Jiwei Ring-11 High-pressure Protection Liquid Level Switch Widely Applied in No.3 Power Plant of Shanghai Waigaoqiao

Thermal power generation generally refers to the use of oil, coal, natural gas and other fuel combustion heat to heat water, so that water into high temperature, high pressure steam, and then steam driven generator to generate electricity. The thermal system of power plant is consisted of boiler, steam turbine and its auxiliary equipment connected by pipes and accessories according to steam water cycle process.

In thermal power generating unit, condensate water is sent to low-pressure heater by the condensate pump, which is heated by the extraction steam from low-pressure cylinder of steam turbine, and then send to the deaerator. At this time, 160 ℃ saturated water is sent to high-pressure heater by feed water pump after being deoxidized by deaerator. The super heated steam extracts from the high-pressure cylinder of steam turbine is used as the heating medium, and finally flows into the boiler to be lifted again by economizer. When temperature is high, water that entering the drum can obtain a considerable amount of heat in advance, so the heat transfer area requires to reach the degree of vaporization can be slightly reduced when circulating heating in the furnace tube.

To ensure the normal operation of boiler, it is necessary to measure the liquid level by reliable liquid level switch, so as to balance the water supply, maintain the water level of steam drum, ensure the steam quality, control the steam pressure and temperature, reduce the heat loss and improve the thermal efficiency of boiler.

The high water temperature of this thermal system and the high temperature and high pressure working ambient put forward higher requirements for the liquid level switch. In order to find a suitable liquid level switch, the client have tried to compare various of level switches.

 

Among various liquid level measuring instruments, the guided wave radar level meter meets the requirements, and has great stability and accuracy, but it is rarely used because of the high expense. Moreover, due to the changing density of high temperature and high pressure water, density correction becomes a significant problem. Some common liquid level switches in the market cannot adapt to this high-pressure environment with the poor sealing technique. Besides, the false alarms problem also seriously affects the production efficiency. Although imported level switches are reliable, but the expense is extremely high. Finally, the client finds Jiwei Ring-11 Liquid Level Switch. As an efficient and cost-effective liquid level measurement instrument, Ring-11 Liquid Level Switch has high pressure protection feature while the quality and performance were comparable to imported product.

Firstly, the high-pressure protective gas-tight leadthrough of Jiwei Ring-11 High-pressure Protection Liquid Level Switch is the glass-metal encapsulation connector that configures between process connection and meter head. The sealing effect is achieved by the cooperation of borosilicate glass and stainless steel, which prevents the fork body from penetrating under high temperature and high pressure in the long run, and prevents the high temperature liquid from penetrating into electronic module of the meter head through addition pipe and process connection, and also prevents the occurrence of flushing out housing leading to the accidentally leakage. In addition, the high-pressure gas-tight leadthrough can also protect the piezoelectric components from moisture. 

Secondly, besides the above characteristics, the electronic part of Ring-11 High-pressure Protection Liquid Level Switch has been modularized. The whole circuit board is installed in a half cylinder plastic box. At the same time, pouring sealant is injected into the case to prevent electronic material from oxidizing, thus achieving better sealing and insulation effect.  That is to say, the electronic modular is waterproof, anticorrosive and insulating, it greatly improves the instrument reliability, extends the service life and simplifies the maintenance while users can just directly replace the circuit module.

Thirdly, Ring-11 is specially made of 316L stainless steel with aluminum alloy meter head, which enables the instrument to be used in corrosive environment. In order to adapt to the complex working conditions of high temperature and strong corrosive liquid level, the special setting of high-pressure protective gas-tight leadthrough makes Ring-11 High-pressure Protection Liquid Level Switch effectively prevent accidental leakage of high-pressure strong corrosive liquid. More than that, the high-temperature extension tube can be chosen from ECTFE and PFA coating, so it is suitable for measuring the liquid level of hydrochloric acid, sulfuric acid, nitric acid, alkali liquor, syrup, liquid medicine and industrial waste water, and is especially suitable for high-pressure liquefied gas (such as LNG) and complex measuring occasions with bubbles, bubbles, viscous liquids and vibration interference.

With the excellent quality, design, techniques and ultra-high performance price ratio, Ring-11 High-pressure Protection Liquid Level Switch has been widely applied in No.3 Power Plant of Shanghai Waigaoqiao.