PFS Engineering


Client: PFS Engineering
Site:
Contact Energy - Wairakei
Project: Non-Combustible Gas upgrade (NCG)

Duration: 2 Years

 

Wairakei B station in Taupo has three 30MW generators that have been in operation for decades.

The NCG project encapsulates this idealogy by installing a NASH gas removal system (GRS) which reduces energy loss due to air leakage into the condenser. Therefore the same amount of power can be generated with less incoming steam.The majority of the geothermal fluid taken from the Wairakei field wells is now directed to the recently commissioned Te Mihi station. Therefore Contact Energy has undertaken a drive to improve efficiencies in the Wairaikei stations to produce the same amount of power from less supplied steam.

We upgraded and installed the following on all three 30MW units:

  • Replace 150KVA transformer with larger 750KVA 3.3/0.4kV unit.
  • Replace existing 3.3kv cabling via basement (confined space entry) with larger size to feed new transformer.
  • Replace transformer outgoing cable to new Unit Auxiliary Switchboard.
  • Remove existing Reyrolle switchboard.
  • Install Unit Auxiliary Switchboard.
  • Installation of 300KW ABB VSD on turbine floor level.
  • Installation of VSD cabling to 300KW Liquid Ring Vacuum pump on NASH skid.
  • Installation of multiple power and control ladder racks on four different floor levels.
  • Build PLC Control centre cabinets and install.
  • Install 1000 metres of Fibre Optic ring communication network from local PLC to Gauge Panel PLC cabinet for DCS monitoring.
  • Upgrade of DCS ABB rack, profibus card addition, and Hirschman fibre adaptors.
  • Supply and installation of pressure, temperature, level transmitters, Magflow transmitters and motorized valves.
  • Installation of cabling to all instruments and digital devices.
  • Swagelok stainless steel impulse tube bending and installation.
  • Documented pre-testing of all cabling and instrumentation.
  • Software testing of all actuators and instrumentation.
  • Documented pre-testing of all cabling and instrumentation.
  • Software testing of all actuators and instrumentation.
  • Commissioning, calibrating, operator training and as built documentation.