The irreversibility of heat exchanger network (HEN) is measured by equivalent thermal resistance. The equivalent thermal resistance is defined based on entransy, a recently introduced physical quantity describing heat transfer ability of an object. The relation between irreversibility and performance of HEN is studied. In general, the annual costs decreases with the decrease of equivalent thermal resistance of HEN in two studied HEN problems. The uniformity principle of temperature difference field for HEN is purposed, which shows that equivalent thermal resistance of HEN can be reduced by improving the uniformity of temperature difference field between process streams of HEN. Present analysis may provide useful design guidelines for future HEN synthesis
Finding the junction temperature is the key to everything. But it turns out that the only way of calculating it is based on ancient mythology instead of physics. “But all legends have some basis in fact,” as Captain Kirk says, so maybe you just stick with the myth until something better comes along. Lessons : Conduction; definition of the thermal resistance between junction and case .