RESULT AND ANALYSIS
Table 1
FT1 FT2 TT 1 TT 2 TT 3 TT 4
(LPM) (LPM) (̊C) (̊C) (̊C) (̊C)
10.0 2.0 35.2 30.4 47.3 47.8
10.0 4.0 31.7 29.4 46.7 47.3
10.0 6.0 29.8 28.6 46.4 47.2
10.0 8.0 30.1 29.2 47.5 48.3
10.0 10.0 30.8 29.9 47.9 47.1
Table 2
FT1 FT2 TT 1 TT 2 TT 3 TT 4
(LPM) (LPM) (̊C) (̊C) (̊C) (̊C)
2.0 10.0 30.6 30.0 46.2 48.6
4.0 10.0 30.8 30.3 46.2 48.6
6.0 10.0 31.0 30.3 47.1 48.7
8.0 10.0 31.1 30.3 47.4 48.4
10.0 10.0 31.2 30.3 47.2 47.9
CALCULATION STEPS: Cp hot@48̊ C = 4.181 kJ/kg. K
VH and VC (convert LPM to m3/s) Cp cold@28̊ C = 4.179 kJ/kg. K
A = 0.067 m2
ṁH/ ṁC = V̇H/ V̇C x ρ
ρ = 988.1 kg/m3
Minimum heat capacity, Cmin = ṁC x Cp cold @ 28 °C
Heat capacity, qH = ṁH. Cp hot (THin – TH out)
Max heat transfer, q max = Cmin (TH in – TC in)
𝑞𝐻
Efficiency = x 100 %
𝑞 𝑚𝑎𝑥
𝚫𝐓𝐢𝐧− 𝚫𝐓 𝐨𝐮𝐭
Log Mean Temperature Difference, ΔTm = 𝚫𝐓 𝐢𝐧
𝒊𝒏
𝚫𝐓 𝐨𝐮𝐭
𝒒
U = 𝑨 𝒙 𝚫𝐓𝐦
For the first calculation, ( FT1 = 10 LPM, FT2 = 2 LPM )
𝑳 𝟏 𝒎𝒊𝒏 𝟏 𝒎𝟑 −𝟒 𝒎𝟑
VH = 10 𝑴𝑰𝑵 x x 𝟏𝟎𝟎𝟎 𝑳 = 𝟏. 𝟔𝟔𝟕𝟏𝟎
𝟔𝟎 𝒔 𝒔
𝑳 𝟏 𝒎𝒊𝒏 𝟏 𝒎𝟑 −𝟒 𝒎𝟑
VC = 2 𝑴𝑰𝑵 x x 𝟏𝟎𝟎𝟎 𝑳 = 𝟎. 𝟑𝟑𝟑𝟏𝟎
𝟔𝟎 𝒔 𝒔
−4 𝑀3 𝑘𝑔 𝑘𝑔
ṁH = VH x ρ = 1.66710 𝑥 988.1 = 0.1647
𝑆 𝑚3 𝑠
−4 𝑘𝑔 𝑘𝑔
ṁC = VC x ρ = 0.33310 𝑥 988.1 = 0.0329
𝑚3 𝑠
Cmin = ṁC x Cp cold @ 28 °C
𝑘𝑔 𝐾𝐽
= 0.0329 x 4.181 𝑘𝑔 x ( 320.8 – 320.3K )
𝑠
𝑘𝐽
= 0.1375 𝐾 . 𝑠
qH = ṁH. Cp hot (THin – TH out)
𝑘𝑔 𝑘𝐽
= 0.1647 𝑥 4.181 𝑥 (320.8 − 320.3𝐾)
𝑠 𝑘𝑔
= 0.3443 kW
q max = Cmin (TH in – TC in)
𝑘𝐽
= 0.1375 𝐾 . 𝑠 x (320.8 – 303.4K)
= 2.3925 kW
𝑞𝐻
Efficiency = 𝑞 𝑚𝑎𝑥 x 100 %
0.3443
= x 100
2.3925
= 14.4%
𝚫𝐓𝐢𝐧− 𝚫𝐓 𝐨𝐮𝐭 (𝟑𝟐𝟎.𝟖−𝟑𝟎𝟑.𝟒 𝑲)−(𝟑𝟐𝟎.𝟑−𝟑𝟎𝟖.𝟐𝑲)
ΔTm = 𝚫𝐓 𝐢𝐧 = 𝟑𝟐𝟎.𝟖−𝟑𝟎𝟑.𝟒 = 𝟏𝟒. 𝟓𝟗 𝑲
𝒊𝒏 𝑰𝒏 ( )
𝚫𝐓 𝐨𝐮𝐭 𝟑𝟐𝟎.𝟑−𝟑𝟎𝟖.𝟐
𝒒
U = 𝑨 𝒙 𝚫𝐓𝐦
𝟎.𝟑𝟒𝟒𝟑 𝒌𝑾
= 𝟎.𝟎𝟔𝟕 𝒙 𝟏𝟒.𝟓𝟗 = 𝟎. 𝟑𝟓𝟐𝟐 𝒎𝟑 . 𝑲
The calculation steps above were repeated for all data in table 1 and 2