Gross Calorific Value -a Guide to Optimum Washing of Power Coals

Gross Calorific Value -a Guide to Optimum Washing of Power Coals

GROSS CALORIFIC VALUE A GUIDE TO OPTIMUM WASHING OF POWER COALS Chandan Das, Senior Research Fellow and Dr Kalyan Sen, Prof. Emeritus Bengal Engineering & Science University, Shibpur 2nd Asian Mining Congress, Kolkata, 17-19th Jan.2008

Basic Issue Requirement of power plants Washed coal with consistent quality Quality Parameters : GCV, Ash and MoistureAR (as received) basis Introduction About 70% coal produced in India is consumed in thermal

power plants. Indian non-coking coals : Permian era, optimum maturity and petrological composition High Volatile Matter low Sulphur, Mercury, Nitrogen and Chloride, etc. Burn efficiently Large amount of Stones and obvious dirt lead to loss of sensible heat Erosion in coal handling, crushing, grinding, ash handling, etc.

Gross Calorific Value (GCV) Gross calorific value of coal depends upon its chemical composition, which is governed by geological environment during its coalification process, mainly on its maturity. Combustible elements present in coal : Carbon, Hydrogen, Sulphur, etc

Non-combustible mineral contents : Silica, Iron, Aluminum, Calcium, Magnesium, etc. GCV-Ash Relationship

GCV Ash Relationship Close relation between ash content vs Gross Calorific Value (GCV) of coal For Central Coalfield (CC) coals : GCV at zero ash (pure) coal varies from 7000 to 8000 kcal/kg, av. being 7800 kcal/kg GCV becomes zero (completely inert) at very high ash content i.e. about 80 to 90%, av. being 88%.

It is also proved that both ash and GCV contents are related to the Relative Density (RD) of coal. Yield & Quality of Washed Coal Fractional yield is a random property varies from seam to seam and day to day Cumulative yield at any cut point depends

upon the Limiting GCV vs sp gr of cut and Efficiency of Washers If the Particle of Limiting GCV is combustible in a given furnace, then all other particles are ensured to burn Optimum Result an example To limit GCV of particles to 3000 kcal/kg, the

corresponding characteristic ash will be about 55% at RD of cut 1.875. The cumulative GCV of theoretical cleans will be 5200 kcal/kg and ash content 30% with cumulative yield of 85%. Conclusion Concept of limiting GCV can optimize coal washing

It is suggested that if the worst particle can be effectively burnt in a given system of combustion, all better quality particles can be used up at ease. The actual cumulative yield of cleans and their quality will depend upon the raw coal supplied from day to day and efficiency of washing. However, the efficiency of combustion will remain practically the same. GCV is suggested to be used as a major factor to grade the

coal as well as to optimize

Recently Viewed Presentations

  • Overview of AI Planning - University of Toronto

    Overview of AI Planning - University of Toronto

    URL for the location of these slides. An Overview of AI Planning Fahiem Bacchus University of Toronto Outline Planning Domains and Problems Representing Actions (the transitions) Formalisms STRIPS ADL (Action Description Language) Situation Calculus with successor state axioms Features Modular...
  • Synergy at the Interface International WaTER Conference ...

    Synergy at the Interface International WaTER Conference ...

    Peter Winch, Director, Social and Behavioral Interventions Program, Johns Hopkins Bloomberg School of Public Health - Behavior Change. Oral presentations and posters from experts around the world. Post-conference workshop on well drilling, biosand filters and eco-latrine construction.
  • GCSE ICT -

    GCSE ICT -

    sounds, suck and puff switches used by those people unable to use their hands. to manipulate a keyboard or mouse and the input devices used in computer. games (such as wireless games controllers) and at supermarket terminals. Nb:Please. write out...
  • Spelling, Grammar and Punctuation Revision Its time to

    Spelling, Grammar and Punctuation Revision Its time to

    (Fronted adverbial) eg Later that day, That night, Under the trees, In the palace. When, where, how. Turn these sentences into direct speech - include all punctuation in the new sentence. "I hate playtimes!" shouted Tahmida.
  • Functions of Haemoglobin

    Functions of Haemoglobin

    HbA structure. Oxygen binding to hemoglobin. Types of hemoglobin. Fetal hemoglobin (HbF): Major hemoglobin found in the fetus and newborn. Tetramer with two a and two g chains. Higher affinity for O 2. than HbATransfers O 2. from maternal to...
  • Minamata, Japan

    Minamata, Japan

    The emergency shutdown mechanism couldn't stop the plant, and their Geiger counters weren't advanced enough to tell them how high the radiation levels were. The crew stayed 3 days after the explosion not knowing the high radiation levels, as they...
  • Object Oriented development Risks

    Object Oriented development Risks

    Executive Level Briefing SAS meeting July 2004 Outline Problem Approach Importance/benefits Relevance to NASA Accomplishments Next steps Problem Statement NASA has considerable experience applying IV&V to traditional function-based software systems Emerging use of OO brings unique challenges and risks There...
  • ATOMIC PHYSICS The Nuclear Atom and Radioactivity

    ATOMIC PHYSICS The Nuclear Atom and Radioactivity

    Nuclear fission. Nuclear fission is the splitting of a heavy nucleus into two lighter nuclei, when the nucleus of an atom is bombarded with a neutron. The energy of the neutron causes the target nucleus to split into two (or...