JP2001255089A - Cold accumulating device and method using clathrate hydrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a cold accumulating medium derived from a gas hydrate within a range of 0 deg.C to minus 50 deg.C, without being subjected to the regulation of a high-pressure gas safety law and regulations. SOLUTION: A cold accumulating vessel is supplied with a specified quantity of liquefied petroleum gas after being charged with alcohol aqueous solution in specified concentration so as to cool that alcohol aqueous solution, and then liquefied petroleum gas of a specified quantity per unit time is sucked and is discharged into the above alcohol aqueous solution. It is to be desired that the alcohol aqueous solution should be ethylene glycol aqueous solution or ethanol aqueous solution. For liquefied petroleum gas, it is to be desired that one or more should be selected and used from among propane, butane, pentane, and hexane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative heat storage system using inclusion hydrate (gas hydrate), and more particularly to a method and an apparatus for realizing a cooling system at 0.degree.

[0002]

2. Description of the Related Art Inclusion hydrates have been attracting attention as a transport medium of cold heat, and methane, ethane, propane, chlorofluorocarbon 11 and chlorofluorocarbon 1 are contained in a cage-like inclusion lattice composed of water molecules.
A compound in which gas molecules such as 2 are encapsulated as guests and crystallized. A certain amount of heat is generated in the process in which the guest molecules are wrapped in the host molecules, and a cold storage medium that stores cold heat is generated. Therefore, it can be used as a transport medium for cold heat.

[0003] As a cold storage system using such a subsumed hydrate, for example, a system disclosed in Japanese Patent Application Laid-Open No. H11-264681 is conventionally known. This realizes a cooling system of 0 ° C. or higher for cooling air conditioning by using, for example, a tetra-n-butylammonium salt as a guest molecule. The invention described in Japanese Patent Application Laid-Open No. 10-259978 realizes a cooling system in a temperature range of 0 to 12 ° C. using an onium salt as a guest molecule.

[0004]

The conventional cooling system using the phase change latent heat at the time of gas hydrate generation is a technology on the premise of transporting a regenerative heat medium at 0 ° C. or more. It was a method of generating a heat medium.
In other words, in the conventionally proposed gas hydrate device,
There is a problem that a cooling system having a temperature of 0 ° C. or less cannot be applied to a practical device (for example, a freezer or a freezing case).

[0005] On the other hand, a cooling case or a cool box for frozen foods or fresh foods in a food section of a department store or a supermarket often needs cooling conditions of minus 0 ° C or less. In addition, if it is possible to generate a cold storage medium derived from inclusion hydrate at minus 0 ° C. or lower, the cold storage medium can be used in various practical systems including air conditioning. In particular, if the cold storage heat medium is generated at night using electric power at midnight and allowed to cool in the daytime, the power demand can be equalized and the power cost can be reduced for the user. Also, various advantages can be obtained, such as reducing the capacity of the refrigeration facility that has conventionally been adjusted to the peak load to the capacity of the refrigeration facility with an average load and enabling high-efficiency operation at a constant load.

It has been known in experiments that propane is conventionally used as a guest molecule when producing gas hydrate. However, propane is a gas at normal temperature and low pressure, and cannot produce a large amount of gas hydrate. In addition, since the use of liquefied propane is subject to restrictions on the handling of high-pressure gas, there are still complicated laws and regulations and safety issues to operate as a practical device in various stores.

[0007] An advantage of propane is its availability.
However, it has disadvantages such as high commercial cost due to its high utility value, and there is still a cost disadvantage in using it for a commercial cooling system.

Accordingly, an object of the present invention is to make it possible to generate a cold storage medium derived from gas hydrate in the range of 0 ° C. to −50 ° C. without being restricted by the handling of high-pressure gas.
Another object of the present invention is to increase the gas hydrate generation efficiency and minimize the operation loss.

[0009]

In order to achieve the above object, a cold storage method according to the present invention is characterized in that a cold storage tank is filled with an aqueous alcohol solution having a predetermined concentration, the alcohol aqueous solution is cooled, and then the cold storage tank is cooled. After a predetermined amount of liquefied petroleum gas is supplied, a predetermined amount of liquefied petroleum gas is suctioned and discharged into the alcohol aqueous solution per unit time. The alcohol aqueous solution is preferably an ethylene glycol aqueous solution or an ethanol aqueous solution. The liquefied petroleum gas is desirably used by selecting one or more of propane, butane, pentane, and hexane.

In order to achieve the above object, a regenerative heat storage device according to the present invention comprises a regenerative heat storage tank, a cooling device for cooling the inside of the regenerative heat storage tank, and a subsumed hydrate generated in the regenerative heat storage tank. A refrigerant device to be sent out to the subsequent stage, and the regenerative heat storage tank includes a filling port for an aqueous alcohol solution, and a filling port for liquefied petroleum gas supplied through a pressure reducing valve, and one or more disposed in a substantially vertical direction. A rotary arm having a hollow inside, and a suction arm for sucking liquefied petroleum gas in accordance with the rotation of the rotary shaft at an appropriate position, and a discharge arm for discharging the sucked liquefied petroleum gas into an aqueous alcohol solution. Wherein the suction arm and the discharge arm are both hollow inside and communicate with the hollow portion of the rotary shaft.
An opening is provided in the rotation direction of the rotation shaft.

The discharge arm is a straight tube projecting substantially at right angles from the rotation axis, and has an opening cut obliquely at an angle of about 45 degrees with respect to the rotation direction of the rotation axis. It is desirable to be opened in the direction opposite to the direction.

[0012]

According to the present invention, an alcohol aqueous solution serving as a host is cooled, and a liquefied petroleum gas serving as a guest is supplied thereto, thereby achieving low-pressure liquefaction of the petroleum gas. Because it is liquefied under low pressure, it is not subject to the regulations of the High Pressure Gas Safety Law. More specifically, the low pressure refers to a pressure within the system of 0.2 MPa or less at a temperature of 35 ° C. or less (the same applies hereinafter).

The liquefied petroleum gas forms a separate layer from the aqueous alcohol solution. In the case of ordinary LPG, a layer is formed on the alcohol aqueous solution. For this reason, various configurations can be adopted as a device structure in which liquefied petroleum gas is sucked into the upper layer portion and released and dispersed in the lower alcohol aqueous solution.

[0014] However, considering the production efficiency of the inclusion hydrate,
It is desirable to minimize the agitation of the guest gas, which eventually causes heat input. For this reason, in the device of the present invention, the liquid guest gas flowing from the opening of the suction arm with the rotation of the rotating shaft extending in the vertical direction is caused to flow downward through the hollow portion of the rotating shaft, and is discharged at the lower portion. The liquid is discharged into the aqueous alcohol solution (host) by centrifugal force (and negative pressure effect) from the opening of the arm. Accordingly, gas hydrate is generated, and the generated concentration of the cooling medium, that is, the cold storage temperature can be controlled according to the concentration of the aqueous alcohol solution. When liquefied petroleum gas is used as the guest, the practical control temperature range is 0 ° C. or less, and the maximum is −50 ° C.

The present invention does not limit the addition of an inert gas for the following reasons. That is,
An inert gas (nitrogen gas, etc.) that is not liquefied and does not dissolve in an aqueous solution in the range of the cold storage temperature (0 to minus 50 ° C.) according to the present invention is added to the upper LPG layer of the cold storage tank at a ratio of about 50 mol% or more. This is because the risk of explosion can be more reliably suppressed by adding in the above. Further, depending on the combination of the liquefied petroleum gas fluids, there is a possibility that the operation of reducing the pressure excessively. However, in order to prevent this, an inert gas may be used for buffering the pressure.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a cold storage technology according to the present invention will be described.
An example in which the present invention is applied to various types of refrigerators (commodity cases / refrigerators) will be described. First, an overall device system will be described with reference to FIG. Reference numeral 11 denotes a cooling case,
For example, fresh foods such as frozen foods, vegetables and seafood, refrigerated foods such as cheese and frozen desserts, and beverages are delivered. The set temperatures of the cooling cases 11 may be different from each other. Cooling case 1
1 is provided with an existing cooling device 41 using Freon gas or the like. Although there are usually a plurality of cooling cases, only one is illustrated for simplification of the drawing.

On the other hand, reference numeral 20 denotes a cold storage tank for generating a cold storage medium derived from gas hydrate. The generated regenerative heat medium is circulated and supplied to the cooling case 11 via a pump 31, a circulation pipe 32, and a flow control valve 33.

Reference numeral 40 denotes a cooling device for cooling the inside of the cold storage tank 20 to a set temperature. The refrigerator includes a refrigerator 41, a chiller 42, a pump 43, and a refrigerant circulation pipe 44. The refrigerant circulation pipe 44 is disposed so as to pass through the internal space of the cold storage heat tank 20. Since the refrigerant circulation pipe 44 cools the alcohol aqueous solution filled in the cold storage heat tank 20, the refrigerant circulation pipe 44 is designed, for example, in a spiral shape in order to improve the heat exchange rate, and increases the contact area with the alcohol aqueous solution. It is desirable. The number of the refrigerant circulation pipes 44 is not limited to one. A plurality may be provided according to the internal volume of the cold storage heat tank 20.

The cold storage tank 20 is provided with a supply port 21 for an aqueous alcohol solution and a supply port 22 for liquefied petroleum gas. still,
24 is an LPG cylinder obtained by liquefying high-pressure liquefied petroleum gas, 25 is a pressure reducing valve, 26 is a stop valve, 27 is a safety valve,
28 is a security valve, 29 is a pressure gauge. Reference symbol Q denotes an alcohol aqueous solution (host), and G denotes liquefied petroleum gas (guest).

The alcohol aqueous solution serving as a host may be an aqueous solution of a lower alcohol such as ethanol or methanol, but at a high concentration, it is regulated by dangerous substances under the Fire Service Law.
Therefore, in the case of an ethanol aqueous solution, it is desirable to lower the concentration and use it at, for example, less than 60 Wt%. Ethylene glycol is not subject to the same regulations over the entire concentration range. Therefore, in practical use, an ethylene glycol aqueous solution is preferable.

The regenerator tank 20 is provided with a rotating shaft 50 that is rotated by the motor 23. The number of rotating shafts 50 is not limited. In this embodiment, only one rotation shaft 50 is illustrated. The rotating shaft 50 uses a hollow pipe. Round tube,
Regardless of the square tube. The rotating shaft 50 extends in the up-down direction. The arrangement position of the motor 23 does not matter. In this embodiment, the motor 23 is disposed above the regenerative heat storage tank 20, and the rotating shaft 50 is directly driven.

An oil / gas suction arm 51 is provided near the upper end of the rotating shaft 50. In addition, oil gas exhaust arms 57 and 58 are provided below the rotating shaft 50. The suction arm 51 and the discharge arms 57 and 58 project in a direction substantially perpendicular to the rotation shaft 50. The number of arrangements is not limited. This is because the design of the amount of suction and the amount of discharge can be changed as appropriate in accordance with the desired device performance. However, it is desirable to arrange them symmetrically with respect to the rotation axis 50. This is to balance the motion balance of the rotating shaft 50.

The suction arm 51 has a suction opening 52 that opens in the direction of rotation of the rotation shaft 50 (illustrated by an arrow X), for example, as shown in FIG. Preferably, for example, an elbow tube having a curved portion 53 as shown in FIG. 3 is used. When the elbow pipe is used, the flow of the liquefied petroleum gas is smooth, and the efficiency of generating the cold storage heat medium is reliably increased.

On the other hand, for the discharge arms 57 and 58, a pipe material having a discharge opening 55 at a terminal portion is used. The shape does not matter. This is because liquefied petroleum gas can be discharged by centrifugal force. However, preferably, for example, as shown in FIG.
A discharge opening 55 cut obliquely in a direction opposite to the rotation direction (arrow X) of the rotation shaft 50 is provided.

The reason why the discharge opening 55 is cut obliquely in the direction opposite to the rotation direction is to increase the discharge efficiency of the liquefied petroleum gas by utilizing the negative pressure. Further, even if the pipes have the same inner diameter by being cut obliquely, the opening area becomes large, so that there is an advantage that the discharge arms 57 and 58 can be made smaller and lighter. The angle θ at the time of cut molding
Is desirably about 45 degrees. This is because a low-pressure portion is uniformly generated near the discharge opening 55. By installing a baffle plate on the inner wall of the heat storage tank, it is also effective to level the interface and efficiently suck the liquid phase as a high-density liquid phase.

Next, a procedure for generating and using a cold storage medium using such an apparatus will be described (see FIG. 5). First, a preparation operation is performed in the following procedure. An aqueous solution having an ethylene glycol concentration (60 Wt%) corresponding to a specified phase change temperature (for example, −25 to −30 ° C.) is supplied from the supply port 21 to the cool storage heat tank 20 in a predetermined amount (for example, 80 vol% of the internal volume of the cool storage heat tank 20). ) Is filled (S1).
Note that the phase change temperature depends on the concentration of the alcohol aqueous solution. When liquefied petroleum gas is used as the guest gas, the cold storage temperature can be controlled in the range of 0 ° C. or less to −50 ° C. The rotating shaft 50 is rotated at a specified speed (for example, 200 RPM) to uniformly mix the ethylene glycol aqueous solution (S
2). The refrigerator 41 and the pump 43 are started, and the cold storage medium flows into the cold storage tank 20 via the refrigerant circulation pipe 44 (S3). Then, the ethylene glycol aqueous solution in the cold storage heat tank 20 is gradually cooled to, for example, −20 ° C. (S4).
The cooling temperature in this case differs depending on the components of the LPG gas. Since the purpose of cooling in the preparatory operation is to liquefy LPG gas under low pressure, butane (boiling point -0.5 ° C),
Pentane (boiling point 36.1 ° C), hexane (boiling point 68.7)
When using a petroleum gas having a relatively high boiling point, such as 4 ° C.), it can be liquefied at a low pressure without cooling to −20 ° C.

In this embodiment, the regenerative heat storage tank 2 up to -20.degree.
The reason why 0 is cooled is to explain an example in which a propane mixed gas that is most easily used at the present time is used. Propane has a boiling point of -42.1 ° C, and when a mixture of butane and pentane is used, particularly when a commercially available LPG gas containing propane as a main component is used, low-pressure liquefaction can be performed at about -20 ° C. In addition, since propane has a low boiling point and is difficult to liquefy under low pressure, even when propane is used as the host gas according to the present invention, the amount of propane used should not exceed 50 Wt%, and heavy oil of butane or less should be used. Mix and use as appropriate. Methane and ethane have even lower boiling points, are difficult to liquefy under low pressure, and are practically difficult to use as guests. The operation is performed with the rotating shaft 50 lowered to the minimum speed (eg, 100 RPM) (S5). When the temperature of the cold storage tank 20 reaches -20 ° C., the cold storage tank 20 is gradually filled with LPG from the LPG cylinder through the pressure reducing valve 25 (S6). In this case, filling is performed while monitoring the pressure with the pressure gauge 29 so that the internal pressure of the cold storage heat tank 20 does not exceed 0.15 MPa. The LPG layer (G), which is liquefied and laminated on the upper part of the ethylene glycol aqueous solution, is filled while being checked with a viewing window (not shown).

The virgin aqueous solution used first tends to be supercooled. However, an aqueous solution having a history of gas hydrate generation even once is less likely to be supercooled thereafter. This is because once gas hydrate is generated and dissociated, liquefied petroleum gas is generally said to be insoluble in an aqueous solution. However, since 0.016 mol% or more is dissolved, the liquefied petroleum gas is not dissolved in the second or subsequent gas hydrate generation. The reason is that the liquefied petroleum gas component already dissolved and finely dispersed in the aqueous solution becomes a nucleus for gas hydrate generation and suppresses supercooling. Therefore, in the actual apparatus, the liquefied petroleum gas is sufficiently dissolved before the main operation in order to completely prevent the supercooling. Specified height (for example, about 90 VOL% of cold storage heat tank 20)
Is reached, the stop valve 26 is closed to stop the filling of LPG (S7). In this case, in order to ensure safety, the safety valve 28 is set to, for example, 0.17 MPa, and the temperature of the cold storage heat tank 20 is maintained at a set pressure or less. Further, the safety valve 27 is set to, for example, 0.19 MPa,
The rupture of the regenerative heat storage tank 20 is prevented from occurring due to an increase in pressure. Thus, the preparation operation is completed.

Next, the cold storage operation is performed in the following procedure. The refrigerating machine 41 is set to a specified capacity, the pump 43 drives the regenerative heat storage medium to a specified flow rate, and the motor 23 drives the rotating shaft 50 to a specified number of revolutions (for example, 200 RPM) to start a cool storage operation (S8). Cold storage operation uses inexpensive nighttime power. These specified values are determined in consideration of the time allowed for the cold storage operation. (It is desirable to take the time as slowly as possible to prevent overcooling and prevent ice from sticking to the heat transfer surface). When the specified time has elapsed, the refrigerator 41 and the rotating shaft 5
0, the pump 43 (cooling storage medium flow rate) is reduced to the minimum capacity (S9). At this time, the layer height of the LPG layer G can be confirmed from the viewing window (not shown), and the gas hydrate in the ethylene glycol aqueous solution (Q) can be confirmed from the other viewing windows (not shown). To ensure the operation value, the contents may be extracted from the drain and the specific gravity of the ethylene glycol concentration in the aqueous solution may be measured, or the gas hydrate formation concentration may be calculated by a refraction method. However, the state of generation of the cold storage heat medium can be grasped almost certainly by visual recognition from the viewing window. Finally, the end point stage of the cold storage medium generation is checked (S10), and the cold storage operation is terminated (S11). The stop check is performed by visual inspection, by measuring the specific gravity of the ethylene glycol concentration, or by calculating the gas hydrate generation concentration by a refraction method. For normal operation, time measurement is also a reference for stopping operation. At the end of the gas hydrate production,
As the water in the host aqueous solution becomes scarce, the generation rate of gas hydrate decreases, and the outlet temperature T2 of the cold storage heat storage tank 20 of the cold storage heat medium rapidly decreases (FIG. 6). If this phenomenon occurs, there is a possibility that ice with extremely poor thermal conductivity may adhere to the heat transfer surface, and it is therefore desirable to operate the apparatus while avoiding this phenomenon as much as possible. This is as follows.

For example, when the ethylene glycol aqueous solution containing no liquefied petroleum gas shown in FIG. 6 is simply cooled, or even when liquefied petroleum gas is included, the supply of the liquefied petroleum gas fluid that is insoluble in the cooling rate cannot keep up with the aqueous solution. FIG. 6 shows that a supercooling phenomenon occurred without generation of gas hydrate,
Ice alone precipitates with the II line. The single solid ice deposited in this manner is dense and hard and firmly adheres to the cooling coil (refrigerant circulation pipe 44) in the cold storage heat tank, has a large heat transfer resistance, and has a cooling heat represented by the overall heat transfer coefficient. A remarkable decrease in speed is caused, and the regenerative heat storage tank itself cannot function.

In a system containing a liquefied petroleum gas fluid, if it is possible to supply the liquefied petroleum gas fluid to the aqueous solution according to the cooling rate by elaborating the apparatus as described above, FIG.
As shown in line I, a gas hydrate composed of liquefied petroleum gas and water is generated at a temperature about 10 degrees higher than the temperature at which the ice alone precipitates. This gas hydrate is very fine and free flowing, and hardly adheres to the cooling surface, and a substantially constant high cooling rate is maintained for a long time. In addition, since the surface area is large and the generation and reverse dissociation are easy, the supercooling phenomenon, which is one of the biggest problems in the regenerative heat storage tank value, hardly occurs. This is due to the three-dimensional structure of the gas hydrate in which the liquefied petroleum gas fluid is taken in a basket formed by a plurality of water molecules.

Due to these characteristics, supercooling in the regenerative cooling stage can be suppressed, and a large portion of water in the aqueous solution initially added is generated as a gas hydrate of the latent heat storage medium without a significant decrease in the cooling rate. By doing so, a cold storage heat device having a high cold storage density as in the present invention can be realized.

The cold storage medium derived from gas hydrate stored in the cold storage tank 20 as described above is operated to cool down as follows. The pump 31 is started, and the cold storage medium derived from the gas hydrate flows from the cold storage tank 20 to the cooling case 11 (S12). The flow rate of the cold storage heat medium in the cooling case 11 is controlled by adjusting the flow rate adjusting valve 33. The cooling case 11 has a different cooling temperature level depending on the product to be stored, but the control temperature range is +/− 2 to 3.
It is an accuracy of ° C., and so strict temperature control is not required for practical use. At any time, the temperature in the cooling case 11 is measured (S1
3) At that time, the flow rates of the respective regenerative heat storage media flowing through the cooling case 11 are adjusted (S14). When there are a plurality of cooling cases, the flow rates are adjusted to keep the respective ranges within specified ranges.

The cooling operation described above is performed according to the purpose of use, such as keeping cold during the night and increasing the cooling capacity during the day. By generating a large amount of cold storage medium derived from gas hydrate, free use of the cold storage medium in a predetermined cycle (for example, in a 24-hour cycle) is possible. The power used during cold storage and cooling is much less than in conventional refrigeration systems, and there is a time lag between cold storage and cooling, so low-cost power can be used freely to use the cold storage medium. This makes it possible to turn around, and exhibits various usefulness in practical use, such as labor saving and dramatic improvement in equipment capacity in various cooling facilities that require a minus temperature.

[0035]

As described above, according to the cold storage method and apparatus according to the present invention, the cold storage heat medium derived from gas hydrate can be used in the temperature range of 0 ° C. to −50 ° C. without being restricted by the High Pressure Gas Safety Law. Can be generated. In addition, as a device configuration, it is possible to reliably increase the efficiency of producing subsumed hydrates by providing a rotating device (suction / discharge arm) for improving the efficiency of inflow of guest gas and release / dispersion to host gas. Made it possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of a system according to the present invention.

FIG. 2 is a diagram illustrating an opening of a suction arm according to the present invention.

FIG. 3 is a view showing a preferred opening example of a suction arm according to the present invention.

FIG. 4 is a diagram illustrating a discharge arm according to the present invention.

FIG. 5 is a block diagram illustrating a procedure for operating the system according to the present invention.

FIG. 6 is a graph showing a difference in cooling rate due to ice generation and gas hydrate generation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Cooling case 20 Cold storage heat tank 21 Alcohol aqueous solution supply port 22 Petroleum gas supply port 23 Motor 24 LPG cylinder 25 Pressure reducing valve 26 Stop valve 27 Safety valve 28 Security valve 29 Pressure gauge 31 Pump 32 Circulation pipe 33 Flow control valve 40 Cooling device 41 refrigerator 42 chiller 43 pump 44 refrigerant circulation pipe 50 rotating shaft 51 suction arm 52 suction opening 55 discharge opening 57, 58 discharge arm

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F25B 23/00 F28D 20/00 G 25/00 C09K 5/00 F (72) Inventor Wakinori Maekawa Sapporo, Hokkaido Michio Takahashi 3-27-7 Oyabe, Yokosuka City, Kanagawa Prefecture, Japan (72) Inventor Katsunori Matsushita Katsunori Matsushita 4-Jo 17-Chome, Toyohira-ku, Sapporo-shi, Hokkaido 14-1 No. 1 Domi 25 May Kanto 302 (72) Inventor Junichi Watanabe 1-38-5 Kitakase, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture No. 1 Inside the Institute of Industrial Science and Technology, Hokkaido Institute of Industrial Technology (72) Inventor Tsutomu Uchida No. 2-1, 17-2 Tsukikanhigashi, Toyohira-ku, Sapporo City, Hokkaido Inside the Institute of Industrial Science and Technology, Hokkaido Institute of Technology (72) Inventor Ebinuma Takaro F-term (reference) 3E072 AA03 DA01 DB10 3L093 NN01 PP09 PP19 RR01 2-1, 17-2, Tsukikanto, Toyohira-ku, Sapporo-city, Hokkaido, Japan

Claims (5)

[Claims] An aqueous alcohol solution having a predetermined concentration is filled in a cold storage tank, and after cooling the aqueous alcohol solution, a predetermined amount of liquefied petroleum gas is supplied into the cold storage tank. A cold storage method using a subsumed hydrate, wherein the petroleum gas is sucked and released and dispersed in the alcohol aqueous solution. 2. The method according to claim 1, wherein the alcohol aqueous solution is an ethylene glycol aqueous solution or an ethanol aqueous solution. 3. The liquefied petroleum gas is propane, butane,
The method according to claim 1 or 2, wherein at least one selected from pentane and hexane is used. 4. A regenerative heat storage tank, a cooling device for cooling the inside of the regenerative heat storage tank, and a refrigerant device for sending the subhydrated hydrate generated in the regenerative heat storage tank to a subsequent stage. A filling port for an aqueous alcohol solution and a filling port for liquefied petroleum gas supplied through a pressure reducing valve, and one or more rotating shafts arranged in a substantially vertical direction. The rotating shaft has a hollow inside. A suction arm for sucking the liquefied petroleum gas in accordance with the rotation of the rotating shaft, and a discharge arm for releasing and dispersing the liquefied petroleum gas into the alcohol aqueous solution at an appropriate position, wherein the suction arm and the discharge arm are either A regenerative heat storage device using a subsumed hydrate, characterized in that the suction arm has an opening opened in the rotation direction of the rotation shaft. . 5. The discharge arm is a straight pipe protruding at a right angle from a rotation axis, and has an opening cut obliquely at an angle of about 45 degrees with respect to the rotation direction of the rotation axis. 5. The regenerative heat storage device using a subsumed hydrate according to claim 4, wherein the device is opened in a direction opposite to the rotation direction.