空调系统节能若干问题的探讨

本文对空调系统实现节能控制的若干问题进行了分析和探讨     

Models for nuclear smuggling interdiction

We describe two stochastic network interdiction models for thwarting nuclear smuggling. In the first model, the smuggler travels through a transportation network on a path that maximizes the probability of evading detection, and the interdictor installs radiation sensors to minimize that evasion probability. The problem is stochastic because the smuggler's origin-destination pair is known only through a probability distribution at the time when the sensors are installed. In this model, the smuggler knows the locations of all sensors and the interdictor and the smuggler “agree” on key network parameters, namely the probabilities the smuggler will be detected while traversing the arcs of the transportation network. Our second model differs in that the interdictor and smuggler can have differing perceptions of these network parameters. This model captures the case in which the smuggler is aware of only a subset of the sensor locations. For both models, we develop the important special case in which the sensors can only be installed at border crossings of a single country so that the resulting model is defined on a bipartite network. In this special case, a class of valid inequalities reduces the computation time for the identical-perceptions model.     

Optimal scrap combination for steel production

In steel production, scrap metal is used for cooling the enormous quantity of heat produced by blowing oxygen on hot metal. Scrap differs in regard to the content of iron and of some tramp elements. The price of the scrap depends on these attributes. Each melting bath unit of steel has its own material constraints for the amount of iron and tramp elements in order to guarantee the desired quality. In addition, the transportation of scrap is restricted because it needs time and space: the scrap is kept in some railroad cars in the scrap hall; empty cars must leave the hall, filled cars must be taken from several railroad tracks in the scrap yard and assembled to a train before transportation to the hall. There are upper limits for the number of cars in the hall and in the train, also for the number of railroad tracks used for assembly.Our objective is to find a minimum cost scrap combination for each melting bath unit of steel that obeys the material and transportation constraints. We model the problem using a MIP (mixed integer linear programming) approach. Real-life situations are solved with the commercial MIP-solver CPLEX. We present computational results which show significant improvement compared to the strategy applied today.     

空调工程节能设计的探讨

空调能耗大,空调节能是建筑节能的重点内容。本文从节能、建筑节能、空调节能角度,结合作者多年从事空调工程设计的经验和体会,论述空调节能设计的措施及方法。     

制冷系统中湿式冷却塔的节能分析

指出对制冷系统中湿式（蒸发式）冷却塔的能耗应给予与制冷机同样的重视，系统节能应整体考虑。分析了冷却塔出水温度、冷却塔飘水对制冷系统性能的影响。     

珠海市公共图书馆中央空调主机选型节能设计思考

介绍了珠海市公共图书馆中央空调主机选型节能设计改造方案.     

水环真空泵能效评价方法研究

给出了水环真空泵能效值的3种表示方法和计算公式,分析了能效考核点的确定方法。通过比较研究,提出了水环真空泵产品的能效评价方法及判定体系:采用单位功率的抽气量表示水环真空泵的能效,依据水环真空泵极限真空度的不同分别设定能效考核点,叶轮转速作为参考因素。通过能效值考核和评价,可以有效地推动和引导水环真空泵行业节能技术的发展,促进相关产业过程的节能及可持续发展。     

大温差下冷水机组的节能运行方案探讨

本文探讨了在大温差工况下冷水机组的节能运行问题，指出冷水机组串连运行可明显节约机组的运行能耗。     

我国建筑能耗现状下的建筑节能标准解析及节能潜力

介绍了我国严寒、寒冷地区,夏热冬冷地区及夏热冬暖地区居住建筑节能设计标准规定性指标以及公共建筑节能设计标准。并简要分析了我国建筑能源消耗状况,从用能特点出发,对建筑物和建筑用能途径进行了新的分类,给出各类的现状、问题和节能潜力。     

A natural gas cash-out problem: A bilevel programming framework and a penalty function method

One of the many complex problems that arise from the transmission and marketing of natural gas is when a shipper draws a contract with a pipeline company to deliver a certain amount of gas among several points. What is actually delivered is often different from the amount that had been originally agreed upon. This phenomenon is called an imbalance. When an imbalance occurs, the pipeline penalizes the shipper by imposing a cash-out penalty policy. Since this penalty is a function of the operating daily imbalances, an important decision-making problem for the shippers is how to carry out their daily imbalances so as to minimize their incurred penalty. In this paper, we introduce the problem of minimizing the cash-out penalty costs from the point of view of a natural gas shipping party. We present a mixed integer bilevel linear programming model and discuss its underlying assumptions. To solve it efficiently, we reformulate it as a standard mathematical program and describe a penalty-function algorithm functions for its solution. The algorithm is well-founded and its convergence is proved. Results of numerical experiments support the algorithm’s robustness providing a valuable solution technique for this very important and complex problem in the natural gas market.     

空调系统中冷却塔运行节能的探讨

通过分析不同因素对冷却塔冷却能力的影响，从运行过程中节约风机、水泵等能耗的观点出发，总结了利用冷却塔节能的各种实施方法。室外空气湿球温度，入口水温，及冷却水量的变化都将引起冷却塔冷却能力的变化。为了用户的最大限度节能，冷却塔的生产厂家在设计与制造过程中应多考虑冷却塔的自控功能，并且提供冷却塔在冬夏两种工况的热工参数。     

冷冻食品加工企业生产能效评估及节能分析

目前我国多数冷冻食品加工企业能耗费用支出占总产值的比率高于企业利润率,能耗费用高支出成为阻碍企业利润率增长的瓶颈。因为企业生产能耗偏大,所以节能降耗成为企业降低成本提高利润率的有效手段。文章列举实例分析了某速冻车间的能耗与产量现状,进行能效评估,指出了目前我国一些冷冻食品加工企业仅凭增加产量来提高利润率的错误;找出了能效、产量、利润率三者之间的关系和节能降耗的关键;系统地分析了如何节能,并且给予了合理性的建议。     

A blockchain-based approach for a multi-echelon sustainable supply chain

Blockchain technology is destined to revolutionise supply chain processes. At the same time, governmental and regulatory policies are forcing firms to adjust their supply chains in response to environmental concerns. The objective of this study is therefore to develop a distributed ledger-based blockchain approach for monitoring supply chain performance and optimising both emission levels and operational costs in a synchronised fashion, producing a better outcome for the supply chain. We propose the blockchain approach for different production allocation problems within a multi-echelon supply chain (MESC) under a carbon taxation policy. As such, we couple recent advances in digitalisation of operations with increasingly stringent regulatory environmental policies. Specifically, with lead time considerations under emission rate constraints (imposed by a carbon taxation policy), we simultaneously consider the production, distribution and inventory control decisions in a production allocation-based MESC problem. The problem is then formulated as a Mixed Integer Non-Linear Programming (MINLP) model. We show that the distributed ledger-based blockchain approach minimises both total cost and carbon emissions. We then validate the feasibility of the proposed approach by comparing the results with a non-dominated sorting genetic algorithm (NSGA-II). The findings provide support for policymakers and supply chain executives alike.     

空气净化器能效限定值及能效等级国家标准研究

本文论述了制定空气净化器能效限定值及能效等级国家标准的背景和意义,介绍了标准研制的总体思路和原则,空气净化器能效限定值的确定,能效等级的划分,以及试验方法等.通过国标的研制与实施,将淘汰高耗能空气净化产品的生产,有效提升空气净化器产品的能效水平.     

关于空调冷冻水输送能效比计算的一点看法

本文针对在《公共建筑节能设计标准》（GB50189—2005）中提出的空调冷冻水输送能效比计算公式不能满足复杂、新型空调方式（如多级泵系统、冷辐射系统等）的要求,提出了根据空调计算冷负荷分布的“加权法”对整个水系统的输送能效比进行计算的新方式,供设计研究人员进行参考。     

Optimization Models for Scheduling of Jobs

This work is motivated by a particular scheduling problem that is faced by logistics centers that perform aircraft maintenance and modification. Here we concentrate on a single facility (hangar) which is equipped with several work stations (bays). Specifically, a number of jobs have already been scheduled for processing at the facility; the starting times, durations, and work station assignments for these jobs are assumed to be known. We are interested in how best to schedule a number of new jobs that the facility will be processing in the near future. We first develop a mixed integer quadratic programming model (MIQP) for this problem. Since the exact solution of this MIQP formulation is time consuming, we develop a heuristic procedure, based on existing bin packing techniques. This heuristic is further enhanced by application of certain local optimality conditions.     

合理下料问题的整数规划模型

本文给出了合理下料问题的两种一般表述形式；提出了线材合理下料问题的三个整数规划模型，这些模型是严谨的，没有漏洞和缺陷，并且很容易在此基础上修改或添加一些其他约束条件，便于在实际工程中进行应用。     

冷冻食品加工企业能效评价

目前我国综合食品加工企业都使用单化产值的能耗量或能耗费用水衡量能耗的程度,山于这种指标没有反映出使用水平、营业水平和质量水平对企业、能效的影响,所以在企业之间能效比较时难以作出正确评价。文章以实例列举出国内外有代表性的大型综合食乩加工食品企业的能耗现状进行对比;分析了日前企业使用的能耗评价指标在横向比较、评价时出现错误的原因：提出了可反映使用水半、营业水半和质量水平新的能效评价方法,对国内六家有代表性的食品企业进行能效评价,结果移示食业之间能效芹芹十分显著,节能降牦提高能效成为食品企业迫切需要解决的问题。     

空调水系统节能技术分析

本文从空调水系统目前存在的问题为切入点,以节能为原则,探讨和分析了空调水系统中变流量技术应用特点和节能效果,结合工程实例,通过对水泵变频调速技术在空调水系统中的应用和相应投资、运行费用的详细分析,阐明了空调水系统采用水泵变频调速技术可以带来明显的节能效果,空调制冷系统的冷冻水、冷却水变流量系统可使冷水机组在部分负荷下运行带来显著的节能效果.     

全瓷冠桥专用智能升降电炉设计及能效分析

为了满足氧化锆全瓷冠桥（义齿）生产需要,根据实验电炉的最新设计理念,运用有限元技术时炉膛材料和结构、加热元件数量和分布进行了优化设计。通过智能技术、高性能材料的集成优化,实现了全瓷冠桥专用智能升降电阻炉的批量生产。最终,经效能分析和性能评估可知,本电炉具有结构紧凑、节能环保、温度场均匀和升降温速度快等优点,特别适用于牙科全瓷冠桥、实验室样品制备等领域应用。