RU2624723C2 - Automatic control system of technological processes of heating system - Google Patents

Abstract

FIELD: heating system.

SUBSTANCE: automatic control system of the technological processes of the heating system contains the controller located in the control cabinet for controlling the technological processes of the heating system to maintain a constant temperature of the water in the heating network, the operator panel, the Ethernet switch and the optical cross for the exchange of information on industrial protocols with the automated operator workplace, frequency converters to optimize the operation of the network pumps, the starting equipment for the commutation in the power cabinet of actuator circuits, manual control unit, actuators including frequency-controlled drive of the network pump, pumps: source water, make-up, recirculation, metering pump, fuel, valves: three way to automatically maintain a predetermined temperature in the heating system, the electromagnetic proportional, solenoid shut-off, fan exhaust, means for measuring and control of process parameters: the energy meter-recorder connected to the flowmeter, temperature sensors and pressure sensors overpressure alarms, temperature sensors, flow line, and reverse feed water, gas analyzers gas content in the room, the complex to measure the amount of gas in the supply line the reserve fuel, liquid fuel counters.

EFFECT: expansion of the functionality of the automatic process control system of the heating system.

1 dwg

Description

The invention relates to automation of control of technological processes, namely, systems for automatic control of technological processes of installations of hot water and heating plants.

The water-heating installation (heating plant) is designed to produce hot water and for heating residential and industrial premises.

Known automated heating installation [patent for utility model RU 105713 U1, publ. 06/20/2011, IPC F22B 33/12], containing a closed system of automatic control (ATS). ATS is two series-connected microprocessor thermostats to maintain at a given level the necessary temperature of the coolant at the outlet of the boiler and the maximum combustion temperature of the fuel in the vortex furnace. In addition, the ATS contains a time relay unit, consisting of a parallel-connected time relay and a voltage relay. In the “automatic” mode, the time relay has the ability to control the screw-agitator motor block in the “work-pause” mode. Electric motors of boost fans and ejector with the help of voltage relays have the possibility of continuous operation. Thermostats have the ability to alternately supply a control signal to turn off the time relay unit when the controlled temperatures deviate from the set level, for which the time relay unit is connected in parallel with the manual-automatic mode switch to the screw-agitator electric motor block and to the boosters and ejector electric motors, and said electric motor unit and fan motors are connected in parallel to the network. In the “manual” mode, the electric motors of the fans and the electric motor block have the possibility of independent on-off.

Also known is an automated heating installation [patent for invention RU 2463518 C1, publ. 10.10.2012, IPC F22B 33/12], equipped with an ATS, which ensures that the required temperature of the coolant at the outlet of the boiler and the maximum temperature of fuel combustion in the furnace are maintained at a given level. ATS is closed and consists of two series-connected microprocessor thermostats and a time relay unit, consisting of a parallel time relay and a voltage relay. When one of the controlled temperatures reaches the set value, the corresponding thermostat sends a signal to the time relay unit, which turns off and thereby turns off the motors of all controlled mechanisms. After the temperature drops, the signal from the thermostat to the time relay unit is stopped, and the unit, together with the electric motors of the controlled mechanisms, is turned on in the initial mode.

The disadvantage of the described systems for automatic control of heating systems is low reliability due to the use of relay-contactor control and monitoring circuits. All elements of automation are selected and configured to work as part of a heating system designed to burn only solid fuel. In addition, in automatic control systems of heating systems, control via remote access is not provided.

Also known is the automation system of a boiler plant [patent for utility model RU 67681 U1, publ. 10.27.2007, IPC F22B 33/18], adopted as a prototype, comprising a boiler room remote control, boiler control stations, boiler mechanism starters, process parameters sensors, boiler mechanism status sensors, programmable logic controllers, remote data collection modules and a workstation boiler plant operator. Programmable logic controllers can significantly simplify the relay-contactor nodes and reduce their number. The use of remote data collection modules reduces the required number of cable products and reduces the number of connections between system nodes. This provides increased system reliability, simplified installation, commissioning and operation, and connecting controllers to the mine Ethernet network allows you to include a boiler unit in the dispatch system.

The disadvantages of the prototype are:

- lack of optimization of the operation parameters of the heat supply system due to the installation of variable frequency drives of network pumps;

- lack of optimization of boiler equipment operating modes due to automatic regulation and stabilization of hydraulic modes of the heating system;

- lack of automation of the process of generation and supply of thermal energy depending on the temperature of the outside air.

The task to which the claimed invention is directed is to increase the level of automation of a heating installation for heating individual buildings and structures.

The technical result of the claimed invention is to expand the functionality of the automatic control system of technological processes of a heating system with forced circulation of a coolant with a temperature of up to 115 ° C and a maximum working pressure of up to 0.7 MPa.

The specified technical result is achieved, and the problem is solved due to the fact that the automatic control system of technological processes of the heating installation contains a controller located in the control cabinet, configured to control the technological processes of the heating installation, an operator panel equipped with software, an Ethernet switch and an optical cross, made with the possibility of ensuring the exchange of information on industrial protocols with a remote workstation Emperor of the frequency converters configured to optimize the network of pumps; starting equipment located in the power cabinet, made with the possibility of switching actuator circuits, a manual control unit, configured to provide manual control of the pumps and emergency stop of the entire heating installation; actuators, including a variable frequency drive network pump; pumps: feed water, make-up, recirculation, metering pump, fuel; valves: three-way to automatically maintain the set temperature in the heating network, electromagnetic proportional, electromagnetic shut-offs installed at the inputs of the damper tank, fuel pumps, reserve fuel supply pipe, heated water supply pipe for heating the fuel tank, exhaust fan; measuring and control tools for technological parameters, including: a heat meter-recorder connected to flow meters, temperature and pressure sensors installed on the source water supply pipe and on the water supply and drain pipes from the heating network; gauge pressure sensors configured to measure the pressure at the outlet of the source water pump, at the inlet of water from the heating system and the supply of water to the heating system, at the inlet and outlet of network pumps, at the inlet and outlet of boilers, at the inlet and outlet of fuel pumps, pressure fuel gas; alarms made with the possibility of determining the water level in the damper tank for purification and storage of the source water, the presence of a stream at the outlet of the network pumps, the presence of water in the boiler, and leakage of liquid fuel under the burners; temperature sensors, made with the possibility of measuring the temperature of the water in the pipelines for supplying and discharging water from the heating network, at the inlet and outlet of boilers of hot water, liquid fuel at the inlet of fuel pumps, outdoor air and air in a room with a heating installation; direct and reverse make-up water flow meters installed at the outlet and inlet of the damper tank, as well as at the outlet of boilers; gas analyzers configured to measure carbon monoxide, methane and propane in a room; a complex for measuring the amount of gas in the reserve fuel supply pipeline; liquid fuel meters installed on pipelines for supplying and discharging liquid fuel; the controller is configured to receive data from measuring and controlling technological parameters, analyze and process the received data, receive control commands to open / close valves, change the speed of the network pumps using converters to maintain a constant temperature of the water in the heating system.

The drawing shows a structural diagram of a system for automatic control of technological processes of a heating installation.

The designations indicated in the drawing correspond to the following positions:

1 - control cabinet;

2 - controller;

3 - operator panel;

4 - frequency converter;

5 - Ethernet switch;

6 - optical cross;

7 - power cabinet;

8 - starting equipment;

9 - manual control unit;

10 - variable frequency drive of the network pump;

11 - source water pump;

12 - make-up pump;

13 - recirculation pump;

14 - metering pump;

15 - fuel pump;

16 - three-way valve;

17 - proportional electromagnetic valve;

18 - electromagnetic shut-off valve;

19 - exhaust fan;

20 - heat meter-recorder;

21 - liquid fuel meter;

22 - a complex for measuring the amount of gas;

23 - gauge overpressure;

24 - signaling device;

25 - temperature sensor;

26 - flow meter;

27 - gas analyzer.

The automatic control system (ACS) of the heating system technological processes includes a control cabinet and a power cabinet. The control cabinet 1 carries out the functions of monitoring the state of the heating installation, performs logical tasks, issuing control signals, exchanging information according to industrial protocols, delivering data to the operator and organizing a human-machine interface. The control cabinet 1 is designed to accommodate and protect against external influences of the controller 2, the operator panel 3, Ethernet switch 5, optical cross 6 and frequency converters 4.

Controller 2 provides control of technological processes of the heating installation: receiving data from measuring instruments and monitoring technological parameters, analyzing and processing received data, receiving control commands to open / close valves, changing the speed of network pumps using converters to maintain a constant temperature of the water in the heating system. The programming of controller 2 is carried out in accordance with IEC 61131-3 using languages such as ST (Structured Text), IL (Instruction List), LD (Ladder Diagram) and FBD (Function Block Diagram).

The operator panel 3 is equipped with software to perform the following functions:

- reception and processing of technological signals from sensors and actuators;

- smoothing and filtering instantaneous signal values;

- validation checks on the limit (physical and technological) values and the rate of change of signal parameters;

- control of specified operating modes of technological equipment;

- issuing control signals to actuators;

- transfer of technological information to the operator’s workstation and microprocessor automation system (not shown in the drawing);

- performance of the given algorithms;

- diagnostics of the operability of equipment and communication channels with the delivery of messages.

Ethernet switch 5 and optical cross 6 provide the exchange of information on industrial protocols with a remote automated workstation of the operator. Frequency converters 4 optimize the operation of network pumps.

Power cabinet 7 is designed for the distribution of electrical energy between consumers, as well as for switching actuator circuits. Launching equipment and manual control unit 9 are located in the power cabinet. Starting equipment 8 is used for switching actuator circuits. The manual control unit 9 provides pump control and emergency shutdown of the entire heating system in manual mode.

Control actions from controller 2 go to the starters of the starting equipment 8 of the power cabinet 7, where the switching and supply of the supply voltage (220/380 V) takes place directly to the actuators: frequency-controlled drives of the pumps 10, pumps 11, 12, 13, 14, 15 , exhaust fans 19, solenoids of electromagnetic shut-off valves 18.

On the front panel of the manual control unit 9 there are buttons, lamps and mode switches (not shown in the drawing). Using the buttons, the pumps 11, 12, 13, 14, 15 are stopped and started, and the electromagnetic shut-off valves are closed 18. The operation (opening) status is indicated by the lamps.

The control mode of the pumps 11, 12, 13, 14, 15 and electromagnetic shut-off valves 18 are switched from automatic control to manual control and vice versa by means of switches (not shown in the drawing).

In manual mode, the pumps 11, 12, 13, 14, 15 are controlled from the manual control unit 9, in automatic mode, switching on and off is performed automatically, according to the control signals of measuring and control of technological parameters: heat meter-recorder 20, liquid fuel meter 21, a complex for measuring the amount of gas 22, an overpressure sensor 23, an alarm 24, a temperature sensor 25, a flow meter 26, a gas analyzer 27.

Emergency stop of the entire system of automatic control of technological processes of the heating installation is carried out by a button from the manual control unit 9.

The self-propelled guns also includes actuators: a frequency-controlled drive of the network pump 10, feed water pump 11, make-up pump 12, recirculation pump 13, fuel pumps 15, metering pump 14, three-way valves 16, electromagnetic proportional 17 and electromagnetic shut-off 18, exhaust fan 19. The three-way valve 16 is designed to automatically maintain the set temperature in the heating system. The three-way valve 16 receives commands for regulating the temperature of the water leaving the heating system (depending on the ambient temperature and the heating schedule) by mixing water from the pressure of the network pumps (not shown in the drawing) to the boiler (not shown in the drawing) and water with boiler exit. Heating schedules have the ability to adjust from the operator’s workstation. The electromagnetic shut-off valves 17 are installed at the inlets of the damper tank (not shown in the drawing), fuel pumps 15, the reserve fuel supply pipe (not shown), the heated water supply pipe for heating the fuel tank (not shown). A proportional electromagnetic valve 17 is installed on the hot water supply line to the fuel tank heater and serves to ensure regular minimum circulation of heated water at sub-zero temperatures to prevent freezing of the water pipeline.

In addition, the ACS contains means for measuring and controlling technological parameters, including a heat meter-recorder 20, gauge pressure sensors 23, signaling devices 24 and temperature sensors 25. Flow meters, temperature and pressure sensors installed on the source water supply pipe and on the water supply and drain pipelines from the heating network, connected to the heat meter-recorder 20. Overpressure sensors 23 allow you to measure the pressure at the outlet of the source water pump, at the inlet of water from the heating system and the water supply in the heating s on entering and leaving the network pumps, inlet and outlet water boilers, the inlet and outlet of the fuel pump. In addition, gauges overpressure 23 allow you to measure the pressure of the fuel gas and the pressure (rarefaction) of flue gases in the ducts of boilers. Signaling devices 24 are designed to determine the water level in the damper tank for cleaning and storing the source water, the presence of a stream at the outlet of the network pumps, the presence of water in the boiler and the presence of liquid fuel leaks under the burners. Temperature sensors 25 are designed to measure the temperature of the water in the pipelines for supplying and discharging water from the heating network, at the inlet and outlet of boilers for hot water, liquid fuel at the inlet of fuel pumps, outdoor air and air in a room with a heating installation.

ACS also includes flow meters 26 of direct and reverse make-up water installed at the outlet and inlet of the damper tank, as well as at the outlet of boilers, gas analyzers 27, configured to measure the content of carbon monoxide, methane and propane in the room, a complex for measuring the amount of gas 22 in the reserve fuel supply pipe and liquid fuel meters 21 installed on the liquid fuel supply and removal pipelines.

Gas analyzers 27 contain sensors for measuring the content of carbon monoxide, methane and propane (not shown) in the room. When the gas level of the room is higher than permissible by the signals of gas analyzers, the exhaust fans 19, light and sound alarms are automatically turned on on the control panel 3, the electromagnetic shut-off valves 18 are turned off and information is transmitted to the remote access workstation.

The operation of the automatic control system of technological processes of the heating installation includes the steps of data collection, data processing and the stage of issuing control commands.

The stage of data collection is that the values of the parameters corresponding to the established requirements for the operation of the heating installation and the heating network are introduced into the controller 2 from the installation operator 3. The controller 2 automatically receives information about the parameters of water and liquid fuel from temperature sensors 25, gauges of overpressure 23, water level sensors 24, liquid fuel meters 21 installed on pipelines for supplying and discharging water and liquid fuel (not shown in the drawing). Information from the flow, pressure and temperature sensors on the source, direct and reverse network water lines (not shown in the drawing) is transmitted to the controller 2 through the heat meter-recorder 20, followed by display on the operator panel 3, at the operator's automated workstation and transfer to the microprocessor system automatics. The controller 2 transmits information from the temperature sensors 25 of the outdoor air and air in the room with a heating installation.

The data processing stage consists in the fact that the operator panel 3 compares the received data from sensors and devices 20-27 of the measuring and control of technological parameters with the data entered into the controller that correspond to the established requirements for the operation of the heating installation and heating network. In accordance with the software algorithms, a logbook of the parameters of the heating system operation is generated with archiving of the recorded data, data is exchanged with the microprocessor automation system and information is transmitted on the operation parameters of the boilers (not shown) of the heating system, its current state and the state of the control system. The information exchange between the control cabinet 1 and the operator's automated workstation and the microprocessor automation system is carried out according to standard data transfer protocols via Ethernet switches and optical crossovers.

The stage of issuing control commands is that a command is automatically issued for an emergency stop of the heating system equipment when a deviation of the processed data from the data corresponding to the established requirements for the operation of the heating system and heating network is detected.

In the normal operating mode of operation of the installation, a command is formed to open / close the three-way valve 16 if the readings of the water temperature sensor behind the boiler do not match the water temperature requirements established by the readings of the water temperature depending on the outdoor temperature data. A command is given through frequency converters 4 to frequency-controlled drives of the network pumps 10 to maintain the water pressure in the heating network at a predetermined level and to achieve a smooth start-stop, capacity control and the generated pressure.

Maintaining the temperature of the water at the inlet to the boilers (not shown in the drawing) is not lower than that set by the command to turn on / off the recirculation pumps 13, which mix the water from the boiler output to the input.

To maintain the temperature of liquid fuel in a given temperature range, a command is formed to open / close the electromagnetic shut-off valve 18 installed on the return pipe for supplying heated water from the heating network to heat the fuel tank (not shown in the drawing).

A command is issued to display the alarm condition on the operator panel 3 and the operator's automated workstation, as well as a command to start the audible alarm of the microprocessor automation system when the processed data deviates from the set data by an amount corresponding to the emergency state.

The prototypes of the invention, made for heating plants with a thermal power of 1 MW, 2 MW and 4 MW with a temperature of the coolant (water) up to 115 ° C and a maximum working pressure of up to 0.7 MPa, provide:

- measurement of process parameters;

- automatic protection and blocking of control of technological equipment;

- implementation of automatic control programs for technological equipment;

- automatic control of flow, temperature and other parameters of technological processes;

- registration, archiving, documenting and displaying information about the operation of technological equipment;

- Communication with other automation systems and information systems.

In the invention achieved:

- optimization of the operation parameters of the heat supply system through the installation of variable frequency drives of network pumps;

- optimization of boiler equipment operating modes due to automatic regulation and stabilization of hydraulic modes of the heating system;

- automation of the process of generation and supply of thermal energy depending on the temperature of the outside air.

This ensured the expansion of the functionality of the automatic control system of technological processes of the heating system with forced circulation of the coolant with a temperature of up to 115 ° C and a maximum working pressure of up to 0.7 MPa.

Claims (10)

The system of automatic control of technological processes of a heating installation, characterized in that it contains: - a controller located in the control cabinet that is capable of controlling the technological processes of the heating installation, an operator panel equipped with software, an Ethernet switch and an optical cross, configured to ensure the exchange of information on industrial protocols with a remote automated workstation of the operator, frequency converters made with the ability to optimize the operation of network pumps; - starting equipment located in the power cabinet, made with the possibility of switching actuator circuits, a manual control unit, configured to provide manual control of the pumps and emergency stop of the entire heating installation; - actuators, including a variable frequency drive network pump; pumps: feed water, make-up, recirculation, metering pump, fuel; valves: three-way to automatically maintain the set temperature in the heating network, electromagnetic proportional, electromagnetic shut-offs installed at the inputs of the damper tank, fuel pumps, reserve fuel supply pipe, heated water supply pipe for heating the fuel tank, exhaust fan; - measuring and control tools for technological parameters, including: a heat meter-recorder connected to flow meters, temperature and pressure sensors installed on the source water supply pipeline and on the water supply and drain pipelines from the heating network; gauge pressure sensors, configured to measure the pressure at the outlet of the source water pump, at the inlet of water from the heating system and the supply of water to the heating system, at the inlet and outlet of network pumps, at the inlet and outlet of boilers, at the inlet and outlet of fuel pumps, pressure fuel gas; alarms made with the possibility of determining the water level in the damper tank for purification and storage of the source water, the presence of a stream at the outlet of the network pumps, the presence of water in the boiler, and leakage of liquid fuel under the burners; temperature sensors, made with the possibility of measuring the temperature of the water in the pipelines for supplying and discharging water from the heating network, at the inlet and outlet of boilers of hot water, liquid fuel at the inlet of fuel pumps, outdoor air and air in a room with a heating installation; - flow meters of direct and reverse make-up water installed at the outlet and inlet of the damper tank, as well as at the outlet of boilers; - gas analyzers made with the possibility of measuring the content of carbon monoxide, methane and propane in the room; - a complex for measuring the amount of gas in the reserve fuel supply pipeline; - liquid fuel meters installed on pipelines for the supply and removal of liquid fuel; - at the same time, the controller is configured to receive data from measuring instruments and control of technological parameters, analyze and process the received data, receive control commands to open / close valves, change the speed of the network pumps using converters to maintain a constant temperature of the water in the heating system.

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