DCS interlock logic diagram
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Do experts say that this approach results in incorrect interlocking? How should it be changed? DCS system
Composition: The DCS interlock logic diagram consists of the following components: 1. Equipment model: It records information related to each device, including its input and output parameters, functions, and operational requirements. 2. Control logic: Determine a versatile control method based on the device model to support the corresponding devices and operations. 3. Signal control: Based on control logic, it determines the signal exchange between devices in order to achieve the corresponding control objectives. 4. Safety strategy: Based on signal control, the safety settings in the control environment (such as circuit breakers and interlocks) are designed securely to ensure the safe operation of the system. 5. Operational inspection: Conduct operational inspections in accordance with safety policies and signal controls to ensure that no unsafe conditions arise. -For reference only
The last edit to this post was made by A Bai_ugUmK on 2023-2-23 at 12:04. The relief valve generally opens in case of an FO fault; the solenoid valve opens when it loses power
It’s not something that can be solved by just changing a picture.
That’s the key point: it requires acting against logic. Say that this won’t work
A high pressure in the pilot light simply results in a larger flame in the pilot light; why then shut off the main gas valve?
The DCS interlock doesn’t have this requirement, right? That’s what safety instrumented systems require. Normal is 1, interlock is 0.
The pilot light trigger interlock shuts down the main flame, while the pressure in the main flame pipeline trigger interlock does not shut down the pilot light; the pilot light must burn steadily.
The logic must be fail-safe; when a fail-safe input interlock is triggered, the contacts should be open
The expert means that the power-off vent valve should be opened. The valve on site is currently likely to be of the fail-closed type, that is, an FC valve. To make the necessary changes, the logic does not need to be altered; instead, the description should be changed to \"solenoid valve loses power\", the DCS wiring connection should be set to a normally closed configuration, and the valve should be replaced with one of the fail-open type.
Shouldn’t the output be maintained using a trigger?