摘要
建立了一个包含多种不可逆性的不可逆热机模型,并将热漏分为外热漏和内热漏两种方式。在此基础上求得存在热阻、热漏和内不可逆损失的定常态流不可逆卡诺热机的功率、效率关系。分析了两种热漏方式对热机最优性能的影响,发现内热漏对热机功率效率特性的影响不同于外热漏,而且与摩擦、涡流和非平衡等不可逆效应也不同;内热漏不能归结于外热漏作为整个热机的热漏或合并为除热阻和热漏外的其他不可逆性。分析表明,当有内热漏存在时,一定温比下热机的最佳功率和最佳效率工作状态分别对应不同的面积比。所得结果对热机设计具有一定指导意义。
An irreversible Carnot engine model with irreversibilities such as heat-resistance, heat leakage, friction, turbulence and other undesirable irreversible factors, was discussed in this paper. The heat leakage model including external （device heat leakage） and internal heat leakage （working fluid heat leakage） is different from the so-called ＂irreversible cycle＂ models proposed by some other authors. The influence of two kinds of heat leakage on the optimal performance of heat engine was analyzed. It is found that the influence of internal heat leakage on the power -- efficiency characteristics of heat engines is different from that of outer heat leakage and other internal irreversibilities, such as friction, turbulence etc. The heat engine with different heat leakage has two optimal working conditions, the optimum power and optimum efficiency cann＇t be attained at the same heat transfer area ratio. Numerical examples illustrated the effectiveness of the new model and some useful results were presented.
出处
《热科学与技术》
CAS
CSCD
2006年第2期95-100,共6页
Journal of Thermal Science and Technology
关键词
有限时间热力学
不可逆热机
最优性能
热漏
finite time thermodynamies
irreversible heat engine
optimal performances heat leak
