Warmth cycle: How Moscow flats are heated

Warmth cycle: How Moscow flats are heated
The heating season has started in Moscow. The city’s buildings are completely ready. This mos.ru article describes where the heat comes from and how it gets into Moscow’s buildings.

Where heat comes from

Powerful TETS 12 (thermal heating station), one of sixteen power stations, can be seen from Berezhkovskaya Embankment. A pass is needed to enter the plant, but everything is even more impressive inside the gate. The best way to get around the grounds is by car. Turbines, generators, boilers, pipes and other equipment fill multi-level production areas: this is how Moscow flats are heated during the autumn, winter and spring.

Steam and gas turbines, heat recovery boilers and other equipment reside in the engine room of the PGU-220 combined cycle gas turbine’s power unit. Moscow heating stations operate in electricity and heat combined generating mode. To produce thermal energy, steam is generated by turbines and released to horizontal heating grids. The water that runs through the grids is heated and then pumped to the city heating system under pressure.

This power unit is fully automatic, and the continuous process is monitored in the control room. Monitors located on the walls and operators’ desks show information on the parameters and working modes of the equipment. If a problem arises, the technicians will be able to mitigate it quickly. It is interesting that the heating stations can switch to heating mode any time, even in the summer if necessary: the equipment is always ready to go.

Moscow residential and public buildings have been receiving heat since 28 September, after public requests.

“At this point, the heating of schools and health facilities is completely covered, and the heating of residential buildings is almost completed,” Deputy Mayor of Moscow Government on Housing, Utilities and Improvement Pyotr Biryukov said.

According to the city’s heating plan, MOEK ensures heat distribution to a building, and then the owners of building or the management companies are responsible for the internal distribution of the heat.

“It is a difficult and intense period for the utility workers. Operators supervise the correct temperature increase in the heat carrier (water) around the clock. This is very important, because if the temperature schedule is not observed, serious problems can occur. We control this strictly,” Head of the Department of Housing and Utilities Gasan Gasangadzhiyev said.

The current PGU-220 combined cycle gas turbine’s power unit was installed at TETS 12 in 2015. With this upgrade, the plant’s capacity increased by over 50 percent.

Heat is on the way

The heat carrier (water) is sent to pump stations (PS) through pipes. Their task is to generate hydraulic pressure. The hot water pressure from the central heating stations is very high, so it must be reduced for the supply stations at the buildings. Also, the distance to these stations can be lengthy, and the pressure in the pipes can change. Special equipment at pump stations regulates the pressure of the carrier to transfer the heat further, to district heating substations. This is the main task of a pump station: to normalise the pressure.

What’s next? The cycle continues: at the district heating substations (DHS) the heat carrier releases energy to transfer heat into the heating and water systems of the building, where it is distributed among flats and runs through every radiator. After the heat is released, the water comes back to the district heating substation, then to the pump station, where it is pumped back to the central heating plant.

The main requirement for pump station technicians is to wear hardhats. Only specialist can touch the pipes, levers and other controls. The equipment requires high voltage: over 10,000 V, so touching anything is prohibited.

There are 24 pump stations in Moscow.

Heat in Muscovites’ flats

A central district heating substation includes a large amount of equipment in a separate out building that provides heat and hot water for a building or a group of buildings. Water (the heat carrier) comes from the pump station. This small outbuilding is located in the courtyard of a residential building and can be used by several buildings. For example, five residential buildings and a school are connected to the district heating substation on Novokosinskaya Street.

“Everything works automatically. The heat carrier comes to the central district heating substation and then to the heat-exchange unit. From there it goes to the heat distribution system,” said Alexander Kuznetsov, Deputy Chief Engineer at MOEK’s branch No. 5.

The central district heating substation also has a smart device, which measures the temperature in the street with special sensors and sets the water temperature, for residential buildings. The regulations state that the temperature should be no lower than 18 degrees Celsius, and the temperature in the building changes with the weather.