WO2017031986A1

WO2017031986A1 - Lng fueling station employing bog energy storage and pressure differential

Info

Publication number: WO2017031986A1
Application number: PCT/CN2016/077938
Authority: WO
Inventors: 赵品仲; 王颖; 曾建兵; 张静林
Original assignee: 自贡通达机器制造有限公司
Priority date: 2015-08-24
Filing date: 2016-03-31
Publication date: 2017-03-02
Also published as: CN107076358B; CN107076358A; CN106481974A

Abstract

An LNG fueling station employing BOG energy storage and pressure differential comprises: an LNG lorry (1); a pressure-boosting vaporizer (2); a cryogenic LNG tank (12); a gas-fueling apparatus (14); and an LNG liquid-fueling machine (22). An LNG inlet pipe (26) and a BOG discharge pipe (27) are disposed between the gas-fueling apparatus (14) and the LNG liquid-fueling machine (22). The LNG liquid-fueling machine (22) is connected, via a first BOG recycling channel (28), to a BOG heater (20), the cryogenic LNG tank (12) and an inlet pipe (23). The BOG heater (20) is connected to a BOG buffer tank (19). The BOG buffer tank (19) is connected to a BOG compressor (16). The BOG compressor (16) is connected to a BOG storage tank (15). The BOG storage tank (15) is connected, via a second channel (30), to the inlet pipe (23) and the first BOG recycling channel (28), respectively. The cryogenic LNG tank (12) is connected to the BOG heater (20) via a second BOG recycling channel (29). By using connection channels and a stop valve, the fueling station requires no cryogenic submerged pumps and complementary heat insulation pump sumps, thereby saving facility costs. Moreover, using the BOG compressor to recycle and store a BOG having a certain pressure saves operation costs of a fueling station while realizing re-liquefaction of the BOG in a cryogenic tank, thereby minimizing BOG emission, saving energy, and reducing environmental pollution.

Description

BOG energy storage pressure difference LNG filling station

Technical field

The invention relates to the field of an LNG filling station, in particular to a BOG accumulator pressure difference LNG filling station.

Background technique

With the development of new energy vehicles and ships, liquefied natural gas (LNG) vehicles and steamships are rapidly emerging in China. LNG as a fuel for automobiles and ships is safe, economical, clean, efficient, environmentally friendly and storage efficient compared to other conventional vehicle fuels. With obvious advantages, in response to national energy conservation and emission reduction, the use of LNG as an alternative fuel for automobiles and ships can not only effectively reduce environmental pollution and alleviate the pressure of oil resources shortage, but also achieve sustainable economic development. The best choice for improving the environment.

With the country's emphasis on energy conservation and emission reduction work and the improvement of human living environment, the extensive use of LNG will become the main alternative energy source for urban public transport, automobile transportation and ship transportation in the future, and the supporting LNG refueling. The station will also bring vigorous development.

Under the conditions of the prior art,

1. LNG filling station is a liquefied natural gas produced or imported by LNG liquefaction plant. It is transported by tank truck to LNG filling station, and unloading and refueling is completed by submerged pump or self-pressurizing method. During the operation of the gas station equipment, especially in the pre-cooling process of the submersible pump (the submersible pump must be pre-cooled to -100 or so, in the pre-cooling process, it is often necessary to pass multiple BOG venting), a certain part of LNG will be vaporized into BOG (Boil Off Gas) gas, together with BOG gas generated by vehicles and ships. Although these BOG gases can be reliquefied by running equipment, most BOGs Since the cost of recycling is relatively high, the gas is discharged in vain, which not only wastes energy but also pollutes the environment.

2. The most critical core equipment of LNG filling station is low temperature submerged liquid pump. However, the technical content of this pump is high, the conditions for normal operation are relatively high, and the maintenance is difficult. At present, 98% of low temperature submersible pumps rely on very few National imports, there are potential industrial risks.

Summary of the invention

The invention provides a BOG energy storage pressure difference LNG filling station, which aims to solve the prior art problem, and provides an energy storage pressure difference LNG filling station which is energy-saving, environmentally-friendly and fully utilizes BOG gas generated by the process pipeline.

The technical solution adopted by the present invention to solve the problem is:

A BOG energy storage pressure difference LNG filling station, including LNG tank truck, supercharged vaporizer, LNG low temperature storage tank, gas filling equipment and LNG filling machine, LNG tank truck is connected with pressurized vaporizer and LNG low temperature storage tank through pipeline An intake pipe and an outlet pipe are arranged between the supercharged vaporizer and the LNG tank truck, the LNG low temperature storage tank is connected to the LNG dosing machine through the first pipe, and the LNG dosing machine is connected to the gas filling device, characterized in that: the gas filling An LNG intake pipe and a BOG exhaust pipe are arranged between the equipment and the LNG dosing machine, and the LNG dosing machine connects the BOG heater, the LNG cryogenic storage tank and the intake pipe through the first BOG recovery pipe, and the BOG heater is connected to the BOG buffer tank. The BOG buffer tank is connected to the BOG compressor, the BOG compressor is connected to the BOG storage tank, the BOG storage tank is respectively connected to the intake pipe and the first BOG recovery pipeline through the second pipeline, and the LNG cryogenic storage tank is connected to the BOG heater through the second BOG recovery pipeline.

The intake pipe and the outlet pipe are respectively provided with a shut-off valve F1 and a shut-off valve F2, and a connecting pipe F3, a shut-off valve F4 and a shut-off valve F5 are arranged on the connecting pipe between the LNG tank car and the LNG cryogenic storage tank, The first pipe is provided with a shut-off valve F6, the first BOG recovery pipe is provided with a shut-off valve F7 and a shut-off valve F8, a check valve F7 and a shut-off valve F8 and a LNG dosing machine are provided with a check valve, and the second BOG is recovered. The pipeline is provided with a shut-off valve F11, the first BOG recovery pipeline and the second BOG recovery pipeline are connected and connected to the BOG heater through a shut-off valve F12, and the pipeline connected to the BOG buffer tank and the BOG compressor is provided with a shut-off valve F10, the second pipeline A shut-off valve F9 is provided thereon.

The beneficial effects of the invention:

1. No need for low temperature submersible pump and matching insulated pump pool, simplifying process pipeline and saving equipment procurement cost.

2. Using BOG compressor to recover and store BOG gas with a certain pressure, the motor power is reduced by 65% compared with the motor power of the low temperature submersible pump, saving the operating cost of the gas station.

3. It can realize the reliquefaction function in the low temperature storage tank BOG gas station, minimize BOG emissions, save energy and reduce environmental pollution.

4. It can realize short-time power offloading and refueling.

DRAWINGS

Figure 1 is a schematic view of the structure of the present invention.

In the figure: 1, LNG tank car; 2, pressurized vaporizer; 3, shut-off valve F1; 4, shut-off valve F2; 5, shut-off valve F3; 6, shut-off valve F4; 7, shut-off valve F5; 8, shut-off valve F6 ; 9, shut-off valve F7; 10, shut-off valve F8; 11, shut-off valve F9; 12, LNG low-temperature storage tank; 13, shut-off valve F10; 14, gas filling equipment; 15, BOG storage tank; 16, BOG compressor; 17, check valve; 18, shut-off valve F11; 19, BOG buffer tank; 20, BOG heater; 21, shut-off valve F12; 22, LNG dosing machine; 23, intake pipe; 24, outlet pipe; First pipe; 26, LNG intake pipe; 27, BOG exhaust pipe; 28, first BOG recovery pipe; 29, second BOG recovery pipe; 30, second pipe.

detailed description

The invention is further described below in conjunction with the drawings and specific embodiments.

As shown in FIG. 1 , a BOG accumulator pressure difference LNG filling station includes an LNG tank car 1, a supercharging vaporizer 2, an LNG cryogenic storage tank 12, a gas filling device 14 and an LNG dosing machine 22, and the LNG tank car 1 passes The pipeline is respectively connected with the supercharged vaporizer 2 and the LNG cryogenic storage tank 12, and between the supercharged vaporizer 2 and the LNG tanker 1 is provided with an intake pipe 23 and an outlet pipe 24, and the LNG cryogenic storage tank 12 is connected to the LNG dosing machine 22 through the pipe 25. The LNG dosing machine 22 is connected to the gas filling device 14, and between the gas filling device 14 and the LNG dosing machine 22, an LNG intake pipe 26 and a BOG exhaust pipe 27 are provided, and the LNG dosing machine 22 passes the first BOG recovery pipe. 28 connects BOG heater 20, LNG low temperature storage tank 12 and intake pipe 23, BOG heater 20 is connected to BOG buffer tank 19, BOG buffer tank 19 is connected to BOG compressor 16, BOG compressor 16 is connected to BOG storage tank 15, BOG storage tank 15 is connected to the intake pipe 23 and the first BOG recovery pipe 28 through the second pipe 30, respectively, and the LNG cryogenic storage tank 12 is connected to the BOG heater 20 through the second BOG recovery pipe 29.

The intake pipe 23 and the outlet pipe 24 are respectively provided with a shut-off valve F1 3 and a shut-off valve F2 4 , and a connecting pipe between the LNG tank car 1 and the LNG cryogenic storage tank 12 is provided with a shut-off valve F3 5 and a shut-off valve F4. 6 and the shut-off valve F5 7, the first pipe 25 is provided with a shut-off valve F6 8, the first BOG recovery pipe 28 is provided with a shut-off valve F7 9 and a shut-off valve F8 10, a shut-off valve F7 9 and a shut-off valve F8 10 and LNG plus A check valve 17 is disposed between the liquid machines 22, and a shutoff valve F11 18 is disposed on the second BOG recovery pipe 29, and the first BOG recovery pipe 28 and the second BOG recovery pipe 29 are connected and connected to the BOG heater through the shutoff valve 12 21 20. The pipeline connecting the BOG buffer tank 19 and the BOG compressor 16 is provided with a shut-off valve F10 13, and the second conduit 30 is provided with a shut-off valve F9 11.

The working principle of the invention is: mainly utilizing the compressibility of the gas and the incompressibility of the liquid, and collecting the stored or liquid-converted gas as energy, and when the liquid natural gas is converted into a gaseous state, the volume is increased by 600 times (this is LNG One of the intrinsic properties) these gases can only generate pressure in a limited volume of the container. Through the gas storage tank, the gas compressor, the valve, and the corresponding process pipeline, the gas is subjected to directional pressure distribution, so that a directional pressure difference is formed between the containers, and since the liquid specific gravity is much larger than the specific gravity of the gas, the high pressure container The conveyed material (LNG liquid) is pressed into a container with a low pressure, and the workflow is as follows:

First, unloading the car:

Self-boosting unloading: After the LNG tanker 1 is in communication with the LNG cryogenic storage tank 12 and the pressurized vaporizer 2, the shut-off valve F1 3, the shut-off valve F2 4, the shut-off valve F3 5, the shut-off valve F4 6 and the shut-off valve 5 7 are opened. At this time, the LNG liquid in the LNG tanker 1 flows into the supercharged vaporizer 2 for vaporization, and the vaporized gas enters the LNG tank truck 1 through the pipeline of the shutoff valve F1 3 to be pressurized, when the LNG tanker 1 and the LNG cryogenic tank 12 When a certain pressure difference is reached, the LNG liquid in the LNG tanker 1 flows into the LNG low temperature storage tank 12 to realize self-pressurization unloading. After the unloading is completed, the original valves of the various shut-off valves are restored (ie, closed).

In addition to the self-pressing unloading truck in the prior art, the LNG tanker 1 can be pressurized by using the stored BOG gas in the BOG storage tank 15, without the need to pressurize the LNG liquid after the steaming, when the LNG tanker 1 and After the corresponding pipes of the LNG low temperature storage tank 12 and the BOG storage tank 15 are connected, the shut-off valve F1 3 and the shut-off valve F8 10 are opened, and the shut-off valve F8 10 is closed after the LNG tank car 1 and the LNG low-temperature storage tank 12 are pressed, and the cut-off valve is opened. Valve F3 5, shut-off valve F4 6 (or shut-off valve F5 7) and shut-off valve F9 11, BOG gas in the BOG storage tank 15 (pressure greater than the pressure of the LNG tank truck 1) enters the LNG tank truck 1 to pressurize it, when LNG in LNG tanker 1 when the pressure reaches the set pressure The liquid enters the tank from the top (or bottom) of the LNG cryogenic storage tank 12 to realize unloading. After the unloading is completed, the shut-off valves are restored to their original state.

Second, add liquid:

1. After the LNG intake pipe 26 and the BOG exhaust pipe 27 between the gas filling device 14 and the LNG dosing machine 22 are connected, the shutoff valve F6 8 and the shutoff valve F7 9 (or the shutoff valve F8 10) are opened, and the gas filling device is installed. The return air of 14 enters the bottom (or top) of the LNG cryogenic storage tank 12, and the LNG cryogenic storage tank 12 is isostatic with the gas filling equipment 14, and the LNG cryogenic storage tank 12 is operated due to the gravitational potential energy of the liquid in the LNG cryogenic storage tank 12. The LNG liquid enters the gas filling device 14 through the LNG dosing machine 22 to effect dosing. After the filling is completed, the shut-off valves are restored to their original state.

2. When the gravitational potential energy of the liquid in the LNG cryogenic storage tank 12 cannot satisfy the liquid addition, the shut-off valve F6 8 , the shut-off valve F10 13 and the shut-off valve F12 21 are opened, and then the filling device 14 and the BOG buffer tank 19 are pressed. Since the volume of the BOG buffer tank 19 is greater than a certain multiple of the tank volume of the gas filling device 14, the pressure of the tank of the gas filling device 14 is rapidly reduced to be lower than the set working pressure of the LNG storage in the LNG low temperature storage tank 12, at which time LNG The LNG liquid in the low temperature storage tank 12 enters the storage tank of the gas filling device 14 through the shut-off valve F6 8 and the LNG liquid adding machine 22, so as to add liquid to the gas filling device 14, and the working pressure range set by the BOG buffer tank 19 passes through the BOG. The compressor 16 is interlocked. When the working pressure of the BOG buffer tank 19 reaches the upper limit of the set pressure, the BOG compressor 16 is automatically started, and the BOG gas in the BOG buffer tank 19 is pressed into the BOG storage which is a certain multiple of its volume. The BOG gas stored in the tank 15 and stored in the BOG storage tank 15 serves as a pressurized gas source for the LNG tank 1 and the LNG cryogenic storage tank 12, that is, BOG energy storage. When the working pressure of the BOG buffer tank 19 reaches the set pressure lower limit, the BOG compressor 16 is automatically stopped.

3. Reliquefaction:

When the pressure in the LNG cryogenic storage tank 12 reaches the upper limit of the set pressure, the shut-off valve F11 18, the shut-off valve F12 21, the shut-off valve F10 13, the shut-off valve F9 11, the shut-off valve F7 9, the BOG compressor 16 is started, and the LNG is turned on. The BOG gas in the cryogenic storage tank 12 is pressed toward the bottom of the LNG cryogenic storage tank 12, and part of the BOG gas is liquefied by the cold energy of the LNG liquid in the LNG cryogenic storage tank 12.

Claims

A BOG accumulating pressure difference LNG filling station includes an LNG tanker (1), a supercharged vaporizer (2), a LNG cryogenic storage tank (12), a gas filling device (14), and an LNG dosing machine (22), The LNG tank truck (1) is respectively connected with a pressurized vaporizer (2) and an LNG cryogenic storage tank (12) through a pipeline, and an intake pipe (23) and a liquid outlet are provided between the pressurized vaporizer (2) and the LNG tank truck (1). The tube (24), the LNG cryogenic storage tank (12) is connected to the LNG dosing machine (22) through the first pipe (25), and the LNG dosing machine (22) is connected to the gas filling device (14), characterized in that: An LNG intake pipe (26) and a BOG exhaust pipe (27) are disposed between the gas device (14) and the LNG dosing machine (22), and the LNG dosing machine (22) is connected to the BOG through the first BOG recovery pipe (28). Heater (20), LNG cryogenic storage tank (12) and intake pipe (23), BOG heater (20) connected to BOG buffer tank (19), BOG buffer tank (19) connected to BOG compressor (16), BOG compression The machine (16) is connected to the BOG storage tank (15), and the BOG storage tank (15) is respectively connected to the intake pipe (23) and the first BOG recovery pipe (28) through the second pipe (30), and the LNG cryogenic storage tank (12) passes The second BOG recovery pipe (29) is connected to the BOG heater (20).
The BOG accumulating pressure difference LNG filling station according to claim 1, characterized in that: the intake pipe (23) and the outlet pipe (24) are respectively provided with a shut-off valve F1 (3) and a shut-off valve F2 ( 4) The connecting pipe between the LNG tanker (1) and the LNG cryogenic storage tank (12) is provided with a shut-off valve F3 (5), a shut-off valve F4 (6) and a shut-off valve F5 (7), the first pipe ( 25) There is a shut-off valve F6 (8), and the first BOG recovery pipe (28) is provided with a shut-off valve F7 (9) and a shut-off valve F8 (10), a shut-off valve F7 (9) and a shut-off valve F8 (10) A check valve (17) is arranged between the LNG dosing machine (22), a shut-off valve F11 (18) is arranged on the second BOG recovery pipe (29), and the first BOG recovery pipe (28) and the second BOG are recovered. The pipe (29) is connected and passes through the shut-off valve F12 (21) Connect the BOG heater (20), the BOG buffer tank (19) and the BOG compressor (16) are connected with a shut-off valve F10 (13), and the second pipe (30) is provided with a shut-off valve F9 ( 11).
A method for unloading a vehicle using a BOG energy storage differential pressure LNG steam station according to claim 1 or 2, characterized in that: connecting LNG tank car (1) with LNG low temperature storage tank (12), BOG storage tank ( 15) After the corresponding pipe, open the shut-off valve F1 (3) and the shut-off valve F8 (10). After the LNG tank truck (1) and the LNG low-temperature storage tank (12) are pressed, close the shut-off valve F8 (10) and open. The shut-off valve F3 (5), the shut-off valve F4 (6) and the shut-off valve F9 (11), the BOG gas in the BOG storage tank (15) enters the LNG tank truck (1) to pressurize the LNG tank truck (1) when the pressure When the set pressure is reached, the LNG liquid in the LNG tanker (1) enters the LNG cryogenic storage tank (12).
A method for adding liquid using a BOG energy storage differential pressure LNG steam station according to claim 1 or 2, characterized in that LNG is connected between the gas filling device (14) and the LNG dosing machine (22) After the intake pipe (26) and the BOG exhaust pipe (27),

When the gravitational potential of the liquid in the LNG cryogenic storage tank (12) satisfies the dosing, the shut-off valve F6 (8) and the shut-off valve F7 (9) are opened, and the return air of the refueling device (14) enters the LNG cryogenic storage tank (12) Inside, the LNG cryogenic storage tank (12) is equal to the gas filling equipment (14), and the LNG liquid in the LNG cryogenic storage tank (12) enters the gas filling device (14) through the LNG filling machine (22) to achieve gas filling. Equipment (14) adding liquid;

When the gravitational potential energy of the liquid in the LNG cryogenic storage tank (12) does not satisfy the dosing, the shut-off valve F6 (8), the shut-off valve F10 (13) and the shut-off valve F12 (21) are opened, and the gas filling device (14) storage tank and The BOG buffer tank (19) is flattened so that the pressure of the tank of the gas filling equipment (14) drops to less than the set working pressure of the LNG storage in the LNG low temperature storage tank (12), and the LNG low temperature storage tank (12) The LNG liquid enters the tank of the gas filling device (14) through the shut-off valve F6 (8) and the LNG dosing machine (22), thereby adding liquid to the gas filling device (14).
A method for reliquefying using a BOG energy storage differential pressure LNG steam station according to claim 1 or 2, characterized in that when the pressure in the LNG cryogenic storage tank (12) reaches the upper limit of the set pressure, it is turned on. Shut-off valve F11 (18), shut-off valve F12 (21), shut-off valve F10 (13), shut-off valve F9 (11), shut-off valve F7 (9), start BOG compressor (16), LNG cryogenic storage tank (12 The BOG gas in the pressure is pressed to the bottom of the LNG cryogenic storage tank (12), and part of the BOG gas is liquefied by the cold energy of the LNG liquid in the LNG cryogenic storage tank (12).
A method for storing energy using a BOG energy storage differential pressure LNG steam station according to claim 1 or 2, characterized in that BOG compression is performed when the working pressure of the BOG buffer tank (19) reaches the upper limit of the set pressure The machine (16) is automatically started, and the BOG gas in the BOG buffer tank (19) is pressed into the BOG storage tank (15) for storage, and the BOG gas stored in the BOG storage tank (15) is used as the LNG tank (1), A pressurized gas source for the LNG cryogenic storage tank (12).