Previous Projects

With over 30 years of experience in power and industrial steam generation services, Tetra Engineering has along history of projects.

Selected recent Global Technical Projects are summarized and presented in this section

For more information on any of these projects or Tetra capabiltites contact your regional Tetra office here.

HRSG Boiler Preservation Study, 2014

A CCGT power plant employed Tetra to perform a review of possible boiler preservation options within the context of the present and planned operating regime. The review relied on information supplied by the plant staff, Tetra field experience and latest industry trends and practices to identify the most promising strategy for preservation. The ideal solution for this client was Dry Layup that is systematically applied when it reaches the end of the standby period.  This would require that resulting startup timing meets requirements imposed by the governing network operator.

Client region: Middle East

Thermohydraulic Attemperator Study using PPS&D, 2014

The primary purpose of this study was to validate the effect of an interstage attemperator between two superheaters with respect to the primary superheater and primary reheater outlet steam temperatures. The CCGT in question had already had problems with creep failures of the P91 components, and needed to assure that exit temperatures did not exceed 570°C. Currently, the primary superheater outlet temperatures exceed 600°C at certain loads and the primary reheater temperatures exceed 590°C. Initial results were based on steady-state analysis, while final results included dynamic modeling of cold-, warm- and hot starts, as well as ramp up and ramp down. The study was performed using the software simulation tool PPS&D.

Client region: Europe

Stress Analysis Study of SH Section, 2014

A CCGT Power Plant suffered repeated tube failures between 2003 and 2014 in the SH section of their boiler. Failures were exclusively located at the tube-header weld, at varying positions on the tube sheet. The client engaged Tetra Engineering to analyze the problem and simulate the existing stresses during various load conditions. The scope of work included a review of historical failures and metallurgical reports, operational data analysis, Finite Element Analysis (FEA) and Fatigue Analysis.

Client region: South East Asia

HRSG Vibration Study, 2013

A HRSG operated by a European client appeared to be subject to excessive vibration, based on high noise near the unit and vibration of the casing in certain sections of the roof.  The OEM and EPC had initially agreed that the vibration was a potential problem, so for this reason a study was commissioned by them. This included a field survey of noise using microphones, confirming that there were high noise levels in three different frequencies at some points outside the HRSG casing. Subsequently the OEM/EPC modified their position to hold that the observed noise was not a problem and that no further action was required. The client then requested that Tetra Engineering independently review the problem and perform additional analysis as required. The scope of work included field measurements, thermohydraulic boiler simulations and vibration risk calculations.

Client region: Europe

CFD Analysis of failed 180° Bend, 2013

A CFD study on one of the 4th quadrant pipe bends at a thermal power plant steam boiler was performed. The purpose of the analysis was to analyse the change in flow velocity due to an increase in the bend nominal size from 3” to 4”. The connecting pipe run was kept at 3” and standard expander/reducers are used to join the pipe with the bend. Input process parameters were taken from a PPSD model.

Client region: Middle East

LP Economiser Header Failure Analysis, 2010

The LP economiser lower header on a HRSG ruptured shortly after a diverter damper incident. Tetra was approached by the client to investigate the possible root causes for the rupture. The unit went into single element control at the time of the incident and the LCV cycled through fully open / fully closed positions to maintain the drum level after “shrink”. When the damper re-opened the LCV remained closed as the drum level increased (swell). The economizer temperature increased and there was an associated increase in pressure. The safety valve failed to operate as it was accidentally gagged, causing serious over pressurisation and a burst header.

Client region: Middle East

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