Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.
One of the problems of natural gas pressure reduction stations (City Gate Stations; CGS) is blocking the gas passage due to reduction of temperature in the regulator. In order to prevent this problem, gas is heated in a gas heater before pressure dropping. The gas heater includes, gas passage pipes, intermediate fluid and hot fluid passage pipes. Hot fluid is combustion products of an atmospheric burner and has high thermal energy. Since
utilizing of porous media technology has many advantages in combustion systems, the idea of applying this type of burners instead of conventional burners has been widely considered. In this study, replacing of an atmospheric burner with a porous burner in the gas heater of a CGS has been studied numerically. First, by modelling the gas heater with an atmospheric burner, the values of produced heat fluxes at the different equivalence ratios have been studied. The results of these simulations determine the condition which leads to maximum efficiency of combustion in the atmospheric burner. The results indicate that maximum thermal efficiency of the atmospheric burner is obtained in 60 percent of the primary air. In the next step, by modelling the gas heater with a porous burner at various sizes and various equivalence ratios, produced heat fluxes were calculated and compared with those of the atmospheric burner. According to the results, although the gas heater of the pressure reduction station has not been designed for a porous burner, but utilizing a porous burner instead of the atmospheric burner, causes the thermal performance of the heater to increase. The increase of thennal performance at lean equivalence ratios is higher.