JPS5855650A - Hot-water supply apparatus utilizing solar heat - Google Patents

Abstract

PURPOSE:To remove the positional restriction of hot-water feed taps and to enable to install the hot-water feed taps even on the second floor, by providing a pressure detecting means in a hot-water feed pipe branched from a heat collecting pipe, and obtaining a pump starting signal from the output of said pressure detecting means. CONSTITUTION:When a heat collector 1 is heated by the solar rays and the temperature difference of the heat collector 1 and a heat accumulating tank 2 is increased, it is detected by a high-temperature sensor 17 and a low-temperature sensor 18, and a pump 5 is set into operation by the aid of a control means 19. Here, since a two-way valve 8 is opened and a three-way valve 6 is communicated with a lower portion of the heat accumulating tank 2, water in the tank 2 is supplied to the heat collector 1, where heat is collected. On the other hand, when hot-water feed taps 13 is opened for feeding hot water, pressure in a pipe 4 is lowered and the two-way valve 8 is closed through operation of a pressure switch 10. At the same time, the three-way valve 6 is shifted to communicate with a by-pass pipe 7, so that hot water at the upper portion of the tank 2 is supplied to the taps 13 by the pump 5. Here, fluctuation of pressure caused, for instance, at the time of starting the pump 5 is absorbed by a tank 12.

Description

[Detailed Description of the Invention] The present invention relates to a solar water heater that has a hot water supply pipe branched from a heat collection pipe and a pump that has both heat collection and hot water supply pressurizing functions, and eliminates restrictions on the installation position of a hot water tap. ,
The purpose of the present invention is to provide a solar water heater with stable operation and simplified configuration.

Conventionally, this type of solar hot water heater was developed in U.S. Pat. No. 64-138
There were problems as seen in Publication No. 034, Publication of Utility Model Publication No. 54-40499, etc. Figure 2 is Utsukai 64-138
This shows the outline of No. 034, which includes a solar heat collector 21 and a thermal water tank 22 that stores hot water, an outbound route 23 that sends water to the solar heat collector 21, and a return route 24 that returns water to the solar heat collector 21.
are connected by. Also, from the outward route 23, the hot water supply pipe 2
5 is branched and provided with a three-way valve 26 and a solenoid valve 2.
7, the heat collection path and the hot water supply pipe 25 are switched.

Pressure pump 2 also has the function of heat collection and hot water supply pressurization.
8 is provided in the outgoing path 23, and the three-way valve 26 is switched by a signal from the flow switch 29 provided in the hot water supply pipe 25, and the pressure pump 28 is operated to perform pressurized hot water supply operation and solar heat collector. A heat collecting operation is performed based on the temperature difference between the heat insulating water tank 21 and the heat insulating water tank 22. Note that 30 is a hot water tap.

Moreover, in Utility Model Publication No. 54-40499, a pump for supplying pressurized water to the heat collector and the hot water tap is provided, a flow switch is provided in the hot water supply flow path to control the operation of the pump, and the hot water tap is located at the bottom of the gas tank. The flow switch is installed at a position that has a difference in altitude to ensure the flow rate to operate the flow switch, and the pressurized hot water supply operation is configured such that the flow switch detects changes in the flow rate according to the opening and closing operations of the hot water tap to control the pump.

Since the conventional solar water heater has the above-mentioned configuration, it has the following drawbacks.

(1) Pressurized hot water supply operation relied on the signal from the flow switch, so the hot water tap had to be installed at the bottom of the water supply system, which is the water supply device, which caused installation constraints such as making it impossible to supply hot water to the second floor. was big.

(2) A stable operating condition could not be obtained because the hot water faucet was directly affected by pressure fluctuations caused by the start and stop of the pump, as well as pulsations in the discharge pressure of the pump itself.

(3) When using a three-way valve with a "closed" mode and limiting the amount of hot water supplied to the hot water tap, when the hot water tap is closed to end hot water supply and the three-way valve is then turned to the "closed" mode, the three-way valve is closed. The hot water between the valve and the hot water faucet is cooled, and the internal pressure becomes negative pressure.
Piping could be damaged if air was sucked in from the seal gasket.

In view of the above-mentioned conventional drawbacks, the present invention provides a check valve and pressure detection means in a hot water supply pipe branched from a heat collection pipe to obtain a signal for starting a pump that has the functions of collecting heat and pressurizing hot water supply. In addition, by providing the hot water supply pipe with a tank that serves as a heat collection path and an expansion tank that absorbs the thermal expansion and contraction of water in the hot water supply pipe, and a pressure tank that absorbs internal pressure fluctuations of the hot water supply pipe, the above-mentioned conventional method can be improved. It is designed to solve the shortcomings of.

Hereinafter, the present invention will be explained based on drawings showing one embodiment thereof. In FIG. 1, reference numeral 1 denotes a heat collector that collects solar heat, and water that is heated and collected by the heat collector 1 is stored in a heat storage tank 2. The heat collector 1 and the heat storage tank 2 are connected by a single heat collection pipe 3, and a hot water supply pipe 4 is provided branching off from the heat collection pipe 3. Reference numeral 6 denotes a pump that is disposed in the heat collection pipe 3 and has the functions of collecting heat and pressurizing hot water supply.The suction side of this pump 5 is connected to a hot water supply bypass via an electric three-way valve 6 that has a "close" mode. A pipe 7 is connected to the upper part of the heat storage tank 2. Further, the heat collection pipe 3 is provided with an electric two-way valve 8 after the branching point with the hot water supply pipe 4. This electric two-way valve 8 and the electric three-way valve 6 are connected to the heat collection path and the hot water supply path It plays the role of switching between The hot water supply pipe 4 is provided with a check valve 9 and a pressure switch 1o serving as pressure detection means.
Further, each of the heat collecting pipes 3 is provided with a flow rate switch 11 as a flow rate detection means, and the pressure switch 1o is
is configured to receive a signal for starting the pump 6, and the flow rate switch 11 is configured to receive a signal for stopping the pump 5, respectively.

Furthermore, the hot water supply pipe 4 includes a heat collection path such as the heat collection pipe 3 and the heat collector 1, an expansion tank that absorbs thermal expansion and contraction of water in the hot water supply pipe 4, and a pressure tank that absorbs internal pressure fluctuations of the hot water supply pipe 4. A tank 12 that also serves as a tank is provided. Also, hot water supply piping 4
A hot water tap 13 is connected to the terminal. 14 is a ball tap which is a water supply device, and water supplied through a communication pipe 15 is guided to the lower part of the heat storage tank 2. 16 is an air vent valve, which is attached to the upper part of the heat collector 1. A high temperature side center 17 is attached to the trench heat collector 1, and a low flow side sensor 18 is attached to the heat storage tank 2, and these are included in a control device 19 together with a pressure switch 1o and a flow rate switch 11.

The operation of the above configuration will now be described.

When the heat collector 1 is heated by sunlight and the temperature difference between it and the heat storage tank 2 increases, the high temperature side sensor 17 and the low temperature side sensor 1
8 detects this and operates the pump 6 via the control device 19. At this time, the second electric valve 8 is open, and the three-way electric valve 6 is in communication with the lower part of the heat storage tank 2. Then, the water in the heat storage tank 2 is sucked from the bottom by the pump 5,
It is also supplied to the heat collector 1 through the heat collection pipe 3. As a result, the air that had accumulated in the heat collector 1 until then is forced out through the air vent valve 16. When the heat collector 1 is filled with water, the flow of water stops, so the flow rate switch 11 detects this and first closes the electric three-way valve 6 in the close mode, and then stops the operation of the pump 5. do. Heat collector 1
The water inside will not fall out. In addition, the water pumped into the heat collector 1 gradually increases in temperature due to the heat of the sun and expands thermally.
Since this thermal expansion is absorbed by the tank 12 provided in the hot water supply pipe 4, the pressure inside the heat collector 1 and the heat collection pipe 3 does not become abnormally high. When the hot water in the heat collector 1 is sufficiently heated, the high temperature side sensor 17 and the low temperature side sensor 18 are again
detects this and controls the electric three-way valve 1 via the control device 19.
6 is communicated with the hot water supply bypass pipe 7 side, and the hot water in the heat collector 1 is allowed to fall to the upper part of the heat storage tank 2. After that, repeat the above operation when heat collection is possible.

Next, we will discuss the operation of hot water supply. When the need for hot water supply arises and the hot water tap 13 is opened, the check valve 9 and the hot water tap 1 are closed until then.
The pressure of the high pressure water that was stored between 3 and 3 drops. The pressure switch 1σ detects this, and the electric two-way valve 8 first closes the heat collection pipe 3, then starts the pump 5,
and the electric three-way valve 6 is switched to the hot water supply bypass pipe 7 side,
The hot water in the upper part of the heat storage tank 2 is supplied to the hot water tap 13. At this time, a sudden pressure increase due to activation of the pump 6 and pulsations in the pump pressure during hot water supply are absorbed by the tank 12, and pressurized hot water is supplied in a stable state. Furthermore, when the hot water tap 13 is closed, the pump 6 enters shut-off operation, but when the tank 12 is filled with water and the flow stops, the flow rate switch 11 detects this and stops the operation of the pump 5, and the electric two-way valve 8
Opens and electric three-way valve ef: closes. At this time, high-temperature hot water is maintained between the check valve 9 and the hot water tap 13 at a pressure close to the cut-off pressure of the pump 5. Even if the temperature of the muddy water drops, the internal pressure will not drop drastically due to the action of the tank 12.

In the above embodiment, the heat collecting pipe is one heat collecting pipe 3.
This structure facilitates piping work, and since the pump 6 does not always run during heat collection operation but rotates intermittently, operating costs are reduced. In addition, since the stop signal of the pump 5 is detected by the flow rate switch 11, which is a flow rate detection means, the stop signal of the pump can be set without being affected by variations in the head of the pump 5, compared to a system that relies on a pressure switch to detect the stop signal of the pump. When the flow rate is reached, the operation of the pump 6 can be reliably stopped. In addition, when the cold heat pipe 3'f is configured with one pipe, the completion of water supply to the heat collector 1 is also detected by the same flow rate switch 11.

can do.

As described above, the solar water heater of the present invention includes a check valve and a pressure detection means in the hot water supply piping, obtains a signal for starting the pump by at least the pressure detection means, and further includes an expansion tank and a pressure tank in the hot water supply piping. Since it is equipped with a tank that also serves as a tank, it has various excellent effects such as the following.

10.- (1) During the hot water supply pressurized operation, the pump is activated at least by the pressure detection means, so there is no restriction on the installation position of the hot water faucet, and hot water can be supplied on the second floor.

(2) The action of the tank that serves as both an expansion tank and a pressure tank eliminates the effects of pressure fluctuations on the hot water tap and pulsations in the pump discharge pressure that occur when the pump starts and stops.

(3) By using a tank that serves as both an expansion tank and a pressure tank, it is possible to prevent an abnormal increase in internal pressure or negative pressure due to thermal expansion and contraction of water in the heat collection path and hot water supply piping.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of a solar water heater showing an embodiment of the present invention, and FIG. 2 is a system configuration diagram of a conventional solar water heater.

Claims (1)

[Scope of Claims] (1) 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. , a hot water supply pipe that is branched from the heat collection pipe and has a hot water supply tap, a switching valve that switches between the heat collection pipe and the hot water supply pipe, and a pump that has the functions of collecting heat and pressurizing hot water supply. A check valve and a pressure detection means are provided in the hot water supply pipe, and at least a signal for starting the pump is obtained by the pressure detection means, and the hot water supply pipe is further provided with a heat collection path and a thermal expansion of water in the hot water supply pipe. A solar water heater equipped with a tank that serves as an expansion tank to absorb shrinkage and a pressure tank to absorb internal pressure fluctuations in hot water piping. ? ) The solar water heater according to claim 1, wherein the heat collecting pipe is composed of one pipe. (3) The solar water heater according to claim 1 or 2, wherein the signal for stopping the pump is obtained by a flow rate detection means.