The Far Horizon for HVAC and Appliances

The Far Horizon for HVAC and Appliances

Abigail Daken

Phoenix, AZ

September 5, 2018

This Photo by Unknown Author is licensed under CC BY-NC

http://flickr.com/photos/frostnova/1783668500

https://creativecommons.org/licenses/by-nc/2.0/

Is Product Efficiency Running Out?

• > 30 years of product efficiency

standards

• Many simple advances made

• Chasing diminishing returns

No! Reframe • Controls and system efficiency

• Radically new approachesThis Photo by Unknown Author is licensed under CC BY-ND

http://www.thelastamericanvagabond.com/social-change/eight-signs-world-undergoing-paradigm-shift/

https://creativecommons.org/licenses/by-nd/4.0/

Postcards from the Horizon

• Bob Swilik, Carrier: 5 year context: market and regulatory changes

• Dennis Nasuta, University of Maryland/Optimized Thermal Systems: Advanced heat exchangers: small size, weight and charge

• Xioabing Liu, Oak Ridge National Laboratory: Reducing cost and increasing flexibility of GHP

• John Whinery, Lennox: Controls potential on 5 year time scale

• Ayyoub Momen, Oak Ridge National Laboratory: Radically new dehumidifier technology

We can rebuild it…

• Same efficiency, lower cost

• Additional product capabilities

• Higher efficiency

4

Mix and Mingle

5

You Are Here

ORNL is managed by UT-Battelle, LLC for the US Department of Energy

Innovative Low-Cost Ground Heat Exchanger for Ground Source Heat Pump Systems

Xiaobing Liu, PhD

9/5/2018

For ESPPMUnderground Thermal Battery

Conventional Ground

Heat Exchanger

22 Open slide master to edit

Challenges

• Climate change and economic development

• Grid resilience and intermittent operation of renewable power

Primary Energy Saving Potential of GSHPs in Each County

(Source: Liu et al. 2017)

(Trillion Btu)

“Duck-curve” Effect with Steep Ramping Needs and Overgeneration Risk

(Source: CAISO 2013)

• Ground source heat pumps (GSHPs) have huge potential to reduce energy consumption and carbon emissions, but the cost of ground heat exchangers (GHXs) must be reduced


Since ground temperature below 30

ft from the grade is constant, and

only the inside of the borehole can be engineered, why drill deep with

small boreholes?

• Previous R&D focuses on improving borehole heat

transfer

– Thermally enhanced grout

– High-performance plastic pipe

– New heat exchanger design

• Cost reduction potential is limited

– Relatively small impact on overall ground heat

transfer

• Drilling contributes the most to the overall GHX

cost (~$3K/cooling ton)

Preparation,

19%

Drilling related,

74%

Post

process,

7%

GHX Cost Breakdown by Tasks

Double-

U

Single-U Co-axial

Multi-U (“Twister”)

Spiral Loop

20

0 -

60

0 f

t

How Can We Reduce GHX Costs?


• Low cost due to less drilling (<20 ft)

• Large heat capacity from mass of water and phase change materials (PCMs)

• Rechargeable with natural heat sink and heat source (e.g., geothermal, solar, air)

Pending US Patent 62/672,921

0

500

1000

1500

2000

2500

3000

3500

4000

VBGHX UTB (Est.)

Inst

alle

d C

ost

[$]

Other

Site Restoration

Charging Loop

Pressure/Flow Test

Flushing & Purging

Looping

Grouting

Heat Exchanger

Drilling

Mobilization

Site Evaluation

30% cost reduction

Drilling

Next-Generation GHX: Underground Thermal Battery (UTB)


UTB vs. Conventional Vertical Bore Ground Heat Exchanger


Performed computational fluid dynamics simulations and built a small-scale prototype to characterize performance of UTB

4 f

t

8 in

Water

tank (with

PCMs

immersed)

Sand

tank

Heat

exchanger

Insulated

tube

Rotameter

Pump

Heater/

cooler

T – Thermocouple

P – Pressure transmitter

W – Wattmeter

Six thermocouple trees inside

UTB and surrounding soil

Current Status


Potential Impacts

• Reduce energy consumption and carbon emissions by electrifying space heating and water heating with GSHPs

• Stabilize electric grid by enabling active transactive controls without sacrificing thermal comfort

• Match renewable power supply with thermal energy demand by load shifting

UTB

Hybridize with other low-grade heat sink/source (e.g.,

air, solar thermal, wastewater

UTB

Match thermal demand with electricity supply → reducedpeak electricity demand and

improved stability of grids

Replace expensive (vertical) or large area

(horizontal) conventional GHXs

Sky cooling ASHP

RE


• Investigate feasibility of applying UTBs in cold climates

• Introduce UTB to GSHP industry for field tests and improvement

• Collaborate with utilities to apply UTB for transactive controls

• Engage with industry partners to manufacture UTB as a self-contained product

• Revolutionize heating, ventilation, and air-conditioning equipment with new-generation GSHPs

Next Step


Thank You

Oak Ridge National Laboratory

Xiaobing Liu, PhD

[email protected]

1U.S. DEPARTMENT OF ENERGY OFFICE OF ENERGY EFFICIENCY & RENEWABLE ENERGY

Mechanical Dehumidification Using

High-Frequency Ultrasonic Vibration

Performing Organization(s): Oak Ridge National Laboratory

PI Name and Title: Ayyoub Momen, Subprogram Manager for HVAC&R,

Water Heating, and Appliances

PI Tel and/or Email: [email protected]

mailto:[email protected]


Project Summary

• Start date: 10/1/2017

• Planned end date: 9/31/2019

Key Milestones

• Milestone 1; Evaluate absorption and mechanical

water ejection rate of piezoelectric/

desiccant, 9/31/2018

• Milestone 2; Evaluate first-generation system,

3/31/2019

• This will make the dehumidification process 3-

5 times more efficient than in current state-of-

the-art vapor compression dehumidifiers.

• Bench-scale stand-alone humidifier module of

0.1 L/day capacity in a laboratory environment

will be developed.

• This aligns with MYPP for BTO’s

dehumidification target.

Timeline: Key Partners:

Project Outcome:


Team:

ORNL Team

BTRICMembrane

and separation team

STEMiNC Inc.

Virginia Tech.

Power Electronics and

embedded systems

Shima Shahab

Assistant Professor, VT

Piezoelectric energy harvesting,

Acoustics and Dynamics,

and Mechanics of Materials

Martins Oswalnyr

President, CEORoger Kisner

Distinguished R&D Staff

Kyle Reed

PhD student

Brian Bischoff

R&D Staff

GO! Program PhD student at ORNL

• Modeling and evaluation of the piezoelectric

transducers

Ayyoub Momen

PI & R&D Staff

Viral Patel

R&D StaffKashif Nawaz

R&D Staff

Eric Dupuis

PhD student

• Exp. Design & Analysis

• Prototype fabrication

• Model development

• Membrane fabrication• Custom piezo fabrication

• Power Drive/Amplifier

development


Technology Background/History

Ultrasonic Clothes Dryer:

• The team invented and developed ultrasonic clothes

dryer technology in 2015-17.

• It is shown that high frequency vibration of

piezoelectric transducers can mechanically remove

water from the wet fabric in the form of the cold mist

(bypassing water latent heat of evaporation).

• Drying efficiency improved by 5X

(1/5th of power input).

Take-Away Message:

Don’t evaporate water, shake it out

http://money.cnn.com/2016/06/21/technology/ultrasonic-dryer/index.html

http://www.bbc.com/news/technology-39643452


Challenge

• Latent load ~ 40% of the cooling load of buildings.

• Withdrawing moisture from the air can significantly improve the performance of the HVAC systems

(Separate sensible and latent cooling (SSLC) systems).

• Dehumidification is conventionally achieved by vapor compression cycle by cooling air below the dew point

to condense water and reheat- A highly inefficient process for dehumidification.

• Liquid/solid desiccant dehumidification systems are 30-50% efficient compared to the VC based systems-

Regeneration of the desiccant materials and management of the heat of sorption are critical issues.

• Innovative solution is needed to avoid the intense heat needed for regeneration

Efficiency:972–3000 kJ/kg water removalSource: http://chem.engr.utc.edu/Webres/435F/Dehumidifier/Dehumid/R5-435-1.html


Approach

The Solution: Bypassing the heating-based regeneration!

We have already shown that piezoelectric vibration could significantly boost the drying

efficiency.

Capillary

condensation mechanical

water removal

(ultrasonic

vibration)

Moist

air

Dry

air

Typical electric resistance

clothes dryers


Approach

Fabrication process for small pores on sheets

Desiccant identification

Integration with appropriate piezo

Evaluation of the water ejection rate

Evaluation of the water absorption rate

Evaluation of the water ejection rate

Pick the best method

Fab./Eval. 1st gen. prototype

Fab./Eval. Final gen. prototype

Mo

del D

evelop

men

t

Year 1Year 2

Capillary condensation:

2ln m

sat m

VP

P r RT

Step 1: Capillary condense water out of the air

Step 2: Mechanically eject water out

Decision criteria:

Cost/scalability/Performance


Advantage, Differentiation, and Impact

‒ Introducing a new dehumidification process (proof of

concept prototype capacity ~ 0.1 l/Day)

‒ 3-5 times more efficient dehumidification process (~250

kJ/kg of water removal compared to 372-3000 kJ/Kg in

conventional systems). This translates to 32-85%

operating cost savings.

‒ Grid tie flexibility (eco mode/ performance mode)

Knobs: voltage, and duty cycle.

‒ Opens up new opportunities for Separate sensible and

latent cooling (SSLC) systems due to 48% enhanced

efficiency and 30% compactness.

‒ The technology can save 715 TBtu of energy annually by

2030

‒ This amount of savings would support 6,020 new jobs

over 10 years

Target Market:‒ Short term: Residential and commercial dehumidifiers

‒ Long term: SSLC for HVAC


Screening the viable manufacturing processes

Identified the viable manufacturing processes for fabrication of capillary pores:

Various micromachining processes and specifications

Technology / Feature

Geometry

Minimum Feature

Size / Feature

Tolerance

Feature

Positional

Tolerance

Materials

Removal Rate Material

Dual-beam SEM/FIB

(fused ion beam)

200 nm / 20 nm 100 nm 5 μm3/s Any

3D direct-write fab

(LASER lithography)

1 μm / submicron submicron 40,000 μm3/s Polymers, ceramics,

metals

Atomic layer

deposition

10 nm / 2 nm 100 nm NA Polymers, ceramics,

metals

Helium-ion milling 5 nm (10–15× better

than fused ion beam)

10–20 nm 5 μm3/s Polymers, ceramics,

metals

E-beam lithography 4 nm 10–20 nm 1 μm3/s Metals

Micromilling/

microturning (2D/3D)

25 μm / 2 μm 3 μm 10,000 μm3/s PMMA, Al, brass,

mild steel

Micro-EDM sinker or

wire (2D/3D)

25 μm / 3 μm 3 μm 25 million μm3/s Conductive

materials

LIGA (2D) 0.02–0.05 μm /

submicron

~0.3 μm NA Cu, Ni, polymer,

ceramics

Focused ion beam E-Beam Lithography

Laser Lithography

Atomic Layer Deposition Helium-ion Milling


Progress: Paths currently under investigation

Organized structures

MeshUn-organized structures

Tubular design

Un-organized structures

Coating on the piezo


Promising Initial Results:

Nano perforated plate of Aluminum Oxide

Moisture adsorption/desorption behavior of the AAO

sample measured by dynamic vapor sorption device

The transient and steady state response of

the sample were recorded using dynamic

vapor sorption and were used to calculate

the moisture diffusivity of the sample using

appropriate model.

Following important observations were made:

• The desorption rate for the sample is

higher compared to the adsorption rate

(45% RH to 85% RH compared to 85% RH

to 45% RH).

• The sample can absorb around 5.0% of

the dry mass under extreme conditions.

• There is a minor hysteresis (0.275%) in

adsorption and desorption processes.


Experimental Validation

(1)

(5)(2)

(3)

(4)

(1) Single point laser vibrometer

(2) Amplifier

(3) Data acquisition unit

(4) Mounted transducer

(5) Scanning vibrometer

(4)

(4)


Remaining Project Work

Achieved in the last 6 months:

‒ Develop or identify viable capillary fabrication processes

‒ Design high-volume-density pores in sheets of material

‒ Preliminary measurement of the condensation kinetics

‒ Piezo model successfully developed (both analytical and FEM)

Remaining work for the next 18 months:

‒ Develop small-scale perforated sheet

‒ Evaluate absorption and mechanical water ejection rate of piezoelectric/

desiccant

‒ Tie piezo model to the adsorbing material

‒ Fabricate first-generation system

‒ Evaluate and improve first-generation system


Thank YouPerforming Organization(s): Oak Ridge National Laboratory

PI Name and Title: Ayyoub M. Momen, R&D Staff

PI Tel and/or Email: [email protected]

BTRIC


REFERENCE SLIDES


Progress

1/34/34ca f

3density [kg/m ]

surface tension [N/m]

excitation frequency [Hz]f

Eric Dupuis, Ayyoub M. Momenb, Viral K. Patel, and Shima Shahaba Multiphysics modeling of mesh piezoelectric atomizers,

SPIE, March 2018.


Stakeholder Engagement

Communication:

- Weekly meeting among the ORNL team

- Bi-Weekly meeting with Virginia Tech.

- Bi-weekly meeting with the whole team including the industrial partner

Team members role:

ORNL’s BERG:

Early stage research on Nano structures, Nano pores, viable

manufacturing process, rate measurements, integration of the piezo and Nano

pores.

- ORNL’s membrane team:

Developing the proprietary membrane to enhanced capillary condensation

- ORNL’s GO! PhD student from Virginia Tech:

Developing the comprehensive analytical and FEM models

Guide the design

September 10, 2018 1This document contains information proprietary to Optimized Thermal Systems (OTS), Inc. This document and the

contained information cannot be used, copied, transmitted, fully or partly, without prior written authorization of OTS, Inc.

Advanced Heat Exchangers for the Future of

HVAC and Appliances

Dennis Nasuta



Motivating Factors

Major contributor to losses

Common target for cost reduction

Flammable refrigerants and charge limitations

HXs contain majority of refrigerant charge



• 6 tube diameters (5 mm, 1/4”, 7 mm, 5/16”, 3/8”, 1/2”)

• 6 fin types (flat, wavy-smooth, wavy-herringbone, slit, louver, wavy-louver)

• 10 fin densities

• 10 tube lengths

• 10 vertical pitches

• 10 horizontal pitches

• 10 circuitries

• …

• Already 3.6 million designs!

HX Design Options

How many ways are there to design a tube-fin heat exchanger?At least:



• Modeling tools, availability of empirical data,

and optimization

• Computational Fluid Dynamics (CFD)

• Manufacturing

– E.g. microchannels, small-diameter tube-fins,

additive manufacturing

Solutions

❑ What tools do we have to solve this problem?

Image: Burr Oak Tool



• Should be mathematically-rigorous!

• Can yield significant gains with conventional technology

Near-Term

Window AC: 40% lower condenser cost

10% less refrigerant (system)

4% higher COP

❑Optimization

Domestic refrigerator:41% reduction in

condenser internal volumeHeat Pump Water Heater

>78% more capacity in same space

Image: Sub-Zero Image: Friedrich

Image: A.O. SmithImage: PNNL

Split AC:Up to 50% material cost savings

70% volume reduction80% charge reduction



Future of Heat Exchangers

0

10

20

30

40

50

60

70

80

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0

Air

sid

e S

urf

ace

Den

sity

(cm

²/cm

³)

Tube Diameter (mm)

Finless Round Tubes

Finned Round Tubes

(20 FPI)

Material Utilization (cm²/cm³)

100 100010

Internal Volume (cm³)

80 8008

Surface Area (m²)Surface Density =

Volume (space occupied, m³)



Future of Heat Exchangers

0

10

20

30

40

50

60

70

80

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0

Air

sid

e S

urf

ace

Den

sity

(cm

²/cm

³)

Tube Diameter (mm)

Finless Round Tubes

Finned Round Tubes

(20 FPI)

Material Utilization (cm²/cm³)

100 100010

Internal Volume (cm³)

80 8008

State of the artCurrent Interest

Nex

t G

ener

atio

n o

f H

X’s

(N

GH

X)

Surface Area (m²)Surface Density =

Volume (space occupied, m³)



>100% higher heat transfer coefficient than microchannel

Next Generation Concepts: Optimization and Design

Bare Tube Heat Exchanger:0.8 mm diameter

Shape-optimized heat exchanger:



Next Generation Concepts: Prototype ManufacturingStainless steel finless construction 3D-printed Titanium



Thank you for your interest in [email protected]



• Bacellar, D. 2016. Airside Passive Heat Transfer Enhancement using Multi-Scale Analysis and Shape Optimization, for Compact Heat Exchangers with Small Characteristic Lengths. PhD Dissertation, University of Maryland, College Park.

• Bacellar, D., Aute, V., Huang, Z., & Radermacher, R. 2017. Design optimization and validation of high-performance heat exchangers using approximation assisted optimization and additive manufacturing, Science and Technology for the Built Environment, 23:6, 896-911

• Cotton, N., Rhoads, A., Bortoletto, A., Shabtay, Y. 2018. Optimization of MicroGroove Copper Tube Coil Designs for Flammable Refrigerants. Purdue Refrigeration and Air Conditioning Conference, Lafayette, IN, July 19, 2018.

• Domanski, P., Henderson H., Payne, V., Sensitivity Analysis of Installation Faults on Heat Pump Performance, NIST Technical Note 1848, October 2014.

• International Copper Association. 2017. In The Spotlight: Friedrich and OTS Optimize AC Coil with CoilDesigner. Microgroove Update Vol. 7 Issue 1, May 2017

• Nasuta, D., Sarpotdar, S., Martin, C. (2016). Comparative Study of Optimized Small Diameter Tube-Fin Heat Exchangers Vs. Traditional, Larger Diameter Tube-Fin Heat Exchanger Designs. ASHRAE Winter Conference, Las Vegas, Nevada, January 26-February 1, 2017.

References



• 30% refrigerant undercharge can lead to 17-23% increase in energy use (Domanski et al., 2014)

• Advanced serpentine heat exchangers project (DE-EE0007680) aims to reduce leakage, minimizing direct AND indirect emissions and mitigating flammability risks

• 70-85% reduction in number of joints without reducing thermal-hydraulic performance through CFD-based optimization techniques

Near-Term

❑Minimizing Faults



Future of HX Design

Approximation Assisted Optimization (AAO)Concept Heat

ExchangerParameterize

Geometry

Manufacturing Constraints

Current Technology

HX Volume

Air

ΔP

BestDesigns

ManufacturableDesigns

Optimized HX

HX Volume

Air

ΔP Current

Technology

Optimized HX

BestDesigns

Approximation

DOE

PPCFD

Air ΔP / HTC

Optimization

Optimizer New Design

Assemble HX(CoilDesigner®)

Air ΔP, Volume, Matl’, Heat Load,…

Reusability



Next Generation Concepts

h

(W/m².K)70

400

MCHXNTHX-001

RTHX-0.8mm

(In-line)

NTHX-OPT03

NGHX13

(Abdelaziz et al., 2010)

NTHX-OPT01 NTHX-OPT02

-1

0

1

2

3

4

5

6

7

8

9

-1 4 9 14 19-1

0

1

2

3

4

5

6

7

8

9

-1 4 9 14 19

-1

0

1

2

3

4

5

6

7

8

9

-1 4 9 14 19

-1

0

1

2

3

4

5

6

7

8

9

-1 4 9 14 19

RTHX-0.5mm

RTHX-0.8 mm

FTHX-0.5mm



Next Generation Performance

UTC Climate, Controls, & Security Confidential and Proprietary Information – Not for further Distribution

HVAC CHALLENGE

Refrigerant ComplexityHigh Efficiency

2024 phasedown

2006 2015 2023

30%40%

60%

Today Future


OTHER OPPORTUNITIES

Smart AppliancesTechnician

Shortage

Installation right

the first time

Pinpoint

diagnostic done

right the first time

Ongoing

information and

adjustment


HFC PHASE DOWN2019

2024

2029

2034

2036

HF

C c

onsum

ptio

n Without phase down

Phase down

2024 first HVAC phase down

35%-50% of volume year one

Refrigerant 2029 to 2034

Mildly flammable refrigerant


FUTURE SYSTEMS

More environmentally friendly

2023 -16 SEER New Construction

At least 2-stage above minimum

Sell up - Smart – Very Smart

Installation analysis

Diagnose themselves and house

Connect to cloud

Far Horizons HVAC Possibilities of the IOT Home for HVAC

Future Home

Smart Homeowner

If This, Then That

Oven informs A/C

Shower informs fan & dehumidifier

CO2 from bedroom informs night setback

Front door handle informs lights & A/C

Constant Monitoring

Smart HVAC System informs homeowner

and contractor of required service call,

before failure!

Technology – Faster, Smarter, Smaller

Geo-Fence

Learning

Smart

Predictive Maintenance

Simplified Troubleshooting

Performance Evaluation

Variable Speed Control

Auto Commissioning

Ultra Smart Intuitive

Technology Enablers & Interactive HVAC

Smart Equipment

Heat Cool Ventilate

Intelligent Home Temperature Relative Humidity IAQ, CFM Weather Occupancy Lights Appliances

Temp RH

CFM

Capacity Power Status

Wireless Connectivity

& Cloud

Secure Transfer & Storage

Phone Pool Car

The Far Horizon for HVAC and Appliances

Documents

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