To regulate and optimize the functioning of boiler units, technical means began to be used at the initial stages of automation of industry and production. Today's level of development in this area can significantly increase the profitability and reliability of boiler equipment, ensure the safety and intellectualization of the staff.
Tasks and Goals
Modern boiler house automation systems are able to guarantee trouble-free and efficient operation of equipment without direct operator intervention. Human functions are reduced to online monitoring of the health and parameters of the entire complex of devices. Boiler house automation solves the following tasks:
- Automatic start and stop of boiler units.
- Boiler power control (cascade control) according to the set primary settings.
- Management of feed pumps, monitoring of coolant levels in the working and consumer circuits.
- Emergency stop and the inclusion of signaling devices, in case the operating values of the system go beyond the set limits.
Automation object
Boiler equipment as an object of regulation is a complex dynamic system with many interconnected input and output parameters. Automation of boiler rooms is complicated by the fact that steam units have very high speeds of technological processes. The main adjustable values include:
- flow rate and pressure of the coolant (water or steam);
- discharge in the furnace;
- level in the feed tank;
- In recent years, increased environmental requirements have been imposed on the quality of the prepared fuel mixture and, as a result, on the temperature and composition of smoke exhaust products.
Automation levels
The degree of automation is set during the design of the boiler room or during overhaul / replacement of equipment. It can range from manual control according to testimony to fully automatic control by weather-dependent algorithms. The level of automation is primarily determined by the purpose, power and functional features of the operation of the equipment.
Modern automation of the boiler room implies a comprehensive approach - the control and regulation subsystems of individual technological processes are combined into a single network with functional group management.
General structure
Boiler house automation is built on a two-level control scheme. The lower (field) level includes local automation devices based on programmable microcontrollers that implement technical protection and blocking, adjusting and changing parameters, and primary converters of physical quantities. Equipment intended for converting, encoding and transmitting information data is also included here.
The upper level can be represented in the form of a graphic terminal built into the control cabinet or the operator’s workstation based on a personal computer. Here, all the information coming from the lower level microcontrollers and system sensors is displayed, and operational commands, adjustments and settings are entered. In addition to dispatching the process, the problems of optimizing the modes, diagnosing the technical condition, analyzing economic indicators, archiving and storing data are also solved. If necessary, the information is transmitted to the general enterprise management system (MRP / ERP) or settlement.
Automation of boiler equipment
The modern market is widely represented as individual devices and devices, as well as automation systems of domestic and foreign production for steam and hot water boilers. Automation tools include:
- ignition and flame control equipment that starts and controls the process of burning fuel in the combustion chamber of the boiler unit;
- specialized sensors (weight gauges, temperature, pressure sensors, gas analyzers, etc.);
- executive devices (solenoid valves, relays, servos, frequency converters);
- control panels for boilers and boiler equipment (remotes, touch mnemonic diagrams);
- switching cabinets, communication lines and energy supply.
When choosing technical means of control and monitoring, the closest attention should be paid to safety automation, which excludes the occurrence of emergency and emergency situations.
Subsystems and Functions
Any boiler house automation scheme includes subsystems of control, regulation and protection. Regulation is carried out by maintaining the optimal combustion mode by setting the vacuum in the furnace, the primary air flow rate and the parameters of the coolant (temperature, pressure, flow rate). The control subsystem displays actual data on the functioning of the equipment on a human-machine interface. The protection devices guarantee the prevention of emergency situations in violation of normal operating conditions, the supply of a light, sound signal or the shutdown of boiler units with fixing the cause (on a graphic display, mnemonic diagram, panel).
Communication protocols
Automation of boiler plants based on microcontrollers minimizes the use of relay switching and control power lines in the functional diagram. To communicate the upper and lower levels of the ACS, transfer information between sensors and controllers, to transmit commands to executive devices, an industrial network with a specific interface and data transfer protocol is used. The most widely used standards are Modbus and Profibus. They are compatible with the bulk of the equipment used to automate heat supply facilities. They are distinguished by high indicators of reliability of information transfer, simple and understandable principles of operation.
Energy-saving and social effects of automation
Automation of boiler houses completely eliminates the possibility of accidents with the destruction of capital buildings, the death of staff. ACS is able to ensure the normal functioning of equipment around the clock, to minimize the influence of the human factor.
In light of the continuous increase in fuel prices, the energy-saving effect of automation is not of the least importance. Natural gas savings of up to 25% during the heating season are ensured by:
- optimal gas / air ratio in the fuel mixture at all boiler room operating modes, correction for the level of oxygen content in the combustion products;
- the ability to customize not only boilers, but also gas burner devices ;
- regulation not only by temperature and pressure of the coolant at the inlet and outlet of the boilers, but also taking into account environmental parameters (weather-dependent technologies).
In addition, automation allows you to implement an energy-efficient algorithm for heating non-residential premises or buildings that are not used on weekends and holidays.