瑞典TA平衡阀授课资料中文版

,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Hydronic College,Jean-Christophe Carette, Hydronic College BU Western Europe,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Hydronic College,Jean-Christophe Carette, Hydronic College BU Western Europe,Tour and Andersson,The Three Hydronic Conditions,for an accurate control in HVAC systems,精确控制,HVAC,系统的三个水力工况条件,Why and how to satisfy them in the simplest way,为什么及如何用最简单的方法满足这些条件,1,空调系统的目的,All HVAC installations should reach 2 fundamental objectives:,所有,空调采暖,系统应达到两个主要目的,:,To deliver the specified comfort level,提供要求的舒适度,To reach the first objective, by consuming a minimum quantity of energy,以最少的能耗达到以上目的,Production,冷热源,Distribution,输配系统,Terminal units,末端装置,2,理论和实践,In theory, current technology makes it possible to achieve these 2 objectives,理论上,现代控制技术使实现这两个目标成为可能,In practice, even the most sophisticated control systems lead,often to reduced comfort at increased operation costs,但实际上,即使是最复杂的控制系统也不能带来满意的效果,而且运行成本较高,3,奇怪的现象,Too hot,in some parts,too cold,in others,在某些地方,太热,在某些地方,太冷,Start up after a set-back difficult in some rooms,在一些房间里回设之后的启动比较困难,Installed power is not deliverable,装机功率不能充分利用,Higher energy consumption than expected,比预期的能耗更高,4,奇怪的现象,In most cases, solutions are to be found on the hydronic side,在大部分案例中,我们可以从水系统找到答案,5,水力系统平衡简介,为什么水力系统要平衡？,采暖,及,空调系统,中,水力平衡的技术是节能及提高供冷或供热品质的关键,常见的问题,在供热或空调系统中，由于种种原因，大部分输送环路及冷热源机组环路存在水力失调，使得流经终端用户及机组的,实际流量与设计流量不符,。,多数,水泵选型偏大,或,水泵运行在不合适的工作点处,，导致水系统处于,大流量、小温差,运行工况，水泵运行效率低、热量输送效率低。,各用户处室温不一致、不稳定,，近热源处室温偏高，远热源处室温偏低。近冷源处室温偏低，远冷源处室温偏高。,对热源或冷源机组来说，机组达不到其额定出力，,使实际运行的机组台数超过按负荷要求的台数。,6,水力系统平衡的好处？,采暖,及,空调系统,中,水力平衡的技术是节能及提高供冷或供热品质的关键,提高舒适度,保证室温达到设计要求，短时间内达到设定温度,流量分配合理,水力平衡阀可以吸收超量压差，还可以控制及设定系统所需的流量,节约能量，降低运行费用,在空调系统中温度每降低1,C，,会造成能耗升高15%。,在供热系统中温度每升高1 ,C，,会造成能耗升高10%。,水力系统平衡简介,7,为什么水力系统要平衡？,采暖,及,空调系统,中,水力平衡的技术是节能及提高供冷或供热品质的关键,水力系统平衡简介,8,水力平衡系统的几种方法？,水力失调分为静态水力失调与动态水力失调。,静态水力失调是,指由于设计、施工、设备材料等原因导致的系统管道特性阻力数比值与设计要求的系统管道特性阻力数比值不一致，从而使系统各户的,实际流量与设计要求流量不一致，引起的水力失调，叫做静态水力失调。,静态水力失调是稳态的、根本性的，是系统本身所固有的，是暖通空调水系统中水力失调的重要因素。,通过在管道系统中增设静态水力平衡阀，在系统初调试过程中对系统管道特性阻力数比值进行调节，使其与设计要求一致，当系统总流量达到设计流量时，各空调单元也同时达到设计流量。,水力系统平衡简介,9,水力平衡系统的几种方法？,水力失调分为静态水力失调与动态水力失调。,动态水力失调是,指系统实际运行过程中当,某些阀门开度变化引起水流量改变时,，系统的压力产生波动，,其他用户的流量也发生改变,，偏离系统要求流量，从而引起的水力失调，叫做动态水力失调。,动态水力失调是动态的、变化的，不是系统本身所固有的，在系统运行的过程中产生的。,通过在管道系统中增设动态水力平衡设备，当其它用户阀门开度发生变化时，通过动态水力平衡设备的屏蔽作用，使自身的流量不发生变化，末端流量不互相干扰。,水力系统平衡简介,10,水力循环系统的三个条件,The design flow must be available,at all terminal units in design conditions,所有末端装置必须都能够达到设计流量,The differential pressure across the control valves,must not vary too much.,通过控制阀的压差不能有太大的变化,The water flows must be compatible at system interfaces.,一二次环路水流量必须一致,11,第一个水力工况条件,The design flow must be available,at all terminal units in design conditions,所有末端装置必须都能够达到设计流量,第一个水力工况条件,12,“,实用性,”,优于同程系统,对于需要安装同程管道的同程系统，因为系统的不平衡较大的单元将得到更多的流量。,只有在所有单元尺寸相等的情况下同程回路可达到平衡,同程回路中各单元尺寸不一致,不平衡,同程管道,13,自动流量平衡阀淘汰了同程管的使用，节余资金的同时提升系统的工作表现。,“,实用性,”,优于同程系统,自动平衡的异程回路,同程回路连接不同型号的单元,更好的工作状态,减少管路和投资,14,在亚洲通常还在使用同程系统,+,手动平衡,“,实用性,”,优于同程系统,自动平衡的异程回路,在同程系统应用手动平衡,更好的工作状态,减少管路和投资,15,手动平衡阀的安装,Branch Balancing,Valves,Riser Balancing,Valves,Main Balancing,Valve,16,输配系统,Flow,Emission,At,start-up, the first circuits are,in overflow to the detriment of the last ones.,在刚开始启动时,最近的回路发生过流而损害了最后的回路的流量,.,The start-up time will be longer for the last circuits.,最不利环路的启动时间将相对较长,.,An overflow does not necessarily mean an increased heat output.,过流并不会成比例增加热量的输出,17,输配系统,When a plant is balanced, start-up can be achieved as required,by design.,当系统平衡时，起动将很快很好地达到设计所需的要求,When a plant is unbalanced, it must be started earlier.,当系统不平衡时，必须更早地开始工作（开机）,.,hours,Extra start-up time,unbalanced,Room temp.,balanced,24C,18,输配系统,In many cases, the control system does not control,the two-way valves any longer :,在许多情况下，控制系统根本不能很好地控制两通阀门,Start-up,起动,Sudden load variation,负荷突然变化,Weird set-point at the,thermostat,温控装置的不理想设置,19,输配系统,Each user adjusts the thermostat set-point according to his own feeling of comfort.,每个用户按照他自己的感觉和舒适度来调节温控器的设置点,.,This often leads to an uncontroled system.,这经常导致系统的不平衡,.,Balancing allows to obtain the right room temperature everywhere.,平衡将使每个房间获得舒适的温度,% rooms,室内,Room temperature,室内温度,C,Unbalanced,不平衡,Unbalanced,Supply t,D,ecreased,Balanced,平衡,20,不舒适的成本,The cost of,1C too high,room temperature in winter:,6 to 11%,在冬季室温每升高,1,度的成本,:,百分之,6,到,11,The cost of,1C too low,room temperature in summer:,12 to 18%,在夏季室温每降低,1,度的成本,:,百分之,12,到,18,Unbalanced,Supply t,decreased,Balanced,平衡,Unbalanced,不平衡,Room temperature,室内温度,C,% rooms,室内,21,A,METAL,TM,alloy A,METAL,TM,合金,Stem with EPDM O-ring,颈部,EPDM,的,O,型圈,Fast and easy to access,self-sealing,measuring nipples,自密封测量口,Draining cock,泄水口,Shut off,V,alve,关断阀,Fixed,orifice,固定孔板,Valve with removed,handwheel,手轮可卸,Drain,泄水阀,All in one STAD,、,STAD,囊括所有功能,Mechanical,memory,机械式记忆装置,STAD,平衡阀,22,STAD,平衡阀,Spring,for,m,echanical play,tightening,弹簧压紧装置,Handwheel with,digital indication,(80 setting positions),数字手轮（,80,个开度位置）,Draining kit can be installed,during operation,使用中可安装泄水装置,23,STAF,手动平衡阀,160,，,240,或者,320,位的数字式手轮，机械式记忆设置位置。,快速方便的连接测量头,自平衡阀芯,24,TA-CBI,仪表,流量，压差以及温度测量,快速设置,计算机内置平衡法：,TA,平衡法,可与计算机通讯，配合,TA Select,II,软件编辑平衡数据,数据记录（流量，压差以及温度）,最多记录,24000,个数据,The advanced balancing instrument,先进的平衡仪器,25,TA-CMI,仪表,Flow,D,p and temp.,M,easurement,流量，压差以及温度测量,Viscosity correction (Glycol),粘度修正（乙二醇）,Wireless communication,无线通讯,The hydraulic multimeter,多功能水力测量仪表,26,平衡选型软件,Calculation/Suggestion,计算,Info/technical documentation,技术规格书,List of selected products,选择结果,Project/TA-CBI data,项目,/TA-CBI,数据,TA Select II,27,平衡选型软件,TA Select II:,Editing TA-CBI measured/logged data,TA Select II,：编辑,CBI,测量,/,记录的数据,28,Through balancing, many operational problems may be detected:,通过平衡,许多运作问题可能被发现,Filters or valves clogged,过滤器或阀门阻塞,Terminal units or exchangers wrongly mounted,终端单元和热交换器的错误安装,Pipe damaged or not connected as expected,管道损坏或安装错误,Shut-off valves partially shut,截止阀不能关紧,Check valves or pumps installed back-to-front,止回阀或泵安装方向错误,Balancing exposes these flaws while they can still be cheaply repaired.,平衡诊断出了这些缺陷，而且它们能被轻易的改正,诊断的要点,Diagnostics is the 2nd main use of balancing valves.,系统诊断是使用平衡阀的另一个主要原因,29,为什么要平衡,?,Adjusting the,design flows,in all terminal units in,design conditions,(when all control valves are fully open),while creating,minimum,additional,pressure drops,.,调整每个末端的流量至设计流量（当控制阀全开时），同时产生最小的额外压差,1),Open a fortune cookie.,2) Have a method.,30,各式各样的平衡方案,3 kPa,11 kPa,10 kPa,15 kPa,22 kPa,20 kPa,15 kPa,6 kPa,2 kPa,5 kPa,4 kPa,3 kPa,10 kPa,25 kPa,= 43 kPa,= 50 kPa,= 65 kPa,1.,2.,3.,.,20 kPa,15 kPa,20 kPa,18 kPa,17 kPa,22 kPa,29 kPa,33 kPa,32 kPa,37 kPa,44 kPa,31,分割成单元,32,分割成单元,Simplifying the drawing,is essential,最关键的是简化系统图,33,分割成单元,34,Proportional method,比例法,adapted from air system balancing methodologies,采用空气系统平衡方法,not optimal,in pressure drops,系统压降方面不是最佳,Compensated method,(Pr. Robert Petitjean),补偿法,designed for application with balancing valves,专门为设有平衡阀的系统而设计,optimal,in pressure drops,系统压降最优,TA Balance method,(Pr. Robert Petitjean),TA,平衡法,fully computerized: automatic determination of the index valve,全电脑计算；自动判断最不利环路,optimal,in pressure drops,系统压降最优,系统平衡方法,35,平衡显示了最佳的设置点,Minimum pressure drops in the balancing valves,(with the Compensated Method and TA-Balance),使通过平衡阀的压降最小（补偿法以及,TA,平衡法）,All the pump head in excess islocated in the main valve,所有过多的压头都位于主阀上,Re-open the main valveand adjust the pump speed,重新开启主阀，调整泵速,1,2,3,36,实际案例,Pfizer,pharmaceutical,production unit nearby Tours (France),图尔斯（法国）附近的辉瑞制药工厂,Installed cooling capacity of 5.4 MW (3 chillers in cascade),总冷量,5.4MW,（,3,台冷冻机并联）,Total design flow: 773,m/h,总设计流量：,773 m/h,Problem: production alarms!,问题：生产线问题,80 TA balancing valves from STAD 15/14 to STAF 200,80,个,TA,平衡阀，从,STAD 15/14,到,STAF 200,Audit of plant with TA Circuit based on a first measurement campaign,利用,TA Circuit,做系统评估,Presettings calculated with TA Circuit,TA Circuit,计算出结果后进行预设定,Viscosity corrections checked with TA Select II,利用,TA Select II,进行粘度修正,Full balancing performed using TA-Balance on one TA-CBI,利用一台,TA-CBI,仪器完成了系统平衡的调试,37,实际节约能耗,Industrial plant,5.4 MW,cooling capacity,889 m/h,335 kPa pump head,AFTER,B,alancing,平衡后,773 m/h (-13%),270 kPa pump head (-20%),Pumping power saving,电力节约,: 39 kW,Savings,节约,: 17200/year,BEFORE,B,alancing,平衡前,38,实际案例,Berlaymont Brussels,布鲁塞尔,(Belgium,比利时,),European Union Commission building,欧盟总部,242000 m; 3000 people,70 interpreter rooms for simultaneous translation,70,个同声翻译室,39,实际案例,Berlaymont Brussels,布鲁塞尔,(Belgium,比利时,),8.7 MW cooling capacity: 7.2MW centrifugal -,glycolised water; 1.5 MW absorption,8.7 MW,制冷量：,7.2MW,离心机,;,1.5 MW,溴化锂吸收式制冷,Ice storage capacity: 324 tons of ice/day.,畜冰量：,324,吨,/,天,7.8 MW heating capacity,7.8 MW,供热量,8 floors with 1200 cooling ceiling units per floor,8,层楼，每层楼,1200,个左右末端,13000 TA balancing valves (STAD 10 to STAF 300),总共,13000,个左右,TA,平衡阀 （,STAD 10 to STAF 300,）,9730 TA terminal control valves + actuators,9730,个,TA,末端控制阀以及执行器,Presettings calculated with TA Circuit,TA Circuit,计算出结果后进行预设定,Full air and hydronic balancing achieved by The CommTech Group,由,CommTech,集团进行全面的空气以及水力平衡,Hydronic balancing by 2 technicians with 2 TA-CBI,2,位工程师用,2,台,CBI,完成了整个系统的水力平衡,40,第二个水力工况条件,The differential pressure across the control valves,must not vary too much.,通过控制阀的压差不能有太大的变化,第二个水力工况条件,41,对非线性特性进行补偿,Cooling/heating coil,Control valve,Control is easy !,供冷,/,供热盘管,调节阀,控制非常容易！,42,两通调节阀阀权度,The available,D,p on a fully shut two-way control valve depends on the,load conditions,(i.e. on the opening of all other control valves).,两通阀全关时资用压差取决于负荷情况,（即取决于所有其它调节阀的开启度,The,available,D,p,at one given location is:,某一点的资用压,min. at design conditions,最小值：发生于设计工况下,max. for the min. total flow in the plant,pump head.,最大值：发生于系统流量最小情况下,水泵扬程,设计流量下调节阀全开时,调节阀全关时,43,在现实条件下控制阀阀权度经常远远不能满足要求,现实条件下,两通阀的尺寸选择过大以及根据系统要求流量变化而变化的压差导致阀权度远达不到要求,在较低的系统要求下,只有很少的流量和管道摩擦力,导致作用于控制阀的压差增大,一个很小的室温的变化可观的增加输出能量,结果,=,振荡控制,44,两通调节阀阀权度,Control valve authority should not be lower than 0.25,控制阀阀权度不应低于,0.25,行程,流量,45,压差的变化,0,1,0,2,0,3,0,4,0,5,0,6,0,7,0,8,0,9,0,1,0,0,1,1,0,1,2,0,1,3,0,5,0,1,0,0,1,5,0,2,0,0,2,5,0,3,0,0,Flow,Heat output,50 %,power,20 %,flow,4% pressure,drop,At 50 % of the heat output, the flow in the plant is only 20% of the design value and the pressure drops are reduced to 4%.,All the available pump head applies itself on the 2-way control valves.,在,50%,热输出时，系统中流量只有设计流量的,20%,，压降降至设计压降的,4%,。,所有的水泵资用压头作用于两通调节阀上。,100%,46,控制质量下降,Modulating control becomes ON/OFF !,Flow,Flow,Opening,Opening,Power,50%,9%,34%,50%,开度,调节型控制变成了开关型！,功率,流量,开度,流量,47,过低的阀权度使调节控制工作如开,/,关阀,!,变化的压差造成的过低的阀权度导致昂贵的两通阀的工作状态象便宜的开,/,关阀门,结果,:,温度高低波动,Temperature,Set point,Time,Temperature,Set point,Time,Theory,Reality,48,压差的变化,If C is less than 0.4,如果,C,小于,0.4,The differential pressure must be locally stabilised to ensure stable and accurate modulating control.,则必须对压差进行就地控制以确保稳定和精确的调节型控制。,How to determine in which plants differential pressure variations will significantly affect the controllability?,?,Use the C coefficient:,怎样判断在哪些系统中压降的变化将显著影响控制能力？,利用系数,C,：,设计水泵扬程,最不利环路设计压降,49,工作过程,+,-,+,-,D,P,STAP,STAD,Flow,measurement,Differential,pressure,adjustment,D,H,流量测量,压差调节,50,工作过程,pB,pA,= pA-pB = Circuit Dp for design flow,D,p STAP,D,p STAD,Spring pushes to open the STAP.,Secondary diff. pressure,D,p,l,applies itself on the membrane:,二次侧压差,p1,作用于膜片上：,When,D,p,l,increases, the STAP shuts.,当,pl,增加时，,STAP,关闭。,When,D,p,l,decreases, the STAP opens.,当,pl,减小时，,STAP,打开。,在设计流量下环路压降,弹簧驱动打开,STAP,。,pB,pA,51,压力A,通过与,STAF,的泻水口,(1)STAP,的出水口,(2),相连的毛细管传导,压力B,作用于阀芯隔膜,(3),的另一侧,当,作用于阀芯隔膜,(3),压差,(AB),大于设定弹簧拉力时,阀将逐渐关小只到到达新的平衡点,(4),(3),A,B,(2),D,pL,H,(1),(2),(4),B,A,STAP,如何工作,52,STAP,安装在支路,S,T,A,P,STAD, STAM or STAF,53,平衡阀门,设计流量,(100%),50%,设计流量,部分流量时典型阀权度,手动平衡,54,自动平衡,(,动态,),设计流量,(100%),50%,设计流量,部分流量时典型阀权度,自动平衡,55,压差控制器,(STAP),安装于各个环路,设计流量,100%,50%,设计流量,部分流量时典型阀权度,STAP,安装在支路,56,STAP,安装在各个盘管,STAD, STAM or STAF,STAP,57,压差控制器,(STAP),安装于各个控制阀,设计流量,100%,50%,设计流量,部分流量时典型阀权度,STAP,安装在各个环路,58,Stabilisation of the differential pressure applied on the control valves.,稳定控制阀两端的压差,Ensures stable and accurate modulating control.,确保稳定及精确的调节型控制,Reduces the risk of noise in terminal unit control valves.,降低末端调节阀产生噪音的危险,Allows the shutting of 2-way control valves even for high pump heads.,即使水泵压头很高,两通阀也能关闭,Dynamic balancing,动态的平衡,Simple procedure.,平衡步骤简单,Ideal for staged projects.,对分期实施的项目效果更好,差压控制器的好处,59,第三个水力工况条件,The water flows must be compatible at system interfaces.,一二次环路水流量必须一致,第三个水力工况条件,60,TA Autoflow,自动平衡阀,AC & YR,型,15 50mm,易于拆卸的阀芯,用于小口径管道,WS,对夹型,50 350mm,使用多个,80mm,的阀芯,用于大口径管道,。,61,TA Autoflow,自动平衡阀,AC,型, 15 50mm,防脱锌,(,DZR,),铜合金阀体,英制标准螺纹接口。,阀芯的筒体和弹簧由等级,300,的不锈钢制成。,弹簧,阀芯,测量点,关断,(,球阀,),接盘管的连接末端,62,全,“,自动,”,操作,自动流量限制式平衡阀芯。,平衡阀由工厂预设，,避免在施工现场调整,。,63,TA Autoflow,自动平衡阀自动限制流量,64,TA Autoflow,自动平衡阀自动限制流量,65,TA Autoflow,自动平衡阀自动限制流量,66,TA Autoflow,自动平衡阀自动限制流量,67,TA Autoflow,自动平衡阀自动限制流量,68,TA Autoflow,自动平衡阀自动限制流量,69,不同压差下工作状态,压差超过最大设计要求，阀芯筒体全收缩,-,与节流孔板的功能一致。,阀芯筒体根据压差的变化调整开度精确保持设计流量在,5,%,的范围内。,压差低于最小设计要求，阀芯筒体全开,-,与节流孔板的功能一致。,70,不同压差下工作状态,如下所示例子，压差范围,14,210,kPaD,Design Flow,Pressure drop (kPaD),14 (22),kPaD Range,Minimum,210,kPaD Range,Maximum,Flow (L/s),Flow limiting zone,Best to avoid operating above control range,71,解决冷冻机分步启动的问题,在没有自动平衡设备的条件下，即使每台冷冻机都安装一台泵，流量也会因为冷冻机分步启动而产生波动。,Chiller Condenser,ON,10 L/s,Cooling,Towers,30L/s,Chiller Condenser,ON,10 L/s,Chiller Condenser,ON,10 L/s,72,解决冷冻机分步启动的问题,对并联运行的定流量水泵，总流量由总的阻力决定,-,包括管道。,Head,Pressure,Total flow (l/s),System resistance curve,30,All units on,0,3 Combined pumps head curve,1 pump head curve,2 Combined pumps head curve,10,20,Operating point all units running,73,解决冷冻机分步启动的问题,在系统没有自动平衡的条件下，当部分设备关闭时，管道中流量减少，泵头阻力减少，保持工作的泵加速运行产生过流。,Chiller Condenser,ON,17 L/s,Cooling,Towers,17L/s,Chiller Condenser,OFF,0 L/s,Chiller Condenser,OFF,0 L/s,74,解决冷冻机分步启动的问题,在没有自动平衡设备的条件下，当管道中的流量降低，泵头的压力将导致泵速度的增加和持续工作设备的过流。,Head,Pressure,Total flow (l/s),System,resistance curve,30,All units on,0,3 Combined pumps head curve,1 pump head curve,2 Combined pumps head curve,10,Design 1 unit,17,Actual 1 unit,Operating point 1 pump,75,解决冷冻机分步启动的问题,在冷机后安装平衡阀可以有效地解决问题,Chiller Condenser,ON,10 L/s,Cooling,Towers,30L/s,Chiller Condenser,ON,10 L/s,Chiller Condenser,ON,10 L/s,76,解决冷冻机分步启动的问题,当泵的工作数量变化时，自动平衡阀将根据系统阻力的变化调整以保持设计流量,。,Head,Pressure,Total flow (l/s),System resistance curve,30,All units on,0,3 Combined pumps head curve,1 pump head curve,2 Combined pumps head curve,10,Design 1 unit,Operating point 1 pump,77,重要,:,检查阀门的最小,和最大,作用压差在阀门的调整范围内,!,最大,kPaD,将在一台泵工作的时候得到。,Head,Pressure,Total flow (l/s),System curve All 3 units on,30,All units on,0,10,1 unit on,dPmax,applied,dPmin applied,System curve 1 unit on,dPmax,valve,Problematic selection,78,自动平衡简化系统设计,自动平衡阀只需要装在空气处理机组，风机盘管，冷机，冷凝器等处。,不需要模块设计,。,Cooling Tower,Cooling Tower,Chiller,Chiller,Primary pump,Primary pump,Secondary VSD pump/s,Decoupling Bypass,=,自动平衡阀,FCU & AHU,FCU & AHU,79,水力循环系统的三个条件,Let controllers control,使控制器发挥作用,Make your HVAC system satisfy the three hydronic conditions,确保暖通空调系统满足三个水力工况条件,80,定流量系统与变流量系统,定流量系统,定流量是指系统中不含任何动态阀门，主要用于末端设备无须通过流量来调节的系统，如风机盘官采用三速开关，空调箱采用变风量调节温度的空调系统以及系统要求较低，只需补偿器调节供暖水温即可满足需要的采暖系统。,定流量系统只存在静态水力失调，不存在动态水力失调，因此只要在相关部位安装静态水力平衡阀即可。,通常在系统机房的,集水器,以及,关键的垂直、水平回水支管上,安装静态水力平衡阀。,水力系统平衡简介,81,定流量系统与变流量系统,变流量系统,变流量是指在系统运行过程中各分支环路的流量随着外界环境负荷的变化而变化的。大部分时间系统流量是低于设计流量。,变流量系统一般即存在静态水力失调也存在动态水调，因些既要安装静态水力平衡阀，又要合理选择动态水力平衡设备。,通常在系统机房的,集水器,以及,关键的垂直、水平回水支管上,安装静态水力平衡阀。,在需要,恒定流量的锅炉及冷机管路,附近安装固定式动态流量平衡阀。,在需可调式动态流量平衡时采用静态阀与差压阀结合，对流量进行调节，主要,用于重要分支管理及需精确调节的空气处理单元。,水力系统平衡简介,82,动态水力平衡设备可以取代静态水力平衡阀吗？,静态水力平衡阀,有一个非常可贵的特点，当调试完毕后，既与系统中其他管件组成一体，它保证的不是系统中某一段管道的流量不变，它维持的是系统中各串并联管道间的流量比值与设计流量比值一致。当系统处于部分负荷运行状态时总流量减少时，,系统中各分支管路会自动,等比例,的减少流量，而各分支管道的流量比值不变,。,动态水力平衡设备,是解决暖通空调水系统动态水力失调问题，使系统达到动态水力系统平衡，,它的一个基本特征就是克服水力系统流量的变化，既在系统的压力波动时维持自身,流量不变,。,水力系统平衡简介,83,手动平衡阀的安装,