THERMODYNAMIC ANALYSIS FOR PROSPECTIVE APPLICATION OF THREE-STAGE CASCADE HEAT PUMP AT HIGH TEMPERATURES

• Main Author: Paul Alfredo Purba, Rado
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/76267
• Institution: Institut Teknologi Bandung

Vapor compression-type heat pumps are increasingly in demand as heaters because they have higher performance than gas, oil, or electric heaters. Existing compression heat pumps are used to heat water to a temperature of less than 80?. Heating temperatures in various process industries usually require more than 100?. This heat pump uses a working fluid (refrigerant) which may harm the environment. For this reason, a system that can reach high temperatures with high performance and uses environmentally friendly refrigerants is needed. One development that can be made is the implementation of a cascade system. Therefore, this study analyzes the thermodynamics and environmental aspects of a three-stage heat pump system with temperatures up to 150ºC. This research begins with calculating the ideal Carnot refrigeration cycle for each stage. The study parameters include condensation temperature for each stage, global warming and ozone depletion potential, performance, and refrigerant safety class. Performance calculation of the vapor compression cycle uses the condensing temperature with the appropriate refrigerant for each stage. Refrigerant pairs obtained are then compared to each other based on performance, impact on the environment, and risk of use. The simulation shows the highest performance using methyl oleate, cyclopentane, and water can achieve performance of 2.07. The multi criteria analysis (thermodynamic, environmental, and safety) can achieve performance of 2.04. In the selection of refrigerants, refrigerants that are safe to use are still unable to achieve higher performance than dangerous refrigerants.