静压式液位变送器由于其使用简单、精度高、安装维护简便等特点,在石化,电力,冶金,环保等行业得到了广泛应用。但是在实际使用过程中由于某些原因导致测量误差偏大,影响了这种测量原理仪表的使用。
Static pressure type liquid level transmitter because of its use of simple, high precision, easy installation and maintenance characteristics, in the petrochemical, electric power, metallurgy, environmental protection and other industries has been widely applied. But in actual use because of some causes of measurement error, affected the use of this instrument measuring principle.
由于工程的循环水为水库存水,水中含大量的微生物、藻类,并且其中富含大量的气体。在水的循环过程中,时刻在释放水中的气体,由于本工程设计单位采用的是投入式的
静压式液位变送器,膜片在变送器本体,投入水中的只是一段不锈钢短管及引压管,该管路中存在比较大的可积存气体的空间,当水中的气体释放并进入该管路中并慢慢积累,使管内气体压力p慢慢增加,抵消了水的高度产生的压力,致使作用在膜片上的压力P减小,从而使变送器输出量减小。
The circulation water engineering for the reservoir water storage, water containing microorganisms, algae, and which is rich in a lot of gas. In the water cycle, time in the gas release water, because the engineering design unit is used in static pressure type liquid level transmitter type, diaphragm in the transmitter body, into the water is a stainless steel tube and pressure guiding pipe, the existence of relatively large up the gas pipeline in space, when water gas release and enter the pipeline and slowly accumulated, so that the tube gas pressure P slowly increased, offsetting the height of water pressure, the pressure of P acting on the diaphragm is reduced, so that the transmitter output decreases.
我们分析了误差产生的原因,并且由于
静压式液位变送器不能完全消除误差产生的原因,故不再采用该原理的液位测量仪表。我们在循环泵房前池选用了非接触式的超声波液位变送器。经过长时间试运行,循环泵房的前池液位测量准确,未再发生周期性测量偏差。可以认为本次改进措施是可行的,成功的。循环泵入口的液位测量仪表的更换将在以后的改进中实施。
We analyzed the causes of error, and the static pressure type liquid level transmitter does not completely eliminate the error, it is no longer used the principle of liquid level measuring instrument. We in the circulating pump house forebay used non-contact ultrasonic level transmitter. After a long time of trial operation, measurement of tank level circulation pump is accurate, no recurrence of periodic measurement deviation. You can believe that the measures are feasible, successful. The replacement of liquid level measurement instrument of circulating pump entrance will be improved in the future.