Huaneng Yingcheng thermal power plant 220KV GIS equipment SF6 gas density relay calibration valve application

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应用案例

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Huaneng Yingcheng thermal power plant 220KV GIS eq

Huaneng Yingcheng Thermal Power Co., LTD. Phase I project installed capacity of 1*3500MW supercritical unit +1*350MW back pressure heating unit, the project designed annual power generation of 2.3 billion KWH, annual heating capacity of 15.11 million GJ. GIS equipment adopts ZF11-252 (L) GIS circuit breaker produced by Pinggao Group Co., LTD., which was installed in June 2011 and officially put into operation at the end of December. The external output voltage is 220KV, including 8 groups of feed output, including 227#, 224# and 226#. SF6 gas density relay adopts WIKE,SF6 gas density relay is connected to Pinggao electrical equipment body and SF6 gas density relay meter calibration valve, but before SF6 gas density relay meter calibration valve cannot meet the requirements of online calibration SF6 gas density relay, so this time by modifying and installing SF6 gas density relay meter calibration valve. In order to meet the requirements of SF6 gas density relay regular inspection, the State Grid Company attaches great importance to the development of DL/T596-1996 "Preventive Test Procedures for Power Equipment" and the National Energy Administration "Twenty-five Key Requirements for the Prevention of Power Production accidents and Interpretation" Item 13 “ Prevent GIS, switchgear mishaps ” Article 13.1.6, Item 12 in the revised edition of State Grid Corporation's Eighteen Major Anti-Accident Measures for Power Grids “ Prevent GIS, switchgear mishaps ” 12.1.1.6 The connection mode between the medium sulfur hexafluoride density relay and the switchgear body shall meet the requirements that the parity density relay is not disassembled.

The installation of SF6 gas density relay calibration valve is as follows:

Because the SF6 gas density relay like other manometers after a period of use, its alarm and lock value will produce a certain drift; In addition, because the contact action of the density relay is not frequent, the contact action may be insensitive or ineffective. If not inspected, there is a security risk. Density relay quality problems exist for the following reasons:

1, its vibration resistance is not enough, after the strong impact of the switch closing, the pointer is stuck, the contact will never fail (no action or always action), the deviation exceeds the standard and other faults.

2. Due to oil leakage, its vibration resistance is reduced, and after the strong impact of switching and closing, the pointer is stuck, the contact will never fail (no action or always action), and the deviation exceeds the standard.

3, because the commonly used relay contact is magnetically assisted electrical contact, its contact closing force is small, the time is slightly longer, the contact is oxidized, the contact will be blocked or the contact is unreliable. For the oil-free type, magnetically assisted electric contact contacts are exposed to air and are very prone to oxidation or dust accumulation.

4, the contact is easy to contact poor or impassable; For the oil-filled type, the magnetic-assisted electric contact contact is immersed in silicone oil, but for a long time, after several moves, its contact performance will decline, and the oil film has an insulating effect, and the contact will also be poor or blocked.

5, due to its own manufacturing quality problems, there is inaccurate temperature compensation, and the error is seriously large (overcompensate or undercompensate).

6, due to insufficient aging or material problems, for a long time, it will drift, and the accuracy will be seriously large (the stress is not eliminated).

7, due to design defects, there will be failure at low temperatures (never move).

8, due to design defects, at high temperatures, the action and display value will be seriously deteriorated.

9, for the relative cavity type density relay, due to internal or external reasons, the standard cavity will leak, there is a large error in the action value or failure.

10, due to severe vibration during transportation, it will cause relay failure and poor accuracy.

11, due to the quality of the components, the time is a little longer, may cause relay failure, accuracy becomes worse.

12, because the shell vent is not loosened, or the shell sealing problem, the internal pressure of the shell changes, so that the accuracy changes.

13, due to the erosion of rain or corrosive gases, it will cause relay failure and poor accuracy.

14, due to improper use, will also affect the use. (Installation position).

15, due to process problems, it will cause the failure of the density relay, or the accuracy is poor.