Security Technology Exchange Edition: Daily Question (2016.5.23-24)

Chemical plant automation systems should all be equipped with UPS power supplies; even if the main power supply fails, the control system can still function. Under normal circumstances, the interlock system will initiate a shutdown according to the preset procedures. First, the material supply should be cut off by closing the relevant valves.

The principle for dealing with power outages in chemical plants is to identify the fault location as quickly as possible, determine the cause of the outage, resolve the issue promptly, and restore power supply in the shortest time possible.

A sudden power outage occurred, and the operators promptly activated the emergency response plan for power outages and carried out the actions required by that plan.

　　Hazards and countermeasures in case of power outages in chemical plants: ① If both lines A and B in a chemical plant lose power simultaneously, the main transformers No. 1 and No. 2 in the main substation also cease to function, resulting in the shutdown of all high- and low-voltage electrical equipment. This can cause serious disruptions to production, and may even lead to fires or explosions, resulting in casualties. 　　② During maintenance on one of the lines, Line A or Line B, in the chemical plant, the other line operates the #1 and #2 main transformers via the 35KV300 busbar switch. Although this does not affect normal production, it reduces the safety level of production. Therefore, once the maintenance on that line is completed, the restoration of power to that line must not be delayed unless there are special circumstances. Since a single-line power outage does not affect normal production and can cause no accidents to personnel or equipment, no emergency measures are required. 　　③The hazards when the 6KV I and II busbars in a chemical plant lose power are the same as those that occur when both lines A and B fail simultaneously. 　　① Power loss in any section of the 6KV I or II busbars in the chemical plant. If one of the 1# or 2# main fans loses power, it will cause fluctuations in the production of the catalytic unit; in severe cases, it may lead to a shutdown. 　　Extended knowledge: Principles for dealing with power outages in chemical plants: The principle behind handling power outages in chemical plants is to identify the fault location as quickly as possible, determine the cause of the outage, and resolve the issue swiftly so that power supply can be restored in the shortest time possible.

1. Notify the factory management and electrician immediately. 2. Stop steam heating. 3. The negative-pressure equipment should maintain a vacuum state; venting should be carried out once the vacuum level approaches zero. 4. For positive pressure equipment, pay close attention to the safety devices (such as safety valves) and perform manual pressure relief in case of overpressure. 5. Be careful to retain the water in the condenser; try to prevent it from being completely siphoned off or flowing back through the inlet. 、、、、、、、

Give priority to protecting the heating furnace and compressors

The unit was shut down urgently; personnel were sent to key locations to monitor the situation and prevent pressure from building up, and emergency venting was initiated

In the event of a power outage in the 200,000-ton sulfur-based acid production plant, first check whether the turbine DC oil pump starts up, verify whether the liquid level in the circulating acid tank is too high, check the boiler water level, and replenish water using a steam reciprocating pump if necessary