Tetra has published a series of guides which are available for ordering.
A selection of technical papers available for reference.
Selected papers, presentations and articles from major industry conferences and events.
With over 30 years of experience in power and industrial steam generation services, Tetra Engineering has along history of projects.
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.
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.
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.
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.
