JPH0351663Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a heat storage device, and particularly to a heat storage device such as a solar system using a latent heat storage material.

(b) Conventional technology In general, heat storage bodies that store thermal energy are broadly divided into sensible heat materials that utilize changes in heat retention due to changes in the temperature of substances such as water and stones, and those that use sodium sulfate hydrated materials. Heat of fusion (heat of solidification) like salt or ice
There are also latent heat materials that utilize sensible heat around the melting point.

Conventionally, most of the heat storage devices or tanks that have been put into practical use and are widely used utilize the sensible heat of water, and the principle of the sensible heat utilization method is that the amount of heat stored per unit volume is smaller than that of the latent heat utilization method. There were some disadvantages.

(c) Problems that the invention aims to solve This invention was made in view of the above circumstances, and one of its main objectives is to improve the efficiency of heat storage utilization in order to compensate for the disadvantages of the sensible heat utilization method as much as possible. The objective is to increase the utilization efficiency of the system, and in particular to ensure that its utilization efficiency is always high.

(d) Means for solving the problem and its effect This invention is a method in which a sealed heat storage tank is equipped with a sensible heat storage medium that exchanges heat with a heat collecting heat medium. A vapor space is formed for storing the heat medium vapor generated due to the phase change, and the enclosure of the latent heat storage heat medium stores the heat stored by the sensible heat storage heat medium as latent heat. and further extends from the vapor space of the heat storage tank,
Equipped with a heat pipe that exchanges heat between the condensing part and the load, a sub-tank for sensible heat storage heat medium connected to the bottom of the heat storage tank via a solenoid valve, and an exhaust part communicating with the vapor space of the heat storage tank. The aspirator part, which is formed by circulating an aspirator and a pump, and the high vapor pressure in the vapor space of the heat storage tank.
a control unit that outputs a control signal that controls the operation or stopping of the pump in response to a low level, and the closing/opening operation of the solenoid valve in response to a high or low level of the sensible heat storage medium in the heat storage tank; This is a heat storage device comprising:

In other words, this idea solves the drawbacks of the sensible heat utilization method by providing a heat pipe in the heat storage tank that extends from the vapor space to the external load, and takes advantage of the fact that heat can be extracted with less loss in the heat pipe. It can be supplemented.

Furthermore, this invention ensures that the vapor space of the heat storage tank is maintained at a reduced pressure by a specific configuration including an aspirator, and that heat can always be extracted by the heat pipe.

(e) Examples This invention will be described in detail based on the examples shown in the figures below. Note that this invention is not limited to this.

First, in FIG. 1, a heat storage device A mainly includes a heat storage tank 1, a heat pipe 9 extending from the heat storage tank to an external load, and an aspirator section 3.
1 and a controller 25.

Here, sealed stainless steel heat storage tank 1
A sensible heat storage heat medium 3 is installed inside the unit, and a steam space 5 is formed for storing heat medium vapor 3A generated as a result of phase change of the sensible heat storage heat medium 3. A latent heat storage heat medium 4 that stores the heat stored by the medium 3 as latent heat is enclosed in an enclosure 7, and the enclosure 7 is disposed within the sensible heat storage heat medium 3.

A heat storage heat exchanger 6 for supplying heat to the sensible heat storage heat medium 3 is installed in the lower part of the heat storage tank 1. flows. Further, as the sensible heat storage heat medium 3, a material having a large amount of sensible heat and a large specific heat, such as water, is used. The latent heat storage medium 4 is made of an organic substance mixture mainly composed of organic substances, such as N-paraffin, and is filled in the enclosing container 7 made of polyethylene (or polypropylene). The vapor space 5 is located above the heat storage tank 1.
A heat medium vapor outlet 8 is formed at the upper end of the heat storage tank 1, and a hollow heat pipe 9 is connected to the outlet.
are connected via a flare-jointed and hermetically sealed coupler 10. A water supply pipe 11 is fitted onto the tip condensing part 9a of the heat pipe 9, and the water supply pipe 11
A hot water supply heat exchanger 12 is configured by the condensing section 9a. In addition, in the figure, 13 is a water supply port, and 14 is a tap water outlet. A heat insulating material 15 is wrapped around the outer peripheral wall of the heat storage tank 1, and a heat storage unit 6 is formed by the heat storage tank 1, the heat insulating material 15, the latent heat storage heat medium 4, the sensible heat storage heat medium 3, and the heat exchanger 6. is configured.
Note that 17 is a heat collector and 30 is a circulation pump.

In the above configuration, heat is first transferred to the sensible heat storage medium 3 by the heat exchanger 6 piped to the heat collector 17 . The heat stored in the sensible heat storage heat medium 3 is stored as sensible heat of the latent heat storage heat medium 4 up to the phase shift temperature of the latent heat storage heat medium 4, and as latent heat at that phase shift temperature. That is, the heat storage form of the heat storage tank 1 is a heat storage form that coexists in three ways: as sensible heat of the sensible heat storage heat medium 3, and as sensible heat and latent heat of the latent heat storage heat medium 4.

The vapor space 5 is made up of a sensible heat storage heat medium 3 obtained by evacuating the entire system before transporting the sensible heat storage heat medium 3 into the heat storage tank 1 and enclosing a certain amount of the sensible heat storage heat medium 3. It is a saturated vapor space, and its heat medium vapor 3A
The pressure usually follows the internal pressure of the heat storage tank 1. For heat transfer, the saturated heat medium vapor 3A is transferred to the condensing section 9a by the heat pipe 9, and heat is exchanged therewith. That is, the saturated steam 3A condenses and gives latent heat to the water (external load) in the water supply pipe 11, thereby performing heat transport. On the other hand, the heat medium vapor 3A that has been condensed into a liquid returns to the heat storage tank 1 as a liquid stream. Further, in the steam space 5, the pressure decrease in the condensing section 9a sends the steam 3A toward the coupling pipe 10, and the shortage is filled by the sensible heat-latent heat phase change of the sensible heat storage heat medium 3. . The heat taken here is supplemented from the amount of heat stored in the latent heat storage heat medium 4.

Furthermore, the heat storage device A shown in FIG. 1 has a forced circulation type aspirator part 31, and the vapor space 5 of the heat storage tank 1 and the exhaust part a of the aspirator 20 of the aspirator part are connected by an exhaust pipe 26. A circulation pump 21 is connected to the aspirator section 31, and a circulation outgoing pipe 27 is branched on the suction side of the circulation pump.
A replenishment path 29 is formed at the bottom of the heat storage tank, and the replenishment path is opened and closed by a solenoid valve 22. In addition, a vapor pressure sensor 23 for detecting the pressure and temperature of the steam space 5 and a level sensor 24 for detecting the water level of the heat medium 3 are inserted into the heat storage tank 1, and a controller 25 controls the circulation pump 21 and the temperature. The operation of the solenoid valve 22 is controlled. The vapor pressure sensor 23 described above also detects temperature in addition to pressure, but this is because saturated vapor pressure has temperature dependence, and in order to maintain the vapor space at saturated vapor pressure, pressure and temperature are required. detection is essential. Furthermore, a sub-tank 18 is provided in the aspirator section 31, and a heat medium 3 is supplied to the sub-tank 18.
is fulfilled. Further, the solenoid valve 22 is normally closed.

When the pressure in the steam space 5 increases in this way, the steam pressure sensor 23 detects the temperature and pressure in the steam space, and in response to that signal, the controller 25 outputs a control signal, the circulation pump 21 starts operating, and the subtank 1
The heat medium 3 of 8 circulates in the order of circulation outgoing pipe 27 → circulation pump 21 → aspirator 20 (b → c) → circulation return pipe 28. At this time, the inside of the aspirator 20 is the nozzle 2.
The flow path is constricted at 0-1, and the flow passes from b to c at a high flow rate, and the suction action causes the exhaust pipe 26
The steam space 5 is evacuated via. When the pressure in the steam space 5 is reduced to a constant value, the controller 25 stops the circulation pump 21. At this time, the check ball 20-2 inside the aspirator 20 is attracted to the a side, and the exhaust path 26 is closed. In addition, sub tank 1
8 is provided with a replenishing means 19 for the heating medium 3 (water is used as the heating medium 3, and the water level is controlled by a ball tap).

Incidentally, a rotary vacuum pump is another well-known exhaust device and is used for exhausting the gas phase, but when exhausting the steam space as in the above embodiment, the oil is severely degraded by the steam. Use is not recommended. In other words, the aspirator 20 is inexpensive and excellent for exhausting the vapor space 5.
However, in principle, such discharge of steam would also release the vapor of the heat medium 3 along with the noncondensable gas, so the heat medium 3 in the heat storage tank will decrease during use, and the heat storage performance will decrease. There is a problem that the value decreases. However, in the above embodiment, in addition to the above-described exhaust function, the above-mentioned problems of the general aspirator 20 can also be solved.

That is, when the heat medium 3 in the heat storage tank 1 falls below a specified level, the level sensor 24 is activated and the controller 2 is activated.
5 to open the solenoid valve 22. Then, the heat medium 3 in the sub-tank 18, which is open to atmospheric pressure, is automatically replenished to the heat storage tank 1, which is under reduced pressure, due to the pressure difference between the two. When the specified level is reached, the solenoid valve 22
is closed.

Note that since the heat is transferred by heat pipe heat transport, the conventional system requires water supply piping to the heat storage tank 1, but this becomes unnecessary.
Further, in this embodiment, a domestic solar hot water supply system has been described, but this invention can be easily applied to other cases such as a solar heat collecting hot water supply system, air conditioning and heating.

In summary, heat pipes are used especially for heat extraction, but in order to maximize the performance of the heat pipes, the steam space must always be kept in a reduced pressure state (sensible heat storage heat medium). (saturated vapor pressure).
However, in reality, non-condensable gas is generated from the inner wall of the heat storage tank, the sensible heat storage medium, etc., which increases the pressure in the steam space above the saturated vapor pressure, reducing the performance of the equipment during the period of use. It turns out. The above-mentioned aspirator section 31 can automatically prevent the performance of the device from deteriorating without loss of heat medium.

(f) Effects of the device As is clear from the above explanation, according to this device, heat storage can be extracted with high efficiency by using a heat pipe, and by using a specific aspirator, the vapor space of the heating medium can be kept constant at all times. Not only can the reduced pressure state be maintained, but the amount of heat medium can also be maintained constant, making it possible to maintain long-term heat storage performance without loss of heat medium.

[Brief explanation of drawings]

FIG. 1 is a structural explanatory diagram showing an embodiment of this invention, and FIG. 2 is an enlarged sectional view of the aspirator portion thereof. A... Heat storage device, 1... Heat storage tank, 5... Steam space, 9... Heat pipe, 18... Sub-tank, 20... Aspirator section, 21... Circulation pump, 22... Solenoid valve, 23... vapor pressure sensor,
24...Level sensor, 25...Controller.

Claims (1)

[Scope of Claim for Utility Model Registration] A sealed heat storage tank is equipped with a sensible heat storage medium that exchanges heat with a collecting heat medium, and the heat generated as a result of the phase change of the sensible heat storage medium. A vapor space for storing medium vapor is formed, and a sealed container for a latent heat storage heat medium that stores the heat stored by the sensible heat storage heat medium as latent heat is disposed within the sensible heat storage heat medium, and further a heat storage tank is provided. A sensible heat storage heat medium sub-tank extending from the steam space, equipped with a heat pipe that exchanges heat between the condensing part and the load, and connected to the bottom of the heat storage tank via a solenoid valve, communicating with the steam space of the heat storage tank. The aspirator section is formed by connecting an aspirator and a pump with an exhaust section, respectively, and the sensible heat storage heat of the heat storage tank is activated or stopped according to the high or low vapor pressure in the vapor space of the heat storage tank. A heat storage device comprising: a control section that outputs control signals for respectively controlling closing and opening operations of the electromagnetic valve in response to high and low levels of the medium.