综合管廊电缆舱基于射流风机的局部通风方法研究

Study on local ventilation method of cable compartment in utility tunnel based on jet fan

地下综合管廊长建设里程需求,廊内增设防火门使其电缆舱内的通风散热问题变得十分严峻.长度越长,管廊温度会逐渐升高,防火门增加会在管廊角落等狭小空间形成高温聚集区,均会阻碍管廊散热.采用局部通风的手段,目的是以较小的风量排除温度异常点,降低管廊全局通风换气量.运用数值模拟结合实验验证的手段对常规电缆舱与局部通风电缆舱在不同边界条件下进行比较,分析了局部通风策略的降温规律.结果表明:在同一总风量比例下增加换气次数可以强化风机控制区域的换热效果,且由于管廊总风量会与风机局部风量相互影响,一味增加总风量比例并不能明显改善管廊内温度分布.利用局部通风方法,电缆舱内降温幅度进一步增大,在局部区域会比常规电缆舱温度低2.58℃.局部通风方法能以较小的风量冷量达到与常规工况相似的降温效果,具备一定的节能优势.

The long construction mileage demand of the utility tunnel,and the addition of fire compartments in the tunnel makes the ventilation and heat dissipation problem in the cable compartment very serious.The longer the length,the temperature of the tunnel will gradually rise,and the increase of the fire door will form a high temperature gathering area in a small space such as the corner of the tunnel,which will hinder the heat dissipation of the utility tunnel.The purpose of local ventilation is to eliminate temperature anomalies with a small air volume and reduce the overall ventilation volume of the utility tunnel.In this paper,numerical simulation combined with experimental verification is used to compare the conventional cable compartments with the local ventilation cable compartments under different boundary conditions,and the cooling law of local ventilation strategy is analyzed.The results show that increasing the number of air changes under the same total air volume can strengthen the heat dissipation in the fan-controlled area,the total air volume of the tunnel will interact with the local fan air volume,and changing the total air volume does not significantly improve the heat exchange.By using local ventilation methods,the temperature reduction in the cable compartments is further increased,and the temperature in the local area will be 2.58℃lower than that in conventional cable compartments.The local ventilation method can achieve a cooling effect similar to that of conventional working conditions with a small air volume and has certain advantages in energy saving.