Risk Assessment for Commercial Refrigerating appliance
Working Group for Risk Assessment of Lower Flammability Refrigerant

Introduction

Conclusion[Subject system] Commercial Refrigerating appliance using A2L[Refrigerants (A2L)] R32, R1234yf, R1234ze(E)[Model of risk assessment]
Refrigerated display cabinet installed in Supermarkets< Dominant risk factors >Risk cases

Leakage gas retention

FactorHigh concentration

Leakage on joint
parts of upper
pipes
Leakage on joint
parts of pit pipes/Leakage in display
area of Open typeLeakage in display
area of Reach-intypeSupermarkets (small size)
open type vertical refrigerated
display cabinet

reach-in-type refrigerated
display cabinet

Causepipes

Safety measures

Safety measures

Installation/Service stages

Usage stage
Ignition sources

Human error
Refrigerant recovery
Refrigerant recovery
Cooker, HeaterGas burnerElectrical wiring“Outputting an alarm with a leak detector”“Education for workers” and“Education for“Carrying a portable leak detector”
store staffs”“Outputting an alarm with a leak detector” and “Fan operating with a leakdetector”“Education for
store staffs”

Safety measures

Disposal stage“Education for workers” and“Carrying a portable leak detector”“Outputting an alarm with a leak detector” and “Closing a shut-off valve”“Education for workers” and“Education for“Carrying a portable leak detector”
store staffs”• In all cases, the amount of refrigerant is limited. （a quarter of LFL or less）．
• It is required to install a leak detector.

Condensing Unit

System / Installation

Risk case / Safety measures• Cooling capacity: 5.0 ~ 40.0 kW (ET=-10℃)• Charge amount of refrigerant: 20 kg(the maximum charged amount for Model of risk assessment)• Type：Setting one or more than one Refrigerated displaycabinet to one Condensing Unit
• Total number of Refrigerated display cabinet : about 1.3
million in Japan• User: Supermarket etc.

[Refrigerated display cabinet ]• Refrigerant pipes joint：Top of refrigerated display cabinet / Pit of refrigerant pipes• Leakage location：Joint parts of upper pipes / Joint parts of pit pipes / Display area
• Safety measures：Leakage from joint parts of pit pipes・・・Leak detector + Circulation fanLeakage in display area of Open type・・・ Leak detector + Circulation fan
Leakage in display area of Reach-in type・・・ Leak detector + Shut-off valve, Check valve<Construction of upper pipes> <Construction of pit pipes of open typerefrigerated display cabinet>
Refrigerant
pipes

Leak detector※(Display area)

Leak detector

Display area

Leak detector(outside)

Pit of refrigerant
pipes

Shut-off valve

Expansionvalve

Display area
Display area

Leak detector

Check valve

Circulation fanDoor(Closed)Circulation fan

Display area

Refrigerant circuit<Construction of pit pips of reach-in-typerefrigerated display cabinet>

Evaporator

Pit of refrigerant
pipes※Condensation-resistant typeShut-off valve, Check valve

Concerning showcases,
the brazing for the pit pipes is often performed. To conduct RA strictly, the joint parts of pipes which are brazed are set as the leakage point.

Ignition source[Spark]• Match, Oil lighter[Open flame]• Match, lighter• Combustion equipment(Cooker, Heater, etc.)• Gas burner (for brazing)

Flammable volume-time integration

Risk assessment• Refrigerated display cabinet• Effect of safety measures

Floorarea

Amount oftherefrigerantLeakrate

Flammable
volume-time
integration

m2kg

kg/h

m3･minJoint parts of upperpipes

84.7

20104.23

Joint parts of pit pipes

84.7

2075

610.2

Display area

84.7

2075

2103.0

Display area (withsafety measures)

84.7

20750.0016

Leak location

Open type※ The places where ignition sources
such as cookers and etc. are installedcannot be controlled. The measures
shall be taken under all conditions,then ensures safety.

Reach-in type

Life stage［allowable level］[ ≦ 2.0×10-7 ]Without circulation fan⇒From the result of RA, in the case of the leakage on the joint
part of the pit pipe and in the display area of open type, it isnecessary to circulate with a circulation fan.
Reach-in type is sealed, therefore, safety measures arerequired, then RA is conducted.

Usage

ServiceDisposal[ ≦ 2.0×10-8 ][ ≦ 2.0×10-7][ ≦ 2.0×10-7]

Safety measures

without

withwithout

withwithout

withwithout

withOpen type

7.56×10-6

8.21×10-8

2.80×10-8

5.51×10-11

8.89×10-4

4.43×10-8

3.38×10-6

1.80×10-8

Reach-in type7.68×10-7

8.89×10-9

4.11×10-10 8.45×10-11

2.23×10-5

5.12×10-9

4.70×10-8

2.53×10-10※As for Reach-in type, we have conducted a risk assessment of when the door
is opened, as it becomes risk higher when the door is opened in the event ofleakage in display area.
RA of the Commercial Refrigerators and Freezers which isanother main use of the Commercial Refrigerating appliance isproceeded in the future (August, 2016 – June, 2017）.

With circulation fan

LFLLFL⇒Circulating the refrigerant with acirculation fan, then ensuring safety
Concentration distribution whenleakage occurs (circulation fan stops)[Reach-in type]• Result (Refrigerant: R32)
Installation(modification)[Open type]

With safety shut-off valve

Leakagelocation
Leak rate
Alarm setting value(5000ppm)

LFL⇒Shutting off the leakage
by the shut-off valve,then ensuring safety

5.4 m

10 kg/h
75 kg/h
Alarm setting value(5000ppm)

LFL⇒If a detector is within 5 m from theleakage point, it is possible to detect.

Documentation
1. Guideline of design construction for ensuring safety against refrigerant leakage from commercial refrigerating appliance lower flammability (A2L)
refrigerants JRA GL-18：2016
2. Requirements for ensuring safety against refrigerant leakage from commercial r refrigerating appliance using lower flammability (A2L) refrigerants
JRA 4072：2016