Liquefied natural gas gasification system and method

Abstract

The invention discloses a liquefied natural gas gasification system in the technical field of natural gas gasification, which comprises a liquefied natural gas storage tank, a water bath type gasifier, a pressure regulating device, a metering and odorizing device and a natural gas pipe network, a gaseous gas outlet of the water bath type gasifier is connected to a pressure regulating device through a pipeline b, the pressure regulating device is connected to a metering and odorizing device through a pipeline c, and the metering and odorizing device is connected to a natural gas pipe network through a pipeline d; the water bath type vaporizer is communicated with an external circulating water pool through a circulating pipeline x, the water bath type vaporizer supplies heat through the circulating water pool, the circulating water pool is communicated with an external air compressor cooling system through a circulating pipeline y, and the air compressor cooling system supplies cold through the circulating water pool. The working temperature of the air compressor is recycled to be indirectly used for gasifying liquefied natural gas by the water bath type gasifier, and energy conservation and carbon reduction can be achieved.

Description

Technical Field

[0001] The invention relates to a liquefied natural gas gasification system and method, belonging to the technical field of natural gas gasification. Background Art

[0002] In LNG gasification stations, the vaporizer is the most important equipment. Currently, there are two main types of vaporizers: air-temperature vaporizers, water-bath vaporizers with electric heating, and hot water circulation. In the smelting industry, smelters with self-built LNG storage and distribution stations basically use air-temperature vaporizers as the gasification process equipment. However, this process has low gasification efficiency and foggy environment around the vaporizer. For details, see Figure 1 . Especially in coastal areas, when the temperature is low, the air-temperature vaporizer will freeze from bottom to top. At this time, in order to ensure the gasification efficiency, it can only be used in rotation, or workers can be asked to clean the ice with water. The result is that more air-temperature vaporizers need to be arranged as spares, which increases the land area. On the other hand, the labor intensity of workers is high. The use of circulating water water bath vaporizer can better solve the problems of gasification efficiency and environmental fog; but this method is to build an electric heating device in the water bath vaporizer, and the water in the vaporizer is continuously heated by power, so as to exchange heat with the LNG in the coil, so that the liquid natural gas is gasified into gaseous natural gas. There are problems such as high power consumption, environmental pollution, and difficulty in troubleshooting. Summary of the invention

[0003] In order to solve the above problems existing in the prior art, the present invention provides a liquefied natural gas gasification system and method.

[0004] The technical solution of the present invention is as follows:

[0005] A liquefied natural gas gasification system, comprising a liquefied natural gas storage tank, a water bath gasifier, a pressure regulating device, a metering odorizing device and a natural gas pipeline network, wherein the LNG storage tank is connected to a liquid gas inlet of the water bath gasifier through a pipeline a, the gaseous gas outlet of the water bath gasifier is connected to the pressure regulating device through a pipeline b, the pressure regulating device is connected to the metering odorizing device through a pipeline c, and the metering odorizing device is connected to the natural gas pipeline network through a pipeline d;

[0006] The water bath gasifier is connected to an external circulating water pool through a circulation pipeline x, and the water bath gasifier is heated by the circulating water pool. The circulating water pool is connected to an external air compressor cooling system through a circulation pipeline y, and the air compressor cooling system is cooled by the circulating water pool.

[0007] As a preferred solution, the liquefied natural gas storage tank is connected to a self-pressurizing gasifier via a circulation pipeline z.

[0008] As a preferred solution, the liquid natural gas storage tank is connected to the pipeline b via a pipeline e, and a BOG heater is serially connected to the pipeline e.

[0009] As a preferred embodiment, the water bath gasifier includes a liquid gas inlet, a gaseous gas outlet, a hot water supply inlet and a hot water supply outlet, the pipeline a and the pipeline b are respectively connected to the liquid gas inlet and the gaseous gas outlet, and the circulation pipeline x is respectively connected to the hot water supply inlet and the hot water supply outlet.

[0010] A liquefied natural gas gasification method, comprising the above-mentioned liquefied natural gas gasification system, the method comprising: a. transporting liquefied natural gas from a liquefied natural gas storage tank to a water bath type gasifier, the gaseous natural gas after gasification by the water bath type gasifier is successively subjected to pressure regulation treatment by a pressure regulating device and odorization treatment by a metering odorization device, and finally input into a natural gas pipeline network;

[0011] b. Through the circulation pipeline x, the circulating water pool supplies heat to the water bath gasifier for gasification and processing of liquefied natural gas;

[0012] Through the circulation pipeline y, the circulating water pool supplies cold to the air compressor cooling system for cooling the working temperature of the air compressor, thereby recovering the working temperature of the air compressor and indirectly using it in the water bath vaporizer to gasify liquefied natural gas.

[0013] As a preferred solution, the liquefied natural gas storage tank is connected to a self-pressurizing gasifier via a circulation pipeline z; the internal pressure of the liquefied natural gas storage tank is regulated by the self-pressurizing gasifier.

[0014] As a preferred solution, the liquid natural gas storage tank is connected to pipeline b via pipeline e, and a BOG heater is serially connected to pipeline e; the BOG heater is used to recover and heat the evaporated natural gas in the liquid natural gas storage tank, and send the treated natural gas into pipeline b.

[0015] Beneficial Effects

[0016] The liquefied natural gas gasification system of the present invention adopts a water bath type gasifier to replace the traditional air temperature type gasifier, thereby eliminating the problems of low gasification efficiency and large floor space occupied by the existing air temperature type gasifier. In addition, the heat supply of the water bath type gasifier of the present invention comes from the working temperature of the air compressor, and circulating heat exchange is achieved through a circulating water pool and a circulating pipeline, so that the working temperature of the air compressor is recovered and indirectly used for gasifying liquefied natural gas in the water bath type gasifier, thereby achieving energy saving and carbon reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the pipeline structure of the natural gas gasification system of the present invention;

[0018] Figure 2 for Figure 1 Schematic diagram of the pipeline expansion structure at point A in the figure. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1

[0021] See also Figure 1-2 This embodiment discloses a liquefied natural gas gasification system, including a liquefied natural gas storage tank 10, a water bath gasifier 20, a pressure regulating device 30, a metering and odorizing device 40, and a natural gas pipeline network 50.

[0022] Among them, the water bath vaporizer 20 includes a liquid gas inlet 201, a gaseous gas outlet 202, a hot water supply inlet 203 and a hot water supply outlet 204. The liquid gas inlet 201 and the gaseous gas outlet 202 are respectively the two ends of the natural gas coil inside the water bath vaporizer 20. The liquid natural gas enters the water bath vaporizer 20 and is heated and vaporized and then discharged from the gaseous gas outlet 202. The hot water supply inlet 203 and the hot water supply outlet 204 are respectively the two ends of the heating water channel inside the water bath vaporizer 20. After entering the water bath vaporizer 20, the high-temperature water exchanges heat with the liquid natural gas, and the cooled water is discharged from the hot water supply outlet 204.

[0023] The LNG storage tank 10 is connected to the liquid gas inlet 201 of the water bath vaporizer 20 through the pipeline a12, the gaseous gas outlet 202 of the water bath vaporizer 20 is connected to the pressure regulating device 30 through the pipeline b23, the pressure regulating device 30 is connected to the metering odorizing device 40 through the pipeline c34, and the metering odorizing device 40 is connected to the natural gas pipeline network 50 through the pipeline d45; the liquid natural gas storage tank 10 is connected to the self-pressurizing vaporizer 80 through the circulation pipeline z18, the liquid natural gas storage tank 10 is connected to the pipeline b23 through the pipeline e19, and the pipeline e19 is serially connected with a BOG heater 90.

[0024] The water bath gasifier 20 is connected to an external circulating water pool 60 through a circulating pipe x26. The hot water output end of the circulating water pool 60 is connected to the hot water supply inlet 203 of the water bath gasifier 20 through the outflow pipe of the circulating pipe x26. The hot water supply outlet 204 of the water bath gasifier 20 is connected to the hot water return end of the circulating water pool 60 through the return pipe of the circulating pipe x26. The water bath gasifier 20 is heated by the circulating water pool 60. When working, the hot water in the circulating water pool 60 is transported to the water bath gasifier 20 to heat exchange and heat up the liquid natural gas in the water bath gasifier 20. The heated natural gas is converted from liquid to gaseous, completing the gasification process, and the cooled hot water flows back to the circulating water pool 60.

[0025] The circulating water pool 60 is connected to the external air compressor cooling system 70 through the circulating pipe y67. The cold water output end of the circulating water pool 60 is connected to the cooling water inlet of the air compressor cooling system 70 through the outflow pipe of the circulating pipe y67. The cooling water outlet of the air compressor cooling system 70 is connected to the cooling water return end of the circulating water pool 60 through the return pipe of the circulating pipe y67. The air compressor cooling system 70 is cooled by the circulating water pool 60. When working, the cold water in the circulating water pool 60 is transported to the air compressor cooling system 70 to cool the air compressor. The cooling water that absorbs heat heats up and flows back to the circulating water pool 60.

[0026] Example 2

[0027] Based on the liquefied natural gas gasification system of Example 1, this embodiment discloses a liquefied natural gas gasification method, the method comprising:

[0028] a. Liquid natural gas is transported from a liquid natural gas storage tank 10 to a water bath vaporizer 20. The gaseous natural gas vaporized in the water bath vaporizer 20 is successively subjected to pressure regulation by a pressure regulating device 30 and odorization by a metering odorizing device 40, and finally input into a natural gas pipeline network 50;

[0029] b. Through the circulation pipeline x26, the circulation water pool 60 supplies heat to the water bath vaporizer 20 for gasification and processing of liquefied natural gas; through the circulation pipeline y67, the circulation water pool 60 supplies cold to the air compressor cooling system 70 for cooling the working temperature of the air compressor, thereby recovering the working temperature of the air compressor and indirectly using it in the water bath vaporizer 20 to gasify liquefied natural gas.

[0030] Furthermore, the liquefied natural gas storage tank 10 is connected to a self-pressurizing gasifier 80 via a circulation pipeline z18 ; the internal pressure of the liquefied natural gas storage tank 10 is regulated by the self-pressurizing gasifier 80 .

[0031] Furthermore, the liquefied natural gas storage tank 10 is connected to the pipeline b23 via the pipeline e19, and a BOG heater 90 is serially connected to the pipeline e19; the BOG heater 90 is used to recover and heat the evaporated natural gas in the liquefied natural gas storage tank 10, and send the treated natural gas to the pipeline b23.

[0032] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A liquefied natural gas gasification system, characterized in that: The invention comprises a liquefied natural gas storage tank (10), a water bath vaporizer (20), a pressure regulating device (30), a metering odorizing device (40), and a natural gas pipeline network (50), wherein the LNG storage tank (10) is connected to the liquid gas inlet of the water bath vaporizer (20) via a pipeline a (12), the gaseous gas outlet of the water bath vaporizer (20) is connected to the pressure regulating device (30) via a pipeline b (23), the pressure regulating device (30) is connected to the metering odorizing device (40) via a pipeline c (34), and the metering odorizing device (40) is connected to the natural gas pipeline network (50) via a pipeline d (45); The water bath gasifier (20) is connected to an external circulating water pool (60) via a circulation pipeline x (26), and the water bath gasifier (20) is heated by the circulating water pool (60). The circulating water pool (60) is connected to an external air compressor cooling system (70) via a circulation pipeline y (67), and the air compressor cooling system (70) is cooled by the circulating water pool (60).

2. A liquefied natural gas gasification system according to claim 1, characterized in that: The liquefied natural gas storage tank (10) is connected to a self-pressurizing gasifier (80) via a circulation pipeline z (18).

3. A liquefied natural gas gasification system according to claim 1, characterized in that: The liquefied natural gas storage tank (10) is connected to the pipeline b (23) via the pipeline e (19), and a BOG heater (90) is serially connected to the pipeline e (19).

4. A liquefied natural gas gasification system according to claim 1, characterized in that: The water bath type vaporizer (20) comprises a liquid gas inlet (201), a gaseous gas outlet (202), a hot water supply inlet (203) and a hot water supply outlet (204); the pipeline a (12) and the pipeline b (23) are respectively connected to the liquid gas inlet (201) and the gaseous gas outlet (202); and the circulation pipeline x (26) is respectively connected to the hot water supply inlet (203) and the hot water supply outlet (204).

5. A liquefied natural gas gasification method, comprising a liquefied natural gas gasification system as claimed in claim 1, characterized in that: a. Liquid natural gas is transported from a liquid natural gas storage tank (10) to a water bath vaporizer (20). The gaseous natural gas vaporized in the water bath vaporizer (20) is successively subjected to pressure regulation by a pressure regulating device (30), odorization by a metering odorizing device (40), and finally input into a natural gas pipeline network (50); b. Through the circulation pipeline x (26), the circulation water pool (60) supplies heat to the water bath type vaporizer (20) for gasification and processing of liquefied natural gas; through the circulation pipeline y (67), the circulation water pool (60) supplies cold to the air compressor cooling system (70) for cooling the working temperature of the air compressor, thereby recovering the working temperature of the air compressor and indirectly using it in the water bath type vaporizer (20) to gasify the liquefied natural gas.

6. A liquefied natural gas gasification method according to claim 5, characterized in that: The liquefied natural gas storage tank (10) is connected to a self-pressurizing gasifier (80) via a circulation pipeline z (18); the internal pressure of the liquefied natural gas storage tank (10) is regulated by the self-pressurizing gasifier (80).

7. A liquefied natural gas gasification method according to claim 5, characterized in that: The liquid natural gas storage tank (10) is connected to the pipeline b (23) via the pipeline e (19), and a BOG heater (90) is provided in series on the pipeline e (19); the BOG heater (90) is used to recover and heat the evaporated natural gas in the liquid natural gas storage tank (10), and to send the treated natural gas into the pipeline b (23).

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