www.solr.uni-kassel.dewww.solar.uni-kassel.de1

SOLNET

Milan

05.03.2008

Optimization of the air-to-water heat exchanger configuration for water preheating in open district

heating nets

Janybek Orozaliev

Janybek Orozaliev www.solar.uni-kassel.de2

To my person

1998 – 2003 Kyrgyz-Russian Slavic University, Bishkek

major: Renewable Energies

2003 – 2005 Kassel University (Germany)

major: Power and Environmental Engineering

master, scholarship from DAAD

10/2005 -? Kassel University (Germany)

PhD study

scholarship from Volkswagen Foundation 09/06 –

02/10

Janybek Orozaliev www.solar.uni-kassel.de3

G ro u n d W a te r (T = 1 2 ° C )in

B o ile r

H o t W a te rS to ra g e

R e tu rn F lo w (o n ly d u r in g w in te r )

(T = 6 0 ° C d u rin g su m m e r)u s e

D o m e s ticH o t W a te r

R a d ia to rs

Strong intercontinental climate In summer: high solar irradiation and ambient temperatures

Solar preheating

Kyrgyzstan – favorable conditions for solar heating

Open district heating net Hot water withdraw directly out of the net

High steady load and low inlet temperatures

Janybek Orozaliev www.solar.uni-kassel.de4

Strong intercontinental climate In summer: high solar irradiation and ambient temperatures

Kyrgyzstan – favorable conditions for solar heating

Open district heating net Hot water withdraw directly out of the net

High steady load and low inlet temperatures

Application of uncovered collectors

Janybek Orozaliev www.solar.uni-kassel.de5

Strong intercontinental climate In summer: high solar irradiation and ambient temperatures

Open district heating net Hot water withdraw directly out of the net

High steady load and low inlet temperatures

Strong intercontinental climate In summer: high solar irradiation and ambient temperatures

Kyrgyzstan – favorable conditions for solar heating

Open district heating net Hot water withdraw directly out of the net

High steady load and low inlet temperatures

Application of uncovered collectors

Tamb > Tin

collector power during the night

-50

0

50

100

150

200

-16 -14 -12 -10 -8 -6 -4 -2 0

Tf - Ta in K

quse

in

W/m²

hourly mean valuesm²h

l40>v&

useq&

Janybek Orozaliev www.solar.uni-kassel.de6

Air-to-water heat exchanger (AHX)

Uncovered collector

20 °CahxT

12 °CinT , 25 °Cabs inT , 35 °Cabs outT

Multicomponent-System

30 °CambT , 45 °Cahx inT

Uncovered air collector

Air Collector (31 m²)

Uncovered Collector (62 m²)

Air-to-Water Heat Exchanger (AHX)

Janybek Orozaliev www.solar.uni-kassel.de7

What is the optimal configuration of the system?(depending on climate and boundary conditions)

How should components be dimensioned?(depending on climate)

How should components be operated/controlled?(depending on weather)

Potential analysis in CIS countries

Multicomponent-System – Research

mathematical models

experimental set up

Janybek Orozaliev www.solar.uni-kassel.de8

Air-to-water heat exchanger (AHX)

Uncovered collector

20 °CahxT

12 °CinT , 25 °Cabs inT , 35 °Cabs outT

My part

30 °CambT , 45 °Cahx inT

Uncovered air collector

Janybek Orozaliev www.solar.uni-kassel.de9

Extension of numerical models: Description of thermal and hydraulical performance of AHX Further developing of the model, which considers geometry in detail

Based on Nu-correlations (not CFD)

Aims and work packages

Cost functions: of components depending on their properties (geometry, power, etc)

Optimization: Optimal configuration of AHX for this application Optimization calculations coupled with system simulations in TRNSYS

Guidelines for dimensioning and operation of AHX: e.g. in form of characteristic curves for different climates

Janybek Orozaliev www.solar.uni-kassel.de10

Thanks for your attention

Janybek Orozaliev

Solar and Systems EngineeringKassel University, Germany+49 561 804-2636orozaliev@uni-kassel.de

Janybek Orozaliev www.solar.uni-kassel.de11

Luft-Wasser-Wärmeübertrager

unabgedeckter Kollektor

20 °CahxT

12 °CinT , 25 °Cabs inT , 35 °Cabs outT

Arbeitsbereich Christian Budig

30 °CambT , 45 °Cahx inT

unabgedeckter Luftkollektor

Janybek Orozaliev www.solar.uni-kassel.de12

Validierung und Parameteranpassung: Die numerischen Modelle sollen anhand der Messdaten validiert und eine Parameteranpassung vorgenommen werden

Ziele und Arbeitspakete Christian Budig

Systemsimulationen: Untersuchung der mögl. Systemkonfigurationen in Abhängigkeit verschiedener Klimata

Richtlinien zur Dimensionierung und Regelung von Systemen:

Identifizierung geeigneter Luftkollektorsysteme: Untersuchung von Folien- und Polymerkollektoren; thermische Abbildung soll über bereits vorhandene Kennlinien erfolgen