Engineering optimization of an improved plancha stove

Abstract

This paper presents an engineering model of an improved plancha stove and demonstrates the use of advanced numerical analysis to improve plancha stove effectiveness. The advanced numerical techniques used include coupling a genetic algorithm searcher with a computational fluid dynamics evaluation of the stove performance. The plancha stove is a popular stove design. Built from steel, brick, or cement, the plancha stove is a sealed stove with a steel or cast-iron cooking surface. This permits the combustion gases to be exhausted from the living quarters via a chimney. Frying of breads (i.e., tortillas) and other foods is performed directly on the cooking surface of the stove. In contrast, cooking operations requiring boiling or simmering are performed by placing a pot containing the food on the cooking surface. Because of this two-tiered arrangement (flame-stove, surface-pot-food), the plancha stove is thought to be less efficient than stoves in which the cookpot is in direct contact with the flame. There are several standard efficiency tests; in most cases these involve heating and boiling a given amount of water, measuring the fuel used, and accounting for latent and sensible heat. On this basis, efficiency is established as the ratio between the heat absorbed by the water and heat released by the fuel. Plancha stoves are used for a variety of cooking tasks, and many of these tasks conflict with one another. For example, cooking tortillas requires a large area heated to moderate temperatures (∼250°C); simmering requires a small area of slightly higher temperatures (∼400°C); and bringing a large pot to a quick hard boil is most efficient with very high temperatures (>600°C). Because of this, traditional measures of efficiency do not provide a complete understanding of the fitness of the stove for specific applications. Using numerical modeling and experimental testing, this paper demonstrates how a measure of fitness can be used to provide a more complete understanding of plancha stove efficiency and effectiveness. This understanding can be used to assess various plancha stove designs and to determine which design provides the most benefit in a specific application.