For users who need to purchase hot water boilers, there are two main concerns: the purchase cost of boilers and how to operate safely and stably.Zhengzhou fang fast boiler plant on the 3 tons of gas hot water boiler as an example, for everyone to answer these two questions.
At present, the purchase cost of 1 ton gas hot water boiler on the market ranges from 80,000-160,000 yuan. The specific purchase price mainly depends on the boiler body and the configuration of auxiliary machines. If the boiler body has high operation efficiency and good quality of auxiliary machines, the purchase cost will naturally rise to a certain extent.
And how to ensure the safe and stable operation of gas hot water boiler?Mainly through the following aspects to achieve.
In order to stable combustion, if the volatilization of fuel, calorific reduction, must increase the excess air coefficient, the boiler furnace flue gas temperature is bound to reduce, the evaporation of water wall decreases, from the radiation heat transfer formula of the furnace, the furnace flue gas temperature reduction on the radiation heat transfer is a power of 4 relationship.
In order to maintain the evaporation capacity of the boiler, should be in the same air-fuel ratio increase in fuel and air, flue gas flow rate increases, the flow area because the flue is changeless, superheater in which part of the flue gas velocity will increase, according to the steady-state criterion equations of forced convection, the increase of the flue gas velocity in the convective heat transfer coefficient of flue gas side effects of the NTH power of flue gas flow rate, n = 0.6 to 0.65.
To sum up, the decrease of volatile matter and calorific value of fuel more reduces the radiant heat transfer of furnace, but less increases the convective heat transfer of superheater, that is, the heat absorption ratio of water wall decreases, and the heat absorption ratio of superheater increases.
If the calorific value of the fuel is lower than the design amount, the burnout time will be extended, the excess air coefficient is greater than the design value, the theoretical combustion temperature will be reduced, the flue gas temperature in the furnace will also be reduced, so that less ash will melt and evaporate, and the pollution degree of the water wall will be reduced, and the pollution coefficient will be increased.On the contrary, the pollution coefficient decreases.