JP2010096474A - Air-conditioning control device and air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-conditioning control device and an air conditioning system capable of suppressing lowering of an indoor temperature with a comparatively simple structure when a defrosting operation is performed. <P>SOLUTION: Whether the air conditioning system 1 satisfies conditions of a pre-defrosting operation or not is determined by an operating condition determining means 22 during a heating operation. When the conditions of the pre-defrosting operation are satisfied, an enhanced operation for indoor heating is instructed by a pre-defrosting operation instructing means 23 so that the indoor temperature reaches a target set temperature higher than a reference set temperature. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air conditioning control device and an air conditioning system for a cold region where the temperature is below freezing in winter and the like.

  When a heating operation is performed using an air conditioner in a cold region, a phenomenon is known in which frost accumulates on the outdoor heat exchanger and the heat exchange rate of the outdoor heat exchanger deteriorates. For this reason, a defrosting operation mode for removing frost accumulated on the outdoor heat exchanger is usually prepared in an air conditioner installed in a cold district. When defrosting is performed, the amount of heating is supplied to the outdoor heat exchanger, so the heating operation temporarily stops and the room temperature decreases. As a countermeasure, the air conditioner disclosed in Patent Document 1 has a heat storage tank for storing a heat storage heat exchanger and a heat storage material, and accumulates heat in the heat storage material while heating the air-conditioned room. In addition, by using the warm heat accumulated in the heat storage material, it is possible to remove frost attached to the outdoor heat exchanger while heating the air-conditioned room.

Moreover, as shown in Patent Document 2, in an air conditioning system that air-conditions a room with a plurality of indoor units each having a plurality of individual outdoor units, when there is an indoor unit in a defrosting state, The heating capacity of the indoor unit is maintained by increasing the heating capacity of the indoor unit.
JP-A-5-26542 JP-A-6-273010

  However, in the air conditioner disclosed in Patent Document 1, the refrigerant discharged from the compressor is discharged in the order of the heat storage heat exchanger, the indoor heat exchanger, and the outdoor heat exchanger in the heating and heat storage operation. In the flow and heating / defrosting operation, the discharged refrigerant flows in the order of the indoor heat exchanger, the heat storage heat exchanger, and the outdoor heat exchanger. For this reason, in this air conditioner, the flow of the refrigerant and the state of the refrigerant are appropriately controlled, and in the heating / heat storage operation, the indoor heat exchanger (heating) and the heat storage heat exchanger (heat storage) are heated. During the defrosting operation, it is necessary to distribute an appropriate amount of heat to the indoor heat exchanger (heating) and the outdoor heat exchanger (defrost). However, such control is very complicated and lacks feasibility.

  Moreover, in the air conditioning system disclosed in Patent Document 2, a set of at least two or more outdoor units and indoor units is required.

  The subject of this invention is providing the air conditioning apparatus which can suppress the fall of room temperature when performing defrost operation with a comparatively simple structure.

  The air conditioning control device according to the first aspect of the present invention is a control device for an air conditioning system capable of performing at least an indoor heating operation and a defrosting operation, and includes an operating condition determination unit and a pre-defrosting operation instruction unit. The operating condition determining means determines whether or not the air conditioning system has reached the operating condition before defrosting. The pre-defrosting operation instruction means instructs the enhanced operation of the indoor heating when the operation condition determination means determines that the pre-defrost operation condition is satisfied.

  This air conditioning system can perform at least indoor heating operation and defrosting operation. Usually, when performing a defrosting operation, the amount of heating is supplied to the outdoor heat exchanger, so the heating operation temporarily stops and the room temperature often decreases.

  However, in the present invention, the operation condition determining means determines whether or not the air conditioning system has reached the pre-defrost operation condition, and if it is determined that the pre-defrost operation condition is satisfied, the pre-defrost operation instruction means The room heating is instructed to be strengthened.

  That is, the indoor temperature can be raised to a predetermined temperature by performing the indoor heating strengthening operation before defrosting. Therefore, even if the heating operation is temporarily stopped during the defrosting operation, the room temperature can be lowered by the temperature that has been increased in advance, so that the temperature during the normal heating operation can be maintained even during the defrosting operation. Can do.

  An air conditioning control device according to a second aspect of the present invention is the air conditioning control device according to the first aspect of the present invention, wherein the air conditioning system includes an outdoor unit operating condition detecting means for detecting an operating condition of the outdoor unit. The operating condition determining means determines that the pre-defrosting operating condition has been reached when the outdoor unit operating status detected by the outdoor unit operating status detecting means has reached a predetermined status.

  This air conditioning control device detects the outdoor unit operating status by the outdoor unit operating status detecting means, and when the outdoor unit operating status detected by the outdoor unit operating status detecting means reaches a predetermined status, the operating condition determining means Based on the above, it is determined that the operating condition before defrosting has been reached.

The air conditioning control device according to the third invention is the air conditioning control device according to the first invention, and the operating condition determining means has reached the operating condition before defrosting when a predetermined time has elapsed from the previous driving before defrosting. The air conditioning control device according to a fourth aspect of the present invention is the air conditioner according to any one of the first to third aspects, wherein the air conditioning system is a second air temperature higher than a predetermined first indoor temperature. The room temperature setting means for setting the room temperature is further provided. When the operation condition determining means determines that the pre-defrosting operation condition has been reached, the room heating is enhanced so as to reach the second indoor temperature determined by the room temperature setting means. Instruct driving.

  An air conditioning control device according to a fifth aspect of the present invention is the air conditioning control device according to the fourth aspect of the present invention, wherein the air conditioning system further includes an indoor temperature measuring means for measuring the indoor temperature, and the indoor temperature measured by the indoor temperature measuring means is A defrosting operation instruction means for instructing a defrosting operation when the second room temperature is reached is further provided.

  An air conditioning control device according to a sixth aspect of the present invention is the air conditioning control device according to the fifth aspect of the present invention, wherein the defrosting operation instruction means starts the defrosting operation after a few minutes from the time when the predefrosting operation condition is reached. Instruct.

  An air conditioning system according to a seventh aspect of the present invention includes a compressor, an outdoor unit provided with a heat source side heat exchanger, an indoor unit provided with a use side heat exchanger, and the indoor unit functioning as a condenser to evaporate the outdoor unit. An air conditioning system comprising a switching mechanism capable of switching between a heating state to function as a vessel, and a defrost state in which the indoor unit functions as an evaporator and the outdoor unit functions as a condenser, and an expansion mechanism, An air conditioning control device according to any one of claims 1 to 6 is provided.

  An air conditioning system according to an eighth aspect of the present invention is the air conditioning system according to the seventh aspect of the present invention, wherein the indoor unit is configured to move the flaps in the horizontal direction during the pre-defrosting operation period and the wind rising lower flap that blows wind into the room. Or a flap drive mechanism that is set upward.

  In the air conditioning control device according to the first aspect of the present invention, the room temperature can be raised to a predetermined temperature by performing the indoor heating strengthening operation before defrosting. Therefore, even if the heating operation is temporarily stopped during the defrosting operation, the room temperature can be lowered by the temperature that has been increased in advance, so that the temperature during the normal heating operation can be maintained even during the defrosting operation. Can do.

  Further, in the air conditioning control device according to the second aspect of the present invention, when the outdoor unit operation state reaches a predetermined state, it is determined that the pre-defrost operation condition has been reached. Judgment can be made.

  Furthermore, in the air-conditioning control apparatus according to the third aspect of the present invention, it is determined that the pre-defrost operation conditions have been reached when a certain time has elapsed since the previous pre-defrost operation. May not be provided separately.

  In the air conditioning control apparatus according to the fourth and fifth inventions, the operation target setting temperature before defrosting is provided, and the operation before defrosting is not set depending on whether the room temperature has reached the target installation value. And the period of the enhanced operation of the indoor heating before defrosting can be determined.

  In the air conditioning control device according to the sixth aspect of the invention, the defrosting operation can be performed with simple control by starting the defrosting operation after a few minutes from the time when the pre-defrosting operation condition is reached.

  In the air conditioning system which concerns on the 7th and 8th invention, the air-conditioning control apparatus which concerns on the 1st-6th invention is provided. Further, by changing the direction of the flap of the indoor unit, it is possible to suppress discomfort caused by warm air that is higher than usual during the reinforced operation before defrosting.

<First Embodiment>
[Configuration of air conditioner]
FIG. 1 shows an external view of an air conditioning system 1 in which an embodiment of the present invention is employed.

  The air conditioning system 1 is an air conditioning apparatus (an air conditioning apparatus for a cold region where the temperature is below freezing in winter etc.) that can perform not only cooling operation and heating operation but also defrosting operation. An indoor unit 2 attached to the upper part and an outdoor unit 3 installed outside are provided. The indoor heat exchanger accommodated in the indoor unit 2 and the outdoor heat exchanger accommodated in the outdoor unit 3 constitute the refrigerant circuit 10 by the respective heat exchangers and refrigerant piping connecting these heat exchangers. is doing.

  FIG. 2 shows a system diagram of the refrigerant circuit 10. The refrigerant circuit 10 is mainly provided with a compressor 111, a four-way switching valve 113, an outdoor heat exchanger 112, an expansion valve 172, an indoor heat exchanger 171, and a gas-liquid separator 114. As shown in FIG. 2, they are connected via a refrigerant pipe.

(1) Outdoor unit The outdoor unit 11 mainly includes a four-way switching valve 113, a gas-liquid separator 114, a compressor 111, an outdoor heat exchanger 112, a first refrigerant gas pipe 121, an expansion valve 172, and a refrigerant liquid pipe. 122.

  The compressor 111 is a device for sucking and compressing low-pressure gas refrigerant flowing through the suction pipe 125 and then discharging it to the discharge pipe 126. In the present embodiment, the compressor 111 is a positive displacement compressor such as a scroll type or a rotary type.

  The four-way switching valve 113 is a valve for switching the flow direction of the refrigerant corresponding to each operation, and the cycle of the refrigerant circulation circuit 1 can be switched between a cooling / defrosting operation cycle and a heating operation cycle. During the cooling operation and the defrosting operation, the discharge pipe 126 of the compressor 111 and the gas side of the outdoor heat exchanger 112 are connected, and the suction pipe 125 and the gas side shut-off valve 132 of the compressor 111 are connected to the gas-liquid separator 114. In the heating operation, the discharge pipe 126 of the compressor 111 and the second gas side shut-off valve 132 are connected, and the suction pipe 125 of the compressor 111 and the gas side of the outdoor heat exchanger 112 are connected to the gas-liquid separator. It is possible to connect via 114.

  The outdoor heat exchanger 112 can condense the high-pressure gas refrigerant discharged from the compressor 111 during the cooling operation using air outside the air-conditioning room as a heat source, and the liquid returned from the indoor heat exchanger 171 during the heating operation. It is possible to evaporate the refrigerant.

  The outdoor heat exchanger 112 is provided with an outdoor unit temperature sensor 212 for detecting the temperature of the outdoor heat exchanger 112, and an outdoor temperature sensor (not shown) for detecting the outdoor temperature.

(2) Indoor Unit The indoor unit 17 mainly has an indoor heat exchanger 171, an indoor fan 173 (shown in FIG. 3), a refrigerant gas pipe 181 and a refrigerant liquid pipe 182.

  The indoor heat exchanger 171 is a heat exchanger for exchanging heat between indoor air that is air in the air-conditioned room and the refrigerant. The indoor fan 173 is a fan that takes in the air in the air-conditioned room into the indoor unit 17 and sends out conditioned air that is air after heat exchange with the refrigerant via the indoor heat exchanger 171 to the air-conditioned room again. By adopting such a configuration, the indoor unit 17 exchanges heat between the indoor air taken in by the indoor fan and the liquid refrigerant flowing through the indoor heat exchanger 171 during the cooling operation, thereby generating conditioned air (cold air). It is possible to generate conditioned air (warm air) by exchanging heat between the indoor air taken in by the indoor fan and the gas refrigerant flowing through the indoor heat exchanger 171 during heating operation and heating and defrosting operation. It has become.

  Here, a cross-sectional view of the indoor unit 2 is shown in FIG. The indoor heat exchanger 171 and the cross flow fan 173 described above are accommodated in the casing 14 of the indoor unit 2. A suction port 142 made up of a plurality of slit-like openings is provided in the upper part of the casing 14. At the lower part of the casing 14, a blow-out port 143 having an opening that is long in the longitudinal direction of the indoor unit 2 is provided. Further, the blowout port 143 is provided with a horizontal flap (upper and lower flaps) 144 for determining the blowout direction of the air blown into the room by the cross flow fan 173. The horizontal flap 144 is provided so as to be rotatable about an axis parallel to the longitudinal direction of the indoor unit 2. The horizontal flap 144 can determine the air blowing direction by being rotated by a flap drive motor (not shown). As shown in FIG. 6A, when the end portion 144a of the horizontal flap 144 is directed substantially in the horizontal direction or substantially vertically downward, the conditioned air is blown out in the substantially horizontal direction or substantially vertically downward. . Further, as shown in FIG. 6B, when the end portion 144a of the horizontal flap 144 faces substantially vertically upward, the conditioned air is blown out substantially vertically upward. Further, when the operation of the air conditioning system 1 is stopped, the end portion 144 a of the horizontal flap 144 is in contact with the end portion of the casing 14. In this case, the horizontal flap 144 almost completely covers the outlet 143.

(3) Control Device FIG. 4 is an outline of functional blocks of the control device 20 having the microcomputer 21 and the memory 27. The control device 20 reads various programs stored in the memory 27 on the microcomputer 21 and executes them to control various electric devices such as the compressor 111, the four-way switching valve 113, and the expansion valve 172.

  The control device 20 can receive information on the outdoor temperature Ta detected by the outdoor temperature sensor 211 and the outdoor unit temperature Tb detected by the outdoor unit temperature sensor 212, and the indoor temperature T detected by the indoor temperature sensor 213. Can receive. The control device 20 can also receive other operation information in the indoor unit 17 and the outdoor unit 11. The operation information referred to here includes state information regarding the operation state of each component of the indoor unit 17 and the outdoor unit 11, setting information regarding operation settings input from a user via a remote controller (not shown), and the like. included. And in the control apparatus 20, various electric equipments 111, 113, 172 grade | etc., Are controlled based on such information.

  As means related to the defrosting operation, the control device 20 determines that the operation condition determination means 22 for determining whether or not the air conditioning system has reached the operating condition before defrosting, and that the operating condition before defrosting is satisfied. In such a case, the room temperature setting means 25 for setting the room temperature to a predetermined temperature, the pre-defrosting operation instruction means 23 for instructing the strengthening operation of the room heating, and the time measurement for measuring the time elapsed from the previous defrosting operation Means 26 and defrosting operation instruction means 24 for instructing the defrosting operation are provided.

[Operation of air conditioner]
The operation of the air conditioning system 1 will be described with reference to FIG. As described above, the air conditioning system 1 can perform a cooling operation, a heating operation, and a defrosting operation.

(1) Cooling operation During the cooling operation, the four-way switching valve 113 is in the state indicated by the solid line in FIG. 2, that is, the discharge pipe 126 of the compressor 111 is connected to the gas side of the outdoor heat exchanger 112 and the compression is performed. The suction pipe 125 of the machine 111 is connected to the gas side closing valve 132 side through the gas-liquid separator 114. The expansion valve 172 is undercooled (hereinafter referred to as SC control). When the expansion valve 172 is SC-controlled, the valve opening degree of the expansion valve 172 is a difference obtained by subtracting the refrigerant temperature on the liquid side of the outdoor heat exchanger 112 from the refrigerant temperature on the gas side of the outdoor heat exchanger 112. Is adjusted to a constant negative value (for example, −5 ° C.). Then, the liquid side closing valve 133 and the gas side closing valve 132 are opened.

  When the compressor 111 is started in the state of the refrigerant circuit 10, the gas refrigerant is sucked into the compressor 111 and compressed, and then is discharged to the outdoor heat exchanger 112 via the discharge pipe 126 and the four-way switching valve 113. It is sent and condensed in the outdoor heat exchanger 112 to become a liquid refrigerant. Then, this liquid refrigerant is sent to the expansion valve 172. The liquid refrigerant sent to the expansion valve 172 is decompressed and then supplied to the indoor heat exchanger 171 via the liquid side closing valve 133 to cool the indoor air and evaporate to become a gas refrigerant. Then, the gas refrigerant is sucked into the compressor 111 again via the second gas side closing valve 132, the four-way switching valve 113, and the gas-liquid separator 114. In this way, the cooling operation is performed.

(2) Heating operation During the heating operation, the four-way switching valve 113 is in the state indicated by the broken line in FIG. 2, that is, the discharge side of the compressor 111 is connected to the second gas side shut-off valve 132 and the compressor 111 The suction side is connected to the gas side of the outdoor heat exchanger 112 via the gas-liquid separator 114. The expansion valve 172 is SC controlled. When the expansion valve 172 is SC-controlled, the valve opening degree of the expansion valve 172 is a difference obtained by subtracting the refrigerant temperature on the liquid side of the indoor heat exchanger 171 from the refrigerant temperature on the gas side of the indoor heat exchanger 171. Is adjusted to a constant negative value (for example, −5 ° C.).

  When the compressor 111 is started in the state of the refrigerant circuit 10, the gas refrigerant is sucked into the compressor 111 and compressed, and then passes through the discharge pipe 126, the four-way switching valve 113, and the second gas side closing valve 132. Then, it is supplied to the indoor heat exchanger 171.

  The gas refrigerant heats the indoor air in the indoor heat exchanger 171 and is condensed to become a liquid refrigerant. This liquid refrigerant is sent to the expansion valve 172. The liquid refrigerant sent to the expansion valve 172 is depressurized and then sent to the outdoor heat exchanger 112 via the liquid side closing valve 133 and is evaporated in the outdoor heat exchanger 112 to become a gas refrigerant. The gas refrigerant returns to the suction pipe 125 via the four-way switching valve 113 and the gas-liquid separator 114 and is sucked into the compressor 111 again. In this way, the heating operation is performed.

(3) Defrosting Operation FIG. 5 shows a control flowchart related to the defrosting operation of the air conditioning system 1. During the heating operation, first, in step S1, it is determined whether or not an operation start condition before defrosting is satisfied.

  Usually, when performing a defrosting operation, the amount of heating is supplied to the outdoor heat exchanger, so the heating operation temporarily stops and the room temperature often decreases. Therefore, in the present embodiment, before starting the defrosting operation, the operation before defrosting for raising the indoor temperature to a predetermined temperature higher than the heating temperature is performed.

  First, it is determined whether or not the operation status of the outdoor unit detected by an outdoor temperature sensor which is an example of the outdoor unit operation status detection means has reached a predetermined status. In a normal heating operation state, the temperature Tb of the outdoor heat exchanger 112 is maintained at a substantially constant value To. When the frosting on the outdoor heat exchanger 112 gradually increases as the heating operation continues, the temperature of the outdoor heat exchanger 112 gradually decreases. When the temperature value measured by the outdoor unit temperature sensor 212 is equal to or lower than a predetermined temperature (for example, Tb <To−ΔT), it is determined that the frost formation amount on the outdoor heat exchanger 112 is equal to or greater than the reference frost formation amount. It is determined that the pre-defrosting operation start condition is satisfied. Here, the reference frost amount is a frost amount before the efficiency of the outdoor heat exchanger is reduced unless the defrosting is performed, and the heating operation is hindered.

  If it is determined in step S1 that the pre-defrost operation start condition is satisfied, the process proceeds to step S2. If it is determined in step S1 that the pre-defrost operation start condition is not satisfied, the heating operation is continued. Do.

  In step S2, it is determined whether or not the pre-defrosting operation is to be set. The pre-defrosting operation is an operation for raising the indoor temperature to a predetermined temperature higher than the heating temperature before starting the defrosting operation. Therefore, when the room temperature T measured by the room temperature sensor 213 has reached the target set temperature Tg higher than the reference heating temperature Te, it is not necessary to perform the pre-defrosting operation, and the process proceeds to step S6 to perform the defrosting operation. I do. On the other hand, when the room temperature T is lower than the target set temperature Tg, the process proceeds to step S3, where the room temperature setting means 25 sets the target set temperature Tg higher by α ° C. than the current reference set temperature Te, for example, 2 ° C. higher than the normal heating set temperature. Set a higher target set temperature.

  In step S4, the direction of the flap is set upward in order to avoid the hot air blown out from the blowout outlet from directly hitting a person in the room. As shown in FIG. 6 (b), the end 144a of the horizontal flap 144 is controlled so as to face substantially vertically upward, and the air blown from the blowing outlet is blown substantially vertically upward.

  After that, in step S5, the operation before defrosting is performed, and a message “In-operation before defrosting” is displayed on the remote controller so that a person who notices an increase in the room temperature does not arbitrarily set the air temperature low. To do.

  When the operation before defrosting is performed, the room temperature gradually increases. As shown in FIG. 7, when the room temperature is the reference set temperature Te at time t1, the room temperature reaches the target set temperature Tg by performing the operation before defrosting for a certain time (for example, t2-t1). For example, the room temperature can be increased by 1 to 2 ° C. by performing the operation before defrosting for about 5 minutes.

  Thereafter, in step S6, it is determined whether or not the defrosting operation start condition is satisfied. Here, when the indoor temperature rises by the operation before defrosting and 1 to 2 minutes have elapsed after reaching the target set temperature Tg, it is determined that the defrosting operation start condition has been reached, and the process proceeds to step S7 to perform the refrigeration cycle. When the defrosting operation is performed and the defrosting operation start condition is not reached, the process proceeds to step S2.

  The defrosting operation by the refrigeration cycle is performed as follows.

  During the defrosting operation, the four-way switching valve 113 is in the state indicated by the solid line in FIG. 2, that is, the discharge pipe 126 of the compressor 111 is connected to the gas side of the outdoor heat exchanger 112 and the suction of the compressor 111 The pipe 125 is connected to the second gas side shut-off valve 132 side via the gas-liquid separator 114. Further, the expansion valve 172 is in a state of maintaining a predetermined opening degree.

  When the compressor 111 is started in the state of the refrigerant circuit 10, the gas refrigerant is sucked into the compressor 111 and compressed, and then is discharged to the outdoor heat exchanger 112 via the discharge pipe 126 and the four-way switching valve 113. The frost that is sent and melts on the outer surface of the outdoor heat exchanger 112 is melted and condensed to become a liquid refrigerant.

  Then, the liquid refrigerant condensed in the outdoor heat exchanger 112 is sent to the expansion valve 172. The liquid refrigerant sent to the expansion valve 172 is depressurized and then supplied to the indoor heat exchanger 171 via the liquid-side closing valve 133, cooling the air around the indoor heat exchanger 171 and evaporating the gas. Becomes a refrigerant. At this time, the indoor fan is controlled not to be driven so as not to actively cool the air-conditioned room. Then, the gas refrigerant is sucked into the compressor 111 again via the second gas side closing valve 132, the four-way switching valve 113, and the gas-liquid separator 114.

  As shown in FIG. 7, when the pre-defrosting operation is not performed, in the defrosting operation process from t2 when the defrosting operation is started, the room temperature gradually decreases and becomes a value lower than the heating reference set temperature Te, People in the room feel cold.

However, in this embodiment, before performing the defrosting operation, the operation before the defrosting is performed at t1, and the room temperature is raised to Tg that is a value higher than the heating reference set temperature Te in advance. Accordingly, in the defrosting operation process from t2 when the defrosting operation is started, the room temperature gradually decreases.
Since the temperature does not become lower than the heating reference set temperature Te, it is possible to avoid a person in the room from feeling cold due to the defrosting operation.

  In step S8, it is determined whether or not the defrosting operation end condition has been reached. When the temperature Tb of the outdoor heat exchanger 112 is increased by the defrosting operation and the frost adhering to the outdoor exchanger 112 is melted, the outdoor unit temperature Tb measured by the outdoor unit temperature sensor 212 is a temperature during normal operation. When the value To is reached, it is determined that the defrosting operation end condition has been reached, and the operation is switched to the heating operation at t3. On the other hand, when it is determined in step S8 that the defrosting operation start condition is not satisfied, the defrosting operation in step S7 is continued.

[Characteristics of air conditioner]
(1)
In the air conditioning system 1 according to the first embodiment, an indoor unit and an outdoor unit correspond one-to-one. When the heating operation is stopped in order to perform the defrosting operation during the indoor heating operation period, it is first determined whether the predefrosting operation needs to be performed by the predefrosting operation condition determination unit. Normally, when performing a defrosting operation, the amount of heating is supplied to the outdoor heat exchanger, so the heating operation temporarily stops and the room temperature often decreases. The room temperature can be raised to a predetermined temperature by instructing the room heating enhanced operation by the operation instruction means and performing the room heating enhanced operation before defrosting. Therefore, even if the heating operation is temporarily stopped during the defrosting operation, the temperature in the room can be lowered by the temperature that has been raised in advance, so that the temperature during the normal heating operation can be maintained even during the defrosting operation. Can do.

(2)
In the air conditioning system 1 according to the first embodiment, the operating state of the outdoor unit is detected based on the temperature value of the outdoor unit temperature sensor 212 attached to the outdoor heat exchanger 112 of the outdoor unit 3. In the heating operation state, the temperature Tb of the outdoor heat exchanger 112 is maintained at a substantially constant value To. When the frosting on the outdoor heat exchanger 112 gradually increases as the heating operation continues, the temperature of the outdoor heat exchanger 112 gradually decreases. When the temperature value measured by the outdoor unit temperature sensor 212 is equal to or lower than a predetermined temperature (for example, Tb <To−ΔT), it is determined that the frost formation amount on the outdoor heat exchanger 112 is equal to or greater than the reference frost formation amount. It is determined that the pre-defrosting operation start condition is satisfied. Therefore, it is possible to determine the operation start condition before defrosting with a simple structure.

(3)
In the air conditioning system 1 according to the first embodiment, a target set temperature Tg that is higher by α ° C. than the reference set temperature Te, which is a normal heating temperature, is set as a standard for the pre-defrosting operation that performs the enhanced operation of the indoor heating. . When the operating condition before defrosting is reached, the indoor temperature is stored by performing the strengthening operation until the room temperature reaches the target set temperature Tg. Further, during the strengthening operation, in order to avoid the hot air from directly hitting a person, the end portion 144a of the horizontal flap 144 is controlled to face substantially vertically upward. Therefore, in the strengthening operation before defrosting, it is possible to suppress discomfort caused by warm air that is higher than usual.

[Modification]
(A)
The air conditioning system 1 according to the first embodiment is configured to detect the operation status of the outdoor unit based on the temperature value of the outdoor unit temperature sensor 212 attached to the outdoor heat exchanger 112 of the outdoor unit 3. However, instead of the temperature value of the outdoor unit temperature sensor 212, the outdoor heat exchanger is based on the temperature value of the outdoor temperature sensor 211 or the difference between the temperature value of the outdoor temperature sensor 211 and the temperature value of the outdoor unit temperature sensor 212. It can be determined whether or not the frost amount on 112 exceeds the reference frost amount.

(B)
Moreover, in the air conditioning system 1 which concerns on 1st Embodiment, although the operating condition judgment means has judged whether the operation before defrost should be performed based on the driving | running state of an outdoor unit, before the last defrost It is also possible to determine that the pre-defrost operation conditions have been reached when a certain time has elapsed since the operation.

  There may be a case where an error or failure occurs in the outdoor unit temperature sensor for determining the operation status of the outdoor unit in a cold region. Therefore, a reference period is set that the pre-defrost operation should be performed at regular intervals at the outside air temperature in a specific area, and the defrost is automatically performed when the predetermined reference period has elapsed since the previous pre-defrost operation. It can also be determined that the pre-run conditions have been reached.

(C)
In the air conditioning system 1 according to the first embodiment, the target set temperature Tg that is higher by α ° C. than the reference set temperature Te that is a normal heating temperature is set, and the operation period before defrosting is determined based on the measured value of the room temperature. It has become. However, it is also possible to instruct the defrosting operation instruction means to start the defrosting operation several minutes after reaching the pre-defrosting operation condition.

1 is an external view of an air conditioning system in which an embodiment of the present invention is employed. The refrigerant | coolant piping system diagram which shows a refrigerant | coolant circulation circuit. AA sectional drawing of an indoor unit. The block diagram which shows a control apparatus. The flowchart figure which shows the control relevant to a defrost driving | operation. Schematic which shows the blowing direction of the air by the motion of the flap of an indoor unit. Schematic which shows the change of the room temperature at the time of driving | running before defrosting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioning system 10 Refrigerant circulation circuit 11 Outdoor unit 111 Compressor 112 Outdoor heat exchanger 113 Four-way switching valve 17 Indoor unit 171 Indoor heat exchanger 172 Expansion valve 2 Indoor unit 20 Controller 211 Outdoor temperature sensor 212 Outdoor heat exchanger Temperature sensor 213 Indoor temperature sensor 22 Operating condition determination means 23 Pre-defrost operation instruction means 24 Defrost operation instruction means 25 Indoor temperature setting means 24 Defrost operation instruction means 3 Outdoor unit

Claims (8)

In the control device of the air conditioning system capable of at least the indoor heating operation and the defrosting operation,
Operating condition determining means for determining whether the air conditioning system has reached the operating condition before defrosting;
When it is determined by the operation condition determination means that the pre-defrost operation condition is satisfied, the pre-defrost operation instruction means for instructing the enhanced operation of indoor heating;
Air conditioning control device equipped with. The air conditioning system includes an outdoor unit operation status detection means for detecting the operation status of the outdoor unit,
The operating condition determining means determines that the operating condition before defrosting has been reached when the operating condition of the outdoor unit detected by the outdoor unit operating condition detecting means reaches a predetermined condition.
The air conditioning control device according to claim 1. The operating condition determining means determines that the operating condition before defrosting has been reached when a predetermined time has elapsed since the previous operation before defrosting;
The air conditioning control device according to claim 1. The air conditioning system further includes room temperature setting means for setting the room temperature to a second room temperature higher than a predetermined first room temperature,
When it is determined by the operating condition determining means that the operating condition before defrosting has been reached, the room heating setting operation is instructed to reach the second indoor temperature determined by the indoor temperature setting means.
The air-conditioning control apparatus according to any one of claims 1 to 3. The air conditioning system further includes room temperature measuring means for measuring a room temperature,
When the room temperature measured by the room temperature measuring means has reached the second room temperature, further comprising a defrosting operation instruction means for instructing a defrosting operation,
The air conditioning control device according to claim 4. The defrosting operation instruction means instructs to start the defrosting operation after a few minutes from the time when the predefrosting operation condition is reached.
The air conditioning control device according to claim 5. A compressor,
An outdoor unit equipped with a heat source side heat exchanger;
An indoor unit equipped with a use side heat exchanger;
A switching mechanism capable of switching between a heating state in which the indoor unit functions as a condenser and the outdoor unit functions as an evaporator, and a defrost state in which the indoor unit functions as an evaporator and the outdoor unit functions as a condenser. When,
An expansion mechanism;
The air conditioning control device according to any one of claims 1 to 6,
Air conditioning system with The indoor unit has a wind improving lower flap that blows wind into the room,
During the pre-defrosting operation period, the flap drive mechanism that sets the flap horizontally or upward,
The air conditioning system according to claim 7.

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