4.54 Saturated liquid nitrogen at 600 kPa enters a boiler at a rate of 0.008 kg/s and exits as saturated vapor (see Fig. P4.54). It then flows into a superheater also at 600 kPa, where it exits at 600 kPa, 280 K. Find the rate of heat transfer in the boiler and the superheater.

hello the figure attached to your question is missing attached below is the missing diagram

answer :

i) 1.347 kW

ii) 1.6192 kW

Explanation:

Attached below is the detailed solution to the problem above

First step : Calculate for Enthalpy

h1 - hf = -3909.9 kJ/kg ( For saturated liquid nitrogen at 600 kPa )

h2- hg = -222.5 kJ/kg ( For saturated vapor nitrogen at 600 kPa )

second step : Calculate the rate of heat transfer in boiler

Q1-2 = m( h2 - h1 )  = 0.008( -222.5 -(-390.9) = 1.347 kW

step 3 : find the enthalpy of superheated Nitrogen at 600 Kpa and 280 K

from the super heated Nitrogen table

h3 = -20.1 kJ/kg

step 4 : calculate the rate of heat transfer in the super heater

Q2-3 = m ( h3 - h2 )

        = 0.008 ( -20.1 -(-222.5 ) = 1.6192 kW