A reheat Rankine cycle operates with water as the working fluid. Steam enters the first turbine at 8 MPa and 450°C and exits at 0.8 MPa. It is then reheated to 400°C before entering the second turbine, where it exits at 10 kPa. If the amount of work into the pump is 8.04 kJ/kg and the net work per cycle produced is 1410.25 kJ/kg, determine the thermal efficiency of the cycle

The thermal efficiency, , of the Rankine cycle with reheat is 36.81%

Explanation:

p₁ = 8 MPa = 80 Bars

T₁ = 450°C = 723.15 K

From steam tables, we have;

v₁ = 0.0381970 m³/kg

h₁ = 3273.23 kJ/kg

s₁ = 6.5577 kJ/(kg·K) = s₂

The p₂ = 0.8 MPa

T₂ = Saturation temperature at 0.8 MPa = 170.414°C = 443.564 K

h₂ = 2768.30 kJ/kg

= 400°C = 673.15 K

= at 400°C and 0.8 MPa = 3480.6 kJ/kg

p₃ = 10 kPa = 0.1 Bar

T₃ = Saturation temperature at 10 kPa = 45.805 °C = 318.955 K

h₃ = 2583.89 kJ/kg

h₄ = = 191.812 kJ/kg

The thermal efficiency, , of a Rankine cycle with reheat is given as follows;

Therefore, we have;

Which in percentage is 36.81%.

since you're a real machine, your ama is always less than your ima, because you can never totally eliminate friction.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation: