Waste Heat Recovery System
Waste Heat Recovery System
Waste Heat Recovery System
System (WHRS)
for Reduction of Fuel Consumption,
Emissions and EEDI
Contents
Summary...................................................................................................... 5
Introduction.................................................................................................. 5
Description of the Waste Heat Recovery Systems.......................................... 6
Power concept and arrangement............................................................. 6
Power turbine and generator (PTG).......................................................... 7
Steam turbine and generator (STG).......................................................... 7
Steam turbine, power turbine, and generator (ST-PT)................................ 8
Main engine and WHRS system control.................................................. 10
Installation aspects................................................................................ 11
Power turbine WHRS solution................................................................ 12
Steam turbine WHRS solution................................................................ 12
Full steam and power turbine WHRS solution......................................... 12
Main Engine Performance Data................................................................... 15
Main engine tuning for WHRS................................................................ 15
Exhaust gas bypass with power turbine.................................................. 15
Exhaust gas bypass without power turbine............................................. 15
Exhaust gas boiler and steam systems................................................... 16
Single-pressure steam system............................................................... 16
Dual-pressure steam system....................................................................... 17
Steam and water diagram ME WHRS element..................................... 18
Main engine steam production power (SPP) guarantee........................... 19
Obtainable Electric Power of the WHRS....................................................... 20
Power and steam turbine generator output dual pressure.................... 20
Payback time for waste heat recovery system........................................ 22
Emission Effects of using WHRS.................................................................. 25
WHRS Effect on Ships EEDI........................................................................ 26
Conclusion.................................................................................................. 28
Reference................................................................................................... 28
Nomenclature / abbreviations...................................................................... 29
Summary
The increasing interest in emission re-
Shaft power
Output 49.3%
Fuel 100%
(167 g/kWh)
Lubricating oil
cooler 2.9%
Lubricating oil
cooler 2.9%
Jacket water
cooler 5.2%
Jacket water
cooler 5.2%
Exhaust gas
25.5%
Air cooler
16.5%
Air cooler
14.2%
Heat radiation
0.6%
Fuel 100%
(168.7 g/kWh)
Heat radiation
0.6%
Fig. 1: Heat balance for large-bore MAN B&W engine types without and with WHRS
Introduction
also be lowered.
sign.
lead to a further reduction of CO2 emisWaste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
Dual pressure
exhaust gas
boiler
HP
LP
HP
Power Turbine
0,5 3,5 MWel
Generator
LP
GB1
GB2
Renk AG
Gearboxes 1 u. 2
PTI /
PTO
tricity production.
unit).
performance of the ship. For more inAlso, the revised pressure drop in the
in Fig. 2.
bined installation
signed to communicate.
CO2 emissions of the ship, but the interest for WHRS solutions is spreading
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
To funnel
To funnel
To funnel
GenSet
Economiser
GenSet
Economiser
Composite
boiler
Feed water
amount.
Exhaust gas
TC
Power
turbine
TC
PT unit
Exhaust gas receiver
PTO/
PTI
produces extra output power for electric power production, which depends
Circ. pump
GenSet
Scavenge
air cooler
Main engine
~/~ OO
Frequency-converter
GenSet
the power turbine is economical desirable, which stop when the ancillary engine blower(s) start.
emissions.
Ref. 2.
Steam turbine and generator (STG)
see Fig. 4.
For power turbine solutions, the main
engine receiver will be equipped with
two exhaust gas connections, one for
engine exhaust gas by-pass (EGB) and
one for the power turbine. The connection for the power turbine must typically
be larger as the power turbine unit typically is arranged several meters away
from the main engine in the engine
room. The exhaust gas by-pass with
exhaust gas bypass control valve and
orifice is part of the engine delivery and
will be tested at the engines shop test.
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
turbine.
50% SMCR.
design.
Steam Turbine
Gearbox
Generator
increase. This will increase the obtainable steam production power for the
exhaust gas fired boiler.
By installing a steam turbine (often
called a turbo generator), the obtainable steam production from the exhaust
boiler system can be used for electric
power production. The steam turbine
is installed on a common bedplate with
the generator in the same manner as
the power turbine and the generator.
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
Gearbox
Power Turbine
GenSet
Economiser
LP steam drum
GenSet
Economiser
LP-circ.
pump
LP
LP Evaporator
LP-circ. pump
HP-steam
drum
HP
HP Evaporator
HP-circ. p.
HP
heating
LP-steam
for heating
services
HP Superheater
LP
Exhaust gas
TC
TC
PTO/
PTI
Steam
turbine
Power
turbine
HP-steam
for heating
services
ST & PT unit
Hot well
tank
Scavenge
air cooler
Condensater
pump
Jacket
water
Condenser
Main engine
Buffer
tank
Feedwater
pump
Vacuum deaerator tank
Main engine power < 15,000 kW PTG or ORC (Organic Rankine Cycle) *
emission
requirements,
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
control
PMS
Speed setp.
Etc.
Min. speed
for SG
ME-ECS
SG/SM
Allwd. PT CV range.
Increase exh. energy
Safety
system
WHRS
limits.
turbine.
ditions.
Stack
Steam from
Steam Turbine
Speed and Load Exhaust Boiler
Power Turbine Speed and Load Control Control
Exhaust
Boiler
control.
The engine control and the WHRS
PT
Shut-down
Valve
PT
Control Valve
PT
ST
WHRS Control
Engine Control
System (ECS)
Orice
EGB
Control Valve
Exhaust Gas Receiver
Scavenge Air
PT Pressure
(Pscav)
Scavenge Air Receiver
Generator
10 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
T/C
Ambient Air
Installation aspects
%
140
120
100
80
60
MaxBP
MinBP
40
20
0
-20
20
40
MinBP
60
Load
80
100
120
Fig. 11: Control strategy of the WHRS ST-PT system bypass control
way:
1. WHRS generator
tor.
changes.
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
11
To funnel
To funnel
To funnel
GenSet
Economiser
GenSet
Economiser
Circ. pump
Composite
boiler
Steam for
heating
services
Feed water
Exhaust gas
TC
TC
Power
turbine
PT unit
PTO/
PTI
GenSet
Scavenge
air cooler
Main engine
GenSet
~/~ OO
Frequency-converter
Main
switchboard
stand-alone solution.
systems, and because the main connection between the WHRS PTG and
the MAN B&W engine is only the exhaust gas by-pass line. Fig. 12 shows
an example of a diagram.
Steam turbine WHRS solution
The steam turbine installation is quite
extensive as many different components must be connected. Firstly, it is
likely that the boiler installation has to
be in-creased in size. From the boiler,
one or two pipes should be connected
to the steam turbine, depending on
whether the single or dual pressure
system is applied. The condenser must
be installed under the bedplate of the
steam turbine and, in some cases, it
12 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
LP economiser
LP steam drum
HP economiser
HP super heater
HP steam drum
Pumps, etc.
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
13
Fig. 16: Container ship engine room and casing arrangement transversal section
Fig. 17: Container ship engine room and casing arrangement horizontal section
system.
Fig. 18: CFD calculations for placing guide vanes in the exhaust flow.
14 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
Exhaust System:
Exhaust boilers
Bypass pipe
Exhaust collector
Connections to turbochargers
bined.
turbine
pressures, if required.
Parameters
8 to 12%
-13%
+50C
turbine
The exhaust gas bypass and turbine are
available with the following approx. effects, compared with a standard highefficiency main engine version without
an exhaust gas bypass, Table I.
Parameters
Exhaust gas bypass, approx.
8 to 12%
-13%
+65C
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
15
Preheater
Evaporator
Circ. pump
Superheater
Exhaust gas
Surplus
valve
Sat. steam
for heating
services
Steam
turbine
tems
The exhaust gas boiler and steam tur-
Feedwater
pump
Condenser
Hot well
Fig. 20: Process diagram for the single pressure exhaust gas boiler system
Temperature
C
300
Superheated
steam
250
Exh. gas
200
Steam/water
Saturated
steam 150
min 20C
Exhaust
gas
7 bar abs/165
100
50
Feed
water
Ambient air
0
20
40
60
80
100 %
Heat-transmission
Fig. 21: Temperature/heat transmission diagram for the single pressure steam system
16 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
LP-steam drum
LP
LP-Evaporator
LP-circ. pump
HP-Preheater
HP-steam drum
HP-Evaporator
ture may result in corrosion in the exhaust piping when running on normal
HFO with sulphur content.
HP-circ. pump
HP-Superheater
The
HP
Exhaust
gas
Surplus
valve
LP
more
complex
dual-pressure
HP-steam
for heating
services
Steam
turbine
Condenser
Hot well
Fig. 22: Process diagram for the dual pressure exhaust gas boiler system
Exh. gas
200
Saturated
Hp steam
Superheated
LP steam
10 bar abs/180 C
min 15 C
Exhaust gas
Feedwater
preheated
by alternative
WHR sources
services.
The exhaust gas boiler has to be designed in such a way that the risk of
soot deposits and fires is minimised,
50
Ambient air
0
4 bar abs/144 C
100
min 20C
Steam/water
150
20
40
60
80
Fig. 23: Temperature/Heat transmission diagram for the dual pressure steam system
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
17
WHR element.
WHRS element
tank, etc.
4.0 bar g
LP steam
drum
EVA
LT
SUP
LP economizer
FT
10.0 bar g
To soot
blowers
TT
SP 144 C
LP circ.
pumps
Service
steam
system
HP steam
drum
EVA
LT
FT
FT
SUP
FT
Drain
Tank
HP circ.
pumps
HP economizer
ME WHR
element
80-85 C
ME Jacket
Water
ST
90 C
Vacuum
45 C Deaerator
A
Feed water
pumps
S.W
Vacuum
condenser
40 C
Condensate
pumps
Fig. 24: Recommended steam and water diagram for a dual pressure WHRS
18 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
kj
h
SSP[kW]=1.06[____
] (MixedExhaustGasTemp[C] - 160[C]) ExhGasAmount[__] _____
kgC
3600s
h
Exhaust Gas
Temperature
Amount
+ 1.0C
+ 2.2%
+ 17.0C
- 5.0%
- 0.1C
+ 0.3%
+ 5.0C
- 1.2%
figure.
The SPP guarantee is provided with a
tolerance of +/-7 %-points.
It will be possible/allowed to adjust one
at the expense of the other to obtain
the best possible steam power production (SPP).
will occur. For the scavenge air temperature, an increase of 12C over the
ing conditions:
load.
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
19
TCS PTG:
STG Single pressure system:
STG Dual pressure system:
Full WHRS (ST - PT):
of the ship.
bines.
20 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
Load Point
WHS data based on:
MAN B&W
10S90ME-C9.2
Power:
48,510 kW
Bypass:
11.6%
Recoverly rate:
8.6% at 90% SMCR
Service steam:
1.0 ton/h
At ISO conditions
100%
90%
85%
70%
60%
50%
SMCR
SCMR
SCMR
SCMR
SCMR
SCMR
bar(a)
10.0
9.2
8.6
7.4
6.7
6.5
Temperature
259
258
257
254
254
256
Flow
t/h
11.83
10.88
10.31
8.99
8.10
6.97
Flow
t/h
1.00
1.00
1.00
1.00
1.00
1.00
Pressure
bar(a)
10.7
9.7
9.2
7.7
6.9
6.8
Pressure
bar(a)
4.5
4.5
4.5
4.5
4.5
4.5
Temperature
148
148
148
148
148
148
Flow
t/h
3.92
3.39
3.09
2.28
1.787
1.45
Pressure
bar(a)
0.057
0.052
0.049
0.045
0.045
0.045
Temperature
35.3
33.6
32.5
31.0
31.0
31.0
Flow
t/h
15.75
14.27
13.40
11.27
9.88
8.42
Steam turbine
kW
2,477
2,248
2,108
1,766
1,539
1,280
Power turbine
kW
1,836
1,515
1,360
1,766
754
526
kW
4,313
3,763
3,468
2,747
2,293
1,806
HP Service Steam
Condensing Steam
Output
Fig. 26: WHRS recovery output data for a large container ship.
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
21
5,000
Power: 48,510 kW
Bypass: 11.6%
Recovery rate: 8.6%
at 90% SMCR
4,500
MAN 10S90ME-C9.2
4,000
3,500
3,000
Winter
ISO
Tropical
2,500
2,000
1,500
1,000
500
0
500
60
70
85
90
100
Fig. 27: WHRS recovery output data for a large container ship
Sailing time %
25
20
15
Sailing time %
Typical for large
container ship
10
5
0
12
14
16
18
20
22
24
Sailing time %
70
60
50
40
30
Sailing time %
Typical for Tankers
and Bulk Carriers
20
10
0
10
12
22 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
14
16
use 2 g/kWh more to increase the exhaust temperature and support bypass
engine load.
WHRS will provide an acceptable payback time, the above running patterns
container rates.
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
23
Fig. 30: Large container ship WHRS output and payback calculation for WHRS
Fig. 31: Large container ship project operational profile and WHRS outputs
24 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
Fig. 32: Large container ship payback calculation for WHRS net present value
11,260 tons
319 tons
214 tons
29 tons
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
25
Fig. 34: 11,000 teu container ship without WHRS attained EEDI
26 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
Fig. 36: 11,000 teu container ship with WHRS attained EEDI
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
27
Conclusion
Reference
[4]
https://www.bimco.org/Products/
EEDI.aspx
28 Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
Nomenclature / abbreviations
CAMS
CFD
Computational Fluid Dynamics a tool which can simulate exhaust gas flow into the exhaust boiler
EEDI
EGB
EVA
Evaporator - steam
HP
LP
MDT
ME-ECS
MaxBP
Maximum By-pass
MinBP
Minimum By-pass
ORC
Organic Rankine Cycle energy recovery system based on synthetic fluid for energy transportation
PMS
Power Management System system to control energy producers (Aux. diesel gensets, WHRS unit,
PTO) and energy consumers
PTG
PTI
Power Take In electric motor or Power Turbine, where the produced mechanical power is used for
propulsion boost or boost of a PTO solution (Renk)
PTO
Power Take Off generator driven by main engine via gears (Renk solution) or generators mounted directly on propulsion drive line.
RCS
SG/SM
SFOC
SMCR
SPP
Steam Production Power a value for the available exhaust energy for steam production
STG
ST-PT
SUP
TCS-PTG
MDT product name for PTG: Turbo Compound System Power Turbine Generator unit.
WHR
WHRS
WHRS STPT
Full WHRS with both Steam Turbine (ST) and Power Turbine (PT) arranged as a unit with gear and generator
WHRS STG
WHRS with Steam Turbine (ST), gear and generator (G) arranged as a unit
WHRS PTG
WHRS with Power Turbine (PT), gear and generator (G) arranged as a unit
Waste Heat Recovery System (WHRS) for Reduction of Fuel Consumption, Emission and EEDI
29
All data provided in this document is non-binding. This data serves informational
purposes only and is especially not guaranteed in any way. Depending on the
subsequent specific individual projects, the relevant data may be subject to
changes and will be assessed and determined individually for each project. This
will depend on the particular characteristics of each individual project, especially
specific site and operational conditions. CopyrightMAN Diesel & Turbo.
5510-0136-03ppr Aug 2014 Printed in Denmark