Entropy production minimisation of a compression-resorption heat pump

Waste heat recovery is essential to reduce energy consumption in industry. A heat pump can be used to upgrade waste heat to a temperature level that is suitable for process heat. This study concerns a compression-resorption heat pump. The goal is to optimise the heat pump energetically, while keeping the investment attractive. Entropy production is a measure for energy dissipation and therefore this will be used to quantify the exergetic losses of the cycle. To minimise entropy production is equivalent to optimising the energetic performance. A literature study is performed and two models are developed and applied to an example case from industry. For the example case the calculations showed that the COP can be increased by 26 % with respect to the currently installed pentane vapour-compression heat pump. The theory of non-equilibrium thermodynamics is applied to find the local entropy production distribution in the resorber. The calculations showed that especially in the beginning of the process the entropy production rate is high. Together the models are used to evaluate the economic performance of the system. To reduce the payback period new configurations of the heat exchanging process in the resorber are investigated using the criterion of equipartition of entropy production. These investigations show that distributing the inlet mass flow over the length of the heat exchanger does not decrease the required heat transfer area. Decreasing the cross-sectional area for the flow however, does cause a reduction of the heat transfer area.Mechanical, Maritime and Materials EngineeringProcess and Energ