Exergoeconomic optimisation of the geometry of continuous fins on an array of tubes of a refrigeration air cooled condenser

摘要

An exergy method for optimising the geometrical parameters of continuous fins on an array of tubes in an air-cooled condenser is developed in this paper. The method is based on exergy, economic analysis and optimisation theory. The condenser is characterised by the single/two phase flow inside the coil and the two components of exergy destruction, I~(ΔP) and I~(ΔT), for refrigerant and air sides are calculated for different geometries. A change in geometry was obtained by varying the condenser tube diameter for a selected condenser capacity, and hence the condenser tube length and total heat transfer area are calculated for a fixed condenser face length. In this way the effect of changes in the geometry on the total number of exergy destruction units is investigated. Also, the optimum balance between the two components of destruction is determined thereby giving the optimum solution for the heat exchanger area. The total cost function is expressed on the basis of annual cost of capital investment and the cost of compensation for the irreversibilities. The results show that the effect of the total irreversibility is 3.885% of the condenser capacity.