化工离心泵在选用中的节电技术

化工离心泵在选用中的节电技术四川省新达水泵厂张元华化工离心泵运行效率低的主要原因是泵的实际运行工况点（Ｑ、Ｈ）偏离最高效率点（亦称为设计点），因化工离心泵的驱动电机一般不能调速，大多是在泵的出口闸进行节流调节，简单易行，操作方便。但从节能方面来讲，泵...     

变频调速在离心泵上的应用

变频调速在离心泵上的应用沈阳市辽中化工总厂任东油水泵在实际运行中普遍存在着匹配不合理及在调节流量、压力过程中大量的节流损失等，造成严重的能源浪费现象。在生产中，随着管网压力等工况的变化，需要经常调节泵的压力、流量，以保持生产系统的平衡与稳定。根据离心...     

2t／h燃气锅炉的节能分析

某酒店的2t／h燃气锅炉的运行效率低下，通过热工测试发现过量空气系数过低是主要原因，后经调整配风，达到额定效率。可见，在燃气锅炉中，过量空气系数过小造成的气体不完全燃烧热损失在锅炉运行中不容易被发现。     

多级轴流压气机失速特性分析

为了对某九级低压压气机的低工况性能进行改进和优化,分析压气机在低工况下的特性是必要的。采用三维黏性数值模拟方法对非设计工况进行了计算,根据压气机在近失速状态下的级特性,详细分析了第一级、第二级和末级的流场特性。结果表明:第一级转子扩压负荷过大,顶部发生了突尖波失速,是造成压气机不稳定运行的主要原因,且使下游的进气条件变差,导致第二级叶片顶部发生流动分离;末级静子扩压负荷较大,静子通道涡造成的漩涡耗散损失使末级的绝热效率低下。     

多级离心泵叶轮相位交错对转子受力变化影响的研究

本文以一六级多级离心泵为模型，设计A、B、C、D四组不同的交错方案，A为叶轮相位不交错、 B为叶轮相位交错一个流道相位的1/2、C为叶轮相位交错一个流道的1/(Z-1)、D为叶轮相位交错一个导叶流道的1/(Z-1)(其中Z叶轮为叶片数)。通过四组方案对多级离心泵的三维全流场进行数值分析，得到不同叶轮交错方案在不同工况条件下流场对机械部件的荷载变化。分析结果表明：叶轮相位交错使转子的径向力矢量分布向轴心集中；叶轮相位交错结构可以有效地减小转子受到的径向力，使转子运行稳定性得到提高；叶轮相位交错会造成不同工况下的转子受力波动幅值和成分发生改变；在设计工况下数值计算轴向力绝对值要高于理论计算的结果     

变频调速器在输油泵上的应用

一、前言 离心泵在其额定工况下的效率最高。但就我厂的实际情况来说,管线流程的总阻力往往随着季节的变化、管线结垢情况、原油温度的高低而发生变化,在工艺流程设计时,往往按可能发生的最大工况选择泵型,离心泵电机功率的选配,又储备功率太高,再加上现有转油站的产液量增加或减少了,因此,使得离心式输油泵很难在额定工况运行,输油系统效率很低。 根据离心泵的相似律,通过改变泵的转速就可以实现改变泵的排量、扬程。这是一种改变泵的工况的最佳途径,也就是说,通过改变电机的转速来实现离心泵的调节,即     

大力发电厂细粉分离器的经济运行

细粉分离器是火力发电厂制粉系统中的重要设备。本文通过实验研究了细粉分离器的经济运行问题，指出运行工况对细粉分离器的分离效率及阻力损失的影响。     

火力发电厂细粉分离器的经济运行

细粉分离器是火力发电厂制粉系统中的重要设备。本文通过实验研究了细粉分离器的经济运行问题，指出运行工况对细粉分离器的分离效率及阻力损失的影响。     

离心泵变频调速技术的应用及效果

联合站油水系统运行过程中，普遍采用调节流量的变工况运行方式。本文从实际应用出发，简要阐述了离心泵变频调速节能的基本原理，给出了现场应用实例。结果表明，变频控制系统运行状况良好，节能效果明显。     

多级轴流涡轮的变工况特性线分析

选用第一级静叶出口折合速度λc1和转子折合转速λu两个自变量进行计算，获得了不同工况参数πT（压比）和λu（转速）下的涡轮级通用特性线网。对4种广泛使用的速度系数进行最小二乘法均值拟合，并将其应用于变工况计算模型之中。研究了3级涡轮变工况下的效率、流量以及功率等总体特性的变化规律，详细分析了涡轮各级的焓降分配、动叶进口的撞击损失以及流出余速损失所发生的变化。结果表明：各级对于工况变动的敏感程度不同，后几级在变工况下各参数变动的幅度比前几级剧烈；变工况下余速损失的变动尤为剧烈，其对级效率的影响甚大。因此，在变工况下，从各级所处的特定角度来考虑其性能的优化极为重要。图11参6     

RS抽油机节能减速器在A油田的应用

A油田部分油井存在供液不足、泵效低、耗电高等问题。要提高油井泵效和节能效果,就需要降冲次。在成本、改造技术难度等方面对比了各种降冲次方法的优缺点,最终确定采用安装节能减速器的方法来降低冲次。在抽油机的电机和减速箱之间增加一套辅助减速装置即为节能减速器。减速器可大幅降低抽油机的惯性负荷,因此能起到一定的节能作用。介绍了节能减速器安装尺寸的确定方法。A油田在126口井安装、应用了节能减速器。安装节能减速器后,126口井平均消耗功率由3.526kW下降到3.000kW,综合节电率达到14.08%;系统效率由5.943%上升到7.116%;平均单井日节电13.2kW.h,预计可实现年节电60.7×104kW.h;抽油机运转较平稳,减小了惯性载荷,从而减少了抽油机的机械故障;优化了油井运行参数,提高了泵效,减少了杆管磨损。     

600MW机组汽泵全过程给水分析

一般机组设计启动过程采用电动给水泵完成机组启动前期的锅炉给水工作，由于电泵是耗电大户，增加了厂用电率。用汽动给水泵代替电动给水泵完成机组启动全过程锅炉给水的工作，有效地降低机组启停阶段的厂用电耗，从而达到节能的目的，     

The use of heat pumps in reducing fuel consumption for nonsolar climate control of buildings

Heating and climate control are of world-wide importance since these processes demand a large percentage of the total energy consumption of all nations. Conversion of energy stored in fossil fuels for heating, by direct combustion in a furnace or by electrical resistance heating via power produced in a power plant, exhibits very low efficiency. This implies that our consumption of primary fuels is several-fold larger than the amount really needed for accomplishing the desired climate-control function. Large improvements are possible and should be achieved. These improvements can be attained by reversible heating, i.e. by use of optimized heat pumps powered by work produced from fuels with high efficiency. Several systems are described which utilize readily available technology and know-how. Similar improvements are possible by identical means in other low-temperature processes.     

Energy efficiency in pumps

In this paper, “energy efficiency” studies, done in a big industrial facility’s pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data.

Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated.

The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems.     

化工装置减少机泵泄漏改造实践

介绍了磁力泵、屏蔽泵等无密封泵和干气密封的工作原理及性能特点。比较了采用磁力泵、屏蔽泵和干气密封三种对泄漏机泵进行改造的方法的优缺点。据此，中国石化广州石化分公司对其化工装置有泄漏问题的机泵进行了分类，制订并实施了改造方案。     

Toward generalized models for estimating molecular weights and acentric factors of pure chemical compounds

In this work, four prompt and robust techniques have been used to introduce new generalized models for estimation of the physical properties of pure substances, including molecular weight and acentric factor. These methods were developed based on radial basis function (RBF) neural networks, group method of data handling (GMDH), multilayer perceptron (MLP), and least square support vector machine (LSSVM) techniques. Models were introduced based on a set of experimental data including 563 pure compounds that were collected from available literature. Input parameters for estimation of molecular weight were considered as specific gravity and normal boiling point. Critical temperature, critical pressure and normal boiling point were selected as inputs for estimation of the acentric factor. Statistical and graphical error analyses normal boiling point revealed that all of the developed models are accurate. The designed RBF models give the most accurate results with an AAPRE of 5.98% and 1.92% for molecular weight and acentric factor, respectively. The developed GMDH models are in the form of simple correlations, which can be used easily in hand calculation problems without any need to computers. Comparison of the developed models with the available methods showed that all of the developed models are more accurate than the existing methods. Using the relevancy factor, the impact of each input parameter on the output results was determined. Additionally, to find out the applicability region of the developed models, and to demonstrate the reliability of the models, the Leverage method has been used. There are few data out of the applicability domain of the proposed models. All the statistical and graphical resolutions, demonstrate the reliability of the developed models in estimating the molecular weight and acentric factor.     

Experimental and numerical investigation on application of half vane diffusers for centrifugal pump

Vaned diffusers are widely used in centrifugal pumps, but little research has been published regarding action mechanism and the influence of diffuser vane height on dynamics performance of centrifugal pumps. Experimentally and numerically, the present investigation was focused on the dynamics performances of a low specific speed centrifugal pump equipped with vane diffusers with different vane heights. The pump performance was appraised when the diffuser vane height (h/b) was 0 (vaneless), 0.5, 0.6, 0.8 and 1 (vaned) times the diffuser width respectively. The pressure fields were numerically simulated in order to study the influence of half vane diffusers on inner flow field. The experimental results of operating performance showed that the efficiency was significantly improved for 2.5% at design flow point and the head was significantly improved for nearly 3 m at over flow point. The best efficiency point shifted towards higher flow rate with h/b reducing, and the high efficiency area was broadened by using half vane diffusers. Besides, half vane diffusers could reduce the intensity of pressure fluctuations at the leading edge of the stator vanes, and reduce the influence of rotor-stator interaction in tongue region. The numerical results showed that half vane diffusers could enhance flow uniformity in pumps, symmetry of pressure distributions on the impeller outlet and preferable regularity of radial force distributions. Therefore, it is very useful and feasible to apply half vane diffusers in centrifugal pumps.     

提高注聚区地面系统效率的措施及实施效果

介绍了注聚地面系统效率的概念和简化计算公式。通过现场调查，分析了影响孤东油田二区地面注聚系统效率的因素，指出主要影响因素为注聚泵系统。提出并根据实际情况应用了提高注聚地面系统效率的主要措施．主要有：调整注聚泵配置，减少低频运行台数；对注聚泵及时清阀，提高容积效率；应用平衡式低剪切截止调节阀．减少注聚泵开泵台数。     

Model construction and energy management system of lithium battery,PV generator,hydrogen production unit and fuel cell in islanded AC microgrid

The external electrical characteristics of the lithium battery, PV generator, hydrogen production unit (HPU) and fuel cell in islanded AC microgrid are well analyzed with mathematic models, based on which an energy management system among the abovementioned elements is proposed by using the bus frequency signaling. Specifically, the functions of lithium battery with the variables of the residual capacity and instantaneous working power are well designed to deliver its operation information to other units. The P-f droop control strategy is designed for the PV generator to make it adaptively work off from the maximum power point to the reference power point. The control strategy of HPU can make it work from the maximum efficiency point mode to the allowable maximum power point mode to absorb PV output power as much as possible when the lithium battery is almost getting full charged. Similarly, the fuel cell controller can regulate its power generation from the maximum efficiency point mode to the maximum power point to supply the local load as much as possible when the lithium battery is almost getting full discharged. Finally, the proposed energy management system is verified based on RTLAB experimental platform to show the effectiveness of the proposed coordination control strategy.     

国产600MW机组一次风机喘振原因分析及对策

针对珠海金湾发电公司国产600MW大容量机组锅炉轴流式一次风机运行中喘振事故频繁发生的问题,在了解分析造成轴流式一次风机喘振原理的基础上,对造成一次风机喘振的原因进行分析.主要原因为一次风管阻力特性的变化,使一次风机动叶开度过大,一次风机工作点处在高风压区低流量的工况点,是造成一次风机喘振的主要原因,提出了运行中减少一...