Friday, May 29, 2015
"60-days non-stop operation" Acceptance Requirement for New Thermal Power Plants.
Thermal power plants are designed to operate at least for 30-years. In practice, they do not exceed 20-year operation. Those exceeding 10-years operation without major overhaul are in limited numbers. Today, with inexpensive design and poor material applications, those plants which are supplied and installed by east Asian contractors merely pass 2-3 year temporary (trial) acceptance period without major shutdown.
These new power plants are designed to poor specs, poor quality norms. They have insufficient number of spare parts, computer programs for instrumentation and control of the combustion are not capable, coal mills and electrostatic dust precipitator electrodes are eroded fast. Blowers and fans do not work properly. Electrostatic dust precipitators are designed so small that they do not meet necessary international minimum stack emission criteria, flue gas desulphurization systems do not properly work.
Everything is indexed to the plant design to keep the overall price very cheap. Such products, designs, thermal power plants, are not seen in Western Europe, not in North America. Why do we deserve such poor plants with poor operation? Why don't our regulatory authorities avoid and interfere such poor applications? Why don't local companies design, manufacture, construct new power plants? What is avoiding us?
In the past decades, Turkish Electricity Authority had famous "60-day non-stop operation" rule prior to temporary acceptance certificate of the new thermal power plants. Before two-year temporary acceptance period, power plant contractors are to prove the quality of their new plant with "60-day non-stop operation", so that seller would prove the reliability of the system they were delivering. Turkish Electricity Authority is unbundled into 4-different companies, so in the end the electricity generating company EÜAŞ still has this requirement in their purchasing specs but Company has no budget for new power plant investments. Let us review how to implement "60-day non-stop" operation in details.
- New thermal power plant is expected to operate 72-hours non-stop at full capacity,
- Within 60-days trial period, plant is expected to operate at minimum 75% capacity,
- Within 60-days, plant should not stop (trip) more that 5 times in continuous operation, and those interruptions should not exceed 24-hours.
- If the thermal power plant can not meet those two conditions within 60-days of trial run, then contractor is to make necessary plant improvements and restart again.
- Two-year temporary acceptance period starts after successful completion of the 60-days nonstop performance test.
In two year temporary (trial) period prior to final acceptance of the power plant, plant should work at least 5000 hours at maximum continuous load without interruption, and 50% load must be satisfied within 3000 hours of operation.
Public thermal power plants are tested in accordance with German DIN-1942, and DIN-1943 for steam boiler and turbine generator respectively. These conditions are later modified with new US based EPRI rules and updated. In local "Electrical Installations Acceptance Regulation" as released in our Official Gazette in year 1995, No. 22280, there are many tests, rules and regulations listed for final acceptance, but "60-days of non-stop operation" requirement is not covered any more.
Today, new power plant investments are realized by private investor companies. They are buying the cheapest plants and equipment available in the international markets, which are mostly supplied by east Asian contractors. Suppliers are to present their supplier credit financing for the projects they are selling in international markets. Since financing is the key factor of the contract, the local investor company accepts whatever is delivered. Electricity generated during test run is delivered to the national grid free-of-charge, so that private investors prefer to shorten that test period into 10-30 days, instead of 60-days.
These de-facto purchase procedures are not correct in the long run. After barely working for 2-3 years, the new plant plants become problematic. They can not be operated further without having major overhaul, expensive and time consuming rehabilitation. They need renewal of equipment, instrumentations, new spare parts, coal mill grinders, e/p electrodes, fans, blowers, new feedwater pumps etc.
"I'm not rich enough to buy cheap things" is an old English saying. This is very wise saying that would be found in all languages in a different form. One should hire independent reliable audit institutions to monitor and record the plant acceptance test, and should implement "60-day non-stop operation" rules, prior to temporary acceptance of the new power plants, thermal, nuclear, or any other applicable.
All in all, the plant design with appropriate domestic coal firing thermal power plants can not be left to the mercy of the foreign companies, that could escape the country immediately after delivery. Domestic companies should lead the power plant contracts with local project financing services. Oberstdorf, Germany, 30 May 2015
Haluk Direskeneli, is a graduate of METU Mechanical Engineering department (1973). He worked in public, private enterprises, USA Turkish JV companies (B&W, CSWI, AEP), in fabrication, basic and detail design, marketing, sales and project management of thermal power plants. He is currently working as freelance consultant/ energy analyst with thermal power plants basic/ detail design software expertise for private engineering companies, investors, universities and research institutions. He is a member of ODTÜ Alumni and Chamber of Turkish Mechanical Engineers Energy Working Group.