Here is a turbine engineer web site.
While dealing with the Cocohouse web site built a bit of web design skills.
Internet is a great thing that made our world smaller and all human kind closer to each other. As turbine people are also some sort of human kind internet made all of us closer as well. 🙂
Hence I decided to put online some of my turbine (control) expertise gained through a lifetime of hands-on experience in the power engineering. To be used by turbine engineers or anybody who wants to become one.
Putting online some papers and web applications that are available for your non-commercial use. The applications are listed and briefly explained below:
- Steam Turbine Thermodynamic
A simplified core steam turbine design. The calculus is based on input steam parameters and design conditions. It predicts the design operating point and the expected output. It also calculates any off- design operating point and predicted output in a case of inlet pressure deviates from the rated one. This kind of assessment is particularly required in geothermal engineering world.
- ThreeP (bang-bang)
A time simulation with a bang-bang loop controlling the water level in a vessel. Was taught this type of bang-bang loop by my teacher prof Sherman back than at the university. Believe it is quite superior to whatever I’ve seen around since. This application allows you to tune the whole thing, play with it and understand how ThreeP works.
- TMC Playground
TMC stands for Turbo Machinery Controls. This application demonstrate some basic TMC features. It simulates two turbo-generators that can operate in all kind of real life scenarios. Also demonstrates some advanced load sharing features that I developed through the years of dealing with the matter. Its User Manuals explain well how to go around the playground.
- Synch Playground
This application simulates synchronizing generator to grid in a manual mode as it ones used to be. These days AutoSynch unit does it all by itself. The simulation gives operators and engineers idea of what is actually happening during synchronizing process. It has its User’s Manual as well.
There is also a part here called Linear Control Theory. That part was put together by prof. Šerman with me just shaping it up for the web publishing on this site. Had a privilege to be his uni student and later on worked together through some tough projects.
Here are few presentations covering turbine control basics. They are focused onto the process aspect of the whole turbine control thing.
These days I see sharp young guys with a deep and detail PLC knowledge doing controls. Sometimes I don’t see the same strength at the process control side.
That is easily understood as the PLC technology is so easily accessible these days. Just Google alone can bring you to all the nitty gritties of, Siemens, Allan Bradley, ABB, Honeywell, and others.
However, with the process control expertise it’s much harder to get on top of it. It gets to you only through years of hands on dealing with the matter.
Hence, here are some basic process control things related to turbine controls. It is put into three presentations already delivered to their targeted audience a year ago. The feedback was quite positive all together.
The presentation are:
- TURBINE CONTROLS BASICS;
- TECHNICAL THERMODYNAMIC
Selected Fundamentals Related To Steam Turbine Controls;
- STEAM TURBINE CONTROLS;
Click to cover page link gets you to each of their .pdf versions.
Turbomehanika successfully retrofitted the controls for two identical steam turbine trains that are parts of the Old Nitric Acid plant in Petrokemija Kutina. The trains are manufactured by Escher Wyss and commissioned back in 1968. Operating continuously since. Each train consists of a steam turbine, two process compressors and a gas expander all coupled together. The steam turbine being the main drive with the expander supplementing it by expanding the process product gasses through.
The scope of the retrofit was to replace the existing steam turbine control and the compressors antisurge protection with a new PLC based Integrated Turbine Compressor Controls (ITCC) system. Siemens SIMATIC S7-1500 PLC together with Bently Nevada Adapt 3701/55 ESD are used as the PLC hardware.
Turbomehanika have been the main contractor for the job with Arirang and Intea being subcontractors.
The Old Control System
The old control system consisted of hydraulic turbine controls and compressor antisurge protection. They were both using the same 7barg hydraulic/lube oil system.
Steam Turbine Controls had a flywheel isochronous governor operating three steam control valves actuated by a linear hydraulic servomotor. The governor and the trip unit were both integrated together at the steam turbine front pedestrian. The project spec required to use the existing trip device. Separating one from each other was quite a challenging task that required gaining a deep knowledge of the Escher Wyss control concept. The governor was cut out while the trip device and the servomotor remained a part of the current system.
Compressor Antisurge System had a control unit and the blow-off valve operated by a hydraulic servomotor. The control unit was cut out while the blow-off valve with its servomotor remained parts of the current ITCC.
All through the recent years the customer were keep experiencing issues with the antisurge controls. It would open the blow-off valve when it was not supposed to causing costly plant shutdowns. While commissioning the new controls we found that in some operating modes compressors are expected to run quite near to the surge region. The old antisurge controls were most probably not being able to deal with that operating situation.
Continue reading “STEAM TURBINE ITCC RETROFIT IN PETROKEMIJA KUTINA”
A.Kostyuk and V.Frolov, STEAM AND GAS TURBINES
At university they taught us turbine theory and practice using this book.
It was also used as guidance to my older colleagues when they were establishing Jugoturbina turbine design practice.
This is “the” book for learning turbines if you are limited to the English language as myself.
The steam turbine section has a lot of details, numbers, examples. Following those you would be able design a turbine for real.
The gas turbine section presents you with the basics that can be easily extrapolated to wherever are your needs.
I haven’t been involved with geothermal power field since year 2000.
Here is what we did for the Wayang Windu project in Indonesia.
At the time Fuji Electric installed there the largest geothermal steam turbine ever, though it might not be the largest any more.
We implemented a concept not previously used in geothermal plant control. Used “turbine follow” approach, used normally in conventional and nuclear plants. Worked well at the end.
Like all new ideas it was not accepted without some resistance.
I gave the technology and supervised the engineering. however, there were many others pushing it through. Some of them are in the paper authors list.
In the meantime Fuji Electric installed another unit there. Guess they extended the integrated concept further. Would like to hear from my Fuji Electric friends how that all went through.
( A STUDY BASED ON TURBINE OVERSPEED PROTECTION )
Virtually all turbines are required to operate either at a fixed speed or over a range of fix speeds. Operating speed can range from less than 100 RPM for low head hydro turbines to up to 500,000 RPM for some micro gas turbines. The operating speed is held constant by ensuring that the input power matches the power needed by the driven machine. That balance is maintained by control system usually called the “governor”.
Relying on the governor only is not sufficient to guarantee safe turbine operation. Since the early turbine designs there have always been two independent systems responsible for keeping turbine within the safe operating speed range, they are governor and overspeed protection.
The first governors and overspeed units were mechanical devices. Further on hydraulics took over, later on to be replaced by analog electronic. However, these days governors and overspeed units are normally PLC devices driven by a specially designed software.
Since PLC took over turbine control there is always a discussion on how fast the PLC needs to be to do the job.
This paper is dealing with the same issue. It is trying to quantify overspeed protection requirements for prompt reaction. It is done by combining real world data with dynamic modelling and simulating.
Continue reading “HOW FAST NEEDS TO BE TURBINE PLC GOVERNOR?”