大型汽轮机房人工环境的仿真和通风调节方案的研究

【作者】 王建新；

【导师】 朱华；

【作者基本信息】 浙江大学 ， 工程热物理， 2005， 硕士

【摘要】 目前,我国的能源日趋短缺,绿色建筑已成为研究热点,建筑设计必须考虑能源的节约利用。火力发电厂具有热负荷大、空间大及需求风量大的特点。在汽轮机房运转层及其以下,有很多发热设备、加热器和热力管道,其通风方案的选取至关重要。如果通风效果不好,有可能造成局部温度过高,不利于操作运行,甚至可能造成设备的故障,影响电厂生产的安全性。现有的通风方案在设计过程中大多依赖经验,很难有效地考虑到能源的节约和环境的优化,为此提出了应用FLUENT软件研究火力发电厂的通风系统,对汽轮机房内人工环境进行仿真计算,以得到更为合理、有效的通风设计方案,并为火力发电厂的汽轮机房通风和控制策略的研究提供理论依据。 本文通过对汽轮机房内热力设备的合理简化,利用AUTOCAD和Gambit软件建立模型和划分网格,然后建立数学模型、设定边界条件、进行区域离散,将复杂的偏微分方程转化为代数方程,最后选用合理的计算方法。计算时采用多机并行计算,提高了计算的效率。本文利用FLUENT仿真技术为工具,对不同季节汽轮机房内温度和速度分布规律、自然通风和机械通风的影响、风机开度及其运行模式对室内人工环境的影响、不同运行工况下特征点温度和速度变化规律以及控制方案等进行了研究。 通过计算,本文得到了风机开度大小对室内温度场和速度场的影响情况、一定风量下室外环境温度对室内特征点温度的影响、风机的运行模式对特征点温度和速度的影响、自然通风下风速对室内温度的影响以及开窗通风对室内温度的影响等规律。通过现场测试数据与理论计算进行比较,二者结果基本一致,因此证明了本文的计算方法的可行性和计算模型的合理性。本文的研究结果和研究方法为电厂通风供暖和空气调节的设计和研究提供了理论依据,对电厂汽机房通风方案的设计和改进具有参考价值。更多还原

【Abstract】 Nowadays, the energy runs short in our country. Energy saving in building has become a hotspot in research, and should also be considered during the building designing. Thermal power plant has the characteristics of high heat flux and ventilation flux, high temperature and large space, especially in the turbine machine room because there are many thermal equipments, heat exchangers and heating pipes in it. The selection of the turbine machine room ventilation project is crucial as it may lead to some local high temperatures that are inconvenient for operation if the ventilation is not very good, and even might cause malfunction of some machines and impact the security of the electrical power plant. The ventilation designing depends mostly on experience before and it is very difficult to considering energy saving. Thus the research of the ventilation system of power plant by CFD techniques is proposed in this paper. By simulating artificial environment in the turbine machine room by Fluent, the effective and reasonable ventilation system was obtained.Thermal equipment in the three floors of the turbine machine room was predigested reasonably in order to form calculable models. Grids and boundary conditions set up by AutoCAD, FLUENT and Gambit software. Complicated partial difference equations have been transferred into algebra equation by domain discretization. The calculation methods were selected to simulate the big turbine machine room. The parallel computation was used to improve computional efficiency and saving time. The temperature and velocity performance during different seasons, the comparison of the natural ventilation with the mechanical ventilation, and the influence of opening window on natural ventilation, the effect of the fan power on the artificial environment, the effects of operating conditions such as environment temperature, wind velocity on the indoor special points are studied in this paper.It is proved that it is feasible to simulate ventilation and heat transfer systems of huge turbine room by Fluent and the physical and mathematical model made are acceptable as the experimental data are identical with the simulation results. The opening extent of the fan has an inverse proportion with indoor temperature. The temperature change of special point is effected obviously by outdoor temperature and wind velocity. Operating mode and the opening of the fans are important factors to adjust the indoor temperature. The temperature of special points reduce with the increase of opening extend of fans and natural wind velocity. Operating mode has little influence on the temperature of special points. The results obtained in this paper have important values to the investigation and designing of the air conditioning system in the huge turbine machine room of the thermal power plant.更多还原