On-Site Services

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HRSG Combined Cycle Power Plant Boiler

From the front to the back of the boiler (or HRSG), the extreme conditions faced by pressure parts are a challenge for any designer to overcome. The same applies to other components in the steam cycle, from the condensers, to the Power Piping, and of course the steam turbine.

Degradation is an unfortunate but inevitable reality for the power plant’s pressure equipment. Effective operation and maintenance (O&M) of the plant requires informed management of maintenance activities during planned shutdowns and demands judicious responses to unexpected failures. It is difficult to achieve the delicate balance of having optimal thermal process performance, maintaining appropriate water/steam chemistry while controlling O&M costs that will minimize equipment wear and aging.

With over 25 years of experience in thermal power plants – including conventional plants with radiant boilers (gas, oil, coal, biomass), and combined cycle plants with HRSGs – at Tetra Engineering we have the required resources and competence to support you during planned (or unplanned) outages and to assist you remotely in preparation.

Our field services include:

  • HRSG or Boiler Visual Inspection: This basic activity is the best measure of the boiler’s present condition – don’t leave it to amateurs.
  • Hot Walkdowns: For in-service inspection of equipment including checking for leaks and performing thermography
  • Hot/Cold Piping Inspection: If you haven’t adjusted any piping supports for the last five years, your team is probably not inspecting them!
  • NDE Inspection Planning and On-site Supervision: Optimise outage resources by targeting NDT inspection locations – avoid the trap of letting NDE contractors decide where to inspect.
  • Welding Repair / Refurbishment Supervision: Unsupervised welding activities are a recipe for trouble. Experience shows that paper quality does not equal weld quality.
  • Online Tuning of Control Systems: Reduce the unnecessary cycling of equipment and improve the safety measures that protect your equipment.

Engineering & Analysis

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failedtubemetWith over 25 years‘ experience in power- and industrial-steam generation services, Tetra Engineering has developed a broad range of services to assist you in O&M activities that maximise performance and reliability.

Performance and Efficiency

How has your actual operating profile “drifted” since the plant / boiler was designed? Today’s plants can achieve near 60% efficiency when new and operating at the optimised load-case, but operating off-design can severely reduce efficiency and heat-rate. The challenge is twofold:

  1. How can you identify where the lost Watts are going?
  2. When found, what is the best way to win them back?

Typically, performance losses are associated with age-related degradation (for example fouling), off-design operation, or modifications that lead to changes in process conditions (for example, a GT upgrade that affects downstream HRSG performance).

Tetra Engineering has the range of experience for identifying which performance losses from among the multitude of causes are recoverable in considering feasibility and cost-effectiveness.

Optimised Non-Destructive Evaluation (NDE)

By design, ASME pressure parts (piping and boilers) are intended to be inspected at regular intervals. While many damage mechanisms can be detected visually, others are best discovered with various NDE methods, in particular:

  • Fatigue cracking
  • Creep
  • Corrosion-assisted cracking
  • Flow-accelerated Corrosion

NDE contractors are expensive and usually don’t know your plant or process well enough to know which components are most at-risk for degradation and wear. If they inspect in the wrong places (i.e. where the rate of wear/damage is not highest), they’ll end up giving a false sense of security.

Optimised NDE means carefully selecting the locations that are most susceptible to damage, according to your components’ design and the way they are operated. Tetra Engineering has the requisite multi-disciplinary experience and tools (thermal simulation, life assessment, structural calculations….) in-house to help you get the most out of your NDE campaigns, by providing pre-outage planning, on-site supervision and post-inspection review.

Root Cause of Failure

Knowing the fundamental causes leading to failure is essential to mitigate the risk of the failure repeating. Tetra Engineering calls on an interdisciplinary team to assess the failure (or degradation) and determine the root cause.

The assessment may include:

  • Operational Data Review
  • Metallurgical Examination in a laboratory
  • Mechanical Testing
  • Chemical and Fuel Analysis
  • Scanning Electron Microscopy
  • Finite Element
  • Boiler Process Modelling

Related and follow-up services for remediation may include fitness-for-service (FFS) or remaining life assessment, as needed.

The underlying objective is to “use” the failure as an opportunity to improve operational practices or identify potential design problems and thereby ensure long-term reliability of the steam cycle.

Third Party Consulting

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HRSG Boiler gas-path CFD SimulationThird Party Engineering

When making real decisions for high-value assets, independent advice is key. Warranty claims, legal disputes, and maintenance problems are difficult to resolve when parties have a financial interest in the outcome. A third-party specialist engineer can provide an unbiased opinion and help make the right choices.

The specialists at Tetra Engineering have both the expertise and the experience needed to provide assistance on a broad range of technical problems in thermal power plants. As we don't sell equipment or have arrangements with repair contractors, our advice is always objective. Services can be provided at all project/plant phases:

  • Specification
  • Fabrication and Assembly
  • Commissioning and Warranty Claims
  • Operation
  • Removal from Service

Expert Witness

Tetra Engineering is experienced in standing as expert witness for the resolution of disputes and is recognized for its independence and integrity. We are available to provide legal services if the need arises in the field of steam generation in radiant boilers or HRSGs, steam and water Power Piping as well as other components in the steam cycle.

Training

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Tetra offers a series of regular courses every year in the USA, France and Dubai.  Custom courses are also available on site.

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About Us

Established in 1988, Tetra Engineering has more than 25 years experience providing solutions to the power industry. We specialize in solutions for HRSGs, conventional boilers & steam-cycle balance of plant.

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