TERMOTEHNICA 2/2014 37 ENVIRONMENTAL CONSEQUENCES AND RISK FACTORS AFTER A FIRE IN A ROAD TUNNEL Silviu CODESCU 1 , Alexandru CHISACOF 2 , Ion ANGHEL 3 , V. PANAITESCU 4 1 ''GHEORGHE ASACHI'' TECHNICAL UNIVERSITY OF IASI, MANUFACTURING ENGINEERING AND INDUSTRIAL MANAGEMENT FACULTY, ''POLITEHNICA'' UNIVERSITY OF BUCHAREST, ENERGETIC FACULTY, 2 ''POLITEHNICA'' UNIVERSITY OF BUCHAREST, 3 POLICE ACADEMY, FIRE OFFICERS FACULTY, 4 ''POLITEHNICA'' UNIVERSITY OF BUCHAREST, ENERGETIC FACULTY Abstract. Nowadays the world is facing increasly road traffic, due to high number of cars running on the street ant not highways. This is, unfortunately a very important source of pollution for the environment. Although there are many laws and projects, discussions and rules regarding environmental protection. The pollution from automotive industry mainly, for at least few decades, one of the major challenge for the next generation. In this context, the closed and semi-closed spaces will be affected by this kind of the pollution. Road tunnels can be framed in the category above mentioned, being exposed to a high traffic, because most of them are 20-30 years old and were built for the traffic estimated of those times. A simulation using Pyrosim software is based on the physical model in which one electrical fault accident involving a car appear. The accident, consisting in a fire event at one stationary car, is modeled at 1.5 m from height. Considering an electrical fault followed by a fire, we obtained temperature and CO 2 fields depending on time in this tunnel. These information allow us to realize an appropriate impact on the event in aim of minimizing the time for a promptly intervention. Also, with these size field parameters we may check even fresh air flux that can be dislocated. Keywords: environmental pollution, road tunnel fire, heat release, Pyrosim software. 1. INTRODUCTION Cars engines, either diesel, petrol or LPG are pollutant and emit noxious. Road tunnel pollution depends on the tunnel characteristics (length, ven- tilation systems, fire protection systems), number of cars, time of the day and year etc. One of the greatest level pollution that can be reached in a road tunnel occurs in a fire event. There are, also, others major pollution sources developing as factories, power and chemical plant etc., but the automotive industry is increasing, also the pollution due of it. With all new trends in behalf of replacing classic pollution fuels (diesel and petrol) in favour of unconventional fuels (electricity, as an example), the next decades of internal com- bustion using and exhausted burning gases will affect the road tunnels and semi-closed spaces of them. The pollution involving exhausted gases is really felt in the tunnels, this increasing drastically when accidents and fire events occurs. In this situa- tion, a traffic block with high release of pollutant substances per tunnel volume unit. The O 2 level may decrease at a dangerous concentration for human being and animals. It can be related then open spaces such road and highways represent most important pollution spaces, both closed and semi-closed ones also can be pollution areas. One of these is represented by road tunnels, which involve a high density of traffic each day. A very important factor to be considered is that most of the road tunnels existing today are 20-30 years old, so they were built in terms of traffic esti- mate at that time. In the past 10-15 years, the number of cars running on the roads significantly increased and the road tunnels built are practically the same. These conditions given, the pollution rate registered in road tunnels nowadays is higher than usually. It is also known that diesel vehicles are more pollut- ing that petrol ones, due to diesel burn properties. Measures taken over time indicated, in the morning and evening rush hours values of monoxide carbon just over 100 ppm and peak values up to 500 ppm were recorded at times [1]. Oxides of nitrogen were determined in some of the experi- ments and there was always more nitric oxide than nitrogen dioxide, experiencing eye irritation to users, also the cause of it was not analysed. The concentrations of pollution in the road tunnels do