Dry low emission process limits impact from noxious gases

July 1, 2005
Adry low emission (DLE) kit has been developed by the Volvo Aero Corp. to help gas turbine customers limit emissions of nitrogen oxide and other noxious gases.

Adry low emission (DLE) kit has been developed by the Volvo Aero Corp. to help gas turbine customers limit emissions of nitrogen oxide and other noxious gases. The move looks timely given the desire of many operators to improve the environmental performance of their turbines, and of governments to find new ways of meeting 2010 emissions commitments under the Kyoto protocol. Eventually operators are likely to be required to make such an upgrade, according to Simon Raymond, sales manager for marketing and sales in Volvo Aero’s Land and Marine Gas Turbine division.

Wintershall retrofit

Next spring, the company will perform its first DLE retrofit to an offshore Dresser Rand DR990 turbine, on Wintershall’s P6-A platform in the Dutch North Sea. Recently, it also installed a system on an onshore-based DR990. The company also provides a maintenance service on five LM1600 gas turbines converted to DLE on ConocoPhillips’ Ekofisk field off Norway.

DR990 gas turbine fitted with DLE (dry low emission) combustion chambers.

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DLE technology provides cleaner combustion at higher temperatures, thereby reducing emission levels per unit of power generated. Fuel is mixed in a pre-mixing chamber, one of which is attached to each of the turbine’s seven combustion chambers. Use of the kit enables NOx emissions to be reduced from 170 ppm to 31, the company says.

Nigerian service

As one of only two LM1600 service providers licensed by GE, Volvo Aero is a leading player in the maintenance of this turbine, with responsibility for 20 units, including seven offshore.Volvo Aero is also service provider for an LM1600 unit owned by NAM in The Netherlands, and for Shell’s three turbines in Nigeria. In addition, it is the sole service provider to the 90 DR990 turbines in service around the world, of which 20 are on offshore duty.

Turbine overhauls are conducted at Volvo Aero’s plant in Trollhättan, Sweden. It also has an LM1600 service center at Zaragoza, Spain, where it first started offering maintenance for this model back in 1992. Three main types of service contract are available. The customer can pay a set price per running hour or calendar period for fixed services at scheduled intervals. Alternatively, unscheduled service can be included, or services can be provided on an as-required basis. And turbines can also be provided on lease as replacements for units undergoing maintenance.

In addition to its role as service provider for the LM1600, it is a component partner with GE for several models, including the LM1600, LM2500, LM6000, and the new LMS100, a 100 MW industrial turbine, and with other manufacturers for a number of non industrial turbines.

Repair v. changeout

Opportunities are being looked at to develop the company’s service portfolio. These may include partnerships with contractors offering maintenance of parts not handled by Volvo Aero, such as gear boxes and alternators.

Cross-section of a DLE combustion chamber

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Volvo Aero also repairs parts, which can create significant cost savings as replacement material can account for up to 85% of the overall maintenance cost of gas turbines. Compared with aero and marine engines, which have critical parts that have to be retired after a fixed period in service, the land and offshore turbine has the advantage that it can remain in use almost indefinitely - assuming it is well maintained, says Raymond.

Last year, the company took a strategic decision to end manufacture of the VT4400 and VT600 turbines and concentrate instead on the after-market. Following reorganization, the Land & Marine Gas Turbine division became part of Volvo Aero Engine Services. It now shares the same resources as its counterparts in the aero section. “The restructuring has proved positive for the division,” Raymond says.

With sales manager Anders Malm, he is responsible for boosting the company’s profile as an after-market specialits. Both will be taking advantage of the company’s sponsorship of the 2005-06 Volvo Ocean race to make new contacts at all ports visited by the race entrants from the start in Vigo, Spain, in November until the finish in Gothenburg next June.

The company is currently busy tendering for new work or contract renewals, targeting both LM1600 andDR990 users.

For more information, contact Simon Raymond, Volvo Aero Corp. Tel +46 520 944 05, fax +46 520 477 549, [email protected], www.volvoaero.com.