The energy efficiency monitoring of a refrigeration unit

In the paper, a monitoring system of a refrigeration unit is presented. This system consists of several measurement elements e.g. (pressure, temperature, energy, etc. sensors) connected using a serial RS485 network. A measurement level is a source of data for both SCADA environment and a PLC controller which are essential elements of the whole control system. The first stage of the study was related to the selection of measurement devices and a construction of a serial network. The authors also described how to link a serial 485 network with a PLC controller and how to introduce it into TCP/IP network. In the first part of the paper, there is presented a refrigeration unit as a subject of the monitoring. Then the authors describe a theoretical background needed for the energy efficiency calculation. After that the system structure with selected details about hardware integration and SCADA software implementation is presented. The final part contains selected real time experiments to show typical working modes of the refrigeration unit and to prove the efficiency of the developed monitoring system.