QUESTION 2(q3) Please explain your answer step by step. How many tonnes of coal
ID: 1657485 • Letter: Q
Question
QUESTION 2(q3) Please explain your answer step by step.
How many tonnes of coal must be burned per day by an electric power plant that delivers 500 MWe continuously if the efficiency is 30%? (1 ton = 0.907 tonne = 1000 kg). Put your answer in whole numbers only, no commas, no symbol. For example for 23.8 tonnes, you write 24! Hint: a. calculate how many kilowatt hours you need for 24 hours of 500W at 30% efficiency. Remember generation of 100 W at 30% efficiency yields only 30 W. b. Next find out from the book, how much energy 1 ton of coal yields and from that calculate how much energy 1 tonne of coal will yield. c. Now it is simple calculation to find out how many tonnes is required for
Explanation / Answer
let n tonnes of coal must be burnt per day
Power of power plant, P = 500 MW
efficiency, e = 0.3
n tonnes = n*1000/0.907 kg coal = 1102.535 n kg coal
calorific value of coal = 20,000,000 J / kg
also, energy requirement by power plant in one day = 500*10^6*24*60*60/0.3 = 0.144*10^15 J
hence 20,000,000 ( 1102.535 n) = 0.144*10^15
n = 6530.404 tonnes
n = 6531 tonnes in round figures