Application of EoEP principle with variable heat transfer coefficient in minimizing entropy production in heat exchangers
Application of EoEP principle with variable heat transfer coefficient in minimizing entropy production in heat exchangers
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DOI：
10.1016/j.enconman.2004.10.020
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发表时间：
2005-08
影响因子：
10.4
通讯作者：
F. Balkan
中科院分区：
文献类型：
--
作者：
F. Balkan
一个更现实的应用熵最小化原则EoEP。该原理规定了沿着热交换器的均匀局部熵产生，以便最小化仅由传热引起的总熵产生率。对于现有交换器的特定热负荷和面积，这通过改变一种流体的温度而另一种流体的温度保持恒定来完成。然而，由于热负荷是固定的，因此在改变之后流体的温度的改变有时可能导致其流速的急剧改变。这可能导致总传热系数（U）的显著变化，并因此导致熵产生率的显著变化。根据流体的选择，新的熵产生率可能高于或低于基于常数U的熵产生率，如最近发表的论文中的情况。因此，需要修改EoEP原理的经典应用，以实现更真实的熵产生率。在这项研究中，EoEP与变量U的原则适用于一些情况下的热交换，并提出了一个简单的方法作为一个标准，适当选择的流体被改变。
A more realistic application of the entropy minimization principle EoEP is presented. This principle dictates uniform local entropy generations along the heat exchanger in order to minimize the total entropy generation rate due only to heat transfer. For a certain heat duty and area of an existing exchanger, this is done by changing the temperatures of one fluid while the temperatures of the other fluid are held constant. Since the heat duty is fixed, the change in the temperatures of the fluid after the change, however, may sometimes cause a drastic change in its flow rate. This may cause considerable changes in the overall heat transfer coefficient (U) and, consequently, in the entropy generation rate. Depending on the choice of the fluid for changing, the new entropy generation rates may be higher or lower than those based on constant U as is the case in papers recently published. So, the classical application of the EoEP principle needs to be modified to achieve more realistic entropy generation rates. In this study, the principle of EoEP with variable U is applied to some cases of heat exchange, and a simple method is presented as a criterion for the proper choice of the fluid to be changed.