TO-22-A008 - Method for Brazed Plate Heat Exchanger Heat Load Estimation: Analytical Approach and Experimental Verification

Brazed plate heat exchangers (BPHX) are widely used for building cooling and heating systems. To efficiently operate such heat exchangers smart-control software, that used mapped heat transfer curves, was developed and integrated into the system. For precise control of a BPHX it is critical to characterize the actual performance of the BPHXs in the development phase and integrate verified performance correlations into the software. This paper focuses on analytical approaches to determining heat transfer coefficients and estimating heat loads for a brazed plate heat exchanger, and verification of the correlations that were developed with experimental testing according to AHRI-400 standards. A brazed plate heat exchanger (Model: Z400H-90) was tested with water at varying flow rates. The measured outlet temperatures successfully match predictions and heat transfer coefficients fit well to values extrapolated from correlations in the literature. The experimental results verify that the method developed works well in estimating the performance of brazed plate heat exchangers. The high accuracy of heat transfer predictions allows the performance of the heat exchanger to be optimized by control software using performance maps.