Introduction to the medium-temperature superheater: The medium-temperature superheater is arranged on the front and rear walls of the upper part of the combustion chamber, perpendicular to the front and rear walls. There are 8 panels on each of the front and rear walls. Each medium-temperature superheater screen is composed of 37 tubes. The diameter is Φ51×7mm, and the material is 12Cr1MoVG and SA-213T91. The medium temperature superheater is a membrane tube screen with a pitch of 70mm and a fin material of 12Cr1MoV?. The lower surface of the medium temperature superheater is covered with wear-resistant castable. The entrance collection box is Φ406×57mm, the entrance header of each screen is Φ219×28mm, the outlet header is Φ219×28mm, and the header material is 12Cr1MoVG. Steam temperature adjustment method: The superheated steam temperature is adjusted using two-stage water spray desuperheaters, which are located on the pipes between the low-temperature superheater and the screen superheater, and on the pipes between the screen superheater and the high-temperature superheater. The water source for spraying water comes from the outlet of the feed water pump and before the high-temperature heating. The desuperheater adopts a flute-shaped tube type. (Three-stage water-reducing warm water was added to boiler #1 during maintenance A in 2012.) Under the designed coal type B-MCR working condition, the water injection volume of the first-stage desuperheater is 20.16 tons/hour, which reduces the steam temperature from 378°C. to 371°C, the water spray volume of the II-stage desuperheater is 13.32 tons/hour, reducing the steam temperature from 475°C to 462°C. ?3. Over-temperature situation: Over-temperature regulations: 520℃ below the pipe wall is overtemperature; 510℃ above the I pipe wall is overtemperature; 550℃ above the II pipe wall is overtemperature; 530℃ below the pipe wall is Overtemperature; 610℃ above the pipe wall is overtemperature; 565℃ above the pipe wall is overtemperature. Under abnormal operating conditions of the unit or during the start-up process of the unit, over-temperature may easily occur if the pipe wall passes through. Main over-temperature period: When the unit is started in cold state, the turbine rushes, the generator is connected to the grid, and after the grid is connected, the load is between 50MW and 130MW, including when the water supply bypass is cut from the main road, the medium-temperature superheater tube wall overtemperature occurs . When the unit operates with a single primary fan or a single induced draft fan, and the load is below 120MW, the medium-temperature superheater tube wall overheats. ?