Technical and economic potential of energy recovery and re-use on board surface mining haul trucks

Abstract

This thesis investigates the technical and economic feasibility, as well as emissions related benefits, of incorporating energy recovery systems (ERSs) on board mine haul trucks (MHTs) used in surface mining. More specifically it aims to answer the research question: "What practical combination of hybrid drive topology, and energy storage technology, capacity and use on board mine haul trucks, will maximise the economic benefit of energy recovery and re-use, considering variation in haul route characteristics and the time value of money through the life of a surface mining project?" To answer this question, a simulation program was developed and progressively expanded to conduct each of four main stages of the research. In Stage One, the simulation program was used to determine the potential of various technologies to reduce the fuel consumption per tonne mined for each of a range of pit depths. Appropriately informing the simulation program required identifying and quantifying representative input values for truck, haul route, and ERS characteristics. Truck and haul route characteristics determine the energy recovery rate and amount of energy recoverable to the trucks' DC-links. ERS characteristics enable evaluating the potential and practical implications of each ERS technology to capture this recovered energy. ERS technologies considered include ultra-capacitors, lithium-ion capacitors, chemical batteries, and electro-mechanical flywheels (EMFWs).

Performance and Total Cost of Ownership of a Fuel Cell Hybrid Mining Truck

“…The power for the radiator systems is siphoned after conditioning in the DC-link before delivery to the inverters. for traction [7,12,18]. An electric braking retarder is used for the regenerative recovery of braking energy and storing it in the battery.…”

“…All engine efficiencies exclude losses due to fan power. The FCS hybrid powertrain in Figure 1b is similar to the diesel powertrain, but it directly generates DC electrical power that is delivered to a DC bus and then either stored in the battery or delivered to the inverter/rectifier, motor/generator, gearbox, and wheel for traction [7,12,18]. An electric braking retarder is used for the regenerative recovery of braking energy and storing it in the battery.…”

“…Sectors 15 and 0 are ingress to and egress from the dump site, which must be traversed carefully as the dynamic soil poses a significant danger to the haul truck [17,24]. The ramp grade is 10%, and the fill takes 120 s [17,18,24,25]. The vehicle remains nearly stationary during fill and dump, maneuvering only slightly to receive and deposit the earth.…”

“…The vehicle speed is determined by road limits which are regulated and depend on the quality and degree of maintenance of the roads. Speed is maximized (subject to 28 mph road limit) to increase the rate of earth hauled, except for during the ascent, where the vehicle's rated power (3500 hp for the diesel genset) limits the speed [17,18,24,25]. The true ascent speed and time are calculated using a vehicle dynamics model, given by Equation ( 1) [17,18,26,27].…”

“…Well-maintained roads exhibit a 2% rolling resistance factor, and the aerodynamics include a drag coefficient of 0.9, air density of 1.146 kg/m 3 at 35 • C and 1 atm, and a vehicle frontal area of 67.5 m 2 [17,18,23].…”