Industrial boilers 48 hours standard operation standard process

1. Subject content and scope of use 1.1. This standard specifies the basic contents and requirements for the 48-hour trial run of industrial boilers and hot water boilers.

1.2. This standard is applicable to the commissioning of fixed steam boilers and fixed pressure hot water boilers with a rated operating pressure of not more than 2.5Mpa with water as medium.

1.3. This standard does not apply to the commissioning of utility boilers, cast iron boilers, transport vehicles and boilers on ships, electric heating boilers and nuclear energy boilers.

2. Reference standard "Code for construction and acceptance of industrial boiler installation engineering" (GB50273-98)

"Steam boiler installation technology supervision regulations"

3. Process Contents 3.1. Conditions for Trial Operation 3.1.1. Before the boilers are commissioned, inspections for ovens, boilers, steam purging, steam tightness tests, and safety valve adjustments have been completed. Visas have been issued by the boiler inspection agency. .

3.1.2. Boiler auxiliary machinery and ancillary systems as well as fuel, water supply, dedusting, electricity systems and other sub-units are qualified for trial operation, which can meet the requirements of full-load boiler operation.

3.1.3. The thermal engineering, electrical and control devices required for the commissioning of the boiler have been installed, tested and adjusted according to the design. The instructions are correct and the operation is good.

3.1.4. The production unit has been ready for production, and the boiler workers and water treatment personnel have been specially trained and assessed, and they have issued licenses issued by the quality and technical supervision departments.

3.1.5. The chemical supervision work can be performed normally and the fuel used for trial operation has been analyzed.

3.1.6. Reserve sufficient qualified fuel.

3.1.7. The boiler operation procedures have been approved and have been on the wall.

3.2. Organizational division of labor 3.2.1. During the trial operation, the operation is performed by the owner (boiler use unit).

3.2.2. Boiler operation procedures are prepared by the owner (boiler use unit).

3.2.3. The installation unit is responsible for handling the installation defects and necessary inspections and repairs during the trial operation.

3.3. Test run steps and requirements 3.3.1. Open the furnace door, flue door, natural ventilation for 15 minutes.

3.3.2. Filling fuel and firelighters.

3.3.3. Water the boiler.

3.3.4. Ignition: During the firing process, the firepower should not be too large. In order to make the waterwall tube in the combustion chamber heated evenly and prevent thermal deviation, the header drain valve should be used 1 or 2 times to release high temperature water to make the temperature of the boiler water rise uniformly; open the superheater The steam trap on the outlet header cools the superheater and shuts off after normal steaming. After the fire rises, the water temperature rises and the volumetric expansion level will gradually increase. At this time, attention should be paid to monitoring the water level, and use water release to maintain the normal water level. The new boiler firing time is not less than 4 to 6 hours, and the short-term boiler shutdown should not be less than 2 to 4 hours.

3.3.5. Boost: When the boiler is boosted to 0.05~0.1Mpa, the flushing water level meter shall be flushed, and each shift shall not be less than once. When the pressure rises to 0.15～0.2Mpa, the air valve on the drum and the superheater collection box should be closed, and the pressure gauge pressure tube should be flushed; check the reliability of the pressure gauge, and pay attention to whether the two pressure gauges are consistent. When the pressure rises to 0.3-0.4Mpa, the connection bolts of valves, flanges, manholes, and hand holes in the boiler range shall be hot-tightened. The main valve is slightly opened to warm the main steam pipe.

3.3.6. The boiler water will evaporate during the start-up process, the water level will drop, and the boiler needs to be replenished in time. Because the combustion is not stable, the temperature of the feed water entering the steam drum through the economizer is low, and the large flow of feed water will suddenly cool the joint between the boiler feed pipe and the steam drum, adversely affecting the welding joint and the expansion joint, so the water supply should be small. Continuous water supply to ensure the safe operation of the boiler.

3.3.7. Once the boiler's combustion conditions have stabilized, it can gradually increase the pressure and increase the load. Boiler boost can not be too fast, because the pressure rises too fast, the steam temperature must rise quickly, and the drum wall is generally thicker, and the boiler wall temperature is not high, when the pressure rises, there will be a temperature difference between the inner and outer wall of the drum. The greater the temperature difference, the faster the boost pressure will give additional wall thermal stress to the drum wall.

For the steam boiler, the upper part of the upper drum is a steam space. After the fire is generated, the steam space is filled with steam due to the evaporation of the boiler water. Steam passes through the condensation to transfer heat to the upper wall of the drum, and the heat transfer method is transmitted. The thermal coefficient is much higher than the convective heat transfer coefficient of the pot water to the lower drum, so that there is a temperature difference between the upper and lower drum walls, and this temperature difference will also generate a huge thermal stress on the drum. The temperature difference is constantly changing during the rising process, and will decrease with the increase of the pressure, because with the increase of the pressure and the water temperature in the drum, the circulation speed of the boiler water increases, and the convective heat release coefficient of the boiler water to the drum wall is increased. Increased, and steam space vapor condensation coefficient of heat to the drum wall gradually decreased. Therefore, there is a maximum value of the upper and lower wall temperatures. Tests have shown that the boosting speed increases, and the maximum temperature difference occurs at higher pressures, which is unfavorable to the safety work of the drum. Therefore, it is necessary to limit the boosting speed at the time of starting, generally controlled at 0.59~0.78Mpa/h.

3.3.8. When the air temperature at the outlet of the air preheater is 120°C, cool air should be introduced. After the boiler is put into operation, the flue door to the economizer can only be opened and the bypass flue can be closed. No bypass flue should close the economizer circulation valve.

3.3.9. Adjust the working conditions of coal conveying, grate (spraying, fuel injection), blower, and slag removal equipment according to the design parameters of the boiler unit, and adjust the automatic control, signal system and instrument working status to meet the design requirements. In particular, adjust the boiler combustion conditions to eliminate the impact of the rated parameters.

3.4. Trial Run Inspection 3.4.1. When the boiler is in trial operation, the inspection of various parts of the boiler shall be strengthened. Attention shall be paid to the condition of the furnace wall under load. Water shall be promptly given, effluent and soot blown according to the operating instructions, and the operation records shall be carefully prepared.

3.4.2. Boiler test run acceptance inspection:

(1) Records of installation and construction of boilers, boiler room ancillary equipment and pipelines, quality assessment visa records, material certificates, and electrical and instrument installation and commissioning record reports;

(2) Whether the installation of boilers, boiler room auxiliary equipment and pipelines meet the design requirements, and whether the thermal equipment and pipeline insulation and corrosion protection are qualified;

(3) Whether the safety attachments of boilers and pressure vessels are installed correctly and reasonably, and whether the performance is reliable;

(4) Whether the electrical equipment of the boiler room is installed correctly and is safe and reliable; whether the automatic control, signal system and instrument are qualified for debugging are sensitive and reliable;

(5) Whether the installation quality of boiler expansion and expansion pipes and the installation of expansion indicators such as drums, superheaters, and economizers are correct;

(6) Operation of coal, combustion and slag removal systems;

(7) Furnace wall masonry quality;

(8) Whether there is any smoke leakage, running wind, cracking, etc. during the test run;

(9) Quality of water treatment and water supply equipment installation, check whether the quality of water supply and furnace water meets the national standards;

(10) Oven, boiler, steam tightness test and safety valve adjustment records, to understand whether the parameters of the boiler test run to meet the design requirements;

(11) Implementation and implementation of various provisions (such as lighting, safety evacuation, access, fire protection, and explosion protection) related to the safe operation of boilers.

3.5. Overall Acceptance After the 48-hour test run of the boiler unit, after the working parameters, soft drinks quality, combustion conditions, auxiliary engine systems and furnace walls meet the design requirements, Party A and Party B shall complete the transfer formalities and submit them to the construction unit for management and operation; After the overall acceptance, the construction unit will sort out the as-built data and technical documents, and submit them to the construction unit for safekeeping. As one of the certification documents for the construction unit to apply for the “Boiler Usage Registration Certificate” to the local labor department, it will be stored in the boiler file.