Air reversing R744 conditioning system

SINTEF Energy Research

8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

1

AIR REVERSING R744 AIR CONDITIONING

SYSTEM

A.HAFNER ¹ ; S. MEMORY ² ; J.A. MANZIONE ³

3 Environmental Systems Project Office Power

Technology Branch Army Power Division, C2D Communications Electronics RD&E

Center

2 Modine Manufacturing Company,

1500 DeKoven Avenue, Racine, WI

53403-2552

1 SINTEF Energy Research 7465 Trondheim

Norway

SINTEF Energy Research

8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

CONTENTS

„ Background

„ Experimental set-put

„ Components

„ Measurement results

„ Energy demand

„ Summary

„ Conclusion

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

3

Reversible R744 systems

„ Refrigerant reversing unit

„ Several valves required

„ Additional cost

„ Heat exchanger mode changes

INDOOR

OUTDOOR

Alternative:

Reverse Air flow!

8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Reversible systems

„ CANTABRIA = Concept of University of Cantabria

„ Reversing the air flow

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

TU Dresden, 19.11.2008 Reversible R744 Klimaanlagen Folie 5 von 16

„ Controlling the air flow with flaps

Reversible systems

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Set-up (heating)

INDOOR heating OUTDOOR

cooling

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7

Animation

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Components ^{Top view} bottom view

bottom view

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Evaporator configurations

„ Top view

Conf. A Conf. B

Conf. C Conf. D

Inlett

Inlett Inlet

Inlet Inlett Outlet Outlet

Outlet

Outlet

Outlet

8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Temperature distribution

Air side - downstream of the evap.

Conf. A Conf. B

Conf. C Conf. D

Inlett

Inlett Inlet

Inlet Inlett Outlet Outlet

Outlet

Outlet

Outlet

4-5 3-4 2-3 1-2 0-1 -1-0 -2--1 -3--2 -4--3 -5--4 Diffe r e nce fr om m e an air outle t te m pe r ature , inte r ior HX [K]

Inlet Outlet

4-5 3-4 2-3 1-2 0-1 -1-0 -2--1 -3--2 -4--3 -5--4 Diffe r e nce from m e an air outle t te m pe r ature , inte r ior HX [K]

Inlet Outlet

Config: B; 1.3 kg/min Config: A; 1.3 kg/min

Max capacity for ECU

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Temperature distribution

Air side - downstream of the evap.

Conf. A Conf. B

Conf. C Conf. D

Inlett

Inlett Inlet

Inlet Inlett Outlet Outlet

Outlet

Outlet

Outlet

Config: D; 3 kg/min Config: C; 3 kg/min

4-5 3-4 2-3 1-2 0-1 -1-0 -2--1 -3--2 -4--3 -5--4 Difference from m ean air outlet tem perature, interior HX [K]

Inlet Inlet

Outlet

4-5 3-4 2-3 1-2 0-1 -1-0 -2--1 -3--2 -4--3 -5--4 Difference from m ean air outlet tem perature, interior HX [K]

Inlet Inlet

Outlet

If applied in other applications

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Measurement set-up

„ Entire ECU between two climate chambers

„ Refrigerant mass flow meter and calorimetric energy balance applied to calculate capacities

ECU Chamber I

Evaporator side [-20°C – +30°C]

Chamber II Gascooler side

[+20 – +53°C]

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

13

Gascooler Temperature Profile

Refrigerant Outlet air Inlet air

Temperature [°C]

Gascooler rel. length [-]

40 50 60 70 80 90 100 110 120

550 650 750 850

Enthalpy [kJ/kg]

P ressur e [ b ar ]

50°C

ambient

temperature

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Picture of the R744 turn-table ECU

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Results

1 2 3

-20 -10 0 10 20 30 40 50

Umgebungstemperatur [°C]

C O P [- ] & He iz -/ Kü h lle is tu n g [ k W

10 12 14 16 18 20 22 24 26 28 30

In nenr a um te m p er at ur [ °C ]

COP Heizen COP Kühlen

Q Heizen Q Kühlen

Innenraumtemperatur

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Temperature bin / Climate / Location

0 500 1000 1500 2000 2500

< -2 0 -2 0 t o -1

5 -1 5 t o -1

0 -1 0 to

-5

-5 to 0

0 t o 5

5 t o 10

10 to 15

15 to 20 20 to

25

25 to 30

30 to 35

35 -4 0

40 -4 5

>4 5

Temperature range [°C]

N u m ber of annual hour s Beijing Baghdad New Delhi

24 h/day (total 8760h)

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0 1 2 3 4 5 6

MW h/ a

D ie sel gen er at or

Ko hl ek raf tw er k En er gi emi

x C hi na

En er gi emi x In di en

J ä hr lic her E n er gi ebed ar f [M W h /a ] .

0 1 2 3 4 5 6

J ä hr lic h er äqui v . C O 2 A u s s to ß [m etr i. to n / a ]

Peking Bagdad Neu Delhi

Office hours

(8 a.m. – 5 p.m.)

„ 3-3.2 MWh/a

„ Dieselgenerator 2.3-2.5 m.ton/a

„ Coal power p.

2.8-3 m.ton/a

„ China / India

2.25 / 2.7 m.ton/a

Energy Demand & CO2 Emissions

8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Energy Demand & CO ₂ Emissions

Non-office hours (5pm – 8am)

„ 4.9 - 5.1 MWh/a

„ Dieselgenerator 3.7 - 3.9 m.ton/a

„ Coal power p.

4.6 - 4.8 m.ton/a

„ China / India

3.7 / 4.3 m.ton/a

0 1 2 3 4 5 6

MW h/ a

D ie se lge ner

at or

Ko hl ekr aft w er k

En erg

ie mi x Ch in a En er gi em

ix Ind ie n

J ähr lic h er E n er giebedar f [ M W h /a ] .

0 1 2 3 4 5 6

J ähr lic h er äquiv . CO 2 A u s s to ß [m e tr i. to n / a ]

Peking Bagdad Neu Delhi

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COP & Capacity limiting factors

„ Lines = ok

„ no disadvantage due to current fitting technology

„ Gascooler => ok (low temperature approach)

„ Evaporator

„ fin pitch adjustment required (frosting)

„ refrigerant side distribution => ok

„ Expansion devices

„ TBR = small adjustment of temperature pressure curve

„ MBR = ok

„ Receiver = ok

„ IHX (internal heat exchanger) = ok

„ Compressor (3cm ³ proto-type)

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Summary

„ An air reversing, turn-table ECU was designed and experimentally investigated.

„ The refrigerant circuit can be unchanged, when directing the air through the designated heat

exchanger by rotating the entire refrigeration unit.

Therefore the function of the heat exchanger does not change, i.e. the gascooler can be

optimized for a low temperature approaches.

Refrigerant charge issues can be handled since

no ‘dead’ lines are present.

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Conclusion

„ This concept study showed that a turn-table residential AC-unit, applying R744 as

working fluid, is a viable option for many global areas, where both heating and

cooling is required during a year.

„ This concept is also feasible for ‘mobile’

HVAC system in busses and trains…

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8^thVDA WINTER MEETING 2009, Saalfelden 11.- 12. February 2009

Thank you

for your attention!

Questions are welcome!!!

Contact:

Armin.Hafner@sintef.no S.Memory@modine.com John.A.Manzione@us.army.mil

Acknowledgement:

Many thanks for financial support of this effort from US-Army, and Modine.

Thanks to Embraco for the compressor.

A special thanks to the team at Lumikko OY, which build up this compact unit, for their cooperation and good workmanship.

More real facts at www.R744.com