THE QUASI-FULL LOAD METHOD FOR OPTIMUM STRUCTURAL DESIGN

This paper presents the quasi-full load method, which has many advantages. Its thinking is simple and direct. Its program is easily carried out, its convergence rate is fast and the optimal result is safe, reliable, economical and practical. This paper gives the mathematical model of the space trusses optimum design in practical project, and points out the shortcomings of optimum method often applied by engineers. The method and the peculiarity of quasi-full load structural design are gone into details.     

Analysis on the Load Characteristics and Process Design of Laminated Air-conditioning in Summer in the Powerhouse of Sanxia Hydropower Station

Considering the particularities in the powerhouse design of Sanxia Hydropower Station, the load characteristics and process design of laminated air-conditioning at the generator level in summer have been analyzed and discussed. Several methods of load calculation have been analyzed. Based on the results of calculation by these methods, the load characteristics and energy saving benefits have been discussed. Taking a normal section at generator level for an example, the design condition and refrigeration demand have been dissected, thus providing some experiences to this or other project.     

A RESEARCH ON THE ARCHITECTURE DESIGN AND BUILDINGS'' AIRCONDITIONING ENERGY SAVING

Taking part in the formulation of "the Standard for Chinese Hotel Air-Conditioning Energy Consumption," the authors study the thermal characteristics and carry out dynamic simulation of annual air-conditioning(heating) energy consumption of six well-known hotels located in Beijing, Shanghai and Guangzhon. This paper particularly analyses how the architectural design and the thermal characteristics (including building orientation, building plane, wal lstructure, window area and structure) effect air-conditioning load and air-conditioning energy consumption. Some views and suggestions on methods of architectural design are put forward, which aim to reduce energy costs, capital costs, and space requirement.     

COMPOSITE SYSTEM RELIABILITY EVALUATION CONSIDERING LOAD MODEL

The study for dealing with the load model in composite system reliability evaluation is almost at a standstill because of the inherent computational complexity. In this paper, an algorithm for composite system reliability evaluation considering load model is proposed. This method is powerful in computation because it can avoid unnecessary state enumeration by means of the relationship among basic reliability informations of load levels. As an example, the IEEE 24-node Reliability Test System is tested on VAX-11/750 computer. The average CPU time to calculate the reliability indices of the system corresponding to a load level is about 5 seconds.     

ECONOMIC LOAD RATE OF DISTRIBUTING TRANSFORMERS

On the basis of the analysis of load operational characteristics, this paper discusses the features of five methods for determining the economic load rate of transformers, and finally suggests a method to choose the economic load rate of the distribuing transformers.     

DECENTRALIZED LOAD FREQUENCY CONTROL OF HYDROTHERMAL POWER SYSTEM

The decentralized load frequency control (LFC) of hydrothermal power system is designed with overlapping information set. The conflicts among the generation regulation constraint (GRC) ,the process of reheat steam turbines,the governor dead-band effects,and the dynamic response of LFC have been coordinated.     

LOAD FREQUENCY CONTROL USING DECOMPOSED DISCRETE MODELS

Decomposed discrete models, can be used to design load frequency' controllers in multi-area power systems.Considering the exchanging real power in tie-lines as a measurable disturbance, the multi-area power system is decomposed into several subsystems.On the basis of generalized minimum variance control principles, an expanded control rule is induced. Using discrete models, the proposed method greatly decreases the number of varialles in be measured and simplifies the control system. The method is illustrated with a two-area power system example and its simulation Jesuits.     

粮仓应用铝箔空气层隔热冷负荷的计算

本文详细介绍了粮仓应用铝箔空气层隔热冷负荷的计算方法.为经济、合理地选择冷源设备提供了可靠的依据.     

THE DECENTRALIZED LOAD FREGUENCY CONTROL FOR MULTI-AREA POWER SYSTEMS

A decoupled load-frequency control model of a multi-area interconnecting power system is presented and a practical and effective decentralized control method is developed, which needs only its own state information and the information measured in it. It can also improve the stability and dynamic characters of the system. The dynamic simulation of the numerical example of a three-area interconnecting system with this controller showes the dynamic characters are almost the same as the centralized full state feedback optimal control.     

A PRIMARY STUDY ON A LIFTING PERFORMANCE CURVE ADAPTED FOR THE MECHANICAL LOAD MOMENT LIMITER

The condition when forces are applied to load mechnical mornent limiter of tow-er cranes is analysed and disctissed in this paper.A lifting performance curve adapted for the me-chanical load moment limiter is also obtained.And finally,the curve drawing method is explainedthrough the practical example.     

Influence of Indoor Temperature and Humidity on Thermal Comfort and Energy Consumption of Air-Conditioning Systems

Taking a central air-conditioning system as an example,this paper presents the influence of indoor design temperature and relative humidity on thermal comfort and energy consumption in an office building in Guangzhou,P.R.China.The study shows that under the identical indoor thermal comfort conditions,the air-conditioning system cooling load increases with the increase of indoor temperature.Increasing the indoor temperature can not decrease energy consumption.In order to reduce the energy consumption in a central air-conditioning system meeting the required indoor thermal comfort condition,an indoor design condition with larger relative humidity and lower temperature is recommended.     

THE DECOUPLJNG CALCULATION OF MULTI-AREA POWER SYSTEM LOAD FREQUENCY CONTROL

The calculating burden of the decoupling judgement of multi-area power system load frequeney centrel is very large by tranditional methods. This paper changcs the decoupling judgement problem into a minimum cost network flow problem. The solution algorithm is out-of-kilter . algorithm which is characterized by simple manipaultion, fast and reliable convergence. In the paper, we discuss and calculate the decoupling problem of two arca power system load frequency control. The results show that the proposed approach is feasible and effective.     

THE COMPREHENSIVE HYDRAULIC TESTING SET WITH A LOAD SENSING SYSTEM

This paper introduces the comprehensive hydraulic testing set for many kinds of hydraulic elements with hydraulic drive, hydraulic regulation and hydraulic loading. It has rational structure compact arrangement, reliable characteristics and advanced technique. In order to reduce the energy loss in the hydraulic system of the testing set, 1 ad sensing control is used. The static and dynamic characteristics of the load sensing system are analysed with the method of numeral simulation on computer. the testing witk load sensing control results show energy may be saved obviously and the heat load in hydraulic system may be reduced effectively, then testing quality is improved and the volume cf oil case is lessened. The lead sensing valve design is satisfied with simplifying structure so that it may be used reliably for the fixed flow hydraulic system of the testing set or other machines.     

AN A. C. LOAD FLOW ANALYSIS OF THE RELIABILITY EVALVATION OF COMPOSITE GENERATION AND TRANSMISSION SYSTEMS

An A. C. load flow analysis of the reliability evaluation of composite generation and transmission systems is presented on the basis of a fast outage simulation algorithm and an optimal model of active and reactive power adjustment after outage contingencies. The information of the first -level outage events is utilized for simulating higher -level outage events in the fast outage simulation algorithm ; the optimal model is satisfactory in speed and accuracy with the application of concentric relaxation and linear increment constraint on the comprehensive adjustment of active and reactive power. As an example. the IEEE Reliability Test System is tested and the results show that the method is accurate and well-matched in speed with the method studied by R. Bllinton, et al.     

Multi-server Technology for Internet-based Collaborative Design

A distributed Client/Multi-Server system is developed, in which the multi-server system controlled the collaborative clients by the mechanism of collision arbitration. This is made to avoid collaborative clients to become completely dependent on the single server and to improve the stabilization and reliability of the server system. A mathematic model of multi-server system based on queuing theory is presented. The solution of mathematic model is analyzed, which includes the average utilization frequency of servers, the length of queuing and waiting time. The theory system, which is intuitionistie and convenient, is redounded to reflecting the dynamic data change of the system, reasonably organizing the system and optimizing the design methodology of the multi-server system.     

PRACTICAL DESIGN OF PROBABILISTIC LIMIT STATES FOR STEEL STRUCTURES OF TALL BUILDING

For design purposes, this paper presents performance coefficients for steel structures of tall building, and furthermore design values of strength of heavy plates. The calculated results show that suggested coefficients meet the requirements of probabilistic limit states design method. They can serve as a supplement to GBJ17-88 and the expression of limit states design provided in this paper is available for reference in compilation of concerned standard.     

自适应加权最小二乘支持向量机的空调负荷预测

为了提高建筑空调负荷的预测精度,在分析空调负荷主要影响因素的基础上提出了一种基于自适应加权最小二乘支持向量机(AWLS-SVM)的建筑空调负荷预测方法。该方法根据预测误差的统计特性,采用基于改进正态分布加权规则,自适应地赋予每个建模样本不同的权值,以克服异常样本点对模型性能的影响。建模过程中采用粒子群优化(PSO)算法对模型参数进行优化,以进一步提高模型预测精度。基于DeST模拟数据将AWLS-SVM方法应用于南方地区某办公建筑的逐时空调负荷预测中,并与径向基神经网络(RBFNN)模型、LS-SVM模型及WLS-SVM模型作比较,其平均预测绝对误差分别降低了51.84 %、13.95 %和3.24 %,并进一步基于实际空调负荷数据将该方法应用于另一办公建筑的逐日空调负荷预测中。预测结果表明：AWLS-SVM预测的累积负荷误差为4.56 MW,亦优于其他3类模型,证明了AWLS-SVM具有较高的预测精度和较好的泛化能力,是建筑空调负荷预测的一种有效方法。     

MODEL EXPERIMENT OF HYPOID GEAR UNDER LOAD

The tooth contact mechanism of hypoid gear under load with similar model experiments is presented and the effect of mounting deflections and tooth deformation on tooth contsct is discussed. Thus, the basis of founding loaded tooth contact analysis calculating method of hypoid gear is brought about.     

华南地区空调控温储存大米技术研究

根据华南地区气候条件,在高温季节,通过采用空调制冷等综合控温技术手段,合理控制仓温粮温,基本实现了准低温、低药量储存大米,有效地延缓了大米品质劣变,抑制了虫霉活动。