High-pressure gas supply system

Abstract

The invention provides a high-pressure fuel gas supply system which comprises an LNG storage tank, an LNG supply pump, an LNG high-pressure pump, a high-pressure evaporator, a gaseous LNG pressure regulating valve and a gas supply valve group, an inlet of the LNG supply pump is communicated with the LNG storage tank, an outlet of the LNG supply pump is communicated to an inlet of the LNG high-pressure pump, an outlet of the LNG high-pressure pump is communicated to an inlet of the high-pressure evaporator, an outlet of the high-pressure evaporator is divided into two paths, and the two paths are communicated with the gas supply valve group. Wherein one path is communicated to a gas supply valve group, an outlet of the gas supply valve group is communicated to gas utilization equipment, the other path of the outlet of the high-pressure evaporator is communicated to an inlet of a gaseous LNG pressure regulating valve, an outlet of the gaseous LNG pressure regulating valve is communicated to an LNG storage tank, and the gaseous LNG pressure regulating valve is used for regulating the gas supply quantity and the gas pressure from the high-pressure evaporator to the gas utilization equipment. By means of the high-pressure gas supply system, a high-pressure LNG buffer tank and a liquid LNG pressure regulating valve are omitted, the system cost is saved, the space occupied by the whole system is reduced, and convenience is brought to arrangement and installation construction.

Description

Technical Field

[0001] The present invention belongs to the technical field of shipbuilding, and particularly relates to a high-pressure gas supply system for LNG dual-fuel ships. Background Art

[0002] Liquefied natural gas (LNG) has now become a widely used clean energy. Using LNG as the fuel for ship main engines can significantly reduce harmful emissions, such as sulfur compounds, nitrogen oxides, and solid particle emissions. A dual-fuel engine for ships needs to operate efficiently and stably under specific conditions. A high-pressure liquefied natural gas supply system can provide a stable high-pressure natural gas supply to ensure that the engine can work according to the design requirements and avoid a decline in engine performance or failures caused by insufficient or unstable gas supply.

[0003] In a traditional high-pressure liquefied natural gas supply system, a high-pressure LNG gas buffer tank and a liquid LNG pressure regulating valve play key roles. The high-pressure LNG gas buffer tank has multiple important functions in the gas supply system of an LNG dual-fuel powered ship, such as buffering system pressure fluctuations, protecting system equipment, improving system efficiency, saving energy and reducing consumption, and adapting to diverse requirements. The liquid LNG pressure regulating valve has multiple functions in the LNG system, including pressure control, flow regulation, safety protection, and adapting to low-temperature environments. It is one of the key devices to ensure the stable operation and safety of the LNG system.

[0004] However, as a high-pressure pressure vessel, the high-pressure LNG gas buffer tank needs to meet strict manufacturing, inspection, and certification standards to ensure its safety and reliability. This results in high certification costs, increasing the procurement and operation costs of the ship. Since the high-pressure LNG gas buffer tank needs to withstand a relatively high working pressure, its volume and weight are usually large, occupying a large space in the gas equipment room. This requires the ship to design a larger gas preparation room, further increasing the construction cost and the difficulty of space utilization.

[0005] In addition, the liquid LNG pressure regulating valve needs to operate at an extremely low working temperature (-196°C), which poses extremely high requirements for its materials and manufacturing processes. To meet these requirements, special materials and technologies need to be used, resulting in a significant increase in procurement costs. Summary of the Invention

[0006] An embodiment of the present invention provides a high-pressure gas supply system, including an LNG storage tank, an LNG supply pump, an LNG high-pressure pump, a high-pressure evaporator, a gaseous LNG pressure regulating valve, and a gas supply valve group. The inlet of the LNG supply pump is connected to the LNG storage tank, the outlet of the LNG supply pump is connected to the inlet of the LNG high-pressure pump, the outlet of the LNG high-pressure pump is connected to the inlet of the high-pressure evaporator, the outlet of the high-pressure evaporator is divided into two paths. One path is connected to the gas supply valve group, and the outlet of the gas supply valve group is connected to the gas-using equipment. The other path of the outlet of the high-pressure evaporator is connected to the inlet of the gaseous LNG pressure regulating valve, and the outlet of the gaseous LNG pressure regulating valve is connected to the LNG storage tank. The gaseous LNG pressure regulating valve is used to adjust the gas supply volume and gas pressure from the high-pressure evaporator to the gas-using equipment.

[0007] Further, it includes a first safety valve, and the first safety valve is arranged between the gaseous LNG pressure regulating valve and the LNG storage tank.

[0008] Further, it includes a second safety valve, and the second safety valve is arranged between the high-pressure evaporator and the gas supply valve group.

[0009] Further, it includes a pressure relief pipeline, the pressure relief pipeline is connected to the LNG pressure regulating valve, and the outlet end of the pressure relief pipeline is connected to a breather mast.

[0010] Further, it includes a gas flow sensor and a gas flow controller, and the gas flow sensor and the gas flow controller are connected to the gas supply valve group for controlling the gas supply valve group.

[0011] Further, it includes a reflux pipeline, one end of the reflux pipeline is connected to the outlet of the high-pressure evaporator, and the other end is connected to the LNG storage tank. A reflux regulating valve is arranged between the high-pressure evaporator and the LNG storage tank.

[0012] Further, it includes an LNG tank pressure sensor, and the LNG tank pressure sensor is connected to the LNG storage tank for detecting the pressure inside the LNG tank.

[0013] Further, it includes a reflux controller, and the reflux controller is connected to the LNG tank pressure sensor and the reflux regulating valve for controlling the reflux regulating valve according to the pressure inside the LNG tank.

[0014] Further, it includes a temperature sensor, and the temperature sensor is connected to the reflux pipeline for monitoring the temperature of the reflux gas in the reflux pipeline.

[0015] Further, it includes a temperature control valve, and the temperature control valve is connected to the reflux pipeline for controlling the gas flow rate of the reflux pipeline according to the temperature of the reflux gas monitored by the temperature sensor.

[0016] Through the high-pressure gas supply system provided by the present invention, the overall system pipeline and device are simple and efficient, eliminating the high-pressure LNG gas buffer tank and the liquid LNG pressure regulating valve, saving the procurement cost. Moreover, the space occupied by the gas preparation of the entire LNG gas supply system is reduced, bringing convenience to the layout and installation construction. Brief Description of the Drawings

[0017] Figure 1 It is a schematic diagram showing a high-pressure gas supply system according to an embodiment of the present invention.

[0018] In the figure, 1 - LNG storage tank, 2 - LNG supply pump, 3 - LNG high-pressure pump, 4 - high-pressure evaporator, 5 - gaseous LNG pressure regulating valve, 6 - gas supply valve group, 7 - gas-using equipment, 9 - first safety valve, 10 - second safety valve, 11 - pressure relief pipeline, 12 - breather mast. Detailed Embodiments

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] In the description of the present application, unless otherwise clearly defined and limited, the terms "connected", "connected to", "communicated with", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, a liquid flowable connection, or a gas flowable connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] As Figure 1 shown, Figure 1Schematic diagram showing a high-pressure gas supply system according to an embodiment of the present invention. The high-pressure gas supply system includes an LNG storage tank 1, an LNG supply pump 2, an LNG high-pressure pump 3, a high-pressure evaporator 4, a gaseous LNG pressure regulating valve 5, and a gas supply valve group 6. The inlet of the LNG supply pump 2 is connected to the LNG storage tank 1, the outlet of the LNG supply pump 2 is connected to the inlet of the LNG high-pressure pump 3, the outlet of the LNG high-pressure pump 3 is connected to the inlet of the high-pressure evaporator 4, the outlet of the high-pressure evaporator 4 is divided into two paths. One path is connected to the gas supply valve group 6, and the outlet of the gas supply valve group 6 is connected to the gas-using equipment 7. The other path of the outlet of the high-pressure evaporator 4 is connected to the inlet of the gaseous LNG pressure regulating valve 5, and the outlet of the gaseous LNG pressure regulating valve 5 is connected to the LNG storage tank 1. The gaseous LNG pressure regulating valve 5 is used to regulate the gas volume and gas pressure from the high-pressure evaporator 4 to the gas-using equipment 7.

[0022] This system first relies on the LNG storage tank 1 to store liquefied natural gas, which is the starting point of the system and stores the LNG for subsequent processes. When the system needs to supply gas, the LNG supply pump starts to work. Its inlet is connected to the LNG storage tank and is responsible for pumping out the LNG in the tank. The pumped-out LNG is then sent to the LNG high-pressure pump. The function of this pump is to pressurize the LNG so that it can be transported to the high-pressure evaporator. The pressurized LNG enters the high-pressure evaporator. Here, the LNG is heated and converted into a gaseous state so that it can be used for subsequent gas supply. The outlet of the high-pressure evaporator is divided into two paths. One path is directly connected to the gas supply valve group, and the gas supply valve group then transports this gaseous LNG to the gas-using equipment to meet its gas demand. The other path is connected to the gaseous LNG pressure regulating valve. The function of this regulating valve is to regulate the gas volume and gas pressure from the high-pressure evaporator to the gas-using equipment. By adjusting this valve, the system can precisely control the gas volume and pressure supplied to the gas-using equipment to meet different operating requirements.

[0023] When the load of the gas-using equipment changes, the gas-using equipment sends a demand signal to the LNG gas supply system. On the one hand, the LNG high-pressure pump adjusts its speed to increase or decrease the supply volume of liquid LNG. On the other hand, the gaseous LNG pressure regulating valve can directly return the over-pressure LNG gas in the pipeline to the LNG storage tank to rapidly reduce the LNG gas supply volume in the pipeline. When there are minor pressure fluctuations in the evaporator, the gaseous LNG pressure regulating valve, through the program of the LNG gas supply system, is set to open when the instantaneous pressure in the pipeline exceeds a certain range (specifically determined according to different models of gas-using equipment) of the instantaneous demand pressure value of the gas-using equipment, and directly return the over-pressure LNG gas to the LNG storage tank, which can eliminate the pressure fluctuation problem of gaseous LNG. This helps to balance the pressure of the system and ensure the stable operation of the entire system.

[0024] This high-pressure gas supply system realizes stable and precise gas supply to gas-using equipment through steps such as storage, pressurization, gasification, distribution, and regulation of LNG. At the same time, through the circulation and pressure stabilization mechanism of gaseous LNG, the system can also maintain its own stable operation.

[0025] Specifically, the LNG storage tank includes a shell, an inner tank, an outer tank, a piping system, accessories, and instruments. Among them, the shell is usually made of high-strength steel with excellent low-temperature performance, such as Q345R (carbon steel) and 16MnR (low-alloy steel). The wall thickness design of the shell needs to consider the low-temperature characteristics of LNG and the overall strength of the storage tank. The LNG storage tank adopts a double-wall structure, that is, an inner tank and an outer tank. The inner tank is in direct contact with LNG, and the outer tank plays a role in protection and support. A thermal insulation layer is provided between the two to reduce heat transfer and maintain the low-temperature state of LNG. It also includes a bottom liquid inlet pipe, a top liquid inlet pipe, a bottom liquid outlet pipe, an upper gas phase pipe, an overflow pipe, etc. These pipes are responsible for the inlet and outlet of LNG, gas phase balance, and overflow treatment. The LNG storage tank is also equipped with accessories such as a liquid level gauge, a pressure gauge, a vacuum gauge valve, a rupture disk, a nameplate, etc., and instruments such as a safety valve, a pressure sensor, and a temperature monitoring system to ensure the safe operation and precise control of the storage tank.

[0026] The LNG supply pump is mainly used to pump liquefied natural gas out of the storage tank and pressurize it for transportation to the LNG high-pressure pump. The flow rate range of the LNG supply pump is generally 50 - 2000 m 3 / h, specifically depending on the pump design and application scenario. The head can be selected according to user requirements, with a maximum of over 2000 m. The LNG supply pump needs to have a low net positive suction head (NPSH) to prevent cavitation during transportation.

[0027] The LNG supply pump includes components such as a motor, a main shaft, bearings, an impeller, and a diffuser. The motor is the power source of the LNG supply pump and adopts a vertical shielded structure, running immersed in the LNG liquid. This structure helps to ensure the cooling effect and operation stability of the motor. At the same time, the torque of the motor will decrease at low temperatures, so special attention needs to be paid to its electrical characteristics and starting performance. The main shaft is the component connecting the motor and the impeller and needs to withstand large torques and axial forces. To ensure its stiffness and stability, the main shaft is manufactured by integral forging technology. The bearings are used to support the rotational movement of the main shaft and the impeller and bear radial and axial loads. The bearings of the LNG supply pump need to have good wear resistance and corrosion resistance to ensure the long-term stable operation of the pump. The impeller is one of the core components of the LNG supply pump and is used to suck in and pressurize and discharge the LNG liquid. The design of the impeller needs to consider the fluid flow characteristics and the head requirements of the pump. The diffuser is usually set at the inlet of the pump to improve the fluid flow characteristics and reduce the fluid resistance at the suction inlet. This helps to ensure the stable operation of the pump and improve its efficiency.

[0028] In addition, some LNG supply pumps are also equipped with components such as thrust self-balancing mechanisms to further improve their operating stability and reliability. The thrust self-balancing mechanism can automatically adjust the pressure on the pressure balance drum, making the axial thrust zero, thereby extending the service life of the bearings and reducing the failure rate of the pump.

[0029] The LNG high-pressure pump can adopt a variable-frequency high-pressure pump for liquid LNG. Specifically, the variable-frequency high-pressure pump for liquid LNG can boost LNG from a low-pressure state to a high-pressure state to meet the requirements of long-distance transportation or high-pressure injection. Through the adjustment of the variable-frequency motor, precise control of the LNG flow rate can be achieved to meet the demands under different working conditions. The use of the variable-frequency motor enables the pump to adjust its power according to actual needs during operation, thereby saving energy and reducing carbon emissions. The variable-frequency high-pressure pump for liquid LNG can monitor and adjust the operating state of the pump in real time to ensure its stable operation.

[0030] Furthermore, according to the requirements of ship operation, two or more variable-frequency high-pressure pumps for liquid LNG can be arranged in parallel or in series to increase the pressure.

[0031] The main function of the LNG high-pressure evaporator is to convert liquid LNG into gaseous natural gas to meet the power requirements of the ship's main engine. Under high-pressure conditions, LNG absorbs heat through heating elements (such as heat exchangers) inside the evaporator, thereby achieving the phase change from liquid to gas. During this process, the evaporator not only provides a necessary heat exchange site but also ensures the stable and efficient conversion of LNG.

[0032] The LNG high-pressure evaporator includes a shell, heat exchange elements, heating medium, inlet and outlet pipes, and a control system. Among them, the shell is the external structure of the evaporator, used to accommodate the internal heat exchange elements and fluids. The shell is made of high-strength and low-temperature-resistant materials to ensure its structural integrity and safety. The heat exchange elements are the core part of the evaporator, used to achieve heat exchange between LNG and the heating medium. These elements include structures such as finned tubes and spiral tubes to increase the heat exchange area and improve the heat exchange efficiency. The heating medium is used to provide heat to the LNG inside the evaporator. In this application, the heating medium can include steam, hot water, heat-conducting oil, etc. These media conduct heat exchange with LNG through the heat exchange elements, thereby realizing the evaporation of LNG. The inlet and outlet pipes are used to connect the evaporator to other equipment or systems. The inlet pipe introduces LNG into the evaporator, while the outlet pipe transports the evaporated natural gas to subsequent processing or utilization links. The control system is used to monitor and control the operating parameters of the evaporator, such as temperature, pressure, flow rate, etc. Through the control system, remote monitoring and automatic adjustment of the evaporator can be achieved to ensure its stable operation and efficient conversion.

[0033] One component of the gaseous LNG pressure regulating valve replaces the two components of the traditional high-pressure LNG gas buffer tank (usually with a maximum working pressure of 35 MPa) and the liquid LNG pressure regulating valve. The main function of the gaseous LNG pressure regulating valve is to regulate and control the gas pressure in the system to ensure its operation within a safe and stable range. In the LNG system, as the gas is consumed or the system changes, the pressure in the pipeline may vary. The pressure regulating valve can sense these changes and automatically adjust the valve opening to maintain the system pressure within the set range. This helps protect the system from damage caused by excessive or too low pressure and ensures the safe and efficient utilization of LNG.

[0034] The gaseous LNG pressure regulating valve includes a valve body, a valve core, a spring, a diaphragm, and seals, etc. The valve body is the main structure of the regulating valve and is usually made of high-strength and low-temperature-resistant materials. It contains one or more channels inside for the flow and regulation of gas. The gas flow and pressure are regulated by changing the position of the valve core. The valve core is made of wear-resistant and corrosion-resistant materials to ensure its long-term stable operation. Among them, the spring is used to provide the reset force for the valve core. When the system pressure changes, the spring can push the valve core to move, thereby changing the valve opening. The diaphragm is usually used together with the spring to sense the change of the system pressure and transmit it to the valve core. The diaphragm material needs to have good elasticity and low-temperature resistance. Seals are used to ensure the sealing performance of the regulating valve and prevent gas leakage. Commonly used sealing materials include PTFE, rubber, etc.

[0035] The gas supply valve group can accurately regulate the gas pressure and flow according to the system requirements to ensure the stable and safe operation of the LNG system. At the same time, the gas supply valve group also has an emergency cut-off function. When an abnormal situation occurs in the system, it can quickly cut off the gas supply to prevent the situation from expanding.

[0036] The gas supply valve group includes a main valve body, a regulating mechanism, a safety valve, and a filter. The main valve body is the main structure of the valve group and is made of high-strength and low-temperature-resistant materials. It contains one or more channels inside for the flow and regulation of gas. The regulating mechanism is used to regulate the gas pressure and flow. It consists of components such as a valve core, a spring, and a diaphragm, and regulates the gas flow and pressure by changing the position of the valve core. The safety valve is used to cut off the gas supply when an abnormal situation occurs in the system. It includes a set pressure value. When the system pressure exceeds this value, the safety valve will automatically open and cut off the gas supply. The filter is used to filter impurities and particles in the gas to prevent them from entering the valve group or the system and causing damage or failure. The filter is set at the inlet of the valve group to ensure that the gas entering the valve group is clean.

[0037] In another embodiment, the high-pressure gas supply system further includes a first safety valve 9, and the first safety valve 9 is arranged between the gaseous LNG pressure regulating valve 5 and the LNG storage tank 1.

[0038] Specifically, the high-pressure gas supply system includes a pressure relief pipeline 11, which is indicated by the dashed line in Figure 1 . One end of the pressure relief pipeline 11 is connected to the outlet of the high-pressure evaporator 4, and the other end is connected to the LNG storage tank 1. The gaseous LNG pressure regulating valve 5 is arranged on the pressure relief pipeline 11, and the first safety valve 9 is arranged on the pressure relief pipeline 11 and is arranged between the gaseous LNG pressure regulating valve 5 and the LNG storage tank 1. The first safety valve 9 is connected to the vent mast 12.

[0039] The main function of the first safety valve 9 is to automatically open and discharge the excess gas when the pressure of the pressure relief pipeline 11 exceeds the set value, thereby preventing the pressure relief pipeline 11 from malfunctioning or being damaged due to excessive pressure. This is crucial for protecting the integrity and safety of the LNG system. When the first safety valve 9 opens, the excess gas in the pressure relief pipeline 11 will be discharged into the vent mast 12. The design of the vent mast 12 can ensure that these gases are discharged to a high point far from the deck surface and are dispersed by the sailing wind, thereby reducing the impact on the surrounding environment and the safety of the ship. By precisely adjusting the set values of the pressure regulating valve and the safety valve, the pressure of the LNG system can be ensured to fluctuate within a stable range, thereby improving the stability and reliability of the system.

[0040] In another embodiment, the high-pressure gas supply system further includes a second safety valve 10, which is arranged between the high-pressure evaporator 4 and the gas supply valve group 6.

[0041] The main function of the second safety valve 10 is to automatically open and discharge the excess gas when the pressure entering the gas supply valve group 6 exceeds the set value, thereby preventing the pressure entering the gas supply valve group 6 from being too high. When the second safety valve 10 opens, the excess gas coming out of the high-pressure evaporator 4 will be discharged into the vent mast 12.

[0042] In another embodiment, the high-pressure gas supply system further includes a gas flow sensor and a gas flow controller. The gas flow sensor is arranged between the gas supply valve group 6 and the gas-using equipment 7 and is used to monitor the gas flow rate of the gas flowing from the gas supply valve group 6 to the gas-using equipment 7. The gas flow controller is connected to the gas flow sensor and the gas supply valve group 6. When the gas flow rate entering the gas-using equipment 7 exceeds a certain set threshold, the gas flow sensor sends a signal to the gas flow controller, and the gas flow controller controls the opening degree of the valve of the gas supply valve group 6 to reduce the opening degree of the valve to reduce the gas volume entering the gas-using equipment 7. When the gas flow rate entering the gas-using equipment 7 is lower than a certain set threshold, the gas flow sensor sends a signal to the gas flow controller, and the gas flow controller controls the opening degree of the valve of the gas supply valve group 6 to increase the opening degree of the valve to increase the gas volume entering the gas-using equipment 7.

[0043] The settings of the gas flow sensor and the gas flow controller can further precisely control the gas flow, optimize the supply control of the gas-using equipment, save energy, and facilitate operation.

[0044] In another embodiment, the high-pressure gas supply system further includes a reflux pipeline. One end of the reflux pipeline is communicated with the outlet of the high-pressure evaporator 4, and the other end is communicated with the LNG storage tank 1. A reflux regulating valve is arranged between the high-pressure evaporator and the LNG storage tank.

[0045] During the continuous outflow of LNG from the storage tank, the pressure in the LNG storage tank 1 will gradually decrease. When the pressure is too low, the vaporized natural gas pressurized by the high-pressure evaporator is refluxed to the LNG storage tank through the reflux pipeline to achieve the pressurization of the storage tank. The reflux regulating valve is used to open or close the reflux pipeline according to the pressure demand in the LNG and regulate the reflux pressure.

[0046] In a further embodiment, a pressure sensor is included in the LNG tank body. The LNG tank body pressure sensor is communicated with the LNG storage tank and is used to detect the pressure in the LNG tank body.

[0047] The pressure sensor can real-time monitor the pressure change in the LNG tank body to ensure that the tank body operates within a safe pressure range. The regulating valve can automatically regulate the pressure refluxed into the tank body according to the pressure change in the LNG tank body. When the pressure in the LNG storage tank exceeds the preset value, the regulating valve will open to allow part of the LNG or gas to reflux into the tank body from the system, thereby reducing the pressure in the tank body. On the contrary, when the pressure in the tank body is lower than the preset value, the regulating valve will close to reduce the reflux to maintain the pressure stability in the tank body. This helps to maintain the pressure stability in the tank body and prevent potential safety hazards caused by pressure fluctuations.

[0048] In a further embodiment, a reflux controller is included on the reflux pipeline. The reflux controller is communicated with the pressure sensor of the LNG storage tank and the reflux regulating valve and is used to control the reflux regulating valve according to the pressure in the LNG tank body.

[0049] The reflux controller receives the pressure condition in the LNG storage tank transmitted by the pressure sensor and real-time adjusts the opening degree of the reflux regulating valve. By real-time monitoring and automatically regulating the pressure, this system can significantly improve the safety of the LNG storage system. It can take timely measures when the pressure is abnormal to prevent accidents and protect the safety of personnel and property.

[0050] In a further embodiment, a temperature sensor is included. The temperature sensor is communicated with the reflux pipeline and is used to monitor the temperature of the reflux gas in the reflux pipeline.

[0051] The temperature sensor is connected to the reflux pipeline and is used to monitor the temperature of the reflux gas in the reflux pipeline. When the reflux gas flows through the temperature sensor, the sensor will capture the temperature information of the gas and convert it into corresponding electrical signals for output. The output electrical signals can be further processed, such as being converted into digital signals through an analog-to-digital converter, and then transmitted to the control system or monitoring equipment. The control system can, based on the received temperature signals, monitor and control the temperature of the reflux pipeline in real time.

[0052] In a further embodiment, it includes a temperature control valve. The temperature control valve is connected to the reflux pipeline and controls the gas flow rate of the reflux pipeline according to the temperature of the reflux gas monitored by the temperature sensor.

[0053] By monitoring the temperature of the reflux gas, the control system can obtain real-time temperature data and precisely control the reflux process based on these data. For example, when the temperature exceeds the preset value, the control system can take corresponding measures, such as adjusting the opening degree of the reflux valve or starting the cooling equipment, etc., to keep the temperature of the reflux gas within the safe range.

[0054] This high-pressure gas supply system adopts a design scheme of a gaseous LNG pressure regulating valve (normal temperature and high pressure: generally the maximum working pressure is 35 MPa, the minimum working temperature is -25 °C). Its procurement cost is at least 200,000 yuan cheaper than that of a high-pressure LNG gas buffer tank (generally the maximum working pressure is 35 MPa) and a liquid LNG pressure regulating valve (generally the maximum working pressure is 35 MPa, the minimum working temperature is -196 °C). The total cost saved for the series of ships will exceed one million yuan.

[0055] Moreover, it reduces the space occupied by the gas preparation of the entire LNG gas supply system, bringing convenience to the layout and installation construction.

[0056] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A high-pressure gas supply system, comprising an LNG storage tank, an LNG supply pump, an LNG high-pressure pump, a high-pressure evaporator, a gaseous LNG pressure regulating valve, and a gas supply valve group, wherein, The inlet of the LNG supply pump is connected to the LNG storage tank, the outlet of the LNG supply pump is connected to the inlet of the LNG high-pressure pump, the outlet of the LNG high-pressure pump is connected to the inlet of the high-pressure evaporator, the outlet of the high-pressure evaporator is divided into two paths, one of which is connected to the gas supply valve group, the outlet of the gas supply valve group is connected to the gas-using equipment, the other path of the outlet of the high-pressure evaporator is connected to the inlet of the gaseous LNG pressure regulating valve, the outlet of the gaseous LNG pressure regulating valve is connected to the LNG storage tank, and the gaseous LNG pressure regulating valve is used to regulate the gas supply volume and gas pressure from the high-pressure evaporator to the gas-using equipment.

2. The high-pressure gas supply system according to claim 1, further comprising a first safety valve, and the first safety valve is arranged between the gaseous LNG pressure regulating valve and the LNG storage tank.

3. The high-pressure gas supply system according to claim 2, further comprising a pressure relief pipeline, one end of the pressure relief pipeline is connected to the outlet of the high-pressure evaporator, the other end is connected to the LNG storage tank, the gaseous LNG pressure regulating valve is arranged on the pressure relief pipeline, the first safety valve is arranged on the pressure relief pipeline, and the first safety valve is arranged between the gaseous LNG pressure regulating valve and the LNG storage tank, and the first safety valve is connected to the ventilation mast.

4. The high-pressure gas supply system according to claim 1, further comprising a second safety valve, and the second safety valve is arranged between the high-pressure evaporator and the gas supply valve group.

5. The high-pressure gas supply system according to claim 1, further comprising a gas flow sensor and a gas flow controller, and the gas flow sensor and the gas flow controller are connected to the gas supply valve group for controlling the gas supply valve group.

6. The high-pressure gas supply system according to claim 1, further comprising a return pipeline, one end of the return pipeline is connected to the outlet of the high-pressure evaporator, the other end is connected to the LNG storage tank, and a return regulating valve is arranged between the high-pressure evaporator and the LNG storage tank.

7. The high-pressure gas supply system according to claim 1, further comprising an LNG tank pressure sensor, and the LNG tank pressure sensor is connected to the LNG storage tank for monitoring the pressure inside the LNG storage tank.

8. The high-pressure gas supply system according to claims 6 and 7, further comprising a return controller, and the return controller is connected to the LNG tank pressure sensor and the return regulating valve for controlling the return regulating valve according to the pressure inside the LNG storage tank.

9. The high-pressure gas supply system according to claim 6, further comprising a temperature sensor, and the temperature sensor is connected to the return pipeline for monitoring the temperature of the return gas in the return pipeline.

10. The high-pressure gas supply system according to claim 9 further includes a temperature control valve, which is connected to the return pipeline and controls the gas flow rate of the return pipeline according to the temperature of the return gas monitored by the temperature sensor.

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