6 MW gas engine for the big time1 June 2001
Caterpillar has launched a new gas engine designed for electric power generation, CHP and petroleum applications. The new G16CM34 engine offers a power output of 6.1 MW at 750 rpm and boasts electrical efficiency levels of 43.4 per cent (44.5 per cent mechanical efficiency), heat efficiency levels of 49.5 per cent and a combined efficiency close to 95 per cent making it one of the most efficient gas engines in the world. The company is aiming, with this large unit, the largest they have ever built, to become a major player in the growing power generation industry worldwide.
As an example of what this increased efficiency could mean to customers, installing this new engine with 43.4per cent electrical efficiency as a replacement for older technology offering 40per cent electrical efficiency would result in fuel savings of more than 1 million Euros. This calculation is based on annual usage of 6000 hours, at a rating of 5920 kW output and a gas price of 0.015 euro cents per kW/h over a ten year life-cycle. With gas prices increasing and fuel costs accounting for over 65per cent of the overall cost of the power generation solution, the benefits of the higher levels of electrical efficiency offered by the new Cat G16CM34 are becoming an even more important differentiation factor.
The first Caterpillar gas engine to be built at Kiel in Germany, the 85 tonne G16CM34 engine is designed for a major overhaul interval of 120,000 hours. Designed to meet the needs of utility companies, larger distributed power companies, energy intensive manufacturing facilities and larger district/community heating schemes, the 16 cylinder G16CM34 is based on the highly successful Caterpillar CM 32 heavy fuel engine in terms of casings and crankshaft, but it has otherwise been completely redesigned for natural gas fuel. Major changes include a new cylinder head, a complete new fuel system and “state of the art” electronic engine monitoring and governing systems.
The monitoring system allows the engine to be monitored remotely at a number of locations including the Kiel plant and in a variety of locations within the customer organisation. Other major design advances include a lean burn combustion chamber, spark ignited pre chamber, electronically controlled gas admission valve for each cylinder, independent fuel pressure control for pre chamber and main chamber lines and detonation control for each cylinder. The one piece engine block (free from cooling water) is constructed of nodular cast iron and the engine features cylinder liners designed for low lube oil consumption with a calibration ring and low exhaust gas emissions better than the German TA Luft standard.
The engine itself measures 8.09 m (length), 3.47 m (height) and 2.96 m (width) and can be supplied in a variety of forms depending on the application. For petroleum applications in which the G16CM34 uses natural gas to provide electrical power for offshore or onshore installations, the engine is set up according to customer specifications. On the other hand, for CHP applications it can be supplied as a complete CHP unit with all generating and heat recovery systems in place.
Caterpillar has carried out an extensive programme of testing on the G16CM34 engine in live conditions in Bramming Fjernvaerme in Denmark and the engine has now been handed over. Notwithstanding the high capital cost of the unit, (2.5 to 3.5 million dollars installed) two other orders for G16CM34 engines have also been secured recently.