Electronic indicator for low speed units

18 Oct 2011
The IMES EPM-XP hand-held electronic engine indicator

The IMES EPM-XP hand-held electronic engine indicator

German cylinder pressure measurement company IMES has announced that a further major engine builder has opted for its EPM-XP hand-held electronic engine indicator in place of traditional mechanical devices.

Hyundai Heavy Industries (HHI) of Ulsan, Korea, said to be the largest builder of two stroke engines, is to supply the EPM-XP device for periodic monitoring of cylinder pressure with the two-stroke MAN B&W MC/MC-C and Wärtsilä RT-flex diesels it builds and sells under licence. IMES reports that the new contract with HHI builds on an earlier cooperation which saw the joint development of a cylinder pressure monitoring system for HHI’s Himsen four stroke medium speed engines in 2008,followed shortly by a number of two strokes.

IMES says that to date it has sold over 600 EPM-XP devices, a figure it hopes to more than double by the end of 2012. It also says that HHI, in common with other engine builders, sees the attractions of modern electronic equipment for its customers.

As well as very accurate key engine operating information which can be read out from the EPM-XP device immediately after data acquisition on the engine, recorded values can be downloaded to a PC or notebook via a USB cable and distributed as data files over the internet to interested parties, e.g. the ship owner, engine builder and ship management and service organisations.

“In this way, both engine builders and end users can be increasingly confident that engines in the field are set-up according to their guidelines and will thus run more economically and more reliably,” states IMES company owner Dipl Ing Stefan Neumann. “For example, the electronic data recorded directly during periodic measuring by the EPM-XP can be compared with electronic data from the engine’s factory test runs and the ship’s trials. As well as optimising fuel consumption, an evaluation of the cylinder pressure pattern allows the calculation of mean effective pressure for all cylinders. This feature is of special significance given the 2011 introduction of the IMO Tier II limits for oxides of nitrogen (NOx)."

The IMES software package is delivered on CD-Rom. It is menu-guided and allows graphic representation of key values in various forms. Following download from the hand-held EPM-XP device to a PC or laptop, the acquired data can be processed at leisure. Visualisation includes x-y axis graphs for the pressure patterns of all cylinders which can be superimposed for the purpose of comparisons and depicting spreads and deviations from the data recorded during the factory testing and sea trials. Trends can be derived and visualised from the comparative data. The processed data can be immediately fed into a monitoring and diagnostic system onboard.

The EPM-XP cylinder pressure indicating device is designed for up to 160 measurements per cylinder over a maximum of eight output steps in a range from 25% to 110% on engines with up to 20 cylinders. The relevant engine speed ranges are 40rpm to 300rpm on two stroke engines and up to 1500rpm on four strokes. Cylinder pressures can be recorded in a range from 0 to 300 bar with a claimed precision deviation of 0.5% (full scale).

The EPM-XP device comprises:

  • Hand-held measuring device with LCD display in a robust protective casing powered by a rechargeable block battery – the USB port of the device serves for both data transfer and battery recharge;
  • IMES HTT pressure sensor with flexible armoured hose incorporating a sprung Thompson adapter for rapid connection to the indicator cock;
  • USB cable; 
  • IMES evaluation and visualisation software on a CD-Rom;
  • Instrument carrying case.

The firmware stored in the device allows the acquisition of a complete test bed run. The CD-Rom contains dedicated software allowing the data acquired and/or calculated per load step by the EPM-XP to be evaluated and visualised offline. Capabilities comprise: calculation and depiction of complete pressure patterns per measured cylinder: the maximum compression pressure; the maximum pressure rise (Palpha); the indicating cylinder output and indicated mean effective pressure (IMEP). Further advanced data processing encompasses a compensation function for mean pressure (Pmean) in which deviations from the derived values for maximum cylinder pressure are calculated and visualised for all cylinders. In the Pmean visualisations function all medium pressure curves for all cylinders are superimposed in order to give a graphic representation of deviations in combustion pressure patterns. To check the accuracy of the EPM-XP according to ISO 9001, it can be loaded with static pressure from a pressure testing device and re-calibrated via its software.

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