CSP-4: Small-Scale Positive Displacement ORC Expander
To develop an advanced high-volume-ratio scroll expander suitable for an organic Rankine cycle (ORC) power block operating from a solar collector temperature source at 150°–250°C. The major design goal is to achieve an isentropic efficiency surpassing previously tested two-stage scroll expansion (70% isentropic), while simplifying the ORC and improving the delivery and control of power to the DC bus, using solar-thermal energy at >150°C.
C16: Thermo-mechanical modeling and optimization (12 months).
C17: Detailed CAD modeling and prototyping (30 months).
C18: Testing on ORC loop at Florida (36 months).
C19: Prototyping in India with design adaptations (48 months).
C20: Testing on ORC loop in India and tuning of controls (60 months).
Task 1: Small-scale positive-displacement ORC expander
- Massachusetts Institute of Technology (MIT)
- MIT/STG International
- University of South Florida (USF)
- Indian Institute of Science (IISc)
Development of low-cost, high-efficiency scroll expanders for micro-CSP ORC units (~3–25 kW) suitable for off-grid power systems. A model–prototype–evaluate process will be followed to generate new insights regarding the geometric and thermo-mechanical variables influencing cost and performance. System- and component-level modeling will be collaborative between MIT and IISc, and include development of general positive displacement expander design tools. Prototype expanders and controls will be tested in a small 5-kWe CSP ORC plant in Florida. Engineering design tools and CAM processes will be transferred by STG to collaborators in India for scaled prototyping and evaluation on a CSP test loop in India.