Integrated APCS of the 300 MW pulverized coal power-generating unit of Ugljevik CHPP

The system is designed for monitoring and control automation of technological processes and operating modes of thermotechnical and electrotechnical equipment of the power-generating unit No. 1 and plantwide equipment.

The system is based on DCS¹ “TORNADO-N” developed by “Tornado Modular Systems” company.

The DCS remote terminal unit (DCS RTU) signals ware created in the progress of main design development. Signals are given in the Table.

Signs in the table:

• AI – analog input signal;
• AO – analog output signal;
• DI – digital input signal, 220 V;
• DO – discrete output signal, 220 V;
• RTD – signal fr om a resistance temperature detector;
• TC – signal from a thermocouple.

Automation object characteristics

The automation objects are:

• Power-generating unit No. 1 composed of:
  • Boiler unit of Ep-670-13,8-545 BT type;
  • Turbine of T-185 / 220-12,8-2 type;
  • Generator of TZFP 220-2U3 type;
  • Auxiliary equipment of the power-generating unit;
  • Plantwide thermotechnical equipment of the main building of the launching complex of the power-generating unit No. 1;
  • Plantwide electrical & technical equipment of the starting complex of the power-generating unit No. 1 as a part of the main scheme.

Short description of the Ep-670-13,8-545 BT boiler unit

The Ep-670-13.8-545 BT steam boiler (TPE-216 commercial model), supplied by OJSC “The Taganrog Boiler-Making Works “Krasny Kotelshchik”” is the main one. The lower lim it of the controlled load range while burning coal is 55%.

The drum boiler is with chamber combustion of coal dust, bottom-ash removal, reheat, single-hull, П-shaped form with an external tubular air heater, balanced draft, gastight design and three-tiered angular placement of the burners. The boiler has two independent paths for both water and steam flows.

The nominal values of the main parameters of the boiler are given in Table 3.1

Table 3.1.

Short description of Т-185/220-12.8-2 turbo unit

The T-185 / 220-12.8-2 steam turbine manufactured by OJSC “Power Machines” (The branch of “LMZ²”) is a single-shaft three-cylinder aggregate with a double-flow low pressure cylinder.

The turbine has nozzle steam distribution. A fresh steam at the pressure of 12.8 MPa and the temperature of 540 °C is admitted to two valve blocks, each of which consists of one isolation and two control high pressure cylinder (HPC) valves. Steam admission to the HPC is performed via four nozzle chests. Steam supply to each of the four nozzle chests is performed via own control valve. The steam is admitted to reheat after the HPC. After reheat, the steam is admitted to the two medium pressure cylinder (MPC) isolation valves, and then to four MPC control valves, which are controlled by two servomotors. Axial adaptive stages of low pressure cylinder (LPC) are controlled via level mechanism by one servomotor, which is located directly on the LPC. These stages control the steam pressure of heat extraction. The steam from heat extraction is routed to two horizontal boilers. The processed steam is admitted to the double-flow surface condenser at the output of the last stages of the double-flow LPC.

The main parameters of the T-185 / 220-12,8-2 turbine are given in Table 3.2

Table 3.2.

Brief description of the generator and auxiliary equipment of unit

Along with the turbine the generator of TZFP-220-2UZ type, manufactured by OJSC “Power Machines” (“Electrosila” branch), St. Petersburg, should by installed.

The generator characteristics:

• Capacity: 220 MW;
• Voltage: 15.75 kV;
• Air cooling;
• Efficiency: 98.6%

The generator has a thyristor excitation system of STS-2P-270-3200-2.5 U4 type.

The generator with a double-wound transformer is connected to the 220 kV buses.

Auxiliary equipment of the power-generating unit

The auxiliary equipment of the power-generating unit includes:

• two PE-720-185 feed-water pumps with adjustable rotating speed;
• 6 atm deaerator;
• heating plant (two delivery water calorizators and pumps for condensate extraction);
• steam-release fast-response pressure-reducing and desuperheating station;
• pressure-reducing cooling unit of auxiliaries and reheat system;
• continuous blowdown expander with a heat-exchange unit;
• drainages of high and low pressure pipelines;
• drain tanks with the pumps;
• delivery water calorizators for an economizer of low pressure of a boiler with condensate pumps;
• etc.

1^ Distributed control system.

2^ Leningradsky Metallichesky Zavod.