Multi-Climate Transient Seasonal Analysis of Integrated Solar Assisted Desiccant Indirect Evaporative Cooling System with Dynamic Building Loads

Abstract

Thermal comfort demand in the building sector is increasing remarkably due to population growth, urbanization, and global warming, particularly in hot and humid climates like Pakistan. However, the performance of such systems is strongly influenced by dynamic building loads and transient climate conditions, such as solar irradiance, ambient air temperature, and humidity. This study investigated the adequacy of the solar-assisted desiccant cooler with the Maisotsenko cycle cooler (SADC-Mc) system by performing a transient seasonal analysis for multiple climate zones of Pakistan. The climate zones include humid subtropical (Cwa), Warm semi-arid (BSh), and Warm desert climate (BWh), as exemplified by various cities such as Peshawar, Taxila, Lahore, Multan, and Karachi. Furthermore, the performance of SADC-Mc is also compared with a traditional solar-assisted desiccant cooling system with a direct evaporative cooler (SAD-DEC) in each climate. A detailed solar-assisted desiccant cooling system model was developed in TRNSYS, and a Maisotsenko cycle cooler (M-cycle) EES component model was also incorporated to perform the seasonal (April-September) transient simulation analysis under dynamic building loads for the selected climates. The system model validation findings showed good agreement with published experimental data, with a mean percentage error of 2.7%. The SADC-Mc system was found to be 40-60% more efficient than the traditional desiccant cooling system in terms of COPth for the less humid climates of Taxila, Peshawar, and Lahore. In terms of cooling capacity (CC), the integrated system performed effectively well in all cities, achieving its peak monthly performance in Multan at 5407 kWh. Furthermore, the maximum thermal energy requirement of the SADC-Mc system was reported for Karachi (6603 kWh) in June. In contrast, the SAD-DEC system's thermal energy requirement is almost double (17072 kWh) as compared to the SADC-Mc system. Similarly, the monthly average variation in COP thermal was recorded as ranging from 0.8 to 1.2, along with a total seasonal solar energy gain of 40 MWh for the Taxila climate.