某dme休闲艇发动机喷雾.doc
约61页DOC格式手机打开展开
某dme休闲艇发动机喷雾,摘 要基于低碳、低排放是未来船用发动机技术的发展方向，本文以某艇用柴油发动机作为研究对象。主要做了如下几方面工作：1．综合缸径、压缩比、燃料物性等相关因素，对该艇用发动机燃烧室结构进行了适当地改进，并建立了燃烧室改进前后的三维几何模型。2．在linux系统下，基于es-ice软件建立了该艇用发动机燃烧室改进前后的动网格...
内容介绍
此文档由会员 违规屏蔽12 发布
摘 要
基于低碳、低排放是未来船用发动机技术的发展方向，本文以某艇用柴油发动机作为研究对象。主要做了如下几方面工作：
1．综合缸径、压缩比、燃料物性等相关因素，对该艇用发动机燃烧室结构进行了适当地改进，并建立了燃烧室改进前后的三维几何模型。
2．在LINUX系统下，基于Es-ice软件建立了该艇用发动机燃烧室改进前后的动网格模型。
3．运用湍流控制涡团破碎燃烧模型，即EBU模型对其燃烧室改进前后燃用DME的性能、缸内气体流动状况、混合气形成状况、主要污染物分布情况、及其排放特性等均进行了数值摸拟计算，并相应地作了对比与分析。
4．本文还对燃烧室改进后艇用DME发动机的喷油提前角与涡流转速两个性能参数进行了优化分析，对其燃烧室改进前后不同喷油提前角与涡流转速下燃用DME的性能、排放特性及缸内主要污染物分布情况分别进行了仿真研究。
通过对数值计算结果的对比与分析，得出主要结论如下：
1．发动机燃烧室改进后，改善了缸内气体后期的流动状况，有利于DME的雾化，促进了燃烧的进行，且发动机功率未受影响，工作却更加柔和；
2．NOX与CO2较改进前分别下降约7.3626% 和2.641%；
3．燃烧开始后，NOX与CO2均先在燃烧室中上部产生，然后逐渐向两侧扩散，且两者中心区域的质量分率都较低；
4．燃烧室改进后的DME发动机，其喷油提前角与涡流转速分别选为BTDC -9°CA和5040 r/min时较为理想。
上述结论为艇用DME发动机燃烧室的改进及其性能参数的优化提供了参考依据，对未来船用发动机的发展具有很好地指导意义。
关键词：艇用DME发动机、燃烧室改进、喷油提前角、涡流转速、污染物
ABSTRACT
The future direction of development in marine engine technology will be low-carbon and low emission. One yacht diesel engine is studied in this paper. The main tasks were completed as follows:
1. The structure of combustion chamber was properly improved based on cylinder diameter, compression ratio, fuel properties and other related factors. Besides, the three-dimensional geometric models before and after the combustion chamber improved were built.
2. The dynamic mesh models were established respectively before and after the combustion chamber improved by Es-ice in LINUX system.
3. The engine performance, gas flow condition, mixture formative situation, major pollutants distribution and emission characteristics were numerically calculated when the engine fueled with DME based on combustion model of turbulence-controlled eddy break-up (that is EBU model) before and after the combustion chamber improved. Besides, these calculations were compared and analyzed.
4. Two performance parameters of fuel injection advance angle and swirl rate were optimally analyzed after the combustion chamber improved on the DME yacht engine. The engine performance, emission characteristics and major pollutants distribution in cylinder in different fuel injection advance angles and swirl rates when fueled with DME before and after the combustion chamber improved were numerically studied.
Comparison and analysis on the results of numerical calculation, main conclusions were gained as follows:
1. The later gas flows in cylinder was perfected, but also DME atomization and combustion were promoted after the combustion chamber improved. Besides, the engine power was not affected, on the contrary, the work of the engine was more gentle.
2. NOX and CO2 emissions were declined approximately 7.3626% and 2.641% respectively compared with the previous engine.
3. Both NOX and CO2 were first produced in the middle and upper part of the combustion chamber after burning, then spread to the sides gradually, and the mass fraction in center was low.
4. The fuel injection advance angle and swirl rate after the combustion chamber improved on the DME engine were selected BTDC -9 °CA and 5040 r/min to be ideal.
Above all, these will be provided a reference basis for improving the combustion chamber and optimization performance parameters of the DME yacht engine, besides, these also have a great significance for the development of future marine engines.
Key words: DME yacht engine; combustion chamber improved; fuel injection advance
angle; swirl rate; pollutant
目 录
摘 要 I
ABSTRACT III
注释表-缩写词 IX
第一章 绪 论 - 1 -
1.1 选题背景及意义 - 1 -
1.2 二甲醚的化学结构与理化性质分析 - 2 -
1.2.1 二甲醚的化学结构 - 2 -
1.2.2 二甲醚的理化性质 - 3 -
1.3 国内外二甲醚制取技术简介 - 4 -
1.4 发动机燃用二甲醚的研究现状 - 4 -
1.4.1 国外研究现状 - 4 -
1.4.2 国内研究现状 - 7 -
1.5 本文的主要工作内容 - 8 -
1.6 本章小结 - 10 -
第二章 建立数学模型与改进燃烧室结构 - 11 -
2.1 本文选用的数学模型 - 11 -
2.1.1 缸内气体湍流扩散模型 - 11 -
2.1.2 喷雾与着火模型 - 12 -
2.1.3 燃烧模型 - 13 -
2.1.4 NOX生成模型 - 15 -
2.2 样机的基本参数与初始、边界条件的确定 - 15 -
2.2.1 样机的基本参数 - 15 -
2.2.2 初始、边界条件的确定 - 16 -
2.3 燃烧室改进的依据及其物理模型的建立 - 17 -
2.4 燃烧室改进前后气缸网格的划分 - 19 -
2.5 本章小结 - 21 -
第三章 燃烧室改进前后数值计算结果的对比与分析 - ..
基于低碳、低排放是未来船用发动机技术的发展方向，本文以某艇用柴油发动机作为研究对象。主要做了如下几方面工作：
1．综合缸径、压缩比、燃料物性等相关因素，对该艇用发动机燃烧室结构进行了适当地改进，并建立了燃烧室改进前后的三维几何模型。
2．在LINUX系统下，基于Es-ice软件建立了该艇用发动机燃烧室改进前后的动网格模型。
3．运用湍流控制涡团破碎燃烧模型，即EBU模型对其燃烧室改进前后燃用DME的性能、缸内气体流动状况、混合气形成状况、主要污染物分布情况、及其排放特性等均进行了数值摸拟计算，并相应地作了对比与分析。
4．本文还对燃烧室改进后艇用DME发动机的喷油提前角与涡流转速两个性能参数进行了优化分析，对其燃烧室改进前后不同喷油提前角与涡流转速下燃用DME的性能、排放特性及缸内主要污染物分布情况分别进行了仿真研究。
通过对数值计算结果的对比与分析，得出主要结论如下：
1．发动机燃烧室改进后，改善了缸内气体后期的流动状况，有利于DME的雾化，促进了燃烧的进行，且发动机功率未受影响，工作却更加柔和；
2．NOX与CO2较改进前分别下降约7.3626% 和2.641%；
3．燃烧开始后，NOX与CO2均先在燃烧室中上部产生，然后逐渐向两侧扩散，且两者中心区域的质量分率都较低；
4．燃烧室改进后的DME发动机，其喷油提前角与涡流转速分别选为BTDC -9°CA和5040 r/min时较为理想。
上述结论为艇用DME发动机燃烧室的改进及其性能参数的优化提供了参考依据，对未来船用发动机的发展具有很好地指导意义。
关键词：艇用DME发动机、燃烧室改进、喷油提前角、涡流转速、污染物
ABSTRACT
The future direction of development in marine engine technology will be low-carbon and low emission. One yacht diesel engine is studied in this paper. The main tasks were completed as follows:
1. The structure of combustion chamber was properly improved based on cylinder diameter, compression ratio, fuel properties and other related factors. Besides, the three-dimensional geometric models before and after the combustion chamber improved were built.
2. The dynamic mesh models were established respectively before and after the combustion chamber improved by Es-ice in LINUX system.
3. The engine performance, gas flow condition, mixture formative situation, major pollutants distribution and emission characteristics were numerically calculated when the engine fueled with DME based on combustion model of turbulence-controlled eddy break-up (that is EBU model) before and after the combustion chamber improved. Besides, these calculations were compared and analyzed.
4. Two performance parameters of fuel injection advance angle and swirl rate were optimally analyzed after the combustion chamber improved on the DME yacht engine. The engine performance, emission characteristics and major pollutants distribution in cylinder in different fuel injection advance angles and swirl rates when fueled with DME before and after the combustion chamber improved were numerically studied.
Comparison and analysis on the results of numerical calculation, main conclusions were gained as follows:
1. The later gas flows in cylinder was perfected, but also DME atomization and combustion were promoted after the combustion chamber improved. Besides, the engine power was not affected, on the contrary, the work of the engine was more gentle.
2. NOX and CO2 emissions were declined approximately 7.3626% and 2.641% respectively compared with the previous engine.
3. Both NOX and CO2 were first produced in the middle and upper part of the combustion chamber after burning, then spread to the sides gradually, and the mass fraction in center was low.
4. The fuel injection advance angle and swirl rate after the combustion chamber improved on the DME engine were selected BTDC -9 °CA and 5040 r/min to be ideal.
Above all, these will be provided a reference basis for improving the combustion chamber and optimization performance parameters of the DME yacht engine, besides, these also have a great significance for the development of future marine engines.
Key words: DME yacht engine; combustion chamber improved; fuel injection advance
angle; swirl rate; pollutant
目 录
摘 要 I
ABSTRACT III
注释表-缩写词 IX
第一章 绪 论 - 1 -
1.1 选题背景及意义 - 1 -
1.2 二甲醚的化学结构与理化性质分析 - 2 -
1.2.1 二甲醚的化学结构 - 2 -
1.2.2 二甲醚的理化性质 - 3 -
1.3 国内外二甲醚制取技术简介 - 4 -
1.4 发动机燃用二甲醚的研究现状 - 4 -
1.4.1 国外研究现状 - 4 -
1.4.2 国内研究现状 - 7 -
1.5 本文的主要工作内容 - 8 -
1.6 本章小结 - 10 -
第二章 建立数学模型与改进燃烧室结构 - 11 -
2.1 本文选用的数学模型 - 11 -
2.1.1 缸内气体湍流扩散模型 - 11 -
2.1.2 喷雾与着火模型 - 12 -
2.1.3 燃烧模型 - 13 -
2.1.4 NOX生成模型 - 15 -
2.2 样机的基本参数与初始、边界条件的确定 - 15 -
2.2.1 样机的基本参数 - 15 -
2.2.2 初始、边界条件的确定 - 16 -
2.3 燃烧室改进的依据及其物理模型的建立 - 17 -
2.4 燃烧室改进前后气缸网格的划分 - 19 -
2.5 本章小结 - 21 -
第三章 燃烧室改进前后数值计算结果的对比与分析 - ..
