Lu Caiyuan, Zhong Xiaoxing, Chen Mujun, Liang Yuntao
Key Laboratory of Gas and Fire Control for Coal Mines, Ministry of Education, China University of Mining and Technology, Xuzhou 221116, China.
School of Safety Engineering, China University of Mining and Technology, Xuzhou 221006, China.
ACS Omega. 2024 Jul 10;9(29):31646-31656. doi: 10.1021/acsomega.4c01862. eCollection 2024 Jul 23.
In order to solve the difficulty of the existing compressed air foam system with low FER and difficult in having both the FER and range. A new type of foam generator for CAFS was designed, an air-liquid coaxial foam generator, which produces foam with high FER (the ratio of the foam volume to the volume of the foam solution) and large output momentum. In this paper, experiments on the foam production performance of a gas-liquid coaxial jet foam generator were carried out with different parameters, such as liquid flow rate, gas flow rate, and foam output end diameter. The variation of FER, foam half-life, range, foam volume, and compressed air utilization rate with the experimental parameters were analyzed. The results show that the foaming performance of the foam generator tends to rise in the range of 8-12.4 m/h at a fixed gas flow rate, the FER and foam half-life are negatively related to it, and the foaming performance tends to decrease in the range of 12.4-18 m/h. The best foaming performance was achieved when the liquid volume of the foam generator was 12.4 m/h. For the liquid volume value in different intervals, the foaming performance varies with the air supply volume. When the liquid volume is higher than 12.4 m/h, increasing the air supply volume is beneficial to improve the foaming performance, and when the liquid volume is lower than 12.4 m/h, increasing the air volume does not improve the foaming performance. The effect of the diameter of the foaming chamber on the foaming performance is not monotonic, and an optimum value exists. Compared with similar devices, the gas-liquid coaxial jet foam generator has strong advantages in FER and range and has better application prospects for fire control in restricted spaces.
为了解决现有压缩空气泡沫系统灭火效能（FER）低、难以兼顾高FER和作用距离的难题，设计了一种新型的压缩空气泡沫系统泡沫发生器——气液同轴泡沫发生器，其能够产生高FER（泡沫体积与泡沫液体积之比）且输出动量较大的泡沫。本文针对气液同轴射流泡沫发生器，开展了不同参数（如液体流量、气体流量、泡沫输出端直径）下的泡沫产生性能实验，分析了FER、泡沫半衰期、作用距离、泡沫体积及压缩空气利用率随实验参数的变化规律。结果表明，在固定气体流量时，泡沫发生器的发泡性能在8 - 12.4 m/h范围内呈上升趋势，FER和泡沫半衰期与之呈负相关，在12.4 - 18 m/h范围内发泡性能呈下降趋势，泡沫发生器液体流量为12.4 m/h时发泡性能最佳。对于不同区间的液体流量值，发泡性能随空气供给量而变化，当液体流量高于12.4 m/h时，增加空气供给量有利于提高发泡性能，当液体流量低于12.4 m/h时，增加空气量并不能提高发泡性能。发泡腔直径对发泡性能的影响并非单调，存在一个最佳值。与同类装置相比，气液同轴射流泡沫发生器在FER和作用距离方面具有较强优势，在受限空间灭火中具有较好的应用前景。
