Calculation of flue gas heating with coke oven gas

Thread Content

This post was last edited by yggswl on 2016-4-20 at 20:02. It is known that the volume of flue gas is 10,000 cubic meters, with a specific heat capacity of approximately 0.32 kilocalories per cubic meter·°C. Coke oven gas is to be used to heat the flue gas from 200 degrees to 300 degrees; it is necessary to determine how much gas will be required And what is the total amount of flue gas after mixing? (The low calorific value of gas is taken as 4000 kcal per standard cubic meter.) 1. If calculated solely based on the calorific value: the heat required to raise the temperature of the flue gases is 10000*0.32*100 = 320,000 kcal; 320,000/4000 = 80 standard cubic meters of coke oven gas. It seems unreasonable to do it this way. Since there is an air excess factor in the combustion of coke oven gas, this heat value of 4000 kcal can only represent the heat released by the flue gases resulting from the complete combustion of the gas and air in a fixed ratio. Then, for the excess air due to this air excess factor, does it not mean that the temperature needs to be raised from 20 degrees to 300 degrees? This should consume some of the heat, right? How exactly should this be calculated? (Assuming the data provided earlier are correct) 2. The total amount of flue gas should be the amount of flue gas generated by the combustion of gas, calculated based on the actual excess factor, plus the original amount of 10,000 units of flue gas – in other words, the sum of these two amounts. What is a suitable value for the air excess factor under these operating conditions?