With the global demand for natural gas rising and a 50% increase expected by 2030, Wärtsilä is introducing its popular 34SG gas engines to the gas compressor market. Having outputs of 4,050kW – 9,000kW (5,430bhp to 12,070bhp), these gas engines offer considerable lifecycle cost improvement for compressor owners and operators. Typical applications are for gas pipelines and gas storage.

For a typical 9,000kW (12,000hp) compressor drive installation, owners with a Wärtsilä 34SG gas engine driver can expect to lower their lifecycle costs by around 20% to 40%, compared with other prime movers currently on the market. The cost savings will be even bigger when compared with existing, older compressor drives, making upgrades an attractive prospect.

The Wärtsilä 34SG engines are available in three variants: the nine-cylinder, in-line Wärtsilä 9L34SG with 4,050kW (5,430bhp) shaft power, the 16-cylinder Wärtsilä 16V34SG engine of 7,200kW (9,655bhp), and the 20-cylinder Wärtsilä 20V34SG with 9,000kW (12,070bhp) shaft power. The nominal speed is 750rpm.

Compared with gas turbines often used for driving compressor sets in this power range, Wärtsilä 34SG engines offer substantially lower fuel gas consumption and greater turndown ratios.

The engines have a full-load efficiency of 46.3% (heat rate 5493 BTU/hph), a 30% speed turndown ratio (to 525rpm) and a 70% torque turndown ratio. Furthermore, both engine efficiency and exhaust emissions remain virtually unchanged on the whole load range.

The Wärtsilä 34SG engine has low exhaust emissions. NOX emissions remain below the 500mg/Nm3 dry at 5% O2 level throughout the entire speed and torque range.

The Wärtsilä 34SG compressor-drive engine is based on a thoroughly proven engine family, the world-famous Wärtsilä 32. In all, Wärtsilä has delivered more than 5,000 engines of the Wärtsilä 32 and 34 types. This corresponds to more than 20,000MW of installed power worldwide, establishing Wärtsilä as the absolute market leader for this size of engine.

The new compressor-drive engine is derived from the second-generation Wärtsilä 34SG, which in 2001 succeeded the first-generation Wärtsilä 34SG engines, originally introduced in 1995. Since its introduction to the power generation market, the second-generation Wärtsilä 34SG has sold more than 300 engines, accounting for 2500MW of power.

The Wärtsilä 34SG engine has a fully electronic engine control system for all the principal engine functions: gas feed, charge air flow, fuel gas flow control, individual cylinders and ignition control. Through complete control of these critical engine functions, engine performance can be optimized over the whole operating field.

As a true heavy-duty engine, the Wärtsilä 34SG is well-suited to continuous high load applications, such as gas compressor drives on pipelines. The intervals between planned maintenance requirements are extensive, with for example, 24,000 running hours between cylinder head and piston overhauls.

The new compressor-drive engines are supported through Wärtsilä’s extensive worldwide network of trained field support and spare parts resources. Wärtsilä will also provide long-term service and support agreements that are tuned to meet the specific needs of customers.