Does the control system of gas-steam combined cycle power plant need to add ESD?
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Dear friends, does the control system of gas-steam combined cycle power plant need to add ESD? GTG control by PLC STG control by PLC HRSG control by DCS There is no clear word ESD in ITB, only 2 out of 3 philosophies shall be adopted for critical control loops and interlocking system. At present, some of the information reported by DCS manufacturers include ESD, and some manufacturers say that the function of ESD is implemented in DCS. Generally speaking, in China, are there any regulations regarding the use of ESD in the DCS of combined cycle power plants?
This post was last edited by liuei on 2010-4-13 22:49 The function of ESD is implemented in DCS. This is no longer ESD, but DCS. The purpose of setting up ESD is to separate it from the DCS to ensure that the ESD system is protected when the DCS fails. The reliability of the ESD system and cards is much higher than that of the DCS system! If the safety requirements of the system reach the level where ESD is required, it cannot be replaced by DCS or PLC! The key control loops and interlocking systems must use the 2-out-of-3 concept. This requires DCS to be able to do it. In your case, you can consider DCS+Tricon!
If there is no requirement, the safety interlocking can be implemented in the DCS or using the PLC system.
If you write like this, can DCS do it? Or you need to add ESD For protection, multi-channel measurements shall be provided. All trip circuits shall be triple modular redundant, performed with 2-out-of-3 logic. In case of faulty channels, the voting shall be automatically changed to 1-out-of 2 selections.
For protection, multi-channel measurements must be provided. All loops should be triple redundant and implement 2-out-of-3 logic. In the event of a wrong channel, voting will automatically change to 1-out-2. The requirements are very high! ESD needs to be set.
4# wimyme0506 I personally think that it is not a problem that DCS cannot do it, but that it is not needed! System architectures such as "triple redundancy", "two out of three", and "reduced to one out of two" mentioned above are definitely targeted at safety instrumented systems (SIS/ESD). Therefore, safety instrumented systems (SIS/ESD) must be included.
The control system of a general gas-steam combined cycle power plant is divided into two parts: The gas turbine and steam turbine control systems use the equipment factory's own control system. Like GE's MARKVI system, the controller uses triple redundancy. The waste heat boiler, auxiliary system and public system use ordinary DCS. Compared with the coal-fired boiler, the waste heat boiler only has a steam and water system but no combustion system, so it is generally not equipped with ESD.
Hey, in fact, whether to use SIS or not should be decided by the design unit. I don’t know if the poster belongs to the owner. Didn't you ask a design institute to design your device? If you do, asking this question here is equivalent to asking someone to work for you, but you have done the work of a wage earner (sometimes God does not have the right to do the things of small gods. ) Don’t you feel it’s a loss?
This post was last edited by Yi Xing on 2010-4-18 08:26 8# leslieshe I don’t agree with this statement. The owner can fully communicate with the design institute in the early stage of the project to discuss and then order (as long as it is not required by the specification). Moreover, the workers I invited to join did not really think about themselves. I can't just let the workers make all the decisions.
In general gas-steam combined cycle, gas turbines with gas part must have ESD. For example, Alstom's configuration is generally ABB DCS+ HIMA ESD. GE's configuration is generally mark VI. Mark VI itself has a triple TMR structure, and the security level is high enough to realize the integration of DCS + ESD. In fact, you can understand that it is just using an ESD-level hardware system to make ESD and DCS. The steam part of the combined cycle unit does not use ESD. There is no potential danger of flammability and explosion in that part of the gas turbine. So we see many projects, which are conventional DCS systems such as Ovation system or Info90.
I would like to ask if it is necessary to request TMR for the PLC of the steam turbine part?