原文：
　 　    通常所说的自力式压差控制阀，其功能是控制网路中某个支路或某个用户的压差，使之基本恒定，而自身消耗的压差则是变化的，正是通过调整自身的开度，来调整自身所消耗的压差，以实现被控对象的压差恒定。这种压差控制阀在供热空调工程已有了较多的应用，尤其是在分户计量供暖工程中被广泛采用，所以被大家熟悉和了解。本文介绍一种功能与其不同的自力式压差控制阀，它的作用是控制自身的压差，因而可称为自身压差控制阀。同时，探讨它在暖通工程中的应用。

 　　1、结构与工作原理 　　这里以ZY47—16C型自身压差控制阀为例，介绍自身压差控制阀的工作原理。图1为该阀的结构与工作原理示意图。弹簧、感压膜和阀杆固结在一起，通过导压管将出口压力P2导入感压膜上部的密封腔，感压膜下部为入口压力P1。根据P1-P2的设定值ΔPs（以下简称设定压差）确定弹簧的预压缩量，即使弹簧的弹力与设定压差条件下感压膜对弹簧的作用力相等。并按照阀塞的行程远小于弹簧预压缩量的原则选择弹簧。这样就使得在阀门任一开度的平衡状态，阀的进、出口压差ΔP与设定压差ΔPs近似相等。严格地说，开度不同，平衡状态的ΔP是不相等的。显然，随着开度的增大，平衡阀平衡状态的ΔP是增大的。但通过对弹簧的选择，完全可以在阀塞的全行程内，将平衡状态的ΔP相对于ΔPs的偏离控制在一定的范围（比如10％）之内。 图1 ZY47-16C型自身压差控制阀结构示意图

　　自力式自身压差控制阀在系统中的工作可分为两种情况进行说明：①当前状态为关闭。若阀前后压差ΔP小于设定压差ΔPs，则继续关闭，这时就是一个关断阀。若ΔP大于ΔPs，则感压膜克服弹簧的弹力，带动阀塞上升，阀门开启；达到平衡状态时，进、出口压差ΔP近似回落到设定压差ΔPs。②当前状态为开启。若系统稳定运行，进、出口压差ΔP近似为设定压差。若由于系统工况的改变，使ΔP增大，则阀门开大，流量增大；达到平衡状态时，ΔP又近似回落到ΔPs。阀门为最大开度时，出现ΔP大于ΔPs的情况，阀门不再具有调控压差的能力。若由于系统工况的改变，使进、出口压差ΔP小于ΔPs，则阀门关小，流量减小，达到平衡状态时，ΔP又近似上升到ΔPs。直至阀门关闭时，出现ΔP小于ΔPs的情况，就不再具有调控压差的能力，而成为一个关断阀。 电站阀门简而言之，自力式自身压差控制阀在关闭状态时，ΔP必须大于ΔPs才能开启；在开启状态时，可自动调整开度，保持阀门前后的压差基本恒定。

　　2、自身压差控制阀在暖通工程中的应用

　　2.1 在保护冷热源方面的应用 　　近年来，在供热工程中，燃油和燃气机组有了较多的应用。由于对供暖实行计量收费，用户自主调节流量的意识大大增强，加上生活用热水在一天之内用量变化较大，使得供热系统的流量有很大的变化范围。若流量过小，可能造成燃油和燃气机组的局部沸腾，进而使机组受到破坏。对于空调系统中的冷水机组，如果冷冻水流量太小，也可能造成蒸发排管局部冻结，进而使机组受到破坏。对于以上两种情况，可如图2所示，在旁通管路上，装设自力式自身压差控制阀。由于用户调节等原因使系统流量减小，压差控制阀前后的压差ΔP就会随之增大，当ΔP大于设定压差ΔPs时，压差控制阀开启，增大通过冷热源的流量，保障机组安全运行。在压差控制阀为开启状态时，可始终保持阀前后的压差基本恒定。而通过阀的流量则与用户系统的流量呈相反的变化。即用户系统的流量减小，水力控制阀通过压差控制阀的流量就会增大；反之，用户系统的流量增大，则通过压差控制阀的流量减小。这样就可保证通过冷热源的流量不致有太大的变化，既保护了冷热源，又提高了机组运行的稳定性。

 　　保护冷热源的传统方式是在旁通管路上装设电动压差控制阀。当系统流量减小，使电动阀前后压差大于设定压差时，电信号驱动电动阀开启，使冷热源机组维持必须的最小流量。但电动压差控制阀由于对电源和传递电信号的线路的依赖，可靠程度不如自力式压差控制阀。另外，价格也高于后者很多。所以，在保护冷热源方面，低温阀门完全可以用自力式自身压差控制阀替代传统的电动控制阀。顺便提及，在图2所示的旁通管路上装设电磁阀是不恰当的，因为电磁阀只有关闭和全开两种状态，所以它的每一次动作，都将对用户系统的流量产生较大的影响。

　　2.2 在集中供热系统中的应用

　　在集中供热工程中常常出现这样的情况：供暖用户有低建筑（较矮的建筑或地势较低的建筑）和高建筑（高层建筑或地势较高的建筑），若热网的压力工况满足低建筑的散热器不被压坏的要求，高建筑就会出现倒空现象；若热网的压力工况满足高建筑不出现倒空现象，则低建筑的散热器承受的压力就会超过其承压能力。借助自身压差控制阀往往可以解决这个矛盾。 　　图3是一个地势高差悬殊，热源位于低处的例子。顺着地势特点，在供水管路适当位置设置加压水泵，在回水管路适当位置装设自力式自身压差控制阀。在系统运行过程中，压差控制阀前后的压差可保持基本恒定。这样就将网路的动水压线分为两个部分，前部的动水压线相对较低，可满足低建筑的散热器不被压坏的要求；后部的动水压线相对较高，可满足高建筑不发生倒空现象的要求。在系统停止运行时，整个网路的测压管水头有达到一致的趋势，而压差控制阀则通过减小开度竭力维持原有的压差基本不变，直至压差控制阀关闭。这时，压差控制阀与供水管路上的止回阀一起，过滤器将网路后部与前部隔离开来。网路前部的静水压线由设置在热源的补水定压装置保证。网路后部的静水压线由与压差控制阀配装在一起的定压补水泵保证。 图3 自身压差控制阀用于集中供热工程

        （一）      1热源 2循环水泵 3系统补给水泵 4自身压差控制阀 5加压水泵 6止回阀 7网路后部补给水泵 8补水压力调节阀 9热用户 　　相反，若地势相差悬殊，而热源在高处，则如图4所示，顺着地势特点，在供水管路适当位置装设自身压差控制阀，在回水管路适当位置装设加压水泵。系统运行时，压差控制阀前后的压差可保持基本恒定，这样就使网路后部的动水压线相对较低，可满足低建筑的散热器不被压坏的要求；网路前部的动水压线相对较高，可满足高建筑不发生倒空现象。系统停止运行时，压差控制阀自动关闭，与回水管路上的止回阀一起，将网路后部与前部隔离开来。网路前部的静水压线由设置在热源的补水定压装置保证，网路后部的静水压线则由连通前、后部的补水管路上的补水调节阀保证。 图4 自身压差控制阀用于集中供热工程 

       （二） 　　1 热源 2循环水泵 3系统补给水泵 4自身压差控制阀 5加压水泵 6止回阀 7后部补水压力调节阀 8热用户 　　3、结论 　　自力式自身压差控制阀为关闭状态时，若阀前、后的压差小于设定压差，则继续关闭；若阀前、后的压差大于设定压差，则阀门开启。为开启状态时，可自动调整开度，使阀前、后的压差基本恒定。

 　　自力式自身压差控制阀可用于对冷热源的保护，与传统的电动控制保护相比，有控制可靠、价格低廉的优点。 　　自力式自身压差控制阀可用于解决集中供暖工程中高建筑与低建筑高度相差悬殊所产生的对压力工况要求不同的矛盾。

“ Application of self-pressure control valve HVAC engineering ”是由中国控制阀网提供的阀门行业新闻，译文仅供参考。另外，中国控制阀网还提供相关产品搜索： 自动控制阀、 水力控制阀、 执行器和附件、 更多控制阀产品、 控制阀价格 等。

译文：
         Commonly referred to as Self-pressure control valve, its function is to control the network, a slip or a user's pressure, so that almost constant, while its consumption is the change in pressure, it is by adjusting opening itself to adjust its consumption by the pressure to achieve a constant pressure differential controlled objects. This pressure control valve in heating and air conditioning works have had more applications, especially in the Metering works that are widely used, they were all familiar with and understand. This paper presents a feature with a different Self-pressure control valve, its role is to control their pressure, which can be described as self-pressure control valve. At the same time to explore it in HVAC engineering. 1, structure and working principle Type here to ZY47-16C self-pressure control valve, for example, introduced its own differential pressure control valve works. Figure 1, the valve structure and working principle diagram. Spring, a sense of lamination and consolidation with stem, through the guide tube to the outlet pressure P2 pressure being laminated into the top of the sealed chamber, the inlet pressure being laminated lower part P1. According to Butterfly Valves P1-P2 settings ΔPs (hereinafter referred to as setting pressure) of the spring pre-compression, even if the spring will set the pressure with a sense of squeeze film under the force of the spring equal. Valve plug in accordance with the trip is far less than the amount of spring pre-selected the compression spring. This makes the valve opening balance of any state, the valve inlet and outlet pressure ΔP and the pressure ΔPs set approximately equal. Strictly speaking, opening different balance of ΔP are not equal. Clearly, as the opening increases, the balance of ΔP is increasing. But through the choice of spring, can plug in the valve within the entire trip, will balance the ΔP deviation relative to ΔPs control in a certain range (eg 10%) within. Figure 1 ZY47-16C type pressure control valve itself Schematic Self-self-pressure control valve in the system can be divided into two situations are explained: ① the current state is off. If the valve before and after the pressure difference ΔP is less than set pressure ΔPs, continued to close, then that is a shutoff valve. If ΔP is greater than ΔPs, then laminated to overcome the spring will feel to drive up valve plug, valve open; reach equilibrium, the inlet and outlet pressure drop ΔP approximation to the desired pressure ΔPs. ② the current status of open. If the system is stable and running, import and export differential pressure ΔP is approximately set. If conditions change because the system, so that ΔP increases, the large valve opening, flow increases; reach equilibrium, ΔP it down to approximately ΔPs. Valve opening for the maximum occurs when ΔP is greater than ΔPs case, the valve no longer has the ability to control pressure. If conditions change because the system, so that import and export pressure difference ΔP is less than ΔPs, then the valve is small, flow decreased to reach equilibrium, ΔP has risen to approximately ΔPs. Until the valve closes, there is less than ΔPs ΔP situation no longer has the ability to control pressure, but as a shutoff valve. In short, self-operated pressure control valve in its closed state, ΔP must be greater than ΔPs to open; in the open state, can automatically adjust the aperture to maintain nearly constant pressure around the valves. 2, self-pressure control valves in HVAC Engineering 2.1 in the protection of the application of cold and heat source In recent years, heating engineering, oil and gas unit with more applications. Since the implementation of the heating metering and charging, user self-regulating traffic greatly increased awareness, coupled with domestic hot water consumption change in one day, Bellows Seal Valvesand made the flow of the heating system has a great range of variation. If the flow is too small, may result oil and gas unit of local boiling, and then to units damaged. The air conditioning system chiller, if the chilled water flow is too small may result in evaporative emission control partial freeze, then to units damaged. For both cases, can be shown in Figure 2, the bypass road, installation of self-operated pressure control valve itself. As the user adjust the system flow decreases and other reasons, the pressure difference before and after the pressure control valve will increase with ΔP, when ΔP is greater than set pressure ΔPs, the pressure control valve to open, increasing through the hot and cold sources traffic, protection of the safe operation of unit. In the pressure control valve is turned on, it can always maintain a nearly constant pressure around the valve. The flow through the valve while the flow with the user's system shows a reverse trend. The user's system flow decreases, the flow through the pressure control valve will increase; the contrary, increase the flow of user's system, through the pressure control valve of the flow decreases. This would ensure that the flow through the cold and heat source without much change, both to protect the heat source, and also enhance the stability of operation of the units. To protect the traditional way of cold and heat source is installed in the bypass road electric pressure control valve. When the system flow decreases, so that electric valve differential pressures greater than the set pressure, the electrical signal driving electric valve is opened, cold and heat source unit to maintain the required minimum flow. However, pressure control valves electric power supply and transmission of electrical signals because of the dependence of the line, as the reliability of Self-pressure control valve. In addition, the price is also higher than the latter. Therefore, in the protection of cold and heat source, the total can be self-operated pressure control valve itself instead of the traditional electric control valve. Incidentally, as shown in Figure 2, a bypass valve installed on the pipeline is not appropriate, because the solenoid valve closed and fully open only two states, so it's every movement, all traffic will be generated user system greater impact. 2.2 in the central heating system In the central heating works often happens: the user has a low heating buildings (the lower low-lying buildings or buildings) and high buildings (high-rise buildings or buildings higher ground), if the pressure of work heating network meet the low status of the building will not be crushed radiator requirements, there will be empty of high architectural phenomenon; if the pressure of heating network condition does not appear to meet the high buildings empty phenomenon, the low-pressure radiator construction will more than its loading capacity. With its pressure control valve can often solve the problem. Figure 3 is a disparity in the terrains, the heat source is located in the lower example. Along the terrain features, Check Valvesstrategically placed in the water supply pipe pressure pumps, piping strategic locations in the backwater Self-pressure control valve itself. The system is running, the pressure difference before and after the pressure control valve can maintain almost constant. This dynamic pressure line network will be divided into two parts, the front line of the dynamic pressure is relatively low, which can meet the low building requirements of the radiator is not crushed; the rear of the hydraulic lines are relatively fixed high, which can meet high architectural phenomenon does not occur to empty demands. When the system stops running, 整个 network has reached the same piezometric head trend Er pressure control valve Ze Tongguojianxiao strive to maintain the original opening pressure Jibenbubian, Zhi Zhi 压差 control valve Guanbi. At this time, pressure control valve and check valve on the pipeline with water, the rear and the front of the network to isolate. Hydrostatic pressure web front line by setting the constant pressure in the heat of the replenishment system guarantees. Network cable from the back of the hydrostatic pressure and differential pressure control valve installed together with pumps to ensure constant pressure up. Figure 3 self-pressure control valves for central heating project (1) 1 2 circulating pump 3 heat pump system supplies its own pressure control valve 4 5 6 Check valve pressure pump 7 network back up water pump supply water pressure regulator valve 8 9 hot Users On the contrary, if the significant differences between the terrain, while the heat source at high levels, is shown in Figure 4, along the terrain features in the appropriate place to install their own water supply pipeline pressure control valve, installed in the appropriate place in the backwater pressure pipeline pump. System is running, the pressure difference before and after the pressure control valve can maintain almost constant, thus making the dynamic pressure of the rear line of networking is relatively low, which can meet the low building requirements of the radiator is not crushed; network before Department of relatively high dynamic pressure line, which can meet high building to empty the phenomenon does not occur. The system stops running, pressure control valves automatically close, and back to the way the valve with water, the rear and the front of the network to isolate. Hydrostatic pressure web front line by setting the constant pressure in the heat replenishment device to ensure the network from the rearPlug Valves of the hydrostatic pressure line connecting the former, the road back up water supply water control valve guarantees. Figure 4 Pressure control valve for their central heating works (2) 1 2 circulating pump 3 heat pump system supplies its own pressure control valve 4 5 6 Check valve pressure pumps supply water pressure regulating valve 7, 8, rear heat users 3, Conclusion Self-own differential pressure control valve is closed, if the valve before and after the pressure is less than set pressure, the continued closure; if the valve before and after the pressure is greater than set pressure, the valve opens . Is turned on, it can automatically adjust the aperture, the valve before and after the pressure is almost constant. Self-self-pressure control valve can beSafety Valves used for protection against cold and heat sources, electrical control and protection of the traditional than the controlled and reliable, low cost advantages. Self-self-pressure control valve can be used to solve the central heating project of high construction and low construction height difference of the pressure generated by poor working conditions require different contradictions.

原文来源：http://www.1kongzhifa.com/

2010-09-02 08:40

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