JP2007192439A - Heat pump water heater - Google Patents

Abstract

A heat pump water heater according to the present invention causes direct operation of a direct operation using hot water heated by a heat pump, causing a decrease in direct operation capability depending on the timing of the defrosting operation, leading to a lack of hot water. The heat pump water heater which can prevent the capability fall of the heat pump 6 and can prevent hot water shortage is provided.
SOLUTION: Defrosting operation means for performing defrosting before stopping the compressor after the direct operation of directly using hot water heated by a heat pump is completed is provided.
[Selection] Figure 1

Description

  The present invention relates to a heat pump water heater that supplies hot water by storing heated hot water in a hot water storage tank.

  FIG. 2 shows a conventional hot water heater. This will be described with reference to the figure.

  As shown in FIG. 2, the heat pump water heater includes a hot water storage tank 8 and a heating source 1 by the heat pump 6. Connected. The heat pump 6 is configured by connecting the compressor 2, the radiator 3, the decompression means 4, and the air heat exchanger 5 in an annular shape.

  In the boiling operation, the high-temperature and high-pressure gas refrigerant pressurized by the compressor 1 of the heat pump 6 is sent to the radiator 3 to exchange heat with the cold water at the bottom of the hot water storage tank 8 conveyed by the boiling pump 7. And becomes a low-temperature refrigerant. Then, the refrigerant radiated to the cold water by the radiator 3 is decompressed by the decompression device 4 and becomes a two-phase refrigerant, which is sent to the air heat exchanger 5 to exchange heat with the atmosphere to become a low-temperature gas refrigerant and circulate to the compressor 2. .

  On the other hand, the cold water at the bottom of the hot water storage tank 8 is conveyed to the radiator 3 by the boiling pump 7, absorbs the heat of the refrigerant, becomes hot water, and is sent to the upper portion of the hot water storage tank 8 through the boiling pipe 9. At this time, the hot water is not mixed with water due to the density difference, and the hot water is stacked from the upper part of the hot water storage tank 8 so that the hot water is accumulated in the hot water storage tank 8.

  The hot water storage temperature detection means 10a, 10b, 10c, 10d detects the amount of hot water, and the incoming water temperature sensor 15 detects the temperature of the water entering the radiator 3. When the hot water storage temperature detecting means 10d or the incoming water temperature sensor 15 becomes equal to or higher than a predetermined temperature, the boiling operation is finished.

  When the temperature of the atmosphere is low, moisture in the atmosphere adheres to the air heat exchanger 5 as frost during the boiling operation, and the heat exchange between the atmosphere and the refrigerant in the air heat exchanger 5 is hindered. The boiling capacity of 6 will decrease. At this time, defrost operation for melting frost is performed.

In the conventional invention, when the temperature detected by the air heat exchanger temperature detecting means 35 is lower than a predetermined value, the temperature detected by the hot water storage temperature detecting means 10d or the incoming water temperature sensor 15 is equal to or higher than the predetermined temperature, and the boiling is finished. When this happens, the defrost operation is forcibly performed (for example, see Patent Document 1).
JP 2001-263800 A

  By the way, in recent years, a water heater that performs direct hot water is desired. According to direct hot water supply, hot water heated by a radiator can be used directly from a hot water supply terminal (for example, Karan), so there is no need to downsize the hot water storage tank or install a hot water storage tank. Space can be saved.

However, in order to perform direct hot water, tap water must be instantaneously raised to a set temperature, and in order to achieve the corresponding heating capacity, the number of rotations of the compressor increases and the air heat exchanger The amount of heat exchange also increases. Furthermore, since direct hot water is discharged every time the user requests hot water, frost formation is likely to occur in the air heat exchanger as compared with a hot water heater as in the prior art.

  And once frosting occurs in the air heat exchanger, it will not be possible to obtain a sufficient amount of heat from the outside, so the heating capacity of the heat pump will be greatly reduced, especially not possible to operate like direct hot water, There was a problem of chronic hot water shortages.

  The purpose of the present invention is to remove all frost formation up to now by forcibly performing defrost operation after the end of direct operation, and to prevent the heat pump from degrading in the next direct operation and to prevent running out of hot water The purpose is to provide a water heater.

  In order to achieve this object, the water heater of the present invention is provided with a defrosting operation means for performing defrosting before the direct operation using the hot water heated by the heat pump is completed and the compressor is stopped.

  Thereby, the capability fall of a heat pump can be prevented in the next direct operation.

  The heat pump water heater of the present invention is provided with defrosting operation means for performing defrosting before the direct operation using the hot water heated by the heat pump is finished and stopping the compressor. It is possible to provide a heat pump water heater that can prevent a decrease in capacity and prevent hot water from running out.

  The first invention is provided with a defrosting operation means for performing a defrosting operation before the direct operation using the hot water heated by the heat pump is finished and stopping the compressor, and the heat pump is used in the next direct operation. It is possible to prevent a decrease in ability.

  The second invention is the first invention in particular, and the operation of the heat pump water heater until the compressor is stopped is a hot water filling operation to the bathtub, and the capacity of the heat pump is reduced in the next direct operation. Can be prevented.

  The third invention is the first invention in particular, and the operation of the heat pump water heater until the compressor is stopped is a hot water supply operation to a faucet or a shower. Decline can be prevented.

  The fourth invention is the first invention in particular, and the operation of the heat pump water heater until the compressor is stopped is a heat radiation operation such as floor heating using hot water, and in the next direct operation, the heat pump It is possible to prevent a decrease in ability.

  According to a fifth aspect of the present invention, in the first to fourth aspects of the invention, the defrosting operation means performs the defrosting operation when the amount of discharged hot water is greater than a predetermined amount according to the amount of discharged hot water in direct operation. The degree of frost can be detected and useless defrosting operation can be avoided.

According to a sixth aspect of the invention, particularly in the first to fourth aspects of the invention, the defrosting operation means performs a defrosting operation when the amount of stored heat is greater than a predetermined amount according to the amount of heat stored in the hot water storage tank. The defrosting operation can be performed only when the danger of running out can be detected and the amount of heat stored in the tank is large and the danger of running out of hot water is low.

  According to a seventh aspect of the present invention, in the first to fourth aspects of the invention, the defrosting operation means performs the defrosting operation when the operation time is longer than a predetermined time according to the operation time until the compressor is stopped. Therefore, the degree of frost formation can be detected and useless defrosting operation can be avoided.

  In an eighth aspect of the invention, in particular, in the first to fourth aspects of the invention, the defrosting operation means performs the defrosting operation according to the outside air temperature when the outside air temperature is lower than a predetermined temperature. Therefore, it is possible to avoid useless defrosting operation.

  According to a ninth aspect of the invention, particularly in the first to fourth aspects of the invention, the defrosting operation means performs the defrosting operation according to the temperature of the evaporator when the temperature of the evaporator is lower than a predetermined temperature. Thus, the degree of frost formation can be detected and useless defrosting operation can be avoided.

  In a tenth aspect of the invention, particularly in the first to ninth aspects of the invention, a refrigerant pumped to a critical pressure or higher is used for the heat pump, and the refrigerant flowing through the radiator is pressurized to a critical pressure or higher by the compressor. Therefore, even if the heat is taken away by the radiator and the temperature falls, it does not condense, and it becomes easy to form a temperature difference between the refrigerant and water in the entire radiator, and the heat exchange efficiency can be increased.

(Embodiment)
Hereinafter, a water heater according to an embodiment will be described with reference to the drawings. FIG. 1 is a circuit diagram of a heat pump water heater in an embodiment of the present invention.

  The outline of the apparatus includes a hot water storage tank 8 in which low-temperature hot water and high-temperature hot water are stored in a layered state, and a heat pump 6 that is a heating source 1 for heating the hot water. The water is heated and boiled and stored for hot water supply.

  First, the configuration of the heat pump 6 that is the heating source 1 will be described. The heat pump 6 includes a compressor 2 that compresses the refrigerant, a radiator 3 that cools the refrigerant, a decompression unit 4 that decompresses the refrigerant, and an air heat exchanger 5 that evaporates and evaporates the refrigerant.

  The heat pump 6 is connected from the discharge side of the compressor 2 to the decompression means 4 via the radiator 3 and further connected to the suction side of the compressor 2.

  Further, in the heat pump 6, carbon dioxide is used as the refrigerant, and the refrigerant compressed by the compressor 2 enters the radiator 3 as a high-temperature and high-pressure supercritical refrigerant, and radiates and cools it here. . Thereafter, the pressure is reduced in the decompression means 4 to become low-temperature and low-pressure wet steam, and the air heat exchanger 5 exchanges heat with the atmosphere to evaporate and return to the compressor 2.

  At this time, the rotational speed of the compressor 2 is determined based on the atmospheric temperature detected by the atmospheric temperature sensor 36, and the continuous operation time is detected by the operation timer 37.

  On the other hand, as a configuration relating to boiling of hot water, the boiling pipe 9 is connected to the radiator 3 of the heat pump 6 from the lower part of the hot water storage tank 8 and is connected to the upper part of the hot water storage tank 8 via the direct mixing valve 41.

  The upper part of the hot water storage tank to which the boiling pipe 9 is connected is sufficient if the hot water is on the high temperature layer side of the hot water storage tank 8, and the lower part of the hot water storage tank 8 is if the hot water is on the low temperature layer side of the hot water storage tank. Good.

In order to send hot water from the hot water storage tank 8 to the heat pump 6 and return it to the hot water storage tank 8, a boiling pipe 9
Is provided with a boiling pump 7 capable of arbitrarily changing the output.

  In addition, an incoming water temperature sensor 15 for detecting the temperature of the low hot water before being heated in the heat pump 6 is raised in the vicinity of the inlet side of the radiator 3 of the boiling pipe 9, and a hot water temperature sensor 16 for detecting the temperature of the heated hot water is raised. The pipe 9 is provided near the outlet of the radiator 3.

  And in order to grasp | ascertain the temperature distribution of the hot water storage tank 8, the hot water storage temperature detection means 10a-10d is provided in the perpendicular | vertical direction to the outer wall surface.

  As a configuration relating to hot water supply, a water supply pipe 19 for supplying water from a water supply source is connected to the bottom of the hot water storage tank 8, and the water supply source is decompressed to an appropriate pressure by a pressure reducing valve 20 and supplied to the water supply pipe 19. In addition, a water supply temperature sensor 18 is provided on the water supply pipe 19 in order to detect the water supply temperature.

  A hot water supply pipe 21 is connected to the upper part of the hot water storage tank 8 for discharging the hot water stored in the hot water and using it for hot water supply, and a water supply bypass pipe 22 from the water supply pipe 19 is connected in the middle thereof. Further, a hot water mixing valve 23 capable of mixing high temperature water from the hot water supply pipe 21 and low hot water from the water supply bypass pipe 22 at an arbitrary ratio is provided.

  A hot water supply temperature sensor 25 is provided on the downstream side of the hot water supply mixing valve 23 to detect the mixed hot water supply temperature, and a hot water supply terminal 24 typified by a faucet or a shower is connected to the tip thereof.

  When a user opens the hot water supply terminal 24 for hot water supply, hot water in the hot water storage tank 8 is first discharged from the hot water supply pipe 21 and supplied from the water supply pipe 19 to the hot water storage tank 8. At the same time, the heat pump 6 is operated and the hot water heated by the radiator 3 of the heat pump 6 and the hot water in the hot water storage tank 8 are mixed by the direct mixing valve 41 and sent to the hot water supply pipe 21. Thereafter, as the temperature detected by the hot water temperature sensor 16 increases, the ratio of hot water discharged from the hot water storage tank 8 is decreased. At this time, the flow rate of hot water passing through the radiator 3 is measured by the flow rate sensor 17.

  For hot water supply, water supply is branched by a water supply bypass pipe 22, and hot water mixed with hot water heated by the hot water storage tank 8 and the radiator 3 and low water from the water supply are mixed at the mixing valve 23 at different mixing ratios. Thus, hot water is supplied to the hot water supply terminal 24 by changing the hot water supply temperature. The mixing ratio at this time is controlled in accordance with the hot water temperature detected by the hot water temperature sensor 25 and is kept at a predetermined hot water temperature.

  As a configuration related to pouring into the bathtub 13, a pouring pipe 28 that branches from the middle of the hot water supply pipe 21 and pours into the bathtub 13 is provided. As with the hot water supply, the heat pump 6 is operated simultaneously with the pouring of the bath 13 and the hot water heated by the radiator 3 of the heat pump 6 and the hot water in the hot water storage tank 8 are mixed by the direct mixing valve 41. It is sent to the hot water supply pipe 21. Thereafter, as the temperature detected by the hot water temperature sensor 16 increases, the ratio of hot water discharged from the hot water storage tank 8 is decreased. At this time, the flow rate of hot water passing through the radiator 3 is measured by the flow rate sensor 17.

  A bath mixing valve 26 is provided so that hot water from the hot water supply pipe 21 and low temperature hot water from the water supply bypass pipe 22 can be mixed and poured, and a pouring temperature sensor 34 is provided downstream thereof.

  The pouring pipe 28 is provided with a pouring electromagnetic valve 27. When the user instructs pouring with a remote controller (not shown), the pouring electromagnetic valve 27 is arbitrarily opened to start pouring automatically, and the bathtub After pouring 13, the pouring solenoid valve 27 is automatically closed and the process ends.

Regarding the circuit configuration of the bath heating operation for heating and keeping hot water in the bathtub 13, the use side circuit 3
1, hot water in the bathtub 13 is circulated to the bath heat exchanger 14 by the use-side pump 12. In addition, a bath water temperature sensor 32 is provided to detect the temperature in the bathtub 13.

  In the heat source side circuit 30, hot water from the upper part of the hot water storage tank 8 is circulated to the bath heat exchanger 14 by the heat source side pump 11, and heat exchange with the low temperature hot water in the use side circuit 31 is performed. After raising the temperature, it circulates to the low temperature part of the hot water storage tank 8.

  A circulating temperature sensor 33 for detecting the temperature of hot water circulated and circulated by the use side pump 11 from the bath heat exchanger 14 and controlling the flow rate of the use side pump 11 is attached.

  Further, in the operation of the heating radiator 39, the heating electromagnetic valve 38 is opened and the direct mixing valve 41 is switched so that hot water does not flow to the boiling pipe 9 side. The heat pump 6 is operated, and the low-temperature hot water in the lower part of the hot water storage tank 8 conveyed by the boiling pump 7 is sent as high-temperature hot water to the heating radiator 39 by the radiator 3.

  The heating radiator 39 radiates heat to the atmosphere, and the hot water that has become low temperature is returned to the low temperature portion of the hot water storage tank 8 again.

  Next, the operation of the defrosting operation, which is an operation for defrosting the frost attached to the air heat exchanger 5, will be described. First, the high-temperature and high-pressure refrigerant discharged from the compressor 2 is sent to the radiator 3. At this time, in order to minimize heat exchange on the water side of the radiator 3, it is necessary to reduce the circulation amount of the boiling pump 7. The refrigerant sent from the radiator 3 to the decompression device 4 reaches the air heat exchanger 5 through the decompression device 4. At this time, in the decompression device 4, it is necessary to adjust the throttle amount appropriately so as not to make the refrigerant as cold and cold as possible. In this manner, the high-temperature refrigerant sent to the air heat exchanger 5 returns to the compressor 2 while exchanging heat with the frost attached to the air heat exchanger 5 to defrost.

  In the compressor 2, the refrigerant is heated again and repeatedly circulated, and all the frost attached to the air heat exchanger 5 is dissolved. At this time, the refrigerant is heated by exchanging heat with the components of the compressor 2 having a high temperature in addition to the temperature rise due to the compression in the compressor 2. In this way, the heating capability of the heat pump 6 can be recovered.

  The timing for performing the defrosting operation will be described. The defrosting operation detecting means 42 performs the defrosting operation after the pouring operation to the bathtub 13 is completed and before the compressor 2 is stopped. To do. Since the defrosting operation is performed at this timing, the refrigerant heated by the compressor 2 is heated by exchanging heat with the components of the compressor 2 having a high temperature in addition to the temperature rise due to the compression by the compressor 2. As a result, defrosting does not occur, and it is possible to prevent a decrease in the capacity of the heat pump in the next direct operation.

  Note that it may be performed at a timing other than the above, for example, after the hot water supply operation to the faucet or shower which is the hot water supply terminal 24 is finished and before the compressor 2 is stopped.

  Further, it may be performed after the heat radiation operation of the heating radiator 39 is finished and before the compressor 2 is stopped.

Further, when the amount of hot water detected by the flow meter 17 is larger than a predetermined amount, for example, when it becomes 2.5 L / min or more, or the heat storage of the hot water storage tank 8 estimated by the temperature detected by the hot water temperature detecting means 10a to 10d. When the amount is larger than a predetermined amount, for example, 50% or more of the maximum hot water storage amount, or when the operation time of the compressor 2 detected by the operation timer 37 is longer than the predetermined time, for example, the operation time of the compressor 2 is 30 minutes or more. Or when the atmospheric temperature detected by the atmospheric temperature sensor 36 is lower than a predetermined temperature, for example, 3 ° C. or lower, or the temperature of the air heat exchanger 5 detected by the air heat exchanger temperature detecting means is higher than the predetermined temperature. The defrosting operation may be performed before the operation of the compressor 2 is stopped by any one or more combinations in a case where the temperature is low, for example, 3 ° C. or lower.

  As described above, since the direct operation using the hot water heated by the heat pump 6 is finished and defrosting is performed before the compressor is stopped, the refrigerant heated by the compressor 2 is the compressor 2. In addition to the temperature rise due to compression, the components of the high-temperature compressor 2 are also heat-exchanged and heated, and defrosting does not occur, preventing the heat pump from degrading in the next direct operation. it can.

  As described above, the water heater according to the present invention is provided with the defrosting operation means for performing defrosting before the direct operation using the hot water heated directly by the heat pump is finished and stopping the compressor. In direct operation, it is useful as a heat pump water heater that can prevent a decrease in the capacity of the heat pump and prevent hot water from running out.

Circuit diagram of a water heater in an embodiment of the present invention Circuit diagram of a conventional water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating source 2 Compressor 5 Air heat exchanger 6 Heat pump 7 Boiling pump 8 Hot water storage tank 13 Bathtub 24 Hot water supply terminal

Claims (10)

The water in the hot water storage tank is heated by the heat pump by circulating water from the bottom of the hot water storage tank by the boiling pump, and the hot water heated by the heat pump is directly used in the hot water storage device that stores the hot water in the hot water storage tank. A heat pump water heater characterized by having a defrosting operation means for performing a defrosting operation before the direct operation is finished and the compressor is stopped. The heat pump water heater according to claim 1, wherein the operation of the heat pump water heater until the compressor is stopped is a hot water filling operation to the bathtub. 2. The heat pump water heater according to claim 1, wherein the operation of the heat pump water heater until the compressor is stopped is a hot water supply operation to a faucet or a shower as a hot water supply terminal. The heat pump water heater according to claim 1, wherein the operation of the heat pump water heater until the compressor is stopped is a heat radiation operation such as floor heating using hot water. The heat pump water heater according to any one of claims 1 to 4, wherein the defrosting operation means performs the defrosting operation when the amount of hot water discharged in the direct operation is larger than a predetermined amount. The heat pump water heater according to any one of claims 1 to 4, wherein the defrosting operation means performs the defrosting operation when the amount of heat stored in the hot water storage tank is larger than a predetermined amount. The heat pump water heater according to any one of claims 1 to 4, wherein the defrosting operation means performs the defrosting operation when the operation time before the stop of the compressor is longer than a predetermined time. The heat pump water heater according to any one of claims 1 to 4, wherein the defrosting operation means performs the defrosting operation when the outside air temperature is lower than a predetermined temperature. 5. The defrosting operation unit according to claim 1, wherein the defrosting operation unit performs the defrosting operation when the temperature of the air heat exchanger that performs heat exchange between the atmosphere and the refrigerant is lower than a predetermined temperature. Heat pump water heater. The heat pump water heater according to claim 1, wherein a refrigerant whose pressure is raised to a critical pressure or higher is used for the heat pump.

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