汽车尾气余热温差发电装置优化与分析

发布时间：2018-01-05 05:13

本文关键词：汽车尾气余热温差发电装置优化与分析　出处：《沈阳理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着汽车工业的迅猛发展,全球经济的发展得到了快速地推进,与此同时,大量的石油资源也消耗得几近枯竭,并产生过量温室气体及NOX、PM等污染物排放。汽油是汽车的主要动力能源,在实际使用中仅利用了大致30%,40%左右都以汽车尾气的形式排放掉和被冷却系统冷却掉。本文涉及一种圆筒式汽车尾气温差发电装置,利用温差发电技术回收汽车尾气中的余热。换热器是温差发电装置热端的主要部件,其表面温度的大小与均匀程度对温差发电装置的输出有很大的影响。本文针对废热回收再利用,主要对温差发电装置换热器以及该装置整体结构展开了相关的研究。本文根据换热器内置翅片结构的不同,提出了两种换热器,即螺旋斜翅片换热器和螺旋线翅片换热器,主要研究螺旋斜翅片螺旋角、螺旋线翅片螺距、翅片厚度和翅片高度对换热器热性能的影响,其换热器热性能是以温度均匀性系数、换热器背压和壁面平均温度为指标来体现的。在CATIA三维建模软件中建立了上述带有不同的翅片结构的换热器模型,并导入到ANSYS Workbench仿真平台中,建立换热器流固耦合共轭换热计算模型,通过GT-Suite获取指定的发动机工况下的边界条件,利用CFD软件CFX展开数值仿真研究。通过翅片结构对换热器热性能影响的仿真结果,对螺旋线翅片换热器进行了优化,提出了变螺距式螺旋线翅片换热器,对上述新、旧换热器做了相同的热分析过程。最后,对带有该变螺距式螺旋线翅片换热器的温差发电装置模型进行了模拟仿真,估算出了该装置能产出的最大电能。本文的研究方法为以后汽车尾气余热温差发电装置的设计和改进提供了方法指导。
[Abstract]:With the rapid development of automobile industry, the development of global economy has been rapidly promoted, at the same time, a large number of oil resources are almost depleted, and produce excessive greenhouse gas and NOX. Pm and other pollutants emissions. Gasoline is the main vehicle power energy, in practical use only about 30%. About 40% is emitted in the form of automobile exhaust gas and cooled by cooling system. This paper relates to a cylinder type thermoelectric device of automobile exhaust gas. The heat exchanger is the main component in the hot end of thermoelectric power generation unit, which uses thermoelectric technology to recover the waste heat from automobile exhaust gas. The size and uniformity of the surface temperature have a great influence on the output of thermoelectric equipment. This paper aims at waste heat recovery and reuse. This paper mainly studies the heat exchanger of the thermoelectric unit and the whole structure of the unit. In this paper, two kinds of heat exchangers are put forward according to the difference of the inner fin structure of the heat exchanger. The helical oblique fin heat exchanger and the helical fin heat exchanger mainly study the influence of helical angle helical angle helical fin pitch fin thickness and fin height on the thermal performance of the heat exchanger. The thermal performance of the heat exchanger is based on the coefficient of temperature uniformity. The back pressure of heat exchanger and the average temperature of the wall are taken as the index. The heat exchanger model with different fin structure is established in CATIA 3D modeling software. The model of fluid-solid coupling conjugate heat transfer of heat exchanger is established by introducing it into ANSYS Workbench simulation platform, and the boundary conditions under specified engine conditions are obtained by GT-Suite. The numerical simulation study was carried out by using CFD software CFX. The helical fin heat exchanger was optimized by the simulation results of the influence of fin structure on the thermal performance of the heat exchanger. The variable pitch helical fin heat exchanger is put forward. The same thermal analysis process is done for the new and old heat exchangers. Finally. The model of thermoelectricity generator with the variable pitch helical fin heat exchanger is simulated. The maximum electric energy produced by the device is estimated. The research method in this paper provides a method guidance for the design and improvement of the afterheat differential power generation device of automobile exhaust gas in the future.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464.134.4;TM913

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