Liddell Power Station Water Plant Systems – C&I Upgrades

PROJECT TITLE:
Liddell Power Station Water Plant Systems – Controls and Instrumentation Upgrade

CLIENT: 
Macquarie Generation

Background:
Liddell Power Station, which is owned and operated by Macquarie Generation, is a 4*500MW conventional coal fired power station located in the Hunter Valley in NSW Australia. PROVECTA won two significant contracts (under open tender) to upgrade the controls for the Liddell Power Station major water plant systems ( Condensate Polishing / Regeneration and Demineralised Water Plant).  Both projects required the control and instrumentation systems to be upgraded without impacting on the power station generation output.  This required detailed project management and planning. Some site upgrade work was performed with generation plant in service (polishers) , and  some upgrade work involved staging and minimising the amount of water plant out of service at any one time by performing controls upgrade work on plant over short intensive periods.

Condensate Polishing and Regeneration Plant Upgrade:
The Liddell Condensate Polishing Plant consists of a set of four polisher vessels for each of the four generating units. Exhausted vessels are automatically regenerated with sulphuric acid and caustic via one of two identical regeneration trains. Provecta performed the work to upgrade the controls for the Condensate Polishing and associated Regeneration Plant from the original Modicon 984 PLCs to a Yokogawa CS3000 DCS platform. The project included design, supply, installation and commissioning of control and instrumentation systems and equipment, including new operator interface and operator training.

Demineralised Water Plant Upgrade:
This plant (consisting of 4 trains and total throughput capacity of  4000 KL) had for many years been controlled by a number of Modicon PLCs with a rudimentary HMI system. This project involved the complete removal of these PLC controls and HMI and replacement with an integrated Yokogawa CS3000 DCS. The project involved switchboard modifications, design of DCS infrastructure, supply and installation of new instrumentation, fiber optic network installation, and plant logic enhancements.