optemus project: how to create a micro- climate around the...

OPTEMUS Project: How to create a micro-

climate around the passengers to dispense with

climatizing the entire cabin

Felix Weidmann, Fraunhofer LBF

OPTEMUS 2

Agenda

• OPTEMUS energy reduction ambition

• Fiat 500e vs. OPTEMUS Fiat 500e

• OPTEMUS technologies

• Evaluation of thermal comfort

• Creation of localized climates

• Macro climate vs. Micro climate

• OPTEMUS micro climate technologies

• Summary

Figure: CRF

OPTEMUS 3

OPTEMUS Ambition

• Absolute driving range 160km (NEDC)

• High range variation dependent on ambient climate

Most critical: extreme cold

• Reasons

• Temperature dependency of battery pack

• Climate comfort technologies cannot harvest dissipated heat from ICE

• Optemus ambition:

Reduction of driving range variation due

to ambient climate

How to do that?

SotA Fiat 500e OPTEMUS Fiat 500e

<1%

<1% -36%

-18%

OPTEMUS 4

OPTEMUS Ambition

Extreme ambient temperatures mostly affect energy consumption of

comfort technologies

Reduction of energy consumption of interior climate comfort to reduce

range variation

0

50

100

150

200

250

Stota Optemus

traction

comfort

componentheating/cooling

0

50

100

150

200

250

Stota Optemus

traction

comfort

componentheating/cooling

Hot ambient climate Cold ambient climate

-60%

-15%

-78%

-15%

Ene

rgy C

on

sum

ption [W

h/k

m]

Ene

rgy C

on

sum

ption [W

h/k

m]

OPTEMUS 5

OPTEMUS Technologies

OPTEMUS 6

OPTEMUS Technologies

OPTEMUS 7

OPTEMUS Comfort Technologies

Weather

Data

Preconditioning

strategy

Eco routing/

driver profile

OPTEMUS 8


Weather

Data

Preconditioning

strategy

Eco routing/

driver profile

Preconditioned climate Localized climate Thermal Comfort

OPTEMUS 9


Weather

Data

Preconditioning

strategy

Eco routing/

driver profile


OPTEMUS 10

OPTEMUS Evaluation of Thermal Comfort

Evaluation of Thermal Comfort

Predicted Mean Vote PMV (Fanger, 1972)

• Developed for thermal evaluation of buildings

• Adaption for inhomogenities in vehicle interiors

• Separation of passenger body in segments

• Solar insolation included

PMV index Description

-3 cold

-2 cool

-1 slightly cool

0 neutral

+1 slightly warm

+2 warm

+3 hot

0

10

20

30

40

50

60

70

80

90

100

-3 -2 -1 0 1 2 3

Pre

dic

ted

Perc

en

tag

e o

f D

issati

sfi

ed

(P

PD

) / %

Predicted Mean Vote (PMV) / -

OPTEMUS 11

OPTEMUS Evaluation of Thermal Comfort

Evaluation of Thermal Comfort

Predicted Mean Vote PMV (Fanger, 1972)

• Calculation om comfort based on quantitative measurements

Enables use of thermal manikins

𝑄 𝑟𝑎𝑑𝑖𝑎𝑡𝑖𝑜𝑛

𝑄 𝑐𝑜𝑛𝑣𝑒𝑐𝑡𝑖𝑜𝑛

𝑄 𝑐𝑜𝑛𝑑𝑢𝑐𝑡𝑖𝑜𝑛

𝑄 𝑚𝑒𝑡𝑎𝑏𝑜𝑙𝑖𝑐

𝑃𝑀𝑉 = 0,303 ∙ 𝑒−0,03∙𝑞 𝑚𝑒𝑡 + 0,028 ∙ 𝑞 𝑚𝑒𝑡 − 𝑞 𝑖

𝑛

𝑖=1

𝑞 𝑖𝑛𝑖=1 = 𝑞 𝑟𝑎𝑑 + 𝑞 𝑐𝑜𝑛𝑣 + 𝑞 𝑐𝑜𝑛𝑑

OPTEMUS 12

OPTEMUS Localized Climate

Weather

Data

Preconditioning

strategy

Eco routing/

driver profile


OPTEMUS 13


Stota Fiat 500e

• Passenger comfort systems

based on convective heat

transfer

Climatizing whole interior

• Targeted comfort systems as

contribution • Smart Seat

• Smart dashboard

Climatizing specific locations

OPTEMUS Fiat 500e

Energy consumption reduction with micro climates at equal comfort

OPTEMUS 14


Weather

Data

Preconditioning

strategy

Eco routing/

driver profile


OPTEMUS 15


Smart seat • Heating and cooling function

• Peltier elements at bottom and back

• Heating and/or cooling of different body parts

• Direct contact with body

• Material requirements • Thermal conductive polymer based materials

• Flexibility in order to adapt to passenger body

• Energy consumption • less than 100 W (per seat)

• Heat dissipation • Liquid cooling by integration into thermal layout

Contact pressure Heat transfer

[Source:Karimi, 2004]

OPTEMUS 16


Weather

Data

Preconditioning

strategy

Eco routing/

driver profile


OPTEMUS 17


Smart Dashboard

OPTEMUS 18


Smart Dashboard – Targeted radiation Heating

• Cold ambient climate: targeted radiation heating

Targeted radiation heating

OPTEMUS 19


• Heating concepts

resistive heating concepts (A & B):

• Joule Principle

and thermoelectric concept (C):

• Peltier Principle

• Variation of parameters:

heating concept

panel thickness

panel material

effect on temperature homogenity

BA C

2 mm1 mm 4 mm

1 W/m K0.5 W/m K 5 W/m K

Figure 1: Variation of heating concepts

Figure 2: Variation of panel thickness

Figure 3: Variation of thermal conductivity

𝑃 ∝ 𝐼2 ∙ 𝑅

𝑄 = ∏𝐴𝐵𝐼 = ∏𝐴 −∏𝐵 𝐼


OPTEMUS 20


• Experimental testing:

• Evaluation of energy consumption and heat up time

PMV = 0

0

20

40

60

80

100

rel. h

ea

t up

tim

e &

en

erg

y c

on

su

mp

tio

n /

% -30%

prototypePTC - reference

heat up time

energy consumption

Combined use of PTC convective and radiation heating systems

Reduction of energy consumption of ~30% at equal PMV


OPTEMUS 21


Smart Dashboard – Heat transfer device

• Hot ambient climate: anisotropic heat transfer de Anisotropic heat transfer

OPTEMUS 22


Smart Dashboard – Heat transfer device

• Heat-up of interior due to solar insolation 𝑸 < 𝟏𝟎𝟎𝟎 𝑾/𝒎²

• Dashboard temperature can reach ~100°C

• Absorbed heat needs to be reduced by climate comfort technologies

Increase of energy consumption for climate comfort

OPTEMUS 23


Heat-up due to insolation

Solar Radiation 𝑄

OPTEMUS 24


30% reduction of

absorbed solar energy

while appearing black

Thickness insensitive

spectrally selective (TISS)

Layer



OPTEMUS 25


30% reduction of





Layer

Form-stable Phase Change Materials

Deceleration of temperature

increase during phase change



OPTEMUS 26


30% reduction of





Layer

Form-stable Phase Change Materials

Deceleration of temperature

increase during phase change

Anisotropic Heat Transfer



Transfer of exzessive heat to

panel backside using TME

OPTEMUS 27

OPTEMUS Summary

Summary

• OPTEMUS target:

Reduction of range variation by reduction of

energy consumption of comfort technologies

• Novel OPTEMUS holistic technologies:

• Smart Seat

• Smart dashboard

Generation of micro climates

• Evaluation of resulting thermal comfort:

PMV based approaches

Thank you for your attention!

The OPTEMUS consortium

OPTEMUS 29

Thermal comfort definition

- Which zones are keen to be cooled down for localized cooling?

The Equivalent Homogeneous Temperatures (EHT) temperatures of the Thigh, Pelvis, and

Back are significantly impacted by the seat cooling discharge and are sensitive to the

changes in discharge parameters in terms of the airflow rate and temperature [1].

Heat transfer between body and seat depends on the contact

pressure distribution [2].

[1] M. Wang et al. Localized Cooling for Human Comfort, SAE Int. J. Passeng. Cars - Mech. Syst., Volume 7, Issue 2, 2014.

[2] G. Karimi et al., Thermal Modeling of Driver/Seat Interfaces in Automotive Applications, SAE Technical Paper, 2004.

[3] S.Paulke and E. Kreppold, The Application of Thermal Simulation Techniques for Seat Comfort Optimizations, 2008.

Contact pressure

[2] [3]

Heat transfer

OPTEMUS 30

Task 2.1 – Novel Materials

Form-stable phase change materials

• PCM-Polymer-Composites

• Micro-encapsulated PCM-Epoxy-Composite

• Manufacturing of PCM-Epoxy-Composites at varying wt% (30,40,50)

• PCM-Epoxy-Composites provide processability at low temperatures

• PCM-Polymer-Blends

• PCM-HDPE-Blend

• Twin-screw-extrusion of HDPE and liquid paraffin

• Manufacturing of HDPE-Paraffin- Granulate at varying wt% (30,40,60)

• Must be processed above melting point of PCM-HDPE-Blend (~110 °C)

PCM-Epoxy-Composites chosen for integration into battery modules due to processing temperatures

OPTEMUS 31

Bologna - Localized conditioning

Micro Climate

Climate control only of limited areas

Climate technologies targeting specific passengers

OPTEMUS 32

Form-stable phase change materials

• HDPE-Paraffin-Blend

50-60% of PCM latent heat

Little/no leakage (to be tested)

Little change of tensile properties

at phase change

T2.3 Interior: Smart Cover Panel – Heat Transfer

HDPE + Frozen PCM HDPE + Liquid PCM

OPTEMUS 33

Thickness insensitive spectrally selective coating (TISS)

• Materials

• “Cool Leather”

• Differently coloured PP

• Testing of spectral selectivity

• Spectroscopy

Cool leather with very small

absorptance in NIR spectrum

• Testing of heat build-up

• ASTM 4803

• Miniature Interior

T2.3 Interior: Smart Cover Panel – Heat Transfer

scattered directed

Air Temperature

Surface Temperature

1

2

3

Windshield

Panel

Interior Housing

Radiation Source

Solar Spectrum

Wavelength Wavelength

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