各种流量调节阀的工作原理及选型_中国调节阀网_新浪博客

译文:
计量收费主要通过三个途径宏观节能:首先是装设了流量调节阀,实现了流量平衡,进而克服了冷热不均现象;其次是通过温控阀的作用,利用了太阳能、家电、照明等设备的自由热;第三是提高了用热居民的节能意识,减少了开窗户等的无谓散热。而这三条节能途径,其中有二条都是通过流量调节阀来实现的。可见,流量调节阀,在计量收费的供热系统中,占有何等重要的地位。因此,如何正确的进行流量调节阀的选型设计,就显得非常重要。   一、温控阀阀   1、散热器温控阀的构造及工作原理   用户室内的温度控制是通过散热器恒温控制阀来实现的。散热器恒温控制阀是由恒温控制器、流量调节阀以及一对连接件组成,其中恒温控制器的核心部件是传感器单元,即温包。温包可以感应周围环境温度的变化而产生体积变化,带动调节阀阀芯产生位移,进而调节散热器的水量来改变散热器的散热量。恒温阀设定温度可以人为调节,恒温阀会按设定要求自动控制和调节散热器的水量,从而来达到控制室内温度的目的。温控阀一般是装在散热器前,通过自动调节流量,实现居民需要的室温。温控阀有二通温控阀和三通温控阀之分。三通温控阀主要用于带有跨越管的单管系统,其分流系数可以在0~{bfb}的范围内变动,流量调节余地大,但价格比较贵,结构较复杂。二通温控阀有的用于双管系统,有的用于单管系统。用于双管系统的二通温控阀阻力较大;用于单管系统的阻力较小。温控阀的感温包与阀体一般组装成一个整体,感温包本身即是现场室内温度传感器。如果需要,可以采用远程温度传感器;远程温度传感器置于要求控温的房间,阀阀体置于供暖系统上的某一部位。   2、温控阀的选型设计   温控阀是供暖系统流量调节的最主要的调节设备,其他调节阀都是辅助设备,因此温控阀是必备的。一个供暖系统如果不设置温控阀就不能称之谓热计量收费系统。在温控阀的设计中,正确选型十分重要。温控阀的选型目的,是根据设计流量(已知热负荷下),允许阻力降确定KV值(流量系数);然后由KV值确定温控阀的直径(型号)。因此,设计图册或厂家样本一定要给出KV值与直径的关系,否则不便于设计人员使用。   在温控阀的选型设计中,绝不是简单挑选与管道同口径的温控阀即完事大吉。而是要在选型的过程中,给选定的温控阀造成一个理想的压差工作条件。一个温控阀通常的工作压差在2~3mH2O之间,{zd0}不超过6~10 mH2O。为此,一定要给出温控阀的预设定值的范围,以防止产生噪音,影响温控阀正常工作。当在同一KV值下,有二种以上口径的选择时,应优先选择口径小的温控阀,其目的是为了提高温控阀的调节性能。   二、电动调节阀   电动调节阀是适用于计算机监控系统中进行流量调节的设备。一般多在无人值守的热力站中采用。电动调节阀由阀体、驱动机构和变送器组成。温控阀是通过感温包进行自力式流量调节的设备,不需要外接电源;而电动调节阀一般需要单相220V电源,通常作为计算机监控系统的执行机构(调节流量)。电动调节阀或温控阀都是供热系统中流量调节的最主要的设备,其它都是其辅助设备。   三、平衡阀   平衡阀分手动平衡阀和自力式平衡阀。无论手动平衡阀还是自力式平衡阀,它们的作用都是使供热系统的近端增加阻力,限制实际运行流量不要超过设计流量;换句话说,其作用就是克服供热系统近端的多余资用压头,使电动调节阀或温控阀能在一个许可的资用压头下工作。因此,手动平衡阀和自力式平衡阀,它们都是温控阀或电动调节阀的辅助流量调节装置,但又是非常重要的,如果选型不当,或设计不合理,电动调节阀或温控阀都不能很好工作。   1、手动平衡阀   1.1、手动平衡阀的工作原理   手动平衡阀是一次性手动调节的,不能够自动地随系统工况变化而变化阻力系数,所以称静态平衡阀。手动平衡阀作用的对象是阻力,能够起到手动可调孔板的作用,来平衡管网系统的阻力,达到各个环路的阻力平衡的作用。能够解决系统的稳态失调问题:当运行工况不同于设计工况时,循环水量多于或小于设计工况,由于平衡阀平衡的是系统阻力,能够将新的水量按照设计计算的比例平衡的分配,使各个支路的流量将同时按比例增减,仍然满足当前负荷下所对应的流量要求   1.2、手动平衡阀的选型与设计中应注意的问题(2)   (1)阀门特性曲线决定了阀门的调节性能,如截止阀的流量曲线,如果认为95%~{bfb}之间的流量变化是没有意义的,那么开度从0~5%即实现了流量的全程变化,这样的阀门是不能作为水利工况平衡调节使用的。由于阀门理论特性曲线实在顶压差下测定的,而实际工况只要阀权度不为1则阀门在小开度线阀门前后压差大,大开度是阀前后压差小,导致阀dG/dC值在小开度变大,在大开度时变小,使阀门实际工作曲线向快开方向偏移,阀权度越小其偏移越大,对于直线特性的阀门由于实际性能的偏移会导致阀门的有效调节的得开度空间变小,因此阀门的理论性曲线以下弦弧如等百分比特性为好。等百分比特性曲线阀门,在阀权度0.3~0.5时实际工作曲线可能接近直线特性。   (2)通常阀门在小开度情况下阀门的流速过高,在阀后会形成旺盛紊流的涡旋区,涡旋区和新压力很低,该处压力低于水温对应的饱和压力时水蒸气的闪发挥导致汽水击现象:严重的噪音,阀门及管道的振动,阀门、管道、管支架的破坏。防治这种事故的发生首先在阀们流道设计上考虑阀塞和阀座在小开度时形成狭长的节流通道,约束旺盛紊流涡旋的形成;其次选用阀门时尽量加大阀权度,以避免阀门在小开度下运行。另外,在不牵涉压力工况问题时尽量碱平衡阀安装在水温较低的回水管道上。   2、自力式平衡阀   2.1、自力式平衡阀工作原理   自力式平衡阀则可在没有外接电源的情况下,自动实现系统的流量平衡。自力式平衡阀是通过保持孔板(固定孔径)前后压差一定而实现流量限定的,因此,也可称定流量阀。   定流量阀作用对象是流量,能够锁定流经阀门的水量,而不是针对阻力的平衡。他能够解决系统的动态失调问题:为了保持单台制冷机、锅炉、冷却塔、换热器这些设备的高效率运行,就需要控制这些设备流量固定于额定值;从系统末端来看,为了避免动态调节的相互影响,也需要在末端装置或分支处限制流量。   在设计中应当注意,自力式流量控制阀的缺点是在于阀门有最小工作差的要求,一般产品要求最小工作压差20KPa,如果安装在最不利回路上,势必要求循环水泵多增加2米水柱的工作扬程,所以应采取近端安装,远端不安的方法。用户离热源距离大于供热半径的80%时就不要安装这种自力式流量控制阀。   四、差压调节阀   1、差压调节阀的原理   差压调节阀的原理,本质上和自力式平衡阀是一样的。只不过自力式平衡阀中,孔板是作为一个部件存在于阀体中的;而差压调节阀中没有孔板这一部件,而是把差压调节阀后面的系统看作一个孔板,因此,调节阀的差压值实际指的是其后系统出入口压力差值。从差压调节阀的结构可以看出:这种调节阀,目的是控制其后系统出入口压力差值固定不变。基本功能是根据热用户热负荷的需求,自动调整热用户的运行流量。当一幢建筑,由于有的热用户要求室温降低,则相应房间温控阀的开度变小,导致差压调节阀的压差值变大,超过设定值,此时压差调节阀自动关小阀芯,增大节流作用,使其系统压差值减小,直至恢复为设定值。最终的效果是减少流量,适应热用户的需热要求,借以减轻温控阀的频繁操作。热用户要求提高室温时,压差调节阀的作用正好相反。   2、在设计时应注意的问题   有人认为在各户内系统或立管上,都应装置压差调节阀。经过模拟计算:如果在建筑物的热入口,统一安装了平衡阀(含手动、自力式)或压差调节阀(但设计要合理),则室内温控阀在任何调节范围内,其前后压差都不会超过6~10 mH2O,即温控阀都能在合理的条件下工作。因此,过多安装压差调节阀没有必要,也是不经济的。   五、循环水泵变流量运行时,流量调节阀的选择   这里主要指手动平衡阀、自力式平衡阀和压差调节阀的选择。在循环水泵变流量运行时,手动平衡阀呈等比失调,最有利于温控阀的运行;但其缺点是手工操作太多,难以实现理想调节。循环水泵变流量运行,各热用户入口最理想的设定压差值应是随室外气温变动的。对于这一点,自力式平衡阀、差压调节阀,都不够理想,但不会出现调节的失控。因此可采用这一类型的调节阀,这对提高供热系统的调节性能是有好处的。

“a variety of flow control valve of the working principle and model selection ”是由提供的国际阀门新闻,译文仅供参考。另外,中国调节阀网还提供相关产品搜索:、、、、等。


 

原文:
Metering and charging through three channels of macro energy: first is to install a flow control valve to achieve a flow balance, and thus overcome the Lengrebujun phenomenon; followed by the role of temperature control valve, use of solar energy, appliances, lighting, etc. equipment, free heat; third is to raise the awareness of energy saving thermal residents, reducing unnecessary heat open the window and so on. This energy-efficient means of three, including two through flow control valve to achieve. Can be seen, flow control valve in the metering and charging of the heating system, what occupies an important position. Therefore, how to properly conduct the selection of the design flow control valve, it is very important. 1, temperature control valve valve 1, radiator temperature control valve of the structure and working principle of Users indoor temperature control valve through the radiator temperature control to achieve. Radiator temperature control valve is from the constant temperature controller, flow control valve, as well as a pair of connecting pieces of the composition, temperature controller, which is the core component of sensor units, namely, temperature package. Wen package can sense changes in ambient temperature produces volume change, driven generated displacement control valve spool, thus regulating the amount of water to change the radiator radiator's heat output. Thermostatic valve set temperature can be artificially adjusted thermostatic valve will be set according to demand automatic control and regulation of the radiator water, and thus to achieve the control room temperature. Temperature control valve is generally installed in the radiator before, by automatically adjust flow to achieve the needs of the residents at room temperature. Temperature control valve with two-pass temperature control valve and the thermostatic valve of the three points. Three temperature control valve with a bypass pipe is mainly used for single-tube system, its division ratio in the range of 0 to {bfb} within the changes in flow conditioning room for large, but the price expensive, more complex structure. Two-way temperature control valve, some for dual-pipe system, and some for single-pipe system. For the twin-tube system, two-pass temperature control valve resistance is relatively large; for single-pipe system of the resistance is small. Thermostatic valve for temperature-sensitive packages and assembled into a whole body in general, temperature package itself is on-site indoor temperature sensor. If necessary, you can use a remote temperature sensor; remote temperature sensor placed in temperature controlled rooms, valve body placed in a certain position on the heating system. 2, temperature control valve of the type design Temperature control valve is the main heating system, the regulation of flow regulating devices, other auxiliary equipment control valve is, so temperature control valve is necessary. A heating system if you do not set the temperature control valve that can not be termed a heat metering and charging systems. In the temperature control valve design, the correct selection is very important. The purpose of temperature control valve selection is based on the design flow (a known heat load) to allow the pressure drop to determine KV value (flow coefficient); then determine the temperature control valve KV value of the diameter (model). Therefore, the design book or manufacturers must be given a sample and the diameter of the relationship between the KV values, or does not facilitate the design personnel. Selection of the temperature control valve design, is by no means a simple selection and pipeline with the diameter of the temperature control valve that bin down. But to the selection process, to the selected temperature control valve differential pressure caused by an ideal working conditions. A temperature control valve is usually the work of pressure in the 2 ~ 3mH2O between the maximum of no more than 6 ~ 10 mH2O. To this end, we must give thermostatic valve pre-set range of values in order to prevent noise, affecting temperature control valve work properly. When the same KV values, there are two or more caliber options, priority should be given a small-caliber temperature control valve, which aims to improve the temperature control valve regulating the performance. 2, the electric control valve Electric control valve is applicable to a computer monitoring system for traffic conditioning equipment. Generally more in the thermal station unattended use. Electric control valve from the valve body, drive mechanism and the transmitter component. Temperature control valve is a temperature-sensitive packets through the self-operated flow regulating device, no external power supply; and electric control valves generally require single-phase 220V power supply, usually as a computer monitoring system of the implementing agencies (adjusted traffic). Electric control valve or thermostatic valve regulating the flow heating systems are the most important equipment, and other are property of their auxiliary equipment. Third, balance valve Manual Valves Valves minutes and Self-balancing valve. Balancing valve, whether manual or a Self-balancing valve, their role is to increase the resistance heating system proximal to restrict the flow of the actual operation should not exceed the design flow; in other words, its role is to overcome the excess heating system funded by the proximal pressure head, so that electric control valve or thermostatic valve can be funded by a license to work under pressure head. Therefore, manual balancing valve, and Self-balancing valve, and they are temperature control valve or electric auxiliary flow control valve regulating device, but it is very important, if the selection of inappropriate or badly designed, the electric control valve or the temperature valves can not work well. 1, Manual Valves 1.1, manual balancing valve works Manual balancing valve is a one-time manual adjustment can not automatically change with the system operating conditions change in drag coefficient, so that the static balance valve. Manual balancing valve effect the object of resistance, can play the role of manually adjustable orifice to balance the resistance of pipe network system to achieve balance between all the role of the resistance of the loop. Able to solve the steady-state system disorders, a problem: When the operating conditions different from the design condition, the cycle of water is more than or less than the design condition, due to a balanced balancing valve is the system resistance to the new design and calculation of the amount of water in accordance with the proportion of a balanced distribution, so that each branch of traffic will also increase or decrease in proportion to still meet current load requirements under the corresponding traffic 1.2, selection and design of manual balancing valve should pay attention to issues (2) (1) the valve characteristic curve determined the valve regulating performance, such as the cut-off valve of the flow curve, if we think 95% ~ {bfb} of the flow change is meaningless, then the opening from 0 to 5% of achieving a changes in full flow, so that the valve can not be adjusted as the water balance of operating conditions used. As the valve characteristic curve theory, it is measured under pressure the top, while the actual working conditions as long as the valves of the right degree is not a valve in a small line of the valve opening pressure before and after the big, big pressure before and after the valve opening is small, lead to valve dG / dC value is larger in the small opening, large opening, when smaller, so that the actual work curve of the valve opening direction of the fast shift, the smaller the degree of offset of the right valve the larger properties for linear valves As the actual performance of the offset gate will lead to effective regulation of the valve opening space was smaller, so the theoretical curve of the valve, such as the following chord-arc features such as the percentage is better. Equal percentage valve characteristic curve, in the valve of the right degree of 0.3 ~ 0.5, the curve of the actual work could be close to a straight line features. (2) The valve is usually a small opening under the valve flow rate is too high, the valve after the formation of strong turbulence of the vortex area, scroll area and the new pressure is very low, where the pressure below the saturation temperature corresponding to of water vapor pressure to play a leading soft drinks hit flash phenomenon: a serious noise, vibration of valves and piping, valves, piping, tube damage. Prevention of such accidents have occurred first in the valve flow path design considerations valve plug and valve seat in the small opening of the throttle when the formation of narrow channels, bound by strong turbulent vortex formation; followed by selection of the valve when the valve as far as possible to increase the right degree, in order to avoid opening the valve in a small run. In addition, the pressure condition does not involve the question as far as possible alkali balance valve installed in the lower water temperature return water pipe. 2, Self-balancing valve 2.1, Self-balancing valve works Self-balancing valve may be in the absence of an external power supply case, the system automatically flow balance. Self-balancing valve orifice by maintaining (fixed aperture) must be achieved before and after the differential pressure flow of qualified and, therefore, also can be said to be flow valve. Given the role of targeted traffic flow valve can be locked water flowing through the valve, rather than resistance balance. He was able to solve the system's dynamic imbalance problem: In order to maintain a single chillers, boilers, cooling towers, heat exchanger, high efficiency operation of these devices, they need to control the flow of these devices fixed on the rating; from the system end of the term, in order to avoid dynamic adjustment of the mutual influence also need to branch office at the end device or restrictions on traffic. In the design should be noted that self-operated flow control valve is the valve of the drawback is that there is minimal difference between the work requirements, the general minimum working pressure product requirements 20KPa, if installed in the most adverse way back, it will certainly require more than the increase circulating pump 2 m water column work head, it should be taken to install the proximal and distal disturbing way. User distance from the heat source radius of more than 80% of heat, do not install the self-operated flow control valve. 4, differential pressure regulating valve 1, the principle of differential pressure regulating valve The principle of differential pressure regulating valve, in essence, and Self-balancing valve is the same. Self-balancing valve only, the orifice plate as a component exists in the body in; while there is no differential pressure regulating valve in the orifice of this part, but the differential pressure regulating valve behind the system as an orifice, Therefore, the value of the actual differential pressure regulating valve refers to the subsequent system, the pressure difference between import and export. From the differential pressure regulating valve structure can be seen: This regulating valve, the purpose is to control the import and export system, the pressure difference was fixed. Basic function is based on heat load heat demand for the user to automatically adjust the heat to run the user's traffic. When a building, due to lower temperature and some hot-user requirements, the corresponding room temperature control valve for opening smaller, causing the value of differential pressure regulating valve larger than the value set, this time differential pressure regulating valve automatically Guan small spool, increasing the throttling effect, so that the value of the system pressure decreases, until the restore settings. The net effect is to reduce the flow, the user's need to adapt to hot thermal requirements, so as to reduce the frequency of operation of temperature control valve. Hot-user requirements to improve at room temperature, pressure regulating valve of the role of the opposite. 2, in the design should pay attention to the problem Some people think that in all indoor system, or riser, the pressure regulating valve should be installed. After simulation: If you heat the building entrance, unified balancing valve installed (including manual, self-type), or differential pressure regulating valve (but not designed to be reasonable), then the indoor temperature control valve within the scope of any regulation, its pressure before and after difference is no more than 6 ~ 10 mH2O, temperature control valve that is able to work under reasonable conditions. Thus, too much pressure regulating valve is not necessary to install, it is not economical. 5, circulating water pump run-time variable flow rate, flow control valve selection Here mainly refers to manual balancing valve, Self-balancing valve and pressure regulating valve choice. Variable flow in the circulating pump run-time, manual balancing valve was geometric disorder, most conducive to the operation of temperature control valve; but its drawback is that manual too much, it is difficult to achieve the desired adjustment. Circulating pump variable flow operation, the heat users the ideal entry pressure value should be set with the outdoor air temperature change. For this, the Self-balancing valve, differential pressure regulating valve, are not ideal, but it will not adjust out of control. Therefore, this type of control valve can be used, which is to improve the regulation of heating system performance is beneficial.


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