Among the scientists who were awarded the February 16 Science and Technology Prize not long ago are researchers of the thermal engineering institute of the State Academy of Sciences.
The researchers are the pioneers of heavy oil-free firing technology for large boilers, the first of its kind in the DPRK’s history of thermal-power generation.
Until some years ago, the thermal power stations in the country used pulverized anthracite and heavy oil to kindle fire in boilers. But heavy oil had to be imported. This hugely hindered the normal operation of boilers.
Putting an end to the history of dependence on heavy oil in the sector of thermal power generation presented itself as an urgent issue which brooked no further delay.
And in 2018 the Pukchang Thermal Power Complex promoted the project for installing additional generating equipment in order to increase the generating capacity sharply. The researchers decided not to use heavy oil at all for new boilers and buckled down to relevant work.
In the process of finding ways to ensure safe normal operation of generators and stabilize thermal strokes, they selected oxygen as igniting material.
“We fixed various design parameters, including the position of ignition point according to the density of pulverized coal and the density of oxygen needed for stable ignition, made a new oxygen-pulverized coal ignition device, completed a technology of stabilizing combustion and established an automatic control system to stabilize the combustion process in boiler furnace in real time,” said Jang Sung Jun, section chief of the institute.
In December 2018, the technology was introduced into the aforesaid complex where the installation of additional generating equipment had been completed.
The successful firing of boilers by means of oxygen and pulverized anthracite, an achievement, which was made by breaking with the existing concept that it is absolutely impossible to fire a boiler by means of domestic anthracite with less volatile substances, was as good as a revolution in the sector of thermal power generation. It meant a big stride in enhancing the Juche character and independence of the electric-power industry.
However, several problems arose in the process of operating large boilers.
Ignition in the boilers was accompanied by loud noise and shakes of their bodies and unburned pulverized coal flew away through the chimney. The generators did not fully display their capacities while consuming much coal as combustion efficiency of the boilers was lower than the standard.
At that time, workers of the complex would be worried that the boilers might be out of order, saying it was wasteful to use the coal produced at coal mines with so much effort like that.
The researchers reproached themselves seeing the workers who were deeply concerned that the precious treasure of the country was wasted.
The Pukchang Thermal Power Complex required a new heavy oil-free kindling technology.
The operation of a heavy oil-free boiler was an issue decisive of whether or not to keep running the complex, which takes a big share in the overall electric power system of the country, by relying on locally available resources.
They buckled down to a new research project.
The main thing in the research was to drastically increase the thermal output of the existing ignition devices.
“Together with field technicians and workers, we formulated a plan for the structure of the new ignition device and that for installing it and thus completed the design of oxygen-pulverized coal ignition device whose thermal output is much higher than that of the previous one,” said researcher Hyon Thae Ho.
People were amazed by the new plans completely free from the existing concept and method.
Finally, the device’s first trial ignition took place at boiler No. 1 in October 2021.
When the signal for the input of igniter No. 1 of the boiler rang, the new ignition device sent out flames and extended combustion took place as all other igniters were input in succession. The flames expanded causing no explosive combustion.
The complex introduced the new technology into boiler No. 2 as well.
As a result, the boiler combustion efficiency remarkably improved and the output of power per generator increased, making it possible to save a large amount of coal every year and increase the time of continuous operation of boilers.
Last year alone, the complex increased power production by tens of millions of kilowatts while saving large quantities of coal.
Some time ago section chief Jang Sung Jun, Merited Scientist and PhD, was selected as one of the top scientists and technicians of 2022 in the DPRK.
Now, the researchers push ahead with the introduction of the technology into other boilers of the complex at the final stage.