Experimental Study On Combustion And Emission Of Heavy Duty Diesel With PODE Blended Fuel

Polyoxymethylene Dimethyl Ethers (PODE) is a kind of flammable liquid which is colorless and has a slight ether odor. PODE can be prepared by methanol which can be made from coal. PODE has high cetane number and nearly 50% of the oxygen content. PODE can be miscible with diesel oil. As having high oxygen content, PODE is conductive to reduce the diesel engine soot particle emission and promote clean combustion of diesel engine. At the same time, the application of PODE as an alternative fuel in internal combustion engine can promote the clean combustion of coal resource and reduce dependence on petroleum product. In this paper, the effect of PODE diesel mixed fuel on combustion and emissions of diesel engine was studied by experimental study.First, an experimental study was conducted to investigate the effect of operating parameters, fuel injection control strategy and PODE fuel in a heavy duty diesel. It is found that improving the injection pressure can effectively reduce soot emission. Delaying the CA50 can reduce soot and NOx emission, but it will increase the BSFC. EGR can effectively reduce NOX emission, but it will increase the BSFC and soot emission. The pilot injection can reduce the maximum pressure rise rate and slightly reduce BSFC at low load, but it is not obvious effect in medium low. The post injection can effectively reduce soot emission, but need to select post parameter carefully. PODE fuel can effectively reduce the soot emission of diesel engine, which the reduction of soot emission can reach to 79%.Secondly, an experimental study was conducted to investigate the effect of multiple injection combined with EGR and PODE fuel on combustion and emission of diesel engine. It is found that, under the condition of NOx emission control in 1.3g/kw.h, PODE fuel can effectively reduce soot, HC and CO emission. It also can reduce BSFC and improve the trade-off of NOX-soot and NOx-BSFC. A further decrease of the maximum pressure rise rate can be achieved by using the pilot injection strategy and the PODE fuel at low load. Under the condition of using PODE fuel, diesel engine using multiple injection strategy can not reduce emission more. From the point of view of reducing emission, diesel engine using PODE fuel can simplify the fuel injection strategy. As using PODE20 fuel,the ESC cycle test showed that NOx can be reached 1.18g/KW · h. Meanwhile, CO, HC and soot emission are 0.34g/KW · h, 0.095g/KW · h and 0.01g/KW · h respectively, both of which are under the limit value of Euro VI emission regulations. Therefore, the diesel engine fueled with PODE fuel is an effective measure to improve its combustion and emissions at this stage.