heat pipe in hvac systems

School of Engineering and Design

HEAT PIPES AND THEIR APPLICATIONS TO HEAT PIPES AND THEIR APPLICATIONS TO HVAC SYSTEMSHVAC SYSTEMSHVAC SYSTEMS HVAC SYSTEMS

&&PROGRESS WITH THE SIRAC KICK STARTPROGRESS WITH THE SIRAC KICK STARTPROGRESS WITH THE SIRAC KICK START PROGRESS WITH THE SIRAC KICK START

FUNDING FUNDING

byDr Hussam Jouhara

S h l f E i i d D i B l U i iSchool of Engineering and Design, Brunel University

Tel: +44 (0) 1895 2 67656, Email: [email protected]

www.brunel.ac.uk/about/acad/sedCentre of Energy & Built Environment Research (CEBER)


OverviewOverviewHeat pipe, what is it?Heat Pipe in HVAC Systems: Sample ProjectsTh P i h h SIRAC Ki k S F dThe Progress with the SIRAC Kick-Start Fund



Why Heat Pipes!

The technology is challenging as of the various heat transfer mechanisms involved. The technology is challenging as of the various heat transfer mechanisms involved.

It is an old technology which is finding its way to be irreplaceable by the industry It is an old technology, which is finding its way to be irreplaceable by the industryin certain applications.

Heat pipe base energy systems: This area is still a fertile ground for IP Generation.



Heat Pipe in a laptop


In case you have not seen a Heat Pipe, it is everywhere


Heat Pipe in HVAC Systems: Sample Projects

Experimental and theoretical investigations are being carried out onh i h h (HPHEX ) f li i iheat pipe heat exchangers (HPHEXs) for applications in:

Free reheat in dehumidification systemsWaste energy recovery (heating or cooling effects) fromWaste energy recovery (heating or cooling effects) from

building stalled air

H ti E ittHeating Emitters



Sample Project 1:Sample Project 1:

HPHexHPHex for Application in Energy Efficient for Application in Energy Efficient Dehumidification SystemsDehumidification Systems



Typical Dehumidification SystemTypical Dehumidification SystemTypical Dehumidification SystemTypical Dehumidification System

Energy wastage in the reheating process



Heat Pipe based Dehumidification SystemHeat Pipe based Dehumidification SystemHeat Pipe based Dehumidification SystemHeat Pipe based Dehumidification System

HPHEX Chilled Coil

No reheat energy required



Energy Analysis

0.95

90

100

110 120

1

30 0.95

90

100

110 120

1

30

The assumed humid air mass

flow rate is 1 kg/s

halpy

- kJ

/kg(a

)

tem

pera

ture

- de

g C

(

a

)

20

0

95

60

70

80

110

120

1

halpy

- kJ

/kg(a

)

tem

pera

ture

- de

g C

(

a

)

20

0

95

60

70

80

110

120

12

flow rate is 1 kg/s

Entha

Satu

ratio

n te

u

m

i

d

i

t

y

r

a

t

i

o

-

g

/

k

g

(

0.90 Volume - cu.m

/k3

40

50

60

90

100

20Coil Energy Load 52 kW

Entha

Satu

ratio

n te

u

m

i

d

i

t

y

r

a

t

i

o

-

g

/

k

g

(

0.90 Volume - cu.m

/k3

40

50

60

90

100

20

Coil Energy Load 47 kW

Coil Energy Load52kW

Coil Energy Load47kW

H

10

40%

60%

80%

0.85

kg(a)

10

20

30

70

80

10

2 3

Heater Energy Consumption 7.2 kW (Electric)

H

10

40%

60%

80%

0.85

kg(a)

10

20

30

70

80

10

43

Heater Energy Consumption 7.2kW (Electric)

Heating Energy Consumption0kW

Dry bulb temperature - deg C0 10 20 30 40 50

20%

0.80060

Dry bulb temperature - deg C0 10 20 30 40 50

20%

0.80060

The chilled coil becomes 10% smaller and no heaters are needed. (Jouhara, 2009)



Waste Heat Recovery, Loop HP HEXWaste Heat Recovery, Loop HP HEX



Air-Side Thermocouples

T1 T2 T3 T4

8 0

5 0

6 0

7 0

a

t

u

r

e

(

C

)

Th

3 0

4 0

5 0

A

i

r

T

e

m

p

e

r

a

Tc Tc=Th


0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0 1 . 2 1 . 42 0

D i s t a n c e ( m )



HPHexHPHex for application in Waste Energy for application in Waste Energy Recovery from Building Stalled AirRecovery from Building Stalled Air



Typical Air Conditioning ConfigurationTypical Air Conditioning Configuration



Typical Heat Pipe based Air Conditioning ConfigurationTypical Heat Pipe based Air Conditioning Configuration

Free heating


(Heating Energy Recovery Mode)(Heating Energy Recovery Mode)


Inline Configuration Staggered Configuration

Aluminium Condenser fin stack500/m

section

Adiabatic section

Evaporator

HPHEX Investigated

section

For Lower Pressure Drop For Higher Heat Transfer Rate



Cold Air Inlet Cold Air Exit

Rotating Base

Hot Air Exit Hot Air Inlet



Waste Heat Recovery SHP HEX

I li ti M h i


Inclination Mechanism


Passive Waste Heat Recovery Heat Exchanger for Applications in Process Industries Passive Waste Heat Recovery Heat Exchanger for Applications in Process Industries &V il i S&V il i S&Ventilation Systems.&Ventilation Systems.

Wicked Heat Pipe System

Wickless Heat Pipe System

Typical configurations



Sample Experimental and Modelling ResultsSample Experimental and Modelling Results

0.6

0.45

0.5

0.55

0.35

0.4

0.45

f

e

c

t

i

v

n

e

s

s

0.25

0.3

E

f

f

E i l Eff i

0 1

0.15

0.2 Experimental Effectivnes

Theoretical effectivness

0.10.04 0.05 0.06 0.07 0.08 0.09 0.1

Mass flow rate (Kg/s)




Heat Pipe Based Heating EmittersHeat Pipe Based Heating Emitters



New Patent: Heat Pipe based Emitter New Patent: Heat Pipe based Emitter

(J h & R b 2010)


(Jouhara & Robinson, 2010)


The SIRAC KickThe SIRAC Kick--Start FundStart Fund



hhThe TeamThe Team

Innovative Manufacturers of Heat Exchange Products

Commercialisation Consultants(specialising in heat transfer & engineering) Research &

Novel Heat Pipe

Introduced at SIRAC event

Novel Heat Pipe Technology


Introduced at SIRAC eventSIRAC Kick-Start Fund instrumental in Consortium


SIRAC Kick Start FundSIRAC Kick Start FundSIRAC Kick Start FundSIRAC Kick Start Fund

500 granted by SIRAC in March 20092009

Travel & research costs covered facilitating consortium meetings, design and development

founded by

Long-term collaborative relationships established funded byrelationships established y



Heat Exchanger DesignHeat Exchanger DesignHeat Exchanger DesignHeat Exchanger Design

Several design meetings considering g g gtechnology and the needs of the market

Designs finalised between Coolers & Designs finalised between Coolers & Condensers and Brunel University



Market StudyMarket Studyyy

Report prepared by NeQstep Limited



Where is the Demand?Where is the Demand?Where is the Demand?Where is the Demand?

Code of Conduct on Data Centres Energy Efficiency 2008 defines two key areas:2008 defines two key areas:

IT Load IT Load

Facilities Load (inc cooling systems

... and states energy

cooling systems

efficiency must be maximised to meet EU energy policies


EU energy policies


Th C d f C d t h lTh C d f C d t h lThe Code of Conduct has alsoThe Code of Conduct has alsoalready identified an increasing willingness ofalready identified an increasing willingness of

manufacturers and vendors to compete on the basis of energy efficiency in data centresenergy efficiency in data centres

Businesses are becoming increasingly aware of their i l i d h d d henvironmental impacts and the need to reduce these.

Data centres operators need to be aware of the financial, p ,environmental and infrastructure benefits to be gained from improving the energy efficiency of their facilities through p g gy y goptimisation of power distribution, cooling infrastructure,

IT equipment and IT output.



Free CoolingFree CoolingFree CoolingFree Cooling

ASHRAE's Thermal Guidelines for Data Processing Environments recommends:Environments recommends:

temperature 2025C

humidity 4055%

ma de point 17C max dew point 17C

outside temperature of 15 20C i d15-20C required to gain 'free cooling'



6,783 hours of 'free cooling' out of a possible 8,760


g p

hours


ConclusionConclusionConclusionConclusion

Between 30 60% of data centre energy consumption is Between 30-60% of data centre energy consumption is attributed to cooling technology

Th i l i b i l i f h H Pi The potential saving by implementation of the Heat Pipe solution would save UK data centres between approximately 2 1 - 4 3 TWh2.1 - 4.3 TWh

Heat transfer coefficient of the Heat Pipe solution and the th l ti / f th b ildi i f ththermal properties/response of the building require further study

Clear potential identified - development in partnership with the data centre market now sought



Other ResultsOther Results



Active CollaboratorsActive CollaboratorsActive CollaboratorsActive Collaborators

Coolers & Condensers and Brunel University have continued to collaborate on many heat transfer and energy projects

Further plans for a possible joint application for Further plans for a possible joint application for research funding in the sector

C l & C d l d ti MS Coolers & Condensers already supporting MSc students project in Brunel University



Thank YouThank You

END


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