JP2005076932A - Storage type hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage type hot water supply system that can effectively reuse the heat energy of the last bath by a simple system structure. <P>SOLUTION: The storage type hot water supply system comprises a water storage tank 1 for storing hot water heated by a heater 6, a bathtub 20 supplied with the hot water stored in the water storage tank 1, a first heat exchanger 4 disposed in the water storage tank 1 to recover heat of the hot water in the bathtub 20 and heat the hot water in the water storage tank 1 with the heat, and a second heat exchanger 5 disposed in the water storage tank 1 to recover heat of the hot water in the water storage tank 1 and heat the hot water in the bathtub 20 with the heat. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hot water storage type hot water supply apparatus including a hot water storage tank for storing hot water to be supplied in a bathtub.

  In recent years, from the viewpoint of energy conservation, hot water storage water heaters that use night discount power to boil hot water at night, store the boiled hot water in a hot water storage tank, and supply hot water to the kitchen, bath, washroom, etc. as needed I am doing. In such a hot water storage type hot water supply apparatus, various devices are used as a heat source, and an electric water heater using an electric heater, a gas water heater using a gas water heater, a heat pump type water heater using a heat pump circuit, and the like are known. It has been.

  Conventionally, hot water filled in a bathtub is generally drained after bathing. There is no exception in the hot water storage hot water supply system, and the bath water after bathing was drained as sewage. Thus, the thermal energy remaining in the bath water after bathing is discarded as it is, and was wasted from the viewpoint of effective use of energy.

  However, in recent years, in hot water storage type hot water supply apparatuses, it has been studied to reuse waste heat of hot water supplied to a bathtub. For example, in a heat pump type hot water supply machine, heat from unneeded hot water is exchanged with refrigerant flowing in the heat pump circuit, so that the heat of the hot water is recovered by the refrigerant and used to boil hot water stored in a hot water storage tank. A method of reusing is known (see, for example, Japanese Patent Laid-Open No. 5-26512 (Patent Document 1), Japanese Utility Model Publication No. 58-9680 (Patent Document 2), etc.).

  If constituted in this way, it can be an excellent hot water supply apparatus from the viewpoint of energy saving, but it is necessary to provide a water-refrigerant heat exchanger separately from the heat pump circuit, so that the apparatus configuration becomes complicated and manufactured. There was a problem that the cost increased.

Conventionally, when the hot water filled in the bathtub is hotter than necessary, it is adjusted to lower the hot water temperature by pouring water adjusted to a low temperature (usually about 30 ° C). Was common. However, when such a method is adopted, as a result, water is wasted to lower the hot water temperature, which is not preferable from the viewpoint of effective use of resources.
Japanese Patent Laid-Open No. 5-26512 Japanese Utility Model Publication No. 58-9680

  The problem to be solved by the present invention is that the thermal energy and water for hot water possessed by Suiyu are wasted. Therefore, an object of the present invention is to provide a hot water storage type hot water supply apparatus capable of effectively reusing the thermal energy of a mai hot water with a simple apparatus configuration. It is another object of the present invention to provide a hot water storage type hot water supply apparatus that can optimize the hot water temperature without wasting water when hot water filled in the bathtub is hotter than necessary.

  A hot water storage type hot water supply apparatus according to the present invention includes a hot water storage tank for storing hot water heated by a heat source, a bathtub to which hot water stored in the hot water storage tank is supplied, a hot water storage tank, and the hot water in the bathtub. And a first heat exchanger that uses the heat to heat the hot water in the hot water storage tank.

  In the hot water storage type hot water supply apparatus according to the present invention, the second heat exchanger provided in the hot water storage tank recovers the heat of the hot water in the hot water storage tank and uses the heat to heat the hot water in the bathtub. Furthermore, it is preferable to provide.

  In the hot water storage type hot water supply apparatus according to the present invention, the first and second heat exchangers are preferably provided inside the hot water storage tank. In this case, the first heat exchanger is preferably positioned below the second heat exchanger in the hot water storage tank.

  The hot water storage type hot water supply apparatus according to the present invention includes first temperature detection means for detecting the temperature of hot water located in the vicinity of the first heat exchanger among hot water stored in the hot water storage tank, and hot water filling in the bathtub. It is preferable to include a second temperature detecting means for detecting the hot water temperature of the hot water. Then, the hot water temperature detected by the first temperature detecting means is compared with the hot water temperature detected by the second temperature detecting means, and the hot water temperature detected by the second temperature detecting means is used as the first temperature detecting means. When the temperature is higher than the detected hot water temperature, it is preferable to further include a control means for controlling the heat exchange by the first heat exchanger.

  In the hot water storage type hot water supply apparatus according to the present invention, the control means makes a predetermined temperature difference between the hot water temperature detected by the first temperature detection means and the hot water temperature detected by the second temperature detection means. Until it becomes, it is preferable to control to perform heat exchange by the first heat exchanger.

  By setting it as the hot water storage type hot water supply apparatus based on this invention, it becomes possible to recycle | reuse the thermal energy of a unyu hot water effectively with a simple apparatus structure. Moreover, by using the hot water storage type hot water supply apparatus according to the present invention, when the hot water filled in the bathtub is hotter than necessary, the hot water temperature can be optimized without wasting water.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a piping system diagram showing a configuration of a hot water storage type hot water supply apparatus according to an embodiment of the present invention. The hot water storage type hot water supply apparatus shown in FIG. 1 is an electric hot water supply type hot water storage type hot water supply apparatus using an electric heater as a heat source.

(Device configuration of hot water storage type water heater)
As shown in FIG. 1, the hot water storage type hot water supply apparatus in the present embodiment mainly includes a hot water storage tank 1, a first heat exchanger 4, a second heat exchanger 5, a bathtub 20, and a pipe connecting them. It consists of a system.

  The hot water storage tank 1 is a water storage tank having a predetermined internal volume, and has a hot water supply port 2 on the upper surface of the tank portion and a water supply port 3 on the lower surface of the tank portion. A heater 6 that heats the water stored in the hot water storage tank 1 is disposed at a lower portion of the hot water storage tank 1.

  A water supply port 3 of the hot water storage tank 1 is connected to a pressure reducing check valve 8 and a water stop cock 7 through a pipe. The stop cock 7 is connected to the water supply. By the action of the pressure reducing check valve 8, the water pressure supplied from the water supply port 3 to the hot water storage tank 1 is adjusted to be lower than the normal tap water pressure (about 170 kPa). A safety valve 25 is attached to the pipe extending from the water supply port 3 side of the hot water storage tank 1. The safety valve 25 is a valve for releasing the pressure in the hot water storage tank 1 when the pressure in the hot water storage tank 1 rises abnormally.

  The hot water supply port 2 of the hot water storage tank 1 is connected to a hot water supply mixing valve 9 and a hot water filling mixing valve 10 via a pipe. The hot water supply mixing valve 9 and the hot water filling mixing valve 10 connected to the piping on the hot water supply port 2 side are also connected to the piping on the water supply port 3 side. A relief valve 24 is attached to the pipe extending from the hot water supply port 2 side of the hot water storage tank 1. The relief valve 24 is a valve for releasing the pressure in the hot water storage tank 1 when the pressure in the hot water storage tank 1 rises.

  The hot water mixing valve 9 is a valve that mixes hot water flowing from the hot water supply port 2 of the hot water storage tank 1 and low temperature water flowing from the pressure reducing check valve 8. On the other hand, the hot water filling mixing valve 10 is a valve that mixes hot water flowing from the hot water supply port of the hot water storage tank 1 and cold water flowing from the pressure reducing check valve 8 during hot water filling.

  The hot water filling mixing valve 10 is connected to a first three-way valve 14 via an electromagnetic valve 11, a flow sensor 12 and a check valve 13. The first three-way valve 14 is connected to the second three-way valve 17 via the circulation pump 15 and the flow switch 16. The second three-way valve 17 is connected to the third three-way valve 18 via the first heat exchanger 4 and the second heat exchanger 5 connected in parallel. The third three-way valve 18 is connected to a hot water supply device 21 provided on the side wall of the bathtub 20 via the forward pipe 19. The water heater 21 is also connected to the first three-way valve 14 via a return pipe 22.

  The first heat exchanger 4 is provided at the lower part of the tank inside the hot water storage tank 1. The second heat exchanger 5 is provided in the upper part of the tank inside the hot water storage tank 1. That is, the first heat exchanger 4 is located below the second heat exchanger 5 in the hot water storage tank 1.

  A first temperature sensor 1a serving as a first temperature detecting means for detecting the temperature of the hot water stored in the hot water storage tank 1 is installed on the surface of the tank portion where the first heat exchanger 4 of the hot water storage tank 1 is provided. ing. The hot water supply 21 provided on the side wall of the bathtub 20 is provided with a second temperature sensor 20a as a second temperature detecting means for detecting the temperature of the hot water in the bathtub 20. A pressure sensor 23 is attached to the return pipe 22.

  A drain port 26 is provided on the bottom surface of the bathtub 20. The drain 26 is connected to the sewer, and the bath water after bathing is discarded into the sewer through the drain 26.

  Although not shown, the circulation pump 15, the second three-way valve 17, the third three-way valve 18, the first temperature sensor 1a, the second temperature sensor 20a, and the like are connected to a control device as a control means. Yes. The operation of each element is controlled by this control device, and temperature information detected by each element is input to the control device.

(Operation of hot water storage type hot water supply system)
Below, the operation | movement in the hot water storage type hot water supply apparatus of the said structure is divided and demonstrated for every operation mode.

(A. Water heater operation)
In the hot water storage type hot water supply apparatus having the above-described configuration, the hot water is heated using the night discount power. The hot water stored in the hot water storage tank 1 is used for hot water supply during the daytime, and the hot water storage tank 1 is pressurized by tap water pressure and filled with low temperature water. This low-temperature water is heated to a predetermined temperature (for example, about 65 ° C. to 85 ° C.) by the heater 6 provided in the hot water storage tank 1 at night. The heated hot water is kept warm until daytime and supplied for hot water supply.

(B. Hot water supply operation)
In the hot water storage type hot water supply apparatus configured as described above, hot water is supplied to a kitchen, a washroom, or the like using high-temperature hot water stored in the hot water storage tank 1. Specifically, high temperature hot water supplied from the hot water storage tank 1 through the hot water supply port 2 and low temperature tap water supplied from the pressure reducing check valve 8 are mixed in the hot water mixing valve 9 to obtain an appropriate temperature ( For example, the temperature is adjusted to 30 ° C. to 48 ° C., 50 ° C., 60 °, etc.) and supplied to a kitchen or a washroom.

(C. Hot water filling operation)
In the hot water storage type hot water supply apparatus having the above configuration, hot water filling of the bathtub 20 is performed using high temperature hot water stored in the hot water storage tank 1. Specifically, high temperature hot water supplied from the hot water storage tank 1 through the hot water inlet 2 and low temperature tap water supplied from the pressure reducing check valve 8 are mixed in the hot water filling mixing valve 10 to obtain an appropriate temperature. (For example, from 30 ° C. to 48 ° C.) The adjusted hot water is supplied into the bathtub 20 via the solenoid valve 11, the flow sensor 12, the check valve 13, the first three-way valve 14, the return pipe 22, and the water heater 21. To supply. Usually, this hot water filling operation is often configured to be performed fully automatically, and the hot water storage type hot water supply apparatus in the present embodiment also detects the hot water filling amount using the flow rate sensor 12 and the pressure sensor 23. The hot water filling operation is stopped when the hot water filling amount set in advance is reached.

(D. Thermal insulation operation)
In the hot water storage type hot water supply apparatus having the above-described configuration, after the hot water filling into the bathtub 20 is completed, the operation proceeds to the heat retaining operation. FIG. 2 is a diagram illustrating the flow of hot water during a heat retaining operation in which the second heat exchanger is operated in the hot water storage type hot water supply apparatus having the above configuration. In addition, the arrow shown in the figure has shown the flow of hot water.

  During the heat retaining operation, the first three-way valve 14, the second three-way valve 17 and the third three-way valve 18 are switched by the control means, and the hot water in the bathtub 20 is supplied with the hot water supply device 21, the return pipe 22, and the first three-way valve 14. The closed circuit is formed so as to return to the bathtub 20 in the order of the circulation pump 15, the flow switch 16, the second three-way valve 17, the second heat exchanger 5, the third three-way valve 18, the outgoing pipe 19, and the water heater 21. Is done.

  And the hot water temperature of the hot water in the bathtub 20 is detected using the 2nd temperature sensor 20a for every fixed time (for example, 10 minutes). When the detected temperature is equal to or lower than a predetermined set value, the circulation pump 15 is operated to exchange heat between the hot water in the hot water storage tank 1 and the hot water in the bathtub 20 using the second heat exchanger 5. . This state is maintained for about several minutes, and the operation of the circulation pump 15 is stopped when the hot water temperature detected by the second temperature sensor 20a reaches a set value.

  The hot water located in the upper part of the hot water storage tank 1 is maintained at a high temperature even after filling. This is because the hot water has a lower density than the low temperature water, and the hot water located above the hot water storage tank 1 is always maintained at a high temperature unless all the hot water in the hot water storage tank 1 is used. Because. For this reason, since the heat of the hot water in the hot water storage tank 1 is recovered by the second heat exchanger 5 and the hot water in the bathtub 20 is heated using the heat by the above-described operation, the bathtub 20 is always used. The inside temperature can be maintained at an appropriate temperature. Although not described here, the hot water temperature in the bathtub 20 can be raised by forming the closed circuit as described above and operating the circulation pump 15 even in the reheating operation. .

(E. Hot water cooling operation)
In the hot water storage type hot water supply apparatus having the above configuration, when the temperature of the hot water in the bathtub 20 is higher than necessary, the thermal energy is recovered by the water in the hot water storage tank 1. FIG. 3 is a diagram illustrating the flow of hot water during a hot water cooling operation in which the first heat exchanger is operated in the hot water storage type hot water supply apparatus having the above configuration. In addition, the arrow shown in the figure has shown the flow of hot water.

  During the hot water cooling operation, the first three-way valve 14, the second three-way valve 17 and the third three-way valve 18 are switched by the control means, and the hot water in the bathtub 20 is supplied with the hot water supply device 21, the return pipe 22, and the first three-way valve 14. A closed circuit is formed so that the circulation pump 15, the flow switch 16, the second three-way valve 17, the first heat exchanger 4, the third three-way valve 18, the outgoing pipe 19, and the hot water supply 21 are returned to the bathtub 20 in this order. Is done.

  Then, the circulation pump 15 is operated to exchange heat between the low-temperature water in the hot water storage tank 1 and the hot water in the bathtub 20 using the first heat exchanger 4. This state is maintained, and the operation of the circulation pump 15 is stopped when the hot water temperature detected by the second temperature sensor 20a reaches the set value.

  In the lower part of the hot water storage tank 1, low-temperature water is located after the hot water filling. This is because hot water flows from the hot water supply port 3 provided on the lower surface of the hot water storage tank 1 into the hot water storage tank 1 by supplying hot water from the hot water supply port 2 provided on the upper surface of the hot water storage tank 1. It is. Since the low-temperature water has a higher density than the high-temperature hot water, the water located at the lower part of the hot water storage tank 1 is always kept at a low temperature unless the heater 6 is heated.

  Therefore, the heat of the hot water in the bathtub 20 is reduced to the hot water in the hot water storage tank 1 by the first heat exchanger 4 by the above-described operation. Water is heated at the same time, and the waste heat in the bathtub 20 is effectively reused.

(F. Heat recovery operation of Senmaiyu)
In the hot water storage type hot water supply apparatus having the above-described configuration, the thermal energy of the remnant hot water remaining in the bathtub 20 after bathing is recovered by the water in the hot water storage tank 1. In the heat recovery operation of this hot water, a closed circuit similar to the above-described hot water cooling operation is configured.

  And before opening the drain 26 provided in the bottom face of the bathtub 20, the circulation pump 15 is operated, and the low-temperature water in the hot water storage tank 1 and the hot water in the bathtub 20 are used by using the first heat exchanger 4. Heat exchange. Maintaining this state, the temperature difference between the hot water temperature detected by the second temperature sensor 20a and the hot water temperature detected by the first temperature sensor 1a has reached a predetermined temperature difference (for example, 2 ° C.). At the time, the operation of the circulation pump 15 is stopped. And the drain outlet 26 is open | released and the finishing water in the bathtub 20 is discarded. It should be noted that the device may be configured such that the drain opening 26 is opened by a user, or the device may be configured to be automatically opened by a control device.

  Usually, there are about 35 ° C. to 45 ° C., so it is very effective to recover the thermal energy of this hot water. By the above-described operation, the heat of the hot water in the bathtub 20 is reduced to the hot water in the hot water storage tank 1 by the first heat exchanger 4, so that the water in the hot water storage tank 1 is heated by the in-house hot water. Thus, the waste heat in the bathtub 20 is effectively reused.

(Effect in this Embodiment)
As described above, by using the hot water storage type hot water supply apparatus as in the present embodiment, it is possible to effectively reuse the thermal energy of the non-hot water with a simple apparatus configuration, and the hot water in the bathtub. When stretched hot water is hotter than necessary, it becomes possible to optimize the hot water temperature without wasting water. As a result, it becomes a hot water storage type hot water supply apparatus that is energy saving and excellent in economic efficiency.

(Modification)
In the above-described embodiment, the electric hot water storage type hot water supply apparatus using a heater is illustrated and described as the hot water storage type hot water supply apparatus. However, the application target of the present invention is particularly limited to this. is not. The present invention is naturally applicable to, for example, a gas hot water storage hot water supply apparatus using gas as a heat source, a heat pump hot water storage hot water supply apparatus using a heat pump as a heat source, and the like.

  Further, in the above-described embodiment, the operation of the hot water storage type hot water supply apparatus is described by specifically exemplifying a water heating operation, a hot water supply operation, a hot water filling operation, a heat retention operation, a reheating operation, a hot water cooling operation, and a hot water heat recovery operation. Of course, other operation modes may be prepared.

  Thus, the above-described embodiment disclosed herein is illustrative in all respects and is not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a piping system figure showing the composition of the hot water storage type hot water supply apparatus in an embodiment of the present invention. In the hot water storage type hot water supply apparatus shown in FIG. 1, it is a figure which shows the flow of the hot water in the case of operating a 2nd heat exchanger. In the hot water storage type hot water supply apparatus shown in FIG. 1, it is a figure which shows the flow of the hot water when operating a 1st heat exchanger.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Hot water storage tank, 1a 1st temperature sensor, 2 hot water supply port, 3 water supply port, 4 1st heat exchanger, 5 2nd heat exchanger, 6 heater, 7 stop cock, 8 pressure reduction check valve, 9 for hot water supply Mixing valve, 10 Hot water filling mixing valve, 11 Solenoid valve, 12 Flow rate sensor, 13 Check valve, 14 First three-way valve, 15 Circulation pump, 16 Flow switch, 17 Second three-way valve, 18 Third three-way valve, 19 Outward pipe, 20a Second temperature sensor, 20 Bathtub, 21 Hot water supply, 22 Return pipe, 23 Pressure sensor, 24 Relief valve, 25 Safety valve, 26 Drain port.

Claims (5)

A hot water storage tank for storing hot water heated by a heat source;
A bathtub to which hot water stored in the hot water storage tank is supplied;
A hot water storage type hot water supply apparatus, comprising: a first heat exchanger provided in the hot water storage tank for recovering the heat of the hot water in the bathtub and using the heat to heat the hot water in the hot water storage tank.   The hot water storage according to claim 1, further comprising a second heat exchanger provided in the hot water storage tank for recovering heat of the hot water in the hot water storage tank and heating the hot water in the bathtub using the heat. Water heater. The first and second heat exchangers are provided inside the hot water storage tank,
The hot water storage hot water supply apparatus according to claim 2, wherein the first heat exchanger is located below the second heat exchanger in the hot water storage tank. Of the hot water stored in the hot water storage tank, first temperature detection means for detecting the temperature of hot water located in the vicinity of the first heat exchanger;
Second temperature detecting means for detecting the temperature of the hot water filled in the bathtub,
The hot water temperature detected by the first temperature detecting means is compared with the hot water temperature detected by the second temperature detecting means, and the hot water temperature detected by the second temperature detecting means is the first temperature. The hot water storage type hot water supply according to any one of claims 1 to 3, further comprising a control means for controlling heat exchange by the first heat exchanger when the temperature is higher than the hot water temperature detected by the detection means. apparatus.   The control means uses the first heat exchanger until the hot water temperature detected by the first temperature detecting means and the hot water temperature detected by the second temperature detecting means become a predetermined temperature difference. The hot water storage type hot water supply apparatus according to claim 4, wherein the hot water storage apparatus is controlled to perform heat exchange.

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