The heat loss from the casing of the turbine and the bearings is negligible. (i) Find the change in enthalpy across the turbine, if the inlet velocity is negligible and exit velocity is 360 m/s and the change in potential energy is negligible. (ii) Find the change in enthalpy across the turbine, if the velocity at entry is 66 m/s and the inlet pipe is 3 m above the exit pipe. - Mumbai university > MECH > SEM 3 > THERMO

Marks: 12M

Year: Dec 2013

Given: m = 5000kg/hr; P = 550 kW; Q = 0

Solution:

a. Case 1: v1 =0 m/s; Δz=0m

The Steady flow energy equation is given as $$W = m(Δh + \frac{v_1^2 - v_2^2}{2} + 9.81 * (z_1 - z_2))$$ $$550 X 10^3 = \frac{5000}{3600}(Δh - \frac{360^2}{2})$$ $$Δh = 460.8 KJ / kg$$

b. Case 1: v1 =66m/s; Δz=3m

The Steady flow energy equation is given as $$W = m(Δh + \frac{v_1^2 - v_2^2}{2} + 9.81 * (z_1 - z_2))$$ $$550 X 10^3 = \frac{5000}{3600}(Δh - \frac{66^2 - 360^2}{2} + 3*9.81)$$ $$Δh = 458.592 KJ / kg$$