TCFRC Unité de Régulation de la Puissance et des Défauts dans les Installations de Réfrigération, Contrôlée par Ordinateur (PC)

The purpose of the Computer Controlled Capacity Control and Faults in Refrigeration Systems, "TCFRC", is to investigate different methods of capacity control and to simulate 18 different typical faults in refrigeration systems.

The efficient control of the capacity and temperature in refrigeration systems is an important topic in refrigeration technology. The "TCFRC" has been designed by EDIBON to carry out different methods of capacity control in refrigeration systems.

The components of a refrigeration circuit with refrigeration and freezing chambers are arranged clearly in this unit.

The "TCFRC" includes solenoid valves which enable the separate or parallel operation of the evaporators in the two chambers. Besides, the circuit is equipped with a capacity controller, a start-up controller and a combined pressures switch for the delivery and intake sides of the compressor. One heat exchanger in the inlet of the two evaporators enables the supercooling of the refrigerant to be investigated for the efficiency of the process. The refrigeration capacity of the two individual chambers is controlled by a thermostat. On the other hand the refrigeration chamber also features an evaporation pressure controller. There are two defrosting methods for the freezing chamber: an electric defrost heater and a hot gas defrosting where hot refrigerant is fed directly from the compressor in the opposite direction through the evaporator. The unit is designed to simulate 18 different faults, such as faulty valves or clogged pipes. The faults are activated using a touch panel connected to a PC with a Data Acquisition Board which allows:

• Relevant measured values that are transmitted directly to the touch panel from the PC.
• Representation of the thermodynamic cycle in the log p-h diagram.
• Recording of the test measurements versus time and generation of a file compatible with spreadsheet applications.

The following are the most important objectives and experiments which can be carried out with this unit:

• Familiarization with the key devices for changing the refrigeration capacity:

• Thermostat.
• Capacity controller.
• Start-up controller.
• Evaporation pressure controller.
• Condensation pressure controller.

• Fault finding in refrigeration system components.
• Effect of refrigerant supercoiling.
• Familiarization with defrosting methods:

• Electric defrost heater.
• Hot gas defrosting.
• Representation of the thermodynamic cycle in the log p-h diagram.

The Data Acquisition and Control Software of the "TCFRC" unit allows:

• The calculation of representative magnitudes: power of the combustion engine and specific consumption of fuel.
• The representation of the characteristic curves of the combustion engines: torque, power or specific consumption versus velocity of the combustion engine.
• The representation of the measured and calculated magnitudes curves, in signal versus signal charts. Free configuration of the axes of these charts.
• The representation in real time of all the measured and calculated magnitudes.

This Computer Controlled Unit is supplied with the EDIBON Computer Control System (SCADA), and includes: The unit itself + a Control Interface Box + a Data Acquisition Board + Computer Control, Data Acquisition and Data Management Software Packages, for controlling the process and all parameters involved in the process.