system drop in tests of r refrigerants d4y, n r air cooled

1 2014 Daikin Applied

System Drop‐in Tests of R‐134a Alternative Refrigerants D4Y, N‐13b, R‐1234ze(E) in an

Air‐Cooled Screw Chiller and a Water‐Cooled Centrifugal Chiller

Daikin Applied AmericasFrank CakmakciPhillip JohnsonKazushige KasaiMichael Zamalis


Refrigerants Tested

Water‐Cooled Air‐Cooled RefrigerantIPCC AR4(2007)

UNEP RTOC AR(2010)

Hodnebrog et.al.(2013) R‐134a R‐1234ze(E) R‐1234yf

● ● R‐134a 1430 1370 1300 100%● N‐13b ‐ 579 ~547 42% 58%

● D4Y ‐ ~551 ~521 40% 60● R‐1234ze(E) ‐ 6 <1 100%

R‐1234yf ‐ <4.4 <1 100%

Chiller Type CompositionGWP100


Equipment Description

• Centrifugal Chiller• Nominal 145 TonsR• Single compressor chiller• 2 stage, non‐economized• Variable Speed• Magnetic Bearing• Shell & Tube Heat Exchangers◦ Flooded evaporator

• Refrigerants◦ R‐134a (baseline)◦ N‐13b



• Test chiller built specifically for AREP testing• Test Location: Verona, VA

Compressor

IGV Motor2P

3P

4P


Test Methodology

• Drop‐in testing• Inlet guide vanes were held constant at 100% open• Speed controlled manually to achieve capacity• Electronic expansion device operated in manual control at each test point

• Charge amount optimized at full load point for each refrigerant


Performance of N‐13b

• Full load capacity was reduced by 15.2%• Efficiency relative to baseline of R‐134a:


Performance of N‐13b

% LoadCapacity

COP

R‐134a N‐13b R‐134a N‐13b

100 151 128 ‐15.2% 5.25 4.98 ‐5.2%

75 115 98 7.89 7.53 ‐4.5%

50 76 64 11.92 11.38 ‐4.5%

25 38 32 11.80 10.99 ‐6.9%

100 (high lift) 130 114 ‐12.3% 4.38 4.17 ‐4.7%

• IPLV (COP) was reduced by 4.9%• Additional high lift full load point for reference only◦ 44°F leaving evaporator, 100°F entering condenser



• 200 RT Air‐Cooled Screw Chiller◦ single refrigerant circuit◦ variable speed screw compressor◦ economizer refrigerant cycle◦ PVE type oil

• Refrigerants◦ R‐134a (baseline)◦ R‐1234ze(E)◦ D4Y



Capillary tubeExpansion valve


Test Setup & Protocol

• Drop‐in testing• Tests performed in accordance with AHRI 550/590• For each refrigerant, charge quantity optimized for best full load COP

• For each candidate refrigerant, compressor speed was set to the same value as for the baseline R‐134a.

• EEV of the test chiller was controlled automatically to maintain target values of superheat and subcooling.


Test Results

• Results relative to the baseline R‐134a


Test Results

• Results relative to the baseline R‐134a

Capacity COP RefrigerantQuantity

Predicted Actual Predicted Actual Actual

R‐1234ze(E) 75.0% 77.4% 101.0% 105.5% 104.3%

D4Y 97.0% 99.9% 98.0% 97.4% 110.8%

system drop in tests of r refrigerants d4y, n r air cooled

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