General Requirements for Fuel-Fired and Gas-Fired Boilers
Fuel-fired and gas-fired boilers should provide high thermal efficiency, reliable operation, a compact structure and a high level of automation. Proper design of the heating surfaces, pressure-bearing components, auxiliary equipment and safety protection systems is essential for safe and efficient boiler operation.
High Efficiency, Reliable Structure and Automated Operation
Fuel-fired and gas-fired boilers should combine efficient combustion, reasonable heat transfer design, reliable pressure-bearing structures and convenient operation. For small and medium-sized boilers, improving thermal efficiency mainly depends on reducing exhaust heat loss and optimizing the rear heating surfaces. The boiler should also have a compact and flexible structure, sufficient strength under rated working pressure, reliable water circulation and adequate cooling of all heating surfaces.
A complete boiler system should use properly matched auxiliary equipment, including feedwater pumps, fuel pumps, fuel heaters, forced-draft fans and other necessary components. For packaged boilers, the auxiliary equipment should be arranged to facilitate transportation, installation and operation.
At the same time, modern fuel-fired and gas-fired boilers should feature a high level of automation. A fully automatic combustion control system, together with multi-level safety protection, helps simplify operation and improve overall system reliability.
A 1.25 MPa steam boiler without an economizer may have an exhaust gas temperature of around 250°C.
Reliable structure: Pressure-bearing components should have sufficient strength and be able to accommodate thermal expansion and contraction during operation.
Safety protection: The system should include low-water, overpressure, over-temperature and flame-failure protection, as well as ignition sequence control, safety interlocks, leakage detection and audible, visual and electrical alarms.
