SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT B.Tech. [SEM IV (ME-41, 42,43 & 44)] QUIZ TEST-1 (Session: )

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1 QUIZ TEST-1 Q.1. In a stage of an impulse turbine provided with a single row wheel, the mean diameter of the blade ring is 80cm and the speed of the rotation is 3000rpm. The steam issues from the nozzle with a velocity of 300m/s and the nozzle angle is 20. The rotor blades are equiangular and due to the friction in the blade channels the relative velocity of steam at outlet from the blade is 0.86 times the relative velocity of the steam entering in the blades. What is the power developed in the blades when the axial thrust on the blades is 140N? Q.11 [2+3] Q.2. A cyclic steam power plant is to be designed for the steam in turbine inlet of C and an exhaust pressure of 0.08 bar. After isentropic expansion of steam in turbine, the moisture content at the turbine exhaust is not to exceed 15%. Determine the greatest allowable steam pressure at the turbine inlet, and calculate the Rankine cycle efficiency for steam condition. Q.1 [3+2] Q.1. A steam power station uses the following cycle Steam at boiler outlet- 150 bar, C Reheat at 40 bar to C Condenser at 0.1 bar. Using the Mollier chart and assuming ideal processes, find the (a) Quality at turbine exhaust, (b) Cycle efficiency, and (c) Steam rate [3+3+2] Q.2. Define the types of feedwater heater (FWH) with proper block and T-S diagram? Also derive the energy balance equation for FWH. [2+2+2] Q.3. What do you know from compounding? Draw the Sketch diagram for pressure -velocity compounded Impulse Turbine. [2+2+2] Date: 04 / 02/ 2012

2 B SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT B.Tech. [SEM IV (ME-41, 42, 43 & 44)] QUIZ TEST-1 Q.1 Steam flows from the nozzles of a single row impulse turbine with a velocity 450m/s at a direction which is inclined at an angle of 16 to the peripheral velocity. Steam comes out of the moving blades with an absolute velocity of 100m/s in the direction at 110 with the direction of blade motion. The blades are equiangular and steam flow rate is 6kg/s. Determine the power developed and the power loss due to the friction. Q.3 [3+2] Q.2. A steam at 20 bar, C is expended in steam turbine to 0.08 bar. It then enters a condenser, where it is condenced to saturated liquid water. The pump feeds back the water into the boiler. (a) Assuming the ideal processes, find per kg of steam the net work and cycle efficiency. (b) If the turbine and the pump have each 80% efficiency, find the percentage reduction in the net work and cycle efficiency. Q.14 [2+3] Q.1. A steam power station uses the following cycle Steam at boiler outlet- 150 bar, C Reheat at 40 bar to C Condenser at 0.1 bar. Using the Mollier chart and assuming ideal processes, find the (a) Quality at turbine exhaust, (b) Cycle efficiency, and (c) Steam rate [3+3+2] Q.2. Define the types of feedwater heater (FWH) with proper block and T-S diagram? Also derive the energy balance equation for FWH. [2+2+2] Q.3. What do you know from compounding? Draw the Sketch diagram for pressure -velocity compounded Impulse Turbine. [2+2+2] Date: 04 / 02/ 2012

3 c SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT QUIZ TEST-1 Q.1. The mean diameter of blades of an impulse turbine with a single row wheel is 105 cm, and the speed is 3000rpm. The nozzle angle is 18, the ratio of blade speed to steam speed is 0.42 and ratio of the relative velocity at outlet from the blades to that at inlet is The outlet angle of blade is to be made 3 less than that inlet angle. The steam flow is 8kg/sec. Draw the velocity diagram for the blades and find the following (a) resultant thrust on the blades (b) tangential thrust on the blades (c) axial thrust on the blades (d) power developed in blades, and (e) blading efficiency. Q.6 [ ] Q.2. In a stage of an single stage impulse reaction turbine operating with half degree reaction, the fixed and moving blades are of identical section and outlet angle is 18. The absolute velocity of discharge from the moving blade is 40m/s in the direction 110 to the direction of motion of the blades, and the change of velocity produced by the moving blades parallel to that direction. Draw the velocity diagram and find (a) mean velocity of the blades (b) ratio of velocity of blade to the velocity of efflux, and (c) work done per kg of steam. Q.10 [2+2+1] Q.1. A steam power station uses the following cycle Steam at boiler outlet- 150 bar, C Reheat at 40 bar to C Condenser at 0.1 bar. Using the Mollier chart and assuming ideal processes, find the (a) Quality at turbine exhaust, (b) Cycle efficiency, and (c) Steam rate [3+3+2] Q.2. Define the types of feedwater heater (FWH) with proper block and T-S diagram? Also derive the energy balance equation for FWH. [2+2+2] Q.3. What do you know from compounding? Draw the Sketch diagram for pressure -velocity compounded Impulse Turbine. [2+2+2] Date: 04 / 02/ 2012

4 QUIZ TEST-1 Q.1 In a single stage impulse turbine, the steam velocity at nozzle mouth is 300m/s, the nozzle angle is 18, and the mean blade velocity is 144m/s. Draw to a suitable scale the diagram of relative velocities for the steam assuming that the outlet angle of blade is 3 less than inlet angle and that the relative velocity of the steam at outlet from the blade is 0.84 of the relative velocity at entrance. If the power is to be developed is 1000 kw. Calculate the mass of steam that must pass through the turbine per second. Neglect friction and leakage loss. Q.5 [3+2] Q.2. In a single- heater regenerative cycle the steam enters the turbine at 30 bar, C and the exhaust pressure is 0.1bar. The feed water heater is a direct-contact type which operates at 5bar. Find efficiency and the stem rate of cycle. Q.2 [1+2+2] Q.1. A steam power station uses the following cycle Steam at boiler outlet- 150 bar, C Reheat at 40 bar to C Condenser at 0.1 bar. Using the Mollier chart and assuming ideal processes, find the (a) Quality at turbine exhaust, (b) Cycle efficiency, and (c) Steam rate [3+3+2] Q.2. Define the types of feedwater heater (FWH) with proper block and T-S diagram? Also derive the energy balance equation for FWH. [2+2+2] Q.3. What do you know from compounding? Draw the Sketch diagram for pressure -velocity compounded Impulse Turbine. [2+2+2] Date: 04 / 02/ 2012

5 B.Tech. [SEM IV (ME-41, 42, 43 & 44)] QUIZ TEST-1 Q.1. Draw the velocity diagram for a stage in impulse turbine with two rings of moving blades for the following particulars, Nozzle angle=15, moving blade tip discharge angle=30, fixed blade discharge angle=20 and final discharge is axial. Friction loss per blade is 10% of relative velocity. It occurs both on fixed and moving blades. Find the blade velocity for a nozzle steam exit velocity of 500m/s and the diagram efficiency of the stage. Q.7 [2+3] Q.2. The following particulars relate to a two row velocity compounded impulse wheel which forms the first stage of combination turbine:- steam velocity at nozzle outlet=650m/s, mean blade velocity =125m/s, nozzle outlet angle =16, outlet angle(first row of moving blades)=18, outlet angle (fixed guide blades)=22, outlet angle(second row of moving blades )=36, steam flow per second=2.5kg/s. The ratio of the relative velocity at outlet to that at inlet is 0.84 for all blades. Determine for each row of moving blades the following:- (a) the velocity of whirl (b)the tangential thrust on the blades (c) the axial thrust on the blades (d) the power developed (e) what is efficiency of wheel as whole? Q.8 [ ] Q.1. A steam power station uses the following cycle Steam at boiler outlet- 150 bar, C Reheat at 40 bar to C Condenser at 0.1 bar. Using the Mollier chart and assuming ideal processes, find the (a) Quality at turbine exhaust, (b) Cycle efficiency, and (c) Steam rate [3+3+2] Q.2. Define the types of feedwater heater (FWH) with proper block and T-S diagram? Also derive the energy balance equation for FWH. [2+2+2] Q.3. What do you know from compounding? Draw the Sketch diagram for pressure - velocity compounded Impulse Turbine. [2+2+2] Date: 04 / 02/ 2012

6 QUIZ TEST-2 Q.1. A steam engine has a stroke equal to 1.3 times the diameter and a diagram factor of 0.8. It is supplied with dry saturated steam at 9.8 bar and exhaust at 1.05bar. If the ratio of expansion is 2.5, the speed 200 rpm and indicated power 185kW, find the dimension the cylinder. Q.1 [ 2+2+1] Q.2. A convergent- divergent nozzle is to be designed in which steam initially at 14bar and 80 C of superheat is to be expanded down to a back pressure of 1.05bar. Determine the necessary throat and exit diameters of the nozzles for a steam discharge of 500kg/hr. Q.4 [3+2] Q.1. Derive the condition of pressure ratio for chocked flow condition and also derive expression for maximum discharge through nozzle. [3+3] Q.2. Steam at a pressure of 20 bar, C is supplied to an engine. Steam expands up to a pressure of 2.4 bar when the release occurs. Steam is exhausted to 1.1 bar. The steam flow rate is 2 kg/s. Determine the following per kg of steam: (a) The work done for modified cycle (b) Heat supplied and ideal thermal efficiency. [3+3+2] Q.3. Initially dry saturated steam remains in dry saturated steam expands in a nozzle from 15 bar to 6 bar. During expansion upto throat the steam remains in dry state whereas expansion is frictionless throughout. What is the degree of supersaturation and of undercooling? [3+3] Date: 14 / 03/ 2012

7 B SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT QUIZ TEST-2 Q.1 The nozzles of certain turbine have a throat diameter of 0.6cm each. The power develops by the turbine is 150kW and steam consumption is about 9.5kg/kWh. The upstream pressure is 14 bar and temperature is 300 C. The back pressure is 0.05bar. Assuming that the flow is isentropic between entrance and exit, find the numbers of nozzles and the steam consumption based on these conditions. Neglect the velocity of approach. Q.5[3+2] Q.2 Steam is expanded in the set of the nozzles from 10bar and 200 C to 5bar. Is the nozzle convergent or convergent-divergent? Neglecting the initial velocity, find the minimum area of the nozzles to flow 3kg/s of steam under the given conditions. Assume the expansion of the steam is isentropic. Q.3[1+4] Q.1. Derive the condition of pressure ratio for chocked flow condition and also derive expression for maximum discharge through nozzle. [3+3] Q.2. Steam at a pressure of 20 bar, C is supplied to an engine. Steam expands up to a pressure of 2.4 bar when the release occurs. Steam is exhausted to 1.1 bar. The steam flow rate is 2 kg/s. Determine the following per kg of steam: (a) The work done for modified cycle (b) Heat supplied and ideal thermal efficiency. [3+3+2] Q.3. Initially dry saturated steam remains in dry saturated steam expands in a nozzle from 15 bar to 6 bar. During expansion upto throat the steam remains in dry state whereas expansion is frictionless throughout. What is the degree of supersaturation and of undercooling? [3+3] Date: 14 / 03/ 2012

8 C SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT QUIZ TEST-1 Q1. In a test on vertical double acting steam engine, the following observations were taken: Indicator card =10.05 cm 2 Spring constant for indicator used = 0.08Mpa/cm Speed = 120 rpm; Diameter of piston = 21.5cm; Diameter f piston rod = 3.7cm; stroke =30.7cm. Calculate indicated power. If mechanical efficiency of engine is 80% at given load, find the Brake torque developed. Q.2[3+2] Q2. A nozzle expands steam from the 14bar and 300 C to 6bar. If the flow rate is 1kg/s, Find the throat and exit area. What should be the coefficient of the velocity, if exit velocity is 550m/s? Q.6[2+3] Q.1. Derive the condition of pressure ratio for chocked flow condition and also derive expression for maximum discharge through nozzle. [3+3] Q.2. Steam at a pressure of 20 bar, C is supplied to an engine. Steam expands up to a pressure of 2.4 bar when the release occurs. Steam is exhausted to 1.1 bar. The steam flow rate is 2 kg/s. Determine the following per kg of steam: (a) The work done for modified cycle (b) Heat supplied and ideal thermal efficiency. [3+3+2] Q.3. Initially dry saturated steam remains in dry saturated steam expands in a nozzle from 15 bar to 6 bar. During expansion upto throat the steam remains in dry state whereas expansion is frictionless throughout. What is the degree of supersaturation and of undercooling? [3+3] Date: 14 / 03/ 2012

9 QUIZ TEST-1 Q1. Determine the throat and exit height of a Delaval nozzle to discharge 27kg of a perfect gas per minute. The inlet and the exit pressures are 480kPa and 138kPa respectively. Initial temperature of the gas is 535 C. The molecular weight of the gas is 29 and its adiabatic index is 1.4. Assume square cross-section of the nozzle. Q.9 [2+3] Q2. A covergent-divergent nozzle required to discharge 2kg of steam per second. The nozzle is supplied with steam at 6.9bar and 180 C and discharge takes place against a back pressure of 0.98bar. Expansion upto throat is isentropic and the frictional resistance between the throat and exit equivalent to 62.76kj/kg of steam. Taking approach velocity of 75m/s and throat pressure 3.9bar, Estimate suitable areas for the throat and exit. Q.supp. 1[2+3] Q.1. Derive the condition of pressure ratio for chocked flow condition and also derive expression for maximum discharge through nozzle. [3+3] Q.2. Steam at a pressure of 20 bar, C is supplied to an engine. Steam expands up to a pressure of 2.4 bar when the release occurs. Steam is exhausted to 1.1 bar. The steam flow rate is 2 kg/s. Determine the following per kg of steam: (a) The work done for modified cycle (b) Heat supplied and ideal thermal efficiency. [3+3+2] Q.3. Initially dry saturated steam remains in dry saturated steam expands in a nozzle from 15 bar to 6 bar. During expansion upto throat the steam remains in dry state whereas expansion is frictionless throughout. What is the degree of supersaturation and of undercooling? [3+3] Date: 14 / 03/ 2012

10 QUIZ TEST-1 Marks] [10 Q1. A Delaval type impulse turbine is to develops 150kW with a probable consumption of 7.5kg of steam per kwh with initial pressure being 12bar and the exhaust 0.15bar. Taking the diameter of the throat of each nozzle as 6mm. Find the number of the nozzles required. Q.10[5] Q2. The steam nozzle is supplied steam at 15bar, 350 C and discharges steam at 1bar. If the diverging portion of the nozzle is 80mm long and the throat diameter is 6mm. Determine the cone angle of the divergent portion. Assume 12% of the total available enthalpy drop is lost in friction in the divergent portion. Also determine the velocity and temperature of the steam at throat. Q.11 [2+3] Q.1. Derive the condition of pressure ratio for chocked flow condition and also derive expression for maximum discharge through nozzle. [3+3] Q.2. Steam at a pressure of 20 bar, C is supplied to an engine. Steam expands up to a pressure of 2.4 bar when the release occurs. Steam is exhausted to 1.1 bar. The steam flow rate is 2 kg/s. Determine the following per kg of steam: (a) The work done for modified cycle (b) Heat supplied and ideal thermal efficiency. [3+3+2] Q.3. Initially dry saturated steam remains in dry saturated steam expands in a nozzle from 15 bar to 6 bar. During expansion upto throat the steam remains in dry state whereas expansion is frictionless throughout. What is the degree of supersaturation and of undercooling? [3+3] Date: 14 / 03/ 2012

11 QUIZ TEST-3 Q.1.. A single cylinder was supplied with gas having the following percentage volumetric analysis, CO=5, CO 2 =10, H 2 =50,CH 4 =25,N 2 =10. The percentage volumetric analysis of dry gases was CO 2 =8, O 2 =6 and N 2 =86. Determine the air fuel ratio by volume. Q.3 [3+2] Q.2. Derive TdS equations (i) (ii) Q.9 [2+3] Q.1. Define coefficient volume expansivity and coefficient of isothermal compressibility. Determine the volume expansivity of steam at 350kPa and C. [2+2+3] Q.2. What is inversion of curve in throttling process? Define is joule-thomson coefficient and the significance of inversion curve in cooling and heating of gas in throttling process. [2+2+3] Q.3 What is clausius clapyorn equation? Using Maxwell relationship derive this equation. [3+3] Date: 19 / 03/ 2012

12 B SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT QUIZ TEST-3 Q.1 A sample of fuel has the following percentage composition: carbon=86%,h 2 =8%,sulphur=3%,O 2 =2%,ash=1%.For A/F ratio=12:1. Calculate (i) Mixture strengths as a percentage rich or weak. (ii) Volumetric analysis of the dry products of combustion.. Q.5[2+3] Q.2. In case of a gas obeying the equation of state,where B function of T only, show that, Where (C p ) 0 is the value at very low pressures. Q.7[5] Q.1. Define coefficient volume expansivity and coefficient of isothermal compressibility. Determine the volume expansivity of steam at 350kPa and C. [2+2+3] Q.2. What is inversion of curve in throttling process? Define is joule-thomson coefficient and the significance of inversion curve in cooling and heating of gas in throttling process. [2+2+3] Q.3 What is clausius clapyorn equation? Using Maxwell relationship derive this equation. [3+3] Date: 19 / 03/ 2012

13 C SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT QUIZ TEST-3 Q1. Percentage volumetric analysis of a sample of flue gases of a coal fired boiler gave CO 2 = 10.4, CO=0.2, O2=7.8 and N 2 =81.6 (by difference).gravemetric percentage analysis of coal was C=78,H 2 =6,O 2 =3 and incombustible=1.3. Estimate (i) Weight of dry flue gases per kg of fuel. Q.2[5] Q2. Derive the equation for the difference of heat capacities Q.10[5] Q.1. Define coefficient volume expansivity and coefficient of isothermal compressibility. Determine the volume expansivity of steam at 350kPa and C. [2+2+3] Q.2. What is inversion of curve in throttling process? Define is joule-thomson coefficient and the significance of inversion curve in cooling and heating of gas in throttling process. [2+2+3] Q.3 What is clausius clapyorn equation? Using Maxwell relationship derive this equation. [3+3] Date: 19/ 03/ 2012

14 QUIZ TEST-1 Q1. A fuel (C 10 H 22 ) is burnt using a air fuel ratio of 13:1 by weight. Determine complete volumetric analysis of the products of combustion, assuming that the whole amount of hydrogen burns to form water vapor and there is neither any free O 2 nor any free carbon. The carbon burn to CO 2 and CO. Air contain 77% of N 2 and 23% O 2. Q.4[5] Q2. The Joule- Kelvin coefficient µ j is a measure of the temperature change during throttling process. A similar measure of temperature change produced by an isentropic change pressure is provided by the coefficient of µ s, Q.8[5] Q.1. Define coefficient volume expansivity and coefficient of isothermal compressibility. Determine the volume expansivity of steam at 350kPa and C. [2+2+3] Q.2. What is inversion of curve in throttling process? Define is joule-thomson coefficient and the significance of inversion curve in cooling and heating of gas in throttling process. [2+2+3] Q.3 What is clausius clapyorn equation? Using Maxwell relationship derive this equation. [3+3] Date: 19 / 03/ 2012

15 QUIZ TEST-1 Q1.Find the stoichiometric air fuel ratio for the combustion of ethyl alcohol (C 2 H 6 O), in a petrol engine. Calculate the air fuel ratios for the extreme mixture strengths of 80%. Determine the wet analyses by volume of the exhaust gas for given mixture strength. Q.1[2+3] Q2. (a) Derive the equation (b) Prove that Cp of ideal gas is a function of T only. Q.6[3+2] Q.1. Define coefficient volume expansivity and coefficient of isothermal compressibility. Determine the volume expansivity of steam at 350kPa and C. [2+2+3] Q.2. What is inversion of curve in throttling process? Define is joule-thomson coefficient and the significance of inversion curve in cooling and heating of gas in throttling process. [2+2+3] Q.3 What is clausius clapyorn equation? Using Maxwell relationship derive this equation. ] [3+3] Date: 19 / 03/ 2012

16 QUIZ TEST-4 Q.1. A boiler has a chimney of 30m height to produce natural draught of 12 mm of water column. Ambient air temperature is 27 C and boiler furnace requires 20kg of air per kg of fuel for complete combustion. Determine the minimum temperature of burnt gases leaving chimney. Q.5[2+3] Q.2. A stem condenser is supplied with 1000kg/min steam in 0.9dry state. The pressure at the suction of air extraction pump on condenser is 70 cm of Hg and barometers reads 77cm of Hg. Temperature in suction pipe is 30 C and air leaks at the rate of 5x10-4 kg per kg steam. Cooling water temperature gets increased by 15 C. Determine the mass handled by dry air extractor and cooling water circulation rate in kg/min. Q.3[2+3] Q.1 What do you mean by Boiler draught? Derived the condition of maximum discharge of Chimney. [2+5] Q.2. What do you know about the Boiler mountings according to Indian Boilers regulations? Define boiler accessories used in Boiler and explain Air preheater. [2+2+2] Q.3. In a condenser test, the following observation were made : Vacuum = 70 cm of Hg Barometer = 76 cm of Hg; Mean temperature of condensation = 35 0 C Hot well temperature = 29 0 C ; Mass of cooling water = 45500kg/h ; Inlet water temperature = C ; Outlet temperature is= 31 o C ; Mass of condensate= 1200kg/h Determine (a) The mass of air present per unit condenser volume (b) The state of steam entering the condenser (c) Vacuum efficiency [2+2+3] Date: 09 /04/ 2012

17 B SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT QUIZ TEST-4 Q.1 In a surface condenser vacuum of 70 cm Hg is maintained when the barometric pressure is 76 cm Hg. Steam enters 0.85 dry into condenser at the rate of 300kg/min. Temperature of condensate is 30 C and the rise in circulating temperature is 20 C. For sending water through condenser and piping pressure head of 5m is required. For surface condenser, Determine (i) the flow surface area required when water flows at 50m/min, and (ii) the cooling surface area required when heat transfer rate is 15x10 5 kj/m 2 -hr- C. Q.4[2+3] Q.2 Determine the height of the chimney required in the boiler having natural draught equivalent to 20mm of water. The flue gases are at the temperature of 300 C, atmospheric air temperature is 27 C and 18kg air per kg of fuel is required in boiler. Q.6[5] [20 Marks Q.1 What do you mean by Boiler draught? Derived the condition of maximum discharge of Chimney. [2+5] Q.2. What do you know about the Boiler mountings according to Indian Boilers regulations? Define boiler accessories used in Boiler and explain Air preheater. [2+2+2] Q.3. In a condenser test, the following observation were made : Vacuum = 70 cm of Hg Barometer = 76 cm of Hg; Mean temperature of condensation = 35 0 C Hot well temperature = 29 0 C ; Mass of cooling water = 45500kg/h ; Inlet water temperature = C ; Outlet temperature is= 31 o C ; Mass of condensate= 1200kg/h Determine (a) The mass of air present per unit condenser volume (b) The state of steam entering the condenser (c) Vacuum efficiency [2+2+3] Date: 09 / 04/ 2012

18 C SHRI RAMSWAROOP MEMORIAL COLLEGE OF ENGG. & MANAGEMENT QUIZ TEST-4 Q1. In a surface condenser operating with the steam turbine the vacuum near the inlet of air pump is 69cm of Hg when barometer reading is76cm of Hg. Temperature at inlet of vacuum pump is 30 C. Air leakage occurs at the rate of 60kg/hr. Determine (i) the capacity of the air pump in m3/hr and mass of vapour extracted with air in kg/hr, and (ii) the dimension of reciprocating air pump cylinder if it runs at 240rpm and L/D ratio is 1.5. Q.2[2+3] Q2. A Lancashire boiler generates 2400kg of dry steam per hour at a pressure of 11 bar. The grate area is 3 m 2 and 90 kg of coal is burnt per 2 m 2 of grate area per hour. The calorific value of the coal is 33180kJ/kg and the temperature of the feed water is 17.5 C. Determine (i) Actual evaporation per kg of coal (ii) Equivalent evaporation from and at 100 C and(iii) efficiency of the boiler. Q.10[2+2+1] Q.1 What do you mean by Boiler draught? Derived the condition of maximum discharge of Chimney. [2+5] Q.2. What do you know about the Boiler mountings according to Indian Boilers regulations? Define boiler accessories used in Boiler and explain Air preheater. [2+2+2] Q.3. In a condenser test, the following observation were made : Vacuum = 70 cm of Hg Barometer = 76 cm of Hg; Mean temperature of condensation = 35 0 C Hot well temperature = 29 0 C ; Mass of cooling water = 45500kg/h ; Inlet water temperature = C ; Outlet temperature is= 31 o C ; Mass of condensate= 1200kg/h Determine (a) The mass of air present per unit condenser volume (b) The state of steam entering the condenser (c) Vacuum efficiency [2+2+3] Date: 09 / 04/ 2012

19 QUIZ TEST-4 Q1. Determine the temperature of the hot flue gases and natural draught produced for Max m discharge through chimney having height of 80m. Boiler furnace is the supplied with 20kg air per kg of fuel./ The minimum temperature of hot gases with artificial draught is 110 C. Temperature of surroundings is 27 C and specific heat of flue gases is kJ/kg-K.. Q.7[2+3] Q2. The following observations were made in boiler trial: Coal used 250kg of calorific value 29800kJ/kg, water evaporated 2000kg, steam pressure 11.5bar, dryness fraction of the steam 0.95 and feed water temperature 34 C. Calculate the equivalent evaporation from and at 100 C per kg of coal and the efficiency of the boiler. Q.9[3+2] Q.1 What do you mean by Boiler draught? Derived the condition of maximum discharge of Chimney. [2+5] Q.2. What do you know about the Boiler mountings according to Indian Boilers regulations? Define boiler accessories used in Boiler and explain Air preheater. [2+2+2] Q.3. In a condenser test, the following observation were made : Vacuum = 70 cm of Hg Barometer = 76 cm of Hg; Mean temperature of condensation = 35 0 C Hot well temperature = 29 0 C ; Mass of cooling water = 45500kg/h ; Inlet water temperature = C ; Outlet temperature is= 31 o C ; Mass of condensate= 1200kg/h Determine (a) The mass of air present per unit condenser volume (b) The state of steam entering the condenser (c) Vacuum efficiency [2+2+3] Date: 09 / 04/ 2012

20 QUIZ TEST-4 Q1. A boiler may have waste gases leaving the installation when artificial draught is used at 150 C. The natural draught chimney is of 60m height. The hot gases in the chimney are at the temperature of 300 C and air requirement is 19kg/kg of fuel burnt. The atmospheric air is at 17 C temperature and mean specific heat of the gases is kJ/kg-K. The calorific value of fuel burnt is 32604kJ/kg. Determine (i) the draught produced in mm of water, an (ii) the efficiency of the chimney. Q.8[2+3] Q2. A condenser has a vacuum of 70cm of Hg when barometer reading is 76cm. Condenser has a temperature of 30 C. Air leaks into condenser at the rate of 1kg air per 2500kg steam. Calculate (i) the capacity of the air pump per kg of steam for removal of air from steam entering condenser, and (ii) the mass of the water vapour accompanying by this air. Q.1[3+2] Q.1 What do you mean by Boiler draught? Derived the condition of maximum discharge of Chimney. [2+5] Q.2. What do you know about the Boiler mountings according to Indian Boilers regulations? Define boiler accessories used in Boiler and explain Air preheater. [2+2+2] Q.3. In a condenser test, the following observation were made : Vacuum = 70 cm of Hg Barometer = 76 cm of Hg; Mean temperature of condensation = 35 0 C Hot well temperature = 29 0 C ; Mass of cooling water = 45500kg/h ; Inlet water temperature = C ; Outlet temperature is= 31 o C ; Mass of condensate= 1200kg/h Determine (a) The mass of air present per unit condenser volume (b) The state of steam entering the condenser (c) Vacuum efficiency [2+2+3] Date: 09 / 04/ 2012