Abstract:

The uniformity principle of temperature difference field is a phenomenological principle，which has not been theoretically provedFor onedimensional two-and three-stream heat exchangers，the extremum principle of entransy dissipation was used to optimize the heat transfer process by variational calculusIt was indicated that the temperature difference field between the hot and cold fluids should be completely uniform if the entransy dissipation reached a minimum for a given heat duty，or if the heat duty reached a maximum for a given entransy dissipationSo，the uniformity principle of temperature difference field of heat exchangers was primarily proved.

Key words:

换热器, 温差场均匀性原则, 火积耗散极值原理

摘要： 换热器的温差场均匀性原则是一个唯象原理，还没有得到理论上的证明。采用变分方法，用火积耗散极值原理对两股流和三股流一维换热器的传热过程进行了优化，表明不管是给定换热量寻求火积耗散最小，还是给定火积耗散寻求换热量最大，均应使冷热流体的温差场完全均匀，从而初步证明了换热器温差场均匀性原则的正确性。

关键词:

换热器, 温差场均匀性原则, 火积耗散极值原理