Powerful, Efficient and Reliable Liebherr Gas Engines · 2018-06-02 · Lean-burn engine based on spark ignition principle ... (such as FEM and CFD), ... the ignition process in the

Powerful, Efficient and Reliable Liebherr Gas Engines

Liebherr Gas Engines2

Liebherr Gas Engines

Liebherr Gas Engines 3

Advantages

Engineering competency

State-of-the-art development methods and decades of experience

Performance and efficiency

The most efficient engines of their class

Full equipment

“Plug & play” solution for quick and easy installation

Service and maintenance

Global organisation for local availability and support

Quality and availability

More than 8,000 operating hours per year

Gas engines are developed and manu-factured by Liebherr at the Bulle site in Switzerland. They are designed for sta-tionary applications such as combined heat and power units and for operation with biogas or natural gas.

Gas engines from Liebherr are available in various configurations from 4-cyl-inder inline engines up to 20-cylinder V-engines. The performance spectrum covers a mechanical output range of 145 kW to 1,070 kW at 50 Hz and 169 kW to 1,070 kW for 60 Hz applications.

Reliability, availability and high efficiency are success factors that make Liebherr gas engines extremely cost-effective. The engines are required for non-stop operation and are therefore

extremely reliable, durable and have a high level of quality. The gas engines are characterised by their high power density, which contributes to the high mechanical efficiency of over 43 %.


Liebherr has many years of experience in the design and manufacture of gas engines. In as early as 1996, the first 6-cylinder gas engine was produced in Bulle. The current engine generation was orientated consistently around the

requirements for stationary use in combined heat and power units and special gas systems. Synergy potentials with Liebherr diesel engines are used appropriately.

Engineering expertise


Lean-burn engine based on spark ignition principleThe air-gas mixture in the cylinder is ignited externally by a spark plug. The ignition timing and ignition energy are freely adjustable for ideal combustion. This means safe operation of the engine is assured without misfiring and knocking.

Optimised componentsDuring component design, recourse was taken to practical load profiles. With the aid of modern design and simulation programs (such as FEM and CFD), complete engines and individual components have been optimised in terms of strength, strain, vibrations and flow characteristics.

Application-specific designAll engine components have been examined with regard to their suitability for use in gas engines and have been optimised specifically to the application. For example, the pistons, cylinder heads, valves and mixture cooling system have been especially adapted for natural gas and biogas operation in order to achieve optimum combustion in each case.

Modern test benchesFor optimum adaptation of all engine parameters and ideal calibration of the engines, prototypes at the Bulle site have to endure extensive trial programmes on test benches - in accordance with state-of-the-art engineering - while being run on natural gas and synthetic biogas. The operating behaviour and service life are analysed with continuous operation tests under realistic operating conditions and overload tests.

State-of-the-art development methods and decades of experience

Analyses by means of finite element method

With the finite element method (FEM), the ideal strength can be achieved through optimum material distribution and improved geometry. Parts that are exposed to particularly high levels of stress, such as the conrods, pistons or cylinder head, are examined using this method in order to facilitate a long service life.

CFD flow simulation

Through three dimensional simulation of the flow properties and combustion processes, all of the relevant components are optimised even at the design phase. The image shows the ignition process in the combustion chamber and the sequential spread of the flame front.

Test benches

The test benches are used for functional testing of series production engines and for development. Continuous testing and overload tests provide information about the service life and make it possible to further improve durability.


Performance and efficiency

With a mechanical efficiency rating of over 43 %, gas engines from Liebherr offer the best efficiency values of their performance category. This value is the result of many years

of application experience, careful selection of components, intensive development work and also a high degree of system integration in the area of hard and software.


Economic operationAll components have been selected and optimised with the aim of achieving the longest possible maintenance intervals. This results in low life cycle costs. Thanks to the high efficiency and performance of the engines, operators of a combined heat and power unit or biogas plant can expect a very attractive total cost of ownership (TCO).

Efficient designThe constant inflow and filling of the combustion chambers with mixture ensures that all cylinders are equal. Together with optimal exchange cycles, an even load distribution and high efficiency are therefore possible.

For every engine, the ideal turbocharger has been selected and adjusted optimally. The high efficiency of the turbocharger means that highly efficient exchange cycles and thereby very good overall efficiency can be achieved.

Optimised combustionThe combination of four-valve technology with a gas-specific ideal combustion chamber geometry encourages rapid combustion, which is as complete as possible. This increases the specific power and efficiency. The consistent reduction in cylinder clearances speeds up the start of combustion and improves the complete combustion of the gas mixture, which reduces the fuel consumption and emissions.

The most efficient engines of their class

Ignition system

The ignition energy and ignition phase of ignition systems in Liebherr gas engines can be adjusted according to demand. The result: a high degree of efficiency, fault-free operation and long spark plug durability. Thanks to stable ignition, emissions are also reduced.

Cylinder heads

Thanks to their intelligent and robust design, the four-valve cylinder heads provide efficient combustion and are even suitable for maximum ignition pressures.Six cylinder head bolts facilitate a good distribution of the pressures on the cylinder head and ensure perfect tightness.


Liebherr gas engines are designed for permanent operation. Thanks to the high level of reliability and low downtimes, an availability of considerably more than 8,000 operating

hours per year can be achieved. With the high quality during development and production, Liebherr contributes directly to its customers‘ success.

Quality and availability


More than 8,000 operating hours per year

Two-stage charge air cooler

The two-stage intercooler, which is made entirely from stainless steel, has a high resistance to corrosion even when used with biogas. Due to the design, the heat exchanger is very efficient and well protected against contamination.

One-piece steel piston

To ensure a long service life, even under high combustion pressures, Liebherr gas engines are fitted with one-piece steel pistons. Their geometry has been specially optimised to achieve an ideal combustion chamber and efficient combustion.

Innovative bearing materials

To guarantee the durability of the crankshaft bearings under increasing loads, Liebherr uses special coatings on the composite bearing shells. The Sputter bearings are distinguished by a high resistance to corrosion.

High availabilityLow downtimes ensure minimal maintenance and operating costs. The key contributors to these benefits are the safe dimensioning of the engines, their sophisticated control system and engine peripherals, high mechanical strength as well as high resistance to wear. The operating status of the engine, ignition system and Lambda control is continuously monitored by the engine control system.

Quality assurance throughoutTo safeguard quality, Liebherr employs a contemporary computer-assisted quality management system (CAQ system) that is implemented as early as the product creation process and covers the entire product life cycle. Statistical assessments, FMEA (Failure Mode and Effects Analysis) and CIP (Continuous Improvement Processes) are examples of a consistent process philosophy.

Highest quality standardsQuality assurance at the Bulle site is certified according to DIN EN ISO 9001/2008 and complies with VDA standards (reliability control group).


Through a high level of availability and global logistics partners, assurance is provided that Liebherr engines can be supplied with spare parts day and night. Professional staff in customer services advise competently and work out the best

solution for each customer in terms of costs and speed. The customer service offer is rounded off by a comprehensive training programme.

Service and maintenance


Global organisation for local availability and support

Optimum accessibility

Thanks to the clearly defined concept and accessibility of the parts fitted, engine maintenance is easy and efficient.

Global availability of spare parts

Spare parts are made available around the world in a matter of hours. Competent Liebherr staff members are quickly at the scene around the world whenever they are needed. The Liebherr network is utilised optimally according to requirement.

High quality of repair

Maintenance and repair kits simplify handling and ensure a high level of quality in the maintenance and repair work that needs to be carried out.

means, for example, that oil filters are easy to reach and cylinder heads can be replaced individually. The practical arrangement of maintenance and spare parts kits also contributes towards a high level of availability.

Structured documentationLiebherr provides extensive documentation on the reliable planning and calculation of requisite maintenance or repair work. Well structured documents make it is easier to perform the tasks.

Fitter training courses with qualificationThe comprehensive training programme prepares our customers’ fitters for efficient customer service tasks. Liebherr therefore offers practical basic and continuation training courses. At the well-equipped training centre, the experienced trainers can simulate even extreme repair tasks.

Simple maintenance and repairTo make service work as easy as possible, special attention was given to the overview and accessibility of all parts. This


Full equipment

Liebherr gas engines are distinguished by a high degree of efficiency and availability. To safeguard these attributes in the long-term, the engines are supplied fully equipped. This equipment has been optimally adapted to the engines

and offers a “plug & play” solution. All components have been validated for the engines and extensively tested. Straightforward integration in the system saves time and money.


Plug & play solution for quick and easy installation

Optimised hardware

All components have been carefully selected and optimally adapted, tested and validated for the engines. Fine calibration for adaptation to the specific application is very straightforward.

Electrical equipment

All of the sensors installed in the engine are supplied wired. For installation in the system, they just have to be connected to the control unit.

Software and engine programming

The supplied engine software already contains all of the requisite parameters. With the carefully validated and adapted values, the performance values of Liebherr engines can be achieved reliably. At the same time there is enough scope for fine tuning in the field.

Sensors• Coolant temperature sensor• Coolant pressure sensor• Gas mixture temperature sensor• Gas mixture pressure sensor• Engine oil temperature sensor• Engine oil pressure sensor• Speed sensor• Ignition signal sender

Engine control and ignition system• Engine control system and colour display• Ignition system• Ignition control unit• Knock monitoring system• Electronic speed regulator• Sensor technology and engine wiring

More options on request

Equipment• Starter• Turbocharger• Two-stage charge air cooler• Gas / air mixer with actuator• Thermal sensor in every cylinder head• Secure attachment• Spark plugs• Control flap with actuator• Engine control and ignition system

Gas engines from Liebherr are supplied ready for installation as complete units and can be installed as core components in combined heat and power units. The engine is connected to the alternator via a standard flange according to SAE.


Wiring harness with sensor technology

Liebherr gas engines are supplied fully wired. All of the sensors are already integrated in the wiring harness.

Throttle valve

This compact unit with integrated actuators controls the speed and output of the engine by regulating the volume of the gas mixture.

Ignition system

The modern ignition system is integrated optimally in the engine concept and contributes towards steady ignition and thereby a high degree of efficiency.

Full equipment


Two-stage stainless steel intercooler

The stainless steel, two-stage intercooler is designed for natural gas and biogas, thereby ensuring maximum energy recovery.

Turbocharger

The turbocharger was especially designed for gas operation and ensures that the engines run steadily and highly efficiently.

Gas mixer

Compact design, with integrated actuator valve and venturi, enables high resolution lambda settings. Flexible means of application are enabled by the modular venturi structure.

Basic engine

The basic engines impress with their sturdy design. They are tried and tested under tough conditions.


Engine G934Full equipment availability yesConfiguration 4 in-lineCapacity dm3 7Bore mm 122Stroke mm 150Weight kg 950Dimensions (LxWxH) mm 1,480 x 990 x 920

50 Hz 60 HzRated speed rpm 1,500 1,800Rated power (mech.) kW 145 145Max. effect. mean pressure bar 16.50 13,75Air ratio λ > 1.6 > 1.6Flywheel housing SAE 1Mass moment of inertia kg*m² 2.37Mechanical efficiency % 41.5 40.1

Engine G944Full equipment availability yesConfiguration 4 in-lineCapacity dm3 8Bore mm 130Stroke mm 150Weight kg 950Dimensions (LxWxH) mm 1,480 x 990 x 920

50 Hz 60 HzRated speed rpm 1,500 1,800Rated power (mech.) kW 164 164Max. effect. mean pressure bar 16.50 13.75Air ratio λ > 1.6 > 1.6Flywheel housing SAE 1Mass moment of inertia kg*m² 2.37Mechanical efficiency % 41.5 40.1

Engine G946Full equipment availability yesConfiguration 6 in-lineCapacity dm3 12Bore mm 130Stroke mm 150Weight kg 1,250Dimensions (LxWxH) mm 1,800 x 990 x 1,100


Product overview


Engine G9508Full equipment availability yesConfiguration 8 in V configurationCapacity dm3 16.7Bore mm 130Stroke mm 157Weight kg 1,700Dimensions (LxWxH) mm 1,370 x 1,120 x 1,500


Engine G9512Full equipment availability yesConfiguration 12 in V configurationCapacity dm3 25Bore mm 130Stroke mm 157Weight kg 2,150Dimensions (LxWxH) mm 1,550 x 1,200 x 1,550


All technical information refer to ISO 3046/1 under standard conditions. For methane percentages, please refer to the technical data sheets.

Version with optimised efficiency.

The details in this overview serve as a means of information only and are not binding values.The details and values specified in the offer are relevant.

Engine G9620Full equipment availability yesConfiguration 20 in V configurationCapacity dm3 48.7Bore mm 135Stroke mm 170Weight kg 4,500Dimensions (LxWxH) mm 2,590 x 1,340 x 1,970

50 Hz 60 HzRated speed rpm 1,500 1,800Rated power (mech.) kW 1,070 1,070Max. effect. mean pressure bar 17.6 14.6Air ratio λ > 1.6 > 1.6Flywheel housing SAE 0Mass moment of inertia kg*m² 5.0Mechanical efficiency % 44


Examples of use


BiogasThe use of gas produced from biomass makes it possible to tap into previously unused energy sources. Liebherr gas engines can run on biogas and thus make a contribution to the renewable energy power supply.

Natural gasNatural gas impresses by its very high efficiency and low CO2 emissions. The clean combustion of the gas means a Liebherr gas engine can be operated with low maintenance costs.

Special deployment

Gas engines from Liebherr can also be operated with other gases, such as sewage gas or landfill gas.

Operation with biogasBiogas, which results from the fermentation of organic material, is increasingly being used for environmentally-friendly generation of power and heat. Due to the variable composition of the raw materials and variable fermentation processes, the components and properties of the biogas and the energy content of the biogas fluctuate widely and must be conditioned in certain circumstances. Thanks to their stainless steel charge air coolers and special bearing material, Liebherr gas engines are very resistant to corrosive gas components and are also suitable for use with a leaner methane content.

Environmentally-friendly useThanks to the low NOx, CO and HC emissions, Liebherr gas engines are very environmentally-friendly. They fulfil the requirements of TA Luft (technical guidance for air quality control) and 1/2 TA L for NOx emissions. The CO emissions can be further reduced by the use of an oxidation catalyst.

Operation with natural gasNatural gas is used mainly to run combined heat and power units for decentralised power supply, e.g. for cogeneration of heat and power in swimming pools, hospitals and residential complexes. The composition of natural gas varies from region to region and this, along with the blending of various gases, leads to a heavy fluctuation of the methane number. Gas engines from Liebherr are also knock-resistant should gas compositions change. This is further safeguarded through knock control.

Liebherr gas engines are suitable for operation with natural gas and biogas. They can be used in combined heat and power units, biogas systems, pump stations, gensets and other stationary applications. The engines are designed for decentralised power supply in continuous operation. Aside from their performance and reliability, customers value the engines mainly because the units are supplied ready for installation.

Liebherr Components

From A to Z – the components division of the Liebherr Group offers a broad range of solutions in the area of mechanical, hydraulic, electric and electronic drive system and control technology. The efficient components and systems are pro-duced at a total of ten production sites around the world to the highest standards of quality. Central contact persons for all product lines are available to our customers at Liebherr-

Components AG and the regional sales and distribution branches.

Liebherr is your partner for joint success: from the product idea to development, manufacture and commissioning right through to customer service solutions like remanufacturing.

components.liebherr.com

Gas engines Diesel engines Fuel injection systems Axial piston hydraulics Hydraulic cylinders

Human-machine interfacesand gateways

Control electronics and sensor technology

Power electronics Control cabinets Software

Slewing bearings Gearboxes and winches Electric machines Remanufacturing

Liebherr-Components AGPost box 222, CH-5415 Nussbaumen / AG +41 56 296 43 00 [email protected]

Liebherr USA, CO.1465 Woodland Drive, Saline, MI 48176, USA +1 734 944 63 34 [email protected]

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Documents

Powerful, Efficient and Reliable Liebherr Gas Engines · 2018-06-02 · Lean-burn engine based on spark ignition principle ... (such as FEM and CFD), ... the ignition process in the