Work

Realising hidden exergetic potential in a gas engine-driven polyvalent absorption heat pump via temperature sensitivity mapping: a case study

Year: 2025

Type: article

Abstract: • Extending primary indicators for GEAHPs and confirming linear temperature relation. • GEAHP systems can be rendered insensitive to absorber and condensation temperatures. • Even 4 % hidden exergy realization yields 26–38 % exergetic improvements in subsystems. • Adjusting return water temperature is the safest way to raise exergy content. • Exergy content increase is greatest in cooling system at a 3 °C temperature change. Urbanization and increasing comfort requirements are creating rising challenges for HVAC systems, particularly in the integrated management of cooling, heating, and electricity demands. Trigeneration systems employing gas-engine-driven polyvalent absorption heat pumps (GEAHP) offer a promising solution for a multipurpose energy supply. This study adapts and investigates four critical primary indicators characterizing the polyvalent absorption heat pump: the COP ER , the Total Exergy System Efficiency (η sys,ER ), the Primary Energy Ratio (PER), and the Primary Exergy Ratio (PXR). Each indicator exhibits high linear temperature sensitivity (R 2 > 0.998); therefore, a temperature sensitivity–based approach is proposed to improve the system’s efficiency. The method is applied to a real-life GEAHP system. According to results, even a limited realization of hidden exergetic potential (4.03 % with 3 °C adjustment) results in significant exergetic gains: 37.96 % in the cooling system, 26.41 % in the low-exergy heating system, and 6.05 % in the high-exergy heating system. Additionally, appropriate selection of the Thermo-Chemical Performance Index (β) renders the system insensitive to variations in absorption and condensation temperatures. These results could serve as a basis for exploring hidden exergetic potentials and optimizing the energy utilization of trigeneration systems.

Source: Applied Thermal Engineering

DOI: 10.1016/j.applthermaleng.2025.129303

Authors: Gábor L. Szabó, Szabolcs Józsa, Béla Bodó

Institution: University of Debrecen

Language: English

Topic: Thermodynamic and Exergetic Analyses of Power and Cooling Systems

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Climate action

Open Access status: hybrid

Estimated APC paid: $3,660