It is part of the HSI training system for refrigeration and air conditioning technology. In combination with the base unit the operational model of a refrigeration system with refrigeration and freezing stage results. The model is plugged onto the base unit, secured using fasteners and connected with refrigerant hoses to become a complete refrigeration circuit.
In refrigeration and freezing combinations evaporators are preferably connected in parallel. To increase the refrigeration capacity, evaporators are operated connected in series. Here different pressure levels in the evaporators can be used to obtain different temperature ranges for refrigeration or freezing.
It includes two separate refrigeration chambers with evaporator and expansion elements. The evaporators can be optionally operated connected in series or in parallel. Two fans in the refrigeration chambers support the achievement of an even temperature distribution. With heaters cooling loads can additionally be simulated. One of the refrigeration chambers can optionally be operated with an expansion valve or a capillary tube as expansion element. The various operation modes are set via solenoid valves. An evaporation pressure controller permits in parallel operation the independent adjustment of the temperature level in the upper chamber. All components are clearly arranged on a panel.
Learning Objectives/Experiments
Design and operation of a refrigeration system with two evaporators
Series and parallel connection of two evaporators
Familiarisation with the different expansion elements
Operation with capillary tube
Operation with expansion valve
Operating behaviour under load
Refrigeration cycle in the log p-h diagram
Effect of the evaporation pressure
Fault simulation
Specification
Model of a refrigeration system to plug onto the base unit
Training system with HSI technology
Each refrigeration chamber includes: evaporator with fan (to recirculate the air) and heater to generate the cooling load
Refrigeration chambers with transparent front
Adjustable evaporation pressure controller
Selectable expansion elements: expansion valve or capillary tube
Operating modes of the system configurable via 5 solenoid valves
Sensors to record temperature and pressure
Operation of solenoid valves, fan, heater and fault simulation via software
Technical Data
Refrigeration chamber: L x W x H: 270x270x220mm
Electric PTC heater as cooling load: 210W
Capillary tube: length 2m
Evaporation pressure controller: 0…5,5bar
Measuring ranges
temperature: 6x ±50°C
pressure: 2x -1…9bar
