10.07.2015   EUROSUN 2008

Validation of the Simulation

Charging and discharging processes where calculated in EES and Matlab and validated with experimental Data. Figure 8 compares the simulated and experimental progress of the charging rate at a charging temperature of -10°C. With the exception of the starting-period, the agreement between measured and predicted values is very good. For the starting period, the simulation predicts an average value without the artificial fluctuations caused by the thermostat.

Figure 9: Comparison of simulated and experimental Charging Rate

 

Nomenclature

Q cond

Conducted heat flow rate,

W

•

Qlat

Latent heat flow rate,

W

•

Q kon

Convective heat flow rate,

W

^■ice

thermal conductivity of ice layer,

W/(mK)

A.

-T^ice

Outer surface of ice layer,

m2

rice

Radius of ice cylinder,

m

Ahs

latent heat of solidification,

kJ/(kgK)

mice

Mass of ice,

kg

pice

Density of ice,

kg/m3

aout

heat-transfer coefficient,

W/(m2K)

Ltube

Length of tube,

m

Temperature of liquid water,

°C

Temperature at ice surface,

°C

References

[1] Brendel, T., Spindler, K., Muller-Steinhagen, H.: Aufbau einer Versuchs — und

Demonstrationsanlage zur solaren Kuhlung, DKV Jahrestagung Bremen, 2004, S. 105-118

[2] Hilligweg, A.: Vordimensionierung von Eisspeichern; TGA Fachplaner 6-2003; S. 29

[3] Streit, D.: Freie Konvektion am horizontalen Rohr in einer Kies/ Wasser-Schuttung mit Bildung und Schmelzen von Eis; Dissertation; 1996; S. 59