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An overview of Research in the Alternative and Renewable Energy
Sector at Villanova University Amy Fleischer
Professor, Mechanical Engineering
VCASE Focus Area: Alternative and Renewable Energy
Energy Systems
Energy Sustainability
Energy Efficiency
• Thermal management solutions for high power electronics.
• Phase change material energy absorption
• Waste heat to energy systems • Nanostructured thermal materials
development
• Energy-efficient system design for data center cooling and building HVAC systems
• Computational and theoretical analysis of heat and mass transfer in nanoscale and microscale systems
Faculty Team leads
Amy Fleischer Aaron Wemhoff
• Two Phase Change and Multiphase Flow and Heat Transfer on microstructured surfaces
• Renewable Energy Conversion and Storage (PEM Fuel Cell and Concentrating Solar Power)
• NanoAdditives for Biofuel Combustion
• Fluid Dynamics of Porous Media • Biomimicry
Qianhong Wu Calvin Li
• Synthesis and Characterization of Energy Storage Materials with Nanostructures
• Synthesis and Characterization of Nanoparticle Thin Film
Gang Feng G.F. Jones
• Heat Exchanger Analysis and Design • Solar Thermal Engineering and Technology • Heat Transfer in Electronics Cooling • Gravity-Driven Water Networks and Micro-
Hydroelectric Power Systems
• Renewable Energy • Solar Electric Engineering • Power Electronics
Pritpal Singh Nisha Kondrath
• Power Electronics
The A&RE team can • Leverage existing expertise in alternative energy
and energy efficient systems to: – Design systems to reduce overall energy consumption
and/or to store thermal energy for later use – Evaluate the energy and exergy efficiency of systems
to identify high impact areas – Design and evaluate various alternative energy
systems including fuel cells, gravity driven water networks and solar thermal systems
Energy and Exergy Efficiency Modeling Faculty member: Aaron Wemhoff
http://energyefficientillinois.com/comprehensive-home-energy-evaluation/
System Modeling Tool
Energy efficiency
1st-law efficiency: amount of energy
consumed by system
2nd-law efficiency: amount of lost work consumed by system
Calculations of Energy Efficiency
Exergy is “quality” of available energy
Exergy analysis provides an
apples-to-apples comparison of
different component efficiencies
Tool examines the destruction of
exergy Large exergy
destruction low second-law efficiency
Users can pinpoint the efficiency
bottlenecks in the system
Tool Development From Existing Applications • Connects HVAC and cooling
component models via a novel flow network.
• Tool is flexible. It can: – Be applied to a variety of systems – Adapt to new cooling
technologies – Integrate cooling component
models created by other team members
Physical Layout
Computational Model
Adapted from image by Marcelo del Valle
Racks
Subfloor
CRAH Chiller
Cooling tower
Racks
Subfloor
CRAH
Chiller
Cooling tower
The existing data center modeling tool divides the cooling system into interconnected component models of cooling equipment.
Energy Storage Faculty members: Amy Fleischer, Gang Feng, Aaron Wemhoff PCM absorbs heat (melts) when
supply exceeds demand PCM rejects heat (solidifies) when
demand exceeds supply
• absorb peak loading • steady-state system is smaller and lighter • saves money, space and weight.
Energy storage applications
Graphene-enhanced hybrid phase change materials for thermal management of Li-ion batteries, Journal of Power Sources 248 (2014) 37-43.
With PCM
Without PCM
http://www.thermalcore.info/product-info.htm
http://www.netspeed.com.au
http://thetomorrowcompany.com/energy-efficient-houses/
Organic Rankine Cycle • Benefits:
– on-site electricity production from waste heat – generation of chilled water for cooling – possible elimination of the need for a chiller due to complete
extraction of heat during the AR process – no issues with site co-location and the technology – can be retrofit into existing data centers if space permits.
• Challenges:
– not suitable for air cooled data centers – relatively low overall system efficiencies (5-20%) associated with the
low operating temperatures. – may be space issues when retrofitting systems to existing data centers
Advantages/Disadvantages
20
Use of structured surfaces for orders-of-magnitude higher heat transfer enhancement through liquid-vapor phase change in electronics cooling • Faculty member: Calvin Li
Boiling curve of nucleate boiling on modulated porous structure and uniform porous structure
Modulated Porous Structures
Li et al., International Journal of Heat and Mass Transfer, 2011
Multiscale surface structures
+
+
cm to m patterns
micron to mm features
nm surface modifications
• Ultra high heat flux capacities
• 100 W/cm2 to 400 W/cm2.
• 4x improvement in h
Modulated Porous Structures
Li et al., International Journal of Heat and Mass Transfer, 2011
Orders-of-magnitude performance enhancements
Ultra high heat flux capacity
Pattern structure: Change the bubble dynamics Delay the hydrodynamic instability of vapor columns. Features: Control Vapor nucleation Surface modifications: Enhance capillary pump liquid replenishing and active nucleation sites.
Flow Channel Area
Water Accumulation
Gas Diffusion Layer
Membrane Electrode Assembly
Capillary action
Turhan et al., Journal of Power Sources , 2008 Trung V. Nguyen, J. Electrochem., 1996
Thermal and Water Management of PEM Fuel Cell
25
Solar Thermal Technologies and Gravity Driven Water Distribution
http://www.tech-etch.com/photoetch/fuelcell.html
Faculty member: G.F. (Jerry) Jones
Solar Thermal Technologies - G F Jones • The Passive (no pump) Solar Thermal Diode
– Efficiently collects solar radiation during day – Water in reservoir heats by free convection from the diode tongue;
hot tongue below cooler reservoir – During sunless periods, tongue cools from exposure to the outside;
cool tongue below warm reservoir prevents free convection – only weak conduction
– Thus, device acts as a “thermal diode” • Outperforms all other passive solar collectors for home heating
• State and Needs – Performance is understood and
models have been developed – Use limited b/c optimization and
regional sizing guidelines do not yet exist; research and production needed
Optimization and Smart, Low-Cost Active Control of Gravity-Driven Water Networks
• most appropriate for developing regions that lack clean water access • Introducing cost minimization produces unique designs for GDWN
– Systematic cost minimization seldom done by any entity except Villanova; we have been doing this for more than a dozen years
• Major issues – Networks are passively controlled; fixed valve settings almost always wrong –
need low-cost, smart control valves – Correct network operations and need for correct valve types not fully
understood by most partners and operators • Pipe ruptures due to water hammer are common • Lack of understanding of need for appropriately sized throttling valves, flow cavitation,
proper valve closing & opening rates
– Research underway on K values for locally available globe valves (data do exist/not accessible) and on control valves
29
Optimization and Smart, Low-Cost Active Control of Gravity-Driven Water Networks – G F Jones
30 *Analysis and Design of GDWNs, G F Jones, John Wiley & Sons, 2011
Renewable Energy-Related Research in the ECE
Department
Faculty members: Pritpal Singh and Nisha Kondrath
Solar Cell Fabrication • Electrochemical Atomic
Layer Deposition (ECALD) to deposit thin films on ITO coated glass of: – CdTe – PbTe – superlattice structure of
CdTe/PbTe • Supervisor:
– Dr. Pritpal Singh • Students:
– Fei Qin (PhD Student) – Arlene Wangia (Masters
student)
Electrochemical Atomic Layer Deposition (EC-ALD) system
The model of the superlattice fabrication.
The structure of CdTe/CdS on ITO Solar Cell.
Power Electronic Converters • Development of
Control algorithms for DC-DC Converters
• Supervisors: – Dr. Nisha Kondrath
• Students: – Mace Al-Chalabi
(Masters) – Soroush Tafvizi
(Masters)
Energy Storage • Battery monitoring • State-of-charge estimation • State-of-health estimation • Supervisors:
– Dr. Pritpal Singh
• Students: – Rita Atallah (Masters)
Microgrid Research Power System Dynamics and Stability
• Large signal stability analysis of microgrids using Lyapunov techniques
• Supervisor: – Dr. Pritpal Singh
• Student: – Mahmoud Kabalan (PhD Candidate)
Demand Side Management • Prediction algorithms for:
– electricity demand – wind generation
• Supervisor: – Dr. Pritpal Singh
• Student: – Stephen Suffian (PhD
Candidate)
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Microgrid Research – Cont’d • Rural electrification
research • Supervisor:
– Dr. Pritpal Singh • Students:
– Saul Nunez (Masters) – John Beyer (Masters) – Mahmoud Kabalan
(PhD Candidate)