Investigation of a Heat Pipe Heat Exchanger Integrated with a Water Spray for the Heat Recovery from Boil Exhaust Gas.

This paper presents a thermodynamic analysis and a numerical simulation of a heat pipe heat exchanger which recovers both sensible and latent heat from the exhaust gases of boiler with a temperature range from 450K to 600K. Compared with the conventional methods of preventing corrosion by avoiding acid dew point or using the anticorrosive material, a water spray is proposed in this work as an innovation to integrate with the heat pipe heat exchanger, which absorbs the corrosive gas such as SO 2 , SO 3 and NO x from the outlet of boiler. The comprehensive theoretical study has shown the convective heat transfer coefficient under wet condition is 1.5-3 times higher than that of dry condition and the optimal location of the water spray in the system has been identified. Meanwhile a the heat and mass transfer in a thirty-row heat pipe heat exchanger with different locations of a water spray has been established by the FLUENT to analyze the flow field and temperature gradient of the heat pipe heat exchanger. The overall analysis has proven that system efficiency of the boiler and the lifetime of heat exchanger can be effectively enhanced with the application of the water spray. [ABSTRACT FROM AUTHOR]