Investigation on non-equilibrium phase transition in wave rotor
Abstract Wave rotor refrigeration is a new method of expansion refrigeration. Non-equilibrium phase transition is one of the key factors that influence the refrigeration performance of wave rotor. Since the process of phase transition is transient and high-frequency, there are challenges in related researches. At first, this paper traces the movement trajectory of small particles in wave rotor and confirms the existence of evaporation in wave rotor. Based on this, the numerical analysis model of wave rotor that takes into account the phase transition regarding evaporation as reverse process of condensation is built up. On this basis, the change of droplet radius, droplet number and liquefaction fraction in wave rotor is obtained. Besides, the influence of inlet pressure and humidity on refrigeration performance of wave rotor is found out. The results show that with the increase of pressure of HP inlet, the isentropic expansion efficiency increases and the increase becomes gentle. With the increase of relative humidity of HP inlet, the efficiency decreases and the decrease reaches 2.8% at maximum. The results can help optimize wave rotor performance and be used for reference to wet gas transient temperature change.