Please show work Problem 1. Each of the parts below is a separate problem. Pleas
ID: 2994707 • Letter: P
Question
Please show work
Problem 1. Each of the parts below is a separate problem. Please look up or calculate the appropriate quantity. You do not have to draw a picture and the system is always the fluid a) What is the specific enthalpy of propane in kJ/kg at 2.0 bar (abs) and 0°C? b) Determine the specific volume of ammonia in ft3/lbm at a pressure of 45 psia if the quality is 0.3 c) What is the ideal gas heat capacity, cp, in kJ/kg K for air at 525 K? d) Air acting as an ideal gas in rigid closed container is cooled from 420 K to 280 K a Calculate the heat transfer in kJ/kg. e) at is the critical temperature (OR) and pressure (atm) of methane? What is the specific enthalpy in kJ/kg of superheated steam at 4.3 bar (abs) f) and 450 C?Explanation / Answer
a)
From propane tables, at P = 2 bar we get sat. temp. = -25.43 deg C which is less than 0 deg C. Therefore, at 0 deg C and 2 bar, state = superheated.
From superheated tables for propane, at 2 bar and 0 deg C we get enthalpy h = 481.1 kJ/kg
b)
From ammonia tables at 45 psia we get v_f = 0.02465 ft^3/lb and v_g = 6.302 ft^3/lb
v = v_f + x*(v_g - v_f)
= 0.02465 + 0.3*(6.302 - 0.02465)
= 1.907855 ft^3/lb
c)
From air tables, at 500 K, we get Cp = 1.029 kJ/kg-K
From air tables, at 500 K, we get Cp = 1.040 kJ/kg-K
Therefore, at 525 K we get by interpolation Cp = 1.029 + (1.040 - 1.029) / (550 - 500) *(525-500)
= 1.0345 kJ/kg-K
d)
Q - W = U2 - U1
Since container is rigid, W = 0.
Q = U2 - U1
= Cv*(T2 - T1)
= 0.721*(420 - 280)
= 100.94 kJ/kg
e)
For methane, from tables, Crtical temperature = 344 R
For methane, from tables, Crtical pressure = 45.8 atm
f)
From superheatd steam properties, at 4.3 bar and T = 450 deg C we get h = 3380 kJ/kg