School of Engineeringand Built Environment Department of Engineering SESSION: 2014/2015 Sample: EXAM PRACTIC (MOCK EXAM PAPER) Energy Conversion Technologies Level: 3 Module Code: M3J923150 Module Leader: Prof M El-Sharif DATE: DURATION: 2 Hours 2015 Time: CANDIDATES SHOULD ATTEMPT FOUR QUESTIONS – TWO FROM SECTION A AND TWO FROM SECTION B All Questions Carry Equal Marks PLEASE READ THE QUESTIONS CAREFULLY MATERIALS TO BE SUPPLIED/ALLOWED: Lined Examination Script Books Unlined Examination Script Books Question Paper (Supplied) Thermodynamic Tables (Attached) Key Formulae Sheet (Attached) Dictionary (Allowed) Calculator (Allowed) T v1 = 0. Steam is extracted at 1000 kPa to serve the closed feedwater heater. Consider a steam power plant that operates on the ideal regenerative Rankine cycle with a closed feedwater heater as shown in Figure Q1. a) b) Show the cycle on a T-s diagram with respect to saturation lines. which discharges into the condenser after being throttled to condenser pressure.9 kJ/kg h6s = 2221.51 kJ/kg Isentropic turbine efficiency .001017 m3/kg h4 h5 h h 4 6 h4 h5 s h4 h6 s .1 kJ/kg h5s = 2851. and operates the condenser at 20 kPa. .SECTION A Attempt TWO Question Q1. the thermal efficiency of the cycle.42 kJ/kg h3 = 763. the specific work consumed by the pump. Assume that the isentropic efficiency of the turbine is 90% before and after steam extraction point. iii. Determine: i. ii.7 kJ/kg h7 = 762. the specific work produced by the turbine. The plant maintains the turbine inlet at 3000 kPa and 350°C.53 kJ/kg h4 = 3116. 4 Turbine Boiler 5 6 (y) (1-y) 7 Condenser 3 Throttle valve Closed FWH 2 1 Pump Figure Q1: Steam power plant Data and Formulae related to Q1: h1 = 251. determine: i.74 kJ/kg h6s = 1088.2 The gas-turbine cycle shown in Figure Q2 is used as an automotive engine. just low enough for this turbine to drive the compressor. The regenerator effectiveness is 70%. iv. the net specific work output of the engine. c 2 s h2 h1 Regenerato r effectiveness. Figure Q2 DATA: h2s = 501. iii. The gas is then expanded through the second turbine (Tur2) connected to the drive wheels. Using data shown in Figure Q2 and assuming no pressure drop in regenerator and burner.Q. the specific enthalpy of the exhaust stream h7 v. the gas expands to pressure P5. the mass flow rate through the engine. reg . In the first turbine (Tur1). the thermal efficiency of the engine. the air temperature leaving the compressor T2 ii. T 5 6 h5 h6 s h h1 Isentropic compressor efficiency . The isentropic efficiency of the compressor is 82% and both turbines have efficiencies of 87%.63kJ/kg TABLE A-22 Ideal Gas Properties of Air (attached) Formulae related to Q2: h3 h2 h6 h2 h h Isentropic turbine efficiency . Saturated vapour P =1. Q s m s S gen system 0 J m J TJ out in Energy rate balance at steady state. the power output or input.Q. in kW. determine: i.0 bar P =1 MPa T = 320 oC Figure Q3 Formulae related to Q3: Steady . ii.state control volume entropy rate balance. the direction of flow.3 Figure Q3 provides steady-state operating data for a well-insulated device having steam entering at one location and exiting at another with a mass flow rate of 10kg/s. 1 he hi (C e2 Ci2 ) g z e z i Q CV W CV m 2 . as appropriate. Neglecting kinetic and potential energy effects. [3 marks] e. [5 marks] ii) Calculate the annual average power available in the wind. what is the relative wind speed at a blade radius of 10m? [5 marks] d. explain how the lift and drag forces on an aerofoil are generated. On a particular wind turbine. assume the density of air is 1.2 kg/m3. [3 marks] iii) What is the annual energy production potential at this location? [2 marks] . If the pitch angle of the blade described in part c is 2o. Cp.SECTION B Attempt TWO Question Q4. a blade is travelling with an angular velocity of 3 rad/s.01. With the aid of a sketch. The distribution of wind speeds over a year at a location 20m above ground level are found to be as follows: 6 hrs/day at 4m/s 6 hrs/day at 7. If the incident air velocity is 6 m/s and the inflow factor can be taken as 0. of a wind turbine? [2 marks] b.5m/s 6 hrs/day at 0m/s 6 hrs/day at 2m/s i) Calculate the root mean cube speed URMC. [5 marks] c. calculate the angle of attack. What is the definition of the coefficient of performance. a. Q5. use a series of sketches to illustrate your description. [5 marks] e) Describe the four steps of the operating cycle for Ebb generation for a tidal barrage scheme. a) What forces influence the generation of tides on earth? [2 marks] b) Will an estuary which has a length of approximately 100 km and an average depth of 25 m experience a resonance effect? [2 marks] c) When considering tidal range power generation. what factors determine the potential energy available? [4 marks] d) Sketch a typical layout for a turbine within the setting of a tidal barrage and label the important components. [12 marks] . [1 mark] what do the values 10 and 5 represent? [2 marks] d. At the atomic scale. Name three nuclear decay modes. Name the two kinds of particle that are at the centre of an atom and give nature of the charge of each. [4 marks] b. [10 marks] Draw a sketch of a boiling water reactor and label the major components .Q6. What is meant by the term mass defect? c. If the element boron is written as 10 5B. a. [3 marks] f. what is the unit for energy and what is its value in Joules [2 marks] e. cos r W W u 2 (1 a) 2 (r ) 2 3 2 U RMC P 1 Cp Pt PW L h 35000 .Formula Sheet. Data Q2: TABLE A-22 Ideal Gas Properties of Air (attached) .