扬程系数,head coefficient
1)head coefficient扬程系数
1.Based on the theory and the experience, the requirements for increasing thehead coefficient under the condition of maintaining the efficiency were proposed in this paper.本文从理论和实例出发,分析了在不降低效率的前提下,提高泵扬程系数的条件。
2.The influences of impeller diameter,throat area and vanes number on the pump performance,head coefficient and flow coefficient are the main investigative parameters.主要研究部分流泵各过流部件(叶轮外径、喉部面积和叶片数)对部分流泵性能的影响以及对扬程系数、流量系数的影响,通过数值计算模拟和对计算结果的分析得出以下结论:1。
2)constant head system定扬程系统
1.Also it analyzed how the changes of pipe-network influenced each user s flux and compared the energy consumption of the above working point with the one ofconstant head system.分析管网的变化,对各用户的流量的影响,以及与定扬程系统的能耗的比较。
3)lift[英][l?ft][美][l?ft]扬程
1.By comparing two means of heightening feed pumplift range of reactor in a chemical plant shows that the method of deflection with short vane is an effective mean for heighteninglift range and efficiency of the low specific speed centrifugal pump.通过对提高某化工装置反应器进料泵扬程两种方法的分析对比、实验研究,提出短叶片偏置设计法是提高低比转速离心泵扬程和效率的有效方法。
2.It is shown after analysis that the efficiency of roto-jet pump is higher than theefficiency of multistage pump and express pump when it operates in the region of low dis-charge and highlift.通过分析得出旋喷泵在小流量和高扬程工况下运行时，效率高于多级泵和高速泵，在研究旋喷泵集流管与叶轮匹配及集流管扩散段损失的基础上，给出了设计扩散管水力参数的公式。
3.From the determination of flow and deliverylift,layout and other aspects analyzed is made.介绍了消防增压设施的种类,对增压设施流量及扬程的确定、位置的布置等方面进行了分析阐述,并对增压设施在消火栓系统和自喷灭火系统中能否合用的问题进行了探讨,以供增压设施设计时参考。
英文短句/例句
1.low-head centrifugal pump低水头离心泵，低扬程离心泵
2.Calculation of Delivery Lift of Circulation Pump in Regional Heating Boiler Plant小区供热锅炉房循环水泵扬程的计算
3.Research on Operation Management and Energy Saving Measures of High-lift Step Pump Station高扬程梯级泵站运行管理与节能措施
4.Study on the Technology and Design of Aie-filled Floating Flap Valve about Lowhead Pumping Station;低扬程泵站充气浮箱拍门的技术研究
5.Practice of water pricing reform in Jingdian Irrigation District;景电高扬程灌区水价改革实践及思考
6.A High Efficient Self-Adaptive Head-Based Control for Energy Saving of a Pump基于扬程自适应的机泵高效节能控制
7.Application of High-lift Pumps in Forestry Fire Prevention in China高扬程水泵在我国森林消防中的应用
8.Study on Water Hammer Protection in Long Distance Water Pipeline with High-lift and Multi-fluctuation长距离高扬程多起伏输水工程水锤防护研究
9.Outlet divergent passages are adopted in large, low head pumping stations whose hydraulic losses are15%~20% of pump water head.大型低扬程水泵采用渐扩出水流道,比水流道水力损失占泵扬程的15%20%右。
10.The distance or space through which something is raised or rises.扬程某物升高或被提高所经过的距离或空间
11.Analysis of Critical Economic Lift for Multilevel Water Pumping Irrigation System多级提水灌溉系统的临界经济扬程分析
12.Analysis of Water-saving Effeot on Irrigation Cost in the High Head Pumping Irrigation Area高扬程电力提灌区节水与灌溉成本关系的探讨
13.A Model on Optimization Distribution of Water Resources in the High-lift Pumping Areas along the Yellow River in Gansu province甘肃省沿黄河高扬程灌区水资源优化分配模型
14.Construction winch-Safety rulesGB13329-1991建筑卷扬机安全规程
15.Yet, somehow, Peter Kenyon is managing it.当然，某种程度上说肯扬做的还不错。
16.Develop What is Useful and Discard What is Usless to Traditional Education in Modern Distance Education;刍议现代远程教育对传统教育的扬弃
17.Promoted the Traditional Sports Culture and Innovation in Physical Education Teaching弘扬传统体育文化创新体育课程教学
18.Inheriting and Development of Physical Education and Health Course from Traditional P.E Course;体育与健康课程对传统体育课程的“扬弃”
相关短句/例句
constant head system定扬程系统
1.Also it analyzed how the changes of pipe-network influenced each user s flux and compared the energy consumption of the above working point with the one ofconstant head system.分析管网的变化,对各用户的流量的影响,以及与定扬程系统的能耗的比较。
3)lift[英][l?ft][美][l?ft]扬程
1.By comparing two means of heightening feed pumplift range of reactor in a chemical plant shows that the method of deflection with short vane is an effective mean for heighteninglift range and efficiency of the low specific speed centrifugal pump.通过对提高某化工装置反应器进料泵扬程两种方法的分析对比、实验研究,提出短叶片偏置设计法是提高低比转速离心泵扬程和效率的有效方法。
2.It is shown after analysis that the efficiency of roto-jet pump is higher than theefficiency of multistage pump and express pump when it operates in the region of low dis-charge and highlift.通过分析得出旋喷泵在小流量和高扬程工况下运行时，效率高于多级泵和高速泵，在研究旋喷泵集流管与叶轮匹配及集流管扩散段损失的基础上，给出了设计扩散管水力参数的公式。
3.From the determination of flow and deliverylift,layout and other aspects analyzed is made.介绍了消防增压设施的种类,对增压设施流量及扬程的确定、位置的布置等方面进行了分析阐述,并对增压设施在消火栓系统和自喷灭火系统中能否合用的问题进行了探讨,以供增压设施设计时参考。
4)head[英][hed][美][h?d]扬程
1.Analysis of influencingfactors on thehead ofscrew centrifugal pump;影响螺旋离心泵扬程的因素分析
2.Pumphead matching in distributed power system;动力分散系统中水泵扬程的匹配
3.Based on the working experience, with respect to general feature of pumps used in chemical factories, a set of methods to calculate the parameters, such as flow volume,head, net positive suctionhead and shutoff pressure, of pumps was summed up.在整理以往工作经验的基础上,针对化工厂用泵的一般特点,总结出了一套计算泵的流量、扬程、净正吸入压头和憋压等设计参数的方法。
5)Lift head扬程
6)pumping head扬程
1.This paper discusses such design problems in heating systems with the pres- sureless boiler as how thepumping head of the cycle pump is selected ,where the cycle pump is installed and whether the expansion tank is necessary.针对无压锅炉供暖系统设计中有关循环水泵扬程的选择、循环水泵的设置高度及是否设置膨胀水箱等问题从理论和实践上进行了探讨,得出了可供设计人员实际应用的计算公式,介绍了几个关键问题的处理方法,澄清了一些模糊认识。
延伸阅读
阀门技术注重流量系数和气蚀系数阀门的流量系数和气蚀系数是阀的重要参数，这在先进工业国家生产的阀门资料中一般均能提供。我国生产的阀门基本上没有这方面资料，因为取得这方面的资料需要做实验才能提出，这是我国和世界先进水平的阀门差距的重要表现之一。3.1、阀门的流量系数
阀门的流量系数是衡量阀门流通能力的指标，流量系数值越大，说明流体流过阀门时的压力损失越小。
按KV值计算式
式中：KV—流量系数
Q—体积流量m3/h
ΔP—阀门的压力损失bar
P—流体密度kg/m3
3.2、阀门的气蚀系数
用气蚀系数δ值，来选定用作控制流量时，选择什么样的阀门结构型式。
式中：H1—阀后(出口)压
H2—大气压与其温度相对应的饱和蒸气压力之差m
ΔP—阀门前后的压差m
各种阀门由于构造不同，因此，允许的气蚀系数δ也不同。如图所示。如计算的气蚀系数大于容许气蚀系数，则说明可用，不会发生气蚀。如蝶阀容许气蚀系数为2.5，则：
如δ＞2.5，则不会发生气蚀。
当2.5＞δ＞1.5时，会发生轻微气蚀。
δ＜1.5时，产生振动。
δ＜0.5的情况继续使用时，则会损伤阀门和下游配管。
阀门的基本特性曲线和操作特性曲线，对阀门在什么时候发生气蚀是看不出来的，更指不出来在那个点上达到操作极限。通过上述计算则一目了然。所以产生气蚀，是因为液体加速流动过程中通过一段渐缩断面时，部分液体气化，产生的气泡随后在阀后开阔断面炸裂，其表现有三：
(1)发生噪声
(2)振动(严重时可造成基础和相关构筑物的破坏，产生疲劳断裂)
(3)对材料的破坏(对阀体和管道产生侵蚀)
再从上述计算中，不难看出产生气蚀和阀后压强H1有极大关系，加大H1显然会使情况改变，改善方法：
a.把阀门安装在管道较低点。
b.在阀门后管道上装孔板增加阻力。
c.阀门出口开放，直接蓄水池，使气泡炸裂的空间增大，气蚀减小。
综合上述四个方面的分析、探讨，归纳起来对闸阀、蝶阀主要特点和参数列表便于选用。两个重要参数在阀门运用中 。
