presentation absorption 07-02-2014 [mode de compatibilité]€¦ · absorption cooling system with...

Automotive

absorption cooling system

with falling film.

Date 07 février 2014PSA-DRD/DRIA/ACBI/INT/THQA

Emmanuel BOUDARDPSA: Responsable d’unité élémentaire d’innovation

Thermique Habitacle et Qualité de l’Air

[email protected]

+33 1 81 22 24 36

2

Sommaire

Contexte

Technologies

Propositions techniques

Evaluations scientifiques

Résultats sur banc d’essais

Conclusion

Summary

Context

Technologies

Technical proposals

Scientific validations

Test bench results

Conclusion

CONTEXT

Context

Technologies

Technical proposals


Test bench results

Conclusion

Automotive CO2 regulations:

PSA Peugeot Citroën – Emmanuel Boudard – 07 février 2014

Effort on CO2 emissions:

regulations worldwide

Cylce WLTP:

Worldwide / more representative

Introduction of MAC regulation

Mobile Air-conditionningConsumption

Automotive absorption cooling system:

Expected benefits


•Engine load:

•70% compressor work (up to

5kW)

Automotive A/C system

•Engine thermal losses: (50 to

80% of combustion energy)

•85% heat conversion

•2 pumps (50W electrical power)

Absorption A/C system

Automotive absorption cooling system

Constraints

Implementation volumes

Power

Heat sources temperatures

Mass

Reliability (>15years)

Raparability & end of life

Industrialization

Cost…

Absorber: 23L

Desorber: 8L

11L

3.7L

Objectives


TECHNOLOGIES

Context

Technologies

Technical proposals


Test bench results

Conclusion

Falling film for absorption

Water

LiBr solution

Benefits:

• Small packaging

• Vapour displacement with low pressure

drop

• Reproduced plates

• Use of water as liquid calorific flow

• Use of solution as liquid calorific flow

Capillarity is used for vibration response

Capillarity is used for inclination response

Constraints:

• Small

• Water dropplets

• Multi-physics


Grids as key point for automotive

Meniscus

LiBr flow 100 L/h

54 % salt mass fraction

Fluid inlet Distribution chamberHole for liquid distribution

Grid glue line

Fluid outletLiquid collector

l =14.4 cm

L=22.3 cm

206µm

388µm

Open ratio: 55%


Interest of capillarity for automotive


TECHNICAL PROPOSAL

SCIENTIFIC VALIDATIONS

Context

Technologies

Technical proposals


Test bench results

Conclusion

Grids limitation

)Y,T(PPP Beq−=∆

The driving force for absorption or “distance to equilibrium” is defined as :

decrease is mainly due to the temperature increaseP∆

0 3 6 9 12 150

3

6

9

12

15

Out

let

driv

ing

forc

e [m

bar]

Inlet driving force [mbar]

Slope=0.7

0 3 6 9 120

0.5

1

1.5

2

2.5

3

3.5x 10

-4

Abs

orpt

ion

rate

per

pla

te [

kg s

-1]

Inlet driving force [mbar]

Absorption rate is roughly equal to one third of the maximal rate that

could be achieved (only valid within the flow rate range of the tests)

R. Goulet. PHD 2011

Development and analysis of an innovative evaporator/absorber for automotive absorption-based air conditioning

systems: investigation on the simultaneous heat and mass transfer

CETHIL, UMR5008 INSA de Lyon - CNRS - UCBL & PSA

Identification of absorption limitations:

meniscus & grids porosity

H. Obame MVE. Ongoing PHD (2011-2014):

Intensification of heat and mass transfer in Lithium Bromide water solution flow confined in grids absorption

[email protected] / +33 1 57 59 70 25 / +33 6 45 57 83 75


Identification of absorption limitations:

Stabilization of interface & LiBr flow modification



[email protected] / +33 1 57 59 70 25 / +33 6 45 57 83 75


Identification of absorption limitationsMass transfer & heat transfer intensification:

• Create more fluid mix in grid spaces

• Increase grids porosoty

• Conserve capillarity effects



[email protected] / +33 1 57 59 70 25 / +33 6 45 57 83 75


Heat flux

W/cm

Robin SCHUCKER, Benjamin BROCHE, Mohamed

SABAH, Jonathan GRANDPERRIN, Shen DENG,Alexandre

BUTTERLIN PSC 2013: Investigation on dropplets,

Laboratoire d'Hydrodynamique (LadHyX), Ecole

Polytechnique, PSA

hL

Droplet %

Affecting absorption

Water dropplets elimination in a water vapor gas flow

Identification of absorption limitations

TEST BENCH RESULTS

Context

Technologies

Technical proposals


Test bench results

Conclusion

Absorbers: configurations & results

LiBr 3,5kW test bench for absorbers (2005 - Bertin Technologies – stainless steel)

• 8,8L evaporator /absorbers (painted aluminium+plastics – PU+PP distribution + PET grids)

• 5 plates (3 LiBr/2 Water) for 2400cm2 absorption surfaces

• Climatic conditions & heating systems representative in car conditions (+30C / +90C)

• Tests with different plates geometry and same grids

0200400600800

100012001400160018002000220024002600280030003200340036003800400042004400

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Pui

ssan

ce e

n W

T en °C

Puissance en fonction de la température d'eau en so rtie absorbeur

Données banc proto_2Empirique 1,7 W/cm²Empirique 1,3 W/cm²Empirique 2 W/cm²Données banc proto_baseEmpirique 2,6 W/cm²Données banc proto_1Données banc proto_1 non dégazé

Absorption prototype plate # 1

Theorical line of performance for car

Theorical line of poor performance

Theorical line of good performance

Absorption standard plate

Theorical line of very good

performance

Absorption prototype plate #2


(with uncondensable gases)

Test bench power limit

Water outlet temperature (C)

Cooling

power

(W)

Area: Not compatible

with car implementation

Area: Poor performance

Area:

Automotive performance

PSA Peugeot Citroën – Patrick BACH – essais 2013

Proto #2Reference

Proto #1

Absorbers: configurations & results

0200400600800

100012001400160018002000220024002600280030003200340036003800400042004400

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Pui

ssan

ce e

n W

T en °C

Puissance en fonction de la température d'eau en so rtie absorbeur

Données banc proto_2Empirique 1,7 W/cm²Empirique 1,3 W/cm²Empirique 2 W/cm²Données banc proto_baseEmpirique 2,6 W/cm²Données banc proto_1Données banc proto_1 non dégazé

Absorption prototype plate # 1

Theorical line of performance for car

Theorical line of poor performance

Theorical line of good performance

Absorption standard plate

Theorical line of very good

performance



(with uncondensable gases)

Test bench power limit

Water outlet temperature (C)

Cooling

power

(W)

PSA Peugeot Citroën - ADTH– Patrick BACH – essais 2013

Proto #2

Reference

Proto #1

Proto #1 &

uncondensable

gases

CONCLUSION

Context

Technologies

Technical proposals


Test bench results

Conclusion

Automotive falling film for absorption:

Conclusion

WaterLiBr

solution

Power on 1/3 on absorber is checked.

Improvements for the future are identified.

Still very difficult to make it work:

- Flow equilibrium between grids

- Flow distribution on grids

- Pressure equilibrium

- Uncondensable gases

The key points are known today but the

optimised characteristics are still to identify.


presentation absorption 07-02-2014 [mode de compatibilité]€¦ · absorption cooling system with...

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