The effect of base oils,sulfur-containing multi-functional additives and dispersants in formulated diesel lubricants on lead corrosion was evaluated by a self-established high temperature corrosion bench test.Test lea...The effect of base oils,sulfur-containing multi-functional additives and dispersants in formulated diesel lubricants on lead corrosion was evaluated by a self-established high temperature corrosion bench test.Test lead coupons were analyzed by XPS to determine the resulting surface chemistry.The results showed a close correlation between the oxidation stability of base oil blend and the lead corrosion of formulated diesel lubricants.The zinc dialkyldithiophosphate(ZDDP)and zinc dialkyldithiocarbamate(ZDDC)have formed different protective films on lead coupon surfaces.A more or less amount of the protective film formed is the main factor affecting the degree of lead corrosion.The glassy zinc phosphates protective film formed by ZDDP is more effective than the zinc sulfides film formed by ZDDC.The interaction between dispersants and ZDDP had a significant impact on lead corrosion.展开更多
The performance and emission characteristics of a PPCCI engine fuelled with ethanol and diesel blends were car- ded out on a single cylinder air cooled CI engine. In order to achieve the optimal process response with ...The performance and emission characteristics of a PPCCI engine fuelled with ethanol and diesel blends were car- ded out on a single cylinder air cooled CI engine. In order to achieve the optimal process response with a limited number of experimental cycles, multi objective grey relational analysis had been applied for solving a multiple response optimization problem. Using grey relational grade and signal-to-noise ratio as a performance index, a combination of input parameters was prefigured so as to achieve optimum response characteristics. It was observed that 20% premixed ratio of blend was most suitable for use in a PPCCI engine without significantly affecting the engine performance and emissions characteristics.展开更多
The fuel dynamic transfer process,including fuel injection,fuel film deposition and evaporation in the intake port,was analyzed for spark ignition(SI) engines with port fuel injection(PFI).The influence of wall-wettin...The fuel dynamic transfer process,including fuel injection,fuel film deposition and evaporation in the intake port,was analyzed for spark ignition(SI) engines with port fuel injection(PFI).The influence of wall-wetting fuel film,especially its evaporation rate,upon the air-fuel ratio of in-cylinder mixtures was also discussed.According to the similarity principle,Fick's law,the ideal gas equation and the Gilliland correlation,an evaporate prediction model of wall-wetting fuel film was set up and an evaporate prediction based dynamic fuel film compensator was designed.Through engine cold start tests,the wall-wetting temperature,which is the key input of the fuel film evaporate prediction model,was also modeled and predicted.Combined with the experimental data of the evaporation characteristics of ethanol-gasoline blends and engine calibration tests,all the parameters of the wall-wetting fuel film evaporate prediction model used in the fuel film compensator were identified.Square-wave disturbance tests of fuel injection showed that with the help of the fuel film compensator the response of the in-cylinder air-fuel ratio was significantly improved and the real air-fuel ratio always closely matched the expected ratio.The fuel film compensator was then integrated into the final air-fuel ratio controller,and the engine tests showed that the air-fuel ratio control error was less than 2% in steady-state conditions,and less than 4% in transient conditions.The fuel film compensator also showed good adaptability to different ethanol-gasoline blends.展开更多
基金financilly supported by the Research Project of China Petroleum&Chemical Corporation(112066)
文摘The effect of base oils,sulfur-containing multi-functional additives and dispersants in formulated diesel lubricants on lead corrosion was evaluated by a self-established high temperature corrosion bench test.Test lead coupons were analyzed by XPS to determine the resulting surface chemistry.The results showed a close correlation between the oxidation stability of base oil blend and the lead corrosion of formulated diesel lubricants.The zinc dialkyldithiophosphate(ZDDP)and zinc dialkyldithiocarbamate(ZDDC)have formed different protective films on lead coupon surfaces.A more or less amount of the protective film formed is the main factor affecting the degree of lead corrosion.The glassy zinc phosphates protective film formed by ZDDP is more effective than the zinc sulfides film formed by ZDDC.The interaction between dispersants and ZDDP had a significant impact on lead corrosion.
文摘The performance and emission characteristics of a PPCCI engine fuelled with ethanol and diesel blends were car- ded out on a single cylinder air cooled CI engine. In order to achieve the optimal process response with a limited number of experimental cycles, multi objective grey relational analysis had been applied for solving a multiple response optimization problem. Using grey relational grade and signal-to-noise ratio as a performance index, a combination of input parameters was prefigured so as to achieve optimum response characteristics. It was observed that 20% premixed ratio of blend was most suitable for use in a PPCCI engine without significantly affecting the engine performance and emissions characteristics.
基金Project (Nos. 51106136 and 50776078) supported by the National Natural Science Foundation of China
文摘The fuel dynamic transfer process,including fuel injection,fuel film deposition and evaporation in the intake port,was analyzed for spark ignition(SI) engines with port fuel injection(PFI).The influence of wall-wetting fuel film,especially its evaporation rate,upon the air-fuel ratio of in-cylinder mixtures was also discussed.According to the similarity principle,Fick's law,the ideal gas equation and the Gilliland correlation,an evaporate prediction model of wall-wetting fuel film was set up and an evaporate prediction based dynamic fuel film compensator was designed.Through engine cold start tests,the wall-wetting temperature,which is the key input of the fuel film evaporate prediction model,was also modeled and predicted.Combined with the experimental data of the evaporation characteristics of ethanol-gasoline blends and engine calibration tests,all the parameters of the wall-wetting fuel film evaporate prediction model used in the fuel film compensator were identified.Square-wave disturbance tests of fuel injection showed that with the help of the fuel film compensator the response of the in-cylinder air-fuel ratio was significantly improved and the real air-fuel ratio always closely matched the expected ratio.The fuel film compensator was then integrated into the final air-fuel ratio controller,and the engine tests showed that the air-fuel ratio control error was less than 2% in steady-state conditions,and less than 4% in transient conditions.The fuel film compensator also showed good adaptability to different ethanol-gasoline blends.
