基于GPRS的中央空调远程监控系统设计

远程监控系统对于中央空调系统的节能、集中管理、维修以及远程诊断有重要的意义。设计了一种基于中国移动GPRS的通信架构,实现中央空调制造商从中国大陆任意通过中国电信接入因特网的PC上监控位于中国大陆的中国移动GSM覆盖网络下的任意中央空调机组。与其他中央空调监控系统相比,具有应用范围广、成本低、数据实时性好的特点。     

冰蓄冷空调系统设计要点浅析

介绍了冰蓄冷设计过程中需要注意的一些问题,比如电价政策、双工况主机和蓄冰槽体选择原则、冷却塔选型注意事项、冷源群控及阀门选型要点等。     

The electro-adsorption chiller: a miniaturized cooling cycle with applications to micro-electronics

A novel modular and miniature chiller is proposed that symbiotically combines adsorption and thermoelectric cooling devices. The seemingly low efficiency of each cycle individually is overcome by an amalgamation with the other. This electro-adsorption chiller incorporates solely existing technologies. It can attain large cooling densities at high efficiency, yet is free of moving parts and comprises harmless materials. The governing physical processes are primarily surface rather than bulk effects, or involve electron rather than fluid flow. This insensitivity to scale creates promising applications in cooling personal computers and other microelectronic appliances.     

燃气轮机进气冷却技术浅析

燃气轮机的性能与环境温度有关，其出力随燃气进气温度升高而降低的问题可通过冷却燃气进气来解决。冷却燃气进气有直接接触和间接接触两种方法。直接接触式有水膜式蒸发冷却和喷雾冷却；间接接触式有压缩式制冷、吸收制冷、蓄冷冷却和液化天燃（改成然）气冷能利用。直接接触式冷却装置的优点是初投资较少，运行及维护费用较低，但冷度较低，受环境湿度影响较大，适用于干燥、炎热地区。在工程中选用何种冷却进气方式应结合实际情况，综合考虑峰谷电价差、资金情况、气象参数、年运行时间等进行技术经济分析确定。     

青岛莱钢大厦空调冷热源方案经济技术分析与比较

本文根据青岛莱钢大厦工程的实际情况，列出了该工程的四种空调冷热源方案，介绍了每种方案的优缺点，并从冷冻站设备的初投资、年运行费用两方面进行了比较，经过技术经济分析，最终得出不同条件下的最佳冷热源方案。     

Important sensors for chiller fault detection and diagnosis (FDD) from the perspective of feature selection and machine learning

The benefits of applying automated fault detection and diagnosis (AFDD) to chillers include less expensive repairs, timely maintenance, and shorter downtimes. This study employs feature selection (FS) techniques, such as mutual-information-based filter and genetic-algorithm-based wrapper, to help search for the important sensors in data driven chiller FDD applications, so as to improve FDD performance while saving initial sensor cost. The ‘one-against-one’ multi-class support vector machine (SVM) is adopted as a FDD tool. The results show that the eight features/sensors, centered around the core refrigeration cycle and selected by the GA-SVM wrapper from the original 64 features, outperform the other three feature subsets by the GA-LDA (linear discriminant analysis) wrapper, with an overall classification correct rate (CR) as high as 99.53% for the 4000 test samples randomly covering the normal and seven typical faulty modes. The CRs for the four cases with FS are all higher than that without FS (97.45%) and the test time is much less, about 28-36%. The FDD performance for normal or each of the faulty modes is also evaluated in details in terms of hit rate (HR) and false alarm rate (FAR).     

天津大唐世家总部基地东区办公楼空调系统的设计应用分析

本文通过天津大唐世家总部基地东区办公楼的空调系统设计,依据独特的建筑特点与要求,从系统的经济节能性、合理性、可靠性、安装调试以及智能化的控制系统等方面,对EVI风冷模块机在办公楼建筑中的应用进行阐述,为今后同类建筑的空调系统设计提供了可借鉴的经验。     

广州电信大厦中央空调系统冷水机组运行负荷率分析

本文根据广州电信大厦中央空调系统2007年全年的运行数据,并结合办公楼空调使用的特点,分析计算了该系统的全年逐时负荷的分布情况,机组负荷率的变化规律及配置运行情况。得出了4台机组的负荷率绝大部分都集中在60%~90%之间,冷水机组的启停及运行模式基本符合大厦全年负荷的时间分布及其性能指标,说明运行调节较合理。     

An integrated model for the design of air-cooled chiller plants for commercial buildings

Cooling load calculation is the first step in designing the air-conditioning system of a building. The calculated cooling capacity with appropriate buffer is then used to select the number and size of chillers in the system. N + 1 is a common formula used by designers to size the chiller plants in Hong Kong buildings, where N is the actual number of chillers required and 1 is a redundant chiller provided to ensure reliability. This paper reviews the problem of excess capacity and discusses the risk exposure of chiller systems without redundant chillers. The cooling load profiles of the chiller plants of four medium-sized commercial buildings in Hong Kong are reviewed. The risk exposure of chiller systems without redundant chillers can be minimized by applying risk-based preventive maintenance. The just-in-demand design reduces capital cost of the building and frees up funds for continuous energy measurement and improving the energy efficiency of chiller plant systems. This paper presents a model for designing chiller plants that improves the energy efficiency of the plant in a cost effective and thoughtful manner. It is designed with consideration of the life cycle of the plant and real-time continuous commissioning, monitoring, measurement, comparison and execution for better energy management.     

Fusion of redundant measurements for enhancing the reliability of total cooling load based chiller sequencing control

Total cooling load based chiller sequence in multiple-chiller plants is essentially the best approach to stage a chiller on or off in order to satisfy thermal comfort requirement and achieve energy efficiency simultaneously. In practice, however, this approach cannot be reliably implemented. The reason is the measurement of the cooling load of multiple-chiller plants is not always consistent enough for staging chillers on or off appropriately. Measurement uncertainties, including noises, outliers and biases, have a significant influence on the performance of the sequencing operation. This paper develops a strategy of fusing available redundant measurements to reduce the measurement uncertainties. With a moving window, the proposed strategy can (i) remove measurement outliers according to a calibrated Moffat distance between redundant measurements; (ii) reduce the influence of measurement noises by merging redundant measurements; and (iii) calibrate the bias of the merged measurements. Simulation studies are represented to show the merits of the proposed strategy for improving the reliability of the total cooling load based chiller sequencing control.