Experimental and theoretical investigation of regenerative total heat exchanger with periodic flow for air-conditioning systems

This study experimentally investigates the theoretical performance of the periodic total heat exchanger. The total heat exchanger has a double flow-circuit heat exchange function for periodic positive- and reverse-directional pumping. The operating period parameters are 2 minutes, 3 minutes, 4 minutes, 6 minutes, and 8 minutes. Under the temperature and humidity ratio differences, 10 °C and 4 g kg−1, the operating period of 3 min results in optimal performance of sensible heat effectiveness, latent heat effectiveness, and total heat effectiveness. This study also proposes the lumped system, with dimensionless analysis assumption applied to the whole, and solves it in a one-dimensional model involving the heat and mass transport equations. The dimensionless operating period dominates latent heat effectiveness, while the latent heat effectiveness decreases when the dimensionless operating period increases.