JP2002195663A - Heat storage system utilizing solar heat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a heating medium from deteriorating in a short period and to deaerate the heating medium completely, at initial injection thereof. SOLUTION: A pressure controller 8 having a valve opening upon pressure rise in a circulation path 7 of heating medium due to expansion thereof and a valve opening upon pressure drop in the circulation path 7, due to the shrinkage of heating medium is provided in the circulation path 7. An expansion tank 9, having a closable heating medium injection opening 10 and absorbing pressure variation incident to expansion/contraction of heating medium, is coupled with the circulation path 7 via the pressure controller 8. An inflow pipe 12 for supplying heating medium in the circulation path 7 directly into the expansion tank 9 and an outflow pipe 13 for returning heating medium in the expansion tank 9 directly back to the circulation path 7 are provided between the circulation path 7 and the expansion tank 9. The inflow pipe 12 and the outflow pipe 13 are provided, respectively, with on/off valves 14 and 15. An on/off valve 16 is provided between the inflow pipe 12 and the outflow pipe 13 in the circulation path 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention circulates a heat medium made of, for example, antifreeze liquid between a solar heat collector and a heat exchanger, and uses the heat exchanger to exchange a high-temperature heat medium with water in a heat storage tank. The present invention relates to a solar heat storage device that heats water in a heat storage tank by heat exchange.

[0002]

2. Description of the Related Art As such a solar heat storage device, a solar heat collector, a heat storage tank, a high-temperature heat medium heated by the solar heat collector and water in the heat storage tank are known. A heat exchanger for exchanging heat with the heat exchanger, a circulation pump for circulating the heat medium between the solar heat collector and the heat exchanger, and provided in the middle of the heat medium circulation path and accompanying the expansion and contraction of the heat medium A device having an expansion tank that absorbs pressure changes has been used.

However, in this solar heat storage device, the expansion tank is provided in the middle of the circulation path, and when the solar heat storage device is operated, the circulating heat medium always passes through the expansion tank. There were the following problems. In other words, the expansion tank has a pressure called a pressure cap that opens when the heat medium expands and allows the air in the tank to escape to the atmosphere, and conversely allows the air to flow in when the heat medium contracts. A control device is provided. Therefore, the atmosphere always exists in the expansion tank, and all the circulating heat medium comes into contact with the air. As a result, when the heat medium is made of an antifreeze, the antifreeze deteriorates in a short period of time.

Therefore, a valve that opens in the circulation path of the heat medium when the heat medium expands and the pressure in the circulation path rises, and a valve that opens when the heat medium contracts and the pressure in the circulation path decreases. There is a solar heat storage device in which a pressure control device is provided, and an expansion tank that absorbs a pressure change caused by expansion and contraction of the heat medium is connected to a circulation path via the pressure control device.

In this thermal storage device utilizing solar heat, only the heat medium escaping into the expansion tank during its operation comes into contact with air, so that even if the heat medium is made of antifreeze, its deterioration can be suppressed. become. However, it has been found that this solar thermal storage device has the following problems. That is, it is necessary to perform the initial injection of the heat medium through the pressure control device. In this case, the air is not sufficiently removed from the heat medium, and the circulation pump may be broken during operation of the solar heat storage device. .

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to prevent the heat medium from being deteriorated in a short period of time, and to completely remove air from the heat medium at the time of initial heat medium injection. It is to provide a heat storage device.

[0007]

Means for Solving the Problems and Effects of the Invention A solar heat storage device according to the present invention comprises a solar heat collector, a heat storage tank, a high-temperature heat medium heated by the solar heat collector, and water in the heat storage tank. And a pump for circulating a heat medium between the solar heat collector and the heat exchanger, a solar heat storage device provided in a heat medium circulation path, A pressure control device having a valve that opens when the pressure in the circulation path increases due to expansion and a valve that opens when the pressure in the circulation path decreases due to contraction of the heat medium due to expansion of the pressure in the circulation path, and a circulation path through the pressure control device An expansion tank having a heat medium inlet that is openable and closable and that absorbs a pressure change due to expansion and contraction of the heat medium, and a heat path provided between the circulation path and the expansion tank, and Inflow path and expansion for allowing the medium to flow directly into the expansion tank Flow path that returns the heat medium in the tank directly to the circulation path, and a flow that controls the flow direction of the heat medium when the heat medium circulates through the expansion tank and when the heat medium circulates without passing through the expansion tank Direction control means.

According to the solar heat storage device of the present invention,
The initial injection of the heat medium is performed as follows. That is, first, the heat medium inlet of the expansion tank is opened, and the flow direction of the heat medium is switched by the flow direction control means so that the heat medium circulates through the expansion tank. Next, a predetermined amount of the heat medium is injected from the heat medium injection port into the expansion tank. Then, when the circulation pump is operated for a predetermined time, the air in the heat medium escapes and the liquid level in the expansion tank stabilizes, thereby confirming that the heat medium has been completely vented. Finally, the heat medium inlet is closed, and the flow direction of the heat medium is switched by the flow direction control means so that the heat medium circulates without passing through the expansion tank. As described above, since air can be completely removed at the time of injecting the heat medium, it is possible to prevent the failure of the circulation pump caused by the air contained in the heat medium during operation of the solar heat storage device.

When the heat medium expands during operation of the solar heat storage device and the pressure in the circulation path rises, one valve of the pressure control device opens and the heat medium escapes to the expansion tank. Further, when the heat medium contracts and the pressure in the circulation path decreases, the other valve of the pressure control device opens to return the heat medium to the circulation path. Therefore, after the initial injection, only the heat medium that has flowed into the expansion tank is exposed to the air, thereby preventing the heat medium from being deteriorated in a short period of time.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of a solar thermal storage device according to the present invention.

In FIG. 1, a solar heat storage device uses an antifreeze as a heat medium, and uses a solar heat collector (1) for heating the heat medium using solar heat, a heat storage tank (2), and a heat storage tank. A heat exchanger (3) disposed in the tank (2) and performing heat exchange between the high-temperature heat medium obtained in the solar heat collector (1) and low-temperature water in the heat storage tank (2); A high-temperature heating medium feed pipe (4) that sends the high-temperature heating medium obtained by the solar heat collector (1) to the heat exchanger (3), and a heat exchanger
A low-temperature heat medium return pipe (5) for returning the low-temperature heat medium passed through (3) to the solar heat collector (1), and a solar heat collector (1) provided in the middle of the low-temperature heat medium return pipe (5). ) And a heat pump (6) for circulating a heat medium between the heat exchanger (3). And the high-temperature heat transfer pipe including the solar collector (1) and the heat exchanger (3)
A heat medium circulation path (7) is formed by (4) and the low-temperature heat medium return pipe (5).

When the heat medium expands in a portion between the heat exchanger (3) and the circulation pump (6) in the low-temperature heat medium return pipe (5), the pressure in the circulation path (7) rises. There is provided a pressure control device (8) having an open valve (not shown) and a valve (not shown) that opens when the pressure in the circulation path (7) decreases due to contraction of the heat medium. In addition, a pressure change caused by expansion and contraction of the heat medium through a pressure control device (8) is applied to a portion between the heat exchanger (3) and the circulation pump (6) in the low-temperature heat medium return pipe (5). An absorbing expansion tank (9) is connected. Heating medium inlet in expansion tank (9)
(10) is formed, and a cap (not shown) is removably attached to the heat medium inlet (10) so that the heat medium inlet (10) can be opened and closed. Pressure control device
(8) and the expansion tank (9) are connected by a hose (11) that allows the heat medium to flow between the low-temperature heat medium return pipe (5) and the expansion tank (9). The end of the hose (11) on the tank (9) side extends into the tank (9). The end of the hose (11) on the tank (9) side is always located below the liquid level of the heat medium in the expansion tank (9) when the required amount of heat medium is injected into the solar heat storage device. It has been made to be.

The heat medium in the circulation path (7) is directly expanded between the low-temperature heat medium return pipe (5) and the expansion tank (9) on the heat storage tank (2) side of the pressure control device (8). An inflow pipe (12) (inflow path) for flowing into the tank (9) and an outflow pipe (13) (outflow path) for returning the heat medium in the expansion tank (9) directly to the circulation path (7) are provided. . The inflow pipe (12) and the outflow pipe (13) are provided with on-off valves (14) and (15), respectively. Also, a low-temperature heat medium return tube
An opening / closing valve (16) is also provided at a portion between the inflow pipe (12) and the outflow pipe (13) in (5). These on-off valves (14) (15)
(16) constitutes a flow direction control means for controlling the flow direction of the heat medium. And the inflow pipe (12) and the outflow pipe
Open the on-off valves (14) and (15) of (13) and return the low-temperature heat medium return pipe.
By closing the on-off valve (16) of (5), the heat medium circulates in the circulation path (7) through the expansion tank (9), and conversely, the inflow pipe (12) and Outlet pipe (13) open / close valve (14)
Close (15) and open / close valve (16) of low temperature heat medium return pipe (5)
By opening, the heat medium circulates in the circulation path (7) without passing through the expansion tank (9).

In such a configuration, the initial injection of the heat medium is performed as follows.

First, the on-off valves (14) and (15) of the inflow pipe (12) and the outflow pipe (13) are opened and the on-off valves of the low-temperature heat medium return pipe (5) are opened.
Close (16), remove the cap and expand the expansion tank
Open the heat medium inlet (10) of (9). Then, heat medium inlet (10)
After injecting a required amount of heat medium into the expansion tank (9), the circulation pump (6) is operated. Then, the heat medium circulates in the circulation path (7) between the solar heat collector (1) and the heat exchanger (3) through the expansion tank (9), and is contained in the heat medium. Air escapes from the heat medium in the expansion tank (9), and the heat medium inlet (1)
It is released into the atmosphere from 0). When the air in the heat medium completely escapes, the liquid level in the expansion tank (9) will be stable,
When this is confirmed, attach the cap and insert the heat medium inlet (10)
Close. Finally, the on-off valves (14) and (15) of the inflow pipe (12) and the outflow pipe (13) are closed, and the on-off valve (16) of the low-temperature heat medium return pipe (5) is opened. Thus, the initial injection of the heat medium is performed,
Preparation for operation of the solar heat storage device is completed.

Circulating pump during operation of the solar heat storage device
When (6) is activated, the heat medium is circulated between the solar collector (1) and the heat exchanger (3) without passing through the expansion tank (9).
(7) Can be circulated inside. Then, the high-temperature heat medium heated while passing through the solar heat collector (1) is supplied to the high-temperature heat medium feed pipe (4).
The heat is then sent to the heat exchanger (3), where it exchanges heat with low-temperature water in the heat storage tank (2), and the water in the heat storage tank (2) is heated. The low-temperature heat medium passed through the heat exchanger (3) is returned to the low-temperature heat medium return pipe (5).
Through the solar collector (1). When the heat medium is heated and its temperature rises, the heat medium expands and the circulation path (7)
The pressure inside rises. When the pressure in the circulation path (7) increases to a predetermined pressure, one valve of the pressure control device (8) opens, and the heat medium is released into the expansion tank (9) through the hose (11).

When the circulation pump (6) stops and the operation of the solar heat storage device ends, the temperature of the heat medium decreases and contracts, and the pressure in the circulation path (7) decreases. When the pressure of the circulation path (7) decreases to a predetermined pressure, the other valve of the pressure control device (8) opens, and the heat medium in the expansion tank (9) is discharged to the circulation path (7).
Is returned to. Thus, the expansion and contraction of the heat medium are absorbed.

Therefore, after the initial injection of the heat medium, only the heat medium that has flowed into the expansion tank (9) is exposed to the air, and the amount of the heat medium exposed to the air is reduced, so that the heat medium is short-lived. The deterioration between them is prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the overall configuration of a solar heat storage device according to the present invention.

[Description of Signs] (1): Solar heat collector (2): Heat storage tank (3): Heat exchanger (6): Circulation pump (7): Circulation path (8): Pressure control device (9): Expansion Tank (10): Heat medium inlet (12): Inflow pipe (inflow path) (13): Outflow pipe (outflow path) (14) (15) (16): On-off valve

Claims (1)

[Claims] 1. A solar heat collector, a heat storage tank, a heat exchanger for exchanging heat between a high-temperature heat medium heated by the solar heat collector and water in the heat storage tank, and heat exchange with the solar heat collector. A solar heat storage device having a pump that circulates a heat medium between the heat medium and a pump, provided in a heat medium circulation path, and a valve that opens when the heat medium expands and pressure in the circulation path increases, and A pressure control device having a valve that opens when the pressure in the circulation path decreases due to contraction of the heat medium; and a heat medium connected to the circulation path via the pressure control apparatus and having a heat medium inlet that can be opened and closed. An expansion tank that absorbs pressure changes accompanying expansion and contraction of the
An inflow path provided between the circulation path and the expansion tank, and through which the heat medium in the circulation path flows directly into the expansion tank and an outflow path through which the heat medium in the expansion tank returns directly to the circulation path; And a flow direction control means for controlling a flow direction of the heat medium when the heat medium circulates and when the heat medium circulates without passing through the expansion tank.