作用于杉木板预热区的侧向水喷雾临界水施加率试验研究

Effects of thickness of Chinese fir board upon lateral critical water flow rate

为了研究作用在壁面装饰材料预热区的侧向水喷雾的临界水施加率,选取10 mm、12 mm、15 mm和18 mm 4种不同厚度的杉木板开展符合ISO 9705标准的全尺寸试验。利用红外热像仪等温线方法划分杉木板的预热区和热解区,得到仅作用于预热区的侧向水喷雾的临界水施加率的试验数据,并同临界水施加率的计算值进行比较。结果表明,临界水施加率试验值与计算值吻合较好,其中10 mm和12mm薄型材料存在较小的误差。临界水施加率和杉木板厚度成非线性关系,随着杉木板厚度的增加,临界水施加率减小。

The paper is aimed to introduce our study results regarding the effect of Chinese fir board thickness upon lateral critical water flow rate when it is used as fitting materials. Chinese fir boards with four different thicknesses （i.e.10 mm, 12 mm, 15 mm and 18 mm） were selected to conduct full scale experiments in compliance with ISO 9705 standard. A new method in which isotherm （290- 310 ℃ ） was set with infrared thermography, was put forward to divide the preheat zone and pyrolyzing zone. The isotherm was monitored in the real-time observation window of infrared thermography. When the setting isotherm maintained in a steady state, the corresponding value of water pressure was recorded to calculate the lateral critical water flowing rate. On the other hand, the experimental data of lateral critical water flow rate were obtained when the water spray acted only on the preheat zone of board and they were compared with the calculated value at later stage. Our experimental data were in conformity with the theoretical data, though there were some minor disparity existed in the experiments with thin board materials （i. e. 10 mm and 12 mm）. To note, in the old computation model the thickness factor was ignored. There was a nonlinear relationship between lateral critical water flow rate and the thickness of Chinese fir board. With the increase of Chinese fir board thickness, the lateral critical water flow rate decreased.