Estimation of the Maximum Annual Loads Modeling for Kingdom of Bahrain

The present paper proposes the impact of the air temperature on electricity demand as expected. It is clear that the annual maximum load is recorded versus the years starting by the year 2009 up to 2012. At present, the graph fitting technique is applied with some mathematical and computational tools based on the actual values of the years 2009 up to 2012 considering the lower values, the higher values and the average values of the annual maximum loads for Kingdom of Bahrain. For the three scenarios, the models are obtained by curve fitting technique. As well, the model of actual loads is obtained finally which has mostly the closest values obtained.

Annual Maximum Loads Estimation Modeling for Kingdom of Bahrain

The present paper proposes the impact of the air temperature on electricity demand as expected. The annual maximum load is recorded versus the years starting by the year 2009. At present, the graph fitting was applied with some mathematical and computational tools considering the lower values, the higher values and the average values of the annual maximum loads of Kingdom of Bahrain. For the three scenarios, the models are obtained by curve fitting technique. As well, the model of actual loads is obtained finally which has mostly the closest values obtained.

Analysis on the Pollution Load of Non-point Source Pollution and Surface Runoff of A Typical Village in Baiyangdian Lake Basin

[Objective] The characteristic of non-point source pollution of a typical village in Baiyangdian Lake basin was studied.[Method] The discharge of domestic sewage and solid wastes of the typical village was investigated,and both pollutant and nutrient element content were monitored,as well as the water quality and quantity of rainfall runoff.[Result] The non-point source pollution of livestock manure was far more serious than the sum of domestic sewage and domestic waste in this village,and the annual emission of total organic carbon(TOC),total nitrogen(TN) and total phosphorus(TP) was 37 794.0,4 102.9 and 1 923.7 kg,respectively.The event mean concentration(EMC)of chemical oxygen demand COD,TN and TP in rainfall runoff was 44.5,78.8,1.3 mg/L,respectively,and annual pollution load was 7.6,13.4 and 0.2 kg/hm2,respectively,while the annual pollution load of COD accounted for 5.1% of standard farmland,and that of TN and TP occupied 4.5% and 0.49% of slope farmland.[Conclusion] Livestock manure was the main source of non-point source pollution in the village and the annual pollution load of non-point source pollution was obtained.

Peak Load Modeling for Kingdom of Bahrain

Deriving some models to estimate the electrical demand for future for the Kingdom of Bahrain is carried out in the present study. The ambient temperature is taken into the account as well as the time factor (Year). The model was developed in away describing the electric power demand during a summer period. The estimated values of the maximum electrical load is obtained and evaluated on actual peak load data of the Kingdom of Bahrain.

Optimal Thermal Insulation Thickness in Isolated Air-Conditioned Buildings and Economic Analysis

The removal building heat load and electrical power consumption by air conditioning system are proportional to the outside conditions and solar radiation intensity. Building construction materials has substantial effects on the transmission heat through outer walls, ceiling and glazing windows. Good thermal isolation for buildings is important to reduce the transmitted heat and consumed power. The buildings models are constructed from common materials with 0 - 16 cm of thermal insulation thickness in the outer walls and ceilings, and double-layers glazing windows. The building heat loads were calculated for two types of walls and ceiling with and without thermal insulation. The cooling load temperature difference method, CLTD, was used to estimate the building heat load during a 24-hour each day throughout spring, summer, autumn and winter seasons. The annual cooling degree-day, CDD was used to estimate the optimal thermal insulation thickness and payback period with including the solar radiation effect on the outer walls surfaces. The average saved energy percentage in summer, spring, autumn and winter are 35.5%, 32.8%, 33.2% and 30.7% respectively, and average yearly saved energy is about of 33.5%. The optimal thermal insulation thickness was obtained between 7 - 12 cm and payback period of 20 - 30 month for some Egyptian Cities according to the Latitude and annual degree-days.

Static loading and vertical displacement at southern Siberia

Seismic method is usually used for elastic parametric estimation. This is why this method presents dynamic parameters of Earth. Frequency seismic range changes greatly from geodynamic modelling time. Now we have opportunity to use geodesy result for some years for elastic parameters estimation. Static solution from elastic theory may be used for the interpretation of long term results. It presents static elastic parameter. The inverse problem for different types of vertical surface loading on one year period is calculated. Two cases of loading with maximal and minimal area are presented. Results are determined by space geodesy and leveling methods. Current relation between atmospheric pressure and vertical displacements was estimated at the center of Siberian Anti Cyclone with size varied from 2000 km to 3000 kin. Pressure-displacement coefficients （PDC） can be achieved by three years obser- vation （0.997 mm/mbar for NVSK GPS station）. It is used for elastic module study of geology medium with maximum thickness up to 600 km. In the context of elastic model, the modulus of rigidity is estimated to be 113 GPa. Vast expanse of anti-cyclone may relate with rheology of crust and upper mantle. Smaller size of surface loading - local loading is seasonal variation of water reservoir. Annual vertical changes were obtained by leveling near the dam of the reservoir. PDC ratio was 1.15 mm/bar for these places. In elastic theory, the Young modulus E = 80 GPa （Poisson ratio = 0.25, the modulus of rigidity - 32 GPa） was calculated by sixteen years of leveling measurements. This result can effectively be represented for upper crust. Our results were checked by solution for coseismic displacement of Chyia- Altai earthquake （Sep. 27, 2003, M = 7.3）. Coseismic results calculated by static modules agree with experimental coseismic GPS data at 10% level.

考虑动态时间锚点和典型特征约束的年日均负荷曲线预测

基于负荷趋势性、周期性和受日历特征影响的特点,考虑动态时间锚点和典型特征约束,实现年日均负荷曲线精确预测。首先,根据历史和预测年的日历关联关系建立动态时间锚点矩阵,结合标幺化和周期平滑处理后的历史年日均负荷形状因子曲线,提出DTA-Soft-DBA方法以获得预测年的日均负荷形状因子预测曲线;然后,进行反标幺化和反周期平滑处理,并结合电力电量特征预测值进行典型特征约束修正,获得年日均负荷预测曲线。基于某地区的算例结果表明,所提方法具有更高的预测精度,其结果与典型特征预测值相吻合,符合年内时序变化规律,能有效整合具有不同日历特征的历史样本时序共性规律。

Deviation of design air-conditioning load based on weather database of reference weather year and actual weather year

In Japan,in order to determine the capacity of air-conditioning equipment,designers usually use the weather database of Reference Weather Year(RWY)to obtain the design air-conditioning load by using software such as New HASP/ACLD and Building Energy Simulation Tool(BEST)that are often used in Japan.In recent years,with the global warming due to climate change,the weather database used to calculate air conditioning load also changes.Thus,in order to determine an appropriate capacity of air-conditioning equipment for energy conservation of buildings,the deviation of design air-conditioning load calculated using the weather database of RWY and Actual Weather Year(AWY)should be discussed.In this paper,New HASP/ACLD was used to calculate the building heat loads of eight major Japanese cities over 30 years(1981-2010)between RWY and AWY.The heat load at an exceedance probability of 2.5%is defined as the design air-conditioning load in this paper.Comparing the design air-conditioning load obtained from RWY and AWY,it is shown that it is not necessarily the most appropriate when using the RWY to calculate the design air-conditioning load,especially for heating load in winter.Additionally,it is also shown that the annual heating load time ratio has decreased and the annual cooling load time ratio has increased over the 30 years.

成都市主城区道路冲洗径流污染研究

为评估城市道路冲洗径流污染程度,于2022年3—8月在成都市主城区内选取交通性路段、商业性路段、生活性路段和餐饮性路段进行冲洗水径流采样,通过对采样结果进行差异显著性分析,探究道路类型、降雨冲刷和较高气温(>30℃)对冲洗径流污染负荷的影响,综合考虑这3个因素推导道路冲洗径流年污染排放量估算公式。结果表明:不同类型道路冲洗径流污染程度存在差异,其中,餐饮性路段严重,生活性路段和商业性路段次之,交通性路段最轻;通过相关性分析推测,路两侧餐饮经营活动的污染排放是导致不同类型道路冲洗径流污染负荷值存在差异的主要原因;此外,较高气温(>30℃)会导致道路冲洗经流污染负荷升高,而降雨则反之;以成都市为例进行估算,2022年主城区道路冲洗径流中化学需氧量(chemical oxygen demand,COD)、总氮(total nitrogen,TN)、总磷(total phosphorus,TP)、悬浮物(suspended solids,SS)和氨氮(ammonia nitrogen,NH3-N)的排放量分别为3 506、167.56、30.32、1 441、55.687 kg。

水库运用对金沙江下游水沙变化的影响

大型水库运用后,金沙江下游水沙时空分布发生重大变化。本文基于金沙江下游干支流水沙观测资料,分析了下游流域水沙时空分布特性。1954-2021年,金沙江下游径流主要来源为金沙江中游及雅砻江,两者年均径流量为1150.73亿m^(3),占总来水量的80.75%;年输沙量主要来自下游区间,其年均来沙量为9943.17万t,占总输沙量的48.12%。运用Mann-Kendall突变检验、R/S分析以及双累积曲线法,分析水库运用对金沙江下游水沙变化趋势的影响。结果表明:1954-2021年金沙江下游水库运用对年径流量变化趋势无明显影响,而对流域年输沙量影响显著。金沙江下游出口水沙关系在1998、2010及2012年发生突变,主要原因为雅砻江、金沙江中游、下游干流上大型水库的拦沙运用,导致下游出口含沙量由1.82 kg/m^(3)逐步降低为1.31、0.86、0.01 kg/m^(3)。利用金沙江下游干支流水沙关系及沙量平衡原理,分别计算局部区间水库拦沙对流域总减沙量的贡献度。1998-2009年二滩水电站建成运行,金沙江下游出口总减沙率为35.16%,雅砻江水库拦沙对下游总减沙贡献度为32.88%;2010-2012年金安桥等中游水电站运行后,下游出口总减沙率为51.43%,金沙江中游、雅砻江、三堆子至白鹤滩区间和白鹤滩至向家坝区间对下游总减沙贡献度分别为21.54%、23.10%、30.67%、24.69%;2013-2021年金沙江下游梯级水库运行后,下游出口总减沙率为99.37%,4个区间对来沙量减少的贡献度分别为19.64%、14.72%、12.34%、53.30%。

Optimal air-conditioning load control in distribution network with intermittent renewables

The coordinated operation of controllable loads,such as air-conditioning load, and distributed generation sources in a smart grid environment has drawn significant attention in recent years. To improve the wind power utilization level in the distribution network and minimize the total system operation costs, this paper proposes a MILP(mixed integer linear programming) based approach to schedule the interruptible air-conditioning loads. In order to mitigate the uncertainties of the stochastic variables including wind power generation, ambient temperature change, and electricity retail price, the rolling horizon optimization(RHO) strategy is employed to continuously update the real-time information and proceed the control window. Moreover, to ensure the thermal comfort of customers, a novel two-parameter thermal model is introduced to calculate the indoor temperature variation more precisely. Simulations on a five node radial distribution network validate the efficiency of the proposed method.

双馈型风电机组传动链降载控制技术研究与仿真

为定量研究双馈型风力发电机组传动链的扭振控制,提出了一种基于卡尔曼滤波的反馈控制策略,并通过仿真计算的方式对比了传动链扭振的控制效果。以7.0 MW双馈型风力发电机组传动链为研究对象,采用卡尔曼滤波估计传动链扭振角度,并以低速轴扭振速度估计值为参考设计了发电机附加电磁转矩作用于风电机组转矩控制,与虚拟阻尼控制、无阻尼控制进行了20年全生命周期内的载荷与发电量计算对比。结果表明:经过卡尔曼滤波估计的低速轴扭角与实际值的相关性可以达到0.99;基于卡尔曼滤波的反馈控制分别与虚拟阻尼控制、无阻尼控制的关键差异为,传动链低速轴等效疲劳载荷分别降低2.11%、4.89%,传动链高速轴等效疲劳载荷分别降低1.99%、4.78%,发电量分别降低200、700 k W·h。卡尔曼滤波对传动链扭角估计较准确,且以卡尔曼滤波估计得到的低速轴扭振速度设计的附加电磁转矩对传动链扭振具有非常好的抑制效果。

State space reconstruction of classic methods in air-conditioning dynamic load calculation

In actual air-conditioning systems,accurate calculation of dynamic loads is demandedfor the energy and materials saving and comfort control.At about the beginning of the1970s,researchers abroad developed the harmonic wave method(HWM),thermal responsefactor method(TRFM)and Z-transfer function method(ZTFM),and made greatachievements on the transition of air-conditioning loads calculation from steady methods

冷热双向全周期维度蓄能空调系统设计优化

蓄能空调系统涉及“源”侧电力供应和“荷”侧建筑冷热需求双重动态变化特性,系统的容量配置是一个技术经济寻优问题。受室内外多种因素共同影响,建筑冷热负荷每天的逐时分布规律差别较大,传统上仅基于设计日等典型周期逐时负荷分布规律的设计方法使得蓄能空调系统容量的配置不合理。突破传统设计方法的不足,提出以空调系统全年运行性能为导向的冷热双向全周期维度蓄能空调系统性能化设计方法,能够考虑到全供暖季、全制冷季每天的逐时动态负荷分布规律,耦合建筑冷热负荷双向需求,获得更加科学合理的蓄能空调系统容量配置方案。用具体案例进行了设计方法展示。

换热器网络调优过程中热负荷回路的量化处理

本研究对换热器网络调优时的热负荷回路提出一种定量化处理方法。对于存在热负荷回路且断开回路后需要能量松弛的换热器网络,分别计算改进前后年度操作费用和年度设备费用的增减幅度,得到年度总费用的变化情况,以便对是否需要改进换热器网络进行决策。年度操作费用与能量松弛幅度和公用工程价格相关,而年度设备费用则与换热器面积、换热器材质和投资回收期等因素相关。能量松弛幅度和换热器材质对年度总费用有显著影响,在本换热器网络案例的研究中考虑了换热器材质对年度总费用的影响。本案例中,随着材质价格升高,换热器网络改进后与改进前年度总费用之差呈下降趋势,当其正负号发生改变时,换热器网络方案也将产生变化。当本案例中换热器使用低廉的材质使年度总费用之差为正值时,应维持原换热器网络方案不变;若使用昂贵的材质使总费用之差为负值时,则应采用能量松弛后的换热器网络方案。本研究对于过程工业中换热器网络的设计调优具有一定的指导意义。

长江干流河道水沙特性与变化趋势初步分析

建立了河道水沙量、水沙影响因子与水沙关系之间的联系,归纳了年径流量与输沙量的4类分析方法:频率统计法、适配线拟合法、相关分析法和累积曲线法。以长江干流河道控制水文站寸滩、宜昌、监利、汉口和大通19502005年实测数据为基础,初步分析了长江干流河道水沙特性与变化趋势。分析表明:①长江干流河道水量沿程增加、沙量沿程变化不大,沙量变化比水量变化约大10倍,水沙关系沿程减弱;②1950 2005年间,长江干流河道年径流量基本保持不变,年输沙量呈减小趋势,年均减小约1%,1990年后呈明显减小趋势,2000年后呈加速减小趋势;③上游来水来沙变化是控制葛洲坝工程和三峡工程(135 m水位运用期)坝下游水沙变化及河道冲刷的主要因素,其影响大于工程的调水调沙作用。

长江上游主要支流水沙特性及其影响因素分析

雅砻江、岷江、嘉陵江和乌江的水沙特性是决定长江泥沙变异的关键因素之一,关乎三峡水库的合理运行,关系着长江流域水资源的合理开发利用及水生态平衡.本文基于2002—2016年期间,长江主要支流设置的桐子林、高场、北碚、武隆4所重要控制性水文站水文泥沙监测资料,深入系统地探讨水文泥沙参量的变化特征及其影响因素,借助统计软件SPSS进一步分析水文泥沙参量的相关性.研究结果表明:在时序上,各支流年均含沙量、年输沙量、年输沙模数降低22.57%~91.54%,年径流量雅砻江、岷江和乌江增大3.28%~17.96%,嘉陵江降低1.58%;嘉陵江和乌江的中值粒径增大50%~80%.水电站的修建导致年均含沙量、年输沙量、中值粒径、年输沙模数降低5%~79.34%;强降雨、滑坡、塌方、泥石流、溃坝等自然灾害以及人为诱发滑坡和向河道倾倒土石体致使年均含沙量、年输沙量、年输沙模数增大20%~702.94%.参数间相关性由强到弱排序为年均含沙量和年输沙量/年输沙模数,年径流量和年均含沙量,年径流量和年输沙量/年输沙模数,年均含沙量和中值粒径,中值粒径和年输沙量/年输沙模数,以及年径流量和中值粒径.研究成果将为长江支流梯级电站的规划设计、三峡水库的合理运行提供理论支撑.

冲角变化对涡轮静叶栅流场的影响

为了研究亚临界600MW汽轮机高压第九级静叶原型和改型叶栅的变冲角气动特性,对两套环形叶栅在0°和±10°冲角下在哈尔滨工业大学能源科学与工程学院的低速环形风洞中进行了对比实验研究。实验结果表明,冲角变化仅影响改型和原型叶栅流道前半部分的横向压力梯度,对流道后半部分的流动影响不大;与原型叶栅相比较,改型叶栅不仅降低了流动损失,而且比原型叶栅具有更好的变冲角特性。

基于建筑负荷特性的地埋管地源热泵系统适用性研究

基于建筑负荷对地埋管地源热泵系统运行性能的影响给出了2个建筑负荷特性指标：建筑全年累计冷热负荷比R和建筑峰值冷热负荷比K。针对寒冷气候区的典型办公建筑,计算了5种R值和2种K值条件下地埋管地源热泵系统的地埋管进出口温度、土壤温度及热泵性能系数,得出了适用于地埋管地源热泵系统的R值范围为0.6-0.8,同时给出了不同K值条件下地埋管换热器的设计依据。

基于GPS和GRACE数据的三维地表形变的比较及地球物理解释

GPS技术能以高空间和高时间分辨率监测地表形变.但由于测量原理的不同,GPS监测的地表形变与GRACE存在差异.本文比较了ITRF2008-GPS残差序列与基于CSR的RL05版本的GRACE球谐系数的地表形变序列的差异.结果表明,GPS和GRACE的周年变化在高程方向上具有较好的一致性,但水平方向的差异明显.重点分析了影响GPS/GRACE地表形变差异(尤其是水平方向)的三个因素:不同GPS站时间序列间的不确定性,热弹性形变和区域形变.GPS站地表形变本身的不确定度在一定程度上导致了GPS/GRACE间的差异(特别是水平方向).结合热弹性形变理论指出,由温度变化引起的热弹性形变也是导致GPS/GRACE的南北方向差异的主要原因之一.因此利用GPS数据研究地表质量负载时,必须消除热弹性形变的影响.区域负载对GPS/GRACE水平方向差异的影响也是不可忽略的,特别是对欧洲区域.