JP2010236816A - Heat pump type air conditioner and method of controlling heat pump type air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously operate a compressor even when the minimum capacity of the compressor is over air conditioning load. <P>SOLUTION: In this heat pump type air conditioner 1, at least a part of heat source water introduced to an external heat source heat exchanger 17 is introduced to an external heat source heat exchanger 17 after heat exchange with an air conditioning object side refrigerant, thus cold or hot heat corresponding to excess of air-conditioning capacity to an air-conditioning target temperature, of the cold or hot heat of the air conditioning object side refrigerant is transferred to the external heat source side refrigerant. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat pump type air conditioner.

  Conventionally, both the cooling operation and the heating operation are performed by switching the four-way valve to evaporate the refrigerant with the heat of the air-conditioning target air during cooling and condensing the refrigerant with the heat of the air-conditioning target air during heating. A heat pump type air conditioner is known.

JP 2007-315682 A

  Conventionally, when an air conditioner performs a partial load operation in which the minimum capacity of the compressor exceeds the air conditioning load, an intermittent operation in which the operation stop / restart of the compressor is repeated is performed, and the COP (Coefficient Of Performance) of the air conditioner is performed. ) Is known to decrease.

  FIG. 8 is a diagram showing a change in room temperature (in the case of cooling operation) and a compressor state during intermittent operation in a conventional air conditioner. According to the example shown in FIG. 8, it is detected that the room temperature has decreased due to the cooling operation and has fallen below the set temperature Ts, and at the same time, the operation of the compressor is stopped. It can be seen that the intermittent operation is resumed. At this time, since the operation is performed with a partial load where the minimum capacity of the compressor exceeds the air conditioning load, the room temperature immediately falls below the set temperature Ts (in the case of heating operation) as soon as the operation of the compressor is resumed. The compressor is repeatedly stopped / restarted in a short time.

  Further, in the partial load operation, since the capacity of the compressor is higher than that of the air conditioning load, an overshoot in which the room temperature exceeds the set temperature and is cooled or heated easily occurs, and the power consumption is large. For this reason, intermittent operation as described above has been a cause of COP reduction in conventional air conditioners. In intermittent operation, the room temperature of the air-conditioner repeatedly increases / decreases in a short time, so that the comfort of the resident is impaired, and the product life of the air-conditioner is repeated to repeatedly stop / restart the operation. There is also the problem of affecting it.

  In view of the above-described problems, an object of the present invention is to enable continuous operation of a compressor even when the minimum capacity of the compressor exceeds the air conditioning load.

  The present invention transfers a part of the cold or hot heat of the refrigerant (heat medium) flowing through the air-conditioning target heat exchanger side to the refrigerant flowing through the external heat source heat exchanger side, so that the minimum capacity of the compressor reduces the air-conditioning load. Even in such a case, the compressor can be continuously operated, and the COP reduction of the air conditioner can be prevented.

  Specifically, the present invention is a heat pump type air conditioner in which a compressor, an air conditioning target heat exchanger, an expansion valve, and an external heat source heat exchanger are connected via a refrigerant flow path so as to form a refrigeration cycle. In the refrigeration cycle, heat transfer for transferring a part of the cold or hot heat of the air-conditioning target side refrigerant flowing on the air-conditioning target heat exchanger side to the external heat source side refrigerant flowing on the external heat source heat exchanger side by heat exchange It is a heat pump type air conditioner provided with a means.

  The refrigeration cycle uses the compressor and the expansion valve as a boundary, the condensation side through which the refrigerant passes through the compressor and reaches the expansion valve, and the evaporation through which the refrigerant passes through the expansion valve and reaches the compressor Can be divided into sides. In the present invention, among the parts of the refrigeration cycle that are divided with the compressor and the expansion valve as a boundary, the part including the air conditioning target heat exchanger is referred to as the air conditioning target heat exchanger side and includes the external heat source heat exchanger. The part is referred to as the external heat source heat exchanger side. It should be noted that the correspondence relationship between the air-conditioning target heat exchanger side and the external heat source heat exchanger side, the condensation side, and the evaporation side changes depending on whether the heat pump type air conditioner is in a cooling operation or a heating operation.

  Further, in the present invention, the heat transfer means converts the cold heat or hot heat corresponding to the excess of the air conditioning capability with respect to the target air conditioning temperature among the cold heat or hot heat of the air conditioning target side refrigerant by heat exchange to the external heat source side refrigerant. May be relocated.

  That is, in the heat pump type air conditioner according to the present invention, an excessive temperature change of the air-conditioning target is achieved by transferring the heat or heat corresponding to the surplus air-conditioning capacity from the air-conditioning target-side refrigerant to the external heat source-side refrigerant by heat exchange. It is possible to effectively suppress the intermittent operation in which the operation stop / restart of the compressor is repeated, and to extend the period during which continuous operation is possible.

  Further, the heat pump air conditioner is a heat pump that operates by receiving supply of heat source water as an external heat source, and the heat transfer means receives at least a part of the heat source water introduced into the external heat source heat exchanger. Then, after exchanging heat with the air-conditioning target side refrigerant, it may be transferred to the external heat source-side refrigerant by introducing it into the external heat source heat exchanger so as to transfer a part of the cold or warm heat of the air-conditioning target-side refrigerant.

  Here, examples of the heat source water include cooling water supplied from a cooling water temperature adjusting device such as a cooling tower, and hot water supplied from a boiler or the like. In the present invention, after a part or all of the heat source water introduced into the external heat source heat exchanger is introduced into an auxiliary water heat exchanger or the like once provided on the air conditioning target side and heat exchanged with the air conditioning target side refrigerant, By introducing it into the external heat source heat exchanger, a part of the cold or warm heat of the air conditioning target side refrigerant is transferred to the external heat source side refrigerant.

  Moreover, the heat pump type air conditioner according to the present invention is configured to adjust the amount of water used for heat exchange between the heat source water introduced into the external heat source heat exchanger and the air-conditioning target side refrigerant by the heat transfer means. Adjustment means may be further provided.

  By providing such a water amount adjusting means, the amount of water transferred is adjusted so that the amount of cold or warm transferred by heat transfer becomes cold or hot corresponding to the surplus of air conditioning capacity, and the period of continuous operation is extended. Is possible.

  Further, the heat transfer means uses a refrigerant heat exchanger into which the external heat source-side refrigerant and the air-conditioning target-side refrigerant are introduced, to transfer a part of the cold or hot heat of the air-conditioning target-side refrigerant to the external heat source side It may be transferred to a refrigerant.

  By transferring cold heat or warm heat by such a method, heat transfer between refrigerants can be performed with a simpler configuration. In particular, even in heat pump air conditioners that do not use heat source water such as cooling water (for example, heat pump air conditioners in which the external heat source heat exchanger is air-cooled), heat transfer between refrigerants is performed during partial load operation, It becomes possible to suppress intermittent operation.

  The heat pump air conditioner according to the present invention may further include a refrigerant amount adjusting unit that adjusts the amount of the refrigerant used for heat exchange in the refrigerant heat exchanger.

  By providing such a refrigerant amount adjusting means, the amount of refrigerant is adjusted so that the amount of cold or hot transfer due to heat transfer becomes the cold or hot equivalent to the surplus of air conditioning capacity, and the continuous operation period Can be extended.

  The heat pump air conditioner according to the present invention includes a temperature acquisition unit that acquires a temperature of an air-conditioning target, and the heat transfer unit when a difference between the temperature of the air-conditioning target and a target temperature of the air conditioning is equal to or less than a predetermined value. And a control means for initiating heat transfer by.

  When the difference between the air-conditioning target temperature (for example, room temperature) and the target temperature for air conditioning becomes less than a predetermined value, the air-conditioning capability is achieved when the target temperature approaches a predetermined value or more by starting heat transfer as described above. It is possible to perform continuous operation with lowering, i.e., to suppress intermittent operation after passing through the target temperature.

  In the heat pump air conditioner according to the present invention, the plurality of air conditioning target heat exchangers are connected to the compressor and the external heat source heat exchanger, and the operation is performed among the plurality of air conditioning target heat exchangers. When the number of air-conditioning target heat exchangers to be stopped becomes equal to or less than a predetermined value, a control unit that starts heat transfer by the heat transfer unit may be further provided.

  By providing such a control means, for example, in an air conditioning system in which an air conditioning target heat exchanger is provided in each room of an air conditioning target building, the intermittent operation of the compressor is suppressed and continuous operation is performed. Is possible.

  Moreover, this invention can also be grasped | ascertained as a control method of a heat pump type air conditioner. For example, in the present invention, a compressor, an air conditioning target heat exchanger, an expansion valve, and an external heat source heat exchanger are connected via a refrigerant flow path so as to form a refrigeration cycle, and the air conditioning target heat is included in the refrigeration cycle. In a heat pump air conditioner comprising heat transfer means for transferring a part of the cold or hot temperature of the air-conditioning target side refrigerant flowing through the exchanger side to the external heat source side refrigerant flowing through the external heat source heat exchanger side by heat exchange. A temperature acquisition step of acquiring a target temperature, and a control step of starting the heat transfer in the heat transfer step when a difference between the temperature of the air-conditioning target and a target temperature of the air-conditioning becomes a predetermined value or less. It is a control method of a heat pump type air conditioner.

  According to the present invention, it is possible to enable continuous operation of the compressor even when the minimum capacity of the compressor exceeds the air conditioning load.

It is a figure which shows schematic structure of the heat pump type air conditioner which concerns on 1st embodiment. It is a figure which shows the relationship between the air-conditioning load and the air-conditioning capability obtained by the inverter control of a compressor according to the external temperature at the time of air_conditionaing | cooling operation of a heat pump type air conditioner. It is a flowchart which shows the flow of the start of the heat transfer process which concerns on embodiment. It is a figure which shows control of the compressor and control of a proportional three-way valve according to room temperature at the time of air_conditionaing | cooling operation of the heat pump type air conditioner which concerns on embodiment. It is a figure which shows schematic structure of the heat pump type air conditioner which concerns on 2nd embodiment. It is a figure which shows schematic structure of the heat pump type air conditioner which concerns on 3rd embodiment. It is a figure which shows schematic structure of the heat pump type air conditioner which concerns on 4th embodiment. It is a figure which shows the room temperature fluctuation | variation in the case of the intermittent operation in the conventional air conditioner, and a compressor state.

  Embodiments of a heat pump air conditioner according to the present invention will be described below with reference to the drawings.

<First embodiment>
FIG. 1 is a diagram showing a schematic configuration of a heat pump air conditioner 1 according to the first embodiment. The heat pump air conditioner 1 is a water heat source heat pump that receives coolant water (heat source water) controlled in temperature by a cooling water temperature adjusting device (not shown) such as a cooling tower (cooling tower) and adjusts the temperature of the refrigerant. Type air conditioner, which uses the supplied cooling water as an external heat source to exchange heat with the refrigerant, the water heat exchanger 17 as an external heat source heat exchanger, the compressor 14 for compressing the refrigerant, and the refrigerant to expand The expansion valve 16, the air heat exchanger 13 as an air conditioning target heat exchanger that performs air conditioning by performing heat exchange between the refrigerant and the air to be air conditioned, and the cooling operation and heating by switching the refrigerant flow path. It has a four-way valve 15 for switching between operation. These components are connected by a refrigerant pipe 19 to form a refrigeration cycle, and switching between a cooling operation and a heating operation can be performed by switching the four-way valve 15.

  Further, the heat pump air conditioner 1 has a blower 21, and indoor air is taken into the heat pump air conditioner 1 through a filter (not shown) as return air by the blower 21, and the air heat exchanger After the temperature adjustment by 13, it is sent to the room as supply air. In the cooling operation, the refrigerant circulates in the order of the compressor 14, the water heat exchanger 17, the expansion valve 16, and the air heat exchanger 13, and in the heating operation, the compressor 14, the air heat exchanger 13, the expansion valve 16, The refrigerant circulates in the order of the water heat exchanger 17.

  The heat pump air conditioner 1 according to the present embodiment is controlled by the control device 90. For example, the control device 90 switches between the cooling operation and the heating operation by switching the four-way valve 15 according to the setting content by the user, and the room temperature detected by the room temperature sensor 91 installed in the room to be air-conditioned is Inverter control and operation / stop control of the compressor 14 are performed so that the set temperature (air conditioning target temperature) Ts is obtained. However, the present invention may also be applied to a heat pump type air conditioner using a constant speed compressor that is not variable in capacity such as inverter control.

  The compressor 14 of the heat pump type air conditioner 1 according to the present embodiment is a variable capacity compressor 14 that can be controlled by an inverter. For this reason, if the air conditioning capacity with respect to the air conditioning load becomes excessive by changing the set temperature Ts of the air conditioning or changing the room temperature, in the heat pump air conditioner 1, the capacity of the compressor 14 is controlled. Thus, the air conditioning capacity is adjusted. Hereinafter, the continuous operation performed while the air conditioning load corresponds to the air conditioning load in a range where the air conditioning load does not fall below the minimum capacity of the compressor 14 is referred to as a normal load operation.

  FIG. 2 is a diagram showing the relationship between the air conditioning load and the air conditioning capability obtained by inverter control of the compressor 14 according to the outside air temperature during the cooling operation of the heat pump type air conditioner 1. As can be seen from FIG. 2, when the outside air temperature decreases, the air conditioning load for the cooling operation decreases, that is, the necessary air conditioning capacity decreases. For this reason, up to a certain outside air temperature (26 degrees Celsius in the example of FIG. 2), the compressor 14 is inverter-controlled to adjust the air conditioning capacity from the rated capacity to the minimum capacity, thereby performing energy saving operation. COP can be improved. However, the compressor 14 has a minimum capacity. Therefore, when the air conditioning load is further lower than the air conditioning capability provided by the compressor 14 operating at this minimum capacity (in the example of FIG. 2, the outside air temperature is 26 degrees Celsius or less), that is, at the time of partial load, In the air conditioning capability control only by the compressor 14, a surplus will appear in the air conditioning capability (see FIG. 2).

Such a partial load state is likely to occur in an intermediate period excluding summer and winter. When the air conditioner is in a partial load operation state where the air conditioning capacity for the air conditioning load is excessive, the conventional air conditioner is operated when it is detected that air conditioning up to the set temperature has been achieved. Stopping and resuming the operation of the air conditioner when it is detected that the room temperature has deviated from the set temperature are repeated (see FIG. 8 showing the intermittent operation of the conventional air conditioner).

  In order to prevent such a situation that occurs in the conventional air conditioner, in the heat pump type air conditioner 1 according to the present embodiment, when the air conditioning load is low to the extent that it is difficult to cope with only the inverter control of the compressor 14 (partial load) ), An auxiliary water heat exchanger 18 is provided in the refrigerant flow path between the expansion valve 16 and the air heat exchanger 13 in order to prevent a decrease in COP due to repeated stop / restart of the air conditioner (intermittent operation). Then, the cooling water before being introduced into the water heat exchanger 17 is introduced into the auxiliary water heat exchanger 18 via the cooling water bypass duct 12 and the refrigerant on the air conditioning target side (air conditioning target heat exchanger side). Heat exchange.

  By doing in this way, at the time of air_conditionaing | cooling operation, the excessive cold heat with respect to an air-conditioning load is transferred from the refrigerant | coolant by the side of an air conditioning to the refrigerant | coolant by the side of an external heat source via cooling water, and the condensation pressure of the compressor 14 may be reduced. I can do it. Further, since the temperature of the refrigerant on the air conditioning target side rises, cooling more than necessary is suppressed, and repeated repetition of operation stop / resumption of the air conditioner is suppressed, and continuous operation is possible even at partial load.

  Here, the air-conditioning target side is the air-conditioning target heat among both sides of the refrigeration cycle of the heat pump air conditioner 1 according to the present embodiment, which is divided into the evaporation side and the condensation side by the compressor 14 and the expansion valve 16. It refers to the side to which the exchanger (air heat exchanger 13 in this embodiment) belongs. In addition, the external heat source side refers to an external heat source heat exchanger (of both sides of the refrigeration cycle of the heat pump air conditioner 1 according to the present embodiment, which is divided into an evaporation side and a condensation side by the compressor 14 and the expansion valve 16 ( In this embodiment, it refers to the side to which the water heat exchanger 17) belongs.

  Hereinafter, surplus cold heat or heat transfer processing from the air conditioning target side refrigerant to the external heat source side refrigerant during partial load operation is referred to as heat transfer processing. The heat pump air conditioner 1 according to the embodiment includes a proportional three-way valve 11 capable of performing the start / end of heat transfer processing and the flow rate adjustment of cooling water to be detoured to the auxiliary water heat exchanger 18. During normal load operation, the proportional three-way valve 11 sends the entire amount of cooling water supplied from a cooling tower or the like to the water heat exchanger 17 and does not send it to the auxiliary water heat exchanger 18. On the other hand, at the time of partial load operation, the proportional three-way valve 11 temporarily bypasses part or all of the cooling water supplied from the cooling tower or the like to the auxiliary water heat exchanger 18 and heats it with the refrigerant on the air conditioning target side. After the replacement, the water heat exchanger 17 is introduced. In this embodiment, the proportional three-way valve 11 is adopted, but instead of the proportional three-way valve 11, a switching three-way valve that does not adjust the flow rate may be adopted, and also when the flow rate adjustment is performed, A configuration other than the proportional three-way valve 11, for example, a combination of a switching three-way valve and an expansion valve may be employed.

  FIG. 3 is a flowchart showing a flow of starting the heat transfer process according to the present embodiment. The processing shown in this flowchart is periodically executed by the control device 90 while the heat pump air conditioner 1 is in operation. Note that the details of the processing and the processing order are not limited to those shown in this flowchart, and are preferably adopted as appropriate according to the embodiment.

First, the control device 90 acquires the operation state of the compressor 14 from the compressor 14 and determines whether or not the compressor 14 is operating at the minimum capacity, that is, the heat pump air conditioner 1 is in a partial load operation state. Whether or not (step S101). When the heat pump type air conditioner 1 is in the partial load operation state, the control device 90 determines whether it is in the cooling operation or the heating operation by referring to the current setting content (step S102). And the control apparatus 90 acquires the room temperature of air conditioning object regularly from the room temperature sensor 91, and when it is in air_conditionaing | cooling operation, compared with the acquired room temperature and preset temperature Ts (for example, in this embodiment). The threshold value Ts + 2 set to a temperature higher by 2 degrees Celsius is compared (step S103). As a result of the comparison, when the room temperature becomes lower than the threshold value Ts + 2, the control device 90 determines that intermittent operation may occur, and opens the route to the coolant bypass pipe 12 in the proportional three-way valve 11. Thus, the heat transfer process is started (step S105). Similarly, during the heating operation, the acquired room temperature and the threshold value Ts-2 set to a temperature lower by a predetermined temperature (for example, 2 degrees Celsius in this embodiment) than the set temperature Ts, Compare (step S104). As a result of the comparison, when the room temperature becomes higher than the threshold value Ts-2, the control device 90 determines that there is a possibility that intermittent operation may occur, and determines the route to the cooling water bypass conduit 12 in the proportional three-way valve 11. The heat transfer process is started by opening the valve (step S105).

  FIG. 4 is a diagram showing the control of the compressor 14 and the control of the proportional three-way valve 11 according to the room temperature during the cooling operation of the heat pump air conditioner 1 according to the present embodiment. According to FIG. 4, as described in FIG. 3, when the room temperature falls below the threshold value Ts + 2 set higher than the set temperature Ts by a predetermined temperature, the route to the coolant bypass pipe 12 in the proportional three-way valve 11 is opened. It can be seen that the heat transfer process is started. When the heat transfer process is started, cooling water is introduced into the auxiliary water heat exchanger 18, and excess cooling heat exceeding the air conditioning load is taken away from the refrigerant flowing on the air conditioning target side. For this reason, the excess air conditioning capability with respect to an air conditioning load is suppressed, the intermittent operation which is the operation stop / resumption of the compressor 14 in a short period is prevented, and the heat pump air conditioner 1 can be continuously operated. According to FIG. 4, the balance between the air conditioning capability and the air conditioning load is improved, so that the rate at which the room temperature decreases toward the set temperature Ts is reduced, and the intermittent operation of the heat pump air conditioner 1 is prevented. I understand.

  In addition, also when the room temperature becomes lower than the set temperature by the heat transfer process described above (in the heating operation, when the room temperature becomes higher than the set temperature), the operation of the compressor 14 and the heat transfer process are performed. Stopping (closing of the route to the coolant bypass pipe 12 in the proportional three-way valve 11) is performed (see FIG. 4).

  Further, the cold transferred to the external heat source side is returned again to the air-conditioning target side by the flow of the refrigerant if it remains as it is. For this reason, the temperature of the refrigerant on the air conditioning target side further decreases by increasing the temperature of the cooling water supplied from the cooling tower (decreasing the operating capacity of the cooling tower) or adjusting the opening of the expansion valve 16. This may be prevented. In this way, even in the state of partial load operation, it becomes possible to perform continuous operation with the minimum capacity for a longer time with the room temperature maintained at the set temperature, further improving COP. It becomes possible to make it.

  Further, the proportional three-way valve 11 transfers the surplus except for the refrigerating capacity necessary for the set temperature and the outside air temperature from the refrigerant on the air conditioning target side to the refrigerant on the external heat source side in order to lengthen the continuous operation time. Thus, the opening degree is controlled. In the present embodiment, in the cooling operation, the temperature sensor 92 detects the cooling water supplied from the cooling tower or the like, which has been measured in advance during normal load operation, as the reference cooling water temperature at the outlet of the water heat exchanger 17. The degree of opening of the proportional three-way valve 11 is feedback-controlled so that the outlet cooling water temperature of the water heat exchanger 17 is “reference water temperature−ΔTa”.

The value of ΔTa used to determine the target water temperature of the outlet cooling water temperature of the water heat exchanger 17 is the outlet cooling water temperature of the water heat exchanger 17 during normal load operation (in the example shown in FIG. 1, 30 degrees Celsius). 2 degrees), and the cooling water temperature at the outlet of the water heat exchanger 17 when the total amount of cooling water is sent to the auxiliary water heat exchanger 18 by the proportional three-way valve 11 (in the example shown in FIG. 1, 28.53 Celsius). (In the example shown in FIG. 1), it is determined within a range of 30.2 degrees Celsius−28.53 degrees Celsius = 1.67 degrees. In the example shown in FIG. 1, ΔTa is within the range of 0 to 1.67 degrees so that the COP at the time of partial load operation becomes the highest by experiments or simulations in advance, or continuous operation after the start of the heat transfer process. The optimum value is selected so that the time is the longest. For example, when 1 degree is selected as ΔTa, the target water temperature of the outlet cooling water temperature of the water heat exchanger 17 is 30.2 degrees Celsius-1 degree = 29.2 degrees Celsius, and the control device 90 can control the proportional three-way valve 11. Is controlled so that the outlet cooling water temperature of the water heat exchanger 17 detected from the temperature sensor 92 becomes the target temperature. In the present embodiment, the opening degree of the proportional three-way valve 11 is controlled based on the fluctuation range of the outlet cooling water temperature of the water heat exchanger 17 during the normal operation and the heat transfer process. Instead of the inlet cooling water temperature of the auxiliary water heat exchanger 18 (25.2 degrees Celsius in the example shown in FIG. 1) and the outlet cooling water temperature (23.53 degrees Celsius in the example shown in FIG. 1). The amount of heat transfer is grasped based on the change width (in the example shown in FIG. 1, 25.2 degrees Celsius−23.53 degrees Celsius = 1.67 degrees), and the opening degree control of the proportional three-way valve 11 (bypassing) It is also possible to adjust the amount of water). In this case, since the amount of bypass water is adjusted based on the temperature change of the cooling water at the inlet and outlet of the auxiliary water heat exchanger 18, it is possible to perform control that more accurately reflects the amount of surplus heat transferred. .

<Second Embodiment>
FIG. 5 is a diagram showing a schematic configuration of a heat pump air conditioner 1b according to the second embodiment. Also in the heat pump type air conditioner 1b according to the second embodiment, by performing heat transfer processing for transferring excess cold heat during partial load operation from the refrigerant on the air conditioning target side to the refrigerant on the external heat source side, The same applies to the point that intermittent operation is suppressed and continuous operation is possible. However, the heat pump type air conditioner 1b according to the second embodiment uses the refrigerant heat exchanger 18b to transfer the excessive cold heat of the air-conditioning target side refrigerant to the external heat source side refrigerant without using cooling water for the transfer of the cold heat. This is different from the heat pump air conditioner 1 shown in the first embodiment. Note that, in the description of the present embodiment, the same reference numerals are given to components that are substantially the same as those in the first embodiment, and the description thereof is omitted.

  The heat pump type air conditioner 1b is a water heat source heat pump type air conditioner, and includes a water heat exchanger 17, a compressor 14, an expansion valve 16, an air heat exchanger 13 as an air conditioning target heat exchanger, and a four-way valve 15. This is the same as the heat pump air conditioner 1 according to the first embodiment. However, the heat pump air conditioner 1b is replaced with the proportional three-way valve 11, the cooling water bypass conduit 12, and the auxiliary water heat exchanger 18 included in the heat pump air conditioner 1 according to the first embodiment for heat transfer processing. Thus, it differs from the heat pump air conditioner 1 according to the first embodiment in that it includes the refrigerant bypass duct 19b, the closing valve 31, the flow rate adjustment valve 32, and the refrigerant heat exchanger 18b.

  In the present embodiment, an expansion valve is used as the flow rate adjustment valve 32. However, since the flow rate adjusting valve 32 is used not for the purpose of reducing the refrigerant pressure but for adjusting the flow rate, it is possible to adjust the flow rate between the refrigerant sent to the refrigerant heat exchanger 18b and the refrigerant not sent by adjusting the opening degree or the like. Anything is acceptable. In the case of an embodiment in which the entire amount of refrigerant may be sent to the refrigerant heat exchanger 18b during the heat transfer process without adjusting the refrigerant flow rate, instead of the flow rate adjustment valve 32, a closing valve that can be controlled only for opening and closing is provided. It may be adopted (illustration is omitted).

  During normal load operation, the closing valve 31 is closed and the flow rate adjusting valve 32 is fully opened. On the other hand, when the heat transfer process is started in the partial load operation, in this embodiment, the closing valve 31 is opened, and the flow rate adjusting valve 32 is closed or the opening degree is adjusted. In this embodiment, by performing such control, part or all of the refrigerant on the external heat source side is once introduced into the refrigerant heat exchanger 18b before reaching the expansion valve 16, and the refrigerant on the external heat source side And the refrigerant on the air conditioning target side are subjected to heat exchange, and excess cold heat of the refrigerant on the air conditioning target side is transferred to the refrigerant on the external heat source side.

  Since the flow of the heat transfer process start process is substantially the same as the flow described with reference to FIGS. 3 and 4, the description thereof is omitted. Further, when the room temperature passes the set temperature, the heat transfer process and the operation of the compressor are stopped as in the first embodiment.

Here, the opening degree control of the flow rate adjustment valve 32 in the heat transfer process of the present embodiment will be described. In order to lengthen the continuous operation time, the flow rate adjustment valve 32 transfers the surplus except for the refrigerating capacity necessary for the set temperature and the outside air temperature from the refrigerant on the air conditioning target side to the refrigerant on the external heat source side. Then, the opening degree is controlled. In the present embodiment, the control device 90 is configured so that the difference between the refrigerant temperatures before and after the expansion valve 16 (that is, the degree of opening of the flow rate adjustment valve 32 is 0%) that has been previously measured by the temperature sensors 93a and 93b during the normal load operation. Refrigerant temperature difference) and refrigerant before and after the expansion valve 16 when the flow rate adjustment valve 32 is fully opened (opening degree 100%) during partial load operation (when the entire amount of refrigerant is sent to the refrigerant heat exchanger 18b). The temperature difference is obtained in advance, and the fluctuation range of the obtained refrigerant temperature difference, that is, the refrigerant temperature difference when the flow rate adjustment valve 32 is fully opened during partial load operation from the refrigerant temperature difference during normal load operation. The maximum fluctuation range is calculated. And the control apparatus 90 determines the ratio of the fluctuation range of the refrigerant temperature difference before and after the expansion valve 16 during the partial load operation with respect to the maximum fluctuation range calculated in advance, and according to the ratio of the fluctuation range as the target value, The opening degree of the flow rate adjustment valve 32 is determined.

  For example, during normal load operation of cooling operation (the opening degree of the flow rate adjustment valve 32 is 0%), the refrigerant temperatures measured by the temperature sensors 93a and 93b are 34 degrees Celsius and 12 degrees Celsius, respectively, and during partial load operation In the heat transfer process, when the opening degree of the flow rate adjustment valve 32 is 100%, the refrigerant temperatures measured by the temperature sensors 93a and 93b are 22 degrees Celsius and 14 degrees Celsius, respectively. In this case, the refrigerant temperature difference before and after the expansion valve 16 is 34-12 = 22 degrees when the opening degree of the flow rate adjustment valve 32 is 0%, and 28-14 = 14 degrees when the opening degree is 100%. The maximum fluctuation range from the refrigerant temperature difference (22 degrees) during normal load operation to the refrigerant temperature difference (14 degrees) when the flow rate adjustment valve 32 is fully opened during partial load operation is 22 degrees-14 degrees = 8 degrees. is there. For this reason, when it is desired to set the target value of the refrigerant temperature difference before and after the expansion valve 16 to 4 degrees, the control device 90 sets the opening degree of the flow rate adjustment valve 32 to 50%. By performing such opening degree determination processing and the control device 90 adjusting the opening degree of the flow rate adjustment valve 32, an appropriate amount of refrigerant can be sent to the refrigerant heat exchanger 18b during partial load operation. Also in this embodiment, a target temperature may be provided for the refrigerant temperature measured by the temperature sensors 93a and 93b, and the opening degree of the flow rate adjustment valve 32 may be feedback controlled so as to achieve this target temperature.

  Further, in the heat pump air conditioner 1b according to the present embodiment shown in FIG. 5, a second flow rate adjustment valve (for example, an expansion valve; for example, shown in the figure) is provided instead of the stop valve 31 at the position where the close valve 31 is provided. (Omitted) may be provided. In this case, the flow rate adjustment valve is closed during normal operation so that the refrigerant does not flow to the refrigerant heat exchanger 18b, and during the heat transfer process, the opening of the second flow rate adjustment valve is kept constant, and the flow rate adjustment valve By controlling the opening degree of 32, the bypass amount of the refrigerant can be adjusted.

<Third embodiment>
FIG. 6 is a diagram showing a schematic configuration of a heat pump air conditioner 1c according to the third embodiment. Unlike the water heat source heat pump air conditioners 1 and 1b shown in the first and second embodiments, the heat pump air conditioner 1c is an air heat source heat pump type that adjusts the temperature of the refrigerant by an air heat exchanger as a so-called outdoor unit. It is an air conditioner. The heat pump air conditioner 1c includes an air heat exchanger 17b as an external heat source heat exchanger that exchanges heat with refrigerant using outside air as an external heat source, a compressor 14 that compresses refrigerant, and an expansion valve 16 that expands refrigerant. The air heat exchanger 13 as an air conditioning target heat exchanger that performs air conditioning by performing heat exchange between the refrigerant and the air to be air conditioned, and the cooling operation and the heating operation are switched by switching the refrigerant flow path. A four-way valve 15 is provided. Note that, in the description of the present embodiment, the same reference numerals are given to configurations that are substantially the same as those in the first embodiment or the second embodiment, and the description thereof is omitted.

  The heat pump air conditioner 1c further includes a blower 22 in addition to the blower 21 for indoor units. The blower 22 takes outside air into the air heat exchanger 17b as an external heat source heat exchanger and adjusts the temperature of the refrigerant passing through the air heat exchanger 17b.

Also in the heat pump type air conditioner 1c according to the third embodiment, by performing heat transfer processing for transferring excess cold heat during partial load operation from the refrigerant on the air conditioning target side to the refrigerant on the external heat source side, It is the same as that of other embodiment about the point which suppresses intermittent operation and enables continuous operation. The heat pump type air conditioner 1c is similar to the heat pump type air conditioner 1b shown in the second embodiment for the heat transfer process, and the refrigerant bypass pipe 19b, the closing valve 31, the flow rate adjusting valve 32, and the refrigerant heat exchanger 18b. Is provided. Further, when the closing valve 31 is closed during the normal load operation and the flow rate adjusting valve 32 is fully opened, and when the heat transfer process is started during the partial load operation, the closing valve 31 is opened and the flow rate adjusting valve is opened. The closing or opening degree adjustment of 32 is also substantially the same as in the second embodiment, and thus the description thereof is omitted.

  Since the flow of the heat transfer process start process is substantially the same as the flow described with reference to FIGS. 3 and 4, the description thereof is omitted. Further, when the room temperature passes the set temperature, the heat transfer process and the operation of the compressor are stopped, the opening degree control of the flow rate adjustment valve 32, and a second flow rate adjustment valve is provided instead of the stop valve 31. This may be the same as in the first or second embodiment.

<Fourth embodiment>
FIG. 7 is a diagram illustrating a schematic configuration of a heat pump air conditioner 1d according to the fourth embodiment. The heat pump air conditioner 1d is a building multi-use heat pump air conditioner that is installed in a building and performs air conditioning with a plurality of indoor units connected to an outdoor unit 2d that adjusts the temperature of the refrigerant with an air heat source. The air heat exchanger 17d as an external heat source heat exchanger that exchanges heat with the refrigerant as the heat source of the air, the blower 22d for taking outside air into the air heat exchanger 17d, the compressor 14 for compressing the refrigerant, and the cooling operation As a cooling expansion valve 16a that expands the refrigerant, a heating expansion valve 16b that expands the refrigerant during heating operation, an air conditioning target heat exchanger that performs air conditioning by performing heat exchange between the refrigerant and the air to be air-conditioned, By switching the air heat exchanger 13d, the air heat exchanger 13d, the air blower 21d for taking in air to be air-conditioned, and the refrigerant flow path, Having a four-way valve 15 for switching. Note that, in the description of the present embodiment, the same reference numerals are given to configurations that are substantially the same as those in the first embodiment or the second embodiment, and the description thereof is omitted.

  Also in the heat pump air conditioner 1d according to the fourth embodiment, by performing a heat transfer process for transferring excess cold heat during partial load operation from the refrigerant on the air conditioning target side to the refrigerant on the external heat source side, It is the same as that of other embodiment about the point which suppresses intermittent operation and enables continuous operation. The heat pump air conditioner 1d includes a refrigerant bypass pipe 19d, flow rate adjusting valves 33 and 34, and a refrigerant heat exchanger 18d for heat transfer processing.

  In the present embodiment, expansion valves are used as the flow rate adjusting valves 33 and 34. However, since the flow rate adjusting valves 33 and 34 are used not for the purpose of reducing the refrigerant pressure but for adjusting the flow rate, the flow rate adjustment between the refrigerant sent to the refrigerant heat exchanger 18d and the refrigerant not sent by adjusting the opening degree or the like is performed. Anything is possible. In the case of an embodiment in which the entire amount of refrigerant may be sent to the refrigerant heat exchanger 18d during the heat transfer process without adjusting the refrigerant flow rate, instead of the flow rate adjustment valves 33 and 34, the closing can be controlled only for opening and closing. A valve may be employed (not shown).

  During normal load operation, the flow rate adjustment valve 34 is closed and the flow rate adjustment valve 33 is fully opened. On the other hand, when the heat transfer process is started in the partial load operation, in the present embodiment, the flow rate adjustment valve 34 is opened at a constant opening (may be fully open), and the flow rate adjustment valve 33 is Closed or opened. In this embodiment, by performing such control, a part or all of the refrigerant on the external heat source side reaches the expansion valve 16a or 16b (the expansion valve 16a during the cooling operation and the expansion valve 16b during the heating operation). The refrigerant is once introduced into the refrigerant heat exchanger 18d before, and heat exchange is performed between the refrigerant on the external heat source side and the refrigerant on the air conditioning target side, and the excessive cold heat of the refrigerant on the air conditioning target side is transferred to the refrigerant on the external heat source side. Move to.

  As for the flow of the heat transfer process start process, a process similar to the process described with reference to FIGS. 3 and 4 may be used. However, the heat pump air conditioner 1d includes a plurality of indoor units (air heat exchangers). 13d), in addition to the room temperature, the number of indoor units in the partial load operation state may also be used as a judgment material when starting the heat transfer process. For example, when the number of indoor units that have reached the set temperature Ts or a predetermined threshold (for example, the threshold Ts-2 or Ts + 2 used in the first embodiment) exceeds a predetermined number, the flow rate adjustment valve 34 is opened. Control may be performed to start the heat transfer process. When all the indoor units that have reached the set temperature Ts or the predetermined threshold have reached all units, the heat transfer process and the operation of the compressor are stopped.

  Here, the opening degree control of the flow rate adjustment valve 33 in the heat transfer process of the present embodiment will be described. In order to lengthen the continuous operation time, the flow rate adjustment valve 33 is configured to transfer the surplus except for the refrigerating capacity necessary for the set temperature and the outside air temperature from the refrigerant on the air conditioning target side to the refrigerant on the external heat source side. Then, the opening degree is controlled. In the present embodiment, the refrigerant temperature t1 before and after the flow rate adjustment valve 33, which is measured in advance by the temperature sensors 94a and 94b during the normal load operation (the temperature sensor because the flow rate adjustment valve 33 is fully open during the normal load operation). 94a and 94b detect substantially the same temperature), and when the flow regulating valve 33 is closed (opening degree 0%) and the flow regulating valve 34 is fully opened (opening degree 100%) during partial load operation (refrigerant of the refrigerant). The refrigerant temperatures t2 and t1 before and after the flow rate adjustment valve 33 (when the whole amount is sent to the refrigerant heat exchanger 18d) are acquired in advance. Then, the control device 90 determines the ratio of the refrigerant temperature difference before and after the flow rate adjustment valve 33 during the partial load operation to the maximum temperature difference (t2−t1) between the refrigerant before and after the flow rate adjustment valve 33, and sets this target value. The opening degree of the flow rate adjustment valve 33 is determined according to the temperature difference ratio.

  For example, during the normal load operation of the cooling operation (the opening degree of the flow rate adjustment valve 33 is 100%, the opening degree of the flow rate adjustment valve 34 is 0%), the refrigerant temperatures measured by the temperature sensors 94a and 94b are both t1. In the heat transfer process during partial load operation, when the opening degree of the flow rate adjustment valve 33 is 0% and the opening degree of the flow rate adjustment valve 34 is 100%, the refrigerant temperatures measured by the temperature sensors 94a and 94b are t2. , T1. In this case, the refrigerant temperature difference before and after the flow rate adjustment valve 33 is 0 degree when the opening degree of the flow rate adjustment valve 33 is 100% and t2−t1 when the opening degree is 0%. The degree of opening of the flow rate adjustment valve 33 is determined according to the target value of the refrigerant temperature difference (for example, when the refrigerant temperature difference is set to (t2−t1) / 2), the degree of opening of the flow rate adjustment valve 33 is set to 50%. To do). By performing such opening degree determination processing and the control device 90 adjusting the opening degree of the flow rate adjusting valve 33, an appropriate amount of refrigerant can be sent to the refrigerant heat exchanger 18d during partial load operation. Also in this embodiment, a target temperature may be provided for the refrigerant temperature measured by the temperature sensors 94a and 94b, and the opening degree of the flow rate adjustment valve 33 may be feedback controlled so as to achieve this target temperature.

  When a closing valve is employed instead of the flow rate adjusting valve 34, the closing valve is closed during normal load operation, and the closing valve is opened during heat transfer processing during partial load operation. In this case, in the heat transfer process, the flow rate of the refrigerant sent to the refrigerant heat exchanger 18d can be adjusted by the opening degree of the flow rate adjustment valve 33.

<Effect>
According to the heat pump type air conditioners shown in the first to fourth embodiments, continuous operation at the time of partial load operation becomes possible, and it becomes possible to prevent a decrease in COP. Specifically, when the intermittent operation as in the past is performed, the air conditioning capacity is larger than the air conditioning load, so that more air conditioning capacity than necessary is obtained and power is consumed more than necessary. According to the heat pump type air conditioner shown in the embodiment, it is possible to perform continuous operation even at a partial load, so that it is possible to demonstrate the ability corresponding to the air conditioning load, and the period power consumption is less than that of intermittent operation Become. According to the calculation of the present inventor, in the conventional air conditioner, the total power consumption due to the intermittent operation of the conventional air conditioner under the intermediate air temperature condition in which the compressor is intermittently operated, and the heat pump type shown in the present embodiment Comparing the total power consumption by continuous operation of the air conditioner, the calculation result shows that the total power consumption of the heat pump type air conditioner shown in this embodiment is reduced by 57% compared to the total power consumption of the conventional air conditioner. Obtained.

  Moreover, according to the heat pump type air conditioner according to the present embodiment, the occupant's comfort can be improved without repeatedly increasing / decreasing the room temperature of the air-conditioning target in a short time even during partial load operation. Furthermore, according to the heat pump type air conditioner according to the present embodiment, since the stop / restart of the operation due to the intermittent operation is suppressed, the number of times of contact of the machine parts due to on / off is reduced, and the life of the compressor 14 is reduced. The life of the magnet used for the compressor 14 is extended.

<Other embodiments>
In the above embodiment, the means for transferring heat from the air conditioning target side refrigerant to the external heat source side refrigerant (for example, the auxiliary water heat exchanger 18 and the refrigerant heat exchangers 18b and 18d) is expanded. Although provided in the refrigerant flow path between the valve 16 and the air heat exchanger 13, means for transferring heat from the air-conditioning target side refrigerant to the external heat source side refrigerant are, for example, the air heat exchanger 13 and the compressor 14. It may be provided at any position on the air-conditioning target side such as a refrigerant flow path between them. Moreover, in the said embodiment, the heat exchanger between refrigerant | coolants is implement | achieved by extending the refrigerant | coolant pipe line by the side of an external heat source, and drawing in to the heat exchanger (refrigerant heat exchanger 18b, 18d etc.) by the side of air-conditioning. However, on the contrary, the refrigerant line on the air conditioning target side may be extended to be drawn into the heat exchanger on the external heat source side, or both the external heat source side and the refrigerant line on the air conditioning target side may be extended. It is good also as drawing in to the refrigerant | coolant heat exchanger provided in this position.

  The start control of the heat transfer process may be controlled in accordance with the number of compressor stop signals issued from the control device 90. Specifically, the heat transfer process may be started when the compressor stop signal reaches a set number of times (for example, 3 times). By doing in this way, it is possible to start the heat transfer process for suppressing the intermittent operation with a simple configuration, when the intermittent operation has actually started. In this case, the heat transfer process and the stop of the compressor can be controlled according to the number of stop signals of the compressor. That is, when the compressor stop signal becomes the set number plus one (for example, 3 + 1 = 4 times), the heat transfer process is terminated and the compressor is stopped.

1, 1b, 1c, 1d Heat pump air conditioner 11 Proportional three-way valve 12 Cooling water bypass pipe 13 Air heat exchanger 14 Compressor 15 Four-way valve 16 Expansion valve 17 Water heat exchanger 18 Auxiliary water heat exchanger 18b, 18d Refrigerant Heat exchanger 19 Refrigerant pipe line 21, 22 Blower 31 Stop valve 32, 33, 34 Flow rate adjusting valve 90 Controller 91 Room temperature sensor 92, 93a, 93b, 94a, 94b Temperature sensor

Claims (9)

A heat pump air conditioner connected via a refrigerant flow path so that the compressor, the heat exchanger subject to air conditioning, the expansion valve, and the external heat source heat exchanger form a refrigeration cycle,
Heat transfer means for transferring a part of the cold or hot air of the air-conditioning target side refrigerant flowing on the air-conditioning target heat exchanger side in the refrigeration cycle to the external heat source side refrigerant flowing on the external heat source heat exchanger side by heat exchange. Comprising
Heat pump air conditioner. The heat transfer means transfers, to the external heat source side refrigerant by heat exchange, cold heat or hot heat corresponding to a surplus of air conditioning capability with respect to a target temperature of air conditioning among the cold heat or hot heat of the air conditioning target side refrigerant,
The heat pump type air conditioner according to claim 1. The heat pump air conditioner is a heat pump that operates by receiving supply of heat source water as an external heat source,
The heat transfer means exchanges heat with at least a part of the heat source water introduced into the external heat source heat exchanger with the air conditioning target-side refrigerant, and then introduces the heat into the external heat source heat exchanger. Transferring a part of the cold or warm heat of the target side refrigerant to the external heat source side refrigerant,
The heat pump type air conditioner according to claim 1 or 2. The heat transfer means further includes water amount adjusting means for adjusting the amount of water used for heat exchange with the air conditioning target side refrigerant of the heat source water introduced into the external heat source heat exchanger.
The heat pump type air conditioner according to claim 3. The heat transfer means uses a refrigerant heat exchanger into which the external heat source side refrigerant and the air conditioning target side refrigerant are introduced, and uses a part of the cold or warm heat of the air conditioning target side refrigerant as the external heat source side refrigerant. Move,
The heat pump type air conditioner according to claim 1 or 2. A refrigerant amount adjusting means for adjusting the amount of the refrigerant used for heat exchange in the refrigerant heat exchanger;
The heat pump type air conditioner according to claim 5. Temperature acquisition means for acquiring the temperature of the air-conditioning target;
Control means for starting heat transfer by the heat transfer means when the difference between the temperature of the air-conditioning target and the target temperature of the air-conditioning becomes a predetermined value or less;
The heat pump air conditioner according to any one of claims 1 to 6, further comprising: A plurality of the air conditioning target heat exchangers are connected to the compressor and the external heat source heat exchanger,
Of the plurality of air-conditioning target heat exchangers, when the number of air-conditioning target heat exchangers related to operation stop is equal to or less than a predetermined value, the control unit further starts a heat transfer by the heat transfer means,
The heat pump type air conditioner according to any one of claims 1 to 6. The compressor, the air conditioning target heat exchanger, the expansion valve, and the external heat source heat exchanger are connected via a refrigerant flow path so as to form a refrigeration cycle, and the air conditioning that flows on the air conditioning target heat exchanger side in the refrigeration cycle. In a heat pump type air conditioner comprising heat transfer means for transferring a part of the cold or warm heat of the target side refrigerant to the external heat source side refrigerant flowing through the external heat source heat exchanger side by heat exchange,
A temperature acquisition step for acquiring the temperature of the air-conditioning target;
A control step of starting heat transfer in the heat transfer step when the difference between the temperature of the air-conditioning target and the target temperature of the air-conditioning becomes a predetermined value or less;
A control method for a heat pump air conditioner.

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