室內(nèi)燃氣火災(zāi)中氣相轟燃機理的研究.pdf

1、河北工業(yè)大學(xué)碩士學(xué)位論文室內(nèi)燃氣火災(zāi)中氣相轟燃機理的研究姓名：閆美娟申請學(xué)位級別：碩士專業(yè)：熱能工程指導(dǎo)教師：吳晉湘20081201室內(nèi)燃氣火災(zāi)蔓中氣相轟燃機理的研究 iiSTUDY ON THE MECHANISIM OF GASEOUS FLASHOVER OCCURRS DURING COMPARTMENT GASEOUS FIRE ABSTRACT Flashover is an important transition dur

2、ing building fire, in the event of which, buildings and goods will be strongly destroyed. When gas fuel leaked in room and ignited, the spread of flame will transit from spreading as a form of flame surface to a kind of

3、volume flame, which is similar to flashover phenomenon, so it’s defined as gaseous flashover. The number of gaseous fires increases year after year, so it is important to study gaseous flashover and its mechanism. In th

4、is paper, a simplified model was found by abstracting the reality of room firstly. Then we study compartment gaseous fire and gaseous flashover by experiment combined with numerical simulation and the impact of window op

5、ening, leakage velocity, ignition position and box volume were analyzed. The critical condition of gaseous flashover and mechanism was studied. A great deal of experiment data and numerical simulation results was analyz

6、ed and several conclusions were found. The first, the numerical simulation results agreed well with the experimental ones, which meant that the study method of numerical simulation was satisfying. The second, at the same

7、 experiment conditions, the bigger of the room, the later gaseous flashover occurs and the longer gaseous flashover lasts. The faster of the leakage velocity, the larger of the feasibility of gaseous flashover. The third

8、, after studied a great deal of experimental data, we defined a parameter to describe the feasibility of gaseous flashover, and when which is larger then the upper critical value, it’s necessary that gaseous flashover oc

9、curs; when which is smaller than the lower critical value, it’s impossible that gaseous flashover occurs. The fourth, after computing heat release rate, we found that there were two peak value of heat release rate, the r

10、eason of the first one is that plenty of heat is released when premixed layer burned, the reason of the second one is that a lot of vortexes stirred the remained gas fuel and oxygen and made the fire fierce. KEY WORDS: g