Water at 1MPa and 383 K enters a vertical pipe that is 10 m in length. The pipe has a diameter 0.1 m. The mass flow rate of the pressurized water is 1.5 kg/s. The pipe passes through a furnace and heat is transferred from the furnace to the water flowing through the pipe such that at steady state steam at 700 kPa and 873 K exits the pipe. Determine:

a. the rate of enthalpy change between inlet and outlet of the pipe.
b. the rate of change in mechanical energy (kinetic and potential together) between inlet and outlet.
c. the rate of change in total energy between inlet and outlet.
d. the net transfer rate at which heat is transferred to water from the hot furnace.

Question

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Respuesta :

batolisis batolisis · Answer 1 · 2020-10-02T17:53:31+02:00

Answer:

A) 4857 kw

b) 9.1605 Kj/s

c) 4866.161 kw

d) 4866.16 kw

Explanation:

water pressure = 1 MPa

temperature = 383 k

vertical pipe height = 10 m

pipe diameter = 0.1 m

mass flow rate of pressurized water (m) = 1.5 kg/s

A) determine rate of enthalpy change

Δh = h2 - h1

= 3700 - 462 = 3238 kj/kg

enthalpy change = m( Δh ) = 1.5 * 3238 = 4857 kw

attached below is the remaining parts of the solution

From steam table

at inlet : 1 Mpa , 383 k

h1 = 462 kj/kg

Q1 = 0.0015 m^3/kg

z1 = 0 m

at outlet : 700 kPa, 873 k

h2 = 3700 kj/kg

Q2 = 0.574 m^3/kg

z2 = 10 m