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 in real time. 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 touch screen displays the main parameters of the process, such as the pressure ratio of the compressor and the coefficient of performance.
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. Access to stored measured values is possible from end devices via WLAN with integrated router/ LAN connection to the customer’s own network. When using a direct LAN connection, the measured values can be transferred to a PC and read out and stored there (for example with MS Excel).