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.

The challenge

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 solution

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.

Test parameters Range Control accuracy
Superheat 5 … 40 K ≤ ±1.5 K
High pressure 10 … 40 bar (absolute) ≤ ±0.3 bar
Low pressure 1.5 … 5 bar (absolute) ≤ ±0.2 bar
Mass flow 30 … 800 kg/h Result value, not controlled


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.:

  • LIN
  • CAN
  • PWM
  • Analog

The advantages

  • 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

Contact person

You are looking for an electronic (expansion) valve test bench and our IPEvalve does not meet your requirements? Or you want to test refrigerant circuit (expansion) valves with other refrigerants, such as R290 (propane) or R744 (CO2)? Please do not hesitate to contact us – we will be happy to discuss your special requirements!

+49 7221 9922 222

This might also interest you

Practical Examples

HVAC compressor acceptance testing

Practical Examples

NVH measurements on HVAC compressor systems

Practical Examples

Cooling capacity testing under extreme conditions