浅谈高效制冷机房系统在节能改造中的应用

本文以某酒店节能改造项目为例,针对空调制冷机房系统进行能耗分析、节能诊断。通过主机优化选型,输配系统节能降阻,水泵、冷却塔变频改造,增设自控系统,提升控制策略,运用BIM技术指导设计施工,采用高效制冷机房设计理念降低系统能耗,提升制冷机房系统能效,达到节能低碳运行的目的。     

浅谈程控交换机房的空调设计

根据程控交换机房的空调系统特点，阐述了程控交换机房空调机房空调设备的选型及系统设计中一系列问题。     

高温水源工况下带冷却塔预冷的制冷机房控制策略研究

为了降低高温工况下的水源制冷机房能耗,本文提出了对高温水源水先进行冷却塔预冷的运行策略.通过在TRNSYS软件上建立制冷机房模拟平台,对预冷控制方式和常规控制方式下的制冷机房总能耗进行比较研究.结果表明:当水源温度高于一定值时,先对高温冷却水先进行预冷,可有效降低制冷机房总功率,实现节能;通过比较不同水温下和不同变频风机风量下的制冷机房能耗,确定了预冷的转换点温度、预冷终温取值和最佳风量值.     

制冷机房冷却侧大温差节能特性分析

据统计,约40%的建筑能耗为空调系统能耗,空调系统能耗中大约有60%能耗来自制冷机房。由此可知,制冷机房节能是建筑节能的关键。目前,对制冷机房中冷冻侧大温差的节能技术有了大量的研究和实际应用。但是,对于冷却侧大温差的节能研究仍有待发展。目前设计师大多采用32/37℃的冷却水进出水温进行制冷系统的设计。为了给设计师提供冷却侧大温差的设计参考,通过能耗模拟软件对采用冷却侧大温差设计的制冷机房进行能耗预测,并根据模拟结果得到制冷机房最优的大温差设计方案。结果表明:当冷却侧温差由5℃增加至7℃时,冷却水进出水温为32/39℃的节能率(8%～9%)比31/38℃的节能率(约3%)更高。将制冷机房的冷却侧温差加大至8、9、10℃时,杭州、北京、广州均为8℃温差(冷却水进出水温为32/40℃)时最节能;而昆明则是10℃温差(冷却水进出水温为28/38℃)时最节能。     

提高数据中心设计温度的可行性及节能分析

随着数据中心的发展,其冷却能耗占总能耗40%以上。提高数据中心机房温度能够有效降低数据中心总能耗,但提高机房温度是否对IT系统的安全和寿命产生负面影响?对提高数据中心能效和降低能耗的贡献到底有多少?本文对这2个问题进行分析,结合资料调研、分析计算和实际案例,指出提高数据中心机房温度对服务器可靠性影响较小,能够降低空调系统能耗。     

某通信机房空调系统改造

对某通信机房温度分布进行实测,发现虽然机房内整体温度满足要求,但是存在局部热点。针对测试结果给出改造方案,并对改造前后机房内温度分布和气流组织进行数值模拟,结果表明改造方案能够解决该机房的局部热点问题。     

基于基站机房的能耗数据采集与分析

基站机房的节能降耗是通信行业的重中之重,全面而透彻地分解和分析基站机房的能耗组成、来源是节能降耗的首要目标。文章通过在试点机房建立能耗数据采集系统以获取实时数据,结合话务、数据流量等基础参数,深入地进行了基站机房的能耗组成、变化规律及作用机制的研究分析。     

重庆某空调系统节能改造与能耗模拟

利用重庆某建筑的原有空调设备和周边地理环境,以节能改造为目的,提出了将该建筑原有电锅炉采暖方式改为湖水源热泵采暖的方案,设计了该湖水源热泵冷热源系统的改造原理和实施方案.通过建筑的DeST模型,计算建筑冬季的逐时热负荷,再利用湖水源热泵设计评估软件对热泵的采暖运行进行能耗模拟,模拟结果显示:整个冬季水源热泵系统的运行能耗比电加热锅炉系统节省410841.2kWh,节能率为71.13％,最后模拟分析了该热泵系统中变流量与定流量取水系统的能耗特征,并提出了设计建议.     

数据中心冷通道封闭对室内热环境影响的模拟研究

降低数据中心空调系统能耗对节能具有重要意义。冷通道封闭技术可以优化机房气流组织、节省数据中心空调能耗。本文利用数值模拟的方法对北京市某数据中心冷通道封闭前后机房内热环境进行分析,结果表明,冷通道封闭可以减少冷热气流的掺混及局部热点的产生,可将空调送风温度由18℃提高至22℃,每年可节能约1×10~5 kW·h。     

数据中心气流组织特性及节能改造方案研究

针对数据中心机房由于机架上架率不同、气流组织分布不均匀等原因导致局部热点现象严重、末端空调设备长时间高负荷运行造成大量能耗浪费的问题,以夏热冬暖地区某数据中心机房为研究对象,利用CFD模拟软件,分析数据中心机房热环境温度场分布特征,利用机架冷却指数(RCI)、回风温度指数(RTI)、供热指数(SHI)及掺混指数(IOM)4种不同性能指标,评价3种不同节能改造方案的优劣。在此基础上,通过调节风柜频率,探讨不同供风量对机房热环境的影响。结果表明,提出的第三种方案能够有效改善机房热环境,减少供风能耗。     

转轮式全热换热器在SPF实验动物环境中的应用探讨

通过对目前SPF实验动物房能源消耗大,运行成本高昂等问题的分析,对转轮式全热换热器和板式全热换热器进行了全面的经济性比较,并探讨了转轮换热器引起的交叉污染的解决方法。认为转轮式全热换热器节能效果明显,应用在SPF实验动物房空调系统中具有较好的经济效益。     

‘Green’ composites Part 2: Characterization of flax yarn and glutaraldehyde/poly(vinyl alcohol) modified soy protein concentrate composites

In the present research, soy protein concentrate (SPC) was modified using glutaraldehyde (GA) and polyvinyl alcohol (PVA). The modified resin allowed to process soy protein polymer without any plasticizer. The modified resin also showed increased tensile properties, improved thermal stability and reduced moisture resistance as compared to SPC resin. Besides the tensile and thermal properties, modified SPC resin was also characterized for its dynamic mechanical properties. Unidirectional composites were fabricated using modified SPC and flax yarn. Composite specimens, approximately 1 mm thick, were prepared in both longitudinal and transverse directions. The composite specimens were characterized for their tensile and flexural properties. The fracture surface of the composite was also analyzed in both longitudinal and transverse directions. These composite specimens exhibited a fracture stress of 126 MPa and 2.24 GPa, respectively, in the longitudinal directions. The composite properties were also predicted using the rule of mixture in longitudinal direction. It was observed that the experimental values are lower than the predicted values for a variety of reasons.     

建筑物通风换热器工作特性的实验研究

用实验手段对自行设计加工的用于空调系统中显热回收的通风换热器进行研究，得到了空调房间室内、外温差和不同迎面风速对换热器的换热性能和流动阻力特性的影响，拟合出了该换热器的传热和流动阻力准则关系式；以冬季工况为例进行了节能效果分析；实验结果表明，该换热器的换热效率可以达到64．5％，其阻力损失不超过20Pa，具有明显的节能效果。说明其在实际应用中是可行的、有效的，是值得推广的空调节能技术。     

The funnel experiment: The Markov‐based SPC approach

The classical funnel experiment was used by Deming to promote the idea of statistical process control (SPC). The popular example illustrates that the implementation of simple feedback rules to stationary processes violates the independence assumption and prevents the implementation of conventional SPC. However, Deming did not indicate how to implement SPC in the presence of such feedback rules. This pedagogical gap is addressed here by introducing a simple feedback rule to the funnel example that results in a nonlinear process to which the traditional SPC methods cannot be applied. The proposed method of Markov‐based SPC, which is a simplified version of the context‐based SPC method, is shown to monitor the modified process well. Copyright © 2007 John Wiley & Sons, Ltd.     

无接触热阻全铝换热器空调系统制冷性能研究

本文用新型无接触热阻全铝换热器对传统家用空调换热器进行了替代设计,利用空气焓值法对使用新型换热器和管片式换热器的家用窗式空调器进行对比试验,优化并测试了毛细管规格和制冷剂充灌量对新型换热器空调系统制冷性能的影响。研究结果表明：新型无接触热阻全铝换热器在换热面积减小37.53%时,制冷量反而提高3.59%,能效比EER提高7%。新型换热器有更强的换热能力,是目前家用空调换热器的理想替代产品。     

Characterization of a sustainable sulfur polymer concrete using activated fillers

Sulfur polymer concrete (SPC) is a thermoplastic composite concrete consisting of chemically modified sulfur polymer and aggregates. This study focused on the characterization of a new SPC that has been developed as a sustainable construction material. It is made from industrial by-product sulfur that is modified with activated fillers of fly ash, petroleum refinery residual oil, and sand. Unlike conventional sulfur polymer cements made using dicyclopentadiene as a chemical modifier, the use of inexpensive industrial by-products enables the new SPC to cost-effectively produce sustainable, low-carbon, thermoplastic binder that can compete with conventional hydraulic cement concretes. A series of characterization analyses was conducted including thermal analysis, X-ray diffraction, and spatially-resolved X-ray absorption spectroscopy to confirm the polymerization of sulfur induced from the presence of the oil. In addition, mechanical testing, internal pore structure analysis, and scanning electron microscope studies evaluate the performance of this new SPC as a sustainable construction material with a reduced environmental impact.     

Biodegradable green composites made using bamboo micro/nano-fibrils and chemically modified soy protein resin

Micro/nano-sized bamboo fibrils (MBF) and a modified soy protein resin were used to fabricate environmentally friendly composites. With the incorporation of MBF the fracture stress and Young’s modulus of the soy protein concentrate (SPC) increased significantly. With the addition of 30 parts of MBF (SPC is 100 parts, based on weight), the fracture stress and Young’s modulus were increased from 20.2 MPa to 59.3 MPa and from 596 MPa to 1816 MPa, respectively. The addition of MBF, however, did not show significant decrease in the fracture strain of the specimens. As a result, the toughness of the MBF reinforced SPC increased. The toughness of the SPC based composites containing 30 parts of MBF was 6.0 MPa compared to 2.7 MPa for SPC without MBF. MBF reinforced SPC was then cross-linked using a silane, (3-isocyanatopropyl)triethoxysilane (ITES). Although the fracture strength and Young’s modulus did not show significant increase, the modification using ITES showed significant increase in the fracture toughness. SPC containing 30 parts of MBF, 10 parts of ITES and 2 parts of glycerol showed fracture stress of 82 MPa, Young’s modulus of around 3.2 GPa and toughness of 4.3 MPa. The environment-friendly, fully biodegradable green composites, based on MBF and modified SPC resins, have excellent properties and great potential to replace the traditional petroleum-based materials in many applications.     

5mm管径铜管换热器应用的冷凝性能研究

近年来,随着小管径换热器研究的深入和推广,目前各空调厂家已逐步应用推广。小管径换热器特点在于提高换热性能和节约产品材料成本。同时国内销售的空调器已由R22定频转向R410A变频空调器,小管径换热器随R410A冷媒的替代其强化传热影响更加显著,具备良好的应用前景。综合5mm管径换热器在空调系统中应用的性能数据比较,其冷凝性能优于大管径换热器,满足制冷量和能效的条件下,尤其空调制热量的提高非常显著。     

平行流蒸发器冷凝水排除问题研究

平行流换热器因其结构紧凑、换热效率高,被当作冷凝器广泛地应用于汽车空调系统。近年来,又作为蒸发器被应用于家用空调器。但是,平行流蒸发器的冷凝水排除问题限制了其在家用空调器的应用发展和普及。本文针对家用空调器用的平行流蒸发器的冷凝水排除问题进行综合性评述,系统讨论蒸发器材料表面特性、蒸发器布置及导流、蒸发器内通道均流等因素对冷凝水排除的影响。     

Spray-Drying of Liposomes for a Pulmonary Administration. II. Retention of Encapsulated Materials

Abstract

Extruded multilamellar vesicles containing atropine sulphate were spray-dried in the presence of 10 % lactose. The particle mean diameter of the spray-dried product was about 7 μm and 3.5 μm when the spray-drier was equipped with a rotary atomizer or a nozzle, respectively. The size of the vesicles was not significantly modified after rehydration of the dry residue. Atropine sulphate was entrapped in liposomes constituted of soybean phosphatidylcholine (SPC), hydrogenated SPC and SPC: Cholesterol (1:1 molar ratio) with an efficiency of 4–6%, but an important leakage (65 to 80%) of the incorporated drug occurred during the spray-drying process. On the other hand, α-tocopherol used as a lipophilic drug model was incorporated in SPC vesicles with an efficiency of 92 % and no significant leakage was detected during the dehydration-rehydration cycle. Thus, spray-drying constitutes an interesting method to dehydrate liposomes (especially when lipophilic drugs are incorporated) into the form of small particles that could be delivered to the respiratory tract and reconstituted in situ.