Numerical investigation of thermal performance in a cross-flow indirect evaporative cooling system for arid and high-temperature environments

Abstract

In arid, high-temperature environments, traditional cooling systems often struggle due to high energy demand and inefficiency. As a result, indirect evaporative cooling (IEC) emerges as a viable and sustainable cooling technology, particularly in areas where energy efficiency and water conservation are essential. This study conducts a numerical examination of the thermal performance of an IEC system configured in a cross-flow arrangement. We use numerical methods, specifically the finite difference method combined with the fourth-order Runge–Kutta method, to assess the effects of key parameters, including secondary air velocity, humidity ratio, and the wettability of the water film on the heat exchanger surface. The secondary air velocity was systematically varied between 1 m/s and 5 m/s, resulting in notable enhancements in the cooling of the primary air leaving the evaporator decreased by approximately 3 °C, and its cooling capacity increased from 24 kJ/kg to 27 kJ/kg. Conversely, an increase in secondary air humidity adversely affected system performance due to constraints on the evaporation process. The wettability factor played a crucial role in system efficiency; achieving full plate coverage significantly increased wet-bulb efficiency to 78% and lifted the cooling capacity to 26 kJ/kg. These findings underscore the need to optimize airflow dynamics and water distribution within IEC systems.