广义辐射传热有热漏换热过程■耗散最小化  

Entransy Dissipation Minimization for Heat Exchange Processes with Heat Leakage and Generalized Radiative Heat Transfer Law

作　　者：夏少军 陈林根 孙丰瑞[3] XIA Shao-Jun;CHEN Lin-Gen;SUN Feng-Rui(Institute of Thermal Science and Power Engineering, Wuhan Institute of Technology, Wuhan 430205, China;School of Mechanical & Electrical Engineering, Wuhan Inst it ute of Technology, Whhan 430205, China;College of Power Engineering, Naval University of Engineering, Wuhan 430033, China)

机构地区：[1]武汉工程大学热科学与动力工程研究室,武汉430205 [2]武汉工程大学机电工程学院,武汉430205 [3]海军工程大学动力工程学院,武汉430033

出　　处：《工程热物理学报》2019年第6期1350-1361,共12页Journal of Engineering Thermophysics

基　　金：国家自然科学基金项目资助(No.51576207,No.51606218);海军工程大学自主立项科研项目(No.20161504)

摘　　要：换热器性能的提高有利于提高能源利用效率。本文研究了广义辐射传热规律[q∝△(T^n)]下与外界环境间存在热漏的换热过程,应用平均最优控制理论导出了过程[火积]耗散最小时的最优性条件。基于普适的优化结果,进一步得到了牛顿(n=1)、线性唯象(n=-1)、辐射(n=4)以及一类混合传热规律下的特例结果,并与热流率和热流体温度分别为定值的常规传热策略进行了比较。给出了数值算例,揭示了传热量和热漏对换热器最小[火积]耗散及相应热、冷流体温度最优分布规律的定性与定量影响规律,明晰了有热漏条件下热流率和热流体温度分别为定值时的两种传热策略的优劣性。本文结果可用于指导实际换热装置的优化设计。The improvement of the performance of the heat exchanger is beneficial The heat transfer process with heat leakage and generalized radiative heat transfer law [q ∝△(T^n)] is investigated in this paper, and the optimality condition for the minimum entransy dissipation of the process is derived by applying averaged optimal control theory. On the basis of the general optimization result, the results for four special cases of Newtonian(n = 1), linear phenomenological(n =-1),radiative(n = 4), and mixed heat transfer laws are further obtained. The optimal paths are also compared with the common strategies of constant heat flux rate and constant hot fluid temperature operation. Numerical examples are presented, and influences of both the amount of heat transferred and the heat leakage on the optimization results are also analyzed. The obtained results in this paper could provide some theoretical guidelines for optimal design and operation of real heat transfer devices.

关 键 词：换热过程 热漏 广义辐射传热规律[火积]耗散最小 有限时间热力学 

分 类 号：TK123[动力工程及工程热物理—工程热物理]