Feed water temperature and gas boiler thermal efficiency
For the gas fired boiler,in addition to pay attention to safety operation,we also need to improve the thermal efficiency of gas-fired boiler.The feed water temperature is the temperature of the water entering the gas boiler,in this paper,we will analyze the impact of feed water temperature on gas fired boiler thermal efficiency.
The same amount of fuel:when the feed water temperature increases,the temperature and pressure of economizer reduces,the economizer outlet flue gas temperature rises,the preheater heat absorption capacity increases,the exhaust temperature increases,the boiler thermal efficiency is lowered.Because the hot blast temperature rises,the furnace temperature rises,the heat absorption capacity of water wall increases.After the increase of feed water temperature,the heat used to improve the water temperature decreases,while the heat used for evaporation increases,so when the feed water temperature increases,if the fuel amount is the same,the evaporation increases,but the boiler thermal efficiency is lowered,therefore,if you want to improve the gas boiler thermal efficiency,the feed water temperature should be reduced.
Evaporation remains the same: when the feed temperature rises, the heat absorption capacity of economizer decreases,for the heat transfer temperature difference is reduced,the flue gas temperature increases,the temperature and pressure of air preheater increase,the capacity of heat transmission increases,hot air temperature increases slightly,the exhaust temperature rises,which lowers the boiler efficiency.But after the feed water temperature increase,the heat used for evaporation increases,the evaporation increases.In order to maintain the constant evaporation,the amount of fuel must be reduced, which reduces the exhaust temperature,and the boiler thermal efficiency is improved.
So in the different conditions,the influence of feed water temperature on gas boiler thermal...