Capacity Control Methods in Refrigeration- Engineering Lab Training Systems

Technical Description This unit demonstrates several possible ways of regulating the capacity. The cooling capacity of the system with 2 separate evaporators can be changed by adjusting the speed of the open compressor. The compressor drive motor is controlled using a frequency converter. The evaporators are in individual insulated compartments. In the first compartment the temperature is regulated using an intake pressure controller and thermostat (mechanical regulation), in the second compartment using a case controller (electronic regulation). In both cooling compartments a cooling load can be generated using an electrical heater. Fans ensure even temperature distribution. A bypass capacity regulator is installed in the refrigerant circuit that connects the high and low pressure sides of the compressor. The system is equipped with temperature sensors at all relevant measuring points. The signals provided by these sensors are also used by the case controller.