Abstract—In Indian Coal mines, underground mines, mineral ore mines syngases at high pressure and high temperature are found in large quantities. This syngas is highly toxic, harmful and flammable gases which are present in atmosphere. It may cause many accidents. Hence it is necessary to reduce the content of syngas from mines in the atmosphere. This paper describes convective heat transfer characteristics of high pressure gas in mines. Heat transfer in convection cooling section of pressurized coal gasifier with the membrane helical coils and membrane serpentine tubes under high pressure is experimentally investigated. High pressure single gas (He or N2) and their mixture (He + N2)gas serve as the test media in the test pressure range from 2.5 Kg/cm2 to 10 Kg/cm2. The results shows that the convection heat transfer coefficient of high pressure gas is influenced by the working pressure, gas composition and symmetry of flow around the coil, of which the working pressure is the most significant factor. The average convection heat transfer coefficients for various gases in heat exchangers are systematically analyzed. The heat transfer coefficient of heat exchanger with membrane helical coils is greater than that of the membrane serpentine-tube heat exchanger under the same conditions. It is found that the heat transfer coefficient increment of the membrane helical-coil heat exchanger is greater than that of the membrane serpentine-tube heat exchanger with the increase of gas pressure and velocity.

 Index Terms—Membrane helical coil, High pressure gas, Convective heat transfer, Membrane serpentine tube

Cite: Sagar S Gaddamwar and Rupesh S Shelke, " Experimental Investigation of Heat Transfer Characteristics of High Pressure Gas in an Augmented Heat Exchanger," International Journal of Mechanical Engineering and Robotics Research, Vol. 2, No. 4, pp. 148-153, October 2013.