Transcript Waste Heat Recovery from PV Panels FINAL PRESENTATION

Waste Heat Recovery from PV Panels
FINAL PRESENTATION
Background
• Started from Solar Decathlon
HU/ODU Project
• SunDrum’s role as a heat
recovery unit for this project
Testing Rig’s Function
• Water, which is pumped through
the heat recovery units, carries
the waste heat produced by the
PV panels during system
operation to a hot water tank.
• The PV panels capture the sun’s
energy, which is dissipated into
a pair of variable resistance
heatsinks. Heat recovery units
(SunDrum) are attached to the
back of 3 panels (6 total).
Experimental Process
• Main Goal: To monitor and quantify the removal and capture of waste
heat from back of PV panels
• Variables which will be measured:
• Primary - Temperature rise of water in tank and of the fluid flow through closed
loop.
• Secondary - Data as provided by Tigo (Power production) and panel surface
temperature (infrared laser thermometer gun)
Panels
with
SunDrum
Junction
boxes
(resistors
&
breakers)
Pump
station
MMU
Hot water
tank
Plumbing/Water System
•
Installation of flexible piping between Sundrums
•
Connection of pump to closed loop system
•
Installation of hot water tank as heat dump
•
System filled and pressurized.
TIGO-Data Acquisition
Three pieces of Tigo
equipment
• Maximizer
• Module Management
Unit (MMU)
• Gateway
Electrical System
• Design:
•Variable resistance heatsinks
provided load for panels.
•Resistors/breakers inside weather
rated enclosures, mounted to lower
wooden structure
•Clamp affixed to a grounded pipe
acted as the main ground
connection.
Results
● The graph to the
right shows the
three measured
temperatures
throughout a day
with favorable
conditions.
● It is worth noting
that pump was left
running
overnight, which
cycled that heat
which recovered
by the SunDrums
back out of the
tank.
Results
● The graph to the
right shows the
three measured
temperatures
throughout a day
with favorable
conditions.
● It is worth noting
that pump was
turned off
overnight, which
had a profound
effect on the
amount of
retained heat in
the tank.
Results
● The graph to the
right shows the
three measured
temperatures
throughout a 36
hour period.
● Power increase
between the
panels with
SunDrum and
those without was
roughly 12%.
Rainy
day
Coldest
Night
End of
day
Conclusions
• After observation of the tank temperature at the end of each
testing session, it was determined that 3 units alone would not be
sufficient to provide enough heat for domestic hot water usage.
• Temperature to safely kill off formation of Legionella bacteria,
source of Legionnaire’s disease, is 140F. Final tank temperature on
clear days was on average ~104F (when pump was running) and
122F (when pump was off).
• Resistance limitations-The resistors which were in place were found
to be operating at a higher resistance (~130 Ω) than what was read
from the specification sheet (47 Ω). This limited power output, and
subsequently, heat removal potential.
Modifications
To increase power output
• More suitable resistors
To increase maximum temperature of hot water tank
• Surface color of SunDrum
• Higher current PV Panels
To increase rate of heat transfer
• Plumbing connections in parallel
Variable Resistors
• Resistor temperature increased
up to 330 degrees F
• ↑ resistor temperature causes
↓ resistance
• Bosch PV Panel maximum
current ~ 8 amps
• By equation P=RI^2, ↓
resistance causes ↓ power
output
Surface Color of SunDrum Units
• Maximum achieved temperature of hot
water was 122°F. Goal temperature for
domestic application is 140°F
• Maximum temperature of hot water
tank ~ temperature of the back of PV
panels
• Limiting factors are PV panel and
SunDrum surface temperatures
• Increase temperature by maximizing
absorption of solar radiation with matte
Gantt Chart
Questions?