Industrial buildings have numerous kinds of energy-losing equipment, such as engines, ovens, boilers and heat exchangers. Energy losses are related to inefficient energy use and lousy work conditions for the people inside the buildings. This work is devoted to the recovery of lost energy from industrial buildings. Firstly, the residual energy of the building is extracted to be used to warm water. Consequently, the work conditions of the people inside industrial buildings can be improved by maintaining the adequate temperature. The recovery of the energy is performed by a multipurpose heat pump system (HP system). The working fluid used in the HP system is R134a, which is a traditional and cheap working fluid. The thermophysical properties of R134a are obtained through the PC-SAFT equation of state. This work presents a performance mapping based on the intercepted areas framework to evaluate which working conditions are the optimal operating variables. The latter depends on several key parameters, such as compressor work, heat delivery, heat absorbed and exergetic efficiency. The results show that the optimal work conditions are found at different condenser and evaporator temperatures, and these may be limited by what the designer considers a sound performance of the heat pump system.

The transition towards sustainable energy systems demands efficient utilization of low- and medium-temperature thermal sources, which offer a promising alternative to pollutant energy carriers like fossil fuels. Among these, solar thermal, geothermal, and residual heat emerge as leading candidates for clean energy generation. Organic Rankine Cycles (ORCs) stand out as robust technologies capable of converting these thermal sources into electricity with high efficiency. A critical factor in ORC performance lies in the effective transfer of heat from the thermal source to the working fluid. This study systematically evaluates various thermal oils as intermediate heat transfer media, aiming to optimize their selection based on key performance indicators. The analysis focuses on thermal and exergetic efficiencies, alongside mass and volumetric flow rates of both the working fluid and the thermal oil. The findings reveal that the integration of thermal oils notably boosts the exergetic efficiency of the ORC system, underscoring their pivotal role in maximizing energy conversion from sustainable heat sources.

Industrial buildings have numerous energy-losing equipment, such as engines, ovens, boilers, and heat exchangers. Energy losses are related to inefficient energy use and lousy work conditions for the people inside the buildings. This work is devoted to the recovery of lost energy from industrial buildings. Firstly, the residual energy of the building is extracted to be used to warm water. Consequently, the work conditions of the people inside industrial buildings can be improved by maintaining the adequate temperature. The recovery energy is done by the multipurpose heat pump system (HP system). The working fluid used in the HP system is R134a, which is a traditional and cheap working fluid. The thermophysical properties of R134a are obtained through the PC-SAFT equation of state. This work presents a performance mapping based on the intercepted areas framework to evaluate which working conditions are the optimal operating variables. The latter depends on several key parameters, such as compressor work, heat delivery, heat absorbed, and exergetic efficiency. The results show that the optimal work conditions are found at different condenser and evaporator temperatures, and that may be limited by what the designer considers a good performance of the heat pump system.

Low- and medium-temperature thermal sources have the potential to reduce reliance on pollutant energy carriers such as fossil fuels. Among the most promising sources globally are solar thermal, geothermal, and residual heat. Organic Rankine Cycles (ORCs) are systems capable of harnessing these resources to produce electricity efficiently. The method by which heat is transferred from the thermal source to the working fluid plays a crucial role in ORC performance. This study evaluates several thermal oils as intermediate heat transfer media between the thermal source and the working fluid, aiming to support their selection based on key performance indicators. The parameters assessed include thermal and exergetic efficiencies, as well as mass and volumetric flow rates of both the working fluid and the thermal oil. Results indicate that incorporating a thermal oil significantly enhances the exergetic efficiency of the ORC system.