管道热输原油过程的(火用)传递分析

在求解热油管道温度场、压力场的基础上,给出了其包括压Yong、压Yong流密度、压Yong传递系数及其常影响因子在内的Yong传递分析指标。对大庆油田某热油管道的应用数值模拟表明：Yong传递分析不仅可对管道输送过程主导势场Yong传递的时空变化规律进行描述,对温度场、压力场二基本势场的协同作用机制作以合理解释,还提出了诸如增大压力可有效提高输油管道的压Yong传递系数等改进输送过程的技术途径。     

Yong传递的研究现状与发展方向

回顾了历史上Yong传递研究的形成与发展过程，并重点介绍了国内外Yong研究的现状，对现阶段Yong传递研究的方法概要地进行了分类，建议今后工程Yong传递的具体研究方向可以从典型Yong传递过程，复杂工程Yong传递问题，Yong传递过程强化/减弱方法，用能设备的Yong传递优化设计等方面开展。     

单元初始Yong效率和Yong流价值分布

分析了Yong的不等价性，在此基础上提出了Yong弹性系数、初始Yong损耗率等概念。以Yong弹性系数为计算基础，分析了在单一系统内各组元Yong效率对整个系统Yong效率的影响，导出了初始Yong损耗率的计算方法，并以实例进行了分析计算。分析表明：系统内各组元的单位Yong所消耗的初始Yong更能反映系统各组元的Yong耗特性，从而有利于更科学地分析系统各单元的节能潜力。     

基准Yong与热力过程Yong变量计算方法

从Yong的基本概念出发，阐述了物理Yong和化学Yong的计算方法，推导了热力学中常见热力过程的Yong变量表达式，为工程Yong分析提供了理论计算基础。     

基于能级概念的Yong经济学计价策略

正确合理地对Yong流计价，确定从燃料到产品Yong流的转换过程中费用形成及变化过程，是实现能量系统的炯经济学分析和优化的关键之一。将能级的概念引入热经济学计价体系。把供入能流按能级拆分，依据能级相近最大化相供的原则，解决能量取出与供入间的对应问题，提出了基于能级相近最大化相供的Yong流计价策略，以减少求解过程中所涉及的未知变量数。说明产品Yong流存在时的附加方程引入情况。最后以典型的热电联产系统(CGAM系统)的Yong经济分析优化中Yong流计价为例，介绍了该计价方法的应用。     

热泵定义及Yong效率计算方法探讨

热力学中对热泵的定义与工程实际中的热泵意义不一致。由此导致热泵用效率计算方法的出入，以至产生热泵Yong效率大于1的原则性错误，本文以热泵，Yong分析基本理论为依据，就热泵定义及热泵Yong效率计算方法问题进行了广泛深入的探讨，提出了新的热泵定义，给出了符合Yong分析理论原则的热泵Yong效率计算方法。     

冷量Yong与热量Yong计算方法的统一性研究

以热力学第一、二定律为基础，结合Yong、Wu的基本定义，探讨了冷量Yong、冷量Wu的计算方法，指出了当前Yong分析理论体系中存在的‘冷量Yong、冷量Wu计算方法不能与热力学第一定律相统一’的问题，提出了新的计算方法，使得冷量Yong计算方法更科学、严谨。     

阶跃热流加热下两接触平板间的非Fourier传热研究

建立两接触平板在阶跃热流加热下的非Fourier导热模型,研究了两平板间的接触热阻及平板的导热系数、导温系数、松弛时间对非Fourier传热过程的影响,指出各平板内热波的传递具有反射性、波幅衰减性和瞬时性的特点。     

热经济学中计价方法的探讨

Yong经济学是以Yong为核算对象的成本核算方法，以最小产品成本为目标函数，结合一定的Yong经济学评价指标，对能量系统进行分析、评价，得到改进的途径。文章基于Yong成本方程，对Yong费用方程进行了讨论，明确了过程Yong损的计价方法，提出了有效的Yong经济学系数。用能级概念可以更为全面的描述能流的品质，能级匹配是减小系统Yong损失的有效途径。文章将能级的概念引入热经济学计价体系，提出了基于能级分析的计价策略和评价指标。以联产模型为实例，进行了讨论。     

吉林镍业公司干燥炉窑节能分析

通过对吉林镍业公司干燥炉窑进行热平衡及Yong平衡的计算。得出了热效率和Yong效率，据眩分析并提出了该干燥炉窑的有效节能途径。     

地热-高温水源热泵供热系统的分析

运用能量系统的为(火用)分析方法.建立地热-高温水源热泵供热系统的炯分析理论模型.以实际工程项目为例,分析和讨论了系统运行条件下的能量有效利用,并计算了地热-高温热泵供热系统的火甩效率和各部分(火用)损失、(火用)效率.从计算结果看出,板式换热器的火用损失所占比例较大.     

Determination of loss coefficients for high-temperature flow devices: An entropy-based approach

Thermodynamic analysis of a high-temperature confined turbulent gas-jet is presented in this paper. The numerical model is two dimensional, steady, and includes the effect of gravity in the governing equations. Computations are carried out with a commercial CFD code and the local exergy losses are determined as post processed quantities. The analysis takes into account the second law effects of viscous dissipation, heat conduction and convection, and radiative heat transfer. The study is extended by conducting a parametric investigation to determine the effects of Reynolds number, inlet fluid temperature, optical thickness, and Planck number on the exergy loss coefficient, which is defined as the total exergy destroyed per unit mechanical energy input. The results show that exergy loss trough radiation entropy production is higher than that due to heat conduction and convection when the inlet gas temperature is high. It has also been found that in contrast to the conventional head loss coefficient, the exergy loss coefficient increases with inlet gas temperature, optical thickness, and Planck number.     

Exergy transfer characteristics of forced convective heat transfer through a duct with constant wall heat flux

The examination of exergy transfer characteristics caused by forced convective heat transfer through a duct with constant wall heat flux for thermally and hydrodynamic fully developed laminar and turbulent flows has been presented. The exergy transfer Nusselt number is put forward and the dependence relationships of the exergy transfer Nusselt number on the heat transfer Nusselt number, Reynolds number and Prandtl number are obtained. Expressions involving relevant variables for the local and mean convective exergy transfer coefficient, non-dimensional exergy flux and exergy transfer rate, etc. have been derived. By reference to a smooth duct, the numerical results of exergy transfer characteristics for fluids with different Prandtl number are obtained and the effect of the Reynolds number and non-dimensional cross-sectional position on exergy transfer characteristics is analyzed. In addition, the results corresponding to the exergy transfer and energy transfer are compared.     

Exergy transfer characteristics of forced convective heat transfer through a duct with constant wall temperature

The exergy transfer characteristics of fluid flow and heat transfer inside a circular duct under fully developed laminar and turbulent forced convection are presented. Temperature is kept constant at the duct wall. The exergy transfer Nusselt number is put forward and the analytical expressions for exergy transfer Nusselt number are obtained as functions of heat transfer Nusselt number, Reynolds number, Prandtl number, etc. The variations of the local and mean convective exergy transfer coefficient, non-dimensional exergy flux, exergy transfer rate, etc. with operating parameters are presented graphically. By reference to a smooth duct and taking air as working fluid, a numerical analysis of the influence of the Reynolds number and non-dimensional cross-sectional position on exergy transfer characteristics has been conducted. The results show that the process parameters and configuration in the fluid flow and heat transfer inside a duct should be properly selected so that the forced convection process could have the best exergy utilization. In addition, the results corresponding to the exergy transfer and energy transfer are compared.     

板式换热器火用传递特性研究

文中运用推导逆流换热器对数平均温度的方法,得到了板式换热器中冷热流体及板上的温度分布.在此基础上运用火用传递理论,推导出了热流体至板、板至冷流体的局部火用传递系数.以某板式换热器为例进行了算例分析,从火用传递角度分析了该换热器的换热性能,此结果可以作为对板式换热器进行优化和改进的一种可行有效的重要参考.     

Optimization of the rate of exergy output of a multi-stage endoreversible combined refrigeration system

A general endoreversible refrigeration cycle model which includes the irreversibility of heat transfer across finite temperature differences and the heat leak loss between the external heat reservoirs is used to analyze the rate of exergy output of a multi-stage combined refrigeration system. The relations between the rates of exergy output and refrigeration and between the rate of exergy output and coefficient of performance are derived. The efficiency of exergy output is calculated. The optimal problems relative to the rate of exergy output are discussed. Some characteristic curves of the refrigeration system are presented. The results obtained here are suitable for an arbitrary-stage endoreversible combined refrigeration system.     

竖壁膜状凝结传递特性研究

传递的分析方法比能量平衡的分析方法更加关注能量品质的蜕变规律。借鉴努塞尔蒸汽层流膜状凝结的分析解中竖直平壁凝结液膜的厚度与传热系数表达式,引入传递理论的研究方法,得到竖直平壁凝结换热局部传递系数表达式,通过对不同壁面过冷度情况下对壁面液膜厚度、传热系数及传递系数计算,结果显示过冷度越大,壁面厚度增大,传热系数减小,但传递系数变大。通过对计算结果的分析可知,壁面过冷度增加可增加传量,达到强化换热的目的。     

过冷式小型冰蓄冷系统(火用)分析

通过对过冷式小型冰蓄冷系统火用分析模型的建立,采用[火用]分析的方法,揭示了小型过冷式冰蓄冷系统的能量转换的薄弱环节以及过冷度对各部件[火用]损失系数和系统火用效率的影响。分析了减少火用损失的途径,节约能源。并为系统的改进和优化提供有力的理论参考。     

R245fa有机朗肯循环余热发电系统火用分析

以低品位热能驱动的有机朗肯循环发电系统,是实现将低品位热能转变为电能,进而提高热力系统总体热效率,降低污染排放的有效途径之一。本文建立了低品位热能发电系统火用分析模型,对以R245fa为工质的温度低于383.15 K的低品位热能有机朗肯循环余热发电系统进行了火用分析,得到了各环节的能量转换效率并确定了对系统性能影响最大的环节;通过改变蒸发器和冷凝器的压降和传热系数值,分析了主要换热设备的设计和运行性能参数对系统火用效率、热效率和发电量的影响趋势,提出了低品位热能发电系统的优化方向。