Chinese sources reported that scientists in the country have created the world’s most powerful thermoacoustic Stirling generator. The almost silent, 2 m long compact unit produces 100 kW of electrical energy. The device was once patented by NASA (LEW-TOPS-80), but the agency still has not produced a working installation. Such generators are ideal for use in space and submarines. China is considering both application areas.

The presented thermoacoustic Stirling generator was created at the Technical Institute of Physics and Chemistry (TIPC) of the Chinese Academy of Sciences (CAS). Its length reaches 2 m with a maximum diameter of 0.63 m. The generator looks like a dumbbell. During a recent demonstration, the prototype produced a revolutionary power of 102 kW at a heat source temperature of 530°C. For the first time in the world, a generator of this type has crossed the 100 kW threshold, which is an important milestone in terms of its practical application.

“Currently, the efficiency of thermoelectric conversion is about 28%, and when using a hotter refrigerant at 600 degrees, the efficiency can reach 34%” — said the developers. Thus, the promising installation approached classical steam turbines in terms of efficiency and retained many of their advantages – almost silent operation, the use of absolutely any heat sources, simplicity of construction and a small number of moving parts.

The innovative system consists of a Stirling thermoacoustic motor and a linear motor housed in a rigid shell (providing additional sound insulation). The engine converts the heat into sound waves that resonate to create a working sound wave. The sound wave drives the pistons of a linear generator that produces alternating current.

“Helium at high pressure of 15 MPa (150 atmospheres) serves as the operating medium, and the absence of mechanical parts requiring lubrication means that the service life of the generator can exceed ten years,” explains the development.. “It operates quietly and efficiently and can use different types of heat such as solar energy, waste heat and biomass.”

In addition, China is currently testing Stirling engines with linear generators in space. So, in April this year, it was reported that one of these prototypes was tested at the Tiangong station, and this was the first test of the Stirling engine in orbit.