Basic experiments in the field of refrigeration. The trainer includes a closed refrigeration circuit with open compressor, a condenser with fan, a thermostatic expansion valve and an evaporator in a refrigeration chamber with transparent door. A fan in the refrigeration chamber ensures an even temperature distribution. A cooling load is simulated by an adjustable heater in the refrigeration chamber. The drive unit drives the compressor via a V-belt. The compressor speed is set at the . The circuit is equipped with a combined pressure switch for the delivery and intake side of the compressor.
All relevant measured values are recorded by sensors. Digital displays indicate the measured values. The simultaneous transmission of the measured values to a data recording software enables convenient analysis and the representation of the process in the log p-h diagram. The software also displays the important characteristics variables of the process, such as the refrigeration capacity and the coefficient of performance.
The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.The unit perform the following experiments and investigations:
Learning Objectives / Experiments
fundamentals of refrigeration
design and components of a refrigeration system
open compressor with drive
condenser
evaporator
thermostatic expansion valve
pressure switch
determination of important characteristic variables
coefficient of performance
compressor capacity
refrigeration capacity
compression ratio
volumetric efficiency
representation of the thermodynamic cycle in the
log p-h diagram
determination of the compressor efficiency
effect of the compressor flow rate on the
refrigeration circuit
Specification
investigation of a refrigeration circuit with speed-controlled compressor
refrigeration circuit with open compressor, condenser, thermostatic expansion valve and evaporator in refrigeration chamber
cooling load in the refrigeration chamber adjustable via heater
drive and speed adjustment of the open compressor via Universal Drive and Brake Unit
condenser and evaporator with fan
pressure switch to protect the compressor
digital displays for pressure, temperature, flow rate, power and speed
software for data acquisition via USB under Windows Vista or Windows 7
refrigerant R134a, CFC-free
Technical Data
Open compressor
Refrigeration capacity: approx. 845W (at speed:
975min-1 and -10/40°C)
Speed: 500...1000min-1
Condenser with fan transfer area: 2,5m²
Capacity: approx. 1935W at 25°C air temperature (ambient) / deltat=15°C
Evaporator
Transfer area: 3,62m²
Capacity: 460W at 3°C air temperature (chamber) / deltat=13°C