Duty Cycle Study of Coal Mine Shuttle Cars

Open Access
Author:
Lashkari, Hamed
Graduate Program:
Energy and Mineral Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
August 04, 2014
Committee Members:
  • Jamal Rostami, Thesis Advisor
  • Dr Larry Grayson, Thesis Advisor
Keywords:
  • duty cycle
  • shuttle car
  • room and pillar
  • battery
  • energy
  • power
  • haulage cycle
Abstract:
With recent advancements in battery technology, there is an acute interest in increasing the number of battery-powered haulers for use in underground mining. In an attempt to commercialize and implement the new battery technologies, machine manufacturers must determine the capacity, durability, and performance of these batteries over critical and tough conditions in underground mining operations. Study of the duty cycle of underground haulage units is the basis by which verification of the need and demands for power for such units can be determined for the purpose of sizing suitable batteries. This thesis discusses the measurement of duty cycles of coal mine shuttle cars in two underground coal mines in central Pennsylvania along with the discussion and analysis of the measured duty cycles. Observations and measurements were made to quantify/differentiate the performance of the shuttle cars under different road conditions and mine operating requirements. The measurement of the duty cycles for various shuttle cars was mostly performed by recording the available machine information through the vehicle on-board communication ports such as CAN bus interfaces. Each work cycle includes real time power consumption during different work segments (e.g., loading, loaded tramming, dumping, and empty tramming), mean power for the entire duty cycle, order and duration of peak powers, and required energy for the entire cycle and different work segments. Moreover, cycle timing and intermittent delays occurring during each work segment are included in the duty-cycle study. The required energy by work cycle is summed over the course of each work shift and then correlated with utilization. Analysis of the data has allowed for evaluation of these parameters and quantification of the arithmetic average, root mean square, and dispersions of related parameters such as cycle time, delay times, average power and energy consumptions, peak power and energy consumptions, and finally the proportion of power consumption in each segment of the duty cycle as well various functions. Statistical analysis is used to develop formulas for estimation of operating parameters of such haulage units based on the distance, weight of the haulage units, and road conditions. The statistical models include average and peak power and energy consumptions. Also a separate analysis was performed to estimate the amount of machine utilization and delay times for each component of the work cycle. The observations and developed models allow for estimation of the required battery power and storage capacity for underground haulage units and expansion of the results to similar operational conditions with different panel geometries.