Maintenance, installation and troubleshooting of gas turbine flowmeters

Project Overview

The working principle of the gas turbine flowmeter is: the measured gas entering the flowmeter, after being accelerated by the flow guide frame with a shrinking cross-section, acts on the turbine blades through the inlet channel, pushing the impeller to rotate. The impeller shaft is installed on the rolling bearing. The impeller rotation number, which is proportional to the volume of the gas being measured, is transmitted to the counter or flow computer after multi-stage deceleration to display the actual volume of the gas being measured. In order to ensure the long-term normal operation of the gas turbine flowmeter, the operating status of the turbine flowmeter must be checked frequently, maintenance work must be done, and problems must be eliminated in a timely manner. The technician below introduces the key points of daily maintenance of gas turbine flow meters:

Installation precautions for gas turbine flow meters

1. Before installation and use, follow the manufacturer's instructions to guide construction;

2. After the pipeline construction is completed, it should be purged and thoroughly removed welding slag, rust and other dirt;

3. Horizontal installation is recommended;

4. Welding Heat will completely damage the flowmeter, and welding adjacent flanges with meters should be absolutely avoided;

Gas turbine flowmeter maintenance methods

1. Before putting the turbine flowmeter into operation, the instrument must be inspected When setting the coefficient, check carefully to make sure that the flow meter wiring is correct and the grounding is good before powering on.

2. Clean, inspect and recalibrate the flow meter regularly. For flowmeters equipped with lubricating oil or cleaning fluid injection ports, lubricating oil or cleaning fluid should be injected regularly according to the instructions to maintain the good operation of the impeller.

3. Monitor the status of the display instrument, evaluate the reading of the display instrument, and check for any abnormalities in time.

4. Keep the filter open. If the filter is blocked by impurities, it can be judged from the increase in the reading difference between the pressure gauges at the inlet and outlet. If the blockage occurs, remove it promptly, otherwise, the flow rate will be seriously reduced.

5. For large-flow trade settlement measurement, in order to ensure the accuracy of the flowmeter, the flowmeter must be calibrated frequently. The site should be equipped with online calibration equipment or a movable calibration device. Although the one-time investment is relatively large, it is worthwhile in terms of long-term economic benefits.

1. The gas turbine flowmeter sensor or supporting display instrument has no output signal; cause of failure: incorrect wiring, impeller stuck and unable to rotate, detection coil open circuit or short circuit, poor preamplifier If the amplifier has no power or the power supply voltage is too low, it indicates that the instrument itself is faulty; troubleshooting method: check whether the wiring is correct, check whether there are any debris in the pipeline, inspect the amplifier, inspect the amplifier, inspect the amplifier, or increase the power supply voltage to meet the requirements and inspect the display.

2. There is still a signal output when the flow rate is zero; Cause of the fault: The strong electromagnetic field interferes with the vibration of the pipeline, causing the impeller to swing back and forth. The vibration of the pipeline causes relative movement between the magnet and the coil. Solution: Check whether the shielding wire is grounded. Good or eliminate interference eliminate pipe vibration eliminate pipe vibration.

3. The indicated flow does not match the actual flow. Cause of failure: The second cause of the failure is that the preamplifier is defective. Air or steam is mixed into the pipeline. The outlet pressure is too low. The bearing is worn. Impurities and dirt are attached to the impeller.Poor material piping indicates instrument failure. Troubleshooting method: Eliminate pipeline vibration, overhaul the amplifier, install an air separator, increase pressure, replace bearings, clean the pipeline, re-pipe, overhaul the display instrument.

Routine maintenance directly affects its service life. In fact, strict attention should be paid to the gas turbine flowmeter before installation. For example, use mouth blowing or hand-driving the impeller to make it rotate quickly and observe whether there is any display. When there is Install the gas turbine flowmeter when displayed. If there is no display, check the relevant parts and eliminate the fault.