PC-based and microcontroller- based temperature profiling of an LPG-fueled oven.

Date

4-2011

Degree

Bachelor of Science in Applied Physics

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Emmanuel A Florido

Abstract

The temperature profile of the prototype Liquid Petroleum Gas (LPG) fueled oven was determined by measuring the air temperature inside the oven during heating and cooling using a fabricated data-logging system. The thermocouples were directly connected to a signal conditioning and amplifier circuit while the output of the said circuit was connected directly into the microcontroller's Analog-to-Digital Converter (ADC) ports. The microcontroller outputs the data to a computer via its Universal Asynchronous Receiver/Transmitter (UART). The data read by using a Graphical User Interface (GUI) or Microsoft© Windows Hyper Terminal is saved directly into a text file for processing. The thermocouples used in the system were Type-N welded tip glass fiber insulated thermocouples. Calibration results showed a 4th degree polynomial relationship between the temperature and the thermocouple voltage with a correlation of 0.99 and a percent error of 0.1%. The average maximum temperature of the oven was approximately 226°C at the center where most of the heated air passed through as a result of convection. No even heating was observed during the data gathering sessions as the oven was allowed to operate with natural convection only. The air temperature's heating and cooling function was approximated by a bounded exponential function and an exponential decay function respectively, with both having correcting factors that served as a y-intercept (for heating function) and an asymptote (for cooling function). The functions were dependent on parameters such as initial temperature and the region's average maximum temperature which were determined experimentally. Factors such as burner location, amount of cool air entering the oven while heating and cooling, and internal component placements such as griller tray and sample oven loads, affected the average maximum temperature of a region inside the oven compartment. The minimum time needed for the oven air temperature to reach maximum was found to be approximately 48.5 minutes for all regions and greater than 2 hours for the sample oven loads.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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