experimental results of a waste heat recovery system with ... · experimental results – mfb....

ORC 2019 Conference

Experimental Results of a Waste Heat Recovery System with Ethanol using the Exhaust Gases of a Light-Duty Engine

Jelmer Rijpkema, Sven B. Andersson, Karin MunchChalmers University of Technology

Fredrik Ekström, Volvo Car Corporation

Athens, 2019-09-11jelmer.rijpkema@chalmers.se

• CO2 emissions Engine efficiency• Engine efficiency Heat loss• Heat loss WHR

• Excellent addition to hybridization• City driving vs. high-way driving

Why ORC for WHR in a passenger car?

2019-09-11 Jelmer Rijpkema - ORC 2019 2

© autoevolution.com

• Published experimental results• Integrated system

• Compact design considering vehicle packaging

• Automatic control• Difference with other systems

• Clutch• Two evaporators

• Design methodology• Ekström, F., et al. (2019), A Mild Hybrid SIDI Turbo Passenger Car Engine

with Rankine Waste Heat Recovery, SAE Technical Paper 2019-24-0194

Why this research?

2019-09-11 Jelmer Rijpkema - ORC 2019 3

© volvocars.com

• Experimental setup• Control strategy• Main results• Conclusions

Outline

2019-09-11 Jelmer Rijpkema - ORC 2019 4

Experimental Setup

2019-09-11 Jelmer Rijpkema - ORC 2019 5

Experimental Setup

2019-09-11 Jelmer Rijpkema - ORC 2019 6

Ethanol

Control Strategy

2019-09-11 Jelmer Rijpkema - ORC 2019 7

• Mechanical Feedback (MFB)• Expander connected to

engine• Pump speed to control

expander inlet temp.• Expander speed =

1.5 * engine speed• Bypass valve position to

control system pressure

Control Strategy

2019-09-11 Jelmer Rijpkema - ORC 2019 8

• Electrical Feedback (EFB)• Expander connected to

generator• Pump speed to control

expander inlet temp.• Expander speed to control

system pressure• EFB MFB

• Synchronize expander speed to 1.5 * engine speed

Conditions and Constraints

2019-09-11 Jelmer Rijpkema - ORC 2019 9

Experimental Results – Engine

2019-09-11 Jelmer Rijpkema - ORC 2019 10

• Engine speed• 1750 – 2500 RPM• Increments of 250 RPM

• Engine torque• 100 – 225 Nm• Increments of 25 Nm

• 16 experimental points

Experimental Results – Exhaust

2019-09-11 Jelmer Rijpkema - ORC 2019 11

Experimental Results – MFB

2019-09-11 Jelmer Rijpkema - ORC 2019 12

𝜂𝜂tot,mfb =�̇�𝑊exp,mfb

�̇�𝑄tot=

�̇�𝑊exp,mfb�̇�𝑚𝑒𝑒𝑒𝑒𝑒 ℎexh,ev1,in − ℎexh,amb

Experimental Results – EFB

2019-09-11 Jelmer Rijpkema - ORC 2019 13

𝜂𝜂tot,efb =�̇�𝑊sh,gen�̇�𝑄tot

No electrical losses

Experimental Results – EFB

2019-09-11 Jelmer Rijpkema - ORC 2019 14

• MFB expander power• 0.5 – 2.5 kW• BSFC reduction: 4 – 12 g/kWh (1 – 5.5 %)• Excluding pump losses

• EFB expander power• 0.5 – 2.5 kW• Excluding pump and electrical losses

• Excellent for combining with hybrid system with fuel savings up to 5.5% at high-way driving conditions

• System design and control concept allow for integration in car

Conclusions

2019-09-11 Jelmer Rijpkema - ORC 2019 15

2019-09-11 Jelmer Rijpkema - ORC 2019 16

Volvo Cars

Thank you