RU109583U1 - AUTOMATIC CONTROL SYSTEM FOR BUILDING HEATING WITH PROGRAMMABLE LOGIC CONTROLLER - Google Patents

Abstract

 An automatic heating control system for a building with a programmable logic controller, comprising outdoor temperature sensors, an automatic switch, network water temperature and heat load controllers, an external disturbance compensation device, adders, characterized in that the automatic switch further includes a logic unit, the inputs of which are connected with a signal of the current time of day and a signal of the current date, the output of the logic unit is connected to three adders, the first adder is made with the possibility of inverting the actual air temperature signal arriving at it in a heated room and is connected to the second adder, configured to invert the signal arriving at it from the outdoor temperature sensor, the output of the second adder is connected to the input of the third adder through the amplification unit.

Description

The utility model relates to the field associated with control systems and temperature control by electrical means, and can be used for automatic control systems (CAP) for heating buildings with central, as well as individual water heating for solving energy conservation problems.

A known system for automatically controlling the heating of a building using a heat exchanger (Livchak V.I. Energy saving in district heating systems at a new stage of development // Energy saving, 2000. No. 2. - P.4-9), containing at the input to an individual heat point (ITP ) a heat meter (designated as ТС - heat meter), consisting of 2 temperature sensors, a heat carrier flow meter and a heat meter, a direct-acting differential pressure regulator, a control valve with an actuator connected to the regulator, which is a clock thermostat, the input of which is connected to a temperature sensor, a heat exchanger, a circulation pump, heating devices in a building heating system with thermostats, an expansion tank with a safety valve.

The main disadvantage of this technical solution is the low efficiency of CAP heating of buildings, since the temperature schedule of the coolant supply from heating networks, the outdoor temperature and the temperature inside the building are not taken into account.

The well-known "System of automatic regulation of building heating taking into account climatic factors" (Patent for the invention of the Russian Federation No. 2247422, IPC G05D 23/19, 2005), which contains a local controller (LC), an immersion temperature sensor for the coolant and outdoor and indoor air temperature sensors located respectively on one of the external facades of the building and in the room on the side of this facade, connected to the inputs of the LC from 1 to 3. The following are installed on the pipelines of the heating system: control valve connected to the external heating networks, circus lation between the pump and check valve bridge connecting the supply and return conduits. The actuator of the control valve and the electric circulating pump are connected to 1 and 2 outputs of the LC. In addition, CAP has additional control valves and air temperature sensors. CAP contains an additional controller (DC) and hydraulic distributors with branches of the heating system along the facades of the building, and on all or several supply or return branches covering the facades of the building with the exception of the north, additional control valves with actuators 1 through m are installed. In addition, additional external temperature sensors from 1 to j and internal from 1 to i of air are located on the remaining external facades and one in the premises of each of the building facades covered by branches with additional control valves. In addition, the actuators 1 to m are connected to the outputs of the DC from 1 to m, and the temperature sensors for the external air from 1 to j and the internal air from 1 to i are connected to its corresponding inputs from 1 to (j + i) or through a communication adapter to 1 digital communication port (DPC) of the DC, while 2 DPCs of the additional controller are connected to the DPC of the local controller.

The main disadvantage of the above solution is the need to install additional temperature sensors inside the heated room and control valves for each of the building facades and an additional DC controller, which is often economically inexpedient for buildings of short length and buildings whose heat loss slightly depends on the direction and speed of the wind and the position of the sun on skyline during the heating season.

The prototype of the proposed utility model is “Automatic heating control system for a building with an automatic setpoint” (Patent for the invention of the Russian Federation No. 2348061, IPC G05D 23/00, 2009), which contains an immersion temperature sensor for the coolant, an outside temperature sensor and control valves with actuators mechanisms, an automatic controller for generating the necessary temperature of hot water in the heating circuit, with one of the inputs of which an external temperature sensor is connected, and the other input signal specifying the room temperature, the automatic setting unit includes serially connected first adder configured to inversion of one of the received him signal amplification unit and the second adder, wherein the sum signal from the amplifier output signal and defining a room temperature.

The main disadvantages of this solution are:

- the lack of correction of the system according to the temperature signal in the room, which can lead to significant deviations from the set one.

- the building’s operating mode is not taken into account, for example, in administrative buildings, some municipal institutions, some industrial facilities, as well as office premises at night and on weekends due to a decrease in coolant consumption, the room temperature can be reduced by this time to the minimum standards temperatures for such buildings, i.e. by 3-7 ° C, which will provide additional savings in heat energy for heating.

The technical result is the saving of thermal energy due to automatic control of the temperature of the flow of hot coolant with the help of an automatic controller, as part of a programmable logic controller (PLC), in accordance with the operating mode of the building and the standards for permissible temperature reduction in heated rooms.

The technical result is achieved by the fact that the automatic heating control system of the building with a programmable logic controller, comprising an automatic controller whose inputs are connected to an outdoor temperature sensor and a room temperature sensor, regulators of network water temperature and heat load, regulating bodies, adders, an external disturbance compensation device . The system includes a programmable logic controller, including an automatic controller, regulators of network water temperature and heat load, a device for compensating external disturbances, adders, while the automatic controller further includes a logic unit whose inputs are connected to a signal of the current time of day and a signal of the current date, output the logic unit is connected to three adders, the first adder is configured to invert the actual air temperature signal arriving at it in a heated room and connected to a second adder configured to inversion signal coming to it from outside air temperature sensor, the output of the second adder via the gain block is connected to the input of the third adder.

The inventive system of automatic control of heating of a building with a programmable logic controller is illustrated by the drawings presented in figure 1, figure 2 and figure 3. Figure 1 shows a structural diagram of a building heating with its own boiler room. Figure 2 shows a diagram of automatic regulation of heating of a building from a city heating system. Figure 3 shows the structure of the automatic master.

The following notation is used in the drawings: additional sensor for outdoor temperature 1, signal, current time of day 2; signal, current date 3; room temperature sensor 4; ZD automatic adjuster 5; adder 6; direct network water temperature regulator 7; regulatory body affecting the consumption of heat in the heating system 8; adder 9; thermal load regulator 10; regulatory body affecting fuel consumption in the furnace of the boiler 11; regulation object 12; a device for compensating external disturbances 13; logic unit 14, adders 15, 16, 18, amplification unit 17. Moreover, in the heating circuit of the building with its own boiler room (Fig. 1), an automatic controller 5, an adder 6, a temperature regulator of direct network water 7, an adder 9 are implemented as a part of the logic controller; heat load regulator 10 and an external disturbance compensation device 13. In the building heating circuit from the city heating network (Fig. 2), an automatic controller 5, an adder 6, a direct network water temperature controller 7 and an external compensation device are implemented as a logical controller 13. perturbation M - vector external disturbances affecting the temperature of the mains water line (they must be considered in case of a significant effect of external factors on the mains water temperature); Q2 is the current amount of heat entering the control object.

The signal from the outdoor temperature sensor 1, the signal of the current time of day 2, the signal of the current date 3, the signal from the temperature sensor in room 4 are fed to the input of the setter 5, where a reference signal is generated, which represents the required temperature of hot water in the heating circuit. Then the signal goes to the adder 6, where the current temperature in the circuit is subtracted from it. Next, the mismatch signal is fed to the input of the temperature regulator of direct network water 7, which generates a control signal and directs it to the regulatory body 8, which affects the heat flux into the heating circuit. On the adder 9, the following occurs: the mismatch signal for the direct network water temperature controller 7 is formed as the difference between the reference signal from the setpoint 5, presented as the amount of heat required to maintain the set temperature in the circuit and the heat signal currently entering the circuit. In addition, with the help of an external disturbance compensation device 13, it is possible to take into account an external disturbance if it significantly affects the adjustable parameter (for example, the outdoor temperature must be included here with a large length of heating systems). The mismatch signal, formed in this way, then goes to the input of the heat load controller 10, at the output of which a control action is generated for the regulatory body 11, which affects the fuel consumption in the boiler furnace. Further, a change in fuel consumption leads to a change in the state of the control object 12, characterized by the parameters Q2 and Tcv (Fig. 1) or only Tcv (Fig. 2). The circuit in figure 2 works similarly.

The structure of the automatic master (figure 3) includes a signal for the outdoor temperature of the sensor 1; signal of the current time of day 2; current date signal 3; a correction signal for the actual temperature in the heated room 4. A signal for the air temperature in the room 4 corrects the operation of the system according to the current value of the room temperature. The system also compares this signal with the signal from the output of the logic unit 14, which generates a task for the temperature in the room depending on the current time of day 2 and a signal for the current date 3. The signal for the outdoor temperature of sensor 1 is corrective, it adapts the system to temperature changes the environment. At the output of the automatic setpoint 5, a signal is generated that determines the required temperature of the network water in the heating circuit.

A feature of the proposed CAP is that it involves the installation of an additional air temperature sensor in a heated room, input into the system of additional signals of the current time of day and date, as well as the installation of a programmable logic controller (PLC) to calculate the reference signal and implement control algorithms for direct temperature controller network water 7 and heat load regulator 10.

Consider the principle of operation of the system in the event of a decrease in outdoor temperature. The input of logic block 14 receives a signal of the current time of day 2 and date 3, at the output, if the date is a day off, or the current time is not working for this object, a lower set room temperature (Tvvzd) is formed. If none of these conditions is met, then a normal reference signal is generated. Next, the signal Tvvzd goes to the adder 15, where it is added with the inverted signal of the temperature in the room 4. Then the signal from the output of the adder 15 goes to the adder 16, where it is added with the signal from the output of the logic unit 14 and the inverted signal of the outdoor temperature of the sensor 1. When decreasing the signal of the outdoor temperature at the output of the adder 16, the signal increases (relative to the previous value). Then, the signal is amplified from the output of the adder 16 in the amplification unit 17 and then it is summed in the adder 18 with the signal of the set room temperature from the output of the logic unit 14. From the output of the adder 18, this signal is fed to the adder in front of the direct network water temperature controller 7, where it is formed a signal for the opening of control valves, which provides an additional influx of heat into the consumer’s building. In the case when the system has the form of FIG. 1, a signal is additionally generated to open the control valves to supply fuel to the boiler.

The principle of operation of the system in the event of a decrease in the room temperature below the set value is as follows: the signal of the logic unit 14 receives a signal of the current time of day 2 and date 3, at the output, if the date is a day off, or the current time is not working for this object, A reduced set temperature in the room is formed. If none of these conditions is met, then a normal reference signal is generated. Next, the signal TVvzd arrives at the adder 15, where it is added with the inverted temperature signal in the room 4. When the temperature signal in the room 4 decreases, the signal from the output of the adder 15 increases and goes to the adder 16, where it is added to the signal from the output of the logic unit 14 and with inverted the outdoor temperature signal 1. When the temperature signal in the room 4 decreases, the output of the adder 16 increases the signal value (relative to the previous value). Then, the signal is amplified from the output of the adder 16 in the amplification unit 17 and then it is summed in the adder 18 with the signal of the set room temperature from the output of the logic unit 14. From the output of the adder 18, this signal is fed to the adder in front of the direct network water temperature controller 7, where it is formed a signal for the opening of control valves, which ensures an increase in the influx of heat into the consumer's building. In the case when the system has the form of FIG. 1, a signal is additionally generated to open the control valves to supply fuel to the boiler.

The principle of operation of the system in the event of a decrease in the reference signal generated by the logic unit 14 is as follows: The signal of the current block of the day 2 and the signal of the current date 3 are output to the input of the logic block 14, if the date is a day off or the current time is non-working for this object, a reduced set temperature in the room is formed. That is, at the output of logic block 14, the signal (Tvvzd) decreases. Next, the signal from the output of the logic unit 14 goes to the adder 15, where it is added with the inverted signal of the temperature in the room 4. When the signal from the output of the logic unit 14 decreases, the signal from the output of the adder 15 decreases and goes to the adder 16, where it is added to the signal from the output of the unit logic 14 and with an inverted signal of the outdoor temperature 1. When the signal from the output of the logic unit 14 decreases at the output of the adder 16, the signal value also decreases (relative to the previous value). Then, the signal is amplified from the output of the adder 16 in the amplification unit 17 and then it is summed in the adder 18 with the signal of the set room temperature from the output of the logic unit 14. From the output of the adder 18, this signal is fed to the adder in front of the direct network water temperature controller 7, where it is formed a signal to close the control valves, which ensures a decrease in the influx of heat into the consumer’s building. In the case when the system has the form of Fig. 1, an additional signal is generated to close the control valves to supply fuel to the boiler.

Thus, the proposed technical solution provides an increase in the efficiency of CAP heating by the building, taking into account climatic factors, the current air temperature in the room, the current time of day, and also the current date, in particular, it allows to reduce the room temperature in accordance with the standards (SNiP 2.01.01, GOST R 51617-2000, etc.) at night and on weekends, as well as adjust the reference signal when the temperature in the room changes due to increased wind, increased heat input to the room due to the sun radiation and with others.

Claims (1)

An automatic heating control system for a building with a programmable logic controller, comprising outdoor temperature sensors, an automatic switch, network water temperature and heat load controllers, an external disturbance compensation device, adders, characterized in that the automatic switch further includes a logic unit, the inputs of which are connected with a signal of the current time of day and a signal of the current date, the output of the logic unit is connected to three adders, the first adder is made with the possibility of inverting the actual air temperature signal arriving at it in a heated room and connected to the second adder, configured to invert the signal arriving at it from the outdoor temperature sensor, the output of the second adder is connected to the input of the third adder through the amplification unit.