Supercharging Characteristics And Refrigeration Cycle For R718 Wave Rotor With Phase Change

The energy exchange between high pressure fluid and low pressure fluid with the influence of shock wave and expansion wave is the gas wave supercharging technology. At present, it has been applied to the natural gas, vehicle turbocharger, combustiongasturbine and refrigeration. It has many advantages, such as simple structure, good performance with liquid and high isentropic efficiency, so it is a good application prospect technology. Gas wave technology is usually used in the gas-gas flow, but the research on the gas-liquid two phase flow is rarely reported. Because Gas wave supercharging technology in the gas-liquid aspect usually involves complex phase change process and its flow filed is complicated. The gas-liquid mixed two phase area in the shock wave tube would have seriously impact on the movement of shock wave. So the research on gas wave technology in the gas-liquid aspect is full of challenges.Wave rotor with phase change which was usually applied to R718 vapor compression refrigeration was in details studied. It also studied unsteady compression process and thermodynamic cycle with the flash evaporation and condensation. The R718 vapor compression refrigeration with flash evaporation was already built and the related experiments were carried out. The mainly tasks and conclusions were as follows:(1) The research on muti-phase flow with flash evaporation and condensation in the wave rotorThe CFD model of a novel intermediate medium vaporizer with evaporation, condensation and pool boiling has been built and the prototype was also made. The CFD model of flash evaporation which can capture the strong discontinuity was successfully developed and the diagram of shock wave and expansion wave for R718 flow and R134a in the shock tube was also captured for the first time. We had obtained the law of the movement of shock wave, expansion wave and interface in the process of flash evaporation. It is concluded that the supercharge ration for steam could be 6 when the expansion ratio is 5. The supercharge way which compress the high vacuum steam in the flashing wave is feasible.(2) Wave supercharger rotor with the flash evaporation and R718 vapor compression refrigeration systemAccording to the axial and radial wave rotor, we successfully developed wave supercharger rotor with phase change and constructed R718 vapor compression. It covers an area of 10 m2. The ration of expansion liquid and refrigerant flow was maintained at 125 based on the large liquid gas separator (CN201210060005.4)(3) R718 vapor compression thermodynamic cycleThe R718 VCR procedure with phase change was developed according to ASME STEAM model and the maximum COP can be 9.0. It is concluded that wave supercharging rotor with phase change belongs to the unsteady compression technology in essence. Its efficiency is more than steady compression process. The technology was also applied to heat pump system and we had declared two patents (CN 201410707512.1,CN 201410710970.0).