Читать книгу Practical Power Plant Engineering - Zark Bedalov - Страница 9

This book is a result of 50 years of practical experience from working in a number of industries with ever‐changing technologies and by associating with many experienced engineers; electrical and other engineering backgrounds.

Starting as an engineer is not easy. You are facing a big transition. I'm certain this book will help get you through the most critical phase of your development as an electrical engineer and make you the confident and knowledgeable professional that you wanted to be when you decided to be an engineer.

There are a lot of books on the market explaining the theory of electrical engineering, but there are no books on practical engineering and experience. There used to be the old Westinghouse (now ABB) TD (blue) Book and Donald Beeman, General Electric Co. 1955: Industrial Power Systems Handbook, both of which I have proudly used as a young engineer. Both books now seem to be largely outdated. Computers have taken over much of the handmade calculations.

The information contained in this book is by no means all encompassing. An attempt to present the entire subject of practical electrical engineering would be impractical. However, this book does present guidelines to provide the reader with a fundamental knowledge sufficient to understand the concepts and methods of practical design and equipment selection and operations.

The first hint of a book came in Venezuela. After three years on a job with a local engineering company heading the engineering department, I decided to move on. The boss called me with a special request, saying: “Please stay on for another 3 months and write a book on how to do electrical engineering. You seem to do this work with a lot of common sense. I thank you for your help in leading and teaching our younger engineers. So, stay on, please.”

The above dialog happened three years after seeing the movie Papillion (1978) filmed in Venezuela with Steve McQueen. The day after the movie, I fell into a snowy ditch somewhere north of Toronto. I had to leave the car and walk alone in the snow for a couple of hours in a total whiteout. A day later I spoke to my wife, we were going to Venezuela. Both of us loved the tropics and had it enough of Canadian winters.

Einstein: Theory is when everything is known but nothing works.

Experience is when everything works but no one knows why.

When we join theory and experience nothing works and no one knows why.

We quit our jobs, sold everything, and went to Caracas. “How smart was that,” I heard it many times? Once in Caracas, I left my resume with six major engineering companies and then we went to a beach. Two weeks later, we returned to the Hotel Sabana Grande in Caracas. The owner said that I had many calls. I had five job interviews and took a job with a company that had a contract to build a 4 × 400 MW power plant. They badly needed an experienced electrical engineer. At that time, I had about 10 years of experience with a great company called Shawinigan Engineering from Montreal, Canada. That company was later taken over by SNC‐Lavalin, Inc., my last employer.

Three years later, after the plant was built, I told my Venezuelan boss that I enjoyed it greatly, but I gotta be moving on. I moved on to Riyadh, Saudi Arabia. It was 1981. It seemed I was at the right place at the right time. There was so much going on in Saudia. At that time, some large generation existed in the Eastern province for oil production and barely in the cities of Riyadh and Jeddah. We began the electrification of the country in a major way. After Saudia, I went to several other international posts with companies like Fluor and Bechtel. Finally, I ended up with SNC‐Lavalin for the past 17 years as a commissioning engineer. That makes it a total of 50 years as a lead design and commissioning engineer for power plants, heavy industrial plants, and power systems. Of that, 10 years were as an independent engineer on my own.

In the years after Venezuela, I often lectured younger engineers on many engineering issues and had discussions with companies to create a manual that would help their electrical engineers to follow and practice good engineering. It took a while. Finally, in 2015, I agreed to do a book. It took me one and half years to complete a draft copy. Now, it is here in your hands.

As an experienced electrical engineer I have noted huge obstacles young engineers were facing to become experienced engineers. I'm not talking about civil or mechanical, but electrical engineers. Let me explain. For mechanical engineers, everything is visible. Here's a pump, pipe, valve, filter, and strainer. All of it, recognizable objects. What's on the drawing is what you see in the real life. Open a valve and water or oil flows. You see it, hear it. If it leaks, you see it and you replace a gasket or clean a clogged filter.

Electrical engineers, however, in the same environment face an invisible world. Some call it “The mystery world”. You may be able to recognize a few pieces of equipment from the drawings, but this is not what matters. In the electrical engineering, it is what you don't see that matters. If something goes wrong, you don't know which way to look. There are no electrons anywhere to be seen? Where do you start? Well, the first several years will be difficult, but with some experience and guidance, you start seeing the invisible. One young engineer told me that he came to his first job interview ready to solve a bunch of differential equations, but all that school teaching didn't seem to matter.

It is clear that mechanical engineers have a head start in the plants and the plant designs. Right off the bat, they are confident about themselves, of what they are seeing, doing, and learning. They will eventually become project managers and will boss the electrical engineers. I have seen this over and over again, anywhere in the world. Young mechanical engineers talk job immediately with confidence and are liked by the bosses because they talk the same language. Meanwhile electrical engineers are fearful to ask questions or suggest anything. They struggle for years. The bosses seem don't know how to talk to them.

So, while our mechanical engineering colleagues confidently talk about the things they do, and advance in their experience and carriers, we the electrical engineers appear shy and aimless, struggling in the world that has no resemblance to what we studied so diligently for many years.

Even the language is different. Here come buzzwords. Everyone uses buzzwords and most of them you don't understand. If that is bad enough, it gets even worse. Young mechanical engineers appear to be smarter. They seem to be learning faster every day in their visual world. As they say, a picture is worth 1000 words. On the other hand, a young electrical engineer gets very little visual information and thus retains less. Mechanical engineers are immediately immersed into the overall (big) picture of the plant, while the electrical engineers are pinned down to look at details.

Without an experienced engineer to explain things and to guide him, a young electrical engineer is lost. It would help if he only knew the questions. Not even that. He goes home after work and wonders: What is the reason for having me there? Will I ever be useful?

Let me give you an idea what happens on your first day on the job. You graduated from a difficult faculty of electrical engineering. It was tough and struggle, but you studied hard and endured, and felt you were on the top of the world. The world is yours. What a great feeling of accomplishment and exuberation that you can do anything.

Then you start looking for a job, and soon realize that the world is not all yours. The employers are not looking at your grades but at your experience, of which you have not much to show for. You cannot choose your job and will be happy to take anything that comes along. Finally, after three months of job searching, an engineering company was willing to give you a try.

You will be working on a new project. On the first day, you are introduced to your colleagues from all the disciplines and given a lot of drawings and reports to read. The material is mostly process and mechanical, to give you an orientation of what the project is all about. You were also told to talk to everyone and ask any questions you might have regarding the material you were reading as well as to acquaint yourself with the things the others were doing.

Then after a month of “doing nothing” your lead electrical engineer gives you for instance a couple of tender documents for a 10 MVA transformer just received from the bidders. One is for a transformer with 8% impedance and the other with 9.5%. The first one is more expensive than the other. The Lead tells you to evaluate the cost benefit of one over the other and if you have any questions feel free to ask. Since you were a junior engineer and need a bit of a help, he reminds you that the larger impedance causes more Watt and Var losses and higher voltage drop, while the lower impedance allows for higher fault level on the downstream bus, which may force the project to use more expensive equipment.

Wow, what now? That day back at home you look through your text books and find nothing relevant to help you out. Well, of course not. The text books tell you about the transformers and the transformation in general, but nothing specific for a particular application. That may be the last time you looked at your school books.

This actually is your first day at work. Remember that exuberating feeling when you graduated? You could do anything? Well, your Lead lowered you down to the real world. Now you feel hopeless and lacking confidence. You start asking questions all around and gradually acquire some knowledge but you are still far away from being able to decide which transformer to recommend. Fortunately, your Lead had already made that decision. Of course, he wouldn't let his junior engineer to decide on such an important matter. He just wanted to test you on how you think, how you formulate your questions, and how you deal with the engineers around you.

Welcome to the job. It'll be tough and it'll take time. All of us have started like this. You'll be doing fine if you immerse yourself into the project and start building up your practical experience over several years of working with experienced engineers on a variety of projects. This also includes those of other disciplines to learn what is important to them and how to select the electrical equipment to drive and automate their equipment. This real world book will help you get there.

This book is a result of 50 years of design and field engineering by experienced engineers and teaching others to do the same. As an experienced engineer with acquired practical knowledge, I'm ready to share it with the new coming engineers and lead them through a transition for which there is no blueprint or book, until now. This book provides useful information as a reference guide for all the electrical engineers. It fills the gap between the Academia and being an experienced engineer. If you read this book, you will learn a half of it you need to know and all the proper questions you should ask.

Hopefully this book will spawn others to write books. Your first job is a step into the open, away from your school. As soon as you start reading it, you realize this is a different world and it won't be easy. I agree, it won't be easy, but this unique book in your hands will give you a kick start, help you interact with other engineers and understand what is going on in the design office and in the field around you.

Why not searching on Google? Yes, there is plenty of this stuff and hundreds of answers on the internet. Well, if you only knew what you were looking for and had knowledge to properly assess it for your application? Without proper feedback, you don't know what is right and what is wrong and how to resolve doubts. “The Internet often seems to be a source of befuddlement rather than enlightenment,” as Gregg Easterbrook eloquently put it in his outstanding book “Sonic Boom.” This book gets straight to the point of what you need to know.

It's not an easy task to cover all the electrical engineering activities into a single readable 500+ page book. Many chapters would require a book by itself. The goal was to summarize the engineering activities and to direct the reader onto the right path and base from which he (she) can build experience needed to make proper engineering decisions. Everything in it, this author has experienced and then confirmed through commissioning and discussions with other engineers.

The theory is essential. It forms your basic knowledge fundamentals. The fact is this; our professors teach us to become professors. That's fair enough. The best students in our class became professors. An engineer you become with practical experience by associating with other engineers, facing multiple engineering applications and problems, making mistakes and reaching accomplishments.

Recently, I spoke to a professor about Variable frequency drives (VFDs), Chapter 15. I was telling him how I use them to regulate the plant flows on demand so I can employ smaller storage tanks, etc., while he was talking about flux vectors inside the rectifiers. “I'm not trying to make rectifiers. I'm just applying them for various useful plant applications,” I told him? That's the difference. Because of this issue, many engineering schools are changing. Nowadays, students are forced to work between the semesters. Students are telling me that it's a hard go, as it is not easy to land summer jobs as unfinished engineers.

If you happen to get a job with a manufacturer, your life may be a bit easier. You will be trained for a specific job to work on some electrical equipment, such as improving a lightning arrester, rectifier, or a grounding switch. Soon, you will notice that designing a piece of electrical equipment is mostly of making it smaller, cooler, and with different materials. Then, you also realize that the job is 10% electrical and 90% mechanical engineering, and start wondering: “Is that it?” Well, maybe you'll like it. I didn't.

I graduated with a diploma on power transformers. My first job for two years was mostly how to make better cooling for transformers. I worked on hollow conductors for cooling water passing through them. There was nothing electrical about that. Why didn't they hire a mechanical engineer to do that, I wondered? On the other hand, if you get a job to design power systems for various plants it's a different story. It's an electrical story.

So, between you and me, I had enough of mechanical engineering and them taking advantage of us and bossing us around by saying; “I was not smart enough, so I went into mechanical engineering.” I heard that line a lot. With this book, I want to even out the playing field and help you young electrical engineers stand your ground, be productive, and contribute almost immediately.

One of my first job interviews was at Toronto Hydro. An engineer showed me a picture and asked me if I knew what it was? I saw six bushings and said that it was a transformer. I was wrong. It was a high voltage oil circuit breaker. I failed that job interview. I should have known that a breaker had six identical insulators. Transformer has 3 + 3 unequal bushings.

I moved on, looking for my first job in Canada and ended up at Pinkerton Glass for a job interview. A secretary gave me a test sheet to fill in before meeting an engineer. The sheet said “Practical test for electricians.” I filled it up as best as I could, guessing on a half of it. I failed that one too. None of those famous differential equations could have helped me. It was so bad; the Engineer didn't even waste his time to see me.

Many years later I was already an experienced engineer. Our company, Fluor, had a project with the Xerox Corp. in NY State. As a lead electrical engineer I was invited to visit the plant and scope the work for adding a new ink toner line to the existing plant. We started touring this large plant. As an electrical engineer I prefer to look first at the plant overall one line diagram. This is the Chapter 2 in this book. Having acquired the big picture, then I visit the plant and observe it from my electrical perspective. Well, anyway, we started touring as soon as I got there. The mechanical engineer, my tour guide, looked at me and said: “You are an electrical engineer, right?”

“Yes, any problem with that,” I answered jokingly?

“No nothing, but, let me pass one by you. Here we have a problem,” he started talking. “We've been struggling for 2 years now with it. Occasionally, we have light flickers in the plant. It happens suddenly and then nothing for a few days and then again. The whole plant flickers and then everything is back to normal. Do you have any suggestion what that might be,” he asked?

“I really don't know. It can be anything,” I answered. “Does it happen at night or day, high load, low load,” I inquired? Suddenly, I realized I was in an invisible world of electrical engineering.

“Well, I agree,” the plant engineer said. “It's unpredictable; anytime. We checked it with the local utility. They said that it must be something internal within our plant as they don't experience flickers on their system.”

“If I were you I would look at the main transformer since the whole plant is flickering. It may be coming from there,” I said. “Otherwise, you may have to shut down the plant and megger all the major electrical equipment, starting from the incoming transformer.”

“Hmm, I'll mention it to my electrician,” he answered.

So much for that, I thought. We continued touring and got into a rather noisy room. My guide pointed to their 2000 HP, 5 kV compressor, the biggest drive in the plant. I came closer to the compressor and spotted a drop of oil below its big cabinet on which it read: “Surge Pack.” I told him that there was no reason for the oil to be on the floor here and suggested that if he wouldn't mind we open the cabinet.

“Don't worry about the oil, I'll call our cleaning staff to clean it up,” my tour guide mentioned it somewhat embarrassed. I insisted and we opened the cabinet. Inside it I saw more oil, obviously leaking from the surge capacitor. I turned to him and said: “This may be your source of flicker. The capacitor is leaking and occasionally breaks down and creates a brief short circuit to discharge itself.”

Weeks later, he called me and thanked me for the discovery. They replaced the capacitor and, thank goodness, resolved the issue. I wrote back to him, “We were lucky to be in the room before the cleaning lady had a chance to remove the oil drop. Please don't fire that lady.”

In the invisible electrical world, you often have to be lucky.

Read this book and practice it. If you have read it and understood 80% of it, you don't need more schooling, though it would help. Not even calculus. I have nothing against math. I was pretty good at it. Nowadays, since the use of computers for power system studies, the highest level of math I have used was and cos φ on my calculator. True, I have been using “per unit” a lot in my conservative short circuit fault calculations, though. Most of all, I needed know how to prepare estimates for various project options and calculate percentage power losses or voltage drops in power lines. And, of course, it was always important to be able to answer questions right on the spot during the project meetings with the project owners.

This book will not make you an expert on any of these subjects. For that you will need a lot of experience and hopefully some good mentoring. But it will give you a good start and capability to discuss the subject with some confidence and ask good questions during your job interviews. With this knowledge, you can start your job from a solid base, rather than starting from nothing.

Hopefully, this book will point to you the path on how engineers think in planning and resolving the problems and the basic elements of the engineering considerations; scope of work – big picture, engineering tasks, economics (cost of equipment and production), reliability, and automation requirements.

A few more notes.

As a junior engineer, I grasped from other engineers the concept of looking at the big picture, and what matters, while leaving other things for later. These are likely to change anyway, so why bother thinking of them now. Looking at a big picture means developing a design criteria for all parts of the project right at the start, such as, determining the short circuit levels (by computer) at various plant busses, allowable voltage drops, outage contingencies, big motor start, etc. Then, I develop overall key one line diagram. Once I have done that and have it on paper, I have my base and reference and talking points for everything that fits inside. It's not frozen in concrete. I can adapt it as I go along. If you do this once, you can replicate it again and again on other projects, based on the clients' requirements and new requests, capacity of production and levels of automation and security demanded.

Most employers do look for individuals who talk in terms of looking forward and grasping the whole concept of the project. One day at SNC‐Lavalin, I had a chance to see my file they made after my job interview and it read, “Impressive view of looking at big picture.”

Also, as a beginner engineer, I was once interviewed by an American company. In their books of potential candidates, next to my name was written: “Capable of looking and seeing a bigger picture. Hire him, when opportunity comes up.” I heard that little jewel from a head hunter who called me up and offered me other positions. Head hunters dig out their information from their contacts in the HR (Human Resources) of the companies they deal with. I was not born with it. I looked up to and learned it from other engineers who had impressed me.

When you do your work, share it with others. Be a team worker to be able to succeed in this type of work. There are other disciplines involved on the project and often you will find out something that will help you make a proper decision or make a modification you didn't notice before. So, be a team player. Then, when you are done with an assignment, tell your boss that you are done. He loves to hear that. If you are holding it back, soon it will be noticed. Bosses like to hold onto their best producers and keep them busy.

When you are finished with your assignment, tell your lead engineer to give you feedback. Don't be afraid of his review. Don't work in isolation. Share the ownership of your assignment with him. Involve him as you work on it. He will appreciate that. Besides, he is likely far more experienced than you are and experience is what counts in electrical engineering. He may have a different approach for certain parts. Broaden your thinking, evaluate his input and implement it if beneficial and more economical.

Always show interest. I was always curious. As a kid I wanted to be an engineer. Being a medical doctor also crossed my mind. Later on I realized that being a doctor would have been a mistake. I was not made for it. I function by logical thinking. I don't want to learn anything by heart. I learn and gain experience through logical interaction. Most of it was by observing and listening to others. Being interested puts you in front of the events. Many a time I was sent to investigate a situation about which I had not a clue. Nobody else on the project had a clue either. So, others rejected it and declined to be involved. I always went for it, tried my best and most of the time I found solutions.

Enjoy engineering. This has been your biggest investment so far. Go for it.

Vancouver, BC, Canada

16 June 2019

Zark Bedalov