Identification of time-varying system and energy-based optimization of adaptive control in seismically excited structure

The combination of structural health monitoring and vibration control is of great importance to provide components of smart structures.While synthetic algorithms have been proposed,adaptive control that is compatible with changing conditions still needs to be used,and time-varying systems are required to be simultaneously estimated with the application of adaptive control.In this research,the identification of structural time-varying dynamic characteristics and optimized simple adaptive control are integrated.First,reduced variations of physical parameters are estimated online using the multiple forgetting factor recursive least squares(MFRLS)method.Then,the energy from the structural vibration is simultaneously specified to optimize the control force with the identified parameters to be operational.Optimization is also performed based on the probability density function of the energy under the seismic excitation at any time.Finally,the optimal control force is obtained by the simple adaptive control(SAC)algorithm and energy coefficient.A numerical example and benchmark structure are employed to investigate the efficiency of the proposed approach.The simulation results revealed the effectiveness of the integrated online identification and optimal adaptive control in systems.

Strategies for Introducing Energy Saving Idea into Residential Planning and Design in Urban and Rural Areas of China

Currently,energy saving design has been conducted on single building but not on the whole residential community in urban and rural areas.So,the paper has proposed energy saving measures for residential planning from the perspective of site selection and layout of buildings.Specific measures are as follows.Firstly,buildings should be constructed on the sunny side and leeside;secondly,buildings on the south should be lower than those on the north;the east side of the building should be open while the west side should be closed;thirdly,climate protection unit should be set;fourthly,buildings should be of northsouth direction primarily,and the main room should be set on the east side and the assistant rooms or passage on the west side in the buildings of east-west direction;fifthly,it should select compact and wellarranged households and the units should not be combined in point and dislocation and jointing.

Application of Variable Strategies in the Low-cost and Energy-saving Rural Residences in Transitional Areas

Changeful and complex rural family structure and climatic features of transitional areas in China make the application of variable strategy in energy-saving rural residence designs possible.Aiming at the low cost,several effective and reasonable variable strategies were proposed for the design of interior spaces,main bedroom,sunshine room,staircase,west wall,door and window design to satisfy changing structure of a family during different periods and their different thermo-technical requirements in winter and summer.In this way,thermal comfort of rural indoor spaces will be improved,more energy saved,useful experience and thoughts provided for the energy-saving residence design in cold regions and regions hot in summer and cold in winter.

Summary of Steam System Optimization and Energy Saving and Carbon Reduction Practice in Yanshan Petrochemical Company

This paper analyzes the main problems of Sinopec Beijing Yanshan Petrochemical Co.,Ltd.,such as decentralized steam system layout,many types of fuels,obvious increase in fuel cost,low operation efficiency of turbine and boiler and high self consumption loss,and puts forward and implements optimization and improvement measures such as pressure raising transformation of natural gas system,adjustment of energy consumption structure,reduction of energy consumption cost,improvement of steam production quality and equipment efficiency.The results showed that compared with the fuel consumption in 2018,the consumption of coal coke was reduced by 550000 t,the consumption of natural gas was increased by 170000 t,and the total consumption of fuel gas and fuel oil was increased by 50000 t,equivalent to 246000 t of standard coal;the purchased electricity was increased by about 5×10^(8) kW·h.Green power trading and 14.76 MW distributed photovoltaic projects were carried out.According to the calculation of 1400-1600 h annual power generation in class II photovoltaic areas and the emission factor of North China regional power grid baseline,the annual emission reduction was about 55000 t CO_(2) in 2021.After the above transformation,the goal of zero-coking is achieved;the steam consumption of units is reduced by 21.5%,the steam production of boilers is reduced by 24.9%,and the annual emission reduction is about 760000 t CO_(2),which has achieved good results.

Design of Weigh Feeder Control System for Energy Saving Using Performance-Adaptive Method

This paper discusses a design method for the control system of a weigh feeder that supplies powder and granular material at a constant rate. Most weigh feeders employed in industry are controlled by proportional and integral （PI） compensation, and the control performance is decided by the selection of parameters. To attain advanced control performance by PI control, the PI parameters are designed on the basis of generalized minimum variance control （GMVC）. In this study, to achieve user-specified control performance by GMVC-based PI control, the design parameters of GMVC are automatically adjusted using a performance-adaptive method. The control performance discussed in this study consists of the variance of the control error and that of the difference in the control input. In a conventional performance-adaptive method, the variance of the control error is reduced. In this study, to reduce energy consumption and to achieve user-specified control performance, the variance of the difference in the control input is specified and the design parameter is determined. To demonstrate its effectiveness, the proposed method is applied to an actual weigh feeder.

PHOENIX’S FIRST NET-ZERO ENERGY OFFICE RETROFIT: A GREEN AND LEAN CASE STUDY

Many in the construction industry view lean practices as a means for reducing cost and schedule while maintaining or improving quality. This paper argues that lean practices can also be used to promote energy savings throughout a building’s life cycle. This paper presents a case study of an existing building retrofit in Phoenix, Arizona. The project owner, a general contractor, self-performed much of the building construction and worked to ensure the project team aligned around the project’s net-zero energy goal. All building systems, excepting the walls and roof, were re-designed and re-constructed. After retrofit, the building has achieved net-zero energy consumption;that is, the building produces as much energy as it consumes on an annual basis. Deep building energy retrofits typically result in larger energy savings than operational changes alone can provide, as these retrofits take a whole-building approach to design (i.e., optimize the whole) and implement integrated project delivery methods (e.g., (AIA, 2007)). This paper discusses a net-zero energy retrofit and how lessons learned on this project could apply to other deep energy retrofits for commercial buildings (where “deep” refers to energy savings of 25% or more) that may significantly improve building value (Miller and Pogue, 2009). The inefficiency of existing building stock supports the need for retrofitting: energy consumption in the existing building stock in the United States accounts for approximately 41% of the total primary energy consumption (US DOE, 2012). In order to reduce this consumption, existing buildings must be retrofit, through replacement or upgrade of their existing building systems, to improve their energy performance. Beyond the energy motivation, a building’s operating costs account for the largest portion of the life cycle cost. Thus, deep energy retrofit projects offer an opportunity to significantly reduce both national energy consumption and expenditures. While much research exists on the topic of energy retrofits, very little explores the role of the contractor. This paper explores the contractor’s role (rather than the designer’s or engineer’s role) in delivering deep energy retrofit projects. The contractor plays a critical role in delivering a project that meets the owner’s expectations and goals and satisfies the specifications (Ahn and Pearce, 2007). Namely, the contractor executes the plans and specifications, giving physical reality to the design team’s vision. In the case of deep energy retrofits, this role is particularly important, as installation and operation must conform to the design intent to achieve the predicted energy performance. Moreover, the contractor must understand the existing condition to effectively retrofit the building. This paper explores critical building energy efficiency measures and processes for achieving deep energy savings in retrofit projects. Specifically, we present the role of the contractor in a case study project in Phoenix, Arizona where the contractor was engaged in the project early in the design stage. This paper discusses the process of developing and selecting energy efficiency measures (EEMs). It explains the reasons for choosing particular EEMs, including a discussion of selecting an appropriate baseline for energy savings calculations, and documents the impact of EEMs on total energy consumption and design intent. The paper concludes with a discussion of recommendations that, if applied in part or whole, will increase the effectiveness of future construction teams in delivering deep energy retrofit projects.

A process-level hierarchical structural decomposition analysis (SDA) of energy consumption in an integrated steel plant

A hierarchical structural decomposition analysis(SDA) model has been developed based on process-level input-output(I-O) tables to analyze the drivers of energy consumption changes in an integrated steel plant during 2011-2013. By combining the principle of hierarchical decomposition into D&L method, a hierarchical decomposition model for multilevel SDA is obtained. The developed hierarchical IO-SDA model would provide consistent results and need less computation effort compared with the traditional SDA model. The decomposition results of the steel plant suggest that the technology improvement and reduced steel final demand are two major reasons for declined total energy consumption. The technical improvements of blast furnaces, basic oxygen furnaces, the power plant and the by-products utilization level have contributed mostly in reducing energy consumption. A major retrofit of ancillary process units and solving fuel substitution problem in the sinter plant and blast furnace are important for further energy saving. Besides the empirical results, this work also discussed that why and how hierarchical SDA can be applied in a process-level decomposition analysis of aggregated indicators.

Nanotechnology in Nuclear Reactors: Innovations in Fusion and Fission Power Generation

This article explores the transformative potential of nanotechnology and MMs(memory metals)in enhancing the design and operation of nuclear reactors,encompassing both fission and fusion technologies.Nanotechnology,with its ability to engineer materials at the atomic scale,offers significant improvements in reactor safety,efficiency,and longevity.In fission reactors,nanomaterials enhance fuel rod integrity,optimize thermal management,and improve in-core instrumentation.Fusion reactors benefit from nanostructured materials that bolster containment and heat dissipation,addressing critical challenges in sustaining fusion reactions.The integration of SMAs(shape memory alloys),or MMs,further amplifies these advancements.These materials,characterized by their ability to revert to a pre-defined shape under thermal conditions,provide self-healing capabilities,adaptive structural components,and enhanced magnetic confinement.The synergy between nanotechnology and MMs represents a paradigm shift in nuclear reactor technology,promising a future of cleaner,more efficient,and safer nuclear energy production.This innovative approach positions the nuclear industry to meet the growing global energy demand while addressing environmental and safety concerns.

IRP/DSM and Sustainable Development

This paper introduces the energy consumption status in China, elaborate the affects of the unreasonable energy consumption structure on energy environment and sustainable development of economy. Simultaneously, it points out the solution, i.e., to implement integrated resources planning (IRP)/demand side management (DSM), and gives some recommendations on the way of implementing IRP/DSM.

Multi-Effect Evaporation Coupled with MVR Heat Pump Thermal Integration Distillation for Separating Salt Containing Methanol Wastewater

Due to the high energy consumption for separation of salt containing methanol wastewater, in this work, the multi-effect evaporation coupled with mechanical vapor recompression (MVR) heat pump and thermal integration technologies were raised for the first time. The ELECNRTL thermodynamic model is used to simulate and optimize the evaporation rectification process. Energy consumption and total annual cost (TAC) are taken as objective functions. The results show that multi-effect evaporation coupled with conventional distillation process can save energy consumption and TAC by 44.12% and 39.14%. The multi-effect evaporation coupled with distillation process based on MVR heat pump technology can save energy consumption and TAC by 55.27% and 47.49%, which is super to three-effect evaporation coupled with conventional distillation process. The three-effect evaporation coupled with MVR heat integration process can save energy consumption and TAC by 81.32% and 58.55%, which is more economical than other processes. It can be clearly seen that three-effect evaporation coupled with MVR heat integration process is more competitive to deal with the salt containing methanol wastewater.

Experimental Study on the Thermal Performances of a Tube-Type Indirect Evaporative Cooler

The so-called indirect evaporative cooling technology is widely used in air conditioning applications.The thermal characterization of tube-type indirect evaporative coolers,however,still presents challenges which need to be addressed to make this technology more reliable and easy to implement.This experimental study deals with the performances of a tube-type indirect evaporative cooler based on an aluminum tube with a 10 mm diameter.In particular,the required tests were carried out considering a range of dry-bulb temperatures between 16℃ and 18℃ and a temperature difference between the wet-bulb and dry-bulb temperature of 2℃∼4℃.The integrated convective heat transfer coefficient inside the tube in the drenching condition has been found to lie in the range between 36.10 and 437.4(W/(m^(2)⋅K)).

Low Carbon Building Design Optimization Based on Intelligent Energy Management System

The construction of relevant standards for building carbon emission assessment in China has just started,and the quantitative analysis method and evaluation system are still imperfect,which hinders the development of low-carbon building design.Therefore,the use of intelligent energy management system is very necessary.The purpose of this paper is to explore the design optimization of low-carbon buildings based on intelligent energy management systems.Based on the proposed quantitative method of building carbon emission,this paper establishes the quota theoretical system of building carbon emission analysis,and develops the quota based carbon emission calculation software.Smart energy management system is a low-carbon energy-saving system based on the reference of large-scale building energy-saving system and combined with energy consumption.It provides a fast and effective calculation tool for the quantitative evaluation of carbon emission of construction projects,so as to realize the carbon emission control and optimization in the early stage of architectural design and construction.On this basis,the evaluation,analysis and calculation method of building structure based on carbon reduction target is proposed,combined with the carbon emission quota management standard proposed in this paper.Taking small high-rise residential buildings as an example,this paper compares and analyzes different building structural systems from the perspectives of structural performance,economy and carbon emission level.It provides a reference for the design and evaluation of low-carbon building structures.The smart energy management system collects user energy use parameters.It uses time period and time sequence to obtain a large amount of data for analysis and integration,which provides users with intuitive energy consumption data.Compared with the traditional architectural design method,the industrialized construction method can save 589.22 megajoules(MJ)per square meter.Based on 29270 megajoules(MJ)per ton of standard coal,the construction area of the case is about 8000 m2,and the energy saving of residential buildings is 161.04 tons of standard coal.This research is of great significance in reducing the carbon emission intensity of buildings.

A comparative study of different arrangements for methanol distillation process

The current study presents an effective method of determining and optimizing distillated methanol alternative arrangements. To complement the information required to run the rigorous simulation, Vminmethod is used as a base for the selection of the optimum arrangement among different alternatives. Results obtained from Vmindiagram and shortcut simulation are utilized, by means of the simulator, for the precise simulation of alternative arrangements of methanol distillation under optimum conditions. Taking into account target function profit and the process parameters and conditions, the most optimum parameter value for reaching maximum profit was obtained, based on which all the arrangements with or without their heat integration were compared to each other. Technical and economic analysis results indicate, that increased profit by Prefractionator with heat integration arrangement is 4.79% compared to the base arrangement, while the three-column, four-column and five-column arrangements have benefits increase by 3.61%, 3.55% and 3.46%, respectively.

Key Technologies for Energy Efficient Al(OH)_3 Dilute Phase Fluidized Bed Roasting Furnaces

Research on new tes of castab/es, pre-cast assembly parts and thermal insulation materials with good resistance to wear, thermal shock and erosion, and low thermal conductivity, was dong to solve problems of high system energy consumption, cracking and spalling of partial lining and mismatch of furnace top material and hanging material and so on, caused by unreasonable design of China＇ s Al（ OH ）3 dilute phase fluidized bed roasting frnace lining. Several difficult problems such as the matching tf different materials,

冰上运动建筑曲面光伏参数化集成设计研究

2022年冬奥会成功举办,国内掀起了冰上体育运动的热潮,冰上运动建筑需求量和能源消耗量随之增长。光伏建筑一体化(Building Integrated Photovoltaic,BIPV)作为建筑节能的主要手段之一,在体育建筑屋面具有较大的集成潜力。通过建立寒冷地区曲面冰上运动建筑典型模型进行集成设计研究,基于Grasshopper参数化平台实现新型柔性CIGS薄膜光伏组件沿屋面曲线形态的优化布置,从两个层级出发,提出参数化设计方法与构造措施。通过Honeybee进行能耗模拟,结果表明,该柔性光伏系统全年可以为冰上运动建筑降低15.82%的能量消耗,进而验证了该方案的节能性,为建筑师进行寒冷地区曲面冰上运动建筑设计的节能优化设计提供数据支撑及科学依据。

严寒地区农村住宅围护结构现状分析与优化研究

我国严寒地区气候寒冷且供暖季漫长,农村住宅采暖能耗问题突出,多数住宅采用自建形式,围护结构的热工性能普遍不理想。本研究从严寒地区农村住宅围护结构实际情况出发,对本溪农村地区200余户现有住宅进行调研。结果显示,本溪现有农宅基本未设置外墙保温,虽部分住宅屋顶设置保温,但保温材料均已超过使用年限,保温效果较差。有86.95%的农宅室内温度基本维持在18℃以下,农户满意度仅24.2%。实地测量3户典型农宅的室内环境温度。采用EnergyPlus模拟得到农宅围护结构的传热系数相比居住建筑节能设计标准规定限值超出300%~400%。根据实测数据和模拟数据对外墙、屋顶、外窗进行热工性能改造。对比单一围护结构改造前后的供暖季热负荷,得出外墙的改造效果最好。

外窗节能设计与集成技术

建筑外窗作为建筑围护构件中最不节能的部件,包括传热系数(U值)、可见光透射率(T_(vis))、太阳热增益系数(S_(HGC))等在内的光热性能指标直接影响了建筑的能耗。为了更加全面地了解建筑外窗节能设计的关键技术,通过数据库资料详细梳理了前人的相关研究成果。研究发现:窗墙比、建筑遮阳、窗框、窗玻璃、气密性等是影响建筑外窗节能的关键要素;集成技术在外窗节能设计方面具有明显的优越性,能够极大提高外窗的节能效率;人的行为方式对外窗节能效率也会产生较大的影响。

可再生能源综合系统现状与未来发展趋势研究

通过分析中国能源结构现状与能源转型面临的主要挑战,结合未来能源需求,研究适合中国国情的低碳、低成本的能源转型现实路径,提出以可再生能源为主体、多能源互补、“冷热电”联供、集“源网荷”于一体的新型能源系统解决方案——可再生能源综合系统;然后对可再生能源综合系统的现状与关键技术进行了研究,并分析了其未来发展趋势。研究结果表明:围绕用户侧构建分层次、分场景的以可再生能源为主体的集“冷热电”“源网荷”于一体的新型能源系统,是中国实现能源转型的系统解决方案。

外显、灵活、多维、高效——从2022中国国际太阳能十项全能竞赛看建筑与光伏一体化设计趋势

建筑光伏一体化技术是实现建筑行业节能减碳的重要途径。以第三届中国国际太阳能十项全能竞赛(SDC2022)为例,对15个参赛作品在建筑与光伏一体化设计上的特征进行了比较,从美学表现、构造整合、功能复合、性能提升4个维度分析了当前建筑与光伏一体化的设计新趋势,指出:在美学表现上,通过光伏组件材质外观和光伏方阵形成积极外显的形态;在构造上,采用不同类型光伏灵活组合衍生多种应用场景;在功能上,将光伏发电与建筑围护结构的采光、集热、遮阳、防护等功能进行多维度复合;在性能上,通过光伏朝向与倾角、散热设计和电气系统综合提升产能效率。为建筑与光伏一体化技术的推广和应用提供新思路。

信息化与工业化融合能否促进企业出口“增量提质”?

在逆全球化背景下,基于数字经济的迅速崛起,推动信息化与工业化融合发展以实现出口贸易的“增量提质”,不仅是中国经济高质量发展的重中之重,更是打造出口竞争新优势与构筑高水平国际循环模式的关键所在。引入双重差分模型,综合评估了两化融合对企业出口数量与质量的影响强度及内在作用机制。研究发现:首先,两化融合显著促进了企业出口“增量提质”,这一效应在外资参与、产权保护程度高、一般贸易、高新技术及规模大的企业中更为显著;其次,两化融合可以通过产品转换、行业竞争与创新等路径促进“增量提质”。此外,讨论了两化融合“增量提质”效应对环境外部性的影响,研究发现,两化融合在促进企业出口“增量提质”的过程中,实现了企业生产效益和环境效益的“双改进”。研究结论为推进信息化与工业化深度融合、优化出口贸易结构提供了政策启示。