Confusions of DCS beginners
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I’ve just started working with DCS recently. My supervisor asked me to study the process diagrams, and I would like to ask the experts here: what should I pay attention to in process diagrams and how should I read them? The description should be detailed; it’s best to provide an example, hehe, thank you!
The method of learning process diagrams is very important; of course, it is closely related to one’s own abilities and the field of study. General methods: 1. Understand the origin and purpose of each process medium – what is its function (is it the main fuel, a catalyst, a cooling medium, etc.)? 2. Have an understanding of the labeling and colors of the process pipes, as well as their diameters; know the characteristics of the valves on these pipes and the features of flow meter installation ； 3 Refer to the process diagram and compare it with the actual equipment to approve any added or reduced process steps. One must definitely have an understanding of the principle behind these 4 pairs of processes.
Reading process diagrams is the most fundamental way to get started with instrumentation and DCS systems: it involves understanding the flow of the process, the location and function of various measurement points along the process pipelines and equipment, determining which ones are for on-site indication, which ones are for remote monitoring, and where the alarm values lie； Which measuring points and control devices make up the automatic control loop ； Those are manual control circuits ； Fault conditions of control valves and the direction of action based on deviations ； Once familiar with these, one can refer to the accompanying DCS I/O list, as well as the layout of AI, AO, DI, and DO modules within the DCS cabinet, to understand the specific methods used to implement simple automatic control loops in the configuration ； Logical principles of complex circuits ； Methods for remote control and measurement of electrical equipment ； Logical implementation methods for interlock circuits ； Methods for implementing sequential control circuits and the practical significance of various parameters involved ； Further understand the inputs, outputs, and the meaning of the internal parameters of each functional block in the configuration. Further on, it is possible to understand the hardware components of the DCS system, network communication, power supply system, as well as the wiring methods for various signals. With this, one should have a pretty good understanding of the DCS system. Then, by referring to past failure cases, one can learn from them and analyze them, which helps to avoid taking unnecessary detours when encountering problems, and experience can be accumulated gradually through regular maintenance and programming tasks.
How should one learn DCS configuration?
DCS is designed to serve the process; only by understanding the process thoroughly can DCS control it effectively
It’s not scary to not understand something; what’s scary is not asking or taking action. You can ask the designers, supervisors, experienced employees, etc. – you can ask them very specifically, using drawings or actual samples.