A novel heat-driven thermoacoustic natural gas liquefaction system. Part I: Coupling between refrigerator and linear motor

Nowadays, heat-driven thermoacoustic Stirling refrigerator is of great interest in the world, which utilizes thermoacoustic heat engine to drive thermoacoustic Stirling refrigerator with high reliability and simplicity. This system is suitable for natural gas liquefaction by burning a small amount of natural gas to liquefy the rest. In this paper, a heat-driven thermoacoustic Stirling refrigerator with linear motor phase adjuster is proposed. The linear motor is used to not only provide a suitable acoustic field for the refrigerator to achieve a high performance but also convert the expansion work into electricity. Thus, the system efficiency can be greatly improved. Due to the complicated energy conversion mechanism between heat, acoustic work, cooling power and electric power in the system, here we only try to investigate the coupling relationship between refrigerator and linear motor by adjusting load resistance and equivalent inductance. According to the simulation, optimum results of a cooling power of 463.1 W at 110 K with relative Carnot efficiency of 31.3%, an electric power of 553.7 W and a total exergy efficiency of 53.7% are achieved. Since several refrigerator and motor units are used in this system, this technology may provide a new way for natural gas liquefaction. (C) 2016 Elsevier Ltd. All rights reserved.