Experimental Studies on Heating and Burning of Fuel Droplets with Various Compositions

Abstract

In this research single drop biofuel is used to investigate the evaporation and combustion characteristics to improve the combustion efficiency of the industrial furnace This research consists of two experiments such as single suspended droplet experiment and free falling droplet experiment The single suspended droplet experiment is used to investigate the evaporation behaviors of the single droplet in a stationary motion at three different high ambient temperatures and the free falling droplet experiment is used to investigate the combustion behaviors of the freely falling isolated droplet in the high temperature oxidizing combustion chamber The suspended droplet experiment of biofuels results showed that some admiring phenomena were founded such as expansion micro-explosion ejection bubbling char formation and char ignition In heavy oil series fuels evaporation observed without char formation For bio-oil series fuels at 400oC after the evaporation of volatile components in the fuel char formation was observed without ignition of char particles and increasing to 500oC leads to ignition of char particles Increasing ambient temperature will be increasing evaporation rate and a number of micro-explosion per sec bubbling swelling phenomena of biofuels and reducing the initial heat absorption period droplet lifetime In free falling droplet experiment result shows that the evaporation constant rate was higher for DAO fuel among other fuels For DAO and DAO: PFO (1:1) fuel the variation of drop squared diameter with time curve was linear Ignition burning and extinction of flame were observed in the free falling droplet experiment and we observed some interesting events in the burning droplet such as fuel jet ejection when the gas velocity and droplet velocity were similar or equal and micro-explosion was observed after the droplet burning For NCKU A & NCKU B fuels there was no evaporation occurred and burning behaviors of the droplet were not observed

Date of Award	2017 Jan 17
Original language	English
Supervisor	Ta-Hui Lin (Supervisor)