YC6112ZLQ型CNG单燃料发动机的开发研究
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摘要
本文介绍了在YC6112ZLQ 型增压中冷柴油机的基础上,通过改进燃烧系统、增加CNG 燃气系统、改进零部件的可靠性,成功开发出YC6112ZLQM 型CNG 电控单燃料发动机的试验研究。结果表明:采用稀薄燃烧、电控单点喷射技术,能使YC6112ZLQM 型CNG 单燃料发动机的动力性和经济性都能很好地满足使用要求;通过采用二元催化转化装置,发动机的排放指标的稳定达到欧Ⅱ水平;通过对气门和气门座圈的改进,发动机的可靠性得到提高。
With the world economy continuously increasing, the problem of the energy sources increasingly becomes the focus of every country government. Furthermore, with the quantity of the automotives retain, its emissions have become the most fearful pollutant. Nevertheless, the automotives combustion with the natural gas, one of which advantages is much cleaner and its exhaust emission is lower than the common automotives. On the development of future, the natural gas will be the best fuel “which bring on low emission”. Therefore, it’s greatly significant to solve the problem of the energy sources and environment by developing the natural gas engine.
On the type of YC6112ZLQ, turbocharged and intercooled diesel engine, by improving the combustion system, adding the natural gas supply system, ignition system and control system, the compression ignition engine will be transferred to the spark ignition engine, and the single fuel of natural gas engine is designed, which is electronic controlled, turbocharged and intercooled, lean burning and single spraying, and its engine has good performances of power, economy and emission. The improving work process on the base engine is introduced in this thesis.
The electronic control natural gas engine is transformed from the diesel engine. And its improving works could be summarized as follows:
1. Improving the air intake and the burn systems. The type of the combustion chamber is transformed from the reentrant ωto the tub, the compression ratio is decreased from 17.5 to 10.5, and the spray nozzle hole on the cylinder cap is changed into the spark plug hole.
2. Improving on the material of the valve and valve retainer. Add some material which is able to bear high temperature and has good lubricated into the material of the valve and valve retainer, which could enhance their wearability on high temperature. 3. Design the setting position of temperature and pressure sensors. 4. Add the natural gas supply system, igniting system and engine control system which are made by WOODWARD Company in America. 5. Reduce the diesel provide system such as the high pressure fuel injection pump and the fuel spray nozzle. Additional, the matching and optimizing demarcating tests of the key accessories is carried on. Such as follows. Choose the appropriate turbocharger to meet the design demand on the full load characteristic curve, the exhaust gas bypass valve of turbocharger should have appropriate angle. At high speed, the bypass valve should open at certain angle, which would make the boosted pressure decrease and the torque of engine decrease to the designing need. Choose the appropriate compression ratio and combustion chamber. The compression ratio should meet the demand of the power performance and a wide ignition range. The type of the combustion chamber must be enhancing combustion and could be shortening the combustion duration. By the tests of the engine parameters such as fuel-air ratio (phi)and spark advance angle (adv), and considering the economy performance, exhaust temperature and emission and etc. On
every operating conditions, we can choose the appropriate fuel-air ratio and spark advance angle, which will optimize the engine performance. By using the two-way catalyst apparatus, the exhaust emission could meet Europe II level, and the reliability level could meet the design demand. Conclusions could be summarized by the test results as follows: 1. From the view of the technique and the cost of development, developing the natural gas engine is a good method on the diesel engine. The technique of single injecting and lean burning, could improve the power and economy performances meanwhile. Its cost is acceptable for consumer because of using the original accessories. 2. From the result of the test, the tub combustion chamber could not only improve fuel and air mixture combustion, but also could maintain combustion stability and improve the thermal efficiency and decrease the NOx emission if making the mixture leaner. 3. Comparing with the turbocharged and intercooled diesel engine, the maximum combustion pressure decreases much on the CNG engine. So removing the first compression piston ring groove austenitic carrier, which could advance the piston intensity and heat transferring capability. Because of the combustion temperature of CNG engine is much higher than the diesel engine, to avoid the piston ring blocked by heat expanding, the first piston ring glove clearance should be appropriately increased. 4. To shorten flame travel, the combustion chamber center should depart the piston center and close to the spark plug, which could make the combustion better.
With the world economy continuously increasing, the problem of the energy sources increasingly becomes the focus of every country government. Furthermore, with the quantity of the automotives retain, its emissions have become the most fearful pollutant. Nevertheless, the automotives combustion with the natural gas, one of which advantages is much cleaner and its exhaust emission is lower than the common automotives. On the development of future, the natural gas will be the best fuel “which bring on low emission”. Therefore, it’s greatly significant to solve the problem of the energy sources and environment by developing the natural gas engine.
On the type of YC6112ZLQ, turbocharged and intercooled diesel engine, by improving the combustion system, adding the natural gas supply system, ignition system and control system, the compression ignition engine will be transferred to the spark ignition engine, and the single fuel of natural gas engine is designed, which is electronic controlled, turbocharged and intercooled, lean burning and single spraying, and its engine has good performances of power, economy and emission. The improving work process on the base engine is introduced in this thesis.
The electronic control natural gas engine is transformed from the diesel engine. And its improving works could be summarized as follows:
1. Improving the air intake and the burn systems. The type of the combustion chamber is transformed from the reentrant ωto the tub, the compression ratio is decreased from 17.5 to 10.5, and the spray nozzle hole on the cylinder cap is changed into the spark plug hole.
2. Improving on the material of the valve and valve retainer. Add some material which is able to bear high temperature and has good lubricated into the material of the valve and valve retainer, which could enhance their wearability on high temperature. 3. Design the setting position of temperature and pressure sensors. 4. Add the natural gas supply system, igniting system and engine control system which are made by WOODWARD Company in America. 5. Reduce the diesel provide system such as the high pressure fuel injection pump and the fuel spray nozzle. Additional, the matching and optimizing demarcating tests of the key accessories is carried on. Such as follows. Choose the appropriate turbocharger to meet the design demand on the full load characteristic curve, the exhaust gas bypass valve of turbocharger should have appropriate angle. At high speed, the bypass valve should open at certain angle, which would make the boosted pressure decrease and the torque of engine decrease to the designing need. Choose the appropriate compression ratio and combustion chamber. The compression ratio should meet the demand of the power performance and a wide ignition range. The type of the combustion chamber must be enhancing combustion and could be shortening the combustion duration. By the tests of the engine parameters such as fuel-air ratio (phi)and spark advance angle (adv), and considering the economy performance, exhaust temperature and emission and etc. On
every operating conditions, we can choose the appropriate fuel-air ratio and spark advance angle, which will optimize the engine performance. By using the two-way catalyst apparatus, the exhaust emission could meet Europe II level, and the reliability level could meet the design demand. Conclusions could be summarized by the test results as follows: 1. From the view of the technique and the cost of development, developing the natural gas engine is a good method on the diesel engine. The technique of single injecting and lean burning, could improve the power and economy performances meanwhile. Its cost is acceptable for consumer because of using the original accessories. 2. From the result of the test, the tub combustion chamber could not only improve fuel and air mixture combustion, but also could maintain combustion stability and improve the thermal efficiency and decrease the NOx emission if making the mixture leaner. 3. Comparing with the turbocharged and intercooled diesel engine, the maximum combustion pressure decreases much on the CNG engine. So removing the first compression piston ring groove austenitic carrier, which could advance the piston intensity and heat transferring capability. Because of the combustion temperature of CNG engine is much higher than the diesel engine, to avoid the piston ring blocked by heat expanding, the first piston ring glove clearance should be appropriately increased. 4. To shorten flame travel, the combustion chamber center should depart the piston center and close to the spark plug, which could make the combustion better.
引文
1.《国外代用燃料汽车发展概览》作者:邹祖烨等中国铁道出版社
2.《内燃机清洁高效燃烧国际学术研讨会暨中国内燃机学会第五届燃烧、节能、净化分会首次年会论文集》天津大学内燃机燃烧学国家重点实验室
3.《内燃机燃烧与排放学》作者:蒋德明西安交通大学出版社
4.《汽车用柴油机的CNG 化及电子控制系统的开发》雅马哈发动机株式会社技术论文
5.《多点循序喷射天然气发动机的开发研究》作者:郝利君等内燃机学报2001 年第4 期
6.《火花点火式天然气发动机技术分析》作者:邱先文等小型内燃机与摩托车2001 年第4 期
7.《天然气车用发动机的开发》作者:Kichiro Kato 等[日]国外内燃机2001 年第6 期
8.《燃气汽车的特点和技术关键》作者:胡定军等小型内燃机与摩托车2001 年第4 期
9.《Automobile Fuels and Pollution for the 21 Century》作者: Doo Sung Baik[韩]2002.8 天津内燃机清洁高效燃烧国际学术研讨会论文
10.《M906LAG 型多点气体喷射稀薄燃烧天然气发动机的开发》戴姆勒-克莱斯勒股份公司动力装置业务部
11.《车用天然气发动机技术与性能研究》作者:宋钧等车用发动机2001 年第6 期
2.《内燃机清洁高效燃烧国际学术研讨会暨中国内燃机学会第五届燃烧、节能、净化分会首次年会论文集》天津大学内燃机燃烧学国家重点实验室
3.《内燃机燃烧与排放学》作者:蒋德明西安交通大学出版社
4.《汽车用柴油机的CNG 化及电子控制系统的开发》雅马哈发动机株式会社技术论文
5.《多点循序喷射天然气发动机的开发研究》作者:郝利君等内燃机学报2001 年第4 期
6.《火花点火式天然气发动机技术分析》作者:邱先文等小型内燃机与摩托车2001 年第4 期
7.《天然气车用发动机的开发》作者:Kichiro Kato 等[日]国外内燃机2001 年第6 期
8.《燃气汽车的特点和技术关键》作者:胡定军等小型内燃机与摩托车2001 年第4 期
9.《Automobile Fuels and Pollution for the 21 Century》作者: Doo Sung Baik[韩]2002.8 天津内燃机清洁高效燃烧国际学术研讨会论文
10.《M906LAG 型多点气体喷射稀薄燃烧天然气发动机的开发》戴姆勒-克莱斯勒股份公司动力装置业务部
11.《车用天然气发动机技术与性能研究》作者:宋钧等车用发动机2001 年第6 期