冷却塔外复杂流场的数值模拟与实验研究
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摘要
对某能源中心楼顶的冷却塔组、烟囱、通风孔等散热设备及整个楼顶空间的流场与温度场进行了整体数值模拟,探讨了高温烟囱帽引起的排烟方向改变对冷却塔组进风处空气温度场及流场的影响,并进行了实验测试。结果表明,烟囱帽使排烟向下折转,导致冷却塔进风处下部位置空气温度显著升高;较低的烟囱烟气直排时,高温烟气会先抬升一段距离,然后受冷却塔进风处负压区吸引进入冷却塔内。
The numerical simulation of flow and temperature fields of cooling tower groups, chimneys, ventilation holes as well as the whole space of the distributed energy resource roof were carried out concerning an energy center building. The effects of the presence of chimney rain hat on temperature and flow fields at the inlet of cooling tower groups were discussed, which were also validated through the experiments. The results showed that the existence of the rain hat caused the high temperature backflow to the roof ground, so the temperature at the lower part of the cooling tower inlet was relatively higher. After removing the rain hat, the high temperature flue would lift a certain distance first and then be sucked into the cooling towers due to the negative pressure zone.
The numerical simulation of flow and temperature fields of cooling tower groups, chimneys, ventilation holes as well as the whole space of the distributed energy resource roof were carried out concerning an energy center building. The effects of the presence of chimney rain hat on temperature and flow fields at the inlet of cooling tower groups were discussed, which were also validated through the experiments. The results showed that the existence of the rain hat caused the high temperature backflow to the roof ground, so the temperature at the lower part of the cooling tower inlet was relatively higher. After removing the rain hat, the high temperature flue would lift a certain distance first and then be sucked into the cooling towers due to the negative pressure zone.
引文
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[6] ZALEWSKI W, GRYGLASZEWSKI P A. Mathematical model of heat and mass transfer processes in evaporative fluid coolers [J]. Chemical Engineering and Processing, 1997, 36(4):271-280.
[7] ANISIMOV S, PANDELIDIS D, DANIELEWICZ J. Numerical study and optimization of the combined indirect evaporative air cooler for air-conditioning systems [J]. Energy, 2015, 80(2):452-464.
[8] CHAHINE A, MATHARAN P, WENDUM D, et al. Modelling atmospheric effects on performance and plume dispersal from natural draft wet cooling towers [J]. Journal of Wind Engineering and Industrial Aerodynamics, 2015, 136:151-164.
[9] ZHAI Z, FU S. Improving cooling efficiency of dry-cooling towers under cross-wind conditions by using wind-break methods [J]. Applied Thermal Engineering, 2006, 26(10):1008-1017.
[10] LEE J H, MOSHFEGHI M, CHOI Y K, et al. A numerical simulation on recirculation phenomena of the plume generated by obstacles around a row of cooling towers [J]. Applied Thermal Engineering, 2014, 72(1):10-19.
[11] 李永华,甄海军,潘昌远,等. 横向风速影响下湿式冷却塔内温度场及防冻措施的数值研究 [J]. 中国电机工程学报, 2013, 33(8):58-64. LI Yong-hua, ZHEN Hai-jun, PAN Chang-yuan, et al. Numerical study on the temperature field in wet cooling tower and the anti-icing measures under the influence of horizontal wind speed [J]. Proceedings of the CSEE, 2013, 33(8):58-64. (in Chinese)
[12] CHAO D, LI J, YANG L. Effects of acoustic barriers and crosswind on the operating performance of evaporative cooling tower groups [J]. Journal of Thermal Science, 2016, 25(6):532-541.
[13] GE G, XIAO F, WANG S, et al. Effects of discharge recirculation in cooling towers on energy efficiency and visible plume potential of chilling plants [J]. Applied Thermal Engineering, 2012, 39:37-44.
[2] ELLIS R M. Cooling tower noise generation and radiation [J]. Journal of Sound and Vibration, 1971, 14(2):171-182.
[3] SCHAUDINISCHKY L, SCHWARTZ A. Noise control of air conditioning cooling towers [J]. Heat Transfer, 1971, 22(1):509-514.
[4] LU Y, GUAN Z, GURGENCI H, et al. Experimental study of crosswind effects on the performance of small cylindrical natural draft dry cooling towers [J]. Energy Conversion and Management, 2015, 91(5):238-248.
[5] LU Y, GUAN Z, GURGENCI H, et al. Windbreak walls reverse the negative effect of crosswind in short natural draft dry cooling towers into a performance enhancement [J]. International Journal of Heat and Mass Transfer, 2013, 63(3):162-170.
[6] ZALEWSKI W, GRYGLASZEWSKI P A. Mathematical model of heat and mass transfer processes in evaporative fluid coolers [J]. Chemical Engineering and Processing, 1997, 36(4):271-280.
[7] ANISIMOV S, PANDELIDIS D, DANIELEWICZ J. Numerical study and optimization of the combined indirect evaporative air cooler for air-conditioning systems [J]. Energy, 2015, 80(2):452-464.
[8] CHAHINE A, MATHARAN P, WENDUM D, et al. Modelling atmospheric effects on performance and plume dispersal from natural draft wet cooling towers [J]. Journal of Wind Engineering and Industrial Aerodynamics, 2015, 136:151-164.
[9] ZHAI Z, FU S. Improving cooling efficiency of dry-cooling towers under cross-wind conditions by using wind-break methods [J]. Applied Thermal Engineering, 2006, 26(10):1008-1017.
[10] LEE J H, MOSHFEGHI M, CHOI Y K, et al. A numerical simulation on recirculation phenomena of the plume generated by obstacles around a row of cooling towers [J]. Applied Thermal Engineering, 2014, 72(1):10-19.
[11] 李永华,甄海军,潘昌远,等. 横向风速影响下湿式冷却塔内温度场及防冻措施的数值研究 [J]. 中国电机工程学报, 2013, 33(8):58-64. LI Yong-hua, ZHEN Hai-jun, PAN Chang-yuan, et al. Numerical study on the temperature field in wet cooling tower and the anti-icing measures under the influence of horizontal wind speed [J]. Proceedings of the CSEE, 2013, 33(8):58-64. (in Chinese)
[12] CHAO D, LI J, YANG L. Effects of acoustic barriers and crosswind on the operating performance of evaporative cooling tower groups [J]. Journal of Thermal Science, 2016, 25(6):532-541.
[13] GE G, XIAO F, WANG S, et al. Effects of discharge recirculation in cooling towers on energy efficiency and visible plume potential of chilling plants [J]. Applied Thermal Engineering, 2012, 39:37-44.