JP2010032063A - Outdoor unit and heat pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent frost attached to a heat exchanger from remaining without defrosted in a defrosting operation. <P>SOLUTION: In the heat pump air heating/hot water supply device, an operation of a fan is restarted (step S55) in a case when an outside air temperature becomes lower than α°C (step S52: Yes) after stopping the operation of the fan (step S51) during the defrosting operation, and when a heat exchange temperature reaches a temperature lower than a defrosting operation termination temperature Te by a°C (Step S54: Yes), before A minutes passes from the start of the defrosting operation (step S53: No). And the operation of the fan 17 is stopped again (step S58) in a case when the heat exchange temperature becomes c°C or less(S56: Yes) after restarting the operation of the fan, or when the heat exchange temperature reaches a temperature lower than (Te-a)°C by b°C, or less (step S57; Yes). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an outdoor unit and a heat pump device that perform a defrosting operation of a heat exchanger.

  In the outdoor unit, a phenomenon (frosting phenomenon) occurs in which moisture in the air becomes frost and adheres to the outdoor heat exchanger that serves as an evaporator during heating operation. And if the amount of frost formation which adheres to an outdoor heat exchanger increases during heating operation, the ventilation resistance of an outdoor heat exchanger will increase and it will become difficult to maintain predetermined heating capacity. Therefore, when the amount of frost formation in the outdoor heat exchanger increases to a predetermined amount, a defrosting operation is performed to remove frost attached to the outdoor heat exchanger (see, for example, Patent Document 1).

In the air conditioner disclosed in Patent Document 1, when the outdoor heat exchanger temperature becomes equal to or lower than the defrosting operation start temperature, the defrosting operation is started, the outdoor fan is stopped, and the refrigerant is changed to the cooling cycle. To do. Thereafter, when the outdoor heat exchanger temperature exceeds the defrosting operation end temperature, the defrosting operation is ended, the fan operation is restarted, and the refrigerant is returned to the heating cycle.
JP-A-11-94330

  However, the air conditioner disclosed in Patent Document 1 has a disadvantage that the temperature of the outdoor heat exchanger locally increases when the refrigerant flowing inside the outdoor heat exchanger drifts. At this time, when the temperature in the vicinity of the thermistor for detecting the temperature of the outdoor heat exchanger rises locally and reaches the defrosting operation end temperature, the defrosting is performed while the frost remains unmelted in the outdoor heat exchanger. There is a problem that driving ends.

  Therefore, the present invention has been made to solve the above-described problems, and an outdoor unit and a heat pump that can suppress the frost attached to the heat exchanger from being melted and remaining during the defrosting operation. An object is to provide an apparatus.

  An outdoor unit according to a first aspect of the present invention includes a heat exchanger in which a refrigerant circulates, a blower attached to the heat exchanger, a heat exchanger temperature detecting means for detecting the temperature of the heat exchanger, a heat And a control unit that stops the operation of the blower and starts the defrosting operation of the heat exchanger when the heat exchanger temperature detected by the exchanger temperature detecting means becomes equal to or lower than the defrosting operation start temperature. When the heat exchanger temperature reaches the first temperature equal to or lower than the defrosting operation end temperature before the first predetermined time has elapsed since the start of the defrosting operation during the defrosting operation of the heat exchanger, Resume driving.

  In this outdoor unit, when the heat exchanger temperature reaches the first temperature before the first predetermined time has elapsed from the start of the defrosting operation, the refrigerant flowing inside the heat exchanger is drifted. By presuming and actively operating the blower, it is possible to lengthen the defrosting time and to prevent the frost adhering to the heat exchanger from remaining unmelted.

  An outdoor unit according to a second aspect of the present invention is the outdoor unit according to the first aspect of the present invention, further comprising an outside air temperature detecting means for detecting the outside air temperature, wherein the control unit The outside temperature detected by the temperature detection means is less than the second temperature, and the heat exchanger temperature reaches the first temperature that is equal to or lower than the defrosting operation end temperature before the first predetermined time has elapsed since the start of the defrosting operation. If this happens, restart the fan.

  In this outdoor unit, when the outside air temperature is equal to or higher than the second temperature, it is assumed that frost is not easily melted, and the defrosting operation is terminated early without actively operating the blower. Can do.

  The outdoor unit according to the third aspect of the present invention is the outdoor unit according to the first or second aspect of the present invention, wherein the control unit resumes the operation of the blower during the defrosting operation of the heat exchanger, and then the heat exchanger temperature is increased. When the temperature falls by a predetermined temperature from the first temperature, the operation of the blower is stopped again.

  In this outdoor unit, since the operation of the blower is stopped when the heat exchanger temperature is lowered from the first temperature by a predetermined temperature, the heat exchanger temperature can be prevented from being lowered excessively.

  An outdoor unit according to a fourth aspect of the present invention is the outdoor unit according to any one of the first to third aspects of the present invention, wherein the control unit resumes the operation of the blower during the defrosting operation of the heat exchanger, When a predetermined time or more has elapsed, the operation of the blower is stopped again.

  In this outdoor unit, it is possible to prevent the heat exchanger temperature from being excessively lowered by limiting the time during which the blower is actively operated.

  An outdoor unit according to a fifth aspect of the present invention is the outdoor unit according to any one of the first to fourth aspects of the present invention, wherein the control unit restarts the operation of the blower during the defrosting operation of the heat exchanger, and then performs heat exchange. When the chamber temperature reaches the third temperature or lower, the operation of the blower is stopped again.

  In this outdoor unit, even when the blower is actively operated, it is possible to reliably prevent the heat exchanger temperature from becoming the third temperature or lower.

Outdoor unit according to a sixth aspect of the present invention, in such an outdoor unit to the first to fifth invention of any one of the CO ₂ used for the refrigerant.

Even in an outdoor unit using a CO ₂ refrigerant, it is possible to suppress the frost adhering to the heat exchanger during the defrosting operation from remaining unmelted.

  A heat pump device according to a seventh aspect of the present invention includes any one of the outdoor units described above, a hot water storage tank for storing the circulating liquid heated by the outdoor unit, and the outdoor unit and the hot water storage for the circulating liquid stored in the hot water storage tank. A circulation circuit that circulates between the tank and the tank.

  In this heat pump device, by using any of the above-described outdoor units, it is possible to suppress the frost attached to the heat exchanger from being melted and remaining during the defrosting operation.

  As described above, according to the present invention, the following effects can be obtained.

  In the first invention, when the heat exchanger temperature reaches the first temperature before the first predetermined time has elapsed since the start of the defrosting operation, the refrigerant flowing inside the heat exchanger drifts. As a result, it is possible to prolong the defrosting time by actively operating the blower, and to prevent the frost attached to the heat exchanger from remaining unmelted.

  Further, in the second invention, when the outside air temperature is equal to or higher than the second temperature, it is assumed that frost is not easily melted, and the fan is not operated actively, and the defrosting operation is performed early. Can be terminated.

  Moreover, in 3rd invention, since the driving | operation of a fan is stopped when heat exchanger temperature falls only predetermined temperature from 1st temperature, it can prevent that heat exchanger temperature falls too much.

  Moreover, in 4th invention, it can prevent that a heat exchanger temperature falls too much by restrict | limiting the time which drives a fan actively.

  In the fifth invention, even when the blower is actively operated, it is possible to reliably prevent the heat exchanger temperature from becoming the third temperature or lower.

Further, in the sixth aspect of the invention, it is used CO ₂ refrigerant, that the frost adhering to the heat exchanger will remain molten can be suppressed at the time of defrosting operation.

  Moreover, in 7th invention, the heat pump apparatus which can suppress that the frost adhering to the heat exchanger remains unmelted by using one of the above-mentioned outdoor units can be obtained.

  Hereinafter, based on drawing, embodiment of the heat pump heating hot-water supply apparatus which concerns on this invention is described.

(First embodiment)
FIG. 1 is a schematic diagram illustrating a configuration of a heat pump heating hot water supply apparatus according to a first embodiment of the present invention. 2 is a cross-sectional view showing details of a hot water storage tank and a hot water supply heat exchanger of the heat pump heating hot water supply apparatus shown in FIG. Hereinafter, with reference to FIG.1 and FIG.2, the structure of the heat pump heating hot-water supply apparatus 100 is demonstrated in detail.

  As shown in FIG. 1, the heat pump heating and hot water supply apparatus 100 of the present embodiment mainly includes a heat pump unit 1 that is an outdoor unit, a hot water storage tank 2, a hot water supply heat exchanger 3, a heating circulation circuit 4, and a boiling point. And an upward circulation circuit 5. In the heat pump heating and hot water supply apparatus 100 of the present embodiment, the circulating fluid stored in the hot water storage tank 2 is supplied to the radiator A through the heating circulation circuit 4, and the water that has flowed inside the hot water supply heat exchanger 3 is supplied. It is supplied to a hot water supply terminal B such as a kitchen or bathroom.

The heat pump unit 1 is attached to the hot water storage tank 2, heats the circulating liquid in the lower region in the hot water storage tank 2, and returns it to the upper region in the hot water storage tank 2. This heat pump unit 1 has a refrigerant circuit 16 having an outdoor heat exchanger (evaporator) 11, a compressor 12, a water heat exchanger (condenser) 13, a supercooling heat exchanger 14, and an electric expansion valve 15. Yes. A CO ₂ refrigerant circulates in the refrigerant circuit 16. The outdoor heat exchanger 11 is provided with a fan 17 that adjusts the capacity of the outdoor heat exchanger 11. Further, the heat pump unit 1 of the present embodiment is provided with a control unit 18 that controls the operations of the compressor 12, the electric expansion valve 15, the fan 17, and the like. The control unit 18 is housed in an electrical component box (not shown). Further, the heat pump unit 1 is provided with a thermistor 19a for detecting the temperature of the outdoor heat exchanger 11 and a thermistor 19b for detecting the outside air temperature.

The control unit 18 heats the circulating fluid in the lower region of the hot water tank 2 based on a signal related to a temperature detected by a temperature sensor 22 provided in the hot water tank 2 to be described later, and the top side of the hot water tank 2. Boil up to return to During the boiling operation, the above-described CO ₂ refrigerant circulates in the outdoor heat exchanger 11 to absorb and heat the air in the air sent by the operation of the fan 17. After being compressed to a critical pressure or higher and becoming high temperature, it reaches the water heat exchanger 13 and exchanges heat with the circulating fluid taken out from the hot water storage tank 2 described above. As a result, the CO ₂ refrigerant becomes lower in temperature than before entering the water heat exchanger 13 and moves toward the supercooling heat exchanger 14. The CO ₂ refrigerant is further cooled by the supercooling heat exchanger 14 and then returns to the outdoor heat exchanger 11 via the electric expansion valve 15.

  Further, the control unit 18 suppresses the heat exchange from being hindered due to frost formation in the outdoor heat exchanger 11, so that the temperature of the outdoor heat exchanger 11 detected by the thermistor 19 a (hereinafter referred to as “heat”). When the defrosting operation start temperature Ts ° C. or lower is reached, the operation of the fan 17 is stopped and the defrosting operation for melting the frost adhering to the outdoor heat exchanger 11 is started. And this defrost operation is complete | finished when heat exchange temperature becomes more than defrost operation end temperature Te (> Ts), or when the predetermined period has passed since the defrost operation start. In addition, in this heat pump unit 1, the normal cycle defrost operation which makes the cycle direction of the refrigerant | coolant in a defrost operation the same as the time of a boiling operation is performed.

The above-described defrosting operation end temperature Te is a temperature that changes according to the outside air temperature. When the outside air temperature is low, the defrosting operation end temperature Te is high, and when the outside air temperature is high, the defrosting operation end temperature Te is low. Become. This is because the frost attached to the outdoor heat exchanger 11 does not melt unless the heat exchange temperature is higher when the outside air temperature is lower. Specifically, the defrosting operation end temperature Te is determined by the following equation.
Defrosting operation end temperature Te = −f × outside air temperature at start of defrosting operation + 10 ° C.
(4 ° C ≦ defrosting operation end temperature Te ≦ 10 ° C.)
(Where f is a positive constant)

  Here, in the present embodiment, the controller 18 detects that the outside air temperature detected by the thermistor 19b during the defrosting operation of the outdoor heat exchanger 11 is less than α ° C. (second temperature) (for example, 5 ° C. or less). And before A minute (1st predetermined time) (for example, 3 minutes-5 minutes) does not pass from the defrost operation start, heat exchange temperature is a degree (for example, 2 degreeC-from defrost operation end temperature Te). 5 ° C.) When the temperature reaches the lower temperature (first temperature), the operation of the fan 17 is resumed. That is, in the heat pump unit 1 of the present embodiment, even during the defrosting operation, the heat exchange temperature is (Te−) before the outside air temperature is less than α ° C. and the A minute has not elapsed since the start of the defrosting operation. a) The time until the outdoor heat exchanger 11 reaches the defrosting operation end temperature Te when the fan 17 is actively operated when the temperature reaches 1 ° C. (first temperature) is determined during the defrosting operation. 17 is made longer than the case where it is always stopped. Then, after the operation of the fan 17 is resumed, the heat exchange temperature is changed from (Te-a) ° C. to b ° C. (eg When the temperature decreases by 2 ° C to 3 ° C), the operation of the fan 17 is stopped again.

  The hot water storage tank 2 is connected to the above-described heat pump unit 1 via the boiling circulation circuit 5 and to the radiator A via the heating circulation circuit 4. The heated circulating fluid is stored.

  As shown in FIG. 2, a heater 20 that directly heats the circulating fluid in the hot water storage tank 2 is provided at a substantially central portion in the vertical direction in the hot water storage tank 2. Thereby, even when the heat pump unit 1 fails, the circulating fluid in the hot water storage tank 2 can be heated using the heater 20, and also when the amount of heat given to the circulating fluid by the heat pump unit 1 is insufficient, The shortage of heat can be supplemented by the heater 20. In addition, since the heater 20 is disposed at a substantially central portion in the vertical direction in the hot water storage tank 2, the circulating fluid above the heater 20 is mainly heated, but the upper portion in the hot water storage tank 2 is heated. Since the circulating fluid in the region is hotter than the circulating fluid in the lower region in the hot water storage tank 2, the circulating fluid can be heated to a high temperature in a short time. This is particularly effective when the heating load increases instantaneously.

  Further, the hot water storage tank 2 is provided with a pipe 21 having one end portion 21 a located outside the hot water storage tank 2 and the other end portion 21 b located in the hot water storage tank 2 and in the vicinity of and above the heater 20. Yes. One end 21 a of the pipe 21 is connected to the other upstream end 4 b of the heating circulation circuit 4, and the circulating fluid immediately after being heated by the heater 20 can be sent to the heating circulation circuit 4. It has become.

  The hot water storage tank 2 is provided with a plurality of temperature sensors 22 (see FIG. 1) for detecting the temperature of the circulating fluid at each height position in the hot water storage tank 2. A signal related to the temperature detected by the temperature sensor 22 is used to start or stop the above-described boiling operation.

  On the lower side of the hot water storage tank 2, a use side return connection port 23, a heat source side forward connection port 24, and a freeze prevention return connection port 25 are provided. A downstream end 4c of the heating circulation circuit 4 is connected to the use-side return connection port 23. As a result, the circulating fluid that has dissipated heat from the radiator A and has a low temperature is introduced into the lower region in the hot water storage tank 2. As a result, it is possible to suppress the mixing of the relatively high temperature circulating liquid in the upper region in the hot water storage tank 2 and the circulating liquid having a relatively low temperature in the radiator A, so that the temperature becomes low. The upstream end 5a of the boiling circulation circuit 5 is connected to the heat source side forward connection port 24. As a result, the relatively low temperature circulating liquid present in the lower region in the hot water storage tank 2 can be sent to the boiling circulation circuit 5. As a result, the relatively low temperature circulating liquid in the lower region in the hot water storage tank 2 is supplied to the water heat exchanger 13 of the heat pump unit 1, so that the COP of the heat pump unit 1 is improved. The freezing return return connection port 25 is connected to the downstream end portion 5 b of the boiling circulation circuit 5. As a result, the circulating fluid that is not sufficiently heated during the freeze prevention operation can be introduced into the lower region in the hot water storage tank 2. The above-described freeze prevention operation is performed while the boiling operation is stopped.

  A forward / return connection port 26 is provided at the top of the hot water storage tank 2. The forward / return connection port 26 is connected to the upstream one end 4 a of the heating circuit 4 and the downstream other end 5 c of the boiling circuit 5. Thereby, it becomes possible to introduce the relatively high temperature circulating liquid boiled by the heat pump unit 1 into the upper region in the hot water storage tank 2 and the relatively high temperature existing in the upper region in the hot water storage tank 2. The circulating fluid can be sent to the heating circulation circuit 4. The upstream one end 4a of the heating circulation circuit 4 and the downstream other end 5c of the boiling circulation circuit 5 form a common flow path.

  As shown in FIG. 2, the hot water supply heat exchanger 3 is formed of a coiled pipe, and is arranged from the lower region to the upper region in the hot water storage tank 2. Thereby, the water which is supplied from the water supply source C (refer FIG. 1) and distribute | circulates the pipe is heated by the circulating liquid stored by the circumference | surroundings. Specifically, the water supplied from the water supply source C is introduced into the lower coil portion 3 a disposed in the lower region in the hot water storage tank 2 through the water supply passage 31. And the water which flowed upward through this lower coil part 3a is introduced into the upper coil part 3b arrange | positioned at the upper area | region in the hot water storage tank 2. FIG. And the water which flowed upward through this upper coil part 3b is supplied to each hot-water supply terminal B via the hot water flow path 32. FIG. As described above, the hot water supply heat exchanger 3 is arranged from the lower region in the hot water storage tank 2 to the upper region, and the water from the water supply source C is directed from the lower region in the hot water storage tank 2 to the upper region. The water is sufficiently heated by the circulating liquid in the hot water storage tank 2 while flowing in the hot water supply heat exchanger 3. Therefore, hot hot water can be discharged from the hot water supply heat exchanger 3. In addition, the lower coil part 3a and the upper coil part 3b are arrange | positioned so that the above-mentioned heater 20 may be straddled.

  In addition, as shown in FIG. 1, a mixing valve 33 is provided between the water supply flow path 31 and the hot water flow path 32. The mixing valve 33 is provided to adjust the temperature of hot water passing through the hot water flow path 32. Specifically, by opening the mixing valve 33, the hot water passing through the hot water flow path 32 and the water passing through the water supply flow path 31 are mixed to adjust the temperature of the hot water supplied at the hot water supply terminal B. ing.

  The heating circulation circuit 4 circulates the circulating liquid stored in the hot water storage tank 2 between the hot water storage tank 2 and the radiator A. The upstream one end 4 a of the heating circulation circuit 4 is connected to the forward / return connection port 26 provided at the top of the hot water storage tank 2, and the downstream end 4 c is connected to the use-side return connection port 23. Yes. Further, the other upstream end 4b is connected to one end 21a of a pipe 21 (see FIG. 2) provided in the hot water storage tank 2. On the heating circulation circuit 4, a bypass pipe 41, a mixing valve 42, a three-way valve 43, temperature sensors 44 and 45, a circulation pump 46, and a plurality of radiators A are provided.

  The bypass pipe 41 is provided to guide a part of the circulating fluid that returns to the hot water storage tank 2 via the radiator A to the mixing valve 42.

  The mixing valve 42 mixes and mixes the inlet into which the circulating fluid sent out from the hot water storage tank 2 flows, the inlet into which the circulating fluid guided by the bypass pipe 41 flows, and the circulating fluid flowing in from these inlets. And an outlet to be provided.

  The three-way valve 43 includes an inlet (hereinafter referred to as a first inlet) through which the circulating fluid fed from the forward / return connection port 26 to which the upstream one end 4a of the heating circuit 4 is connected, An inlet (hereinafter referred to as a second inlet) through which the circulating fluid fed from the other end 21b of the pipe 21 to which the other upstream end 4b of the circulation circuit 4 is connected, and a circulating fluid that has flowed in from each of the inlets And an outlet for feeding out. When the high temperature region of the circulating fluid in the hot water storage tank 2 does not exist in the vicinity of the other end 21 b of the pipe 21, the three-way valve 43 opens the first inlet and opens the forward / return connection port 26. When the circulating fluid is taken out and the high temperature region of the circulating fluid in the hot water storage tank 2 exists in the vicinity of the other end 21b of the pipe 21, the second inlet is opened and the circulating fluid is opened from the other end 21b of the piping 21. Take out.

  The temperature sensor 44 is provided to detect the temperature of the circulating fluid from the hot water storage tank 2 toward the radiator A (forward circulating fluid temperature), and the temperature sensor 45 is the temperature of the circulating fluid from the radiator A toward the hot water storage tank 2. It is provided to detect (return circulating fluid temperature).

  The circulation pump 46 is provided for circulating the circulating fluid in the hot water storage tank 2 in the heating circulation circuit 4.

  Each radiator A directly takes out the heat of the circulating fluid circulating in the heating circulation circuit 4 and dissipates it into the room in which the radiator A is installed. As a result, the heat of the circulating fluid circulating in the heating circulation circuit 4 can be efficiently supplied to the radiator A, so that sufficient heating can be performed even in regions with a high heating load such as Northern Europe.

  The boiling circulation circuit 5 circulates the circulating liquid stored in the hot water storage tank 2 between the hot water storage tank 2 and the heat pump unit 1. An upstream end portion 5 a of the boiling circulation circuit 5 is connected to a heat source side forward connection port 24 provided on the lower side of the hot water storage tank 2, and a downstream one end portion 5 b is provided on the lower side of the hot water storage tank 2. The other end 5 c on the downstream side is connected to a forward / return connection port 26 provided at the top of the hot water storage tank 2. A circulating pump 51, the water heat exchanger 13 of the heat pump unit 1, the three-way valve 52, and the temperature sensor 53 are provided on the boiling circulation circuit 5.

  The circulation pump 51 is provided to circulate the circulating liquid in the hot water storage tank 2 in the circulating circuit 5 for boiling.

  The three-way valve 52 has an inlet through which the circulating fluid heated in the above-described water heat exchanger 13 flows, an outlet for sending the circulating fluid toward the forward / return connection port 26 (hereinafter referred to as a first outlet), It has an outlet (hereinafter referred to as a second outlet) for sending the circulating fluid toward the freezing return return connection port 25. When the circulating fluid that has passed through the water heat exchanger 13 is sufficiently hot, the three-way valve 52 opens the first outlet and opens the hot water storage tank 2 through the forward / return connection port 26. When the circulating fluid is returned to the upper region of the water and the circulating fluid that has passed through the water heat exchanger 13 is not sufficiently hot, the second outlet is opened and the freezing prevention return connection port 25 is used. The circulating fluid is returned to the lower region in the hot water storage tank 2. Therefore, it is possible to prevent the circulating fluid that does not reach a sufficiently high temperature from being returned to the upper region in the hot water storage tank 2 when the heat pump unit 1 is started or during the freeze prevention operation. Thereby, it is possible to prevent the temperature distribution in the hot water storage tank 2 from being disturbed due to the circulating fluid that is not sufficiently high in temperature being returned to the upper region in the hot water storage tank 2. In this way, in the hot water storage tank 2, a liquid layer (temperature distribution) is formed so that the relatively hot circulating fluid is located in the upper region and the relatively cold circulating fluid warm water is located in the lower region.

  The temperature sensor 53 is provided to detect the temperature of the circulating fluid from the water heat exchanger 13 toward the three-way valve 52 (the temperature of the circulating fluid boiled up by the heat pump unit 1).

  FIG. 3 is a flowchart showing an operation flow of the heat pump unit of the heat pump heating and hot water supply apparatus shown in FIG. 1, and FIG. 4 is a flowchart showing details of the defrosting operation shown in FIG. Next, the operation of the heat pump unit 1 will be described in detail with reference to FIGS. 3 and 4.

  First, the control unit 18 determines whether or not to start the boiling operation based on a signal related to the temperature detected by the temperature sensor 22 provided in the hot water storage tank 2 (step S1). And when starting a boiling operation (step S1: Yes), after operating the fan 17 (step S2), the control part 18 operates the compressor 12 (step S3). On the other hand, when the boiling operation is not started (step S1: No), the determination in step S1 is repeated.

  Next, the control unit 18 determines whether or not the heat exchange temperature has become equal to or lower than the defrosting operation start temperature Ts ° C. as a start condition for the defrosting operation (step S5) described later (step S4). When the alternating temperature is equal to or lower than the defrosting operation start temperature Ts ° C (step S4: Yes), the defrosting operation is started (step S5), and the heat exchange temperature is higher than the defrosting operation start temperature Ts ° C. (Step S4: No), the process proceeds to Step S7. That is, here, the frost formation state of the outdoor heat exchanger 11 is estimated based on the heat exchange temperature, and it is determined whether to start the defrosting operation (step S5).

  When the defrosting operation (step S5) ends, the control unit 18 resumes the operation of the fan 17 stopped in the defrosting operation (step S6). Thereafter, the control unit 18 determines whether or not to end the boiling operation based on a signal related to the temperature detected by the temperature sensor 22 provided in the hot water storage tank 2 (step S7). When the boiling operation is finished (step S7: Yes), the control unit 18 stops the compressor 12 (step S8) and stops the fan 17 (step S9). End driving. On the other hand, when the boiling operation is not terminated (step S7: No), the process returns to step S4 again to determine whether or not the heat exchange temperature has become equal to or lower than the defrosting operation start temperature Ts ° C.

  Next, details of the defrosting operation in step S5 will be described.

  First, when the defrosting operation is started, the control unit 18 stops the fan 17 (step S51). Then, the control unit 18 determines whether or not the outside air temperature is less than α ° C. (for example, 5 ° C. or less) (step S52). When the outside air temperature is less than α ° C. (step S52: Yes), the control unit 18 determines whether or not A minutes (for example, 3 to 5 minutes) have elapsed since the start of the defrosting operation ( Step S53). On the other hand, when the outside air temperature is equal to or higher than α ° C. (step S52: No), the control unit 18 performs a process of step S59 described later. That is, here, when the outside air temperature is equal to or higher than α ° C., the operation of the fan 17 in step 55 described later is not performed.

  And when A minute has not yet passed since the defrost operation start (step S53: No), the control part 18 is a degree of heat exchange temperature from defrost operation end temperature Te (for example, 2 to 5 degreeC). It is determined whether or not a low temperature has been reached (step S54). On the other hand, when the A minute has already elapsed from the start of the defrosting operation (step S53: Yes), the control unit 18 proceeds to the process of step S59 described later.

  In the present embodiment, when the heat exchange temperature reaches a temperature a ° C. lower than the defrosting operation end temperature Te (step S54: Yes), the control unit 18 resumes the operation of the fan 17 (step S55). ). On the other hand, when the heat exchange temperature has not reached a temperature lower than the defrosting operation end temperature Te by a ° C. (step S54: No), the control unit 18 again passes A minutes from the start of the defrosting operation. It is determined whether or not it has been done (step S53).

  Then, after resuming the operation of the fan 17 (step S55), the control unit 18 determines whether or not the heat exchange temperature has become equal to or lower than c ° C. (step S56). When the heat exchange temperature becomes equal to or lower than c ° C. (step S56: Yes), the heat exchange temperature is too low, and the control unit 18 stops the operation of the fan 17 again (step S58). On the other hand, when the heat exchange temperature is higher than c ° C. (Step S56: No), the heat exchange temperature becomes lower than the above (Te-a) ° C. by a temperature lower by b ° C. (for example, 2 ° C. to 3 ° C.). It is determined whether or not (step S57). When the heat exchange temperature becomes equal to or lower than the above (Te−a) ° C. by b ° C. (step S57: Yes), the controller 18 stops the operation of the fan 17 again (step S58). ). The operation of the fan 17 (step S55) is performed until the heat exchange temperature becomes lower than (Te-a) ° C. by a temperature lower by b ° C. (2 ° C. to 3 ° C.) (step S57: No).

  And the control part 18 judges whether the completion | finish conditions (step S59, S60) of a defrost operation are satisfy | filled, and when the said conditions are satisfy | filled, a defrost operation is complete | finished. Specifically, the control unit 18 determines whether or not the heat exchange temperature is equal to or higher than the defrosting operation end temperature Te ° C (step S59), and the heat exchange temperature is equal to or higher than the defrosting operation end temperature Te ° C. When it becomes (step S59: Yes), a defrost operation is complete | finished. When the heat exchange temperature is lower than the defrosting operation end temperature Te ° C (step S59: No), the control unit 18 determines whether or not a predetermined period has elapsed from the start of the defrosting operation (step S60). When the predetermined period has elapsed since the start of the defrosting operation (step S60: Yes), the defrosting operation is terminated. On the other hand, when the heat exchange temperature is lower than the defrosting operation end temperature Te ° C (step S59: No) and the predetermined period has not elapsed since the start of the defrosting operation (step S60: No), again. It returns to step S52 and it is judged whether the outside temperature became less than (alpha) degreeC. As described above, the defrosting operation is completed.

[Features of Heat Pump Heating / Hot Water Supply Device 100 of First Embodiment]
The heat pump heating hot water supply apparatus 100 of the first embodiment has the following characteristics.

In the heat pump heating and hot water supply apparatus 100 of the present embodiment, when the heat exchange temperature reaches (Te-a) ° C. before the A minute has elapsed since the start of the defrosting operation, it is circulated inside the outdoor heat exchanger 11. It is estimated that the CO ₂ refrigerant to be drifted is drifted, and the fan 17 is actively operated to lengthen the defrosting time, thereby suppressing the frost adhering to the outdoor heat exchanger 11 from remaining unmelted. Can do.

  Moreover, in the heat pump heating hot water supply apparatus 100 of this embodiment, when the outside air temperature is α ° C. or higher (step S52: No), it is assumed that frost is not easily melted, and the fan 17 in step S55 is positively activated. The defrosting operation can be terminated at an early stage without driving.

  Further, in the heat pump heating and hot water supply apparatus 100 of the present embodiment, when the heat exchange temperature is lowered by (b-C) from (Te-a) ° C (step S57: Yes), the operation of the fan 17 is stopped (step S58). It is possible to prevent the temperature of the outdoor heat exchanger 11 from being excessively lowered.

  However, when the defrosting operation end temperature Te changes according to the outside air temperature as in the present embodiment, when the heat exchange temperature decreases from (Te-a) ° C. by b ° C. (step S57: Yes). If the operation of the fan 17 is stopped only (step S58), the heat exchange temperature may be too low (for example, 0 ° C. or lower). Therefore, in the present embodiment, the heat exchange temperature is prevented from excessively dropping below c ° C. (for example, 3 ° C. to 5 ° C.) (step S56), so the defrosting operation end temperature Te changes according to the outside air temperature. In this case, it is possible to prevent the heat exchange temperature from being excessively lowered.

(Second Embodiment)
FIG. 5 is a flowchart showing details of the defrosting operation of the heat pump unit according to the second embodiment of the present invention. In the heat pump unit according to the second embodiment, the operation stop condition of the fan 17 after the operation of the fan 17 is resumed is different from that of the first embodiment. Details will be described below.

  In the heat pump unit according to the second embodiment, as in the first embodiment described above, when the outside air temperature is less than α ° C. (step S52: Yes), and A minutes have not elapsed since the start of the defrosting operation. On the other hand (step S53: No), when the heat exchange temperature reaches a temperature a ° C. lower than the defrosting operation end temperature Te (step S54: Yes), the operation of the fan 17 is resumed (step S55).

  And in this 2nd Embodiment, after restarting the driving | operation of the fan 17 (step S55), the control part 18 judges whether the heat exchanger temperature became c degrees C or less (step S56). When the heat exchange temperature becomes equal to or lower than c ° C. (step S56: Yes), the heat exchange temperature is too low, and the control unit 18 stops the operation of the fan 17 again (step S58). On the other hand, when the heat exchange temperature is higher than c ° C. (step S56: No), after the operation of the fan 17 is restarted, B minutes (second predetermined time) (for example, 0.5 minutes to 1 minute) or more are required. It is determined whether or not the time has elapsed (step S157). If more than B minutes have elapsed since the operation of the fan 17 was resumed (step S157: Yes), the control unit 18 stops the operation of the fan 17 again (step S58). The operation of the fan 17 (step S55) is performed until B minutes or more elapses after the operation of the fan 17 is restarted (step S157: No).

  And the control part 18 judges whether the completion | finish conditions (step S59, S60) of a defrost operation are satisfy | filled, and when the said conditions are satisfy | filled, a defrost operation is complete | finished. The details are the same as those in the first embodiment, and a description thereof will be omitted.

[Characteristics of Heat Pump Heating / Hot Water Supply Device of Second Embodiment]
The heat pump heating hot water supply apparatus of the second embodiment has the following characteristics.

  In the heat pump heating and hot water supply apparatus of this embodiment, it is possible to prevent the temperature of the outdoor heat exchanger 11 from being excessively lowered by limiting the time during which the fan 17 is actively operated.

(Third embodiment)
FIG. 6 is a flowchart showing details of the defrosting operation of the heat pump unit according to the third embodiment of the present invention. In the heat pump unit according to the third embodiment, the operation stop condition of the fan 17 after the operation of the fan 17 is resumed is different from that of the first and second embodiments. Details will be described below.

  In the heat pump unit according to the third embodiment, as in the first embodiment described above, when the outside air temperature is less than α ° C. (step S52: Yes), and A minutes have not elapsed since the start of the defrosting operation. If the heat exchange temperature reaches a temperature a ° C. lower than the defrosting operation end temperature Te (step S54: Yes), the operation of the fan 17 is resumed (step S55).

  And in this 3rd Embodiment, after restarting the driving | operation of the fan 17, the control part 18 judges whether the heat exchanger temperature became c degrees C (for example, 3 degrees C-5 degrees C) or less (step S256). ). Then, when the heat exchange temperature becomes equal to or lower than c ° C. (step S256: Yes), the control unit 18 stops the operation of the fan 17 again (step S58). The operation of the fan 17 (step S55) is performed until the heat exchange temperature becomes c ° C. or less (step S256: No).

  And the control part 18 judges whether the completion | finish conditions (step S59, S60) of a defrost operation are satisfy | filled, and when the said conditions are satisfy | filled, a defrost operation is complete | finished. The details are the same as those in the first embodiment, and a description thereof will be omitted.

[Features of Heat Pump Heating / Hot Water Supply Device of Third Embodiment]
The heat pump heating hot water supply apparatus of the third embodiment has the following characteristics.

  In the heat pump heating and hot water supply apparatus of the present embodiment, even when the fan 17 is actively operated, the heat exchange temperature does not become c ° C. or lower, so that it is possible to reliably prevent the heat exchange temperature from being excessively lowered. .

  As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment. The scope of the present invention is shown not only by the above description of the embodiments but also by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

For example, in the above-described embodiment, the example in which the CO ₂ refrigerant is used in the heat pump unit 1 has been described. However, the present invention is not limited thereto, and an NH ₃ refrigerant, an R22 refrigerant, or the like may be used.

  Moreover, although the said embodiment demonstrated the example which applied this invention to the heat pump heating hot-water supply apparatus provided with the heating function and the hot-water supply function, this invention was not limited to this but was provided with either the heating function and the hot-water supply function. It can also be applied to a heat pump device. That is, the present invention can be applied to a heat pump heating device in which the heat exchanger for hot water supply in the heat pump heating hot water supply device of the first embodiment is omitted, and the heat pump hot water supply device in which a circulation circuit for heating is omitted. It is also possible to apply the present invention.

  Moreover, although the said embodiment demonstrated the example which applied this invention to the heat pump apparatus which boils the circulating fluid stored in the hot water storage tank 2, this invention is not limited to this, The outdoor of an air conditioner (what is called an air conditioner) It is also applicable to the machine.

  Moreover, although the said embodiment demonstrated the normal cycle defrost operation which makes the direction of the flow of the refrigerant | coolant during a defrost operation the same as the time of a boiling operation, this invention is not limited to this, The refrigerant | coolant in a defrost operation It is also applicable to a reverse cycle defrosting operation in which the flow direction is reversed from that during the boiling operation.

  Moreover, although the said embodiment demonstrated the example which drive | operates the fan 17 during a defrost operation (step S55) only when the external temperature becomes less than (alpha) degreeC (step S52: Yes), this invention is this. However, it is not always necessary to consider the outside air temperature.

  Moreover, although the said embodiment demonstrated the example using the heat pump unit 1 which has the supercooling heat exchanger 14, this invention is not restricted to this, Even if it uses the heat pump unit which does not have the supercooling heat exchanger 14. Good.

  If this invention is utilized, it can suppress that the frost adhering to the heat exchanger at the time of a defrost operation will not melt | dissolve.

It is a schematic diagram which shows the structure of the heat pump heating hot-water supply apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the detail of the hot water storage tank and hot water supply heat exchanger of the heat pump heating hot-water supply apparatus shown in FIG. It is the flowchart which showed the operation | movement flow of the heat pump unit of the heat pump heating hot-water supply apparatus shown in FIG. It is the flowchart which showed the detail of the defrost operation shown in FIG. It is the flowchart which showed the detail of the defrost driving | operation of the heat pump unit which concerns on 2nd Embodiment of this invention. It is the flowchart which showed the detail of the defrost driving | operation of the heat pump unit which concerns on 3rd Embodiment of this invention.

Explanation of symbols

100 Heat pump heating hot water supply device (heat pump device)
1 Heat pump unit (outdoor unit)
2 Hot water storage tank 5 Boiling circuit (circulation circuit)
11 Outdoor heat exchange 17 Fan (blower)
18 controller 19a thermistor (heat exchanger temperature detection means)
19b thermistor (outside temperature detection means)

Claims (7)

A heat exchanger through which the refrigerant flows; and
A blower attached to the heat exchanger;
Heat exchanger temperature detecting means for detecting the temperature of the heat exchanger;
A control unit that stops the operation of the blower and starts the defrosting operation of the heat exchanger when the heat exchanger temperature detected by the heat exchanger temperature detection means becomes equal to or lower than the defrosting operation start temperature; With
In the defrosting operation of the heat exchanger, the control unit reaches the first temperature that is equal to or lower than the defrosting operation end temperature before the first predetermined time has elapsed from the start of the defrosting operation. When it does, the operation | movement of the said air blower is restarted, The outdoor unit characterized by the above-mentioned. It further comprises an outside air temperature detecting means for detecting the outside air temperature,
During the defrosting operation of the heat exchanger, the control unit is configured so that the outside air temperature detected by the outside air temperature detecting means is less than a second temperature and the first predetermined time has not elapsed since the start of the defrosting operation. Furthermore, when the said heat exchanger temperature reaches | attains 1st temperature below defrost operation end temperature, the driving | operation of the said air blower is restarted, The outdoor unit of Claim 1 characterized by the above-mentioned.   In the defrosting operation of the heat exchanger, the control unit restarts the operation of the blower when the temperature of the heat exchanger decreases by a predetermined temperature from the first temperature after restarting the operation of the blower. The outdoor unit according to claim 1, wherein the outdoor unit is stopped.   In the defrosting operation of the heat exchanger, the control unit restarts the operation of the blower when the second predetermined time has elapsed after the operation of the blower is resumed. The outdoor unit according to any one of claims 1 to 3.   In the defrosting operation of the heat exchanger, the control unit restarts the operation of the blower when the temperature of the heat exchanger reaches a third temperature or less after restarting the operation of the blower. The outdoor unit according to any one of claims 1 to 4, wherein The outdoor unit according to claim 1, wherein CO ₂ is used as the refrigerant. The outdoor unit according to any one of claims 1 to 6,
A hot water storage tank for storing the circulating fluid heated by the outdoor unit;
A heat pump device comprising: a circulation circuit that circulates a circulating liquid stored in a hot water storage tank between the outdoor unit and the hot water storage tank.

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