JP2006292195A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent storage of a lot of hot water of a vague temperature after heat exchange in a lower part of a hot water storage tank when performing the heat exchange between stored hot water and bathtub hot water. <P>SOLUTION: This heat pump water heater has: a primary side bath circulation path 24 connecting an upper part of the hot water storage tank 20 and a lower part of the hot water storage tank 20 through a bath heat exchanger 23; a secondary side heating circulation path 31 connecting a heating heat exchanger 27, a radiator 29 and an auxiliary heat exchanger 30; a flow passage selector valve 32 provided on an outlet side of the bath heat exchanger 23 on the primary side bath circulation path 24; and a bypass path 33 connecting the flow passage selector valve 32 and a lower part of the hot water storage tank 20 through the auxiliary heat exchanger 30. When an outlet hot water temperature of the bath heat exchanger 23 of the primary side bath heat exchange circulation path 24 is higher than a prescribed temperature, excess heat is imparted to the secondary side heating circulation path 31 through the auxiliary heat exchanger of the bypass path 33 to reduce the hot water temperature, and hot water thereof is returned to the lower part of the hot water storage tank 20, by the flow passage selector valve 32. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat pump water heater.

  Conventionally, water in a hot water storage tank is boiled using a heat source such as a heater or a heat pump, and hot water heated to a high temperature is supplied to a heat exchanger provided separately from the hot water storage tank to exchange heat with bathtub water or heating water. In this way, bathing or heating operation is performed, and the hot water after heat exchange is returned to the lower part of the hot water storage tank (see, for example, Patent Document 1).

  FIG. 4 shows a bath-heating hot water supply apparatus using a conventional heat pump described in Patent Document 1 as a heat source. As shown in FIG. 4, 1 is a hot water storage tank, which has a heat pump outlet 2, a heat pump return 3, a heat exchanger outlet 4, and a heat exchanger return 5, and exchanges heat with the heat exchanger outlet 4. A tank circulation circuit A that circulates high-temperature water in the hot water storage tank 1 between the container return ports 5 is formed. 6 is a heat pump unit, 7 is a boiling pump, 8 is a reheating heat exchanger, heat exchange primary inlet 9 for heat exchange of high-temperature water in tank 1, heat exchange primary outlet 10 and heat for heat exchange of bath water It has a secondary exchange inlet 11 and a secondary heat exchange outlet 12, and a bath circulation circuit B is formed via the secondary heat exchange inlet 11 and the secondary heat exchange outlet 12. 13 is a tank circulation pump, 14 is a bath circulation pump, and 15 is a bathtub.

  Conventionally, in the above-described configuration, when boiling hot water in the hot water storage tank 1, the low temperature water in the lower part of the hot water storage tank 1 is heated from the heat pump outlet 2 and sent to the heat pump unit 6 by the pump 7 and converted to high temperature water by the heat pump unit 6. The water was supplied from the upper heat pump return port 3 and gradually heated from the upper part of the hot water tank 1 to the whole tank.

  At the time of bathing, the hot water in the upper part of the hot water storage tank 1 is supplied from the heat exchanger outlet 4 to the heat exchange primary inlet 9 of the heat exchanger 8 by the tank circulation pump 13 and is heat-exchanged to become a low temperature. Hot water is returned from the heat exchange primary outlet to the heat exchanger return port 5 of the hot water storage tank 1, and a high-temperature water circulation circuit in the hot water storage tank 1 is formed on the primary side of the heat exchanger 8. And the hot water of the bathtub 15 is replenished by the bath circulation pump 14 and supplied to the heat exchange secondary inlet 11 of the heat exchanger 8, and heat exchange with the high-temperature water on the primary side is performed to increase the temperature, and the heat exchange secondary outlet. He returned from 12 to the tub 15 and chased away.

And what became the middle temperature water after the heat exchange returned to the hot water storage tank 1 lower part was supplied to the heat pump unit 6, and it boiled up again.
JP-A-9-89369

  However, in the conventional configuration, when the bath is reheated, the hot water in the upper part of the hot water storage tank 1 is supplied from the heat exchanger outlet 4 to the heat exchanger primary inlet 9 of the reheat heat exchanger 8 by the tank circulation pump 13, The hot water that has been exchanged and has reached an intermediate temperature is returned from the heat exchange primary outlet to the heat exchanger return port 5 of the hot water storage tank 1.

  In this case, if the number of revolutions of the tank circulation pump 13 is low and the flow rate is small, the amount of heat exchange to the bath circulation circuit is small, and it takes time to boil, and if the number of revolutions of the tank circulation pump 13 is high and the flow rate is large. The amount of heat exchange to the bath circulation circuit is large, and the boiling time is shortened. However, if the circulation flow rate is increased in order to increase the boiling time, the medium-temperature water that has not been sufficiently heat-exchanged returns to the lower part of the hot water storage tank 1, and the intermediate temperature water is stored in the hot water storage tank 1. It will be.

  When medium temperature water having a relatively high temperature is supplied from the hot water storage tank 1 to the heat pump unit 6, if the temperature of water entering the heat pump unit 6 is high as a characteristic of the heat pump, the efficiency is poor, and thus high efficiency boiling operation cannot be performed. It had the problem that. Moreover, when the temperature of water entering the heat pump unit 6 is further increased (for example, about 60 ° C.), the boiling operation is stopped.

  The present invention solves the above-mentioned conventional problems, and when hot water is reheated, hot water at the top of the hot water storage tank is supplied to the reheating heat exchanger and heat exchange is performed, and when hot water reaches a relatively high intermediate temperature, An object of the present invention is to provide a boiling operation by a highly efficient heat pump by supplying it to the bypass path and returning it to the heat exchanger return port of the hot water storage tank at a relatively low temperature.

  In order to solve the above-mentioned conventional problems, the heat pump water heater of the present invention connects a hot water storage tank, a heating means for heating water in the hot water storage tank, and an upper part of the hot water storage tank from the lower part of the hot water storage tank via the heating means. A boiling path to be connected, a primary side bath circulation path connecting the lower part of the hot water storage tank from the upper part of the hot water storage tank via a bath heat exchanger, and a secondary side bath circulation path connecting the bath heat exchanger and the bathtub The primary side heating circulation path connecting the lower part of the hot water storage tank from the upper part of the hot water storage tank via the heating heat exchanger, and the secondary side heating circulation path connecting the heating heat exchanger, the radiator and the auxiliary heat exchanger And a flow path switching valve provided on the outlet side of the bath heat exchanger on the primary side bath circulation path, and a bypass path connecting the lower part of the hot water storage tank from the flow path switching valve via the auxiliary heat exchanger Is.

  As a result, when the hot water at the top of the hot water storage tank is supplied to the reheating heat exchanger when the bath is reheated and the heat is exchanged and the hot water becomes a relatively high medium temperature, the hot water is supplied to the bypass path to a relatively low temperature. By returning to the heat exchanger return port of the hot water storage tank, boiling operation with a highly efficient heat pump can be performed.

  The heat pump water heater of the present invention supplies hot water to the bypass path when hot water at the top of the hot water storage tank is supplied to the reheating heat exchanger when the bath is reheated, and heat exchange is performed and the warm water becomes a relatively high intermediate temperature, By raising the temperature to a relatively low temperature and returning it to the heat exchanger return port of the hot water storage tank, it is possible to perform a boiling operation with a highly efficient heat pump.

  The first invention includes a hot water storage tank, heating means for heating the water in the hot water storage tank, a heating path connecting the upper part of the hot water storage tank from the lower part of the hot water storage tank via the heating means, and a bath from the upper part of the hot water storage tank The primary side bath circulation path connecting the lower part of the hot water storage tank via the heat exchanger, the secondary side bath circulation path connecting the bath heat exchanger and the bathtub, and the upper part of the hot water storage tank via the heating heat exchanger The primary side heating circulation path connecting the lower part of the hot water storage tank, the secondary side heating circulation path connecting the heating heat exchanger, the radiator and the auxiliary heat exchanger, and the bath heat on the primary side bath circulation path A heat pump water heater comprising a flow path switching valve provided on the outlet side of the exchanger and a bypass path connecting the lower part of the hot water storage tank from the flow path switching valve via an auxiliary heat exchanger.

  As a result, when the hot water at the top of the hot water storage tank is supplied to the reheating heat exchanger when the bath is reheated and the heat is exchanged and the hot water reaches a relatively high intermediate temperature, the hot water is supplied to the bypass path to a relatively low temperature. By returning to the heat exchanger return port of the hot water storage tank, boiling operation with a highly efficient heat pump can be performed.

  In particular, the second invention includes, in the first invention, a primary-side outlet temperature detection unit that detects the temperature of hot water on the outlet side of the bath heat exchanger on the primary-side bath circulation path. When the temperature detected by the temperature detection unit is higher than the predetermined temperature, the flow path switching valve is switched to the auxiliary heat exchanger side. When the temperature detected by the primary outlet temperature detection unit is lower than the predetermined temperature, the flow path switching valve is switched to the hot water storage tank. Switch to the side.

  As a result, the hot water at the top of the hot water storage tank is supplied to the reheating heat exchanger when the bath is reheated, and when the heat is exchanged and the hot water becomes a medium temperature higher than the predetermined temperature, the hot water is supplied to the auxiliary heat exchanger of the bypass path. In addition, when the temperature is set to a relatively low temperature and returned to the heat exchanger return port of the hot water storage tank, a boiling operation by a highly efficient heat pump can be performed.

  In particular, the third invention includes, in the second invention, a secondary side inlet temperature detection unit for detecting the temperature of hot water on the inlet side of the heating heat exchanger on the secondary side heating circulation path, and a primary side outlet. When the temperature detected by the temperature detector is lower than the temperature detected by the secondary inlet temperature detector, the flow path switching valve is switched to the hot water tank side, and the temperature detected by the primary outlet temperature detector is detected by the secondary inlet temperature. When the temperature is higher than the detected temperature by the section, the flow path switching valve is switched to the auxiliary heat exchanger side.

  As a result, it is possible to prevent the hot water temperature on the heating heat exchanger side from being lowered and to perform a boiling operation with a highly efficient heat pump.

  According to a fourth aspect of the invention, in particular, in any one of the first to third aspects of the present invention, an air tank is provided on the secondary side heating circulation path to replenish the fluid circulating in the secondary side heating circulation path. The heat exchanger is provided in the air tank and can be configured with high cost performance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1 shows a diagram of a heat pump water heater in an embodiment of the present invention.

  In FIG. 1, 20 is a hot water storage tank for storing hot water, 21 is a heating means for heating water in the hot water storage tank 20, and 22 is a boiling point connecting the upper part of the hot water storage tank 20 from the lower part of the hot water storage tank 20 via the heating means 21. It is a raising route. The heating means 21 is a heat pump unit using, for example, carbon dioxide as a refrigerant.

  Reference numeral 23 denotes a bath heat exchanger, 24 denotes a primary circulation path connecting the upper part of the hot water storage tank 20 to the lower part of the hot water storage tank 20 via the bath heat exchanger 23, 25 denotes a bathtub, and 26 denotes the bath heat exchanger 23. And a secondary-side bath circulation path to which the bathtub 25 is connected.

  In addition, 27 is a heating heat exchanger, 28 is a primary heating path connecting the upper part of the hot water storage tank 20 to the lower part of the hot water storage tank 20 via the heating heat exchanger 27, 29 is a radiator, and 30 is an auxiliary heat exchanger. , 31 is a secondary side heating circulation path connecting the heating heat exchanger 27, the radiator 29 and the auxiliary heat exchanger 30, and 32 is a flow path switching valve on the primary side bath circulation path 24 of the bath heat exchanger 23. Provided. The radiator 29 is, for example, a floor heating radiator plate or a bathroom drying radiator plate, and can also be used for additional cooking of a bathtub.

  33 is a bypass path connecting the lower part of the hot water storage tank 20 from the flow path switching valve 32 via the auxiliary heat exchanger 30, and 34 is a primary detecting the outlet temperature of the bath heat exchanger 23 of the primary side bath circulation circuit 24. Side outlet temperature detector 35, a secondary side inlet temperature detector 35 for detecting the hot water temperature on the inlet side of the heating heat exchanger 27 on the secondary side heating path 31, and 36 on the secondary side heating circulation path 31, An auxiliary heat exchanger 30 is provided inside the air tank to replenish the circulating liquid. In addition, although the effect that it can implement | achieve at low cost by design can be anticipated by providing the auxiliary heat exchanger 30 in the air tank 36, the auxiliary heat exchanger 30 is on the secondary side heating circulation path 31, and is a heating heat exchanger. 27 may be on the upstream side.

  About the heat pump water heater comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  FIG. 2 shows a processing procedure of the flow path switching valve 32 in the embodiment of the present invention.

  First, the primary side outlet temperature detection part 34 detects the temperature of the hot water (step 201). And a control means (not shown) compares the temperature detected by the primary side outlet temperature detection part 34 detected by step 201, and the preset predetermined temperature (step 202). If the temperature detected by the primary side outlet temperature detection unit 34 is lower than the predetermined temperature, the flow path switching valve 32 is switched to flow to the hot water storage tank side 10 (step 203). If the temperature detected by the primary side outlet temperature detector 34 is higher than the predetermined temperature, the flow path switching valve 32 is switched to flow to the auxiliary heat exchanger side 30 (step 204).

  In this way, by switching the flow path switching valve in accordance with the temperature detected by the primary side outlet temperature detection unit 34, the hot water in the upper part of the hot water storage tank is supplied to the reheating heat exchanger when the bath is reheated, and heat is exchanged. When the hot water reaches an intermediate temperature higher than the predetermined temperature, it is highly efficient by supplying the hot water to the auxiliary heat exchanger in the bypass path and returning it to the heat exchanger return port of the hot water storage tank at a relatively low temperature. Boiling operation with a heat pump can be performed.

  Further, the flow path switching valve 32 may be controlled by a processing procedure as shown in FIG. In FIG. 3, first, the primary side outlet temperature detection unit 34 detects the temperature of hot water (step 301). Next, the secondary side outlet temperature detection part 35 detects the temperature of the hot water (step 302), and the control means (not shown) detects the temperature detected by the primary side outlet temperature detection part 34 detected in step 301, The temperature detected by the secondary side inlet temperature detector 35 detected in step 302 is compared (step 303). If the temperature detected by the primary outlet temperature detector 34 is lower than that of the secondary inlet temperature detector 35, the flow path switching valve 32 is switched to flow to the hot water storage tank 10 (step 304). If the temperature detected by the primary outlet temperature detector 34 is higher than the secondary inlet temperature detector 35, the flow path switching valve 32 is switched to flow to the auxiliary heat exchanger side 30 (step 305). ). Note that either of the processing order of step 301 and step 302 may be performed first.

  In this way, by switching the flow path switching valve based on the temperatures detected by the primary side outlet temperature detection unit and the secondary side inlet temperature detection unit, it is possible to prevent a decrease in the hot water temperature on the heating heat exchanger side. Boiling operation with a high-efficiency heat pump can be performed.

  As described above, the hot water storage type water heater according to the present invention has a low temperature when the temperature returned to the hot water storage tank is suppressed to a predetermined temperature or less and the heat source for heating the hot water in the hot water storage tank is constituted by a heat pump. Since hot water is reheated to hot water, efficient operation is possible, and it can be applied to uses such as using a heat pump directly for heating bath water.

The block diagram of the hot water storage type water heater by one Example of this invention Control flow diagram of the hot water heater Control flow diagram of the hot water heater Configuration of conventional hot water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Hot water storage tank 21 Heating means 22 Boiling path 23 Bath heat exchanger 24 Primary side bath circulation path 26 Secondary side bath circulation path 27 Heating heat exchanger 28 Primary side heating circulation path 29 Radiator 30 Auxiliary heat exchanger 31 Secondary side heating circulation path 32 Flow path switching valve 33 Bypass path 34 Primary side outlet temperature detector 35 Secondary side inlet temperature detector 36 Air tank

Claims (4)

A hot water storage tank, heating means for heating water in the hot water storage tank, a heating path connecting the lower part of the hot water storage tank to the upper part of the hot water storage tank via the heating means, and bath heat from the upper part of the hot water storage tank A primary side bath circulation path connecting the lower part of the hot water storage tank via an exchanger, a secondary side bath circulation path connecting the bath heat exchanger and the bathtub, and a heating heat exchanger from the upper part of the hot water storage tank A primary side heating circulation path that connects the lower part of the hot water storage tank via a heat source, a secondary side heating circulation path that connects the heating heat exchanger, a radiator and an auxiliary heat exchanger, and the primary side bath circulation A heat pump water heater comprising: a flow path switching valve provided on the outlet side of the bath heat exchanger on the path; and a bypass path connecting the lower part of the hot water storage tank from the flow path switching valve via the auxiliary heat exchanger . When a primary side outlet temperature detection unit for detecting the temperature of hot water is provided on the outlet side of the bath heat exchanger on the primary side bath circulation path, and the temperature detected by the primary side outlet temperature detection unit is higher than a predetermined temperature The heat pump water heater according to claim 1, wherein the flow path switching valve is switched to the auxiliary heat exchanger side, and the flow path switching valve is switched to the hot water storage tank side when the temperature detected by the primary side outlet temperature detection unit is lower than a predetermined temperature. A secondary side inlet temperature detection unit for detecting the temperature of hot water is provided on the inlet side of the heating heat exchanger on the secondary side heating circulation path, and the temperature detected by the primary side outlet temperature detection unit is the secondary side inlet temperature detection. The flow path switching valve is switched to the hot water tank side when the temperature is lower than the temperature detected by the section, and the flow path is switched when the temperature detected by the primary side outlet temperature detecting section is higher than the temperature detected by the secondary side inlet temperature detecting section. The heat pump water heater according to claim 2, wherein the valve is switched to the auxiliary heat exchanger side. The air tank which replenishes the fluid which circulates through the said secondary side heating circulation path on a secondary side heating circulation path is provided, and an auxiliary heat exchanger is provided in the said air tank. Heat pump water heater.

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