JP2002333168A - Cold storage system and method for regenerating cold medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold storage system capable of extracting a water solution contaminated by a chemical to produce an inclusion hydrate to remove impurity and reusing the water solution, from which the impurity is removed, as a cold medium and to provide a method for regeneration of a water solution, polluted by a chemical, producing a inclusion hydrate into the water solution usable as a cold medium. SOLUTION: A water solution regeneration device 30 is provided to extract a water solution of the chemical to produce a quasi-inclusion hydrate compound circulated for use in a cold storage system or an inclusion hydration compound to remove impurity. A cold medium storage tank 10 stores an inclusion hydrate slurry. A manufacturing part 12 produces the inclusion hydrate slurry. Air conditioning equipment 17 utilizes cold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a semi-clathrate hydrate compound or a clathrate hydrate compound (hereinafter, the description of a semi-clathrate hydrate compound or a clathrate hydrate compound is simply referred to as a clathrate hydrate) The present invention relates to a cold heat storage system that stores heat of the slurry as a cold heat medium and uses the cold heat, and a method of regenerating the cold heat medium used in the cold heat storage system.

[0002]

2. Description of the Related Art In a building air conditioner or district air conditioner, a cooling medium is cooled and stored by nighttime electric power, and the cooling medium is taken out and used in the daytime of the next day. The system is being developed. In recent years, various studies have been made on a cold heat storage system that uses a clathrate hydrate slurry that has a latent heat of fusion in the air conditioning temperature range of 5 ° C. to 12 ° C. and has a large heat storage amount as a cooling medium.

The above-mentioned clathrate hydrate is a hydrate of a compound such as a quaternary ammonium salt, and is obtained by crystallizing a molecule of the following compound by being wrapped in a large number of water molecules. is there. As an agent for producing clathrate hydrate, tetra n
-Butylammonium salt, tetraiso-amylammonium salt, tetra-n-butylphosphonium salt, triiso-amylsulfonium salt and the like.

FIG. 5 is a view showing an example of a conventional cold heat storage system using an aqueous solution of a drug for producing clathrate hydrate as a cooling medium. In this figure, reference numeral 10 denotes a cooling / heating medium storage tank for storing clathrate hydrate in a slurry state, and reference numeral 12 denotes a slurry production for cooling an aqueous solution of a drug for producing clathrate hydrate to produce a clathrate hydrate slurry. Department. Reference numeral 11 denotes a circulation pump for the aqueous solution. The slurry production section 12 is provided with a refrigerator 13 as a source of cold heat and a cooler 14 for flowing a cooling medium discharged from the refrigerator. Reference numeral 17 denotes an air conditioner utilizing cold heat. Reference numeral 15 denotes a pump for discharging the clathrate hydrate slurry, 16 denotes a discharge pipe for sending the clathrate hydrate slurry to the cold heat utilization unit, and 18 denotes a return pipe for the aqueous solution after the cold heat is used.

[0005] In the above-mentioned cold heat storage system, an aqueous solution of a drug that forms clathrate hydrate is stored in the cold heat medium storage tank 10, and the aqueous solution is sent to the cooler 14 to be cooled.
Crystals of clathrate hydrate are formed. Then, by circulating and cooling the aqueous solution in the cooling medium storage tank 10, clathrate hydrates are sequentially accumulated in the cooling medium storage tank 10. The generated clathrate hydrate is fine crystals, and is stored in the cooling medium storage tank 10 in a slurry state.

[0006] The clathrate hydrate slurry stored in the cooling medium storage tank 10 is withdrawn by the discharge pump 15 and sent to the air conditioner 17. The clathrate hydrate slurry sent to the air conditioner 17 is heat-exchanged into an aqueous solution, and is returned to the cooling medium storage tank 10 via the return pipe 18.

As described above, the clathrate hydrate slurry is used not only as a heat storage medium but also as a cooling medium transport medium, and is circulated.

[0008] However, the aqueous solution of the chemical that forms the clathrate hydrate is contaminated by foreign substances such as rust and dirt in the piping while being circulated and used. There is a need to. For this reason, an aqueous solution must be prepared with an agent that newly generates an inclusion hydrate.

The present invention provides a cold heat storage system capable of extracting an aqueous solution of a drug producing contaminated clathrate hydrate to remove impurities and reusing the aqueous solution from which the impurities have been removed as a cooling medium. It is an object of the present invention to provide a method for regenerating an aqueous solution of a drug that produces a contaminated clathrate hydrate into a reusable medium as a cooling medium.

[0010]

In order to solve the above-mentioned problems, a cold heat storage system according to the first aspect of the present invention stores heat of a clathrate hydrate slurry as a cold heat medium and uses the cold heat. A cold heat storage system, comprising: an aqueous solution regenerating device for extracting an aqueous solution of a drug producing a clathrate hydrate circulated in the cold heat storage system and removing impurities other than the drug. system.

According to a second aspect of the present invention, in the cold heat storage system according to the first aspect, the aqueous solution regenerating apparatus generates a quasi-clathrate hydrate compound or a clathrate hydrate compound that is circulated and used. It has a processing tank that performs processing to separate impurities from the aqueous solution of the drug, and this processing tank has a built-in heat exchanger and supplies a heat medium for cooling and a heat medium for heating to the heat exchanger by switching. It is characterized in that piping is connected.

According to a third aspect of the present invention, there is provided a method for regenerating a cooling medium, wherein the aqueous solution of the quasi-clathrate hydrate compound or the agent for producing the clathrate hydrate compound used as the cold medium of the cold heat storage system is heat-exchanged. Into a treatment tank equipped with a heat exchanger, a cooling medium is passed through a heat exchanger to generate crystals of the quasi-clathrate hydrate compound or clathrate hydrate compound, and an aqueous solution remaining after the crystals are formed Is discharged, the heating medium is passed through the heat exchanger to heat and melt the semi-clathrate hydrate compound or the clathrate hydrate compound crystal, and the semi-clathrate hydrate compound from which impurities have been removed. Alternatively, an aqueous solution of a drug that produces a clathrate hydrate compound is obtained. To regenerate the cooling medium.

According to a fourth aspect of the present invention, there is provided a method for regenerating a cooling medium according to the third aspect of the present invention, comprising heating an aqueous solution of a drug for producing a clathrate hydrate from which impurities have been removed, obtained by the method according to the third aspect of the present invention. The method is characterized in that a drug that forms a clathrate hydrate is precipitated by concentration, and the precipitate is separated to obtain a drug that forms a clathrate hydrate.

According to a fifth aspect of the present invention, there is provided the method for regenerating a cooling medium according to the fourth aspect of the present invention, wherein the quasi-clathrate hydration compound from which impurities have been removed or the drug that produces the clathrate hydration compound is used. It is characterized in that a high-temperature fluid discharged from a cold heat generator is used as a heat source when heating an aqueous solution.

[0015]

FIG. 1 is a diagram showing an example of a configuration according to an embodiment of a cold heat storage system of the present invention. 1, the same components as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, an aqueous solution for removing impurities by extracting an aqueous solution of a drug that forms a clathrate hydrate that is a cooling medium stored in the cooling medium storage tank 10 is used by being circulated in the cooling heat storage system. A playback device 30 is provided. The aqueous solution regenerating device 30 may be used in accordance with the degree of contamination of the aqueous solution of the drug that forms the clathrate hydrate,
It is a device that is operated as appropriate, but is a device that operates during the season when the cold heat storage system is operated or at predetermined intervals to purify an aqueous solution of a drug that generates clathrate hydrate.

The aqueous solution regenerating apparatus 30 is connected to the main body of the cold heat storage system by an aqueous solution receiving pipe 50 branched from the delivery pipe 16 and an aqueous solution return pipe 51 for returning an aqueous solution of the purified drug to the cold medium storage tank 10. I have.

FIG. 2 is a diagram showing the configuration of the aqueous solution regenerating apparatus in FIG. In FIG. 2, reference numeral 31 denotes a treatment tank which receives an aqueous solution of a chemical which produces contaminated clathrate hydrate by being circulated and used in the cold heat storage system to remove impurities. Is provided. 3
3 is a receiving tank for the aqueous solution from which impurities have been removed in the processing tank;
Is a receiving tank for an aqueous solution containing impurities. Reference numeral 35 denotes a refrigerator that generates cold water used as a cooling heat medium, 36 denotes a cold water supply pump, 37 denotes a cooling water tower that cools the refrigerator, and 38 denotes a cooling water pump.

The heat transfer tube 32 incorporated in the processing tank 31 can be supplied by switching between a heat medium for cooling and a heat medium for heating. Cold water generated by a refrigerator is supplied as a heat medium for cooling, and normal-temperature water is supplied as a heat medium for heating. The cooling water sent from the cooling water pump 38 is used as the normal temperature water. For this reason, the pipe 39 of the heat medium for cooling
Is connected to a pipe 43 branched from a cooling water pipe 41 of the refrigerator, and a pipe 40 of a cooling medium and a cooling water pipe 42 of the refrigerator are connected by a pipe 44. 45 and 46 are switching valves.

Here, the heat transfer tube 32 is used as a heat exchanger.
However, the heat exchanger cools or heats the fluid in the tank by circulating a heat medium inside the heat exchanger, and the shape is not limited to a tubular shape, and a plate type or the like is used. Can also be used.

An operation method of the aqueous solution regenerating apparatus configured as described above will be described with reference to FIGS. While the cold heat storage system is stopped, an aqueous solution of a chemical that generates contaminated clathrate hydrate is received from the cold heat medium storage tank into the treatment tank 31, and the refrigerator 35 is started to flow cold water through the heat transfer tube 32. By this cooling, as shown in FIG. 3A, crystals of the clathrate hydrate 101 are formed on the outer surface of the heat transfer tube 32, and the layer of the clathrate hydrate 101 grows gradually.

A sufficient layer of clathrate hydrate 101 is formed,
At the stage where the concentration of the drug that forms the clathrate hydrate contained in the aqueous solution in the treatment tank 31 has decreased to a predetermined value, the refrigerator 35 is stopped, and as shown in FIG. The aqueous solution 103 containing impurities remaining after the crystals of the object 101 are generated is extracted from the bottom of the processing tank to the receiving tank 34. At this time, impurities other than the crystals of the clathrate hydrate 101 are contained in the aqueous solution 103 and discharged, and only the crystals of the clathrate hydrate 101 are removed from the treatment tank 3.
Remains within 1.

Next, the heat medium flowing through the heat transfer tube 32 is switched to a heating medium for heating. To switch to the heating heat medium, the flow path of the cooling water is switched by switching the cooling water switching valves 45 and 46, and normal-temperature water flows through the heat transfer tubes 32 via the pipes 43 and 44. By switching to normal temperature water, as shown in FIG. 3C, the clathrate hydrate attached to the heat transfer tube 32 is heated and melted to form a clathrate hydrate from which impurities have been removed. The resulting solution is an aqueous solution 102 of the drug. This aqueous solution is extracted from the bottom of the processing tank 31 to the receiving tank 33. The aqueous solution 102 of the drug that forms the clathrate hydrate from which the impurities have been removed is sent to the cooling medium storage tank of the heat storage system main body and reused.

The aqueous solution 102 withdrawn into the receiving tank 33 is a solution in which the crystals of the clathrate hydrate containing no impurities are melted, so that the purity of the solution for forming the clathrate hydrate as an aqueous solution is increased. Further, the concentration is increased to a concentration (about 40 mass%) at which the melting point shows a maximum value. Therefore, the aqueous solution of the drug is used for adjusting the concentration.

On the other hand, the aqueous solution 1 extracted into the receiving tank 34
03 contains impurities, but a drug that forms clathrate hydrate remains, so this aqueous solution was filtered to remove solids such as rust and dirt, and then concentrated. Of the aqueous solution 103 by sending
Recover the above drug remaining in.

FIG. 4 is a diagram showing an example of an embodiment according to a method for regenerating a cooling medium according to the present invention. According to this embodiment, the aqueous solution of the drug from which impurities are removed or the aqueous solution of the drug from which impurities have been removed is obtained from the aqueous solution of the drug that forms the clathrate hydrate that has been circulated and used in the cold heat storage system. Can be

In FIG. 4, reference numeral 30 denotes an aqueous solution regenerating apparatus having the same configuration as in FIG. This aqueous solution regenerating device 30 is denoted by the same reference numerals as in FIG. Reference numeral 60 denotes a storage tank for the pre-treatment aqueous solution that receives and stores an aqueous solution of a drug that produces a contaminated clathrate hydrate. Numeral 70 is a storage tank for a treated aqueous solution for receiving and storing an aqueous solution of a drug which is processed by the aqueous solution regenerating device 30 to form clathrate hydrate from which impurities have been removed. Reference numeral 80 denotes a crystallizer for obtaining crystals of the drug from an aqueous solution of a drug that is processed by the aqueous solution regenerating device 30 to form an inclusion hydrate from which impurities have been removed.

The operation of the apparatus having the above configuration is performed as follows. A pretreatment aqueous solution storage tank 60 receives an aqueous solution 100 of a drug that is used in a cold heat storage system and generates contaminated clathrate hydrate, and sends the aqueous solution of the drug to an aqueous solution regenerating device 30 to remove impurities. The aqueous solution 102 of the drug that produces the clathrate hydrate from which the impurities have been removed is drawn out to the receiving tank 33.

The aqueous solution 102 of the drug extracted into the receiving tank 33 is divided into two uses depending on the supply and demand situation. What is provided for the first use is sent to the storage tank 70 for the aqueous solution after treatment and stored therein, and is supplied to the cold heat storage system as an aqueous solution of a drug that produces a clathrate hydrate with increased purity and concentration.

In the second application, the product is sent to an evaporator 81 of a crystallizer and concentrated to precipitate a drug that forms clathrate hydrate. 82 is a heater built in the evaporator. As a heat source to be supplied to the heater 82, it is preferable to use a high-temperature fluid discharged from the cold heat generator. For example, when an absorption refrigerator is provided as the refrigerator 35 of the aqueous solution regenerating device, the condensate of steam discharged from the evaporator can be used.

The drug which forms clathrate hydrate precipitated in the evaporator 82 is extracted together with the mother liquor and sent to a separator 83 to separate the mother liquor, whereby crystals of the drug 104 are obtained. The obtained chemical 104 for producing clathrate hydrate is obtained by two crystallization treatments, in other words, two impurity removal treatments, and has a very high purity. That is, in this embodiment, the first impurity removal processing by crystallization is performed in the treatment tank 31 of the aqueous solution regenerating apparatus, and the second impurity removal processing by crystallization is performed in the evaporator 81 of the crystallizer. Done.

[0031]

According to the cold heat storage system of the present invention,
Since an aqueous solution regenerating device is provided for extracting an aqueous solution of a drug that forms a clathrate hydrate used as a cooling medium and removing impurities, the impurities are removed from the contaminated aqueous solution of the drug, and the impurities are removed. The aqueous solution from which is removed can be reused as a cooling medium.

In the method for regenerating a cooling medium according to the present invention,
The aqueous solution of the drug that forms the clathrate hydrate used as the cooling medium of the cooling heat storage system is charged into a processing tank provided with a heat transfer tube to which the cooling heat medium and the heating heat medium are switched and supplied. By cooling, the clathrate hydrate crystals are generated around the heat transfer tube, and after discharging the remaining aqueous solution, heating is performed to melt the clathrate hydrate crystals formed around the heat transfer tube. Since an aqueous solution of a drug that produces a clathrate hydrate with high purity and high concentration can be obtained, the contaminated aqueous solution of the drug can be regenerated into a reusable medium as a cooling medium.

Further, in the method for regenerating a cooling medium according to the present invention, the aqueous solution of a drug for producing a clathrate hydrate from which impurities are obtained, obtained by the above method, is heated and concentrated to precipitate the drug. Then, by separating this, it is possible to obtain an agent that produces a highly pure clathrate hydrate. Therefore, the aqueous solution of the drug that forms the clathrate hydrate can be stored in the form of a powder, and the storage and transport of the drug used as the cooling medium source can be facilitated.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a configuration according to an embodiment of a cold heat storage system of the present invention.

FIG. 2 is a diagram showing a configuration of an aqueous solution regenerating apparatus in FIG.

FIG. 3 is an explanatory diagram relating to a processing operation of the aqueous solution regenerating apparatus.

FIG. 4 is a diagram showing an example of an embodiment according to a method for regenerating a cooling medium of the present invention.

FIG. 5 is a diagram showing an example of a conventional cold heat storage system that uses an aqueous solution of a drug that produces a clathrate hydrate as a cold medium.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Cooling medium storage tank 12 Slurry manufacturing part 13 Refrigerator 14 Cooler 15 Slurry discharge pump 16 Slurry discharge pipe 17 Air conditioner 18 Return pipe 30 Aqueous solution regenerating device 31 Processing tank 32 Heat transfer pipe 33 Receiving tank of aqueous solution from which impurities were removed, 34 Receiving tank for aqueous solution containing impurities 35 Refrigerator 36 Cold water supply pump 37 Cold water tower 38 Cooling water pump 39, 40 Cold water piping 41, 42 Cooling water piping 43, 44 Cooling water piping 50 Aqueous solution receiving piping 51 Aqueous solution returning piping 80 crystals Analyzing device 81 Evaporator 82 Heater 83 Separator 100 Aqueous solution of drug producing contaminated clathrate hydrate 101 Clathrate hydrate 102 Aqueous solution of drug producing clathrate hydrate from which impurities have been removed 103 Aqueous solution containing impurities remaining after generation of clathrate hydrate crystals 104 Generate clathrate hydrate Drug

Continuation of the front page (72) Inventor Hidemasa Ogoshi 1-2-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 3L054 BH02

Claims (5)

[Claims] 1. A semi-clathrate hydration circulating in a cold heat storage system in a cold heat storage system that stores heat of a semi-clathrate hydrate compound or a slurry of a clathrate hydrate compound as a cooling medium and uses the cold heat. A cold heat storage system comprising an aqueous solution regenerating device for extracting an aqueous solution of a compound or a drug that produces a clathrate hydrate compound and removing impurities other than the drug. 2. An aqueous solution regenerating apparatus has a processing tank for separating impurities from an aqueous solution of a circulating semi-clathrate hydrate compound or an agent for producing a clathrate hydrate compound. 2. The cold heat storage system according to claim 1, wherein a heat exchanger is built in, and a pipe for switching and supplying a heat medium for cooling and a heat medium for heating is connected to the heat exchanger. 3. An aqueous solution of a quasi-clathrate hydrate compound or an agent for forming a clathrate hydrate compound used as a cooling medium of the cold heat storage system is charged into a treatment tank equipped with a heat exchanger, After passing the cooling heat medium through to generate crystals of the quasi-clathrate hydrate compound or the clathrate hydrate compound, and discharging the aqueous solution remaining after the generation of the crystals, the heating heat medium is passed through the heat exchanger. Is heated to melt the crystals of the quasi-clathrate hydrate compound or the clathrate hydrate compound to obtain an aqueous solution of a drug that produces the quasi-clathrate hydrate compound or the clathrate hydrate compound from which impurities are removed. A method for regenerating a cooling and heating medium, comprising: 4. A semi-clathrate hydration solution obtained by the method according to claim 3, wherein the aqueous solution of the quasi-clathion hydrate compound from which impurities have been removed or a drug producing the clathrate hydration compound is heated and concentrated. Precipitating a compound or a drug that produces a clathrate hydrate compound, and separating the precipitate to obtain a drug that produces a quasi-clathrate hydrate compound or a clathrate hydrate compound. Playback method. 5. A high-temperature fluid discharged from a cold-heat generator is used as a heat source for heating an aqueous solution of a quasi-clathrate hydrate compound from which impurities have been removed or a drug that produces a clathrate hydrate compound. The method for regenerating a cooling medium according to claim 4, wherein: