CRYOSTAR

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• Advantages of using Radial Inflow Turbines for
  Kalina and Organic Rankine Cycles

Frédéric Marcuccilli, PhD, Senior Process
Engineer Damien Thiolet, Business Development
GRC, Geothermal Energy 2008 October 5-8, 2008
www.cryostar.com frederic.marcuccilli_at_cryostar.
com
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Contents

• 1. General Presentation
• 1.1 Cryostar in figures
• 1.2 Cryostar in the market place
• 1.3 Cryostar new markets
• 1.4 Soultz-sous-Forêts
• 2. Radial Turbines for Binary Cycles
• 2.1 Turbine description
• 2.2 Sealing system
• 2.3 Overall turbine efficiency
• 3. Binary Cycle Optimisation
• 3.1. Off-design efficiency
• 3.2. Effect of working pressure
• 4. Conclusions

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1. General Presentation 1.1 Cryostar in figures
Who is Cryostar ?

• More than 500 employees worldwide
• 100 employees in Engineering
• 35 employees in RD
• 190 Million turnover in FY 2007
• 90 export
• 15 Million investments in 2005-07
• Part of the

Skid mounted HC turboexpander
Boil-Off gas reliquefaction unit
High pressure reciprocating pump
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1. General Presentation 1.1 Cryostar in figures

• Cryostar Worldwide

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10
Head quarter 500 people
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14
1
5
2
6
7
13
8
15
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1- CRYOSPAIN S.L (Spain) 6- TACHYON CORP. (South
Korea) 11- A.H.P (Malaysia) 2- KARBOSAN
(Turkey) 7- A-TEC CO. LTD (Japan) 12- I.R.D
(South Africa) 3- TECNOCRYO (Italy) 8- INOX INDIA
(India) 13- PETROTEC (Qatar) 4- CRYOPOSLKA
(Poland) 9- GAS TECHNOLOGY PTY Ltd
(Australia) 14- SOJITZ (Japan) 5- RACI
(Italy) 10- HESTAR (Czech Republic) 15- GIA
KHUONG (Vietnam)
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1. General Presentation 1.2 Cryostar in the
market place
Recognised as worldwide experts in the following
areas

• Industrial gases
• No.1 in the application of cryogenic pumps for
  industrial gases,
• major supplier of expansion turbines for air
  separation
• Oil Gas
• One major supplier of turbo-expander/compressors
  in oil gas treatment (HC dew point control,
  ethylene plants)
• LNG carriers
• No.1 in  boil-off  gas handling and recovery
  (90 market share)
• Energy recovery
• Principal supplier of energy recovery expanders
  for  geo-pressure  application on natural gas
  grids (30 MW installed in Europe in the last
  years plus North America ongoing)

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1. General Presentation 1.3 Cryostar new markets

• Geothermal and heat recovery expansion turbines

TG Turboexpander generator type
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1. General Presentation 1.3 Cryostar new markets

• Two types of binary cycles technology
• Two European forefront projects

One type of turbine Cryostar radial inflow
expander coupled to a generator - TG
Kalina cycle
Organic Rankine cycle

• Process fluid NH3/H2O mixture
• Non explosive but toxic
• Siemens Power Plant in Unterhaching

• Process fluid Hydrocarbons
• Non toxic but explosive
• 1st Enhanced Geothermal System Power Plant in
  Soultz-ss-Forêts built with Turboden

TG 500 delivering 3.7 MWe
TG 400 delivering up to 2.5 MWe
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General Presentation 1.4 Soultz-ss-Forêts
Transformer
Turbo Generator
Control Room
Steam Water separator
Air Condensers
Heat Exchanger
Technical Room
Production Wells
Injection Well
Filters
Back up Heat Exchangers

• Soult-sous-Forêts geothermal Power Plant 2.5
  MWelec
• Groupement Solidaire Turboden / Cryostar

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General Presentation 1.4 Soultz-ss-Forêts

• Cycle Overview 2.5MW

Regenerator
Air Condenser
Turbo Generator
Circulation Pump
Heat Exchangers Vaporizer
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General Presentation 1.4 Soultz-ss-Forêts

• Cooling system (ORC)

Inlet Collector
Air Condensers
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General Presentation 1.4 Soultz-ss-Forêts

• Cooling system (ORC)

Outlet Collector
Circulation Pump
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General Presentation 1.4 Soultz-ss-Forêts

• Vaporizer

Vaporizer
Turbine
Preheater 2
Preheater 1
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General Presentation 1.4 Soultz-ss-Forêts

• Turbo Generator

Turbine
Generator
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Contents

• 1. General Presentation
• 1.1 Cryostar in figures
• 1.2 Cryostar in the market place
• 1.3 Cryostar new markets
• 1.4 Soultz sous-Forêts
• 2. Radial Turbines for Binary Cycles
• 2.1 Turbine description
• 2.2 Sealing system
• 2.3 Overall turbine efficiency
• 3. Binary Cycle Optimisation
• 3.1. Off-design efficiency
• 3.2. Effect of working pressure
• 4. Conclusion

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2. Radial Turbines For Binary Cycles 2.1 Turbine
description

• radial inflow turbines are standard equipments

• E.g. Cryostar installed base
• More than 1600 turbo-expanders 1000
  compressors in operation
• ca 150 TG machines generating more than 80 MW
  electricity

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2. Radial Turbines For Binary Cycles 2.1 Turbine
description

• Cryostar turbine type

A turbine is a rotating machine that converts
energy from a process stream into mechanical
energy. At Cryostar, this equipment is a radial
inflow expansion turbine. Gas, at a high
pressure level, is expanded through a turbine
wheel to a lower pressure level. Thus, the power
generated, can drive a compressor or a generator.
High pressure (radial flow inlet)
T1
INLET
Low pressure (axial flow outlet)
T2lt T1
TURBINE EXPANSION POWER RECOVERY
DISCHARGE
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2. Radial Turbines For Binary Cycles 2.1 Turbine
description
Expander casing

• Main elements
• Acceleration and deflection of gas through inlet
  guide vanes (IGV) or nozzles

IGV or Nozzle assembly
2. Enthalpy of the gas changed into angular
momentum of the turbine wheel
Turbine Wheel (impeller)
3. Velocity of gas leaving the turbine at low
pressure reduce in discharge diffuser.
Expander diffusor
4. Power generated by the wheel given to a shaft
rotating in high speed bearings.
Rotor Shaft Wheel
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2. Radial Turbines For Binary Cycles 2.2 Sealing
system

• Challenge Sealing gas for closed cycle.
• Role of the seal gas
• prevent contamination of process gas by the
  lubricant
• Limit or eliminate gas leakage around the shaft

• Kalina cycle
•   Dry Gas Seal  system
• Use of process fluid impossible NH3/H20 leads to
  liquid formation and corrosion problems
• Inert Nitrogen is often chosen
• Needs to limit the flow of N2 which is lost
  afterwards
• Little losses of process gas unavoidable.
  Separation of N2 and NH3 needed.

• ORC cycle
•  Dry gas seal  system
• Use of ORC fluid possible clean dry iC4, iC5,
  R134A used as seal gas
• Seal gas migrating into oil system is cleaned
  from oil (coalescing filter)
• Cleaned seal gas is recovered by recompression to
  inlet of condenser
• No losses of the process gas.

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2. Radial Turbines For Binary Cycles 2.2 Sealing
system

• Kalina cycle
• Dry Gas seal
• Need of external source of Nitrogen
• Low flow is necesssary 1-2 m3/h
• Polluted N2 by NH3 H2O needs to be stored
  before treatment
• Possibility to  wash  the NH3 gas to recover in
  the storage tank.

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2. Radial Turbines For Binary Cycles 2.2 Sealing
system

• Example of sealing arrangement
• Dry Gas Seal recompression zero leakage

Lubricant
Process gas
Process gas lubricant
Recompression in the cycle Very low flow ca 1
Nm3/h
Zero leakage
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2. Radial Turbines For Binary Cycles 2.3 Overall
turbine efficiency

• Losses from turbine wheel to electrical network
  (1/2)

Nozzles
Isentropic efficiency
Wheel
High speed bearings
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2. Radial Turbines For Binary Cycles 2.3 Overall
turbine efficiency

• Losses from turbine wheel to electrical network
  (2/2)

Epicyclic gear box
Source BHS brochure
Generator
Source WEG website
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2. Radial Turbines For Binary Cycles 2.3 Overall
turbine efficiency
Typical values of relative losses for TG
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Contents

• 1. General Presentation
• 1.1 Cryostar in figures
• 1.2 Cryostar in the market place
• 1.3 Cryostar new markets
• 1.4 Soultz sous-Forêts
• 2. Radial Turbines for Binary Cycles
• 2.1 Turbine description
• 2.2 Sealing system
• 2.3 Overall turbine efficiency
• 3. Binary Cycle Optimisation
• 3.1. Off-design efficiency
• 3.2. Effect of working pressure
• 4. Conclusion

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3. Binary Cycle Optimisation 3.1. Off-design
efficiency

• Expander variable nozzle control

• Nozzles series of vanes.
• Jets gas tangentially and inwardly into the
  wheel.
• Simple construction pneumatically actuated.
• Wide possible flow range w/o wastefull
  throttling
• Expansion energy recovered in the rotor.

Good off-design performances
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3. Binary Cycle Optimisation 3.1. Off-design
efficiency

• Average ambiant temperature in Reno

Air coolers more pressure drop across turbine -gt
more electricity produced in winter
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3. Binary Cycle Optimisation 3.1. Off-design
efficiency

• Importance of off-design efficiency

Design
Evaporation
Regenerator
Summer
Winter
Expansion
Pump
1623 kW
1892 kW
2111 kW
Condensation
Regenerator
Air coolers more pressure drop across turbine -gt
more electricity produced in winter
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3. Binary Cycle Optimisation 3.1. Off-design
efficiency

• Do not forget off-design efficiency !

1 Pressure Ratio
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3. Binary Cycle Optimisation 3.1. Off-design
efficiency

• For 37 MWelec Power Plant Electricity resale
  price 0.08 USD / kWh
• lost of revenue 15 Mio USD over 10 years
  operation
• Off design efficiency should not be forgotten !

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3. Binary Cycle Optimisation 3.2. Working
pressure

• Hypothesis hot water at 265F air at 90 F

Compromise between turbine size (price) and
efficiency
propane
isobutane
n-butane
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3. Binary Cycle Optimisation 3.2. Working
pressure

• Hypothesis hot water at 320F air at 90 F

Compromise between turbine size (price) and
efficiency
isobutane
n-butane
pentane
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3. Binary Cycle Optimisation 3.2. Working
pressure

• Ability to fit ORC process data and the expander
  at the same time

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Contents

• 1. General Presentation
• 1.1 Cryostar in figures
• 1.2 Cryostar in the market place
• 1.3 Cryostar new markets
• 1.4 Soultz sous-Forêts
• 2. Radial Turbines for Binary Cycles
• 2.1 Turbine description
• 2.2 Sealing system
• 2.3 Overall turbine efficiency
• 3. Binary Cycle Optimisation
• 3.1. Off-design efficiency
• 3.2. Effect of working pressure
• 4. Conclusions

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4. Conclusions

• radial inflow turbines for binary cycles are

TG500/110 delivering 3.8 MWe
Standard machines Max power 15 MWelec
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4. Conclusions

• Radial inflow turbines for binary cycles are
  standard machines

Flexible design with high efficiency
Ability to control the flow to smooth seasonal
variation and give better yearly revenues
Optimise at the same time process and machine to
increase overall efficiency
Working at high pressure decrease machine frame
size for better heat recovery
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• Kalina

• Rankine

Thank you for your attention You are welcomed at
our booth.