Heat loss of the furnace body
Generally, the surface temperature of the furnace body should not be higher than the ambient air temperature by 50°C. When the gas boiler is in operation, the surface temperature of the furnace wall, steel frame, pipes and other accessories is higher than the surrounding temperature, and the surface of the furnace body is radiating heat outward at this time. The greater the surface area of the furnace body, the worse the heat preservation performance, and the greater the heat dissipation.
To solve this situation, more effective insulation materials are usually used outside the furnace to reduce heat loss.
Mechanical incomplete combustion heat loss
The mechanical incomplete combustion heat loss of gas boilers is a major heat loss of gas boilers.
The ash discharged from the gas boiler that burns solid fuel and the fly ash carried with the flue gas contain unburned fuel particles and charcoal. The heat stored in these unburned solid combustibles is called the mechanical incomplete combustion heat loss of the gas boiler.
This is also the case with gas boilers. For example, the combustion in the fuel burner is not sufficient, and the exhaust gas is discharged to cause waste.
In order to solve this problem, block clean boilers usually adopt full premixed combustion methods to improve combustion efficiency to reduce losses.
Other heat loss
When burning solid fuels, the heat loss caused by removing the ash which still has a relatively high temperature from the gas boiler is called the ash physical heat loss.
The other heat loss of the gas boiler refers to the cooling heat loss of the physical heat loss taken away by the ash and slag. Some parts of the gas boiler absorb the heat of the flue gas on one side, and are cooled by water or air on the other side. The heat taken away by water or air cannot be sent back to the gas boiler system for application, which causes the cooling heat loss of the gas boiler.
In order to solve this problem, the square clean boiler mostly adopts condensation technology to recover and reuse the waste heat in the exhaust gas.
The three heat losses are related to the amount of excess air. If the excess air coefficient is too large, the exhaust heat loss will increase, but the chemical incomplete combustion heat loss and mechanical incomplete combustion loss will be reduced accordingly.
On the contrary, if the excess air coefficient is reduced, the heat loss of exhaust gas is reduced, but the heat loss of chemical incomplete combustion and the loss of mechanical incomplete heat report increase.
Therefore, the excess air ratio when the sum of q2, q3 and q4 of the gas boiler is made smaller is the preferable excess air ratio.
