Ship fuel gas supply system

Abstract

The utility model discloses a ship fuel gas supply system which comprises a main gas supply pipeline, a liquid inlet of a liquid input pipe is connected and communicated with a liquefied natural gas filling station, a liquid outlet of the liquid input pipe is connected and communicated with a liquid gas storage tank, and a liquid inlet of a liquid output pipe is connected and communicated with the liquid gas storage tank. A liquid outlet of the liquid output pipe is connected and communicated with a liquid inlet of the low-pressure vaporizer, a gas outlet of the low-pressure vaporizer is connected and communicated with a gas inlet of the gas-state gas storage tank, a gas outlet of the gas-state gas storage tank is connected and communicated with ship gas equipment, and a liquid inlet of the liquid circulating pipe is connected and communicated with the liquid output pipe; a liquid outlet of the liquid circulating pipe is communicated with the liquid input pipe, and liquid inlets of the liquid output pipe are two branch liquid inlets which are respectively communicated with liquid outlets of two low-pressure pumps arranged in the liquid gas storage tank. According to the system, volatile gaseous natural gas flows back and is utilized, variable-frequency low-pressure operation is adopted for the low-pressure pump, the rotating speed of the low-pressure pump is automatically adjusted through PID, real-time monitoring is achieved, and control and protection are integrated.

Description

Technical Field

[0001] This utility model relates to a gas supply system for ships. Background Technology

[0002] As the shipbuilding industry becomes increasingly stringent in its requirements for energy conservation and emission reduction, these issues have become important topics for the shipbuilding and shipping industries. They are related to issues such as reducing fuel consumption, reducing carbon dioxide emissions, and environmental protection. With the rise of dual-fuel ships, the gas supply system (FGSS) is an important control system in dual-fuel ships. Whether the design of the ship's gas supply system can be in line with energy conservation and emission reduction, and whether it can form a coordinated operation, is also related to the economic efficiency and safety of ship operation. Utility Model Content

[0003] Purpose of the utility model: The purpose of this utility model is to provide a gas supply system for ships that is economical and energy-saving, and to provide a facility foundation for the automatic operation of related equipment.

[0004] Technical Solution: A marine gas supply system includes a main gas supply pipeline consisting of a liquid gas storage tank, a gaseous gas storage tank, a low-pressure vaporizer, a liquid input pipe, a liquid output pipe, and a liquid circulation pipe. The inlet of the liquid input pipe is connected to a liquefied natural gas refueling station, and the outlet of the liquid input pipe is connected to the liquid gas storage tank. The inlet of the liquid output pipe is connected to the liquid gas storage tank, and the outlet of the liquid output pipe is connected to the inlet of the low-pressure vaporizer. The outlet of the low-pressure vaporizer is connected to the inlet of the gaseous gas storage tank, and the outlet of the gaseous gas storage tank is connected to the ship's gas-using equipment. The inlet of the liquid circulation pipe is connected to the liquid output pipe, and the outlet of the liquid circulation pipe is connected to the liquid input pipe. The inlet of the liquid output pipe consists of two branch inlets, which are respectively connected to the outlets of two low-pressure pumps installed in the liquid gas storage tank.

[0005] Furthermore, it also includes an auxiliary gas supply pipeline consisting of a preheater, an air compressor, an aftercooler, and a steam return pipe. The inlet of the steam return pipe is connected to a liquid gas storage tank, and the outlet of the steam return pipe is two branch outlets. One branch outlet is connected to a steam return filling station, and the other branch outlet is connected to the inlet of the preheater. The outlet of the preheater is connected to the inlet of the air compressor, the outlet of the air compressor is connected to the inlet of the aftercooler, and the outlet of the aftercooler is connected to the inlet of the gas storage tank.

[0006] Furthermore, the liquid inlet pipe has two outlets, one of which is equipped with a spray device and is located in the upper part of the liquid storage tank, while the other outlet is located in the lower part of the liquid storage tank, thereby enabling top filling and bottom filling of liquefied natural gas respectively.

[0007] Furthermore, the low-pressure pump is located in the lower part of the liquid storage tank.

[0008] Furthermore, a PID valve is installed at the outlet of the liquid output pipe, and the PID valve is associated with the operating signal in the gas storage tank and the operating signal of the low-pressure pump.

[0009] Furthermore, the inlet of the vapor return pipe is connected to the top of the liquid gas storage tank, allowing the upward-flowing gaseous natural gas generated by the volatilization of the liquefied natural gas in the liquid gas storage tank to return.

[0010] Furthermore, the air compressor is a BOG air compressor, which is associated with the operating signals inside the gaseous storage tank.

[0011] Beneficial Effects: The advantages of this utility model are: Firstly, this ship gas supply system recirculates and reuses the gaseous natural gas that evaporates from the liquid storage tank in the main gas supply pipeline, improving the efficiency and economy of natural gas supply. Secondly, it adopts variable frequency low-pressure operation for the low-pressure pump in the liquid storage tank, automatically adjusting the pump speed via PID control based on the pressure demand of the gas-using equipment. Combined with conventional data signal acquisition such as pressure, temperature, and liquid level, it provides the infrastructure for the automatic operation of related equipment. The integrated real-time monitoring, control, and protection ensures stable and reliable operation of the gas supply system, and can immediately trigger protection in case of emergencies, further enhancing system safety performance. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a ship's gas supply system. Detailed Implementation

[0013] The present invention will be further explained below with reference to specific embodiments.

[0014] A marine gas supply system, as shown in the attached Figure 1 As shown, it includes a liquefied natural gas refueling station 1, a liquefied input pipe 2, a liquefied gas storage tank 3, a liquefied output pipe 4, a low-pressure vaporizer 5, a gaseous gas storage tank 6, a liquefied circulation pipe 7, a vapor return pipe 8, a vapor return refueling station 9, a preheater 10, an air compressor 11, and an aftercooler 12.

[0015] The inlet 201 of the liquid input pipe 2 is connected to the liquid natural gas refueling station 1. The outlet of the liquid input pipe 2 is two branch outlets 2011 and 2012. The branch outlet 2011 extends into the lower area of ​​the liquid storage tank 3. A spray device 203 is installed on the branch outlet 2012. The spray device 203 is located in the upper area of ​​the liquid storage tank 3. The liquid output pipe 4 has two sub-inlets 4011 and 4012, which extend into the liquid gas storage tank 3. Two low-pressure pumps 3011 and 3012 are installed in the lower part of the liquid gas storage tank 3. Sub-inlet 4011 is connected to the outlet of low-pressure pump 3011, and sub-inlet 4012 is connected to the outlet of low-pressure pump 3012. The outlet 402 of the liquid output pipe 4 is connected to the inlet 501 of low-pressure vaporizer 5. The outlet 502 of low-pressure vaporizer 5 is connected to the inlet 601 of gas storage tank 6 through a pipeline. The outlet 602 of gas storage tank 6 is connected to the ship's gas-using equipment, such as generators, main engines, and boilers, through a pipeline. The inlet 701 of the liquid circulation pipe 7 is connected to the liquid output pipe 4, and the outlet 702 of the liquid circulation pipe 7 is connected to the liquid input pipe 2. A PID valve 403 is installed at the outlet 402 of the liquid output pipe 4. The PID valve 403 is associated with the operating signals in the gas storage tank 6, such as gas volume and pressure, and is also associated with the operating signals of the low-pressure pumps 3011 and 3012. This part of the structure constitutes the main gas supply pipeline.

[0016] The inlet 801 of the vapor return pipe 8 extends into the top area of ​​the liquid gas storage tank 3. The outlet of the vapor return pipe 8 consists of two branch outlets 8011 and 8012. Branch outlet 8011 is connected to the vapor return filling station 9, and branch outlet 8012 is connected to the inlet 1001 of the preheater 10. The outlet 1002 of the preheater 10 is connected to the inlet 1101 of the air compressor 11 via a pipeline. The outlet 1102 of the air compressor 11 is connected to the inlet 1201 of the aftercooler 12 via a pipeline, and the outlet 1202 of the aftercooler 12 is connected to the inlet 601 of the gas storage tank 6 via a pipeline. This part of the structure constitutes the auxiliary gas supply pipeline.

[0017] Liquid natural gas (LNG) enters the liquid storage tank 3 from the LNG refueling station 1 via the liquid input pipe 2. The liquid outlets 2011 and 2012 respectively realize bottom refueling and top refueling. The low-pressure pumps 3011 and 3012 are both controlled by frequency converters and are configured as one for standby. The low-pressure pumps 3011 / 3012 transport the LNG in the liquid storage tank 3 to the low-pressure vaporizer 5 via the liquid output pipe 4 and then into the gas storage tank 6. The liquid circulation pipe 7 can be turned on or off as needed to introduce the LNG flowing through the liquid output pipe 4 into the liquid input pipe 2 for circulation.

[0018] The liquefied natural gas in the liquid storage tank 3 will evaporate to produce upward-flowing gaseous natural gas. Part of the evaporated gaseous natural gas can enter the steam reflux refueling station 9 through the steam reflux pipe 8, and part can enter the preheater 10. Since the temperature of the evaporated gaseous natural gas is low, it is heated and vaporized by the preheater 10 before entering the air compressor 11 for pressurization. The temperature of the pressurized gaseous natural gas is too high, so it enters the aftercooler 12 for cooling before entering the gaseous storage tank 6.

[0019] The gaseous natural gas in the gas storage tank serves as the gas supply for gas-consuming equipment such as ship generators, main engines, and boilers. The pressure setpoint required for the gas supply varies based on the needs of the gas-consuming equipment. The pressure setpoint is automatically adjusted by a high-performance PID valve to regulate the speed of the low-pressure pump, providing a more stable gas supply.

[0020] The air compressor uses a BOG (Bottle-Off Gas) air compressor, which is linked to the operating signals inside the gaseous storage tank. It is mainly used to control the pressure inside the gaseous storage tank. For example, when the ambient temperature of the gaseous storage tank rises, BOG vapor will automatically form. When the amount of BOG vapor reaches a certain level, it will cause the pressure in the gaseous storage tank to gradually increase. If it is not dealt with in time, when the pressure reaches a certain limit, it will trigger the safety valve protection. In this way, a large amount of BOG gas will be discharged into the air, causing economic losses and hazards, and easily causing fires, explosions and other incidents. However, after the BOG air compressor is linked to the operating signals inside the gaseous storage tank, it can handle the situation automatically and in a timely manner.

[0021] The marine gas supply system disclosed in this application, on the one hand, recycles the gaseous natural gas that evaporates from the liquid storage tank in the main gas supply pipeline, improving the utilization efficiency and economy of natural gas supply; on the other hand, it adopts variable frequency low-pressure operation for the low-pressure pump in the liquid storage tank, and automatically adjusts the pump speed according to the pressure demand of the gas-using equipment through PID control. Combined with conventional data signal acquisition such as pressure, temperature, and liquid level, it provides the infrastructure foundation for the automatic operation of related equipment. The integrated real-time monitoring, control, and protection system ensures stable and reliable operation of the gas supply system and can immediately trigger protection in case of emergencies, further enhancing system safety performance.

Claims

1. A marine fuel gas supply system, characterized by: The main gas supply pipeline consists of a liquid gas storage tank, a gaseous gas storage tank, a low-pressure vaporizer, a liquid input pipe, a liquid output pipe, and a liquid circulation pipe. The inlet of the liquid input pipe is connected to the liquefied natural gas refueling station, and the outlet of the liquid input pipe is connected to the liquid gas storage tank. The inlet of the liquid output pipe is connected to the liquid gas storage tank, and the outlet of the liquid output pipe is connected to the inlet of the low-pressure vaporizer. The outlet of the low-pressure vaporizer is connected to the inlet of the gaseous gas storage tank, and the outlet of the gaseous gas storage tank is connected to the ship's gas equipment. The inlet of the liquid circulation pipe is connected to the liquid output pipe, and the outlet of the liquid circulation pipe is connected to the liquid input pipe. The liquid output pipe has two separate inlets, which are respectively connected to the outlets of two low-pressure pumps installed in the liquid gas storage tank.

2. Marine fuel gas supply system according to claim 1, characterized in that: It also includes an auxiliary air supply pipeline consisting of a preheater, an air compressor, an aftercooler, and a steam return pipe. The inlet of the steam return pipe is connected to a liquid storage tank. The outlet of the steam return pipe is two branch outlets. One branch outlet is connected to a steam return filling station, and the other branch outlet is connected to the inlet of the preheater. The outlet of the preheater is connected to the inlet of the air compressor. The outlet of the air compressor is connected to the inlet of the aftercooler. The outlet of the aftercooler is connected to the inlet of the gas storage tank.

3. Marine fuel gas supply system according to claim 1, characterized in that: The liquid inlet pipe has two outlets. One outlet is equipped with a spray device and is located in the upper part of the liquid storage tank. The other outlet is located in the lower part of the liquid storage tank.

4. The ship gas supply system according to claim 1, characterized in that: The low-pressure pump is located in the lower part of the liquid storage tank.

5. The ship gas supply system according to claim 1, characterized in that: The liquid outlet is equipped with a PID valve, which is associated with the operating signals in the gas storage tank and the operating signals of the low-pressure pump.

6. The ship gas supply system according to claim 2, characterized in that: The inlet of the vapor return pipe is connected to the top of the liquid storage tank.

7. The ship gas supply system according to claim 2, characterized in that: The air compressor is a BOG air compressor, which is associated with the operating signals inside the gaseous air storage tank.

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