阅读说明：本技术 一种含有缓冲装置的船用燃气供给系统及燃气供给方法 (Marine fuel gas supply system with buffer device and fuel gas supply method ) 是由 井雷雷 冯发鸿 王磊 窦旭 于 2021-06-25 设计创作，主要内容包括：本发明提供一种含有缓冲装置的船用燃气供给系统及燃气供给方法,所述船用燃气供给装置包括LNG储存舱、压缩机、热交换器、燃气缓冲装置及燃气阀组单元,所述LNG储存舱、所述压缩机、所述热交换器、所述燃气阀组单元依次连接,所述燃气缓冲装置旁通连接与所述热交换器与所述燃气阀组单元之间。本发明采用燃气缓冲装置作为燃气管道压力骤增时的临时储存装置,进而提升燃气供给管路所能容纳的最大燃气量,以便在发生事故时,降低燃气管道压力的增速,为系统调整供需状态提供更长的反应时间,从而提高天然气供给系统的稳定性与安全性。燃气缓冲装置被安装在热换热器与燃气阀组之间,它会在系统报警或者人为操作后开启,容纳过量的天然气,缓解供气压力。(The invention provides a marine fuel gas supply system with a buffer device and a fuel gas supply method. The gas buffer device is used as a temporary storage device when the pressure of the gas pipeline suddenly increases, so that the maximum gas amount which can be contained by the gas supply pipeline is increased, the acceleration of the pressure of the gas pipeline is reduced when an accident occurs, longer reaction time is provided for the system to adjust the supply and demand states, and the stability and the safety of a natural gas supply system are improved. The gas buffer device is arranged between the heat exchanger and the gas valve group, and can be opened after system alarming or manual operation, so as to contain excessive natural gas and relieve gas supply pressure.)

1. A marine fuel gas supply system containing a buffer device is characterized by comprising an LNG storage tank, a compressor, a heat exchanger, a fuel gas buffer device and a fuel gas valve group unit, wherein the LNG storage tank, the compressor, the heat exchanger and the fuel gas valve group unit are sequentially connected, the fuel gas buffer device is connected between the heat exchanger and the fuel gas valve group unit in a bypass manner,

gas buffer includes buffer container, gas inlet pipeline, high-pressure nitrogen gas inlet pipeline, gas exhaust pipe and pressure sensor, buffer container is airtight container, gas inlet pipeline high-pressure nitrogen gas inlet pipeline gas exhaust pipe all with buffer container's inside intercommunication, gas inlet pipeline set up in buffer container's bottom, gas inlet pipe connects heat exchanger's exit end, high-pressure nitrogen gas inlet pipeline set up in buffer container's lower part, gas exhaust pipe set up in buffer container's upper portion, the gas inlet pipeline all be provided with the check valve on the high-pressure nitrogen gas inlet pipeline, pressure sensor install in be used for monitoring the pressure in the buffer container on the buffer container.

2. A gas supply system for a ship including a buffer device according to claim 1, wherein said compressor is a low load compressor and the outlet temperature of said heat exchanger is less than 50 ℃.

3. A gas supply system for ships including a buffer device according to claim 1, wherein said buffer container is provided with a man hole, said man hole being located below said pressure sensor.

4. The gas supply system for ship with buffer device as claimed in claim 1, wherein said gas exhaust pipe is connected to said ventilating mast, and said gas exhaust pipe is provided with an exhauster and a shutoff valve.

5. The gas supply system for ships with buffer devices as set forth in claim 1, wherein the top of the buffer vessel is welded with a lifting lug, and the bottom of the buffer vessel is welded with a base pin.

6. The marine gas supply system containing a buffer device according to claim 1, wherein the buffer container is made of carbon steel, the wall thickness of the buffer container is 6-8mm, and the inner side wall of the buffer container is coated with tar-free epoxy paint.

7. The marine gas supply method including a buffer device according to claim 1, using the marine gas supply system according to any one of claims 1 to 6, comprising the steps of:

the method comprises the following steps that firstly, natural gas in an outlet pipeline of an LNG storage cabin is extracted by a compressor, and negative pressure is generated in the pipeline;

step two, the LNG storage cabin is opened, the natural gas stored in the LNG storage cabin is gasified to increase the pressure in the LNG storage cabin, the natural gas is pumped into and discharged from the pipeline,

and step three, the natural gas is compressed by the compressor and then is conveyed to the gas valve group unit, the gas valve group unit mixes the natural gas with air, and mixed gas is flushed into a gas inlet pipeline of a user to complete gas supply.

8. The method for supplying fuel gas to a ship having a buffer unit according to claim 7, wherein in the third step, if the fuel gas pipe is suddenly raised, the fuel gas inlet pipe and the gas outlet pipe of the fuel gas buffer unit are opened, the fuel gas flows into the fuel gas buffer unit after being heat-exchanged by the heat exchanger, the fuel gas is temporarily buffered and discharged by the ventilating mast, and a circulating state is formed until the pressure in the pipe is stabilized and the pressure is reduced to a normal level.

9. The method for supplying fuel gas for ships according to claim 8, wherein the natural gas in the buffer container is replaced with nitrogen gas by opening the high-pressure nitrogen gas inlet line after the fuel gas buffer device is used.

Technical Field

The invention relates to the technical field of ship construction, in particular to a marine fuel gas supply system with a buffer device and a fuel gas supply method.

Background

Clean gas fuel ships powered by LNG (liquefied natural gas) are rapidly developing with the improvement of environmental regulations and the improvement of emission standards on a global scale. Natural gas is a mainstream fuel for future shipping due to the cost advantage and the increased investment in relevant supporting infrastructure in developed countries such as the japan and korea of the european union.

In a twin-shaft ship using natural gas as fuel, gas is transported mainly by a low-load compressor to deliver the gas as a main fuel to a gas user. Because the low-load compressor is very easily influenced by the pressure of the pipeline, the pressure of the pipeline is suddenly increased due to the cutting-off of any branch, and the low-load compressor is stopped, so that the gas supply of all systems is stopped, and the normal operation of the ship is greatly influenced.

Therefore, how to reduce the risk of using the gas supply system is a challenge that must be faced with natural gas as the main fuel. Particularly, when a diesel engine running at full load in a certain gas mode in the double-propulsion shafting is suddenly shut down due to a fault, the gas pressure in a pipeline is inevitably increased, and then the low-load compressor is shut down due to overhigh discharge pressure. Therefore, under the condition, how to slow down the increasing speed of the gas pressure in the pipeline and leave enough operation reaction time for workers so as to ensure that the diesel engine can normally run in a gas-carrying mode, and the problem to be solved at present is solved.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a gas supply system for ships including a buffer device for mitigating impact on the gas supply system due to pressure variations in a gas pipeline. In addition, the invention also provides a marine fuel gas supply method comprising the buffer device.

In order to achieve the above objects and other related objects, the present invention adopts the following technical solutions:

in a first aspect of the present invention, a gas supply system for a ship including a buffer device is provided, including an LNG storage tank, a compressor, a heat exchanger, a gas buffer device, and a gas valve bank unit, wherein the LNG storage tank, the compressor, the heat exchanger, and the gas valve bank unit are connected in sequence, the gas buffer device is connected between the heat exchanger and the gas valve bank unit by a bypass,

gas buffer includes buffer container, gas inlet pipeline, high-pressure nitrogen gas inlet pipeline, gas exhaust pipe and pressure sensor, buffer container is airtight container, gas inlet pipeline high-pressure nitrogen gas inlet pipeline gas exhaust pipe all with buffer container's inside intercommunication, gas inlet pipeline set up in buffer container's bottom, gas inlet pipe connects heat exchanger's exit end, high-pressure nitrogen gas inlet pipeline set up in buffer container's lower part, gas exhaust pipe set up in buffer container's upper portion, the gas inlet pipeline all be provided with the check valve on the high-pressure nitrogen gas inlet pipeline, pressure sensor install in be used for monitoring the pressure in the buffer container on the buffer container.

As a preferred technical scheme, the compressor is a low-load compressor, and the outlet end temperature of the heat exchanger is less than 50 ℃.

Preferably, the buffer container is provided with a manhole, and the manhole is located below the pressure sensor.

Preferably, the gas discharge pipeline is connected with a ventilating mast, and an exhauster and a stop valve are arranged on the gas discharge pipeline.

As a preferable technical scheme, a lifting lug is welded at the top of the buffer container, and a base foot is welded at the bottom of the buffer container.

As a preferred technical scheme, the buffer container is made of carbon steel, the wall thickness of the buffer container is 6-8mm, and tar-free epoxy paint is sprayed on the inner side wall of the buffer container.

In a second aspect of the present invention, there is provided a method for supplying gas to a ship, the method including:

the method comprises the following steps that firstly, natural gas in an outlet pipeline of an LNG storage cabin is extracted by a compressor, and negative pressure is generated in the pipeline;

step two, the LNG storage cabin is opened, the natural gas stored in the LNG storage cabin is gasified to increase the pressure in the LNG storage cabin, the natural gas is pumped into and discharged from the pipeline,

and step three, the natural gas is compressed by the compressor and then is conveyed to the gas valve group unit, the gas valve group unit mixes the natural gas with air, and mixed gas is flushed into a gas inlet pipeline of a user to complete gas supply. If the gas pipeline suddenly rises, opening a gas inlet pipeline and a gas discharge pipeline of the gas buffer device, exchanging heat through a heat exchanger, then flowing into the gas buffer device, temporarily buffering the gas, and discharging the gas through a ventilating mast to form a circulation state until the pressure in the pipeline is stable and the pressure is reduced to a normal level; after the gas buffer device is used, a high-pressure nitrogen inlet pipeline is opened, and natural gas in the buffer container is replaced by nitrogen.

As described above, the gas buffer device is used as a temporary storage device when the pressure of the gas pipeline increases suddenly, so that the maximum gas amount which can be accommodated by the gas supply pipeline is increased, the acceleration of the pressure of the gas pipeline is reduced when an accident occurs, a longer reaction time is provided for the system to adjust the supply and demand states, and the stability and the safety of the natural gas supply system are improved. The gas buffer device is arranged between the heat exchanger and the gas valve group, and can be opened after system alarming or manual operation, so as to contain excessive natural gas and relieve gas supply pressure.

Drawings

Fig. 1 is a schematic structural diagram of a marine gas supply system according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a gas buffer device according to an embodiment of the present invention.

Fig. 3 is a schematic perspective view of a gas buffer device according to an embodiment of the present invention.

Wherein the reference numerals are specified as follows: LNG storage tank 1, compressor 2, heat exchanger 3, gas buffer 4, gas valves unit 5, buffer container 6, gas exhaust pipe 7, high-pressure nitrogen inlet pipe 8, gas inlet pipe 9, lug 10, pressure sensor 11, manhole 12, base foot 13.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Please refer to fig. 1 to 3. It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.

The embodiment provides a marine gas feed system who contains buffer, including LNG storage tank 1, compressor 2, heat exchanger 3, gas buffer 4 and gas valves unit 5, LNG storage tank 1 is the storage vessel of natural gas on boats and ships, compressor 2 provides sufficient pressure for it when the natural gas supplies, heat exchanger 3 makes the natural gas after compressor 2 compresses reduce to suitable temperature, compressor 2 is low-load compressor 2, the exit end temperature of heat exchanger 3 is less than 50 ℃, gas buffer 4 prevents that the natural gas from supplying excessively, provides sufficient buffer space for the natural gas. LNG storage tank 1, compressor 2, heat exchanger 3, gas valve group unit 5 connect gradually, 4 by-pass connections of gas buffer device and heat exchanger 3 and between gas valve group unit 5.

The gas buffering device 4 comprises a buffering container 6, a gas inlet pipeline 9, a high-pressure nitrogen inlet pipeline 8, a gas discharge pipeline 7 and a pressure sensor 11, the buffering container 6 is a closed container, a lifting lug 10 is welded at the top of the buffering container 6, and a base foot 13 is welded at the bottom of the buffering container 6. The buffer container 6 is made of carbon steel, the wall thickness of the buffer container 6 is 6-8mm, tar-free epoxy paint is sprayed on the inner side wall of the buffer container 6, and the requirement on the inner surface treatment is not high because the gas contained in the container is not oxidizing gas.

Gas inlet pipe 9, high-pressure nitrogen gas inlet pipe 8, gas exhaust pipe 7 all communicates with buffer container 6's inside, gas inlet pipe 9 sets up in buffer container 6's bottom, gas inlet pipe 9 connects heat exchanger 3's exit end, high-pressure nitrogen gas inlet pipe 8 sets up in buffer container 6's lower part, gas exhaust pipe 7 sets up in buffer container 6's upper portion, the gas admission line, all be provided with the check valve on the high-pressure nitrogen gas inlet pipe 8, the gas admission line, high-pressure nitrogen gas inlet pipe 8, the flange is all installed to gas exhaust pipe 7's the mouth of pipe, install the asbestos fiber gasket on the flange. A pressure sensor 11 is mounted on the buffer container 6 for monitoring the pressure inside the buffer container 6. The buffer container 6 is provided with a manhole 12, and the manhole 12 is positioned below the pressure sensor 11. The gas discharge pipeline 7 is connected with the ventilating mast, and an exhauster and a stop valve are arranged on the gas discharge pipeline 7.

The embodiment also provides a marine fuel gas supply method with a buffer device, which comprises the following steps: firstly, a compressor 2 extracts natural gas in an outlet pipeline of an LNG storage cabin 1 and generates negative pressure in the pipeline;

step two, the LNG storage cabin 1 is opened, the natural gas stored in the LNG storage cabin 1 is gasified to increase the pressure in the LNG storage cabin 1, the natural gas is pressurized to enter and exit the pipeline,

and step three, the natural gas is compressed by the compressor 2 and then is conveyed to the gas valve group unit 5, the gas valve group unit 5 mixes the natural gas with air, and mixed gas is flushed into a gas inlet pipe 9 of a user to complete gas supply.

When the gas pressure in a gas supply pipeline behind the compressor is too high but does not reach a threshold value, the system can prompt a controller of a control room whether to start a gas buffer device or not, and when the controller selects the starting device, a starting process starts;

on the pipeline of connecting gas buffer and gas supply line, the check valve that admits air opens, and high-pressure gas can pass through connecting tube and get into the buffer container 6 that is in the low pressure state, and the process of admitting air stops for the first time until the pressure in the pipeline is close with the pressure in the middle of the buffer. If the pressure in the supply pipeline is still high, measures are taken, the exhaust stop valve is opened, the gas in the buffer device is discharged into the ventilating mast to form a circulating state until the pressure in the pipeline is stable and the pressure is reduced to a normal level; then, the exhaust stage is carried out, the high-pressure nitrogen inlet pipeline 8 is opened, and nitrogen flows in to flush the container of the buffer device; after the flushing is finished, the exhaust machine on the gas discharge pipeline 7 is started, the gas in the container is pumped out to reach a low-pressure state, the stop valve is closed, and one starting period of the buffer device is finished.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.