Question

A steam pipe for a 300-m-tall building receives superheated steam at 200 kPa at ground level. At the top floor the pressure is 125 kPa, and the heat loss in the pipe is 110 kJ/kg. What should the inlet temperature be so that no water will condense inside the pipe?

Answer 1

inlet temperature is
`170^(\circ)C`be so that no water will condense inside the pipe

Step-by-step explanation:

Assumptions,

• No change in the kinetic energy
• Steady state

• single inlet and exit flow

The energy equation is given by

`q+h_i=h_e+gZ_e`

No condensation means

`h_(e)=h_(g) \text { at } 125k P a=2685.4 \mathrm{kJ} / \mathrm{Kg}`

`h_i=h_e+gZ_e-q`

Substituting the values,

=
`2685.4+(9.807 * 300)/(1000) -(-110)`

=
`2685.4+(2942.1)/(1000) -(-110)`

=
`2685.4+ 2.9421 -(-110)`

=
`2685.4+ 2.9421 + 110`

=2798.34 kJ/kg

At 200 kPa T
`\sim` 170