JPS62162866A - Method of storing cold heat energy - 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 [Field of Industrial Application] The present invention relates to a method for storing cold energy of low-temperature liquefied gas such as LNG.

[Background of the invention]

There are currently several LNG plants in Japan, including those under construction.
There are receiving terminals such as LNG, and the cold energy of low-temperature liquefied gas such as LNG is used for cold power generation and fJ freezing warehouses.

However, because the consumption of LNG etc. varies depending on the season and the time of day, and because this cold energy is difficult to store, only about 30% of the base load is used, and other cold energy is dumped. The current situation is that Therefore, a large amount of cold energy has to be discarded as described above, and in the gas industry and electric power industry, which use large amounts of LNG and the like, there is a great demand for effective use of cold energy.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and solves the problems of the prior art by simple and rational means, by transferring cold energy obtained from low-temperature liquefied gas to a liquid medium at room temperature and high pressure, This cold energy is stored, taken out and used as appropriate, and the gas medium after this use is absorbed and carried by a liquid such as water, and the liquid such as water is heated to produce gas. It is an object of the present invention to provide a method that can effectively utilize and store cold energy without wasting it by storing the medium in circulation.

[Means for Solving the Problems] The configuration of the present invention that solves the conventional problems is that when storing the cold energy of low-temperature liquefied gas such as LNG, a gas dissolved in a liquid such as ammonia is used as a cold energy storage medium. , these medium gases are cooled to low temperature in a cold heat exchanger? 1, the liquefied medium is converted to nl by the cold heat of the chemical gas, and the pressure of this liquefied medium is increased using a pump or other means, and then the temperature is raised using a heat exchanger using seawater etc. to obtain a liquid medium at room temperature and high pressure. After that, the storage medium at room temperature and high pressure is appropriately taken out and expanded to a low temperature and low pressure state by an expansion valve to supply cold heat to a frozen warehouse etc., and then in a gas absorption tank. A gaseous medium similar to the above is obtained by dissolving the medium gasified by endotherm in a liquid such as water, storing it, and heating the solution under reduced pressure in a gas release tank. The liquid is circulated through the cold heat exchanger, and the liquid from which the gas has been released is pressurized by a pump and then sent back to the gas absorption tank.

[Embodiment 2] (FIG. 1) A first embodiment of the method of the present invention will be described with respect to the stage shown in FIG. For this example and the following examples, ammonia (N[h2) and water (H20) are used.

At the source, the gaseous medium (NHZ) at room temperature and low pressure supplied from the gas holder 1 is exchanged with the cold heat of low-temperature liquefied gas such as LNG in the cold heat exchanger 2 to become a low-temperature and low-pressure liquid. The liquefied medium is stored in a receiver tank 3. The stored liquefied medium is pressurized by a boost pump 4 and subjected to heat exchange using seawater etc.
The temperature is raised at step 5, and the medium becomes a liquid medium at room temperature and high pressure. This liquid medium is at room temperature and high pressure in the medium storage tank 6.
be temporarily stored. This medium is taken out as required by the load side and expanded to a low temperature and low pressure state by the expansion valve 7, and the resulting cold energy is used to supply cold heat to the load 8 such as a cold rR warehouse. It is endothermically gasified at load 8, and Konogore Sosa 9
The medium (for example, Nlh 2 ) pressurized by the gas absorption tank 12 is dissolved in a liquid (for example, water) to obtain a solution. This solution is sent to the gas release tank 16 by piping with a pump 13 or by means of transportation such as a lorry. The solution is fed by the expansion valve 14 to a low-temperature, low-pressure gas release tank 16, and the solution is heated in the gas release tank 16 with easily available seawater, air, etc.
The gaseous medium of the solution is released from the water. Is the generated room temperature, low pressure gas (NH,, It□0) a gas? y purification equipment 20
The gas medium (Nil, ) obtained by removing moisture (H20) is stored in the gas holder 1, supplied to the cold heat exchanger 2 as appropriate, and circulated in the cycle described above. In addition, liquid such as water that has generated a gas medium in the gas discharge tank 16 is increased in pressure by a booster pump 17, and is supplied to the gas absorption tank 12, where it efficiently absorbs the gas medium. A heat exchanger 18 is installed to exchange sensible heat between the liquid that has released the gas medium and the solution that has absorbed the gas medium, and cools the solution that has absorbed the gas medium to a normal temperature and high pressure state. FfI+2
The heat generated when the gas melts can be used in things like heat bongos.

[Example 2] (Fig. 2) A second example of the method of the present invention will be described using the equipment shown in Fig. 2. In this embodiment, the gas holder 1 in the first embodiment is omitted, and the gas medium (N
[+, ) are sent as they are to the cold heat exchanger 2 via the gas purification equipment 20. Furthermore, as shown by imaginary lines, the pressurizing bongo 17 and the gas absorption tank 12
Separately from the heat exchanger 18 provided in the conduit connecting the two, a heat exchanger M18a using a heat medium remaining in the vicinity is provided, and the other configuration is the same as that of the first embodiment. Therefore, detailed explanation will be omitted.

[Example 3] (Fig. 3) A third example of the method of the present invention will be described with respect to the equipment shown in Fig. 3. The means for liquefying the gas medium, pressurizing it, cyclizing it at room temperature, storing it, lowering the temperature and pressure using the expansion valve 7, and utilizing the cold energy in the load 8 are the same as in the first embodiment, so the details thereof will be omitted.

The medium gasified by the endothermic action of load 8 (Nth l
is supplied into the gas absorption tank 12, dissolved in the liquid (for example, water) in the gas absorption tank 12, and becomes a solution. (This solution becomes, for example, NH40.) This solution is stored in a storage tank 19 by a pump 13. This stored solution is
The gas (N)l, , l! is reduced in temperature and pressure by the expansion valve 14 and sent to the gas release tank 16, where it is heated as described above and generated. 20)! Well, gas purification equipment 2
The gas medium (Nil, ) obtained by removing moisture (It20) is sent to the cold heat exchanger 2, and the rest (well, since it is the same as the first embodiment, a detailed explanation thereof will be given below. Note that depending on the design, the heat exchanger 18 may be omitted in each embodiment.

The liquid (individual I [20) obtained by heating the melt overnight (for example, N1 (40 g)) in the gas release tank 16 and gasifying the medium (individual I [20]) is sent to the storage tank 15 by the bongo 17 and stored there. This liquid is increased in pressure by the booster pump 21 and sent to the gas adsorption tank 12, where it absorbs or adsorbs the gas medium.The heat generated in the gas adsorption tank 12 is used for a gas adsorption tank or the like.

〔effect〕

As described above, according to the present invention, the following effects can be obtained.

(al) The medium liquefied by the cold heat of low-temperature liquefied gas such as LNG can be stored in a liquid state at room temperature and high pressure, as shown by the Pi concave curve in Figure 4, and can be taken out and used as needed. The cooled energy can be stored as a liquid medium at room temperature and high pressure, as described above.

(bl) Utilizing the property of the gaseous medium absorbed in the load to dissolve in liquid, this gaseous medium is dissolved in liquid, stored and managed at room temperature and high pressure, and then stored in a gas release tank. By heating under reduced pressure, the medium is again gasified and recycled.

[Brief explanation of drawings]

The drawings schematically show the equipment for carrying out the method of the present invention, and Figs. 1 to 3 are schematic diagrams of the system, respectively, and Fig. 4 is a Pi curve diagram. ■ Gas holder, 2 Cold heat exchanger, 3 Receiver tank 24 Pump, 5...Heat exchanger, 6 Medium storage tank, 7 Expansion valve, 8 Load, 12 Gas absorption tank, 1
3 Bongos, 14 Expansion valve, 15 Liquid storage tank from which the gas medium has been released, 16 Gas release tank, 17 Interfacial pressure valve, 18 Heat exchanger, 19 Storage tank for the solution that has absorbed the gas medium, 20 Gas purification equipment (dehydration equipment) ).

Claims (1)

[Claims] [Claim 1] (a) When storing the cold energy of low-temperature liquefied gas such as LNG, (b) Using gases dissolved in liquids such as ammonia as a medium for cold energy storage, the gases of these media is liquefied in a cold heat exchanger using the cold heat of low-temperature liquefied gas, (c) This liquefied medium is pressurized using a pump or other means, and then heated in a heat exchanger using seawater etc. to form a liquid at room temperature and high pressure. Obtain a medium, temporarily store it in a medium storage tank, (d) After that, take out the storage medium at room temperature and high pressure as appropriate and expand it to a low temperature and low pressure state with an expansion valve to supply cold heat to a frozen warehouse etc. (e) Then, in a gas absorption tank, the medium that has been gasified by endotherm is dissolved in a liquid such as water; (f) After storing this, the medium is dissolved under reduced pressure in a gas release tank. By heating the solution, a gas medium similar to the above was obtained, which was then circulated to the cold heat exchanger, and the liquid from which the gas had been released was pressurized by a pump and sent back to the gas absorption tank. A method for storing cold energy characterized by the following.