Research On Prediction Of Thermodynamic Performance Of Scroll Compressor

With the proposal of the national strategy of "carbon peak and carbon neutrality",efficient and clean energy use has become the development trend of today’s society.As an efficient and energy-saving equipment,scroll compressor is widely used in energy,chemical industry,aviation industry,medical and health care and other fields.Because the performance status of scroll compressor is directly related to the reliability of its work,so the prediction and analysis of its thermal performance changes is helpful to understand its operation status,and can effectively prevent problems such as poor operation.The existing thermodynamic performance prediction of scroll compressor is limited to the traditional theoretical calculation and simulation,but the theoretical calculation needs a simplified model,the calculation is complex and large,the software simulation is time-consuming,and the simulation results are not reliable.Aiming at the problem of predicting the thermodynamic performance of scroll compressors,this paper proposes a method for predicting the state parameters of scroll compressors based on particle filter algorithm.The state parameters are predicted,and the predicted results are compared with the theoretical calculation values and simulation results.The main research contents include the following points:(1)According to the situation that the scroll compressor is subjected to variable forces during operation and the scroll structure is complex,the geometric parameters of the scroll compressor are analyzed and calculated,and the dynamic and stationary scroll profile equations are deduced;considering the scroll head For the interference problem with the machining tool,the double-arc correction method was used to correct the profile of the scroll tooth beginning;and the volume change law of the compression cavity was calculated,and finally the gas force acting on the scroll was calculated and analyzed.The results show that the volume of the compressed gas increases first and then decreases until the cavity is completely eliminated.The maximum volume of the working cavity is about 12° before the end of suction.Among the three air forces affected by the dynamic scroll,the axial air force has the largest amplitude,and the maximum peak value is 5187.89 N.The change of radial air force is very small compared with the axial and tangential air force,and its influence on the dynamic scroll is insignificant and can be ignored.(2)Considering the influence of leakage and heat exchange on the scroll compressor,the thermodynamic model of the scroll compressor is established based on the law of thermodynamics,and the change of the thermal performance of the compressed gas is analyzed by theoretical calculation methods.Firstly,the leakage model of the compression cavity was established,and the variation curve of the leakage line and the amount of leakage with the crankshaft angle was calculated;the second was to analyze the heat exchange model of the compression cavity,and the heat transfer method in the working cavity was studied by the heat exchange method of the spiral plate heat exchanger.Thirdly,euler formula was used to solve the mathematical model of temperature,pressure and mass,and data counting software was used to write algorithm program to calculate the temperature,pressure and mass of the scroll compressor in the process of working.(3)Combination based on particle filter algorithm is proposed in this paper the thermodynamic performance prediction method,reference thermodynamic mathematical model of compressed gas pressure and temperature changes of state equation and observation equation,set up the standard particle filter algorithm,19℃ temperature initial value and initial value 102 k Pa pressure generation into the forecasting model and to forecast the gas state parameter and error analysis.Considering that the standard particle filter algorithm has the problem of particle degradation,which leads to the low accuracy of the algorithm,this paper also optimizes the original algorithm,and uses the improved algorithm to predict the temperature,and compares the different results The results showed that the particle filter algorithm has better prediction results for the temperature and pressure changes of the gas in the compression chamber.The improved algorithm increased the stability and prediction accuracy,and its performance was better than the traditional particle filter algorithm.(4)This chapter used the CFD calculation method to simulate the threedimensional flow field of the scroll compressor.Corresponding data and graphs were obtained by observing specific points,and the theoretical calculation and prediction values of temperature and pressure were selected to compare with the simulation results.The results showed that the simulation results were in good agreement with the theoretical calculation,prediction results and the accuracy was high,which verified the rationality and accuracy of the filter algorithm for the performance prediction of scroll compressor.