Convegni ATI - Accesso riservato soci CTI

Autore: M.A. Abd El-Baky, M.M. Mohamed

Collana: BT - 34 - Mag 06 - Energy: production, distribution and conservation

Note:
The heat pipes heat exchangers are used in heat recovery applications to cool the incoming fresh air in air conditioning applications. Two streams of fresh and return air have been connected with heat pipes heat exchanger to investigate the thermal performance and effectiveness of heat recovery system. Ratios of mass flow rate between return and fresh air of 1, 1.5 and 2.3 have been adapted to validate the heat transfer and the temperature change of fresh air. Fresh air inlet temperature of 32 – 40°C has been controlled while the inlet return air temperature is kept constant at about 26°C. The results showed that the temperature changes of fresh and return air are increased with increasing the inlet temperature of fresh air. The effectiveness and heat transfer for both evaporator and condenser sections are also increased to about 48% when the inlet fresh air temperature is increased to 40°C. The effect of mass flow rate ratio on effectiveness is positive for evaporator side and negative for condenser side. The enthalpy ratio between the heat recovery and conventional air mixing is increased to about 85% with increasing fresh air inlet temperature. The optimum effectiveness of heat pipes heat exchanger is estimated and compared with the present experimental data. The results showed that the effectiveness is close to the optimum effectiveness at fresh air inlet temperature near the refrigerant operating temperature of heat pipes.