BOG processing tooling assembly and processing method

Abstract

The application discloses a BOG processing tool assembly and a processing method, and relates to the field of BOG processing tools.The BOG processing tool assembly comprises a BOG gas phase pipeline, a high-pressure natural gas pipeline, a medium-pressure natural gas pipeline and an injection pipe group.The injection pipe group is provided with an adjustable ejector, and the injection pipe group is provided with an air inlet end, an air outlet end and a flow guide end.The air inlet end of the injection pipe group is communicated with the high-pressure natural gas pipeline, the flow guide end of the injection pipe group is communicated with the BOG gas phase pipeline, and the air outlet end of the injection pipe group is communicated with the medium-pressure natural gas pipeline.In this way, the adjustable ejector of the injection pipe group can mix BOG gas in the BOG gas phase pipeline and high-pressure natural gas in the high-pressure natural gas pipeline to obtain medium-pressure natural gas, and the medium-pressure natural gas is sent out through the medium-pressure natural gas pipeline, while the BOG gas is sucked into the adjustable ejector, which does not need power (the power relies on the negative pressure generated when the high-pressure natural gas jet flow in the adjustable ejector), and the mixing effect of the BOG gas phase and the high-pressure natural gas is good.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of natural gas transportation, and particularly relates to a BOG treatment tool assembly and a treatment method. BACKGROUND

[0002] According to different BOG treatment modes, currently, domestic operating or under-construction receiving stations usually adopt three BOG treatment processes, namely, a BOG direct compression process, a BOG recondensation process and a BOG reliquefaction process. The BOG direct compression process is to pressurize the BOG generated in the LNG receiving station to the pressure of the external transmission pipeline network through a BOG low-pressure compressor or a high-pressure compressor, and the BOG enters the external transmission pipeline network in the form of high-pressure or low-pressure natural gas for use by users. The process energy consumption is determined by the outlet pressure of the compressor, and the higher the pipeline pressure, the higher the energy consumption. The BOG recondensation process generates corresponding energy consumption in the recondensation and gasification processes, and the system energy consumption is reduced compared with the direct compression process, but still has the characteristic of high energy consumption. The BOG reliquefaction process is mainly used in the situation that the downstream supporting facilities have not been completed or there is no downstream market demand, which leads to the inability to gasify and transmit, and cannot produce economic value, and generates high equipment energy consumption. The LNG receiving station will generate a large amount of BOG during the production and operation period due to the influence of factors such as operation conditions and external environmental heat leakage. If this part of BOG is not timely recovered and treated, it may cause overpressure of the storage tank and bring about safety hazards such as fire and explosion, or energy waste caused by flare emission, which often leads to serious consequences. The BOG treatment process of the LNG receiving station has always been a difficulty in the industry, and in addition, the three BOG treatment processes, namely, the BOG direct compression process, the BOG recondensation process and the BOG reliquefaction process, all generate high equipment energy consumption. SUMMARY

[0003] In order to solve the above technical problems, the purpose of the present application is to provide a BOG treatment tool assembly with low energy consumption, small equipment investment and good running safety.

[0004] In order to achieve the above purpose, the technical scheme of the present application is as follows: a BOG treatment tool assembly, comprising a BOG gas phase pipeline, a high-pressure natural gas pipeline, a medium-pressure natural gas pipeline and an ejector group, the ejector group having an adjustable ejector, the ejector group having an air inlet end, an air outlet end and a flow guide end, the air inlet end of the ejector group being in communication with the high-pressure natural gas pipeline, the flow guide end of the ejector group being in communication with the BOG gas phase pipeline, and the air outlet end of the ejector group being in communication with the medium-pressure natural gas pipeline.

[0005] The beneficial effects of the above technical solution are that: in this way, the adjustable ejector with the ejector pipe group can mix the BOG gas in the BOG gas phase pipeline and the high-pressure natural gas in the high-pressure natural gas pipeline to obtain medium-pressure natural gas, and the medium-pressure natural gas is sent out through the medium-pressure natural gas pipeline, while the BOG gas is sucked into the adjustable ejector, which does not need power (the power relies on the negative pressure generated by the high-pressure natural gas jet in the adjustable ejector), and the mixing effect of the BOG gas phase and the high-pressure natural gas is good.

[0006] In the above technical solution, the ejector pipe group is provided with a plurality of.

[0007] The beneficial effects of the above technical solution are that: in this way, the ejector pipe group can be redundantly designed to ensure that at least one of the ejector pipe groups can normally operate.

[0008] In the above technical solution, the communication position of the medium-pressure natural gas pipeline and the gas outlet end of the plurality of ejector pipe groups is provided with a first valve.

[0009] The beneficial effects of the above technical solution are that: in this way, the first valve can be used as the gas inlet total gate of the medium-pressure natural gas pipeline.

[0010] In the above technical solution, the ejector pipe group further includes an air injection pipe, an air inlet pipe, an air outlet pipe, and an air-temperature type gasifier, the adjustable ejector has an air inlet, a flow guide port, and an air outlet, the air inlet of the adjustable ejector is communicated with the high-pressure natural gas pipeline through the air inlet pipe, the flow guide port of the adjustable ejector is communicated with the BOG gas phase pipeline through the air injection pipe, the air outlet of the adjustable ejector is communicated with the medium-pressure natural gas pipeline through the air outlet pipe, the air-temperature type gasifier is communicated on the air injection pipe, a second valve is arranged at the inlet of the air-temperature type gasifier, a third valve is arranged at the outlet of the air-temperature type gasifier, a fourth valve is arranged on the air inlet pipe, and a fifth valve is arranged on the air outlet pipe.

[0011] The beneficial effects of the above technical solution are that: in this way, the fourth valve can be used as the gas inlet total gate of the air inlet pipe, and the fifth valve can be used as the gas outlet total gate of the air outlet pipe, and specifically, the BOG gas in the BOG gas phase pipeline can be heated and gasified into normal-temperature low-pressure gas by the air-temperature type gasifier before being transported into the adjustable ejector, so that the BOG gas can form medium-pressure natural gas after being mixed with the high-pressure natural gas.

[0012] In the above technical solution, the air injection pipe is further sequentially provided with a flow monitoring element, a temperature monitoring element, a safety valve, an emergency shut-off valve, a pressure monitoring element, and a check valve between the air-temperature type gasifier and the adjustable ejector.

[0013] The beneficial effects of the above technical solution are that the flow, temperature and pressure values on the air guide pipe can be monitored in real time to ensure its safe operation, and the safety valve and emergency shut-off valve can further ensure the safety of the air guide pipe operation, and the check valve on the air guide pipe can prevent high-pressure natural gas from overflowing into the BOG gas phase pipe through the air guide pipe.

[0014] In the above technical solution, the flow monitoring element is a flow sensor, the temperature monitoring element is a temperature sensor, the pressure monitoring element is a pressure sensor, and the fourth valve and the fifth valve are both electric valves.

[0015] The beneficial effects of the above technical solution are that the degree of intelligence is high.

[0016] In the above technical solution, the flow monitoring element, the temperature monitoring element, the pressure monitoring element, the fourth valve and the fifth valve are all electrically connected to the controller.

[0017] The beneficial effects of the above technical solution are that the degree of automation and intelligence can be further improved.

[0018] In the above technical solution, the check valve on the air guide pipe is provided with two.

[0019] The beneficial effects of the above technical solution are that by providing two check valves on the air guide pipe, redundancy design can be achieved, and high-pressure natural gas can be prevented from overflowing into the air guide pipe due to damage of a single check valve.

[0020] In the above technical solution, the injection coefficient of the adjustable ejector is 0.065.

[0021] The beneficial effects of the above technical solution are that the injection coefficient can enable the adjustable ejector to completely suck in the BOG gas after the air temperature type gasifier gasification, so that the processing efficiency is high.

[0022] The second purpose of the present application is to provide a BOG processing method with low operating cost based on the above BOG processing tool assembly.

[0023] In order to achieve the above purpose, another technical solution of the present application is as follows: a BOG processing method based on the above BOG processing tool assembly, the BOG gas with a temperature of -110 DEG C in the BOG gas phase pipe is gasified by the air temperature type gasifier into a normal temperature low pressure gas above 0 DEG C, and is delivered to the adjustable ejector to mix with the natural gas delivered from the high pressure natural gas pipe and jet into the medium pressure natural gas pipe.

[0024] The beneficial effects of the above technical scheme are that the processing method can use only the pressure energy of the high-pressure natural gas as power to suck the BOG gas into the adjustable ejector for mixing, and eject the mixed gas, the process flow is simple, convenient to apply, safe and reliable, which achieves the purpose of processing the BOG in the receiving station, can meet the demand of BOG processing capacity under different working conditions, achieves the BOG processing effect, does not generate equipment energy consumption, saves the cost, and generates great economic benefits while being environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A result schematic view of the BOG processing tool assembly described in embodiment 1 of the present application;

[0026] Figure 2 An electrical connection schematic view of the controller described in embodiment 1 of the present application.

[0027] In the figure: 1, BOG gas phase pipeline; 2, high-pressure natural gas pipeline; 3, medium-pressure natural gas pipeline; 4, ejector pipe group; 41, adjustable ejector; 42, air injection pipe; 421, flow monitoring element; 422, temperature monitoring element; 423, safety valve; 424, emergency shut-off valve; 425, pressure monitoring element; 426, check valve; 43, air inlet pipe; 431, fourth valve; 44, air outlet pipe; 441, fifth valve; 45, air temperature type gasifier; 451, second valve; 452, third valve; 5, first valve; 6, controller. DETAILED DESCRIPTION

[0028] The principles and features of the present application are described below in conjunction with the accompanying drawings, and the examples are used only to explain the present application and are not used to limit the scope of the present application. In the following paragraphs, the present application is described in more detail with examples. The advantages and features of the present application will be clearer according to the following description and claims. It should be noted that the drawings are very simplified and use non-precise proportions, only to facilitate, clearly assist in explaining the purpose of the embodiments of the present application.

[0029] Embodiment 1

[0030] As Figure 1As shown, the embodiment provides a BOG processing tool assembly, which comprises a BOG gas phase pipeline 1, a high-pressure natural gas pipeline 2, a medium-pressure natural gas pipeline 3, and an ejector group 4. The ejector group 4 has an adjustable ejector 41. The ejector group 4 has an air inlet end, an air outlet end, and a flow guide end. The air inlet end of the ejector group 4 is in communication with the high-pressure natural gas pipeline 2. The flow guide end of the ejector group 4 is in communication with the BOG gas phase pipeline 1. The air outlet end of the ejector group 4 is in communication with the medium-pressure natural gas pipeline 3. In this way, the adjustable ejector of the ejector group can mix the BOG gas in the BOG gas phase pipeline with the high-pressure natural gas in the high-pressure natural gas pipeline to obtain medium-pressure natural gas. The medium-pressure natural gas is sent out through the medium-pressure natural gas pipeline. The BOG gas is sucked into the adjustable ejector. The adjustable ejector does not need power (the power relies on the negative pressure generated by the high-pressure natural gas jet in the adjustable ejector). The adjustable ejector can make the mixing effect of the BOG gas phase and the high-pressure natural gas good.

[0031] In the above technical solution, the ejector group 4 is provided with multiple ejector groups. In this way, the ejector groups can be redundantly designed to ensure that at least one of the ejector groups can normally operate. In the embodiment, the ejector group can be provided with two ejector groups.

[0032] In the above technical solution, the communication position of the medium-pressure natural gas pipeline 3 and the air outlet end of the multiple ejector groups 4 is provided with a first valve 5. In this way, the first valve can be used as an air inlet total gate of the medium-pressure natural gas pipeline.

[0033] In the above technical solution, the ejector group 4 further comprises an air guide pipe 42, an air inlet pipe 43, an air outlet pipe 44, and an air temperature type gasifier 45. The adjustable ejector 41 has an air inlet, a flow guide, and an air outlet. The air inlet of the adjustable ejector 41 is in communication with the high-pressure natural gas pipeline 2 through the air inlet pipe 43. The flow guide of the adjustable ejector 41 is in communication with the BOG gas phase pipeline 1 through the air guide pipe 42. The air outlet of the adjustable ejector 41 is in communication with the medium-pressure natural gas pipeline 3 through the air outlet pipe 44. The air temperature type gasifier 45 is in communication on the air guide pipe 42. A second valve 451 is arranged at the air inlet of the air temperature type gasifier 45. A third valve 452 is arranged at the air outlet of the air temperature type gasifier 45. A fourth valve 431 is arranged on the air inlet pipe 43. A fifth valve 441 is arranged on the air outlet pipe 44. In this way, the fourth valve can be used as an air inlet total gate of the air inlet pipe. The fifth valve can be used as an air outlet total gate of the air outlet pipe. Specifically, in the embodiment, the BOG gas in the BOG gas phase pipeline can be heated and gasified into a normal-temperature low-pressure gas by the air temperature type gasifier before being transported into the adjustable ejector. In this way, the BOG gas can form medium-pressure natural gas after being mixed with the high-pressure natural gas.

[0034] The air guide pipe 42 is further sequentially provided with a flow monitoring element 421, a temperature monitoring element 422, a safety valve 423, an emergency cut-off valve 424, a pressure monitoring element 425 and a check valve 426 between the air temperature type gasifier 45 and the adjustable ejector 41, so that the flow, temperature and pressure values of the air guide pipe can be monitored in real time to ensure its safe operation, and the safety valve and the emergency cut-off valve can further ensure the safety of the operation of the air guide pipe, and the check valve provided on the air guide pipe can prevent high-pressure natural gas from overflowing into the BOG gas phase pipe through the air guide pipe.

[0035] The flow monitoring element 421 is a flow sensor, the temperature monitoring element 422 is a temperature sensor, the pressure monitoring element 425 is a pressure sensor, and the fourth valve 431 and the fifth valve 441 are both electric valves, so that the degree of intelligence is high.

[0036] As shown in Figure 2 The flow monitoring element 421, the temperature monitoring element 422, the pressure monitoring element 425, the fourth valve 431 and the fifth valve 441 are all electrically connected to the controller 6, so that the degree of automation and intelligence can be further improved, and the two ejector pipe groups in the embodiment can share one controller 6, and the controller in the embodiment can adopt an arm series single-chip microcomputer.

[0037] The check valve 426 on the air guide pipe 42 is provided with two check valves, which can realize redundant design and avoid the overflow of high-pressure natural gas into the air guide pipe due to the damage of a single check valve.

[0038] The injection coefficient of the adjustable ejector 41 is 0.065, which can make the adjustable ejector completely suck in the BOG gas after the air temperature type gasifier is gasified, so that the processing efficiency is high (under this injection coefficient, the daily evaporation gas during the production and operation of the LNG receiving station can be effectively recovered, and the daily evaporation rate of a 160,000 cubic meter LNG storage tank is usually 0.05%).

[0039] The gas sending pressure in the high-pressure natural gas pipeline 2 in the embodiment is about 8Mpa, and the gas sending pressure in the medium-pressure gas pipeline is about 5MPa.

[0040] For a single air pipe group, when the corresponding flow monitoring element 421, temperature monitoring element 422 and pressure monitoring element 425 monitor that the flow, temperature and pressure in the air pipe group are abnormal, the corresponding fourth valve and fifth valve can be controlled by the controller to adjust the opening degree, when the flow of high-pressure natural gas entering the adjustable ejector is reduced, the flow of BOG gas sent out in the BOG gas phase pipe will also be reduced accordingly.

[0041] Embodiment 2

[0042] The embodiment provides a BOG treatment method based on the BOG treatment tool assembly as described in Embodiment 1, the BOG gas with a temperature of-110 DEG C in the BOG gas phase pipe 1 is gasified into normal-temperature low-pressure gas with a temperature of 0 DEG C or above by the air temperature type gasifier 45, and is delivered into the adjustable ejector 41 to be mixed with the natural gas delivered by the high-pressure natural gas pipe 2 and jetted into the medium-pressure natural gas pipe 3, the treatment method can use the pressure energy of the high-pressure natural gas as power to suck the BOG gas into the adjustable ejector for mixing, and jet the mixed gas, the process flow is simple, application is convenient, and safety and reliability are high, the purpose of treating the BOG in the receiving station is achieved, the demand of the BOG treatment amount under different working conditions is met, the BOG treatment effect is achieved, equipment energy consumption is not generated, cost is saved, environmental protection is achieved, and great economic benefits are also achieved.

[0043] The above description is only the preferred embodiment of the present application, and does not limit the present application in any form; any ordinary technical personnel in the industry can smoothly implement the present application according to the above description and the drawings; however, any equivalent change, modification and evolution of the above-mentioned embodiments made by the technical personnel without departing from the technical scheme of the present application, and using the disclosed technical content, are equivalent embodiments of the present application; meanwhile, any equivalent change, modification and evolution of the above-mentioned embodiments made according to the essential technology of the present application, still belong to the protection scope of the technical scheme of the present application.

Claims

1. A BOG processing tooling assembly, characterized in that, It includes a BOG gas phase pipeline (1), a high-pressure natural gas pipeline (2), a medium-pressure natural gas pipeline (3), and an ejector assembly (4). The ejector assembly (4) has an adjustable ejector (41). The ejector assembly (4) has an inlet end, an outlet end, and a drain end. The inlet end of the ejector assembly (4) is connected to the high-pressure natural gas pipeline (2). The drain end of the ejector assembly (4) is connected to the BOG gas phase pipeline (1). The outlet end of the ejector assembly (4) is connected to the medium-pressure natural gas pipeline (3). The ejector assembly (4) further includes a gas inlet pipe (42), an inlet pipe (43), an outlet pipe (44), and an ambient temperature vaporizer (45). The adjustable ejector (41) has an inlet, a duct, and an outlet. The inlet of the adjustable ejector (41) is connected to the high-pressure natural gas pipeline (2) through the inlet pipe (43), and the duct of the adjustable ejector (41) is connected to the BOG gas phase pipeline (1) through the gas inlet pipe (42). The outlet of the gas generator (41) is connected to the medium-pressure natural gas pipeline (3) through the gas outlet pipe (44). The ambient air vaporizer (45) is connected to the gas inlet pipe (42). A second valve (451) is provided at the inlet of the ambient air vaporizer (45), a third valve (452) is provided at the outlet of the ambient air vaporizer (45), a fourth valve (431) is provided on the gas inlet pipe (43), and a fifth valve (441) is provided on the gas outlet pipe (44). The ejection coefficient of the adjustable ejector (41) is 0.

065.

2. The BOG processing tooling assembly according to claim 1, characterized in that, The ejector tube assembly (4) is provided in multiple forms.

3. The BOG processing tooling assembly according to claim 2, characterized in that, A first valve (5) is provided at the connection point between the medium-pressure natural gas pipeline (3) and the gas outlet of the plurality of ejector tube groups (4).

4. The BOG processing tooling assembly according to claim 1, characterized in that, The air intake pipe (42) is provided with a flow monitoring element (421), a temperature monitoring element (422), a safety valve (423), an emergency shut-off valve (424), a pressure monitoring element (425), and a check valve (426) in sequence between the ambient temperature vaporizer (45) and the adjustable ejector (41).

5. The BOG processing tooling assembly according to claim 4, characterized in that, The flow monitoring element (421) is a flow sensor, the temperature monitoring element (422) is a temperature sensor, the pressure monitoring element (425) is a pressure sensor, and the fourth valve (431) and the fifth valve (441) are both electric valves.

6. The BOG processing tooling assembly according to claim 4, characterized in that, It also includes a controller (6), wherein the flow monitoring element (421), temperature monitoring element (422), pressure monitoring element (425), fourth valve (431) and fifth valve (441) are all electrically connected to the controller (6).

7. The BOG processing tooling assembly according to claim 1, characterized in that, There are two check valves (426) on the air intake pipe (42).

8. A BOG processing method based on the BOG processing tooling assembly as described in any one of claims 1-7, characterized in that, The ambient temperature vaporizer (45) vaporizes the BOG gas at -110°C in the BOG gas phase pipeline (1) into a normal temperature low-pressure gas above 0°C, and delivers it to the adjustable ejector (41) to mix with the natural gas delivered by the high-pressure natural gas pipeline (2) and jet into the medium-pressure natural gas pipeline (3).

Images