线性与非线性传热过程的Curzon-Ahlborn热机在任意功率时的效率

发布时间：2017-12-30 19:30

本文关键词：线性与非线性传热过程的Curzon-Ahlborn热机在任意功率时的效率　出处：《物理学报》2017年13期 　论文类型：期刊论文

【摘要】：热机性能的优化是热力学领域的一个重要问题,而工质与热源之间的传热过程是热机工作时产生不可逆的主要来源.本文在引入功率增益和效率增益两个重要参数的基础上,基于一个简化的Curzon-Ahlborn热机模型并利用合比分比原理,给出了线性与非线性传热过程的热机在任意功率输出时的效率表达式,结合数值计算详细讨论了热机在任意功率输出时的特性.研究表明,参数ξ作为功率增益δP的函数存在两个分支:在第一分支上(不利情形),效率呈现出单调变化特征;在第二分支上(有利情形),效率随着的δP变化是非单调的且有最大值.随着传热指数的增加,热机的工作区域减小,这源于非线性传热过程包含热辐射所致.进一步发现功率-效率关系曲线存在权衡工作点,热机在该点附近工作能够实现最有效的热功转换.研究结果有助于深入理解具有不同传热过程热机的优化执行.
[Abstract]:The optimization of heat engine performance is an important problem in the field of thermodynamics. The heat transfer process between the working fluid and the heat source is the main source of irreversibility when the heat engine works. This paper introduces two important parameters of power gain and efficiency gain. Based on a simplified Curzon-Ahlborn heat engine model and using the ratio principle, the efficiency expression of the heat engine with linear and nonlinear heat transfer processes under arbitrary power output is given. The characteristics of heat engine at arbitrary power output are discussed in detail with numerical calculation. It is shown that there are two branches of parameter 尉 as a function of power gain 未 P: on the first branch (disadvantage case). Efficiency shows monotonic variation; In the second branch (favorable case), the variation of efficiency with 未 P is non-monotone and has the maximum value. With the increase of heat transfer index, the working region of the heat engine decreases. This is due to the nonlinear heat transfer process including thermal radiation. It is further found that there are tradeoff points in the power-efficiency curve. The most effective thermal power conversion can be achieved when the heat engine works near this point. The results of the study are helpful to understand the optimal performance of the heat engine with different heat transfer processes.
【作者单位】：中国矿业大学物理学院;
【基金】：中央高校基本科研业务费专项资金(批准号:2015XKMS082)资助的课题~~
【分类号】：O414.1
【正文快照】： 1引言热机是将外界输入的热能转变成有用功的装置,热机效率的改进成为第一次工业革命的引擎,这是自然科学指导人类生产实践的典型范例.迄今为止,热功转换一直是热力学领域中的一个重要问题,热机性能的优化成为热力学发展的驱动力之一.当前,随着经济的全球化与社会的快速发展,

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