blob: 717757b51993af77810e94707e9c2098930d7c5d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
clear;
clc;
// Illustration 3.8
// Page: 81
printf('Illustration 3.8 - Page: 81\n\n');
printf('Illustration 3.8 (a)\n\n');
// Solution (a)
//***Data****//
// a = water b = air
Nb = 0;
h = 1100;// [W/square m]
//*****//
Ma = 18.02;// [kg/kmol]
Cpa = 2090;// [J/kg.K]
T1 = 600;// [C]
Ti = 260;// [C]
// The positive dirn. is taken to be from the bulk gas to the surface.
Has = 2.684*(10^6);// enthapy of saturated steam at 1.2 std atm, rel. to the liquid at 0 C in [J/kg]
Hai = 2.994*(10^6);// enthalpy of steam at 1 std atm, 260 C in [J/kg]
// Radiation contributions to the heat transfer from the gas to the surface are negligible. Eqn. 3.70 reduces to
Na = -((h/(Ma*Cpa))*log(1-((Cpa*(T1-Ti))/(Has-Hai))));// [kmol/square m.s]
printf('The rate of steam flow reqd. is %f kmol/square m.s\n\n',Na);
// negative sign indicates that the mass flux is into the gas
printf('Illustration 3.8 (b)\n\n');
// Solution (b)
//***Data****//
// a = water b = air
h = 572;// [W/square m]
T1 = 25;// [C]
//******//
Ti = 260;// [C]
// The positive dirn. is taken to be from the bulk gas to the surface.
Has = 1.047*10^(5);// enthapy of saturated steam at 1.2 std atm, rel. to the liquid at 0 C in [J/kg]
Hai = 2.994*(10^6);// enthalpy of steam at 1 std atm, 260 C in [J/kg]
// Radiation contributions to the heat transfer from the gas to the surface are negligible. Eqn. 3.70 reduces to
Na = -((h/(Ma*Cpa))*log(1-((Cpa*(T1-Ti))/(Has-Hai))));// [kmol/square m.s]
printf('The rate of steam flow reqd. is %f kmol/square m.s',Na);
// negative sign indicates that the mass flux is into
|
