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Plan for boiler drying, heating up, and trial operation. Introduction: Once the installation of the boiler itself is complete, it enters the stage of drying and heating up, which means the boiler has reached the final stage of commissioning. To ensure the smooth commissioning of the boiler and maintain its operational quality in the future, this plan is formulated for reference during the commissioning process. At the same time, the construction unit and the installation unit, together with the boiler manufacturer and other collaborating parties, form a boiler commissioning and acceptance team to be responsible for the organizational leadership of the boiler’s startup, debugging, and trial operation. To ensure the consistent implementation of directives, clear definition of responsibilities for various tasks, as well as mutual cooperation and coordination, thereby guaranteeing the smooth progress of the startup and commissioning processes. Ensure the boiler is completed and put into operation on schedule, smoothly and to high quality. I. Oven Drying 1. Purpose of oven drying: Since the newly installed boiler has absorbed a large amount of moisture in the materials used for the oven walls as well as during their construction, when it comes into contact with high-temperature flue gases, the moisture contained in those walls evaporates rapidly due to the large temperature difference. This results in the generation of large amounts of steam, and the rapid expansion of this steam causes the oven walls to deform and crack. Therefore, before a newly installed boiler is put into formal operation, it is necessary to slowly dry the furnace walls so that the moisture within them can escape gradually, thereby ensuring the quality of the furnace walls’ performance under operational conditions. 2. Conditions required for furnace drying: 2.1 All boiler pipelines have been installed, and the hydrostatic test has passed. 2.2 The furnace wall construction and insulation work have been fully completed and have passed inspection. 2.3 The flue and air ducts have been installed, insulation work is complete, and the supply and exhaust fans have been installed and tested successfully, ready for operation. 2.4 All the thermal and electrical instruments required for furnace drying have been installed and verified to be in good working condition. 2.5 As required by regulations, mortar mixtures have been placed on both sides of the middle section of the superheater. 2.6 The firewood, diesel, coal required for furnace heating, as well as various tools (including those for inspection and on-site lighting) have all been prepared. 2.7 All facilities required for furnace drying shall be installed, and all other temporary facilities that are not related to furnace drying shall be removed, leaving the site clean. 2.8 The furnace heating personnel have all completed the required training, an attendance schedule has been established, and they arrive at their posts on time as specified. 3. Furnace drying process: (1) Based on the structural characteristics of this boiler, the flame drying method can be employed. ①Wood should be placed on the rack in the middle of the combustion chamber; once ignited, the flame should be kept in the center, and natural ventilation should be used to maintain a low intensity of burning. The combustion process lasts for 2 to 3 days, with the intensity of the fire gradually increasing over time. ②On the first day, the exhaust gas temperature at the furnace outlet should be below 50°C; thereafter, the temperature increase per day should not exceed 20°C. A correction for errors should be made for the final maximum temperature, which should be 0.5%. 1. The pressure difference between the operating pressure and the reset pressure for the safety valves of this boiler is as follows: Operating pressure: 1) Safety valve for the steam drum: 1.06*5.82=6.17; 2) Control safety valve for the steam drum: 1.04*5.82=6.05; 3) Superheater safety valve: 1.04*5.29=5.5. Reset pressure difference: The reset pressure difference for the safety valves is 4%–7% of the above operating pressures: 1) Safety valve for the steam drum: 0.247–0.432; 2) Control safety valve for the steam drum: 0.242–0.424; 3) Superheater safety valve: 0.22–0.385. 2. Preparatory work before adjusting the safety valves: 1) Before installation, the safety valves should be disassembled, cleaned, and inspected. 2) The locking device inside the safety valve should be removed before debugging. 3) The relevant supports for the safety valve, as well as the supports for the steam exhaust pipes, should be carefully inspected, and the electric valves used should be tested once. 4) All personnel responsible for adjustments should be familiar with the internal structure of safety valves and the safety measures for adjusting them, organize proper division of tasks, and take appropriate precautions to reduce noise. 3. Adjustment methods and steps: 1) For ease of adjustment, it is advisable to use a safety valve that does not need to be loaded, that is, it should be adjusted during the pressure-raising phase after pipe flushing. 2) Pressure boosting and inspection: After the pipe flushing is completed, the on-duty operator is required to conduct a thorough inspection of the boiler unit; once no abnormalities are detected, the equipment can be started. During the B boosting process, the boosting speed is strictly controlled and carried out in accordance with the operating procedures. C. When the pressure rises to 0.1 Mpa, close the air valve to flush the water level gauge once; when the pressure reaches 0.4 Mpa, carry out a complete drainage operation. When the pressure reaches 0.5 Mpa, flush the steam and water pipes again. When the pressure reaches 2.0 Mpa, it is necessary to conduct a thorough inspection of the boiler and all equipment to ensure there are no abnormalities before continuing to increase the pressure. When the pressure reaches 5.29 Mpa, a dedicated person must monitor the water level, flush the water level gauge once more and verify the readings, keeping records of these values. When the pressure reaches 5.8 Mpa, adjust the venting to the atmosphere, check whether the electric valves are functioning properly (by testing them), and then continue to increase the pressure. Switch the boiler’s steam output to venting to the atmosphere, adjust the air volume and coal feeding rate, and keep raising the steam pressure, taking into account the settings of the first safety valve on the steam drum. The second one adjusts the steam drum safety valve, and the third one adjusts the superheater safety valve. D. Operating pressure of the drum safety valve: 6.17 Mpa; the reset pressure difference is 0.247 Mpa – 0.432 Mpa. Once the safety valve activates, the coal supply should be reduced immediately, and steam should be vented to the atmosphere to relieve pressure. The reset pressure should be recorded to verify whether it meets the requirements. If it does not meet the requirements, or if the valve fails to activate even when the pressure reaches the maximum allowable value, the pressure must be reduced immediately, and the issue should be referred to the installation crew for inspection and adjustment, followed by re-testing. E. Then check the drum control safety valve. Operating pressure: 6.05 Mpa; reset pressure difference: 0.242 Mpa–0.424 Mpa. The superheater safety valve was recently checked, with an operating pressure of 5.5 Mpa and a reset pressure difference of 0.22 Mpa–0.385 Mpa. During the adjustment process, strict control is exercised over changes in steam temperature and water level; steam pressure can be regulated by adjusting the amount of steam discharged to the atmosphere. VII. 72-hour trial operation: After the boiler unit has been installed and undergone partial trials, it must go through a 72-hour full-scale trial operation. 1. Purpose of the trial run: (1) To evaluate the construction, design, and equipment under normal operating conditions; to check whether the equipment can achieve the specified output and whether its various performance parameters meet the requirements of the original design. It also allows for the assessment of the quality of boiler installation and manufacturing, as well as the operation of all auxiliary equipment – in particular, to determine whether there is any vibration in the rotating machinery or overheating in the bearings during operation. (2) Before the boiler is put into trial operation, a thermal adjustment test of the boiler should be conducted. (I) Adjustment tests: ① Adjustment of combustion conditions ； ②Check the quality of installation for any leaks of air or water. ③ Identify the reasons why the boiler’s rated steam parameters and evaporation capacity are not met. ④ Determine the boiler’s efficiency and obtain its technical and economic characteristics under optimal operating conditions. (II) Contents of the adjustment tests: (1) Tests on the aerodynamic field of the furnace in a cold state, as well as tests on the performance of fans and ducts. (2) Tests to detect leaks in the smoke exhaust ducts of the furnace. (3) Calibration of safety valves and tests on thermal efficiency. 2. Conditions that must be met before starting the boiler unit: Conditions at the site where testing is carried out: (1) The site should be relatively level, with proper facilities for fire protection, traffic flow, and pedestrian access. The floors of each level in the factory building should have a rough surface; it is preferable to use a proper flooring material. The test area should be clearly marked and demarcated, while hazardous areas should be enclosed with fences and warning signs. (2) All construction scaffolding in the trial operation area shall be removed, and the site shall be cleaned thoroughly to ensure safe operation. (3) Ladders, walkways, railings, and guard plates in the commissioning area shall be installed in accordance with the design before being put into formal use. (4) The drainage channels in the newly expanded area are unobstructed, and the channel covers and tunnel lids are all in place. (5) The commissioning site shall have sufficient regular lighting; emergency lighting must be operational, and adequate fire-fighting equipment shall be available. (6) The industrial, fire protection, and domestic water systems within the commissioning scope should be ready for normal use, and sufficient fire-fighting equipment should be available. (7) Each operational post should have formal communication facilities. 2. The equipment, pipes, valves, etc. in the following systems have been installed and insulated. (1) Pipelines within the boiler area, steam and water systems, drain systems, venting systems, chemical dosing systems, auxiliary steam systems, and sludge discharge systems. 3. The following equipment has passed the commissioning tests: (1) The primary and secondary fans, as well as the exhaust fan, have been adjusted to the required speed and meet the specifications. (2) The commissioning of the thermal measurement, control, and protection systems meets the requirements for ignition. 4. Organizational structure, staffing, and preparation of technical documents ； (1) The power plant shall, in accordance with the commissioning plan, assign operators and testers for various positions, and establish clear job responsibility systems. The operating personnel must be properly trained and capable of performing their duties as well as handling any faults that may arise. (2) The construction unit shall, in accordance with the requirements of the trial operation plan, provide sufficient facilities for maintenance and repair, and establish clear job responsibility systems. Maintenance personnel should be familiar with the performance of the equipment systems in their respective positions. It can also carry out maintenance work under unified command, preventing equipment and personal accidents as well as interruptions to the commissioning process. (3) The construction unit shall have ready the installation and acceptance certificates for the equipment systems involved in the trial operation, as well as the records of the partial trial operations. (4) Formulate measures for the adjusted commissioning plan; after being approved by the commissioning command, it should be printed out, and briefings and training sessions should be conducted accordingly. (5) The operating unit shall display at the commissioning site diagrams of the combustion system and thermal system that reflect the actual conditions; the commissioning unit shall post there the necessary charts related to commissioning, ignition, pressure increase, etc. 3. Inspections and preparations before starting the boiler unit: (1) Steam system: The main steam valve is closed after a switching test; the isolation valves and bypass valves are also closed (this applies before the 70-hour trial operation). (2) Feedwater system: The feedwater valves, feedwater bypass valves, and drain valves are closed, while the feedwater intermediate valve and the economizer inlet valve are open. (3) Desuperheating water system: The manual door of the desuperheater is open, while the electric door is closed. (4) Drainage system: The drain valves of each header, the continuous drainage valve, and the emergency drain valve are closed, while the main regular drainage valve and the primary continuous drainage valve are open. (5): All the drain valves before the main air valve of the hydrophobic system, as well as the drain valve behind the main air valve, shall be opened. (6) Steam and boiler water sampling doors, the drum dosing door is open, while the dosing valve is closed. (7) The valves of the furnace drum water level gauge are opened, the water inlet valve is opened, and the drain valve is closed. (8) Open the primary valves for all pressure gauges, and open the primary valves for all flow meters. (9) The air valve is opened (the feedwater air valve can be closed), and the exhaust air valve is opened. 2. Check all damper switches and ensure they are in the following positions. (1) The inlet damper of the induced draft fan was closed after a switch test, while the outlet damper was opened. (2) The inlet baffles of the primary and secondary fans were closed after switch testing, and the return air damper was closed as well. (3) The ash discharge door at the bottom of the cyclone chamber is closed, and the ash discharge door at the bottom of the combustion chamber is also closed. 3. Check that there is no coke residue or debris inside the combustion chamber, material bed, return conveyor, etc.: All manholes, inspection doors, coking removal doors, and explosion-proof doors are intact and tightly closed ； The ash discharge door operates smoothly and is in the closed position ； The ash discharge door operates smoothly and is in the closed position ； The ash drainage ditch is unobstructed ； All covers are in place. 4. Check that the dust collector is in good working condition. 5. Check that the lubricating oil for rotating machinery and bearings is clean ； Oil level is normal ； The cooling water flow is normal when it is turned on, and the foot screws and safety devices are secure. 6. Contact the relevant personnel and make the following preparations: (1) Water supply duty personnel: Fill the water supply pipes with water. (2) Thermal duty personnel: Bring various instruments and control devices into operation, and are responsible for replacing the heating thermocouples. (3) Fuel attendant: Loading coal into the raw coal hopper. (4) Chemical duty personnel: Test the quality of boiler water. (5) Electrical duty personnel: Supply power to electrical equipment. (6) Ensure an adequate supply of ignition materials; the particle size of the firing bituminous coal should be 10 mm, with a VR value of 25%, and a QDY value of greater than 5500 kcal/kg – such materials are considered suitable. Additionally, boiling slag is required, with a certain content of combustible substances