Our Products

Need help? Try our Application Assistant for quick support.

View All

View All

Air Squared Articles

Scroll Expander Testing Services

Using an advanced ORC test rig, Air Squared has the capability to fully evaluate and characterize scroll expanders over a wide range of operating conditions.

A complete ORC Test Rig
Complete ORC Test Rig

Air Squared offers scroll expander testing services using an advanced organic Rankine cycle (ORC) test rig that is purpose-built to accommodate expanders of varying size over a wide range of operating conditions.

The ORC test rig has four primary components:

  1. Scroll Expander – Produces power by expanding the working fluid
  2. Condenser – Cools the expanding gas and converts it to a liquid
  3. Pump – Provides the required flow rate at the desired pressures
  4. Evaporator – Converts the liquid to a higher pressure and temperature gas


A process water heater acts as the heat source, providing the required heat input to the evaporator. To reject heat from the condenser, a cooling tower is used.

An ORC Test Rig Schematic
ORC Test Rig Schematic

Integrated with a data acquisition system for collecting and analyzing data, various sensors are used throughout the rig for process control and measurement. Thermocouples and pressure sensors are placed at the inlet and outlet of all primary components to control and monitor fluid temperatures and pressures.

High-precision Coriolis flow meters are used to measure the mass flow rate of the working fluid. Turbine type flow meters are used to measure the hot water loop and cold water loop.

To measure work output, a torque sensor is connected to the expander. All the generated power is transferred to braking resistors and dissipated as heat.

The maximum achievable values for all primary system parameters are as follows:

  • Working Fluid: R134a, R245fa 1
  • Heat Source < 50 kW
  • Heat Sink < 85 kW
  • Temperature < 110 °C 2
  • Pressure < 3,500 KPa
  • Flow Rate < 21 lpmv
  • Speed < 3,600 RPM
  • Shaft Power < 12 kW

1. Compatibility with additional working fluids is possible, but requires evaluation on a case-by-case basis.
2. Compatibility with higher temperatures is possible, but requires evaluation on a case-by-case basis.