Field Evaluation and Anaysis of a Liquid Desiccant Air Handling System

Abstract

A thermal liquid desiccant air handling machine was procured, installed, and fieldtested. The goal of the present investigation is to evaluate the field performance of themachine and characterize its operation for the temperature range of a solar thermalarray. The system studied includes a natural gas boiler supplying the heat, and acooling tower for heat rejection. System performance was evaluated for the 50 to 90Ctemperature range, the operating range of solar thermal collectors. Cooling powervaried between 4.3 kW and 22.8 kW for this range of temperature, with a latent heatratio between 1.1 and 1.9, confirming that the unit is significantly dehumidifying theprocess air stream. Electrical COP varied between 0.58 and 4.48. Performance dataindicates higher temperature solar collectors such as evacuated tube or double glazedflat plat collectors would be optimum in a solar cooling application with this system.Empirical correlations for the regenerator and conditioner components were obtainedusing a multivariate linear regression model. 5 empirical relations were derived andcan be used to characterize the thermal dehumidification concept. These relationsand methods will be used in future work to simulate and optimize a solar thermaldriven dehumidification system for dedicated outdoor air systems.