JPS5924356B2 - heat storage device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat storage device, and more particularly to a heat storage device formed by combining a heat storage material that utilizes latent heat and a heat storage material that utilizes sensible heat.

In recent years, based on the demand for energy conservation, there has been a great deal of interest in the effective use of various heat sources such as solar energy, and various studies have been conducted for this purpose.

There is usually a time lag between the acquisition and use of this heat, such as when solar energy is acquired during daytime sunshine and used at night or during cloudy or rainy days. Regenerators are used to effectively bridge such time gaps.

A heat storage device that uses latent heat mainly stores and releases heat by using the latent heat that is absorbed or released when the heat storage material undergoes a phase change such as melting or solidification. A metal, an inorganic compound, an organic compound, or the like having a melting point within a temperature range of 100 to 100 mm is encapsulated in a finned tube, capsule, or the like, and is generally constructed as shown in FIG.

That is, the outer wall of the heat storage container 1 is covered with a heat insulating material 2, and a filling layer 5 of a heat storage material sealed in a capsule is formed inside the container 1.

Further, openings 3 and 4 are provided at both ends of the container 10, and during the heat storage period, a heat medium is introduced into the container 1 through the opening 3, contacts the heat storage material filling layer 5, and melts the heat storage material. During the heat release period, the heat medium is introduced from the opening 4 and comes into contact with the heat storage material filling layer 5, and the heat released when the heat storage material solidifies is released from the opening 4. Absorb it and take it out.

When a heat storage device using latent heat is stored from a heat source such as solar energy, which has a heat input peak around noon and gradually decreases after that, the temperature distribution inside the heat storage device will change. becomes a chevron curve as shown in Figure 2,
Low-temperature portions that do not reach the melting point Tm are generated on both sides near the openings 3 and 4.

Such a temperature distribution can also be caused by leaving the heat storage device for a long time after storing heat so that the entire packed bed has a uniform temperature, but this is because heat escapes in the direction of the heat medium flow path. This is because it is generally thicker than heat escaping in the lateral direction.

In this way, the existence of a low-temperature part below the melting point Tm on the opening side, especially on the outflow side of the heat medium during the heat release period, means that the amount of heat per hour obtained by feeding the heat medium at a constant flow rate during the heat release period is However, it shows a temporal variation as shown by the dotted line in FIG. 3, which means that the thermal response speed of the heat storage device decreases significantly.

In other words, immediately after the start of heat radiation, the high amount of heat in the center of the heat storage device is used to melt the heat storage material near the outlet via the heat medium.
The temperature of the heat medium coming out of the heat storage device does not easily rise to the melting point of the heat storage material.

The present invention has been made in view of the above, and includes forming a packed layer of a heat storage material that utilizes sensible heat on the exit side of the heat medium during the heat release period,
Embodiments of the present invention will now be described in detail with reference to the drawings.

As shown in FIG. 4, in the heat storage device of the present invention, the outer wall of a metal container 6 made of an iron plate or the like is covered with insulating bricks 7, and openings 8.9 are provided at both ends of the metal container 6 to serve as entrances and exits for the heat medium. A packed layer 10 of a latent heat storage material that stores and releases heat by utilizing phase change is formed inside the housing, and a layer 10 of a heat storage material that utilizes latent heat is formed inside the opening 8 that serves as an outlet for the heat medium during the heat release period. and a packed layer 1 made of a heat storage material that utilizes sensible heat without phase change during release.
1, and as a heat storage material using latent heat,
For example, an aluminum capsule containing magnesium nitrate hexahydrate is used, while alumina balls or the like are used as a heat storage material that utilizes sensible heat.

In the above-described heat storage device, when the heat medium is introduced from the opening 8 during the heat storage period, this heat medium comes into contact with the packed layer 11 for utilizing sensible heat and the packed layer 10 for utilizing latent heat, and the packed layer 11
Sensible heat is absorbed in the packed bed 10, and latent heat is absorbed in the packed bed 10 as the phase changes to a molten state.

In addition, during the heat release period, the heat medium is introduced from the opening 9,
It comes into contact with the latent heat-utilizing packed bed 10 and is given the amount of heat released by its phase transformation into a solid state, and then flows out through the sensible heat-utilizing packed bed 11 through the opening 8 .

Therefore, the packed bed 11 for sensible heat utilization in which the heat medium is in a low temperature state
When in contact with the packed bed, sensible heat absorption is performed by this packed bed, but this sensible heat absorption is performed in a very short time compared to latent heat absorption accompanied by phase transformation, and therefore, the temperature of the heating medium flowing out from the opening 8 decreases. quickly reaches a constant value as shown by the solid line in FIG. 3, and a stable heat output can be obtained for a long time.

As described above, according to the heat storage device of the present invention, since the packed layer for utilizing sensible heat is formed on the exit side of the heat medium during the heat release period, the temperature of the heat medium rises to a predetermined temperature immediately after the heat release starts. It is possible to obtain a constant heat output and therefore significantly increase the thermal response of the regenerator, and according to experiments, a diameter of 2 cm can be obtained.
Approximately 4,000 pieces of heat storage material made by enclosing magnesium nitrate/hexahydrate in aluminum capsules with a height of 2 cm form a packed bed that utilizes latent heat.
When the packed layer is formed with approximately 700 α alumina balls, compared to when the entire packed layer is formed using a heat storage material surrounding latent heat,
The time required to obtain a constant amount of heat output was reduced to about 1/4.

[Brief explanation of the drawing]

FIG. 1 is a schematic structural diagram of a heat storage device using latent heat, FIG. 2 is a temperature distribution diagram in the heat storage device before application of the present invention, FIG. 3 is a diagram showing the amount of heat output from the heat storage device during heat radiation, and FIG. FIG. 4 is a schematic structural diagram showing an embodiment of the heat storage device according to the present invention. 6... Container, 8, 9... Opening, 10
... Packed bed using latent heat, 11 ... Packed bed using sensible heat.

Claims (1)

[Claims] 1 A packed layer of heat storage material is provided in an insulated container equipped with openings at both ends for the entrance and exit of the heating medium, and the heating medium is allowed to flow from one opening to the other, thereby storing and releasing heat. In such a device, the packed layer of the heat storage material is formed by a packed layer of a latent heat storage material that stores and releases heat through phase change, and the phase change is performed on the exit side of the heat medium during the heat release period. A heat storage device characterized by having a packed layer of a heat storage material that utilizes sensible heat without any heat storage.