深圳某区域外融冰集中供冷系统的应用与分析

随着社会的发展,国内众多高层次城市新区的建设选择区域集中供冷,外融冰蓄冷系统依靠其固有的亮点成为了区域集中供冷的首选技术。本文主要阐述了外融冰蓄冷系统的特征,并结合深圳某区域集中供冷项目,剖析了外融冰蓄冷系统在区域集中供冷中的应用,并提出了外融冰蓄冷系统在区域集中供冷建设中需注意的问题,为今后区域集中供冷系统的建设提供了参照。     

工程实例中空调冷热源的技术经济分析比较

 以杭州市某办公大楼空调冷热源的选择为例，分析比较了热水型溴化锂机组供冷加热力管网供热、直燃型溴化锂机组供冷供热、电制冷机组供冷加热力管网供热的3种方式的各自特点，给出它们的分析比较结果，认为电制冷机组供冷加热力管网供热是较适宜的空调冷热源方案，对杭州市热力政策提出了合理化建议．     

地铁集中供冷的几个问题

本文结合理论计算和广州地铁二号线集中冷站系统的工程实例,对地铁车站冷负荷、区间内冷冻水管尺寸限制、管网承压进行了分析,为地铁集中实施集中供冷提供了参考.     

保障型不间断供冷系统设计

本文介绍了一套保障型不间断供冷系统的设计。系统利用已有的两个区域供冷站同时向用户供冷，双冷源互为备用，并利用复杂的矩阵型管网实现多种方式的切换和配置，达到全年365天不间断供冷的目的。     

集中供冷与窗式空调能耗和造价比较

集中供冷主要应用于公共场合如医院、酒店、旅馆、写字楼等地，这些大型公共场所为何采用集中供冷而不是分散供冷，其主要原因是集中空调具有效率高、能耗低、噪音小、方便集中维修管理且可实现自动控制等优点；相比之下，窗户空调能耗较大、噪音大。本文将对集中供冷与窗式分散式供冷的能耗、造价进行比较，并提出合理建议。     

关于广州大学城区域供冷管网调试问题的思考

介绍广州大学城区域供冷管网建设、调试和运行情况，并对管网调试中出现的问题和现象进行介绍和思考。     

云计算产业园区域供冷适应性分析

以重庆市某云计算产业园区域供冷项目为例,分析区域供冷在云计算工业园区的适应性。应用模拟和理论计算,分析云计算产业园的全年动态负荷特性及二次管网冷量损失,结果表明:空调负荷全年处于高负荷状态,负荷率稳定,有利于区域供冷的能效提升;二次管网冷量损失主要由水泵引起;在满负荷二次管网冷量损失仅占输送总冷量的2.04%。     

北京市某区域集中供冷蓄冷系统的应用与分析

近年来,随着社会生产力的提高,区域集中供冷在我国取得了较快的发展。本文分析探讨了区域供冷中3种蓄冷方案(动态冰蓄冷、外融冰蓄冷、水蓄冷)的特点,并以北京市某区域供冷项目为例,介绍了3种蓄冷系统的规模、装机配置、组成等,同时进行了经济分析,提出了适合本项目的蓄冷方案:动态冰蓄冷系统与外融冰蓄冷系统耦合供冷。并就动态冰蓄冷方案中遇到的“冰堵”难点及蓄冰池蓄冷、蓄热出现的热胀冷缩安全问题提出了解决办法。对今后区域集中供冷系统的建设提供了参考。     

空调集中供冷系统调试及联动试车

本文从设计、施工、试车准备、调试、联动试车等环节,详细阐述了空调集中供冷系统调试及联动试车施工过程中的技术要点,供同类工程施工参考。     

珠江新城地下空间项目集中供冷站冷却系统方式比较

本文针对珠江新城地下空间项目具体实际情况，对集中供冷站各种冷却系统形式的优缺点作了比较；并以集中供冷站为35160kw（10000RT）为例，对各种冷却系统形式作了运行能耗分析比较；同时提出冷却形式的最佳方案。     

Uniform temperature cooling power of the superfluid Stirling refrigerator

Uniform temperature cooling power measurements of a superfluid Stirling refrigerator are presented for³He-⁴He molar concentrations of 5.9%, 17% and 36% and for temperatures between 0.37 K and 1.4 K. The results are compared to an ideal Fermi gas model and to a more general thermodynamic model. The Fermi model agrees well with the 5.9% concentration data; however, the more elaborate model is needed for higher concentration mixtures.     

热致相分离法EVOH微孔膜的制备和形态

选择乙烯的摩尔分数为38％的乙烯-乙烯醇的共聚物(EVOH)为原料，聚乙二醇(PEG)为稀释剂，采用热致相分离方法(TIPS)制备了亲水性高分子微孔膜．用扫描电子显微镜观测了微孔膜的形态．结果表明，分相的方式及微孔的大小由聚合物的含量及冷却速度决定．EVOH含量越少，则越易发生液-液相分离；冷却速度越慢，则微孔的尺寸也越大、EVOH摩尔分数为60％时，如果冷却速度很慢，则发生液-固相分离；如果冷却速度较快，则可同时观察到液-固相分离和液-液相分离的形态．     

Effect of cooling rate on phosphorus segregation behavior and the corresponding precipitation of γ″ and γ′ phases in IN718 alloy

Effect of segregation behaviors of P at different cooling rates on the precipitation of γ″ and γ′ phases and the corresponding strength are investigated. The precipitation of γ″ and γ′ phases during cooling is sensitive to P concentration. With increasing the concentration of P, the amount of γ″ and γ′ particles increases after air cooling. With decreasing the cooling rate, the accelerating effect of P on the precipitation of γ″ and γ′ phases decreased first and then increased, which demonstrates the concentration of P dissolved in the grain interior decreases first and then increases. The different effects of P on γ″ and γ′ phases with different cooling rates were analyzed by the kinetic characteristic of nonequilibrium grain-boundary segregation. The characteristic of nonequilibrium grain-boundary segregation of P in superalloy is further confirmed, and the phenomenon caused by critical cooling rate is captured.     

酯化大单体的冷却速度和含量对聚羧酸高效减水剂性能的影响

通过丙烯酸和聚乙二醇1000在75～100℃之间的酯化反应制备了聚乙二醇单甲基丙烯酸酯大单体.在酯化率接近50%时停止反应,控制大单体的降温速度并配制不同浓度的大单体溶液,然后将不同降温速度所得到的大单体和不同浓度的大单体溶液与其它几种单体共聚生成大分子的高效减水剂.采用水泥净浆试验,检验所合成聚羧酸高效减水剂的分散性及与水泥的适应性,系统研究了酯化大单体的冷却速度和含量对聚羧酸高效减水剂性能的影响.结果表明,酯化大单体的合适降温速度为0.9～1.6℃/min,合适的质量分数为70%～80%.     

Study on the Gelling Behaviour of Low Concentration Gelatin Solutions in the Cooling Process

Abstract

The authors have already reported the examination of the gelling characteristics of gelatin solution by a thermal sensor method. At solution concentrations below 4%, the gelling process was studied by optical rotatory power measurement. In this paper, the cltanges of the molecular iveight distribution (MWD) in the gelling process during the cooling period were investigated. The MWD of the gelatin solution was measured at the gelling temperature by gel permeation chromatography. The concentration of the gelatin solution was more related to the gelling phenomena than the cooling temperature. Some differences were observed in the changes of MWD among the types of gelatins.     

不同保护剂浓度和不同降温速率对脂质体玻璃化转变温度的影响

玻璃化转变是动力学的非平衡过程,玻璃化转变量温度是和过程有关的参数。测量了在降温速率分别为５℃/min和１０℃/miｎ,升温速率为１０℃／ｍｉｎ条件下,葡萄糖、蔗糖、甘露醇、海藻糖浓度为５％（Ｗ／Ｖ）的脂质体悬浮的玻璃化转变温度Ｔ‘g,在降温速率为５℃ｍｉｎ、升温为１０℃/min条件下,测量了葡萄糖、蔗糖、甘露醇、海藻糖浓度为１５％（Ｗ／Ｖ）的脂质体的Ｔ’ｇ;并分析了不同降温速率和不同保护剂浓度对脂质体玻璃化转变温度Ｔ’g的影响因素。     

Measurements of the Superfluid Joule–Thomson Refrigerator Using High Concentration 3He–4He Mixtures

The superfluid Joule–Thomson refrigerator (SJTR) uses a liquid superfluid ³He–⁴He mixture to provide cooling below 1 K. Performance measurements of the SJTR using 5% and 11% ³He concentration mixtures are reported. High concentration operation shows higher cooling powers at high temperature. Ultimate temperatures are seen to increase with increasing concentration due to a pinching of the temperature defect in the recuperative heat exchanger. This pinching effect is due to the variation of the heat capacity of the ³He–⁴He mixture with temperature and concentration and is discussed in detail and design changes are suggested to mitigate it.     

液体真空冷却过程中失水及浓度变化问题研究

研究真空冷却过程中失水与液体质量之间的关系以及二元溶液的浓度变化问题.以上海理工大学能源与动力工程学院自行研制的真空冷却装置为试验平台,选取不同的水质量和容器形状进行试验以研究其对失水率的影响,另外选取不同浓度的蔗糖溶液研究真空冷却对二元溶液浓度的影响.为便于比较,提出相对失水率、相对高度,相对浓度的概念.试验结果表明,当容器内液位增加时,失水率随之增加,并且变化趋势越来越明显;采用较高的窄口容器可明显降低失水,相对失水率最低仅为1.08,实际失水非常接近理论失水;蔗糖溶液经真空冷却后浓度会有所升高,但变化不大.     

Effect of cooling rate on the formation of metastable icosahedral quasicrystal phase in rapidly solidified Al-8.2 at % Mn alloy

The microstructure of rapidly solidified Al-8.2 at % Mn alloy was analysed by X-ray diffraction, transmission electron microscopy and energy-dispersive analysis of X-rays and the effect of cooling rate on the formation of the metastable icosahedral quasicrystal phase (IQP) was investigated. The formation of IQP was found to be sensitive to the cooling rate in a rapidly solidified alloy of a certain composition. A lower critical cooling rate at which metastable IQP starts to appear and an upper critical cooling rate at which IQP suppresses completely the stable crystalline phase exist. The fact that the amount and the manganese concentration of IQP change non-linearly with the cooling rate suggests that there is an optimum cooling rate at which both the amount of IQP and its solute concentration reach maximum values in an alloy of a certain composition.     

Energy consumption characteristics of an absorption chiller during the partial load operation

The objectives of this study are to analyze performance characteristics during partial load operation and to calculate energy consumption amount of H₂O/LiBr absorption chiller with a capacity of 210 RT. The effect of cooling water flow rate and cooling water inlet temperature on the absorption performance and energy saving is quantified during the partial load operation. It is found that the performance of absorption system is more sensitive to the change of inlet water temperature rather than the cooling water flow rate. Even if the cooling water flow rate is reduced to 60% of the standard value, the capacity is recovered if the temperature of cooling water decreases about 2.0 °C. The pumping power of cooling water is 4 times higher than that of cooling tower during the partial operation mode and the pumping power of cooling water becomes more significant with decreasing the partial load. It is concluded that when the partial load is in the range of 100–40%, the reduction of the required power by 23% can be realized by decreasing the cooling water inlet temperature of 1.0 °C.