通风方式和风速对综合管廊温湿度场的影响

Influence of Ventilation Modes and Air Speeds on Temperature and Humidity Field of Utility Tunnel

通过数值模拟方法,对青岛某综合管廊200 m长热力舱在3种通风方式(自然进风+机械排风、机械进风+自然排风,机械进风+机械排风)下和不同进风速度(3.0、3.5、4.O,4.5、5.0 m/s)下,冬季温度及夏季相对湿度分布特性进行对比分析。结果表明:祝械进风+自然排风方式下,进口速度为3.0 m/s时,沿综合管廊长度方向温度明显升高。机械进风+机械排风方式下综合管廊内温度最低,机械进风+自然排风稍高,两者温度最大相差1.8K。机械进风+机械排风方式下,随着进风速度的增大,同一截面上的平均温度降低。进风速度的增大也使综合管廊内壁的表面传热系数增加,综合管廊内的温度降低。机械进风+自然排风方式下,进风速度4.0 m/s时,综合管廊入口段相对湿度较低,中间段及出口段的相对湿度处于较高状态,同一截面竖直方向出现相对湿度分层,下部的相对湿度高于上部。3种通风方式下,进风速度4 m/s时,综合管廊沿长度方向相对湿度均呈现上升趋势,但在后半段趋于平缓。改变通风方式对除湿效果的影响不大。机械进风+机械排风方式下,不同进风速度下在130 m后综合管廊的相对湿度趋于一致。相同通风方式下,随着进风速度的增加,温度分布越均匀,而相对湿度的均匀性则越差。在进风速度相同时,不同通风方式下温湿度均匀性由优到劣依次是机械进风+机械排风、自然进风+机械排风,机械进风+自然排风。3种通风方式下,温度不均匀系数最大相差为15.6%,相对湿度不均匀系数最大相差为13.9%。

Through the numerical simulation method,the distribution characteristics of temperalre in winter and relative humidity in summer in 200 m heating compartment of a utility tunnel in Qingdao are compared and analyzed under three ventilation modles(natural air intake+mechanical exhaust,mechanical air intake+natural exhauust,mechanical air intake+mechanical exhaust)and different air intake speeds(3.0,3.5,4.0,4.5 and 5.0 m/s).The results show that under the mode of mechanical air intake+nalural exhauust,when the air intake speed is 3.0 m/s,the temperature along the length of the utility tunnel increases significantly.The temperature in the utility tunnel is the lowest under the mode of mechanical air inake+mechanical exhaust,and that under the mode of mechanical air in take+natural exhaust isshightly higher.The maximum temperature difference between both is 1.8 K.Under the mode of mechanical air intake+mechanical exhaust,as the air intake specd increascs,the average tenmperature on the same section decreascs.The increase of the air intake speed also increases the suface heat transfer-roefficient of the inner wall of the utility tunnel and redaces the temperature in the utility tunnel.Under the mode of mechanical air intake+nalural exhaust,when the air intake speed is 4.0 m/s,the relative humidity of the inlet section of the utiliay tunnel is lower,and the relative hamidity of the middle section and the outlet section is high.The relative humidity saratification appears in the vertical direction of the same section,and the relative haridity of the lower part is higher than than of the upper part.Under the three ventilation modes,when the air intake speed is 4.O m/s,the relative hunidity along the length of the utility lunnel shows an upward trend,but it tends to be flat in the second half。Changinag the veantilation modle has little effect on the dehu-suxidlificatiow effect.Undler the mode of mechanical airintake+mechanical exhawus,the relative hurmidity ofthe utility tunnel tends to be the same after 130 m atdlifferent air intake speeds.Under the same ventilation mode,as the air intake speed increases,the ltemperalture distribution becomes more uniform,and the rela-tive humidlity uniforwity becomes worse.When the airintake speed is the same,the ovder of teaperature and haanidity uniforzmity under dlifferent ventilation modes,frotm superior lo inferior,is echaical air iniake+mechanical exhaust,nalural air intake+mechanicalexhaust and mechanical air intake+natural exhaust.Under the three ventilation modes,the maximaum difference in leneperalure unevenness coefficien is 15.6%,and the maximum difference in relative humidity unevenness coefficient is 13.9%.