High-pressure gas supply system with combined high-pressure injection and reliquefaction functions

Abstract

The invention discloses a high-pressure gas supply system with a combined high-pressure injection reliquefaction function, which belongs to the technical field of high-pressure gas supply and reliquefaction of ships and comprises a high-pressure gas supply system and a high-pressure injection reliquefaction system sharing a high-pressure compressor unit with the high-pressure gas supply system. The high-pressure gas supply system compresses and cools fuel cabin evaporation gas through a high-pressure compressor unit and then conveys the fuel cabin evaporation gas to the main machine through a high-pressure gas supply pipeline to supply energy to the main machine. The high-pressure injection reliquefaction system injects part of boil-off gas compressed by the high-pressure compressor unit into a condensation tank by means of an injection pump, the boil-off gas in the tank is condensed into liquid fuel to be conveyed back to a fuel cabin, and the uncondensed boil-off gas enters the high-pressure compressor unit again through a pipeline to be compressed and is conveyed into the condensation tank again through the injection pump to be liquefied. By sharing the high-pressure compressor unit, single equipment has the functions of high-pressure gas supply and reliquefaction, stable energy supply of a main engine is guaranteed, meanwhile, boil-off gas is recycled, the depressurization requirement and storage safety of a fuel cabin are met, the pipeline complexity and space occupation are reduced, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of high-pressure gas supply and reliquefaction technology for ships, and particularly to a high-pressure gas supply system that combines high-pressure injection and reliquefaction functions. Background Technology

[0002] The ME-GI main engine is a high-pressure main engine specifically designed for LNG (Liquefied Natural Gas) fuel. It is the core propulsion unit for LNG-powered ships and is a high-pressure main engine supplied by MAN Energy Solutions. Its gas supply design pressure is 300-400 barG. The ME-GI main engine has high thermal efficiency and good fuel economy. In terms of environmental protection, it has excellent methane escape control, which is in line with future carbon emission taxes and environmental policy trends.

[0003] ME-GI main engines require a stable and efficient high-pressure compression system to compress the LNG fuel tank vapors to the pressure required by the main engine. Meanwhile, large merchant ships, considering the high space utilization of fuel tanks, often use Type B or membrane tanks as fuel tanks. However, these fuel tanks are atmospheric pressure tanks and cannot maintain pressure for extended periods. The naturally evaporating gas in the fuel tanks requires a reliquefaction system to maintain stable pressure within the tanks. The high cost of installing a separate reliquefaction system results in poor economic efficiency for this type of vessel. Summary of the Invention

[0004] This invention provides a high-pressure gas supply system that combines high-pressure injection and reliquefaction functions to overcome the above-mentioned problems.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A high-pressure gas supply system combining high-pressure injection reliquefaction function includes a high-pressure gas supply system and a high-pressure injection reliquefaction system that shares a high-pressure compressor unit with the high-pressure gas supply system. The high-pressure gas supply system includes a high-pressure compressor unit and a high-pressure gas supply pipeline. The high-pressure compressor unit can compress and cool the evaporated gas from the fuel tank and then deliver it to the main engine through the high-pressure gas supply pipeline to power the main engine. The high-pressure jet reliquefaction system includes a jet pump, a condenser, and reliquefaction system piping. The injection pump is used to inject part of the evaporated gas after compression and cooling by the high-pressure compressor unit into the condenser tank. The condenser tank is used to condense the evaporated gas in the tank into liquid fuel that can be transported back to the fuel tank. The uncondensed evaporated gas in the condenser tank can be compressed and cooled again by the high-pressure compressor unit through the reliquefaction system pipeline and injected into the condenser tank by the injection pump for reliquefaction.

[0006] Furthermore, the high-pressure jet reliquefaction system also includes a heat exchanger. The evaporating gas compressed and cooled by the high-pressure compressor unit is high-pressure evaporating gas, and the uncondensed evaporating gas is low-temperature uncondensed evaporating gas. The heat exchanger is used to exchange heat between the high-pressure evaporating gas and the low-temperature uncondensed evaporating gas before entering the jet pump.

[0007] Furthermore, the high-pressure gas supply line includes an evaporator gas line and a high-pressure gas supply line. One end of the evaporator gas line is connected to the fuel tank, and the other end of the evaporator gas line is connected to the high-pressure compressor unit. One end of the first high-pressure gas line is connected to the high-pressure compressor unit, and the other end of the first high-pressure gas line is connected to the main unit.

[0008] Furthermore, the reliquefaction system pipeline includes a second high-pressure gas pipeline, a non-condensable gas pipeline, a third high-pressure gas pipeline, and a condensate return pipeline; The inlet end of the second high-pressure gas pipeline is connected to the first high-pressure gas pipeline, and the outlet end of the second high-pressure gas pipeline is connected to the inlet end of the jet pump. The inlet end of the third high-pressure gas pipeline is connected to the outlet end of the jet pump, and the outlet end of the third high-pressure gas pipeline is connected to the inlet end of the condenser. The inlet end of the non-condensable gas pipeline is connected to the outlet end of the condenser tank, the outlet end of the non-condensable gas pipeline is connected to the evaporating gas pipeline, and the outlet end of the condensate return pipeline is located on the side of the evaporating gas pipeline close to the high-pressure compressor unit. The inlet end of the condensate return pipeline is connected to the condensate outlet of the condensate tank, and the outlet end of the condensate return pipeline is connected to the fuel tank. The uncondensed gas pipeline and the second high-pressure gas pipeline exchange heat through the heat exchanger.

[0009] Furthermore, the reliquefaction system pipeline also includes an evaporation gas intake pipeline, the inlet end of which is connected to the fuel tank, and the outlet end of which is connected to the inlet end of the injection pump. When the injection pump is working, it generates a negative pressure inside the evaporation gas intake pipeline.

[0010] Furthermore, the high-pressure compressor unit includes a high-pressure compressor and an aftercooling device; The high-pressure compressor can compress and pressurize the evaporating gas into high-temperature evaporating gas; The post-cooling device can use seawater or ethylene glycol water to cool the high-temperature evaporated gas, forming the high-pressure evaporated gas.

[0011] Furthermore, a first control valve is provided on the evaporator pipeline and between the fuel compartment and the high-pressure compressor unit; A second control valve is provided at one end of the first high-pressure gas pipeline near the main unit; A third control valve is provided on the first high-pressure gas pipeline and between the main unit and the second high-pressure gas pipeline.

[0012] Furthermore, a fourth control valve is provided on the second high-pressure gas pipeline; A fifth control valve is installed on the uncondensed gas pipeline; A sixth control valve is provided on the condensate return pipeline; A seventh control valve is provided on the evaporative gas intake pipeline.

[0013] Furthermore, the fuel tank is a type B tank or a membrane tank.

[0014] The beneficial effects of this invention are: This invention discloses a high-pressure gas supply system combining high-pressure injection and reliquefaction functions. Addressing the low-pressure characteristics of fuel tanks, this system shares a high-pressure compressor unit with the high-pressure gas supply system, enabling a single compressor to perform both high-pressure gas supply and high-pressure injection reliquefaction functions. This provides stable power to the ship's main engine while efficiently recovering and reliquefying evaporated gas. It not only meets the fuel tank pressure maintenance requirements caused by evaporated gas accumulation, ensuring storage safety, but also significantly simplifies the system architecture through equipment reuse, reducing pipeline complexity and equipment space requirements, greatly lowering equipment costs and facilitating future maintenance. Furthermore, the recirculation and reprocessing design of uncondensed evaporated gas improves fuel utilization and reduces emission losses. While ensuring system operational stability, it also offers energy-saving and environmental benefits, making it particularly suitable for marine propulsion systems with strict space constraints and sensitive operating costs. This system meets the high-load gas supply needs under normal navigation conditions while also handling naturally evaporated gas during anchoring, providing an economical and efficient high-pressure gas supply solution with reliquefaction capabilities. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a high-pressure gas supply system with combined high-pressure injection and reliquefaction functions disclosed in an embodiment of the present invention.

[0016] In the picture: 1. High-pressure gas supply system; 101. High-pressure compressor unit; 102. Evaporator gas pipeline; 103. First high-pressure gas pipeline; 104. First control valve; 105. Second control valve; 106. Third control valve; 2. High-pressure jet reliquefaction system; 201. Jet pump; 202. Condensate tank; 203. Heat exchanger; 204. Second high-pressure gas line; 205. Uncondensed gas line; 206. Third high-pressure gas line; 207. Condensate return line; 208. Evaporator gas intake line; 209. Fourth control valve; 210. Fifth control valve; 211. Sixth control valve; 212. Seventh control valve; 3. Fuel tank; 4. Host computer. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example: like Figure 1 The figure shown is a high-pressure gas supply system with combined high-pressure injection and reliquefaction functions provided in this embodiment, including a high-pressure gas supply system 1 and a high-pressure injection and reliquefaction system 2 that shares a high-pressure compressor unit 101 with the high-pressure gas supply system; The high-pressure gas supply system 1 includes a high-pressure compressor unit 101 and a high-pressure gas supply pipeline. The high-pressure compressor unit 101 can compress the evaporated gas of the fuel tank 3 and deliver it to the main unit 4 through the high-pressure gas supply pipeline to supply energy to the main unit 4. The high-pressure jet reliquefaction system 2 includes a jet pump 201, a condenser tank 202, and reliquefaction system pipelines; The injection pump 201 is used to inject part of the vaporized gas compressed by the high-pressure compressor unit 101 into the condenser tank 202. The condenser tank 202 is used to condense the vaporized gas in the tank into liquid fuel that can be transported back to the fuel tank 3. The uncondensed vaporized gas in the condenser tank 202 can be recompressed by the high-pressure compressor unit 101 through the reliquefaction system pipeline and injected into the condenser tank 202 by the injection pump 201 for reliquefaction.

[0019] Because the high-pressure compressor unit is very expensive, the high-pressure gas supply system and the high-pressure injection reliquefaction system in this invention share a single high-pressure compressor unit. The reliquefaction system also uses the high-pressure compressor unit in non-gas supply conditions, saving on the investment cost of the main equipment. At the same time, the two systems are controlled to work separately by setting valves, which realizes the switching between two working modes: high-pressure gas supply mode and anchoring mode. When in high-pressure gas supply mode, the high-pressure compressor unit provides high-pressure gas to the main engine. When in anchoring mode, the natural vapor gas in the fuel tank can be processed by the high-pressure injection reliquefaction system driven by the high-pressure compressor unit to avoid excessive pressure in the fuel tank.

[0020] The high-pressure compressor unit typically supplies gas at a pressure of 300-400 bar and uses a low-temperature, oil-free compressor. When the main unit supplies gas, it can be used as a gas supply compressor; when not supplying gas, it can be used as a reliquefaction compressor. The reliquefaction system is driven by the high-pressure compressor unit, reliquefying the gas through high-pressure injection. Its efficiency, depending on the equipment parameters, can reach 10%-15% of the compressor capacity. Calculations are performed based on both the high-pressure compressor unit's gas supply and reliquefaction operating conditions to select a suitable and economical compressor.

[0021] This combined high-pressure injection reliquefaction system features a simple structure, high reliability, and low maintenance costs. However, its reliquefaction efficiency is relatively low. For vessels with a suitable ratio of natural gas evaporation to high-pressure fuel gas consumption, it is highly economical. However, it is not suitable for LNG carriers or other vessels with low propulsion power and high natural gas evaporation rates.

[0022] This invention discloses a high-pressure gas supply system combining high-pressure injection and reliquefaction functions. Addressing the low-pressure characteristics of fuel tanks, this system shares a high-pressure compressor unit with the high-pressure gas supply system, enabling a single compressor to handle both high-pressure gas supply and high-pressure injection reliquefaction. This provides stable power to the ship's main engine while efficiently recovering and reliquefying evaporated gas. It not only meets the real-time pressure reduction requirements of fuel tanks due to accumulated evaporated gas, ensuring storage safety, but also significantly simplifies the system architecture through equipment reuse, reducing pipeline complexity and equipment space requirements, greatly lowering equipment costs and facilitating future maintenance. Furthermore, the recirculation and reprocessing design of uncondensed evaporated gas improves fuel utilization and reduces emission losses. While ensuring system operational stability, it also offers energy-saving and environmental benefits, making it particularly suitable for marine propulsion systems with strict space constraints and sensitive operating costs. This system meets the high-load gas supply needs under normal navigation conditions while also handling naturally evaporated gas during anchoring, providing an economical and efficient high-pressure gas supply solution with reliquefaction capabilities.

[0023] In a specific embodiment, the high-pressure jet reliquefaction system 2 further includes a heat exchanger 203. The evaporating gas compressed and cooled by the high-pressure compressor unit 101 is high-pressure evaporating gas, and the uncondensed evaporating gas is low-temperature uncondensed evaporating gas (the temperature of the high-pressure evaporating gas is higher than that of the low-temperature uncondensed evaporating gas). The heat exchanger 203 is used to exchange heat between the high-pressure evaporating gas and the low-temperature uncondensed evaporating gas before entering the jet pump, so that the low-temperature uncondensed evaporating gas is heated before entering the evaporating gas main pipeline and the high-pressure compressor unit 101. This helps to avoid cold shock damage to the main pipeline and compressor components caused by low temperature, and improves the compressor inlet temperature to optimize compression efficiency. At the same time, the heat exchanger 203 pre-cools the high-temperature evaporating gas to form low-temperature high-pressure evaporating gas through heat exchange between the high-temperature evaporating gas and the low-temperature uncondensed evaporating gas. After being pressurized and injected into the condenser tank 202 by the jet pump 201, it can reach the condensation temperature threshold more quickly, significantly improving the condensation rate and liquefaction recovery rate. This energy cascade utilization design reduces the system's dependence on external cold sources and reduces the heat load of high-pressure components, thereby enhancing the overall system's operational stability and energy efficiency.

[0024] In a specific embodiment, the high-pressure gas supply pipeline includes an evaporation gas pipeline 102 and a first high-pressure gas pipeline 103. One end of the evaporation gas pipeline 102 is connected to the fuel tank 3, and the other end is connected to the high-pressure compressor unit 101. One end of the first high-pressure gas pipeline 103 is connected to the high-pressure compressor unit 101, and the other end is connected to the main unit 4. The evaporation gas in the fuel tank 3 is input to the high-pressure compressor unit 101 through the evaporation gas pipeline 102. After the high-pressure compressor unit 101 compresses it to the pressure required by the main unit 4, it is delivered to the main unit 4 through the first high-pressure gas pipeline 103 to supply power, ensuring the stability of fuel supply and meeting the power output requirements of the main unit 4. At the same time, the independent evaporation gas pipeline 102 and the first high-pressure gas pipeline 103 enable the orderly separation and efficient connection of the two links of low-pressure evaporation gas collection and high-pressure fuel supply, which can not only ensure the low-pressure safety environment of the fuel tank 3, but also provide a stable gas source foundation for the high-pressure gas supply system, further improving the reliability of the entire system operation.

[0025] In a specific embodiment, the reliquefaction system pipeline includes a second high-pressure gas pipeline 204, an uncondensed gas pipeline 205, a third high-pressure gas pipeline 206, and a condensate return pipeline 207. The inlet end of the second high-pressure gas line 204 is connected to the first high-pressure gas line 103, and the outlet end of the second high-pressure gas line 204 is connected to the inlet end of the jet pump 201. The inlet end of the third high-pressure gas pipeline 206 is connected to the outlet end of the jet pump 201, and the outlet end of the third high-pressure gas pipeline 206 is connected to the inlet end of the condenser 202. The inlet end of the non-condensable gas pipeline 205 is connected to the outlet end of the condenser tank 202, the outlet end of the non-condensable gas pipeline 205 is connected to the evaporating gas pipeline 102, and the outlet end of the condensate return pipeline 207 is located on the side of the evaporating gas pipeline 102 close to the high-pressure compressor unit 101. The inlet end of the condensate return pipe 207 is connected to the condensate outlet of the condensate tank 202, and the outlet end of the condensate return pipe 207 is connected to the fuel tank 3. The uncondensed gas pipeline 205 and the second high-pressure gas pipeline 204 exchange heat via the heat exchanger 203. A portion of the high-pressure gas is diverted from the first high-pressure gas pipeline 103 to the second high-pressure gas pipeline 204. The second high-pressure gas pipeline 204 and the uncondensed gas pipeline 205 exchange heat via the heat exchanger 203. After the heat exchange, the temperature of the high-pressure gas in the second high-pressure gas pipeline 204 decreases and it enters the injection pump 201. Simultaneously, a portion of the evaporated gas in the fuel tank 3 is drawn into the injection pump 201 via the evaporated gas intake pipeline 208 under the negative pressure generated by the operation of the injection pump 201 (Venturi effect). The two gas streams converge and are pressurized within the injection pump 201 before entering the condenser tank 202 via the third high-pressure gas pipeline 206. Part of the gas in the condenser tank 202 is condensed and liquefied into liquid fuel, which is then returned to the fuel tank 3 via the condensate return pipeline 207 for continued use as liquid fuel. The uncondensed evaporated gas in the condenser tank 202 is discharged through the uncondensed gas pipeline 205 and exchanges heat with the gas in the second high-pressure gas pipeline 204 at the heat exchanger 203. After heat exchange, the temperature of the uncondensed evaporated gas rises, and it then flows into the evaporated gas pipeline 102, where it merges with the newly discharged evaporated gas from the fuel tank 3. It then re-enters the high-pressure compressor unit 101 for compression, and is then diverted through the second high-pressure gas pipeline 204 into the high-pressure injection reliquefaction system 2 to achieve reliquefaction and complete the cycle.

[0026] In a specific embodiment, the reliquefaction system pipeline further includes an evaporation gas intake pipeline 208. The inlet end of the evaporation gas intake pipeline 208 is connected to the fuel tank 3, and the outlet end of the evaporation gas intake pipeline 208 is connected to the inlet end of the injection pump. When the injection pump is working, it creates a negative pressure inside the evaporation gas intake pipeline 208, so that some of the evaporation gas in the fuel tank 3 is drawn into the evaporation gas intake pipeline 208 under the action of negative pressure and enters the injection pump 201. The injection pump 201 directly injects the evaporation gas into the condenser tank 202 for condensation and liquefaction, thereby reducing the pressure in the fuel tank 3. The direct injection and liquefaction of the evaporation gas from the fuel tank 3 into the injection pump 201 is synchronized with the evaporation gas compressed by the high-pressure compressor unit 101 entering the injection pump 201, forming a dual-path gas flow. The efficient operation mode of source-source co-processing, with the synchronous action of dual airflows within the jet pump, not only quickly relieves the pressure in fuel tank 3 through direct diversion, but also enhances liquefaction power through high-pressure airflow. The two paths work together to flexibly adapt to different evaporation rates in fuel tank 3, maximizing liquefaction recovery efficiency while ensuring pressure stability, and avoiding power redundancy or insufficient capacity issues that may occur with single-path processing. At the same time, the dual-path synchronous operation mode also improves the system's response speed to pressure fluctuations in fuel tank 3. It can maintain stable liquefaction recovery efficiency under normal conditions, and avoid fuel tank 3 pressure overload through dual-path diversion when the evaporation gas volume increases suddenly (when the ship is moored), achieving a dynamic balance between safe pressure control and energy recovery, and further optimizing the system's operational flexibility and energy utilization economy.

[0027] In a specific embodiment, the high-pressure compressor unit 101 includes a high-pressure compressor and an aftercooling device; The high-pressure compressor can compress and pressurize the evaporating gas into high-temperature evaporating gas; The post-cooling device can use seawater or ethylene glycol water to cool the high-temperature evaporated gas, and after cooling, the high-pressure evaporated gas is formed (the temperature of the high-pressure evaporated gas is higher than the temperature of the low-temperature uncondensed evaporated gas). Specifically, the inlet of the high-pressure compressor is connected to the evaporator pipeline 102, the outlet of the high-pressure compressor is connected to the inlet of the aftercooling device through a pipeline, and the outlet of the aftercooling device is connected to the inlet of the first high-pressure gas pipeline 103. The high-pressure compressor compresses the evaporator, and the outlet temperature of the high-pressure compressor reaches about 100°C. After compression, the high-temperature evaporator is cooled by ethylene glycol water or seawater through the aftercooling device, reducing its temperature to about 35°C, forming high-pressure evaporator. This is the first stage of cooling. Then, the high-pressure evaporator is respectively transported to the heat exchangers of the main unit power supply and the high-pressure jet reliquefaction system for heat exchange, further cooling the high-pressure evaporator to about -100°C, achieving the second stage of cooling.

[0028] In a specific embodiment, a first control valve 104 is provided on the evaporator pipeline 102 and between the fuel tank 3 and the high-pressure compressor unit 101; A second control valve 105 is provided at one end of the first high-pressure gas pipeline near the main unit 4; A third control valve 106 is provided on the first high-pressure gas pipeline and between the main unit 4 and the second high-pressure gas pipeline. Each control valve can achieve precise airflow distribution and pressure control through independent or coordinated adjustment: the first control valve 104 can flexibly adjust the amount of evaporative gas entering the high-pressure compressor unit 101 according to the pressure of the fuel tank 3 and the gas demand of the main unit 4, which can both avoid the sudden pressure drop in the fuel tank 3 from affecting storage safety and provide a stable intake flow for the compressor; the second control valve 105, as the terminal control component for the gas supply of the main unit 4, can dynamically adjust the gas supply pressure and flow according to the real-time power demand of the main unit 4, ensuring that the fuel supply is precisely matched with the load of the main unit 4, and can quickly adjust the gas supply pressure and flow when the main unit 4 is shut down or under maintenance. The first control valve 104 quickly cuts off the gas supply to ensure system safety. The third control valve 106 is responsible for allocating the gas flow ratio from the first high-pressure gas pipeline 103 to the main engine 4 and the reliquefaction system. When the gas demand of the main engine 4 decreases, the high-pressure gas flowing to the main engine 4 can be reduced by adjusting the third control valve 106, thereby indirectly increasing the gas flow to the second high-pressure gas pipeline 204 and improving the processing efficiency of the reliquefaction system. When the main engine 4 is operating under high load, the gas supply to the main engine 4 can be ensured by adjusting the third control valve 106, thus achieving optimal allocation of gas energy. The first control valve 104, the second control valve 105, and the third control valve 106 work together to enable the system to flexibly adapt to different operating conditions such as ship startup, cruising, and berthing. While ensuring a stable power supply to the main engine 4, the system maximizes the reliquefaction recovery rate of evaporated gas and improves the adaptability of system operation.

[0029] In a specific embodiment, a fourth control valve 209 is provided on the second high-pressure gas pipeline 204 to control the flow rate of high-pressure gas flowing into the jet pump 201, thereby matching the liquefaction treatment requirements of the condenser 202 and avoiding exceeding the maximum pressure and flow rate of the condenser 202 due to excessive gas volume. The uncondensed gas pipeline 205 is equipped with a fifth control valve 210, which is used to control the return flow rate of the uncondensed evaporating gas. It works in conjunction with the first control valve 104 to adjust the total intake air volume into the high-pressure compressor unit 101, ensuring that the compressor operates under a stable load. At the same time, by controlling the return ratio, it balances the mixing ratio of the new evaporating gas exported from the fuel tank 3 and the circulating gas, thereby optimizing the compression efficiency. The condensate return pipeline 207 is equipped with a sixth control valve 211, which is used to control the condensate return flow rate and adjust the liquid level balance in the fuel tank 3. This avoids pressure fluctuations in the fuel tank 3 caused by excessively fast condensate return and enables timely recovery of condensate through precise control, preventing excessive liquid accumulation in the condensate tank 202 from affecting the liquefaction space. The evaporative gas intake pipe 208 is equipped with a seventh control valve 212, which is used to control the flow rate of the intake gas according to the actual ship operating conditions. The seventh control valve 212 works in conjunction with the third control valve 106 and the fourth control valve 209 to flexibly switch between single-path or dual-path intake modes of the reliquefaction system. When the main engine 4 is under high load, the direct intake volume can be reduced to prioritize the gas supply to the main engine 4. When the pressure in the fuel tank 3 is too high, the intake volume can be increased to accelerate the pressure reduction. Alternatively, when the ship is anchored, the flow rate of the natural evaporative gas intake to the jet pump 201 can be adjusted according to the actual amount of natural evaporative gas, thereby achieving the optimal operating state of the system under different operating conditions.

[0030] In this embodiment, all valves are solenoid valves, which can automatically regulate opening, closing, and flow rate according to actual working conditions.

[0031] In a specific embodiment, the fuel tank 3 is either a Type B tank or a membrane tank. Type B tanks are independent liquid tanks, while membrane tanks are non-independent liquid tanks. Both have high capacity utilization and low natural evaporation rates, and are generally used in large ships. This type of fuel tank is equipped with a high-pressure oil-free compressor. The high-pressure compressor unit pressurizes the evaporated gas in the fuel tank to meet the main engine's operating requirements, approximately 300-400 bar. When natural evaporation is insufficient, forced evaporation is used to supplement the high-pressure compressor unit, providing sufficient gas displacement to ensure high-pressure gas supply operation.

[0032] This solution is equipped with temperature sensors, pressure sensors, and controllers to achieve real-time monitoring of gas / liquid parameters in the pipeline, the working status of various valves and equipment, and to realize automated control and regulation of the system through the controller. Since the above-mentioned sensors, controllers and other components are common equipment / devices in the field and are not the inventive point of this solution, their specific principles will not be elaborated here.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-pressure gas supply system combining high-pressure injection and reliquefaction functions, characterized in that, The system includes a high-pressure gas supply system (1) and a high-pressure jet reliquefaction system (2) that shares a high-pressure compressor unit (101) with the high-pressure gas supply system. The high-pressure gas supply system (1) includes a high-pressure compressor unit (101) and a high-pressure gas supply pipeline. The high-pressure compressor unit (101) can compress and cool the evaporated gas in the fuel tank (3) and then deliver it to the main unit (4) through the high-pressure gas supply pipeline to supply energy to the main unit (4). The high-pressure jet reliquefaction system (2) includes a jet pump (201), a condenser (202), and reliquefaction system piping; The injection pump (201) is used to inject part of the vaporized gas compressed by the high-pressure compressor unit (101) into the condenser tank (202). The condenser tank (202) is used to condense the vaporized gas in the tank into liquid fuel that can be transported back to the fuel tank (3). The uncondensed vaporized gas in the condenser tank (202) can be compressed again by the high-pressure compressor unit (101) through the reliquefaction system pipeline and injected into the condenser tank (202) by the injection pump (201) for reliquefaction.

2. The high-pressure gas supply system with combined high-pressure injection and reliquefaction functions according to claim 1, characterized in that, The high-pressure jet reliquefaction system (2) also includes a heat exchanger (203). The evaporating gas after compression and cooling by the high-pressure compressor unit (101) is high-pressure evaporating gas, and the uncondensed evaporating gas is low-temperature uncondensed evaporating gas. The heat exchanger (203) is used to exchange heat between the high-pressure evaporating gas and the low-temperature uncondensed evaporating gas before entering the jet pump (201).

3. The high-pressure gas supply system with combined high-pressure injection and reliquefaction functions according to claim 2, characterized in that, The high-pressure gas supply pipeline includes an evaporator gas pipeline (102) and a first high-pressure gas pipeline (103). One end of the evaporator gas pipeline (102) is connected to the fuel tank (3), and the other end of the evaporator gas pipeline (102) is connected to the high-pressure compressor unit (101). One end of the first high-pressure gas pipeline (103) is connected to the high-pressure compressor unit (101), and the other end of the first high-pressure gas pipeline (103) is connected to the main unit (4).

4. The high-pressure gas supply system with combined high-pressure injection and reliquefaction functions according to claim 3, characterized in that, The reliquefaction system piping includes a second high-pressure gas pipeline (204), an uncondensed gas pipeline (205), a third high-pressure gas pipeline (206), and a condensate return pipeline (207). The inlet end of the second high-pressure gas pipeline (204) is connected to the first high-pressure gas pipeline (103), and the outlet end of the second high-pressure gas pipeline (204) is connected to the inlet end of the jet pump (201). The inlet end of the third high-pressure gas pipeline (206) is connected to the outlet end of the jet pump (201), and the outlet end of the third high-pressure gas pipeline (206) is connected to the inlet end of the condenser (202). The inlet end of the non-condensable gas pipeline (205) is connected to the outlet end of the condenser (202), the outlet end of the non-condensable gas pipeline (205) is connected to the evaporator pipeline (102), and the outlet end of the condensate return pipeline (207) is located on the side of the evaporator pipeline (102) close to the high-pressure compressor unit (101). The inlet end of the condensate return pipeline (207) is connected to the condensate outlet of the condensate tank (202), and the outlet end of the condensate return pipeline (207) is connected to the fuel tank (3). The non-condensable gas pipeline (205) and the second high-pressure gas pipeline (204) exchange heat through the heat exchanger (203).

5. The high-pressure gas supply system with combined high-pressure injection and reliquefaction functions according to claim 4, characterized in that, The reliquefaction system pipeline also includes an evaporation gas intake pipeline (208), the inlet end of which is connected to the fuel tank (3), and the outlet end of which is connected to the inlet end of the injection pump. When the injection pump is working, it generates a negative pressure inside the evaporation gas intake pipeline (208).

6. The high-pressure gas supply system with combined high-pressure injection and reliquefaction functions according to claim 5, characterized in that, The high-pressure compressor unit (101) includes a high-pressure compressor and an aftercooling device; The high-pressure compressor can compress and pressurize the evaporating gas into high-temperature evaporating gas; The post-cooling device can use seawater or ethylene glycol water to cool the high-temperature evaporated gas, forming the high-pressure evaporated gas.

7. The high-pressure gas supply system with combined high-pressure injection and reliquefaction functions according to claim 5, characterized in that, A first control valve (104) is provided on the evaporator pipeline (102) and between the fuel tank (3) and the high-pressure compressor unit (101). A second control valve (105) is provided at one end of the first high-pressure gas pipeline (103) near the main unit (4); A third control valve (106) is provided on the first high-pressure gas pipeline (103) and between the host (4) and the second high-pressure gas pipeline (204).

8. The high-pressure gas supply system with combined high-pressure injection and reliquefaction functions according to claim 5, characterized in that, A fourth control valve (209) is provided on the second high-pressure gas pipeline (204); The non-condensable gas pipeline (205) is equipped with a fifth control valve (210); The condensate return line (207) is equipped with a sixth control valve (211); The evaporative gas intake pipe (208) is equipped with a seventh control valve (212).

9. The high-pressure gas supply system with combined high-pressure injection and reliquefaction functions according to claim 1, characterized in that, The fuel tank (3) is a type B tank or a membrane tank.

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