The turbines awaiting reinstallation
Thaddeus Berry & Martin ‘Nobby’ Marsh, HPI, USA
In 2003, a set of 2X GEC EAS1 generators were installed in a water treatment plant in the Karkh region of Iraq, about 27 km north of Baghdad in Tajii. Two years later in 2005, the power plant was severely damaged by an incident that left the building’s circuitry, switchgear, circuit breakers, generators, auxiliaries and air-conditioning systems at the water treatment facility completely inoperable.
The equipment that remained intact eroded because of the extreme environmental conditions of the Iraqi desert. Without the facility, roughly
6 million people in Baghdad were left with few choices for their potable water supply.
In 2008, HPI of Houston, USA, was awarded a contract as part of a project run by the US Army Corps of Engineers and the Government of Iraq to refurbish the turbines and associated controls. To restore plant operation the project required a
multi-disciplined, multi-cultural team to work together through challenging conditions, seven days a week for six months.
KARKH’S RECENT HISTORY
In addition to serving the communities around Karkh, the water treatment plant supplies about 40 per cent of Baghdad’s potable water with a daily output of
1.36 million litres. Water is supplied to the cities through a 2.1-meter diameter pipe which connects several storage facilities located in and around Baghdad.
Adjacent to the water treatment plant is a dedicated power generation facility that provides back-up power to the treatment facility. Power outages at the plant stop the output cycle and water reserves and resources diminish.
During an inspection of the site in 2008, Iraqi contractors discovered that Hawker Siddeley Dynamics Engineering (HSDE), a British turbine supply and engineering firm, had provided the original twin
Rolls-Royce jet turbine generators for the power plant. When HSDE ceased operations in the United States, HPI assumed many of the company’s prior business relationships. Several of the managers of HPI are also former HSDE employees. This led Iraqi contractors to contact HPI to discuss the replacement of the turbine controls for the power plant, commencing with a mechanical survey of the existing turbines.
A COOPERATIVE EFFORT
Appreciating the importance of the facility, HPI submitted the rehabilitation proposal mid-August of 2008. In October 2008, the company was awarded the project because of its familiarity with the specific turbine set and extensive industry relationships with equipment part distributors.
The final scope of the work included replacing the turbine control system and performing a complete mechanical rehabilitation of the turbine generators.
As part of the contract, HPI also provided new motor control centres (MCCs), integrated switchgear, rebuilt the earthing and grounding system, re-cabled the control and instrumentation systems, installed switchgear cabling, and rehabilitated the black start system (water cooling system and controls). The company also installed the first of its kind fire suppression system.
TECHNICAL CHALLENGES AND SCOPE
The original condition of the site presented a number of technical challenges, including having large parts of the original plant systems missing, such as batteries, MCC, control equipment, fire & gas system; most of the cabling having been cut during the theft of the panels or damaged by the explosion; and many of the electrical motors having been removed. There was structural damage to the turbine enclosure and exhaust and one of the units had suffered an overspeed and the power turbine had exited through the turbine hall wall.
Upon arriving on site, one of the first priorities for the HPI team was arranging removal of the sand that permeated everything. The gas turbine was then removed for inspection, and repairs or replacements were made to the mechanical turbine components. Parts were sourced from suppliers worldwide. HPI’s large technical library contained a complete set of OEM manuals, which enabled the replacement equipment to be quickly specified.
The turbine fuel system was upgraded with aftermarket Woodward liquid fuel valves
The new control system was built around the Allen Bradley ControlLogix PLC and incorporated Entek vibration monitoring, Beckwith generator protection relay and a Basler DECS200 AVR. Using a touch-screen HMI as the main interface, the system was designed to require minimal operator interaction, with a single operator action to bring the unit online.
Additional aspects of HPI’s work included:
- Design of a new fire suppression system as the original installation did not have this system.
- Redesign and refurbishment of the black start engine’s starting and cooling system.
- Design of the fuel forwarding and filtering system because all piping between the turbine and the main fuel storage tanks had been removed.
- Installation of a water wash system, designed and fabricated in the US.
- Rebuilding of the fuel filtering and control system inside the turbine hall.
- Re-cabling of the control cabling between the turbine and the control system, the MCCs and the generator switchgear, all of which had been damaged or removed.
- Replacement of the turbine fuel system utilizing new aftermarket Woodward liquid fuel valves, block and vent valves, and repairing the fuel pipe work, which had been damaged.
- Repairing the structural damage to air inlet and exhaust stacks, as well as replacing the existing double bank of air filters, which weighed ten times their normal weight each due to prolonged exposure to the elements.
- The entire MCC room had been looted and HPI provided a new MCC system, rebuilt the entire universal power supply, and integrated this with the switchgear assembly. Furthermore, HPI designed and installed the earthing and grounding network for this equipment despite the fact that was not in the original scope.
The main acceptance test of the generator required the unit to be black started and to accept the starting of the two main water pumps. Each pump effectively equates to a 45 per cent step load increase and requires active tuning of the AVR in order to maintain the voltage within limits when the pumps are initially started.
The project became close to the hearts of HPI and Iraqi project team members. Getting the plant back into operations was more than a technical and commercial objective, it was a humanitarian one.
In several instances the HPI team elected to go beyond the contracted scope of work: “The project meant a lot to us”, says Thaddeus Berry, a member of the project support team at HPI. “Our motive went well beyond satisfying our contractual obligations. The team focused on supplying the people of Karkh and the surrounding areas with fresh drinking water”.
By July 2009, 90 per cent of the project had been completed. Total site time was just under six months and despite harsh living conditions and limited phone and computer access, every team member stayed.
The bonds formed were so strong, no one wanted to be rotated out because they wanted to see the project to the end. Of course, challenges did arise that delayed the fast track pace. Shipments were difficult to bring into Iraq – some were misdirected and never recovered. Batteries were stuck at the border in Jordan and had to meet government approvals before being released and all refurbished parts required export. Regardless of the source, every shipment had to go through multiple layers before they could reach the final destination.
FAST TRACK TO STARTUP
The HPI/Iraqi team worked seven days a week for six months, ending each day with a military escort to the local US base. The plant was completed in February 2010 after receipt of a long-awaited fuel shipment.
Despite the harsh conditions faced in Iraq, HPI was proud to have participated in this project. “Providing drinking water to millions of people is a rewarding project”, says Nobby Marsh, project manager, HPI.
The Karkh water treatment plant is still operating smoothly and has the full support of HPI should it need anything in the future. The shared goals of the HPI and Iraqi team members, despite cultural differences, created a bond among the team that facilitated the work and will last a lifetime. MEE