基于遥感数据源的大凌河分布式水沙耦合模型的构建与运用

以大凌河大城子水文站以上流域为例,将改进的垂向混合产流模型和改进的通用土壤侵蚀方程进行耦合,基于流域数字高程、土地利用及土壤类型分布等遥感数据,构建了基于水文模型的大凌河流域分布式水沙耦合模型,运用大城子水文站2001~2010年水文资料对模型参数进行率定和校验,并基于土壤侵蚀空间模拟结果,设定三种土地利用模式情景定量分析土地利用变化对流域土壤侵蚀的影响。结果表明,基于遥感数据源的分布式水沙耦合模型适合于大凌河流域的水土流失模拟,在率定期和验证期模拟的年含沙量相对误差均在20%以内,确定性系数都在0.5以上,可满足泥沙模拟的精度要求;三种土地利用模式情景中旱地面积增加10.0%,土壤侵蚀模数增加12.9%,林地和草地面积增加10.0%,流域土壤侵蚀模数分别减少14.63%和6.78%,为流域水沙耦合模拟和水土流失预测和防治提供了参考。     

通用河网二维水沙数值模拟

合理的水沙数值模式可为水流运动、河床演变的分析提供依据。基于通用河网二维水流的计算模式,将流域二维河网划分为单一河道、树状河道、环状河道和十字形河道等河网二维基本计算单元,采用二维浅水方程和悬移质输沙基本理论建立节点水位和悬沙控制方程,通过不规则稀疏矩阵的求解获得所有节点上的水位、流速及含沙量,实现全流域的二维水沙耦合计算。通过长江下游澄通河段的验证,在汊道处的计算能很好地体现流场间的相互作用,该模型能满足精度要求。     

多沙粗沙区5流域水沙变化及其对人类活动的响应

基于多沙粗沙区皇甫川、孤山川、窟野河、秃尾河和无定河流域（5个流域）中各水文站1956~2012年逐月降雨、径流和输沙实测资料,对比了5个流域水沙情势,并定量分析了降水和人类活动对水沙变化的贡献率。结果表明,1956~2012年径流量、输沙量减少趋势明显,输沙量主要集中在汛期,占全年的96%,2000年以后,输沙量急剧减少;截止2010年,该地区实测水库总库容67 899.5×104m3,仅为原库容的62.8%,同时该地区建有淤地坝9 114座,是水沙量减少的另一重要因素;在黄土高原北部区域,水库、淤地坝、灌区引水和煤矿开采等人类活动对径流量和输沙量的减少作用明显,也是水沙减少的关键因素。     

泾河水沙多年变化规律及驱动因素研究

为了解泾河多年水沙变化规律及其驱动力,基于泾河张家山水文站径流及泥沙数据,利用MannKendall趋势检验、Pettitt法、经验模态分解方法(EMD)等对年数据进行趋势、突变点和周期分析,并最终对水沙变化进行了归因分析。结果表明,泾河张家山水文站来水量和来沙量多年来呈减少趋势,并且在1990年代中后期发生突变;水沙变化主要拥有2年周期的波动,在发生突变后,波动幅度变的缓和,波动周期未发生变化;而水沙大幅度减少主要是由于上游流域退耕还林和人类直接取水拦沙活动所造成的。     

多沙粗沙区5流域水沙变化及其对人类活动的响应

基于多沙粗沙区皇甫川、孤山川、窟野河、秃尾河和无定河流域(5个流域)中各水文站1956~2012年逐月降雨、径流和输沙实测资料,对比了5个流域水沙情势,并定量分析了降水和人类活动对水沙变化的贡献率。结果表明,1956~2012年径流量、输沙量减少趋势明显,输沙量主要集中在汛期,占全年的96%,2000年以后,输沙量急剧减少;截止2010年,该地区实测水库总库容67 899.5×104 m3,仅为原库容的62.8%,同时该地区建有淤地坝9 114座,是水沙量减少的另一重要因素;在黄土高原北部区域,水库、淤地坝、灌区引水和煤矿开采等人类活动对径流量和输沙量的减少作用明显,也是水沙减少的关键因素。     

汾河流域梯级水库群水沙联合调节计算

关于水库水沙联合调节计算，国内外尚无成熟的方法。在工程实践中开发出了一套梯级水库群水沙联合调节计算耦合模型，该模型通过数据传输将水库群优化调度动态规划模型、水资源系统模拟模型和水库泥沙冲淤计算模型有机结合起来，耦合模型曾成功应用于汾河眩游下静游水库的可行性研究设计中，有效地提高了设计成果的精度和可靠性。耦合模型也适于应用在其他多沙河流的水库规划设计中。     

三峡水库蓄水运用后进出库水沙变化分析

为了研究三峡水库运用对进出库水沙条件的影响程度,利用水沙指标变化幅度公式,定量分析了三峡水库运用后2003~2009年进出库水沙指标的变幅。结果表明,三峡水库运用后,在均值上,4、5、6月的月均流量变幅最大,6、10、11月的月均含沙量和月均输沙率变幅最大,5、6、11月的月均来沙系数变幅最大;在极值上,非汛期最大流量、汛期最小含沙量、最小来沙系数和最小输沙率变幅最大;在极值之比上,汛期流量、含沙量、来沙系数和输沙率的最大/最小的变幅最大;在极值与年值之比上,汛期流量的最小/年均及非汛期含沙量、汛期来沙系数、年输沙率的最大/年均的变幅最大;在年内分布上,4、5、10月的月均流量/年均流量、5、6、8月的月均含沙量/年均含沙量和月均输沙率/年均输沙率、5、8、9月的月均来沙系数/年均来沙系数、汛期输沙率/非汛期输沙率、汛期含沙量/非汛期含沙量的变幅最大。     

黄河中游水沙过程对水土保持治理的响应研究

为了解水土保持治理对泥沙过程的影响,在分离了气候变化对水沙过程变化的影响后,结合变动范围法研究了黄河中游多沙粗沙区由于水土保持治理等人类活动引起的水文、泥沙变化的时空演变规律。结果表明,1953~2000年由水土保持工程导致较显著的黄河中游水文变化参数为反转数、10月月平均流量、90 d最小流量等12个IHA因子;较显著的泥沙变化参数为10月、4月月平均输沙量、年最大3 d输沙量等8个因子;黄河中游多沙粗沙区中多数流域的水文与泥沙变化程度具有相似的空间分布规律;工程措施对水沙过程变化的影响较直接,而非工程措施中植树造林对黄河中游水沙变化影响较大。     

长江口拦门沙段滩涂形态调整及冲淤响应机制

为研究长江口拦门沙段重要滩涂对水沙条件改变及人类活动的响应机制，以横沙浅滩、九段沙及南汇东滩为例，分析了拦门沙段重要滩涂的平面形态调整特点及其对环境因素变化的响应过程，并建立了代表滩涂面积与汛期水沙条件间的经验关系。结果表明，横沙浅滩、九段沙及南汇东滩近年来滩涂平面形态呈萎缩态势、沙尾总体滞涨，且横沙浅滩及九段沙有不同程度的串沟发育现象；横沙浅滩面积与前7年平均的汛期水流冲刷强度具有良好的幂函数关系，反映了浅滩面积随水沙条件变化的滞后响应过程；河口治理工程对滩涂局部的守护能较快抑制水沙条件改变所引起的冲刷，但其对周边区域可能产生缓慢、长期的累积影响。     

水库运行对径流—泥沙关系的影响分析

为研究水库运行对水沙关系的影响,以黄河上游龙羊峡水库为例,采用CEEMDAN方法对建库前后水沙序列进行多时间尺度分析,并与集对分析和信息熵理论相结合,分析水沙随机变化复杂性及水库运行对水沙关系的影响。结果表明,建库前水沙各序列具有较好的相关性,水库运行对多时间尺度下水沙关系影响显著;径流量、输沙量在短周期上以同一度和联系度为主,在长周期上以对立度为主,且水库运行后二者之间的同一度和联系度减小,差异度和对立度增大;水库运行后径流量与输沙量的熵值同步变化的关系被打破,二者之间熵值年际变化较稳定,说明水库运行改变了水沙同步变化的关系。     

渤海湾滨海平原河网地区降雨径流模拟

渤海湾滨海平原河网地区河道纵横交错,流态多样,降雨径流过程复杂。为准确模拟其降雨径流过程,在水文特征数据矢量化的基础上,将以二维非恒定浅水运动方程为控制方程的二维水动力模型与以河道汇流关系及水文方法为基础的一维河道拟序汇流模型相耦合,建立了适用于平原河网地区的降雨径流模型。经实测数据验证,模型可靠。研究表明,该模型可模拟计算渤海湾滨海平原2015年各时刻各处产流量、水位、流速及其变化过程;计算得出各河道的入水、出水水量及主要河流的入海水量,实现了对平原河网地区的降雨径流模拟。     

Mathematical simulation and experimental study of a modified zeolite 13X–water adsorption refrigeration module

In order to investigate the performance of the adsorption cooling module (16 mm in diameter and 1020 mm in length) with zeolite 13X and water as the adsorption working pair, a dynamic heat and mass transfer model was established based on the linear driving force (LDF) model. For the working process of the main parts of the module, including adsorber and condenser/evaporator, the coupled dynamic equations were set up for each stage of heating/desorbing and cooling/adsorbing, respectively. The model was then solved using the finite difference method, and the performance of the adsorber and condenser/evaporator of the module were analyzed. The calculated results were validated with experimental data and good agreement was observed. By means of the model, simulation and optimization of the adsorption cooling module can be further studied.     

基于IHA分析的小水电工程对黄尾河水沙的影响

为研究小水电工程对黄尾河流域生态水文效应的影响,以黄尾河水文站1972~2011年逐日平均流量和输沙率资料为基础,利用M-K法、滑动T检验法和差积曲线法确定突变年份为1998年,并用IHA法评价小水电工程修建后黄尾河下游河道径流的变化,利用双累积曲线法分析水沙变化趋势。结果表明,小水电工程的修建使黄尾河下游年均径流量和输沙量有所减小,水沙关系发生较大变化,水文指标整体改变度为63.2%,为中度改变,且各月生态流量皆低于RVA下限。研究结果为黄尾河流域生态水文变化需求提供了参考依据。     

分散型流域地貌汇流模型的总体构想

针对集总型流域地貌汇流模型的局限性，提出了分散型流域地貌汇流模型的总体构想，包括单元划分方法，单元汇流过程模拟、汇流参数关系，汇流模型结构，参数估计方法以及分散型模型特点等。     

Calculation of the polycrystalline PV module temperature using a simple method of energy balance

The performance of a photovoltaic module is studied versus environmental variables such as solar irradiance, ambient temperature and wind speed. Two types of simplified models are studied in this paper: a PV module temperature model and a PV module electrical efficiency model. These models have been validated utilizing experimental data from two experiments: a 850 Wp grid connected photovoltaic system and a p-Si module with eight temperature sensors integrated into the module. Both models have been coupled to determine the PV array output power versus the three meteorological parameters. This simple model using a simple energy balance and neglecting the radiation effects is in good agreement with the experimental data.     

Coupled reservoir-wellbore simulation of geothermal reservoir behavior

The reservoir simulator TOUGH and the wellbore simulator WFSA have been coupled to model flow of geothermal brine in the reservoir as well as in the wellbore. An outline of the structure of the two computer codes is given, together with the relevant equations. A new module, COUPLE, has been written to serve as an interface between TOUGH and WFSA. Two sample problems are given to illustrate the use of the coupled codes. One of these problems compares the results of the new simulation method to those obtained by using the deliverability option in TOUGH. The coupled computing procedure is shown to simulate more accurately the behavior of a geothermal reservoir under exploitation.     

Analysis of a full spectrum hybrid lighting system

Hybrid lighting is a new approach to lighting that integrates light from natural and electric sources. A two-axis tracking concentrator collects beam radiation which is reflected onto a mirror that divides the solar radiation into infrared and visible spectra. The visible light is distributed through optical fibers and combined with fluorescent lighting in specially designed luminaires. The infrared portion of the spectrum is used to generate electricity using a thermal photovoltaic array. A simulation of a hybrid lighting system has been created using the TRNSYS transient simulation program. The simulation incorporates the spectral properties of the hybrid lighting components as well as the spectral distribution of the incoming solar radiation that is based upon output from the SMARTS atmospheric transmittance model. An office building model is coupled with the hybrid lighting simulation to predict the annual energy impact upon lighting, heating, and cooling loads. Simulations were performed in six locations within the United States. Hybrid lighting systems performed best in Honolulu, HI and Tucson, AZ justifying system capital costs of $2410 and $1995 per module, respectively, based on a 10 year payback period.     

光伏组件在非标准测试条件下的能量分布

该研究基于非标准测试条件,结合五参数电学模型、热阻模型和损失模型,提出一种评估光伏组件能量分布的耦合模型.通过模拟数据和实验数据的对比,验证该模型在模拟光伏组件发电量和太阳电池温度方面的准确性,并研究非标准测试条件下光伏组件的运行状态和能量分布情况.结果表明,在某个晴天下,对于一个实际运行的光伏组件,21.9％的入射太...     

Long-term validated simulation of a building integrated photovoltaic system

Electrical and thermal simulations of a building integrated photovoltaic system were undertaken with a transient system simulation program using real field input weather data. Predicted results were compared with actual measured data. A site dependent global-diffuse correlation is proposed. The best-tilted surface radiation model for estimating insolation on the inclined surface was selected by statistical tests. To predict the module temperature, a linear correlation equation is developed which relates the temperature difference between module and ambient to insolation. Different combinations of tilted surface radiation model, global-diffuse correlation model and predicted module temperature were used to carry out the simulation and corresponding simulated results compared with the measured data to determine the best combination which gave the least error. Results show that modification of global-diffuse correlation and module temperature prediction improved the overall accuracy of the simulation model. The monthly error between measured and predicted PV output was lied below 16%. Over the period of simulation, the monthly average error between measured and predicted PV output was estimated to be 6.79% whereas, the monthly average error between measured and predicted inverter output was 4.74%.