LABORATORY TEST RIG FOR THERMAL ENERGY STORAGE

1. Design Simulation and Test Rig for Laboratory Scale
Latent Heat Thermal Energy Storage
Sumit Saha, Apurva Verma, Abhinav Bhaskar, Som Mondal
Department of Energy and Environment, TERI University, New Delhi
Contact: sumitincal@gmail.com apurvaverma1991@gmail.com
ACKNOWLEDGMENT
We sincerely thank Ministry of Human Resource Development (MHRD) for funding the project of Centre of Excellence in Thermal Energy Storage
under the initiative of Frontier Areas of Science& Technology (FAST) coeintes@teriuniversity.ac.in
• Stored energy in the form of latent heat can be
utilized to prevent mismatch between the
energy supply and the power demand as well as
for waste heat recovery
• A shell and tube type latent heat thermal
energy storage (LHTES) prototype unit is
developed for the experimental analysis
SEM-EBIC
CENTER OF EXCELLENCE IN
THERMAL ENERGY STORAGE
TERI UNIVERSITY
Solar station Andasol 3,
50 Mwe, 8 hours storage
TESTES
RegeneratorAircooledcondenser
Pump
HEX(Boiler)
4wf
3wf
2wf
5wf
6wf1wf
HTF,inHTF,in
Expander
,HTF sfm ,HTF power blockm 
wfm
Fraction of heat transfer
5
THTF,out
THTF,pinch
T2f
T2g
T3
THTF,in
Temperature
ΔTpinch
ΔTpinch
• Heat transfer fluid is incompressible and viscous heating is neglected
• The fluid flow is radially uniform, and the axial velocity is an
independent parameter
• Heat diffusion in the containment walls is considered only at the
fluid-PCM interface, i.e. zero thickness of the outer wall is assumed
• No natural convection inside the liquid PCM
• Convective terms due to contractions and expansions of the PCM in
the phase change are neglected
Differential scanning calorimetry (DSC) monitors heat effects
associated with phase transitions and chemical reactions as a
function of temperature and is a very informative method
in physical characterization of a compound.
DSC TEST RESULTS
Magnesium Chloride
(MgCl2.6H2O)
Hitec salt (53% KNO3 + 7%
NaNO3 + 40% NaNO2)
𝑾
FLUID
𝝏𝑯 𝑭
𝝏𝒕
+ 𝝆 𝑭 ∙ 𝒄 𝑭 ∙ 𝝑 ∙
𝝏𝑻 𝑭
𝝏𝒙
=
𝟒 ∙ 𝒉
𝑫
∙ [𝑻 𝑾(𝒓 = 𝒓 𝟏) − 𝑻 𝑭] + 𝒌 𝑭 ∙
𝝏 𝟐 𝑻 𝑭
𝝏𝒙 𝟐
WALLS
𝝏𝑯 𝒘
𝝏𝒕
=
𝟏
𝒓
∙
𝝏
𝝏𝒓
(𝒌 𝒘 ∙ 𝒓 ∙
𝝏𝑻 𝑾
𝝏𝒓
) +
𝝏
𝝏𝒙
(𝒌 𝒘 ∙
𝝏𝑻 𝑾
𝝏𝒙
)
PHASE CHANGE MATERIAL
𝝏𝑯 𝑷
𝝏𝒕
=
𝟏
𝒓
∙
𝝏
𝝏𝒓
(𝒌 𝑷 ∙ 𝒓 ∙
𝝏𝑻 𝑷
𝝏𝒓
) +
𝝏
𝝏𝒙
(𝒌 𝑷 ∙
𝝏𝑻 𝑷
𝝏𝒙
)
• To develop the best working models of heat exchanger for latent
heat thermal energy storage
• To create a thermal energy storage research platform for carrying
out fundamental studies with respect to different phase change
materials
• To use the results for ‘scaling’ heat exchanger performance in ideal
med-high temperature heat and power cycles
• To enhance the end-use application of such PCM based heat
exchanger from electricity generation during eclipse hours to
direct motive power utilization in solar air driers for remote areas
• C Bellecci and M.Conti, “Phase Change Thermal Storage: Transient
behaviour analysys of the solar receiver/storage using the
enthalpy method”, Inst. J. Heat Mass Transfer 1992; 36,pp. 2157-
2163.
• Gil A. et al., “State of the art on high temperature thermal energy
storage for power generation. Part 1—Concepts, materials and
modellization”, Renewable and Sustainable Energy Reviews 2010;
14, pp. 31–55.
GEOMETRY DESIGN
• 9 tubes of od 12.7 mm and length 416 mm
• Shell od of 88.9 mm and length 400 mm
• Flange od of 105 mm
• Cap od of 105 mm
GEOMETRY MESHING
• 187762 tetrahedral elements
• 25110 triangular elements
• Average element quality is 0.89
• Mesh volume 9899000 mm3
BOUNDARY CONDITIONS
• No slip condition on walls
• ‘Velocity inlet’ for HTF inlet
• ‘Outflow’ boundary condition for HTF outlet
• Darcy’s law and Ergun’s equation to calculate
viscous flow (4.878 × 106m-2)
• Re ~400 (laminar)
• Side configuration simulated as 3D geometry
𝑾
Charging Discharging
B1
HEX1
T3
T4
T5 T6
P
P
F5
L1
P6
F5
T5
Flow meter Pressure gauge Thermocouple