Downscaling method and experimental study on large-scale plate heat exchangers without phase change

In view of the difficulty of full-scale thermal performance experimental verification of large-scale plate heat exchangers without phase change in industrial applications, a downscaling method for plate heat exchangers based on AHRI 400 and EN 1148 standards is systematically studied, and its reliability in predicting full-scale performance is verified through water-water plate heat exchanger experiments. This paper presents a downscaling calculation model, which combines the reduction of plate number, proportional scaling of mass flow rate, and pressure drop correction formula to realize indirect measurement and calculation of full-scale heat transfer and pressure drop. The experiment selects a plate heat exchanger with a rated heat transfer of 6 000 kW for downscaling (downscaling coefficient 2.746). The results show that the downscaling method can effectively predict the heat transfer performance parameters of a full-scale plate heat exchanger, but there is a large gap between the measured value of pressure drops on the cold and hot sides and the selected value, indicating that the existing selection leaves a large margin in design in terms of pressure drop performance. As the downscaling coefficient changes, the correction amount for final heat transfer needs to be varied accordingly. It is recommended that the downscaling coefficient be controlled within the range of 3 to 8 to balance experimental costs and accuracy requirements.