Geothermal

A Geothermal Industry's Unplanned Downtime Is Costly

When an equipment in the manufacturing line fails, production is down. It may take days or even weeks for repair and replacement to be completed. Workflows are interrupted, there is a loss in output capacity and revenue.

Looking at the average maintenance program for Geothermal Plants, majority of it is still reactive at 55%. Reactive maintenance involves restoring a failed system to a functional state. Meanwhile, 31% is time-based, 12% is predictive, and 2% involves other methods.

Studies still show that 55% of maintenance is reactive while only 43% is preventive.

Preventive Maintenance Is Important

Systems breakdown due to a number or combination of factors, rarely just one. This results in devestating loss of equipment and life in Geothermal Industries. 

Lacking or irregular maintenance procedures also increase the likelihood of equipment failure or human error. Combine this with inconsistent processing situations, the result can be costly with unplanned downtime.

Unplanned downtime negatively affect production capacity and increase operating expenses. The damaged equipment must be inspected properly and repaired fast before beginning operation again.

Preventive maintenance increases the reliability of equipment which is critical to achieve long-term profitable operations and tackle rising materials costs. This entails having detailed site-specific maintenance schedules, procedures, and training.

Maintenance procedures should include five phases:

• - Initial Survey of Process
• - On-Site Study
• - Development of Schedule and Training
• - Implementation of the Maintenance Plan, and
• - Follow-Up to Determine Success Rate. 

Heat Exchangers in the Geothermal Industry

Safe operation of Power Plants require the steady cooling of bearings, lube oils, and rotor blades of diesel, gas motors, steam turbines, or gas turbines. 

Proper cooling and condensing of process steam is also critical in the safe operation of a power. This is where Heat Exchangers in Power Plants come in, making them important to be properly maintained to prevent unexpected failure.

Minimise Tube Failures

Three main areas for improvement to minimise future in-service tube failures are: 

• -Tube Testing 
• - Re-Tubing Strategy During Turnarounds
• - Design Improvements in Heat Exchangers
• 
  

For the first point of tube inspection, we recommend using a suitable tube inspection device. This device needs to have the ability and accuracy to detect the common flaws found in the Heat Exchangers. 

Common Problems

Process Corrosion

Stress-Corrosion Cracking (SCC) of Tubes

Steam or Condensate Corrosion

Process Fouling

Heat Exchangers to Inspect with APRIS

Air Cooled Condenser

Cooler

Evaporator

Iso Butane or Iso Pentane Condenser

Reheater

Vaporise

References: 

1. Sullivan, G.; Pugh R.; Melendez, A.; Hunt, W. Operations & Maintenance Best Practices; U.S. Department of Energy: Washington, DC, USA, 2002.

Tube Inspection with APRIS

Technologies for inspecting Heat Exchanger tubes are constantly changing and improving rapidly. With increased sophistication and complexity of today’s Non-Destructive Examination (NDE) techniques, the operator’s skill level is becoming more vital. 

To correctly identify the flaws and tube failures, a reliable technology and technician is needed.

APRIS is a smart tube inspection device that doesn’t compromise the ease-of-use with higher complexity and sophistication. 

A typical tube inspection tool would require a user to have years of experience. But with APRIS, any technician can accurately find flaws with little training. 

Case Study

Geothermal Plant (Turkey) – Isopentane Condenser Tube Inspection