select criterion for service - electrolux · 3 esse - wilhelm nießen september 2002 purpose the...

September 2002ESSE - Wilhelm Nießen 1

Compressors

Select criterion for Service

2ESSE - Wilhelm Nießen September 2002

Contents

ZEM GL Series 134aRefrigerant PropertiesMass FlowCompare CompressorDefinitions Service CompressorData Sheets Type Codes

PurposeDesign TypesSuitableConstructionFunctionRefrigeration SystemRemove heatRefrigeration capacity


Purpose

The main task of the compressor in refrigerators and freezers is to produce

the required suction and discharge pressure and to carry the refrigerant

around in a circuit.


Design Types

Hermetic Compressors

Rotary Compressors

Scroll Compressors


Suitable

• Scroll Compressors:used in heat pumps.

• Rotary Compressors:used in air conditioner

• Hermetic Compressors:used in household refrigerators and freezers,piston system, fixed or flexible speed.


Suitable

Hermetic for household appliances


Construction (Hermetic)

Cover

Compressor

Asynchronous Motor

Shell

Terminal Board


Function (Hermetic)

suck in


Function (Hermetic)

compress


Function (Hermetic)

discharge


Refrigeration System

Refrigerant flows trough the compressor which raises the pressure of refrigerant and it flows

trough the condenser. It will be condenses from vapour to liquid and goes to the expansion valve (Capillary tube). Finally, the refrigerant flows to

the evaporator. The liquid refrigerant will vaporise.


Remove Heat

Wärme

Heat

Wärme

Heat

Wärme

Heat

Heat or warmth should be moved out of the cabinet and the transportation of heat follows by refrigerants.

Evaporating EnthalpyKJ / Kg Refrigerant

is in relation to the compressor displacement.

The refrigeration capacity is depended by the mass flow of refrigerant which

cool down = less heat


Refrigeration Capacity (W)Wärme

Heat

Wärme

Heat

Wärme

Usually refrigeration capacities by household refrigerators and freezers are approximately 50-250 W

62W 82W

148W


Refrigeration Capacity (W)

GL35AA GL45AA

GL80AA

3,67cc 4,56cc

8,10cc

62W 82W

148W



GL35AA GL45AA

GL80AA

3,67cc 4,56cc

8,10cc

62W 82W

148W

88W 100W

159W



GL35AA GL45AA

GL80AA

3,67cc 4,56cc

8,10cc

62W 82W

148W

88W 100W

159W>62W >82W

>148W


ZEM GL Series 134a

ZEMGL35AA

3.67 cc

1/10 HP (PS)P 88W

Q 62WQ 53Kcal/h

GL35AA

3,67cc

ZEMGL45AA

4.56 cc

1/8 HP (PS)P 100W

Q 82WQ 70Kcal/h

GL45AA

4,56cc

ZEMGL80AA

8.10 cc

1/5 HP (PS)P 159W

Q 148WQ 127Kcal/h

GL80AA

8,10cc


Refrigerant PropertiesRefrigerant

Evaporating point

Condensing 55°C Pabs

Enthalpy by Evap.

Evap. Enthalpy 32/-25°C

Density of Vapour-25°C

Evap. Pressure-25°C Pabs

Volume of Vapour -25°C

R12

- 30 °C

13.72 bar

166 KJ/Kg

122 KJ/Kg

7.69 Kg/m³

1.24 bar

130 dm³/Kg

R134a

- 26 °C

14.91 bar

215 KJ/Kg

156 KJ/Kg

5.56 Kg/m³

1.07bar

180 dm³/Kg

R600a

- 12 °C

7.77 bar

367 KJ/Kg

274 KJ/Kg

1.67 Kg/m³

0.56bar

600 dm³/Kg


Refrigerant comparison (R12=1)

Refrigerant

Evaporating point

Condensing 55°C Pabs

Enthalpy by Evap.

Evap. Enthalpy 32/-25°C

Density of Vapour-25°C

Evap. Pressure-25°C Pabs


R12

- 30 °C

1

1

1

1

1

1

R134a

- 26 °C

1.087

1.295

1.279

0.723

0.863

1.385

R600a

- 12 °C

0.566

2.211

2.246

0.217

0.452

4.615


Refrigeration Capacity = Mass Flow Rate

Sample R134a

1. Factor for displacement

= 1,385 : 1,279= 1,08 time

2. For a similar refrigerating capacity by R134a it requires 1,08 times bigger displacement to an R134a Compressor. Enthalpy is constantDensity is constantSolution: Increase mass flow!

Factor = Vol. Vap Enthalpy:

Refrigerant

Verd. Enth.20/ -25°C

Density of Vapour -25°C


R12

1

1

1

R134a

1.279

0.723

1.385

R600a

2.246

0.217

4.615


Refrigeration Capacity = Mass Flow Rate

Sample R600a

1. Factor for displacement

= 4.615 : 2.246= 2.05 time

2. For a similar refrigerating capacity by R600a it requires 2.05 times bigger displacement to an R600a Compressor. Enthalpy is constantDensity is constantSolution: Increase mass flow!

Factor = Vol. Vap Enthalpy:

Refrigerant




R12

1

1

1

R134a

1.279

0.723

1.385

R600a

2.246

0.217

4.615


Compressor comparisonRefrigerant

Siedepunkt

Enthalpie bei Sdp.




Compressor ModelDisplacement in ccFactor DisplacementRefrigeration capacity W Mass Flow Rate in Kg/hVol Flow Rate in dm³/h liqVol Flow Rate in dm³/h gasVol Flow Compr in dm³/hEffective Vol Flow in %

R12

- 30 °C

1

1

1

1

R134a

- 26 °C

1,3

1.279

0.723

1.385

R600a

- 12 °C

2,2

2.246

0.217

4.615

A1075A4,38

1782,3

1.93730074940

GL 454,561,04821,9

1,76134277944

HL 909,082,07991,3

2,547780155250


Definitions

Important:

1. Specific Evaporation Enthalpy Kcal/Kg or KJ/Kg = constant

2. Specific Density of Vapour Kg/m³ = constant

3. Refrigeration Capacity Kcal/h or W = Mass Flow Kg/h

3. Compressor Speed is constant (approximately 2700 rpm)

4. Refrigeration Capacity Compressor = Displacement Compressor


Service Compressor

Select Service Compressor:

• Order Service Compressor by Spare Part List.

• Alternative for Professionals:Decide if available compressor can be usedby repairing appliances.


Service Compressor

Serviceability for Compressors:1. Compressor must fit the refrigerant. ( for safety reasons e.g. components are encapsuled by R600a compressors or Ester oil by R134a compressors)2. Dimensions of compressors shall fit the appliances. ( electrical and tube connections has to fit the existing refrigerator or freezer )3. Select required refrigeration capacity. ( read notification by data sheets. Observe comparability ! )4. Alternative to point 3 - Roughly selection of refrigeration capacity by compressor displacement.( Displacement of service compressor shall nearly have the same displacement than the original compressor. )


Data Sheets


Data Sheets

GL45AA


Compressor Data Sheet


Convert

Capacity P - in W or J/s or Nm/s

1 J/s = 1 W = 1 Nm/s

Cooling Capacity:Q - in W - Kcal/h - Btu/h

1Kcal/h = 1,16 W = 4,19 KJ/h= 3,97 Btu/h

1 W= 0,86 Kcal/h = 3,6 KJ/h = 0,239Btu/h

1 KJ/h = 0,239 Kcal/h = 0,278 W

.


Type Codes

Aspera

BP 1058 A BP 1058 Y BP 1058 ZBP 1111 A BP 1111 Y BP 1111 Z

Series

First digit of this three shows number of 0which to add onthe last two digits. The result showsthe refrigeration capacity by ASHRAE.(Kcal/h by -23,5°C Evaporating temperature)

RefrigerantA=R12 Y=R600a Z=R134a

ASHRAE x 0,85=

approximatelyin ...WCecomaf

SampleBP 1111 Y110 Kcal/h

R600

BP 1058 Z58 Kcal/h

R134a


Type Codes

Danfoss

TL 4 K TL S 4 K TL X 4 K TL Y 4 KNL 10 K NLE 9 K NL Y 9 K TL V 7 K

Series

Optional:no legend = StandardS = semi direct suctionE = Energy optimisedX,X = high energy optimisedV = variable speed

Displacementin cc

RefrigerantA = R12B = R12

G = R134aF = R134aK = R600a


Type Codes

Embraco

F G S 70 C A F G S 70 C A F G S 70 C A E M U 32 C L P E M U 32 C L P E M U 32 C L P

x 10 = Refrigeration capacity in Btu/h

by 60 Hz

RefrigerantC = R600aH = R134a

Convert:x 2,5 = approximately

Refrigeration capacity in W

Type


Type Codes

ZEM

G Q T 45 A A G Q T 45 A A G Q T 45 A A H L 45 A A G L 45 A A G L 12 A A

Series Displacem. :10 till 9,9

cc45 = 4,5 ccmore than

10 cc12 = 12cc

RefrigerantG = R134aO = R134aH = R600a

EfficiencyM = StandardY = Medium

T = High


Documentation

If the refrigeration capacity can not be selected by compressor type, than you have to use the

RefrigerantG = R134aO = R134aK = R600a

technical documentation.For instance:

TDS ordata sheets fromcompressor manufactory.

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