Comments on the statement that the temperature difference field uniformity principle is a duplicate of the principle, Δ T / T = const, for balanced counter-flow heat exchangers
 作者： Zeng-Yuan Guo,  Yu-Chao Hua 作者单位： 1Department of Engineering Mechanics, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China 刊名： International Journal of Heat and Mass Transfer, 2018, Vol.127 , pp.1343-1346 来源数据库： Elsevier Journal DOI： 10.1016/j.ijheatmasstransfer.2018.07.108 关键词： Balanced counter-flow heat exchanger;  Thermal insulation system;  Heat exchanger effectiveness;  Temperature difference field uniformity principle; 原始语种摘要： Abstract(#br)The optimization principle, Δ T/T = const, was wrongly shown to hold for balanced counter-flow heat exchangers due to an inappropriate analogy between a balanced counter-flow heat exchanger and a one-dimensional thermal insulation system in a paper entitled “A general variational principle for thermal insulation system design” by Bejan and then in his subsequent papers. The heat exchanger effectiveness of a balanced counter-flow heat exchanger is well known to be highest where the local temperature difference between the hot and cold streams is uniform along the entire length, with this principle Δ T = const, being independent of the absolute temperatures of the streams as the uniformity principle of the temperature difference field indicates. That is, the optimization... principle for heat exchangers with the purpose of heating objects is Δ T = const, rather than Δ T/T = const. Hence, Bejan’s accusation that the uniformity principle of the temperature difference field is a duplication of his optimization principle, Δ T/T = const, for the one-dimensional thermal insulation system, is unfounded. These principles should not be confused since they apply to different scenarios.

• uniformity　均匀性
• counter　计数器
• principle　原理
• duplicate　复制
• const　常数
• balanced　平[均]衡
• field
• exchanger　交换器
• Temperature　温度
• effectiveness　有效性