【作者】 陈军；

【导师】 付海明；

【作者基本信息】 东华大学 ， 供热、供燃气、通风及空调工程， 2010， 硕士

【摘要】 在现代社会的生活和工作环境中,室内热环境与人们息息相关,良好的室内热环境不仅有益于人们身心健康,还有助于提高室内工作效率和降低建筑能耗。然而,目前通过电扇和空调设备等人工方法建立室内热中性环境的同时,也导致了室内环境污染、能耗增加、人体体温调节功能和适应能力下降等一系列室内环境问题,这与自然风带来的自然、清新、柔和、多变、吹风感受舒适和降温效果良好的自然环境差异很大。本文综合运用信号测试技术、模拟控制技术、分形及混沌理论和热舒适理论,从理论和实验两方面研究了自然风与机械风的气流特性、自然风模拟技术、自然风与模拟自然风的分形及混沌特性和模拟自然风的热舒适性评价,目的在于研究自然风的特性并应用于空调装置,通过模拟自然风来改进空调末端装置的送风模式,改善吹风的人体热舒适感觉,提高室内热环境的舒适性和节约能源。研究中首先确定了对人体有良好热舒适作用的自然风概念,明确了自然风采样分析和空调装置自然风模拟研究的对象。通过对不同环境下自然风和不同设备的机械风进行采样,建立风速样本数据库,对采样的风速样本进行平均风速、风速概率分布、湍流度、自相关函数和频谱函数等气流特性参数分析。研究表明,采样的自然风与机械风的波动规律、风速概率分布、湍流度、自相关函数和频谱函数等气流紊动特性参数有明显的区别。以Takens定理为基础,基于相空间重构理论,运用G-P算法和小数据量法对采样的自然风进行计算,采用最小二乘法进行一元线性回归分析,得出表征自然风具有分形特性的分形维数和混沌特性的最大Lyapunov指数。同时提出了一种改进的简易识别无标度区间的方法,给出风速序列动态变化的影响因子及系统有效自由度。研究表明自然风具有分形及混沌特性。运用PLC信号控制技术,研制模拟自然风的空调装置,对空调装置在电机变速工况下模拟自然风和恒速工况下稳态机械风的特性进行测试,并分析两组工况下送风的波动规律、湍流度、概率分布、自相关性及频谱特性等气流紊动特性。研究表明,当采用自然风为控制信号来模拟自然风时,此装置能产生与控制信号自然风相似的的动态风,其气流紊动特性与控制信号有很好的一致性,其送风在低频区域能量较高,高频区域能量较低,频谱曲线变化剧烈;当装置电机恒速工况时,其出风频谱曲线变化平缓。同时,运用G-P算法和小数据量法对采样的模拟自然风和控制信号自然风进行计算,得到了表征模拟自然风和控制信号自然风均具有分形特性的分形维数和混沌特性的最大Lyapunov指数,结果表明模拟自然风与控制信号自然风具有相似的分形及混沌特性。基于人体热舒适方程,采用PMV-PPD热舒适性模型,在等温条件下运用PMV-PPD指标对模拟自然风进行指标评价,提出了动态风速与PMV-PPD的关系。同时,进行人体热舒适性实验对模拟自然风和稳态机械风两种不同送风模式的吹风感觉、热环境舒适性、热感觉指标TSV和热舒适指标TCV等指标进行主观问卷调查的投票评价。研究表明,与稳态机械风相比,模拟自然风适合于不同人体的广泛热舒适性范围,其吹风感觉、热环境舒适性、热感觉指标TSV和热舒适指标TCV等方面均有所改善,模拟自然风及其形成的动态室内热环境具有良好的热舒适性评价。更多还原

【Abstract】 In modern society, people’s living and working environment are related to the indoor thermal environment closely. Good indoor thermal environment is not only beneficial to people’s physical and mental health, but also helps to improve work efficiency and reduce building energy consumption. However, using electric fans and air conditioner by artificially can establish indoor thermal-neutral environment, it also leads to a series of indoor environment problems, such as indoor environment pollution, energy consumption increased, body temperature regulation function and adaptable ability reduced. It is different from natural environment, which has natural, fresh, soft, changeable, hair feel comfortable and good cooling effect by natural wind.Signal test technique, analog control technique, fractal and chaotic theory, and thermal comfort theory are used to study on the airflow characteristics of natural wind and mechanical wind, the simulation technology of natural wind, the fractal and chaotic characteristics of natural wind and simulating natural wind, and the thermal comfort evaluation of simulating natural wind. It is purposed to study the characteristics of natural wind, and apply to air-condition device. The simulation of natural wind is used to improve air supply mode of air-condition terminal device, which improve the thermal comfort of hair feel and the comfort of indoor thermal environment, and save energy.The natural wind concept is identified firstly in the research, which has good thermal comfort to human body. It is defined the object of natural wind analysis and natural wind simulation by air-condition device.Natural wind of different environment and mechanical wind of different devices are sampled to establish wind sample database. The airflow characteristic parameters of wind sample are analyzed, such as average velocity, velocity probability distribution, turbulence intensity, self-correlation function and spectral function. It is showed that the fluctuation, velocity probability distribution, turbulence intensity, self-correlation function and spectral function of sampled natural wind and mechanical wind are different significantly.Based on Takens theorem and phase space reconstruction theory, GP algorithm and small data sets are employed to calculate natural wind sample. The fractal dimension and largest Lyapunov index are obtained by using least squares linear regression analysis, which show natural wind has fractal and chaotic characteristics separately. At the same time, an improved method to identify scaleless region easily is put forward. Factors of velocity change and system effective degrees of freedom are given. It is showed that natural wind has fractal and chaotic characteristics.An air-condition device of simulating natural wind is developed by PLC signal control technique. The characteristics of simulating natural wind under variable speed operating condition and steady-state mechanical wind under constant speed operating condition by motor in air-condition device are tested and analyzed, such as the fluctuation, turbulence intensity, probability distribution, self-correlation and spectral characteristic. It is showed, when natural wind signal as control signal to simulate natural wind, the device can generate dynamic wind which is similar to natural wind. The turbulence characteristics of dynamic wind are good agreement with control signal, and energy is higher in low frequency region and lower in high frequency region. The spectral curve of wind changes rapidly. When the motor of device is constant speed operating condition, the spectral curve changes flatly. At the same time, GP algorithm and small data sets are employed to calculate the sampled simulating natural wind and control signal natural wind. The fractal dimension and largest Lyapunov index of simulating natural wind and control signal natural wind are obtained, which show fractal and chaotic characteristics separately. It is showed that fractal and chaotic characteristics of simulating natural wind and control signal natural wind are similar. Based on human thermal comfort equation, PMV-PPD thermal comfort model is used to calculate PMV-PPD index for evaluating simulating natural wind under isothermal condition. The relationship between dynamic velocity and PMV-PPD is put forward. At the same time, the voting indexes of questionnaire survey are obtained by human thermal comfort experiment under two different airflow models of simulating natural wind and steady-state mechanical wind, such as hair feel, thermal environment comfort, thermal comfort index TSV and thermal sensation index TCV, and so on. Studies have shown that simulating natural wind has wider thermal range than steady-state mechanical wind to suit for different human. The hair feel, thermal environment comfort, thermal comfort index TSV and thermal sensation index TCV of simulating natural wind are improved. The simulating natural wind and its dynamic indoor thermal environment have a good thermal comfort evaluation.更多还原