Análises termodinâmica, ambiental e econômica de uma bomba de calor para secagem de alimentos

Abstract

Most foods are thermosensitive materials that suffer modifications in physical and chemical qualities when submitted to high temperatures. It is necessary to control drying conditions to obtain a final product with high quality as well as utilize systems with low consumption of energy, high coefficient of performance and thermal efficiency, and based on clean energy sources. A heat pump promotes dehumidification and heating of air by transferring the available energy in exhaust gases to the drying/input air. Low humidity air is obtained, guaranteeing the quality of dried food products for longer periods of time. Recently, solar energy has been incorporated to heat pumps to improve thermal efficiency and reduce the environmental impacts associated with its operation. This MSc. thesis carried out a detailed literature review on heat pumps assisted by solar energy, and developed thermodynamic, economic and environmental analyses for an experimental setup located at the Center of Alternative and Renewable Energy of the Federal University of Paraíba. The thermodynamic analysis was modeled within the Engineering Equation Solver (EES) platform, allowing for the quantification of heat and mass flows of the system as well as the determination of performance coefficients. The economic and environmental analyses studied the effects of incorporating solar panels for the production of electricity, in comparison to the traditional electricity supply (electric grid). Economic investment analysis utilized the Internal Rate of Return (IRR), Net Present value (NPV), and Payback time to verify the economic viability of the system within the established scenario. The environmental analysis was developed through the application of the Life Cycle Assessment (LCA) methodology, and determined the carbon footprint. It was verified that there is potential for mitigating climate change with the incorporation of solar photovoltaic energy to the heat pump.