Ultrasound Leak Detection- Pipe failure remains a leading cause of unplanned downtime in thermal power plants. A leak in a pipe is caused by damage to the tube, such as bending, cracking, swelling, or wear. Causes of failure include ash, overheating, corrosion and erosion.
Tube failure is still the main reason for unplanned downtime in thermal energy plants. Leaks arise withinside the tubes because of tube screw ups together with bending, cracking, bulging or wear. Reasons for the screw-ups consist of ash, overheating, corrosion and erosion.
The way to find out before the worst is, Employing the use of ultrasound leak detection.
The reheater is important to the overall performance and performance of the energy-era procedure in a thermal energy plant. A standard thermal energy plant uses the Rankine cycle model, which describes how steam-operated warmness engines generate energy through changing warmness into mechanical work.
In short, gas and coal are positioned right into a boiler furnace to warm water (i.e., steam) to the proper temperature and strain. The smoke is heated similarly with an economizer and positioned right into a furnace, wherein the radiant electricity is absorbed into the firewalls. By this factor, the steam temperature has been raised from seven hundred to 800°F (371 to 426°C).
The steam is going right into a superheater at pretty much the important factor so that you can feel warmness as much as 1000°F (537°C). If the steam strain and temperature are higher, the engine has more performance for changing the steam’s warmth into mechanical work. The smoke then goes via the turbine, wherein it loses electricity and, therefore, temperature and strain. (Enthalpy is a dimension of electricity, normally represented in Joules because of the sum of inner electricity made from stress and volume.)
From the turbine, the maximum of the steam is exhausted to a reheater for use once more for a second, decreasing strain collection of mills. The reheater strain is simply one-fourth of the authentic boiler strain. However, the temperatures are the same. This prevents the vapour from condensing for the duration of enlargement and improves performance. The aggregate of mills — excessive strain/excessive temperature and occasional strain/excessive temperature — is extra green than reheating via burning gas.
The steam is then exhausted from the low strain mills into the condenser, wherein cooling water condenses the vapour into water. The section that extrudes from moisture to water creates a herbal vacuum inside the condenser, aided by vacuum pumps. Next, the condensed steam — noted as condensate water — is wiped clean and despatched lower back via the heating procedure.
There, it’ll be transformed from water to a supercritical fluid to keep the once-via cycle over once more. Finally, the cooling water —called circulating water — is despatched from the condenser to the cooling tower. There, the water is air-cooled using evaporative cooling to decrease its temperature earlier than the water is pumped lower back via the condenser.
Leaks are jeopardizing plant efficiency.
Air drawn into the condenser can cause a vacuum to be lost in the turbine. Failure to stop will put stress on the turbine blades. This deformation can lead to blade disengagement due to erosion, possible cracking of the edge, or deformation due to the backpressure of the condenser (low vacuum with air). A testing professional can use ultrasound leak detection with adequate sensitivity to detect and locate leaks whenever an outage is planned. Ultrasound leak detection can detect leaks whenever the gas temperature drops from the water level (a common leak indication). Here are the steps:
The boiler is off. The valves are closed automatically to stop steam from flowing. Next, Then the boiler goes into cooling mode. This will take 6-10 hours, depending on the ambient temperature. A cooling rate of 200°F per hour is maintained to avoid other issues.
: Shut off/disconnect the heater after completion of the cooling process. This allows technicians to walk or crawl in confined spaces.
At the same time, a vacuum is drawn from the condenser through the turbine to the reheater due to the condensation of the steam and the vacuum pump. Therefore, everything connected to the turbine is in a vacuum in autonomous mode. The vacuum level is at least 20 inches Hg, but the desired vacuum level is 25 inches Hg.
The technician uses ultrasound leak detection to sweep the reheater. A reheater can be more than 70 inches long and 20 inches deep. With no leaks, a full leak search only takes a few minutes. If a leak is detected, the leak must be located – the technician hears a hissing from the headset. This is done using the principles of ultrasound (e.g. directivity, sensitivity adjustment, shielding, various acoustic installations, etc.) to pinpoint the tube bundle’s bundle’s exact location. This process may take up to an hour, depending on the leak location. In some cases, a rigid probe tip is used to identify a leaking tube.
The leak location can be tracked by moving it along the tube bundle in the direction of the loudest sound. Repairs must be completed as soon as possible. A code repair is in progress, and repair documentation must be submitted to the insurance company. Repair verification is confirmed by a vacuum test or, rarely, a hydraulic test. The Ultrasound Leak Detection is used to ensure no audible leak when leaking, no leaks during welding or when new tubing is installed.
Ultrasonic Leak Testing Method
Ultrasound leak detection with adequate sensitivity can detect and locate leaks during planned heater shutdowns. Ultrasound leak detection can also detect and locate leaks when the gas temperature drops to a water level, a common indication of a leak. Here are the steps:
- The boiler is off.
- The valve will automatically close to stop the flow of steam.
- The boiler goes into cooling mode. This requires from six to ten hours, depending upon the ambient temperature. To preclude other problems from occurring, a cooling rate of 200°F per hour.
- is maintained
- When the cooling process is complete, the heater will shut off/display. This allows technicians to walk or crawl in confined spaces. At the same time, a vacuum is drawn from the condenser through the turbine to the preheater due to the condensation of the steam and the vacuum pump. Everything connected to the turbine is in a vacuum in autonomous mode. The vacuum level is at least 20 inches Hg, but the desired vacuum level is 25 inches Hg.
- Technicians use ultrasound leak detection to check heaters. Heaters can be over 70 feet long and 20 feet deep. With no
- Leaks, a full leak search only takes a few minutes. If a leak is detected – the
- Technician hears a hissing from the headset – the leak must be located. This is done using ultrasonic principles (e.g. directivity, sensitivity adjustment, shielding, various acoustic attachments, etc.) to pinpoint the exact location of the
- Tube bundle. This process may take up to an hour, depending on the leak location. In some cases, a rigid probe tip is used to detect a leaking tube. The leak location can be tracked by moving it along the tube bundle in the direction of the loudest sound (
- Repairs must be completed as soon as possible. A code repair is in progress, and repair documentation must be submitted to the insurance company. Repair verification is confirmed by a vacuum test or, rarely, a hydraulic test.
- Use the Ultrasound Leak Detection to verify that there is no audible leak when leaking, no leaks during welding or when new tubing is installed.
Use of ultrasonic sensing technology
Power plant personnel can maximize the facility’s facility’s investment in ultrasonic technology by applying ultrasonic technology to other departments and systems when detectors are not being used to detect heater leaks. Ultrasound is generated from a variety of sources, and ultrasound leak detection technology can be used for steam traps and valves, condition monitoring and electrical testing. Identification of insufficient or excessive lubrication and excessive wear through condition-based monitoring of critical bearings, motors and gearboxes complements infrared and vibration analysis. (ultrasound leak detection)
Ultrasound has an advantage over other predictive techniques because defects appear first in the ultrasonic range (about 40 kHz) before audible vibrations, accelerations, or heat are felt. Ultrasound also decays quickly, allowing the user to pinpoint the source. Ultrasound is also used to diagnose valves and steam traps by contacting the valve’s housing with the ultrasound receiver and a solid probe attachment. If the valve or steam trap is closed, no ultrasound should be heard through the headset. (ultrasound leak detection)
If you hear an audible sound, there is a leak in the internal bypass. The electrical system can also test for ultrasound generated by an arc, follower or corona discharge. Infrared indicates excessive resistance and load anomalies, but ultrasound is used to indicate leaking voltage. (Leakage voltage can be annoying as it causes radio frequency interference or catastrophic failure of transformers, relays, and switchgear.)
Consequently, heater and boiler tube failures are a leading cause of unplanned downtime in power plants. A standard ultrasound leak detection program can be implemented to prevent catastrophic failures and improve the overall efficiency of the power generation process. Reliable and intrinsically safe ultrasonic detections can detect just one leak and provide fast recovery.