02-orc_vanslambrouck

23-02-2010 The Organic Rankine Cycle 1

CHP: Technology Update

The Organic Rankine Cycle (ORC)

ing. Bruno Vanslambrouck,

Howest, dept Masters Industrial Sciences

Laboratory of Industrial Physics and Applied Mechanics


• The (Organic) Rankine Cycle

• Working Fluids

• Relevant applications

• Conclusions

• Economic information

• Our ORC related activities

Contence


Steam turbine installation in a power station

1. Electrofilter 5. Transformer

2. Boiler 6. Condensor3. Steam turbine 7. Cooling tower

4. generator

The Rankine Cycle

Source: Electrabel


E-production from recovered heat of a gasturbine exhaust

using a Rankine Cycle

The Rankine Cycle

Source: Electrabel


The Rankine Cycle

Rankine cycle with superheated steam

T-s diagram for a working fluid

Carnot efficiency:


The Rankine Cycle

Working fluid: usually water

Advantages:• cheap, widely available

• non toxic

• high heat capacity: excellent medium for heat transport

• chemical stable: less material requirements

• low viscosity: low friction losses

Disadvantages:• due to low condensation t°: very low pressure, high specific volume, big

installations needed (turbine, condensor…)

• high pressure drop to become a high enthalpy drop: expensive multi stage

turbines needed

• expansion has to start in the superheated area to avoid too high moisture

content after expansion: need of a high t°- heat source but very partically use

• because of this: efficiency loss and limited suitability to waste heat recovery


The Organic Rankine Cycle

Used are:

Toluene, butane,

pentane, ammonia,

refrigeration fluids,

silicone oils…

Organic medium

Organic Rankine Cycle

in the T-s diagram

Disavantages water probably to correct using other working fluids, mostly of

organic origin: Organic Rankine Cycle

(ORC)






ORC Working Fluids

• superheating required

• superheating → efficiency ↑• higher vaporization heat at

lower pressures →evaporation requires a lot

of heat or high pressures

Wet fluid Dry fluid

• remains superheated

after expansion of saturated vapor

• superheating unnecessary• superheating → efficiency ↓

Isentropic fluid

• superheating unnecessary

• recuperator unnecessary• best choice for ORC from

this point of view


ORC Working Fluids


1. Power production from industrial waste heat

Relevant applications





Electrical efficiency = ca 16%

if waste gases are cooled

down to 120°C



• Ca 10% increase of electrical output without extra fuel

• Economical attractive on engines using renewable fuels (landfill gas, biogas, vegatable oils…) because of governmental support (Green Certificates). Simple PBT of 3 years calculated.

• Possibility to upgrade old (build before 2002) cogeneration units with respect to CHP certificates by adding an ORC (increase of relative primary energy savings with 5 %). Very short PBT if feasible (1- 2 years).

• Because of high temperature exhaust gases, a steam turbine can be considered on bigger plants

• Some ORC’s are adapted to use jacket cooling water heat

2. Exhaust heat recovery on stationary combustion

engines or gas turbines


Engine cooling

Exhaust gas (510°C)

Electricity

LT heat Exhaust gas (180°C)

(585 kWth,

incl losses)

Ex: 150 kW ORC by Tri-O-Gen (Nl)


150 kWe

1550 kWe


ORC integration in an (existing) CHP:

CHP

Greenhouse



Turbine

Flue gas

Boiler

Generator

Pre-feed pump

Main feed pump

Inverter

Recuperator

165 kWe

400 V

Working fluid: Toluene

325°C

35°C

50°C

T > 350°C760 kW th

600 kWth

180 °C



ORC on exhaust gases 2 MW Deutz gas engine

Roses farm Olij, De Kwakel – The Netherlands

Tri-O-Gen B.V.Nieuwenkampsmaten 8

7472 DE Goor Nederland


Range: TG30(+) 30 kW; TG60(+) 60 kW

Specific designed to recover biogas engine heat

(+ means integrated use of engine jacket cooling).

Fits on biogas engines in the range 250-500 kW.

Heat source:from 230°C (TG30/TG30+)

from 270°C (TG60/TG60+)

Cooling source:30°C or up to 80°C (CHP-version)


Heinrich-Hertz-Str. 1859423 Unna Germany




Maxxtec new small series Model 60 Model 80 Model 120

Waste heat source:

Thermal need 375 kWth 520 kWth 750 kWth

Thermal oil in/out 280/140 °C 280/140 °C 280/140 °C

Electricity output

Gross 65 kWe 92 kWe 130 kWe

Net (appr.) 51 kWe 81 kWe 114 kWe

Condensor heat output 306 kWth 423 kWth 612 kWth

Condensor circuit in/out 43/64°C 43/64°C 43/64°C

Gross Electric Efficiency 17,3 % 17,7 % 17,3 %

Net Electric Efficiency 13,6 % 15,6 % 15,2 %




ORC with double screw expander

• Heavy duty design, derived from

screw compressors

• Not sensitive to fluid drops: can expand

both superheated or saturated steam,

no damage when fluids drops passes

trough (usefull when large process

variations are going on).

• As ORC usable at lower temperatures

• Adapted to recover jacket water heat


ElectraTherm3208 Goni Road

Carson City,

Nevada 89706

BEP EUROPE NVTen Briele 6B-8200 Brugge

Double srew expander

based ORC




3. ORC, fed by biomass combustion

Many references in CH, A, D, I… (also 1 in NL, 2 planned in Belgium).

In concurrence with the steam cycle.

Always designed as CHP.

Turboden s.r.l.

Viale Cernaia, 10 25124 Brescia - Italy




Turboden ORC-CHP range:



MIROM Roeselare : 2,5 MWe net by Turboden

Heat source: water @180°C17 % net efficiency



ORC integration in an (existing) biomass boiler:

Biomass boilerGreenhouse




4. ORC, fed by geothermal heat sources

Many references known,

from 250 kW to > 100 MW Source temperatures from

75°C up to 300°C.

Same technology usable to recover waste heat on the

same temperature levels.



Heber Geothermal 52 MWe power station (California)



Geothermal ORC 250 kWe (Ormat)

Geothermal fluid temperature in/out:

110/85°C

Thermal power in: ~ 2500 kW

ORC working fluid: Isopentane



ORC derived from a centrifugal chiller (reversed)

Cheap, reliable, proven technology





Pure Cycle 280: 186-257 kWe net



Evacuated tube collector

fitted to temperatures

untill 180-200°C

40 kW solar heat ORC (Turboden, 1984)

5. Power generation from thermal solar energy

• probably cheaper than photovoltaic solar systems

• possible to use condensor heat for sanitary heat water…

• huge potential on desalination systems



Solar-biomass hybrid ORC





Principle design

combined solar driven

electricity and domnestic

hot water production

system

(final work HOWEST,

2004-2005)



Tests (HOWEST) on a scroll expander (2005)

(Sanden scroll car airco compressor TRS-090)



• alternative to gas engine

based micro CHP

• to integrate within a cv-boiler

• in concurrence with other new

technologies as stirling engines,

fuel cells…

6. ORC driven domnestic micro-CHP



Genlec module: 1 kW scroll expander based ORC to

integrate in central heating boilers (micro CHP)

Example: Boiler manufacturor Daalderop (NL)

Energetix Group plc

Capenhurst Technology ParkChesterCH1 6EH UK



7. ORC driven cooling

Alternative if electrical grid connection big chillers is impossible or not allowed.

Been proven having better efficiency (COP) compared to absorption chillers.

Solar powering or hybrid with solar heat feasible.


Some Economics

Some budget prices ORC-modules:

Turboden: 500kW: about € 1900 /kWe

1000 kW: about € 1350 /kWe

2000 kW: about € 950 /KWe

Pure Cycle 280 (ca 250 kWe) : € 335 000 or € 1350/kWe

Maxxtec/Adoratec: confidential prices, but of the same order of Turboden

Also attractive priced new 60, 85 and 120 kW units.

Tri-O-Gen: 150 kW unit @ € 650 000 ca € 4300 /kWe (turn key ?)

BEP-Europe: 50 kW unit @ € 120 000 (module) or € 200 000 (installed)

€ 2400 /kWe € 4000 /kWe

250 kW unit: “lower” price/kWe compared with the 50 kWe unit


Some Economics

• On renewable energy applications, we calculated a simple PBT of 3 year (IRR ca 25%), with the help of green certificates.

• For industrial waste heat recovery, a PBT of 5 year is realistic when available heat is on ‘high temperature’ (~300°C). So the ROI can reach 15%, after taxes, what means that the investment can be asked within the benchmarking agreement. This result is stronglyrelated to the electricity prices.

• Other financing methods (third party) could be considered


- ORC is a proven and commercially available technology for applications

such as industrial waste heat recovery, ICE heat recovery, biomass

burning, use of solar heat, geothermal heat sources…

- main advantage compared with a steam cycle is the higher thermal

efficiency when using heat sources at lower temperatures. The ORC is

also less complicated and easier to operate. Occuring pressures are lower.

- the classical steam cycle should be considered when sufficient

temperature levels are reachable (fuel burning) combined with turbine

scale sizes from about 500 kWe…to 2,5 MWe (to discuss, no clear answer

given when to chose an ORC above a steam cycle)

- favorable economical perspectives, especially in relation to green

certificates or energy benchmarking.

- excellent CHP capability since the condensor heat can be used

Some Conclusions


• 2 master thesises 2003-2005

• TETRA project proposal on ORC in 2005. Technically and scientifically approved but not financed, had to be cancelled.

• New proposal in 2007, focused on renewable energy sources.

Accepted, in progress from Oct 1st 2007 till Dec 31th 2009

• Second proposal on industrial waste heat accepted (Jan 1st 2010- Dec 31 th 2011 or 2012). European ERA-SME concept with Ghent University and Stuttgart University of Applied Sciences as research partners.

A TETRA project is 92,5 % financed by the Flemisch Government (IWT)

and 7,5% by industrial partners (at least 4 SME’s).

2 scientific researchers can work during 2 or 3 years on it.

Cofinancing User Group is the preference partner to receive project

information during project runtime, at the end publical available (by

publications, seminars, website…)

Our ORC related activities


2 th ORC Project structure


Laboratory setup

For research and demonstrational purposes


Heat source:

Maxxtec thermal oil heater

Max 250 kW @ 340°C

Flow: 14 m³/h

10 x 25kW , GC-Heat

Laboratory setup


Cooling loop:

Flow

sensor

Flow

sensor

CirculatorCirculator

3-way valve3-way valve

→

←

→

←

CoolerCooler

- water + glycol

- max. 20m³/h- max. 120°C

Laboratory setup


ing Bruno Vanslambrouck

HOWEST, dept Masters Industrial SciencesLaboratory of Industrial Physics and Applied Mechanics

Graaf Karel de Goedelaan 5, B-8500 Kortijk

Mail: [email protected]: +32 56 241211 or +32 56 241227 (dir)

Thanks for your attention.

Questions ???

02-orc_vanslambrouck

Documents

geothermal

organic rankine

rankine cycle

steam cycle

relevant applicationsorc

working fluid

heat source

biomass boiler