Combustion And Thermal Characteristics Research Of The Civilian Gas Stove In High Altitude Region

As the widely using of natural gas and the developing of West-East Gas Project,natural gas construction has extended to remote areas of our country. Tibet’s first gasstation has been built successfully on October26,2011in Lhasa, Natural gas use moreand more in Lhasa. Lhasa has special geographical environment because of being in theTibet Plateau, special geographical environment, and our country barely research andproduce the gas appliances for high altitude in the past. The stove which design for theplain environment usually appears heat load reduction, high levels of CO in the flue gasand other problem when work in Lhasa. This topic expect to find out detail effects in thehigh altitude environment through experiment and calculation, And for the stove by theproblems, propose several simple suggestions for improvement, improvement ofworking conditions stove in Lhasa.,and propose several simple reform suggestions toimprove performance of the stove in Lhasa.By the comparative tests with the same civil embedded stove in Lhasa andChongqing, we found when ordinary cooking stove run at the same pressure in Lhasa,the traffic flow rate of the stove is increased, measured thermal load is reduced, levelsof CO in the flue gas is higher, flame temperature is lower, NOxcontent is reduced, flowvelocity of the gas-air mixture through fire hole is reduced, the yellow flame is moreand so on. The reason of these problems are the reduction of gas density which is leadedto the reduction of atmospheric pressure in Lhasa, when the density of gas reduce, thenozzle gas velocity increase, traffic flow rate increase, but mess flow rate reduce, thatlead to a series of problems.For the problems appears in Lhasa, we propose four suggestion to reform the stove:increasing the gas pressure before stove, expanding the diameter of the nozzle,increasing the fire hole diameter, increasing the height of the pot stand. These fourmethods were used to reforming the stove, and test the thermal performance and flamestability of the stove according to experiment. Studies have shown that increasing thepressure or expanding the diameter of the nozzle can enhance the stove heat loadeffectively, but at the same time, they will result in increased levels of CO in the fluegas. Notably, the expanding in diameter of the nozzle will results the change of ejectors’critical section, which will change the primary air factor of stove, flame situation willfurther deteriorate, combustion flame length stretched and prone more CO. Increasing fire hole diameter can reduce the velocity of the gas through fire hole to offset the effectdue to the reduced atmospheric, keep the stability of flame, and improve the degree ofcombustion. Increasing the pot stand height appropriately can reduce CO content in fluegas usefully. Finally, to increased pressure before the stove from2000Pa to3000Pa,expand fire-hole total area from705.42mm2to736.86mm2, Enhance the distance offire hole to pot bottle from35mm to41mm, thus make the stove is qualified in Lhasa.