Small engine oxygen depletion shutoff algorithm and implementation

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University of Alabama Libraries

During periods of power loss, gasoline portable generators can be used to provide power to objects such as household appliances and tools which would otherwise be useless. Such generators, however, can pose an immediate health risk and become potentially fatal if not used properly due to their poisonous carbon monoxide (CO) emissions. In an effort to prevent hazardous operating environments and dangerous situations, a previous contract between The University of Alabama (UA) and Consumer Product Safety Commission (CPSC) involved the design of a low CO emissions generator and implementation of an oxygen depletion safety shutdown feature. However, the algorithm developed for generator shutdown was based on a heuristic strategy and possessed several shortcomings in the way of nuisance shutoffs and response time. Another contract between UA and CPSC was initiated for purposes of improving upon the previous safety shutoff algorithm for a Coleman Powermate 7000 generator already modified for low CO emissions. A new shutdown feature was developed based on an oxygen estimation algorithm executed without the use of emissions sensors. The oxygen estimation algorithm was initially derived heuristically, based on test data collected at the National Institute of Standards and Technology (NIST) during the previous contract. It was the effort of creating a more reliable oxygen depletion shutdown algorithm across a broad spectrum of real-life operating scenarios from which this thesis resulted. This thesis presents the development, implementation, and testing of the new oxygen estimation based shutdown algorithm with an engine management system (EMS) equipped gasoline powered generator.

Electronic Thesis or Dissertation
Electrical engineering, Mechanical engineering