JPH10103770A - Hot water producing apparatus employing heat pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce high-temperature hot water by efficiently utilizing the temperature rise capability of a condenser portion of a heat pump. SOLUTION: A double pipe part 28 at which water feed pipe 10 for feed water, comprising a finned pipe, is inserted into a condenser 25, and a pipe parallel part 29 in which the condenser 25 and the water feed pipe 10 are paralled with each other in a closely contact state and fixed to each other by soldering, are provided at a portion of the condenser 25 of a heat pump. A superheating region where a high-temperature refrigerant gas is lowered down to a condensation temperature, and a condensing region where a gas content is gradually liquefied by condensation are set at the double pipe part 28, while a supercooling region where the refrigerant gas is supercooled to be all converted into a liquid refrigerant is set at the pipe parallel part 29. The feed water fed into the water feed pipe 10 is first allowed to exchange heat with the liquid refrigerant in the supercooling region at the pipe parallel part 29 and is successively allowed to exchange heat with the refrigerant containining gas in the condensing region and, moreover, in the superheating region at the double pipe part 28, whereby a temperature of the feed water is increased, and hot water is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an apparatus for producing hot water using a heat pump.

[0002]

2. Description of the Related Art For example, when hot water for rinsing used in a dishwasher is obtained, a device for generating and supplying hot water by a heat pump is being developed for practical use. This is because a condenser in a heat pump and a water supply pipe for supplying raw water are disposed in a heat-exchangeable state, and the raw water is heated using the heat discharged when the refrigerant is cooled with the raw water, and the hot water is heated. Generate it. Specifically, it is conceivable to achieve heat exchange with a double pipe structure in which a water supply pipe with fins is inserted in the condenser. Normally, in the process of cooling the refrigerant by the double pipe portion as described above, as shown in FIG. 14, the region where the refrigerant gas from the compressor is sequentially cooled to the condensation temperature from the inlet side of the condenser (overheating) A region), a region where the gas component gradually liquefies due to condensation (condensation region), and a region where all of the gas becomes a liquid refrigerant and is supercooled (subcooling region). The reason for providing the supercooling region is that if the liquid refrigerant is not supercooled, flash gas may be generated due to a slight pressure loss and the function of the expansion valve may be degraded.

[0003]

By the way, in the portion constituting the double pipe portion, a water supply pipe having fins provided on the outer periphery is used as the water supply pipe as described above. When such a finned tube is used, the heat transfer area is large, so it is very effective for heat exchange between liquid and gas, but there is no significant effect between liquid and liquid. There are circumstances. However, in the conventional one, the cooling capacity of the raw water, in other words, the temperature-raising ability of the refrigerant, has a double-pipe structure including the supercooling region in which the liquid refrigerant, which is a liquid, and the raw water exchange heat with each other. It is not fully utilized and the overall heat exchange efficiency is not always good.

[0004] When hot water is generated by a heat pump, it is important to keep the tap water temperature high. Usually, an automatic water supply valve for controlling the water supply amount is provided in the water supply pipe to keep the pressure on the high pressure side of the compressor constant.
As described above, when the heat exchange efficiency in the double pipe section is poor, the automatic water supply valve attempts to circulate more raw water in an attempt to cover the heat exchange efficiency. Then, the flow rate of the raw water increases, and sufficient heat exchange is not performed in the overheating area that is most effective for raising the temperature.
There was a problem that a desired tapping temperature could not be obtained. The present invention has been completed based on the above-described circumstances, and an object of the present invention is to make it possible to generate high-temperature hot water by efficiently utilizing a temperature-raising ability of a condenser part in a heat pump. It is in.

[0005]

According to the present invention, there is provided a heat pump having a refrigeration cycle constituted by connecting a compressor, a condenser, an expansion valve, and an evaporator with piping. In a hot water generating apparatus configured to generate hot water by exchanging heat between a refrigerant flowing through a condenser portion of a heat pump and raw water supplied to a water supply pipe, a superheated region to a condensed region In the area that spans, a double pipe structure with a water supply pipe inserted in the condenser is used, while in the supercooling area of the condenser, a configuration is adopted in which the condenser and the water supply pipe have a parallel pipe structure in parallel It has features.

[0006]

The operation of the present invention is as follows. The raw water supplied to the water supply pipe is first heat-exchanged with the liquid refrigerant in the supercooled area in the pipe parallel part, and then heat-exchanged with the refrigerant containing gas in the condensed area and the superheated area in the double pipe part to rise. It is heated and hot water is produced.

[0007]

That is, according to the present invention, the double-pipe structure excellent in the heat exchange capability between the liquid and the gas is limited to only the superheated region and the condensed region in which the refrigerant gas flows, and the superconducting region in which the liquid refrigerant flows. In the cooling area, a tube parallel structure with excellent heat exchange capacity between liquids is adopted, so that high heat exchange efficiency can be obtained as a whole of the condenser part and high temperature hot water can be generated. Can be

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is applied to a hot water supply part of a dishwasher will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes a dishwasher, on the side of which a hot water generator 20 equipped with a heat pump 21 is installed. First, the structure of the dishwasher 1 will be described. A washing chamber 2 for accommodating tableware through a rack (not shown) is formed in an upper part of the inside thereof. A pair of cleaning nozzles 3 and rinsing nozzles 4 are provided on the lower surface side. On one side of the bottom surface of the cleaning chamber 2, a cleaning tank 6 for storing cleaning water mixed with an alkaline detergent is formed, and the cleaning water stored therein is pumped up by a cleaning pump 7 and the cleaning nozzle 3 described above. Are sprayed toward tableware, and then circulated and supplied to the washing tank 6.

Below the washing tank 6, a hot water storage tank 8 for storing hot water for rinsing is provided. In the hot water storage tank 8, the hot water generator 2
0 is supplied to the hot water supply pipe 1 provided with the hot water supply valve 9.
0 and stored. The stored hot water is pumped up by the rinsing pump 11, is jetted from the rinsing nozzle 4 toward the tableware, and is collected in the washing tank 6. The washing tank 6 is provided with an overflow pipe 13. The overflow pipe 13 takes in the overflowed hot water from the washing tank 6,
The hot water is discharged through a drain pipe 14 into a waste water recovery tank 30 provided in the hot water generator 20. In addition,
The heater 1 is provided in the cleaning tank 6 and the hot water storage tank 8, respectively.
Thermostats 5 and 16 and a thermostat (not shown) are provided so that the temperature of the washing water is maintained at about 60 ° C. and the temperature of the rinsing water is maintained at about 80 ° C.

That is, when the dishes are stored in the washing room 2,
The washing water is sprayed from the washing nozzle 3 to wash the dishes,
Subsequently, hot water is sprayed from the rinsing nozzle 4 to perform rinsing. The waste water that has overflowed without being collected in the washing tank 6 is discharged to the hot water generator 20 to recover waste heat, and the recovered heat is supplied to the raw water such as tap water supplied to the water supply pipe 10. The hot water is generated by the heat exchange with the hot water storage tank 8.

Next, the hot water generator 20 will be described in detail. The hot water generator 20 includes a heat pump 21 and is housed in a box-shaped main body 22. The heat pump 21, as shown in FIG.
The compressor 24, the condenser 25, the expansion valve 26, and the evaporator 27 are circulated and connected to each other.
2) constitutes a refrigeration cycle by being enclosed in a flowable manner.

The compressor 24 is relatively large,
As shown in FIGS. 2 and 3, it is installed on the bottom surface in the main body 22. A hot water recovery tank 30 with a cover plate 31 is provided on a side of the compressor 24. As shown in FIGS. 4 and 5, a pipe-shaped evaporator 27, which is a component of the refrigeration cycle, is spirally wound around the wastewater recovery tank 30 along the inner peripheral surface thereof. The inlet 27a and the outlet 27b are protruded from the upper surface of the cover plate 31 so that the refrigerant pipe 2
1a. A drainage inlet 32 is provided on one side of the drainage recovery tank 30 and is connected to a drainage pipe 14 drawn from an overflow pipe 13 of a washing tank 6 in the dishwasher 1. The hot water overflowing from 6 can be introduced. On the other side, a discharge port 33 for discharging the overflow water of the waste water recovery tank 30 itself is provided, and a drain pipe 34 is connected.

The hot water recovery tank 30 is provided with a propeller-like agitator 36, which is rotatably driven via a shaft 38 by a drive motor 37 provided on the cover plate 31. . A drain valve 40 is provided on the bottom surface of the waste water recovery tank 30. The drain valve 40 is a normally-open type, and opens and closes at the tip of a rod 41 that is freely movable up and down through the cover plate 31, and contacts and separates from the upper surface side of a valve port 42 opened at the bottom surface. The valve body 43 is provided, and the rod 41 is always urged upward by the spring member 44, and the valve body 43 is pulled up as shown by the chain line in FIG. With the excitation force of a solenoid 46 mounted on the bracket 31 via a bracket 45, the valve port 42 is closed by pushing down the rod 41 and the valve body 43 against the urging force as shown by the solid line in FIG. Has become. The drain valve 40 is connected to the above-mentioned drain pipe 34 so as to be joined therewith. In addition, the lid plate 31 of the hot water recovery tank 30 has two watering nozzles 4 for spraying hot water toward the evaporator 27 to wash it.
8 are provided.

The condenser 25 is in the form of a pipe.
As shown in the figure, on the side connected to the high pressure side of the compressor 24,
A double pipe section 28 for heat exchange is formed, and a pipe parallel section 29 for heat exchange is formed when the double pipe section 28 exits from the double pipe section 28 toward the expansion valve 26. As shown in FIG. 7, the double pipe portion 28 has a structure in which a middle part of the water supply pipe 10 for supplying raw water for rinsing water is inserted into a condenser 25 having a large diameter. A part of the water supply pipe 10 is provided with fins 10 for providing a large heat transfer area on the outer periphery.
It is a finned tube provided with a. This double tube part 2
As shown in FIGS. 2 and 3, 8 is stretched around the inside of the two side surfaces of the main body 22 while turning. As shown in FIG. 8, one of the pipe juxtaposed portions 29 is in close contact with the condenser 25 coming out of the outlet of the double pipe portion 28 and the portion of the raw water supply pipe 10 on the front side into the double pipe portion 28. They are arranged in parallel and fixed by solder 29a, covered with a heat insulating cover (not shown), and piped into the main body 22.

As shown in FIG. 9, the condenser 25 has a superheated region where the refrigerant gas from the compressor 24 is cooled down to the condensing temperature in a portion forming the double pipe portion 28, And a condensing region where the liquid gradually liquefies.
At the portion coming out of 8, a supercooling region is set in which all the liquid refrigerant is supercooled. That is, all of the high-temperature refrigerant gas discharged from the compressor 24 is liquefied while flowing through the double pipe section 28 and the pipe parallel section 2
The supercooled liquid refrigerant flows through 9.

The outlet side of the water supply pipe 10 is connected to the hot water storage tank 8 of the dishwasher 1 as described above. The expansion valve 26 is of a temperature type having a temperature-sensitive cylinder 26a (see FIG. 6). The heat pump 2 is provided inside the main body 22.
A control box 49 containing a device for controlling a refrigeration cycle, water supply and drainage, and the like is provided.

Referring to FIG. 6, the refrigeration cycle will be described. A bypass pipe 51 is provided between the high pressure side and the low pressure side of the compressor 24, and a capacity adjusting valve 52 is provided therein. When the heat load (heat source) is insufficient or when there is no heat at the time of initial hot water supply, the capacity adjusting valve 52 bypasses the gas on the high pressure side of the compressor 24 to the low pressure side, and the pressure on the low pressure side is reduced. Functions to prevent excessive reduction. An automatic water supply valve 53 is provided in the water supply pipe 10 at a position protruding from the double pipe section 28. The automatic water supply valve 53 functions to detect the pressure on the high pressure side, adjust the water supply amount accordingly, and keep the pressure on the high pressure side constant. Along with this, it is possible to take out hot water having a substantially constant temperature.

In the water supply pipe 10, a sprinkling hose 55 having a branch valve 54 interposed is connected to the upstream side of the automatic water supply valve 53. The sprinkling hose 55 is connected to the cover plate of the hot water recovery tank 30. It is connected to a watering nozzle 48 provided at 31. The diverting valve 54 is opened when the operation is stopped, thereby discharging the warm water remaining in the double pipe portion 28 and using it for cleaning the evaporator 27, and at the same time, the transient condensation capacity at the time of starting the operation. Works to prevent shortages.
The auxiliary heat exchange unit 58 is configured by closely connecting the refrigerant pipe 21a on the downstream side of the pipe parallel part 29 and the refrigerant pipe 21a on the outlet side of the evaporator 27 in parallel.
The auxiliary heat exchange section 58 heats the low-temperature refrigerant that has passed through the evaporator 27 with the high-temperature liquid refrigerant that has exited from the condenser 25,
In particular, it functions to suppress the occurrence of the liquid return phenomenon to the compressor 24 in the latter half of the operation, and to enhance the heat utilization efficiency.

A receiver 59 is provided on the refrigerant pipe 21a between the portion constituting the auxiliary heat exchange section 58 and the expansion valve 26. The receiver 59 serves to store the liquid refrigerant when the refrigerant is overfilled or when the internal balance is lost and the liquid refrigerant becomes excessive, thereby preventing the liquid refrigerant from staying in the condenser 25. . A refrigerant solenoid valve 60 is interposed between the receiver 59 and the expansion valve 26. The refrigerant solenoid valve 60 is connected to the expansion valve 2 when the operation is stopped.
6 functions to maintain high pressure by preventing high pressure gas from leaking to the low pressure side.

In this embodiment, a control circuit as shown in FIGS. 10 and 11 is provided. In the figure, SW is a push button switch for starting hot water supply, FM is a drive motor of a fan installed in the main body 22 of the hot water generator 20,
CM is a compressor 24 of the heat pump 21. SV is a refrigerant solenoid valve 60, M is a drive motor 37 of the agitator 36, and S is a solenoid 46 of the drain valve 40. Th1 is a protection thermostat provided at the high-pressure side discharge port of the compressor 24, and Th2 is a protection thermostat provided in the compressor 24. The OCR is a compressor 24
An overload relay, PdSW, which opens when the operating current of the compressor becomes an overcurrent, is a pressure switch that opens when the pressure on the high pressure side of the compressor 24 rises abnormally.

The present embodiment has the above structure,
Subsequently, the operation will be described. First, for convenience of explanation, FIG. 1 shows the operation from the case where the washing tank 6 and the hot water storage tank 8 of the dishwasher 1 are full and in a washable state.
2 will be described with reference to the timing chart. First, dishes to be washed are stored in a rack and accommodated in the washing room 2 (rack operation). When the rack operation is completed, a cleaning cycle is started, and a cleaning operation in which the cleaning water in the cleaning tank 6 is pumped up by the cleaning pump 7 and jetted from the cleaning nozzle 3 is performed for several tens of seconds. After a stop time (draining time) of about 5 seconds, a rinsing cycle is subsequently started, and a rinsing operation in which warm water in the hot water storage tank 8 is pumped up by the rinsing pump 11 and jetted out of the rinsing nozzle 4 is performed for 7 seconds. Done to the extent. Thereafter, a stop time of about 5 seconds (similarly, a draining time) is set, whereby one washing step is completed.

In the above, when the rinsing cycle is started, the hot water supply valve 9 is opened by turning off the float switch provided in the hot water storage tank 8, and the compressor 24 is turned on to start the heat pump 21. Get up and running. At the same time, the refrigerant solenoid valve 60 is also opened. In addition, the solenoid 46 provided in the waste water recovery tank 30 is excited to close the normally open drain valve 40, and the agitator 36 is driven to rotate. The hot water overflowing from the washing tank 6 after the start of the rinsing cycle flows into the hot water recovery tank 30 with a slight delay, and the evaporator 27 actually starts absorbing heat only a few seconds later.

In the hot water recovery tank 30, the hot water overflowing from the washing tank 6 of the dishwasher 1 is taken in little by little (taking several tens of seconds). While the waste water is being taken in, the heat pump 21 is fully operated to supply the liquid refrigerant to the evaporator 27, and the waste water is agitated by the stirrer 36 to promote heat exchange and start absorbing heat. Since the time that can be actually absorbed is several tens of seconds, the expansion valve 26 having a relatively large flow rate (refrigeration capacity) is used, and a large amount of refrigerant is supplied immediately after the rise. During the endotherm,
First, the overflow from the washing tank 6 ends, and the waste water recovery tank 30 becomes full. The heat absorption is continued further, but when the refrigerant reaches the evaporator 27 sufficiently, the temperature-sensitive cylinder 26
The expansion valve 26 starts closing when the temperature detected at a decreases. However, since the timing of the flow control of the expansion valve 26 is necessarily delayed, the liquid returns slightly. Therefore, the liquid is prevented from returning by being heated in the auxiliary heat exchange section 58, and the heat utilization efficiency is also improved.

During this time, the raw water of the rinsing water supplied to the water supply pipe 10 is first heat-exchanged with the liquid refrigerant in the supercooling area in the pipe parallel section 29, and then in the double pipe section 28 in the condensing area and the superheating area. The heat is exchanged with the refrigerant containing the gas, and the temperature is raised to generate hot water. Since the double pipe structure has excellent heat exchange capacity between liquid and gas, and the close parallel structure of pipes has excellent heat exchange capacity between liquids,
The heat is exchanged between the refrigerant 9 and the double pipe section 28 in a state in which the heating capacity of the refrigerant is maximized, and high-temperature hot water is generated.

The generated hot water is gradually supplied to the hot water storage tank 8 of the dishwasher 1 through the hot water supply valve 9. When a predetermined amount of hot water is accumulated in the hot water storage tank 8 and the float switch is turned on, the compressor 24 is turned off and the refrigerant solenoid valve 60 is turned off.
Is closed, and the operation of the heat pump 21 is stopped. In addition, the drain valve 40 of the hot water recovery tank 30 is opened, and the agitator 36 is stopped. As a result, the hot water in the hot water recovery tank 30 is discharged. However, since the hot water is discharged as a vortex due to inertial force, it is assumed that foreign matters such as food chips are mixed in the hot water. Is discharged together with the vortex, and there is no possibility that the inside of the tank 30 becomes dirty. When the float switch is turned on, the flow dividing valve 54 is opened for 10 to 15 seconds, and the warm water remaining in the double pipe portion 28 is divided into the watering hose 55 side. The hot water is
Water is sprayed from the water spray nozzle 48 of the waste water recovery tank 30 toward the evaporator 27, and the surface of the evaporator 27 is washed. After that, the hot water from the hot water recovery tank 30 is completely drained, and the dishwasher 1 is ready for rinsing. As described above, the cleaning operation and the generation of warm water are repeatedly performed.

On the other hand, since the dishwasher 1 handles dirt, the washing tank 6 is completely drained every day at the end of work. Therefore, when starting the business every morning, it is necessary to newly supply hot water to the washing tank 6.
This hot water supply is referred to as initial hot water supply, which will be described below with reference to the timing chart of FIG. In this initial hot water supply, hot water must be stored in the washing tank 6 having a large capacity, and since it is difficult to supply a large volume of hot water at a time, the hot water is basically supplied in the following procedure. The hot water generated by the hot water generator 20 is once taken into the hot water storage tank 8, and when the float switch in the hot water storage tank 8 is turned on, the hot water supply valve 9 is closed to perform a rinsing cycle, and the rinsing pump 11 The hot water is pumped up and jetted from the rinsing nozzle 4 and stored in the washing tank 6. This hot water supply cycle is performed by the cleaning tank 6.
This is continued until a water level sensor (not shown) provided in the inside detects the water level. Thereafter, the above-described hot water supply cycle is executed a predetermined number of times, and the initial hot water supply is completed.

The hot water during the initial hot water supply is also generated by operating the heat pump 21 in the same manner.
That is, since there is no heat source, an operation in which the pressure on the low pressure side becomes extremely low or an abnormal operation (vacuum operation or liquid back operation) is performed as it is. Therefore, at the time of initial hot water supply, the refrigerant gas on the high pressure side is bypassed to the low pressure side by the operation of the capacity adjusting valve 52 attached to the compressor 24. Thereby, the pressure on the low pressure side is maintained at a constant value. In practice, this pressure is set to be about 4 kgf / cm 2, and the relatively high-temperature refrigerant gas on the high-pressure side is supplied to the low-pressure side so as to reach the above-mentioned set pressure. On the other hand, the refrigerant leaks from the expansion valve 26 and returns to the compressor 24 side because there is no heat source. Immediately before the suction of the compressor 24, the high-temperature bypass gas and the returned liquid refrigerant are returned to the compressor 24 while being mixed, and this increases the pressure on the lower pressure side,
This is useful for maintaining the pressure on the high pressure side so that the automatic water supply valve 53 is appropriately opened. The above pressure setting value 4Kgf / c
m2 is conscious of the evaporating pressure of the fluorocarbon gas (R-22) at 0 ° C., and even if low-temperature water remains in the waste water recovery tank 30, there is no possibility of freezing.

Returning to the generation of hot water, the heat pump 21 generates hot water every time the rinsing cycle is performed. Usually, for this purpose, the compressor 24 is operated intermittently in response to the operation and stoppage of the heat pump 21, but frequent intermittent operation is performed for the compressor 24 which dislikes operation and stoppage in a short cycle. Leaving it as expected, however, is problematic in terms of quality and reliability. Therefore, in this embodiment, the compressor 24 is continuously operated during the initial hot water supply. However, when the hot water supply valve 9 of the dishwasher 1 is intermittently closed, the water flow to the condenser 25 is cut off on the refrigeration cycle side of the heat pump 21. Therefore, if the compressor 24 is continuously operated, Even for a short time, an abnormal increase in pressure on the high pressure side is caused.

For this reason, as shown in the timing chart of FIG. 13, the refrigerant solenoid valve 60 is controlled to close in synchronization with the closing operation of the hot water supply valve 9, and during that time, the operation is performed only by the bypass refrigerant by the capacity adjusting valve 52. I do. When the refrigerant solenoid valve 60 is closed, the supply amount of the refrigerant to the low-pressure side of the compressor 24 decreases, so that the pressure on the high-pressure side tends to decrease, so that an abnormal increase in the pressure on the high-pressure side is prevented. Of course, if the refrigerant solenoid valve 60 continues to be closed, the pressure on the high pressure side will increase, but since the valve closing time is at most several seconds to several tens of seconds, the pressure on the high pressure side should be effectively reduced as described above. To work. In this way, the initial hot water supply is performed and the hot water is set in a washable state.

As described above, according to the present embodiment,
In the case where the condenser 25 of the heat pump 21 and the raw water supply pipe 10 are arranged so as to be able to exchange heat, the double pipe section 28 having an excellent heat exchange capacity between the liquid and the gas flows the refrigerant gas. Only the superheated region and the condensed region are limited, and in the supercooled region in which only the liquid refrigerant flows, the tube parallel section 29 having excellent heat exchange capability between the liquids is arranged, so that a high heat exchange efficiency as a whole is achieved. And high temperature hot water can be produced. In addition, the length of the double tube portion 28 can be shortened by limiting the double tube portion 28 to the overheating region and the condensation region. Since the double pipe portion 28 requires a higher manufacturing cost than the pipe parallel portion 29 in which two pipes are closely attached to each other by soldering, the entire length of the double pipe portion 28 can be shortened. Can be manufactured at low cost.

<Other Embodiments> The present invention is not limited to the embodiments described above with reference to the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition, various changes can be made without departing from the scope of the invention. (1) In the above-described embodiment, an example in which chlorofluorocarbon gas is used as a refrigerant has been described. However, a heat pump having a refrigeration cycle using another refrigerant may be used. (2) The present invention is not limited to the case where hot water is supplied to a dishwasher, but can be widely applied to all devices that generate hot water using a heat pump.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the overall structure of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the hot water generator as viewed from above.

FIG. 3 is a sectional view seen from the front.

FIG. 4 is a cross-sectional view of the waste water recovery tank as viewed from above.

FIG. 5 is a sectional view seen from the front.

FIG. 6 is a refrigeration cycle diagram of a heat pump.

FIG. 7 is a partially cutaway front view of a double pipe portion.

FIG. 8 is a partially cutaway front view of the tube juxtaposition portion.

FIG. 9 is an explanatory diagram showing a refrigerant state in the condenser.

FIG. 10 is a control circuit diagram of the hot water generator.

FIG. 11 is a control circuit diagram of the dishwasher.

FIG. 12 is a timing chart during a cleaning operation.

FIG. 13 is a timing chart at the time of initial hot water supply.

FIG. 14 is an explanatory diagram showing a refrigerant state in a condenser according to a conventional example.

[Explanation of symbols]

10: Water supply pipe 10a: Fin 20: Hot water generator
DESCRIPTION OF SYMBOLS 21 ... Heat pump 24 ... Compressor 25 ... Condenser 26 ... Expansion valve 27 ... Evaporator 28 ... Double pipe part 29 ... Pipe parallel part

Claims (1)

[Claims] 1. A heat pump comprising a refrigeration cycle by connecting a compressor, a condenser, an expansion valve, and an evaporator with piping, and a refrigerant flowing through a condenser portion of the heat pump and being supplied to a water supply pipe. In a hot water generator configured to generate hot water by exchanging heat with raw water, a double pipe structure in which a water supply pipe is inserted into a condenser is provided in a region from a superheat region to a condensation region in the condenser. On the other hand, in the supercooling region of the condenser, a hot-water generating apparatus using a heat pump, wherein the condenser and the water supply pipe have a parallel tube structure in which the condenser and the water supply pipe are closely arranged in parallel.