Optimization Analysis On Stepless Capacity Regulation System Of Large Reciprocating Compressor

Large reciprocating compressor is a kind of general machinery used to increase pressure of gas or transport gas by compressing it in process engineering field. Also, it is the high energy-consumption device which is used in many fields. The stepless capacity regulation method of partial stroke pressure-off inlet valve has the advantages of low energy consumption and high efficiency. But because of the action of executing fork, it has been found that the valve block of gas valve fracture early under the action of capacity regulation in practice. Therefore, it is necessary to explore the structure failure reasons of valve block of gas valve under the working condition of stepless capacity regulation, to study on the influence of executing fork on impact loads of valve block of gas valve, to give life prediction and develop structure optimization design.Based on the National Key Technology R&D Program "Key Technology Development Program for High Efficiency Compressor", R&D project of Zhenhai Refining and Chemical Company "Development of the Stepless Capacity Regulation system on Disproportionation unit C102Reciprocating Compressor" and R&D project of Petro China Urumqi petrochemical refinery factory "Stepless Capacity Regulation System of Reciprocating Compressor", this thesis deal with more in-depth theoretical and experimental study on thermodynamic cycle process of reciprocating compressor and motion law of gas valve deeply under the condition of capacity regulation. The model of streamline gas valve was derived, and dynamics analysis was carried out. The result of numerical calculation indicates that streamline gas valve is better for the energy-saving effect compared with normal gas valve. Based on existing capacity regulation device, the orthotropic short fiber composite material valve block model was established, the impact effect of executing fork on the gas valve was analyzed, and the effect of lateral lean of valve block on press-off the inlet valve was studied. Furthermore, through durability fatigue testing software, the relationship among different hydraulic pressure, different angle of inclination and fatigue life of valve block was studied. This study also provided theoretical references for the design and improvement of stepless capacity regulation apparatus in a partial stroke press-off inlet valve and the hydraulic system.The main research contents of the paper are as belows:1) Established streamline gas valve model under stepless capacity regulation, and conducted kinetic analysis, compared streamline gas valve with ordinary gas valve on the effect of capacity regulation. By numerical calculation, the results was derived that under capacity regulation of streamline gas valve, the service efficiency of gas valve and the work efficiency of compressor will be improved after streamline design of the gas channel, and the optimum valve block tangent angle of streamline gas valve is30°. Then streamline gas valve will have better energy conservation.2) Established the orthotropic short fiber composite material valve block model. The impact effect of executing fork on the gas valve was studied under working condition of capacity regulation. Dynamic mechanical property and stress-strain relationship of valve block for press-off inlet valve was analyzed. The fatigue life characteristics of valve block collision under this working condition were studied, the relationship between different hydraulic pressure and fatigue life of valve block was preliminary described. After detailed computational analysis, more reasonable hydraulic pressure was obtained for improving the force condition of valve block. The value range of maximum hydraulic pressure was suggested between4and6Mpa.3) Researched motion law of lateral collision of compressor gas valve under working condition of stepless capacity regulation, and analyzed the dynamic mechanical property of valve block under the action of executing fork of capacity regulation system of press-off inlet valve. Furthermore, the effect of lateral lean of valve block on gas valve block and its life was analyzed. The different gas valve block simulation models ware established according to different angle of inclination. The damage of valve block in lateral collision was simulated, and the influence of lateral lean of valve block on gas valve block life was studied under working condition of capacity regulation. At last the fatigue life of lateral lean valve block was forecasted, and the relationship between lateral lean angle and gas valve life. was preliminarily established...