scholarly journals Operation Analysis of a SAG Mill under Different Conditions Based on DEM and Breakage Energy Method

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5247
Author(s):  
Qiyue Xie ◽  
Caifengyao Zhong ◽  
Daifei Liu ◽  
Qiang Fu ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Critical Speed ◽  
Optimal Operation ◽  
Steel Ball ◽  
Speed Ratio ◽  
Power Simulation ◽  
Sag Mill ◽  
Operation Parameters ◽  
Fill Level ◽  
Mill Speed

As one of the machines widely used in mining, a semi-autogenous grinding (SAG) mill can significantly improve the roughing efficiency of rock. But the SAG mill still faces the obstacles of significant energy consumption and empirical operation parameters. In order to obtain the optimal operation parameters of a SAG mill, in this paper, the discrete element method (DEM) is used to simulate the breakage process of the particles by controlling three parameters, i.e., the mill speed ratio, the mill fill level ratio, and the steel ball ratio. This method simulates the particles size, mill power, and qualified particles quality of crushed particle, which reveal the grinding strength and energy consumption of the SAG mill. In this paper, the grinding changes of a SAG mill under different parameter conditions are explored. Firstly, an experiment on the influence of a single parameter change on the mill’s operation is set up, and then the influence of three parameter changes on the mill’s operation is analyzed. These changes are characterized by particle size and mill power. Simulation results under the ∅5250 × 500 mm mill model show that the mill operates with the optimal effect when the mill is under the condition of 80% critical speed and 15% fill level; the power of the mill does not increase linearly with an increase in the mill speed ratio, but will decrease after 85% of the critical speed, and finally increase again; the optimal steel ball ratio in the SAG mill depends on the simulation time (mill actual working time) and the limitation of the rated power. The mill speed, fill level ratio, and steel ball ratio can significantly affect mill operation, and our conclusions can provide a reference for an actual situation.

scholarly journals Iterative LP water system optimal operation including headloss, leakage, total head and source cost

2013 ◽  
Vol 15 (4) ◽  
pp. 1203-1223 ◽  
Author(s):  
Eyal Price ◽  
Avi Ostfeld
Keyword(s):  
Energy Consumption ◽  
Water System ◽  
Pump Energy ◽  
Optimal Operation ◽  
Water Levels ◽  
Water Leakage ◽  
Pump Operation ◽  
Total Head ◽  
System Optimal ◽  
Water Tanks

Linear water balance optimal operation models are common with relative short solution times but suffer from a lack of certainty whether the given solution is at all hydraulically feasible. Introducing hydraulic headloss, water leakage and changing pump energy consumption, effect the resulting system optimal operation but also create a non-linear problem due to the convex relation between flow, headloss, water leakage and total head. This study utilizes a methodology published by the authors for linearization of convex or concave equations. An iterative linear programming (LP) minimal cost optimal operation supply model is solved including the Hazen–Williams headloss equation, pressure related water leakage equation, changing pump energy consumption and source cost. The model is demonstrated using an example application. ‘Greater than’ or ‘less than’ water head constraints at nodes may force the system to maintain certain water levels in water tanks reducing the available operating volume forcing pumping stations to operate in peak tariff periods as less storage is available in low tariff periods. Operationally, reducing water leakage may be achieved by reducing water heads along the system by means of shifting pump operation periods and maintaining low water levels in water tanks. Source costs may serve as penalties or rewards discouraging or encouraging the use of certain water sources.

scholarly journals Electrified Powertrain with Multiple Planetary Gears and Corresponding Energy Management Strategy

Vehicles ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 341-356
Author(s):  
Daizy Rajput ◽  
Jose M. Herreros ◽  
Mauro S. Innocente ◽  
Joschka Schaub ◽  
Arash M. Dizqah
Keyword(s):  
Energy Consumption ◽  
Energy Management ◽  
Management Strategy ◽  
Hybrid Electric Vehicles ◽  
Mode Selection ◽  
Optimal Operation ◽  
Fourth Generation ◽  
Selection Strategy ◽  
Energy Management Strategy ◽  
Planetary Gears

Modern hybrid electric vehicles (HEVs) like the fourth generation of Toyota Prius incorporate multiple planetary gears (PG) to interconnect various power components. Previous studies reported that increasing the number of planetary gears from one to two reduces energy consumption. However, these studies did not compare one PG and two PGs topologies at their optimal operation. Moreover, the size of the powertrain components are not the same and hence the source of reduction in energy consumption is not clear. This paper investigates the effect of the number of planetary gears on energy consumption under optimal operation of the powertrain components. The powertrains with one and two PGs are considered and an optimal simultaneous torque distribution and mode selection strategy is proposed. The proposed energy management strategy (EMS) optimally distributes torque demands amongst the power components whilst also controlling clutches (i.e., mode selection). Results show that increasing from one to two PGs reduces energy consumption by 4%.

Numerical Study on Mechanism and Parameters Optimization of Temporary Plugging by Particles in Wellbore

2021 ◽  
pp. 1-16
Author(s):  
Tao Zhang ◽  
Ming Li ◽  
Jianchun Guo ◽  
Haoran Gou ◽  
Kefan Mu
Keyword(s):  
Particle Size ◽  
Numerical Study ◽  
Optimal Operation ◽  
Parameters Optimization ◽  
Mass Ratio ◽  
Stimulated Reservoir Volume ◽  
Reservoir Volume ◽  
Pump Rate ◽  
Single Well ◽  
Operation Parameters

Summary The temporary plugging by particles in the wellbore can open new perforation clusters and increase stimulated reservoir volume, but the temporary plugging process of particles is not clear. Therefore, in this paper, we take an ultradeep well in the Tarim Basin as the research object and establish a numerical model based on the coupled computational fluid dynamics-discrete element technology (CFD-DEM) approach, which accurately describes the movement process and mechanism of the temporary plugging particles in the wellbore. Furthermore, the influence of flow rate, concentration of injected particles, and the injected mass ratio of particle size on the temporary plugging effect were studied, respectively. In addition, based on the results of the orthogonal experimental analysis, we obtained the pump rate as the primary factor affecting the effect of temporary plugging, and we recommended the optimal operation parameters for temporary plugging by particles in the field: The pump rate is 2 m3/min, the concentration of the injected temporary plugging particles is 20%, and the ratio of the mass of the injected temporary plugging particles with particle size 1 to 5 mm to the mass of the temporary plugging particles with particle size 5 to 10 mm is 3:1. Finally, a single well that had implemented temporary plugging by particles was used to verify the recommended optimal temporary plugging operation parameters. The research results of this paper provide important guidance and suggestions for the design of temporary plugging schemes on the field.

Control Strategy for the Optimal Operation of a Solar Cooling Installation

2012 ◽  
Author(s):  
Vittorio Verda ◽  
Giorgia Baccino ◽  
Stefano Pizzuti
Keyword(s):  
Energy Consumption ◽  
Solar Radiation ◽  
Control Strategy ◽  
Primary Energy ◽  
Optimal Operation ◽  
Hot Water ◽  
Objective Functions ◽  
Solar Cooling ◽  
Partial Load ◽  
Input Variables

In this paper, a solar cooling installation is analyzed with the aim of optimizing its performances. The system consists of vacuum solar collectors, which supply hot water to a LiBr absorption chiller. A boiler can be used to supply an additional amount of hot water in the case of insufficient solar radiation. In addition, a vapor compression chiller operates as a backup system and integrates the solar driven system in the case of large cooling request. Such system gives multiple operating options, especially at partial load. A model of the system is presented and applied to the real plant. It is shown that if a multi-objective optimization is performed, considering minimum primary energy consumption from fossil fuel and maximum utilization of the absorption system, a Pareto front is obtained. This occurs because the two objective functions are competing. A control strategy based on the use of neural networks is presented. Input variables are the solar radiation, ambient temperature and the cooling request. In this work the control strategy is adjusted in order to reach the minimum fossil energy consumption, but the same approach can be applied with other objective functions.

Energy efficiency in membrane bioreactors

2013 ◽  
Vol 67 (12) ◽  
pp. 2685-2691 ◽  
Author(s):  
B. Barillon ◽  
S. Martin Ruel ◽  
C. Langlais ◽  
V. Lazarova
Keyword(s):  
Energy Consumption ◽  
Specific Energy Consumption ◽  
Hollow Fibre ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Key Factor ◽  
The Usa ◽  
Design Loads ◽  
Operation Parameters ◽  
Energy Audits

Energy consumption remains the key factor for the optimisation of the performance of membrane bioreactors (MBRs). This paper presents the results of the detailed energy audits of six full-scale MBRs operated by Suez Environnement in France, Spain and the USA based on on-site energy measurement and analysis of plant operation parameters and treatment performance. Specific energy consumption is compared for two different MBR configurations (flat sheet and hollow fibre membranes) and for plants with different design, loads and operation parameters. The aim of this project was to understand how the energy is consumed in MBR facilities and under which operating conditions, in order to finally provide guidelines and recommended practices for optimisation of MBR operation and design to reduce energy consumption and environmental impacts.

Deduction and Analysis of Driving Exergy Loss in Oil Pipeline System

2013 ◽  
Vol 291-294 ◽  
pp. 688-692 ◽  
Author(s):  
Qing Lin Cheng ◽  
Meng Zhang ◽  
Xuxu Wang
Keyword(s):  
Energy Consumption ◽  
Fluid Mechanics ◽  
Analytic Formula ◽  
Exergy Loss ◽  
Pipeline System ◽  
Pipeline Transportation ◽  
Element Analysis ◽  
Oil Pipeline ◽  
Insulation Thickness ◽  
Operation Parameters

Pipeline transportation is a substance conveying process that makes crude oil flowing from first station to ultimate station and at the same time takes a certain amount of driving energy for cost. Based on related theories of engineering fluid mechanics, mathematics analytic formula of driving exergy in oil pipeline transportation is deduced by micro-element analysis. We can get the conclusion that driving exergy loss has a positive correlation with diameter and throughput, and also a contrary trend with insulation thickness and outbound temperature by analyzing the influence on driving exergy loss from operation parameters in pipeline process,. This research can provide theoretical guidance for energy consumption classification, and further more, the technical support for energy consumption in pipeline system.

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