G.C.R.G.MEMORIAL TRUST’S GROUP OF INSTITUTIONS

SESSION: 2013-14/ SEM /1st SessionalSub: Applied Thermodynamics [Time: 2.00 hours Paper code: EME-401 [M.M.:30Branch: Mechanical Engg. Roll.No•Use of Steam Tables is allowed.

Q1.Answer any Four parts of the following: (2.5×4=10) (a) Derive an expression for maximum mass of steam discharged through a nozzle.

(b) Discuss the working of steam engine with neat sketch and also plot its working on P-V diagram.

(c) Describe the different operations of a Carnot cycle. Also represent it on a T-S and P-V diagram.

(d) Explain with the help of neat diagram a ‘Regenerative Cycle’.State also the advantages of regenerative cycle over Simple Rankine cycle.

(e) Explain with a neat diagram the working of a Binary Vapour cycle.

Q 2.Answer any Two parts of the following: (4×2=8)

(a) In a Rankine cycle, the steam at inlet to turbine is saturated at a pressure of 30bar and the exhaust pressure is 0.25 bar. Determine :•The pump work, Turbine work, Rankine efficiency, Dryness fraction at the end of expansion and also compare it with Carnot’s cycle.

(b) Compare the Rankine efficiency of a high pressure plant operating from 80

bar and 400⁰ C and a low pressure plant operating from 40 bar and 400⁰ C, if condenser pressure in both cases is 0.07 bar.

(c) A turbine is supplied with steam at a pressure of 32 bar and a temperature of 410⁰ C. If the steam is reheated at 5.5bar to a temperature of 395⁰ C and then expanded isentropically to a pressure of 0.08, what will be the dryness fraction at the end of expansion and thermal efficiency of the cycle?

Q3.Answer any Two parts of the following: (4×2=8) (a) Determine the throat area, exit area and exit velocity for a steam nozzle to pass a mass flow of 0.2kg/s when inlet conditions are 10bar

and 250⁰ C and final pressure is 2 bar. Assume expansion is isentropic

and that the inlet velocity is negligible.Use pv1.3 =constant. Do not

calculate from h-s chart.

(b) A Steam nozzle is supplied steam at 15 bar 350⁰ C and discharges steam at 1 bar. If the diverging portion of the nozzle is 80mm long and the throat diameter is 6mm.Determine the velocity, temperature and diameter at exit.

(c) Air enters a frictionless adiabatic converging nozzle at 10 bar 500K with negligible velocity. The nozzle discharges to a region at 2 bar. If the exit area of the nozzle is 2.5cm2, find the flow rate of air through the nozzle. Assume for air cp= 1005 J/kgK and cv= 718 J/kgK.

Q4 .Answer any one of the following parts: (4×1=4) (a) Draw a layout of power plant with 2 reheating and 2 regeneration and also draw its cycle on h-s diagram.

(b) Explain the following with neat sketches:• Difference between theoretical and actual indicator

diagram.• Difference between Simple Rankine cycle and Modified

Rankine cycle.