Study On Energy Consumption And Energy Saving Technology Of A LNG Terminal In South China

In this paper,the steady-state mathematical model of each devices was established according to the production process of a LNG terminal in south China.The P-R equation was chosen as the equation for calculating the properties.The process was simulated by using HYSYS,a process simulation software,according to the actual operating parameters of equipment.The parameters of material flow and equipment energy consumption were obtained.The effects of some factors on energy consumption,such as components of LNG,amount of BOG,pressure of the BOG compressor outlet,temperature and volume of the output natural gas,outlet pressure of the pump in the tank of liquid and the LNG flow,were analyzed with single-factor analysis method.The process parameters were optimized due to the employ of HYSYS.The total power consumption of the LNG terminal was reduced.The amount of BOG under different operating conditions was calculated combining with the specific circumstances of this LNG terminal.Based on the comprehensive analysis of this LNG terminal,it was proposed to decrease the amount of BOG that a tank stores only the same source of LNG,and it was found that some measures could reduce the equipment energy consumption of the LNG terminal,such as increasing the flow rate of high pressure pump,reducing the temperature of natural gas,adjusting process parameters.It is feasible to control the time ratio between the crest and the trough,taking into account the fact that the electricity price at different times is fluctuating every day.The output pressure should be improved at the low price,and the peak modulation of the pipe should be raised,so as to increase the trough time consumption and decrease the peak period of electricity consumption.The overall power consumption of the LNG terminal will be reduced in this mode.Three-stage utilization of LNG cold energy,i.e.power generation-cold storage-air conditioner was proposed,considering that LNG cold energy of this terminal had not been used.The ratio of cold energy utilization was calculated by using HYSY to simulate the process.The application of the cascade utilization process can not only recover 28.12% of the cold energy,but also reduce the power consumption of the seawater pump,with significant economic benefits.