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Evaluation of compressor durability with new low GWP

Blend Refrigerants

William R. Hill, MACRAE, LLC

Andreas Rittsche, ILK Dresden

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Background

Supplier Evaluations and Results ◦ Test Schedule

◦ Compressor Wear

◦ Oil Analysis

Results of testing at ILK Dresden ◦ Test Schedule

◦ Refrigerant analysis

◦ Oil Analysis

◦ Other Observations

Conclusions

Overview of Presentation

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Background

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Members of the MAC Refrigerant Blend

Cooperative Research Program

sponsored and supported these

activities ◦ Comparative durability tests were run with

R134a and AC6 refrigerant to confirm that

AC6 is acceptable for use in mobile air

conditioning systems

Compressor durability at supplier partners were run

Compressor durability was also run at ILK

Specially developed test rig, running R134a and

AC6 side-by-side

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Supplier Test Schedules

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Each compressor supplier [shown below]

from the MRB CRP selected a test schedule

to do this preliminary durability assessment

Test done in supplier lab at their expense

AC6 refrigerant supplier by Mexichem

R134a refrigerant supplied by testing lab

Oil for use with each compressor/refrigerant

combination selected by supplier

Evaluation criteria base on each supplier normal

criteria for acceptance

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Supplier A

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Test Schedule

Parameter Cycle 1 Cycle 2 Cycle 3

Time [h] 333 333 333

Compressor Speed [RPM] 1000 4000 6000

Evaporation Pressure [kPa] 450 300 280

Condensing Pressure [kPa] 2900 2300 2250

R134a AC6

Capacity

Not Run

Efficiency

Noise

Wear

Results

Hardware

Compressor Medium Variable compressor

System Small Car MAC system

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Supplier B

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Test Schedule

R134a AC6

Capacity

Efficiency

Noise

Wear

Results

Hardware

Compressor Medium Variable compressor

System Water Cooled Condenser

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Supplier C

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Test Schedule

R134a AC6

Capacity

Efficiency

Noise

Wear

Results

Compressor Small Variable compressor System Small Car MAC system

Hardware

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Supplier D

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Test Schedule

Parameter

Time [h] 400

Compressor Speed [RPM] 1000

Compressor Discharge Temp [deg C] 450

Condensing Pressure [kPa] 3100

R134a AC6

Capacity

Efficiency

Noise

Wear

Hardware

Results

Compressor Medium Variable compressor

System Water Cooled Condenser

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Conclusions - Suppliers

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Initial screening tests have been completed

in compressor supplier labs with AC6 as

compared to R134a

No significant differences were noted in the

performance of the compressors with these

two refrigerant alternatives during these tests

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Durability Test at ILK Dresden

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Main Objective was to analyze any breakdown of the

refrigerant and oil that may occur at severe

conditions over extended operation

Desiccant was saturated with H2O at the beginning

of the test to simulate worst case conditions for

break down of refrigerant and oil

Conditions for compressor were high load at three

different speeds

Two compressors were run at once with identical

systems AC6 refrigerant in one system

R134a refrigerant in the parallel system

ILK Experimental Set-up

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Tests at ILK Dresden

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Test Schedule

Parameter Cycle 1 Cycle 2 Cycle 3

Time [h] 333 333 333

Compressor Speed [RPM] 1000 4000 6000

Evaporation Pressure [kPa] 450 300 280

Condensing Pressure [kPa] 2900 2300 2250

Hardware

Compressor Medium Variable compressor

System Midsize car MAC system

Desiccant Saturated with H2O at beginning of test

Compressor Supplier X

R134a AC6

Refrigerant

Oil System Components

Compressor

Results

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Compressor A / Oil A AC6 Refrigerant Contaminates

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Major Contaminates are those

expected with AC6

No significant change over time

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Compressor A / Oil A

R134a Refrigerant Contaminates

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Major Contaminates are those expected with R134a

No significant change over time

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Oil analysis During Test

No significant

differences in the

results from the two

refrigerants

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Compressors after Test

PAPER #

AC6 R134a

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Conclusions

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No difference in system, component wear,

refrigerant, or oil, were detected in system

test at ILK

Initial screening tests for compressor

durability were successful

AC6 is acceptable to proceed to more

extensive durability testing once oil

optimization is completed