Transcript Use of Nanoparticles to Improve Heat Transfer in Heat Pumps

By: Reuben Downs
Faculty Advisor: Dr. Darin Nutter
Graduate Student Advisor: Wei Guo
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Refrigerant travels through evaporator coils changing from a liquid
to a vapor
Refrigerant travels through compressor changing from a low
pressure vapor to a high pressure vapor
Refrigerant travels
through condenser coils
changing from a high
pressure vapor to a high
pressure liquid
Refrigerant travels
through expansion valve
changing from high
pressure liquid to a
mixture of low pressure
liquid and vapor
http://oee.nrcan.gc.ca/publications/infosource/pub/home/gif/heatpump_fig2b_e.gif
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Stephen U. S. Choi [1] coined the term “nanofluids”
in 1995
Metallic and Metallic Oxide Particles used
◦ Enhanced heat transfer of heat transfer fluids
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Two Methods of Making Nanofluids
◦ One Step Method – Metallic Nanoparticles
◦ Chemical process
◦ Two Step Method – Metallic Oxide Nanoparticles
◦ Dry powder produced then dispersed in liquid
Size of
Nanoparticles
% Volume
Concentrations
Au
3nm
0.09%, 0.4%, 1.0%
R123,
R134a
Carbon
Nanotubes
20nm × 1µm
1.0%
Visinee Trisaksri
R141b
TiO2
21nm
0.01%, 0.03%,
0.05%
2009
Guoliang Ding
R113
CuO
40nm
0.15% - 1.5%
2009
M. A. Kedzierski
R134a
CuO
30nm
0.5%, 1.0%, 2.0%
Year
Investigator
Refrigerant Nanoparticles
2007
Da-Wei Liu
R141b
2007
Ki-Jung Park
2009
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Used a cartridge heater concealed in tube to heat
the nanorefrigerant
Fig. 1 Da-Wei Liu’s apparatus [2]
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1.0% concentration performed the best out of the
three concentrations
Fig. 2 Da-Wei Liu’s results for Different Concentrations of Nanoparticles [2]
Fig. 3 Da-Wei Liu’s results for test run on five day intervals [2]
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Degradations
◦ Tube Surface Roughness due to nanoparticles
◦ Particle Size Change (3nm to 110nm)
Fig. 4 Da-Wei Liu’s results for test run on five day intervals with
the tube cleaned for the last test [2]
Fig. 5 Ki-Jung Park’s apparatus [3]
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Ki- Jung Park [3] found that heat transfer was
enhanced up to 36.6% at low heat flux.
High heat flux – more bubble generation causes less
contact for carbon nanotubes
Fig. 6 Ki-Jung Park’s results for carbon nanotubes in the R123
refrigerant [3]
Fig. 7 Ki-Jung Park’s results for carbon nanotubes in the R134a
refrigerant [3]
Fig. 8 Visinee Trisaksri’s apparatus [4]
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Visinee Trisaksri [4] concludes that TiO nanoparticles
degrade the nucleate boiling heat transfer in the
R141 b refrigerant
Fig. 9 Visinee Trisaksri’s results for 0.05 vol% TiO2 nanoparticles in
R141b refrigerant vs. pure R141b refrigerant, both at different pressures
[4]
Fig. 10 Visinee Trisaksri’s results for 0.01 vol% TiO2 nanoparticles in
R141b refrigerant vs. pure R141b refrigerant, both at different
pressures [4]
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R113 – Liquid at room temperature
Fig. 11 Guoliang Ding’s apparatus [5]
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Nanoparticles can be released into the gas phase
◦ Guoliang Ding [5] calls it “bubble adhesion away”
Fig. 12 Guoliang Ding’s Results: “Migrated mass of nanoparticles vs. original
mass of nanoparticles in nanorefrigerant and nanorefrigerant-oil mixture." [5]
Fig. 13 M.A. Kedzierski’s apparatus [6]
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The 1.0% concentration of nanoparticles performed
better than the 2.0% concentration
Fig. 14 M.A. Kedzierski’s Results for CuO nanoparticles
(1.0% concentration) in a refrigerant-oil mixture vs.
refrigerant-oil mixture without nanoparticles [6]
Fig. 15 M.A. Kedzierski’s Results for CuO nanoparticles
(2.0% concentration) in a refrigerant-oil mixture vs.
refrigerant-oil mixture without nanoparticles [6]
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Developed a new model for determining the thermal
conductivity of nanofluids.
Resistance Network Method
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Calculates heat flux, thermal
conductivity, thermal conductivity
between two nanoparticles,
thermal conductivity of
nanoparticle cluster, thermal
conductivity of nanofluid
Difference between his experimental results and the
calculated results from his model for
nanorefrigerants was within ±5%.
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Purpose: To determine if any fouling occurs due to the nanoparticles in the
refrigerant.
Procedure:
◦ 1. Test and observe test surface roughness inside of the test pipe
◦ 2. Set up the apparatus by connecting all of the components (copper
couplings will be used to connect the test pipe) and charge the
nanorefrigerant.
◦ 3. Use the DC variable resistor pump to control the flow rate.
◦ 4. Remove the nanorefrigerant from the unit (vacuum) by the Schrader valve
and dismantle the test pipe.
◦ 5. Test and observe test surface roughness.
◦ 6. Record findings of any changes on the surface of the test pipe.
Description:
◦ Ten trials per pipe: Five Short times and Five long times
◦ Three different surface roughnesses
◦ Three different flow rates
◦ Copper Pipe
Refrigerant Mixture
Insert
Pressure relief valve
Schrader valves
Test Pipe
Valves
DC Pump
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A removable test surface will be inserted into the
test pipe
Test Pipe