JP2010121800A - Method and device of forming hydrate by using heat storage tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for forming hydrate by using a heat storage tank, capable of forming hydrate substantially in a resting state in forming hydrate by using a liquid guest substance and water as a host substance. <P>SOLUTION: A heat storage body 11 receiving the liquid guest substance and the water as the host substance is disposed in a heat storage tank 10, the heat storage tank 10 is filled with a refrigerant 12 cooled by a main refrigerating machine 13, a supercooling section 18 is disposed in the heat storage body 11 to supercool the liquid guest substance and the host substance to be lower than a clathrate hydrate formation temperature, species of the clathrate hydrate is formed by supercooling the liquid guest substance and the host substance at the supercooling section 18, and the formation of hydrate is transmitted on the basis of the species to produce the clathrate hydrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a hydrate generation method and apparatus using a heat storage tank that generates clathrate hydrate with a liquid guest substance and water as a host substance in the heat storage tank.

  Methane hydrate is known as a general hydrate, but the guest substance is methane gas, which may be used for methane storage. However, it can be used for storage of methane. As a medium, the pressure and temperature conditions for producing the hydrate do not match the heat storage application.

  As an example of using a slurry-like hydrate instead of cold water or ice as a cold storage material, in Patent Documents 1 and 2, an aqueous solution of tetra n-butylammonium salt (TBAB) is used, and this is cooled to 5 It has been proposed that a regenerator material is obtained by converting a liquid to a slurry hydrate at -8 ° C.

  However, TBAB is a white crystalline powder that is soluble in water, and is used as a TBAB aqueous solution having a concentration of 20% or more. However, as a hydrate, there is a problem that heat of decomposition is small.

  The present inventor uses a cyclic hydrocarbon as a guest material, and produces a hydrate with the guest material and water, more specifically, a liquid guest material composed of cyclopentane and water as a host material. A method of directly cooling the interface of the solution to form a hydrate (Japanese Patent Application No. 2007-129563), and emulsifying a liquid guest substance composed of cyclopentane and water with a surfactant to form a dispersion, which is cooled Thus, a method for producing a hydrate (Japanese Patent Application No. 2007-129553) was proposed.

  The hydrate is cooled by contacting water as a host and a liquid as a guest material, and the guest is encapsulated in an inclusion lattice constituted by water molecules to crystallize to form a hydrate. However, by appropriately selecting the hydrocarbon liquid of the guest material, a wide range of generation temperatures can be obtained from 0 ° C or higher to minus several tens of ° C. After decomposition, both the host and guest are liquid. There is no pressure loss, and it is possible to make it possible to provide a heat storage and cold heat source suitable for the purpose of use.

Japanese Patent Laid-Open No. 2004-3718 JP 2005-291516 A

  In general, hydrates have supercooling properties, and hydrates do not form unless supercooling is released or contacted with seed crystals in the same manner as water.

  When cyclopentane is used as a guest substance, as shown in FIG. 5, the supercooling of water is canceled to generate ice, and hydrates grow using this as seed crystals, or as shown in FIG. Hydrate grows by adding seed crystals of hydrate.

  However, in order to cancel the supercooling of water, a low temperature of about −6 ° C. is necessary, and the power of the cooling heat source that makes a temperature much lower than the temperature necessary for hydrate formation is wasted. Further, when seed crystals are added, it becomes virtually impossible when there are an infinite number of containers filled with the heat storage material in the heat storage tank, such as capsules.

  Therefore, the object of the present invention is to solve the above-mentioned problems and to adjust the main cold source temperature or to physically convert the seed crystal when producing a hydrate with a liquid guest substance and water as a host substance. It is an object to provide a hydrate generation method and apparatus using a heat storage tank that can stably generate hydrates with low power without being charged into the tank.

  In order to achieve the above object, the present invention according to claim 1 is a method for containing clathrate hydrate by storing a liquid guest substance and water as a host substance in a heat storage body and cooling the heat storage body. In addition, a supercooling part is provided in the heat storage body, and in this supercooling part, a liquid guest substance and water are supercooled to form a clathrate hydrate seed, and hydrate formation is propagated based on that seed. And a clathrate hydrate to produce a hydrate production method using a heat storage tank.

  The invention of claim 2 is a method for producing a hydrate using a heat storage tank according to claim 1, wherein a surfactant is mixed into a liquid guest substance and water to form a dispersion, and the dispersion is accommodated in the heat storage body. is there.

  The invention according to claim 3 is the heat storage tank according to claim 1 or 2, wherein the liquid guest material and water are accommodated in the heat storage body, and the guest material and water are circulated to the supercooling portion in the heat storage body. It is the hydrate production | generation method used.

  Invention of Claim 4 is a hydrate production | generation method using the thermal storage tank in any one of Claims 1-3 in which a supercooling part consists of a cooling coil or a thermoelectric element with which a refrigerant | coolant flows.

  The invention of claim 5 supercools the liquid guest substance and water to a temperature lower by about −2 ° C. than the clathrate hydrate formation temperature, and the supercooled liquid guest substance and water. It is a hydrate production | generation method using the thermal storage tank in any one of Claims 1-4 which are cooled to the temperature by which a clathrate hydrate is produced | generated by a supercooling part.

  The invention of claim 6 is characterized in that the heat storage body comprises a multi-tube collecting pipe in which a heat transfer pipe is connected to the upper header pipe and the lower header pipe. Hydrate generation using the heat storage tank according to any one of claims 1 to 5 Is the method.

  The invention according to claim 7 is provided with a heat storage body containing a liquid guest material and water as a host material in the heat storage tank, and the heat storage tank is filled with a refrigerant cooled by the main refrigerator, and the heat storage body In addition, a hydrate generating apparatus using a heat storage tank is provided with a supercooling section for supercooling a liquid guest substance and water to a clathrate hydrate generation temperature or lower.

  Invention of Claim 8 is a hydrate production | generation apparatus using the thermal storage tank of Claim 7 which connected the circulation line which circulates a liquid guest substance and water to the supercooling part in a thermal storage body to the thermal storage body.

  The invention according to claim 9 is the hydrate generator using the heat storage tank according to claim 7 or 8, wherein the supercooling section is formed of a cooling coil or a thermoelectric element through which a refrigerant flows.

  The invention of claim 10 is characterized in that the heat storage body comprises a multi-tube collecting pipe in which a heat transfer pipe is connected to the upper header pipe and the lower header pipe. Hydrate generation using the heat storage tank according to any one of claims 7 to 9. Is the method.

  According to the present invention, the liquid guest material and the host material water are accommodated in the heat storage body, and the clathrate hydrate is obtained by supercooling the liquid guest material and water in the supercooling section provided in the heat storage body. By forming the seeds, the clathrate hydrate can be produced at a static type and near the clathrate hydrate production temperature.

  A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 shows a hydrate generator using the heat storage tank of the present invention.

  In FIG. 1, a heat storage tank 10 in which a liquid guest substance and water as a host substance are accommodated is provided in a heat storage tank 10.

  The heat storage tank 10 is filled with a refrigerant 12 for cooling the heat storage body 11 or recovering cold heat, and the refrigerant 12 is cooled by the main refrigerator 13. In addition, although not shown, the cold energy recovered from the heat storage body 11 into the refrigerant 12 is supplied to the cold energy utilization system via a heat transfer coil installed in the tank or a heat exchanger installed outside the tank. Yes.

  The heat accumulator 11 is constituted by a multi-tube collecting pipe in which a heat transfer pipe 17 is connected between an upper header pipe 15 and a lower header pipe 16 as shown in the figure.

  FIG. 2 is a perspective view of the heat storage body 11 composed of a multi-tube collecting tube, and a plurality of upper and lower header tubes 15 and 16 are provided in accordance with the size of the heat storage tank 10 and a heat transfer tube 17 is connected. Furthermore, the headers 15 and 16 are connected by a connecting pipe 19 to constitute a heat storage body 11 composed of a multi-tube collecting pipe.

  In the heat storage body 11, for example, a supercooling section 18 is provided in the upper header pipe 15 of the multi-tube collecting pipe, and the supercooling section 18 is controlled by the sub refrigerator 20.

  The supercooling section 18 includes a cooling coil 18a through which a refrigerant flows as shown in FIG. 4A and a thermoelectric element 18b such as a Peltier element as shown in FIG. 4B. When the thermoelectric element 18b is used, the sub refrigerator 20 is not necessary and is connected to a power source instead.

  The supercooling unit 18 cools the liquid guest material and the water, which is the host material, to a temperature at which clathrate hydrate is reliably generated.

Examples of guest substances used in the present invention include cyclic hydrocarbons such as cyclopentane and linear hydrocarbons such as pentane. In the case of cyclopentane (C ₅ H ₁₀ ), a hydrate is produced at a production temperature of about 7 ° C. under atmospheric pressure, but in order to actually produce a hydrate, −2 ° C. with respect to the production temperature. Hydrate is produced | generated by cooling above.

  The composition ratio of the guest substance and water is determined by the hydrate structure. In the case of cyclopentane, cyclopentane: water has a molar ratio of 1:17 (volume ratio of 1: 3.3, weight ratio). 1: 4.4) is a complete clathrate hydrate formation ratio, so if the ratio of cyclopentane is less than this, there is no extra guest substance when clathrate hydrate formation is completed. If the amount is too small, the clathrate hydrate content is small and the performance of the heat storage density deteriorates. Therefore, the composition range is from 1:17 to about 3-fold dilution thereof.

  Further, about 5 wt% of a surfactant may be mixed in the guest substance and water, and this may be stirred to obtain a dispersion.

  Next, the hydrate production | generation method using this collecting pipe type thermal storage tank is demonstrated.

  When the clathrate hydrate of the liquid guest material in the heat storage body 11 and the water as the host material is generated, the refrigerant 12 in the heat storage tank 10 is introduced into the main refrigerator 13 and cooled, Is circulated in the heat storage tank 10.

  As a result, the liquid guest material and water as the host material in the heat storage body 11 are cooled to a temperature slightly lower than the clathrate hydrate formation temperature, and are brought into a supercooled state.

  After cooling the liquid guest material and the water that is the host material in the heat storage body 11 to this supercooled state, the supercooling unit 18 further cools the liquid guest material and the water that is the host material, A clathrate hydrate seed is formed around the cooling section 18. By forming the seed in this manner, the liquid guest substance and water cooled to the supercooled state can be hydrated as a whole by propagation of hydrate formation based on the seed. .

  As described above, when a clathrate hydrate is produced using cyclopentane as a guest substance, the production temperature of the hydrate is about 7 ° C., and the heat storage body 11 is slightly lower than 7 ° C. 5 In this state of cooling to ˜3 ° C., cyclopentane and water are kept in a supercooled liquid state with respect to the production temperature (about 7 ° C.).

  In this state, the sub refrigerator 20 is turned on, and the supercooling unit 18 cools the surrounding supercooled liquid to near −6 ° C., so that the supercooled water becomes ice, and this ice is used as a seed. A seed of clathrate hydrate is formed, and hydrate formation is propagated based on the seed, and clathrate hydrate is generated between the liquid guest material in the heat storage body 11 and water as the host material. .

  Due to the generation of the clathrate hydrate, the supercooling is released and the clathrate hydrate is raised to the production temperature, so the sub refrigerator 20 is turned off, and then the clathrate hydrate is generated in the main refrigerator 13. Can continue. The sub refrigerator 20 may be turned on before the completion of the operation of supercooling all substances in the heat storage body 11 to the clathrate hydrate generation temperature.

  As described above, in the production of clathrate hydrate using a liquid as a guest material, the present invention accommodates the liquid guest material and water as a host material in the heat storage body 11 in the heat storage tank 10, It is possible to produce a clathrate hydrate in a static type by simply cooling the refrigerant 12.

  In addition, after the clathrate hydrate is generated, the refrigerant 12 in the heat storage tank 10 may be used after being transferred to the cold heat utilization system, or the clathrate hydrate in the heat storage body 11 is directly utilized. You may make it transfer to.

  FIG. 3 shows another embodiment of the present invention.

  In this embodiment, the circulation line 22 and the circulation pump 23 are connected to the upper header pipe 15 of the multi-pipe collecting pipe constituting the heat storage body 11 provided with the supercooling section 18, and the inside of the upper header pipe 15 is connected. A liquid guest substance and water are repeatedly circulated in the supercooling section 18 so that the clathrate hydrate can be efficiently generated.

  Further, as indicated by the two-dot chain line, the upper header pipe 15 and the lower header pipe 16 are connected by a circulation line 24 so that a clathrate hydrate can be generated by circulating a liquid guest substance and water throughout. Is.

  In this embodiment, even if the liquid guest substance and water are not dispersed with the surfactant, the liquid guest substance and water are circulated even when they are separated into two layers, thereby enabling the packaging. It is possible to efficiently produce the wet hydrate.

It is a figure which shows one embodiment of this invention. It is a perspective view of the thermal storage body which consists of a multitubular collecting pipe in FIG. It is a figure which shows other embodiment of this invention. It is a figure which shows the detail of a supercooling part in this invention. It is a figure which shows the temperature change of a refrigerant | coolant and a thermal storage material when water is cancelled | released and ice produces | generates and this becomes seed | species and clathrate hydrate production | generation progresses. It is a figure which shows the temperature change of a refrigerant | coolant and heat storage material at the time of clathrate hydrate production | generation progressing by adding a hydrate to a heat storage material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Thermal storage tank 11 Thermal storage body 12 Refrigerant 13 Main refrigerator 18 Supercooling part

Claims (10)

  When a liquid guest material and water as a host material are contained in a heat storage body and the heat storage body is cooled to produce clathrate hydrate, a supercooling section is provided in the heat storage body, and the supercooling section And forming a clathrate hydrate seed by supercooling the liquid guest material and water, and generating a clathrate hydrate based on the seed. Hydrate production method using heat storage tank.   A method for producing a hydrate using a heat storage tank according to claim 1, wherein a surfactant is mixed into a liquid guest substance and water to form a dispersion, and the dispersion is accommodated in a heat storage body.   A method for producing a hydrate using a heat storage tank according to claim 1 or 2, wherein a liquid guest material and water are accommodated in a heat storage body, and the guest material and water are circulated to a supercooling section in the heat storage body. .   The method for producing a hydrate using a heat storage tank according to any one of claims 1 to 3, wherein the supercooling section comprises a cooling coil or a thermoelectric element through which a refrigerant flows.   The liquid guest substance and water are supercooled to a temperature lower by about −2 ° C. than the clathrate hydrate formation temperature, and the supercooled liquid guest substance and water are subcooled in the supercooling section. The hydrate production | generation method using the thermal storage tank in any one of Claims 1-4 cooled to the temperature in which clathrate hydrate is produced | generated.   The heat storage body is a hydrate generation method using a heat storage tank according to any one of claims 1 to 5, wherein the heat storage body includes a multi-tube collecting pipe in which a heat transfer pipe is connected to an upper header pipe and a lower header pipe.   In the heat storage tank, a heat storage body containing a liquid guest material and water as a host material is provided, and the heat storage tank is filled with a refrigerant cooled by the main refrigerator, and the liquid storage medium is filled with the liquid guest material. A hydrate generation apparatus using a heat storage tank, characterized in that a supercooling unit for supercooling water to a clathrate hydrate generation temperature or less is provided.   The hydrate production | generation apparatus using the thermal storage tank of Claim 7 which connected the circulation line which circulates a liquid guest substance and water to the supercooling part in a thermal storage body to the thermal storage body.   The hydrate production | generation apparatus using the thermal storage tank of Claim 7 or 8 which a supercooling part consists of a cooling coil or a thermoelectric element with which a refrigerant | coolant flows.   The heat storage body is a hydrate generation method using a heat storage tank according to any one of claims 7 to 9, wherein the heat storage body includes a multi-tube collecting pipe in which a heat transfer pipe is connected to an upper header pipe and a lower header pipe.

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