原文：
　自力式流量控制阀只能适用于定流量的质调节系统。当系统进行以热源为主动变流量调节时，或者说通过其他手段（变频、减少循环泵数量、换小循环泵等）减小系统的流量时，管网的压力会减小，热网近端用户由于压力的变小，流量阀自动阀芯就会开大，维持原来的流量恒定，流量变化只是远端用户的流量变化。近端用户和远端用户不能随着总流量变化而等比变化（在各并联管段中，任何一个管段的特性阻力数S值发生变化，网路的总特性阻力数也会随之改变，总流量在各管段中的分配比例也相应地发生变化）。这就势必会造成热网的动态水力失调，远端用户达不到用热要求。所以安装自力式流量控制阀的热网不能采用变流量运行模式。目前许多供热企业选择变频、多泵、少泵、大泵、小泵实现变流量运行，热网水力平衡选用自力式流量控制阀是错误的。 当用户主动变流量运行时，阀后用户需要增加流量时，由于自力式流量控制阀的限制，流量增不上去；当阀后用户需要减少流量时，用户之间就会相互干扰，自力式流量控制阀就成了只能消耗水泵功率的无用阀。所以，不管是以用户为主动变流量的热网还是以热源为主动变流量的热网都不能应用自力式流量控制阀。自力式流量控制阀只适用于定流量的质调节系统。

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译文：
Self-operated flow control valve is only applicable to the quality of regulation constant flow system. When the system to the heat source is active when the variable flow control, or through other means (frequency, reducing the number of circulating pumps, pumps for small cycles, etc.) reduce the flow of the system, the pipeline will reduce the pressure, heat net proximal smaller users as pressure, flow valve will automatically open a large spool to maintain the original constant flow, traffic flow changes only change the remote user. Proximal end users and remote users can not change the total flow with the geometric change (in the parallel pipe, any pipe section features a number of S values of the resistance to change, the general characteristics of the resistance network will change the number of total flow in the pipe in the distribution of the ratio changes accordingly). This is bound to cause water imbalance in the dynamic heating network, remote users fail to use the heat requirements. Therefore, self-installed flow control valve with variable flow heat supply network can not run the model. At present, many heating companies have chosen frequency, multi-pump, small pumps, large pumps, small pump and variable flow operation, thermal hydraulic balance of self-selected flow control valve is wrong. When the user take the initiative to variable flow operation, the valve after the user needs to increase traffic, due to self-limit-type flow control valves, flow can not get by; When users need to reduce the flow afterthe valve when the mutual interference between users will, self-Flow control valve can become useless power consumption of pump valve. So, whether based on users active variable flow heat supply network or to the heat source for the active variable flow heat supply network can not be applied self-operated flow control valve. Operated flow control valve is only applicable to the quality of regulation constant flow system.