Optimization Design Of Complex Oil-gas Separator

The Oil Separator is a very important component of the engine crankcaseventilation system, which can effectively reduce the secondary oil content combustion ofcrankcase blow-by in the cylinder, thereby reducing engine oil consumption andemissions caused by the burning of oil, and its high separating efficiency is an importantguarantee for the engine reliability and low emissions performance. Due to its structurallimitations, common single type oil separator can do a good performance only in somespecific operating conditions, failed to adapt itself to the instantaneous change in engine.With the development of the automobile industry, the existing oil gas separation isincreasingly unable to meet emission regulations, more and more people is focusing onthe multi-stage oil separator. A type of multi-stage oil separator is developed in thispaper, which is consist of active and passive part separator, having many advantages notonly the high adaptability engine operating conditions for the active centrifugal part,but also the low cost and high separation efficiency for the passive cyclone part, canseparate sizes of blow-by particular on kinds of engine operating conditions with highefficiency.This paper mainly do works on research and analysis of the structure, application ofthe principle, advantages and disadvantages of the existing oil gas separator, andworking on the study of multi-stage oil separator for further structural optimization, sothat it can fully adapt the engine operating conditions and achieve highly efficientseparation of full diameter particles of the engine blow-by. Firstly, study the related keyfactors of duplex passive oil gas separator internal flow field and separation efficiency bynumerical analysis method in order to optimize the structural parameters of the passivepart o; then build simulation platform and test bench to optimize the structure of thepassive part further, and study the relationship matching two part of the multi-oil separator.There are three aspects studied in this article as follows:First, studied the passive part’s internal gas and two phase field by the numericalcalculations of the cyclone oil-gas separator, finally found the shape of the separator’sinlet shape, inlet velocity, the diameter and insertion depth of the outlet pipe, the angleof the conical part are the key factors which affect the efficiency of the passive part ofthe separation. And ultimately the optimum cyclone oil-gas separator structureparameters is α=104°, hc/dc=de/Do=045, when separator’s inlet velocity is12.82m/s, the separating efficiency of all sizes of the particle can be more than92%.Second, built oil gas separator test bench, further optimize the passive part of themulti oil-gas separator according the bench test data of four trial separator samples ofdifferent structural parameters. Completed the passive part structure optimization of themulti-separator,5×13rectangle inlet,30diameter cyclone oil-gas separator became thefinal choice.Third, built multi oil-gas separator simulation platform and test bench, studied therelationship between the motor speed of the active part and inlet fluid characters, entireseparating efficiency. Matched and verificated the result of the simulation platform andthe fittest of the active motor speed, part of the matching between two parts of themulti oil-gas separator.