GIAN Compressor intro
Transcript of GIAN Compressor intro
1
GIAN @ Indian Institute of Technology Madras; October 2017
Norwegian University of Science and Technology (NTNU)Department of Energy and Process Engineering
Trondheim, Norway
Compressor Development
GIAN @ Indian Institute of Technology Madras; October 2017
Positive - Displacement Compressors
Reciprocating
Single cylinder
OrbitingRotary
Multi cylinder
Single shaft
TrochoidalScrollTwin shaftLinear
Crank shaft
Wash plate
Rotary vane
Twin screw
Single screw
Rolling piston and
swing
Single cylinder
Twin cylinder
Multi vaneSingle vane
GIAN @ Indian Institute of Technology Madras; October 2017
Isentropic exponent,
p
v
c
c
pp
sc T
t
vv
sc T
t
Calculated at to = 0oC and tgas = +20oC
Working fluid R32 1.381
R125 1.159
R134a 1.151
R143a 1.203
R290 1.173
R410a 1.284
R407c 1.175
R404a 1.167
R507 1.177
R600a 1.102
R717 1.362
R744 1.694
GIAN @ Indian Institute of Technology Madras; October 2017
Processes in Ts‐diagram
Specific entropy, s (J/kgK)
Tem
pe
ratu
re, T
(K
)
Isotherm
Isentropic
Isobaric
Isochoric
Isenthalpic
Δt
Δsisobaric
Δsisochoric
GIAN @ Indian Institute of Technology Madras; October 2017
Compressor work (ideal gas)
GIAN @ Indian Institute of Technology Madras; October 2017
Piston compressors
2
GIAN @ Indian Institute of Technology Madras; October 2017
Piston compressor, pV - diagram
LPUP
VsVo
V4-1
UP: Upper positionLP: Lower position
Discharge
GIAN @ Indian Institute of Technology Madras; October 2017
Clearance volumetric efficiency, v
GIAN @ Indian Institute of Technology Madras; October 2017
Pressure ratio versus clearance volume efficiency ( = 1,3)
0
5
10
15
20
25
30
35
40
0 10 20 30 40 50 60 70 80 90 100 110
Pressure, p (bar)
Cylinder volume, V (%)
p2/p1 = 7 = 0.61p2/p1 = 3.5 = 0.82
Clearance volume V0
0.615*Vs0.820*Vs
00
1011.1%
90s
V
V
GIAN @ Indian Institute of Technology Madras; October 2017
Pressure ratio versus clearance volume efficiency
0.0
0.2
0.4
0.6
0.8
1.0
1 3 5 7 9
Efficien
cy, h
v [‐]
Pressure ratio, p [‐]
7 %10 %15 %
00
s
V
V
Clearance volume ratio 0= 10%Different adiabatic exponent from 1.1 to 1.5
Adiabatic exponent =1.3Different compressor clearance volume ratioLarge and semi industrial 0 from 3% to 8%Small 0 from 5% to 15%
0.0
0.2
0.4
0.6
0.8
1.0
1 3 5 7 9
Efficien
cy,
v[‐]
Pressure ratio, [‐]
GIAN @ Indian Institute of Technology Madras; October 2017
Volumetric efficiency,
:v:d
Clearance volume efficiency
Other losses like: Leakage losses pasing piston and valves Absorption of gas in oil Losses through valves or ports Heat exchange losses Non-tightness losses of the constructions
GIAN @ Indian Institute of Technology Madras; October 2017
Influence of adiabatic exponent on the compression and expansion work
0
5
10
15
20
0 10 20 30 40 50 60 70 80 90 100 110
Pre
ssu
re,
P (
bar
)
Cylinder volume, V (%)
1,1
1,2
1,3
1,4
1,5
0.855*Vs
0.820*Vs
0.764*Vs
2 1
1 2
p V
p V
1,1
Working fluid R32 1.381
R125 1.159
R134a 1.151
R143a 1.203
R507 1.177
R410a 1.284
R407c 1.175
R404a 1.167
R290 1.173
R600a 1.102
R717 1.362
R744 1.694
3
GIAN @ Indian Institute of Technology Madras; October 2017
0
5
10
15
20
0 10 20 30 40 50 60 70 80 90 100 110
Pressure, P
(bar)
Cylinder volume, V (%)
1,1
1,2
1,3
1,4
1,5
Isentropic work for κ=1.3
0.855*Vs
0.820*Vs
0.764*Vs
2 1
1 2
p V
p V
GIAN @ Indian Institute of Technology Madras; October 2017
Operating limits : Example (HFC) GEA/Bock
Example:
GIAN @ Indian Institute of Technology Madras; October 2017
Operating limits : Example (R744) GEA/Bock
GIAN @ Indian Institute of Technology Madras; October 2017
Operating limits: Example Bitzer
GIAN @ Indian Institute of Technology Madras; October 2017
Operating limits
Example:
GIAN @ Indian Institute of Technology Madras; October 2017
WORKING FLUIDS
Working Fluid
Chemical formula (weight basis) Name GWP(100) ODPMolar weight
R32 CH2F2 Difluoromethane 650 0 52,0R125 CHF2CF3 Pentafluoroethane 2800 0 120,0R134a CH2FCF3 1,1,1,2‐Tetrafluorethane 1300 0 102,0R143a C2H3F3 1,1,1‐Trifluoroethane 3800 0 84,0R218 C3F8 Octafluoropropane 7000 0 188,0R404a 44% R125, 52% R143a, 4% R134a 3260 0 97,6
R407a 20% R32,40% R125, 40% R134a 1730 0 90,1R407b 10% R32, 70% R125, 20% R134a 2290 0 102,9R407c 23% R32, 25% R125, 52% R134a 1530 0 86,2R410a 50% R32, 50% R125 1730 0 72,6R413a 88% R134a, 9% R218, 3% R600a ISCEON® 49 1770 0 104,0R417a 46,6% R125, 50% R134a, 3,4% R600a ISCEON® 59 1950 0 106,7R507 50% R143a, 50% R125 Suva® 507 3300 0 98,9
R290 C3H8 Propane (20) 0 44,1R600a C4H10 Isobutane (20) 0 58,1R717 NH3 Ammonia 0 0 17,0R744 CO2 Carbon dioxide 1 0 44,0
4
GIAN @ Indian Institute of Technology Madras; October 2017
Pressure ratio for tc= +40oC
0
2
4
6
8
10
‐25 ‐15 ‐5 5 15
Pressure ratio, [‐]
Evaporation temperature, to [oC]
R717
R410a
R407c
R404a
R134a
R290
R600a
R507
R32
R125
R143a
GIAN @ Indian Institute of Technology Madras; October 2017
Pressure ratio for (tc-to) = 30 K
2.00
2.25
2.50
2.75
3.00
3.25
3.50
‐25 ‐15 ‐5 5 15
Pressure ratio,
Evaporation temperature, to [oC]
R717
R410a
R407c
R404a
R134a
R290
R600a
R507
R32
R125
R143a
GIAN @ Indian Institute of Technology Madras; October 2017
Isentropic efficiency – piston compressor (NH3)
150 m3/h cylinder
Pressure ratio, [-]
Ise
ntr
op
ic e
ffic
ien
cy,
is
[-]
GIAN @ Indian Institute of Technology Madras; October 2017
Ideal compressor working process with optimum valve behaviour
hd: discharge valve lift (m)hs: suction valve lift (m)pdo: discharge pressure (bar) pso: suction pressure (bar)pc: cylinder pressure (bar)wp: piston velocity, (m/s): crank angle
Ref: Bredesen,A.M; ”Influence of valve dynamics on compressor performance”, International Journal of Refrigeration, Volume 2, Number 1, January 1979
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
Piston compressor, pV - diagram
5
GIAN @ Indian Institute of Technology Madras; October 2017
Capacity control piston compressors
By-pass from high pressure side to low pressure side (not to be recommended)
On/off regulation of the compressor
Suction valve unloading (most common method for piston compressors)
Speed control (normally down to 40% rpm)
GIAN @ Indian Institute of Technology Madras; October 2017
Screw compressors
http://www.youtube.com/watch?v=YDh2X0cn-3E
GIAN @ Indian Institute of Technology Madras; October 2017
Twin screw compressors
GIAN @ Indian Institute of Technology Madras; October 2017
0
5
10
15
20
25
30
35
40
45
0 10 20 30 40 50 60 70 80 90 100 110
Pressure, p
(bar)
Volume, %
k = 1,3
Compression ratio, = 6
V1V2
This example:Built in volume-ratio, = 3.97
p1
p2
Gas flow
GIAN @ Indian Institute of Technology Madras; October 2017
Volume ratio versus Pressure ratio with different
0
1
2
3
4
5
6
7
1 3 5 7 9 11
Volume ratio
Pressure ratio,
1,1
1,3
1,5
GIAN @ Indian Institute of Technology Madras; October 2017
0
5
10
15
20
25
30
35
40
45
0 10 20 30 40 50 60 70 80 90 100 110
Pressure, p
(bar)
Volume, %
k = 1,3
Compression ratio, = 6
V1V2
p1
p2
p0 =5
pc =35
Under compression
This example: Built in volume ratio, = 3.97
6
GIAN @ Indian Institute of Technology Madras; October 2017
0
5
10
15
20
25
30
35
40
45
0 10 20 30 40 50 60 70 80 90 100 110
Pressure, p (bar)
Volume, %
k = 1,3
Compression ratio, = 6
V1V2p1
p2
p0 =5
pc =25
Over compression
This example:Built in volume ratio, = 3.97
GIAN @ Indian Institute of Technology Madras; October 2017
Typical compressor performance on R717 (NH3 / Ammonia)
100
50
90
80
60
70
1 3
Ise
ntr
op
ic e
ffic
ien
cy,
is
Pressure ratio, 1311975
= 4.9
1
2
V
V
15
Over compression Under compression
GIAN @ Indian Institute of Technology Madras; October 2017
100
50
90
80
60
70
1 3
Eff
icie
nc
y
Pressure ratio, 1311975
= 4.9
= 2.6
= 3.5
= 2.2
Fixed Variable
15
Typical compressor performance on R717 (NH3 / Ammonia)
GIAN @ Indian Institute of Technology Madras; October 2017
Capacity regulating – ScrewUse of slide regulation – step less regulation down to approx. 10%
GIAN @ Indian Institute of Technology Madras; October 2017
Capacity regulation – ScrewUse of slide regulation – step less regulation down to approx. 10%
GIAN @ Indian Institute of Technology Madras; October 2017
1. Single stage, R22, R717, pressure ratio = 2
2. Single stage, R22, R717, pressure ratio = 10
3. Single stage, R22, R717, pressure ratio = 18
4. Economizer, R22, Pressure ratio = 10
5. Economizer, R22, Pressure ratio = 18
6. Economizer, R717, Pressure ratio = 10
7. Economizer, R717, Pressure ratio = 18
The diagram is only intended as a guide
and the figure are approximately only
Screw compressor –Capacity versus slide valve movement
7
GIAN @ Indian Institute of Technology Madras; October 2017
Part load characteristics
0,0 0,40,2 0,80,6 1,0
1,0
0,8
0,6
0,4
0,2
0,0
IdealPistonIdeal screwReal screw
Relative refrigeration capacity, Qo (‐)
Relative work lo
ad, W
(‐)
GIAN @ Indian Institute of Technology Madras; October 2017
Power demand at capacity regulation of a screw compressor
0 500100 200 300 400
Refrigeration load (kW)
300
200
100
0Co
mp
ress
or
po
wer
/cap
acit
y (
kW)
Power to the compressor shaftOil cooler heat
GIAN @ Indian Institute of Technology Madras; October 2017
Capacity control screw compressors
On/off regulation of the compressor
Slide regulation (by-pass back to the inlet) – variable slide position. Capacity down to 10% of full load
Speed control (normally down to 50% rpm, due to oil lubrication)
GIAN @ Indian Institute of Technology Madras; October 2017
Single screw compressors
GIAN @ Indian Institute of Technology Madras; October 2017
Rolling piston compressors
GIAN @ Indian Institute of Technology Madras; October 2017
Rotary vane compressors
http://www.pneumofore.com/img/technology/anatomy.swf
8
GIAN @ Indian Institute of Technology Madras; October 2017
Scroll compressors
https://www.youtube.com/watch?v=dsabYhhOko0
GIAN @ Indian Institute of Technology Madras; October 2017
Trochoidal compressors
GIAN @ Indian Institute of Technology Madras; October 2017
Turbo compressor
GIAN @ Indian Institute of Technology Madras; October 2017
1989 - Testing of transcritical system operation and control
Sabroe CO2 compressor 1926 model
GIAN @ Indian Institute of Technology Madras; October 2017
SINTEF/NTNU developed MAC compressor (1990)Based on a Sanden R12 wobble plate compressor
One-stage, open
Stroke: 32 mm
Bore: 18.5 mm
RPM: 2000
Capacity: 3.1 m3/h
Reed valves.
PV-INDICATION, EFFICIENCY, LUBRICANT DISCH., VALVE SIMULATION.
GIAN @ Indian Institute of Technology Madras; October 2017
9
GIAN @ Indian Institute of Technology Madras; October 2017
Fix Displacement Compressor Development
FDC 15cc (R 744) Scroll 90cc (HFC 134a)
167mm
115
mm
220mm
122m
m
Weight reduction of ~0,68 kg
GIAN @ Indian Institute of Technology Madras; October 2017
Sperre/SINTEF-NTNU (1994)Open, 1 cylinder CO2 compressor
One-stage, open
Stroke: 80 mm Bore: 50 mm
RPM: 1200 Capacity: 11.3 m3/h Ring plate valves
PISTON AND HEAD DESIGN
PV-INDICATION cylinder and chambers,
EFFICIENCY, VALVE SIMULATION.
0.0
0.2
0.4
0.6
0.8
1.0
1 2 3 4 5Pressure Ratio [-]
Eff
icie
ncy
[-]
Isentropic
Volumetric
GIAN @ Indian Institute of Technology Madras; October 2017
50 kW heat pump water heater laboratory prototype at SINTEF/NTNU (95)
0
1
2
3
4
5
50 60 70 80 90 100
Tap Hot Water Temperature, [°C]
hp
-CO
P, [
-] (
incl
. mot
or)
Inlet Water temperature = 10°C
t0 = 10°C
t0 = 0°C
t0 = -5°C
Measured heating COP
GIAN @ Indian Institute of Technology Madras; October 2017
DorinSemihermetic
One-stage, Semi hermetic
Stroke: 17 / 34 mm
Bore: 34 mm
RPM: 1450
Capacity: 2.7 m3/h
Reed valves
PV-INDICATION, EFFICIENCY, LUBRICANT DISCH., VALVE SIMULATION. LOSS ANALYSIS
GIAN @ Indian Institute of Technology Madras; October 2017
DorinSemi hermetic two stage
TWO-stage, Semi hermetic
Stroke: 34 mm
Bore: 48 mm
RPM: 2900
Capacity: 10.7 m3/h
Reed valves
TUBE PULSATIONS, IN / OUT CHAMBER VOLUMES, EFFICIENCY,
LUBRICANT DISCHARGE,
SPACER RING
EXTENDED LUBRICANT VOLUME
SPACER RING
EXTENDED LUBRICANT VOLUME
GIAN @ Indian Institute of Technology Madras; October 2017
DorinSemi hermetic two stage
TWO-stage, Semi hermetic Stroke: 34 mm Bore: 48 mm RPM: 1450 Capacity: 5.3 m3/h Reed valves
TUBE PULSATIONS, IN / OUT CHAMBER VOLUMES,VOLUME RATIOS, EFFICIENCY, LUBRICANT DISCHARGE,
10
GIAN @ Indian Institute of Technology Madras; October 2017
DorinSemi hermetic small capacity
One-stage, Semi hermetic Stroke: 17 mm Bore: 22 mm RPM: 2900 Capacity: 2.3 m3/h Reed / ”ringplate” valves
PV-INDICATION, FLOW / ENERGY LOSS, EFFICIENCY, LUBRICANT DISCH., VALVE SIMULATION.
10
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6 7
Cylinder volume, (cm3)
Pre
ssu
re (
ba
r)
Test 2
GIAN @ Indian Institute of Technology Madras; October 2017
SANYOHermetic, two stage, rolling piston
Two-stage, Hermetic Displacement: 3.16 and 3.33 cm3
RPM: 7200 Capacity: 0.7 m3/h TUBE PULSATIONS, EFFICIENCY, OPERATING RANGE, TEMPERATURE PROFILE, LUBRICANT DISCHARGE,
GIAN @ Indian Institute of Technology Madras; October 2017
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
0 5 1 0 1 5 2 0 2 5 3 0 3 5
C y l i n d r e v o l u m e ( c m 3 )
80_2
0 p
ress
ure
s (b
ar)
D i s c h a r g e c h a m b e r p r e s s u r e C y l i n d r e p r e s s u r e C y l i n d r e p r e s s u r e
D i s c h a r g e c h a m b e r p r e s s u r e S u c t i o n c h a m b e r p r e s s u r e
Dynamic pressure recordings, Two stage compressor, Dorin
GIAN @ Indian Institute of Technology Madras; October 2017
0
2 0
4 0
6 0
8 0
1 0 0
1 2 0
0 5 1 0 1 5 2 0
C y lin d e r v o lu m e [ c m 3 ]
Gas
pre
ssu
re [
bar
]
Dynamic pressure recordings, Single stage compressor, Dorin
GIAN @ Indian Institute of Technology Madras; October 2017
Current CO2 Compressor technology
GIAN @ Indian Institute of Technology Madras; October 2017
2013: SINTEF / NTNU 380ccm compressor
11
GIAN @ Indian Institute of Technology Madras; October 2017
2013: SINTEF / NTNU 380 ccm compressor
GIAN @ Indian Institute of Technology Madras; October 2017
380 ccm compressoroverall efficiency
45 bar suction pressure (tsat = 10 °C)
26 bar suction pressure (tsat = -9 °C)
35 bar suction pressure (tsat = 0 °C)
High side pressures
GIAN @ Indian Institute of Technology Madras; October 2017
380 ccm compressorvolumetric efficiency
45 bar suction pressure (tsat = 10 °C)
High side pressures
35 bar suction pressure (tsat = 0 °C)
26 bar suction pressure (tsat = -9 °C)
GIAN @ Indian Institute of Technology Madras; October 2017
On the market (some examples)
• Bitzer
• GEA/Bock
• Dorin
BITZER CO2 COMPRESSORS FORTRANSCRITICAL APPLICATIONS
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 66 © BITZER Kühlmaschinenbau GmbH
Optimized stroke-bore ratio– 3 piston rings – low dead volume– optimized flow cross
sections – low discharge pulsation
Special adaptation of motor layout and suction gas cooling– 4-pole design for
VSD up to 70 Hz
Highly efficient and robust working valves– large cross sections– optimized shape
and position Extra low oil carry-over– special centrifugal lubrication
THE WELL-PROVEN 4 CYLINDER COMPRESSORS FOR TRANSCRITICAL CO2 APPLICATIONS
High strength pressure: MOP HP up to 160 bar MOP LP up to 100 bar
Separated HP/LP chambers – reduced heat transfer– no external piping
12
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 67 © BITZER Kühlmaschinenbau GmbH
THE NEW 6 CYLINDER COMPRESSORS FOR TRANSCRITICAL CO2 APPLICATIONS
Further optimized cylinder head design, separated HP/LP chambers
/ 26,1 / 30,3 / 38,2 m³/h @ 50 Hz
/ Highest efficiency and reliability
Optimized oil management
Highly efficient and robust working valves Optimized stroke-bore ratio
– 3 piston rings – low dead volume– optimized flow cross
sections – low pulsation and vibration
Special motor layout and suction gas cooling– 4-pole design for
VSD up to 70 Hz
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 68 © BITZER Kühlmaschinenbau GmbH
THE NEW 2 CYLINDER COMPRESSORS FOR TRANSCRITICAL CO2 APPLICATIONS
Optimized cylinder head design, separated HP/LP chambers
/ 3,3 and 4,8 m³/h @ 50 Hz
/ Medium temp & heat pump applications
/ Highest efficiency and reliability
Optimized oil management
Highly efficient and robust working valves
New suction gas flow
Special motor layout and suction gas cooling– 4-pole design for
VSD up to 70 Hz– 2 motor versions
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 69 © BITZER Kühlmaschinenbau GmbH
BITZER COMPRESSORS FOR TRANSCRITICAL APPLICATIONS WITH CO2: APPLICATION RANGES
2
1: Limitation 4PTC2: Limitation 6DTE-50K(Z)
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 70 © BITZER Kühlmaschinenbau GmbH
BITZER COMPRESSORS FOR TRANSCRITICAL APPLICATIONS WITH CO2: CAPACITY RANGE
V geo = 3,3 m³/h V geo = 38,2 m³/h
THE NEW ECOLINE+ COMPRESSOR SERIES
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 72 © BITZER Kühlmaschinenbau GmbH
BITZER PUSHES AHEAD WITH INNOVATION
In an ideal situation, highest annual energy efficiencies are achieved with a natural refrigerant in a simple and cost effective way!
All these attributes are combined with the next generation of energy efficient products:
ECOLINE+
13
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 73 © BITZER Kühlmaschinenbau GmbH
Optimized efficiency for full and part
load
Lowest CO2footprint,
simple, smart, cost-effective
LSPM motor: Efficiency & robustness
IQ module:Operating of integrated functions
New oil return management
CRII for CO2:World novelty,
step less, easy, flexible
Highest eco-efficiency
ECOLINE+ IS THE NEXT GENERATION OF ENERGY EFFICIENT COMPRESSORS!
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 74 © BITZER Kühlmaschinenbau GmbH
LSPMLine Start Permanent Magnet
/ Stator generates rotating field
/ Start: Squirrel cage generates magnetic field (asynchronous start)
/ Operation: Magnetic field in rotor is generated by permanent magnet
/ No current dependent losses in squirrel cage due to heating effect caused by induced current = higher efficiency
/ Synchronous speed, not dependent on torque requirement
/ Higher breaking torque, theoretically acts like a generator at coast down
/ Combines efficiency and robustness, flexible operation on mains and VSD
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 75 © BITZER Kühlmaschinenbau GmbH
NEW MOTOR TECHNOLOGY: GAIN IN EFFICIENCY
Higher COP
/ Increased efficiency is based on
Higher motor efficiency
Higher mass flow rates due to synchronous speed
Higher mass flow rates due to higher suction gas density
Focus on annual energy efficiency is most important
/ Benefit dependent on
Motor size and torque requirement
System configuration (number and size of comp., VSD, etc.)
Climate and load profile of the supermarket
BITZER // Reciprocating Compr. for sub- and trans-critical CO2 Applications // Page 76 © BITZER Kühlmaschinenbau GmbH
SEPR – EN13215:4DTC-25K (ASM) vs. 4DTEU-25LK (LSPM)
8976 kWh
+ 13 %
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
OTHERS
14
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
15
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
16
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
17
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
18
GIAN @ Indian Institute of Technology Madras; October 2017
Dorin
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017
GIAN @ Indian Institute of Technology Madras; October 2017