JP2005241074A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve efficiency an air conditioner for conditioning air by pressurizing a sealing medium to a supercritical range, sealing it in an indoor cycle, and circulating the carrying medium inside the indoor cycle. <P>SOLUTION: The air conditioner is provided with an outdoor cycle 9 having a compressor 2 for compressing refrigerant, a four-way valve 3 for switching a flow passage of the refrigerant, which is discharged from the compressor 2, in response to operation mode, an intermediate heat exchanger 6, in which the refrigerant and the carrying medium pass through, an expansion valve 5 for reducing pressure of the refrigerant or expanding the refrigerant to form a low-pressure refrigerant, and an outdoor heat exchanger 4 for exchanging heat between the refrigerant passing through inside thereof and open air, and provided with an indoor cycle 13 having a carrying medium driving device 10 for circulating the carrying medium pressurized to the supercricital range, the intermediate heat exchanger 6 and at least one indoor heat exchanger 11 for exchanging heat between the carrying medium passing through inside thereof and air to be fed into the room. In the intermediate heat exchanger 6, heat is exchanged between the refrigerant circulating in the outdoor cycle 9 and the carrying medium circulating in the indoor cycle 13. A heating means 7 for raising temperature of the gas refrigerant to be sucked by the compressor 2 is provided upstream of the compressor 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air conditioner that pressurizes a carrier medium in a supercritical region, encloses the carrier medium in an indoor cycle, and performs an air conditioning operation by circulating the carrier medium in the indoor cycle.

Air-conditioning operation is performed by pressurizing the transport medium to the supercritical region and enclosing it in an indoor cycle (also called “secondary cycle” or “use-side cycle”), and circulating the transport medium in the indoor cycle. Examples of the air conditioner to be heated include those that heat or cool the transport medium by heat exchange with the refrigerant circulating in the outdoor cycle (also referred to as “primary side cycle” or “heat source side cycle”). Yes (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-79684 (see, for example, FIG. 7)

  However, in the thing of the said patent document 1, the temperature of the discharge gas discharged from a compressor cannot be raised more than 70 degreeC, and there existed a limit in improving the efficiency of an air conditioner.

  The present invention has been made in view of the above circumstances, and aims to further improve the efficiency of an air conditioner.

The present invention employs the following means in order to solve the above problems.
The air conditioner according to claim 1 is a compressor that compresses a refrigerant, a four-way valve that switches a flow path of the refrigerant discharged from the compressor in accordance with an operation mode, and intermediate heat through which the refrigerant and the transport medium pass. An outdoor cycle having an exchanger, an expansion valve that decompresses and expands the refrigerant to form a low-temperature and low-pressure refrigerant, and an outdoor heat exchanger that exchanges heat between the refrigerant that passes through the interior and the outside air, and the supercritical region. A chamber having a conveyance medium driving device that circulates the pressurized conveyance medium, the intermediate heat exchanger, and at least one indoor heat exchanger that exchanges heat between the conveyance medium passing through the inside and the air blown into the room An air conditioner in which heat is exchanged between the refrigerant circulating in the outdoor cycle and the transport medium circulating in the indoor cycle in the intermediate heat exchanger, and upstream of the compressor In, wherein the heating means for raising the temperature of the gaseous refrigerant is sucked into the compressor is provided.
According to such an air conditioner, the temperature of the gaseous refrigerant sucked into the compressor is preliminarily warmed, the discharge gas temperature of the compressor is increased, and the efficiency of the air conditioner is improved. Become. In particular, when heating operation is performed, for example, when carbon dioxide is used as a carrier medium, heat exchange at a high temperature such as 90 ° C. is possible in the intermediate heat exchanger. Therefore, the air by the indoor heat exchanger in a desired supercritical state is used. Harmony is realized.

The air conditioner according to claim 2 is configured such that a heat exchanger is used as the heating means, and a refrigerant having a temperature higher than that of the gaseous refrigerant sucked by the compressor is led to the heat exchanger. It is characterized by being.
According to such an air conditioner, since the heat energy of the refrigerant circulating in the outdoor cycle is recovered by the refrigerant sucked by the compressor, the loss of heat energy is suppressed, and the air conditioner This will further improve the efficiency.

The air conditioner according to claim 3 is provided with a storage tank for storing a carrier medium circulating in the indoor cycle in the indoor cycle, and a temperature variable means in the storage tank. It is characterized by that.
According to such an air conditioner, when the storage tank is cooled by the temperature variable means, the transport medium circulating in the indoor cycle is recovered in the storage tank, and the pressure in the indoor cycle is reduced. When the storage tank is heated by the temperature variable means, the transport medium recovered in the storage tank is returned to the indoor cycle, and the pressure in the indoor cycle increases. Thereby, in each of the heating operation and the cooling operation, the pressure in the indoor side cycle can be maintained at, for example, 10 MPa during the heating operation and 4 MPa during the cooling operation. While being able to drive | operate, the efficiency of an air conditioner can be improved now.
The storage tank and the temperature variable means are not necessarily provided together with the above-described heat exchanger. For example, as shown in FIG. 5, the storage tank and the temperature variable means may be provided separately from the heat exchanger. it can.
Moreover, in FIG. 5, the same code | symbol is attached | subjected to the member same as FIG. 3 used in order to demonstrate 2nd Embodiment mentioned later.

The air conditioner according to claim 4 is characterized in that a heat exchanger is used as the temperature varying means, and that the refrigerant circulating in the outdoor cycle is guided to the heat exchanger. To do.
According to such an air conditioner, the heat energy of the refrigerant circulating in the outdoor cycle is used to heat or cool the storage tank, so that the storage tank is heated or cooled. There is no need to separately generate thermal energy, and the running cost of the air conditioner is reduced.

The air conditioner according to claim 5 is configured such that the refrigerant in the outdoor cycle passing through the intermediate heat exchanger and the carrier medium in the indoor cycle are opposed to each other during heating operation and parallel flow during cooling operation. It is comprised by these.
According to such an air conditioner, the carrier medium is always circulated in one direction in the indoor cycle, so that the configuration of the indoor cycle is simplified and the cost is reduced. .

According to the air conditioner of the present invention, the temperature of the gaseous refrigerant sucked into the compressor can be pre-warmed, so that the discharge gas temperature of the compressor can be raised and the efficiency of the air conditioner is improved. Can be made.
Moreover, since the heat energy of the refrigerant circulating in the outdoor cycle is recovered by the refrigerant sucked into the compressor, the loss of heat energy can be suppressed, and the efficiency of the air conditioner is further improved. Can be made.
Further, when the storage tank is cooled by the temperature variable means, the transport medium circulating in the indoor cycle is collected in the storage tank, and the pressure in the indoor cycle is reduced. Conversely, the storage tank is heated by the temperature variable means. Then, the transport medium recovered in the storage tank is returned to the indoor cycle, and the pressure in the indoor cycle increases, so that in each of the heating operation and the cooling operation, The pressure in the indoor cycle can be maintained at, for example, 10 MPa during heating operation and 4 MPa during cooling operation, so that the air conditioner can be operated most efficiently and the efficiency of the air conditioner can be improved. Can be improved.
Furthermore, since the heat energy of the refrigerant circulating in the outdoor cycle is used to heat or cool the storage tank, it is necessary to separately generate heat energy for heating or cooling the storage tank. The running cost of the air conditioner can be reduced.
Furthermore, since the carrier medium is always circulated in one direction in the indoor cycle, the configuration of the indoor cycle can be simplified and the cost can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a first embodiment of an air conditioner according to the present invention. An air conditioner 1 shown in FIG. 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, an intermediate heat exchanger 6, an intake gas heater (heating means) 7, and a pipe 8 as main elements. And an indoor cycle 13 having the intermediate heat exchanger 6, the transfer medium driving device 10, the indoor heat exchanger 11, and the pipe 12 as main elements.
The compressor 2 sucks and compresses a low-temperature, low-pressure gaseous refrigerant (as a refrigerant, for example, a hydrocarbon refrigerant such as propane, butane, and isobutane (a refrigerant containing carbon (C) and hydrogen (H)). This is a high-temperature, high-pressure gaseous refrigerant.
The four-way valve 3 is provided on the downstream side of the compressor 2 and switches the flow path of the refrigerant discharged from the compressor 2 between the cooling operation and the heating operation. During the heating operation (solid arrow in the figure) When the refrigerant is circulated in the direction indicated by), a flow path from the compressor 2 toward the intermediate heat exchanger 6 is formed, while on the other hand, during cooling operation (when the refrigerant is circulated in the direction indicated by the broken line arrow in the figure) Is configured to form a flow path from the compressor 2 toward the outdoor heat exchanger 4.
The outdoor heat exchanger 4 functions as a condenser that condenses and liquefies a high-temperature and high-pressure gaseous refrigerant during cooling operation and dissipates heat to the outside air. It functions as an evaporator.
The expansion valve 5 depressurizes and expands the refrigerant that passes through it to form a low-temperature and low-pressure refrigerant.

The intermediate heat exchanger (also referred to as “inter-refrigerant heat exchanger”) 6 allows heat to be exchanged between the refrigerant circulating in the outdoor cycle 9 and the transport medium circulating in the indoor cycle 13. During the heating operation, the transport medium circulating in the indoor cycle 13 is heated by the refrigerant circulating in the outdoor cycle 9, and during the cooling operation, the transport medium circulating in the indoor cycle 13 is cooled by the refrigerant circulating in the outdoor cycle 9. It has come to be. Further, a temperature sensor T is provided in the pipe 8 located in the vicinity of the inlet of the intermediate heat exchanger 6, and refrigerant temperature data in the pipe 8 detected by the temperature sensor T is output to the controller 14. It is like that.
The suction gas heater 7 is a heat exchanger provided on the upstream side of the compressor 2 (that is, between the compressor 2 and the four-way valve 3), and is warm that has passed through the intermediate heat exchanger 6 during heating operation. This is for preheating the refrigerant sucked into the compressor 2 by the refrigerant (increasing the temperature of the refrigerant sucked into the compressor 2).
The pipe 8 connects the compressor 2, the four-way valve 3, the outdoor heat exchanger 4, the expansion valve 5, the intermediate heat exchanger 6, and the suction gas heater 7 so that the refrigerant can circulate between these components. As a result, an outdoor cycle (also referred to as “primary side cycle” or “heat source side cycle”) 9 is formed.
Further, a bypass pipe 8 a is connected to the pipe 8, and the refrigerant that has passed through the intermediate heat exchanger 6 is positioned downstream of the intake gas heater 7 without passing through the intake gas heater 7 during the heating operation. It is led directly to the upstream side of the expansion valve 5.
Flow control valves 15 and 15a are provided in the pipe 8 downstream of the inlet of the bypass pipe 8a and upstream of the intake gas heater 7, and the bypass pipe 8a, respectively. Each of these flow rate adjusting valves 15 and 15a is configured so that the valve opening is adjusted by a signal from the controller 14, and the amount of refrigerant flowing from the intermediate heat exchanger 6 into the intake gas heater 7 and the intermediate amount are adjusted. The amount of refrigerant flowing into the expansion valve 5 from the heat exchanger 6 is adjusted. On the other hand, during the cooling operation, the refrigerant that has passed through the expansion valve 5 does not pass through the intake gas heater 7 but is directly led to the intermediate heat exchanger 6, that is, the flow rate adjustment valve 15 is fully closed and the flow rate is increased. The adjustment valve 15a is fully opened.

The carrier medium driving device 10 is, for example, a pumping means such as a pump or a compressor, and a carrier medium (for example, carbon dioxide) pressurized in the supercritical region (having a maximum thermal conductivity) It is circulated in the indoor cycle 13.
The indoor heat exchanger 11 performs heat exchange between the transport medium passing through the interior and the air blown into the room, and functions as a so-called evaporator during cooling operation and as a so-called condenser during heating operation. .
The pipe 12 connects the intermediate heat exchanger 6, the indoor heat exchanger 11, and the transport medium driving device 10, and enables the transport medium to circulate between these constituent elements. (Also referred to as “secondary cycle” or “use cycle”) 13 is formed.
The pipes 12 positioned on the upstream side of the indoor heat exchangers 11 are each provided with a flow rate adjusting valve 16 to adjust the amount of the transport medium flowing into the indoor heat exchanger 11 from the intermediate heat exchanger 6. It has become so.

As described above, in the present embodiment, the refrigerant flowing into the compressor 2 can be warmed by the suction gas heater 7 and the discharge gas temperature of the compressor 2 can be increased (for example, to 90 ° C.). The COP (Coefficiency of performance) of the outdoor cycle 9 can be increased. That is, as shown in FIG. 2, the cycle drawn on the Mollier diagram can be expanded from the solid line to the broken line, and the COP of the air conditioner can be improved.
Further, by setting the discharge gas temperature of the compressor 2 to a high temperature (for example, 90 ° C.), heat exchange at a high temperature is possible in the intermediate heat exchanger, and the air by the indoor heat exchanger in a desired supercritical state Harmony can be achieved.
Furthermore, since the heat energy of the refrigerant circulating in the outdoor cycle 9 is recovered by the refrigerant flowing into the compressor 2, the loss of heat energy can be reduced, and the COP of the air conditioner can be reduced. Can be further improved.
Furthermore, the opening degree of the flow rate adjusting valves 15 and 15a is automatically adjusted based on data from the temperature sensor T provided in the pipe 8 located near the inlet of the intermediate heat exchanger 6 during heating operation. Therefore, the temperature of the refrigerant in the vicinity of the inlet of the intermediate heat exchanger 6 can always be kept constant.

A second embodiment of the air conditioner according to the present invention will be described with reference to FIG.
The air conditioner 21 in the present embodiment is provided with a transport medium storage tank 22 in the indoor cycle 13 and a heat exchanger (temperature variable) for heating or cooling the transport medium storage tank 22 in the outdoor cycle 9. Means) 23 is different from that of the first embodiment in that it is provided. Since other components are the same as those in the above-described embodiment, description of these components is omitted here.
In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment mentioned above.

A transport medium storage tank 22 in which a part of the transport medium circulating in the indoor cycle 13 is stored is a pipe located on the upstream side of the compressor 2 via the second pipe 24 (that is, all indoor heat exchanges). 11 is connected to the pipe 12, and the conveyance medium flows from the pipe 12 toward the conveyance medium storage tank 22 or from the conveyance medium storage tank 22 toward the pipe 12. It can be done.
On the other hand, a pressure sensor P is provided in the pipe 12 located in the vicinity of the inlet of the transport medium driving device 10 so that pressure data in the pipe 12 detected by the pressure sensor P is output to the controller 25. It has become.
In addition, the second pipe 24 is provided with a gate valve 26 configured to be opened and closed based on a signal from the controller 25, and when fully closed, the second medium 24 is connected to the transfer medium storage tank 22 from the pipe 12. The transfer of the transfer medium from the transfer medium storage tank 22 to the pipe 12 can be blocked, and conversely, when the transfer medium is fully opened, the transfer from the pipe 12 to the transfer medium storage tank 22 or the transfer The transport medium can be moved from the medium storage tank 22 toward the pipe 12.

The heat exchanger 23 cools the transport medium storage tank 22 by introducing a refrigerant having a temperature lower than that of the transport medium stored in the transport medium storage tank 22, and conversely, the transport stored in the transport medium storage tank 22. The conveyance medium storage tank 22 is heated by introducing a refrigerant having a temperature higher than that of the medium. When the transfer medium storage tank 22 is cooled by the heat exchanger 23, the transfer medium circulating in the indoor cycle 13 is collected in the transfer medium storage tank 22 and the pressure in the pipe 12 is lowered. When the transport medium storage tank 22 is heated by the vessel 23, the transport medium recovered in the transport medium storage tank 22 is returned to the pipe 12 and the pressure in the pipe 12 increases.
The second expansion valve 5a is provided in the pipe 8 upstream of the heat exchanger 23 and downstream of the outlet of the bypass pipe 8a, and heat is generated by restricting the second expansion valve 5a. The temperature of the refrigerant flowing into the exchanger 23 can be lowered. The second expansion valve 5a is configured such that the valve opening degree is adjusted by a signal from the controller 25, and the pressure in the pipe 12 is different in each of the heating operation and the cooling operation. 4 is maintained at an optimum pressure.

With such a configuration, the following operational effects can be obtained in addition to the operational effects that can be obtained in the first embodiment described above.
In the present embodiment, since the transport medium storage tank 22 is provided in the indoor cycle 13 and the heat exchanger 23 for heating or cooling the transport medium storage tank 22 is provided in the outdoor cycle 9, In each of the heating operation and the cooling operation, the pressure in the pipe 12 of the indoor cycle 13 can be maintained at an optimum pressure (for example, 10 MPa during the heating operation and 4 MPa during the cooling operation). The machine can be operated most efficiently and the efficiency of the air conditioner can be improved.
Further, by appropriately adjusting the expansion valve 5a and the flow rate adjusting valves 15 and 15a, the pressure in the pipe 12 of the indoor cycle 13 is within an appropriate pressure range (for example, 7 MPa to 10 MPa during the heating operation, and the cooling operation). 3MPa-5MPa), and the temperature in each cycle (heating cycle and cooling cycle) can be changed finely, so that the temperature of the air blown into the room is also finely adjusted. It can be changed.

In the intermediate heat exchanger 6 of the first embodiment and the second embodiment described above, the flow direction of the refrigerant circulating in the outdoor cycle 9 and the flow direction of the transport medium circulating in the indoor cycle 13 are determined during the heating operation. It becomes a counterflow and is comprised so that it may become a parallel flow at the time of air_conditionaing | cooling operation. That is, the outdoor cycle 9 is configured such that the refrigerant flow direction is reversed by the four-way valve 3 during the heating operation and during the cooling operation. In the indoor cycle 13, the relationship is during the heating operation and the cooling operation. The transport medium is always circulated in one direction.
As can be seen from FIG. 4 shown above, there is no temperature difference between the inlet and the outlet of the intermediate heat exchanger during the cooling operation (cooling cycle). Because it ends up.
In this way, since it is sufficient to always circulate the conveyance medium in one direction in the indoor cycle 13, the configuration of the indoor cycle 13 can be simplified, and the cost can be reduced.

It is a schematic block diagram which shows 1st Embodiment of the air conditioner by this invention. It is the graph which showed on the Mollier diagram the state of the refrigerant | coolant which circulates through the outdoor cycle shown in FIG. It is a schematic block diagram which shows 2nd Embodiment of the air conditioner by this invention. It is the graph which showed the state of the conveyance medium which circulates through the indoor side cycle shown to FIG. 1 and FIG. 3 on the Mollier diagram. It is a schematic block diagram which shows another embodiment of the air conditioner by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Compressor 4 Outdoor heat exchanger 5 Expansion valve 6 Intermediate heat exchanger 7 Suction gas heater (heating means)
9 Outdoor cycle 10 Transport medium driving device 11 Indoor heat exchanger 13 Indoor cycle 21 Air conditioner 22 Transport medium storage tank (storage tank)
23 Heat exchanger (Temperature variable means)

Claims (5)

A compressor that compresses the refrigerant, a four-way valve that switches the flow path of the refrigerant discharged from the compressor according to the operation mode, an intermediate heat exchanger through which the refrigerant and the transport medium pass, and a low temperature by decompressing and expanding the refrigerant An outdoor valve having an expansion valve for making a low-pressure refrigerant, and an outdoor heat exchanger for exchanging heat between the refrigerant passing through the inside and the outside air;
At least one indoor heat that exchanges heat between the transport medium driving device that circulates the transport medium pressurized in the supercritical region, the intermediate heat exchanger, and the transport medium that passes through the interior and the air that is blown into the room An indoor cycle having an exchanger,
An air conditioner in which heat exchange is performed between the refrigerant circulating in the outdoor cycle and the transport medium circulating in the indoor cycle in the intermediate heat exchanger,
An air conditioner characterized in that heating means for increasing the temperature of the gaseous refrigerant sucked into the compressor is provided on the upstream side of the compressor.   2. A heat exchanger is used as the heating means, and a refrigerant having a temperature higher than that of the gaseous refrigerant sucked into the compressor is guided to the heat exchanger. Air conditioner as described in.   3. The storage tank according to claim 1, further comprising a storage tank that stores a transport medium that circulates within the cycle, and a temperature variable unit that is provided in the storage tank. The air conditioner described.   The air conditioner according to claim 3, wherein a heat exchanger is used as the temperature varying means, and the refrigerant circulating through the outdoor cycle is guided to the heat exchanger.   The refrigerant in the outdoor cycle passing through the intermediate heat exchanger and the carrier medium in the indoor cycle are configured to be opposed to each other during heating operation and to be parallel flow during cooling operation. Item 5. The air conditioner according to any one of Items 1 to 4.

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