·Gross & Net Calorific Values Gross CVor higher heating value HHV is the CV under laboratory conditions Net CVor lower heating value LHV is the useful calorific value in boiler plant The difference is essentially the latent heat of the water vapour produced Conversions Units From kcal/kg to MJ/kg multiply kcal/kg by
·A nation s ability to use its energy resources efficiently and the expansion of its industrial sector are key factors in its prosperity Most of the industrially developed nations in the world use coal as their main energy source These resources have been utilized mainly for industrial growth such as thermal power plants steel industries and other associated
·On an average in India power generation is contributed using coal as fuel up to % Higher the calorific value higher would be the heat liberated from the coal thus resulting in higher steam generation which would contribute to increase in power generation
·Currently Indian coal is classified on the basis of UHV useful heat value into seven grades from A G UHV is based on ash and moisture contents for non coking coals in line with the Centre directive If the GCV of a particular coal is higher it will have higher price What is UHV coal Ans UHV stands for useful heat value of coal
·Ninety seven percent of cities with a population higher than 100 000 inhabitants in low and middle income countries do not meet WHO air quality guidelines WHO 2018 This is a complex problem and although coal combustion is one of the contaminants it is important to note that the transportation of coal point source home heating and cooking sources vehicle fuel
· Coal India website The Useful Heat Value UHV is the quantity of heat liberated by combusting a unit quantity of fuel at constant volume in oxygen saturated with water vapour and the original material and final products of combustion being at a reference temperature of 25oC This UHV is calculated on the basis of an empirical relationship
·Uses of Coal Description; Power Generation Steam coal also known as thermal coal provides a source of electricity Power plants ground steam coal into a powder and fire it into a boiler to produce heat The heat is used to turn water into steam The steam powers a turbine that along with an alternator generates electricity Steel Industry
·Certain analytical tests are rooted deep in the history of coal science; for example Matthew Carey Lea 1841 1 used proximate analyses to assess coal metamorphism in the Southern Anthracite Field Pennsylvania 2 Based on the chronology laid out by Van Krevelen 1982 this was shortly after by his consideration the birth of coal science in 1831 and the
·Capacity of coal to give energy depends upon the percentage or carbon content [Older the coal much more is its carbon content] Percentage of carbon in coal depends upon the duration and intensity of heat and pressure on wood [carbon content also depends on depth of formation More depth == more pressure and heat == better carbon content]
The heating value of biomass is relatively low especially on a volume basis because its density is very low Higher Heating Value Higher heating value HHV is defined as the amount of heat released by the unit mass or volume of fuel initially at 25 °C once it is combusted and the products have returned to a temperature of 25 °C
5 ·The word coal comes from the Old English col meaning glowing ember Coal is a fossil fuel and can be burned for energy or heat The earliest recognised use of coal by man is from the Shenyang area of China where by 4000 BC Neolithic inhabitants had begun carving ornaments from black lignite Coal from the Fushun mine in north eastern China
·Ans UHV stands for useful heat value of coal What is the difference between net calorific value and gross calorific value The key difference between net calorific value and gross calorific value is that net calorific value is the amount of heat that is created when water is converted into water vapor upon combustion of a material whereas
Factors affecting calorific value; Calorific value of coal varies from one coal sample to another It depends on the ash moisture content and the type of coal But the calorific value of fuel oils is much more consistent Then by dividing this value by theweight of the sample we obtain the calorific value heat of combustion of the
·Calorific value is a measure of the amount of energy produced from a unit weight of coal when it is combusted in oxygen A measured sample of coal is completely combusted in a bomb calorimeter which is a device for measuring heat ASTM method D5865 12; American Society for Testing and Materials 2013 p 648 666
heating value [2] the heat produced by the combustion of a unit quantity at constant volume in an oxygen bomb calorimeter The higher heating value HHV also often called the gross calorific value is an indicator of the chemically stored energy in coal and is a very important parameter when assessing the value of coal as a fuel [3]
The ranking of the coal is done by the amount and the type of carbon that is present in the coal and its ability to produce heat when it is burned The rank of the coal deposit determines the amount of pressure and the heat that has acted on the dead and decayed matter over a prolonged period of time Anthracite It has the highest heating
Heat energy flows from hot objects to cold objects A cup of tea feels warm because it is giving off heat energy It is the hot object you are the cold object
·A hybrid feature selection method combining with wavelet transform WT was proposed to analyze the heat value of coal using laser induced breakdown spectroscopy LIBS The hybrid feature selection method consisted of distance correlation DC method and recursive feature elimination with cross validation RFECV method which combined the advantages of
The ranking depends on the types and amounts of carbon the coal contains and on the amount of heat energy the coal can produce The rank of a coal deposit is determined by the amount of pressure and heat that acted on the plants over time Anthracite contains 86% 97% carbon and generally has the highest heating value of all ranks of coal
The gradation of non coking coal is based on Gross Calorific Value GCV the gradation of coking coal is based on ash content and for semi coking /weakly coking coal it is based on ash plus moisture content as in vogue as per notification Grades of Coking Coal Grade Ash Content
·Coal samples from 2 different coal seams in Zonguldak were analysed in terms of ash content and calorific values The results of these analyses are given in Table 1 and Table 2 Table 1 Results of the ash content and calorific value determinations for Coal Seam A partly adopted from the study of Sarihan [7] E Density Coal Seam A E Density
There are four major types or ranks of coal Rank refers to steps in a slow natural process called coalification during which buried plant matter changes into an ever denser drier more carbon rich and harder material The four ranks are Anthracite The highest rank of coal It is a hard brittle and black lustrous coal often referred to as hard coal containing a high
·A hybrid feature selection method combining with wavelet transform WT was proposed to analyze the heat value of coal using laser induced breakdown spectroscopy LIBS The hybrid feature selection method consisted of distance correlation DC method and recursive feature elimination with cross validation RFECV method which combined the advantages of
·Heating values are widely used in coal combustion research and are becoming more useful in other fuel types as well Many different empirical correlations to predict heating values based on primary organic CHONS elemental composition are found in the literature many of which were originally created to predict heating values of parent coal
