Source: Thermal Power Thermal Automation
1. The analog control system put into operation should be regularly disturbed test. The disturbance test is divided into internal disturbance test and external disturbance test. However, disturbance tests should also be carried out when the following conditions occur: (1) equipment overhaul, (2) control strategy change, (3) adjustment parameter change, (4) analog control system abnormality.
2. Test measures should be prepared before the test, and they can be implemented only after approval. After the end of the test, the test report should be filled. If the test results do not meet the specified control quality, the cause should be analyzed and the solution should be proposed.
1. Disturbance test measures of the fuel regulation system of the unit
1) The purpose of the test
(1) Improve the anti-disturbance ability of the fuel regulation system in the coal feeder and coal mill when the coal flow jams and other phenomena.
(2) Adjust the relevant parameters (such as proportional band, integration time, etc.) appropriately according to the test results to improve the quality of adjustment.
(3) Verify the safety and reliability of the control loop.
(4) Improve the professional quality of maintenance personnel and the adaptability of operation personnel.
2) Test conditions
(1) The feed water flow is adjusted appropriately and stably, and the electrical load is kept stable and unchanged.
(2) The furnace negative pressure adjustment system and the air supply adjustment system are in automatic state.
(3) Under stable working conditions, the main steam pressure should be kept within the range of O.2MPa of a given value.
(4) The milling system is running normally. The milling system will be partially run automatically. Adjust the coal feeder in the manual state to make the output of the automatic coal feeder about 40T, that is, to ensure that the automatic coal feeder has adjusted the upper and lower margins within the linear range.
(5) During the test, the operator should designate a special person to cooperate with the person in charge of thermal control work to carry out the operation test.
(6) The technician of the main control class, the thermal control supervisor of the equipment department, the thermal control supervisor of the maintenance department, and the furnace operation specialist of the power generation department will go to the site for supervision and guidance.
3) Record the main data during the test
The main data are: unit load; feed water flow; main steam pressure, modified parameter values (before and after modification); speed stage pressure; boiler directive; heat signal; coal feeder flow; set value, coal feeder command, cut coal feeder code, boiler master cut manual command.
4) Test steps
(1) Handle the fuel regulation system disturbance test work ticket.
(2) The operator adjusts the working conditions to keep the main parameters stable (load, main steam pressure, feed water flow).
(3) The main control team personnel open the password of the engineer station and enter the process engineer environment.
(4) Under the guidance of the person in charge of the test, the person in charge of the main control class shall check the upper and lower threshold values of the pressure deviation module, and increase the area force deviation value if necessary to meet the needs of the dynamic change of the pressure in front of the machine during the test process (within the allowable range of the test, the boiler main control cutting manual condition is avoided).
(5) The person in charge of the main control class calls up the real-time curve (the display range and time are appropriately set).
(6) The main control team personnel check whether all the I/O points that should be recorded have been stored in the historical database, and check the resolution threshold of the analog signal of the historical data station to avoid the step phenomenon of the analog signal in the retrospective memory.
(7) After the above work is completed, notify the operator to start the test.
(8) According to the need, stop (or put in) the operation of a powder feeder in the manual state in the automatic state, and observe the changes of the negative pressure of the furnace, the main steam pressure and the feed water flow on the CRT screen.
(9) During the test, if the maximum deviation of the pressure does not exceed the soil 0. In the case of 3MPa, it is forbidden to manually adjust the other powder feeders.
(10) From the beginning of the test, the conditioning system should eliminate the disturbance within 5 min and re-stabilize within the range of 0.2MPa of the given value.
(11) Do three tests in the same step, and take two basically the same curves as the test results.
(12) Conduct a comprehensive analysis of the test curve to determine the adjustment parameters of the adjustment system.
5) Security measures
(l) Strict work ticket system.
(2) Strictly implement test measures.
(3) The interval between the start and stop ratio of the milling system should not be less than 1min.
(4) During the test, if the safe operation of the unit is endangered, the operator will immediately withdraw from the test to ensure the safety of the unit!
(5) The operator should anticipate the accident and take preventive measures according to the test measures.
2. Change the main steam pressure fixed value disturbance test measures
1) The purpose of the test
(1) Improve the regulation ability of the fuel conditioning system when the set value changes.
(2) Appropriately adjust the relevant parameters according to the test results, such as proportional band, integration time, etc.), and improve the quality of adjustment.
(3) Verify the safety and reliability of the control loop.
(4) Improve the professional quality of maintenance personnel and the adaptability of operation personnel.
2) Test conditions
(l) The feed water flow rate is adjusted appropriately to keep the load stable and unchanged.
(2) The furnace negative pressure adjustment system and the air supply adjustment system are in automatic state.
(3) Under stable working conditions, the main steam pressure should be kept within the range of 0.2MPa of the given value.
(4) The milling system is running normally. The milling system will be partially run automatically. Adjust the coal feeder in the manual state to make the output of the automatic coal feeder about 40T, that is, to ensure that the automatic coal feeder has adjusted the upper and lower margins within the linear range.
(5) During the test, the operator should designate a special person to cooperate with the person in charge of thermal control work to carry out the operation test.
(6) The technician of the main control class, the thermal control supervisor of the equipment department, the thermal control supervisor of the maintenance department, and the furnace operation specialist of the power generation department will go to the site for supervision and guidance.
3) Record the main data during the test
The main data are: load, feed water flow, main steam pressure, speed stage pressure, boiler directive, heat signal: coal feeder flow, set value, coal feeder command: boiler master control manual command, modified parameter values (before and after modification).
4) Test steps
(1) Handle the work ticket for the disturbance test of the main steam pressure regulation system of the unit.
(2) The operator adjusts the working conditions to keep the main parameters stable (load, main steam pressure, feed water flow).
(3) The main control team personnel open the password of the engineer station and enter the process engineer environment.
(4) Under the guidance of the person in charge of the test, the person in charge of the main control class shall check the upper and lower threshold values of the pressure deviation module, and increase the pressure deviation value if necessary to meet the needs of dynamic changes in the pressure in front of the machine during the test (to avoid the manual condition of the boiler main control cutting within the allowable range of the test).
(5) The person in charge of the main control class calls up the real-time curve (the display range and time are appropriately set).
(6) The main control team personnel check whether all the I/O points that should be recorded have been stored in the historical database, and check the threshold of the resolution of the analog signal of the historical data station to avoid the step phenomenon of the analog signal in retrospective.
(7) After the above work is completed, notify the operator to start the test.
(8) According to the needs of the fixed value step disturbance, the operator adjusts the pressure change rate to the appropriate value.
(9) According to the need, the operator will stabilize the main steam pressure at an appropriate value, and the fuel adjustment system will be automatic, and the temperature will be kept within the range of 0.2MPa of the given value in the automatic state.
(10) On the basis of the current set value, the operator will change the set value to O.3MPa (which can be divided into first decreasing O.3MPa for a test; then waiting for the system to be stable, increasing O.3MPa upwards for a second test), and observe the changes of furnace negative pressure, main steam pressure and main steam flow rate on the CRT screen.
(11) During the test, if the maximum deviation of the pressure does not exceed the soil O.3MPa, it is forbidden to manually adjust other equipment.
(12) From the beginning of the test, the conditioning system should eliminate the disturbance within 5min and re-stabilize within the range of the given value of O.2MPa.
(13) Do three tests in the same step, and take two basically the same curves as the test results.
(14) Conduct a comprehensive analysis of the test curve to determine the adjustment parameters of the adjustment system.
Note that during the test, if the safe operation of the unit is endangered, the operation personnel will immediately withdraw from the test to ensure the safety of the unit!
5) Security measures
(1) Strict work ticket system.
(2) Strictly implement test measures.
(3) During the test, if the safe operation of the unit is endangered, the operator will immediately withdraw from the test to ensure the safety of the unit!
(4) The operator should anticipate the accident and take preventive measures according to the test measures.