Effect of air to air fixed plate enthalpy energy recovery heat exchanger flow profile on air conditioning system energy recovery

摘要

Fixed plate enthalpy heat exchanger which utilizes permeable material as heat and moisture transfer surface has been used as an energy recovery system to recover sensible and latent heat in HVAC systems. The heat exchanger effectiveness is affected by the air flow profile. It is well known that counter flow configuration provides highest effectiveness, however, in real applications, it is not possible to implement a counter flow configuration, as both inlet and outlet ducts of the two flow streams are located on the same side of the heat exchanger. Therefore, several quasi-counter-flow heat exchanger designs including Z-shaped, L-shaped, Z-shaped opposite flow configurations are proposed in this research and their effect on energy consumed by an air conditioning cooling coil has been investigated, where each of the proposed heat exchanger is incorporated in an air conditioning cooling coil model. The modeled cooling coil energy consumption and energy recovered by the heat exchangers are evaluated under Kuala Lumpur weather conditions. It has been found that an air conditioner coupled with L-shaped heat exchanger recorded up to 20% increase in energy recovery in comparison with Z-shaped opposite and Zshaped heat exchanger.