Power Plant - Tutorial Sheets
Kerbala University Power Plant Engineering College Sheet No. 01 Mech. Eng. Dept. – 4th year class 2012 – 2013
------------------------------------------------------------------------------------------------------------
Thermodynamic Review
-----------------------------------------------------------------------------------------------------------
1 – Explain the Temperature – entropy ( T-s ) diagram, defining all lines of significance, and state its use in dealing with a thermodynamic problems.
2 – Repeat Q.1 for Enthalpy – entropy ( h – s ) diagram .
3 - Repeat Q.1 for Pressure – enthalpy ( P – h ) diagram .
4 – Define the following thermodynamic processes and terms :
A - adiabatic - isentropic – isothermal – isobaric - polytropic
B - saturation temperature – saturation line – latent heat – specific heat –
critical point – interpolation -
5 – Define each of the followings, and state the differences between them
A – nozzle – diffuser – throttle
B – pump – compressor – fan – turbine
6 – Explain briefly the four laws of thermodynamics
All groups required to answer the following questions :
7 – convert the following units :
lbm to kg - Btu to Joule - calorie to Joule - feet to meter - ft/s to m/s -
inch to centimeter - psi to atm - Btu/lbm to kJ/kg - Btu/hr to kw - cu.ft to liter – 8 – relate each of the following temperature units to each others :
Deg. C - deg. F - deg. K - deg. R
Kerbala University Power Plant Engineering College Sheet No.02 Mech. Eng. Dept. – 4th year class 2012 – 2013
----------------------------------------------------------------------------------------------------------- 1 – define the following terms:
Reversibility
Irreversibility
Isothermal process
Adiabatic process
Isentropic process
Isobaric process
Polytropic process
2 – explain briefly with the aid a simple schematic and T-s diagram the principle of Carnot cycle.
3 - explain briefly with the aid a simple schematic and T-s diagram the principle of Rankin cycle.
4 - explain briefly with the aid a simple schematic and T-s diagram the principle of Brayton cycle.
5 - explain briefly with the aid a simple schematic diagram the principles of hydro-power station.
6 - explain briefly with the aid a simple schematic diagram the principles of nuclear power generation.
Kerbala University Power Plant Engineering College Sheet No.03 Mech. Eng. Dept. – 4th year class 2012 – 2013
----------------------------------------------------------------------------------------------------------- The followings are general methods of power plant classification, discuss each one in details.
Groups should answer the question number that corresponds to the group number:
1.Status
2.Fuel type
3.Capacity
4.Operation
5.Prime mover
6- Classify a specific power plant
according to above methods and
discuss in brief.
Kerbala University Power Plant Engineering College Sheet No. 04 Mech. Eng. Dept. – 4th year class 2012 – 2013
----------------------------------------------------------------------------------------------------------- Explain with a simple diagram the function of the following components of a power plant :
1 – coal handling system.
2 – ash handling system.
3 – steam generating plant.
4 – plant deaerating methods.
5 – plant cooling arrangements.
6 – flue gas expelling system.
Kerbala University Power Plant Engineering College Sheet No.05
Mech. Eng. Dept. – 4th year class 2012 – 2013 A - PROBLEM STATEMENT:
Indicate whether the following states for water are in the liquid,
saturation, or superheated region. Specify the quality of the states
in the saturation region:
State P (kPa)T (°C)v (m3/kg)
11700200--
21200--0.0010
3--75 3.0
4500202--
5350--0.005
6 10000 311 ---
B – SOLVE THE FOLLOWINGS:
1 - At the beginning of a process, the thermometer reads 15 °F. You want to
stop the experiment when the absolute temperature has doubled. What is the
final temperature in degrees Celsius?
2 - Determine the SI values for the following energy-related quantities: 1
Btu/(ft2-hr), 13,000 Btu/lbm, and 50,000 Btu/h.
3 - The numerical values of the properties x, y are given. Linearly interpolate and obtain the specified property.
Find: y for x = 112.3
4 - The numerical values of the properties x, y, and z are given. Linearly interpolate and obtain the specified property.
Find: z for x = 27 and y = 150
5 - water at P = 0.08 MPa and h = 1000 kJ/kg. Find: T and v
6 - Find the efficiency of an ideal engine working between the steam point and the ice point.
Kerbala University Power Plant Engineering College Sheet No.06
Mech. Eng. Dept. – 4th year class 2012 – 2013
-----------------------------------------------------------------------------------------------------------
1 – Power plant actual output is ( 648000 MWhr ) , if the rated full capacity is (1000 MW).
Find the plant capacity factor (CF) for plant operation of (30)days.
( anws : 0.9 )
2 – A wind farm consists of (10) wind turbines , each of (2)MW full rated capacity. If the wind farm produces (43416)MWhr under certain operating conditions. Calculate the farm (CF) for a period of one year.
( anws : 0.25 )
3 – A /A hydro-power station uses (26) main generators of full rated output of (700)MW each, (2) auxiliary generators of (50)MW each. Find the plant (CF) if the actual output for
one year was (79,47)TWhr.
( anws : 0.4957 )
B / What is the maximum power output of a plant if it’s annual actual generating
power averaging (4.2)TWhr, and the capacity factor is (0.23).
( anws : 2080 MW )
4 – The peak load on a power plant is (60 MW). The load having maximum demand of
(30 , 20 , 10 , 14 )MW are connected to the plant. The capacity of the plant is (80 )
MW and the annual load factor is (0.5). Estimate :
a / the average load on the plant.
b / energy supplied per year .
c / the deman
d factor .
d / th
e diversity factor .
( anws : 30MW , 262.8MW , 0.811 , 2.466 )
5 – A / A plant having a rated capacity of (200MW) and maximum load is (100MW) .
Find the plant utility factor if it’s load factor averaging (80 %) .
( anws : 0.4)
B / Calculate the availability factor and the capacity factor of a plant operating
under the following conditions :
i – ready to operate during a particular week but held as stand-by.
ii – operate at half rated power for one month .
( anws : ( 1.0 – 0.0 ) , ( 1.0 – 0.5 )
6 – A hydro power plant is to be used as peak load plant at an annual load factor of
(30 % ). The electrical energy obtained during the year is ( 750 x 105 )KWhr.
Determine :
i – max demand
ii – reserve capacity of the plant if the plant capacity factor is (24 %)
(Anws : 28530 kW , 7137 kW )
Kerbala University Power Plant Engineering College Sheet No. 07 Mech. Eng. Dept. – 4th year class 2012 – 2013
----------------------------------------------------------------------------------------------------------- 1 – The maximum (peak) load on a thermal power plant of (60 MW) capacity is (50MW) at an annual load factor of (50 %) . The load having maximum demand of (25,20,8,5) MW are connected to the power plant . Determine :
i – average load on the power plant iii – demand factor
ii – energy generated per year . iv – diversity factor
( anws : 25 MW , 219 x 106 kWhr , 0.86 , 1.16 )
2 – A steam power plant has an installed capacity of ( 120 MW) and maximum demand of ( 100 MW) . The coal consumption is ( 0.4 kg/kWhr), and cost of coal is (80 PU). The annual expenses of salaries and overhead charges are ( 50 x 105 PU). The power plant works at a load factor of ( 0.5) , and the capital cost of the plant is ( 4 x 105 PU) where interest rate and depreciation is ( 10 %) of capital cost . Determine the cost
generation per kWhr .
( anws : 0.0435 PU )
3 - 15 electrical power consumption units each require (60)kW to operate, if (5 units, 10 units , and 6 units) groups to operate for a period of (2hrs) in various time of the day. Determine :
I – the connected load ii – maximum demand
Iii – demand factor iv – daily load factor.
( anws : 900kW , 600kW , 66.67 % , 17.5 % ).
4 - A power station has a maximum demand of (15)MW , a load factor of (0.7), a plant capacity factor of (0.525) , and a plant use factor of (0.85) . Find :
i – the daily energy produced .
ii – the reserve capacity of the plant .
( anws : 252 x 103 kWhr , 5000kW )
5 – The annual load on a (30)MW power plant is (25)MW. The PP supplies load having maximum demand of (10 , 8.5 , 5 , 4.5)MW . The annual load factor is (0.45) . Find: i – average load ii – energy supplied per year.
iii – diversity factor iv – demand factor
( anws : 11.25 MW , 98.55 x 106 kWhr , 1.12 , 0.893 )
6 - The maximum demand of generating station is (100)MW. The annual capital charge of transmission & distribution are (2.5 x 106 , 2 x 106)PU , their diversity factor is (1.3), and efficiency is (90 %).The generating station capital cost is (100)PU/annum/ kW demand , plus (0.05)PU / kWhr supplied. Determine :
i – yearly cost / kW demand
ii – cost / kWhr supplied
( anws : 111.538 PU , 0.0522 PU )
Kerbala University Power Plant
Engineering College Sheet No.08
Mech. Eng. Dept. – 4th year class 2012 – 2013
-----------------------------------------------------------------------------------------------------------
1. Find the efficiency of the Carnot’s engine working between the steam
point and the ice point. (answ. : 26.81% )
2. A Carnot’s engine whose temperature of the source is 400K takes 200
calories of heat at this temperature and rejects 150 calories of heat to the
sink. What is the temperature of the sink? Also calculate the efficiency of
the engine. (answ. : 300K)
3. A Carnot engine operates between 227°C and 127°C .If it absorbs 60* 104
calorie at high temperature, how much work per cycle can the engine
perform? ( answ.: 50.4*104 J
4. A Carnot engine absorbs 100J of heat from a reservoir at127°C and
rejects 600J of heat during the cycle. Calculate (i) the efficiency of the
engine (ii) the temperature of the sink and (iii) the amount of useful work
done during each cycle? (answ. : 40% , 240 k , 400J )
5 - A Carnot cycle is performed by air initially at 327°C.Each satge
represents a compression or expansion in the ratio 1:6.Calculate(i) the lowest temperature (ii) efficiency of the cycle, given γ = 1.4?
(answ. : 293K , 51.2% )
6. A Carnot heat engine device receives a heat transfer of 100 kJ of heat
from a source at 100°C. If there is a heat transfer to 20°C, calculate the work
produced and the thermal efficiency of the Carnot engine. ( answ. : 21.45 kJ , 21.4 % )
Kerbala University Power Plant Engineering College Sheet No.09 Mech. Eng. Dept – 4th year. 2012 – 2013
-----------------------------------------------------------------------------------------------------------
q.1- A Carnot cycle running on a closed system . The temperature limits are 300 K and 1000 K. If the work done by the system is (39.61 kJ) . Determine (a) the efficiency, (b) the heat supplied and heat rejected of the system . (ans:70% , 56.58kJ , 16.97 kJ)
q.2 - A Carnot heat engine with an efficiency of 60% receives heat from a source at a rate of 3000 kJ/min, and rejects the waste heat to a medium at 300 K. Determine (a) the power that is generated by the engine, (b) the heat source temperature.(ans:30kw,750K)
q.3 - What is the highest possible theoretical efficiency of a heat engine operating in a closed system with (1.5 kg) working fluid. The heat source is from hot reservoir of furnace gases at (2000 oC) when the cooling water available at (10 oC) . Also find the heat energy supplied and rejected , and the actual work done if the engine (η m ) is ( 85 %) . (ans:87.54%,3426.5 , 560 , 2549.62 kJ)
q.4 - A Carnot cycle operates between the temperature limits (140 , 500) oF , if the heat
supplied is (300 Btu/min) . Determine : a/thermal eff. b/ work & horsepower
c/ heat rejected d/ ΔS during isothermal expansion. (ans: 37.5%, 112.5- 2.65 , 187.5Btu/min , 0.3125 Btu/R.min )
q.5 – A hot reservoir at (800 oC) and cold reservoir at (15 oC) , if Pmax is (210 bar) and Pmin is (1 bar). Assuming air is the working fluid. Calculate :
i – the net work.
ii – gross work.
iii - the work ratio of the cycle
iv – cycle efficiency
(ans : 168 kJ/kg , 793.2 kJ/kg , 0.212 , 73.2 % )
q.6 A Carnot cycle running on a closed system has 1.5 kg of air. The temperature limits are 300 K and 1000 K, and the pressure limits are 20 and 1900 kPa. Determine (a) the efficiency, (b) the net work output. (ans : 70% , 101.85 kJ )
Kerbala University Power Plant Engineering College Sheet No. 10 Mech. Eng. Dept – 4th year . 2012 – 2013
----------------------------------------------------------------------------------------------------------- Q.1 – A Carnot engine has a low temperature sink of (10 oC) and max theoretical efficiency of (38 %). By how much does the temperature of the high temperature source need to be increased to raise the efficiency to (50 %) .
( ans : T h1 = 183 oC , T h2= 293 oC , ΔT h = 110 oC )
Q.2 - Find the efficiency of the Carnot engine working between the steam point and the ice point .
( ans : 26.81 % )
Q.3 – An inventor claims to have an engine that receives (100 Btu) of heat and produce
(25 Btu) of useful work when operating between a source at (140 oF)) and a receiver ( 0 oF) . Is the claim a valid claim .
Q.4 – In a Carnot cycle, the steam pressure varies between (30) and (0.04)bar . Calculate the net (heat & work ) transferred and the cycle efficiency . Discuss your results .
( ans : 725 kJ/kg , 725 kJ/kg , 40.0 % )
Q.5 – A steam power plant operates between boiler pressure of (42) bars and condenser
pressure of (0.035)bar . Calculate the max theoretical efficiency of the plant .
( ans : 43.2 % )
Q.6 – One kg of steam at (7)bar , entropy (6.5 lJ/kg.K) is heated reversibly at constant
pressure until temperature is (250 oC) . Calculate the heat supplied and show on
T-s diagram the area which represent the heat flow .
( ans : 283 kJ/kg )
Kerbala University Power Plant Engineering College Sheet No. 11
Mech. Eng. Dept. – 4th year 2012 – 2013
-----------------------------------------------------------------------------------------------------------
q.1 – Steam enters a turbine superheated at (6 MPa) and (680 oK) , after expansion it
exit the turbine at (0.1 MPa) with quality of (0.89) . The steam flow rate is (12)
kg/s . Determine the power delivered by the turbine.
( ans : 9756 KW ).
q.2 – Determine the flow rate required to produce (25 MW) of shaft power from a steam
turbine in which the steam enters at (10 MPa & 720 oK) , and exit at (5 kPa ) for
the following cases :
i – ideal turbine .
ii – turbine with ηis= 96 %
( ans : 19.53 kg/s , 20.34 kg/s )
q.3 – If steam enters a turbine at (10 MPa & 800 oK) , and exit at a quality of (0.91) and
(100 kPa) . Determine the isentropic efficiency of the turbine .
( ans : 0.935 )
q.4 – Consider a steam turbine in which the steam enters as superheated vapor at (800 oK
& 6 MPa) and exit at (0.1 MPa) . The flow rate of the steam is (15 kg/s), and the
isenptropic efficiency of the turbine is (90 %) . Determine :
i – the outlet state of the steam
ii – the power produced by the turbine .
( ans :{T2 = 372.76 K , h2 = 2623.4 kJ/kg , s2 = 6.2207 kJ/kg.K , x = 0.9772} , 12949KW) q.5 – Steam enters a turbine as saturated vapor at (2MPa) , and exit at (101 kPa) with steam
quality of (0.92). Determine :
i – turbine isentropic efficiency .
ii – how does the ( ηis ) change if the exit pressure is decreased to (35 kPa) .
( ans : 0.6 , 0.71 )
q.6 – State the Rankine cycle assumption , and determine it’s efficiency if the operating
conditions are steam to the turbine at (40 bar & 400 oC) , condenser pressure (0.05 bar).
Draw the plant schematic and T-s diagrams .
( ans : 37.8 % )
Kerbala University Power Plant Engineering College Sheet No. 12 Mech. Eng. Dept. 4th year 2012 – 2013
----------------------------------------------------------------------------------------------------------- Describe in details the power plant represented by each of the following schematic diagrams , then draw it’s expected operation On a ( T-s ) diagram .
1 – power plant ( A )
Describe in details the power plant represented by each of the following schematic diagrams , then draw it’s expected operation On a ( T-s ) diagram .
2 – power plant ( B )
Describe in details the power plant represented by each of the following schematic diagrams , then draw it’s expected operation On a ( T-s ) diagram .
3 – power plant ( C )
Describe in details the power plant represented by each of the following schematic diagrams , then draw it’s expected operation On a ( T-s ) diagram .
4 – power plant ( D )
Describe in details the power plant represented by each of the following schematic diagrams , then draw it’s expected operation On a ( T-s ) diagram .
5 – power plant ( E )
------------------------------------------------------------------------------------------------------------