| Liquid ring compressor is a general machine which uses rotating liquid as a piston to suction or compress gas.It has the advantages of simple structure,convenient operation,isothermal compression of gas,which is suitable for pumping flammable,explosive and dusty gas.Liquid ring compressor is widely used in the fields of petroleum,natural gas,chemical engineering,coal mine,paper printing and so on.However,the gas-liquid two-phase flow of liquid ring compressor is complex,and the deviation between traditional theory of the ideal working cycle and the actual performance is large,which restrict the improvements of suction compression performance and reliability.On the basis of focusing on the performance of liquid ring compressor,the variation law of combination performance of liquid ring compressor and pipeline system was also investigated in this paper,by means of external characteristic performance test,theoretical analysis,performance calculation and numerical simulation,which provided a theoretical basis for the design and operation of liquid ring compressor.The specific jobs of this paper are as follow:(1)External characteristic performance test of liquid ring compressor.Parameters such as suction capacity,shaft power,efficiency and other parameters of different types of liquid ring compressors under given speed and different discharge pressure were measured.On the one hand,the external characteristic test provided data sources for the derivation of the similarity law,and on the other hand,it was compared with the theoretical calculation results,which verified the feasibility of the theoretical model established in this paper to predict the performance of liquid ring compressor.(2)Study on similarity law of liquid ring compressor performance.The test results based on the external characteristic were statistically regressed and fitted by the Matlab's polyfit function.The similar relationships of liquid ring compressor were obtained between the performance parameters such as the suction capacity and shaft power with the parameters such as the rotational speed and the geometric ratio of the liquid ring compressor by semi-empirical and semi-theoretical method.(3)Study on actual working cycle model of liquid ring compressor.Based on the actual working cycle of "suction-compression-discharge-expansion",a universal theoretical model of liquid ring compressor operation was established.The calculation methods of residual gas volume flow,expansion process and gas capacity after expansion of liquid ring compressor were studied.The prediction formulas of actual suction capacity,shaft power and efficiency of liquid ring compressor were obtained,and the prediction for the suction compression performance of liquid ring compressor was realized.(4)Study on factors that affect the system performance.Based on Flowmaster flow system simulation platform,the model of liquid ring compressor system was established,and the variation law of combination performance of liquid ring compressor and pipeline system was explored.The influence of system parameters including impeller speed,impeller radius,pipe length,pipe diameter,valve opening and other parameters on system performance was studied.The influence of liquid ring compressors in series and parallel operation was also studied.Those provided a reference for the regulation of working condition of liquid ring compressor system. |
PDF Full Text Request