JP2011127878A - Hot water heat source machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water heat source machine capable of quickly performing a defrosting operation while saving energy, in the defrosting operation using a reversible refrigerating cycle of binary refrigerating cycle. <P>SOLUTION: This hot water heat source machine 50 includes a low order-side refrigerating cycle 1 as a reversible refrigerating cycle in which a low order-side refrigerant is circulated, and a high order-side refrigerating cycle 2 as a reversible refrigerating cycle in which a high order-side refrigerant is circulated, and performing a hot water heating operation, includes an evaporator refrigerant temperature detecting means 16 detecting a refrigerant temperature in the low order-side evaporator, and a control section 5 performing the defrosting operation by using the low order-side refrigerating cycle, when the refrigerant temperature detected by the evaporator refrigerant temperature detecting means becomes a first reference temperature or lower, and performing the defrosting operation by using the high order-side refrigerating cycle in addition to the defrosting operation by using the low order-side refrigerating cycle, when the refrigerant temperature detected by the evaporator refrigerant temperature detecting means is a second reference temperature or less even after the lapse of a prescribed time from the defrosting operation by using the low order-side refrigerating cycle. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a hot water heat source apparatus that heats hot water using a two-way refrigeration cycle, and more particularly to a hot water heat source apparatus that performs a defrosting operation to prevent melting and adhesion of frost adhered to an evaporator.

  2. Description of the Related Art Conventionally, a hot water heat source device that heats hot water by collecting heat from outside air using a binary refrigeration cycle has been used. In such a warm water heat source machine, moisture contained in the outside air adheres to the low-side evaporator during the warm water heating operation. The adhering moisture grows as frost and causes a reduction in heating capacity, so a defrosting operation for melting the frost adhering to the low-source evaporator is necessary. Reversible refrigeration cycle that uses an electric heater for the defrosting method, uses a four-way valve in the refrigeration cycle, switches the refrigerant circuit, reverses the refrigeration cycle, and defrosts using high-temperature gas refrigerant discharged from the compressor There are methods. Generally, a reversible refrigeration cycle system that can perform a defrosting operation relatively quickly is used.

  The low-side refrigerant circuit compressor discharge side piping and suction-side piping are connected to the four-way valve, and the low-side refrigerant circuit decompression device is connected in parallel with a check valve with the condenser side in the forward direction. By connecting another decompression device and a parallel circuit of another check valve with the decompression device side in the forward direction between the condenser of the low origin refrigerant circuit and the decompression device, For example, Patent Literature 1 discloses a technique that enables a defrosting operation by setting a circuit to a reversible refrigeration cycle.

Japanese Patent Laid-Open No. 7-234041

  According to the above conventional technique, the low-source side refrigerant circuit in the multi-source refrigeration apparatus is a reversible refrigeration cycle, and the amount of heat stored in the cascade condenser that connects the high-source side refrigeration cycle and the low-source side refrigeration cycle is utilized. Defrost the side evaporator. Therefore, when the amount of heat stored in the cascade capacitor is insufficient with respect to the amount of heat necessary for defrosting, there is a problem that sufficient defrosting cannot be performed and frost remains. Moreover, in the defrost operation using the calorie | heat amount stored in the cascade capacitor, there existed a subject that it took time to complete defrost. In addition, in order to prevent the remaining frost and shorten the defrosting time, if you want to store a sufficient amount of heat in the cascade capacitor, prepare a cascade capacitor that exceeds the capacity required for heating hot water. Therefore, there is a problem that the apparatus is increased in size and cost.

  The present invention has been made in view of the above, and in a defrosting operation using a reversible refrigeration cycle of a two-way refrigeration cycle, to obtain a hot water heat source machine capable of performing the defrosting operation quickly and with energy saving. Objective.

  In order to solve the above-described problems and achieve the object, the present invention includes a low-side compressor, a low-side evaporator, a low-side condenser, and a low-side four-way valve that are connected by piping. The low-source side refrigeration cycle, which is a reversible refrigeration cycle in which the low-source side refrigerant circulates, and the high-source compressor, high-end evaporator, high-end condenser, and high-end four-way valve are connected by piping, A low-side evaporator and a high-side condenser are provided with a high-side refrigeration cycle that is a reversible refrigeration cycle through which the high-side refrigerant circulates, so that heat can be exchanged between the low-side refrigerant and the high-side refrigerant. In a hot water heat source machine that performs hot water heating operation in which hot water is heated by heat exchange between the high-side refrigerant and hot water in the high-side condenser, and detects the refrigerant temperature in the low-side evaporator When the refrigerant temperature detected by the refrigerant temperature detecting means and the evaporator refrigerant temperature detecting means falls below the first reference temperature, The refrigerant temperature detected by the evaporator refrigerant temperature detecting means is the second reference temperature even if a predetermined time has elapsed from the defrosting operation using the low-source side refrigeration cycle by performing the defrosting operation using the refrigeration cycle. And a control unit that performs a defrosting operation using the high-side refrigeration cycle in addition to the defrosting operation using the low-side refrigeration cycle.

  According to the present invention, in the defrosting operation using the reversible refrigeration cycle of the two-way refrigeration cycle, the defrosting operation can be performed quickly and with energy saving.

FIG. 1 is a block diagram showing an outline of a system configuration of a hot water heat source apparatus according to Embodiment 1 of the present invention. FIG. 2 is a flowchart for explaining the flow of the defrosting operation in the hot water heat source apparatus. FIG. 3 is a flowchart for explaining the flow of the defrosting operation in the hot water heat source apparatus according to Embodiment 2 of the present invention. FIG. 4 is a flowchart showing the flow of the defrosting operation in the hot water heat source apparatus according to Embodiment 3 of the present invention.

  Hereinafter, embodiments of a hot water heat source apparatus according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an outline of a system configuration of a hot water heat source apparatus according to Embodiment 1 of the present invention. The hot water heat source unit 50 includes a low-source side refrigeration cycle 1, a high-source side refrigeration cycle 2, a hot water circulation cycle 3, and a control unit 5. The hot water heat source unit 50 is used in combination with the radiator 4 that heats the room using the heat of the hot water circulating in the hot water circulation cycle 3.

  The low-source side refrigeration cycle 1 includes a compressor (low-source side compressor) 11, a four-way valve (low-source side four-way valve) 12, a condenser (low-source side condenser) 14, and an expansion valve (low-source side expansion valve). 15, an evaporator (low-source side evaporator) 13 is provided, and these are sequentially connected by piping. A refrigerant (low-source-side refrigerant) circulates in the low-source-side refrigeration cycle 1. Further, the low-source side refrigeration cycle 1 is provided with an evaporator refrigerant temperature detecting means 16 for detecting the refrigerant temperature in the evaporator 13 and a condenser refrigerant temperature detecting means 17 for detecting the refrigerant temperature in the condenser 14. The condenser 14 condenses the refrigerant passing through the interior during the hot water heating operation, and the evaporator 13 evaporates the refrigerant passing through the interior during the hot water heating operation. During the defrosting operation to be described later, the refrigerant circulation direction is reversed, so that the refrigerant may evaporate in the condenser 14 and the refrigerant may condense in the evaporator 13. That is, the evaporator 13 and the condenser 14 are names indicating functions during the hot water heating operation, and the same applies to the high-source side refrigeration cycle 2.

  The installation position of the evaporator refrigerant temperature detection means 16 may be any of a position where the inlet temperature can be detected, a position where the evaporation temperature can be detected, and a position where the outlet temperature can be detected. In general, the inlet temperature can be detected. Thus, it is installed at the entrance side of the evaporator 13.

  The installation position of the condenser refrigerant temperature detection means 17 may be any of a position where the inlet temperature can be detected, a position where the condensation temperature can be detected, and a position where the outlet temperature can be detected. Generally, when the condenser 14 is a double-tube heat exchanger, it is installed at a position where the condensation temperature can be detected, and when the condenser 14 is a plate heat exchanger, it is installed at a position where the outlet temperature can be detected. The

  In the first embodiment, the evaporator refrigerant temperature detecting means 16 is installed at a position where the inlet temperature can be detected, and the condenser refrigerant temperature detecting means 17 is installed at a position where the outlet temperature can be detected. The concept of the inlet / outlet is also determined based on the refrigerant circulation direction during the hot water heating operation.

  The high-side refrigeration cycle 2 includes a compressor (high-side compressor) 21, a four-way valve (high-side four-way valve) 22, a condenser (high-side condenser) 24, and an expansion valve (high-side expansion valve). 25, and an evaporator (high-side evaporator) 23, which are sequentially connected by piping. The evaporator 23 is connected to the condenser 14 of the low-source side refrigeration cycle 1 so that heat exchange is possible.

  The hot water circulation cycle 3 includes a tank 33, a hot water circulation means 31, and a hot water heat exchanger 32, and these are sequentially connected by piping. The hot water heat exchanger 32 is connected to the condenser 24 of the high-side refrigeration cycle 2 so as to be able to exchange heat. The radiator 4 is pipe-connected to the hot water circulation cycle 3 and is disposed indoors. The temperature of the hot water is radiated from the radiator 4 into the room, thereby heating the room.

  Next, the operation at the time of heating operation (at the time of hot water heating operation) will be described. In the low-source side refrigeration cycle 1, the refrigerant is circulated in the direction indicated by the arrow X by the compressor 11. In the low-side refrigeration cycle 1, the refrigerant that has been deprived of heat by the condenser 14 and condensed and liquefied becomes a low-temperature and low-pressure gas-liquid two-phase state by the expansion valve 15, and heat is collected from the outside air by the evaporator 13 and evaporated. A low-temperature and low-pressure gas state is obtained, the gas is compressed by the compressor 11 to become a high-temperature and high-pressure gas refrigerant, heat is again taken away by the condenser 14, and the cycle of condensation and liquefaction is repeated.

  In the high-source side refrigeration cycle 2, the refrigerant is circulated in the direction indicated by the arrow P by the compressor 21. In the high-source side refrigeration cycle 2, similarly to the low-source side refrigeration cycle 1, the refrigerant that has been deprived of heat by the condenser 24 and condensed and liquefied becomes a low-temperature low-pressure gas-liquid two-phase state by the expansion valve 25, and the evaporator 23, heat is collected from the refrigerant of the low-source side refrigeration cycle 1 and evaporated to become a low-temperature and low-pressure gas state, compressed by the compressor 21 to become a high-temperature and high-pressure gas refrigerant, again deprived of heat by the condenser 24, condensed, Repeat the liquefaction cycle.

  In the hot water circulation cycle 3, the hot water is circulated in the direction indicated by the arrow R by the hot water circulation means 31. In the hot water circulation cycle 3, heat is collected from the refrigerant of the high-end refrigeration cycle 2 by the hot water heat exchanger 32 to heat the hot water. The heated warm water is conveyed to the radiator 4 by the warm water circulation means 31, dissipated by the radiator 4, and is sent to the warm water heat exchanger 32 again via the tank 33.

  The control unit 5 is connected to the low-source side refrigeration cycle 1, the high-source side refrigeration cycle 2, and the hot water circulation cycle 3. In addition, illustration of the wiring for connecting these is abbreviate | omitted. The control unit 5 controls the operation / stop of the compressors 11 and 21. The control unit 5 controls switching of the circuits of the four-way valves 12 and 22. Moreover, the control part 5 acquires the refrigerant | coolant temperature detected by each refrigerant | coolant temperature detection means 16 and 17. FIG. In addition, the control unit 5 measures the operation time of the low-source side refrigeration cycle 1, the high-source side refrigeration cycle 2, and the hot water circulation cycle 3 by a timing unit (not shown). The operation of the defrosting operation in the hot water heat source unit 1 will be described later. In this case, when the compressors 11 and 21 are operated and stopped, it is assumed that the operation is performed by control by the control unit 5. In addition, when switching the circuits of the four-way valves 12 and 22, it is assumed that the control is performed by the control unit 5.

  Next, the operation during the defrosting operation will be described. FIG. 2 is a flowchart for explaining the flow of the defrosting operation in the hot water heat source apparatus. When the operation start operation of the hot water heat source device 50 is performed (step S1), the heating operation described above is performed (step S2). And it is judged by control part 5 whether continuation of heating operation reached predetermined time, and if predetermined time has not passed (Step S3, No), it will return to Step S2 and predetermined time will pass. The determination of whether or not has been made is repeated. If a predetermined time has elapsed since the start of the heating operation (step S3, Yes), the refrigerant temperature in the evaporator 13 detected by the evaporator refrigerant temperature detecting means 16 of the low-source side refrigeration cycle 1 is the first reference. The controller 5 determines whether the temperature is equal to or lower than the temperature (step S4). Here, when the refrigerant temperature in the evaporator 13 exceeds the first reference temperature (step S4, No), the process returns to step S2.

  Here, the process of step S3 judges the necessity of a defrost operation by the continuation time of heating operation. The predetermined time is determined based on the time required for the past defrosting operation, and is set in the range of, for example, about 30 minutes to 3 hours.

  In step S4, when the refrigerant temperature in the evaporator 13 is equal to or lower than the first reference temperature (step S4, Yes), the compressor 11 of the low-side refrigeration cycle 1 and the compressor 21 of the high-side refrigeration cycle 2 are used. Is stopped (step S5).

  Here, in the process of step S4, it is determined that the defrosting operation is necessary when the refrigerant temperature at the inlet of the evaporator 13 is equal to or lower than the first reference temperature. The first reference temperature is set from the outside air temperature and humidity conditions, and is set to about -3 ° C, for example. By the processing of Step S3 and Step S4, the defrosting operation is performed only when necessary, and it is possible to prevent the hot water heating capacity from being lowered by unnecessary defrosting operation and to reduce the energy loss accompanying the defrosting operation.

  Next, the circuit of the four-way valve 12 of the low-source side refrigeration cycle 1 and the circuit of the four-way valve 22 of the high-source side refrigeration cycle 2 are switched from the state shown by the solid line in FIG. 1 to the state shown by the broken line (step S6). By this switching, each refrigeration cycle 1 and 2 becomes a cycle opposite to that during heating operation. That is, if the compressor 11 is operated in this state, the refrigerant circulates in the direction indicated by the arrow Y in the low-source side refrigeration cycle 1. The refrigerant discharged from the compressor 11 is a cycle in which the refrigerant flows in the order of the four-way valve 12, the evaporator 13 (condensates the refrigerant during the defrosting operation), the expansion valve 15, and the condenser 14 (evaporates the refrigerant during the defrosting operation). Become.

  Similarly, in the high-side refrigeration cycle 2, when the compressor 21 is operated, the refrigerant circulates in the direction indicated by the arrow Q. The refrigerant discharged from the compressor 21 flows in the order of the four-way valve 22, the evaporator 23 (condensates the refrigerant during the defrosting operation), the expansion valve 25, and the condenser 24 (the refrigerant evaporates during the defrosting operation). It becomes a cycle.

  Next, the compressor of the low-source side refrigeration cycle 1 is operated (step S7), and the defrosting operation using the low-source-side refrigeration cycle 1 is performed. Next, it is determined whether or not the refrigerant temperature in the evaporator 13 detected by the evaporator refrigerant temperature detecting means 16 of the low-source side refrigeration cycle 1 is equal to or lower than the second reference temperature. If present (step S8, Yes), it is determined whether or not the refrigerant temperature in the condenser 14 detected by the condenser refrigerant temperature detecting means 17 of the low-source side refrigeration cycle 1 is equal to or higher than the third reference temperature (step). S10). In step S8, when the refrigerant temperature in the evaporator 13 exceeds the second reference temperature (No in step S8), the compressor 11 of the low-side refrigeration cycle 1 is stopped and the defrosting operation is performed. The process is terminated (step S9).

  Here, in the process of step S8, when the refrigerant temperature at the inlet of the evaporator 13 exceeds the second reference temperature, it is determined that the defrosting process is completed. The second reference temperature is set from the outside air temperature and humidity conditions, and is set to about 5 ° C., for example. When frost remains in the evaporator 13, the refrigerant is cooled by the evaporator, so that the refrigerant temperature is less likely to exceed the second reference temperature. In this way, if the completion of the defrosting process is determined based on the refrigerant temperature at the inlet of the evaporator 13, it is possible to prevent the defrosting operation from being terminated while the frost remains in the evaporator 13. It becomes possible.

  In step S10, it is determined whether or not the refrigerant temperature in the condenser 24 detected by the condenser refrigerant temperature detection means 17 of the low-source side refrigeration cycle 1 is equal to or higher than the third reference temperature. If there is (Step S10, Yes), the process proceeds to Step S11. If the temperature is lower than the third reference temperature (Step S10, No), the process proceeds to Step S12.

  In the process of step S10, it is determined from the refrigerant temperature at the outlet of the condenser 14 whether or not the defrosting process is possible only by the operation of the low-source side refrigeration cycle 1. This is because when the refrigerant temperature at the outlet of the condenser 13 becomes lower than a predetermined temperature, only the low-source side refrigeration cycle 1 is operated, that is, the condenser 14 and the high-source side refrigeration cycle 2 of the low-source side refrigeration cycle 1. It is determined that only the amount of heat stored in the heat exchanger connected with the evaporator 23 is difficult to defrost or requires time. The third reference temperature is set to about 0 ° C., for example.

  In step S11, it is determined whether or not a predetermined time has elapsed since the low-source side refrigeration cycle 1 started the defrosting operation. If the predetermined time has elapsed (step S11, Yes), the process proceeds to step S12. If the predetermined time has not elapsed (step S11, No), the process returns to step S7.

  Here, in the process of step S11, it is determined by the defrosting operation time whether or not the defrosting process is possible only by the operation of the low-source side refrigeration cycle 1. In other words, if the refrigerant temperature at the inlet of the evaporator 13 exceeds the second reference temperature and cannot proceed to step S9 within a predetermined time, the operation is performed only in the low-source side refrigeration cycle 1. Judged that frost treatment is difficult. The predetermined time is set to about 5 minutes, for example.

  In step S12, the high-side refrigeration cycle 2 is operated, and the process proceeds to step S13. When operating the high-source side refrigeration cycle 2, the hot water circulation means 31 may be operated simultaneously. When the hot water circulation means 31 is operated, the defrosting process can be performed using the heat of the hot water circulation cycle 3, and the defrosting process can be completed more quickly.

  In step S13, it is determined whether or not the refrigerant temperature detected by the evaporator refrigerant temperature detecting means 16 of the low-source side refrigeration cycle 1 is equal to or lower than the fourth reference temperature. If the refrigerant temperature is equal to or lower than the fourth reference temperature (step S13). , Yes), the process returns to step S12, and if the fourth reference temperature is exceeded (No at step S13), the process proceeds to step S14 and the defrosting operation is terminated.

  By the processing in step S10 and step S11, it is possible to operate the high-side refrigeration cycle 2 only when it is difficult to perform the defrosting process by operating only the low-side refrigeration cycle 1. As a result, it is possible to achieve both reduction of energy loss due to unnecessary operation of the high-source side refrigeration cycle 2 and reliable and quick defrosting processing using the heat amount of the high-source side refrigeration cycle 2. Furthermore, by utilizing the heat quantity of the high-side refrigeration cycle 2, the capacity of the heat exchanger connecting the condenser 14 of the low-side refrigeration cycle 1 and the evaporator 23 of the high-side refrigeration cycle 2 can be defrosted. It doesn't have to be large just for that.

  In the process of step S13, as in the process of step S8, when the refrigerant temperature at the inlet of the evaporator 13 exceeds the fourth reference temperature, it is determined that the defrosting process is complete. The fourth reference temperature is set from the outside air temperature and humidity conditions, and is set to about 5 ° C., for example.

  In step S14, a process for stopping the operation of both the compressor 11 of the low-source side refrigeration cycle 1 and the compressor 21 of the high-source side refrigeration cycle 2 is performed, and then the process proceeds to step S15.

  In step S15, the circuit of the four-way valve 12 of the low-source side refrigeration cycle 1 and the circuit of the four-way valve 22 of the high-source side refrigeration cycle 2 are switched from the broken line state shown in FIG. By this switching, each refrigeration cycle 1 and 2 becomes a cycle opposite to that during the defrosting operation, and returns to the cycle during the heating operation.

  Next, in step S16, the operation of the low-source side refrigeration cycle 1 is started, and the process proceeds to step S17. In step S17, it is determined whether or not the refrigerant temperature detected by the condenser refrigerant temperature detection means 17 of the low-source side refrigeration cycle 1 is equal to or lower than a fifth reference temperature. If the refrigerant temperature is equal to or lower than a predetermined temperature (step S17, Yes), the process proceeds to step S18, and if the predetermined temperature is exceeded (No in step S17), the process proceeds to step S19.

  In the processing of step 17, the operation start condition of the high-source side refrigeration cycle 2 is determined based on the condenser outlet refrigerant temperature of the low-source side refrigeration cycle 1. After the defrosting operation is completed, the refrigerant evaporates in order to prevent damage to the compressor 21 due to inflow of the refrigerant that has been cooled in the evaporator 23 of the high-source side refrigeration cycle 2 into a liquid state. The low-source side refrigeration cycle 1 is operated independently up to a temperature at which gasification is possible in the vessel 23. The predetermined temperature is set to about 30 ° C., for example.

  In step S18, it is determined whether or not a predetermined time has elapsed since the operation of the low-source side refrigeration cycle 1 in step S17. If the predetermined time has elapsed (step S18, Yes), step 19 is performed. If the predetermined time has not elapsed (step S18, No), the process returns to step 16.

  In the process of step S18, the operation start condition of the high-source side refrigeration cycle 2 is determined by the time during which the low-source side refrigeration cycle 1 is operated alone. Even if the determination based on the condenser outlet refrigerant temperature in step 17 is not satisfied, if the low-source side refrigeration cycle 1 is operated for a predetermined time, it is determined that there is no problem even if the high-source side refrigeration cycle 2 is operated. . The predetermined time is set to about 5 minutes, for example.

  By the processing in step S17 and step S18, it is possible to prevent damage due to the inflow of liquid refrigerant into the compressor 21 of the high-source side refrigeration cycle 2, and to quickly start the heating operation after the completion of the defrosting operation. Become. In step S19, the process which starts the driving | operation of the high refrigeration cycle 2 is performed, and a defrost operation is complete | finished completely. Upon completion of the defrosting operation, the process returns to step S2, and it is determined again whether or not the defrosting operation is necessary based on the duration of the heating operation.

  As described above, according to the present invention, it is possible to prevent a decrease in hot water heating capacity due to unnecessary defrosting operation, to reduce energy loss accompanying defrosting operation, to prevent incomplete defrosting treatment, and to perform rapid defrosting treatment and heating operation. Thus, it is possible to prevent the capacity of the condenser 14 of the low-side refrigeration cycle 1 and the evaporator 23 of the high-side refrigeration cycle 2 from being increased, and the compressor 21 of the high-side refrigeration cycle 2 can be prevented from being damaged.

Embodiment 2. FIG.
FIG. 3 is a flowchart for explaining the flow of the defrosting operation in the hot water heat source apparatus according to Embodiment 2 of the present invention. Since the configuration and function of the hot water heat source machine are substantially the same as those described in the first embodiment, detailed description thereof is omitted. Further, the same configuration as that of Embodiment 1 will be described using the same reference numerals. In addition, a flow part different between the first embodiment and the second embodiment will be described.

  In the second embodiment, the switching process of the four-way valve circuit is performed only for the four-way valve 12 of the low-source side refrigeration cycle 1 in step S6 '. Moreover, the process of step S200 is added after the process of step S11, and the circuit of the four-way valve 22 of the high-source side refrigeration cycle 2 is switched in step S200. In addition, when the process of step S201 is added after the process of step S9, and the defrosting operation is finished only in the low-source side refrigeration cycle 1 in step S201, the circuit of only the four-way valve 12 of the low-source side refrigeration cycle 1 Switching.

  In step S6 ′, only the four-way valve 12 of the low-source side refrigeration cycle 1 is switched in the circuit of the four-way valve, and only in the case where it is determined that the operation of the high-side refrigeration cycle 2 is necessary for the defrosting process, By switching the four-way valve 22 of the original refrigeration cycle 2, it is not necessary to switch the four-way valve 22 of the high refrigeration cycle 2 when the defrosting process is completed only by the low original refrigeration cycle 1. As a result, the number of switching of the four-way valve 22 of the high-source side refrigeration cycle 2 can be reduced, and the life of the four-way valve 22 of the high-source side refrigeration cycle 2 can be extended.

Embodiment 3 FIG.
FIG. 4 is a flowchart showing the flow of the defrosting operation in the hot water heat source apparatus according to Embodiment 3 of the present invention. Since the configuration and function of the hot water heat source machine are substantially the same as those described in the first embodiment, detailed description thereof is omitted. Further, the same configuration as that of Embodiment 1 will be described using the same reference numerals. A flow part different between the second embodiment and the third embodiment will be described.

  In step S <b> 5 ′, the compressor stop process is limited to the compressor 11 of the low-source side refrigeration cycle 1. Moreover, the process of step S300 is added after the process of step S11, and the stop process of the compressor 21 of the high-source side refrigeration cycle 2 is performed in step S300. In addition, after the process of step S201, the process of step S301 is added, and in step S301, when the defrosting operation is completed only with the low-source side refrigeration cycle 1, the low-side refrigeration cycle 1 is operated, The defrosting operation is terminated without determining the refrigerant temperature at the outlet of the condenser 14 such as step S17. Here again, upon completion of the defrosting operation, the process returns to step S2, and the necessity of the defrosting operation is determined again based on the duration of the heating operation and the like.

  In step S5 ′, the compressor stop processing is limited to the compressor 11 of the low-source side refrigeration cycle 1, the operation of the compressor 21 of the high-source side refrigeration cycle 2 is continued, and the high-source side refrigeration cycle 2 is used for defrosting processing. Only when it is determined that the above operation is necessary, in step 300, the compressor 21 of the high-side refrigeration cycle 2 is stopped. As a result, when the defrosting process is completed only in the low-source side refrigeration cycle 1, it is possible to suppress a decrease in the temperature of the hot water due to the defrosting process, and further suppress a deterioration in the indoor thermal environment.

  Further, when the defrosting process is completed only in the low-source side refrigeration cycle 1, that is, when the process proceeds to step S9, the high-source side refrigeration cycle 2 continues the heating operation, so that only the low-source side refrigeration cycle 1 is heated. If the operation is resumed, the normal operation is performed, and the heating operation can be quickly started after the defrosting operation is completed.

  In the above embodiment, the reference temperatures discriminated by the control unit 5 include the first to fifth reference temperatures. However, the same temperatures may be set as these reference temperatures, or different temperatures. May be set. The first to fifth reference temperatures can be variously changed according to the use conditions and use environment of the hot water heat source device 50.

  As described above, the hot water heat source apparatus according to the present invention is useful for a hot water heat source apparatus that performs a defrosting operation, and is particularly suitable for increasing the efficiency of the defrosting operation.

DESCRIPTION OF SYMBOLS 1 Low original side refrigerating cycle 2 High original side refrigerating cycle 3 Hot water circulation cycle 4 Radiator 5 Control part 11 Compressor (low original side compressor)
12 Four-way valve (Lower side four-way valve)
13 Evaporator (Lower Evaporator)
14 Condenser (Low-side condenser)
15 Expansion valve (low-side expansion valve)
16 Evaporator refrigerant temperature detection means 17 Condenser refrigerant temperature detection means 21 Compressor (high-side compressor)
22 Four-way valve (high-side four-way valve)
23 Evaporator (High-source evaporator)
24 Condenser (high-side condenser)
25 Expansion valve (high-side expansion valve)
31 Hot water circulation means 32 Hot water heat exchanger 33 Tank 50 Hot water heat source machine

Claims (6)

Low-source side refrigeration in which a low-side compressor, a low-side evaporator, a low-side side condenser, and a low-side side four-way valve are connected to form a reversible refrigeration cycle in which the low-side refrigerant circulates. A high-end side refrigeration cycle in which a high-end side compressor, a high-end side evaporator, a high-end side condenser, and a high-end side four-way valve are connected to each other, and the high-end side refrigerant circulates. Connecting the low-side evaporator and the high-side condenser so that heat can be exchanged between the low-side refrigerant and the high-side refrigerant, and In a warm water heat source machine that performs warm water heating operation that heats warm water by heat exchange between the original refrigerant and warm water,
Evaporator temperature detecting means for detecting refrigerant temperature in the low-side evaporator,
When the refrigerant temperature detected by the evaporator refrigerant temperature detection means becomes equal to or lower than a first reference temperature, the defrosting operation using the low-source side refrigeration cycle is performed, and the low-source side refrigeration cycle is used. When the refrigerant temperature detected by the evaporator refrigerant temperature detecting means is equal to or lower than the second reference temperature even after a predetermined time has elapsed since the defrosting operation, the defrosting operation using the low-source side refrigeration cycle And a control unit for performing a defrosting operation using the high-source side refrigeration cycle. Further comprising a condenser refrigerant temperature detection means for detecting a refrigerant temperature in the low-side condenser,
When the refrigerant temperature detected by the condenser refrigerant temperature detecting means becomes equal to or lower than a third reference temperature during the defrosting operation using only the low-source side refrigeration cycle, the control unit The hot water heat source apparatus according to claim 1, wherein the defrosting operation using the high-source side refrigeration cycle is performed in addition to the defrosting operation using the side refrigeration cycle.   The control unit determines that the defrosting process is completed when the refrigerant temperature detected by the evaporator refrigerant temperature detecting unit exceeds a fourth reference temperature during the defrosting operation, and the low-side refrigeration is performed. When the refrigerant temperature detected by the condenser refrigerant temperature detection means exceeds a fifth reference temperature, in addition to the low-source side refrigeration cycle, the high-water heating operation using a cycle is performed. The hot water heat source apparatus according to claim 2, wherein the hot water heating operation is performed using a side refrigeration cycle.   The control unit determines that the defrosting process is completed when the refrigerant temperature detected by the evaporator refrigerant temperature detecting unit exceeds a fourth reference temperature during the defrosting operation, and the low-side refrigeration is performed. The hot water heating operation using the cycle is performed, and after a predetermined time has elapsed from the start of the hot water heating operation using the low-source side refrigeration cycle, the high-source side refrigeration cycle is added to the low-source side refrigeration cycle. The hot water heat source machine according to any one of claims 1 to 3, wherein a hot water heating operation is performed.   When performing the defrosting operation using the high-source side refrigeration cycle without switching the circuit of the high-source side four-way valve when performing the defrosting operation using the low-source-side refrigeration cycle, the control unit The hot water heat source apparatus according to any one of claims 1 to 4, wherein the high-side four-way valve circuit is switched.   The hot water heat source device according to claim 5, wherein the control unit continues the operation of the high-side compressor during the defrosting operation using the low-side refrigeration cycle.

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