This is Part Three of a three part series on steam turbine tips, discussing the challenge of inadequate oil supply.
Directly measuring bearing metal temperature is the most effective way to really determine if a bearing is running hot.
Bearing oil drain temperatures are still being utilized on older machines. By the time the bearing oil drain temperature has increased, the bearing may have already been compromised (wiped). PSG recommends that these older machines should have temperature probes (thermocouples or RTD’s) installed in the bearing Babbitt to properly monitor performance.
A two-level alarm is recommended (not automatic trip). Consequently, the first alarm should be set a few degrees above the highest temperature in the recommended normal operating range. Operators should also closely monitor bearing temperature after the first alarm sounds.
Keep in mind that if the temperature rises abruptly and unexpectedly, the bearing may have been compromised and immediate action needs to be taken. Gradual temperature changes which trigger the alarm may be the result of other factors but are still a concern and should be thoroughly investigated.
The second alarm should be set at the maximum operating temperature of the bearing material. Operators should manually trip the unit in a controlled manner as soon as possible after this second alarm sounds and determine the cause.
The critical temperatures for each of the two levels can be supplied by the manufacturer or recommended by PSG for your individual unit configuration. Different temperature ranges are recommended for Tilt Pad, Elliptical, Short Elliptical, and Thrust bearings.
Measuring drain oil temperature is too slow and too imprecise to effectively minimize your overall cost of maintenance. Taking all of this into consideration, the best practice is to retrofit your machine and save your bottom line.
Do you have questions about your steam turbine backup system? Contact PSG today to explore how we can provide support and maintenance options to help you avoid backup system problems.
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/in Safety Tips, Turbine Tips /by Mike.LakePower Services Group Successfully Executes Gas Turbine Major Maintenance in Africa
/in News /by Mike.LakePSG has had a strong start to 2018, with over 70 members of our field service team in Africa performing major maintenance on four combustion turbine-driven compressor trains in a LNG processing facility. Contact us to discuss how Power Services Group can execute your combustion or steam turbine maintenance safely, on schedule, on budget, and with the highest quality.
Power Services Group Attends HRSG Forum 5-7 March 2018
/in News /by Mike.LakePower Services Group is attending this year’s HRSG Forum in Houston, Texas. If you’re attending please stop by booth #42. We look forward to seeing you.
Inadequate Oil Supply: Measure the Cause, Not the Symptom
/in Steam Turbine Tips /by Mike.LakeDirectly measuring bearing metal temperature is the most effective way to really determine if a bearing is running hot.
Bearing oil drain temperatures are still being utilized on older machines. By the time the bearing oil drain temperature has increased, the bearing may have already been compromised (wiped). PSG recommends that these older machines should have temperature probes (thermocouples or RTD’s) installed in the bearing Babbitt to properly monitor performance.
Keep in mind that if the temperature rises abruptly and unexpectedly, the bearing may have been compromised and immediate action needs to be taken. Gradual temperature changes which trigger the alarm may be the result of other factors but are still a concern and should be thoroughly investigated.
The second alarm should be set at the maximum operating temperature of the bearing material. Operators should manually trip the unit in a controlled manner as soon as possible after this second alarm sounds and determine the cause.
The critical temperatures for each of the two levels can be supplied by the manufacturer or recommended by PSG for your individual unit configuration. Different temperature ranges are recommended for Tilt Pad, Elliptical, Short Elliptical, and Thrust bearings.
Measuring drain oil temperature is too slow and too imprecise to effectively minimize your overall cost of maintenance. Taking all of this into consideration, the best practice is to retrofit your machine and save your bottom line.
Do you have questions about your steam turbine backup system? Contact PSG today to explore how we can provide support and maintenance options to help you avoid backup system problems.
Inadequate Oil Supply: Don’t Kill Your Turbine on Startup
/in Steam Turbine Tips /by Mike.LakeYour lube oil temperature needs to be lower at startup and shutdown than at full speed to reduce potential issues.
Your turbine’s rotor does not actually ride on the surfaces of its bearings. It rides on a thin film of oil between the rotor and the bearing. At high turbine speeds the rotor hydroplanes across the oil, eliminating contact with the Babbit of the bearing. The heat generated by the turbine decreases the viscosity of the oil and increases its “slipperiness”, which is important at high speeds.
Failure to lower the lube oil temperature (and therefore increase viscosity) can result in light bearing wipes or smearing. These conditions would occur during turning gear operation, unit startup and unit coast down during shutdown.
The ideal lube oil temperature at these lower speeds is 90 degrees Farenheit. Of course, oil temperature can also be too cold on startup—similar to trying to start your car on a cold winter day. Operational personnel are ultimately responsible for maintaining this lower lube oil temperature by regulating water through the lube oil coolers.
Maintaining lube oil cooler cleanliness is also very important for turbine startups. The tubes must be clean to allow the efficient transfer of heat. Also, as a best practice the bundles should be cleaned every two (2) years. Lube oil coolers are the single most common area for contaminants to hide.
By following these tips, you can ensure the efficient startup of your turbine, as well as greatly reduce any potential operational issues or challenges.
Do you have questions about your steam turbine backup system? Contact PSG today to explore how we can provide support and maintenance options to help you avoid backup system problems.
Power Services Group (PSG) – the Best Alternative to the OEM for Alstom GT24 Gas Turbine Maintenance
/in Combustion Turbine Tips /by Mike.LakePSG’s leading Subject Matter Expert on Alstom GT 24 ICS equipment, Bob Fischer, comments “The demand for GT24 maintenance services is dramatically increasing as the OEM experiences a shortage of skilled and experienced resources and customers are looking for cost effective alternatives. With the GT24 fleet reaching maturity, more owners are searching to reduce their OEM dependency.”
If you are interested in starting a discussion on how PSG can help you be successful with our gas turbine maintenance options, please visit our website to request more information, or email us direct at [email protected].