Rehabilitation in Thermal Power Plants
Today, I would like to mention about activities to increase local share of rehabilitation in the local thermal power plants. Rehabilitation is a very important activity nowadays. Public power generation companies can not finalize the ongoing rehabilitation tenders due to lack of finance as well as lack of appetite in international OEM companies to participate in tenders. Our plants are aging, and we can not have timely upgrading.
It is made public that we have thermal power plants owned by the public operating company with average age of 26 years as of today.
The existing thermal power plants are all designed to fire lignite with pulverized coal firing technology which needs relatively higher calorific value plus less moisture.
In most of our thermal power plants, pulverized coal firing is not appropriate to implement. We may have to employ/ design other firing techniques such as CFB or IGCC.
E/Ps of plants are out of service most of the time. Most of them do not have Flue Gas Desuphurisation. If E/Ps are not working properly in a thermal power plant, and if they have no flue gas desulphurization on the stacks, then it is our sincere feeling that those power plants have to be shut-down since their harm to nearby environment is greater that the expected gain in electricity generation to the national grid.
The original contractors are international boiler suppliers, mostly from East European countries. In most of their boilers, they designed the boilers with almost limited or with no expansion compensation mechanism in their boiler water tube walls. In all thermal power plant steam boiler designs, you put certain compensation detail in all directions in order to compensate the expansion.
The other major problem is created due to incoming poor quality local lignite. Plants are designed to fire lignite with higher lower heating value compared to the existing operation figures. Incoming Lignite usually have much lower heating values. Incoming lignite is to be cleaned, should be free from unburnable stones, soil, etc, should be enriched with water floating process etc.
In most of our thermal power plants, incoming coal is usually fed as received, by conveyors/ belts/machines in the open coal mine, with no cleaning, no enhancing, no screening, no upgrading, no selective mining.
So all unburnable material (stone, soil etc) are grinded with no purpose, fed into the steam boilers with no heat output. Plant is feeding unnecessary amount of supplementary fuel oil in order to fire the poor quality lignite in the boiler. That procedure also reduces operation life of ash dams.
Another important issue is that we have repeated boiler tube failures due to poor quality / cheap safety valves with undesired/ unnecessary longer time to respond. The solution is in replacing the existing poor/ cheap safety valves with better safety valves with shorter response time so that in case of any unexpected pressure increase in boiler operation, they open up in shorter time and avoid tube rapture.
The next missing issue is usually in inadequate number of soot blowers. You should clean the boiler walls in every 8-hour shift with steam wash. If they have high content of calcium in the incoming lignite, that calcium composition are stuck to boiler wall, and they have almost minimum wall cleaning due to inadequate number of steam blowing soot blowers. Result is high power output drop in a few months. They stop the power plant and clean the inside surfaces with pressured water for 1-month each time before start-up again.
So our aging thermal power plants need major rehabilitation, expansion details are to be added to all walls, especially to the roof water tube walls, more soot blowers are to be assembled, and incoming poor quality lignite has to be washed, improved, and cleaned before feeding into boilers.
In most of the cases, thermal power plant boilers have inefficient dust filters, unreasonable amount of boiler tube failures, no flue gas desulphurization etc.
Local environmentalists react, and the public enterprise in charge of power plant operation decides to cease the power plant operation in these power plants. We have almost one quarter of power plants staying idle.
Nowadays, administration wants to sell the plants to private companies. Nobody wants to purchase. All thermal power plants need rehabilitation. World Bank announce rehabilitation fund to rehabilitate the plants, with some addition by the public administration. However we understand that no party is interested.
In market economy, in complete private ownership, you do not work with a client whose performance is not good, who delivered a poor product, a poor system.
There is a saying that “you cannot cheat a client twice, three impossible.”
We have a peculiar case, where a foreign company receives a big important order to construct a high capacity power plant, they cannot satisfy the expected performance values, you do not disqualify them in the second power plant, more than that you invite them to quote for the third power plant. All three power plants are failure. Then you invite them for rehabilitation. That is unbelievable. You should disqualify them at the upfront.
Now we have a rehab tenders with high budget figures.
After evaluation of the proposals, you invite the original supplier for rehabilitation since their price is the lowest. That is again unbelievable.
Rule. You should not invite the original company to the rehabilitation tender.
Rule. You should not award the lowest price
Rule. A foreign company cannot make the rehabilitation- that is for sure
Rule. Rehabilitation has to be made by the qualified/ experienced local companies
Rule. Competitive bidding is a must. There is no easy way to receive order.
Local companies should get organized and make the correct design, appropriate design to fire the available indigenous lignite. These procedures will be enforced by third party independent inspection companies.
Rule. You should not wait that long for rehabilitation of the power plants
Local public R&D funds are to be spent for this purpose to develop local engineering and local contracting.
When young local engineers are paid properly, they work hard as elsewhere even much better for a local accomplishment
Foreign companies can escape/ leave in case of any performance failure, local companies cannot escape, they are destined to succeed
You gain local experience and expertise to use your local coal mines, as well as your own engineering capabilities in design of thermal power plants to fire your local/ indigenous lignite
Rule. Never leave your kitchen to strangers, get control over your own house kitchen
Get control over your power plants to operate properly, make design changes by yourself,
The World Bank funds are not free-of- charge, we shall pay back all together
Rehabilitation works are not so difficult, this is not space technology. We are talking about some bundles of boiler tubes. A country with F-16 fabrication plant, many plants to manufacture passenger cars, TV sets, computers, can do much more/ easier work in thermal power plants.
Our young engineers can do much better, they are no different than other counterparts, I believe that locals are above average, even much better
You will trust to your own young engineers, you give them enough hardware and software tools for proper design,
We engineers all use the similar or same software and hardware
You should support local academicians and local young engineers with public R&D funds
You should support your local companies to handle all design work,
You should not stay under mercy of foreign companies,
If you do, not at the mercy of so-called reputable European/ USA designers or contractors only, but also Chinese and Indians, or Koreans will do your own homework on your behalf,
I hope that above information will help interested parties to enable them to make their further investment and future proposal works.
Non of these local power plants are designed by local engineers however it is my sincere feeling and wish that soon in time, we shall be doing all necessary engineering/ fabrication/ site installation/ construction and smooth operation by our local engineering capability.
Create and nurture your own local engineering staff so that when you design/ manufacture/ install/ construct your own thermal power plants,
then you can always make the rehabilitation/ repowering activities, with no difficulty, without at any mercy of foreign parties.
We need to learn from our past experience whatever how nasty they might have been/ seen.
Last wording. Pay yourself first.