JPS5855651A - Hot-water supply apparatus utilizing solar heat - Google Patents

Abstract

PURPOSE:To enable to use a heat collecting pump also as a hot-water feed pump, by connecting a heat collecting pipe to an upper portion of a heat accumulating tank, and providing a jet pump in a by-pass pipe by-passing a heat collecting pipe in said heat collecting pipe, and connecting the suction opening of the jet pump to a lower portion of the heat accumulating tank. CONSTITUTION:When the temperature of a heat collector 1 is raised by the solar rays and the temperature difference of a high-temperature sensor 13 and a low- temperature sensor 14 is increased, a three-way valve 11 is communicated with a by-pass pipe 8 through operation of a differential-temperature operated means, so that water discharged from a pump 5 is circulated through the by-pass pipe 8 and a jet pump 9 to the pump 5. Therefore, water in a heat accumulating tank 3 is drawn through a suction pipe 10 by the jet pump 9 and supplied to the heat collector 1 via a pipe 4. Thus, heat is collected by the heat collector 1. On the other hand, when a hot-water feed tap 17 is opened for feeding hot water, pressure in a pipe 6 is lowered and a pressure switch 18 is actuated to shift the three-way valve 11 to a position where it is communicated with a suction pipe 7. Resultantly, hot water at the upper portion of the tank 3 is drawn out and supplied to the tap 17 through operation of the pump 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar water heater, and an object of the present invention is to provide a solar water heater that can eliminate operating costs of a heat collection pump and improve heat collection efficiency.

A conventional solar water heater has a configuration as shown in FIG. That is, in FIG. 4, 31 is a heat collector, and the water in the heat storage tank 33 is pumped into the heat collector 31 by a heat collection pump 32 through two pipes: a heat collection feed pipe 34 and a return pipe 35. The heat is constantly circulated through the pipes during heat collection. Further, a water supply tank 3e is provided above the heat storage tank 33, and when the water in the heat storage i33 decreases, water is temporarily supplied to the water supply tank 36 via a ball tap 37. and water tank 3
6 enters the lower part of the heat storage tank 33 through the water supply pipe 38.

When the hot water tap 39 is opened, the hot water in the heat storage tank 33 is pressurized and supplied from the upper part of the heat storage tank 33 by the hot water supply pressure pump 4o. However, the conventional solar water heater described above has the following drawbacks.

(1) Since it is necessary to always operate the heat collecting pump 32 during the heat collecting operation, the operating cost of the heat collecting pump 32 is high.

(2) Two heat collection pipes are required: a feed pipe 34 and a return pipe 3°5. Since hot water is constantly flowing through the feed pipe 34 and the return pipe 35, The losses were huge.

(3) Since the heat collecting pump 32 and the hot water supply pressurizing pump 4o are provided separately, the initial cost is high.

G41 Considering the water supply to the heat collector 31 installed at a high position, a large heat collection pump 32 with a high head was required.

In view of the above-mentioned conventional drawbacks, the present invention consists of a heat collection pipe from the heat storage tank to the heat collector with a single pipe, and a heat collection pump is provided in the heat collection pipe B, and the discharge side of this heat collection pump is The hot water supply piping is branched, and the suction pipe of the heat collection pump is connected to the upper part of the heat storage tank, and a jet pump is installed in the bypass pipe that bypasses the heat collection pump. The suction pipe of the pump is connected to the lower part of the heat storage tank, and is further provided with a switching means for switching the suction direction of the heat collection pump to the heat storage tank side and the bypass pipe side, and is connected to the suction pipe of the jet pump. By providing a backflow prevention means to the heat storage tank, the above-mentioned conventional drawbacks are solved.

Hereinafter, the present invention will be explained based on drawings showing one embodiment thereof.

In FIGS. 1 to 3, reference numeral 1 denotes a heat collector for collecting solar heat, and an air vent valve 2 is provided at the upper part of the heat collector 1. Further, a heat storage tank 3 for storing hot water heated by the heat collector 1 is installed in the lower part, and a heat collection pipe 4 leading to the heat collector 1 is composed of one pipe. Further, a heat collecting pump 6 is disposed in the heat collecting pipe 4, and a hot water supply pipe 6 is branched from the discharge side of the heat collecting pump 6.

The suction pipe 7 of the heat collecting pump 6 is still connected to the upper part of the heat storage tank 3. A bypass pipe 8 bypasses the heat collecting pump 6. A jet pump 9 is disposed in the bypass pipe 8, and a suction pipe 10 of the jet pump 9 is connected to the lower part of the heat storage tank 3. 11 is an electric three-way valve, and this electric three-way valve 11 functions to switch the suction direction of the heat collection pump 6 to the heat storage tank 3 side and the bypass pipe 8 side. 12 is a check valve, and this check valve 12 prevents backflow from the suction pipe 1o of the pump 9 to the heat storage tank 3.

In addition, the control parts of the system include a high temperature sensor 13, a low temperature sensor 14, and a heat collection pipe 4, which are attached to the heat collector 1 and the heat storage tank 3, respectively, and which constitute a differential temperature thermostat.
A flow rate switch 15 provided above and a pressure switch 18 disposed between a check valve 16 of the hot water supply pipe 6 and a hot water tap 17 are provided, and these control components are controlled by a controller 19. 2o is a ball tap for water supply, 21
The make-up water supplied from the ball tap 20 is transferred to the heat storage tank 14.
It is a water conduit that leads to the bottom of the water pipe.

Next, to explain the operation of the above configuration, the temperature of the heat collector 1 rises due to solar radiation, the temperature difference between the high temperature sensor 13 and the low temperature sensor 14 opens, and when a predetermined value is reached, the temperature difference thermostat is activated. Start the water supply operation to the heat collector 1. First, the electric three-way valve 11 is in a state as shown in FIG. It circulates in a circuit leading to the heat pump 6. At this time, the circulating flow has a high flow velocity due to the jet pump 9, and a suction pressurizing action is generated in the jet pump 9, so that the water in the heat storage tank 3 is
It is sucked through the check valve 12 and the suction pipe 1o, and is supplied to the heat collector 1 through the heat collection pipe 4. At this time, heat collection pipe 4
The air inside the heat collector 1 is exhausted to the outside through an air vent valve 2 provided at the top of the heat collector 1. When the heat collector 1 is filled with water, the air vent valve 2 is automatically closed and the flow of water is stopped. The flow rate switch 15 detects this stoppage of the flow of water and stops the operation of the heat collecting pump 5. Even when the operation of the heat collecting pump 5 is stopped, the water in the heat differential device 1 does not fall due to the action of the check valve 12. In addition, the temperature of the water in the heat collector 1 gradually rises,
When the difference between the low temperature sensor 14 on the heat storage N3 side and the high temperature sensor 13 in the heat collector 1 exceeds the setting, the temperature difference thermostat is activated and the electric three-way valve 11 is switched to the circuit shown in Figure 3. . Then, when the switch is made as shown in Fig. 3, the hot water in the heat collector 1 becomes
The heat is returned to the heat storage tank 3 through a suction pipe γ connected to the upper part of the heat storage tank 3. After the water in the heat collector 1 is returned to the heat storage tank 3 in this way - the high temperature sensor 13 and the low temperature sensor 1
If the difference temperature of 4 is a predetermined value, perform the above-mentioned operation,
The water in the heat storage tank 3 is supplied to the heat collector 1 again. By performing such an operation, the temperature of the hot water in the heat storage tank 1 gradually rises.

When hot water is supplied, the hot water tap 17 is opened. When the hot water tap 17 is opened, the pressure between the hot water tap 17 and the check valve 16 decreases. The pressure switch 1'B detects this pressure drop, switches the electric three-way valve 11 as shown in FIG. 3, and operates the heat collection pump 6. As a result, hot water is sucked from the upper part of the heat storage tank 3 by operation of the heat collection pump 6, and hot water is supplied from the hot water tap 17. During this hot water supply, the water in the heat collector 1 does not fall due to the discharge pressure of the heat collecting pump 5, and when the hot water tap 17 is closed and the hot water supply is stopped, the hot water is supplied from the heat collecting pump 5. The shutoff pressure of the heat collecting pump 5 acts on the interior of the hot water supply pipe 6 leading to the tap 17 . The pressure switch 18 detects this shut-off pressure, switches the electric three-way valve 11 to the state shown in FIG. 2, and stops the operation of the heat collecting pump and the like. At this time, electric three-way valve 11
is switched as shown in FIG. 2, so water in the heat collector 1 will not fall.

As described above, in the solar water heater of the present invention, the heat collection piping from the heat storage tank to the heat collector is configured with one pipe, and the jet pump is installed in the bypass pipe that bypasses the heat collection pump provided in the heat collection pipe. and a switching means for switching the suction direction of the heat collection pump to the heat storage tank side and the bypass pipe side, and a means for preventing backflow from the suction pipe of the jet pump to the heat storage tank. Therefore, it has various excellent effects as follows.

(1) Since it is not necessary to constantly operate the heat collection pump during heat collection operation, the operating cost of the heat collection pump is extremely reduced.

? ) Since there is only one heat collection pipe and there is no water circulation during heat collection, there is no heat loss and the heat collection efficiency can be improved.

(3) The 11 heat collection bottles function as a heat collection pump and hot water supply pressurization pump, reducing the initial cost.

(4) When water is supplied to the heat collector, the suction and pressure action of the jet pump is utilized, so the capacity (head) of the heat collector pump can be selected to be small.

[Brief explanation of the drawing]

0 Fig. 1 is a system configuration diagram of a solar water heater showing an embodiment of the present invention, Fig. 2 is a circuit configuration diagram during water supply in Fig. 1, and Fig. 3 is a circuit configuration diagram during hot water supply in Fig. 1. 4 are system configuration diagrams of a conventional solar water heater. 1... Heat collector, 3... Heat storage tank, 4...
... Heat collection piping, 5 ... Heat collection pump, 6 ...
...Hot water piping, completed...Suction pipe, 8...
... Bypass pipe, 9 ... Jet pump, 10
... Suction pipe, 11 ... Electric three-way valve (switching means), 12 ... Check valve (backflow prevention means).

Claims (1)

[Scope of Claims] O) A heat collector that collects solar heat, a heat storage tank that stores water heated by the heat collector, and heat collection piping that connects the heat storage tank and the heat collector. The heat collection piping from the heat storage tank to the heat collector is composed of one pipe, a heat collection pump is provided in this heat collection pipe, and a hot water supply pipe is branched from the discharge side of this heat collection pump. and a suction pipe of the heat collection pump is connected to the upper part of the heat storage tank, and a jet pump is disposed in a bypass pipe that bypasses the heat collection pump, and the suction pipe of the jet pump is A switching means is connected to the lower part of the heat storage tank and further switches the suction direction of the heat collection pump to the heat storage tank side and the bypass pipe side, and reverse flow from the suction pipe of the jet pump to the heat storage tank. A solar water heater equipped with a prevention means. Claim 1, wherein an electric three-way valve is used as a switching means for switching to the bypass pipe side, and a check valve is used as a means for preventing backflow from the suction pipe of the jet pump to the heat storage tank. Solar water heater.