Vapour jet compressor in refrigeration engineering ET 352

Vapour jet compressor in refrigeration engineering

Type: ET 352
Name: Vapour jet compressor in refrigeration engineering


Unlike standard compression refrigeration systems, vapour jet refrigerating machines do not have a mechanical but a vapour jet compressor. This makes it possible to use different heat sources for cold production. Such sources could e.g. be solar energy or process waste heat.

The system includes two refrigerant circuits: one circuit is used for cold production (refrigeration cycle), the other circuit is used for the generation of motive vapour (vapour cycle).
The vapour jet compressor compresses the refrigerant vapour and transports it to the condenser. A transparent tank with a water-cooled pipe coil serves as condenser.

In the refrigeration cycle some of the condensed refrigerant flows into the evaporator connected to the intake side of the vapour jet compressor. The evaporator is a so-called flooded evaporator where a float valve keeps the filling level constant. The refrigerant absorbs the ambient heat or the heat from the heater and evaporates. The refrigerant vapour is aspirated by the vapour jet compressor and compressed again.

In the vapour cycle a pump transports the other part of the condensate into a vapour generator. An electrically heated tank with water jacket evaporates the refrigerant. The generated refrigerant vapour drives the vapour jet compressor. Alternatively to the electric heater, solar heat can be used as drive energy by using ET 352.02 and the solar thermal collector HL 313.

Relevant measured values are recorded by sensors, displayed and can be processed onto a PC. The heater power at the evaporator is adjustable. The cooling water flow rate at the condenser is adjusted using a valve.

Technical details

  • investigation of a vapour jet compressor
  • refrigeration circuit with condenser, evaporator and vapour jet compressor for refrigerant
  • vapour circuit with pump and vapour generator for operating the vapour jet compressor
  • transparent tank with water-cooled pipe coil as condenser
  • transparent tank with adjustable heater as evaporator
  • flooded evaporator with float valve as expansion element
  • vapour generator with heated water jacket (electrically or solar thermally using ET 352.01, HL 313)
  • refrigerant Solkatherm SES36, CFC-free
  • GUNT software for data acquisition via USB under Windows 7, 8.1, 10
  • Technical data

    Vapour jet compressor

    • dmin convergent-divergent nozzle: approx. 1,7mm
    • dmin mixing jet: approx. 7mm


    • tank: approx. 3,5L
    • pipe coil area: approx. 0,17m2


    • tank: approx. 3,5L
    • heater power: 4x 125W

    Vapour generator

    • refrigerant tank: approx. 0,75L
    • water jacket: approx. 9L
    • heater power: 2kW


    • max. flow rate: approx. 1,7L/min
    • max. head: approx. 70mWS

    Measuring ranges
    • temperature: 12x -20…100°C
    • pressure: 2x 0…10bar; 2x -1…9bar
    • flow rate: 3x 0…1,5L/min
    • power: 1x 0…750W, 1x 0…3kW

    230V, 50Hz, 1 phase
    230V, 60Hz, 1 phase, 230V, 60Hz, 3 phases
    UL/CSA optional

    Dimensions and weight

    LxWxH: 1460x790x1890mm
    Weight: approx. 225kg

    Required for operation

    water connection, drain, PC with Windows recommended