Innovative Flow Channel Design

Besides conventional pulse tube cold-head configurations, Lihan has put forward a new type of cold end heat exchanger through the method of hot forging process. With well-designed molds, the process could be quick, accurate and greatly improved batch production efficiency. The innovative design of flow channels at both ends of pulse tube is beneficial to reduce the structure complexity and improve the operation reliability of the cryocooler.

Conventionally, flow straighteners are used at both ends of the empty pulse tube to ensure a uniform flow. This approach complicates the system and becomes a source of flow losses. Another possible issue, which is not often mentioned, is that, for a long lifetime cryocoolers, accumulation of contaminants mostly happens at the coldest area, i.e., the cold side flow straightener. To realize a uniform internal flow in the pulse tube without introducing a flow straightener reduce the manufacturing cost. The structure of cold-end heat exchanger and pulse tube have been intensively simulated and optimized by CFD software and been validated through experiments.

For more information, please visit https://aip.scitation.org/doi/10.1063/1.4915900.