冰蓄冷技术控制系统优化研究北大核心

随着空调的普及,它已经成为高峰期用电负荷增大的主要原因;冰蓄冷技术能够很好地解决在用电高峰期由于空调用电过多造成负荷过大的问题,实现电力资源的移峰填谷功能,但其也带来了总体电力消耗增加的问题。针对此问题,首先建立了与冰蓄冷空调系统相关的数学模型;然后,将系统最小寿命周期成本作为目标函数,采用粒子群算法(PSO,Particle Swarm Optimization)对冰蓄冷空调系统进行优化,并制定出最佳的运行策略。研究结果表明,方法在保证系统运行经济性的前提下,能够有效地降低冰蓄冷空调系统的电力消耗,实现冰蓄冷空调系统的优化,达到节省成本和资源的目的。     

冰蓄冷技术控制系统优化研究

随着空调的普及,它已经成为高峰期用电负荷增大的主要原因;冰蓄冷技术能够很好地解决在用电高峰期由于空调用电过多造成负荷过大的问题,实现电力资源的移峰填谷功能,但其也带来了总体电力消耗增加的问题。针对此问题,首先建立了与冰蓄冷空调系统相关的数学模型;然后,将系统最小寿命周期成本作为目标函数,采用粒子群算法(PSO,Particle Swarm Optimization)对冰蓄冷空调系统进行优化,并制定出最佳的运行策略。研究结果表明,方法在保证系统运行经济性的前提下,能够有效地降低冰蓄冷空调系统的电力消耗,实现冰蓄冷空调系统的优化,达到节省成本和资源的目的。     

干工况风机盘管加冰蓄冷新风系统空调过程研究

采用冰蓄冷装置作为新风系统处理机组 ( AHU )的冷源 ,结合设计实例 ,提出了干工况风机盘管加冰蓄冷新风系统空调设计方案 ,并就冰蓄冷新风系统 ( AHU )及风机盘管末端 ( FCU )的选择作一些探讨。     

冰蓄冷低温送风空调系统风管管路分析研究

研究得出冰蓄冷低温送风空调系统较常规空调系统在风管管路阻力及风管截面积的优越性。依据管路阻力计算公式利用VB语言编写风管比摩阻的计算程序,并利用该计算程序对相同工况下的典型的低温送风温度与常规送风温度的比摩阻进行计算,进而得到风管管路阻力,同时计算得出各送风温度下的风管截面积,并进行对比分析。相同计算条件下,冰蓄冷低温送风空调系统的风管沿程阻力是常规送风系统的40%—70%;采用8℃低温送风方式时,其风管截面积较常规空调可减少20%—30%。与常规空调系统相比,采用冰蓄冷低温送风空调系统可明显减小风管的沿程阻力和截面积,大大降低了风机耗能和建筑层高,节省了运行及建材费用。     

冰蓄冷辐射空调系统方案设计与能耗分析

基于温湿度独立控制思路,提出了一种冰蓄冷辐射空调系统,该系统将冰蓄冷技术和毛细管辐射空调技术相结合,系统还利用地源为毛细管辐射供冷提供主要的高温冷源,以实现电力负荷"削峰填谷"、降低能耗和更好的热舒适性。以杭州地区某办公楼为实例,进行了负荷计算、空调方案设计和蓄冷策略制定等工作,并与常规空调系统相比较进行了节能分析,结果表明冰蓄冷辐射空调系统具有明显的节能优势。     

上海创智311街坊项目冰蓄冷制冷机房系统优化设计

介绍了该工程项目的制冷机房的设计方案,采用冰蓄冷技术结合常规冷水机组的冷源形式,说明了冰蓄冷系统的特点及工况流程,通过分析空调负荷变化规律,分析了不同运行模式的可行性,从而得出优化运行模式,并详述了该运行模式下的具体供冷方案。     

低温送风空调系统的经济性分析

低温送风空调由于其在经济上优势,与蓄冷技术结合成为暖通空调领域的研究热点。从室内设计参数、送风温度、风机水泵的能耗和末端装置等方面探讨了对空调系统经济性的影响,并通过工程实例验证了低温送风技术的经济性优势。     

新型气体水合物蓄冷装置及其性能

1前言蓄冷空调是调峰平谷,缓解电力紧张、提高供电效率的有效途径。目前应用较广的是冰蓄冷。在冰蓄冷系统中,由于蓄冷时制冷机组必须工作在制冰工况,使得机组电耗增加30～40％,同时系统中必须采用不冻液循环。气体水合物能克服这些缺点。气体水合物是水在一种外来气体（如制冷剂、天然气等）的作用下形成的笼状结晶物。这种结晶体可在8～12”C的温度下相变,正适合于空调的制冷温度,且其相变潜热与冰相当,是一种理想的空调蓄冷介质。目前国际上较佳的蓄冷系统是美国开发的Rll气体水合物蓄冷系统,蓄冷温度为8．5”C,实际蓄冷能力…     

闭式循环太阳能空调系统热稳定性分析

闭式循环太阳能空调系统减少了蓄热水箱以及与之相关的热水循环泵,直接在太阳能集热器与制冷机组之间形成热水循环环路,系统得到简化的同时,降低了水泵功耗,具有明显的经济性和节能性。然而,由于系统水容量较低,闭式循环太阳能空调系统在运行过程中呈现出明显的波动性。通过研究主要过程参数的变化率,对系统运行的热稳定性进行了分析,并对系统的应用方式进行了探讨。     

E-Elman神经网络在冰蓄冷空调系统建模中的应用

冰蓄冷技术能够为空调系统带来显著的节能效果, 已广泛地应用在现代建筑当中, 准确的监测数据预测值有利于系统合理地运行; 针对实际冰蓄冷空调工程中的能源管理控制系统（energy management and control system, EMCS）数据采样周期较长所导致在系统制冰与融冰阶段数据不足的问题, 提出了一种改进的机组运行状况预测模型; 模型算法以数据变化趋势为依据, 在传统Elman中引入评价层以约束网络输出值, 增加计算针对性, 从而提高模型输出的准确性; 仿真结果表明, 此种建模方法解决了系统融冰与制冰阶段的数据突变及网络输出值局部最优解等问题, 与传统Elman网络结构相比, 其输出值更为接近测量值, 有效地提高了模型输出的真实性; 通过关联函数, 设计的模型对冷水机组的能源消耗也可起到预测作用, 进一步说明了其实用性。     

基于改进粒子群优化算法的火电厂机组负荷分配

以坑口电厂SIS系统机组负荷优化分配功能模块为应用背景,针对基本粒子群优化算法易陷入局部收敛、收敛速度慢的缺点,提出一种基于惯性权重非线性减小策略的改进粒子群优化算法。并且通过MATLAB与Visual C++混合编程,开发了机组负荷在线优化分配功能模块,提高了算法的计算效率和工程应用价值。     

New Measure of Economic Development Based on the Four-Colour Theorem

The location quotient is one of the basic quantitative tools for identifying the regional poles and the turnpikes of economic growth in spatial economy. The disadvantage of this traditional measure is the limited scope of economic information contained in it. The new measure of economic development proposed in the article encompasses a complex spectrum of phenomena in one number, as it takes into account the influence of the public administration sector, as well as top technology in the form of ICT and its practical business models. It also takes into account the digital prosumption and the platforms for participation. The participation platforms in the public administration sector are the websites of municipal public administration offices. A cluster analysis was used to distinguish four quality classes of these websites. These classes were assigned four different colours, which were then used to draw up a map of the selected province. Each municipality is marked with a colour that corresponds to the quality class of the website of the state administration office operating on its territory. The colour system resulting from the four-colour theorem and the corresponding dual graph play the role of a reference system in relation to each empirical colour distribution and another dual graph related to it. The measure of the economic development of a region is the degree of reduction of the dual graph corresponding to the empirical distribution of colours, which identifies the actual growth poles and determines the routes of growth. The presented indicator better and more precisely identifies poles and routes of economic growth than the traditional location quotient.     

分布式计算机软件数据整合平台设计

为实现当前经济市场中各应用软件的整合,提高我国各行业间个性化软件的开发能力,加强企业间的科学化系统软件设立,保证企业的高效运行,以及质量和系统维护能力;根据较为常用的分布式计算机系统,提出一种软件数据整合平台的设计;以商用软件整合平台设计为例,以开发模式、服务、技术结构、功能为研究方向,在企业正常运行时,可以实现业务系统功能开发以及门户单点登录,提高企业的个性化系统应用和经济效益;本文根据以上基本需求提出该功能软件平台进行设计,并在实际应用中分析出对于当前企业发展所提供的助力;结果显示,在当前经济发展状况下,有效地使用软件数据整合平台可以很大程度上提高企业的科学化管理和有效的资源分配,使企业在市场竞争中提高经济效益和社会效益。     

Effect of Savings on a Gas-Like Model Economy with Credit and Debt

In kinetic exchange models, agents make transactions based on well-established microscopic rules that give rise to macroscopic variables in analogy to statistical physics. These models have been applied to study processes such as income and wealth distribution, economic inequality sources, economic growth, etc., recovering well-known concepts in the economic literature. In this work, we apply ensemble formalism to a geometric agents model to study the effect of saving propensity in a system with money, credit, and debt. We calculate the partition function to obtain the total money of the system, with which we give an interpretation of the economic temperature in terms of the different payment methods available to the agents. We observe an interplay between the fraction of money that agents can save and their maximum debt. The system’s entropy increases as a function of the saved proportion, and increases even more when there is debt.     

土壤源热泵在合肥地区规模化应用绩效研究

介绍了土壤源热泵的工作原理,探讨了土壤源热泵空调应用于中央空调系统的设计方法,以及其主要部件地热换热器的埋管方式、结构、管材、运行等特点。选取几种常用的冷热源系统与土壤源热泵系统进行比较,参考合肥地区的能源价格,计算各方案的运行成本,用动态费用年值法评价了各方案的经济性。最后,对土壤源热泵系统的节能减排量进行了分析。     

Dynamics of wealth inequality

We study an agent-based model of evolution of wealth distribution in a macroeconomic system. The evolution is driven by multiplicative stochastic fluctuations governed by the law of proportionate growth and interactions between agents. We are mainly interested in interactions increasing wealth inequality, that is, in a local implementation of the accumulated advantage principle. Such interactions destabilise the system. They are confronted in the model with a global regulatory mechanism that reduces wealth inequality. There are different scenarios emerging as a net effect of these two competing mechanisms. When the effect of the global regulation (economic interventionism) is too weak, the system is unstable and it never reaches equilibrium. When the effect is sufficiently strong, the system evolves towards a limiting stationary distribution with a Pareto tail. In between there is a critical phase. In this phase, the system may evolve towards a steady state with a multimodal wealth distribution. The corresponding cumulative density function has a characteristic stairway pattern that reflects the effect of economic stratification. The stairs represent wealth levels of economic classes separated by wealth gaps. As we show, the pattern is typical for macroeconomic systems with a limited economic freedom. One can find such a multimodal pattern in empirical data, for instance, in the highest percentile of wealth distribution for the population in urban areas of China.     

Delayed feedback control via minimum entropy strategy in an economic model

In this paper minimum entropy (ME) algorithm for controlling chaos, is applied to the Behrens-Feichtinger model, as a discrete-time dynamic system which models a drug market. The ME control is implemented through delayed feedback. It is assumed that the dynamic equations of the system are not known, so the proper feedback gain cannot be obtained analytically from the system equations. In the ME approach the feedback gain is obtained and adapted in such a way that the entropy of the system converges to zero, hence a fixed point of the system will be stabilized. Application of the proposed method with different economic control strategies is numerically investigated. Simulation results show the effectiveness of the ME method to control chaos in economic systems with unknown dynamic equations.     

Exergy-Based Multi-Objective Optimization of an Organic Rankine Cycle with a Zeotropic Mixture

In this paper, the performance of an organic Rankine cycle with a zeotropic mixture as a working fluid was evaluated using exergy-based methods: exergy, exergoeconomic, and exergoenvironmental analyses. The effect of system operation parameters and mixtures on the organic Rankine cycle’s performance was evaluated as well. The considered performances were the following: exergy efficiency, specific cost, and specific environmental effect of the net power generation. A multi-objective optimization approach was applied for parametric optimization. The approach was based on the particle swarm algorithm to find a set of Pareto optimal solutions. One final optimal solution was selected using a decision-making method. The optimization results indicated that the zeotropic mixture of cyclohexane/toluene had a higher thermodynamic and economic performance, while the benzene/toluene zeotropic mixture had the highest environmental performance. Finally, a comparative analysis of zeotropic mixtures and pure fluids was conducted. The organic Rankine cycle with the mixtures as working fluids showed significant improvement in energetic, economic, and environmental performances.     

Development of low concentrated solar photovoltaic system with lead acid battery as storage device

Energy storage system powered by renewable energies is a viable option to meet energy requirement without addition of carbon footprints to the environment. This study involves development of theoretical and computational models for a solar photovoltaic (PV) system coupled with a lead acid battery. The study commenced with selection of most appropriate lead acid battery and PV system for installation in a representative location in Riyadh, Kingdom of Saudi Arabia. Various technical and economic parameters were assessed and calculated by computational approach. The optimized lead acid battery was integrated with low concentration solar PV panels (CPV) followed by a feasibility study. Theoretical model was developed for the integrated system to calculate various parameters of the CPV and lead acid battery. Technical and economic assessment of this coupled unit was calculated using a theoretical approach. The developed model was then subjected to computational approach for verification and validation analysis of the integrated system. The detailed assessment of batteries and integrated system show the applicability of this system in Riyadh region. The research will be extended to develop energy storage systems for remote areas using lead acid batteries.