JP2005140393A - Hot water storage type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water storage type water heater that stores moderate-temperature water for supplying hot water, reliably utilizes the moderate-temperature water for tapping in hot water supply, and effectively utilizes the amount of heat of hot water storage. <P>SOLUTION: The hot water storage type water heater comprises a high-temperature hot water storage tank 22 for storing high-temperature water heated by a heating source 21; a heat radiating means 27 for radiating heat by circulating high-temperature water stored in the high-temperature hot water storage tank 22; a moderate temperature hot water storage tank 23 for returning moderate water whose temperature is decreased by the radiation of heat by the heat radiating means 27 for storage; and a connecting pipe 29 for connecting the moderate water hot water storage tank 23 to the high-temperature hot water storage tank 22, while a moderate water tapping pipe 34 is provided at the moderate temperature hot water storage tank 23, thus moderate-temperature water stored for supplying hot water can be reliably tapped when supplying hot water and used effectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hot water storage type hot water supply apparatus having a heat radiating means function such as bathing or heating.

  As a conventional hot water storage type hot water supply apparatus of this type, there has been one described in Patent Document 1, for example. FIG. 3 shows a conventional hot water storage type hot water supply apparatus having a bath replenishment function described in Patent Document 1.

As shown in FIG. 4, this hot water supply apparatus includes a hot water storage tank 1, a heating source 2, and a radiator 3, and the hot water in the hot water storage tank 1 heated and stored by the heating source 2 is discharged by the hot water circulation circuit 4. The bath water recirculation operation is performed by heating the water in the bathtub 6 circulated from the bathtub 6 to the radiator 3 by the bathtub water circulation circuit 5 with the heat of the high-temperature water. Then, the medium-temperature water whose temperature has been reduced by heat dissipation in the radiator 3 is returned from the intermediate portion return port 7 in the intermediate portion of the hot water tank 1. In addition, an intermediate hot water discharge pipe 8 is provided in the intermediate part, and hot water in the intermediate part of the hot water tank 1 is discharged.
JP 2002-243275 A

  However, in the above-described conventional configuration, the intermediate temperature water spreads in the hot water tank 1 by the flow generated when the intermediate temperature water after heat dissipation is returned to the hot water tank 1, and the temperature distribution of the hot water tank 1 is deteriorated by mixing with hot water or water. To do. As a result, a mixed layer larger than the amount of medium-temperature water returned to the hot water tank 1 is formed in the vicinity of the intermediate portion return port 7. In addition, the mixed layer spreads from the intermediate return port 7 toward the upper portion of the hot water tank 1 by the flow generated in the hot water tank 1 due to the circulation between the radiator 3 and the hot water tank 1 during the bath reheating operation. It is hot water below the connection position of the intermediate part hot water discharge pipe 8 that can be discharged by the intermediate hot water discharge pipe 8, and the position of the intermediate hot water return pipe 8 and the position in the height direction of the intermediate hot water discharge pipe 8 are substantially the same. The mixed layer above the intermediate hot water discharge pipe 8 is not discharged. Since the temperature of the mixed layer is lowered, it cannot be used for heat dissipation for heating the bath water in the radiator 3, and the amount of stored hot water cannot be used effectively and is wasted. Had problems.

  The present invention solves the above-described conventional problems, and stores hot water for hot water supply, and reliably uses the hot water for hot water supply during hot water supply to effectively use the amount of stored hot water. The purpose is to provide a device.

  In order to solve the above-described conventional problems, the hot water storage type hot water supply apparatus of the present invention includes an intermediate temperature hot water storage tank for returning and storing intermediate temperature water whose temperature has decreased due to heat dissipation by the heat dissipation means, and an intermediate temperature hot water discharge pipe in the intermediate temperature hot water storage tank. Is provided.

  Accordingly, the medium-temperature water can be stored for hot water supply, and the hot water can be reliably discharged at the time of hot water supply and used effectively.

  The hot water storage type hot water supply apparatus of the present invention can effectively use the amount of stored hot water by reliably using medium-temperature water whose temperature has decreased due to heat radiation by the heat radiation means for hot water supply.

  The first invention includes a heating source, a high temperature hot water storage tank for storing high temperature water heated by the heating source, a heat dissipation means for radiating heat by circulating the high temperature water stored in the high temperature hot water storage tank, For hot water supply, it is equipped with a medium temperature hot water tank that returns and stores medium temperature water whose temperature has decreased due to heat dissipation, and a communication pipe that connects the high temperature hot water tank and the medium temperature hot water tank. By storing the medium-temperature water in the hot water supply and reliably using it for hot water supply, the amount of stored hot water can be used effectively.

  In particular, the second invention is provided with a high temperature hot water discharge pipe in the high temperature hot water storage tank of the first invention, and has mixing means for mixing hot water from the high temperature hot water storage tank and the intermediate temperature hot water storage tank. By mixing the hot water from the hot water storage tank with the hot water from the intermediate temperature hot water tank, if the hot water temperature from the intermediate temperature hot water tank is lower than the required hot water temperature, the temperature is raised to the required hot water temperature. Hot water can be supplied.

  In particular, the third invention has a high temperature hot water storage tank and an intermediate temperature hot water storage tank connected in parallel with respect to the hot water, so that the high temperature hot water storage tank and the intermediate temperature hot water storage tank are connected in series. Since the hot water in the tank and the hot water in the intermediate temperature hot water tank can be discharged separately, mixing of the hot water in the high temperature hot water tank and the hot water in the intermediate temperature hot water tank at the time of hot water can be prevented.

  In the fourth invention, in particular, the connection destination of the communication pipe of the first invention is the lower part of the high temperature hot water storage tank, so that the flow from the intermediate temperature hot water storage tank to the high temperature hot water storage tank during heat radiation is low in the high temperature hot water storage tank. Therefore, it is possible to suppress a decrease in the temperature of the high-temperature water stored in the high-temperature hot water storage tank during heat dissipation.

  In the fifth aspect of the invention, in particular, the connection source of the communication pipe of the first aspect of the invention is the lower part of the intermediate temperature hot water storage tank, so that the flow from the intermediate temperature hot water storage tank to the high temperature hot water storage tank during heat radiation is low in the intermediate temperature hot water storage tank. Since it flows out from the lower part, at the time of heat radiation, the amount of heat flowing out from the communication pipe can be suppressed, and the amount of heat can be effectively stored in the intermediate temperature hot water storage tank.

  In the sixth invention, in particular, by storing hot water heated by a heating source in the intermediate temperature hot water storage tank of the first invention, the heat storage density is increased, and the total heat storage amount is increased, or the entire The hot water storage tank capacity can be reduced.

  In the seventh invention, in particular, the high temperature hot water tank and the intermediate temperature hot water tank are connected in parallel to the heating source of the first invention, and the high temperature hot water tank and the intermediate temperature hot water tank can be stored separately. Thus, compared with the case where the high temperature hot water storage tank and the intermediate temperature hot water storage tank are arranged in series, water in the high temperature hot water storage tank and the intermediate temperature hot water storage tank during hot water storage or mixing of hot water can be prevented.

  In the eighth aspect of the invention, in particular, the heat source of the first aspect of the invention is a heat pump, so that heating using atmospheric heat is performed, and hot water is stored with heating energy higher than the input energy. It can be.

  In the ninth aspect of the invention, in particular, the refrigerant circuit of the heat pump of the eighth aspect of the invention is a supercritical refrigerant circuit whose pressure is equal to or higher than the critical pressure, and the refrigerant is heated by heating the water with the refrigerant whose pressure is increased to the critical pressure or higher. Since it is pressurized to a pressure higher than the critical pressure by the compressor, it does not condense even if the temperature is lowered by depriving of heat by heating water. Therefore, it becomes easy to form a temperature difference between the flow path on the refrigerant side and the flow path on the water side over the entire heat exchanger that heats the water with the refrigerant, so that hot water can be obtained and the heat exchange efficiency can be increased.

  In the tenth aspect of the invention, the heating source of the first aspect of the invention is a fuel cell, so that high-temperature water is stored by waste heat generated during power generation and used for heat dissipation and hot water supply, so that the use efficiency of primary energy is high. It can be a device.

  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.

(Embodiment 1)
FIG. 1 is a configuration diagram of a hot water storage type hot water supply apparatus according to a first embodiment of the present invention. First, the basic configuration will be described. A heat pump heat source 21 that collects and heats atmospheric heat as a heating source is provided. The heat pump heat source 21 includes, for example, a compressor 21a, an evaporator 21b, an expansion valve 21c, and a heat exchanger (between water and refrigerant) 21d. The heat pump heat source 21 uses carbon dioxide as a refrigerant. A high temperature hot water storage tank 22 and a medium temperature hot water storage tank 23 for storing high temperature water heated by the heat pump heat source 21 are provided. Water from each lower part is heated by the heat pump heat source 21, and the upper part of each of the high temperature hot water storage tank 22 and the intermediate temperature hot water storage tank 23 is provided. The hot water circulation circuit 24 is connected so as to return. The hot water storage circulation circuit 24 is configured so that the high temperature hot water storage tank 22 and the intermediate temperature hot water storage tank 23 are in parallel with the heat pump heat source 21, and circulation is caused by driving a hot water storage circulation pump 25 provided in the heat pump heat source 21. The hot water storage valve 26 provided downstream of the heat pump heat source 21 can store hot water in the high temperature hot water storage tank 22 and the intermediate temperature hot water storage tank 23 at an arbitrary distribution ratio.

  Then, the upper part of the high-temperature hot water storage tank 22, the bath heating heat exchanger 27, the heat dissipation circulation pump 28, and the upper part of the intermediate temperature hot water storage tank 23 are connected in order so as to supply high-temperature water to the bath-heating heat exchanger 27 as a heat radiating means. The lower part of the high temperature hot water tank 22 and the lower part of the intermediate temperature hot water tank 23 are communicated with each other by a communication pipe 29 to form a heat radiation circuit 30. Further, the bath water circulation circuit 33 is formed by sequentially connecting the bathtub 31, the bath water circulation pump 32, and the bath heating heat exchanger 27 so that the bath water in the bathtub 31 is circulated to the bath heating heat exchanger 27. High temperature water is circulated from the high temperature hot water tank 22 to the bath heating heat exchanger 27 by driving the heat dissipation circulation pump 28, and the bath water in the bathtub 31 is circulated to the bath heating heat exchanger 27 by driving the bath water circulation pump 32. And bath water is heated.

  An intermediate temperature hot water discharge pipe 34 is provided above the intermediate temperature hot water storage tank 23 that heats the bath water and radiates heat to store the intermediate temperature water whose temperature has decreased. Further, a high temperature hot water discharge pipe 35 is also provided at the upper part of the high temperature hot water storage tank 22, and the first hot water mixing valve 36 is configured to be able to mix the hot water from the intermediate hot water hot water discharge pipe 34 and the hot water from the high temperature water hot water discharge pipe 35. The temperature of the hot water from the intermediate temperature hot water discharge pipe 34 can be raised by the hot water from the high temperature water hot water discharge pipe 35. A water supply pipe 37 for supplying tap water is branched and connected to the lower part of the high temperature hot water tank 22 and the lower part of the intermediate temperature hot water tank 23. Further, the hot water mixed with the first hot water mixing valve 36 and the tap water are mixed by the second hot water mixing valve 38 and supplied to the hot water supply terminal 39.

  In the hot water storage type hot water supply apparatus configured as described above, the operation and action thereof will be described first with regard to the bath water heating operation using the heat of the stored hot water. High temperature water stored in the high temperature hot water tank 22 by driving the heat dissipation circulation pump 28 is supplied to the bath heating heat exchanger 27, and at the same time, bath water in the bathtub 31 is supplied to the bath heating heat exchanger 27 by driving the bath water circulation pump 32. By supplying and exchanging heat between hot water and bath water, the bath water is heated and circulated through the bathtub 31 to increase the temperature of the bath water in the bathtub 31. The high-temperature water becomes medium-temperature water whose temperature has been reduced due to heat dissipation. Since this medium-temperature water is returned to the medium-temperature water hot water storage tank 23 provided separately from the high-temperature water storage tank 22, the temperature of the high-temperature water in the high-temperature water storage tank 22 is increased by the medium-temperature water. The heat can be dissipated by the bath heating heat exchanger without reducing the temperature, and the bath water heating operation can be continued while maintaining the heating capacity.

  About circulation at the time of bath water heating operation, the hot water is taken out from the upper part of the high temperature hot water tank 22 and the connection pipe 29 is connected to the lower part of the high temperature hot water tank 22, so that the intermediate temperature hot water tank 23 is transferred to the high temperature hot water tank 22. Therefore, the high-temperature water is taken out from the top of the high-temperature hot water tank 22 in order without lowering the temperature of the high-temperature water stored in the high-temperature hot water tank 22 by the circulation flow. Can be used for bath water heating. Further, by returning the intermediate temperature water to the upper part of the intermediate temperature hot water storage tank 23 and connecting the communication pipe to the lower part of the intermediate temperature hot water storage tank 23, the flow from the intermediate temperature hot water storage tank 23 to the high temperature hot water storage tank 22 is low in the intermediate temperature hot water storage tank 23. Since it flows out from the lower part, the intermediate temperature hot water can be effectively stored in the intermediate temperature hot water storage tank 23 without lowering the temperature of the intermediate temperature water until the intermediate temperature hot water storage tank 23 is filled with the intermediate temperature water.

  When hot water is supplied, hot water is discharged from the intermediate hot water at the upper portion of the intermediate temperature hot water storage tank 23 provided by the intermediate hot water discharge pipe 34. By connecting the high temperature hot water storage tank 22 and the intermediate temperature hot water storage tank 23 in parallel with respect to the hot water supply, the hot water can be discharged without mixing the hot water or hot water in the high temperature hot water storage tank 22 and the intermediate temperature hot water storage tank 23, and the intermediate temperature hot water discharge pipe 34 and the heat radiation. Since both the positions of the return of the intermediate temperature water in the circulation circuit 30 are the upper part of the intermediate temperature hot water storage tank 23, the intermediate temperature water stored in order from the upper part of the intermediate temperature hot water storage tank 23 is reliably discharged from the intermediate temperature hot water discharge pipe 34 for hot water supply. It is possible to do. At this time, the hot water from the intermediate temperature hot water discharge pipe 34 and the tap water from the water supply pipe 37 are mixed by the second hot water mixing valve 38 to supply hot water at a temperature required by the hot water supply terminal 39. If the hot water temperature from the intermediate temperature hot water storage tank 23 is lower than the required hot water supply temperature, the temperature is raised at the first hot water mixing valve by hot water from the high temperature hot water hot water pipe 35 provided at the upper part of the high temperature hot water storage tank 22. In this way, it is necessary depending on the type of load, such as hot water for hot water supply load that requires heat capacity, mainly hot water for hot water supply load that has no problem even if the temperature level is low The hot water stored in hot water can be used effectively.

  After using the heat stored in the bath water and the hot water supply, the water in the hot water tank is heated by the heat pump heat source 21 in the late-night time when the electricity charge is low for the next day to store the hot water. The high temperature hot water tank 22 and the intermediate temperature hot water tank 23 are connected in parallel, and the high temperature hot water tank 22 and the intermediate temperature hot water tank 23 can be stored separately, so that the high temperature hot water tank and the intermediate temperature hot water tank can be stored by the circulation flow during hot water storage. The hot water storage tank 22 and the intermediate temperature hot water storage tank 23 can have different hot water storage temperatures, or only the high temperature hot water storage tank 22 can store hot water. In addition, hot water storage operation is basically performed at midnight hours, but when the amount of hot water storage decreases when using a hot water supply device such as during the daytime, additional hot water storage operation is performed each time. It corresponds also to. At that time, when high-temperature water necessary for bath water heating is required, hot water is stored in the high-temperature hot water storage tank 22 at a high temperature, and when a hot water supply load is suddenly required, the hot-water storage temperature is lowered to reduce the hot water storage temperature. The hot water storage operation is performed in which the heating capacity of the heat pump heat source 21 is ensured as much as possible without reducing the hot water storage temperature of the high temperature hot water storage tank 22. In addition, when it is known that the required load increases in winter or the like, the heat storage amount is increased by setting the hot water storage temperature of the intermediate temperature hot water storage tank 23 to the same high temperature as the hot water storage temperature of the high temperature hot water storage tank 22. It can also handle the load.

  Since the refrigerant used in the heat pump heat source 21 is carbon dioxide and the water is heated by the refrigerant whose pressure is increased to a critical pressure or higher, the refrigerant is pressurized to the critical pressure or higher by the compressor. Condensation does not occur even if the temperature drops due to heat deprivation. Therefore, it becomes easy to form a temperature difference between the flow path on the refrigerant side and the flow path on the water side over the entire heat exchanger that heats the water with the refrigerant, so that hot water can be obtained and the heat exchange efficiency can be increased.

  In the hot water storage operation, the heat pump heat source 21 is an efficient heat source capable of heating with an amount of heat equal to or greater than the input energy because the heat pump 21 is heated by input energy and heat collected from the atmosphere. However, when the temperature of the incoming water to the heat pump heat source 21 rises due to the influence of operating conditions, the COP, which is the ratio between the input energy and the heating capacity, falls. That is, when the same amount of heat is heated and boiled, the COP is lower when boiling from medium-temperature water than when boiling from water. However, since most of the medium-temperature water generated by the bath water heating operation is used by the hot water at the time of hot water supply, the amount of boiling the medium-temperature water is small, and an efficient hot water storage operation can be performed.

  The configuration is not limited to this embodiment, and any configuration that can obtain the same effect may be used. For example, the same effect can be obtained by using a bath heating heat exchanger 27 as a heat radiating means as a floor heating panel that directly circulates high-temperature water in the high-temperature hot water tank 22. Moreover, since it has two tanks, the hot water hot water storage tank 22 and the intermediate hot water storage tank 23, the positional relationship between the two tanks can be freely set, and depending on the installation location, the two tanks can be installed separately. It is also possible to install using the limited space effectively.

(Embodiment 2)
FIG. 2 is a configuration diagram of a hot water storage type hot water supply apparatus according to the second embodiment of the present invention. The basic configuration is the same as that of the first embodiment shown in FIG. 1. Basically, the same reference numerals indicate the same members and have the same functions, so detailed description will be omitted, and different points will be mainly described. To do.

  First, differences from the first embodiment in the basic configuration will be described. Waste heat generated during power generation of the fuel cell 40 is used as a heat source. The fuel cell 40 includes, for example, a stack 40a, an air supply device 40b, a fuel reforming device 40c, an inverter 40d, and a waste heat recovery heat exchanger 40e.

  Further, a heating heat exchanger 41 is provided as a heat radiating means, and heating heat is generated by an antifreeze liquid circulation circuit 43 so that the antifreeze liquid heated by the heating heat exchanger 41 is supplied to a heating indoor unit 42 that heats the room with warm air. The exchanger 41, the heating indoor unit 42, the antifreeze circulating pump 44, and the heating heat exchanger 41 are connected in order so as to return.

  Next, in the hot water storage type hot water supply apparatus configured as described above, its operation and action will be described mainly with respect to different points. First, in the heating operation, the antifreeze liquid circulating circuit 43 is circulated by driving the antifreeze liquid circulation pump 44, and the antifreeze liquid is heated with high-temperature water. Then, the antifreeze liquid is sent to the indoor unit 42 for heating, where heat exchange is performed with indoor air to perform heating operation as warm air.

  Further, waste heat generated during power generation of the fuel cell 40 is used as a heat source, and hot water heated by the waste heat is stored in the high-temperature hot water tank 22 or the intermediate temperature hot water tank 23. The waste heat at this time is cooled by cold water when viewed from the fuel cell 40 side. The cooling at this time has a higher cooling efficiency as the temperature of the supplied water is lower, and the cooling itself becomes difficult as the temperature increases. Since most of the medium-temperature water generated by the heating operation by the hot water supply at the time of hot water supply is used, the amount of medium-temperature water supplied as cooling water to the fuel cell 40 when the hot water is stored in the high temperature hot water tank 22 or the intermediate temperature hot water tank 23 is Therefore, the cooling and hot water storage operation of the fuel cell 40 can be performed efficiently at the same time.

  As described above, the hot water storage type hot water supply apparatus according to the present invention can store hot water heated by a heat source and can effectively use it depending on the temperature level to be used, so the stored heat can be efficiently used. Can be used. In addition to the purpose of use in the home mentioned in the embodiment, such a configuration is large-scale, for example, performing thermal power generation and utilizing the waste heat for various purposes such as hot water supply, heating, and a hot water pool. The same applies to the system.

Configuration diagram of heat pump device in Embodiment 1 of the present invention The block diagram of the heat pump apparatus in Embodiment 2 of this invention Configuration diagram of a conventional heat pump device

Explanation of symbols

21 Heat pump heat source (heating source)
22 High temperature hot water tank 23 Medium temperature hot water tank 27 Bath heating heat exchanger (heat dissipation means)
29 Communication pipe 34 Medium hot water hot water pipe 35 High temperature water hot water pipe 36 First hot water mixing valve (mixing means)
40 Fuel cell (heating source)
41 Heating heat exchanger (heat dissipation means)

Claims (10)

A heat source, a high temperature hot water storage tank for storing hot water heated by the heating source, a heat radiating means for radiating heat by circulating the high temperature water stored in the high temperature hot water storage tank, and a temperature by heat dissipation in the heat radiating means A hot water storage type hot water supply apparatus comprising: a medium temperature hot water tank that returns and stores medium temperature water that has decreased, and a communication pipe that communicates from the medium temperature hot water tank to the high temperature hot water tank, and the medium temperature hot water tank is provided with a medium temperature hot water discharge pipe. The hot water storage hot water supply apparatus according to claim 1, further comprising a mixing means for providing a high temperature hot water discharge pipe in the high temperature hot water storage tank and mixing hot water from the high temperature hot water storage tank and the intermediate temperature hot water storage tank. The hot water storage type hot water supply apparatus according to claim 2, wherein the high temperature hot water storage tank and the intermediate temperature hot water storage tank are connected in parallel with respect to hot water. The hot water storage type hot water supply apparatus according to any one of claims 1 to 3, wherein a connection destination of the communication pipe is a lower part of the high temperature hot water storage tank. The hot water storage type hot water supply apparatus according to any one of claims 1 to 4, wherein a connection source of the communication pipe is a lower part of the intermediate temperature hot water storage tank. The hot water storage type hot water supply apparatus according to any one of claims 1 to 5, wherein hot water heated by a heating source is stored in an intermediate temperature hot water storage tank. The hot water storage device according to any one of claims 1 to 6, wherein the high temperature hot water storage tank and the intermediate temperature hot water storage tank are connected in parallel to the heating source, respectively, so that the high temperature hot water storage tank and the intermediate temperature hot water storage tank can be stored separately. Water heater. The hot water storage type hot water supply apparatus according to any one of claims 1 to 7, wherein the heat source is a heat pump. The hot water storage type hot water supply apparatus according to claim 8, wherein the refrigerant circuit of the heat pump is a supercritical refrigerant circuit whose pressure becomes equal to or higher than a critical pressure, and water is heated by the refrigerant whose pressure is increased to the critical pressure or higher. The hot water storage type hot water supply apparatus according to any one of claims 1 to 7, wherein the heating source is a fuel cell.

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