Construction of the Blast Furnace Gas Heat and Power Plant of Novolipetsk Steel Works (NLMK CHPP)

The recovery cogeneration plant was built to recover NLMK’s blast furnace gas which is a by-product of steel production by way of its combustion in power-generating boilers. Thus, it is used to generate electrical energy and supply heat and steam to the process. Construction and commissioning of the recovery cogeneration plant allowed to reduce steel production cost. Energy intensity of steel production was further decreased driven by use of by-product-fired power generation. The plant was commissioned in 2013. The project capex totalled 8,500 million rubles. The payback period is approximately 8 years.

Summary of key solutions

The recovery CHPP  comprises the following buildings and structures:

• main building (boiler and turbine shop, including three steam turbines with a maximum capacity of 50 MW, electric generators, power boilers with a steam capacity of 220 t/h for burning blast furnace gas mixed with natural gas, equipment for heating and pumping network water and auxiliary equipment);
• chimney (three-barrel – one barrel for each boiler, plus a spare space for the 4th barrel – from the 4th boiler);
• outdoor switchgear 110 kV;
• auxiliary switchgear 6 kV;
• main control panel;
• circulating water supply pumping station;
• fan-type four-section cooling towers (three) for evaporative cooling of service water for steam turbine condensers and auxiliary equipment;
• pumping stations for utility and industrial storm sewers for pumping utility and industrial storm water collected at the CHPP site into NLMK's waste disposal systems;
• water treatment plant with tank facilities for chemical treatment of raw water to feed the steam power cycle of the CHPP;
• a gas control station for supplying power boilers with natural gas;
• administrative building;
• cable gallery between CHPP outdoor switchgear 110kV  and GPP-18 outdoor switchgear 110kV; transition bridge with a cable gallery between the main building and the main control room, a cable tunnel between the main building and the circulating water supply pumping station;
• on-site networks, communications (including technological overpasses), highways.

Main figures

• The installed electric capacity in the condensing mode of the steam turbine operation, MW – 150;
• The rated electric capacity at the maximum steam flow rates from the steam turbines extractions for production and district heating needs, MW – 120;
• The estimated annual electric power supply regarding the base operation mode of the NLMK consumers and the regulatory time intervals and duration of the CHPP main equipment current repairs and overhauls (in conformity with the average annual operation hours quantity of 8000 hours), kWh/year – 959.2 mln;
• The rated pressure, temperature and the supplied steam flow rate for the NLMK production needs – 1.2 МPа, 250°С, 120 t/h;
• The available annual steam heat output for the NLMK production needs regarding the base operation mode of the NLMK consumers, the CHPP main equipment current repairs and overhauls and the equipment operation reliability coefficients, Gcal/year – 694100;
• The maximum rated heat power for the heating system water heating (the temperature chart – 105/700°С, the minimum rated ambient air temperature for heating – 27°С), for heating and ventilation of the NLMK consumers, Gcal/hour – 115;
• The maximum rated heat power for the heating system water heating for the hot water supply, Gcal/hour - 9 (150 t/h of the hot water supply for consumers);
• The total annual rated heat power for the heating, ventilation and the hot water supply to the NLMK consumers – 315300 Gcal /year, including the hot water supply, Gcal/year - 79000;
• The basic economy of the power resources of NLMK recovery CHPP operation is due to combustion of the blast-furnace gas, being formed as the waste by-product of the NLMK metallurgical production process, i.е. as the secondary power resource. The use of the blast-furnace gas for the CHPP power generation boilers operation (up to 120000 nm3/hour per one boiler Е-220-9.8-540 ГД) is equivalent to the economy of the primary power resources of up to 317 thousand tons of equivalent fuel per year;
• The ground area, ha – 9.7, the housing density – 32.4%;
• Reduction of the harmful emissions into atmosphere – because the blast-furnace gas contains 20.7% carbon oxide (СО) and at its afterburning (before the CHPP construction) «at the bleed valve» there takes place «the under-firing» with great СО emission into atmosphere;
• Reduction of the prime cost of the main product, electric power generation and the heat and hot water supply to the consumers, as well as the steam supply for the production needs.