Development of a small scale scroll expander Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/dj52w838c

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • The organic Rankine cycle (ORC) is a versatile approach in the utilization of waste heat in the production of electricity, clean drinking water, and cooling. The efficiency of these cycles must be maximized to make them economical. Parameters for the optimization of ORCs such as evaporator and condenser temperature have practical limits. This is why the expander has the greatest effect in increasing the efficiency of an ORC when recovering waste heat. In this thesis the design, fabrication, and demonstration of a small scale scroll expander will be presented. Scroll expanders are positive displacement expanders that have consistently shown high efficiencies in literature. The fabricated expander was modified from a compliant scroll compressor. It was self-starting and had external control over the seal piston pressure. Spherical miter gears placed the power takeoff on the side of the expander which allowed the lubrication system designed by the compressor manufacturer to function properly. The gears had the unforeseen effect of acting as an oil mister which improved the lubrication of the scroll assembly. It was dynamically balanced to minimize vibration. This expander was demonstrated with both R134a and R245fa as working fluids with varying rotational speeds, expansion ratios, and achieved isentropic efficiencies typically over 70%. It achieved a maximum isentropic efficiency of 87.2% and a maximum power output of 1 [kW]. The performance characteristics such as speed, torque, and power were measured using two separate dynamometers. It was shown that the expander shows good off design performance and has an optimal pressure ratio of approximately 3.3. It was also shown that its performance is a weak function of rotational speed. It is important to note the significant impact that a larger diameter shaft and shaft seal can have on performance. Break-in is another important consideration when evaluating performance.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Keyword
Subject
Rights Statement
Language
Replaces
Additional Information
  • description.provenance : Submitted by Kevin Harada (robertke@onid.orst.edu) on 2010-09-30T17:08:54Z No. of bitstreams: 1 HaradaKevinJ2011.pdf: 6257982 bytes, checksum: 1d7f6792ad86b3606e2eaf657addfddd (MD5)
  • description.provenance : Made available in DSpace on 2010-10-11T21:35:52Z (GMT). No. of bitstreams: 1 HaradaKevinJ2011.pdf: 6257982 bytes, checksum: 1d7f6792ad86b3606e2eaf657addfddd (MD5)
  • description.provenance : Approved for entry into archive by Laura Wilson(laura.wilson@oregonstate.edu) on 2010-10-11T21:35:52Z (GMT) No. of bitstreams: 1 HaradaKevinJ2011.pdf: 6257982 bytes, checksum: 1d7f6792ad86b3606e2eaf657addfddd (MD5)
  • description.provenance : Approved for entry into archive by Julie Kurtz(julie.kurtz@oregonstate.edu) on 2010-09-30T19:12:09Z (GMT) No. of bitstreams: 1 HaradaKevinJ2011.pdf: 6257982 bytes, checksum: 1d7f6792ad86b3606e2eaf657addfddd (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items