The waste-heat recovery system of flue gas comprised of the absorption heat pump and the flue-gas spray tower could effectively collect a large amount of latent heat contained in the exhausted gas from coal-fired combined heat and power plant（CHP）. The flue-gas spray tower is an important component for this system. In this paper, experimental and theoretical investigations are conducted to analyze the thermodynamic process inside the flue-gas spray tower. A one-dimension model for the parallel-flow spray tower has been developed, taking into account the effect of droplet movement on the heat and mass transfer. The droplet sizes are measured and are adopted in the simulation. The simulation results are in accordance with experimental data and the maximum error is 4.3%, which illustrates the one-dimension model could be used to predict the behavior of the flue-gas spray tower. The effects of liquid-gas ratio, droplet size, tower height and gas velocity on flue-gas spray tower are also examined.
Journal of Engineering Thermophysics
waste heat recovery
parallel-flow flue-gas spray tower