Study on the CO[sub 2] Solid-Gas Two Phase Flow with Particle Sublimation and Its Basic Applications

Abstract

A basic study was carried out on the CO2 solid‐gas two phase flow with particle sublimation. The CO2 two phase flow is achieved by liquid CO2 expansion process throughout the CO2 triple point. A cryogenic refrigeration below −56.6 °C is possible from the CO2 solid particle sublimation in the two phase fluid flow. An experiment was conducted in order to investigate some basic points related to the liquid CO2 expanding into the solid‐gas fluid flow, which reveals the CO2 particle size and so on. Based on the primary experiment, a new refrigeration method is introduced by using the CO2 solid‐gas two phase flow with particle sublimation. A CO2 heat pump, which can achieve a cryogenic refrigeration below −56.6 °C is designed, constructed and tested. In the paper, details of the CO2 heat pump system are presented and the obtained results show that a continuous operation is possible with CO2 solid‐gas flow in the closed loop of the heat pump system. Furthermore, the performance of the new CO2 heat pump system is...