ORCHID

Organic Rankine Cycle Hybrid Integrated Device

The ORHID setup implements a circuit in which an organic fluid flows, as a liquid in the low-temperature section, and as a dense vapor in the high-temperature section. The hot vapor can be sent to a supersonic nozzle for fundamental gas dynamics experiments and to a mini ORC turbine for testing purposes.

Research needs/objectives:

  • Non Ideal Compressible Fluid Dynamics experimental information with applications in ORC turbines and non conventional turbomachinery.
  • Accurate measurements for validation of CFD codes.
  • Development of supersonic mini-ORC turbine design guidelines.

Main operational parameters:

  • Maximum thermal energy input = 400 kWth
  • Maximum thermal oil temperature = 400 oC
  • Maximum working fluid pressure = 25 bar.

Two test sections:

  • Supersonic nozzle with optical access: schlieren + pressure profile. Commissioned in 2020. Planned improvements: PIV, Rayleigh scattering. 
  • Fully instrumented 10 kW mini-ORC radial turbine. Preliminary design completed in 2020, planned realization in 2021.

First Experiments in Non-Ideal Flows: Expansions in the Supersonic Nozzle

  • Achievement of stable operating conditions at design points.
  • Continuous Schlieren imaging during start-up and steady operation.
  • Operation with inlet and throat conditions in NICFD regime.
Process variables during a typical operational cycle. Shaded areas: period in which Schlieren images and measurements below were recorded.
Inlet and outlet conditions (left) and Scanivalve measurements during a test run (right).