Towards Improved Efficiency of Low-Grade Solar Thermal Cooling: An RSM-Based Multi-Objective Optimization Study

Autor segons l'article: Saoud, A; Bruno, JC

Departament: Enginyeria Mecànica

Autor/s de la URV: Bruno Argilaguet, Juan Carlos

Paraules clau: Absorption cooling system; Absorption-refrigeration; Box-behnken design; Chiller; Driven; Energy; Exergy; Exergy analysis; Licl-h2o; Low-temperature solar collectors; Multi-objective optimization; Response surface methodology; Response-surface methodology; Single; System; Thermodynamic analysis

Resum: Featured Application The proposed low-grade solar thermal absorption chiller provides a sustainable cooling solution for residential and commercial buildings in sun-rich regions. By operating efficiently at low driving temperatures achievable with evacuated flat plate collectors, the system reduces electricity consumption from conventional vapor compression systems and lowers greenhouse gas emissions. Its optimized design offers a cost-effective pathway for integrating renewable energy into HVAC applications, particularly in hot climates where cooling demand coincides with peak solar availability.Abstract This study investigates an integrated solar-driven single-effect H2O-LiBr absorption chiller powered by low-grade thermal energy. A detailed thermodynamic model, comprising a solar collector, a thermal storage tank, and an absorption cycle, was developed using the Engineering Equation Solver (EES) software V10.561. A comprehensive parametric analysis and multi-objective optimization were then conducted to enhance both the energy and exergy performance of the system. The Response Surface Methodology (RSM), based on the Box-Behnken Design, was employed to develop regression models validated through analysis of variance (ANOVA). The generator temperature (78-86 degrees C), evaporator temperature (2.5-6.5 degrees C), and absorber/condenser temperature (30-40 degrees C) were selected as key variables. According to the results, the single-objective analyses revealed maximum values of COP = 0.8065, cooling capacity = 20.72 kW, and exergy efficiency = 39.29%. Subsequently, the multi-objective RSM optimization produced a balanced global optimum with COP = 0.797, cooling capacity = 20.68 kW, and exergy efficiency = 36.93%, achieved under optimal operating conditions of 78 degrees C generator temperature, 6.5 degrees C evaporator temperature, and 30 degrees C absorber/condenser temperature. The obtained results confirm the significance of the proposed low-grade solar absorption chiller, demonstrating comparable or superior performance to recent studies (e.g., COP approximate to 0.75-0.80 and approximate to 35-37%). This agreement validates the RSM-based optimization approach and confirms the system's suitability for sustainable cooling applications in low-temperature solar environments.

Àrees temàtiques: Astronomia / física; Biodiversidade; Chemistry, multidisciplinary; Ciência de alimentos; Ciências agrárias i; Ciências biológicas i; Ciências biológicas ii; Ciências biológicas iii; Computer science applications; Engenharias i; Engenharias ii; Engineering (all); Engineering (miscellaneous); Engineering, multidisciplinary; Fluid flow and transfer processes; General engineering; General materials science; Instrumentation; Materiais; Materials science (all); Materials science (miscellaneous); Materials science, multidisciplinary; Physics, applied; Process chemistry and technology; Química

Accès a la llicència d'ús: https://creativecommons.org/licenses/by/3.0/es/

Adreça de correu electrònic de l'autor: juancarlos.bruno@urv.cat

Data d'alta del registre: 2026-02-13

Versió de l'article dipositat: info:eu-repo/semantics/publishedVersion

Enllaç font original: https://www.mdpi.com/2076-3417/15/21/11518

Referència a l'article segons font original: Applied Sciences-Basel. 15 (21): 11518-

Referència de l'ítem segons les normes APA: Saoud, A; Bruno, JC (2025). Towards Improved Efficiency of Low-Grade Solar Thermal Cooling: An RSM-Based Multi-Objective Optimization Study. Applied Sciences-Basel, 15(21), 11518-. DOI: 10.3390/app152111518

URL Document de llicència: https://repositori.urv.cat/ca/proteccio-de-dades/

DOI de l'article: 10.3390/app152111518

Entitat: Universitat Rovira i Virgili

Any de publicació de la revista: 2025-10-28

Tipus de publicació: Journal Publications