Optimal Refrigerant Distribution in Electric Vehicles
Test bench for the development and validation of electronic refrigerant valves
The thermal management presents great challenges for electric vehicles. It has to be efficient and tailored to suit the electric drive. This can be achieved by optimizing the distribution of refrigerants to the different consumers. In order to reach this goal, the expansion, multi-way, and shut-off valves must function very effectively. The fully automated component test bench IPEvalve supports the development of such valves and the validation under real operating conditions.
Various expansion, multi-way, and shut-off valves developed for the refrigerant circuit of thermal management systems have to be tested under real thermodynamic conditions. It is vital to conduct the tests with the same refrigerant/oil mixtures used in the vehicle. The test bench is equipped for R134a/R1234yf as well as the standard automotive POE and PAG oils. An integrated refrigerant management system facilitates the test bench setup.
For a substantial validation, the flow curves of the different valve types have to be determined and various development stages have to be compared and tested for functionality. In addition to that, durability tests analyze possible changes in valve behavior or flow rate.
The component test bench IPEvalve has been developed according to the highest standards and meets all the requirements of development engineers. The IPEvalve is a fully automated test bench for thermodynamic performance or durability tests of various automotive refrigerant circuit valve types with the refrigerants R134a or R1234yf. Test groups allow the test bench to be equipped with up to 6 valves at a time.
The IPEvalve is very versatile: In addition to the oil circulation rate (OCR) at various points in the circuit (for functional tests), the superheat of the refrigerant in the suction line, the low pressure, and the high pressure can be controlled via the integrated PLC, in which all control parameters and software limit values are stored. The test bench is operated via a central computer with the IPEmotion test bench software. The integrated safety system automatically switches off the test bench if the set limit values are exceeded or if a refrigerant leakage is detected.
IPEvalve – component test bench for the (expansion) valve validation
Thermodynamic durability tests of:
- Valves for the hot gas line (without oil)
- Valves for the liquid line (with oil)
- Valves for the suction line (with oil)
- Electronic expansion valves (with oil)
Test specimens for the discharge line (gaseous/liquid), suction line, and as expansion valves:
- 3/2-way valves
- Double shut-off valves
- Single shut-off valves
- Single expansion valves
- Double expansion valves
Various durability and performance tests:
- Testing in automatic sequence, one after the other
- Flexible number of valves for the test run
Mass flow and OCR measurement:
- Adjustable OCR (not for valves in the hot gas line)
- Mass flow depending on the compressor RPM
Various signal types for the communication with the test specimens, i.a.:
- Test bench for automated performance, functional, and durability tests
- Use of the refrigerants R134a and R1234yf
- Various expansion valves and/or one-way and multi-way valves can be used
- One-way and multi-way expansion valves can be tested in test groups
- Shut-off valves can be tested in the suction line, in the hot gas line (gaseous refrigerant), or in the liquid line (liquid refrigerant)
- Integrated refrigerant management system facilitates the test bench setup