Performance evaluation of plate heat exchanger with H2O/LiBr refrigerant.

In this study, the heat transfer characteristics of Water/Lithium bromide(LiBr) solution in the plate heat exchanger (PHE) for the absorption chiller application is evaluated. The plate heat exchanger is arranged in single-pass, counter flow and chevron angle of the corrugated plate is 78.5°. The H2O/LiBr solution as the working fluid was used with concentration ranging from 52.40% to 64.92%, Reynolds number ranging between 27.29 and 255.1 and Prandtl number ranging between 4.59 and 19.26. The experiment was conducted within ±10% energy balance error range. As a result, the heat transfer coefficient was evaluated ranging from 0.68 kW/m2-K to 2.92 kW/m2-K. Based on the experimental data, the empirical heat transfer correlation of the H2O/LiBr solution is developed and applicable within ±20% error range. By comparing with the correlations of the others, the validity of the heat transfer correlation of this study is validated.

本研究针对吸收式制冷机应用场景，评估了板式换热器（PHE）中水/溴化锂（LiBr）溶液的传热特性。板式换热器采用单流程、逆流布置，波纹板的人字形角度（chevron angle）为78.5°。工作流体采用H₂O/LiBr溶液，其浓度范围为52.40%至64.92%，雷诺数（Reynolds number）范围为27.29至255.1，普朗特数（Prandtl number）范围为4.59至19.26。实验在能量平衡误差±10%的范围内进行。结果显示，传热系数范围为0.68 kW/m²·K至2.92 kW/m²·K。基于实验数据，建立了H₂O/LiBr溶液的经验传热关联式（empirical heat transfer correlation），其适用误差范围为±20%。通过与其他关联式对比，验证了本研究传热关联式的有效性。