WASTE HEAT RECOVERYLOW- AND HIGH-TEMPERATURE

ENERGIRELATERAD FORDONSFORSKNING 2017

GÖTEBORG, 2017-10-05

JELMER RIJPKEMA, CHALMERS UNIVERSITY OF TECHNOLOGY JELMER.RIJPKEMA@CHALMERS.SE

CHRISTER ODENMARCK, VOLVO CARSCHRISTER.ODENMARCK@VOLVOCARS.COM

PROJECT INFORMATION

2017-10-05 2JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

Name WHR – Low Temperature

Start time – End time 2016-01-01 – 2017-12-31

Partners Swedish Energy Agency

Lund University

KTH

Chalmers

Volvo Cars

AB Volvo

Scania

IAV

TitanX

Gnutti Carlo

Support program FFI, Energy and Environment

Project grant 11 134 000 SEK

PROJECT GOAL

2017-10-05 3JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

In order to meet future requirements for very low fuel consumption combined with low

emissions, heat losses in the engine should be converted to useful work.

The project aims to expand the potential of Rankine based waste heat recovery

systems in internal combustion engines by combining low- and high-temperature heat

sources.

WHY WHR?

2017-10-05 4JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

Trucks

(Indicative figures)

Engine manufacturers have different

strategies to improve engine

efficiency

Some of them already implemented

to reach 50% efficiency, WHR

allows for even higher efficiencies

WHR: 3 – 4%

WHY WHR?

2017-10-05 5JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

Passenger cars

48V Hybrid gives good fuel

consumption benefit for city

driving (WLTC)

WHR gives an additional ~4% or

up to 10% in highway driving

AVAILABLE HEAT SOURCES IN ENGINES

2017-10-05 6JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

High-temperature:

• Exhaust gas out Heat loss: 30% – 40%

• EGR cooler Heat loss: 5% – 25%

Low-temperature:

• Coolant Heat loss: 20% – 30%

• Charge air cooler Heat loss: 5% – 20%

RANKINE CYCLE

2017-10-05 7JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

Main components:

• Pump

• Evaporator

• Expander

• Condenser

WORK PACKAGES

2017-10-05 8JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

WP1: Lund – KCFP

Increased engine coolant

temperature

WP2: KTH – CCGEx

Expanders and system

integration

WP3: Chalmers – CERC

Thermodynamic cycles for

low- and high-temperature

heat sources

WP4: Volvo Cars

Light-duty demonstrator

WP1: LUND – RESULTS

2017-10-05 9JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

• Low-temperature recoverable energy (from the

coolant) shows a peak for an optimum coolant

temperature

• High-temperature recoverable energy (from

exhaust) increased

• Indicated efficiency gain shows a peak for an

optimum coolant temperature of up to 2.5%

• Combustion characteristics showed no significant

change with changing coolant temperature

WP2: KTH – RESULTS

2017-10-05 10JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

• Expanders used mostly are either the piston or the

turbine types

• Limited no. of publications on practical design

conditions of expanders and their effect on the

cycle

• Analysis and modelling of more expander types for

efficient low-temperature heat recovery

WP3: CHALMERS – RESULTS

2017-10-05 11JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

• Results from different thermodynamic

cycles and working fluids

(Thermodynamic potential)

• Potential for all heat sources

combine heat sources

• Best performance depends on

combination of heat source, working

fluid and thermodynamic cycleRijpkema, J., Munch, K. and Andersson, S.B., Thermodynamic Potential of Rankine and Flash

Cycles for Waste Heat Recovery in a Heavy Duty Diesel Engine, Energy Procedia, Vol. 129, 2017

WP4: VOLVO CARS – AIM

2017-10-05 12JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

• Build a demonstrator WHR system

• Implement on a light duty engine

• Show possibility to reduce fuel

consumption in accordance with theory

WP4: VOLVO CARS – SYSTEM ANALYSIS

2017-10-05 13JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

Mechanical Transfer

• High efficiency to propulsion

• Need to be disconnected when there is no torque demand

• Packaging challenge

Electrical Transfer

• Losses of 30-50%, expander to propulsion

(except 12V Board net)

• Can store energy during transients

• Packaging freedom

Electromechanical transfer chosen:

High efficiency through• Mechanical transfer when

possible

• Electric transfer in transients

• Control challenge

• Packaging challenge

System

Simulation

Study

WP4: VOLVO CARS – SYSTEM LAYOUT

2017-10-05 14JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

WP4: VOLVO CARS – SYSTEM LAYOUT

2017-10-05 15JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

ACKNOWLEDGEMENTS

2017-10-05 16JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

Volvo Cars

THANK YOU

WHY WHR?

2017-10-05 18JELMER RIJPKEMA & CHRISTER ODENMARCK - ENERGIRELATERAD FORDONSFORSKNING 2017

Passenger cars

CO2 legislation

Higher loads in WLTP

RDE for CO2

Real-life consumption

Higher engine efficiency needed

2012: η = 20 – 25%

2025: η = 40 – 50%