Reclamation of FRF at Coastal Energen Pvt. Ltd. (Tuticorin)


 Customer: Coastal Energen Pvt. Ltd. (ENERGEN), the power generating flagship company of the coal and oil group, is a 1200 MW coal-fired thermal power plant in the district of Tuticorin in the State of Tamil Nadu, India.

Symptom Observation:

• The power plant was observing a loss in the production of electricity generation

• The operation & maintenance team has identified that the turbine governing command is not functioning properly and is tripping frequently on a regular interval

• On further investigation it was found that the servo valve (Moog valve) has failed and showing hunting or sluggish behavior.

Problem Identification: Failure of the Moog valve was the main reason for the trip of the turbine and ultimately the reason for the breakdown in the power plant.

Poor Oil Analysis Program: an oil analysis is supposed to be done monthly for Particle count & TAN (weekly if the trend is negative) and weekly test for water content but the customer has undefined scheduled for it.

Inadequate Operation Practices: The solenoid valve of the LVDH (oil purification machine) vacuum line was only 20% close, due to which vacuum was not able to generate.

Root Cause Analysis: High ingression of contamination in FRF flowing through the line which choked the filter before servo valve spool. The presence of varnish & silt in the clearance of the spool has created an obstruction for its to-fro movement inside the servo valve. Also, the high TAN value led to electrokinetic erosion of line and accessories of the EHC system & subsequently formation of the fine metal particle (solid contamination). It was concluded that all these factors related to lubricant degradation have contributed to valve failure.



Solutions Implemented: Minimac uses the proven technology for reconditioning EH oil i.e. TAN reduction by ion-exchange method (TRIX) MLC LVDH TRIX 20 which is a combo package designed for simultaneous reduction of TAN, moisture, and NAS value of the EHC fluid. It plays a major role in achieving the properties range within the recommended limits. Onsite training on the function of EH oil re-conditioner, FRF maintenance, and contamination control, the importance of the oil analysis program was provided to their team by Minimac’s service engineer.

Filter consumption: 01 qty of 10-micron filter element and 01 qty of 3 microns consumed to achieve NAS 5 cleanliness

Total consumption of resin: 36 Ltr

Total running hours of equipment: 698 hrs

The below chart is showing the trend of decrease in the values with continuous cycling of EH Oil.



Benefits:

  • Extending oil life
  • Reduced TAN value
  • Eliminate oil replacement cost
  • Increased turbine availability & reliability

Way Forwards: In order to have complete purification of FRF, an external FRF Reconditioning system is recommended. The Minimac’s FRF Reconditioning system comprises 4 major Technologies, all packaged comprehensively in 1 single system.

• Solid contamination super-fine filtration.

• Moisture in oil separation by vacuum dehydration technology

• TAN reduction by ion exchange technique

• EHC system tank Moisture removal and ingress prevention by Inert Gas Blanketing technique.

Comments

Post a Comment

Popular posts from this blog

Control System Of Turbine - Failure & Maintenance

Image
Control System The turbine control system describes the control over the opening of control valves corresponding to demand signals, and steam flows into the turbine with the help of a governing system that facilitates the operation of the turbo set in an interconnected grid system. Governing system is responsible for various function such as speed & load control functions, the start-up/shut-down controls, the over-speed control, turbine stress calculation, to control the initial run-up and synchronization of the Unit, to assists in matching the power generated to that demanded by responding to system frequency changes, to regulate the steam control valves position (and hence the load generated)in response to signal from the operator or from the load dispatch Centre, to restrict the speed rise within acceptable limits should the unit get disconnected (islanding) from the lgridoad and some protective trip functions. With continuous research and developments in modern turbine technolo
Read more

Reconditioning of EH Oil

Image
A 1200 MW coal-fired thermal power plant using Into-Chinese Turbine EHC System in Southern India. The Plant was struggling with the rapid increase in TAN values in the EH oil of the governing system of the turbine. Also, the moisture content was more than permissible limits. Degradation of the oil was due to contamination ingression into the system resulting in by-product formation. Minimac’s EH oil reconditioning system “ MLC LVDH TRIX 20 ” proved to be the savior and an unexpected shutdown of the turbine worth ₹1.05 Cr per day was saved . PROBLEMS A rapid increase in the Total Acid Number (TAN) could degrade the EH oil and lead to the possibilities of failure of servo valve, hunting, power generation loss, unplanned shutdown, etc. Oil Analysis was done to check the properties of EH oil like Moisture, NAS value, Total Acid Number. SOLUTIONS Installation of Minimac’s EH Oil Reconditioning System “ MLC LVDH TRIX 20 ” is comprehensively designed with 4 major technologies to: Remove solid
Read more

Minimac Technology

Image
 The secret recipe of the growth story at Minimac Syste ms has been its capability to drive technological advancement in the field of contamination control for lubrication reliability. Research and development on technology and products have always been the key reason to keep the Minimac products a step ahead of its competitors in the market. Technological development has been one of the core competencies which Minimac possesses, thereby ensuring a definite competitive advantage. Contaminations in lubricants are of various types and characteristics depending on the lubricant, equipment application, ambient conditions, age of equipment, etc. In order to control, separate or eliminate the contamination, there are multiple techniques. Each technique has pros and cons and hence there is no single technology that can be considered universally better than others. ​ Minimac Systems over the years has become equipped with almost all the technologies which are required for contaminat
Read more