensor 55b and the temperature of the heat medium flowing out from the use side heat exchanger 35. This can be covered by controlling the difference to keep it at the target value. As the outlet temperature of the heat exchanger related to heat medium 25, the temperature of either the temperature sensor 55a or the temperature sensor 55b may be used, or the average temperature thereof may be used.

Next, an example of refrigerant expansion power and heat medium conveyance power recovered from the heat source side refrigerant in the heating only operation mode will be described with reference to FIG. The high-temperature and high-pressure refrigerant pressure during the heating only operation mode is given by Pc in the figure, and the low-temperature and low-pressure refrigerant pressure during the heating only operation mode is given by Pe in the figure.

When the pressure, temperature, and refrigerant flow rate of the heat source side refrigerant in the heating only operation mode are given as follows, the expansion power of the heat source side refrigerant can be calculated.
Pc = 2.3 [Mpa], Pe = 0.65 [Mpa], subcool SC = 4 [deg], refrigerant flow rate Gr = 555 [kg / hr].
At this time,
(Enthalpy difference from isentropic change with respect to isoenthalpy change) x refrigerant flow rate = refrigerant expansion power, the refrigerant expansion power in the above example is 0.82 [kW], and this refrigerant expansion power is used as the heat transfer power. It can be used.

[Cooling and heating mixed operation mode]
FIG. 6 is a refrigerant circuit diagram illustrating a refrigerant flow when the air-conditioning apparatus 100 is in the cooling / heating mixed operation mode. In FIG. 6, among the cooling and heating mixed operations in which the thermal load is generated in any one of the use side heat exchangers 35 and the cooling load is generated in the rest of the use side heat exchangers 35. The heating main operation mode will be described. In FIG. 6, the flow direction of the heat source side refrigerant is indicated by solid line arrows, and the flow direction of the heat medium is indicated by broken line arrows.

In the heating main operation mode shown in FIG. 6, in the outdoor unit 1, the first refrigerant flow switching device 11 is connected to the relay unit without passing the heat source side refrigerant discharged from the compressor 10 through the heat source side heat exchanger 12. Switch to 2

In the relay unit 2, the refrigerant expansion heat medium conveyance device 60a and the refrigerant expansion heat medium conveyance device 60b are driven to open the heat medium flow switching flow rate adjustment device 40a to the heat medium flow switching flow adjustment device 40d, Between the heat exchanger 25a and the use side heat exchanger 35 in which the cold load is generated, between the heat exchanger 25b between the heat medium 25b and the use side heat exchanger 35 in which the heat load is generated, respectively. The heat medium is circulated. At this time, the second refrigerant flow switching device 28a is switched to the cooling side, the second refrigerant flow switching device 28b is switched to the heating side, the opening / closing device 27 is closed, and the opening / closing device 29 is closed.

First, the flow of the heat source side refrigerant in the refrigerant circuit A will be described.
The low-temperature and low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 passes through the first refrigerant flow switching device 11, conducts through the refrigerant connection pipe 4 a, passes through the check valve 13 d, and flows out of the outdoor unit 1. The high-temperature and high-pressure gas refrigerant that has flowed out of the outdoor unit 1 flows into the relay unit 2 through the refrigerant pipe 4. The high-temperature and high-pressure gas refrigerant that has flowed into the relay unit 2 flows through the second refrigerant flow switching device 28b into the heat exchanger related to heat medium 25b that acts as a condenser.

The gas refrigerant flowing into the heat exchanger related to heat medium 25b is condensed and liquefied while dissipating heat to the heat medium circulating in the heat medium circuit B, and becomes liquid refrigerant. The liquid refrigerant that has flowed out of the heat exchanger related to heat medium 25b is expanded by the refrigerant expansion heat medium transfer device 60b to become a low-pressure two-phase refrigerant. This low-pressure two-phase refrigerant flows into the heat exchanger related to heat medium 25a acting as an evaporator via the refrigerant expansion heat medium transport device 60a. The low-pressure two-phase refrigerant that has flowed into the heat exchanger related to heat medium 25a evaporates by absorbing heat from the heat medium circulating in the heat medium circuit B, thereby cooling the heat medium. The low-pressure two-phase refrigerant flows out of the heat exchanger related to heat medium 25a, flows out of the relay unit 2 through the second refrigerant flow switching device 28a, and flows into the outdoor unit 1 again through the refrigerant pipe 4.

The low-temperature and low-pressure two-phase refrigerant that has flowed into the outdoor unit 1 flows into the heat source side heat exchanger 12 that acts as an evaporator through the check valve 13b. And the refrigerant | coolant which flowed into the heat source side heat exchanger 12 absorbs heat from external air in the heat source side heat exchanger 12, and turns into a low temperature and low pressure gas refrigerant. The low-temperature and low-pressure gas refrigerant flowing out from the heat source side heat exchanger 12 is again sucked into the compressor 10 via the first refrigerant flow switching device 11 and the accumulator 19.

At this time, the opening degree of the refrigerant expansion heat medium transport device 60b is controlled so that the subcooling (supercooling degree) of the outlet refrigerant of the heat exchanger related to heat medium 25b becomes the target value together with the refrigerant expansion heat medium transport device 60a. Is done. Alternatively, it is possible to adjust by providing a bypass circuit so that the subcooling is constant. It should be noted that the subcool control in which the refrigerant expansion heat medium transport device 60a and the refrigerant expansion heat medium transport device 60b are combined is only required to be able to recover expansion power by expansion of the refrigerant while keeping the subcool constant.

Next, the flow of the heat medium in the heat medium circuit B will be described.
In the heating main operation mode, the heat of the heat source side refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 25b, and the heated heat medium is caused to flow in the pipe 5 by the refrigerant expansion heat medium transport device 60b. . In the heating main operation mode, the heat of the heat source side refrigerant is transmitted to the heat medium in the heat exchanger related to heat medium 25a, and the cooled heat medium is caused to flow in the pipe 5 by the refrigerant expansion heat medium transport device 60a. become. The cooled heat medium that has been pressurized and flowed out by the refrigerant expansion heat medium transport device 60a flows into the use-side heat exchanger 35 where the cold load is generated via the heat medium flow switching flow rate adjustment device 40, The heat medium that has been pressurized and flowed out by the refrigerant expansion heat medium transfer device 60b flows into the use side heat exchanger 35 where the heat load is generated via the heat medium flow switching flow rate adjustment device 40.

At this time, in the heat medium flow switching flow rate adjusting device 40, when the connected indoor unit 3 is in the heating operation mode, the heat exchanger related to heat medium 25b and the refrigerant expansion heat medium transport device 60b are connected. When the connected indoor unit 3 is in the cooling operation mode, the direction is switched to the direction in which the heat exchanger related to heat medium 25a and the refrigerant expansion heat medium transfer device 60a are connected. That is, the heat medium flow switching device 40 can switch the heat medium supplied to the indoor unit 3 between heating and cooling.

In the use side heat exchanger 35, the cooling operation of the indoor space 7 by the heat medium absorbing heat from the room air or the heating operation of the indoor space 7 by the heat medium radiating heat to the room air is performed. At this time, the flow rate of the heat medium flow control device 40 controls the flow rate of the heat medium to a flow rate necessary to cover the air conditioning load required indoors, and flows into the use side heat exchanger 35. It is supposed to be.

The heat medium that has been used for the cooling operation and has passed through the use-side heat exchanger 35 and whose temperature has risen slightly passes through the heat medium flow switching flow rate adjusting device 40 and flows into the heat exchanger related to heat medium 25a, and again becomes a refrigerant. It is sucked into the expanded heat medium transport device 60a. The heat medium that has been used for the heating operation and has passed through the use-side heat exchanger 35 and has slightly decreased in temperature passes through the heat medium flow switching flow rate adjustment device 40 and flows into the heat exchanger related to heat medium 25b, and again becomes a refrigerant. It is sucked into the expansion heat medium transport device 60b. At this time, in the heat medium flow switching flow rate adjusting device 40, when the connected indoor unit 3 is in the heating operation mode, the heat exchanger related to heat medium 25b and the refrigerant expansion heat medium transport device 60b are connected. When the connected indoor unit 3 is in the cooling operation mode, the direction is switched to the direction in which the heat exchanger related to heat medium 25a and the refrigerant expansion heat medium transfer device 60a are connected.

During this time, the warm heat medium and the cold heat medium are introduced into the use-side heat exchanger 35 having a heat load and a heat load, respectively, without being mixed by the action of the heat medium flow switching flow control device 40. As a result, the heat medium used in the heating operation mode receives heat from the refrigerant as a heating application, and the heat medium used in the cooling operation mode receives heat from the heat medium heat exchanger 25b. The refrigerant is introduced into the heat exchanger related to heat medium 25a and exchanges heat with the refrigerant again, and is then transferred to the refrigerant expansion heat medium transfer device 60a and the refrigerant expansion heat medium transfer device 60b.

The air conditioning load required in the indoor space 7 is the difference between the temperature detected by the temperature sensor 55b on the heating side and the temperature of the heat medium flowing out from the use side heat exchanger 35 on the cooling side. This can be covered by controlling the difference between the temperature of the heat medium flowing out from the use side heat exchanger 35 and the temperature detected by the temperature sensor 55a as a target value.

Further, in the air-conditioning apparatus 100 in FIG. 6, in the cooling / heating mixed operation mode, a cooling load is generated in any of the use side heat exchangers 35, and the heating load is generated in the remaining of the use side heat exchangers 35. Among the mixed operations that are occurring, even in the cooling main operation mode, the heat source side refrigerant flow in the refrigerant circuit A and the heat medium flow in the heat medium circuit B are the same as in the heating main operation mode.

Next, an example of refrigerant expansion power and heat medium conveyance power recovered from the heat source side refrigerant in the heating main operation mode will be described with reference to FIG. The high-temperature and high-pressure refrigerant pressure in the heating main operation mode is given by Pc in the figure, and the low-temperature and low-pressure refrigerant pressure in the heating main operation mode is given by Pe in the figure.

When the pressure, temperature, and refrigerant flow rate of the heat source side refrigerant in the heating main operation mode are given as follows, the expansion power of the heat source side refrigerant can be calculated.
Pc = 2.3 [Mpa], Pe = 1 [Mpa], subcool SC = 4 [deg], refrigerant flow rate Gr = 654 [kg / hr].
At this time,
(Enthalpy difference from isentropic change with respect to isoenthalpy change) × refrigerant flow rate = refrigerant expansion power, and the refrigerant expansion power in the above example is 0.53 [kW], and this refrigerant expansion power is used as the heat transfer power. It can be used.

Although the second refrigerant flow switching device 28 is shown as a four-way valve, the present invention is not limited to this, and a plurality of two-way flow switching valves and three-way flow switching valves are used in the same manner. You may comprise so that a refrigerant | coolant may flow.

As the heat medium, for example, brine (antifreeze), water, a mixture of brine and water, a mixture of water and an additive having a high anticorrosive effect, or the like can be used. Therefore, in the air conditioning apparatus 100, even if the heat medium leaks into the indoor space 7 through the indoor unit 3, it contributes to the improvement of safety because a highly safe heat medium is used. Become.

In the present embodiment, the case where the air conditioner 100 includes the accumulator 19 has been described as an example, but the accumulator 19 may not be provided. In general, the heat source side heat exchanger 12 and the use side heat exchanger 35 are provided with a blower, and in many cases, condensation or evaporation is promoted by blowing air, but this is not a limitation. For example, the use side heat exchanger 35 can be a panel heater using radiation, and the heat source side heat exchanger 12 is a water-cooled type that moves heat by water or antifreeze. Can also be used. That is, the heat source side heat exchanger 12 and the use side heat exchanger 35 can be used regardless of the type as long as they have a structure capable of radiating heat or absorbing heat.

In the present embodiment, the case where there are four usage-side heat exchangers 35 has been described as an example, but the number is not particularly limited. Moreover, although the case where the number of heat exchangers between heat mediums 25a and the heat exchangers between heat mediums 25b is two has been described as an example, naturally the present invention is not limited to this, so that the heat medium can be cooled or / and heated. If it comprises, you may install how many. Furthermore, the refrigerant expansion heat medium transfer device 60a and the refrigerant expansion heat medium transfer device 60b are not limited to one each, and a plurality of small capacity refrigerant expansion heat medium transfer devices 60 may be connected in parallel.

As described above, the air-conditioning apparatus 100 according to the present embodiment not only improves the safety without circulating the heat source side refrigerant to the indoor unit 3 or the vicinity of the indoor unit 3, but also the heat source side refrigerant has a high pressure. By using it as the power for transporting the heat medium that uses the expansion power generated when changing from low pressure to low pressure, it leads to a reduction in operating power during cooling operation or heating operation, cooling main operation, and heating main operation In addition, cost reduction and space saving can be achieved by reducing the number of parts.

1 outdoor unit, 2 relay unit, 3 indoor unit, 3a indoor unit, 3b indoor unit, 3c indoor unit, 3d indoor unit, 4 refrigerant pipe, 4a refrigerant connection pipe, 4b refrigerant connection pipe, 5 pipe, 6 outdoor space , 7 indoor space, 8 space, 9 building, 10 compressor, 11 first refrigerant flow switching device, 12 heat source side heat exchanger, 13a check valve, 13b check valve, 13c check valve, 13d check valve , 19 accumulator, 20 bypass piping, 25 heat exchanger between heat medium, 25a heat exchanger between heat medium, 25b heat exchanger between heat medium, 27 switchgear, 28 second refrigerant flow switching device, 28a second refrigerant Channel switching device, 28b second refrigerant channel switching device, 29 switchgear, 35 user side heat exchanger, 35a user side heat exchanger, 5b Use side heat exchanger, 35c Use side heat exchanger, 35d Use side heat exchanger, 40 Heat medium flow switching flow adjustment device, 40a Heat medium flow switching flow adjustment device, 40b Heat medium flow switching flow adjustment device 40c Heat medium flow switching device, 40d Heat medium flow switching device, 50 Control device, 55 Temperature sensor, 55a Temperature sensor, 55b Temperature sensor, 60 Refrigerant expansion heat transfer device, 60A Refrigerant expansion chamber, 60B heat medium transfer chamber, 60a refrigerant expansion heat medium transfer device, 60b refrigerant expansion heat medium transfer device, 61 refrigerant inlet, 62 refrigerant outlet, 63 heat medium inlet, 64 heat medium outlet, 65 partition plate, 66 shaft, 69 sealed container , 87 indoor space, 100 air conditioner, A refrigerant circulation circuit, B heat medium circulation circuit.

Claims (4)

Heat source side refrigerant by connecting a compressor, a heat source side heat exchanger, a plurality of expansion devices, a refrigerant side flow path of a plurality of heat exchangers between heat mediums, and a plurality of refrigerant flow switching devices for switching a refrigerant circulation path through a refrigerant pipe A refrigerant circulation circuit for circulating
A plurality of use-side heat exchangers, and a heat medium circulation circuit that circulates the heat medium by connecting the heat medium side flow paths of the plurality of heat exchangers between the heat mediums with a heat medium pipe,
An air conditioner in which heat is exchanged between the heat source side refrigerant and the heat medium in the intermediate heat exchanger.
In the heat medium circulation circuit,
An air conditioner including a heat medium transport device that uses expansion power of the heat source side refrigerant expanded by the plurality of expansion devices as power for transporting the heat medium. A refrigerant expansion heat medium conveying device in which the expansion device and the heat medium conveying device are integrated;
The refrigerant expansion heat transfer device is
The air conditioning apparatus according to claim 1, wherein the heat medium conveying power is obtained by transmitting expansion power of the heat source side refrigerant as rotational power to the heat medium circuit. A heating only operation mode in which all of the heat exchangers between heat media act as condensers;
A cooling only operation mode in which all of the heat exchangers between heat media act as evaporators;
A part of the heat exchanger related to heat medium acts as a condenser, and a part of the heat exchanger related to heat medium acts as an evaporator.
The refrigerant expansion heat transfer device is
The air conditioner according to claim 2, wherein transport power of the heat medium required in each operation mode is recovered by power when the heat source side refrigerant is expanded. A heat medium flow switching flow rate adjusting device for switching which heat medium flows into and out of the use side heat exchanger among the heat mediums related to heat exchange of the plurality of heat exchangers between heat mediums In preparation for the heat medium circuit,
The heat medium flow switching flow rate adjusting device is:
The air conditioner according to any one of claims 1 to 3, wherein switching of the heat medium circulation circuit and flow rate adjustment to the use side heat exchanger are performed based on a capacity of each use side heat exchanger. .

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