Advantages of Synchronous Reluctance Motors and Synchronous Motors with Permanent Magnets as Drive of Liquid Natural Gas Submerged Pumps for Process Loss Reduction

the article reveals main sources of LNG process losses and boil-off gases generation in large scale, medium scale and small scale liquefied natural gas supply chains. The sources were divided into different groups, the loss caused by the pump unit operation were examined in details. Typical design of cryogenic submerged pump is considered as the source of process loss caused by both pump and electric motor efficiency. Possible way of boil-off gases generation reduction is to apply high efficient electric motors such as synchronous reluctance motors and permanent magnet synchronous motors. Based on existing studies, efficiency, motor heat losses and lifecycle costs of induction motor were compared with permanent magnets synchronous motor and synchronous reluctance motor. The analysis shows that using both types of motors has advantages over applying induction motor, but synchronous reluctance motors are more beneficial in terms of reliability, methane slip reduction and overall lifecycle cost.