ASSIGNMENT 2 Coal and Ash Handling System and Draught Systems

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1 ASSIGNMENT 1 Thermal Power Plant & High Pressure Boiler 1. State the factors to be considered for selection of site for thermal power plant 2. State desirable to control the super heat temperature. Explain desuperheater method. 3. Discuss FBC. Explain CFBC with neat sketch ASSIGNMENT 2 Coal and Ash Handling System and Draught Systems 1. Enumerate different types of Ash handling system. Explain Pneumatic ash handling system with advantages and disadvantages. 2. Explain pulverized coal system and state its merits and demerits. 3. With usual notations derive an expression of estimation of height of chimney and condition of maximum discharge and Prove the following: Maximum discharge through chimney occurs when T g T a = 2(m a + 1) m a Where Tg and Ta are gas and air temperature respectively and ma is mass of air. ASSIGNMENT 3 Steam Nozzles 1. Derive the condition and then equation of maximum discharge through the nozzle, also write maximum discharge for different condition of steam. 2. Derive equation of critical pressure ratio of nozzle and explain its significance. Calculate its value for superheated steam. 1. The pressure and temperature of steam entering the nozzle are 12 bar and 200 C and steam leave the nozzle at 1 bar. The diameter of the nozzle at throat is 10 mm. Calculate the mass flow rate of steam in a nozzle and which type of nozzle is required? Darshan Institute of Engineering and Technology, Rajkot 1.1

2 2. Steam is expanded in nozzle from 15 bar and 350 C to 1 bar. Find the throat and exit area if flow rate is 1 kg/sec. What should be coefficient of velocity if exit velocity is 1150 m/sec? 3. Dry saturated steam at a pressure of 8 bar enters a convergent divergent nozzle and leaves it at a pressure of 1.5 bar. If the flow is isentropic and the corresponding expansion index is Calculate the ratio of cross-sectional area at exit throat for maximum discharge. ASSIGNMENT 4 Steam Turbine 1. Classify steam turbines. 2. Define blade efficiency and derive an expression for maximum blade efficiency for single stage impulse steam turbine. 3. Define the term Degree of Reaction. Derive condition of maximum blade efficiency in case of 50% reaction turbine. 4. The Data pertaining to an impulse turbine is as: Blade speed = 300 m/s, Isenthalpic enthalpy drop in nozzle = 450 kj/kg, Nozzle efficiency = 90 %, Nozzle angle = 20º, Blade velocity co efficient = 0.85, Blade exit angle = 25º. Calculate for a mass of 1 kg/sec; (1) Inlet angle of moving blades (2) The axial thrust (3) The driving force on the wheel (4) The diagram power (5) The energy lost in blades due to friction (6) Blade efficiency 5. A reaction turbine runs at 3000 RPM and steam consumption is kg/hr. The pressure of Steam at a certain pair is 2 bar, its dryness fraction is 0.94 and the power developed by the pair is 52 kw. The discharge blade angle is 20 for both fix and moving blades and the axial flow velocity is 0.72 times the blade velocity. Find out the drum diameter and blade height. Take the tip leakage steam as 8 %. Neglect the Blade thickness. Darshan Institute of Engineering and Technology, Rajkot 1.2

3 ASSIGNMENT 5 Condensers and Cooling Tower and Feed Water Treatment 1. Define Fill, Drift, Approach, Range and cooling efficiency of cooling tower. Explain the methods for obtaining maximum vacuum in condenser. 2. Discuss the importance of condenser in thermal power plant. 3. How the Dalton s law of partial pressure can be applied to condenser application? 4. Why feed water treatment is essential in power plants? 5. Discuss various methods of water treatment. 1. In a condenser, vacuum reads 716 mm of Hg while barometer reads 756 mm of Hg. The temperature of condensate is 25 C. Determine (i) The pressure of the steam and air (ii) Mass of air per kg of steam (iii) The vacuum efficiency. ASSIGNMENT 6 Gas Turbine 1. Explain the parameters affected on work ratio in gas turbine power plant. 2. Derive an expression for air standard efficiency of ideal Bryton cycle in terms of pressure ratio. State the assumption made. 3. The air at p1 and T1 enters into a gas turbine cycle and compressed to p2 (R = p2/p1) and then heated to temperature T3. The air is expanded into two stages having same pressure ratio in each turbine. The air after expansion in first stage is reheated to T3 before passing to second stage of the turbine. Considering all processes ideal and intermediate pressure,p i = p 1 p 2 Prove that, W net = 2T (1 1 ) (K 1) C p T 1 K Where, T = T3 / T1, K = R m and m = γ -1 / γ Also derive for the maximum specific work output, R = ( T 3 2 3m ) T 1 Darshan Institute of Engineering and Technology, Rajkot 1.3

4 4. Explain the effect of operating variables on the thermal efficiency of a gas turbine cycle. 1. A gas turbine operates on Brayton cycle. The temperature range is 1050 K and 288 K. Find pressure ratio for maximum power output. Also determine thermal efficiency, work ratio and power output, if the mass flow rate of air is 20 kg/sec. Take Cp = kj/kg K and ϒ = 1.4 for compression and expansion process. 2. A gas turbine plant is operated between 1 bar and 9 bar pressures and minimum and maximum cycle temperatures are 25 C and 1250 C. A compression is carried out in two stages with perfect intercooling. The gases coming out from H.P. turbine are heated to 1250 C before entering into L.P. turbine. The expansions in both turbines are arranged in such a way that each stage develops same power. Assuming compressors and turbines isentropic efficiencies as 83 %. (a) Determine the cycle efficiency assuming ideal regenerator. (b) Find the power developed by the cycle in kw if the air flow through the power plant is 16.5 kg/sec. Neglect the mass of fuel. All the components are mounted on a single shaft. ASSIGNMENT 7 Nuclear Power Plant and Jet Propulsion 1. List the nuclear reactors. Explain working of Pressurized water reactor. 2. Main components of nuclear reactor and nuclear control 3. Chain Reaction in Nuclear Power plant 4. What is the difference between fissionable and fertile materials? 5. Explain the principle of jet and rocket propulsion with neat sketch. ASSIGNMENT 8 Economics of Power Generation 1. Define the following terms:- (i) Peak load (iii) Plant Capacity factor (v) Demand factor (ii) Average load (iv) Connected load (vi) Diversity factor (vii) Plant use factor Darshan Institute of Engineering and Technology, Rajkot 1.4

5 1. A 200 MW thermal power plant has peak load of 130 MW. The power station supplies load to four town having their maximum demand of 30 MW, 40 MW, 25 MW and 45 MW. The annual load factor is 65%. Find: (i) Average load on the plant (ii) Energy supplied per year (iii) Diversity factor (iv) Demand factor (v) Plant capacity factor. 2. The maximum load on thermal power plant of 70 MW capacity is 55 MW at an annual load factor of 60 %. The Coal consumption is 0.96 kg per unit of energy generated and the cost of coal is Rs. 2 per kg. Find the annual revenue earned if the electric energy is sold at Rs. 2.5 per kwh. Darshan Institute of Engineering and Technology, Rajkot 1.5

6 Darshan Institute of Engineering and Technology, Rajkot 1.6