ausSCIG Conference Apr 2013 - 13a - Systems - Yakov Elgart · 2016. 8. 12. · Australian Solar Cooling Interest Group (ausSCIG) Conference 2013 6 Day 2 – Solar Cooling Conference

Australian Solar Cooling Interest Group (ausSCIG) Conference 2013 www.ausSCIG.org

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Day 2 – Solar Cooling Conference - 12/04/2013Venue: CSIRO, North Ryde, Sydney

E. Pismennyi, B. Rassamakin, S. Khairnasov,

Combined Photovoltaic- Thermal Solar Collector based on aluminium

heat pipes for solar HVAC.

E. Pismennyi, B. Rassamakin, S. Khairnasov,

National Technical University of Ukraine

"Kyiv Polytechnic Institute“, Ukraine

Y. Elgart

Engineering Scientific International Pty Ltd., Australia


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Introduction Development of solar heating and cooling

systems requires an integrated approach:

• development of new types of solar panels

• improvement of the conventional • improvement of the conventional alternative solar cooling technologies

Some of the those technologies are well known and others have just started to be implemented today

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A l t e r n a t i v e c o o l i n g

t e c h n o l o g i e s

Do uble e f fe ct L i B r abso rption

Liquid Desiccant

LiCl cooling

S i n g le E ffe ct

A bso rpti on abso rption C h i l le rs

LiCl cooling systems

A bso rpti on C h i l le rs

Solid Desiccant Silica Gel

cooling systems

M a i s o ts e n k o-c y c l e

e v a p o r a t i ve c o o l i n g s y s t em



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Single Effect Absorption Chillers

� Most common solar air conditioning system

� Average cooling capacity: range from 7kW to 3000kW



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Double effect LiBr absorption Chillers

� More efficient than single stage absorption chillers

� Can produce water of much lower t°C

� Have greater thermal COPCOP

� Require much higher inlet temperature of hot water

� Potential use of renewable energy sources are limited



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Double effect LiBr absorption Chillers Abbreviation Name Abbreviation Name

ABS Absorber EVP Evaporator

BPHX By-pass heat exchanger HTRG High-temperature regenerator

CHSV Cooling/heating switch valve HRHX Heat recovery heat exchanger

CHWBPV Chilled-water by-pass valve HTHX High-temperature heat exchanger

CHWP Chilled-water pump LTHX Low-temperature heat exchanger

COND Condenser LTRG Low-temperature regenerator

CT Cooling tower RBPSV Refrigerant by-pass solenoid


CT Cooling tower RBPSV Refrigerant by-pass solenoid valve

CTOF City-water overflow RP Refrigerant pump

CTWS City-water switch RPH Refrigerant pump heater

CWBPV Cooling-water by-pass valve SF Steam filter

CWDD Cooling-water drain device SP Solution pump

CWDV Cooling-water detergent valve ST Steam trap

CTF Cooling-tower fan SV Steam valve

CWP Cooling-water pump


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Liquid desiccant LiCl cooling systems

� Air is dehumidified and cooled by its direct contact with a liquid desiccant

� Systems are heat driven

� The open cycle air conditioning is ideal for energy intensive conditioning is ideal for energy intensive buildings with high latent loads

� Systems require the low temperature heat

� It works in perfect synergy with solar thermal collectors



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Solid Desiccant Silica Gel Cooling Systems

� Dehumidify the ambient air through a rotary heat exchanger

� Main advantage of these systems : ability to retain substantial amounts of moisture from the air

� Solid desiccants exhibit higher dehumidification potential than liquid desiccant systems

� Can also be used to provide heating for periods with low heating demand

� Flat-plate solar thermal collectors are normally used for this systems



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Maisotsenko-cycle evaporative cooling system

The main advantages HVAC based on a M-Cycle:• environmental safety• small running cost• design simplicity


• design simplicity • reduction of electricity

consumption comparing with current HVAC by up to 80%

See more information


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Maisotsenko-cycle evaporative

cooling system (cont’d)1-2 M-cycle , cooling the air in dry working channel (in the real time)1-3 air cooling in dry working channel3-7 heating and humidification of air in wet working channel3-5 difference between moisture content of direct


moisture content of direct evaporative cooling and M-cycle2-4-6 - heating and humidification of air in wet working channel1-5 ideal process of direct evaporative cooling (humidification) 1-8 the actual process of traditional evaporative cooling

See more information


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� In real life experiment the temperature of outlet air from dry working channel is very close to the dew point and outlet air from wet

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� At initial temperature of air 71°C in the wet channel the absolute humidity in the M-cycle increases from 0.025 to 0.53 kg / kg, i.e. it rises more than 20 fold.

� Humidity of air flow in M-cycle is more than 6.5 times higher than in traditional direct evaporative cooling,(0.025 ... 0.08 kg / kg),where humidity increases only 3.2 times.Engineering & Scientific International www.esiglobalbusiness.comwww.esiglobalbusiness.com

air from wet channel to the temperature of wet bulb .


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Main types of solar collectorsS o l a r T h e r m a l

c o l l e c t o r s

• transform sunlight into the thermal energy

S o l a r P h o t o v o l t a i c c o l l e c t o r s

( P V )• directly convert the sun's light into electricity



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Main types of solar collectors (cont’d)

Solar combined PV-T collector� Combines PV and solar thermal components into a single

module

� Produces two types of energy

� Increases conversion efficiency

� Makes economic use of the space



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Schematic diagrams of PV-T collectors



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Characteristics of different PV-Tcollectors

PV-T modelsAverage

efficiency (%)Advantages Disadvantages

PVPVPVPV----T air T air T air T air

collectorcollectorcollectorcollector24242424----47474747

• Low costLow costLow costLow cost• Simple structureSimple structureSimple structureSimple structure

• Low thermal massLow thermal massLow thermal massLow thermal mass• Large air volumeLarge air volumeLarge air volumeLarge air volume• Poor thermal removal Poor thermal removal Poor thermal removal Poor thermal removal

effectivenesseffectivenesseffectivenesseffectiveness

• High heat lossHigh heat lossHigh heat lossHigh heat loss

• Low costLow costLow costLow cost • High PV temperatureHigh PV temperatureHigh PV temperatureHigh PV temperature

As shown in a table above, some of PV-T collectors designs with the heat pipes (HP)

PVPVPVPV----T liquid T liquid T liquid T liquid


• Direct contributionDirect contributionDirect contributionDirect contribution• High thermal massHigh thermal massHigh thermal massHigh thermal mass• Low flow volumeLow flow volumeLow flow volumeLow flow volume

• Unstable heat removal Unstable heat removal Unstable heat removal Unstable heat removal temperaturetemperaturetemperaturetemperature

• Complex structureComplex structureComplex structureComplex structure• Possible piping freezingPossible piping freezingPossible piping freezingPossible piping freezing

PVPVPVPV----T refrigerant T refrigerant T refrigerant T refrigerant


• Low PV temperatureLow PV temperatureLow PV temperatureLow PV temperature• Stable performanceStable performanceStable performanceStable performance• High efficiencyHigh efficiencyHigh efficiencyHigh efficiency• Heat rejectionHeat rejectionHeat rejectionHeat rejection

• Risk of leakageRisk of leakageRisk of leakageRisk of leakage• High costHigh costHigh costHigh cost• Unbalanced flow distributionUnbalanced flow distributionUnbalanced flow distributionUnbalanced flow distribution•

PVPVPVPV----T with heat T with heat T with heat T with heat

pipepipepipepipe42424242----68686868

• Low PV temperatureLow PV temperatureLow PV temperatureLow PV temperature• Stable performanceStable performanceStable performanceStable performance• High efficiencyHigh efficiencyHigh efficiencyHigh efficiency• Heat rejectionHeat rejectionHeat rejectionHeat rejection• High COPHigh COPHigh COPHigh COP

• High costHigh costHigh costHigh cost• Risk of damageRisk of damageRisk of damageRisk of damage• Risk of leakageRisk of leakageRisk of leakageRisk of leakage• Complex structureComplex structureComplex structureComplex structure•

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Operational principal of a Heat pipes



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Heat pipes (HP) thermal technology

� Excellent heat transfer capabilities

� Reasonable structural � Reasonable structural simplicity

� Cost effective solution for heat transfer Some types of heat pipes used in

Solar Thermal collectors



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Disadvantages of using copper HPs

� Large weight

� Difficult to assemble and install

� Not versatile� Not versatile

� Unscalable

� Lack of design flexibility, which is particularly important when they are facade integrated



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Proposed Combined Photovoltaic -Thermal solar collector (PV-TAHP )

Faculty of Heat Power Engineering of National Technical University of

Ukraine (Kyiv)

in collaboration with

Engineering and Scientific Engineering and Scientific International Pty. Ltd (Australia)


propose to develop a new type of PV-T collector based on extruded aluminium heat pipes (PV-TAHP) with wide

fins and longitudinal grooves


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Sample and section of extruded aluminium heat pipe



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Working fluid for AHP

� Was selected special environmentally friendly coolant AC-KRA7.5-P1

� Temperature range is-100°С to + 250 °С

� Life span of the heat pipe is over 15 years

Real size of heat pipes


See more about HP testings results


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HP testings resultsParameters Values

DimensionsDimensionsDimensionsDimensions 120120120120××××1500 mm1500 mm1500 mm1500 mm

Maximal heat transfer Maximal heat transfer Maximal heat transfer Maximal heat transfer

powerpowerpowerpowernot less than 210 Wnot less than 210 Wnot less than 210 Wnot less than 210 W

Thermal resistanceThermal resistanceThermal resistanceThermal resistance 0.02 …0.07 0.02 …0.07 0.02 …0.07 0.02 …0.07 °°°°C /WC /WC /WC /WThermal resistanceThermal resistanceThermal resistanceThermal resistance

Temperature drop along the Temperature drop along the Temperature drop along the Temperature drop along the

HPsHPsHPsHPs3 С 3 С 3 С 3 С °°°°---- 7 С 7 С 7 С 7 С °°°°

Temperature rangeTemperature rangeTemperature rangeTemperature range 0 0 0 0 ---- 120 С120 С120 С120 С°°°°

Transferred heat powerTransferred heat powerTransferred heat powerTransferred heat power 50 W 50 W 50 W 50 W ---- 300 W300 W300 W300 W

Maximal heat transfer Maximal heat transfer Maximal heat transfer Maximal heat transfer

ability of the HPsability of the HPsability of the HPsability of the HPsup to 300 Wup to 300 Wup to 300 Wup to 300 W

(for the values of tilt angles

from 5° to 90°)



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Schematic diagram of the combined solar PV-TAHP collector

1 – frame2 – glass3 – aluminium heat pipe 3 – aluminium heat pipe 4 – liquid heat exchanger 5 – dielectric layer6 – thermal insulation7 – PV element



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Experimental research

Stand imitates spectrum of solar radiation, changes settings and registers electrical and thermal parameters of collectors



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Testing of working model of PV-TAHP exposed to real solar radiation



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Current-voltage characteristics of PV cells for various temperature values



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Power-temperature characteristics ofPV-TAHP



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Results of PV-TAHP testingParameters Values

Effective area of Effective area of Effective area of Effective area of the heat the heat the heat the heat

absorbing panels absorbing panels absorbing panels absorbing panels 1,5 1,5 1,5 1,5 mmmm2222

Area of Area of Area of Area of photovoltaic panelsphotovoltaic panelsphotovoltaic panelsphotovoltaic panels 1 1 1 1 mmmm2222

Maximum effective heat flowMaximum effective heat flowMaximum effective heat flowMaximum effective heat flow no more no more no more no more 900 900 900 900 WWWW

Water tank capacity Water tank capacity Water tank capacity Water tank capacity up toup toup toup to 80 80 80 80 l

Thermal COP Thermal COP Thermal COP Thermal COP 44440000 … … … … 60%60%60%60%

Inlet temperature ti=18,8°С, outlet - to=23,8°С (with coolant flow up to 1,5 l/min)

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Thermal COP Thermal COP Thermal COP Thermal COP

Electrical COPElectrical COPElectrical COPElectrical COP 14141414…………15%15%15%15%(inlet temperature of water 40 оС)

Effective heating power Effective heating power Effective heating power Effective heating power up to 450 up to 450 up to 450 up to 450 WWWW////mmmm2222

Effective electrical power Effective electrical power Effective electrical power Effective electrical power up toup toup toup to 140 140 140 140 WWWW////mmmm2222

Hydraulic resistance Hydraulic resistance Hydraulic resistance Hydraulic resistance no moreno moreno moreno more 250 250 250 250 PaPaPaPa(with coolant flow up to 3 l/min)

Temperature differenceTemperature differenceTemperature differenceTemperature difference inininin

inlet and outlet *inlet and outlet *inlet and outlet *inlet and outlet *3,53,53,53,5…………5,0 5,0 5,0 5,0 0000СССС

(with coolant flow up to 1,5…4,0 l/min)

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Technical properties of few PVT collector types

Technical propertiesExperimental

PV-TAHP(Ukraine)

PVT “DuoSolar” IDC (Switzerland)

PVT “Volther Hybrid”

SolimPeks(Turkey)

PVT “Solar Air”GRAMMER Solar

(Germany)

HeatHeatHeatHeat----transfer agenttransfer agenttransfer agenttransfer agent waterwaterwaterwater waterwaterwaterwater waterwaterwaterwater airairairair

Maximum electric Maximum electric Maximum electric Maximum electric

capacity[W/mcapacity[W/mcapacity[W/mcapacity[W/m2222]]]]140140140140 120120120120 108108108108 135135135135

Maximum thermal Maximum thermal Maximum thermal Maximum thermal 450450450450 340340340340 475475475475 405405405405


capacity,[W/mcapacity,[W/mcapacity,[W/mcapacity,[W/m2222]]]]450450450450 340340340340 475475475475 405405405405

Efficiency of photoelectric Efficiency of photoelectric Efficiency of photoelectric Efficiency of photoelectric

battery at 40battery at 40battery at 40battery at 40°°°°СССС 15151515 12121212 11111111 13131313

Thermal standard Thermal standard Thermal standard Thermal standard

efficiencyefficiencyefficiencyefficiency,,,, [[[[%]%]%]%] 60606060 50505050 40404040 40404040

Hydraulic resistance,[Pa]Hydraulic resistance,[Pa]Hydraulic resistance,[Pa]Hydraulic resistance,[Pa] 250250250250 5 4005 4005 4005 400 6 2006 2006 2006 200 30303030

Presence of heat pipesPresence of heat pipesPresence of heat pipesPresence of heat pipes yesyesyesyes nononono nononono nononono

ApproximateApproximateApproximateApproximate

cost per cost per cost per cost per mmmm2 2 2 2 [Euro][Euro][Euro][Euro] 495495495495 960960960960 790790790790 850850850850


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Conclusion

Investigation of experimental combined PV-TAHP collector (1600 x 1000) shown:

� Reduces heat-sensing surface by 30-40 % versus two most common collectors on the market : one PV and the other thermal, at the same power

Absorber of PV-TAHP collector provides highly � Absorber of PV-TAHP collector provides highly effective cooling of the PV cells area. That allows increase PV cells power output of around 15-30%, compare to single PV collector, by keeping its surface temperature around 40-50 °°°°C



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� At temperature 40-50 °°°°C PV-TAHP collector’s electric power output is about 140 W/m2,at the same time it produces up to 450W/m2 of thermal energy

� Dispersion of the PV cells surface temperature is only 2%

Conclusion (cont’d)

only 2% � Heat exchanger of PV-TAHP collector has

hydraulic resistance only 250 Pa. This greatly reduces the solar system pump’s capacity

� PV-TAHP and aluminium HPs separately can be used as building elements for roof, facade and thermal control of the buildings, to utilise modular approach:



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Facade construction with built-in aluminium HPs & PV-TAHP

collectors



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� Economic calculation shows that estimated cost of combined PV-TAHP collector will be

1.5-2.0times less than existing common combined solar collector

Conclusion (cont’d)

� Considering above mentioned, the best application for PV-TAHP collectors in modern, alternative solar HVAC systems are:



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A l t e r n a t i v e c o o l i n g

t e c h n o l o g i e s

Liquid Solid

Desiccant Maisotsenko-

cycle


Liquid desiccant

LiCl Cooling Systems

Solid Desiccant Silica Gel Cooling Systems

Maisotsenko-cycle

evaporative Cooling

Systems.


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Your questions, please

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Documents

ausSCIG Conference Apr 2013 - 13a - Systems - Yakov Elgart · 2016. 8. 12. · Australian Solar Cooling Interest Group (ausSCIG) Conference 2013 6 Day 2 – Solar Cooling Conference