EVN requires that the reserve volume of coal warehouses of such plants must be sufficient to operate for at least 10 days
Shortage of coal fuel...
According to the Electricity Supply Plan and operation of the National Grid in 2020 as approved by the Ministry of Industry and Trade, based on calculations, hydrological frequency of 65%, the electricity output of the whole system in 2020 is estimated at VND 261.45 billion kWh, an increase of about 9% compared to 2019. However, the actual water level of hydroelectric reservoirs is lower than the frequency of 65%, EVN is forced to use other fuel sources such as coal, oil etc. In fact, for the last 10 years, EVN has never ever operated all coal-fired power plants of the Group to meet operation requirements, which is equivalent to the maximum capacity (Tmax) of over 7000 hours/year. Therefore, this is a heavy responsibility containing significant challenges for 12 coal-fired power plants of EVN.
Ensuring a stable source of coal fuel for power generation is the first “difficult problem” that power plants must face. The shortage of coal source is no longer a forecast or warning, it is a painful reality, the total coal demand for electricity generation in 2020 is calculated at 67 million tons; however, the coal exploitation output of Dong Bac Corporation and Vietnam National Coal and Mineral Industries Group (TKV) only meets about a half of it, which is about 32 - 35 million tons. Vietnam lacks more than 30 million tons of coal for electricity generation, including many different types such as anthracite coal, bituminous coal and sub-bituminous coal. Import of coal is considered to be the only “way out”. However, this is a rough way.
According to information provided by the EVN’s Technical and Production Department, the import is particularly difficult for anthracite coal type, because the output of this coal type only accounts for about 3% of the world market. For bituminous coal and sub-sbitum coal, the import is “easier” due to its abundant supply sources.
In order to solve difficulties of “inputs”, EVN has directed Power Generation Corporations and other power plants to import coal in the form of international bidding with short-term and medium-term contracts. Therefore, at the same time, there are many coal suppliers for a power plant. At the same time, EVN also requires plant units to proactively provide and import coal for power generation according to the plan in the dry season and during the whole year; the backup volume must be sufficient for operation for at least 10 days. Regarding to TKV and Dong Bac Corporation, EVN's plant units shall discuss and agree to sign long-term coal supply contracts. In addition, the coal quality is also an important factor. Experience has shown that coal sources supplied by partners of TKV, Dong Bac Corporation for EVN’s power plants are mixed coal. Meanwhile, most of EVN's power plants are designed to operate with standards of anthracite coal. The change of the fuel source quality will cause problems in the reliable operations of plant units. In order to solve this problem, EVN’s General Director, Mr. Tran Dinh Nhan has directly worked with partners of TKV, Dong Bac Corporation and required to guarantee the standards of coal supply sources right from sellers, towards the common target of ensuring the national energy security.
Engineers strictly comply with operation procedures
Strict operation procedures
To meet operational requirements of more than 7000 hours (Tmax/year), all power plants must ensure the availability, availability coefficients of plant units of more than 97%. However, in practice, some power plants are obsolete, or some power plants are new but their equipment has not operated smoothly. In 2019, to “solve difficulties”, EVN’s Deputy General Director, Mr. Ngo Son Hai has worked with each power plant and checked actual operation conditions, and also provided specific and close instructions. Power plants are required to minimize incidents, especially avoid repeated incidents or other serious incidents that can stop the operation. The Corporation has also directed to timely establish calibration teams for each power plant, performing supervision tasks of operation regimes, operation situations, quality control of input coal, thereby making timely adjustments in terms of electricity production without causing any incident.
At power plants, many plant units have also actively applied solutions to ensure the safe, reliable and continuous operation of their units. For example, at Duyen Hai Thermal Power Company, the Director, Mr. Nguyen Van Thu said that with Duyen Hai 1 Thermal Power Plant and Duyen Hai 3 Thermal Power Plant, the Company has prepared detailed plans and implemented strict inspection measures for the performance of economic and technical indicators in each hour and each day. At the same time, the expert model is carried out in parallel with the production process to assure the availability of plant units and equipment.
At Vinh Tan 2 Thermal Power Plant, the plant has thoroughly grasped and improved operation procedures, improving the inspection and monitoring operation conditions of equipment, timely finding out unexpected defects and errors. The plant regularly performs industrial cleaning methods in areas and systems to control coal dust that can affect the equipment's service life. Vinh Tan 2 Thermal Power Plant also closely works with EVN GENCO 3 Power Plant Repair Service Company to timely repair failures of equipment to prevent severe damage from the production.
In addition, power plants’ schedules of overhauls, maintenance and repair completion have been arranged by the National Load Dispatch Center from the end of 2019. Many plants have actively implemented repair and maintenance solutions according to the Reliability-centered maintenance (RCM), thereby shortening the repair time, increasing the operation hours of plant units, ensuring effective electricity production.
In addition to the Corporation’s efforts, EVN also proposes the Commission for the Management of State Capital at Enterprises and Ministry of Industry and Trade to direct TKV, Dong Bac Corporation to strictly comply with the Coal supply chart as approved, giving priority to coal for electricity generation. At the same time, power plants apart from EVN are also directed to have plans to ensure fuel sources and be ready to meet high consumption demands to generally implement the target of ensuring the electricity production for socio-economic development in 2020.