PRODUCT  INFORMATION

The task of a refrigeration compressor is to draw refrigerant vapour from the evaporator and compress it to a state where it can easily be condensed into subcooled liquid. Depending on the operating conditions, situations can occur, when small amounts of liquid are carried-over from the evaporator and into the compressor. The consequence of this being liquidhammer which will damage the compressor in the following components:

  • Suction Valve
  • Discharge Valves
  • Pistons and Connecting Rods
  • Gasket
  • Bearings

ESK suction line accumulators incorporate the injection principle which has been tried and tested for many years. Even if the accumulator is full of liquid refrigerant, it is not possible for liquid to enter the compressor suction.

In particular in compact plant with short suction lines, too low a suction superheat (below 7 K) will result in a loss of compressor oil pressure and a subsequent decrease in system capacity through displacement of oil by liquid refrigerant. ESK suction line accumulators protect the compressor against liquid hammer and its subsequent damage. The use of a suction line accu mulator is strongly recommended under the following conditions:

  • Parallel connected compressors
  • Container cooling
  • Transport refrigeration
  • Flooded evaporators
  • Two-stage plant
  • Reverse cycle operation
  • Use of hot-gas defrost
  • Superheat less 7 K

·  Heat pump systemsThe accumulators are also released for an application with R410A.

Suction Line Accumulators (FA)

The task of a refrigeration compressor is to draw refrigerant vapour from the evaporator and compress it to a state where it can easily be condensed into subcooled liquid. Depending on the operating conditions, situations can occur, when small amounts of liquid are carried-over from the evaporator and into the compressor. The consequence of this being liquidhammer which will damage the compressor in the following components:

·         Suction Valve

·         Discharge Valves

·         Pistons and Connecting Rods

·         Gasket

·         Bearings
ESK suction line accumulators incorporate the injection principle which has been tried and tested for many years. Even if the accumulator is full of liquid refrigerant, it is not possible for liquid to enter the compressor suction.

In particular in compact plant with short suction lines, too low a suction superheat (below 7 K) will result in a loss of compressor oil pressure and a subsequent decrease in system capacity through displacement of oil by liquid refrigerant. ESK suction line accumulators protect the compressor against liquid hammer and its subsequent damage. The use of a suction line accu mulator is strongly recommended under the following conditions:

·  Parallel connected compressors

·  Container cooling

·  Transport refrigeration

·  Flooded evaporators

·  Two-stage plant

·  Reverse cycle operation

·  Use of hot-gas defrost

·  Superheat less 7 K

·  Heat pump systemsThe accumulators are also released for an application with R410A.

FL1 – Operation with R717 (ammonia) and R290 (propane)

Most types are approved for R 290, R 600a, R 717, R 723 and R 1270. The
selection is based on the effective displacement. Following types are not
approved for fluids group 1:FA-..-T / FA-..-WT and FA-54-9 / FA-54-9W.

Selection

For dimensioning suction line accumulators the fol low ing points must be
considered:

1.     Relationship between accumulator volume and refrigerant charge. Compressor manufacturers recommend that 50 to 70 percent of the system charge should be able to fit into the accumulator.

2.     The suction gas velocity VSGmin. > 7 m/s ensures an oil return from the
acccumulator. VSGopt. = 14 m/s; the maximum value VSG= 20 m/s must not be exceeded. When a capacity regulation is used for the compressors, the VSGmin. values can be reduced to 5,6 m/s (absolute limit).
Technical specification
Max. allowable operating pressure (PSmax) according to the temp. range

[1] Allow. operating temperature: 100 … –10 °C → PS1 = 28 bar
[2] Allow. operating temperature: 10 … – 50°C → PS2 = 20 bar

Technical specification: Internal heat exchanger

Max. allowable operating pressure: 31 bar
Allowable operating temperature: 100 … – 50 °C

 

Suction line accumulators for use with R 744 (CO2)

The suction line accumulator series FA-CD is made of stainless steel and is applicable for all CO2 application with a maximum suction pressure of 40 bar. Accumulators type FA-CDH are equipped in the suction line of the transcritical units, they are designed for a maximum working pressure of 100 bar. The suction line accumulators should be selected according to the following capacity data.

Technical specification
Max. allowable operating pressure (PSmax) according to the temp. range

[1] Allow. operating temperature: 100 … –10 °C → PS1 : As per table
[2] Allow. operating temperature: 10 … – 50°C → PS2 : As per table