JP5128267B2 - Heat pump type water heater - Google Patents

Description

  The present invention relates to a heat pump type hot water supply apparatus that uses a refrigeration cycle to heat water and convert it into hot water.

  For example, [Patent Document 1] discloses a heat pump type hot water supply apparatus using a supercritical refrigerant used as a refrigerant in a supercritical state. The present invention relates to a refrigeration cycle in which a compressor, a water / refrigerant heat exchanger (condenser), an internal heat exchanger (cooling unit), an expansion valve, and an air heat exchanger (evaporator) are sequentially communicated via a refrigerant pipe. A circuit (refrigerant circuit) is configured.

  In the above water / refrigerant heat exchanger, heat is exchanged between the high-temperature and high-pressure gas refrigerant discharged from the compressor and the water led to the water pipe connecting the hot water storage tank and the pump to heat the water into hot water. Change. The internal heat exchanger exchanges heat between the high-pressure refrigerant derived from the water / refrigerant heat exchanger and the low-pressure refrigerant derived from the air heat exchanger, and takes superheat.

JP 2003-65616 A

  By the way, the temperature of water entering the water / refrigerant heat exchanger is lower than the outside air temperature, and the temperature of the high-pressure refrigerant derived from the water / refrigerant heat exchanger may be lower than the outside air temperature. At this time, even in the technique of the above [Patent Document 1], the temperature difference between the high-pressure refrigerant derived from the water / refrigerant heat exchanger and the low-pressure refrigerant derived from the air heat exchanger that exchange heat in the internal heat exchanger. Becomes smaller.

  That is, the evaporation temperature of the low-pressure refrigerant in the air heat exchanger is controlled so as to substantially correlate with the outside air temperature. Therefore, when the temperature of the high-pressure refrigerant derived from the water / refrigerant heat exchanger is lower than the outside air temperature, the temperature difference from the low-pressure refrigerant derived from the air heat exchanger becomes small.

  Therefore, if the temperature difference between the high-temperature refrigerant derived from the water / refrigerant heat exchanger and the outside air temperature becomes large, the internal heat exchanger cannot take a sufficient degree of superheat, and the refrigerant will not be liquidated in the compressor. This will cause a compressor failure.

  Conventionally, in such a case, the expansion valve is throttled to lower the evaporation temperature of the low-pressure refrigerant, and the temperature difference from the high-pressure refrigerant derived from the water / refrigerant heat exchanger is increased, so that the refrigerant flows into the compressor. I try not to back.

  However, in the above conventional method, since the pressure of the low-pressure refrigerant sucked into the compressor is lowered, the refrigerant circulation amount is lowered, and the heat exchange amount is lowered, so that the ability is lowered.

  The present invention has been made based on the above circumstances, and the object of the present invention is to divide the water / refrigerant heat exchanger into three parts so that the temperature of water led out from the hot water storage tank is lower than the outside temperature. However, the temperature of the high-pressure refrigerant derived from the water / refrigerant heat exchanger is raised by exchanging heat between the intermediate-temperature refrigerant and water, and the temperature of the low-pressure refrigerant introduced into the internal heat exchanger. It is an object of the present invention to provide a heat pump type hot water supply apparatus that increases the difference, prevents a liquid back of the compressor by taking a sufficient degree of superheat, and always secures a hot water supply capacity to improve reliability.

In order to satisfy the above object, the present invention is connected to a compressor, a water / refrigerant heat exchanger, an expansion device, and an air heat exchanger sequentially through a refrigerant pipe, and is derived from the water / refrigerant heat exchanger. The refrigeration cycle circuit connects an internal heat exchanger that exchanges heat between the high-pressure refrigerant and the low-pressure refrigerant derived from the air heat exchanger, and the pump, water / refrigerant heat exchanger, and hot water storage tank are sequentially passed through the water pipe. The heat pump system is equipped with a water cycle circuit that connects to the water cycle and heats the water led to the water / refrigerant heat exchanger of the water cycle circuit with the heat of condensation generated by the water / refrigerant heat exchanger of the refrigeration cycle circuit to convert it into hot water. It is a water heater.
The water / refrigerant heat exchanger includes a first water / refrigerant heat exchanger located on the upstream side of the refrigerant flow led to the refrigeration cycle circuit, and a first water / refrigerant heat exchanger located on the downstream side of the first water / refrigerant heat exchanger. The water / refrigerant heat exchanger is divided into two, and the refrigerant derived from the first water / refrigerant heat exchanger and before being introduced into the second water / refrigerant heat exchanger in the water cycle circuit It divides | segments into the 3rd water and refrigerant | coolant heat exchanger which heat-exchanges with water.

  According to the present invention, the temperature of the high-pressure refrigerant derived from the water / refrigerant heat exchanger is increased to increase the temperature difference from the temperature of the low-pressure refrigerant introduced to the internal heat exchanger, thereby obtaining a sufficient degree of superheat. Thus, the liquid back of the compressor is prevented, and there is an effect that the hot water supply capacity is always secured and the reliability is improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a piping configuration diagram of a heat pump hot water supply apparatus.
In the figure, reference numeral 1 denotes a compressor. A refrigerant pipe Pa connected to a discharge part a of the compressor 1 includes a first water / refrigerant heat exchanger 2, a first fluid control valve 3, and a second fluid control valve 3. Water / refrigerant heat exchanger 4, internal heat exchanger 5, expansion valve 6 that is an expansion device, air heat exchanger 7 that is an evaporator, internal heat exchanger 5, and suction of compressor 1 The parts b are sequentially connected, and these constitute the refrigeration cycle circuit R.

  As described later, water is introduced into the first water / refrigerant heat exchanger 2 and the second water / refrigerant heat exchanger 4 so that heat can be exchanged with the refrigerant circulating in the refrigeration cycle circuit R. It has been. The first fluid control valve 3 is an on-off valve.

  The internal heat exchanger 5 includes a refrigerant led to a refrigerant pipe Pa that connects the second water / refrigerant heat exchanger 4 and the expansion valve 6, and a refrigerant pipe Pa that connects the air heat exchanger 7 and the compressor 1. It is made to be able to exchange heat with the refrigerant led to

  In the refrigeration cycle circuit R, between the first water / refrigerant heat exchanger 2 and the first fluid control valve 3, and between the first fluid control valve 3 and the second water / refrigerant heat exchanger 4. A bypass pipe Pb is connected between them, and a bypass circuit K is configured. In the bypass pipe Pb of the bypass circuit K, a second fluid control valve 8 and a third water / refrigerant heat exchanger 10 are sequentially provided.

  The second fluid control valve 8 is an on-off valve, and is connected in parallel to the first fluid control valve 3 with respect to the first water / refrigerant heat exchanger 2. As with the first and second water / refrigerant heat exchangers 2 and 4, the third water / refrigerant heat exchanger 10 exchanges heat with the refrigerant guided to the bypass circuit K through which water is introduced as will be described later. Made to be able to.

  Originally, in a heat pump hot water supply apparatus, a water / refrigerant heat exchanger that is a condenser may be provided between the compressor and the expansion valve. The water / refrigerant heat exchanger 2, the second water / refrigerant heat exchanger 4, and the third water / refrigerant heat exchanger 10 are divided. Only the third water / refrigerant heat exchanger 10 is provided in the bypass circuit K.

  Furthermore, a water cycle circuit H is provided. In this water cycle circuit H, the hot water storage tank 12 and the suction part c of the pump 13 are sequentially connected via a water pipe Pc. The water pipe Pc connected to the discharge part d of the pump 13 is branched in two directions, and the first flow control valve 14 and the second flow control valve 15 are connected in parallel to each branch water pipe Pc.

  The water pipe Pc connected to the first flow control valve 14 is configured to guide water to the second water / refrigerant heat exchanger 4 and to exchange heat with the refrigerant guided here. The water pipe Pc connected to the second flow rate control valve 15 is configured to guide water to the third water / refrigerant heat exchanger 10 and to exchange heat with the refrigerant guided here.

  The water pipe Pc on the side where water is led out from the third water / refrigerant heat exchanger 10 is connected to the water pipe Pc on the water introduction side in the second water / refrigerant heat exchanger 4. Therefore, the water led out from the third water / refrigerant heat exchanger 10 via the first flow control valve 14 and the second flow control valve 15 merges with each other to perform the second water / refrigerant heat exchange. It is guided to the container 4.

  The water pipe Pc connected to the water outlet side of the second water / refrigerant heat exchanger 4 is connected to guide water to the first water / refrigerant heat exchanger 2, and the first water / refrigerant heat exchanger 4 2 to the hot water storage tank 12.

  In other words, in the water cycle circuit H, a hot water storage tank 12, a pump 13, and a parallel circuit of a first flow control valve 14 and a second flow control valve 15 are sequentially connected. The first flow control valve 14 is in direct communication with the second water / refrigerant heat exchanger 4, and only the second flow control valve 15 is connected to the second water / refrigerant heat exchanger 10 via the third water / refrigerant heat exchanger 10. It communicates with the heat exchanger 4 and is further connected to the hot water storage tank 12 via the first water / refrigerant heat exchanger 2.

  A water supply pipe Pd that communicates with a water supply source (not shown) is provided at the bottom of the hot water storage tank 12, and a water supply valve 17 that is an open / close valve is connected to the water supply pipe Pd. Connected to the upper end of the hot water storage tank 12 is a hot water supply pipe Pe that communicates with a hot water tap (not shown) provided in a hot water supply location such as a bathroom or a washroom.

  In the heat pump type hot water supply apparatus configured as described above, the compressor 1, the first fluid control valve 3, and the expansion valve 6 constituting the refrigeration cycle circuit R are electrically connected to a control unit (not shown) and are necessary. The control signal is received.

  Furthermore, the second fluid control valve 8 constituting the bypass circuit K, the pump 13 constituting the water cycle circuit H, the first flow control valve 14 and the second flow control valve 15 are also provided with a control unit (not shown). It is electrically connected to receive control signals.

  Further, at least a temperature sensor for detecting the temperature of the high-pressure refrigerant introduced into the internal heat exchanger 5 and a temperature sensor for detecting the temperature of the low-pressure refrigerant introduced into the internal heat exchanger 5 are attached, and these are attached to the control unit. It is necessary to connect electrically and send a detection signal. In addition, a temperature sensor or the like for detecting the temperature of hot water in the hot water storage tank 12 is provided.

Next, a normal water heating operation in the heat pump type hot water heater will be described.
For example, when it is time to apply the late-night electricity charge, the control unit sends a drive signal to the compressor 1 to drive it, and starts the refrigeration cycle operation. At the same time, a drive signal is sent to the pump 13 to drive it, and water circulates in the water circuit H.

  At this time, the control unit sends an opening signal to the first fluid control valve 3 and sends a closing signal to the second fluid control valve 8. Further, a full open signal is sent to the first flow control valve 14 and a full close signal is sent to the second flow control valve 15. Each valve 3, 8, 14, 15 opens and closes according to the control signal from a control part.

  The gas refrigerant compressed by the compressor 1 and subjected to high temperature and pressure is discharged from the discharge part a, and is guided as indicated by solid arrows in the figure. That is, it is led from the compressor 1 to the first water / refrigerant heat exchanger 2 to perform the first-stage condensation, and releases the condensation heat. Then, it is guided to the second water / refrigerant heat exchanger 4 through the opened first fluid control valve 3 to release condensation heat in the second stage of condensation. In this state, the gas refrigerant is changed to a liquid refrigerant.

  The liquid refrigerant derived from the second water / refrigerant heat exchanger 4 is guided to the internal heat exchanger 5 to exchange heat as described later. Furthermore, it is led to the expansion valve 6 to undergo adiabatic expansion, is reduced in pressure, is led to the air heat exchanger 7 and evaporates.

  The low-pressure evaporative refrigerant derived from the air heat exchanger 7 exchanges heat with the high-pressure refrigerant derived from the second water / refrigerant heat exchanger 4 in the internal heat exchanger 5 as described above. . Therefore, the temperature of the low-pressure refrigerant rises to some extent, exits the internal heat exchanger 5 and is sucked into the suction portion b of the compressor 1.

  In an operation under normal conditions (normal operation) in which the temperature of the water guided to the second water / refrigerant heat exchanger 4 is higher than the outside air temperature or the temperature of the water is slightly lower, the second water / refrigerant heat exchanger 4 There is a large temperature difference between the refrigerant temperature of the high-pressure refrigerant introduced into the internal heat exchanger 5 and the refrigerant temperature of the low-pressure refrigerant introduced into the internal heat exchanger 5 from the air heat exchanger 7.

  In this state, since the high-pressure refrigerant and the low-pressure refrigerant exchange heat in the internal heat exchanger 5, the temperature of the low-pressure refrigerant rises. That is, a sufficient degree of superheat is obtained by the internal heat exchanger 5, and the low-pressure refrigerant is sucked into the compressor 1 in a completely evaporated state, thereby preventing liquid back.

  Accordingly, the evaporating pressure and evaporating temperature of the refrigerant in the air heat exchanger 7 are increased, and thus the temperature of the gas refrigerant discharged from the compressor 1 is increased, so that the first water / refrigerant heat exchanger 2 and the first The amount of heat of condensation released in the water / refrigerant heat exchanger 4 is increased.

  In the water cycle circuit H, the water stored in the hot water storage tank 12 as the pump 13 is driven is led to the water pipe Pc as shown by the broken line arrow in the figure. The water is once divided into the first flow control valve 14 and the second flow control valve 15, but only the first flow control valve 14 is fully open, so that all the water is in the second water / refrigerant heat exchange. Guided to vessel 4.

  As described above, in the second water / refrigerant heat exchanger 4, the second stage refrigerant condensation is performed and the heat of condensation is released, and the water absorbs this heat and the temperature rises. Thereafter, the water is led to the first water / refrigerant heat exchanger 2 and absorbs the condensation heat released by the refrigerant condensation in the first stage, and the temperature further rises.

  The water whose temperature has risen is led out from the first water / refrigerant heat exchanger 2 and led to the hot water storage tank 12. While heated water circulates through the water cycle circuit H described above, the temperature rise becomes significant. When the temperature sensor installed in the hot water storage tank 12 detects that the hot water has risen to the set temperature and sends the detection signal to the control unit, the control unit sends an operation stop signal to the compressor 1 and the pump 13.

  When the hot-water tap is opened, hot water having a set temperature stored in the hot water storage tank 12 is guided through the hot water supply pipe Pe. That is, a necessary hot water supply operation can be performed. As hot water in hot water storage tank 12 is supplied, water supply valve 17 is opened and water is replenished to hot water storage tank 12. Therefore, the hot water storage tank 12 is always filled with warm water and a predetermined water pressure is maintained.

  In other words, hot water having a set temperature is supplied from a hot water supply pipe Pe connected to the upper end of the hot water storage tank 12, while water is replenished into the hot water storage tank 12 from a water supply pipe Pd connected to the bottom of the hot water storage tank 12. The Therefore, the ratio of hot water having a set temperature and water to be replenished in the hot water storage tank 12 is very small, and there is no problem in hot water supply.

  In short, the refrigeration cycle circuit R includes the internal heat exchanger 5 to take the degree of superheat of the refrigerant, and includes the first water / refrigerant heat exchanger 2 and the second water / refrigerant heat exchanger 4. By heating the water in stages, the hot water in the hot water storage tank 12 can be raised to the set temperature in a shorter time and supplied to hot water.

  Next, the temperature of the water led to the second water / refrigerant heat exchanger 4 decreases with respect to the outside air temperature, and the temperature of the high-pressure refrigerant led out from the second water / refrigerant heat exchanger 4 changes to the outside air temperature. The temperature difference between the temperature of the high-pressure refrigerant derived from the second water / refrigerant heat exchanger 4 and the temperature of the low-pressure refrigerant derived from the air heat exchanger 7 in the internal heat exchanger 5 is The case where it gets smaller will be described.

  As described above, a sufficient degree of superheat cannot be obtained with the internal heat exchanger unless any countermeasure is taken in such a low temperature condition. As a result, the amount of heat of condensation heat discharged from the water / refrigerant heat exchanger is insufficient, and liquid back to the compressor occurs.

However, in the present invention, the following measures are taken under the above temperature conditions.
FIG. 2 is a diagram for explaining control of the refrigerant and water under the above temperature conditions.
The controller closes the first fluid control valve 3 and performs switching control so as to open the second fluid control valve 8, and both the first flow control valve 14 and the second flow control valve 15 have a predetermined amount. Control to open. Then, the compressor 1 is driven to perform the refrigeration cycle operation, and the pump 13 is driven to circulate water in the water cycle circuit H.

  In the refrigeration cycle circuit R, the gas refrigerant discharged from the compressor 1 is guided to the bypass circuit K via the first water / refrigerant heat exchanger 2 as indicated by a one-dot chain line arrow in FIG. That is, it is led to the third water / refrigerant heat exchanger 10 through the opened second fluid control valve 8 and returns to the refrigeration cycle circuit R after heat exchange.

  The refrigerant is a second water / refrigerant heat exchanger 4-internal heat exchanger 5-expansion valve 6-air heat exchanger 7-internal heat exchanger 5-compressor 1-first water / refrigerant heat exchanger. 2 to the bypass circuit K in this order. Therefore, unlike during normal operation, the refrigerant is once led from the refrigeration cycle circuit R to the bypass circuit K and then returned to the refrigeration cycle circuit R.

  In the water cycle circuit H, water stored in the hot water storage tank 12 is discharged from the pump 13 and further divided according to the opening degrees of the first flow control valve 14 and the second flow control valve 15. The water led out from the first flow control valve 14 is directly led to the second water / refrigerant heat exchanger 4 as in the normal operation described above.

  On the other hand, the water led out from the second flow control valve 15 is led to the third water / refrigerant heat exchanger 10 and the refrigerant led to the third water / refrigerant heat exchanger 10 in the bypass circuit K. Exchange heat with. The condensation heat temperature released by the third water / refrigerant heat exchanger 10 is an intermediate condensation heat temperature between the first water / refrigerant heat exchanger 2 and the second water / refrigerant heat exchanger 4. .

  During normal operation, the temperature of the water discharged from the hot water storage tank 12 and guided to the second water / refrigerant heat exchanger 4 via the pump 13 is the same as the temperature when discharged from the hot water storage tank 12. If this state is applied even under the above temperature condition, the temperature of the high-pressure refrigerant led from the second water / refrigerant heat exchanger 4 to the internal heat exchanger 5 through the first water / refrigerant heat exchanger 2 does not increase. .

  However, by performing the control of FIG. 2, even if the temperature of the water directly led from the first flow control valve 14 is the temperature of the water discharged from the hot water storage tank 12, the second flow control valve 15 The water guided to the third water / refrigerant heat exchanger 10 is heated by the intermediate condensation heat released from the third water / refrigerant heat exchanger 10.

Therefore, the water directly led from the first flow rate control valve 14 and the heated water led from the second flow rate control valve 15 join together, and the temperature of the water led to the second water / refrigerant heat exchanger 4. but, of that higher than during normal operation.
On the other hand, the temperature of the high-pressure refrigerant guided to the second water / refrigerant heat exchanger 4 is lower than that during normal operation. Therefore, the amount of heat exchange between the high-pressure refrigerant and water in the second water / refrigerant heat exchanger 4 is smaller than that during normal operation.
However, the temperature of the high-pressure refrigerant derived from the second water / refrigerant heat exchanger 4 is equal to or lower than the temperature of the water guided to the second water / refrigerant heat exchanger 4 and higher than that during normal operation. There is nothing. As a result, the temperature of the high-pressure refrigerant led out from the second water / refrigerant heat exchanger 4 becomes higher than that during normal operation.
Furthermore, the water that comes out of the second water / refrigerant heat exchanger 4 and is guided to the first water / refrigerant heat exchanger 2 exchanges heat with the refrigerant that is guided to the first water / refrigerant heat exchanger 2. Raise.

  Eventually, the temperature difference between the high-pressure refrigerant derived from the second water / refrigerant heat exchanger 4 and the low-pressure refrigerant derived from the air heat exchanger 7 that exchanges heat in the internal heat exchanger 5 is increased. be able to.

  Thus, even under the above temperature conditions, the temperatures of the high-pressure refrigerant and the low-pressure refrigerant that exchange heat with the internal heat exchanger 5 are increased, and a greater degree of superheat is ensured. Therefore, the liquid back of the refrigerant to the compressor 1 can be prevented, the failure factor of the compressor can be removed, the hot water supply capability can be always secured, and the reliability can be improved.

  FIG. 3 is a diagram schematically showing the temperature enthalpy characteristics, in which the temperature of the refrigerant and water is plotted on the vertical axis, and the enthalpy of the refrigerant is plotted on the horizontal axis. In addition, it is the figure demonstrated easily and does not necessarily represent the value of temperature and enthalpy correctly.

  A line A in the figure shows a change in the refrigerant when the temperature of the high-pressure refrigerant derived from the second water / refrigerant heat exchanger 4 is lower than the outside air temperature and is controlled as shown in FIG. The Aa line is a diagram showing the change of the refrigerant in the normal operation shown in FIG. Similarly, the B line in the figure is a diagram showing the change of water when controlled as shown in FIG. 2, and the Bb line is a diagram showing the change of water in the normal operation shown in FIG. .

  As described above, the temperature of the water guided to the second water / refrigerant heat exchanger 4 decreases, and the temperature difference between the high-pressure refrigerant introduced into the internal heat exchanger 5 and the low-pressure refrigerant becomes a predetermined value or less. In this case, the bypass circuit K is opened to guide the refrigerant to the third water / refrigerant heat exchanger 10, and the water is supplied to the third water / refrigerant heat exchanger 10 via the second flow control valve 15. Conduct heat exchange.

  The water is led in the order of the third water / refrigerant heat exchanger 10 -the second water / refrigerant heat exchanger 4 -the first water / refrigerant heat exchanger 2 as shown by the line B, and the temperature is Ascending straight to the right. The rise in water temperature is the same as that of the conventional configuration, but the enthalpy increases as described later.

Further, the refrigerant is guided in the order of the first water / refrigerant heat exchanger 2 -the third water / refrigerant heat exchanger 10 -the second water / refrigerant heat exchanger 4, as indicated by line A above.
With the above configuration, in the refrigerant change A, the temperature of the refrigerant derived from the second water / refrigerant heat exchanger 4 is increased by β, and the temperature of the refrigerant discharged from the compressor 1 is the refrigerant in the normal operation. It becomes higher by α than the compressor discharge temperature in the change Aa.

  That is, the temperature of the high-pressure refrigerant derived from the second water / refrigerant heat exchanger 4 (the temperature of the high-pressure refrigerant introduced into the internal heat exchanger 5) increases, and the low-pressure refrigerant derived from the air heat exchanger 7 Temperature difference (temperature of the low-pressure refrigerant introduced into the internal heat exchanger 5). As a result, the temperature of the refrigerant sucked into the compressor 1 is increased by heat exchange between the high-pressure refrigerant and the low-pressure refrigerant in the internal heat exchanger 5, and liquid back to the compressor 1 can be prevented.

  At the same time, the evaporating pressure and evaporating temperature of the refrigerant are increased in the air heat exchanger 7, so that the temperature of the refrigerant gas discharged from the compressor 1 is higher by α than the compressor discharging temperature in the refrigerant change Aa in the normal operation. Therefore, it is possible to prevent the amount of heating with respect to water from decreasing.

  In order to detect the temperature of the high-pressure refrigerant introduced into the internal heat exchanger 5 and the temperature of the low-pressure refrigerant, temperature sensors are provided, but the present invention is not limited to this. The temperature of the water led to the water / refrigerant heat exchanger 4 may be detected and estimated from this water temperature. Since the low-pressure refrigerant temperature is substantially the same as the refrigerant evaporation temperature of the air heat exchanger 7, it may be estimated from the outside air temperature.

  In the above embodiment, the refrigerant flow path is switched from the refrigeration cycle circuit R to the bypass circuit K by the first fluid control valve 3 and the second fluid control valve 8, but the present invention is not limited to this. Instead of this, the first fluid control valve 3 and the second fluid control valve 8 may not be used, and the refrigerant may be guided to the third water / refrigerant heat exchanger 10 at all times.

  However, if such a configuration is adopted, depending on the conditions, the temperature of the gas refrigerant discharged from the compressor 1 may become too high, so the refrigerant flow path is switched from the refrigeration cycle circuit R to the bypass circuit K. Is more preferable.

  In addition, the first flow control valve 14 and the second flow control valve 15 are provided to adjust the amount of water led to the third water / refrigerant heat exchanger 10 for fine control. The present invention is not limited, and the first and second flow rate control valves 14 and 15 may not be provided, and the entire amount of water may be always led to the third water / refrigerant heat exchanger 10.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments.

The piping block diagram of the heat pump type water heater based on one embodiment in this invention, and the figure explaining the circulation of the refrigerant | coolant and water at the time of normal operation. The figure explaining the circulation of the refrigerant | coolant and water in the condition where the high pressure refrigerant | coolant temperature of a water / refrigerant heat exchanger exit part is lower than external temperature based on the embodiment. The diagram which represented typically the temperature enthalpy characteristic of the heat pump type water heater of this invention based on the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... 1st water / refrigerant heat exchanger, 4 ... 2nd water / refrigerant heat exchanger, 10 ... 3rd water / refrigerant heat exchanger, 6 ... Expansion valve (expansion apparatus), DESCRIPTION OF SYMBOLS 7 ... Air heat exchanger, Pa ... Refrigerant tube, 5 ... Internal heat exchanger, R ... Refrigeration cycle circuit, 13 ... Pump, 12 ... Hot water storage tank, Pc ... Water pipe, H ... Water cycle circuit, 3 ... 1st fluid Control valve, 8 ... second fluid control valve, Pb ... bypass pipe, K ... bypass circuit.

Claims (2)

A compressor, a water / refrigerant heat exchanger, an expansion device, and an air heat exchanger are sequentially connected via a refrigerant pipe, and the high-pressure refrigerant derived from the water / refrigerant heat exchanger and the air heat exchange. A refrigeration cycle circuit to which an internal heat exchanger for exchanging heat with the low-pressure refrigerant derived from the vessel is connected;
A water cycle circuit in which a pump, the water / refrigerant heat exchanger, and a hot water storage tank are sequentially connected via a water pipe;
In the heat pump type hot water supply apparatus that heats the water led to the water / refrigerant heat exchanger of the water cycle circuit with the heat of condensation generated in the water / refrigerant heat exchanger of the refrigeration cycle circuit and converts it into hot water,
The water / refrigerant heat exchanger is
A first water / refrigerant heat exchanger located upstream of the refrigerant flow led to the refrigeration cycle circuit and a second water / refrigerant heat exchange located downstream of the first water / refrigerant heat exchanger Divided into containers,
Third water / refrigerant heat that exchanges heat between the refrigerant derived from the first water / refrigerant heat exchanger and the water before being introduced into the second water / refrigerant heat exchanger in the water cycle circuit. A heat pump type hot water supply apparatus, which is divided into an exchanger. In the refrigeration cycle circuit, a first fluid control valve is provided between the first water / refrigerant heat exchanger and the second water / refrigerant heat exchanger,
Branched between the first water / refrigerant heat exchanger and the first fluid control valve in the refrigeration cycle circuit, and between the first fluid control valve and the second water / refrigerant heat exchanger. The heat pump type hot water supply apparatus according to claim 1, further comprising a bypass circuit in which a second fluid control valve and the third water / refrigerant heat exchanger are provided in a connected bypass pipe.

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