Exergistic approach to estimation of energy-ecological efficiency and fire hazard of cargo transportation on railway transport
Introduction. One of the main trends in the sustainable development of the national economy is an increase in the energy efficiency of processes and industries, fire and industrial safety, rational use of natural resources, and reduction of negative man-made impact. A method for improving energy efficiency and predictive reliability is exergy analysis. However, it is not enough specified for fire safety. Theoretical basis. Exergy is a thermodynamic concept, used for many years within engineering analysis of chemical and mechanical processes and systems. In modern science the concept of exergy is associated with efficiency, economy, and environmental feasibility. However, exergy analysis is practically does not affect issues related to fire safety. Result and discussion. Consider the possibility of using an exergy approach to assess the fire danger of rail transport. At first we establish relationships between thermodynamic characteristics and fire and explosion hazard ratio. The objects of research are hydrocarbons, which are the main components of liquid and gaseous fuels. Exergy is considered as one of the conditions for the occurrence of a fire. We have determined the dependencies between the specific chemical exergy and the fire and explosion hazard ratio of substances for railway transport. Specific chemical exergy was found from literature sources. Lower heat of combustion, flash point, temperature limits of flame propagation, concentration limits of flame propagation parameters were considered. Formulas for calculation are proposed. The correlation of determination R2 was calculated (from 0.950 to 0.999). Using the exergy method of analysis has some preference for fire safety. Conclusions. The offered approach allows to consider in a complex way the questions of energy-ecological efficiency and fire danger of cargo transportations of a railway transportation. It also makes it possible to identify the links between thermodynamic characteristics and technical, economic and environmental indicators and to assess the fire and explosion hazard of substances and materials for railway transport. The obtained dependences allow to rank substances of fuel and energy purpose in terms of their energy efficiency and fire hazard.