JPS58168893A - Heat accumulator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Regarding low heat sources for heat pumps.

Various heat storage devices are known that make use of the latent heat released when a substance is transferred from a liquid state to a solid state at a certain temperature.

As an example, the latent heat of fusion of water at 0° C. can be used.

However, such heat storage devices have the disadvantage that the solid state heat storage body adheres around the heat exchange tubes, which considerably reduces the heat exchange efficiency. In particular, frosting problems are known to occur due to the formation of ice on air-cooled exchangers.

An object of the present invention is to eliminate this disadvantage and provide a heat storage device that can be used particularly as a low heat source for a heat pump.

For this purpose, the invention provides a tank containing at least a lower layer of a heat transfer liquid and an upper layer of a heat storage body in which the density of the solid phase is lower than that of the liquid phase, the lower layer and the upper layer being , there is provided a heat storage device which is separated from each other by a separation surface on which the heat storage bodies cannot adhere and solidify, and further has circulation means for circulating the heat transfer liquid to the lower part of the tank.

Therefore, the heat transfer liquid and the heat storage body are accommodated in the same tank as one overlapping layer.

When heat transfers from the heat storage body to the heat transfer body, the heat storage body changes from a liquid state to a solid state, but since the density of the solid phase of the heat storage body is lower than the density of the liquid phase, the solid phase is mixed with the heat transfer liquid and heat storage body. It cannot be fixed in the heat exchange zone between the liquid phase of the body and floats toward the upper surface of the cypress.

It is desirable that the density of the heat transfer liquid be higher than the density of the liquid phase of the heat storage body.

Therefore, the heat transfer liquid can be separated from the liquid phase of the heat storage body without the use of a solid layer on which the same phase can adhere.

According to a preferred embodiment of the invention, the separating surface is formed by a layer of a liquid having a density exactly intermediate between the density of the heat transfer liquid and the density of the heat storage body and which is immiscible with neither the heat transfer liquid nor the heat storage body.

According to another preferred embodiment of the invention, the liquid phase of the heat storage body and the heat transfer liquid are immiscible with each other, and the upper surface of the heat transfer liquid is in direct contact with the upper layer of the heat storage body.

According to the embodiments described above, the heat storage body cannot adhere to the contact surface upon solidification.

For example, the heat transfer liquid may be salt water, and the upper heat storage body may be water.

In this case, since the carrier liquid and the liquid phase heat storage body are miscible, it is necessary to use a separation liquid such as dibutyl phthalate.

If the heat transfer liquid and the liquid phase heat storage body are immiscible, for example a fluorocarbon and water, respectively, a separating liquid is not essential.

The above circulation means for circulating the heat transfer liquid in the lower part of the tank is
It may include at least seven supply pipes, at least seven return pipes, and a pump disposed on the return pipes. The present invention also relates to a low heat source for a heat pump characterized by comprising the above-mentioned heat storage device. Applicable.

The present invention will now be further described with reference to embodiments shown in the accompanying drawings.

In the illustrated heat pump 1 of the known type, a fluid, for example fluorocarbon, flows in a closed circuit between a compressor 2 and an expansion valve 3 in the direction of arrow F1. This closed circuit comprises two heat exchangers: a condenser 4 between the compressor 2 and the expansion valve 3, and an evaporator 5 between the expansion valve 3 and the compressor 2.

The heating fluid passes through the condenser 4 in the circuit 6, and the heat transfer liquid passes through the evaporator 5 in the circuit w47 connected in a closed circuit to a low heat source.

This configuration is well known and will not be described here.

A low heat source according to the invention is indicated by 8 in the figure.

The low heat source 8 has a cypress formed in the ground, which tank has, by way of example, a circular wall 9 without insulation, optionally completed by a bottom body 10 of hard grout cracks. .

Inside the tank of the low heat source 8, there is a lower layer 11 of heat transfer liquid, and in this example, the heat transfer liquid has a condensation temperature of about -/θ℃ and a density of /
．． / of salt water may be used. Above the lower layer 11 is an upper layer 12 of water with a condensation temperature of approximately θ° C. and a density of approximately /.

Since the liquids in the lower layer 11 and the upper layer 12 are miscible, the condensation temperature is lower than that of the salt water in the lower layer 11, and the density is an intermediate value between the liquids in the lower layer 11 and the upper layer 11 (for example, /, O3 in this example). The layers 11,12 are separated from each other by a separating layer 13 of another liquid, immiscible with water and with salt water, having an aqueous solution (which can be used).

- As an example, dizotyl phthalate may be used in the liquid of layer 13.

A dip tube 14 connects the circuit 7 on the outlet side of the evaporator 5 to the bottom of the tank of the low heat source 8, and another dip tube 15 connects the bottom of the tank to the inlet of the evaporator 5 of the circuit 7. There is.

A pump 16 is arranged in the dip tube 15 in order to circulate the slightly hot liquid in the direction of the arrow 12 to the tube 14.15 and to the bottom of the tank.

The slightly hot liquid fed by the dipping pipe 14 is placed in the lower layer 1 at the bottom of the tank.
2, it removes heat from the water in the lower layer 12 and supplies the heat to the evaporator 5 of the heat pump.

Next, regarding the case where it is used for local heating in winter, for example, /
The operating cycle of the heat storage device over a year will be explained.

In this example, when the temperature of the water in the upper layer 12 is approximately θ°C at the start of the winter operating cycle, when the heat storage device starts operating, it contacts the separation layer 13 and begins to form ice 17; Since its density is lower than that of water, ice 17 floats on the surface,
An ice layer 18 is formed.

This process continues throughout the winter, until the tank is almost completely filled with ice, and in the vicinity of the slightly hot liquid passing through the separation layer 13,
The temperature of water is always close to θ℃. Therefore, complete heat exchange between the heat storage liquid (in this case, the water in the upper layer 12) and the slightly hot liquid (the salt water in the lower layer 11) is ensured.

Therefore, the efficiency of the heat pump 1 becomes high.

If the tank is almost completely frozen at the end of winter, the ice is melted during summer by sunlight, an increase in the temperature of the outside air, or an increase in the ambient temperature at the location where the heat storage device 1 is installed. This ice melting is also carried out under favorable conditions because the surface temperature is around θ°C and heat is easily absorbed from the outside air.

The depth of the bath of the low heat source 8 should be such that during the utilization cycle of the heat pump, ie in the winter season in this example, the corresponding icicle releases the required heat when it freezes.

The ice in the tank will melt during the next summer, but it is maintained at approximately θ℃.

The present invention is not limited to the specific embodiments described above, but can be made in various different configurations within the scope of the invention.

For example, the ice in the tank may be melted by forced circulation of air between the surface of the tank and a cap placed above it, instead of using sunlight. In this case, a heat pump is used to heat the tank in winter. The space can be cooled during the summer.

Instead of the bottom of the tank as shown, a shunt for the slightly hot liquid between the dip tubes 14, 15 may be arranged slightly below the surface of the tank.

Thus, at the beginning of the period of use of the heat pump 1, one begins to freeze the surface of the tank, for example to form a skating rink, and then circulates a slightly hot liquid in the bottom of the tank in order to take advantage of the advantages mentioned above. You can also do it.

[Brief explanation of the drawing]

The figure is a schematic arrangement diagram showing a heat pump utilizing the heat storage device according to the present invention as a low heat source. Explanation of symbols 11...Lower layer, 12...Upper layer,
14.15...Immersion tube (circulation means), 16
...Pump (circulation means).

Claims (1)

[Claims] /) It has a tank containing at least a lower layer 11 of a slightly hot liquid and an upper layer 12 of a heat storage material in which the density of the solid phase is lower than that of the liquid phase, and the lower layer 11 and the upper layer 12 are different from each other. , the heat storage bodies are separated from each other by separation surfaces that cannot solidify upon adhesion thereto; in addition, means 14 for circulating the hot liquid distributed above the tank;
15.16. 2) The heat storage device according to claim 1, characterized in that the density of the slightly heated liquid is greater than the density of the liquid phase of the heat storage body. 3) The separation surface is formed by a layer 13 of a liquid having a density intermediate between the density of the slightly heated liquid and the density of the heat storage body and which is immiscible with neither the slightly heated liquid nor the heat storage body.
Thermal storage device described in section. g) The heat storage device according to claim 1, wherein the liquid phase of the heat storage body and the slightly hot liquid do not mix, and the upper surface of the slightly hot liquid directly contacts the heat storage body of the upper layer 12. S) The heat storage device according to any one of claims 1 to q, characterized in that the slightly hot liquid is salt water or fluorocarbon. B) The heat storage device according to any one of claims 1 to s, characterized in that the heat storage body of the upper layer 12 is water. 7) The heat storage device according to claim 3, wherein the liquid of the separation surface layer 13 is butyl phthalate. Z) The circulation means for circulating the slightly hot liquid in the lower part of the cypress is characterized by comprising at least seven supply pipes 14, at least seven return pipes 15, and a pump 16 disposed in the return pipes 15. A heat storage device according to any one of claims 1 to 7. 9) A low heat source for a heat pump, comprising the heat storage device according to any one of claims 1 to g.