Sun, air, mini-CHP

The power supply of the village in Transbaikalia became a task for the participants of the "Case-in" championship.

"What you are seeing today is the tremendous work of the last four years," Artem Korolev, director of the Reliable Change Charitable Foundation, told the jury, participants and viewers.  – When it all started, there were only two of us, we worked in a coworking center, that is, there was not even a place where to spend all this time. And now the championship has been included in the government's plans. If in the first year there were only 11 universities, today there are 28 universities." The dynamics is obvious in another way: the first "call-up" was 500 people, in 2015 their number increased to 1800, while the international championship will bring together 3-3.5 thousand participants. "We have a particularly warm attitude towards this championship: please note that all five areas are represented at our university," said Alexander Afanasyev, Acting Rector of IRNTU. The members of the Energy 4-Irk team, Yana Kuzkina and Evgeny Polemshchikov, were brief in their address to the audience: "Guys, go ahead!" 

And who are the judges?

Given: the village of Batakan in the Gazimuro-Zavodsky district of the Trans-Baikal Territory with a population of about 600 people, on the territory of which there is a school, kindergarten, paramedic station, fire station, gas station, several sawmills. The power industry consists of a diesel power plant and two backup generators, a small boiler room and furnace heating, 17 transformer substations and power grids built in 1982-1983, designed to accommodate a thousand people. The task: to provide heat and electricity to the village, where in September 2018 a deep wood processing plant with a plug-in load of 750 kW, whose construction is provided for in the state program "Socio-economic Development of the Far East and the Baikal Region", is to be launched. This was the "homework" that 12 teams from the electric power industry league received 10 days before the start of the championship. On March 1, they had to present the results of their work in random order – it was determined by Vadim Fedchishin, director of the Institute of Energy at IRNTU, who was elected chairman of the jury, extracting a piece of paper with the name from the box. The presentation was given six minutes, and compliance with this limit was monitored by a young man sitting in front of the participants with a stopwatch, who could raise a sign warning that time was running out. Penalty points were awarded for exceeding the limit. The teams could receive them both for the inconsistency of the presentation with the requirements, and for the fact that the jury did not receive exhaustive answers to their questions. 

Their performances were judged not only by scientists and teachers – associate professors of the Department of "Power Supply to Industrial Enterprises" of Angarsk State Technical University Igor Golovanov and Natalia Buyakova, employees of the L.A. Melentyev Institute of Energy Systems of the Siberian Branch of the Russian Academy of Sciences Dmitry Efimov, Dmitry Krupenev and Viktor Kurbatsky, professors of the Department of Power Supply and Electrical Engineering of IRNTU Vasily Potapov and Konstantin Suslov, but also Energy practitioners: Andrey Korneev and Konstantin Molodkin, Deputy Chief Engineers of PJSC Irkutskenergo. The latter, by the way, turned out to be the strictest judge. He and the other members of the jury had to evaluate the teams' solutions in terms of their applicability in real conditions, cost-effectiveness, originality and novelty. Other criteria were also taken into account, such as the quality and presentation of the report, and the literacy of the answers to the experts' questions. 

Tesla vs. the Energy Congress

The most popular solutions proposed by the teams were the construction of a mini-thermal power plant powered by wood–processing plant waste and a solar power plant - both options were sounded three times. There were also more original projects – Angara, representing Angara State Technical University, followed the path of distributed energy and proposed to place modular solar power plants, wind turbines, diesel generators and a small hydroelectric power station in Batacan, and use two heat pumps for heat supply. The team estimated the capital costs at 50 million rubles. Another proposal – its presentation was the eleventh in a row – provided for the replacement of existing diesel power plants with 200 kW each with similar energy sources with less power, equipped with a waste gas heat recovery system, which would require investments of 48.7 million rubles. 

Two teams chose wind as an energy source for the village. Tesla's idea is to place four generators in the village and build two boiler houses with a capacity of 2.55 Gcal/h. According to their calculations, this will require 98.5 million rubles, which will pay off in nine years. The Energy Congress, which eventually took second place, estimated the payback period of its project at eight years. The team proposed to build two biofuel boilers and install a wind farm consisting of four installations, each of which, with a nominal capacity of 500 kW, will actually produce 230 kW, taking into account the local climate. At the same time, a diesel power plant remains as a backup power source. 

A non–standard combined option - a solar power plant paired with a mini–CHP plant - was mentioned in two more projects. The Smart Energy team estimated its implementation at 152 million rubles. Their colleagues from Generator have developed a project to create a virtual station combining a mini-CHP (it covers thermal loads, but also takes over part of the electricity consumption), solar panels and vertical wind turbines. At the same time, 200 kW is generated by solar energy, 300 kW is generated by wind, and another 400 kW is accounted for by a diesel power plant, which is maintained as a reserve. Investments in the project are estimated at 117.5 million rubles, with a discounted payback period of 9 years and 4 months. 

The Pchelka team, in turn, considered that the average speed of the winds blowing in the Gazimuro-Zavodsky district of Transbaikalia is low, so it would be advisable to combine a 600 kW solar power plant and five 200 kW diesel generators, ensuring their parallel operation in automatic mode. In this case, pellets can be used to generate heat, which will be produced at a new wood processing plant. This solution is relatively inexpensive – 44.2 million rubles. And the degree of its elaboration brought the team the third place. We should add that another project of a solar-diesel complex and a solar power plant was submitted to the jury.

"Drilling a well"

The Kolosok team took up their homework and prepared five solutions to the problem. Three of them are the construction of a power transmission line to connect to the Unified Energy System of Russia, the use of a diesel power plant and a mini-hydroelectric power station – shoals at once. The remaining mini-thermal power plant and a combined wind-solar station with a capacity of 1.4 MW. "Alternative generation is stochastic, so the installation of batteries is mandatory," team captain Ilya Tarasov began to explain the choice of the optimal option. – For heat supply, it was necessary to modernize the existing boiler houses. And there are still high costs for a diesel power plant – it must operate under variable loads to maintain the reference voltage on the inverters." 

There is a mini-CHP with two generators of 675 kW and two boilers of 0.7 Gcal/h. Initially, production waste from existing sawmills can serve as fuel for it, and later pellets, which will be produced at the new enterprise. It will not be necessary to install any additional equipment for this: the Batakan plant, by definition, will carry out deep processing of wood. The annual production of pellets will amount to 9 thousand tons, of which 5-6 thousand tons will be required for the operation of mini-CHP. 

– I have a short question: how much does firewood cost? Andrey Korneev asked. 

–Pellets – five thousand rubles per ton, firewood – 850 rubles per cubic meter,– came the reply. 

– Where will you get water for the thermal power plant? Konstantin Molodkin asked in his turn. 

– We are drilling a well. 

After that, the contest seemed devoid of intrigue. But, as it turned out at the award ceremony, Kolosok beat the Energy Congress by a slight margin of two points. The prize for winning such a hard–fought battle is a trip to the finals of the engineering Case Solving championship, which will be held in Moscow at the end of May. The Almaz team won the mining league, the Center of the Earth became the best in geological exploration, and the Stakhanovites won in the oil and gas business. The name of the finalist in metallurgy causes deja vu – "Diamond". But it's just a coincidence. 

Egor Shcherbakov

A source: Siberian Power Engineer