Vibration diagnostics on marine diesel engines with IMES EPM-XPplus engine analyser
The well-proven engine analyser EPM-XPplus offers now the possibility of additional vibration measurements on engines. A vibration sensor was specifically developed by IMES. For application it will be electrically connected on one side to the hand-held device via a cable and on the other side via a magnetic holder to the injector or pump. The subsequent evaluation of the measured data will be processed by the EPM-XPplus visualisation software.
By regular measurements during engine operation with the EPM-XPplus without vibration sensor the engineer can detect occurrent failure. Possible causes of failure could be a deviation from the mean indicated pressure (MIP), the peak pressure (Pmax) or compression pressure (Pcomp). The failure can be immediately identified by the analysis of the indicator diagrams. However, there are a number of effects that are very hard to identify only by analysing the indicator diagrams, especially failure at the high-pressure fuel system and failure at the control of the inlet valve and exhaust valve.
With the existing procedure of the cylinder pressure indicator system, the exact point of fuel injection and the valve movement cannot be determined or only inexactly determined. A direct measurement of these processes is very extensive.
The vibration sensor as part of the engine analyser EPM-XPplus offers advanced diagnostic options for marine engines. For direct measurement the vibration sensor will be e.g., magnetically installed on the injector. During cylinder pressure indication the vibration sensor records the point of lifting and landing of the injector needle as well as the beginning and ending of the fuel supply by the injection pump.
The experience in the performance analysis of marine engines shows, that the analysis of vibration diagrams, that have been recorded parallel to the indicator diagrams, delivers very good results.
Marine engineers can achieve the following results by using the EPM-XPplus device including vibration sensor:
Phases of lifting and landing of the injector needle
Beginning and ending of the circulation of the heated heavy fuel in the fuel system
Phases of beginning of fuel supply and of shutdown of the highpressure pump
Phases of closing and in some cases of opening of the gas distribution valves
The user will get all these information directly during operation with the vibration sensor. This method described above also fulfils the requirements of the marine classification societies regarding non-destructive application as there is no need of mechanical intervention at the engine for installing of the vibration sensor.
October 2021
Visit us at the Europort exhibition in Rotterdam
We kindly invite you to visit us at our stand 3407.
The Europort exhibiton will be held in Rotterdam, the largest port city in Europe, from Tuesday 02. November to Friday 05. November 2021.
It is the leading international exhibition for special purpose vessels.
We are please to present you our new and extreme robust cylinder pressure sensor types as well as the new functions of our well proven engine analyser EPM-XP plus and our combustion control module CCM.
August 2021
Visit us at NEVA in St. Petersburg, Russia
NEVA, the International Maritime Exhibition and Conference for Commercial Shipping, Shipbuilding, Offshore Energy, Ports, Inland Waterways and Oceanography, is one of the world’s ten largest maritime industry fairs.
The Neva will take place on 4 days from Tuesday, 21. September to Friday, 24. September 2021 in Saint Petersburg.
We kindly invite you to visit us at our booth G2 347.9 at the German Pavillion.
May 2021
Next generation combustion pressure sensor for continuous pressure measurement on gas pipeline engines
IMES, a leading manufacturer of cylinder pressure sensors, has developed a next generation combustion pressure sensor for permanent installation on reciprocating gas engines. The new sensor, called the HTT-06, is extremely durable and robust. The HTT-06 is also very accurate and has very stable calibration characteristics. The HTT-06 is certified for Class I, Division 2, Groups C & D hazardous environments. The HTT-06 also meets the most stringent ingress protection requirements and is IP 69 rated.
The measuring cell of the new sensor is a high temperature, thin film strain gauge deposited onto a steel diaphragm using TION (Titanium oxynitride), which offers very good temperature stability. The measuring cell is located near the face of the sensor which minimizes pressure resonance. HTT-06 is rated for 300 C (572 F) continuous and 350 C (662 F) for short periods. The sensor can withstand the high levels of shock and vibration associated with engine environments. The HTT-06 has a M14 x 1.25 thread.
IMES sensors are manufactured with a highly automated, high volume production process which allows IMES to offer high quality sensors at very competitive prices.
Sixty-two HTT-06 sensors have been installed on Clark and Cooper-Bessemer engines for the past year with no sensor failures. Over 2000 operating hours have been accumulated on each of three Clark TCV-16 engines in conjunction with Machinery Monitoring Systems (MMS) ProBalance® system. One of the engines uses the HTT-06 sensor for closed-loop cylinder balancing with MMS' ProBalance® Plus system.
Bryan Stewart, CFO of MMS, commented that “We were impressed with IMES’ support throughout the test of the first units installed and have been very pleased with the robust design as well as the HTT-06 sensor's performance and durability.”
The HTT-06 has a design life of 16,000 or more operating hours for approved engine types when installed per IMES' specifications. IMES offers a "Sensor Test Kit" that allows the operator to check the sensor's calibration characteristics (gain and zero offset) using a calibrated hydraulic pressure pump. IMES recommends checking the sensor calibration annually to ensure optimum accuracy and performance.
IMES has over 20 years of experience with cylinder pressure sensors and is a world-leading expert in the field. IMES has developed solutions for many of the difficult challenges facing the engine industry, including alternative fuels, higher power density, increased efficiency, and sensor miniaturization to allow combustion pressure sensing to be used on ever smaller engines.
September 2020
New cylinder pressure sensor generation with extremely robustness for new thermodynamic control concepts on high efficient marine gas engines
The development of modern gas engines is closely related to the measurement and processing of the cylinder pressure, thus with the development of cylinder pressure sensors itself.
At first, cylinder pressure sensors have been used within gas engines management to detect the peak pressure and the detection of knocking and misfiring. The primary goal was to balance the different cylinders and thus to get a smooth engine run.
During the last 5-10 years the development of gas engines reached operating ranges, where now the knowledge of the combustion process of every cylinder in real-time is strictly needed. Moreover, the trend to higher indicated mean effective pressure (IMEP) for gas engines in the broad range of 100... 1800 rpm comes along with additional challenges to the cylinder pressure sensors. Beside the IMEP, also the Heat Release Rate (HRR), Mass Fraction Burned (MFB) as well as other specific thermodynamic values gain more and more importance for gas engine control, even for serial applications.
Other requirements from engine manufacturer regarding the robustness of cylinder pressure sensors are also getting more challenging. Some examples here are (regular) peak pressures of up to 300 bar, high vibration load, shocks up to 1000g and maximum speed of pressure change of up to 1.000 bar/ms.
IMES as a leading manufacturer of cylinder pressure sensors has developed its new cylinder pressure sensor generation type HTT-06CA and CPS-03CA incl. IP69 protection class to fulfil the engine manufacturer requirements for application on new high efficiency gas engines. The new sensors are extremely robust and fulfil the demand of high accuracy with low dynamic- and static zero drift. The sensor membrane can withstand static pressure up to 800 bar and has a natural frequency range of 80 - 100 kHz.
Basic of the sensor is the high temperature strain gauge thin film measuring element based on TION (Titanium oxynitride) which is designed for very good temperature stability. The measuring elements of the new cylinder pressure sensor generation are located in the front of the sensor thread (M10x1 and M14x1,25). A new connection method for temperature up 400 °C incl. withstanding high shock levels was developed and successful tested on laboratory equipment and on test engines.
For application on pressure controlled high efficiency gas engines it is necessary to have a good long-life stability and a good accuracy of sensor for thermodynamic calculations. At the Paul-Scherrer-Institut in Switzerland (LCC) comparison between IMES CPS-03CA sensor and high accuracy piezoelectric type sensor were done in June 2020 on a Wärtsilä 6L20DF engine. The thermodynamic comparison @ 18 bar IMEP showed to the reference sensor deviation of 0,4 bar in Pmax and 0,5bar IMEP.
One of the outstanding capabilities of the IMES new sensor is its long-term stability with constant measuring characteristics.The sensor shall withstand operating life time of 20'000 hours in gas, diesel and dual fuel 4-Stroke engines with a power range equal to or bigger than 100 kW/cylinder. The life-time of the pressure sensor depends typically on the service interval which is 16,000 to 20,000 h running hours which correspondents to an operation time of 2-5 years. Together with the IMES “Check-box” the operator can check with a static pressure device actual span- and offset condition of installed cylinder pressure sensor via serial interface of sensor electronic.
The long-time operation tests were done on MV “BIT Viking” on two Wärtsilä 6L50DF engines. During the long-term operation the sensors were taken off from the engine after 6.000 h and sent back to IMES for checking the original calibration data. The span and offset of each sensor were measured over the full temperature range. The experienced drifts in span and offset were minor, which is very important fort the use on control loops on engines.
HTT-06CA and CPS-03CA received DNV-GL marine type approval. Further marine type approvals are in preparation.
IMES as one of the leading manufacturer of cylinder pressure sensors shows, which solution can be provided to the different faced challenges, the impact of alternative fuels and engine designs as well as miniaturization of the sensors for low cylinder power of only 50 kW/cylinder as well as competitive costs need for serial applications in gas engines.
April 2020
IMES expands company building
IMES GmbH, the specialist for cylinder pressure sensors and combustion control systems, is investing in an extension of the existing building. Ground-breaking was in March 2020.
The annexe has an area of 750 m². As IMES wants to conduct further production stages in-house and to improve quality management, the production area will be extended by 350 m². The remaining area is exclusively for the development department.
Over the past years IMES expands its market position by continuous development of cylinder pressure sensors and combustion control systems according to their customers’ requirements. So the new membrane pressure sensor for the engine- and plastics industry will be also manufactured in the new building.
IMES intends to create 15 new jobs.
The total investment costs for the new building inclusive new production facilities amounts to 1,5 million Euro. In Autumn 2020 the construction of the building will be finished.
