不同功能分区工业厂房内通风数值研究

发布时间：2018-05-28 23:06

本文选题：不同功能分区厂房 + 非稳态传热　；参考：《兰州交通大学》2017年硕士论文

【摘要】：工业厂房由于其生产工艺的特殊性,厂房结构和室内环境参数要求存在较大差异。目前,针对多种结构、不同能耗特点厂房所制定的工业节能规范还存在诸多不足。但工业厂房建筑面积大、多种节能措施的日益完善又为工业厂房通过改善通风策略等手段来节能提供了可能。对于具有不同功能分区的厂房,送风参数和气流组织对改善其内部空气品质、提高舒适性、降低能耗等非常关键。如何降低各功能分区间产生的污染物扩散到其余区域的速率,是实施合理通风策略的最终目标。另外,建筑围护结构的非稳态传热过程与工业厂房建筑能耗的评价密切相关。本文就以上问题对兰州地区某具有多功能分区的工业厂房通风进行探究。所做主要工作如下:(1)采用Z传递函数法对通过厂房围护结构的非稳态传热过程进行了分析。计算中,考虑不同时刻太阳辐射对各朝向围护结构的影响,与室外计算温度进行耦合计算得到室外综合温度,并用Z传递函数法计算得到了通过厂房围护结构进入室内的热流密度逐时值。(2)在给定送风温度条件下,研究不同送风速度(v=1.7m/s、2m/s、2.5m/s)对厂房内速度场、温度场和污染物浓度场的影响特征,结果表明:增大送风速度,沿房间高度方向各区域温度梯度分层现象更加明显,沿水平方向四个区域的温度分布更趋均匀。送风速度不同对不同分子质量的污染物扩散、迁移过程影响不同。随着送风速度的增大,区域3和区域2的O_3浓度降低,而区域1和区域4的O_3浓度增加。各区域C_7H_8的浓度随送风速度由1.7m/s增大到2m/s而增大,但随着送风速度进一步增大到2.5m/s时厂房各区域C_7H_8浓度降低。合理选取多功能分区通风的送风速度可以保证人体活动区域的热舒适性并实现有效提高排污效率。(3)维持送风速度为2m/s时,研究不同送风温度(T=291K、294K、297K)时厂房内的速度场、温度场和污染物浓度场分布特征,结果表明:送风温度较大时,厂房内沿高度方向温度梯度减小,温度分布更趋均匀。随着送风温度的增大,厂房内污染物迁移速率增大,由区域3进入其余各区域的O_3增多,厂房内O_3浓度整体水平升高。送风温度的增大使厂房上下温度梯度减小,被热羽流带入厂房上部的C7H8减小,除区域4其余各区域C_7H_8浓度升高。(4)对不同功能分区厂房进行混合通风的数值模拟结果表明,采用混合通风时,由于室外空气进入室内,厂房内空气温度混合均匀,同一水平面的温度梯度减小,高度方向温度分层明显。兰州夏季主导风向为ESE,污染物浓度受自然通风风向影响,高浓度区向厂房西南侧转移。本文是针对兰州地区某实际工业厂房进行通风研究的初步探索,工业厂房内生产工艺、污染源分布、污染物迁移扩散等的复杂性为不同功能分区厂房通风方案优化提出了更高的技术要求。要获得符合多目标评价的通风方案,还需要开展大量的现场实测工作。
[Abstract]:Because of the particularity of production technology, the industrial plant structure and indoor environmental parameters are different. At present, there are still many deficiencies in the industrial energy conservation specification for various structures and different energy consumption characteristics. However, with the large area of industrial buildings and the improvement of various energy-saving measures, it is possible for industrial buildings to save energy by means of improving ventilation strategies and so on. For the powerhouse with different function zones, air supply parameters and airflow organization are very important to improve the internal air quality, improve comfort and reduce energy consumption. How to reduce the rate of pollutant diffusion to other areas is the ultimate goal of rational ventilation strategy. In addition, the unsteady heat transfer process of building enclosure is closely related to the evaluation of building energy consumption. This paper probes into the ventilation of a multi-functional industrial factory building in Lanzhou area. The main work is as follows: 1) the unsteady heat transfer process through the enclosure structure is analyzed by Z transfer function method. In the calculation, considering the influence of solar radiation at different times on the envelope structure with different orientations, the comprehensive outdoor temperature is obtained by coupling calculation with the outdoor calculated temperature. By using the Z transfer function method, the time-by-hour heat flux density entering the room through the building enclosure structure is obtained.) under the given air supply temperature, the velocity field in the powerhouse with different air supply velocities of 1.7 m / s ~ (2) ~ (2.5 m / s) is studied. The effect of temperature field and pollutant concentration field on temperature field and pollutant concentration field shows that the temperature gradient stratification is more obvious along the height of the room and the temperature distribution is more uniform in the four regions along the horizontal direction. The effect of air velocity on the diffusion and migration of pollutants with different molecular weight is different. With the increase of the air supply rate, the concentration of O _ (3) in region 3 and region 2 decreased, while the concentration of O _ (3) in region 1 and region 4 increased. The concentration of C_7H_8 in each region increases with the increase of air supply velocity from 1.7m/s to 2m/s, but decreases with the increase of air velocity to 2.5m/s. When the air velocity of multi-function district ventilation can ensure the thermal comfort of the human body's active area and realize the effective improvement of sewage discharge efficiency. When the air supply speed is maintained at 2m/s, the velocity field in the factory building is studied when the air supply temperature is 291K / 294K/ 297K). The distribution characteristics of temperature field and pollutant concentration field show that the temperature gradient decreases along the height direction and the temperature distribution becomes more uniform when the air temperature is larger. With the increase of air temperature, the transfer rate of pollutants increases, and the total concentration of O _ 3 increases from region 3 to other regions. With the increase of air supply temperature, the temperature gradient of the upper and lower parts of the powerhouse decreases, and the C7H8 brought into the upper part of the powerhouse by hot plume decreases. The numerical simulation results show that the C_7H_8 concentration in the other regions except region 4 is increased. When mixed ventilation is adopted, because outdoor air enters the room, the air temperature in the workshop is mixed evenly, the temperature gradient of the same horizontal plane decreases, and the temperature stratification in the height direction is obvious. The dominant wind direction of Lanzhou in summer is ESE.The concentration of pollutants is affected by the wind direction of natural ventilation and the high concentration area transfers to the southwest of the workshop. This paper is a preliminary exploration of ventilation research for a practical industrial building in Lanzhou area. The production process and the distribution of pollution sources in the industrial factory building are discussed in this paper. The complexity of pollutant migration and diffusion puts forward higher technical requirements for the optimization of ventilation schemes for different functional sub-area powerhouses. In order to obtain the ventilation scheme which accords with multi-objective evaluation, it is necessary to carry out a lot of field measurement work.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU834.53

【参考文献】