船舶天然气供给气化调压系统试验

Experiment on Vaporization and Pressure Control of Fuel Gas Supply System for LNG Fueled Ships

搭建船舶天然气供气系统(fuel gas supply system,FGSS)样机,通过台架试验,探究FGSS在稳态及非稳态工况下的气化调压特性。试验结果表明:在稳态工况下,供气压力稳定性随着系统负荷的降低而变差,当负荷低于25%时,压力波动可达±4%,波动周期为10 s;供气温度在任意负荷下不呈现周期性波动,保持在25~35℃;系统供气压力和温度满足主流双燃料发动机的供气要求。在非稳态工况下,当负荷突增时,压力波动最大可达32%,弛豫时间为30 s;负荷突减时,压力波动最大为18.5%,弛豫时间为18 s。在兼顾经济性和系统紧凑性的前提下,可通过增大缓冲罐容积和提高调节阀背压来减小压力波动;供气温度对负荷突变响应弱,弛豫时间达到2 min以上。

A marine FGSS(fuel gas supply system)facility was built and through bench test,and the characteristics of pressure(control)of FGSS under steady and unsteady conditions were explored.The results show that,under steady state conditions,the stability of the fuel gas supply pressure will deteriorate with the decrease of the system load.When the load is less than 25%,the pressure fluctuation can reach±4%,and the fluctuation period is 10 s.However,the periodic fluctuation of gas supply temperature under any load is very small,maintained in the range of 25~35℃.The supply pressure and temperature of the system satisfy the requirements of mainstream dual-fuel main engines.Under the unsteady condition,when a sudden load increase occurs,the maximum pressure fluctuation can reach−32%and the relaxation time is 30 s.When the load suddenly decreases,the maximum pressure fluctuation is 18.5%,and the relaxation time is 18 s.The pressure fluctuations can be reduced by increasing the volume of buffer tanks and the back pressure of regulating valves under the premise of considering economy and system compactness.However,the response of gas supply temperature to sudden change of load is weak,and the relaxation time is over 2 min.