换热器性能分析新方法

鉴于以加热或冷却为目的的热量传递过程，其不可逆性应以NFDA1的耗散率来度量，为此可以用换热器中的NFDA1耗散率定义换热器的当量热阻，它既包含换热器中的传热热阻，还包含了由非逆流形式和非平衡流引起的附加热阻. 换热器当量热阻的倒数称之为换热器的当量热导. 通过NFDA1耗散定义的换热器当量热阻建立了传热不可逆性与有效度的联系，并导得了换热器有效度与当量热导（热阻）和热容量流比的统一函数关系式，它适用于不同流程布置的换热器. 因此，有效度-热导（热阻）方法能更方便于不同类型换热器性能的分析和比 关键词： 换热器 热阻 耗散 熵产

A novel method for heat exchanger analysis

Since the heat transfer irreversibility of a heating or cooling process should be measured by the entransy dissipation rate, an equivalent thermal resistance for a heat exchanger was defined based on the entransy dissipation rate of the heat exchanger. The equivalent thermal resistance includes both the overall heat transfer resistance and the extra thermal resistance caused by the non-counter-flow arrangement and the non-equilibrium heat capacity rate ratio of a heat exchanger. The reciprocal of the equivalent thermal resistance was defined as the equivalent thermal conductance. The relationship is established between the heat transfer irreversibility and the effectiveness of a heat exchanger in terms of the equivalent thermal resistance. Finally, a formula describing the relation among the effectiveness, the equivalent thermal resistance and the heat capacity rate ratio is obtained which does not depend on the different flow arrangements. Therefore the effectiveness-thermal resistance （conductance） method is more suitable for the performance comparison of different heat exchangers.