What does the thermal efficiency of a heating furnace relate to?

In order to improve the thermal efficiency of the heating furnace and save energy, methods such as preheating the air entering the furnace, reducing the temperature of the flue gas, and controlling the excess air coefficient have been adopted. Generally, heating furnace control uses flue gas as a heating carrier to preheat the air entering the furnace. By controlling the furnace pressure to normal, the thermal efficiency is ensured and the safe operation of the heating furnace is ensured.

The heat balance formula of the heating furnace (each furnace may use different ones, but the conclusion is the same): Qy=Q-q2-q3-q4 Qy: The effective heat Q absorbed by the charge billet in the furnace: Total fuel heat entering the furnace q2: Heat loss from chemical incomplete combustionq3: Exhaust heat loss q4: It can be seen that the heat dissipation loss of the furnace body needs to improve the thermal efficiency of the heating furnace, mainly to reduce q2, q3, q4 ； q2: The main purpose is to improve the combustion efficiency of the burner and reduce incomplete chemical losses q3: 1. The pressure inside the furnace should be well controlled and the amount of cold air sucked in through the furnace door and fire viewing holes should be reduced as much as possible. ； 2. Install a waste heat recovery device on the flue to further reduce exhaust heat loss ； 3. Reasonably reduce the excess air coefficient and further reduce the amount of flue gas ； q4: Use advanced refractory thermal insulation materials to focus on solving the heat loss at the furnace door and reduce the heat loss of the heating furnace as a whole.

Exhaust smoke temperature, furnace wall temperature (furnace body heat dissipation loss), excess air coefficient

Using flue gas circulation is also a good way to improve efficiency! !