JPS629823B2 - - Google Patents

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 object of the present invention is to provide a solar water heater that has stable operation and a simplified configuration.

Conventionally, this type of solar hot water heater was developed in 1983.
There were some such as those seen in Publication No. 138034, Publication of Utility Model Publication No. 54-40499, etc. Figure 2 is from the 1970s.
This shows the outline of No. 138034, solar heat collector 2
1 and a thermal water tank 22 for storing hot water are connected by an outgoing path 23 that sends water to the solar heat collector 21 and a return path 24 that returns water to the solar heat collector 21. Further, a hot water supply pipe 25 is provided branching off from the outgoing route 23, and the heat collection route and the hot water supply pipe 25 are switched by a three-way valve 26 and a solenoid valve 27. A pressurizing pump 28 also has the function of collecting heat and pressurizing hot water supply.
is provided on 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, solar heat collector 21, and heat insulation. A heat collecting operation is performed based on the temperature difference in the water tank 22. Note that 30 is a hot water tap.

In addition, in Utility Model Publication No. 54-40499, a pump for pressurized water supply is installed in the heat collector and hot water tap,
A flow switch for controlling the operation of this pump is installed in the hot water supply flow path, and the hot water tap is installed at a position at the bottom of the cistern that has an altitude difference that can secure the flow rate to operate the flow switch, and the hot water supply pressurization operation is performed at the hot water tap. The pump is controlled by detecting the change in flow rate according to the opening/closing operation using a flow switch.

Since the conventional solar hot 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 below the cistern, which is the water supply device.
There were major installation restrictions, including the impossibility of supplying hot water to the floors.

(2) Because the hot water faucet was directly affected by pressure fluctuations caused by the start and stop of the pump, as well as the pulsation of the pump's own discharge pressure, stable operating conditions could not be achieved.

(3) When using a three-way valve with a "close" mode to limit the amount of hot water supplied to a hot water tap, etc.
When the hot water tap is closed to end hot water supply, and the three-way valve is then closed, the hot water between the three-way valve and the hot water tap is cooled, and the internal pressure becomes negative, causing air to be sucked in from the seal gasket and causing the piping to close. There were cases of damage.

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 drawbacks of the conventional method can be solved. It was designed to solve the problem.

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 by the heat collector 1 and is heated 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. A pump 5 is installed in the heat collection pipe 3 and has the functions of collecting heat and pressurizing hot water supply.The suction side of the pump 5 is connected to a hot water supply bypass via an electric three-way valve 6 having 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 branch point with the hot water supply pipe 4, and this electric two-way valve 8 and the electric three-way valve 6 connect the heat collection path and the hot water supply path. It plays a role in switching. The hot water supply pipe 4 is equipped with a check valve 9 and a pressure switch 10 which is a pressure detection means.
Further, a flow rate switch 11 serving as a flow rate detection means is provided on the heat storage tank 2 side of the branching portion of the heat collection pipe 3 to the hot water supply pipe 4, and the pressure switch 10
is configured to receive a signal for starting the pump 5, 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 an expansion tank that absorbs heat collection paths such as the heat collection pipe 3 and the heat collector 1, thermal expansion and contraction 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. Further, a hot water tap 13 is connected to the end of the hot water supply pipe 4 . 14 is a ball tap which is a water supply device, and water supplied from 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. Further, a high temperature side center 17 is attached to the heat collector 1, and a low temperature 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 10 and a flow rate switch 11.

The operation of the above configuration will now be described.
The heat collector 1 is heated by the solar radiation, and the heat storage tank 2
When the temperature difference between the high temperature side sensor 17 and the low temperature side sensor 18 increases, the high temperature side sensor 17 and the low temperature side sensor 18 detect this, and the pump 5 is operated via the control device 19. At this time, the electric two-way valve 8 is open, and the electric three-way valve 6 is in communication with the lower part of the heat storage tank 2. The water in the heat storage tank 2 is sucked from the lower part by the pump 5 and is 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 sets the electric three-way valve 6 to the close mode and closes it, and then stops the operation of the pump 5. do. Therefore, the water in the heat collector 1 does not fall. In addition, the water sent into the heat collector 1 gradually rises in temperature due to the heat of the sun and thermally expands, but this thermal expansion is absorbed by the tank 12 provided in the hot water supply pipe 4, so that the heat collector 1 Also, the pressure inside 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 detect this again, and the electric three-way valve 6 is connected to the hot water supply bypass pipe 7 via the control device 19.
The hot water in the heat collector 1 is caused 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 pressure of the high pressure water that had been stored between the check valve 9 and the hot water tap 13 drops. Pressure switch 10
is detected, first the electric two-way valve 8 closes the heat collection pipe 3, then starts the pump 5, and the electric three-way valve 6 switches to the hot water supply bypass pipe 7 side, and the heat storage tank 2
The hot water in the upper part of the tank is supplied to the hot water tap 13. At this time, a sudden pressure rise due to activation of the pump 5 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. When the hot water tap 13 is closed, the pump 5 enters the 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 is opened, and the electric three-way valve 6 is closed. At this time, check valve 9
High-temperature hot water is maintained between the pump 5 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 hot water drops, the internal pressure will not drop drastically due to the action of the tank 12.

In the above-mentioned embodiment, since the heat collection piping is composed of one heat collection pipe 3, the piping work is easy, and the pump 5 does not rotate all the time during heat collection operation, but rotates intermittently. , lower operating costs.

As described above, the solar hot water supply system of the present invention enables the heat collection operation of the pump and the switching valve based on the signal from the high temperature side sensor provided on the heat collector and the low temperature side sensor provided on the heat storage tank, as well as the signal from the flow rate switch. Since the switching is controlled and the hot water supply operation of the pump and the switching valve are controlled based on the signals from the pressure detecting means and the flow rate detecting means, the following various excellent effects can be achieved.

(1) During pressurized hot water supply operation, the pump is started at least by the pressure detection means, so there are no restrictions on the installation position of the hot water tap, and
Floor hot water supply becomes possible.

(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) A tank that serves as both an expansion tank and a pressure tank can prevent abnormal increases in internal pressure and negative pressure caused by thermal expansion and contraction of water in heat collection paths and hot water supply piping.

(4) During heat collection operation, the pump and switching valve are controlled using signals from the high-temperature side sensor and the low-temperature side sensor, resulting in good heat collection efficiency.

(5) Since pump operation is stopped using a flow rate switch, the pump can be reliably stopped even if there are variations in the pump head or voltage fluctuations, eliminating wasteful energy consumption.

[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. 1... Heat collector, 2... Heat storage tank, 3... Heat collection piping, 4... Hot water supply piping, 5... Pump, 6... Electric three-way valve (switching valve), 8... Electric two-way valve ( switching valve),
10...pressure switch (pressure detection means), 11...
...Flow rate switch (flow rate detection means), 12...Tank, 13...Hot water tap, 17...High temperature side sensor,
18...Low temperature side sensor.

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, heat collection piping that connects the heat storage tank and the heat collector, and 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, a pump that has the functions of collecting heat and pressurizing the hot water supply, and the heat collector. a high temperature side sensor provided in the heat storage tank, a low temperature side sensor provided in the heat storage tank, a pressure detection means provided in the hot water supply pipe, an expansion tank for absorbing thermal expansion and contraction of water provided in the hot water supply pipe, and a hot water supply pipe. a tank that also serves as a pressure tank that absorbs internal pressure fluctuations; a flow rate detection means provided on the heat storage tank side of the branch of the heat collection pipe with the hot water supply pipe; and signals from the high temperature side sensor and the low temperature side sensor. and controlling the heat collection operation of the pump and the switching valve based on the signals from the flow rate detection means, and controlling the hot water supply operation of the pump and the switching valve based on the signals from the pressure detection means and the flow rate detection means. A solar water heater equipped with a controller. 2. The solar water heater according to claim 1, wherein the heat collecting pipe is composed of one pipe.