International Safety Standards International Safety Standards (ISO & IEC) and Flammable (ISO & IEC) and Flammable

RefrigerantsRefrigerants

Advancing Ozone and Climate Protection Technologies: Next Steps

29-30 June 2013Bangkok

Osami KataokaJRAIA

Advancing Ozone and Climate Protection Technologies: Next Steps the technology conference

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ContentsContents

1. Introduction

2. International Standard

3. Refrigerant Safety and Climate Change

4. Accident Statistics of Japan 4. Accident Statistics of Japan

5. What is 2L?

6. Overall Relative Risk

7. Japanese Study

8. Conclusion

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11.. IntroductionIntroduction

Experience of presenter• More than 30 years dealing RAC technical issues• Representing Japan for following International standards

– ISO 5149 [ISO TC86 SC1 WG1 (1997- )] FDIS– ISO 817 [ISO TC86 SC8 WG5 (1998- )] FDIS– IEC60335-2-40 [IEC61D]– IEC60335-2-40 [IEC61D]

• JWG (1998-2001) Published• WG7 (2005 -2006) FDIS• WG9 (2011-2013) WD

• Worked for Natural Gas field in 1986-1989.(Methane, Volcanic gas)

2. International Standards2. International StandardsISO817 ISO5149 IEC60335-2-40(24,89)

Title Refrigerants -Designation and safety classification

Refrigerating systems and heat pumps -Safety and environmental requirements

HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES -SAFETY -

Part 2-40: Particular requirements for electrical heat pumps,

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air-conditioners and dehumidifiers

Scope Refrigerant Refrigeration System Appliance

Contents Refrigerant Flammability classificationAllowable concentration

Allowable charge amountDesign of unitInstallation siteService

Allowable charge amountDesign of unitRequirements on manual contents

Process Second FDIS Second FDIS FDIS(Joint), DC(A2L)

Publication(shortest)

End of 2013 End of 2013 End of 2013 (Joint)Summer of 2015 (A2L)

3.1 GWP and Flammability3.1 GWP and Flammability

170 161 152a 143(a) 134a 125 116

Life in Air(yr) 0.3 1.4 3.4(43) 14 29 10 000

GWP(100y) <3 12 124 330(4470) 1430 3500 12 200

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• Lower GWP means less stable or abundant in air.• Lower GWP substances are generally less stable, so more

flammable and/or toxic than high GWP substances

HoC (MJ/kg) 46 25 16 10 6.6 4.0 2.2

C

H C F

F

F

F

HF

F

F

F

FC

H C

F

F

125134a152a

CC

C

H CEthane

H F

F

FF

1234yf

CC

C

6

3.2 Refrigerant Safety and Climate Change3.2 Refrigerant Safety and Climate Change

• Now, it is necessary to minimize GWP of refrigerants. • Precise flammability evaluation of refrigerant is mandatory. • Acceptable flammability depends on charge amount.• Precise charge limitation is necessary.

GWP

Fla

mm

abili

ty(H

oC M

J/kg

)

Allowable Amount

Fla

mm

abili

ty

Allowable Amount

GW

P

0

10

20

30

40

50

60

0 1000 2000 3000 4000

125134a32152a

Ethane

1234yf

3.3 Flammability Indices3.3 Flammability Indices• Detailed flammability evaluation was not necessary

until GWP became an issue. • Indices were not reliable.

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LFLv LFLw HoC% kg/m3 MJ/kgHydrogenHydrogen1.8 0.003 120Iso-Butane

ISO 5149-1993 ASHRAE 34 before 2010

HydrogenMethaneEthylene PropaneIso-ButaneAmmoniaR152aCOR143aR142b

HydrogenEthyleneMethanePropaneIso-ButaneAmmoniaR152aCOR143aR32R142b R32

1.82.12.74.14.75.06.26.89.0

12.512.715.0

0.0030.0310.0330.0390.0440.1060.1290.1460.2170.2750.2850.439 R141b

12050474646

18.6161010998R141b

PropaneEthyleneHydrogenR152aMethaneR143aR142bR141bCOR32Ammonia

Iso-Butane

3.4 Flammability Indices of ISO817 FDIS3.4 Flammability Indices of ISO817 FDIS

• Burning velocity was chosen to be added from several candidates at the WG in 2002. ASHRAE 34 employed it in 2010.

• LFLv is to ensure low

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BV (m/s)

Hydrogen 2.91

Ethylene 0.75

CO 0.11-0.43

Propane 0.43

Iso-Butane 0.38• LFLv is to ensure low probability of occurrence and consistency to EN378.

• Heat of combustion is to ensure total energy to be released and consistency to ASHRAE.

Iso-Butane 0.38

Methane 0.37

R152a 0.23

Ammonia 0.07

R143a 0.07

R32 0.07

R1234yf 0.02-0.06

R141b -

3.5 Allowable Charge 3.5 Allowable Charge –– Pooling EffectPooling Effect• Charge amount was limited to 20 or 25% of

LFL x Room Volume • Floor installation was found dangerous• Not possible to avoid flammable cloud completely• IEC/ISO Joint working group developed requirements

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140

160Release height Release Condition

0

20

40

60

80

100

120

140

Concentration of R134a in Air [vol%]0 5 10 15 20 25 30

10cm

50cm

90cm

Release height180cm

Release Condition

Just after the End of Release

f

Gas:HFC-134a Amount:1300g Port Size: 22 cm Rate:70g/min Velocity:<0.1cm/s

Hei

ght f

rom

Flo

or (

cm)

3.6 Formula for Charge Limit3.6 Formula for Charge Limit• 4 minutes entire release with minimal velocity.• Avoid LFL at floor level and explosion.• Various tests and numerical analysis were

carried out to develop the formula.

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• Accuracy was confirmed by experimental tests.• It was employed to IEC60335-2-40 draft in

2000, then copied to ISO5149 draft in 2004.

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4.14.1 Accident Statistics in JapanAccident Statistics in Japan2000 2001 2002 2003 2004 2005 2006 2007 2008 2009Fuel gas facility(KHK)

Explosion NA 38 51 77 57 48 57 64 53 45

fire NA NA NA NA NA NA 19 51 60 42

Refrigeration FacilityAmmonia Installation 210 257 239 NA 111 168 154 151 132 188

FC Unit sales (CU) 141,928126,079

127,304118,627

124,387115,044

114,063100,337

83,47377,023

Refrigerant FatalityRefrigerant FatalityAmmonia 0 0 0 0 0 0 1 0 0 1Fluorocarbon 0 0 0 0 0 0 0 0 0 0

Refrigerant InjuryAmmonia 2 2 1 5 0 1 2 1 3 9Fluorocarbon 0 3(11) 0 2(39) 0 0 3 0 0 0

• Ammonia accidents did not result in fire except one case, though anti-explosion system is not required with ammonia in Japan. In the case it appears that lubricant is ignited.

Accident data: High pressure gas safety institute JapanFC unit sales data: JRAIAAmmonia sales data: JSRAE

4.2 Cause of accidents in Japan4.2 Cause of accidents in Japan

• Major cause of refrigerant sudden release accidents are human error in service.

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18181818

20202020OperationOperationOperationOperation

FataltyFataltyFataltyFatalty InjuryInjuryInjuryInjury TotalTotalTotalTotal0000

2222

4444

6666

8888

10101010

12121212

14141414

16161616

18181818

FataltyFataltyFataltyFatalty InjuryInjuryInjuryInjury TotalTotalTotalTotal

OperationOperationOperationOperation

Wrong ServiceWrong ServiceWrong ServiceWrong Service

Wrong Service andWrong Service andWrong Service andWrong Service andInstallationInstallationInstallationInstallation

IntentionalIntentionalIntentionalIntentional

Not ClearNot ClearNot ClearNot Clear

CFC, HCFC toxicity accidents

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4.34.3 AC appliance Accident in JapanAC appliance Accident in Japan• Current accident statistic of mini-splits over 100 million.

Cause of accidentsNumberIn 6 yr

1 Improper wiring of power supply cable 34

2 Cleaning detergent damaged electric insulation 29

3 Deterioration due to long use period 18

4 Starting fire from a parts of unit 134 Starting fire from a parts of unit 13

5 Short circuit in outdoor unit by foreign matter 10

6 Injury due to contact with fan or heat exchanger fin 5

7 Dust short circuit at power plug 5

8 Overstress on power cable 4Unknown burnout includes suspected arson cases 117Total 272

Prevention of single failure results in significant accident is required by IEC/ISO. Highly flammable/toxic refrigerants?

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5.15.1 What is 2L?What is 2L?• Based on ammonia flammability. Does not Flash.

Flammability is less than lubricant.• IEC61D WG9 is developing requirements for 60335-2-40.

Propane R152aAmmonia R32

R32 R22+Mineral OilR32+Ether oil

55.2.2 Various test resultsVarious test results15

• Propane 30g Small Chamber• Propane 110g Large Chamber• R152a 1000 g Large Chamber• Ammonia 600g Large Chamber• R32 320g Small Chamber• R32 320g Small Chamber• R1234yf 180g Small Chamber• R32 1000g Large Chamber• Brazing 5% Oil• Brazing 50% Oil

55.3 Difference in Risk of rapid release.3 Difference in Risk of rapid release

• CFD results indicate:– If flow velocity is

considered, A2L does not generate flammable cloud in

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R32 Propane

LFL

rapid release.– Flow speed is too

high to ignite where concentration is high enough.

LFL+speed

200 g /min release

10 m

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5.45.4 Difference between 2L and 3Difference between 2L and 3• In 4 minutes complete charge leaks• A2L class refrigerants dilute below LFL quickly due to

heavy molecule and high LFL.

CFD results

R290（60g/min) R32 (250g/min)

5.5 Decomposition Products5.5 Decomposition Products• 800g refrigerant released into 30 m3 room with operating

combustion heater. (Tokyo university of science results.)• It can reach fatal concentration, but it smells and is slowly

generated. It appears acceptable based on ammonia experience.

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5.6 Expected requirement5.6 Expected requirement19

0

1

2

3

4

5

6

7

8

0 20 40 60 80 100

Opening area and capacity of relayArea to propagate flame Capacity (A)

Ope

ning

(d*)

5.7 Sample of relays5.7 Sample of relays20

• Most relay is Japan appears safe for 2Ls, but relays in the States ay be dangerous.

6. Overall Relative 6. Overall Relative RRiskisk

Concentration limit Other factor

HC Flammability Limit 40g/m3Ignition source of HC is less than population, but considerably exists.

R22 Toxicity Limit 220g/m3 Ignition source density of A2L is far less than population A2L Flammability Limit 300g/m3<

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• Human density is much higher than the density of A2L ignition sources.

• Flammability risk of A2L is less than toxicity risk of R22. So, care shall be taken for applications with toxicity accidents of R22. In Japan, about 50 kg was the minimum charge to cause such accident in statistics.

77.1 A2L Risk Study in Japan.1 A2L Risk Study in Japan22

Project

University of Tokyo

Tokyo University of Science, Suwa

Chair: Dr. Hihara (University of Tokyo)

Secretary: Fujimoto(Industry)

JAMA(Automobile Industry)

JSRAE(Academia)

JRAIA(AC/Ref Industry)

Tokyo University of Science, Suwa

AIST(National Laboratory)

Kyushu University

Observers-NEDO-METI (Government)

Project started in 2011 to share latest information of research relating A2L refrigerants.Academia and Industry supported by the government.

77.2 Research themes and sharing.2 Research themes and sharingBasic Studies• Temp. and humidity effect on combustion• Minimum ignition energy• Thermal decomposition Products• Pressurization with combustion• Thermo-physical Properties• Safety analysis of service procedure

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Tokyo University of Science

University of Tokyo

Kyushu University• Safety analysis of service procedure

• Leakage and stagnation analysis

JRAIA

Risk Assessments

VRF

Mini-Split

Chiller

MAC at repair JAMA

AIST

IEC60335-2-40

ISO 5149ISO 817

7.3 Schedule7.3 Schedule24

2011 2012 2013 2014

CommonAnalysis

SeverityAnalysis

Influence of humidity and temperature

Leakage of refrigerant into a room

Flammability test and Condition of flame propagation

Possibility of explosion

• Excellent results are obtained. Refer http://www.jsrae.or.jp/jsrae/Eindex-2.html (Bottom of right column)

LikelihoodAnalysis

Milestone

Mini-sprit risk assessment

VRF risk assessment

Chiller risk assessment

Progress Report

Progress Report

New legislation

Kobe Symposium

88. Conclusion. Conclusion• ISO and IEC standards are being revised to cope

with climate change. Precise flammability evaluation and quantitative requirements are necessary.

• Burning velocity is employed to assess flammability precisely in ISO817 draft.

• Precise pooling calculation is employed in

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• Precise pooling calculation is employed in IEC60335-2-40 then copied ISO5149 draft.

• A2L flammability appears acceptable for general use, since single failure unlikely results in significant accident.

• IEC61D WG9 is developing requirements for A2L.• Japanese A2L project supporting standardizations.

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ENDEND

Thank you for your attention!