Air-cooled condensers in retail systems using R22 and R404A refrigerants

A steady-state simulation model for a finned-tube air-cooled condenser has been developed by using the distributed modelling method. The model can be used to predict 3-D variations of parameters for both air and refrigerant sides. The model has been validated by comparing outputs from the model with test data, given in reference papers, derived from air-cooled condensers with differing dimensions and refrigerants. Application of the model is concentrated on optimisation and exploration of existing and new control strategies for controlling refrigerant discharge-pressures in retail refrigeration systems, where air-cooled condensers are being utilised. Meaningful results are obtained for both the optimal design and development of the new control strategies and for performance comparisons when different refrigerants are employed in the condensers.