Mechanical Engineering Job Preparation by Ali Imran-DUET
Power Plant Model Test
Full Marks-100
Written 10×10=100 Marks
Time-60Minutes
1. The loads on a power plant with respect to time for 24 hours are given as follows:
Time (hours)
0-6
6-8
8-12
12-14
14-18
18-22
22-24
Load (MW)
40
50
60
50
70
80
40
Find out load factor of the power station. If the loads above 60MW are taken by a standby unit of
20MW capacity also find out the load factor and use factor of the standby unit. Draw the load curve
& Load distribution curve for the power plant.
10
2. (a) Differentiate between base load & peak load power plant with example.
2
(b) A power plant has the following annual factors: Load factor=0.75, Capacity factor= 0.6, Use
factor=0.65. Max. demand is 60MW. Estimate i) The Annual energy produced, ii) the reserve
capacity and iii) hours of operation and hours during which plant was not in service.
8
3. (a) Draw a h-s diagram (Also T-S) to show the isentropic efficiency of turbine and also write down
Equation.
6
(b)Differentiate between BWR & PWR with figure.
4
4. A simple gas turbine is modified with multiple compressor, multiple intercooler, multiple reheater
and regeneration and inlet to outlet pressure to remain constant.
10
a) Does work output increase, decrease or remain same?
b) Does efficiency increase, decrease or remain same?
c) Does work back pressure ratio increase, decrease or remain same?
d) Does exhaust temperature increase, decrease or remain same?
5. (a) Draw TS diagram for Subcritical and Supercritical power plant.
(b) Why condenser is used in steam power plant.
(c) Write formula: Heat Rate, S.S.C, Steam Rate, Net Heat Rate.
4
2
4
6. (a) Why intercooling is done ?
2
(b) A thermal power plant consists of two 60MW units, each running for 8000 hours, and one
30MW unit running for 2000 hours per year. The energy produced by the plant is 876×106KWh
per year. Determine the plant load factor and plant use factor. Consider the maximum load as equal
to the plant capacity.
8
7. (a) Write the formula: Steam generation factor/factor of evaporation, Evaporation Factor,
Boiler draught, boiler power.
4
(b) Draw the schematic diagram of thermal power plant with super heater, air preheater, economizer.
6
8. Consider a simple ideal Rankine cycle with fixed turbine inlet conditions. What is the effect of
lowering condenser pressure: Increase/Decrease/Remain same?
(i)Pump work input, (ii) Turbine work output, (ii) Heat supplied, (iii) Heat rejection,
(iv)Cycle efficiency, (v)Moisture content on turbine exit.
10
9. Draw the block, T-S & P-V diagram of the most abundantly used power plant cycle in Bangladesh.
Also name the processes of that cycle.
10
10. Draw the front sectional view of the following object.
.
For indeed, with hardship [will be] ease [i.e., relief].”
---The End—
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