The Design And Dynamic Analysis Of CO₂ Two Stage Rolling Piston Compressor

Based on the energy conservation and environmental protection, the refrigerant substitution and high efficiency cooling equipment research & development are the key technologies which should be solved in the field of refrigeration and air conditioning. So researches about the natural refrigerant—CO₂ receive more concerns by international society and the development of CO₂ compressor is more important for the application of CO₂ transcritical cycle. In this thesis, studies focus on the CO₂ two stage rolling piston compressor from theory analysis and computer simulation.The theoretic and performance analysis about different type two-stage systems are presented in this study based on the thermodynamic theory. The optimal two stage system is selected by analyzing the impact to optimal high pressure and middle pressure. By referenced the compressor design method and property of transcritical system, the basic parameter of two-stage compressor is selected for the following calculation.Dynamic analysis on the main moving parts of two stage compressor are given in this paper and the various forces on moving parts at different rotational angle are calculated. Based on the quality and energy conservation laws, volume control equation of the suction and exhaust chamber are established. With the help of EULER numerical methods, CO₂ physical parameters and the thermodynamic properties of the compressor at different rotational angle are obtained. The impact of relative height of cylinder and relative eccentric distance on design of compressor are analyzed .All these provide a theoretical reference for the design and improvement of the compressor.By using of elastic mechanics theory and finite element, the deformation and stress field of CO₂ compressor moving parts under the big pressure difference are analyzed with Ansys software. The deformation size and stress field image of the high-level sliding vane, low-level sliding vane, rolling piston and eccentric shaft are obtained in this study. 38CrMoAIA and 40CrNiMo are selected as the manufacture material and the results will provide a theoretical reference for design of compressor and manufacture.