Integrated APCS of the turbo units No. 8 & 9 and the boiler units No. 12 & 14 of Barnaul CHPP-2

In 2013, “Tornado Modular Systems” company together with the CJSC “Siberian Energy Research & Development Center” engineering center executed the stage of the project of technical re-equipment of units No. 8 & 9 of Barnaul CHPP-2.

The automation objects are coal and gas BKZ-210-140F boiler units No. 12 & 14 of Barnaul CHPP-2 and heating turbines of T-60 / 65-130-2M type, a generator of TVF-63-2EU3 type with excitation system and auxiliary equipment of the turbines.

General information about the system

The system is designed as a technically distributed system which follows the principle of centralized automated monitoring and control of the turbo units from the group control desk (GCD) of the turbines involving the operating staff. The system is automated, i.e. it provides operation of the control environment under the staff control.

The central part of the APCS is a distributed control system (DCS) which includes programmable automation devices and other computer equipment.

Automated start-up and exploitation of the turbo units when the DCS is disabled are not provided.

The system has an emergency control panel (ECP) which uses the local monitoring and control equipment to provide safety shutdown of the turbo units in case of the APCS failure. This ECP should match the RD 153-34.1-35.523-2002 requirements.

The system is divided taking into account specific features of a controlled technological object. The controlled objects are conventionally divided into functional units, which are characterized by relative autonomy of technological tasks performed by them.

A separate automation scheme with its corresponding part of the specification of sensors and actuators is implemented for each functional unit. The structure of control algorithms takes into account division of the functional units. This solution provides the modular system structure with intelligible equipment, control algorithms and methods of communication between staff and the system. It also ensures simplification of service management, staff training and operation.

The principle of a single signal input and its multiple use by both information and control tasks is implemented in the system. The exception to the rule is the technological protections for which information input is performed more than once in accordance with the protection algorithms and principle of redundancy of protections that perform shutdown of the turbo units.

The whole DCS is made on the basis of a microprocessor-based hardware, reliability of which meets the reliability requirements of technological protections (technological protection implementation is the highest priority task). At the same time, the equipment implementing the technological protections of the turbo unit shutdown is fully duplicated. Such system provides unification of solutions and increase in reliability of the system as a whole.

The designed APCS is conventionally divided into three subsystems:

1. Lower level (control);

2. Top level (information);

3. Field level (sensors, actuators, etc.).

Indicators of the system reliability

The mean time between failures of the processor-based devices and distributed I/O modules, which are parts of the DCS, including technical service restricted by operating instructions is not less than 150000 hours for systems with redundancy.

The mean time to recovery of the processor-based devices and the distributed I/O modules which are parts of the DCS, is not more than 1 hour.

The lifetime of the DCS basic elements (equipment of controllers cabinets and power and communication servers-cabinets with the exception of its replaceable units) is not less than 10 years. The lifetime of the replaceable units:

• upper level computers – at least 5 years,

• uninterruptable power supply (UPS) battery – at least 3 years,

• mouse pointing devices – 1 year.

The lifetime of the DCS must be at least 10 years during which the non-based elements are replaced. The mean time between failures of the upper level of the DCS (automated workstation (AWS), server) taking into account the operating rules restricted by the instructions is not less than 14000 hours.

The availability ratio value of the DCS is not less than 0.996 for the systems with redundancy – not less than 0.999.

Indicators of the system reliability are given in Table.

Notes:

1. Function restore is performed by means of changing the standard module using the spare parts and accessories.

2. All values of the indications are shown without taking into account reliability of the equipment beyond DCS.

Indicators of technological protections reliability

The indicators of microprocessor-based hardware reliability of technological protections are:

1. Probability of protection failure on request;

2. Probability of false trip.

Reliability requirements for individual technological protection (TP) are defined by the relation of this TP to the particular group: A or B.

The A group includes protections which will be activated in emergency conditions threatening life of the staff and the equipment safety.

Protections of the B group are activated in emergency conditions that rise up a risk of equipment damage or reduction of its life cycle.

The failures for each protection implemented in the microprocessor-based hardware are:

• Critical failure – results in failure at a request of at least one of the most technologically important actuating elements of this protection.
• Non-critical results in failure of any not very important actuating element of this protection.

The average time of malfunction removal detected by diagnostics tools for technological protections is no more than 2 hours. The hardware reliability indicators of the technological protections implemented in the APCS (per one TP) are given in the Table.

The total rate of the false triggering for all technological protections of the A group does not exceed 0.05 / per year, and in the B group it does not exceed 0.15 / per year.

Structural system reliability

The system must provide retention of project monitoring and control functions of the turbo units in full in case of failures of these DCS components:

• One of the modules, which implements the protections functions;
• One of the commutation switches of the Ethernet network;
• One of the database servers;
• One of the workstations, which form AWS of the turbo units operators;
• One of the secondary power supplies of any voltage in each controller;

• One of the uninterruptable power supplies (UPSs).

In addition, the created system provides retention of project control functions of the turbo units in case of electric power supply loss in the 220VAC controllers-cabinets or the cabinets of the upper level electric power supply of the DCS.

1^ Automatic control system.