Numerical modelling and experimental studies of thermal behaviour of building integrated thermal energy storage unit in a form of a ceiling panel

Jaworski, Maciej; Łapka, Piotr; Furmański, Piotr

doi:10.1016/j.apenergy.2013.07.068

Cited by 61 publications

(26 citation statements)

References 18 publications

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“…The presented model has been carefully verified and validated . In the verification, the correctness of both the implementation of the enthalpy‐temperature curve and the steady‐state solution of the 1D energy equation for the air flow (Equation ) were successfully proved.…”

Section: Numerical Modelmentioning

confidence: 90%

“…The numerical model of fluid and heat flow in the considered ceiling panel was developed and presented in detail by Jaworski et al and Łapka et al The model consists of two parts: the first one—3D—which accounts for heat transfer and phase change phenomena in the solid body of the panel, ie, in the gypsum‐microencapsulated PCM composite, and the second one—1D—which deals with fluid flow and heat transfer in air flowing through the U‐shaped channel. The energy equation for the 3D heat flow and phase change process in the composite material was the following:

ρ c_{p} ((),, T, history of T) \frac{\partial T}{\partial t} = \nabla k ((), T) \nabla T,

while the governing equation for the 1D incompressible air flow through the U‐shaped channel was as follows:

c_{p, a} ρ_{a} \frac{\partial T_{a}}{\partial t} + c_{p, a} ρ_{a} u \frac{\partial T_{a}}{\partial x} = k_{a} \frac{\partial^{2} T_{a}}{\partial x^{2}} + \frac{P_{c}}{A_{c}} h_{i} ((), x) ([], T_{a} - T_{w, m} ((),, t, x)),

where A c is the cross section area of the channel, c p is the specific heat, h i is the heat transfer coefficient at internal walls of the channel, k is the thermal conductivity, P c is the perimeter of the channel, t is the time, T is the temperature, T w , m is the temperature of the wall of the channel averaged over the perimeter, u is the air velocity, x is the coordinate along the U‐shaped channel, and ρ is the density.…”

Section: Numerical Modelmentioning

confidence: 99%

“…The internal heat transfer coefficient h i was estimated based on the following Nusselt number correlation for low Reynolds number internal turbulent flows (for the channel under study and air velocities considered, Reynolds numbers were in the range from 4200 to 6300; for more details see Jaworski et al and Łapka et al):

Nu = \frac{h_{i} d_{h}}{k_{a}} = \frac{((), f / 8) ((), {Re}_{a} - 1000) {Pr}_{a}}{1 + 12.7 {(f / 8)}^{0.5} ((), {Pr}_{a}^{2 / 3} - 1)} for ({, \begin{array}{c} 0.5 \leq {Pr}_{a} \leq 2000 \\ 3 \cdot 10^{3} < Re < 5 \cdot 10^{6} \end{array}),

where d h is the hydraulic diameter, Re a is the Reynolds number, Pr a is the air Prandtl number, and μ a is the air dynamic viscosity. The friction factor f in the turbulent flow was calculated assuming smooth tubes from the explicit first Petukhov equation given as:

f = {(0.79 ln Re - 1.64)}^{- 2} for 3 \cdot 10^{3} < Re < 5 \cdot 10^{6} .

…”

Section: Numerical Modelmentioning

confidence: 99%

“…For more details regarding the 1D‐3D numerical simulator and its verification and validation, see Jaworski et al and Łapka et al…”

Section: Numerical Modelmentioning

confidence: 99%

“…The thermal capacity of buildings may be easily increased by the application of PCMs into the building envelope. Therefore, the combination of the ventilation system with PCMs provides a low‐cost technique, which may be used to obtain comfortable indoor conditions in buildings during the summer …”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Efficiency optimisation of the thermal energy storage unit in the form of the ceiling panel for summer conditions

Łapka

Jaworski

2019

Int J Energy Res

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Summary The thermal energy storage unit in the form of the ceiling panel made of the gypsum‐microencapsulated phase change material composite with internal U‐shaped channels was optimised applying previously developed 1D‐3D numerical simulator. Calculations were carried out for variable inlet velocities of air, different properties of the composite expressed by enthalpy‐temperature curves, and summer climatic conditions in Central Poland (Warsaw). Optimal working temperature ranges of the composite were determined. Moreover, studies showed that for Central Poland, composites with wide ranges of the working temperature are preferred due to significant daily variations of ambient temperature during the whole summer.

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Section: Numerical Modelmentioning

confidence: 90%