Application of an engine management system to a stationary spark ignition engine

Date
2017-03
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Abstract
ENGLISH ABSTRACT: The subject of this report is the application of an engine management system to a small spark ignition engine, together with the installation of this engine to an existing small engine test bench. The purpose of this project is to further develop an existing small engine test bench to expand the testing capabilities of the Stellenbosch University Biofuel Test Facility. This was achieved by applying a fully controllable engine management system to a spark ignition engine and incorporating it into the existing small engine test bench. It allowed control over engine parameters such as ignition timing, fuel injection duration and, in turn, the air-fuel ratio. This report includes a literature review regarding spark ignition engines, engine testing and engine management systems. The main focus of the report is the application of an engine management system to a small spark ignition engine and its relevant subsystems, including the configuration and programming of the electronic control unit. The test procedures and data obtained are documented, verifying the engine’s response to ignition timing and fuel injection parameter changes, as well as illustrating the management system’s ability to control the engine over its operating range. In addition, this report also details the further development of an engine-indicating system employing fibre optic and piezoelectric pressure transducers to measure the in-cylinder pressure. The obtained indicating data was used to analyse the combustion process by means of a single-zone, zero-dimensional heat release model. From this model the rate of heat release together with the burn rate was obtained. The work done on the piston during various operating cycles was analysed, using both calculated and measured mean effective pressure values. It is then concluded that the developed engine management system is capable of controlling the test engine through its operating range and that the test setup as a whole is capable of producing accurate and repeatable results.
AFRIKAANSE OPSOMMING: Die onderwerp van hierdie verslag is die toepassing van 'n enjinbeheerstelsel op ʼn klein vonkontstekingsenjin, tesame met die implementering van hierdie enjin op ʼn bestaande klein enjin toetsbank. Die doel van hierdie projek is om die bestaande klein enjintoetsbank verder te ontwikkel om die toetsvermoëns van die Stellenbosch Universiteit Biobrandstof Toetsfasiliteit uit te brei. Dit is gedoen deur die toepassing van ʼn programmeerbare enjinbeheerstelsel op 'n vonkontstekingsenjin en deur die enjin te inkorporeer in die bestaande klein enjin toetsbank. Dit bewerkstellig beheer oor enjin parameters, soos ontstekingstyd, brandstof-inspuitingperiode en gevolglik die lug-brandstof verhouding. Hierdie verslag bevat ʼn literatuurstudie insake vonkontstekingsenjins, enjin toetse en enjinbeheerstelsels. Die verslag dokumenteer die toepassing van 'n enjinbeheerstelsel op ʼn klein vonkontstekingsenjin en toepaslike substelsels, insluitende die opstelling en programmering van die elektroniese beheereenheid. Die toetsprosedures en die verkrygde data is gedokumenteer in hierdie verslag. Dit verifieer die enjin se reaksie op verandering ontstekingstyd en brandstofinspuiting parameters. Dit illustreer ook die beheerstelsel se vermoë om beheer uit te oefen oor die enjin die enjin se verrigtingreik. Hierdie verslag dokumenteer ook die besonderhede van die verdere ontwikkeling van 'n insilinderdruk metingstelsel wat gebruik maak van optiese vesel sowel as piëzo-elektriese drukopnemers. Die verkrygde data is gebruik om die verbrandingsproses te ontleed deur middel van 'n enkel-sone, nul-dimensionele, hitte-vrystelling model. Van hierdie model word die tempo van hitte-vrystelling en die verbrandingstempo verkry. Die werk wat op die suier gedoen is, word ontleed deur die gemiddelde effektiewe drukwaardes te meet. Daar word dan tot die gevolgtrekking gekom dat die ontwikkelde enjinbeheerstelsel in staat is om die toets enjin stabiel te beheer, en dat die toets opstelling in staat is om herhalende en akkurate metings te neem.
Description
Thesis (MEng)--Stellenbosch University, 2017.
Keywords
Spark ignition engines -- Ignition, Piezoelectric transducers, Electronic engine-management systems (Automobiles), UCTD
Citation