原文：
　         简单来看电力流程实际上是水、蒸汽的循环流程，在此流程中选用控制阀既简单又复杂。简单的是过程介质简单，只有水和蒸汽两种，复杂的是水和蒸汽的温度与压力波动范围大，带来系列问题如：闪蒸、气蚀、冲刷、噪音、腐蚀。但首先要考虑的是控制阀的安全性与可靠性。 　　给水阀(主、附锅炉给水阀、复合型给水调节阀)

　　控制要求：控制锅炉进水量，保证蒸汽蒸发量，水力控制阀维持锅炉水位(主、附型锅炉给水阀系统包含两个控制阀，一台用于锅炉启动时使用，一台用于正常给水使用)。

 　　工况情况：锅炉启动时阀门压差可达100-300公斤，流量较小，正常运行时压差较小，流量大，流量可调比为75/1-100/1。　　阀门要求：WCB/WC9，对于双阀系统中的启动阀要求抗气蚀，平衡阀V级关闭等级，对于复合型给水阀需使用特性化阀内件同时满足锅炉启动与正常运行时的需要。一般阀门选择为故障关。

　　锅炉给水泵最小流量循环阀　　控制要求：使锅炉给水泵安全启动及停止运行，消除因流量过小、温升增加、水强烈气蚀使泵损坏。(老式电站有使用开关型的最小流量控制阀，同时还有使用机械式的泵自动循环阀)。 　　工况情况：压降达160-350公斤，低温阀门是电站系统中承受压差最大的阀门，流量为正常流量的30%。

　　阀门要求：抗气蚀，防堵结构，V级密封等级，泵启动与停止运行时阀门连续工作，泵正常启动后此阀门关闭，阀门通常为故障开。　　高低加热器疏水阀(给水加热器疏水、冷凝水加热器疏水)

　　控制要求：控制加热器中冷凝水的位置，及时将冷凝水排放，高水位排放，正常水位疏水

　　工况情况：饱和水，电站阀门加热器之间的控制阀压差一般为6-30公斤，最后一级疏水阀直接连接冷凝器或除氧器。　　阀门要求：抗闪蒸冲刷，V或VI级密封等级，阀门通常为故障开。 　　除氧器水位控制阀(DALC) 　　控制要求：提供流量保持除氧器正常水位，过滤器通过加入蒸汽提高水温消除溶解在水中的气体。

　　工况情况：启动阶段流量较小，压差大温度，正常情况流量大，压差小，工况类似给水阀。

　　阀门要求：较低流量时有效抗气蚀。 　　减温阀(减温器) 　　控制要求：将高压水喷射入蒸汽中使蒸汽温度达到控制要求，工况情况：水，压差较大，

　　阀门要求：类型多样：喷嘴型，辅助雾化型，自我包容型及对夹型。　　减温减压阀(高、低压旁路阀)

　　控制要求：将高温高压蒸汽调整到一定温度压力的蒸汽，给汽机提供一个旁路通道，锅炉能够独立汽机而工作。　　工况情况：高温高压蒸汽。　　阀门要求：抗热冲击，降噪，反应迅速。

“ Power control valve selection and application required to consider safety first ”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：
          Simple view of the power flow is actually water, steam cycle process used in this process both simple and complex control valves. Simple is the process medium is simple, only water and steam are two kinds of complex water and steam temperature and pressure fluctuation range,Suber-water pumps bringing a series of issues such as: flash, cavitation, erosion, noise, corrosion. But the first thing to consider is the control valve of the safety and reliability. To the valve (the main, with a boiler feed water valve, water valve compound) Control requirements: control the boiler into the water to ensure steam evaporation, and the maintenance of the boiler water level (main, with a boiler to the valve system includes two control valves, one for the boiler starts to use, a water supply for normal use). Condition: The boiler starts up to 100-300 kg Screw pumpsof pressure valves, low flow, low pressure drop during normal operation, traffic flow, flow adjustable ratio 75/1-100/1. Valve requirements: WCB/WC9, double valve system to start anti-cavitation valve requirements, V-class closing level for the compound to the water valve need to use properties of trim meet boiler startup and normal operation needs. Generally choose to failure off valve. Boiler feed pump minimum flow valve cycle Control requirements: the safety of boiler feed pump start and stop the run, eliminate the small flow rate, temperature Magnetic pumps increase, water strong cavitation damage to pumps. (The old power station with the minimum use of switch-based flow control valve, as well as use of mechanical pumps automatically cycle valve). Conditions: The pressure drop up to 160-350 kg, is the largest power plant system to withstand pressure valves, flow 30% of normal flow. Valve requirements: resistance to cavitation, attempts to prevent the structure, V-class seal level, the pump start and stop running when the valve continuously, the pump normally starts the valve closed, the valve is usually opened for the failure. High and low heater traps (water Heater, Water Heater condensation) Control requirements: Control the location of condensed water heater, timely condensate discharge, high water discharge, the normal water level of hydrophobic Condition: The saturated water, heaterSelf-priming pumps control valve between the pressure is generally 6-30 kg, and finally a trap directly connected to the condenser or deaerator. Valve requirements: flash erosion resistance, V or VI level seal level, the valve is usually opened for the failure. Deaerator water level control valve (DALC) Control requirements: to provide flow to maintain the normal water level of deaerator, by adding steam to increase temperature to eliminate the gas dissolved in water. Condition: The flow of small start-up phase, a large temperature differential, the normal flow rate, pressure difference,Chemical pumps similar to the valve condition. Valve requirements: low flow cavitation effect at the time. Reduce temperature valve (desuperheater) Control requirements: the high-pressure water jet of steam into the steam temperature of manipulation to control requirements, working conditions: The water pressure greater Valve requirements: type diversity: nozzle type, assisted atomization-type, self-contained type, and on the clip. Reduction Valve (high and low pressure bypass valve) Control requirements: the high temperature high pressure steam to adjust to a certain temperature and pressure of steam, to provide a bypass channel turbine, boiler and steam turbine capable of independent work. Condition: The high temperature high pressure steam. Valve requirements: thermal shock, noise reduction, quick response.

原文来源：http://www.1kongzhifa.com/

2010-08-31 07:19

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