Pressurized water ( 10 bar, 110°c) enters the bottom of an 10-m-long vertical tube of diameter 63 mm at a mass flow rate of 1.5 kg/s. the tube is located inside a combustion chamber, resulting in heat transfer to the tube. superheated steam exits the top of the tube at 7 bar, 600°c. determine the change in the rate at which the following quantities enter and exit the tube: (1) the combined thermal and flow work, (2) the mechanical energy, and (3) the total energy of the water. also, (4) determine the heat transfer rate, . hint: relevant properties may be obtained from a thermodynamics text.

(1)

(2)

(3)

(4) q = 4839.69 kW[/tex]

Solution:

Using Saturated water-pressure table corresponding to pressure, P = 10 bar:

At saturated temperature, Specific enthalpy of water,

At inlet:

Saturated temperature of water,

Specific volume of water,

Using super heated water table corresponding to a temperature of and at  7 bar:

At outlet:

Specific volume of water,

Specific enthalpy of water,

Now, at inlet, water's specific enthalpy is given by:

(1) Now, the change in combined thermal energy and work flow is given by:

(2) The mechanical energy can be calculated as:

velocity at inlet,

Similarly,, the velocity at the outlet,

Now, change in mechanical energy:

(3) The total energy of water is given by:

(4) The rate of heat transfer:

q =

answer:

a

explanation: