WORLD PROSPECTS
Rolls-Royce ' s mtu hybrid drive for mining trucks
Diesel engines remain the ideal prime mover for mining trucks . They are the benchmark for performance , availability , maintainability , refuelling range , costs , and are suitable for extreme environmental conditions . But they also account for about 50 % of the GHG emissions of a typical mining operation . Reducing these emissions is a major lever for mining companies to achieve their ambitious decarbonisation goals .
With their typical operating cycle — hauling loads uphill and returning to the loading position usually the same way downhill — mining trucks provide the opportunity to recuperate a considerable amount of energy downhill and store it in batteries . Depending on the topographic profile of the individual mine , up to 30 % diesel fuel savings , respectively GHG reductions , are possible .
Rolls-Royce is already offering mtu engines that fulfil the strict Tier 4 emissions standard to the mining industry , and with not aftertreatment which is unique in the market . These engines not only bring down fuel consumption – and thus CO2 emissions – by around 6 % compared to Tier 2 engines , but also cut NOx emissions by 45 % and particulate matter by 80 %. At the same time they offer increased power with no power loss at altitudes of up to 5,500 m ( 18,000 ft ) as well as reduced installation , maintenance and total ownership costs .
But battery-hybrid powertrains are also a key milestone toward fully GHG-neutral mining truck propulsion , as they help to diminish the drawbacks of potential GHG-neutral fuels : scarcity , costs and / or limited energy storage density . In a recent presentation by Rolls-Royce Application Engineer Alexander Richter , who also is the technical Product Manager for its Series 2000 engines , the company presented the concept of a hybrid drive system for mining trucks , which it will also highlight at MINExpo in September .
Anew agreement between two innovative Australian manufacturing and technology companies is set to deliver a range of new battery-electric vehicle ( BEV ) solutions for underground mining applications . The collaboration will see the installation of the latest world-class BEV technology designed by Ampcontrol into new PPK Mining Equipment ( PPKME ) personnel carrier vehicles . The companies will work together to also retrofit diesel drive trains in a range of other vehicles manufactured by PPKME , including the COALTRAM
A key point about the solution is that it is based on existing and proven mtu technologies . Richter said that Rolls-Royce envisions equipping mining trucks with battery packs ( socalled mtu EnergyPacks ), allowing for significant CO 2 emissions reductions , less noise and cost savings for the customer at the same time . The batteries are in series production for hybrid trains which will soon enter service , first in the UK .
The mtu EnergyPack is SIL 2 certified for rail passenger transportation and uses lithium – ion technology plus is liquid cooled / heated . They have 30.6 kWh capacity , 75 kW continuous power and 660V nominal voltage . They weigh about 370 kg with 1,600 mm x 750 mm x 220 mm dimensions . mtu DC / DC converters are integrated into the inverter cabinet plus the hybrid system is modular & scalable . The battery state of charge ( SoC ) is about 130 kWh , ie 22 % of total capacity which is good for battery service life . Looking at CO2 savings , simulations for a 220 t truck used assumptions of cycle time 30 min ; travel : 22 min plus queue , load , dump 8 min , so two cycles / h . This equates to 165 l / h and 2.65 kg CO 2 / l diesel fuel : total 6,500 h / year and 100,000 h truck life . Savings are 30 % CO 2 savings for a factory installed hybrid and 22 % CO 2 savings for a retrofit . The overall weight is higher with the hybrid – while 6 t are removed with the smaller engine and 2 t from the smaller tank , the batteries add 7.4 t and the DC / DC converters add 2 t .
For the 220 t truck , there would be 20 x
All Australian coal BEVs partnership
flameproof and explosion protected diesel LHD utility vehicle .
PPKME Global Head of Mining Dale McNamara said : “ This is a fantastic opportunity to combine our respective industry expertise to introduce the first new Australian designed and built batteryelectric personnel carrier vehicle for the
underground coal industry . Expanding our relationship to install Ampcontrol BEV technology
into our COALTRAM utility vehicles will substantially benefit our customers and employees by developing new vehicles for all
EnergyPacks and 10 x DC / DC converters . There is a downsized engine – now using an mtu 16V 2000 S96 , so 3,600 kg vs 9,500 kg and 36 l vs 60 l ; 1,163 kW vs 1,865 kW ( 1,560 hp vs 2,500 hp ) and Tier 4i vs Tier 2 with fuel efficiency optimised operation strategy . Plus obviously there is a reduced tank size . The 20 x EnergyPacks replace the original diesel tank so the downsized diesel tank can be moved to the opposite side ( this is one of many options , to be agreed with customers ).
The batteries are recharged by recuperating braking energy when going downhill . This stored energy is used to provide power to the mining truck when going uphill loaded , which leads to fuel savings and allows for the downsizing of the truck ’ s engine . The solution is based on proven components , an it is planned as a retrofit offering for existing and also being available on newbuilt trucks and will be realised in partnership with customers . The mtu Hybrid System integrates as a subsystem into the truck architecture , plus FLANDERS Inc power electronics and controls can be utilised for retrofits . The powertrain controller and mtu Hybrid Controller continuously communicate dynamic power demand .
Richter also said that in the not so distant future , two more technologies pioneered by Rolls-Royce may help mining operations become green and reach net zero carbon emissions : mtu engines are currently being prepared to run on sustainable fuels which are made from hydrogen with the help of renewable power . These fuels play a key role in reducing greenhouse gas emissions in applications which are hard to electrify . By 2023 , the newest generations of mtu Series 2000 and 4000 engines are set to be compatible with these fuels .
Hydrogen also plays a salient role in another future technology Rolls-Royce is currently working on : Fuel cells will soon be part of the company ’ s portfolio – first in stationary applications ( power generation ) but possibly for mining as well at a later stage . www . mtu-solutions . com
underground mines .”
Ampcontrol BEV technology builds upon the company ’ s expertise and industry reputation , centred around developing engineering solutions for use in hazardous environments , including underground coal mines . “ We are thrilled to be working with the team at PPK Mining Equipment to power their fleet of industry-renowned underground vehicles . Our new BEV technology lets our partners and customers power their existing equipment , converting from diesel to battery-electric energy , and new vehicles under development with a solution where safety and efficiency are absolutely paramount ,” added s
6 International Mining | SEPTEMBER 2021