Performance analysis of a novel thermal transpiration vacuum cooling system

Abstract

ABSTRACT A novel vacuum cooling system, which mainly consists of a 49-stage thermal transpiration based vacuum pump and a 100 L vacuum vessel, is proposed. The novel system can directly be driven by heat, while its structure and operation are similar to those of traditional mechanical vacuum systems. Then, a mathematic model is established to predict the performance of the novel system. The cooling capacity and coefficient of performance of the novel system increase with the rises of both parameters related to vacuum pump (the temperature difference between cold and hot chamber and pressure difference coefficient) and parameters related to vacuum vessel (mass transfer coefficient, chilled water temperature and supplement water temperature). It is a feasible way to raise system performance by cooling cold chambers, while heating hot chambers except for enhancement of mass transfer. The novel vacuum cooling system can produce relatively large cooling capacity exceeding 10,000 W at chilled water temperature over 289 K, the coefficient of performance (ranges from 0.71 to 1.48) of which is still comparable to that of the existing absorption refrigeration. It is clear that the novel thermal transpiration vacuum cooling is competitive among lots of emerging refrigeration technologies.