| Scroll compressor is well known as high efficiency, slight vibration, low noise other obvious advantages and gets a lot of attention, which widely used in air condition, the vacuum pump, refrigeration and other industries. While because of the structure itself and the way it works, they make the geometric and mechanical characteristics of the key components of the scroll plate directly affect the performance improvement of the scroll compressor. Therefore, the research and analysis of scroll compressor comprehensive characteristics is of great significance.New combination scroll compressor which an be used a few number of turns can able to achieve a high pressure ratio, shortening the working medium in the compression chamber residence time and reducing the leakage in the working process, so the combination scroll compressor has been widespread concern and also get a lot of applications in industry. The present more study of combination scroll compressor is first-order continuous combination profile, while the analysis of second-order continuous is less and less. Response to this situation, a new second-order continuous combination scroll profile has been constructed, The models of suction chamber, compressing chamber and discharge chamber were established based on the parameters of the baseline. The dynamic process of dynamic gas forces in a scroll compressor verse crank angle was obtained. The influence of the value of connecting point on dynamic property was approached. By simultaneous solving the above model can get the effect of formation of different scroll profile to performance of scroll compressor, the specific content has the following several aspects:(1) Three sections of involute circle curve, high-order curve and involute circle curve have been selected for the base circle of combination scroll compressor. Based on the analysis of the scroll profile and its working process, models of working chamber were established. On this foundation, the mechanical models of dynamic gas forces were obtained.(2) By using MATLAB analysis software to solve the volume and mechanical model, firstly, the volume characteristics of the compression chamber and the pressure-time history of the working medium are analyzed. Secondly, the dynamic characteristics of operating conditions are analyzed. Especially axial, tangential and radial gas forces are given priority to, and the analysis results of second-order continuous combined scroll compressor are compared with the first-order. The results showed that the profile types of different structures have a significant influence on the dynamics characteristics, including gas axial force fluctuation with little difference, general within 5N. Tangential and radial gas forces have a significant difference. When the crankshaft rotates to the profile at the connection point, second-order continuous and first-order continuous force difference value reaches a maximum.(3) In order to analyze the continuity condition of combination scroll profile at the connection point effect on performance of scroll compressor, the different profile angle 1j,2j of connection points and length of high-order were selected, and the corresponding working volume model and mechanical model were established. By solving the above model, it shows that the angle position of connection point and the length of high-order curve have a great effect on the fluctuation and rate change of tangential and radial gas force.(4) The scroll plate is processed with the existing machine, and the scroll plate is detected with surface roughness tester, and the test results show that the curvature varies continuously will help improve machining precision, it also can make a better contact stiffness and fatigue strength for the scroll meshing process. |
