浅谈天津地区被动式绿色建筑设计条件

被动式节能设计手段是建筑师在方案设计阶段需要重点考虑的策略。被动设计策略主要可以从规划布局设计、建筑单体设计、维护结构设计三个层次上进行研究。参考天津地区气候特征,依据《被动式超低能耗绿色建筑技术导则》对该地区的建筑保温、遮阳、采光、通风等环境因素进行评估与分析,从而对天津地区被动式节能建筑技术策略的适应性手段进行阐述。文中所列节能策略均考虑到天津地区自然气候特征,旨在为天津地区建筑设计实践及旧房改造提供参考依据。     

太阳能新风系统在被动式超低能耗建筑中的应用分析

为减少被动式超低能耗建筑的新风负荷对常规能源的消耗,同时,保持室内良好的空气品质,提出了一种太阳能集热系统与带热回收的新风系统相结合的方案。以西宁市为例,分析计算了该太阳能新风系统在不同集热器安装倾角、不同太阳能保证率下的集热器采光面积。结果表明在太阳能集热器的安装倾角为90°、对新风负荷的太阳能保证率为80%时每户住宅所需的集热器采光面积为4.7 m2,同时系统一年可节约能耗4 022.13 MJ,换算成电量约1 117.26 k W·h,表明该太阳能新风系统在被动式超低能耗建筑中的应用是经济可行的。     

Simple modelling procedure for the indoor thermal environment of highly insulated buildings heated by wood stoves

Space heating using wood stoves is a popular solution in many European countries. The nominal power of the state-of-the-art stoves is oversized compared to the needs of highly insulated buildings, leading to a risk of overheating. A modelling procedure is here developed in order to investigate the indoor thermal environment generated by wood stoves in such buildings. This procedure is kept simple to perform all-year detailed dynamic simulations (e.g. using TRNSYS) at an acceptable computational cost. A specific experimental set-up has been developed for validation, essentially regarding the interaction between the stove and the building. The largest source of error appears to be the thermal stratification in the room where the stove is placed. The experiments prove that the model gives a fair insight into the global thermal comfort. Therefore, it is possible to investigate the conditions required for a stove to be properly integrated in a highly insulated building.     

Moisture balance assessment at room scale for four cases based on numerical simulations of heat–air–moisture transfers for a realistic occupancy scenario

The moisture balance at room scale is influenced by the air change rate, moisture production and vapour transfer with the envelope. However, results may differ strongly from one study to another depending on the sizing of the ventilation system, the boundary conditions and the modelling of vapour transfer in the walls. This paper aims to provide a realistic comparison of usual construction techniques based on energy consumption, indoor comfort and durability. To achieve this objective, an existing whole-building heat–air–moisture simulation tool was selected to compute coupled transfer at room scale over an entire year. Moisture production due to occupancy was modelled using a stochastic approach. Four cases were selected to emphasize the differences of both a vapour-permeable wall assembly and a relative humidity sensitive ventilation system compared to common practices.     

Control of Corner Separation by Optimized Slot Configuration in a Linear Compressor Cascade

为控制压气机叶片吸力面与端壁处所形成的三维角区分离,本文在叶根处引入了从压力面到吸力面的槽道来控制角区分离流动。基于利用优化算法对叶根处槽道几何的优化结果,本文通过数值模拟和实验来分析槽道在不同进口攻角下对角区分离的控制效果。本文通过对比原始和开槽叶栅中总压损失、静压升和三维角区分离特征表明叶根处引入的槽道对角区分离有明显的控制效果。     

A numerical approach for planning offshore wind farms from regional to local scales over the Mediterranean

Renewable energy resources, such as wind, are available worldwide. Locating areas with high and continual wind sources are crucial in pre-planning of wind farms. Vast offshore areas are characterized by higher and more reliable wind resources in comparison with continental areas. However, offshore wind energy production is in a quite preliminary phase. Elaborating the potential productivity of wind farms over such areas is challenging due to sparse in situ observations. The Mediterranean basin is not an exception. In this study we are proposing numerical simulations of near-surface wind fields from regional climate models (RCMs) in order to obtain and fill the gaps in observations over the Mediterranean basin. Four simulations produced with two regional climate models are examined here. Remote sensing observations (QuikSCAT satellite) are used to assess the skill of the simulated fields. A technique for estimating the potential energy from the wind fields over the region is introduced. The wind energy potential atlas and the map of a wind turbine's functional range are presented, locating the potentially interesting sub-regions for wind farms. The ability of models to reproduce the annual cycle and the probability density function of wind speed anomalies are detailed for specified sub-regions.     

基于微尺度压电振动发电机的微电源设计

为弥补传感器网络传统供电存在的不足,该文设计了一种基于微尺度压电发电机的微电源,其可有效拾取周围环境中的振动能量,从而为低功耗的传感器系统提供电能。该电源由具有微尺度效应的微振动发电机与外部高效的无源峰值监测开关电路集成而得,结合Matlab仿真分析可知,其输出电压可达0.24V;无源峰值监测开关电路能保证压电片间电荷的全部输出,与具有经典接口的微电源相比其输出功率提高了3倍。     

利用多转发器直播卫星信号的外辐射源目标探测技术

根据某直播卫星实际信号的特点,分析了该直播卫星信号作为外辐射源的最大探测距离以及距离走动、频率扩散对目标探测的影响。通过实际信号的原理验证实验,进一步证明了该目标探测手段的可行性。提出了利用该直播卫星多路转发器信号实现相参积累的方法,并介绍了相参积累的原理。最后,利用对模糊函数的输出进行二维插值的方法,推导并仿真了相参积累的算法。仿真结果表明：利用该直播卫星信号作为外辐射源的7路转发器信号实现相参积累,检测信噪比可以提高8 dB。     

毫米波辐射计探测装甲目标立体特性建模与仿真分析

以往的毫米波被动探测系统中为了简单往往将装甲目标等效为平面金属目标,忽视了它的复杂立体特性。针对这一问题,提出了装甲目标立体特性的概念,理论推导了装甲目标立体特性的客观存在,仿真分析了装甲目标的立体特性,并概括总结了装甲目标立体特性的影响因素。文中结论对装甲目标毫米波辐射特性研究及毫米波被动探测领域具有一定的参考价值。     

基于变换域的局部最优纯方位航迹关联

针对同平台无源传感器纯方位线关联问题,提出了一种基于变换域的局部最优航迹关联算法。该算法采用霍夫变换( Hough Transform)将方位线映射到参数域等价为点描述,将不同方位线的点描述构建成时间的离散函数,利用时间对准形成具有相同时标的点序列。对关联门限内的目标构建指数判证函数,计算满足关联门限目标的关联矩阵,并确定各航迹关联程度,采用局部寻优方法求取最优关联度的目标作为关联对。实验表明,所提算法具有较好的稳定性及时效性,有效解决了同平台多方位线关联问题。