Due to the high environmental impact of conventional refrigerants, there is interest in the long term in avoiding the use of fluorinated gases and using natural refrigerants instead. One currently promising gas is propane. The gas has very good thermodynamic properties and is available globally.
ET 360 is used to investigate the refrigeration circuit under an adjustable load. The refrigeration circuit consists of a compressor, a condenser with ventilator, a thermostatic expansion valve and a microchannel heat exchanger as evaporator. The evaporator can be operated in a refrigeration chamber or with a permanent flow through.
All relevant measured values are captured by sensors. The simultaneous transfer 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.
The PLC provides accurate data on the condition of the refrigerant, which is used for precise calculation of the refrigerant mass flow. The calculation therefore provides a much more accurate result than measurement with conventional methods.
The experimental unit is controlled by a PLC via touch screen. By means of an integrated router, the experimental unit can alternatively be operated and controlled via an end device. The user interface can also be displayed on additional end devices (screen mirroring). Via the PLC, the measured values can be stored internally.
Digital multimedia teaching material is available at the Science Media Center. In addition to real-time representation directly on the unit, Game-Based Learning is made possible with these online media, e.g. worksheets, e-learning, videos, etc.