RU2298725C1 - Method of using reserve underground storage for liquefied natural gas - Google Patents

Abstract

FIELD: storing or distributing of gas or liquids.

SUBSTANCE: method comprises filling the underground storage with liquefied natural gas, storing the gas, and supplying the gas to the consumer maintaining an excess pressure inside the storage. The reserve underground storage is positioned in the vicinity of the consumer. The gas evaporated from the storage is directed to the consumer through an additional gasifier.

EFFECT: reduced heat influx to the storage.

1 cl, 1 dwg

Description

The invention relates to methods for underground reservation of liquefied natural gas (LNG), namely, economical, fire and explosion-proof underground storages (HR), and can be used for accumulation and storage (issue) of LNG during interruptions in the supply of network natural gas (GHG) or in case of interruptions in the supply (delivery) of LNG.

The relevance of this problem is proved by interruptions in the supply of network gas, which in recent years are increasingly common due to the failure of pipelines that have exhausted their resources.

The prototype of the claimed invention is a method of using an underground storage of liquefied natural gas (LNG), implemented in the device [1] - RF Patent No. 2232342, IPC ⁷ F17C 1/00, B65G 5/00, 07/10/2004, Bull. No. 19.

The method of using LNG HRC according to [1] consists in filling HRC with liquefied natural gas, storing it and delivering LNG to the surface to the consumer by the pumping method, while maintaining guaranteed GH excess pressure in HRC.

With all the advantages of using [1], namely

- direct contact of the LNG storage facility with the atmosphere is excluded, which causes the constantly decreasing loss of LNG from evaporation;

- full deepening of the LNG storage facilities achieve a high degree of fire and explosion safety both in operating conditions and in accidents and various industrial impacts;

- deep deepening of LNG storage facilities achieves environmental safety with long periods of storage of LNG and operation of the storage, since they do not allow the exit of zero isotherm to the surface of the earth,

at the same time, during storage of LNG, as in all storages, evaporation of cryogenic liquid also takes place in the storage facility, and this, in turn, is unacceptable for long periods of storage.

This drawback sets the task of constant compensation for losses of stored liquefied natural gas from heat influx from the environment.

This problem is achieved by the fact that in the known method [1] of using LNG storage facility, which consists in filling the underground LNG storage, storing it and delivering LNG to the surface to the consumer (for example, by pumping), while maintaining guaranteed GH excess pressure in the storage facility, back-up LNG storage facility located near (near) the GHG consumer with its LNG consumable storage and use the LNG provided by the LNG consumable storage to replenish the LNG that has evaporated in the underground storage, and the natural gas evaporated in the PX is sent through additional regazifikator GHG consumer, and when issuing LNG regasification for its use regazifikator disabled at the time a supply LNG storage while maintaining the PG in the backup PH guaranteed overpressure is performed through the additional regazifikator.

The implementation of the method of using the backup underground storage of liquefied natural gas in combination with the foregoing features (restrictive and distinctive features of the claims) is new for underground storage of LNG and, therefore, meets the criterion of "novelty."

The above set of distinctive features is unknown at this level of technology and does not follow from the well-known rules for the design of LNG storages and their auxiliary equipment, which proves compliance with the criterion of "inventive step".

The constructive implementation of LNG storages with the indicated set of essential features does not present any structural, technical and technological difficulties, from which the compliance with the criterion of "industrial applicability" follows.

A diagram explaining the essence of the proposed method is presented in the drawing - a device that implements the method.

The drawing shows a ground LNG consumable storage located on the surface of the earth 1 and a backup LNG storage facility nearby 3 with cryogenic liquid and gas pipelines 3 located in a technological mine with a ladder and hermetic hatches. The output of the LNG filling-dispensing valve 5 of the consumable storage 2 is connected by a cryogenic pipeline to the shut-off valve 6 (LNG input to the evaporator 7) and to the LNG filling-dispensing valve 8 of the LNG underground storage. The gas pipeline ПХ LNG 3 through an additional regenerator 9 is connected to the gas distribution point (GRP) 10 of the consumer (for example, a gas boiler or gas power station with heat recovery in the heating system and hot water supply). The output of the regenerator 7 is also connected to the hydraulic fracturing 10 of the consumer 11.

The work on the proposed method of using the backup LNG storage facility consists of the following 3 modes.

1. When the consumer 11 on LNG consumable storage 2

LNG from the consumable storage 2 through valve 5 and valve 6 is sent to regasifier 7, in which it evaporates, is heated almost to ambient temperature, then natural gas is sent to hydraulic fracturing 10 of consumer 11. Moreover, valve 8 of LNG 3 is closed, and the vaporized ones HRP LNG 3 pairs come through an additional regasifier 9 and from it also go to hydraulic fracturing 10 of consumer 11. The pressure in the steam region of the HRP LNG 3 will be equal to the pressure after regasifier 7, this pressure is maintained by a reverse flow of natural gas through flax regazifikator 9.

2. When consumer 11 is operating on LNG of the on-site storage 2 with LNG replenishment in the reserve LNG storage facility 3

In this mode, the valve 6 is closed, and the LNG from the consumable storage 2 through the open valves 5 and 8 is sent to the LNG storage facility 3, replenishing its cryogenic liquid supply. In this case, LNG vapor through an additional regasifier 9, in which they are heated almost to ambient temperature, and enter the hydraulic fracturing 10 of consumer 11.

3. When consumer 11 is operating on LNG, the backup HRP LNG 3

In this mode, the valve 5 of the consumable storage 2 is closed, and the LNG from the underground storage 3 is sent through open valves 8 and 6 to the regasifier 7, from which the vaporized and heated gas is directed to the hydraulic fracturing 10 of the consumer 11. At the same time, the supercharging of the LNG 3 is carried out by a reverse flow of natural gas through an additional regasifier 9 to a pressure equal to the pressure before hydraulic fracturing 10.

Thus, the implementation of the proposed method allows you to constantly replenish the LNG storage facility with a cryogenic liquid supply along with the consumer’s work from the LNG consumable storage. And at the same time, in case of interruptions in the supply (supply) of LNG to the consumer (or to many consumers), they can work on reserve natural gas from LNG storage facilities.

Compared with the use of ground LNG storage, the use of backup LNG storage facility allows

- ensuring fire and explosion safety of LNG storage facilities;

- providing constantly decreasing (with storage time) heat inflows to the LNG storage facility and its more efficient storage.

The application of the proposed method for the use of reserve LNG storage facility allows you to store LNG at any time (for long periods of storage) and provides constant compensation for the losses of stored liquefied natural gas with decreasing LNG evaporation losses.

Claims (2)

1. The method of using the reserve underground storage of liquefied natural gas, which consists in filling the underground storage with liquefied natural gas, storing it and delivering it to the surface to the consumer, while maintaining the guaranteed excess pressure of natural gas in the underground storage, characterized in that the reserve underground storage of liquefied natural gas is near the consumer of natural gas with their consumable storage of liquefied natural gas and use the liquefied gas produced by the consumable storage natural gas is vaporized to replenish the contingency underground storage of liquefied natural gas, and natural gas is evaporated in the underground Backup regazifikator directed through additional natural gas to the consumer. 2. The method of using the backup underground storage of liquefied natural gas according to claim 1, characterized in that when issuing the liquefied natural gas to the consumer, for its regasification, a regasifier of the expendable storage of liquefied natural gas disconnected at that time is used, and maintaining a guaranteed excess pressure of natural gas in the reserve underground storage is carried out through an additional regasifier.