A dynamic optimization model of an integrated coal supply chain system and its application

Various nodes,logistics,capital flows,and information flows are required to make systematic decisions concerning the operation of an integrated coal supply system. We describe a quantitative analysis of such a system. A dynamic optimization model of the supply chain is developed. It has achieved optimal system profit under conditions guaranteeing a certain level of customer satisfaction. Applying this model to coal production of the Xuzhou coal mines allows recommendations for a more systematic use of washing and processing,transportation and sale resources for commercial coal production to be made. The results show that this model,which is scientific and effective,has an important value for making reasonable decisions related to complex coal enterprises.

Business Operation of Coal Supply and Electric Power Enterprises

In recent years, the prices of primary energy especially coal continue to increase rapidly. This results in a substantial decline of profits and more operating difficulties in the downstream electric enterprises. The listed companies in both coal supply and power industries have quality assets and are the representatives of these industries. Through the analysis of the financial and operational status of the listed coal supply and power companies since 2007, the reasons for the business development difficulties in the electric power industry were discussed. Recommendations were provided including improving the coal pricing system, increasing the degree of business integration of the coal and electric power industries, and adjusting energy structure.

The Way to Relieve Tense Supply Situation of Power and Coal in China

This paper introduces the situation of coal and power production, the tense supply of powercoal and deteriorated coal quality in 2004, analyzes the causes of tense supply of power and coal, one ofwhich is due to the government regulated power tariff against rapid escalation of coal price that powerenterprises can hardly afford. It also presents some policy proposals to relieve the contradiction betweencoal and power, including to intensify macroscopic regulation between industries and regions, solve theproblem of power coal transportation and reduction or exemption of tax on coal industry and circulationlinks, through secondary distribution to regulate profit difference among industries.

A review of state-of-the-art processing operations in coal preparation

Coal preparation is an integral part of the coal commodity supply chain. This stage of post-mining, pre-utilization beneficiation uses low-cost separation technologies to remove unwanted mineral matter and moisture which hinder the value of the coal product. Coal preparation plants typically employ several parallel circuits of cleaning and dewatering operations, with each circuit designed to optimally treat a specific size range of coal. Recent innovations in coal preparation have increased the efficiency and capac- ity of individual unit operations while reinforcing the standard parallel cleaning approach. This article, which describes the historical influences and state-of-the-art design for the various coal preparation unit operations, is organized to distinguish between coarse/intermediate coal cleaning and fine/ultrafine coal cleaning. Size reduction, screening, classification, cleaning, dewatering, waste disposal unit operations are particularly highlighted, with a special focus on the LI.S. design philosophy. Notable differences between the U.S. and international operations are described as appropriate.

Efficient Combustion of the Fixed Coal Layer in an Advanced Combustion Chamber Design for Low-Power Boilers

In the long term,coal will remain a competitive resource in the thermal power sector,primarily due to its abundant global reserves and low costs.Despite numerous factors,including signifi cant environmental concerns,the global share of coal power generation has remained at 40%over the past four decades.Effi cient and clean coal combustion is a high priority wherever coal is used as a fuel.An improved low-power boiler design has been proposed to enhance effi ciency during fi xedbed coal combustion.This design reduces harmful emissions into the atmosphere by optimizing parameters and operating modes.In this study,mathematical modeling of gas velocity and temperature distribution during fi xed-bed coal combustion was conducted for a conventional grate system and an improved grate-free system.Experimental methods were employed to develop descriptive airfl ow models in the fi xed coal layer,considering nozzle diameter and air supply pressure in the furnace chamber without a grate system.Comparative evaluations of fi xed-bed coal combustion rates were performed using an experimental laboratory setup with both grate and grate-free stove systems.

Reliability of Baseload Electricity Generation from Fossil and Renewable Energy Sources

With expanding environmental and climate change regulatory frameworks, the fossil-based baseload generation is forced to decline, thus making room for more and more generation based on renewable and other carbon-free energy sources. This paper deals with a number of controversial issues and open questions concerning the growing penetration of renewable energy sources into power generation systems, often without due care of the impacts of variable as compared to conventional generation on the reliability of electricity supply. Particular attention is paid to baseload generation, power market design, system operation under extreme weather conditions, energy storage, back-up, and reserve power, as well as to the role of mechanical inertia and reliability of on-site fuel supply, demonstrated on an example of coal excavation and delivery to a power plant.