Thread Content
Commissioning Plan for the Turbine Safety Monitoring System of a Power Plant 1. System Overview and Equipment Specifications: The TSI system at Henan Huaneng xx Power Plant is designed to use BENTLY 3500 series safety monitoring instruments for turbine units, manufactured by the American company BENTLY. This system consists of instrument components, sensors, and pre-amplifiers; it is a reliable multi-channel monitoring system that can continuously measure various mechanical operating parameters of the turbine generator’s rotor and cylinders. It enables the monitoring of the turbine’s mechanical condition, and can issue alarm signals as well as trigger the shutdown of the unit when parameters exceed the set limits. This unit is equipped with the expert diagnosis system TDM, which is used for monitoring, diagnosing, and analyzing the operating condition of the turbine rotor. The system is modular, with each module equipped with a microprocessor that provides standard processing capabilities and can interface with computers. To ensure system security, this protection system is equipped with redundant power supply modules that are powered by two separate sources: one from an uninterruptible power supply and the other from a backup power source. These two power sources operate independently of each other, and an alarm is triggered in the event that either source fails, thereby ensuring the safety and reliability of the system. The design of the turbine monitoring system for the units in the first phase of Henan Huaneng XX Power Plant includes the following components: a) Turbine zero speed (2 sets), b) Turbine speed (3 sets), c) Phase detection (1 set), d) Eccentricity (1 set), e) Axial displacement (4 sets), f) Expansion difference of the high-pressure cylinder (2 sets), g) Expansion difference of the low-pressure cylinder (1 set), h) Absolute expansion of the left and right high-pressure cylinders (1 set each), i) Relative shaft vibration in the X direction for turbines 1–8 (1 set each), j) Relative shaft vibration in the Y direction for turbines 1–8 (1 set each), k) Absolute shaft vibration for turbines 1–8 (1 set each). The measurement circuit of TSI consists of probes, pre-amplifiers, and plug-in instrumentation. The working principle of the probe is based on the eddy current electromagnetic differential principle. 2 Preparatory work for debugging 2.1 Collect design drawings and equipment documentation. It mainly includes: the wiring diagrams and equipment layout diagrams of the TSI system, the logic diagrams and configuration diagrams of the TSI system, and the hardware manual for the TSI system. 2.2 Attend technical training on new control equipment and conduct research on new technologies and devices. 2.3 Go to the site to get familiar with thermal control equipment and thermal systems. 2.4 Prepare testing instruments and equipment. 3 Specific requirements of regulations and standards 3.1 Thermal protection devices shall undergo separate tests as well as full-system linkage tests; their operation must be accurate and reliable. 3.2 Sensors for axial displacement and expansion differences shall be subjected to full-system adjustment tests after the rotor is set to its zero position. 3.3 Absolute expansion measurement devices shall be inspected and adjusted when the turbine is at room temperature; the zero position shall be established, and the temperature at that time shall be recorded. 3.5 An analog signal shall be input at the signal generation end of the system to check the operation and logical functions of the audio, lighting, and protection devices, which shall comply with the design specifications. 4 Test Objectives and Items 4.1 Purpose of debugging: The steam turbine safety monitoring device should enable the unit to operate safely and reliably. During the startup, operation, and shutdown of the steam turbine, this device should be able to display the main operating parameter values of the unit. It should issue alarm and shutdown signals when these parameters exceed their allowable limits during operation, and it should also provide monitoring signals as well as computer interface signals. 4.2 Debugging items: 4.2.1 Hardware inspection. Check the correctness of cable wiring and perform insulation resistance tests on all cables that have the TSI system installed. Check whether the signals between the probe, preamplifier, and instrument are matched; conduct performance tests on the probe and preamplifier in the laboratory to verify that their accuracy meets the requirements. 4.2.2 On-site installation and commissioning. Based on the original installation data provided by the manufacturer, the installers carry out the installation of the probes, while the technicians conduct inspections to verify that the installation is correct and that the gaps are appropriate. 4.2.3 Dynamic simulation tests and implementation. Dynamic simulation tests are conducted by simulating changes in measurement parameters on-site. Activate the protection and monitoring functions before starting the turbine. 5 Test Conditions 5.1 Once the TSI control equipment is installed, the wiring to the TSI cabinet must be correct on-site; the insulation between wires must meet the required standards, and the anti-interference measures must also be satisfactory. 5.2 The steam turbine itself meets the test conditions. The bearing covers have been opened, the probe mounting brackets have been installed, and the turbine is in a cold state. There is no electromagnetic interference in the surrounding environment. 5.3 Use a jack to push the rotor so that the thrust disc is pressed against either the working thrust bearing or the non-working thrust bearing. 5.4 The system power is operating normally, the testing tools are complete, and the functions of the TSI device have been fully restored. 5.5 Arrival at the site of the relevant professionals, installers, plant personnel, and personnel from the manufacturer of the equipment. 6 TSI Debugging Procedures 6.1 Pre-power-on inspections in the TSI device laboratory 6.1.1 Visual inspection Verify that all components and parts are undamaged, that the welds are secure, and that the connections between components are tight. 6.1.2 Measure and record the probe resistance; the resistance value shall meet the manufacturer’s requirements. 6.1.3 Measure and record the insulation resistance between the input/output signal terminals, power supply terminals, and output contact terminals relative to the case; this resistance value should be greater than 2 MΩ. 6.1.4 Check whether the probes, extension cables, and pre-amplifiers used meet the requirements of each measurement circuit, to ensure they are suitable. 6.2 Laboratory calibration of TSI 6.2.1 Set the power supply input to 220VAC±10%. 6.2.2 Connect the wiring between the probe, preamplifier, and instrument in accordance with the manufacturer’s diagram requirements. 6.2.3 Check that the instrument remains within the allowable range of power fluctuations, and that its output variations meet the accuracy requirements. 6.2.4 Test the probe characteristic curve on a dedicated test bench to check whether the slope and linear range of the probe curve meet the manufacturer’s requirements. Fill in the probe characteristic inspection test record. 6.2.5 Test method for axial displacement instruments The axial displacement probe is an eddy current sensor. 6.2.5.1 Fix the probes on a dedicated test bench, connect the various independent measurement circuits, and label each channel with its probe number, extension cable number, and preamplifier number, so that they can be properly positioned during installation. 6.2.5.2 Based on the probe’s characteristic curve, the voltage value at the midpoint of the linear segment of the gap voltage/displacement curve is selected as the “0” position to adjust the instrument’s zero point. 6.2.5.3 Adjust the instrument’s full scale to –2mm～+2mm. When the deviation between the upper and lower full-scale positions of the gauge does not meet the 1.5% accuracy requirement, the zero point of the gauge should be adjusted accordingly, that is, the voltage at the ‘0’ position should be changed to re-establish the proper setting. 6.2.5.4 Measure and record whether the corresponding values shown on the instrument when the displacement changes by 0.01 mm meet the 1.5% linearity requirement, and ensure that the errors remain within the specifications specified in the manual across the entire range of operation. 6.2.5.5 Adjust the instrument alarm value to +0.8mm ； -1.25, the trip value is at +1.2 ； -1.65mm. 6.2.5.6 After completing the above tests, re-record the corresponding values at various points on the instrument when the displacement changes by 0.01 mm, both upward and downward, to check whether they meet the manufacturer’s requirements. Fill in the displacement instrument inspection and test record. 6.2.5.7 Determine the shaft zero position according to the manufacturer’s requirements, and calculate the installation zero voltage based on the thrust clearance. 6.2.6 Test methods for indicating instruments: Eddy current probes of type PR6426 are used; the methods for calibration and installation are specified in the test method for axial displacement, 6.2.7. Thermal expansion also necessitates the use of differential coil-type transmitters. 6.2.7. 1 Fix the probe’s differential coil transmitter on the test bench and connect the various measurement circuits. Label the probe number, extension cable number, and preamplifier number for each channel. It is placed in position when ready for installation. 6.2.7.2 Based on the probe characteristic curve and according to the thermal expansion table indicating xx mm to + yy mm, select the \"0\" gap voltage to adjust the instrument’s zero point. 6.2.7.3 Adjust the instrument’s full scale. If necessary, the “0” bit of gap voltage should be adjusted to ensure linear indication of the instrument. 62.7.4 Check and record whether the corresponding values on the instrument for changes in displacement of 0.02 mm satisfy the 1.5% linearity requirement. 6.2.7.5 The distance between the probe and the detection plate, as well as the angle between them, have a direct impact on the measurement accuracy; the optimal position should be selected during calibration. After adjustment, select at least three different gap values to ensure proper positioning during installation. 6.2.7.6 Adjust the thermal expansion table alarm values and trip values. 6.2.7.7 After the above adjustments are completed, recheck and record whether the values at various points corresponding to the instrument’s upward/downward movement when the displacement changes by 0.02 mm meet the requirements of a system error within 3% and a linearity within 1.5%. Redetermine the values for at least three different gaps. 6.2.8 The phase detection probe is an PR6423/01 type eddy current sensor; the calibration method is specified in the calibration requirements for eddy current sensors above. 6.2.9 Calibration method of eccentricity measuring instrument 6.2.9.1 The eccentricity measurement circuit is composed of two eddy current probes of type PR6423/01. For the method of adjusting the instrument zero point, refer to the zero point adjustment of the axial displacement instrument. 6.9.2 Fix the probe on a dedicated test bench and connect all the measurement circuits. Adjust the gauge full scale to xx mm. 6.2.9.3 Adjust the instrument alarm values and trip values. 6.2.9.4 After verification is completed, record the corresponding values for each point as well as the gap voltage value at the probe’s zero position. Fill in the inspection and test record for the eccentricity measuring instrument. 6.2.10 The speed probe uses a PR6376 magnetoresistive sensor, and both the speed probe and the zero-speed probe are calibrated on a speed test bench. The accuracy is ±1rpm. After verification, record the corresponding values for each point as well as the gap value between the probe and the apex of the reference tooth. Fill in the inspection and test record for the speed measurement instrument. 6.2.11 Calibration methods for vibration instruments 6.2.11.1 The shaft vibration probe is of the PR6423/01 type eddy current sensor; the calibration method is the same as that for eddy current sensors as described above. Adjust the alarm value of the vibration meter to 125 mm, and the critical value to 250 mm. 6.2.11.2 The vibration probe is a piezoelectric velocity-type probe; it is mounted on a dedicated vibration testing bench to check whether the linear range of the probe meets the 5% requirement, and a simulated vibration test is conducted. 6.2.11.3 To ensure the correct indication of the vibration instrument, at least three vibration sources with different amplitudes shall be selected to conduct a comparative test between the vibration instrument and a standard vibration instrument. Check whether the accuracy of the instrument indications meets the 5% requirement. 6.2.11.4 Set the alarm value for vibration instruments to 50 mm, and the critical value to 80 mm. 6.3 Calibration of indicating and recording instruments: The specialized indicating and recording instruments in the TSI system shall be calibrated in a laboratory in accordance with the instrument operation manuals, and the calibration results shall meet the requirements specified in the instrument specifications. 6.4 On-site Installation and Commissioning 6.4.1 Perform the installation work according to the probe number, extension cable number, and preamplifier number. 6.4.2 Adjust the probe installation clearance based on the laboratory’s experimental data and tighten the fixing screws. 6.4.3 Measure the gap voltage on-site. Fill in the on-site installation and commissioning record. 6.4.4 For the speed probe, attention should be paid to the installation clearance, which is the distance between the top of the probe and the top of the speed gear. If these two points do not align, manually rotate the shaft so that the tip of the gear aligns with the top of the probe, and then determine the installation clearance. 6.5 Static tests of the TSI system 6.5.1 Check the cable connections. Use tools such as a lamp and multimeter to check the correctness of all cable connections connected to the TSI system. All cable connections must be checked in accordance with the thermal control wiring diagrams provided by the design institute. 6.5.2 Power on the TSI control cabinet. First, set all power supplies to the “off” position and turn off all power supplies feeding into the TSI device. Check the power inlet terminals for any miswiring or external voltage feed caused by improper operations. At the power supply location, contact the electrical team or relevant personnel to turn on the main power switch. At the TSI unit, use a multimeter to measure the voltage at the power supply inlet terminals; this voltage should not exceed ±10% of the rated voltage. If the error is significant, the personnel on the opposite side responsible for power supply should be notified to cut off the power for inspection, and power can be restored only after it is confirmed to be satisfactory. Turn on the power switches of each power supply unit, use a multimeter to measure the DC output voltage of the power supply units, and observe the status indicator lights of the power supply units. The status of the indicator lights should be correct, and the output voltage value should be within the range specified in the manufacturer’s instructions. If an error status indicator appears, a power outage inspection should be conducted; power should be restored only after the issue has been resolved. 6.5.3 Static interlock tests 6.5.3.1 Interlock tests with protection systems and alarm systems First, verify that the thermal signal system has been completed in static debugging and is operating properly, and confirm that the turbine emergency trip system has also been completed in static debugging and is functioning correctly. By changing the high I-value alarm setting of the axial displacement measuring instrument, if the actual axial displacement exceeds this high I-value alarm setting, an alarm for excessive axial displacement will be triggered ； By changing the low I-value alarm setting of the axial displacement measuring instrument, if the actual axial displacement falls below this low I-value alarm setting, an alarm for high axial displacement will be triggered. By changing the high II value alarm setting of the axial displacement measuring instrument, when the actual axial displacement exceeds this high II value alarm setting, the condition for an immediate trip due to excessive axial displacement is met, and a trip signal should be generated in the turbine emergency trip system ； By changing the low II value alarm setting of the axial displacement measuring instrument, if the actual axial displacement falls below this alarm setting, the condition for an immediate shutdown due to excessive axial displacement is met, and a shutdown signal should be generated in the turbine emergency shutdown system. For the testing of other measurement signals, the above method should be followed. However, for the static tests of turbine vibration signals, static interlock tests are not conducted due to limited conditions. 6.5.3.2 Interface test with DCS system: It is necessary to ensure that the analog signals entering the DCS system are accurate and have a uniform range. Any modification to the range of the TSI system or adjustment to its linearity must be promptly communicated to the DCS so that corresponding changes can be made. 6.6 Dynamic commissioning of the TSI system. Before starting the unit, thoroughly check whether the indications of all parameters in the TSI system are normal; no over-limit alarm conditions should exist for any of the measured parameters, to ensure the safe start-up of the unit. During the unit startup process and the 168-hour trial operation, technical analysis should be conducted on any issues that arise, and they should be addressed promptly to ensure the normal operation of the TSI system. Fill in the dynamic test record. 7 Dynamic installation: All in-cylinder measurement probes must be installed before the first rotation of the unit. All TSI measuring instruments are activated prior to the first startup of the unit. During the unit’s commissioning phase, all data is monitored and analyzed to ensure that the parameters under observation are accurate.