气体密度表

 

 

当高压断路器(又称高压开关)在开断电路时会有火花产生又称之为电弧，在电气设备中电弧的产生会对断路器造成烧毁甚至发生***的危害。SF6 气体由于具有绝缘性能好灭弧能力强的特性，目前在高压断路器中被广泛使用。

SF6 气体在电力设备中的灭弧性能取决于设备容器中的SF6 气体的密度。如在不同型号、规格的断路器中的SF6气体的密度就是不相同的，如果SF6气体由于泄漏，密度减小，则灭弧作用就会减弱或起不到灭弧作用，因此，用SF6 密度表对容器内SF6 气体的密度进行监视和控制就显得格外重要。

 

 

The spark happened when the electric switchingor the high pressure breaker (high pressure switch)open or close circuit is the electric arc. The electric arc produced in the electrical equipment may lead the circuit breaker to burn down even explosive. The SF6 gas is widely used in the high-pressured electric appliance because it has the insulating ability of extinguishing arc.

The ability of The SF6 gas extinguishing arc has big relati*** with the SF6 gas density in the equipment vessel. In the different model, specification circuit breaker SF6 gas density is different, when the density SF6 gas is lower than some value, the extinguishing arc function is weaken, therefore, it is important that carrying on the surveillance and the control of the SF6 gas density .

 

公司生产制造的SF6 密度表，有“YM(M1)”T-P 曲线监测“; YWM (M2)”温度补偿监测;“YXM (M3)”温度补偿加控制装置三大系列产品。

 

T-P 曲线监测SF6 气体的密度，是将一定额定工作压力下的SF6 温度- 压力对照情况用一条曲线在表盘上表示出来，让人们从表盘上方便和直观地来监测SF6 气体的密度情况，带这种曲线盘的压力表，称之为T-P 曲线的密度表。

 

一般情况下，表盘上是由3 条T-P 曲线组成，从左至右我们依次叫他们为“左曲线”、“中曲线”、“右曲线”，其中“左曲线”和“右曲线”将表盘分为3 个区域，“左曲线”的左边为红***域、“左曲线”和“右曲线”之间为绿***域、“右曲线”的右边为***区域(如图)

 

 

在用“表盘上带T-P曲线”的密度表对容器内SF6气体密度进行监视时，应首先测试环境温度，然后找出环境温度半圆线与指针的相交点A，若相交点A在绿***域内，则表明器内SF6气体密度在规定的范围内；若相交点在红***域内，则表明器内SF6气体密度低于规定的范围，应当***或检查容器是否有泄漏发生。

The SF6 densimeter made of BRIGHT has three big series products :"YM (M1)" T-P curve monitor; "YM (M2)" temperature compensation monitor, "YXM (M3)" temperature compensation with control device.

 

"YM (M1)" the T-P curve monitor seriesdensimeter principle and service intended

 

Under the fixed working pressure, a curve on the

dial plate shows the SF6 temperature- pressure comparison situation to let the people conveniently and direct-viewing monitors the SF6 gas density situation from the dial plate.

 

　　In the ordinary circumstances, the dial plate is composed by 3 T-P curves, they are "the left curve",

"center the curve", "the right curve" from left to right,"the left curve" and "the right curve" divides the dial plate into 3 regi***, "left curve" left side for red region, "left curve" and "right curve" between for green region,"right curve" right side for yellow region (as chart).

 

　　When using the densimeter " with T-P curve on the dial plate" , you should read the thermometer nearby the densimeter to find out the ambient temperature, then find the point of intersection A of the ambient temperature half-circle line and the pointer, if A is in green region, then the SF6 gas density is in

stipulation scope; If A is in red region, then the SF6 gas density is lower than the stipulation scope, it is necessary to restore vital energy or inspect the vessel whether has divulges occurs.

 

“带温度补偿装置”密度表是在原压力仪表结构上，加装温度补偿装置所组成。是一种不用考虑环境温度的变化(即不用查看温度计)，也不用查看“对照表”，而是直接从密度表的读数就可以判断出容器内的SF6 气体的密度是否在规定的范围内。

 

工作原理是：当环境温度上升时，虽然容器内SF6气体的密度未发生变化但其压力增大，带动指针顺时方向转动，而当温度上升时，双金属补偿装置的“U形”口张大，则推动指针向逆时针方向转动，当两种运动引起表针的偏转量相抵销时，无论环境温度如何变化，指针都不会发生偏转。反之，当环境温度下降时，虽然容器内SF6 气体的密度未发生变化但其压力减小，带动指针向逆时方向转动，而当温度下降时，双金属补偿装置的“U 形”口缩小，则推动指针向顺时针方向转动，当两种可运动个起表针的偏转量相抵销时，无论环境温度如何变化，指针都不会发生偏转。所以只要容器内SF6 气体不发生泄漏，其密度不变化。仪表的示值就不变。从而达到测量和监视其密度的作用。其使用方法是：在20℃的环境温度下，将容器内的SF6气体充至额定工作压力(P额)，在每日的规定监测时间进行监测时，只要密度表的指针指向额定工作压力即为正常状态。

The densimeter "with temperature compensation "installs the temperature compensation in the initial pressure measuring structure. It does not need to c***ider ambient temperature change ( not need to see the thermometer), also does not need to look over "the comparative table", but is directly judge the SF6 gas density whether in stipulation scope.

　　The principle of work is: When ambient temperature rises, the pressure of the SF6 gas increases, drives the indicator along the clockwise rotation, but at the same time, the mouth of the bimetal compensation system "the U shape" publicizes, then impels the indicator to the counter clockwise rotation, when two kind of strength be equilibrium, the ambient temperature change cannot made the indicator deflection. Otherwise, When ambient temperature falls, the pressure of the SF6 gas decreases, drives the indicator counter the clockwise rotation, but at the same time, the mouth of the bimetal compensation system "the U shape" reduces, then impels the indicator to along the clockwise rotation, when two kind of strength be equilibrium, the ambient temperature change cannot made the indicator deflection. So the SF6 gas does not occur divulges, its density does not change. Although pressure in the vessel changes along with the ambient temperature change, under the function of the bimetal piece "temperature compensation installment", the densimeter indicator cannot h***e deflection. Thus the SF6 density value in the vessel is really reflected. Its application method is: ambient temperature under 20 ℃, fill the SF6 gas to the fixed working pressure (P ), Monitor at regulate time daily, it is normal while the indicator pointing the fixed working pressure.

当“YXM (M3)”型SF6 气体密度控制器接入密闭系统后，向系统设备中充入SF6 气体，当SF6 气体密度达到规定值时，密度控制器的指针指向额定工作压力。当工作环境温度发生变化时，虽然SF6 气体的密度并没有发生变化，但SF6 气体的压力将随着温度的变化而改变，密度控制器上的指针本应随压力的改变而发生偏转，此时通过控制器内部的温度补偿装置对SF6气体压力的变化进行补偿，使指针不发生偏转。只有在系统中SF6气体发生泄漏，造成密度下降时，SF6气体密度控制器的指针才发生偏转，从而起到对系统设备中SF6 气体密度的监测作用。

SF6气体密度控制器，通常配置两个设定开关点Ps1和Ps2，设定点Ps1为报警点，设定点Ps2为闭锁点。一旦系统发生SF6 气体泄漏时，随着SF6 气体密度降低，指针上的触头（动触头）与设定开关点Ps1 上的触头（定触头）接触时则发出报警信号；随着密度继续下降，当指针触头与设定点Ps2上的触头接触时，则发出闭锁信号，自动关闭断路器开关，使之不能工作，防止事故的发生。

 

"YXM (M3)" SF6 density controller has installed electric contact device based on the "M2"densimeter. The two contact points is warning point and closedown point. So SF6 density controller can not only monitor but also warn and close automatically. When SF6 gas divulges, internal pressure reduces along with the density of SF6 gas reducing, causes the indicator contact (move touch) with the lower limit point (fixed touch) to send out the alarm, continues along with the density of SF6 gas reducing, the pressure continues to drop, when on the indicator contact (move touch) with the closedown point (fixed touch) to shut-off circuit breaker switch automatically, to prevented the accident occurred.