Individually Finned Heat Pipe Heat Exchanger for Air Conditioning with Freon R404A as Working Fluid by Localized Theoretical Analysis Using Thermal Efficiency Concept

This work contributes to the improvement of energy-saving in air conditioning system. The objective is to apply the thermal efficiency of heat exchangers for localized determination of the thermal performance of heat exchangers with individually finned heat pipes. The fundamental parameters used for performance analysis were the number of fins per heat pipe, the number of heat pipes, the inlet temperatures, and the flow rates of hot and cold fluids. The heat exchanger under analysis uses Freon 404A as a working fluid in an air conditioning system for cooling in the Evaporator and energy recovery in the Condenser. The theoretical model is localized and applied individually to the Evaporator, Condenser, and heat exchanger regions. The results obtained through the simulation are compared with experimental results that use a global approach for the heat exchanger. The thermal quantities obtained through the theoretical model in the mentioned regions are air velocity, Nusselt number, thermal effectiveness, heat transfer rate, and outlet temperature. The comparisons made with global experimental results are in excellent agreement, demonstrating that the localized theoretical approach developed is consistent and can be used as a comprehensive analysis tool for heat exchangers using heat pipes. The maximum absolute error for effectiveness is equal to 58.9%, and the minimum absolute error is equal to 2.2%. The maximum absolute error for heat transfer rate is equal to 41.4%, and the minimum absolute error is equal to 0.9%.