Environmental impact and cost allocations for a dual product heat pump

Fair and reasonable cost allocation among the consumers of different energy services of a multiproduct system can contribute positively to wider acceptance of energy efficiency strategies and reduction of pollutant emissions. Cost allocation can be carried out by the application of thermoeconomic methodologies, which can unravel the cost formation process in complex energy systems. This work applies the UFS (Internal Energy - Flow Work - Entropy) thermoeconomic methodology to allocate costs and environmental impacts in a heat pump utilized for food dehydration and water production. The UFS method evaluates the main components of the heat pump individually, including the expansion valve. Exergy analysis is carried out to identify the components with highest exergy destruction. Economic analysis is carried out for monetary cost evaluation and Life Cycle Assessment calculated the carbon emissions associated with the products of the heat pump. Results revealed that the evaporator and condenser devices are responsible for more than half of the overall exergy destroyed and the overall system presented 1.07% exergy efficiency. The UFS method revealed that the cost of the system (US$ 698.2/month) and carbon emissions (151.5 kg CO2-eq/month) should be allocated to the food dehydration and water production processes in a proportion of 51% and 49%, respectively.