How do cylinder pressure sensors from Kistler make large engines more efficient

Winterthur, December 2019 – Kistler continuously develops its piezoelectric pressure sensors for large engines to pave the way for efficiency gains and new technologies such as dual or multi-fuel operation. Innovative sensor technology, custom adaptations and lifetime-optimized design: these advantages yield sustainable increases in performance and cost efficiency.

Stricter emission guidelines for marine engines and large stationary engines mean that cylinder pressure monitoring is becoming increasingly important. Continuous monitoring yields many benefits in addition to increased engine efficiency: in particular, optimization of the combustion process – the key to operating dual-fuel engines that are more environment-friendly, but also more complex. With solutions from Kistler, fuel savings of up to 2% per year and per large engine can be achieved – an average reduction of environmental pollution equivalent to about 200 tonnes of CO2.

New sensor designs for greater precision and longer lifetimes

The trend towards higher mean effective pressures (MEP) is increasing the requirements for the robustness of sensors that are exposed to high pressure levels, high temperatures (of up to 350°C) and vibrations. Kistler is responding to these needs by developing new sensor architectures that combine maximum ruggedness with high accuracy throughout the sensor's lifetime. The Swiss measurement technology experts have now unveiled their cylinder pressure sensor 6635A1: a solution for use in medium-speed four-stroke engines that sets new standards thanks to a host of innovative features.

Resource-efficient and cost-effective operation over long periods

Engine manufacturers across the globe include cylinder pressure sensors from Kistler in their closed loop control systems to optimize engine performance during operation. Continuously monitored pressure in all cylinders is transmitted to an engine control unit: the values are visualized and adjusted accordingly. This Closed Loop Combustion Control (CLCC) yields multiple benefits: the combustion process is optimized, fuel is saved and premature wear on costly parts – potentially resulting in engine failure – is prevented.

Application-specific know-how

Simulation-based development of new sensor concepts is complemented by close collaboration with the engine manufacturer so that the exact installation and operating conditions can be taken into account. When new engines are being designed it is possible to influence key sensor parameters during the development process: these include the installation position in the cylinder, the type of seal and the electrical interface.

One especially important factor is validation of the sensor's characteristics throughout its service life. For this purpose, Kistler has developed its own testing procedures that can replicate heat- and vibration-induced stresses during more than one billion pressure cycles. However, tests on the actual engine are the only way to obtain definitive information about the real performance of the cylinder pressure sensors for CLCC.

Engine power plants are one of the main application areas for cylinder pressure sensors from Kistler. Thanks to CLCC, growing numbers of these plants can operate in dual-fuel or even multi-fuel mode – and even though the use of solar power and wind energy is set to increase in the future, such large plants will continue to play a key part in stabilizing the power grid.

Benefits of solutions from Kistler at a glance:

• Maximum operational reliability thanks to tried-and-tested high-quality products
• Reproducible, high-resolution cylinder pressure measurement
• Precise engine feedback to optimize combustion
• Lower fuel consumption
• Reduced emissions
• Customer-specific solutions for every application
• Ideal for engines with flexible fuel options (multi-fuel)
• Reduced service outlay
• Attractive ROI thanks to long sensor lifetimes