JPS6071828A - Hot water supply system - Google Patents

Abstract

PURPOSE:To contrive reuse of heat, by a method wherein a heat source such as used hot water is stored in a hot water tank as hot water through a heat exchanger by combining the heat exchanger with the hot water tank which is supplied as the hot water. CONSTITUTION:Hot water of a bathtub 1 is circulated through primary piping 3 by operating a circulating pump 4. Simultaneously with the above cold water supplied from a water supply source 8 of the inside of a hot water tank 5 is circulated through secondary piping 6 by operating a circulating pump 7. With this construction, heat of hot water in the inside of the bathtub circulating in the primary piping 3 is transferred to cold water passing through the secondary piping 6, in a heat exchanger 2. Hot water in the hot water tank 5, whose temperature has risen in this manner is supplied through hot water supply piping 9 for a kitchen and the bathtub use after it is heated by an auxiliary heating device and risen up to an appropriate temperature according to necessity on the following day.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot water supply system that reuses the amount of heat that was wasted for heat radiation after use.

Conventionally, in home water heaters, for example, hot water in a bathtub is left as it is after taking a bath, so the heat gradually radiates, and the temperature drops to about the same temperature as the water in tap water the next morning. Therefore, it was necessary to boil the bathtub again from the initial temperature, or to replace the water in the bathtub.

Furthermore, even in occupations that use a large amount of hot water, it was common for the hot water to be disposed of after use.

An object of the present invention is to combine a heat exchanger and a hot water storage tank to store a heat source such as used hot water as hot water in the hot water storage tank via the heat exchanger, and to reuse heat by supplying hot water. The objective is to provide a hot water supply system that measures the

Another object of the present invention is to provide a heat exchanger and a hot water storage tank, measure the temperature at the primary inlet and secondary outlet of the heat exchanger, and measure the 2) By controlling the flow rate of the circulation on the next side, the used heat source is stored as hot water in the hot water tank via a heat exchanger at a high temperature and high heat exchange rate, and this is used to supply hot water. The aim is to provide a hot water supply system with

The hot water supply system of the present invention will be described in detail below based on a first embodiment in which the heat of hot water after use in a domestic bathtub is reused. FIG. 1 is a diagram showing its configuration, which includes a bathtub 1 as a heat source, a heat exchanger 2, and a primary circulation path 1 for circulating hot water in the bathtub 1 through the heat exchanger 2.
A secondary piping 3, a circulation pump 4, a hot water storage tank 5 on the heat receiving side that has a structure that reduces heat radiation as much as possible, and a secondary circulation path 2 that circulates water in the hot water storage tank through a heat exchanger 2. It is composed of a secondary pipe 6 and a circulation pump 7.

The operation of the hot water supply system of this embodiment will be described next.

First, the circulation pump 4 is operated to circulate hot water in the bathtub 1 through the primary pipe 3. At the same time, the circulation pump 7 is operated to circulate the cold water supplied (3) from the water supply source 8 in the hot water storage tank 5 through the secondary pipe 6. As a result, the heat of the hot water in the bathtub 1 circulating through the primary pipe 3 in the heat exchanger 2 is transferred to the cold water passing through the secondary pipe 6. Therefore, the temperature of the hot water in the bathtub 1 decreases, while the temperature of the hot water storage tank 5 increases. In this way, heat exchange is performed until both temperatures become approximately equal, at which point the operation of both circulation pumps 4 and 7 is stopped.

The hot water in the hot water storage tank 5, whose temperature has increased in this way, is heated by an auxiliary heating means as needed the next day, and after being raised to an appropriate temperature, the hot water pipe 9 is used for use in the kitchen, bathtub, etc. supplied through the

Much of the heat of the hot water in the bathtub 1 after use, which was radiated and wasted in this way, is stored in the hot water storage tank 5, which radiates very little heat, and is used the next day.

In the hot water supply system of this embodiment, cold water is circulated at a constant flow rate through the piping number on the secondary side during heat exchange. As a result, a flow of liquid also occurs within the hot water storage tank 5, resulting in the same state as in the case of stirring, and the temperature (4) degrees within the hot water storage tank 5 is averaged. Therefore, as the heat exchange progresses, the amount of water sent from the hot water storage tank 5 to the heat exchanger 2 rises. As a result, before the temperature of the hot water in the bathtub 1 becomes too low, the temperature of the hot water in the bathtub 1 sent to the heat exchanger 2 and the temperature of the hot water in the hot water storage tank 5 become almost equal, and no heat exchange takes place. A certain amount of heat is dissipated without being reused.

The second embodiment shown in FIG. 2 improves this point and makes it possible to recover heat to the hot water storage tank at an extremely high heat recovery rate. In this figure, 1 is a bathtub, 2 is a heat exchanger, 3 is a primary pipe, 5 is a hot water storage tank, 6 is a secondary pipe, 8 is a water supply source, and 9 is a hot water supply pipe, which are substantially the same as those in the first embodiment. It is the same as above.

Also, 11 is a first temperature sensor installed near the heat exchanger inlet of the primary pipe 3, 12 is a second temperature sensor installed near the heat exchanger outlet of the secondary pipe 6, and 13 is a second temperature sensor installed near the heat exchanger outlet of the secondary pipe 6. A third temperature sensor 14 is provided near the inlet of the heat exchanger.
Second. 15 is a controller that controls the drive of the pump and other components based on signals from each third temperature sensor;
A circulation (5) pump provided in the secondary piping, 16 is a variable flow rate circulation pump provided in the secondary piping. The flow rate of this variable flow rate circulation pump is changed based on the difference between the temperature detected by the first temperature sensor 11 and the temperature detected by the second temperature sensor 12. For example, in this pump 16, the rotation speed of the drive motor that drives the pump 16 is determined by the temperature difference (specifically, inversely proportional to the temperature difference) between the two temperatures detected by the first temperature sensor and the second temperature sensor. It is configured to change depending on the value of

Further, 17 is pulp, and 18 is a pipe for supplying hot water heated by another heat source.

Next, the operation of the second embodiment configured as above will be explained. First, the circulation pump 15 on the primary side is operated, and the temperature switch detected by the first temperature sensor 11 is self-held, and the operation of this pump is continued. As a result, the hot water in the bathtub 1 on the heating side is circulated (6) through the primary circulation path 3 at a constant flow rate (the most desirable flow rate adjusted by adjusting the valve 17). Further, the temperature signal detected by the first temperature sensor 11 and the temperature signal detected by the second temperature sensor 12 are sent to the controller 14, where the difference between the two temperatures is determined and a signal is generated that is inversely proportional to the value. It is sent to the variable flow rate circulation pump 16. For example, a current inversely proportional to the temperature difference is supplied to the motor driving the variable flow rate circulation pump 16. In this case, initially the temperature of the hot water sent to the heat exchanger 2 through the primary pipe 3 is high (for example, 40°C), while the
The temperature at the outlet of the heat exchanger of the next pipe 6 is low because heat exchange is not sufficient. Therefore, the temperature difference detected between the first temperature sensor 11 and the second temperature sensor 12 is relatively large. Therefore, the output signal from the controller 14 is extremely small and the variable flow rate circulation pump 16 hardly operates.

The 92nd order circulation path hardly circulates. As time passes, heat exchange progresses, the temperature detected by the second temperature sensor 12 increases, and when the difference between it and the temperature detected by the first temperature sensor 11 becomes small, the output signal from the controller 14 increases. Then, circulation (7) in the secondary circulation path is performed by the variable flow rate circulation pump 16. As a result, the hot water whose temperature has been increased by the heat exchanger 2 is sent to the hot water storage tank 5. When the temperature difference between the inlet of the primary circulation path and the outlet of the secondary circulation path in the heat exchanger 2 is small, this hot water is hardly sent and is sent only after it becomes small. The temperature is close to the temperature of hot water in a bathtub (for example, 40 degrees).

As the heat exchange progresses in this way, the temperature of the hot water in the bathtub 1 decreases due to the supply of heat. Therefore, the hot water sent to the water storage tank 5 through the secondary circulation path also decreases, but the temperature of the hot water in the bathtub at that point (temperature at the inlet of the primary circulation path of the heat exchanger) always decreases.
The temperature is close to .

As the heat exchange progresses further, the temperature of the hot water in the bathtub 1 decreases significantly, and the difference between the temperature detected by the first temperature sensor 11 and the temperature detected by the third temperature sensor 13, that is, the heat exchanger 2
The temperature difference between the temperature at the inlet of the primary circulation path 3 and the temperature at the inlet of the secondary circulation path 6 is almost eliminated (for example, when the temperature difference is 3°
Since heat exchange beyond this point is almost impossible and is meaningless, both circulation pumps are stopped.

(8) In the above operation, the variable flow rate pump 16 provided in the secondary circulation path 6 is not constantly operating, so the water in the hot water storage tank 5 is not stirred and the upper temperature is low. The temperature at the top and bottom remains low. For example, the top is 40°
At C, the temperature gradually decreases, and at the bottom, the temperature of the water from the water source is always, for example, 9°C. Therefore, sufficient heat exchange is performed until the temperature of the hot water in the bathtub 1 reaches about 12'C. In this way, heat exchange is possible until the temperature on the next side (heating side) becomes low, and heat can be sufficiently recovered and reused.

Next, a case will be described in which the hot water supply system of the present invention is used in a solar hot water supply device. FIG. 3 is a diagram showing an example of the case where the second embodiment of the present invention is used in a solar water heating system. In this figure, the solar collector is connected to the hot water storage tank 5. . The other configurations are substantially the same as shown in FIG. In an apparatus having such a configuration, first, the hot water supply system is turned on after bathing. As a result, the system of the present invention operates as already described in detail (9) based on FIG. 2, and most of the heat of the hot water in the bathtub 1 is recovered as hot water in the hot water storage tank. When the temperature difference between the temperature of the hot water in the bathtub 1 and the temperature of the water supplied from the hot water tank 5 to the heat exchanger 2 becomes a predetermined temperature, for example, 3°C or less, the system of the present invention automatically operates. will be stopped.

In this way, most of the heat of the hot water in the bathtub 1 is transferred to the hot water storage tank 5.
It is absorbed and stored in the hot water inside. The next day, the hot water in the hot water tank 5 is heated by the solar collector. in this case,
When the hot water supply system of the present invention is not used, the temperature of the water supplied to the solar collector is about 7°0-2000°C, but when the heat exchange system of the present invention is used, the temperature is higher than this. Therefore, it is possible to reach a sufficiently high temperature even in the winter when the amount of solar radiation is low.

The following table shows February with the least amount of solar radiation and 5 months with the highest amount of solar radiation.
This is measurement data for August, when the outside temperature is high.

Omotesuki (A) (B) (0) (D) (E) (F)
(G') (10) 279.0007°'c 70a 169.60042
°c174.00063°C5108,00021°c
17° (3234,90059°Q 118.2007
1°C8103,30029°026°(3223,6
0064° (372,00073° in the table (A
) is the slope average solar radiation (Kcat/m3'), (
B) is the outside air temperature, (0) is the water supply temperature, and (D) is the amount of heat collected by the solar collector using three collectors (Kc
at/3 sheets/month), (bound is the temperature reached when using a solar collector, (F) is the amount of heat collected by the second embodiment of the present invention, (G) is the temperature reached when a solar collector is used together) The bathtub is 2oot and the hot water storage tank is 270t.

As is clear from the above table, a hot water supply system using solar heat in combination with the hot water supply system of the present invention can obtain a temperature of about 60° even in winter, so it can be used without using auxiliary heating. Furthermore, in the case of the second embodiment, as can be seen from the above table, the heat recovery rate increases as the water supply temperature decreases in winter.

Therefore, since it is particularly effective in winter when a solar heat hot water supply system is insufficient, the combination of this second embodiment and a solar heat heat system (11) enables stable hot water supply all year round. Become.

As explained above, according to the hot water supply system of the present invention, a considerable portion of the heat from hot water in bathtubs and hot water used in occupations that use boiling water, which was conventionally discarded due to heat radiation or disposal, can be reused. Significant fuel savings can be achieved. The second embodiment is even more effective because of its high heat recovery rate. Furthermore, if the system of the present invention is used in combination with a solar heat utilization system, it can be used almost all year round without supplementary heating, and especially in the case of the second embodiment, heat recovery is possible in winter when the use of solar heat is limited. It is extremely effective due to its high rate.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention, FIG. 2 is a diagram showing the configuration of the second embodiment of the present invention, and FIG. 3 is a diagram showing the configuration of the second embodiment of the present invention. It is a diagram showing a configuration when combined with a hot water supply system for use. 1...Bathtub, 2...Heat exchanger, 3...Primary piping, 4...Circulation pump, 5...Hot water tank, (1
2) 6...Secondary piping, 7...Circulation pump, 11...
...First temperature sensor, 12...Second temperature sensor, 13...Third temperature sensor, 14...
Controller, 15...Circulation pump, 16...
・Variable flow rate ring pump. Applicant Hiroshi Koyama Agent Hiroshi Mukai (13)

Claims (1)

[Scope of Claims] (1) A heat source including a heat source such as hot water in a used bathtub, a hot water storage tank, and a heat exchanger that exchanges heat from the heat source and supplies hot water to the hot water storage tank; A hot water supply system in which heat from a used heat source is stored as hot water in the heat storage tank and can be reused by heating or supplying hot water without heating. (2) Equipped with a heat source such as hot water in a used bathtub, a hot water storage tank, and a heat exchanger that exchanges heat from the heat source and supplies hot water to the hot water storage tank, By changing the flow rate of the secondary circulation path according to the temperature difference between the vicinity of the entrance of the primary circulation path and the vicinity of the exit of the secondary circulation path to the hot water storage tank, the heat from the used heat source is converted into hot water in the hot water storage tank. A hot water supply system that collects hot water at a high recovery rate, stores it, and reuses it by heating it or supplying hot water without heating. (1)