JP2001183082A - Heat accumulating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-accumulating member capable of reducing a pressure loss when a thermal medium flows while a heat exchanging efficiency is being kept high after filling latent heat accumulating material in a container in its high density. SOLUTION: A plurality of heat accumulating plates 5 having latent heat accumulating materials formed into a rectangular shape are oppositely arranged to each other with a predetermined clearance (s) being applied within a duct 3 having a rectangular cross section with its both ends being released and flowing thermal medium being flowed therein. A flow passage for the flowing thermal medium is formed between each of the heat accumulating plates 5 along a duct longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is constructed by filling a latent heat storage material for storing heat by reversible phase change between a liquid phase and a solid phase into a container so as to have a flow path of a fluid heat medium. Regarding heat storage.

[0002]

2. Description of the Related Art In recent years, an air conditioner is operated at night using inexpensive late-night power, and conditioned air heated and cooled by the air conditioner is brought into contact with a heat storage body to store heat (including cold heat). Heat the conditioned air during the daytime by radiating the heat from the heat storage
An air conditioning system that reduces the peak heat load of the air conditioner during the day by cooling is used.

[0003] As this heat storage element, there is used a container having an inlet opening and an outlet opening in which a large number of spherical heat storage materials are densely packed in contact with each other. 7-229690). The heat storage element allows air-conditioned air serving as a heat medium to flow in from the inlet opening, passes air-conditioned air through a gap between the heat storage materials to cause heat exchange between the two, and then causes the air-conditioned air to flow out from the outlet opening. Things. Since the gap is a complicated and complicated path, the heat storage body has good heat exchange efficiency.

[0004]

However, the pressure loss when circulating the conditioned air is large, and the overall energy efficiency of the heat storage air conditioning system as a whole deteriorates.

The present invention has been made in view of the above-mentioned conventional problems, and provides a heat storage element which can maintain a high heat exchange efficiency and reduce a pressure loss during the flow of a heat medium and has excellent overall energy efficiency. The purpose is to: It is another object of the present invention to provide a heat storage element that can improve overall energy efficiency by adjusting both heat exchange efficiency and pressure loss.

[0006]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 provides a latent heat storage material in a duct having a substantially rectangular cross section in which both ends are opened and a fluid heat medium flows. A plurality of heat storage plates formed in a rectangular shape with a smooth surface are opposed to each other with a predetermined gap therebetween, and a flow path for the fluid heat medium is formed between the heat storage plates along the duct length direction. It is characterized by having done.

[0007] According to the above apparatus, since a straight flow path of the heat medium can be provided in the duct, the pressure loss when the heat medium passes through the heat storage body can be significantly reduced. Also,
Since the flow paths are provided on both sides of the heat storage plate, the contact area between the heat medium and the heat storage plate can be increased, and the heat exchange efficiency between the two can be maintained high.

Furthermore, since the heat storage plates having a rectangular shape are arranged to face each other with a predetermined gap therebetween, the heat storage capacity per unit volume of the heat storage body can be increased by arranging the heat storage plates in a layered manner at a high density.
The heat storage can be made more compact.

According to a second aspect of the present invention, in the heat storage element according to the first aspect, the duct is formed so that its cross section can be expanded and contracted, and expansion and contraction means for expanding and contracting the cross section is provided. Features.

According to the above apparatus, even if the gap is fixed, the cross-sectional area through which the heat medium passes changes by expanding and contracting the cross-section, so that the flow rate of the heat medium per unit time can be reduced. The heat medium flow velocity in the heat storage body can be freely adjusted without changing. For this reason, the heat exchange efficiency can be freely adjusted through a change in the convective heat transfer coefficient between the heat medium and the heat storage material due to the change in the flow velocity. Further, since the pressure loss also changes due to the change in the flow velocity, the pressure loss can be freely adjusted by expanding and contracting the cross section. That is,
By adjusting the expansion and contraction of the cross section, both the heat exchange efficiency and the pressure loss can be adjusted, and the adjustment can be performed so that the overall energy efficiency is the best.

Further, since the heat exchange rate (the amount of heat transferred between the heat medium and the heat storage plate per unit time) also changes in accordance with the change in the heat exchange efficiency, the heat storage time and the heat storage time can be adjusted by adjusting the expansion and contraction of the cross section. The heat radiation time can be adjusted.

According to a third aspect of the present invention, in the heat storage element of the second aspect, the expansion and contraction of the cross section is performed in a direction normal to the surface of the heat storage plate, and the gap expands and contracts in accordance with the expansion and contraction. Features.

According to the above apparatus, the gap expands and contracts with the expansion and contraction of the cross section. Therefore, the difference in the cross sectional area between the most expanded state and the most contracted state can be increased, and the heat exchange efficiency and the pressure can be improved. The loss adjustment range can be further widened.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a first embodiment of the heat storage body of the present invention, and FIG. 2 is a longitudinal sectional view as viewed from the right in FIG.

As shown in FIGS. 1 and 2, the heat storage body 1 of the first embodiment is a duct 3 having a rectangular cross section and open at both ends.
And a plurality of heat storage plates 5 having a rectangular flat plate shape provided in the duct 3. Then, it is connected to an air-conditioning duct (not shown) by connecting flanges (not shown) formed at both ends and used. When the conditioned air as the fluid heat medium passes through the heat storage body 1, heat exchange is performed between the conditioned air and the heat storage plate 5.

The width a of the heat storage plate 5 is set to the same size as the inner dimension of the long side of the duct 3 in cross section, and the length is set to the same size as the length L of the duct 3 in the longitudinal direction. Then, both ends of the heat storage plate 5 are locked and fixed to the inner side surface of the duct 3 by locking members (not shown). At this time, the plurality of heat storage plates 5
Are arranged in parallel with each other with a predetermined gap s therebetween, and are arranged in parallel along the axis of the duct 3. The air-conditioned air flows straight in one direction through the gap s. Since the flow path of the conditioned air is formed in a straight line by the gap s, the pressure loss when the conditioned air passes through the heat storage body 1 is significantly reduced. Further, since these flow paths are formed on both sides of each heat storage plate 5, the contact area between the conditioned air and the heat storage plate 5 can be increased, and the heat exchange efficiency between the two can be increased.

The heat storage plate 5 is formed by filling a latent heat storage material 5b in a thin rectangular container 5a having a rectangular parallelepiped shape having excellent heat conduction and closing the container. The outer shape of the container 5a is a flat plate, and is processed into a smooth surface with small surface roughness. As the latent heat storage material 5b filled therein, a heat storage material that stores heat by a reversible phase change between a liquid phase and a solid phase is used, and is selected according to a heat medium and heat storage conditions. In the first embodiment, a paraffin-based organic heat storage material is used for cooling, and its liquid phase / solid phase has a phase change temperature of 15 to 16 ° C. and a phase change heat quantity of about 1 ° C.
It is set to 67 J / g. The density of this heat storage material is 800 kg / m ³ .

The dimension of the duct 3 is such that the duct length L = 1.
500 mm, the long side inner width a = 800 mm, the shorter side inner width b = 499 mm, and the duct inner volume is Vd = 0.
60m ^3.

The heat storage plate 5 has a heat storage plate length L = 1500 m.
m, width a = 800 mm, thickness t = 20 mm (however, the wall thickness tv = 0.5 mm of the container 5a is an outside number of the thickness)
Is set to 1 and 1
Nine are arranged. The total volume Vs of the heat storage material 5b is 0.456 m ³ and the designed heat storage amount Qs is 61.1 M
J.

The conditioned air is supplied to the air conditioner at the time of heat storage.
After cooling to 0 ° C, it is passed through a heat storage body and
(Also referred to as cooling)) is passed at room temperature of about 26 ° C.
The conditioned air is circulated at a flow velocity v = 8 m / sec, and the flow rate m is 0.64 m ³ / sec.

It has been confirmed by a thermal simulation that the following operation state can be achieved by connecting the heat storage body having the above configuration to an air conditioner. In this thermal simulation, the phase change heat storage amount was 144.8 J / g, and Qs was 52.8 MJ. The air-conditioning air (room air) at 26 ° C. is flowed through the heat storage material stored at an initial temperature of about 14 ° C., and the Qs can be absorbed or cooled in about 3 hours. Then, the air-conditioned air cooled to 10 ° C. by the air conditioner is allowed to flow for 5.5 hours to cool the air to the initial temperature of 14 ° C. Further, the pressure loss of the conditioned air during the cooling and the cold storage is extremely small, and good energy efficiency can be achieved. It should be noted that the above numerical values of the heat storage element are merely examples, and are appropriately set according to the use of the heat storage element and the like, and are not limited to these numerical values.

FIG. 3 is a perspective view of a heat storage element according to a second embodiment of the present invention, and FIG. 4 is a sectional plan view taken along the line IV in FIG. Since the basic configuration is the same as that of the above-described first embodiment, the same members are denoted by the same reference numerals, and only the differences will be described.

As shown in FIGS. 3 and 4, one opposed side surface 1 of the duct 13 of the heat storage body 11 according to the second embodiment.
Numeral 7 is formed of a flexible material such as resin in the form of an accordion curtain that is bent a plurality of times in parallel with the flow path, and the cross section of the duct 13 expands and contracts in the normal direction of the heat storage plate 5 surface. ing. The other opposite side surfaces 18 of the duct 13 are formed in a flat plate shape from a material having high rigidity, and serve as a fixed side plate 18a and a movable side plate 18b.

The folded peaks and valleys 17a and 17b of the accordion curtain-shaped side surfaces 17 are mutually connected to the peak 17a and the peak 1a.
7a, the valleys 17b and the valleys 17b face each other, and both ends of the heat storage plate 5 are locked and fixed inside the valleys 17b facing each other. The same number of heat storage plates 5 as the number of the valleys 17b are opposed to each other with a predetermined gap s therebetween and arranged in parallel with each other.
Are also scaled. Note that the gap s can be set to an arbitrary value within the expansion / contraction limit range by the expansion / contraction means provided in the duct 13.

The expanding / contracting means includes a movable side plate 1 of the duct 13.
8b comprises an electric cylinder 19 fixed to the front center and a frame member 21 which receives an operation reaction force of the electric cylinder 19. The frame member 21 is connected to the duct 13
Rectangular plate member 21a slightly larger than the front movable side plate
And four angle members 21b extending in the normal direction from the four corners of the rectangular plate member 21a.

The electric cylinder 19 has its cylinder main body 19b side fixed to substantially the center of the movable side plate 18b in front of the duct 13, and a piston 19a fitted to the cylinder main body 19b is freely retractable in the normal direction of the movable side plate 18b. And its tip is fixed to the center of the plate member 21a.

Each of the four angle members 21b passes through the side of the duct 13, and each end thereof is fixed to the fixed side plate 18a.
Of the fixed side plate 18
It is fixed at the four corners of a. As shown in FIGS. 4 and 5, the gap s forming the flow path shrinks or expands in accordance with the amount of the piston 19a protruding and retracting. Note that the amount of expansion and contraction of the gap s depends on the electric cylinder 19.
Can be adjusted continuously.

A connecting duct (not shown), also formed with an accordion curtain-shaped side plate, is connected to both ends of the duct 13 in the pipe length direction, and is not shown via this connecting duct. Connected to air conditioning duct. That is, the connection duct has flexibility to absorb a dimensional difference between the air-conditioning duct and the duct 13 of the heat storage unit 11, and the connection end side with the duct 13 side according to expansion and contraction of the duct 13. The duct 13
The air-conditioning air is prevented from leaking at the connection part with the air-conditioning duct.

Here, the operation of the heat storage body 11 according to the second embodiment will be described. The heat exchange efficiency and the pressure loss can be freely adjusted by the following operation. The air conditioner connected to the heat storage unit 11 blows conditioned air at a constant flow rate per unit time.

FIG. 4 shows a state in which the heat storage body 11 is contracted.
Since the cross-sectional area is small in the contracted state, the conditioned air flows at a high speed through the flow path in which the gap s is narrowed, and the heat exchange efficiency is improved as the convective heat transfer coefficient between the conditioned air and the heat storage plate 5 is improved. However, since the flow rate of the conditioned air is high, the pressure loss increases. On the other hand, in the expanded state shown in FIG. 5, the state is opposite to the above. That is, the flow velocity is slow due to the large cross-sectional area,
As the convective heat transfer coefficient decreases, the heat exchange efficiency decreases. However, the pressure loss decreases as the flow velocity decreases.

Further, the heat exchange rate changes with the change of the heat exchange efficiency. For example, in the contracted state shown in FIG. 4, the heat exchange rate increases as the heat exchange efficiency increases. Accordingly, when it is desired to rapidly store heat, or when it is desired to rapidly radiate heat from the heat storage body 11 to perform rapid cooling and heating, the contraction state is set.

In a general heat storage unit, the flow rate of air-conditioned air per unit time is increased during rapid heat storage or rapid cooling and heating. For this reason, the pressure loss in the air conditioning duct connected to the heat storage body increases, which promotes the deterioration of energy efficiency. However, the heat storage body 11 of the second embodiment is capable of rapidly storing heat without changing the flow rate of the conditioned air per unit time.
Alternatively, since rapid cooling and heating can be performed, good energy efficiency can be maintained without increasing the pressure loss of the air conditioning duct.

On the other hand, in the expanded state shown in FIG. 5, the heat exchange rate is low. Accordingly, when the heat is gradually released from the heat storage body 11 to perform slow cooling and heating, this expanded state is set.

The amount of expansion and contraction can be continuously adjusted by an electric cylinder, so that the heat exchange rate can be adjusted to an arbitrary value. Therefore, it is possible to store heat for a desired heat storage time or to set a desired cooling / heating speed.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and the following (a) to (e) are described without departing from the gist thereof.
Various modifications as shown in FIG.

(A) In the first embodiment, the heat storage element for storing cold heat for cooling is disclosed. However, the heat storage element for heating may store heat. still,
In that case, the heat storage material is appropriately selected, and other conditions are also set as appropriate.

(B) In the first embodiment, the surface of the heat storage plate is smoothed in order to reduce the pressure loss of the heat medium. However, the present invention is not limited to this. . For example, even if a vertical rib is provided on the outer surface of the heat storage plate along the flow path direction, there is no problem, and the rigidity of the heat storage plate can be increased.

(C) In the first embodiment, the end face of the heat storage plate located at the inlet / outlet of the heat storage body has a rectangular shape with a corner, but the corner of this end face may be chamfered. By this chamfering, the heat medium is smoothly guided to the gap between the heat storage plates particularly at the entrance of the heat storage body, so that the pressure loss can be significantly reduced. This chamfered shape is selected depending on the case such as an arc shape or a straight line shape.

(D) In the first embodiment, a rectangular parallelepiped container is used to keep the shape of the heat storage material on the heat storage plate. However, when the heat storage material changes to a liquid phase, it leaks out. If not, it is not limited to this. For example, a heat storage plate in which the heat storage material is supported on a low-crystalline polyolefin having a degree of crystallinity of less than 40% to prevent elution of the heat storage material without using a container may be used.

(E) In the first embodiment, a paraffinic organic heat storage material is used as a heat storage material for cooling. However, the present invention is not limited to this, and an inorganic heat storage material such as sodium sulfate decahydrate is used. Materials can also be used.

[0041]

As described above, according to the first aspect of the present invention, a plurality of straight heat medium passages are provided in a duct by a plurality of heat storage plates formed in a rectangular shape. Therefore, the pressure loss can be significantly reduced and the heat exchange efficiency can be kept high, so that the overall energy efficiency of the heat storage air conditioning system can be significantly improved. Accordingly, the running cost of the thermal storage air conditioning system can be significantly reduced. Further, the heat storage plates are arranged in a layered manner at a high density to increase the heat storage capacity per unit volume of the duct, thereby making it possible to make the heat storage body compact, thereby increasing the degree of freedom in space utilization.

According to the second aspect of the present invention, the heat exchange efficiency and the pressure loss can be freely adjusted by adjusting the expansion and contraction of the cross section of the duct. Therefore, it is possible to adjust the energy efficiency to be the best from a comprehensive viewpoint. In addition, since the heat exchange rate can be adjusted by the expansion and contraction adjustment, the heat storage time and the heat release time can be freely adjusted. Therefore, when applied to the heat storage air conditioning system, heat can be rapidly stored, and the cooling / heating speed can be finely adjusted from rapid cooling / heating to slow cooling / heating, thereby improving the convenience.

According to the third aspect of the present invention, since the gap expands and contracts with the expansion and contraction of the cross section, the difference in expansion and contraction of the cross section can be increased, and the adjustment range of the heat exchange rate and the pressure loss can be reduced. Can be wider. Accordingly, the adjustment range of the heat storage time when the heat is rapidly stored and the adjustment range of the cooling and heating speed can be widened, and the convenience is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a heat storage body of the present invention.

FIG. 2 is a vertical cross-sectional view as viewed from the right side of FIG. 1;

FIG. 3 is a perspective view showing a second embodiment of the heat storage body of the present invention.

FIG. 4 is a plan sectional view taken along line IV of FIG. 3 and showing a state in which the cross section of the duct is contracted.

FIG. 5 is a diagram showing a state in which the cross section of the duct is expanded.

[Explanation of symbols]

 1,11 heat storage body 3,13 duct 5 heat storage plate 5a container 5b heat storage material s gap

Claims (3)

[Claims] 1. A plurality of heat storage plates each formed by keeping a latent heat storage material in a rectangular shape with a smooth surface in a duct having a substantially rectangular cross section through which a fluid heat medium flows with both ends opened. A heat storage element characterized in that a flow path of a fluid heat medium is formed between each heat storage plate along a duct length direction so as to face each other with a predetermined gap therebetween. 2. The heat storage element according to claim 1, wherein the duct is formed so that its cross section can be expanded and contracted, and expansion and contraction means for expanding and contracting the cross section are provided. 3. The heat storage element according to claim 2, wherein the expansion and contraction of the cross section is performed in a direction normal to the surface of the heat storage plate, and the gap expands and contracts in accordance with the expansion and contraction.