典型气象季在直接蒸发冷却空调中的应用

通过分析直接蒸发冷却(direct evaporative cooling,DEC)空调系统能效比(energy efficiency ratio,EER)对室外气象参数变化的敏感度,发现DEC空调系统的累年平均能效比和额定能效比均无法作为直接蒸发冷却空调设计依据。以乌鲁木齐地区为研究对象,构建并给出了用于评估DEC空调系统性能的典型气象季。结果表明,DEC气象季可准确地反映直接蒸发冷却空调制冷能力随室外气象参数变化的特征,并且由典型气象季计算出的平均和最小能效比可分别作为DEC空调系统的经济评价指标和设备选型的关键依据。     

蒸发冷却与机械制冷复合空调系统分析

从蒸发冷却与机械制冷结合机理、结合方式出发,设计了蒸发冷却与机械制冷复合空调系统.结合气象资料及湿空气焓湿图,分析了蒸发冷却与机械制冷复合空调系统的具体实施方案.结合工程实例及热力学分析得出,蒸发冷却可以有效降低机械制冷系统开启时间和运行负荷.     

论蒸发冷却空调系统在节能中的应用

就蒸发式冷却空调系统进行了简单介绍,蒸发冷却是以水作为制冷剂的,利用水的蒸发取得冷量.但是它不将蒸发后的水蒸气进行压缩、冷凝回到液态水后再进行蒸发,因此与机械制冷相比,蒸发冷却不需要消耗压缩功,一般来讲,蒸发冷却空调的能效比是机械制冷空调能效比的2.5～5倍.还介绍了蒸发式冷却空调系统在不同地区的应用方式,蒸发式冷却空...     

提高矿井制冷系统能效的探讨

通过综合分析目前矿井制冷系统的现状,发现在满足矿井降温要求的前提下,优化矿井内降温系统的各耗能环节以及降低降温系统成本是提高矿井降温系统的经济性和节约能源的关键。为了找出提高矿井制冷系统能效的关键因素,从矿井制冷系统的能耗指标出发,通过对几种能效指标的对比分析,最终采用能效比EER(Energy Efficiency Ratio)指标进行分析。通过对南非Harmony金矿、孙村煤矿、唐口煤矿冰冷降温和井下集中制冷等四种系统形式,用对比分析的方法分别计算了它们的能效比、各设备的效率比等,结果表明采用冰制冷降温系统的能效比最高,唐口煤矿达到1.92;另一方面,冷水机组的功率比相对较高,说明降低冷水机组的功率是提高制冷系统能效比的关键。该结论将对降低矿井能耗、提高经济性起到一定的指导作用。     

严寒地区数据中心降温节能空调系统探究

随着大数据时代的到来,数据中心建设发展迅速。其特点是散热量大,空调能耗高,人工制冷作为数据中心主要室内降温方式且连续运行,耗电量仅次于IT设备用电,PUE值较高。严寒地区冬季温度≤5℃的天数不足170d,夏季超过30℃的天数不足30d,气候特点鲜明。故可充分利用室外空气温度变化来满足室内环境温度需求,即在数据中心空调制冷系统方案中拟采用全热交换、蒸发冷却和人工制冷系统相结合的模式,以达到节能降耗的目的。     

户式温湿分控空调机组运行特性实验

利用焓差实验室对一种户式温湿分控空调机组的设备显热比变化特性进行实验.分别保持通过该机组两侧蒸发器的换热介质的入口参数恒定不变,当压缩机转速和风侧蒸发器的冷剂比例同时变化时,得到设备制冷量、设备显热比SCR以及能效比EER的变化曲线.实验结果表明,改变机组压缩机转速以及风侧冷剂的比例,不但改变机组总制冷量,同时改变机组输出显热冷量与潜热冷量的比例;设备SCR的变化范围0.6~1.0,远远大于传统空调机组的变化范围,可以与房间显热比SHR值更好地匹配,以更好地控制室内热环境.同时表明,设备SCR的调控受到机组总冷量与能效比的限制,在实现设备SCR及总制冷量的前提下,尽量使EER值最大,有利于节能.     

蒸气压缩式和溴化锂吸收式冷水机组的节能分析

在大、中型中央空调工程中,制冷机组的能耗一直是人们关心的问题．不少媒介宣称吸收式冷水机组比蒸气压缩式冷水机组节能,是中央空调发展的方向．本文通过对各种制冷机组的矿物能源能效比进行比较,并进行计算列表分析,结果表明溴化锂吸收式冷水机组比蒸气压缩式冷水机组节电不节能．图３,表１,参６．     

模块化间接-直接蒸发冷却复合冷水机组的设计计算

对模块化间接-直接蒸发冷却复合冷水机组的间接蒸发冷却模块单元、直接蒸发冷却模块单元相关参数进行设计计算.将模块化机械制冷冷水机组的思路引入蒸发冷却冷水机组的结构设计中,提出了一种模块化间接-直接蒸发冷却复合冷水机组.不仅对该模块化蒸发冷却冷水机组在制取高温冷水方面进行理论分析,而且论述了模块化的结构.设计分析计算得出较为合理的模块单元主要参数,为模块化间接-直接蒸发冷却复合冷水机组的设计提供一些参考.     

Development of Temperature-Humidity Independent Control Air-Conditioning Unit for Residential Buildings

Cooling panels are increasingly used in domestic residential buildings.To provide medium temper-ature cold water for the cooling panel,and dehumidify the indoor air simultaneously,a new kind of temperature-humidity independent control air-conditioning unit was developed for single residential house by utilizing multi-variable technology.First,the supply air temperature was studied to determine the proper supply air flow rate for the humidity control.Then,the energy consumption of different temperature-humidity independent eontrol systems was studied.The analysis indicates that unity evaporating temperature can be used to handle the mois-ture load and sensible heat load in two evaporators.So the unit scheme was put forward.Two evaporators were used to produce medium temperature water and dry air separately,and electric expansion valves were used to control the refrigerant distribution between the two evaporators.Then, experimental work was carried out to in-vestigate the influence of compressor frequency,refrigerant distribution on the dehumidification capacity,energy efficiency and refrigeration capacity.In the end,the paper concludes that both compressor frequency and refrig-erant distribution can control the dehumidification capacity,but the former influences the EER more than the latter.while the latter influences the refrigeration capacity more than the former.We can find a proper running point at certain sensible and latent cooling load by adjusting both compressor frequency and electric expansion.valve.The energy consumption of this kind of unit was estimated and compared with present room air condition-ers,which shows that it can save about 41% cooling energy consumption.     

Evaporative Condensers in Comfortable Air Conditioning System

The operating theory of an evaporative condenser was expatiated.The difference between an e-vaporative condensing refrigeration system and a general refrigeration system was analyzed.Compared with the air-cooled and the water-cooled,the virtues of energy-conservation and water-conservation of evaporative con-densers were analyzed.Some questions existing in the application of evaporative condensers were pointed out,the corresponding solving methods were analyzed accordingly,and the development trend of evaporative con-densing technique in mechanical refrigeration system field and the applied foreground of evaporative condensers in comfortable air conditioning were prospected.     

西北地区置换通风与混合通风空调系统的能耗比较

比较了置换通风和混合通风的特性．结合西北地区某一办公建筑，对蒸发冷却＋混合通风和蒸发冷却＋置换通风空调系统在同设计工况下进行了能耗分析．结果表明，后一种方案比前一种节省能耗39．8％；在利用室外空气免费供冷时间上，后者比前者多利用186h／a．     

蒸发式冷凝的应用分析

通过分析对比制冷工艺中几种冷凝方式,指出发展蒸发式冷凝技术对制冷系统节能的重要意义.同时通过分析蒸发式冷凝的换热机理,从试验和实践的基础上提出影响蒸发式冷凝器性能的几个重要因素.     

Condensing Heat Recovery of Centrifugal Chiller

To a kind of centrifugal water chiUer with R22 and about 1745 kW of cooling capacity.a heat exchanger was added between the outlet of compressor and original condenser to get part of or all the condensing heat.Condensing heat can be recovered by compound condensing method,which adopts air-cooling model+wa-ter-cooling model or water-cooling model+water-cooling model at the condensing side of the system.By exergy analysis and experiment research on compound condensing heat recovery of centrifugal chiller,the results are ob-tained that the capability of the whole system increases,the energy efficiency ratio (EER) becomes 3.2～5.0 from 2.2～3.4, which implies the EER increases about 1.0～1.5,the exergy efficiency increases about 10%,and the chiller runs more stably after reformation.     

回热型吸附式空调动态特性

基于在回热型吸附式空调样机上开展的大量实验，研究了有关时间因素（如回热时间，回质时间，半周期时间等）对样机性能制冷系数COP和单位质量制冷功率SCP的影响，分析了SCP的瞬态特性，实际循环p-T图的特点，从而探索回热型吸附式空调的动态特性，为进一步改进其性能打下基础。     

Optimization criteria for the performance of heat and mass transfer in indirect evaporative cooling systems

The wide application of evaporative cooling techniques in which the optimization criteria form the theoretical basis for improving evaporative cooling performance is essential for energy conservation and emission reduction.Based on exergy analysis and the entransy dissipation-based thermal resistance method,this contribution aims to investigate the effects of flow and area distributions in the optimization of the performance of indirect evaporative cooling systems.We first establish the relationships of exergy efficiency,entransy dissipation-based thermal resistance and cooling capacity of a typical indirect cooling system.Using the prescribed inlet parameters,the heat and mass transfer coefficients and the circulating water mass flow rate,we then numerically validate that when the cooling capacity reaches a maximum,the entransy dissipation-based thermal resistance falls to a minimum while the exergy efficiency is not at an extreme value.The result shows that the entransy dissipation-based thermal resistance,not the exergy efficiency,characterizes the heat transfer performance of an evaporative cooling system,which provides a more suitable method for evaluating and analyzing the indirect cooling system.     

常规型游梁式抽油机二次平衡问题的研究

本文提出一种常规型游梁式抽油机的平衡节能新方法“二次平衡法”,并进行了相应的理论分析与优化计算,还提出了一种“二次平衡”法的具体实施方案。试算表明,采用这种方法,节能效果在25％以上,比现有常规型游梁式抽油机改造为偏置相位抽油机其节能效果为13％有较大幅度提高。     

Research of refrigeration system for a new type of constant temperature hydraulic tank

Different from the traditional hydraulic oil cooling method,a new type of constant temperature oil tank cooling system based on semiconductor refrigeration technology is designed. This paper studies the principle of semiconductor refrigeration and establishes a heat transfer model. Semiconductor cooler on piping refrigeration is simulated,and influence of the parameters on the outlet temperature,such as pipe pressure difference of inlet and outlet,pipe length,pipe radius,are gotten,and then hydraulic tank semiconductor refrigeration system is proposed. The semiconductor refrigeration system can control temperature at 37 ± 1°C.     

剖析压缩式制冷装置能耗

所有制冷装置均遵循热力学第二定律工作,在获得冷量的同时必须消耗能量,但这决不意味着制冷装置的运行就无节能措施可言,制冷装置的制冷量和耗能量与许多因素有关,只有充分理解这些因素的影响,才能寻求制冷装置的节能途径。本文就蒸气压缩式制冷的热力循环原理、系统的正确设计、制冷设备的妥善维护和保养等方面对其制冷能耗的影响作阐明,以期达到制冷装置的节能运行。     

传统高温炉的改造

使用传统的高温炉时采用机械式方法进行操作,升温速度靠人工手动电流调节旋钮来控制。在升温过程中必须不断地观察并调节电流大小以控制升温速度,因而在烧结样品时温度控制不够准确,且花费较多的时间、耗费较多的电量。为了满足烧结工艺对炉温的高要求,选用智能控温仪,通过改进线路,对老式高温炉温度控制系统进行技术改造。改造后的高温炉能通过控温程序准确控制烧结过程,温差为±1℃～2℃,并达到了节能、省时的效果。     

集热器对太阳能喷射制冷系统性能的影响

采用寿命期性价比对单、双层盖板平板集热器、全玻璃管、热管真空管及CPC聚焦型集热器对喷射式制冷系统的性能影响进行了评价,并与采用设计工况性价比指标的评价结果进行对比分析。结果表明,寿命期性价比评价指标考虑了太阳辐射与气温变化,比设计工况性价比评价指标更全面、更符合实际情况;双层盖板平板集热器用于太阳能喷射式制冷系统,寿命期性价比最优;CPC聚焦型太阳能集热器热性能最优,在相同制冷量下,所需集热面积最小,可节省安装空间。