Intelligent Supercharging LNG Fuel Control Systems

Most of LNG fuel control systems on the market use direct liquid supply. Due to the ultra-low temperature characteristics of LNG fuel, gas equipment may have long start-up time or even fail to start during cold and hot start-up, which causes waste in resource. During regular gas supply, the reduction of LNG fuel will result in the decrease of pressure inside the fuel tank, making it difficult or impossible to complete liquid supply. This paper proposed an innovative control system, which utilizes sensor data combined with control logic to drive the process control valves and safety control valves at high frequency. It is able to increase the pressure inside LNG fuel tanks intelligently. The algorithm of process control and safety control are separated in independent PLC, which improves the safety of this control system. Kalman filtering was used to improve the stability and anti-interference ability of this control system. Experiments on real ships was performed to compare the new control systems with traditional ones. The startup failure rate and energy consumption have been significantly reduced, proving the effectiveness of this control system.