Feasibility analysis and application design of a novel long-distance natural gas and electricity combined transmission system

Abstract

This paper proposed a novel long-distance combined transmission system, in which LNG (liquefied natural gas) is transported in the pipeline and electricity is transmitted through a high-temperature superconducting cable refrigerated by LNG. Through this system, electricity and LNG could be transmitted simultaneously with high efficiency. This paper analyzed the theoretical feasibility of the proposed system and studied the effects of several key parameters on energy transmission loss. The analysis results show that the loss rate of LNG transportation system decreases with the increase of pipe diameter. There is an economic flow velocity with which the minimum loss rate of the LNG transportation system could be achieved. The total loss rate of the combined system decreases with the increase of the transmission capacity ratio of electricity to LNG. Through an application computation, it is found that the transmission efficiency of the combined system can reach up to 96%, and the loss rate is just 58% of that of the conventional systems. Moreover, the power wasted induced by the heat leakage occupies 85.2% of the total power wasted at the cryogenic refrigeration and pump station, which may suggest improving the insulation performance is significant to the transmission efficiency of the combined system.