Power Plant Engineering - May 2014
Mechanical Engg (Semester 8)
TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.
Answer any one question from Q1 and Q2
1 (a) Explain present status of power generation in India and Maharashtra. Comment on impact of power generation on economical development of nation.(8 marks) 1 (b) A diesel power plant consists of two units of 500 KW capacities and one unit of 200 KW. The fuel used has calorific value of 40,000KJ/Kg and fuel consumption is 0.25 Kg/Kwh. Determine quantity of fuel required for a month of 30 days and its cost if fuel cost is Rs.4000/ton. Take capacity factor of plant as 50% and also find overall efficiency of plant.(8 marks) 10 (a) Explain with neat sketch, construction and working of fuel cell and MHD.(10 marks) 10 (b) State function of electrical equipment in power plant engineering.(8 marks)
Answer any one question from Q11 and Q12
11 (a) Discuss causes and effects of oxides of sulphur, nitrogen and carbon generated in power plant emission.(8 marks)
11 (b) Explain noise pollution caused by thermal power plant and its control.(8 marks)
12 (a) Write short note on:
i) Acid precipitation
ii) Thermal pollution.(8 marks) 12 (b) Write short note on:
i) Green house effect.
ii) Global warming.(8 marks) 2 (a) Discuss relative merits and demerits of thermal, hydraulic and nuclear power plant.(8 marks) 2 (b) Explain performance and operating characteristics of power plant using terms input output curve, efficiency, heat rate and incremental heat rate.(8 marks)
Answer any one question from Q3 and Q4
3 (a) Comment on COM, CWM, and CMM fuels as a replacement to conventional coal as a fuel for thermal power plant.(6 marks)
3 (b) In a co-generation plant, 25 Kg/s steam enters turbine at 40 bar and 400°C. 20% of steam is withdrawn for process heating at 3 bar and remaining continues to expand in turbine up to condenser pressure of 0.08 bar. Neglect pump work. Represent cycle on T-S diagram.
i) Thermal efficiency of cycle
ii) Capacity of power plant in MW
iii) Effectiveness of co-generation(12 marks) 4 (a) Explain construction and working of impact mill and ball mill for pulverization of coal.(8 marks) 4 (b) The steam at 70 bar and 500°C is supplied to the steam turbine. Steam is expanded in high pressure turbine isentropically till it is dry saturated. The steam is reheated to 400°C passing to reheater. Expansion after reheating is carried to condenser pressure up to 0.2 bar. Find efficiency of cycle and work output if flow of steam is 10 Kg/sec. consider pump work. Represent cycle on TS and hS plot and sketch flow diagram.
i) Reheating pressure
ii) Dryness fraction of steam at low pressure turbine outlet.
iii) Thermal efficiency of cycle
iv) Work ratio(10 marks)
Answer any one question from Q5 and Q6
5 (a) Explain the term run off, hydrograph and flow duration curve for hydroelectric power plant.(6 marks)
5 (b) In a gas turbine power plant air enters in compressor at 20°C and 1 bar. The maximum temperature of cycle is limited to 700°C and maximum pressure ratio is limited to 6.The effectiveness of regenerator is 0.7.
Assuming following data find
i) A: F ratio.
ii) Thermal efficiency of cycle.
Calorific value of fuel used 35000 KJ/Kg. Cp of air 1 KJ/KgK and γ = 1.4. Sketch the flow diagram and represent cycle on TS plot.(10 marks) 6 (a) Explain with neat sketch various functional elements of hydroelectric power plant.(8 marks) 6 (b) What is combined power plant? What are its advantages over conventional power plant? Sketch gas and steam combined power plant.(8 marks)
Answer any one question from Q7 and Q8
7 (a) Describe in brief with neat sketch construction and working of gas cooled reactor.(8 marks) 7 (b) Explain construction and working of diesel power plant.(8 marks) 8 (a) Sketch and explain pressurized water reactor.(8 marks) 8 (b) Explain performance operating curves for diesel power plant.(8 marks)
Answer any one question from Q9 and Q10
9 (a) Explain with neat sketch, construction and working of power transformer.(8 marks) 9 (b) Explain with neat sketch, construction and working of central receiver solar power plant.(10 marks)