The components of a refrigeration circuit with refrigeration and freezing chambers are arranged clearly in the trainer. Solenoid valves enable the individual or parallel operation of the evaporators in the two chambers.

An electric defrost heater is available to defrost the freezing chamber. The simulation of 18 different faults, e.g. faulty solenoid valves or faulty relays, is provided for.

The circuit is equipped with a combined pressure switch for the delivery and intake side of the compressor. The refrigeration chamber features an evaporation pressure controller. The effect of the evaporation pressure controller on the overall process is being examined. An inner heat exchanger in the inlet of the two evaporators is used for supercooling the refrigerant to increase the efficiency of the process. At the same time the intake gas is superheated.

Identifying faults in refrigeration systems requires comprehensive knowledge This knowledge also includes the design and purpose of the individual components. helps to acquire this knowledge.

The process schematic at the trainer offers a quick overview. Signal lamps in the process schematic indicate the operating state of selected Components.

Learning Objectives / Experiments:

Design and components of a refrigeration system with 2 evaporators

Components and their functions

Compressor, condenser, evaporator

Thermostatic expansion valve

Evaporation pressure controller

Pressure switch

Electric defrost heater

Thermodynamics of the refrigeration cycle

Effect of refrigerant supercooling

Representation of the thermodynamic cycle in the log p-h diagram

Determination of important characteristic variables

Coefficient of performance

Refrigeration capacity

Compressor work

Fault finding in refrigeration system components.