Published in March 2010 Australian Longwall Magazine

Joint ACARP report author Terry O’Beirne of SkillPro Services said the programmable engine control unit would help development engineers to get customised engines certified by the relevant underground coal mining authority.

“No one else has done this before in this market,” he said. “This is a tool that will allow the engineer to adjust the engine for certification more easily.

“As we get newer engines meeting ever-tightening exhaust emission standards, mechanically controlled diesel engines are less likely. All manufacturers are heading towards an electronic engine control unit for their top-line engines.

“Manufacturers of engines typically design and build engines that cannot be tampered with so they don’t have the flexibility to be easily adjusted to Australia’s unique underground requirements, such as emission controls. Overseas engine manufacturers rarely exhibit much interest in unique standards for small specialised markets such as underground coal.”

In the near future, the use of technology like this is inevitable to control modern engines trying to achieve underground approval. It is seen to be a more comprehensive and robust solution than tampering with factory ECUs and/or their related sensors. Programmable ECUs such as those developed can include extensive data logging and be easily integrated with external devices, like methanometers and speed controllers. They are no more or less difficult to have approved than the locked factory ECUs.

The ECU developed by SkillPro Services was initially retrofitted to a modern common-rail engine, replacing the manufacturer’s (tamperproof) ECU and tested extensively in a surface road vehicle. A complete common-rail injection system, along with the programmable ECU, was then successfully retrofitted to a modern Perkins 1104C-44 direct injection engine and tested to AS3584.

The testing found that the ECU could precisely control the engine performance and emission characteristics, with changes to meet any specified emissions target very simply made. In this project, the common-rail injection system itself made no overall improvement to the power of the test engine, but it is believed this was because of poor matching between the individual injection components chosen and the engine itself.

The ECU has potential to be used by diesel engine and vehicle suppliers for underground coal mines. More work is required to have it approved for underground use and integrated with the electrics onboard the vehicle. Relatively simple adjustments via a laptop computer enable major changes in engine response, power and emissions.

The programmable ECU can be easily configured for engines up to eight cylinders and can offer all the features required by a modern emission-controlled diesel, such as multi-phase injection, closed-loop control, compensation for temperature and altitude.

Even without considering statutory approvals, the ECU and related common-rail injection hardware cannot be easily retrofitted to old-generation indirect injection engines, such as the Mazda/Kia/Perkins 6/247 seen in many PJB Mine Cruisers. To do so would require a new cylinder head and pistons, plus a drive system for the ultra high-pressure fuel pump. The authors of the report did not believe this was a financially viable option given the age of the core engine and, as such, this technology is not an answer for improving emissions from old-generation engines.

In order to secure the adjusted engine performance parameters and to ensure that engines are not tampered with by unauthorised personnel, the ECUs need to have access protocols, O’Beirne said.

“While the ECU would give the development engineers some flexibility, it would also have a hierarchy of access to the controls to ensure that unauthorised in-service tampering with the engines does not take place,” he said.

The engine and ECU testing by SkillPro Services also identified a number of potential risks and benefits with different diesel fuels in these modern common-rail diesel engines. This is the subject of ongoing research.