Studio ed analisi di sistemi di accumulo termico in

CLUB CAST3M
Paris 29-11-2012
Conceptual design of concrete thermal energy
storage system for small size concentration solar
plants.
(Overview on CAST3M application for the analysis
of components for solar plants employing molten
salts)
Giannuzzi Giuseppe Mauro
ENEA-UTRINN-PCI
R.C. Casaccia (Rome, Italy)
E-mail: giannuzzi@enea.it
Objectives of the SOLTECA project
Sensible heat storage in a specially developed concrete mix
Modular storage system, not cast in situ, reduction in the
degassing time at start up.
Working temperature between 120 e 300 °C, able to
operate a ORC power block
Cost containment - (between 20-30 € / kWh_th), (not
expensive O&M costs).
Small plants with peak power (0.5 to 5 MWe), more
placeable in the territory
The project is funded by the Cassa di Risparmio di Trento E
Rovereto (CARITRO)
Scheme of the available solar plant
with concrete TES
4
MCS
HX
5
M TES
3
TORCIN
MORC
TES
2
ORC
7
6
V2
V1
SOLAR FIELD
1
V3
PUMPS
GE
General scheme
with kind permission of DLR
Element-Module-System Scheme
Economic and Physical Features of Solid
Storage Media
TES: Physical Model
cp
Ts
t
2
ks
Ts
r2
1 Ts
r r
ks
c pVA
Tf
z
h 2 ri T f
Ts,w
cp A
Ts
r
h Tf
Tf
t
Ts ,w
Nonstationary Model
Tf ,j
t
V
t
Tf ,j
z
1
Tf ,j
t 1
2
ri z
h t
Tf ,j
cp A z
Tw, j
t 1
Tf ,j
t 1
Semi – Steady State Model
dT f
dZ
Nu
4
Tw T f
Pe
Fengwu Bai
Tf
Nonstationary Model: Charging Phase
Nonstationary Model: Discharging Phase
Effect of Thermal Conductivity on the
Charge Time
NON-STATIONARY MODEL: application to
a realistic case
Time of charging = 1h
Channel Length = 400 m
T Tf
Corners
exit
Schematic of the storage modulus HTCTRAN simulation
with thermo-hygrometric boundary condictions
T_f=300°C
H_f=100
W/m2-C
10 mm
P_a=1700 N/m2
B_a=0.2e-6 s/m
100 mm
T_a=25°C
H_a=5 W/m2-C
Radial Temperature at various time steps
Radial vapour pressure (MPa) at various time steps.
Radial water content (Kg/m3) at various time steps.
HTCTRAN - mechanical elastic coupling
T
u
DT d
T
d
T
DT m K sh dWd
T
db d
u
T
DT m
T
dt d
dp
d
3K s
m dp d
T
DT m
s
3
dT d
HTCTRAN – non-linear coupling
PASAPAS
HTC-NLM
Concrete TES Test Apparatus
ENEL ARCHIMEDE Plant : Parabolic Trough Loop
100 m
300 m
300 °C
with kind permission of ENEL
550 °C
Free Thermal deformation in Priolo Receiver Line
T
r = De /(
TS = 30 C
TS) = 126 m
T = 530 C
L= L
L = 48 m
T = 48 cm
f=L2/(8r) = 2 m
M th
E Jx r
EJ x
Tcf De
th max
E Re r
1
2
E
Tcf
Receiver Line Supports
with kind permission of ENEL
Receiver Support Kinematics
d
R
h
d
4090mm
Cold receiver length
4060mm
h2
2R
Hot receiver length at Tm y410°C
4090mm
Receiver line schematic, mesh, deformation
profile, reactions
a.t. lenght
410 C°
a.t.
Receiver line contraction and deflection
-37cm
-4.2cm
Mass flow and tracking stop accident
with kind permission of ENEL
Flux distribution on receiver surface
Heat released in the glass
Maxi-mini temperature evolution in receiver
Maxi-mini temperature evolution in glass
von Mises in receiver and glass at maxi-Dt
anim
Receiver Vibration
L.Mot.
-Circulating fluid and defocused trough
-Trough focusing
-Vibration amplitude-stabilized after about
2 min.
-Oscillation amplitude 2.6-3 mm
-Frequency 5.5-6 Hz
- The vibration stops after a minute from the
defocusing
Governing Equation of Piping with Moving Fluid
y
Ap
4
EI
x
y
4
A f (P0
f
2
0
V )
2
y
x
2
x
Af
2
f
A f V0
y
x t
f
Af
Physical interpretation of each term:
• 1- flexural restoring forces
• 2- centrifugal force of moving fluid and pressure
force associated with radius of curvature
• 3- Coriolis force
• 4- inertia force of tube and fluid
p
Ap
r
2
y
t
2
2
0
y x2
-1
M T x, t
E
T
Tenv y dA EI
A
M
EI
2
y
x
2
MT
T D
Tenv environment temperature
E modulus of elasticity
MT thermal bending moment
y moment arm
x position along x-axis
α coefficient of thermal expansion
Mechanical effect of thermal-axial gradient in storage tank
-Fatigue damage
(double tank)
-Thermal Ratcheting
(stratified tank)
Thermal Ratcheting due to axial gradient –MATTER Project
ENEA-ENEL
•Axial moving thermal
gradient at sodium-free
level
•Null-primary-stress
condition
Archimede Solar Plant Storage System
THERMAL RATCHETING FACILITY REALIZATION
P91 hollow cylinder
NaNO360%-KNO340%
600° C
• Specimen speed during immersion
• Heat transfer coefficient
•Molten salts temperature (up to 600°C)
•Cylinder diameter and thickness
NaNO360%-KNO340%
Thermal conductivity
Specific heat
Density
Viscosity
Melting Point
0,56 W/m K
1550 J/kg K
1700 kg/m 3
1 mPa sec
221°C
Performed Numerical Analysis
FIRST CYCLE 13-11-2012
Fatigue due to level variation (ASME III NH T-1400)
10,00
8,00
7,00
6,00
5,00
tem po [hr]
6.00
3.00
0.00
21.00
18.00
15.00
12.00
9.00
6.00
3.00
0.00
4,00
21.00
livello [m]
9,00
Critical strain range
strain range
internal side
livel 3m
external side
2,50E-03
limit 2.E4 cycles
m/m
2,00E-03
1,50E-03
1,00E-03
5,00E-04
0,00E+00
250
300
350
400
450
cover gas temperature °C
500
550
CLUB CAST3M
Paris 29-11-2012
THANK YOU FOR YOUR KIND ATTENTION