Optimisation of cooling performance and water consumption of a solid desiccant-assisted indirect evaporative cooling system using response surface methodology

• Published in: International journal of refrigeration 2024-12, Vol.168, p.376-388
• Main Authors: Lai, Lanbo, Wang, Xiaolin, Kefayati, Gholamreza, Hu, Eric, Ng, Kim Choon
• Format: Article
• Language: English
• Subjects: Air-conditioning; Climatisation; Dessiccant solide; Evaporative cooling; Multi-objective optimisation; Méthodologie de surface de réponse; Optimisation multi-objectifs; Refroidissement évaporatif; Response surface methodology; Solid desiccant
• ISSN: 0140-7007
• DOI: 10.1016/j.ijrefrig.2024.09.023

•A solid desiccant cooling system is optimised using a response surface methodology.•Regression models were developed and showed commendable predictive capability.•Multi-objective optimisation was achieved by considering four key parameters.•Case studies demonstrated the system's applicability in Australian climates. Solid desiccant-assisted dew-point indirect evaporative cooling (SD-DPIEC) systems have gained considerable attention as a potential eco-friendly alternative to vapour-compression cooling systems in building cooling applications. However, one major drawback of these systems is their substantial water consumption during evaporative cooling. To tackle this issue, this study aims to improve the cooling efficiency and water utilisation of an SD-DPIEC system using response surface methodology (RSM). This research focuses on optimising four key parameters: supply air temperature, humidity ratio, water consumption rate and coefficient of performance (COP). The independent variables encompass the ambient temperature, relative humidity, regeneration temperature, and recirculation air ratio. Employing a multi-objective optimisation approach via the desirability function, the optimised SD-DPIEC system is subsequently tested in two prevalent weather patterns in Australia. The results demonstrated that the regression models derived from RSM exhibited commendable predictive capability, with the determination coefficient R2 and Adequate Precision exceeding 0.97 and 40.46, respectively. The outcomes revealed that the system attained its optimal performance with a supply air temperature of 20.36 °C, humidity ratio of 12.56 g kg-1, a water consumption rate of 3.11 kg/hr, and COP of 2.03 under the ambient temperature of 33.79 °C, relative humidity of 68.48 %, regeneration temperature of 51.78 °C, and recirculation air ratio of 60 %. Based on the optimisation results, a case study was undertaken to evaluate the system's applicability in representative Australian climates. The results demonstrated that the system could uphold air conditions with the supply air temperature below 19 °C and humidity ratio below 11.51 g kg-1 under the studied Australian climates.