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/

www.nrel.gov

565°C

300°C

Concentrating Solar Power Plant

% Improvement in Thermal Conductivity

Waste Heat to Power Faculty members: Amy Fleischer, Jerry Jones

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.

PEM fuel cell

http://www.tech-etch.com/photoetch/fuelcell.html

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

Thermal and Water Management of PEM Fuel Cell

26

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)

02

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810

1

1.2

1.4

1.6

1.8

2-1.5

-1

-0.5

0

0.5

1

1.5

x 10-3

time in seconds

machine speed deviations

internal generator number

speed in p

u

-0.4 -0.2 0 0.2 0.4 0.6-0.5

0

0.5

θ (rad)

ω (

rad/s

)

Microgrid Research – Cont’d • Rural electrification

research • Supervisor:

– Dr. Pritpal Singh • Students:

– Saul Nunez (Masters) – John Beyer (Masters) – Mahmoud Kabalan

(PhD Candidate)

Power Equipment 5 kW hydrogen fuel cell

Micro hydroelectric simulator

Transmission line simulator

Conclusions • The Villanova Alternative and Renewable

Energy Focus team has extensive experience in energy efficient and sustainable energy designs

• Open to new collaborations with academia and industry