## Description

Starting with the Conservation of Energy equation:

d E

dt = Q˙ − W˙ +

X

N

i=1

m˙ i

hi +

V

2

i

2

+ gzi

−

X

M

j=1

m˙ j

hj +

V

2

j

2

+ gzj

,

and the Continuity equation:

d m

dt =

X

N

i=1

m˙ i −

X

M

j=1

m˙ j ,

Solve the following:

Problem #1

Steam enters a turbine through a pipe with a diameter of 0.2 [m]. The steam enters with a velocity of 100

[m/s], a pressure of 14,000 [kPa] and a temperature of 600 ◦C. The steam is exhausted through a pipe with

a diameter of 0.8 [m], a pressure of 500 [kPa] and a temperature of 180 ◦C. Determine:

a) the exit velocity of the steam;

b) the mass flow rate of the steam.

Problem #2

A device has one inlet with a cross-sectional flow area of 0.6 [m2

] in which steam enters with a velocity of

50 [m/s], a pressure of 1,000 [kPa] and a temperature of 400 ◦C. There are two outlets. One outlet has

saturated liquid exiting through a 0.018 [m2

] pipe with a mass flow rate of 50 [kg/s] at a pressure of 150

[kPa]. Determine:

a) the mass flow rate at the inlet;

b) the mass flow rate of the second outlet.

Problem #3

Air enters a device at 1,000 [kPa] and 580 [K] and leaves with a volumetric flow rate of 1.8 [m3/s] at 100

[kPa] and 500 [K]. Heat is transferred from the device to the surroundings at 347 [kJ] per kilogram of air

entering the device. Determine:

a) the power developed by the device;

b) the the volumetric flow rate at the inlet.

Problem #4

Air flows through a diffuser with a mass flow rate of 0.5 [kg/s] from an inlet condition of 300 [kPa], 290 [K]

and 400 [m/s] to an exit condition of 1,4000 [kPa] and 40 [m/s]. Determine:

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a) the exit temperature of the air;

b) the inlet cross-sectional flow area.

Problem #5

A turbine with sufficient insulation accepts steam at the rate of 85 [m3/min] at 3,000 [kPa] and 400 ◦C. A

portion of the steam is siphoned from the turbine at a pressure of 500 [kPa], a temperature of 180 ◦C at

a velocity of 20 [m/s]. The remainder of the steam, with a mass flow rate of 40,000 [kg/hr] expands to a

pressure of 6 [kPa] with a quality of 90%. Determine:

a) the power developed by the turbine;

b) the diameter of the siphon.

Problem #6

An open feedwater heater (OFWH) accepts liquid water at 1,000 [kPa] and a temperature of 50 ◦C. The

OFWH also accepts water with a mass flow rate per that of inlet one, i.e. ˙m2/ ˙m1=0.22. Saturated liquid

water exits the OFWH. Determine:

a) the temperature of the second incoming stream, if superheated;

b) the quality of the second incoming stream, if saturated.

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