Engineering Thermodynamics 3rd. Edition by R.K. Rajput | 9781934015148 | 1934015148

Thermodynamics

Engineering Thermodynamics

458 SOLVED PROBLEMS

1 SOLVED PROBLEMS

Question: 8.6

An ideal engine operates on the Carnot cycle using a perfects gas as the working fluid. The ratio of the greatest to the least volume is fixed and is x : 1, the lower temperature of the cycle is also fixed, but the volume compression ratio ‘r’ of the reversible adiabatic compression is variable. ...

Verified Answer:

Refer Fig. 1.

\frac{V_{3}}{V_{1}} = x ...

Question: 8.5

An inventor claims that a new heat cycle will develop 0.4 kW for a heat addition of 32.5 kJ/min. The temperature of heat source is 1990 K and that of sink is 850 K. Is his claim possible ? ...

Verified Answer:

Temperature of heat source,

T_{1}[...

Question: 2.9

Estimate the mass of a piston that can be supported by a gas entrapped under the piston in a 200 mm diameter vertical cylinder when a manometer indicates a difference of 117 mm of Hg column for the gas pressure. ...

Verified Answer:

Refer Fig. 2.28. Let m = mass of the piston, kg. p...

Question: 9.21

A tank of capacity 0.45 m³ is insulated and is divided into two sections through a partition. One section initially contains H2 at 3 bar and 130°C and has a volume of 0.3 m³ and the other section initially holds N2 at 6 bar and 30°C. The gases are then allowed to mix after removing the adiabatic ...

Verified Answer:

Total capacity of the tank, V = 0.45 m³

V_{...

Question: 8.7

CO2 flows at a pressure of 10 bar and 180°C into a turbine, located in a chemical plant, and there it expands reversibly and adibatically to a final pressure of 1.05 bar. Calculate the final specific volume, temperature and increase in entropy. Neglect changes in velocity and elevation. If the mass ...

Verified Answer:

At entry to turbine At exit of turbine P...

Question: 11.27

A steam turbine plant developing 120 MW of electrical output is equipped with reheating and regenerative feed heating arrangement consisting of two feed heaters—one surface type on H.P. side and other direct contact type on L.P. side. The steam conditions before the steam stop valve are 100 bar and ...

Verified Answer:

(i) The schematic arrangement including feed heati...

Question: 12.16

Steam at a pressure of 20 bar and 250°C enters a turbine and leaves it finally at a pressure of 0.05 bar. Steam is bled off at pressures of 5.0, 1.5 and 0.3 bar. Assuming (i) that the condensate is heated in each heater upto the saturation temperature of the steam in that heater, (ii) that the ...

Verified Answer:

Refer Fig. 12.20 (a), (b). From Mallier Chart : [l...

Question: 11.25

The following is the analysis (by weight) of a chemical fuel : Carbon = 60 per cent ; Hydrogen = 20 per cent ; Oxygen = 5 per cent ; Sulphur = 5 per cent and Nitrogen = 10 per cent. Find the stoichiometric amount of air required for complete combustion of this fuel. ...

Verified Answer:

On the basis of 100 kg fuel let us assume an equiv...

Question: 4.12

A fluid system, contained in a piston and cylinder machine, passes through a complete cycle of four processes. The sum of all heat transferred during a cycle is – 340 kJ. The system completes 200 cycles per min. Complete the following table showing the method for each item, and compute the net rate ...

Verified Answer:

Sum of all heat transferred during the cycle = – 3...

Question: 16.19

In a duct in which air is flowing, a normal shock wave occurs at a Mach number of 1.5. The static pressure and temperature upstream of the shock wave are 170 kN/m² and 23°C respectively. Determine : (i) Pressure, temperature and Mach number downstream of the shock, and (ii) Strength of shock. Take ...

Verified Answer:

Let subscripts 1 and 2 represent flow conditions u...

Question: 10.9

A steam power plant operates on ideal Rankine cycle using reheater and regenerative feed water heaters. It has one open feed heater. Steam is supplied at 150 bar and 600°C. The condenser pressure is 0.1 bar. Some steam is extracted from the turbine at 40 bar for closed feed water heater and ...

Verified Answer:

The arrangement of the components and the processe...