Huafeng Weiye Company Thailand NPP5A Project Completes Boiler Blowing Task
At local time 11:28 a.m. of November 20th, 2014, the blowing task of Huafeng Weiye Company Thailand NPP5A Project 1×98MW New Constructed Steam Turbine Generator Unit was finished, and this means the NPP5A unit is moving into the whole start-up period.
The weather and environment of Thailand in November is really hot and tough, and the temperature is above 40℃ in average. The commissioning staff of Huafeng Weiye Company was leaded by the commissioning chief engineer of the project, developed the spirit of ‘initiative, responsible, insist’, overcame the difficulties including tight work period, large work load and terrible environment, worked hardly for 5 days from the day of November 15th, finally finished the blowing task on November 20th, and the main indicators including blowing factors and graininess of target plate were all achieved to good standards.
The steam pipe system of this project is coupled made, and the owner disagreed to do the blowing in single way, so after discussion and negotiation, the blowing was taken in the way of coupled made pressure stabilizing for the main steam pipe and bypass, and the blowing would be divided into two periods. When doing the blowing, the pressure of high pressure main steam header was maintained in 4.0 – 6.0Mpa, and the temperature was about 400℃. After full warming the pipe, the pressure of main steam pipe was rose to 0.2Mpa for blowing the main steam supply pressure-equalizing box, bypass supply gland seal and bypass system, and the blowing included 5 times, every time would be in 20 minutes. After finishing the blowing of bypass and gland seal system, the main steam pipe pressure was rose to 0.2Mpa and 0.4Mpa gradually for test blowing after calculating the blowing factors. With the precondition of nothing wrong with the blowing system, the main steam pipe pressure was rose to 0.7 – 0.8Mpa to do the formal blowing of the main steam pipe, and every steady pressure blowing was lasted in 20 – 30 minutes. After 18 times blowing and 2 times target plate checking, the representative of owner and plant accepted the work on site. There were two periods of the blowing work. After the first steady pressure blowing for 3 times, at 18:10 of 15th, the first blowing period was finished, and after cooling for 12hs of main steam pipe, at 10:23 of 16th, the second blowing was did. Finally at 11:28 of 20th, the indicators of target plate were good, and this means the blowing task was successfully completed.
In order to guarantee the process of blowing, the commissioning chief engineer came to the site for leading and inspecting, communicated with all parties, controlled and managed the whole process of blowing test, and made specific <Technical Measures for Preventing Emergency> to require the operators. During the blowing period, the boiler commissioning staff of the project inspected and guided the work in the control room of the owner, traced the commissioning 24 to 7, operated the process according to the commissioning measurements and operation rules strictly, communicated and solved the problems timely, so the whole process had no emergency about drum full water, lack of water or over temperature of wall. By doing the steam blowing for pipe, cleaning the dust inside of the pipe of equipment, the potential hazard was cleared, and that also made firm foundation for the following thermoelectrical unit whole start-up and 72+24 test running works.