Unlike standard compression refrigeration systems, vapour jet refrigeration machines do not have a mechanical but a vapour jet compressor. This makes it possible to use different heat sources, such as solar energy or process waste heat, for cold production.
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 transparent 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, the other part of the condensate is transported to 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 352.01 and the solar thermal collector HL 313.
The heater power at the evaporator is adjustable. The cooling water flow rate at the condenser is adjusted using a valve.
The trainer is controlled by a PLC via touch screen. All relevant measured values are captured by sensors. The simultaneous transmission of the measured values to a PLC enables easy analysis and the representation of the process in the log p-h diagram. Complex processes, such as changes of state, are visualised by real-time representation of the cycle, e.g. in the log p-h diagram. Intuitive operation of the PLC makes it easy to adjust all elements of the cycle. The effect of the modifications is immediately visible on the touch screen.
