Question

Steam enters a horizontal pipe operating at steady state with a specific enthalpy of 3000 kJ/kg and a mass flow rate of 0.5 kg/s. At the exit, the specific enthalpy is 1700 kJ/kg. If there is no significant change in kinetic energy from inlet to exit, the rate of heat transfer between the pipe and its surroundings is:____________

Answer 1

-650 KW

Step-by-step explanation:

We are given that

Initial specific enthalpy=
`H_0=3000 kJ/kg`

Exit specific enthalpy=
`H_f=1700KJ/kg`

Mass flow rate,
`M_r=0.5 kg/s`

We have to find the rate of heat transfer between the pipe and its surroundings.

Change in specific enthalpy=
`\Delta H=H_f-H_0=1700-3000=-1300KJ/kg`

Heat transfer rate=
`\Delta H\cdot M_r`

Heat transfer rate=
`(-1300)* 0.5`

Heat transfer rate=-650 KW