The Performance Study Of Diesel/Methanol & Diesel/ Methanol Blending Water Compound Combustion On Turbocharged Diesel Engine

In these years, China has been keeping the volume of holding cars rising, and subsequently, the supplies of diesel and gasoline which are fuels used for car become scarce day by day, it makes the price of gasoline increasing consistently. For one thing, the additional capacity of the oil production in domestic is limited; the independence of oil import is up to 52.5% in the year of 2009, at the same time, as we know, the energy is connected with the safety and economic development of a state; for another, environmental conservation is so serious that we have to confront the big challenges recently. The challenges are also historical opportunities for making the study of methanol used for alternative fuel, and meanwhile promoting the development of reproducible,sanitary substitution fuel. Those result from the characteristic of"sufficient in coal and scarce in oil"in China, it refers to the skills of making methanol by coal are well while the production cost is low. For these reasons, there is a widespread prospect in using methanol as the alternative fuel of cars.The study made before shows that: the main emissions of NOx and PM have induced greatly in completing the compound combustion in the condition of original or turbocharged diesel engine while the emissions of HC,CO and formaldehyde have been increasing in varying levels, but a solution is to equip additionally oxidation catalytic converter for the removal. For the reason that the diesel engine is in the era of turbocharged inter-cooled, the author will make a experiment on a turbocharged inter-cooled diesel engine of YC4E150-20, and the details about the experiment include that: the test of engine characteristic, the features of the normal or abnormal emissions(HC,CO,formaldehyde,etc), and in the meanwhile, the engine used for experimenting diesel/aqueous methanol compound combustion in order to understand its discharge feature of HC,CO and formaldehyde as a whole when adopts diesel / aqueous methanol compound combustion.The result of the study shows that: the thermal efficiency of diesel/methanol compound combustion is higher than the original diesel engine. The average rate of diesel substitution is about 20%, which is 40% at a maximum; the performance indexes are improved in diesel/aqueous methanol compound combustion which are including the rate of heat release,pressure rise, maximum combustion temperature, etc. The discharge of formaldehyde is increased when methanol is mixed into engine comparison with the original one, but with all speeds and loads, the formaldehyde emission of raw methanol (M90) is lower than pure methanol (M100). The formaldehyde emissions are relatively high when low load, and will decline when heavy load, but there also will arise when the high load, which vary with different loads. With all speeds and loads, the NOx discharge of M90 is slightly lower than M100, and the NOx discharge will be increasing with combustion temperature raise when the loads arise. Compared to the original engine, the emissions of HC and CO in the engine which is mixed with methanol are increased, but the discharge of M90 is lower than M100 with all speeds and loads while both of them are reduced gradually with the loads raise. The conclusions of the study have a critical value and significance in theories and application of energy and environmental conservation.