Thermo-economic analysis and comparison of novel desiccant air conditioning systems

Abstract

Desiccant air conditioning (DAC) systems are considered an effective alternative to traditional vapor compression systems due to their ability to independently control temperature and humidity, coupled with their environmentally friendly design. Consequently, this paper deals with experimental and simulation study on DAC systems. The experiments were conducted on a reference system (RS) equipped with all necessary control and measurement devices. This reference system includes a traditional desiccant evaporative air-conditioning system with an additional heat exchanger placed after the desiccant wheel, functioning as an after-cooler. In addition, steady state and transient simulation models were developed using TRNSYS software to predict the performance of four different configurations of DAC systems and the reference system, under hot and humid climatic conditions.The experimental data verify the precision and relevance of the simulation results, with an average error of 2.57 % for the air temperatures. The steady state findings showed that Config-4 exhibited the best thermal performance compared to the other configurations. Also, Config-4 demonstrates a stable thermal cooling capacity despite fluctuations in outdoor air dry-bulb temperature. Transient results revealed that, Config-4 has levelized costs of CO2 emissions that are 64.2 % lower than RS, followed by Config-3, Config-2, and Config-1. Lower CO2 emissions result in a positive impact on mitigating climate change and improving air quality. Economic analysis revealed that the total levelized cost of cooling (LCOC) for Config-4 is 70.5 % lower than RS, demonstrating the most significant cost reduction. Configurations 3, 2, and 1 also showed lower LCOC compared to the reference system.