Experimental study on condensation heat transfer of exhaust gas in plastic heat exchanger

The condensation heat transfer of exhaust gas with 15%-20% vapor concentration was studied experimentally. The surface of heat exchanger is made of PTFE (politetrafluorotilene) which can withstand temperature up to 260 degrees C and overcome acid-corrosion problem when gas temperature is below dew-point temperature for high sulfur fuel such as coal or oil. The condensing phenomena and dew-point temperature were discussed. The experimental results of heat transfer with and without condensation were given and compared. In the experimental field, the convection heat transfer coefficient with vapor condensing is about 2 times as great as that without condensing phenomenon. The heat transfer of single-phase can not be neglected in flue gas condensation. The experimental results are in good agreement with film model. The sulphur oxides in the flue gas were scrubbed during condensing process.