Automatic storage tank supply switching device of ship fuel gas supply system and switching method of automatic storage tank supply switching device
By designing an automatic switching tank supply device in the marine gas supply system, real-time liquid level difference monitoring and automatic switching is achieved using low-pressure pumps, liquid level sensors and PID valves, the shutdown problem caused by the tank liquid level difference and generator load are solved. The pressure instability caused by changes ensures the stable operation of the system.
Patent Information
- Application Number
- CN202411292233.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2024-12-10
AI Technical Summary
The existing marine gas supply system needs to shut down when the tank liquid level difference is large, and manual switching of the tank supply is made by changing generator load, resulting in unstable outlet pressure, which cannot achieve automatic switching and pressure adjustment without shutdown.
An automatic switching tank supply device is designed. By installing a low-pressure pump, liquid level sensor and data acquisition module in the storage tank, real-time liquid level difference monitoring and automatic switching is achieved using PID valves and circulating valves, and adjusting according to generator load. Exit pressure.
Automatic switching and pressure stability without shutdown are achieved, ensuring stable and reliable operation of the gas supply system, and avoiding gas supply interruptions and pressure fluctuations caused by excessive liquid level difference.
Smart Images
Figure CN119102930A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of LNG utilization, and in particular relates to an automatic switching tank supply device of a ship gas supply system and a switching method thereof. Background Art
[0002] As the requirements of the shipbuilding industry for energy conservation and emission reduction become more and more stringent, energy conservation and emission reduction have become important issues in the shipbuilding and shipping industries around the world. They are also related to reducing fuel consumption, reducing carbon dioxide emissions, and environmental protection. With the rise of dual-fuel ships, the fuel gas supply system (FGSS) is an important control system in dual-fuel ships. The fuel gas supply system (FGSS) is equipped with 2 tanks. When tank 1 is used to supply gas to the downstream equipment of the ship, the liquid level of the tank drops a lot after long-term use, which will cause the liquid level difference between tank 1 and tank 2 to be too large.
[0003] Under existing technology, the ship's gas supply system must be shut down and manually switched to other storage tanks to supply downstream gas-consuming equipment; secondly, the outlet pressure is set at a fixed set value to automatically PID-regulate the variable frequency pump in the tank. If the load of the generator suddenly changes drastically, it will lead to insufficient pressure supply. Summary of the invention
[0004] The purpose of the present invention is to provide an automatic switching tank supply device for a ship fuel gas supply system, which can ensure that the fuel gas supply system does not stop and improve the stability of the fuel gas supply system.
[0005] The technical solution adopted by the present invention is as follows:
[0006] An automatic switching tank supply device for a ship gas supply system comprises a tank 1 and a tank 2, wherein a low-pressure pump A and a low-pressure pump B are installed in the tank 1 and the tank 2 respectively, and the output ends of the low-pressure pump A and the low-pressure pump B are both equipped with outlet valves, and the other ends of the outlet valves both penetrate the tank 1 and the tank 2 and are connected to the same pipeline, a PID valve is installed on the side wall of the pipeline, and the other end of the PID valve is connected to a low-pressure vaporizer, and the output end of the low-pressure vaporizer is connected to a transfer tank, and the output end of the transfer tank is connected to a discharge valve, and the output end of the discharge valve is connected to a generator.
[0007] The pipeline is also connected with a suction valve, and the suction valve is located at the input end of the PID valve.
[0008] The transfer tank is provided with a data acquisition module, and the PID valve is electrically connected to the data acquisition module.
[0009] Liquid level sensors are installed in both the first storage tank and the second storage tank, and the liquid level sensors are electrically connected to the data acquisition module.
[0010] The tail ends of the pipelines are fixedly connected with circulation valves, and the output ends of the circulation valves extend into the first tank and the second tank respectively.
[0011] Switching method of automatic switching tank supply device of ship gas supply system,
[0012] The switching method comprises the following steps:
[0013] S1: Start the medium and low pressure pump A of the storage tank to supply externally, and open the outlet valve and the suction valve, and automatically adjust the pressure through the PID valve according to the transfer tank pressure;
[0014] S2: Real-time monitoring of the liquid level difference between tank 1 and tank 2;
[0015] S3: When the liquid level difference between tank 1 and tank 2 reaches the preset value, the outlet valve and suction valve on the corresponding pipeline of low-pressure pump A in tank 2 are automatically opened;
[0016] S4: The low-pressure pump A in the second tank starts automatically, increases speed until the pressure reaches the set value, and activates the PID valve regulation of the low-pressure pump A. The pressure is maintained stable by the low-pressure pump A, and the PID valve regulation of the low-pressure pump A in the first tank is exited at the same time;
[0017] S5: The low-pressure pump A in the tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed;
[0018] S6: Real-time monitoring of the liquid level difference between tank 1 and tank 2.
[0019] The conversion of the low-pressure pump B in the storage tank 1 and the storage tank 2 comprises the following steps:
[0020] S11: When the liquid level difference between tank 1 and tank 2 reaches a preset value, the outlet valve and suction valve on the corresponding pipeline of low-pressure pump B in tank 1 are automatically opened;
[0021] S12: The low-pressure pump B in the tank 1 starts automatically, increases speed until the pressure reaches the set value, and activates the PID valve regulation of the low-pressure pump B. The pressure is maintained stable by the low-pressure pump B, and the PID valve regulation of the low-pressure pump A in the tank 2 is exited at the same time;
[0022] S13: The low-pressure pump A in the second tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed;
[0023] S14: real-time monitoring of the liquid level difference between storage tank 1 and storage tank 2;
[0024] S15: When the liquid level difference between storage tank 1 and storage tank 2 reaches a preset value, the outlet valve and the suction valve on the corresponding pipeline of the low-pressure pump B in storage tank 2 are automatically opened;
[0025] S16: The low-pressure pump B in the second tank starts automatically, increases speed until the pressure reaches the set value, activates the PID valve regulation of the low-pressure pump B, the pressure is maintained stable by the low-pressure pump B, and exits the PID valve regulation of the low-pressure pump B in the first tank;
[0026] S17: The low-pressure pump B in the storage tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed.
[0027] In the storage tank 1 and the storage tank 2, the steps of switching from low-pressure pump B to low-pressure pump A are as follows:
[0028] S18: Real-time monitoring of the liquid level difference between storage tank 1 and storage tank 2;
[0029] S19: The low-pressure pump A in the tank 1 starts automatically, increases speed until the pressure reaches the set value, activates the PID valve regulation of the low-pressure pump A, and the pressure is maintained stable by the low-pressure pump A, and exits the PID valve regulation of the low-pressure pump B in the tank 2;
[0030] S20: The low-pressure pump B in the second tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed;
[0031] S21: Repeat the above S2 and execute it in a loop.
[0032] The technical effects achieved by the present invention are:
[0033] The automatic switching tank supply device of the ship gas supply system of the present invention collects signals from sensors such as pressure, temperature, and liquid level in real time through a data acquisition module, and calculates the liquid level difference between two tanks in real time. When the preset liquid level difference is reached, the tank supply is automatically switched without stopping the machine, so that the gas supply system can operate stably and reliably; and the outlet pressure setting value can be adjusted in real time according to the load of the generator, so that the gas supply pressure can always be kept stable. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figure 1 It is a schematic diagram of the distribution structure of storage tank 1 and storage tank 2 according to an embodiment of the present invention. DETAILED DESCRIPTION
[0035] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.
[0036] like Figure 1As shown, the ship gas supply system automatically switches the tank supply device, including tank one and tank two, low-pressure pump A and low-pressure pump B are installed in tank one and tank two respectively, the output ends of low-pressure pump A and low-pressure pump B are equipped with outlet valves, the other ends of the outlet valves pass through tank one and tank two and are connected to the same pipeline, a PID valve is installed on the side wall of the pipeline, the other end of the PID valve is connected to a low-pressure vaporizer, the output end of the low-pressure vaporizer is connected to a transfer tank, the output end of the transfer tank is connected to a discharge valve, and the output end of the discharge valve is connected to a generator.
[0037] Among them, the PID valve is a valve used to accurately control the flow of fluids, combining the advantages of PID control theory. The PID controller is a control algorithm widely used in automated control systems. It adjusts the control output of the system through three parts: proportional (P), integral (I) and differential (D) to achieve stable and accurate control goals. In this solution, the pressure change during gas output can be controlled according to the information collected by the data acquisition module to increase the stability of gas supply.
[0038] The pipeline is also connected with a suction valve, which is located at the input end of the PID valve.
[0039] A data acquisition module is provided on the transfer tank, and the PID valve is electrically connected to the data acquisition module.
[0040] Liquid level sensors are installed in both storage tank 1 and storage tank 2, and the liquid level sensors are electrically connected to the data acquisition module.
[0041] Among them, the data acquisition module is used to collect and analyze data, make timely adjustments based on the internal liquid level data of tanks one and two, and issue instructions to control the operation of each valve.
[0042] The tail ends of the pipelines are fixedly connected with circulation valves, and the output ends of the circulation valves extend into the first tank and the second tank respectively.
[0043] Among them, a circulation valve is a valve used to control the circulation flow of a fluid, and is usually used in application scenarios where the circulation flow of a fluid in a system needs to be controlled. It can switch between multiple fluid paths or maintain the circulation of a fluid in a closed system.
[0044] Through the data acquisition module, signals from sensors such as pressure, temperature, and liquid level are collected in real time, and the liquid level difference between the two tanks is calculated in real time. When the preset liquid level difference is reached, the tank supply is automatically switched without stopping the machine, allowing the gas supply system to operate stably and reliably. The outlet pressure setting value can also be adjusted in real time according to the load of the generator, so that the gas supply pressure can always be kept stable.
[0045] The switching method of the ship's gas supply system automatically switches the tank supply device. Taking the external supply of tank one as an example, when the liquid level difference between tank one and tank two is greater than a preset value, it automatically switches to the supply of tank two, thereby ensuring that the liquid levels of tank one and tank two are the same.
[0046] The liquefied natural gas low-pressure pump is controlled by a separate variable frequency drive. According to the pressure demand of the buffer tank, the PID valve is automatically adjusted to keep the external control pressure stable. The switching process will not have any impact on downstream gas-using equipment such as generators.
[0047] The switching method includes the following steps:
[0048] S1: Start the medium and low pressure pump A of the storage tank to supply externally, and open the outlet valve and the suction valve, and automatically adjust the pressure through the PID valve according to the transfer tank pressure;
[0049] S2: Real-time monitoring of the liquid level difference between tank 1 and tank 2;
[0050] S3: When the liquid level difference between tank 1 and tank 2 reaches the preset value, the outlet valve and suction valve on the corresponding pipeline of low-pressure pump A in tank 2 are automatically opened;
[0051] S4: The low-pressure pump A in the second tank starts automatically, increases speed until the pressure reaches the set value, and activates the PID valve regulation of the low-pressure pump A. The pressure is maintained stable by the low-pressure pump A, and the PID valve regulation of the low-pressure pump A in the first tank is exited at the same time;
[0052] S5: The low-pressure pump A in the tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed;
[0053] S6: Real-time monitoring of the liquid level difference between tank 1 and tank 2.
[0054] The conversion of low pressure pump B in tank 1 and tank 2 includes the following steps:
[0055] S11: When the liquid level difference between tank 1 and tank 2 reaches a preset value, the outlet valve and suction valve on the corresponding pipeline of low-pressure pump B in tank 1 are automatically opened;
[0056] S12: The low-pressure pump B in the tank 1 starts automatically, increases speed until the pressure reaches the set value, and activates the PID valve regulation of the low-pressure pump B. The pressure is maintained stable by the low-pressure pump B, and the PID valve regulation of the low-pressure pump A in the tank 2 is exited at the same time;
[0057] S13: The low-pressure pump A in the second tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed;
[0058] S14: real-time monitoring of the liquid level difference between storage tank 1 and storage tank 2;
[0059] S15: When the liquid level difference between storage tank 1 and storage tank 2 reaches a preset value, the outlet valve and the suction valve on the corresponding pipeline of the low-pressure pump B in storage tank 2 are automatically opened;
[0060] S16: The low-pressure pump B in the second tank starts automatically, increases speed until the pressure reaches the set value, activates the PID valve regulation of the low-pressure pump B, the pressure is maintained stable by the low-pressure pump B, and exits the PID valve regulation of the low-pressure pump B in the first tank;
[0061] S17: The low-pressure pump B in the storage tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed.
[0062] In tank 1 and tank 2, the steps for switching from low-pressure pump B to low-pressure pump A are as follows:
[0063] S18: Real-time monitoring of the liquid level difference between storage tank 1 and storage tank 2;
[0064] S19: The low-pressure pump A in the tank 1 starts automatically, increases speed until the pressure reaches the set value, activates the PID valve regulation of the low-pressure pump A, and the pressure is maintained stable by the low-pressure pump A, and exits the PID valve regulation of the low-pressure pump B in the tank 2;
[0065] S20: The low-pressure pump B in the second tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed;
[0066] S21: Repeat the above S2 and execute it in a loop.
[0067] As shown in the following table, the operation sequence of low-pressure pump A and low-pressure pump B in storage tank 1 and storage tank 2 is as follows:
[0068]
[0069]
[0070] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.
Claims
1. Automatic switching tank supply device for ship gas supply system, characterized by: It comprises a storage tank 1 and a storage tank 2, wherein a low-pressure pump A and a low-pressure pump B are installed in the storage tank 1 and the storage tank 2 respectively, the output ends of the low-pressure pump A and the low-pressure pump B are equipped with outlet valves, the other ends of the outlet valves penetrate the storage tank 1 and the storage tank 2 and are connected to the same pipeline, the side wall of the pipeline is equipped with a PID valve, the other end of the PID valve is connected to a low-pressure gasifier, the output end of the low-pressure gasifier is connected to a transfer tank, the output end of the transfer tank is connected to a discharge valve, and the output end of the discharge valve is connected to a generator.
2. The automatic switching tank supply device for a ship gas supply system according to claim 1 is characterized in that: The pipeline is also connected with a suction valve, and the suction valve is located at the input end of the PID valve.
3. The automatic switching tank supply device for a ship gas supply system according to claim 1 is characterized in that: The transfer tank is provided with a data acquisition module, and the PID valve is electrically connected to the data acquisition module.
4. The automatic switching tank supply device for a ship gas supply system according to claim 3 is characterized in that: Liquid level sensors are installed in both the first storage tank and the second storage tank, and the liquid level sensors are electrically connected to the data acquisition module.
5. The automatic switching tank supply device for a ship gas supply system according to claim 1 is characterized in that: The tail ends of the pipelines are fixedly connected with circulation valves, and the output ends of the circulation valves extend into the first tank and the second tank respectively.
6. A method for automatically switching a tank supply device in a ship gas supply system, characterized in that: The switching method comprises the following steps: S1: Start the medium and low pressure pump A of the storage tank to supply externally, and open the outlet valve and the suction valve, and automatically adjust the pressure through the PID valve according to the transfer tank pressure; S2: Real-time monitoring of the liquid level difference between tank 1 and tank 2; S3: When the liquid level difference between tank 1 and tank 2 reaches the preset value, the outlet valve and suction valve on the corresponding pipeline of low-pressure pump A in tank 2 are automatically opened; S4: The low-pressure pump A in the second tank starts automatically, increases speed until the pressure reaches the set value, and activates the PID valve regulation of the low-pressure pump A. The pressure is maintained stable by the low-pressure pump A, and the PID valve regulation of the low-pressure pump A in the first tank is exited at the same time; S5: The low-pressure pump A in the tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed; S6: Real-time monitoring of the liquid level difference between tank 1 and tank 2.
7. The switching method of the automatic switching tank supply device of the ship gas supply system according to claim 6 is characterized in that: The conversion of the low-pressure pump B in the storage tank 1 and the storage tank 2 comprises the following steps: S11: When the liquid level difference between tank 1 and tank 2 reaches a preset value, the outlet valve and suction valve on the corresponding pipeline of low-pressure pump B in tank 1 are automatically opened; S12: The low-pressure pump B in the tank 1 starts automatically, increases speed until the pressure reaches the set value, and activates the PID valve regulation of the low-pressure pump B. The pressure is maintained stable by the low-pressure pump B, and the PID valve regulation of the low-pressure pump A in the tank 2 is exited at the same time; S13: The low-pressure pump A in the second tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed; S14: real-time monitoring of the liquid level difference between storage tank 1 and storage tank 2; S15: When the liquid level difference between storage tank 1 and storage tank 2 reaches a preset value, the outlet valve and the suction valve on the corresponding pipeline of the low-pressure pump B in storage tank 2 are automatically opened; S16: The low-pressure pump B in the second tank starts automatically, increases speed until the pressure reaches the set value, activates the PID valve regulation of the low-pressure pump B, the pressure is maintained stable by the low-pressure pump B, and exits the PID valve regulation of the low-pressure pump B in the first tank; S17: The low-pressure pump B in the storage tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed.
8. The automatic switching tank supply device for a ship gas supply system according to claim 7 is characterized in that: In the storage tank 1 and the storage tank 2, the steps of switching from low-pressure pump B to low-pressure pump A are as follows: S18: Real-time monitoring of the liquid level difference between storage tank 1 and storage tank 2; S19: The low-pressure pump A in the tank 1 starts automatically, increases speed until the pressure reaches the set value, activates the PID valve regulation of the low-pressure pump A, and the pressure is maintained stable by the low-pressure pump A, and exits the PID valve regulation of the low-pressure pump B in the tank 2; S20: The low-pressure pump B in the second tank automatically slows down, and when the speed reaches the lowest frequency, the pump stops and the valve is closed; S21: Repeat the above S2 and execute it in a loop.