Modeling and Design of Net ZEBs as Integrated Energy Systems - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 77

Fig. 2.22 Schematic of a multinode storage tank model

is the outside area of the storage tank i th control volume (m 2 ) A i

i =
1,2…n

is the index for the control volumes of the storage fluid

k i is the global heat exchange coefficient between storage fluid and

ambient air at the i th control volume (W · m −2 K −1 )

T i is the temperature of the i th control volume of the storage fluid (K)

is the volume of the i th control volume of the storage tank (m 3 ) V i

x i−1,j is the distance (m) between the centres of the i th and ( i − 1)th
control volumes for i = 2…n

is the thermal conductivity of the storage fluid (W · m −1 K −1 ) λ

Other approaches have been developed for specific cases. For example, the
zonal method was developed by Inard, Kenjo, and Caccavelli (2007) to take
into account the thermal stratification of a specific type of storage tank.
Shah and Furbo (1998) found correlations from experimental results taking