What is the difference between the positive and negative pressure of the boiler?

Boilers operating under positive pressure have high requirements on the tightness of the whole unit and equipment, and usually have sealed fans.

The advantage is that the air leakage rate of the system is relatively small, which is beneficial to the combustion stability and economy of the boiler, while the disadvantage is that the equipment investment is relatively large, and the reliability requirement are relatively high. In addition, the operation condition at the site may not be very good. Positive pressure system is more complex.

Boilers operating under negative pressure, under normal circumstances, the whole system and boiler furnace maintain a certain negative pressure. The auxiliary machine has relatively large power and large air leakage, which has a certain impact on the cost and thermal efficiency.