In this trainer, great care was taken to make the thermodynamic processes in the refrigeration system as transparent as possible. The capacities of compressor, evaporator and condenser can be measured. Pressure and temperature measuring points are located at all the relevant locations to also allow for the pressure and heat losses in a refrigeration system to be investigated in detail. The refrigeration circuit of contains an open compressor with variable speed, a water-cooled condenser, a thermostatic expansion valve and an evaporator heated by a hot water circuit. The compressor is driven via a pendulum bearing motor with frequency converter for speed adjustment. A force transducer permits the measuring of the drive torque. Using the speed the mechanical drive power of the compressor can thus be determined. The electrical heating power of the hot water circuit can be freely adjusted and is displayed. The condenser capacity is measured via the cooling water flow.
Learning Objectives/Experiments
Cyclic process in the log p-h diagram
Comparison of the real cyclic process and the ideal cyclic process
Balances at the evaporator and condenser
Calculation of the motor power via speed and torque
Determination of losses
Calculation of the coefficient of performance
Operating behaviour under load
Non-steady-state operating behaviour
Specification
Thermodynamic investigation of a refrigeration circuit
Refrigeration circuit with open compressor, water-cooled condenser, thermostatic expansion Valve and indirectly heated evaporator
Compressor drive with speed-controlled motor via V-belt
Motor on pendulum bearing for torque measurement
Tube evaporator with hot water circuit as cooling load
Water-cooled coaxial coil heat exchanger as condenser
Displays for temperature, pressure, flow rate, speed, torque and power at the equipment
Technical Data
Open compressor
refrigeration capacity: approx. 965W (at a speed of 1450min-1 and 5/40°C)
Heater: 1x 1000W
Condenser, capacity: 1300W
Refrigerant
R513A, GWP: 631, filling volume: 2kg, CO2-equivalent: 1,3t
Measuring ranges
temperature: 9x -30…100°C, 1x 0…100°C
pressure: 1x -1…9bar, 1x -1…24bar, 4x -1…15bar
torque: (compressor) 0…10Nm
speed: (compressor) 0…2500min-1
power consumption: (compressor) 0…1125W
power: (heater) 0…1125W
flow rate: (water) 5…70g/s
flow rate: (refrigerant) 0…0,5L/min
230V, 50Hz, 1 phase
230V, 60Hz, 1 phase; 230V, 60Hz, 3 phases
