降压调速在风机类负载中应用的可行性探讨

降压调速在风机类负载中应用的可行性探讨锦州市节能办公室单建伟，唐志１前言风机、水泵的调速节电是国家和省重点推广的节电项目之一。在全国乃至我地区都得到了广泛的应用，取得了可观的节电效果和经济效益。但是在推广应用风机、水泵调速节电项目的过程中发现，小型鼠...     

调速离合器在大功率水泵上的应用

当前,水泵和风机的用电占城市总用电的40%,研究水泵和风机的节电有着重要意义。在风机和水泵的调速技术中,调速型液体粘性离合器,具有结构简单、运行可靠、维修方便、节能显著等特点,是国际上新型的调速节电装置。一、调速离合器的选择1.调速离合器应用于水泵节电有一定条件。首先,要分析水泵运行工况,看用节流调节,还是用回流调节,看调节量的大小,实际运行扬程与水泵名牌扬程的差距,额定流量与实际流     

浅谈风机水泵耗电与节电途径

通过对量大面广、耗电量大的风机水泵节能损失、节电特性以及运行现状分析认为；合理地选型与配套、变频调速控制流量、更新陈旧设备、优化网络系统及应用电容器就地补偿等几项措施是风机水泵节电行之有效的方法。     

抓好煤矿风机水泵节能技改试点项目节电效益显著

抓好煤矿风机水泵节能技改试点项目节电效益显著河北省煤炭工业厅节能办乔泉宪从１９９２年开始，国家决定设立专项资金，以煤炭行业为突破口，开展以煤矿风机水泵为主的节能技术改造，试行用项目节电效益归还贷款的试点工作。这个办法，受到了煤矿干部职工的普遍欢迎。大...     

风机、水泵节能潜力大

据第三次工业普查资料：我国风机、水泵的设备效率平均为75％，比国外低10个百分点；系统实际运行效率更低，仅为3O－40％，比发达国家低15－ZO个百分点，节约的潜力很大。我国风机、水泵设备装机总功率已达1．59亿千瓦（其中风机O．49亿千瓦，水泵1．1亿千瓦，年总耗电量3200亿千瓦时，约占当年全国电力消耗总量的1／3以上，占工业用电量的40％。专家的估算，如采用简易节电技术进行一般更新改造，节电率可达10％，一年就可节电32O亿千瓦时；如果采用先进的调速节电技术进行系统改造，节电率可达3O－50％，年节电可达1100亿千瓦时，社会…     

风机水泵系统节能改造主要途径

风机水泵是广泛应用于工厂企业、农业生产和人民生活和通用机械。其面广量大，耗电较多。据调查，风机水泵系统，普遍在机组、管网、调节、管理等方面存在着许多问题，蕴藏着很大的节电潜力。因此，搞好风机水泵的节能工作，对加速四化建设，缓解电能紧缺状况，具有重要意义。风机水泵的节能工作是多方面的。其节能改造的主要途径如下。一、淘汰、更换低效设备风机水泵的节能，首先要提高机组本身的效率。然而，现在一些企业还有相当一部分陈旧、低效的风机、水泵、电动机。这些设备结构不合理、能耗高、运行效率低，必须予以淘汰或更换。在…     

风机、水泵节电最佳途径——变频调速

<正> 一、前言风机、水泵是国民经济各行业中广泛使用的通用机电设备,其耗电量之多约占全国总耗电量的30％。据推算,如果将风机,泵类的一半运行效率提高20％,全国每年将节电200亿千瓦时。这是一个惊人的数字。因此,风机、水泵的节电问题已越来越引起人们的重视。实践证明,用调速电机驱动风机或水泵,取代原来的阀门或档板控制,节能效果可达20—50％,甚至更多。所以,大力推广风机、水泵的调速节电技术,对国民经济发展具有重大的意义。本文重点介绍电动机变频调速方案及此方案所具有的绝对优势。     

风机,水泵的调速节能技术

目前,电力不足已经影响到正常的工农业生产和人民生活,节电工作已成为国民经济建设中的一件大事。节电潜力最大的是风机、水泵类负载。风机、水泵量大面广,其耗电量约占全国发电量的31％,占全国工业用电量的50％左右。可是,在风机、水泵的运行中,普遍存在下述问题:(1)设备陈旧,效率低;(2)实际工况远低于额定工况,运行效率更低;(3)多采用阀门、挡板节流,功率损耗大。 风机、水泵的特性是功率与转速的立方成正比,当实际流量较低时,采用调速运行     

必须实行机泵系统的经济运行

风机水泵是国民经济各部门中量大面广的通用机械，冶金、化工、纺织、轻工、商业等企业都拥有大量的风机、水泵，它们的耗电量在工业用电中占有很大的比例，且有很大的节电潜力。因此，国家一直把风机、水泵及其系统的节能作为一个重要的工作。根据市有关部门关于节能工作的要求，本市正在对一些大中企业开展机泵及其系统的调研、测试、论证、改选工作，在取得一定经验之后将在全市推广这一工作，实行风机水泵及其系统的经济运行。这也是企业节能工作的重要内容，是机泵及其系统实现科学管理和技术进步的主要方法。本文分四部分。一、介绍了…     

适用于风机水泵的变频调速系统

提出了一种适用于风机水泵类负载的变频调速系统。采用恒转差调速方式，不但可通过调节风机、水泵的转速起到节能作用，而且从电机内部能耗分析来看，也具有节电效果。采用一种新型的可控硅变频器，它比普通的串联二极管变频器节省许多元件，而电流输出波形更好，而且比大功率晶体管变频器的功率大，易于短路保护，故障率低，节省维修费用。是一种比较理想的风机水泵调速装置。     

A unified empirical correlation for evaporation of water at low air velocities

This paper presents a simple empirical correlation to predict the rate of water evaporation from small exposed water bodies. The correlation is a function of air velocity and difference between saturated vapour pressure of water body and partial water vapour pressure of the surrounding air. Earlier correlations were valid only for either still air or for minimum air velocities from 0.9 m/s whereas this correlation can predict the rate of water evaporation even from still air to air velocities up to 5.36 m/s. The correlation is particularly relevant to predicting the evaporation rates of defrosted water in domestic refrigerators where the air velocities in home kitchen environment are very low ie. between 0 and 0.9 m/s.     

工业厂房空压机冷却散热的回收利用

分析了工厂空压机散热量回收的可行性，通过工程实例介绍了利用回收热量预热空调新风、加热空调热水和工艺及生活热水的方法。     

Thermodynamic study of wet cooling tower performance

An analytical model was developed to describe thermodynamically the water evaporation process inside a counter‐flow wet cooling tower, where the air stream is in direct contact with the falling water, based on the implementation of the energy and mass balance between air and water stream describing thus, the rate of change of air temperature, humidity ratio, water temperature and evaporated water mass along tower height. The reliability of model predictions was ensured by comparisons made with pertinent experimental data, which were obtained from the literature. The paper elaborated the effect of atmospheric conditions, water mass flow rate and water inlet temperature on the variation of the thermodynamic properties of moist air inside the cooling tower and on its thermal performance characteristics. The analysis of the theoretical results revealed that the thermal performance of the cooling tower is sensitive to the degree of saturation of inlet air. Hence, the cooling capacity of the cooling tower increases with decreasing inlet air wet bulb temperature whereas the overall water temperature fall is curtailed with increasing water to air mass ratio. The change of inlet water temperature does not affect seriously the thermal behaviour of the cooling tower. Copyright © 2005 John Wiley & Sons, Ltd.     

工业锅炉供热系统存在的问题及节能技术综述

文中介绍了采用二次回风系统,促进燃料完全燃烧,采用合理的调节风量来实现燃料燃烧时的氧气供应,加强水处理促进热能扔效转换以及供热水失调引起的故障分析。     

“Partial pressures” of humid air in wide pressure and temperature ranges

“Partial pressure” in humid air is a question very much concerned by scientists and no satisfactory answer has been found to date. This paper proposes a novel method to obtain the “partial pressures” of the water vapor and dry air in humid air. The results obtained by the proposed method are quite different from that obtained by Dalton’s partial pressure law. The fundamental behaviors of water vapor and dry air are studied in depth in wide pressure and temperature ranges. Semi-permeable membrane models are proposed and applied for both saturated and unsaturated humid air. “Improvement factors” are developed to quantitatively describe the magnitude of the interaction between dissimilar molecules. One discovery is that the “partial pressure” of the water vapor in saturated humid air equals P_s, rather than (f·P_s) which was formerly believed. The other is that the interaction between dissimilar molecules may be omitted when temperature is above “cutting-off temperature” for unsaturated humid air. This paper satisfactorily answers the quest of “partial pressures” in humid air from a new perspective.     

回收空调制冷设备凝结水的节能研究

在整体式空调机组、冷冻去湿机组、制冷机组等设备中 ,广泛采用表面式空气冷却器对空气进行冷却去湿处理 ,从而会产生一定数量的温度较低的凝结水 ,若将其直接排放 ,不仅浪费能源 ,而且造成环境污染。本文将对凝结水的回收进行能量分析 ,为回收凝结水的设计计算提供理论依据 ,并分析节能的主要影响因素 ,最后得出结论     

NPT5型空气压缩机机油乳化的原因及对策

针对NPT5型空气压缩机机油乳化的惯性故障,分析了造成机油乳化的主要原因,提出了拆检空气压缩机出风管路逆止阀、检查气阀和活塞、安装自动排水阀和更换机油等预防措施,并提出了重新界定机油含水量标准、加强油质监控和使用添加剂的建议。     

Simulation study of improved biomass drying efficiency for biomass gasification plants by integration of the water gas shift section in the drying process

This paper examines thermochemical biomass conversion plants that produce synthesis gas that can be converted into synthetic fuels. Biomass requires forced drying before torrefaction or gasification to increase the heating value of the feed, an energy consuming step that weighs heavy in the energy balance of the plant. This paper shows that decreasing the humidity of the admitted drying air greatly improves the efficiency of the biomass drying. It is possible to reduce the humidity of the air by passing the air on a water adsorbent solid such as activated alumina. The alumina loaded with water can then be regenerated with waste heat, but more efficiently by using synthesis gas and convert the adsorbed water to hydrogen in the water gas shift section. The energy saved in the improved drying step amounts to 2–8% of the total fuel consumption of the plant, depending on the ambient conditions.     

Performance analysis of a drop-in-replacement blend for CFC-12, CFC-502, and HCFC-22

In this paper, a performance evaluation of a newly developed blend of HFCs and HCFCs, as a substitute for CFC-12, CFC-502, and HCFC-22, is presented. The blend's performance has been evaluated using water/air, air/air and water/water heat pumps, as well as a domestic refrigerator. The test results showed that the blend is not only environmentally sound, but it also enhances the performance by 7% to 30%, depending upon the application.     

小型风冷式冷热水机组的现状和发展

小型风冷式冷热水机组以其一机两用、微电脑控制自动运行、安装方便，一台机组带多台分离安装的末端设备、可同时调节多个房间的温度、机组可安装于室外阳台的隐蔽处、以及兼具有大型中央空调系统和家用空调器的优点等特点，较好地满足了市场的需求，受到了用户的青睐，在住宅、别墅、商场、餐厅、写字楼等处采用愈来愈多。文章说明了小型风冷式冷热水机组的分类，叙述了小型风冷式冷热水机组的特点，介绍了小型风冷式冷热水机组的制冷和控制系统，阐述了小型风冷式冷热水机组性能提高途径，为小型风冷式冷热水机组的发展奠定了基础。