JPS6349660Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a solar heat utilization system, and particularly to the structure of a heat storage tank that prevents boiling of the heating medium in the system.

[Conventional technology]

In a solar heat utilization system, a heat storage tank temporarily stores heat medium (water) that has received solar heat in a heat collector, and serves to supply hot water as needed. The conventional solar heat utilization system is explained using Figure 1.
It consists of the following main equipment: a heat storage tank 1 surrounded by a heat insulating material 2, a circulation pump 3 that flows a heat medium (water), and a heat collector 4 that collects solar heat, and these are connected through piping 5. Water A injected from the water supply valve 6 is sent to the heat collector 4 by the pump action of the circulation pump 3.
After receiving solar heat and being warmed here, it returns to the heat storage tank 1 again. By repeating this water circulation, the temperature of water A in the heat storage tank 1 rises, and hot water can be supplied at an appropriate temperature. 7 is a safety valve, and 8 is an auxiliary heat source such as an electric heater. This is activated to warm the water A when the temperature of the water A in the heat storage tank 1 drops below a predetermined temperature when the heat collector 4 is not collecting heat (for example, at night).

In such a solar heat utilization system, on the other hand, in the event of overheating when the amount of heat collected is greater than the hot water supply load, water will boil in the heat collector 4 even if the temperature in the heat storage tank 1 is within the allowable range (90 to 95 degrees Celsius). Pressure may build up in the system and damage the equipment. Therefore, conventional measures to prevent water from boiling have been to detect the temperature inside the heat storage tank or the outlet side of the heat collector, drain the high-temperature water in the heat storage tank, and then supply low-temperature water to collect the temperature inside the heat storage tank. The temperature in the heater was lowered to a level that did not cause boiling during operation.

[The problem that the idea aims to solve]

The problems with this type of conventional solar heat utilization system are as follows. In other words, with the boiling prevention measures described above, there is a problem in that a new supply of water is required to compensate for the discarded high-temperature water that is not being used.In addition, when water cannot be supplied for some reason such as a power outage, the temperature inside the heat storage tank can be lowered. Not only will it not be possible to prevent an excessive rise in temperature and pressure inside the heat storage tank, but the water in the heat collector will boil and destroy the equipment, and the sealing material between equipment and piping will deteriorate, causing solar heat There was a problem that the entire system could not be used safely. Deterioration of the connection sealing material can be prevented by using special rubber that is not affected by water vapor at temperatures above 100°C, but such special rubber has the problem of being extremely expensive.

The purpose of this invention is to eliminate the above-mentioned conventional problems and prevent the excessive rise in temperature and pressure in the heat storage tank without having to supply new water, as well as prevent water from boiling in the heat collector. Furthermore, it is an object of the present invention to provide a solar heat utilization system that can be used in a safe state at all times by preventing damage to the equipment and deterioration of the sealing material between the equipment and piping.

[Means to solve the problem]

In order to achieve the above object, according to this invention, a heat storage tank, a circulation pump that flows a heat medium, a heat collector that collects solar heat, and a communication between the heat storage tank, the circulation pump, and the heat collector. In the solar heat utilization system, the heat storage tank includes at least one variable conductance heat pipe that radiates heat at a predetermined temperature or higher, and the variable conductance heat pipe is connected to a heating section, an intermediate section, and a heat radiating section. The heating part is made to protrude into the heat storage tank by penetrating the side wall of the upper part of the heat storage tank with a shaft seal, and the intermediate part and the heat radiating part are installed so as to be outside the heat storage tank, and the intermediate part It is assumed that the surrounding area is thermally insulated by surrounding it with a heat insulating material. Note that this variable conductance type heat pipe is preferably provided with a mixed gas reservoir in the middle part.

[Effect]

In this way, a variable conductance heat pipe that radiates heat at a predetermined temperature or higher is installed in a heat storage tank that constitutes a solar heat utilization system. If the intermediate part and the heat radiating part are installed so that they are outside the heat storage tank, and the intermediate part is surrounded and thermally insulated with a heat insulating material, the temperature of the heat storage tank becomes higher than the specified temperature for some reason. In this case, the heat is released to the outside through the heat dissipation section of the variable conductance heat pipe. Therefore, the temperature and pressure in the heat storage tank will not rise excessively, and the water in the heat collector will not boil and destroy the equipment or deteriorate the sealing material at the connection between the equipment and piping. Nor. Therefore, in a solar heat utilization system having a heat storage tank equipped with this variable conductance type heat pipe, solar heat is always utilized in a safe state.

〔Example〕

An embodiment of the present invention based on the above-mentioned principle will be described below with reference to FIGS. 2 and 3. still,
Components similar to those in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted. The variable conductance heat pipe 9 has a configuration in which a heating section 10, an intermediate section 11, and a heat dissipating section 12 having heat dissipating fins 12a on the outer periphery are connected in communication, and a non-condensable gas C is sealed together with a working fluid B at room temperature and atmospheric pressure. ing. 12b indicates a sealed pipe. This variable conductance heat pipe 9 can be attached to the heat storage tank 1 in an extremely simple manner. That is, the upper side wall of the heat storage tank 1 (second
The heating part 10 is inserted into the heat storage tank 1 by penetrating the shaft seal (see figure), and the heat radiating part 12 and the intermediate part 11 are attached so as to come out of the heat storage tank 1. At this time, the side where the non-condensable gas C is sealed is placed above the side where the hydraulic fluid B is sealed. Further, the outer periphery of the intermediate portion 11 is insulated by a heat insulating material 2. For example, Freon 11, Freon 113, methanol, acetone, etc. are used as the working fluid B, and only when the temperature reaches 90 to 95°C or higher, the vapor Ba of the working fluid B compresses the non-condensable gas C and releases it to the heat radiation part side. It is here that the heat is condensed and dissipated. As a result, the temperature inside the heat storage tank 1 is set to a predetermined temperature (for example, 90 to 95 degrees Celsius).
Only when this happens, the excess heat in the tank above the predetermined temperature is automatically and reliably radiated, and on the other hand, under normal conditions, the hydraulic fluid B does not operate sufficiently, so no heat is radiated. In this way, the inside of the tank can always be kept within a predetermined temperature, so that boiling will not occur if a predetermined amount of heat medium (water) is allowed to flow into the heat collector 4.

FIG. 4 shows a modification of the intermediate part 21 in FIG. 3,
This shows another embodiment in which a mixed gas reservoir 21a is provided. Vapor Ba of working fluid B and non-condensable gas C
The boundary between the two is not clearly defined, but is in a confused state due to the diffusion effect of the vapor/gas interface, and a mixed gas reservoir 21a is provided to accommodate this area.

[Effect of idea]

As described above, according to the present invention, in a solar heat utilization system, a variable conductance heat pipe is installed in the heat storage tank to dissipate heat only when the temperature is higher than a predetermined temperature. It is possible to achieve the effect of radiating excess heat and preventing boiling of the heat collector, and it is possible to reliably prevent destruction of the equipment and deterioration of the sealing material at the connection between the equipment and the piping. Moreover, the effect of preventing excessive temperature and pressure rises in the heat storage tank can also be obtained.
As a result, the solar heat utilization system can be used in a safe manner at all times. Furthermore, since the entire system has an extremely simple configuration, it is possible to provide the device at a low price.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a conventional solar heat utilization system.
Figure 2 is a configuration diagram of a solar heat utilization system that is an embodiment of the present invention, and Figures 3 and 4 are variable conductances showing different embodiments of the present invention, each of which is installed by penetrating the wall of a heat storage tank with a shaft seal. FIG. 2 is a cross-sectional view of a shaped heat pipe. 1... Heat storage tank, 2... Insulating material, 3... Circulation pump, 4... Heat collector, 5... Piping, 9, 19... Variable conductance heat pipe, 10... Heating section, 11, 21 ...Middle part, 12... Heat dissipation part, 1
2a...Radiation fin, 21a...Mixed gas reservoir.

Claims (1)

[Claims for Utility Model Registration] 1. A heat storage tank, a circulation pump that flows a heat medium, a heat collector that collects solar heat, and piping that communicates and connects the heat storage tank, the circulation pump, and the heat collector. In the solar heat utilization system, the heat storage tank includes at least one variable conductance heat pipe that radiates heat at a predetermined temperature or higher, and the variable conductance heat pipe is composed of a heating part, an intermediate part, and a heat radiation part, The heating part is made to protrude into the heat storage tank by penetrating the side wall of the upper layer of the heat storage tank with a shaft seal, and the middle part and the heat radiating part are installed so as to be outside the heat storage tank, and a heat insulating material is provided around the middle part. A solar heat utilization system characterized by being surrounded and thermally insulated. 2. A solar heat utilization system according to claim 1 of the utility model registration, characterized in that the variable conductance heat pipe has a mixed gas reservoir in the middle part thereof.