Application of Magnetic Turning Column Liquid Level Gauge

Application of Magnetic Turning Column Liquid Level Gauge in Blower Hot Well Liquid Level Monitoring

【Abstract】 Based on the reform of the steam well blower hot well liquid level monitoring device, the application of the magnetic turnover column liquid level gauge (magnetic float level gauge) in the steam blower hot well liquid level monitoring device is summarized. The comparison between the liquid level gauge (magnetic float level gauge) and the electrical contact level gauge explains the working principle and measurement potential of the magnetic float level gauge, and demonstrates the effect of this transformation on ensuring the stable operation of production.

1 Introduction

The hot well liquid level is one of the important monitoring data of the steam turbine blower. The hot well liquid level determines the stability of the water circulation system of the steam turbine blower and is the key measurement point for the smooth operation of the steam turbine. Magnetic turnover column liquid level gauge is one of the commonly used liquid level gauges of the instrument. Xuangang Power Plant of Hebei Iron and Steel Group mainly chooses it as a steam turbine blower hot well liquid level measurement device. The newly constructed AV71, AV80 fans all use magnetic turnover column level gauge (magnetic float level gauge) and liquid level switch to realize automatic control of hot well liquid level, with good control effect and high accuracy of monitoring data.

2 Project background

The earliest 3650 fan built by the power plant used an electric contact liquid level gauge, and the control effect was not ideal. The working principle of the electric contact liquid level gauge is to rely on the contact between the electrode and the water to make the electrode conduct. The electrode indicates the current level after conduction The corresponding green light on the display meter lights up, indicating the liquid level. The electric contact liquid level gauge is suitable for the measurement of clean water quality. Because the steam turbine equipment is running for a long time, the water quality of the electric contact liquid level gauge is relatively turbid. The adhesion of the turbid matter on the electrode affects the contact between the electrode and the water, thereby affecting the conduction of the electrode. As a result, the display instrument cannot display the correct liquid level of the hot well liquid level. The solution to this problem is to add fresh water to the measuring cylinder, and use the fluidity of the water to temporarily flush out the turbid matter adhering to the electrode to ensure the short-term conduction of the electrode. This method requires frequent water addition and can only solve the problem in a short time. Therefore, the effect of improving poor electrode conduction is not obvious during the operation of the equipment; and each time the water is added, the electrical contact water level gauge in front of the buoy needs to be frequently switched on and off. Ball valves, frequent opening and closing of ball valves will lead to poor sealing of the ball valves, which will affect the vacuum of the turbine and bring hidden dangers to the safe operation of the turbine.

In order to solve the above problems, the hot well liquid level detection device was replaced, and the electric contact liquid level gauge was changed to a magnetic turnover column liquid level gauge (magnetic float liquid level gauge) with liquid level transmission output. The magnetic turning column liquid level gauge (magnetic float liquid level gauge) with transmission output has an additional local display than the electric contact liquid level gauge, which can display the liquid level on the spot and transmit the liquid level signal to the post. Display instrument, so that the staff can visually see the liquid level status before the scene. The most important thing is that the magnetic level indicator (magnetic float level gauge) is not affected by the water quality in the measuring cylinder.