JPH0311265A - Latent heat accumulator - Google Patents

Abstract

PURPOSE:To prevent the increase of heat loss, the rise of medium pressure in a heat exchanger, the elevation of the surface temperature of a heater, etc., by circulating a medium in the heat exchanger disposed into a heat-accumulating material on heat accumulation operation. CONSTITUTION:On heat accumulation operation, an on-off valve 6 is opened, and on off valves 10, 11 are closed. Electricity is conducted through a heater 5, and the heat-accumulating material 2a of solid phase is heated by the heater 5, thus melting the material 2a. The temperature of a medium in the heat- accumulating material 2b of liquid phase is made higher than that in the heat- accumulating material 2a of solid phase and the medium is lifted by the difference of specific gravity based on the temperature difference regarding the temperature of the medium in a heat exchanger 4 under the state, in which the heat-accumulating material 2a of solid phase is left in the upper section of the heat-accumulating material 2b of liquid phase, and the medium is flowed into the heat exchanger 4 again through a delivery pipe 7, an on-off valve 9, a circulating pipe 8 and a feed pipe 6 in this order. The heat-accumulating material 2b of liquid phase is deprived of heat in the process, and heat is dissipated to the heat-accumulating material 2a of solid phase.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a latent heat storage device that stores heat by utilizing phase change of a heat storage material.

(Prior Art) An example of a conventional latent heat storage device of this kind is shown in FIG.

A predetermined amount of heat storage material 2 made of molten salt or the like is housed in the inner bottom of the can body 1 so that a space 3 is formed above it. A heat exchanger 4 is disposed in the heat storage material 2 so as to cover almost the entirety of the heat storage material 2, and a heater 5 is disposed below the heat exchanger 4.

During heat storage operation, late-night power, etc. is applied to the heater 5 at a rate of 4"+M. Then, the solid phase storage material 2a around the heater 5 is heated by the heater 5, and is melted and becomes the liquid phase heat storage material 2b. As a result, the liquid phase 2b gradually rises and the solid phase accumulation (2nd
When bi: is reached, the M heat operation is terminated.

During heat dissipation operation, a medium such as water is supplied to the heat exchanger 4 through the supply pipe 6. Then, this medium increases in temperature by taking heat from the heat storage material 2 in the process of flowing through the heat exchanger 4, and then
It is sent to a demand destination (not shown) through a delivery pipe 7. During this time,
The liquid phase material 21) changes its phase by releasing its latent heat and becomes the same phase 2a, and almost all of the liquid phase heat storage material 2b becomes the solid phase 2. The heat dissipation operation ends when the temperature reaches 1.

FIG. 4 shows temporal changes in the temperature T of the liquid phase heat storage material 2b during heat storage operation.

As is clear from FIG. 4, this temperature T starts to rise at the same time as the start of heat storage operation, and is maintained at a certain temperature (T, +ΔT) exceeding the melting temperature T0 of the heat storage material 2 by ΔT, When almost all of the heat storage material 2 is melted, it begins to rise again.

(Problems to be Solved by the Invention) In the conventional device described above, the temperature of the liquid phase heat storage material 2b is equal to the melting temperature T of the heat storage material 2 during the storage operation.

It is held at a constant temperature (T, → −ΔT) for a long time, which is much higher than the
This results in problems such as an increase in the pressure of the medium inside the heater 5 and an L-field in the surface temperature of the heater 5.

(Means for Solving the Problems) The present invention was invented to solve the above problems, and the gist thereof is to generate heat by utilizing the phase change of the heat storage material housed in the can. A particular feature of the latent heat storage device for storing heat is that it is provided with a system for circulating a medium within a heat exchanger disposed in the heat storage material during strawberry heat operation.

(Function) Since the present invention has the above-mentioned configuration, the medium circulates within the heat exchanger during storage operation, absorbs heat from the liquid phase G2 material, and converts it into the solid phase storage material. Dissipate heat.

(Example) A first embodiment of the invention is shown in FIG.

A circulation pipe 8 is provided that directly connects the supply pipe 6 and the delivery pipe 7 to each other near the can body 1, and this circulation pipe 8 is provided with an on-off valve 9. The supply pipe 6 is provided with an on-off valve 10 upstream of and close to the connection position of the i-ring pipe 8, and the delivery pipe 7 is provided with an on-off valve 10 adjacent to the connection position of the circulation pipe 8. An on-off valve 11 is provided on the downstream side. The rest of the structure is the same as that shown in FIG. 3, and corresponding members are given the same reference numerals.

Therefore, the on-off valve 9 is opened during the heat storage operation, and
The on-off valves 10 and 11 are closed. Then, the heater 5 is energized and the solid phase heat storage material 2a is heated by the heater 5, thereby melting the liquid phase heat storage material 2b.
When the solid phase heat storage material 2a remains above, the temperature of the medium in the heat exchanger 4 becomes higher than that in the liquid phase heat storage material 2b, and this temperature Due to the difference in specific gravity based on the difference, the medium rises and flows into the delivery pipe 7, Wi ring pipe 8,
Pass through the on-off valve 9 and the supply pipe 6 in this order and return to the heat exchanger 1A 4.
flow inside. That is, at the time of accumulation, during the time when the solid phase accumulation material 2a and the liquid phase accumulation material 2b coexist, the medium circulates inside the Kuhe exchanger 4 due to the natural circulation force. In this process, heat is taken from the liquid phase heat storage material 2b and transferred to the solid phase heat storage material 2a, so the temperature of the liquid phase track storage material 2b during heat storage operation is lower than that of the conventional one, and , in-phase heat storage (the melting of the second a is accelerated).

As shown in FIG. 2, a circulation pump 12 is installed in the VIIiO pipe 8, and the circulation pump 12 is activated during heat storage operation to force heat exchange of the medium (circulation inside the weapon 4). You can also

(Effect of the invention) In the present invention, during heat storage operation, the medium circulates within the heat exchanger, removes heat from the liquid phase heat storage material, and radiates this heat to the solid phase M heat material. The melting of the material can be promoted and the temperature of the liquid phase heat storage material can be maintained lower than that of conventional materials. Therefore, problems such as an increase in heat radiation loss, an increase in medium pressure in the heat exchanger, and an increase in the surface temperature of the heater can be prevented.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a first embodiment of the invention, and FIG. 2 is a system diagram showing a second embodiment of the invention. Figures 3 and 4 show an example of a conventional device; Figure 3 is a system diagram; Figure 4 is a system diagram;
The figure is a diagram showing temporal changes in temperature of a liquid-phase heat storage material.

Claims (1)

[Claims] In a latent heat storage device that stores heat by utilizing a phase change of a heat storage material housed in a can, a system is provided that circulates a medium within a heat exchanger disposed in the heat storage material during heat storage operation. Characteristic latent heat storage device.