1. Manir Ahammed Variable Energy Cyclotron Centre Kolkata
नमस्ते Good Afternoon শুভ অপরাহ্ন
(Namaste) (Subho Aparahanno)
Exergy analysis of cryogenic delivery system of superconducting electron linac
Manir Ahammed
Variable Energy Cyclotron Centre
Kolkata

2. About VECC
Delhi
1500 km
Kolkata
2/4/2019
ICEC26-ICMC2016, Delhi

3. Outlook Overview of the e-Linac Project Cryogenics @ e-linac
2/4/2019
Overview of the e-Linac Project
e-linac
Requirement & distribution
Exergy Analysis
Motivation
Methodology
Exergy and its loss
Universal Entropy Generation
Frictional pressure drop estimation
Optimisation
Results
Layout
Summary
2/4/2019
ICEC26-ICMC2016, Delhi
ICEC26-ICMC2016, Delhi

4. Overview of electron Linac
Phase-1
E-linac would be tested up to ICM at salt lake campus for 10MeV energy
Operating Parameter:
Frequency=1.3GHz
Temperature: 2.1K
Mode: CW
Gradient: 10 MV/m
Current: 2mA
Capture Cryomodule
Injector Cryomodule (ICM)
2/4/2019
ICEC26-ICMC2016, Delhi

5. Cryogenic with E-linac
ICEC26-ICMC2016, Delhi
2/4/2019

6. Cryogenic with E-linac
LHe flow chart
Requirement
Gradient
Unit
10MV/m
14MV/m
From Dewar
gm/s
6.9
9.9
4K cold return
1.5
Refrigeration load W 60
Liquefaction load
5.4
8.4
2K return
4.2
7.1
4K intercept
1.2
1.3
Lit/h
156
240
Equivalent refrigeration load for liquefaction
500
760
Equivalent total refrigeration load
560
820
Simplified P & ID
2/4/2019
ICEC26-ICMC2016, Delhi

7. Exergy analysis: Motivation
Bring Heat Leak and Frictional Pressure Drop into a
same platform interm of EXERGY LOSS. (Not the cost!!!!!!)
Effective use of available ENERGY. (as the energy source is limited!)
How far minimizing length w.r.t BEND is effective?
How to optimize DIAMETER.
Estimate LOSS in exergy
Trace out the components to be designed critically with
respect to exergy loss.
Estimate 2nd law of efficiency for energy transfer.
Prepare exergy flow diagram.
2/4/2019
ICEC26-ICMC2016, Delhi

8. What is Exergy? & What is Exergy loss?
Exergy analysis: Methodology
What is Exergy? & What is Exergy loss?
Maximum useful work that is possible to extract from a system during a process that brings it into equilibrium with the surrounding as heat reservoir or simply availability.
𝐄= 𝐀 𝟏 − 𝐀 𝟐
𝐀=𝚿− 𝚿 𝐨
ψ 𝟏
ψ 𝟐 W E
𝐄 𝐋𝐨𝐬𝐬 = 𝑻 𝒐 𝑺 𝟐 − 𝑺 𝟏 − 𝐓 𝐨 𝚫𝐒 𝐬𝐮𝐫𝐫
𝐄 𝐋𝐨𝐬𝐬 = 𝑻 𝒐 𝜟𝑺 𝒖𝒏𝒊𝒗
ICEC26-ICMC2016, Delhi

9. Exergy analysis: Entropy Generation
Energy Balance
𝐝𝐐=𝐝 𝑯 𝒕𝒑
Entropy Generation
𝐝 𝑺 𝒖𝒏𝒊𝒗 =𝐝 𝑺 𝒕𝒑 − 𝒅𝑸 𝑻 𝒐
Thermodynamic relation
𝐝 𝑯 𝒕𝒑 =𝐓𝐝 𝑺 𝒕𝒑 +𝐌 𝒗 𝒕𝒑 𝐝 𝑷 𝒇
𝐝 𝑺 𝒖𝒏𝒊𝒗 = 𝒅𝑸 𝑻 − 𝒅𝑸 𝑻 𝒐 − 𝐌 𝒗 𝒕𝒑 𝐝 𝑷 𝒇 𝑻
𝐝 𝑺 𝒖𝒏𝒊𝒗 = 𝝅𝑫𝒒 𝑻 − 𝝅𝑫𝒒 𝑻 𝒐 𝐝𝐲+ 𝐌 𝒗 𝒕𝒑 𝑻 − 𝐝 𝑷 𝒇 𝒅𝒚 𝐝𝐲
2/4/2019
ICEC26-ICMC2016, Delhi

10. Exergy analysis: Frictional Pressure drop
There are many correlations to estimate two-phase flow pressure drop
Lockhart & Martinelli
Bankoff
Chawala
Chisholm ( for bend)
Friedel(preferred)
Muller & Heck
Moreno & Thome ( most accurate)
Darcy-Weisbach's equation
2-phase flow multiplier
𝒅𝑷 𝒍 𝚽
𝒅 𝑷 𝒇 =𝟒 𝒇 𝒍 𝒅𝒚 𝑫 𝑴 𝒂 𝟐 𝟏 𝟐 𝝆 𝒍 ∗𝐆+ 𝟑.𝟐𝟒𝐅𝐊 𝐅𝐫 𝐡 𝟎.𝟎𝟒𝟓 𝐑 𝟎.𝟎𝟑𝟓
𝚽 =𝐆+ 𝟑.𝟐𝟒𝐅𝐊 𝐅𝐫 𝐡 𝟎.𝟎𝟒𝟓 𝐑 𝟎.𝟎𝟑𝟓
𝐅𝐫 𝐡 = ( 𝐌 𝐚 ) 𝟐 𝐠𝐃 𝛒 𝐭𝐩 𝟐
Why Friedel?
Good for stratified flow.
𝑴 𝒂 <𝟐𝟎𝟎𝟎 𝒌𝒈 𝒎𝟐.𝒔
𝛍 𝐥 𝛍 𝐯 ˂𝟏𝟎𝟎𝟎
𝑮= (𝟏−𝐱) 𝟐 + 𝐱 𝟐 𝛒 𝐥 𝐟 𝐯 𝛒 𝐠 𝐟 𝐥
𝐑= ( 𝐌 𝐚 ) 𝟐 𝑫 𝛔𝛒 𝐭𝐩
𝐅= 𝐱 𝟎.𝟕𝟖 (𝟏−𝐱) 𝟎.𝟐𝟐𝟒
Both valid
𝑲= 𝝆 𝒍 𝝆 𝒗 𝟎.𝟗𝟏 ( µ 𝒗 µ 𝒍 ) 𝟎.𝟏𝟗 (𝟏− µ 𝒗 µ 𝒍 ) 𝟎.𝟕
𝜟𝑷 𝒕𝒑_𝒃 𝜟𝑷 𝑳_𝒃 =𝟏+ 𝝆 𝑳 𝝆 𝒈 −𝟏 𝟏+ 𝟐.𝟐 𝑲 𝑳 𝟐+ 𝑹 𝒃 𝒅 𝒙 𝟏−𝒙 + 𝒙 𝟐
𝜟𝒑 𝐋_𝒃 = 𝟏 𝟐 𝒇 𝒅 𝝆( 𝑴 𝝆𝒂 ) 𝟐 𝝅 𝑹 𝒃 𝑫 𝜽 𝟏𝟖𝟎 𝒐 + 𝟏 𝟐 𝑲 𝑳 𝝆( 𝑴 𝝆𝒂 ) 𝟐
For Bend

11. Exergy analysis: Results and discussion
Exergy loss in different components
He transfer line
Cryogenic valves
JT valves
Field joint
Bend
Misc.
Total (KW)
Percentage loss
E_loss_H (KW)a
6.54
1.99
0.425
1.54
0.074
2.1
12.669 90
E_loss_P (KW)b
0.06
0.01
1.225
0.02
0.016
1.331 10
6.6 2
1.65
1.56
0.090 14
Percentage loss(%)
47.1
14.3
11.8
11.1
0.6 15
2nd law efficiency for LN2:84%
2nd law efficiency for LHe:77.5%
Mass Flux (G)<2500 kg/m2.s
2/4/2019
Exergy flow diagram chart

12. Present layout
2/4/2019
ICEC26-ICMC2016, Delhi

13. A National Facility for Unstable and Rare Isotope Beams
Summary
ANURIB
A National Facility for Unstable and Rare Isotope Beams
Exergy analysis is carried out to get notion about localized exergy loss.
Accordingly layout for Cryogenic Delivery System has been carried out to maximize the 2nd law efficiency of thermodynamics.
It is being advocated to optimize CDS with varying temperature to avoid being critical on the high temperature part.
In a positive note, hope these efforts in accumulation will ushered us to build our flagship project “ANURIB”.
2/4/2019
ICEC26-ICMC2016, Delhi

14. Thank you !
ধন্যবাদ
(Dhanyabad)
धन्यवाद