Additional Information on the Proposed Methodology“Installation of Energy-efficient Refrigerators Using Natural Refrigerant at Cold Storage”

1. Setting coefficient of performance (COP) values for reference refrigerator at a roomtemperature condition of -25 deg. C(1) Selection of possible type of cooling systems except project cooling system-Considering the cooling temperature of room temperature condition of -25 deg. C and thecooling capacity, following systems are identified as the possible type of cooling systems if
project cooling system is not installed.
a)

HFC dry expansion system (single loop)b)

NH3 flooded, pump system (single loop)c)

HFC/brine system (secondary loop)d)NH3/brine system (secondary loop)(2) Collection of COP values of the refrigerator for possible type of cooling systems-For each cooling system identified above, COP values of the refrigerator are collected frommanufacturers’ catalogues.

-

Among all the possible systems, catalogue values for HFC/brine system and NH3/brine system
are not found. However, the COP values for HFC/brine system and NH3/brine system are always
lower than those of single loop system1 and it is assumed not to affect the conservative
identification of reference COP.

1Brine system requires lower evaporation temperature of primary refrigerant compared to single loopsystem since heat exchange from the primary refrigerant to cooling air via brine (secondary refrigerant).
For this reason, brine system consumes more energy than single loop system to keep the required
temperature therefore, COP value of brine system is always lower than single loop system when primaryrefrigerant is the same for the both systems.

1(3) Determination of the default value of reference COP-COP values of refrigerators for possible systems at -25 deg. C (room temperature) are plotted inthe following figure.

2.0
1.9
1.8
1.7

COP

1.6
1.5
1.4
1.3

HFC Dry Expansion (Company A)

1.2

NH3 Flooded/Pump (Company B,Company C)

1.1
1.0
0.9
0100

200
Cooling Capacity (kW)

300

400

Fig.1 Comparison of COP at room temp. condition of -25 deg. C-Catalogue COP values are collected from the manufactures with high market share in Myanmar:
Company A, Company B and Company C.

-Range of refrigeration capacity found in the manufactures’ catalogues is 42.4 to 340 kW.

-The maximum value amongst the obtained data is 1.71.

-The COP value for the reference refrigerator is determined as a default value of 1.71 in aconservative manner, applicable for the refrigerators with capacity up to 340 kW.

2

2. Setting coefficient of performance (COP) values for reference refrigerator at a room
temperature condition of 0 deg. C and 5 deg. C(1) Selection of possible type of cooling systems except project cooling system-Considering the cooling temperature of room temperature condition of 0 deg. C and 5 deg. C
and the cooling capacity, following system is identified as the possible type of cooling systems if
project cooling system is not installed.
a)

HFC dry expansion system (single loop)(2) Collection of COP values of the refrigerator for possible type of cooling systems-For each cooling system identified above, COP values of the refrigerator are collected frommanufacturers’ catalogues.

i)

Room temperature condition of 0 deg. C-

COP values of refrigerators for possible systems at 0 deg. C (room temperature) are plotted inthe following figure.

4.00
3.50
3.00
COP

2.50
2.00
1.50

HFC Dry Expansion (Company D)

1.00

HFC Dry Expansion (Company A)

0.50
0.00
0100

200
300
400
Cooling Capacity (kW)500600

Fig.2 Comparison of COP at room temp. condition of 0 deg. C-Catalogue COP values are collected from the manufactures with high market share in Myanmar:
Company A and Company D.

-Range of refrigeration capacity found in the manufactures’ catalogues is 73.6 to 516.4 kW.

-The maximum value amongst the obtained data is 2.788.

-The COP value for the reference refrigerator is determined as a default value of 2.79 in aconservative manner, applicable for the refrigerators with capacity up to 516.4 kW.
3ii)

Room temperature condition of 5 deg. C-COP values of refrigerators for possible systems at 5 deg. C (room temperature) are plotted in
the following figure.

4.00
3.50
3.00
COP

2.50
2.00
1.50

HFC Dry Expansion (Company D)

1.00

HFC Dry Expansion (Company A)

0.50
0.00
0100

200

300
400
Cooling Capacity (kW)500600700

Fig.2 Comparison of COP at room temp. condition of 5 deg. C-Catalogue COP values are collected from the manufactures with high market share in Myanmar:
Company A and Company D.

-Range of refrigeration capacity found in the manufactures’ catalogues is 86.2 to 612.6 kW.

-The maximum value amongst the obtained data is 3.197.

-

The COP value for the reference refrigerator is determined as a default value of 3.20 in aconservative manner, applicable for the refrigerators with capacity up to 612.6 kW.

4<ANNEX>Schematic diagrams of cooling systems

Fan
Oil separator

Compressor

Evaporator

Compressor

Oil separator

Secondary loop

CoolerOil pump
Fan

FanCondenser

CO2 pump

Coolingtower

Expansion valve

Circulation pump

Cooling water pump

FanCondenser

Cooling

Oil heater

Expansion
valve

tower
CoolerCirculation

Intermediate cooler

pump

Cooling water pump

<Project cooling system> NH3/CO2 system

HFC dry expansion system

Low pressure

Compressor

Oil separator

Intermediate cooler

Compressor

ReceiverOil pump

Evaporator

Oil separator

Secondary loop

Oil pump
Fan

Refrigerant pumpFan

Oil heater
Fan
Evaporative Condenser

Expansion valve

Coolingtower

Condenser

Brine pumpFan

Oil heater
Expansion valveCooler

CoolerIntermediate

Circulation
pumpcoolerCirculation pumpNH3 flooded, pump system

Cooling water pump

Intermediate cooler

HFC or NH3/brine system

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