The Development And Research For YC4F Turbocharged Intercooled Diesel Engine

1.Project's put forward Lack of petroleum resource in the world and protection for environment is the main problem for vehicle industry in the 21 century, reasonably and effectively using petroleum resource and developing alternative vehicles is the important research project for vehicle industry. Solar energy, electricity and gas vehicles are developed rapidly in recent years,。But in the market, conventional diesel engine predominates. In recent years, under sparkplug and encourage by the department of government, vehicles satisfied emission standard are popularly used in the large city, which not only save petroleum resource but also can reduce the pollution in the city. At present, the diesel engines comply with Euro II standard in China are mostly TCI engine, with the use of VE pump and P type nozzle. Because of the high price of VE pump and the poor quality of fuel in China , we suggest the use of straight pump made in China. So the price will be lower. In the vehicle market of China, light truck has important influence on vehicle industry's increase. But there is no any one TCI engine that comply with Euro II and is used in light truck and passenger car is developed in GuangXi Yuchai Manchinery Company Ltd. In order to fill up the blank, the project developed lean burn TCI engine based on YC4F naturally aspirated engine. The engine's emission comply with Euro II standard. There are important meaning for carrying out emission standard , reducing pollution in city and development of corporation. 2.The whole project design and selection of main parameter of the engine The research object of this project is YC4F diesel engine, which is wildly used on 1~3 ton agricultural car and little bus in city. It is the aim of this project that developing the diesel engine into the most advanced and comply with Euro II emission standard low price TCI diesel engine. The engine is applied to middle and top grade light trunk and passenger car. On choosing technical way, we select lean burn mode and pulse exhaust manifold .The potential emission level can comply with Euro III。After deciding the whole project of developing the engine, the main parameter is selected. Basing on market investigation, we decided that the max power is 75Kw/3200rpm and the max torque is 258N.m/<2200rpm. For satisfying power request and emission standard, intake and exhaust system,fuel supply system ,compression ratio ,overlap angle of valve,air-flue parameter and turbocharge were selected and optimized through matching experiment. AVL FIRE and FLUTNT were used to decide air-flue parameter. 3.The changing design and selection for the main parts For basic engine is non-turbocharging, this project is developing turbocharging inter cooling diesel, the inlet and exhaust system must be rectified and improved. At present, most vehicle supercharging diesel use exhaust turbo-charger. As well as, at low charging compression ratio ,reclaim of the exhaust energy, accelerate and low load performance is well by pulse turbocharge system. This project choose the pulse system. To confirm the over angle of valve of turbocharging diesel, the following will be think out: 1,Scavenging must be take into accout, for which could cooler the combustion chamber wall and clean out the exhaust ,and excessive will waste fresh air and hoist HC emission for overage cooler ; 2 ,Depressing the exhaust temperature ,most time vehicle diesel work at part load, for averting exhaust flow backwards, the angular overlap could not be great; 3,Closing intake port and opening exhaust port must be right . So, we must account basic engine's over angle of valve, to check if the basic camshaft could be used in the turbocharge inter cooling diesel. The injecting rule of original model machine is bound to fail to be the same with charge, inter-cooling diesel engine. In contrary to the original non-charge model, the following demand may be listed: 1) Total fuel supply amount and injection ratio need to increase. 2) On the condition of full load, the fuel supply amount that varied with rotate speed, should meet the regulation that it couldn't fume when in low speed and, the explosion pressure shouldn't be too high when in high speed and, the adequate fuel must be supplied when in maximum torque. There is three ordinary ways to increase fuel inject ratio: one is to increase the diameter of plunger in inject pump, while correctly change the size of inject nozzle. The second is adopting steep cam shell. The third is to increase inject pressure and enlarge the nozzle diameter. Now, we are to discuss the problems after modifying the original model to charge, inter-cooling model. When modified, the power and the torque increases, which increase the heat load, but the original model adopt ωtype combustion chamber in piston with compression ratio of 17.6 without notable difference to common piston, so it may not be directly used. To avoid combustion chamber in piston melt and piston ring agglomerated by high temperature, we can choose the ways: one is to decrease the compression ratio to16.5, 17.0 or 17.5, but this decreasing can lead to other changes. The other is adopt the inner-cooling oil duct foundry piston, which is called inner-cooling piston. The cooled high pressure oil reach the cooling inject nozzlewhich installed on the main oil duct, then be injected to the oil duct intake hole on the inner-cooling piston, then enter into inner-foundry oil cooling duct. The oil oscillates with the piston up-down movement, and continuously scours the piston and absorbs heat. There is a rake in ring-shape inner cooling oil duct, which can ensure the oil flow down to the next outlet by gravity, while the oil absorbed heat be impelled by the frequently injected and low-temperature oil and flow to the outlet. 4.The match test and optimization selection of important parts Some considerations which affect the engine performance and emission are listed in this project, and the tests are alternately conducted with different components, if these considerations are arranged in compounding, we can elicit kinds of test plans and datum, as too many datum are occurred , they did not listed in this article, just choose some typical and convictive datum to analyze. Track this plans in torque,power,fuel consumption,exhaust smoke,NOx exhausting,exhaust temperature,ECER49 standard on the exhausting test rig. The test data is as following: The exhaust test result of YC4F TC Diesel and its comparison with Euro-Ⅱand Euro-Ⅲare as following: YC4F TC Euro-Ⅱstandard Euro-Ⅲstandard CO 0.7 4.0 2.1 HC 0.3 1.1 0.66 NOx 6.8 7.0 5.0 Soot 0.12 0.15 0.1 From the comparison listed above, we can draw a conclusion that the exhaust results gualify the developing target following Euro-Ⅱstandard, and are close-to Euro-Ⅲstandard(except soot and NOx exhausting), If we can keep on reducing the oil consumption and controlling the highest combustion temperature, which needs more research, this diesel exhaustion could qualify the Euro-Ⅱstandard. 5.Conclusion The following main conclusions can be achieved from this dissertation: 1. Firstly, the discharge of the diesel engine was investigated, the making up mechanism and control measurements of harmful exhausts were found out. 2. By investigating and analyzing the primary diesel engine, some measurements for improvement were gained and the technique route was established, design some special parts in advance. 3. By investigating exhaust gas pipe and gas lines by software, the design project was confirmed to satisfy the requirement of diesel engine to performance. 4. Combine different parts and proceed experiment to choose parts, analyze the good and bad of the every kind of project, and confirm the best project to install. 5. Finally install the best project to proceed the discharge experiment, and confirm it lastly. 6. By improving the construction, choosing, matching and marking the main parts, the diesel engine with good motivity and discharge performances can be developed. this is an efficient measurement that diesel engine factory provided the environmental protection power for the incity bus. Key words: diesel engine turbocharged intercooled development experiment research...