GT, HRSG, ST, first fire to first sync
Commissioning software for a combined cycle plant where steam blows and first synchronisation are gates, not milestones on a chart.
A combined cycle plant is three power islands — gas turbine, HRSG and steam turbine — that only earn revenue once every subsystem is chemically clean, steam-blown and proven to the grid. Deskely holds mechanical, electrical, I&C and process subsystems in one register, so first fire, first synchronisation and reliability run are issued from signed evidence rather than assembled the night before.
- Islands
- GT, HRSG, ST, BOP
- Sequence
- Clean, blow, fire, sync
- Gate
- Grid code compliance
- Output
- PAC and reliability run
Choose your project type
The problem
The steam blow package alone can carry hundreds of temporary supports and target plates.
Chemical cleaning, steam blows, boil-out and target plate inspections are logged by different disciplines at different times, and a single missed cycle can force a re-blow weeks later when the schedule has already moved on.
First fire and first synchronisation each depend on dozens of prerequisite systems being mechanically complete, loop-checked and protection-tested — a dependency map that lives in someone's head is discovered wrong at the worst possible moment.
Deskely models every subsystem with its prerequisites explicit, so the readiness for first fire or first sync is a status the system reports, not a meeting the project manager convenes.
Setting up the register
GT, HRSG, ST and balance of plant are subsystems with their own turnover packages.
The plant is broken into systems and subsystems: gas turbine and enclosure, generator and excitation, HRSG pressure parts and ducting, steam turbine and condenser, cooling water, fuel gas, DCS and protection.
P&IDs, single line diagrams and equipment lists are parsed into a reviewed tag register, so every valve, instrument and electrical device carries its drawing reference from day one.
System turnover packages are built subsystem by subsystem, which is what allows the HRSG to be steam-blown while the ST bay is still being wired.
Chemical cleaning and steam blows
Cleanliness targets and blow efficiency are recorded evidence, not a verbal sign-off.
Chemical cleaning circuits, flush sequences, passivation and boil-out results are captured against the piping subsystem, with target plate photographs and pit counts attached where required.
Steam blow records hold pressure, temperature, target plate condition and blow count, and the subsystem stays open until the acceptance criteria are met and signed.
Because the record set is templated per subsystem type, a repeated blow is a new instance of the same record rather than a fresh document to draft under pressure.
First fire and first synchronisation
The GT lights and the plant synchronises only once every prerequisite subsystem is signed.
First fire depends on fuel gas systems, protection relay settings, cooling water and the DCS being commissioned and loop-checked; first synchronisation depends on that plus grid code compliance testing and protection coordination with the transmission or distribution operator.
Deskely gates the first fire and first sync certificates on those prerequisites, so a subsystem left incomplete blocks the certificate automatically rather than relying on someone remembering to check.
Grid code compliance tests — voltage ride-through, frequency response, reactive power capability — are recorded against the interconnection subsystem with the results the network operator will ask to see.
PAC, FAC and the reliability run
The reliability run is the last gate, and trips during it are evidence, not excuses.
Provisional and final acceptance depend on a reliability run at load with a defined trip-free window, and any trip during the run resets the clock against a documented cause.
Deskely tracks the run period, logs interruptions against the subsystem responsible, and issues PAC and FAC certificates from the same signed record set used throughout commissioning.
The completed dossier — cleaning, blows, loop checks, protection settings, grid compliance, reliability run — is exported to the owner as one pack rather than reconstructed from six contractors' files.
Grid support and black start capability
A combined cycle plant is dispatched to keep the grid alive, and governor droop, load rejection and black start tests prove that before the TSO trusts it in an emergency.
Beyond first synchronisation, a grid-critical CCGT has to prove it can be relied on when the system is stressed: governor droop and primary frequency response tests, full and partial load rejection without tripping, and — where the connection agreement requires it — a black start sequence that brings the plant up from a dead grid on its own diesel generators and battery systems.
These tests are usually scheduled once, late in commissioning, on a plant the operator is already under pressure to declare commercially available, and a failed load rejection test can mean re-tuning the governor and steam bypass system and repeating the whole sequence days later.
Deskely holds load rejection, droop response and black start test records against the same subsystem tags used throughout commissioning, so a repeated test is a new dated instance rather than a document overwritten under schedule pressure, and the TSO's witness sees the full attempt history, not just the pass.
What reliability sign-off reads
The records a grid operator and an insurer both want to see before a combined-cycle unit is declared commercial.
A combined-cycle plant proves itself across three distinct machines and a grid interface, on a schedule where a missed steam blow criterion can push first fire by weeks. The dossier keeps turbine, boiler and grid records under one tag set so commercial operation is argued from evidence, not a punch list.
Gas turbine first-fire and start-up log
Combustion, exhaust temperature spread and vibration are within OEM limits at ignition
During gas turbine commissioning, ahead of steam raising
Steam blow completion record
Piping is clean to the target cleanliness before steam is admitted to the turbine
Before HRSG-to-steam-turbine tie-in
Grid code compliance witness test
The unit's voltage, frequency and fault-ride-through response meets the connection agreement
Pre-synchronisation, witnessed by the network operator
HRSG hydrostatic and chemical clean certificate
Pressure boundary integrity and internal cleanliness meet the design code before firing
Pre-commissioning, before first steam
Reliability run and trip-free operation record
The unit sustains rated load without an unplanned trip over the contractual test window
During the performance and reliability test, ahead of commercial operation
Capacity and heat rate performance test report
Output and fuel efficiency meet the contracted guarantee figures
At the guarantee test, after reliability run completion
How it runs
From chemical cleaning to a trip-free reliability run.
Combined cycle projects reward a subsystem structure agreed before construction finishes, because first fire and first synchronisation arrive fast once mechanical work is done.
- 01
Break the plant into subsystems
GT, HRSG, ST, generator, fuel gas, cooling water, DCS and protection, each with its own turnover package.
- 02
Parse the tag register
P&IDs, single lines and equipment lists drafted into a reviewed register with prerequisites mapped between subsystems.
- 03
Run cleaning and steam blows
Chemical cleaning, boil-out and steam blow records captured against the piping subsystem, with target plate evidence attached.
- 04
Loop-check and protection-test
I&C loop checks and protection relay settings signed per device before the subsystem is offered for energisation.
- 05
Gate first fire and first sync
Certificates issued only once fuel gas, cooling water, DCS and grid compliance prerequisites are signed.
- 06
Track the reliability run
Run period, trips and causes logged against the responsible subsystem, PAC and FAC issued from the record set.
FAQ
Questions about Gas and combined cycle scopes.
Keep reading
Power and grid commissioning
The full sector view: subsystems, ITRs, punch categories, energisation and reliability run evidence.
Read moreCertificates
Mechanical completion, energisation, first fire and reliability run certificates issued from signed records.
Read moreITR records
A, B and C records completed in the field and signed against the equipment tag they belong to.
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