Learn more about our help with Assignments: Engineering

Thermal Power Engineering

If three resistor are connected in series, what is the total current if the value of R1= 12 mega ohm R2 = 20 mega ohmR3 = 5 mega ohm and the voltage source is Et = 24 volts

Thermal Power Engineering

Water at an average temperature of 10°C flows inside a

horizontal smooth tube of 5 mm diameter with a velocity of

10 cm/sec. The surface of the tube is maintained at 70°C and

tube is 1 m long. Calculate the rate of heat transfer to the

water.

Thermal Power Engineering

A fluid at 5.15 bar is expanded reversibly according to a law PV = constant to a pressure of 2.15 bar until it has a specific volume of 0.22 m3/kg. It is then cooled reversibly at a constant pressure, then is cooled at constant volume until the pressure is 0.82 bar; and is then allowed to compress reversibly according to a law PVn = constant back to the initial conditions. The work done in the constant pressure is 0.625 kJ, and the mass of fluid present is 0.32 kg. Calculate the value of n in the fourth process, the net work of the cycle and sketch the cycle on a P-V diagram

Thermal Power Engineering

In the single-phase half-wave rectifier shown below, assume that I, is constant (load inductance L is very large). (a) Sketch the load voltage waveform v for a= 90°and find its average value V4c

Thermal Power Engineering

Single phase full-wave fully controlled rectifier bridge is operated from a 110 V, 60 Hz supply Draw the load voltage and current and switch voltage waveforms along with supply voltage assume that 40°.

Thermal Power Engineering

The single-phase half-wave controlled rectifier supplies a resistive load draws an average current of 1.62 A. If the converter is operated from a 240 V, 50 Hz supply and if the average value of the output voltage is 81V, calculate the following: (a) The firing angle a. (b) Load resistance. (c)The rms load voltage. (d) The rms load current. (e) The output d.c. power (f) The ripple factor .

Thermal Power Engineering

2.6 Air flows steadily at a mass flow rate m of 0.85 kg/sec through an air

compressor. The air enters the compressor by a velocity c1 of 6.5 m.s–1,

pressure p1 of 0.95 bar and a specific volume v1 of 1.85 m3/kg, and leaves

the compressor at a velocity c2 of 9.5 m.s–1, pressure p2 of 16.5 bar and a

specific volume v2 of 0.45 m3/kg. The specific internal energy u2 of the air

leaving the compressor is 215 kJ/kg greater than that of the air entering.

Cooling water in a jacket surrounding the cylinder absorbs heat from the air

Qout at the rate of 135 kJ/kg.

a. the mechanical power P required to drive the compressor in kW if the

mechanical efficiency turbine is 80%,

b. the specific change of the air enthalpy h in kJ/kg, and

c. the cross-sectional area at the exit pipe A2 in m2.

compressor. The air enters the compressor by a velocity c1 of 6.5 m.s–1,

pressure p1 of 0.95 bar and a specific volume v1 of 1.85 m3/kg, and leaves

the compressor at a velocity c2 of 9.5 m.s–1, pressure p2 of 16.5 bar and a

specific volume v2 of 0.45 m3/kg. The specific internal energy u2 of the air

leaving the compressor is 215 kJ/kg greater than that of the air entering.

Cooling water in a jacket surrounding the cylinder absorbs heat from the air

Qout at the rate of 135 kJ/kg.

a. the mechanical power P required to drive the compressor in kW if the

mechanical efficiency turbine is 80%,

b. the specific change of the air enthalpy h in kJ/kg, and

c. the cross-sectional area at the exit pipe A2 in m2.

Thermal Power Engineering

Two Carnot engines operate in a series between two reservoirs maintained at 500 oC and 40 oC, respectively. The energy rejected by the first engine is utilized as energy input to the second engine. Determine the temperature of this intermediate reservoir between the two engines, if the efficiencies of both engines are the same?

Thermal Power Engineering

A cylinder contains N2, at a pressure of 200 kPa and a temperature of 80°C. As a result of cooling at night, the cylinder pressure is reduced to 190 kPa and the temperature is 30°C. How much work does the gas do?

Thermal Power Engineering

100 kg/min of steam at 34 bars, 340°C (h=3082.0kJ/kg) expands through a turbine isentropically until the pressure becomes 0.25 bars (h= 2540.37kJ/kg). Find the work in hp.