Experimental Investigations Of Combustion And Heat Transfer In Natural-stracking Porous Media

Porous Media Combustion known as one of the new combustion technology, has lot of strong points, such as high combustion efficiency, wide operation range, low pollution emissions and perfect stabilization. Porous media applied to the gas water heater can significantly reduce the consumption of the metal copper. In this background that our country is promoting clean energy. This paper lay stress on studying on some characteristics of the inter porous media in adiabatic and heat transfer conditions, such as temperature distribution, combustion wave transition, pollutant generation and so on. on the purpose of clean combustion of the gas.Porous media combustion is related to fluid flow, heat transfer and chemical reaction. In this paper, the formation mechanism of super adiabatic combustion and combustion wave and its influencing factors were analyzed theoretically; fluid flow parameters of porous media were calculated. On the basis of studying the principle of the pollutants generation." advance the methods of reducing pollutants generated.Porous media combustion and heat transfer bench were designed, the gas mixture cavity was made optimal design to ensure uniform mixing. Helical coiled heat exchanger device was embedded in packed bed of porous media, which has a higher efficiency than the water jacket heat exchanger device. Procedure is writing using King View combining data acquisition module and industrial control software:the system realized the automatic data acquisition and real time monitoring. The experimental acquisition system hardware was cany out testing on the accuracy and error analysis. Porous medium bummer combustion system was carrying out accuracy testing and error analysis. By changing some parameters such as porous medium sizc and its combinations, the gas load, equivalence ratio, the cooling water flow and so on. to complete the measurement of the temperature field, the combustion wave velocity, pollutant emissions and heat transfer efficiency in the heat insulation and heat transfer conditions.Carrying out the porous media adiabatic burning experiment, get the ideal start way of the porous medium burner by adjusting the equivalent ratio and changing the burning load. The laws of burning wave transfer were studied coming to the conclusion that the particle size of the porous medium is proportional to combustion wave velocity.The influence of the fire load, equivalence ratio and porous medium size combination to pollutants generation were studied experimentally, the greater of the equivalence ratio and the greater of the combustion intensity, the more the NOx emissions; The CO emissions first decrease then increase as the equivalence ratio increases. In different particle size combination conditions, The CO emissions is much higher than the NOx emissions, and the smaller the porosity the higher the CO emissions and the lower the NOX emissions.Porous media burning after adding the heat transfer equipment were studied experimentally, draw the temperature distribution of porous media for heat exchange. Porous medium temperature distribution under different porosity and efficiency of heat transfer under different combustion intensity and equivalence ratio were studied, the highest thermal efficiency is up to107%. The low of pollutant emissions in the heat exchanger state was studied, come to the conclusion that the higher the combustion intensity and the less the NOx. the greater the equivalence ratio and the greater the NOx.NOx generation is not only with the temperature of the combustion chamber, and also oxygen concentration and its residence time in porous media. The CO increases with the increase of the equivalence ratio, and the greater the fire load, the smaller the porosity of the porous medium, the higher the CO emissions.In this paper, some characters of porous media in adiabatic and heal transfer conditions were studied, such as temperature distribution, combustion wave transition, the regularity of pollutants generation, the efficiency of heat transfer etc. which provides a theoretical and experimental date support to development and utilization of gas water healer tor porous media.