HDS Block Diagram

In order to realize safety aspects within the plant model, it is required to represent the plant design model in object-oriented manner within POOM, and then associate safety aspects with the model elements. 

Reactor process has been selected in this example. The P ID of HDS plant has been divided into control group units or CGUs, which is used to analyze process safety in smaller parts of the plant process. This means that fault propagation from one CGU to another is achieved only through the control valves or connection points between these CGUs. The simplified P ID of the reactor CGU (CGU3) can be viewed in figure 3-21. 

For better presentation of the P ID in the object-oriented model the concept of connection point is introduced. The connection point is used to express both merging of two or more lines or splitting of one line into two or more lines. For example, the connection point CP-2-1 represents the merging of the input from H2 and from CGU3. 

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