Development of a rotary union for Gifford-McMahon cryocoolers utilized in a 10 MW offshore superconducting wind turbine

Cryogenic Engineering Conference 2017

材料科学;物理学

Sun, Jiuce^1 ; Sanz, Santiago^2 ; León, Andrés^3 ; Fraser, Jim^3 ; Neumann, Holger^1

Institute for Technical Physics (ITEP), Eggenstein-Leopoldshafen

76344, Germany^1

TECNALIA, C/Geldo, Edif. 700, Derio

48160, Spain^2

Ferrotec (USA) Corporation, 33 Constitution Drive, Bedford

NH

03110, United States^3

关键词: Cooling Capacity;    G-m cryocooler;    Helium compressors;    Low pressures;    Optical fiber channels;    Sealing technology;    Superconducting generator;    Transfer currents;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012067/pdf
DOI  :  10.1088/1757-899X/278/1/012067

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Superconducting generators (SCG) show the potential to reduce the head mass of large offshore wind turbines. By evaluating the availability and required cooling capacity in the temperatures range around 20 K, a Gifford-McMahon (GM) cryocooler among all the candidates was selected. The cold head of GM cryocooler is supposed to rotate together with the rotating superconducting coil. However, the scroll compressor of the GM cryocooler must stay stationary due to lubricating oil. As a consequence, a rotary helium union (RHU) utilizing Ferrofluidic® sealing technology was successfully developed to transfer helium gas between the rotating cold head and stationary helium compressor at ambient temperatures. It contains a high-pressure and low-pressure helium path with multiple ports, respectively. Besides the helium line, slip rings with optical fiber channels are also integrated into this RHU to transfer current and measurement signals. With promising preliminary test results, the RHU will be installed in a demonstrator of SCG and further performance investigation will be performed.