Tube bundle: a bundle of convection heating surfaces composed of parallel tubes F between the same inlet header and outlet header (or boiler).

　　Spirally- wound tubes horizontally surrounding the tube ring: a water-cooled wall tube screen with a horizontal or slightly oblique spiral J-2 liters along the circumference of the furnace.

　　Ribbon panel: multi-stroke horizontal or vertical circuitous water wall panel.

　　Up flow riser tube panel: a water wall tube panel in which the working medium rises vertically for one or more times.

　　Tube panel: a screen-like heating surface composed of parallel pipes between the same inlet header and outlet header (or drum).

　　Header: a cylindrical pressure vessel used to collect or distribute multiple pipes in medium-sized materials.

　　End cover Head: the sealing part of the header.

　　Head: the seal of the drum or shell.

　　Simplified cylindrical shell: the cylindrical part of a drum, shell or header.

　　Pressure part: a part that bears the pressure of internal or external media.

　　Pressure part: a part that bears the pressure of internal or external media.

　　Convection heating surface: a heating surface that mainly absorbs heat from exothermic media by convection heat transfer.

　　Radiant heating surface: a heating surface that mainly absorbs heat from a hot medium by radiation heat exchange.

　　Heating surface: the surface that absorbs heat from the exothermic medium and transfers it to the heated medium.

　　Boiler proper: It is composed of boiler drum, heating surface and their connecting pipes (including flue and air duct), combustion equipment, framework (including platform and escalator) furnace wall and slag removal equipment.

　　Indirect leakage bypass leakage entrained leakage: In the rotary air preheater, the rotor or hood brings air into the flue gas when rotating.

　　Direct leakage leakage leakage: In rotary air preheater, due to the static pressure difference between air and flue gas, air flows to the flue gas side through the sealing gap.

　　Rotating cup atomization; Rotary- cup atomization: oil is atomized by centrifugal force when it is thrown out by high-speed rotation.

　　Twin-fluid atomization: the oil is atomized by the impact force of steam or compressed air, including steam atomization and air atomization.

　　Pressure atomization; Mechanical atomization pressure atomization mechanical atomization: oil is atomized by turbulent pulsation and air shielding force when oil is ejected under pressure.

　　Sectional air supply zone control: it is an air supply mode that divides the air chamber under the mechanical grate into several sections and adjusts them according to the amount of combustion air required by each section along the length of the grate.

　　Negative pressure ventilation induced draft: a ventilation mode that uses induced draft fan pressure head to overcome the resistance of flue to keep negative pressure in the furnace.

　　Positive pressure ventilation forced draft: a ventilation method that overcomes the resistance of flue gas duct with blower head to keep positive pressure in the furnace.

　　Balanced draft: a ventilation method that uses the pressure head of blower to overcome the resistance of air duct and the pressure head of induced draft fan to overcome the resistance of flue to keep negative pressure in the furnace.

　　Mechanical draft: a ventilation method that relies on the pressure head generated by mechanical methods to overcome the resistance of flue gas duct.

　　Natural draft: a ventilation method that relies on self-generated ventilation head to overcome the resistance of flue.

　　Gas recirculation: a part of low-temperature flue gas is extracted from the flue of economizer or other places and sent to the furnace, so as to change the distribution ratio of heat absorbed by radiation and convection heating surfaces or reduce the temperature of flue gas at the outlet of the furnace for steam temperature adjustment or preventing slagging.

　　Fluidized- bed combustion: a way of burning fuel in fluidized state on a fluidized bed under the action of appropriate air velocity.

　　Cyclone- furnace firing: Fuel and air rotate at high speed in a high-temperature cyclone cylinder, and some fuel particles are thrown to the liquid slag film on the cylinder wall for combustion.