Modelado de fuentes generadoras de incendios eléctricos por termoconducción

Abstract

It is quite common to read or to listen for the media of information when news of fires are given, that the primary cause of the same one was "a short circuit", or some related one that in the end of the way falls in the fact that the primary source of energy for the fire is the electricity. From time to time is so common that we think "¿Which is the price that should pay for the progress?" therefore everywhere the technological development goes accompanied by an increment in the use of electric elements inside the projects developed.

Definitively, not for this we can be opposed to the advance and to the technological development, very on the contrary, knowing that all changes brings with they secondary repercussions, our labor like professionals of the engineering and project development dedicated to fire protection, is to ensure that research and technologies advance of the hand, so that solutions could be obtained for the increases of risk, by means of research and application of new technologies in fire protection without prejudice of the technological general advance of the systems, appliances and electric or electronic elements.

Our thesis is supported in a state of the art that compiles the physical facts and up-to-date theoreticians in matter of fire safety. Till now most of the investigation of fires by electrical reasons has been focused in the effect of the electric arch and short-circuit; nevertheless we present hypothetically a mathematical model in whom the thermal conduction of the electric conductors is a fundamental cause of fires, so much or more than the electric arches and short circuits.

The fundamental thing in our analysis during the investigation and even in the development of the model, is to understand what happens physically; beyond the technologies of current application, or beyond the hypothetical concepts based only on previous experiences with fires in electrical conductors, to understand the physical facts on which they are based, which are in his more basic form, the triangle of fire for the ignition and the tetrahedron of fire for the maintenance of the fire. The electrical fires do not escape to the general scheme of ignition and maintenance of the fire, therefore the model develops from physical demonstrated equations that do not contradict the theories of ignition and fire. The model does not contemplates results of previous stochastic models, although utilizes them in some sense as middle of comparison, but has been developed completely in a deterministic sense.

Basically, in matter of electrical systems security for the projects there are two foreheads of assault, and both try to avoid the fire; the first one is the front against the electrical arch and short-circuit, that has been widely developed so much theoretical as practically; the second one, is the front against the generation of heat of the conductor, who has not been developed so much theoretical or practically, like is the case of the first

In the development of this work a deep bibliographical review of the state of the art of the science is carried out, and of the state of the art of the fire protection technology; being careful of seeing which is the current condition in the development of the last concepts and technological advances that contribute to the comprehension of the electric ignitions, and which are the technologies developed to fight them; which are focused chiefly in terminal electric elements and connections among they.

Also a deep analysis of the model of ignition of each one, liquid, solid, or gaseous combustible is carries out; that could be utilized by the generating electric source, to give start to a fire. These models are exposed inside the state of the art of the science as previous verified models that gives physical-math bases to our model, and serve as parallel support to the same one. The physical-math bases that give direct support to our model are developed also verified,

Es bastante común leer o escuchar por los medios de información cuando se dan noticias de incendios, que la causa primaria del mismo fue “un corto circuito”, o “un panel eléctrico en mal estado” o “una conexión eléctrica mal hecha” o algún afín que al final de cuentas recae en el hecho de que la fuente primaria de energía para el incendio es la electricidad. En ocasiones esto nos pone a pensar “¿cual es el precio que tenemos que pagar realmente por el progreso?”; pues en todo el mundo las conexiones y equipos eléctricos inadecuados están a la orden del día y son a todas luces los elementos de ignición preferidos en la mayor parte de nuestros casos de incendios, y aunque no dudamos que las Oficinas de Seguridad y Revisión de Planos de los diferentes estamentos gubernamentales en el mundo entero, definitivamente se esfuerzan en la revisión de planos y proyectos, no ha sido suficiente para cambiar esta tendencia por parte de los elementos eléctricos. En Estados Unidos; país fundador de la asociación de seguridad y protección contra incendios mas grande del mundo, la NFPA (National Fire Protection Association), se tienen cientos de estudios, y análisis estadísticos desde muchos puntos de vista, para tratar de entender el porque de esta situación; pues confrontan los mismos problemas que nosotros, con incendios en buenos porcentajes por causas de la electricidad. Por ejemplo, en los últimos estudios publicados por NFPA que incluyen la recapitulación de causas líderes en incendios domésticos (en hogares); entre 1999 y 2002; los equipos de distribución eléctrica e iluminación se posicionan en el tercer lugar con el 9% de las causas, luego de los equipos identificados de cocina con el 20% y los equipos identificados de calefacción con el 11%. Sin embargo nótese que una gran parte de estos equipos de calefacción son también “equipos eléctricos” (aquellos que trabajan por resistencias eléctricas), y su falla y producción de calor en caso de un incendio, podría computarse también a la electricidad, lo que no ha sido hecho de esta forma.