The Refrigeration System with Open Compressor PolarX - 520 is a trainer built to make the thermodynamic processes of a refrigeration circuit as transparent as possible. It features an open compressor with variable speed, a water-cooled condenser, a thermostatic expansion valve, and an evaporator heated by a hot water circuit. Pressure and temperature measuring points at all relevant locations allow detailed investigation of pressure and heat losses. This refrigeration system with open compressor supports determination of compressor capacity, refrigeration capacity, compression ratio, volumetric efficiency, and coefficient of performance.

Refrigeration System with Open Compressor PolarX - 520, Technical Specifications
| Specification | Detail |
|---|---|
| System Investigation | Investigation of a refrigeration circuit with speed-controlled compressor |
| Circuit Configuration | Open compressor, condenser, thermostatic expansion valve and evaporator in refrigeration chamber |
| Cooling Load Control | Adjustable via heater in the refrigeration chamber |
| Condenser and Evaporator | With fan |
| Thermodynamic Cycle Representation | P-h diagram (software, optional) |
| Compressor Efficiency | Determinable via measured values |
| Compressor Flow Rate Effect | Investigable on the refrigeration circuit |
| Pressure Switch | Protects the compressor |
| Sensors | Pressure, temperature, power and speed |
| Refrigerant Mass Flow Rate | Calculated in software from recorded measured values (optional) |
Technical Data
Open Compressor
| Parameter | Value |
|---|---|
| Refrigeration Capacity | Approx. 970W (at speed: 1450 min-1 and 5/40°C) |
Condenser (with fan)
| Parameter | Value |
|---|---|
| Transfer Area | 2.5 m2 |
| Capacity | Approx. 1950W at 25°C air temperature (ambient), Δt=15°C |
Evaporator
| Parameter | Value |
|---|---|
| Transfer Area | 3.63 m2 |
| Capacity | 460W at 3°C air temperature (chamber), Δt=13°C |
General
| Parameter | Value |
|---|---|
| Heater Power | 1000W |
| Refrigerant | R513A |
| GWP | 631 CO2-equivalent |
Measuring Ranges
| Parameter | Value |
|---|---|
| Temperature | 5x -100°C to 400°C |
| Pressure (Low Side) | -1 to 16 bar |
| Pressure (High Side) | -1 to 24 bar |
| Speed | 0 to 1000 min-1 |
| Flow Rate | 2 to 18 m3/h |
Key Features
Experiments
Construction and Design
The Refrigeration System with Open Compressor PolarX - 520 is built around a refrigeration circuit that includes 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 by a pendulum bearing motor fitted with a frequency converter for speed adjustment. A force transducer measures the drive torque, and the mechanical drive power of the compressor is determined using the speed. The evaporator is located in a refrigeration chamber, with cooling load adjustable via a heater. The condenser and evaporator are each fitted with a fan. Pressure and temperature measuring points are positioned at all relevant locations across this refrigeration system with open compressor, allowing pressure and heat losses to be investigated in detail. A pressure switch protects the compressor. Sensors monitor pressure, temperature, power, and speed throughout the circuit.
Software
Software PolarX - 520 (optional)
DAQ software designed in National Instruments™ LabVIEW™ environment to measure and calculate the results of the apparatus. The software is optional. When the software is used, a set of electronic sensors is included. The software can be run on any Windows™ environment.
Scope of Delivery
Required for Operation
Optional Accessories
Q: What does the Refrigeration System with Open Compressor PolarX - 520 demonstrate?
A: It demonstrates the thermodynamic processes of a refrigeration circuit with an open compressor, water-cooled condenser, thermostatic expansion valve, and evaporator heated by a hot water circuit.
Q: How is the drive torque of the compressor measured?
A: A force transducer measures the drive torque, and the mechanical drive power is determined using the speed.
Q: What refrigerant does the unit use?
A: R513A, with a GWP of 631 CO2-equivalent.
Q: Can measured values be transmitted to a PC?
A: Yes, measured values can be transmitted directly to a PC via USB (optional).
Q: Is the PolarX - 520 software required to operate the unit?
A: No, the software is optional. A set of electronic sensors is included when the software is used.