【JST-036】One-on-one Q&A discussion on CCC and other ITCC system issues. (Technology updated to floor 253)
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This post was last edited by *aojiaoya0546 on 2016-7-13 at 12:46. It is a technical discussion thread intended solely for discussing technical issues related to turbine unit control. My strengths: automation control related to aircraft engines. Work experience: Has been working in aircraft engine control systems since 1996 to the present. I will do my best to answer questions regarding crew control; if I am unable to provide an answer, I will try to find other ways to respond. First, let’s provide an overview of CCC and other common advanced control systems in unit control. -------------------------------------------------------------------- There is a conceptual issue: ITCC does not necessarily have to be an SIS system; ESD is definitely an SIS, while unit control falls outside the scope of SIS. CCC is different from products from other brands. Let’s start with the practical aspects: Some people always like to compare CCC’s hardware with systems such as TRICON, ICS, and HIMA, but in fact there is no basis for such comparison. The hardware from TRICON, ICS, and HIMA is designed for safety systems, while CCC does not produce safety systems at least for now – so what’s the need for SIL certification? The oldest hardware for TRICON and ICS comes from AUGUST Company, and they have the same structure; the design of TRICON has not changed to this day and is now outdated. As for why it’s outdated, this has been discussed many times before, so there’s no need to go into further detail ； ICS is at least still being updated. Why is it said that CCC is always used in combination with HIMA? The reason is that TRICON entered the Chinese market in 1997; with Shengli Blower as the leader and Kangjisen as a supporting partner, efforts were made to promote TRICON products. At that time, TRICON was used only for unit control in China. As ESD applications became more widespread, TRICON began to integrate ESD functions with those of units, resulting in a system where ITCC and ESD operated together. In fact, the international practice is to keep them completely separate; even when using products from the same manufacturer, the unit control and ESD are two distinct controllers that are not integrated into one, which is highly detrimental to safety and imposes very high requirements on the controllers. Therefore, no standard stipulates that ITCC+ESD must be in one controller or use products from the same manufacturer. CCC Company has always been involved only in unit control and does not participate in SIS systems; HIMA, on the other hand, is dedicated to SIS systems. Its involvement in unit control is driven by the conditions in the domestic market, which is quite challenging for them. CCC never wanted to develop SIS; it’s not that CCC’s hardware is inadequate, but they forced themselves to use ITCC+ESD instead. CCC can be used for ITCC; there are no issues with collecting data on temperature, transmitters, etc., and it is possible to write one’s own logic. Many users in China are already using it, though it cannot be used for security systems. Currently, in a project that includes both units and ESD, controller manufacturers are required to have SIL certification. What kind of logic is that? Don’t they know that units do not require SIL certification? Don’t they realize that units and ESD are completely separate things? Speaking of softer aspects: The unit control systems for TRICON and ICS are based on the technology developed by MICON Company. McKenwell in Beijing is MICON’s domestic agent; it entered China a long time ago, but has not been able to achieve much success. MICON is still active internationally at present, but it doesn’t seem to be doing very well. For the unit programs of HIMA in China, we originally wanted to use those from a domestic company; it is said that a set costs 100,000 yuan. But as for the quality of those programs provided by that domestic company, well, I’ve had the chance to examine their programs. It was bought, but it’s never been used. Later, someone within HIMA developed some programs; I’m not sure what the results were. There’s no need to say much about CCC’s unit technology; when it comes to complex controls for natural gas and PTA, no other company can compare to them. 80% of the international aircraft engines are manufactured by CCC. CCC analyzes and implements unit control from a purely process perspective, rather than solely for the purpose of protecting the unit. WOODWARD’s system is excellent; it can be used for ITCC, and its unit control performance is top-notch. It’s not widely used in the country at the moment, but it seems to be gaining some traction recently. GE’s unit control was developed by the personnel at CCC; the algorithms used are basically the same as those at CCC. As for GE’s own units (New Bilong), there are no issues with their control system, including load distribution and decoupling. Most of the controllers used are still ordinary PLCs, such as those from GE and AB. Their programs and parameters are optimized for their own turbines, and it’s unknown what the results will be when applied to turbines from other manufacturers. Choking algorithm: The basic formula used by all manufacturers is the same, which is an algorithm for simplifying flow rate and pressure head. The difference lies in the changes that occur later on. The current algorithm used by TRICON and ICS is to determine the surge point and operating point based on flow rates, with both values being expressed as a ratio of the maximum flow rate. CCC is the same as GE: the surge point and operating point are determined directly using the pressure difference, while flow rate is only used for display purposes. The operating point is not compared to the maximum flow rate, but rather to the surge point. 1. The advantage of using differential pressure over flow rate is that there is no need to consider your throttling element. 2. The disadvantage of using the flow rate ratio is that, whether your maximum flow rate is based on the maximum flow rate of the compressor or that of the throttling element, this maximum flow rate is not accurate; an incorrect selection has a direct impact on the anti-surge margin. The ratio of operating point to surge point – this value is accurate. It seems that ICS is set to be adjusted to the CCC format; I haven’t been able to get hold of Woodward’s algorithm, but I heard it’s also based on the CCC format. That’s all I can think of for now; I’ll add more later.
I just posted a similar new thread, and here’s another one with the same content. Studying*studying* is not bad either; it seems to be meant to encourage CCC. The original poster should judge the system from an objective standpoint; what you mentioned is something that has arisen from objective historical developments. But it is the users’ needs that manufacturers should prioritize, right?
This post was last edited by chengf on 2013-9-11 at 13:12. In fact, many of the original poster’s judgments and ideas are correct. I’m not opposed to using CCC for control either, but since users don’t want to issue separate tenders for the control interlocks of an entire unit, it’s fine to require that these be integrated together for unit control. For a company to grow, it must develop devices that meet the needs of its users; understanding those needs is key. On the basis of ensuring good performance, simplicity is what matters most, rather than focusing on what other companies get wrong. The development of Congisun is precisely in response to this demand. Won’t foreign companies think of using this model of the Congsen system after a few years? I don’t believe they don’t want to simplify things. I prefer GE’s Mark VI, which allows for one-click startup of the gas turbine with no further intervention needed; however, models like CCC, Conergy, and ICS don’t have this feature
It’s already objective; there’s no intention of advocating anything. I’m neither part of CCC nor a user; I’m just someone who works on systems. Currently, many existing users have disabled the anti-surge and speed control functions in TRICON and switched to CCC control instead. For TRICON’s programs, I’ve modified just two of them. More and more users are realizing this now; it’s not me who said it. Whether in terms of hardware or software, every user should know what they need, rather than following what others do. TRICON, ICS, and HIMA are only suitable for SIS systems; it is a fact that CCC has advantages in terms of power units, but many people are not very aware of this. Only with the right system can benefits be brought to enterprises. Why spend millions on implementing a system only to find out it’s not suitable, and then have to modify it? It’s pointless. I am merely putting forward an opinion here; I don’t intend to influence the market. How the market develops is not something I can decide.
I like to analyze problems from a technical perspective. Read my posts carefully, including the previous ones. Let me repeat this here: The hardware for TRICON and ICS is purchased from the same company, AUGUST. This company was acquired by ABB, and it is also this company that developed ABB’s triple-redundancy systems; it only develops the hardware. This hardware platform is a safety system platform, and as for what it can do, that depends on the software. TRICON’s hardware is suitable for ESD and F&G applications due to its SIL certification; it is also appropriate for use in railway systems thanks to its triple redundancy design. Additionally, it is suitable for use in power units, as it comes with control software packages provided by MICON Corporation. CCC develops its own hardware; since it focuses only on units, it does not pursue SIL certifications nor implement triple redundancy. To enable a fast response in unit control, the CCC’s CPU is multi-threaded and multi-tasking; in other words, three different programs run in parallel. One of these programs handles ordinary logic tasks such as performance control, load distribution, and also functions for interlock operations. Another program is dedicated to preventing stalling, while yet another is responsible for speed regulation. The execution cycle for the program related to stalling prevention is 20 ms, and that for speed regulation is 50 ms. These three programs run simultaneously, rather than being executed in sequence like in conventional systems. We can discuss the significance of this point separately. CCC won’t talk to you in great detail about its hardware, because there isn’t much to say about it; instead, it will discuss your manufacturing processes and its own process advantages. TRICON, ICS – why would they want to talk to you about hardware? Because there’s really nothing to discuss regarding its unit control. I can memorize the procedures, let alone their own people. Almost all of their flight crews use that same set of procedures; it’s just different people – those who know the crew better will be able to write the guidelines more effectively. As for the software side, there’s not much to say. Another point is that for complex processes, such as multi-valve units like those used for propylene cooling in ethylene plants, or processes that place a high emphasis on automation and disturbance control such as those involving pipelines and PTA, no company other than CCC dares to take on such projects. CCC helps you address issues related to the unit from a process perspective, such as the installation location of coolers, the installation location of valves, as well as the calculation and selection of valves, and so on. Again, you spent money on an unsuitable system just so everyone has to use it in that way? Is it just to integrate them together? Continue. . . . . .
That brother mentioned Mark VI – a system developed by GE for its own gas turbines. Thanks to their expertise, they were able to create something that was optimal for their products. If you’ve seen the control systems for GE’s gas turbines that use PLCs, you’ll realize that operating such systems isn’t something that anyone who doesn’t understand them can do easily. A single function block has 64 input pins and 32 output pins, and the functions it performs cannot be explained in just a few words. Can TRICON and ICS be as professional as GE? So don’t expect too much from them.
This post was last edited by chengf on 2013-9-11 15:09. Qingqing Zijin has a deep understanding of systems including CCC as well as others. Then, may I ask what your thoughts are on the security performance of CCC’s hardware, including the cards and the FTA cards? Because I want to figure out for myself how to choose a card.
Based on the above points, can I say that CCC has extensive experience in speed control, anti-surge control, extraction control, outlet pressure control (compressor performance control), and load distribution control? Although I do not agree with CCC’s claim that these systems can be used for surge tests in actual operations； But in terms of hardware, compared to other systems, is it still at the level of those old systems? Especially FTA
TRICON’s unit protection system is indeed quite similar to SIS, but it’s not that unacceptable to use it. The systems in our facility don’t rely on CCC, and they still work well. I have a question: if the unit and ESD systems are independent of each other, does that mean I’ll need to install two separate systems, which could lead to redundancy?
To be honest, I’m not aware of how CCC’s hardware is configured, as I’m not an agent either. I’ve only seen CCC’s pre-assembled cabinets, and I was fortunate enough to watch their engineers carry out adjustments on-site; for other reasons as well, I have only a general understanding of CCC. However, their technology remains confidential, so it’s quite impossible to gain a deeper insight into it. It is these things that I know about, which have not been seen in the plans of other companies. The FTA card functions like an IO module. I’m not sure what you mean by security; CCC’s IO modules all have fast sampling rates, and without this capability, no matter how fast the CPU is, it’s useless. This is my view on surge testing. The performance curves provided by the turbine manufacturer are estimated values, merely calculated figures that tend to be on the high side. In reality, the surge line is lower than these estimated values; surge testing is carried out to determine this actual surge line, thereby expanding the operating range. Another use of surge testing is to determine the surge line when you do not know its value. If it has to be done manually, which turbine manufacturer or user would dare to do it? CCC conducts this surge test without applying these parameters directly in practice; it is a process that involves simulation.