Coal Transportation System Research Articles

Optimal Selective Maintenance Strategy for Multi-State Systems Under Imperfect Maintenance

Many systems are required to perform a series of missions with finite breaks between any two consecutive missions. In such a case, one of the most widely used maintenance policies is a selective maintenance in which a subset of feasible maintenance actions is chosen to be performed with the aim at achieving the subsequent mission success under limited maintenance resources. Traditional selective maintenance optimization reported in the literature only focuses on binary state systems. Most systems in industrial applications, however, have more than two states in the deterioration process. In this work, a selective maintenance policy for multi-state systems (MSS) consisting of binary state elements is investigated. Taking the imperfect maintenance quality into consideration, the Kijima model is reviewed, and a cost-maintenance quality relationship which considers the age reduction factor as a function in terms of maintenance cost is established. Moreover, with the assistance of the universal generating function (UGF) method, the probability of the repaired MSS successfully completing the subsequent mission is formulated. In place of enumerative methods, a genetic algorithm (GA) is employed to solve the complicated optimization problem where both multi-state systems, and imperfect maintenance models are taken into account. The effectiveness of the proposed method is demonstrated via a case study of a power station coal transportation system. Finally, a comparative analysis between the strategies with and without considering imperfect maintenance is conducted, and it is concluded that incorporating imperfect maintenance quality into selective maintenance achieves better outcomes.

Optimal Structure in Heterogeneous Multi-state Series-parallel Reliability Systems

The problem of allocating optimum heterogeneous redundancy in multi-state series-parallel reliability structures is addressed in this paper. The objective is to obtain a configuration that minimizes the total cost of system design satisfying the given reliability constraint and the consumer load demand. The demand distribution is presented as a piecewise cumulative load curve and each subsystem is allowed to consist of parallel redundant components of not more than four types to construct a reliable system. The redundant components are capacitated binary and chosen from a list of products available in the market. The components are characterized by their feeding capacity, reliability and cost. A system that consists of elements with different reliability and productivity parameters has the capacity strongly dependent upon the selection of constituent components. A binomial probability based method to compute exact system reliability index is suggested. To analyze the problem and suggest an optimal system structure an ant colony optimization (ACO) algorithm is presented. The solution approach consists of a series of simple steps as used in basic ACO algorithms and is still capable to yield very good solutions with promising time efficiency. A randomly generated problem of power station coal transportation system with initial structure is solved for illustration.

A Novel MagPipe Pipeline Transportation System Using Linear Motor Drives

A novel capsule pipeline transportation system using linear motor drives, called Magplane MagPipe, is under development with the intention to replace trucks and railways for hauling materials from the mine to the rail head, power plant, or processing plant with reduced operating cost and energy consumption. The initial demonstration of a MagPipe line in Inner Mongolia will be a 500-m-long double-pipe coal transport system with the design transportation capacity of 3 Mega-Mg per year. The pipeline consists of 6-m-long plastic pipe modules with an I-beam suspension system inside the pipe to carry sets of five coupled capsules. The pipe will also contain noncontinuous motor winding modules spaced at 50-m intervals. A set of Halbach-arrayed permanent magnets on the bottom of the capsules interact with the linear motor windings to provide propulsion. The motor is driven by variable frequency drives outside the pipe to control the speed. This paper briefly describes the overall MagPipe pipeline transportation system, including the preliminary conclusions of the linear synchronous motor analysis.

Hydraulic calculation of gravity transportation pipeline system for backfill slurry

Taking cemented coal gangue pipeline transportation system in Suncun Coal Mine, Xinwen Mining Group, Shandong Province, China, as an example, the hydraulic calculation approaches and process about gravity pipeline transportation of backfill slurry were investigated. The results show that the backfill capability of the backfill system should be higher than 74.4 m3/h according to the mining production and backfill times in the mine; the minimum velocity (critical velocity) and practical working velocity of the backfill slurry are 1.44 and 3.82 m/s, respectively. Various formulae give the maximum ratio of total length to vertical height of pipeline (L/H ratio) of the backfill system of 5.4, and then the reliability and capability of the system can be evaluated.

Multistate series-parallel system expansion-scheduling subject to availability constraints

This paper addresses the multistage expansion problem for multistate series-parallel systems. The study period is divided into several stages. At each stage the demand distribution is predicted in the form of a cumulative demand curve. The additional elements chosen from a list of available products can be included into any system-component at any stage to increase the total system capacity and/or reliability. Each element is characterized by its capacity (productivity), availability, and cost. The objective is to minimize the sum of costs of the investments over the study period while satisfying reliability constraints at each stage. To solve the problem, a genetic algorithm is used as an optimization tool. The solution encoding technique allows the genetic algorithm to manipulate integer strings representing multistage expansion planes. A solution quality index comprises both reliability and cost estimations. The procedure based on the universal generating function is used for evaluating the availability of multistate series-parallel systems. An example illustrates finding the optimal expansion plan for a coal-transportation system of a power station.

Optimal multistage modernization of power system subject to reliability and capacity requirements

This paper addresses the multistage modernization problem for power systems with series-parallel structure. The study period is divided into several stages according to demand forecast. At each stage the consumer demand distribution is predicted in the form of a cumulative load curve. Different actions, such as modifying existing equipment, changing maintenance policy, or adding new elements, may be undertaken in any system component at any stage to increase the total system capacity and/or reliability. The objective is to minimize the sum of costs of system modernization actions over the study period while satisfying reliability constraints at each stage. In order to solve the problem, a genetic algorithm is used as an optimization tool. The solution encoding technique developed allows the genetic algorithm to manipulate integer strings representing multistage system modernization planes. A solution quality index is comprised of both reliability and cost estimations. The procedure based on the universal generating function is used for evaluation of the availability of multistate series-parallel power systems. This technique allows one to estimate the effect on the entire system availability when both capacity and availability of system elements are varied. An illustrative example is presented in which the optimal expansion plan is found for a coal transportation system of a power station.

The study of a fuzzy set theory for the selection of an optimum coal transportation system from pit to the power plant

ABSTRACT In this paper, we purpose a fuzzy multiple attribute decision making for the selection of an optimal transportation system to a power station to be established in an open pit coal mine located Can, west of Turkey. So far, various types of formulations or solutions methods have been proposed with transportation systems, but most of them exclusively considered linear functions as objective functions. Real world study is decision making under subjective constraints of different importance, after using uncertain data (linguistic variables), where compromises between competing criteria are allowed. The authors have explained in theory and by detailed example a new combination of fuzzy set of transportation systems.

Structure optimization of power system with bridge topology

The problem of optimization of a power system structure which cannot be reduced to series or parallel combinations is considered. The system contains a bridge substructure in which redundant elements are included in order to provide a desired level of reliability. The elements of the system are characterized by their capacity, availability and cost. A procedure which determines the minimal cost system configuration subject to reliability constraints is proposed which provides solutions with different structure topology. In this procedure, system elements are chosen from a list of products available on the market. System reliability is defined as the ability to satisfy consumer demand which is represented as a piecewise cumulative load curve. To evaluate system reliability, a universal generating function technique is applied. A genetic algorithm (GA) is used as an optimization technique. Examples dealing with the determination of the optimal structure of a power station coal transportation system are presented for problems with different constraints.

Structure optimization of power system with different redundant elements

The problem of optimization of the structure of a power system where redundant elements are included in order to provide a desired level of reliability is considered. The elements of the system are characterized by their capacity, availability and cost. A procedure which determines the minimal cost series-parallel system configuration is proposed which allows elements with different parameters to be allocated in parallel. In this procedure, system elements are chosen from a list of products available on the market. System reliability is defined as the ability to satisfy consumer demand which is represented as a piecewise cumulative load curve. To evaluate system reliability, a universal generating function technique is applied. A genetic algorithm (GA) is used as an optimization technique. Basic GA procedures adapted to the given problem are presented, and different versions of the GA are compared to determine the most effective one. An example of the optimal structure determination and optimal extension of a power station coal transportation system are presented.

A multi-area linear programming approach for analysis of economic operation of the Indian power system

The paper discusses the major planning issues pertaining to economic operation of power systems in India viz. integrated operation of the State Electricity Boards (SEBs) through formation of the National Grid, optimal sharing of central sector generation by the SEBs, time-of-day pricing policy for power trading among the SEBs optimal expansion of National Grid and streamlining the coal production and transportation for optimal System operation. A multi-area linear programming (LP) model, NATGRID, is developed to quantify the benefits from National Grid operation, suggest optimal sharing norms for central sector generation and formulate time-of-day pricing scheme for interutility power trading. Four interregional transmission projects are identified by exploiting the duals of the LP problem, for expansion of National Grid. The bottlenecks in coal production and transportation systems are indicated and the system cost savings from removing them are quantified. The analysis aims at encouraging and motivating the utilities to accept the idea of co-operation and making investment more cost-effective.

Improving Throughput of a Coal Transport System with the Aid of Three Simple Models

The Cape Breton Development Corporation had not been achieving the throughput needed from its transport system for moving coal from its coal storage sites to the shipping piers for loading onto ocean going vessels. We used three simple models to analyze this system and to convince management that it could improve the system dramatically with no capital investment. By following these recommendations, the company has approximately doubled the throughput of this system. This leads to significant savings in vessel demurrage costs and improves the market opportunities for coal sales.

ロードヘッダ掘進用運搬設備の新たな展開

ロードヘッダ掘進用運搬設備の新たな展開

CR12 steels for the coal industry

Over the last 25 years stainless steels have rapidly become accepted as a suitable material for coal processing, handling and transportation systems due to their fractional maintenance costs, improved operational efficiency and favourable life cycle costs. The introduction of a new generation of utility ferritic stainless steels with superior structural rigidity now also means that such steels offer significant savings over carbon steels for coal plant construction because they require less material.

An analytic model of load streams in coal mine locomotive transportation systems

The current practice of deterministic calculations of the characteristics of locomotive haulage proceeds from a simplified model of a train flow, with average interval used as the only parameter [i]. More exact probabilistic calculation methods are also known, which are based on the queue theory [2], with a train flow as the elementary case. The expectation of the interval between trains is set equal to its standard deviation, i.e., the train flow is still described by a single parameter. However, a real stream of trains can be essentially different and should be described by several parameters.

選炭・輸送・ハンドリングと新しい石炭のアンローディングシステム

選炭・輸送・ハンドリングと新しい石炭のアンローディングシステム

Coal Transportation System Modeling—The Case of Taiwan: A Comment

In his recent Energy Journal article, G. H. Tzeng emphasizes on the transportation aspects of increased coal use in Taiwan. He does not, however, offer much detail on the economic basis for the switch in National Energy Policy from imported oil to coal. While such a switch confirms that the exercise of rational fuel mix choices has found its due place in Taiwan, it seems appropriate to examine the efficiency of such a switch and its implications, especially for import balances. The new Taiwan energy policy Tzeng describes would increase coal consumption from 7.8 million tons (MT) in 1982 to 43.4 MT over the period ending in 2001. Ninety percent of this requirement would be imported. Of this, more than half would go to the electric power industry (23.8 MT by 2001). The total growth in coal consumption projected by Tzeng for this period amounts to 456 percent in 19 years.

Coal Transportation System Modeling: The Case of Taiwan

The world energy situation has been greatly influenced by the dramatic increase in world oil prices during the 1970s. To adjust to these increases, many countries have shifted to coal as a substitute for oil and have accelerated their research and development of renewable energy sources. Until nonconventional sources become widely available and economical, coal (along with nuclear power) will play a key role in the world's energy supply. Transportation and delivery, rather than production, pose the most difficult problems in meeting the greatly increased demand for coal.

Optimizing freight transshipments: an evaluation of east coast coal export options

Many factors will determine the extent to which the U.S. will be a significant supplier of coal to world markets. Important among these factors is the ability of the domestic coal transport system to move coal from mines to export ports and the capability of these ports to efficiently transship the coal to export markets. This paper describes the use of a mixed-integer mathematical programming model, called the Coal Logistics System (COLS), to provide information for transportation infrastructure planning with regard to increasing U.S. coal exports. COLS is a comprehensive coal transportation model that includes the location and activity levels for coal handling technology. It is used in this study to evaluate potential patterns of export coal movements in the Eastern U.S. with respect to transportation costs, optimal location and activity levels for port coal handling facilities and related investment expenditures.

Environmental impacts of U.S. coal exports

Many factors will determine the extent to which the U.S. will be a significant supplier of coal to world markets. Important among these factors is the ability of the domestic coal transport system to move coal from mines to export ports and the capability of these ports to efficiently transship the coal to export markets. This paper describes the use of a mixed-integer mathematical programming model, called the Coal Logistics System (COLS), to provide information for transportation infrastructure planning with regard to increasing U.S. coal exports. COLS is a comprehensive coal transportation model that includes the location and activity levels for coal handling technology. It is used in this study to evaluate potential patterns of export coal movements in the Eastern U.S. with respect to transportation costs, optimal location and activity levels for port coal handling facilities and related investment expenditures.

Long-Distance, High-Volume Transport of Coal by Slurry Pipeline

Several long-distance, high-volume coal slurry transportation systems are planned or proposed for the United States. These new systems offer a method of transport that is both economical and environmentally attractive. The design of these systems will be a challenge to the pipeline engineer since an integrated, system design of several components is necessary to achieve an optimum overall effect. The pipeline, pump stations, instrumentation and controls, slurry preparation, and utilization facilities must all be considered in the design. The purpose of this paper is to describe the system components of a large coal slurry transportation system in detail and to show the special design considerations required for the overall system design considering the interrelationships of the various components.