Heating PLC control device and method

Abstract

The invention discloses a heating PLC control device and method. In an input link, a sensor group module is in communication connection with an input isolation module, and the input isolation module is in communication connection with an analog quantity input terminal or a digital quantity input terminal of a PLC main control module; a passive signal isolation unit of the input isolation module receives a field equipment state signal and is in communication connection with a PLC digital quantity input terminal; in the output link, a PLC digital quantity output terminal is connected with an intermediate relay group module, and the intermediate relay group module is connected with field equipment; an analog quantity output terminal of the PLC is connected with an analog quantity signal output unit of the output isolation module, and the analog quantity signal output unit is connected with the frequency converter; the system further comprises a cloud server and a mobile terminal. The PLC master control module of the communication link is connected with a communication module, and the communication module is connected with a cloud server or a mobile terminal. According to the invention, signal isolation, an adaptive algorithm and a modular channel are integrated, and high reliability, low cost and intelligent control are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of urban centralized heating automation control, and in particular relates to a heating PLC control device and method. Background Art

[0002] The control system of a central heating heat exchanger station is primarily responsible for monitoring and regulating its operating status to ensure efficient, stable, and safe operation of the heating system. As a key link in the heating system, the heat exchanger station's primary function is to transfer heat generated by the heat source to the secondary network through a heat exchanger, and then supply it to users.

[0003] Chinese invention patent CN 111429034 A discloses a method for distribution network fault prediction, which includes the following steps: the first step: data preprocessing, including analysis of factors affecting distribution network faults and sample screening based on a particle swarm optimization algorithm; the second step: feature variable selection, including preliminary feature selection of each relevant variable, followed by re-screening using a specific selection algorithm to form an optimal feature variable set; the third step: construction of a distribution network fault prediction model based on fault level classification; faults are classified into levels, and the parameters of a support vector machine are optimized using an improved particle swarm optimization algorithm to construct a distribution network fault prediction model. Based on the constructed model, various data of the distribution network are analyzed to output anomaly and fault predictions. The above solutions and traditional urban centralized heating control systems mostly adopt a decentralized modular design, and both have the following problems: 1. Module redundancy and high cost: data acquisition, control, and communication modules need to be configured separately, which has high procurement and maintenance costs; 2. Low reliability: strong inter-module dependence, a single failure can easily lead to system paralysis; 3. Complex wiring: multi-module wiring is prone to errors and troubleshooting is difficult; 4. Lack of intelligence: lack of adaptive adjustment algorithms, reliance on manual intervention, and low energy utilization.

[0004] The present invention solves the above problems through an integrated PLC control system design, integrating signal isolation, adaptive algorithms, and modular channels, and achieves high reliability, low cost, and intelligent control. Summary of the Invention

[0005] In response to the problems raised by the above background technology, the purpose of the present invention is to provide a heating PLC control device and method, which integrates signal isolation, adaptive algorithms, and modular channels to achieve high reliability, low cost, and intelligent control, while realizing data collection, remote control, fault warning and unattended operation of heat exchange station equipment.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0007] A heating PLC control device includes a PLC main control module, an input isolation module, an output isolation module, an intermediate relay group module, a sensor group module, a communication module and a human-computer interaction interface. The input isolation module is used for signal filtering or voltage isolation. The input isolation module is equipped with a passive signal isolation unit to prevent high-voltage interference. The output isolation module is equipped with an analog signal output unit. The PLC main control module includes a PLC analog input terminal, a PLC digital input terminal, a PLC digital output terminal and a PLC analog output terminal.

[0008] It also includes an input link, an output link, and a communication link. In the input link, the sensor group module is communicatively connected to the input isolation module, and the input isolation module is communicatively connected to the analog input terminal or the digital input terminal of the PLC main control module; the passive signal isolation unit of the input isolation module receives the field device status signal and is communicatively connected to the PLC digital input terminal;

[0009] In the output link, the PLC digital output terminal is connected to the intermediate relay group module, which is connected to the field equipment; the PLC analog output terminal is connected to the analog signal output unit of the output isolation module, which is connected to the frequency converter; and the cloud server and mobile terminal are also included.

[0010] The PLC main control module of the communication link is connected to the communication module, and the communication module is connected to the cloud server or the mobile terminal.

[0011] It is further defined that the input isolation module is used for signal protection and voltage isolation, and the input isolation module includes a passive signal isolation unit and an analog signal isolation unit, the passive signal isolation unit is used to receive digital signals, and the analog signal isolation unit is used to receive analog signals.

[0012] It is further defined that the output isolation module includes: a digital signal switching unit and an analog signal output unit, the digital signal switching unit is used to control the intermediate relay, and the analog signal output unit is used to output the execution instruction.

[0013] It is further defined that the PLC main control module has a built-in control logic program, which includes an adaptive PID algorithm and a segmented self-optimizing control algorithm, which is used to adjust the water pump speed and valve opening of the heating device.

[0014] It is further defined that the communication module supports the Modbus RTU / TCP protocol, and the communication module is used to interact with the cloud server and the mobile terminal data.

[0015] Further defined, the sensor group module includes a temperature sensor, a pressure sensor and a flow sensor, and the sensor group module is used to collect the operation parameters of the heat exchange station in real time.

[0016] Further defined, each signal channel module of the device is independently encapsulated and replaced by hot plugging.

[0017] Further defined, the segmented self-optimizing control algorithm divides the load range through fuzzy logic and dynamically optimizes the air-to-coal ratio and the pump frequency;

[0018] The segmented self-optimizing control algorithm divides the load range through fuzzy logic and dynamically optimizes the air-to-coal ratio and the pump frequency;

[0019] Specifically, the segmented self-optimizing control algorithm divides the interval according to the heat load rate Divide the interval: low load (L≤50%): single pump operation; medium load (50%<L≤80%): double pumps in parallel; high load (L>80%): double pumps in parallel and valve opening adjustment.

[0020] A method for a heating PLC control device includes the following steps:

[0021] Step 1: Collect the on-site equipment signals through the input isolation module;

[0022] Step 2: The PLC main control module analyzes the data and generates control instructions;

[0023] Step 3: Drive the actuator through the output isolation module;

[0024] Step 4: When a fault occurs, start the backup control logic built in the PLC main control module and upload the alarm information.

[0025] Further defined, the calculation formula of the adaptive PID algorithm of the PLC main control module is as follows:

[0026]

[0027] Where, e(t) = T set- T real : The deviation between the set temperature and the actual temperature; K p , K i and K d are the basic PID parameters;

[0028] ΔK p (T out ) = 0.1×(T out + 5): Outdoor temperature compensation term, used to dynamically adjust the proportional gain.

[0029] The beneficial effects of the present invention:

[0030] Cost saving: The modules of this solution are all integrated designs instead of multi-module assembly, reducing procurement costs;

[0031] High reliability: The modules of this solution operate independently, and a single channel failure does not affect the overall system;

[0032] Safety: This solution adopts input / output isolation design to prevent high voltage from entering the PLC, protecting equipment and personnel safety;

[0033] Intelligence: Improve heating stability and save energy and protect the environment through adaptive algorithms.

[0034] In summary, the present invention realizes high reliability, low cost, and intelligent control through the design of an integrated PLC control device, integrating signal isolation, adaptive algorithms, and modular channels. It also realizes data collection, remote control, fault warning, and unattended operation of heat exchange station equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0036] Figure 1 This is a module diagram of an input link system of an embodiment of a heating PLC control device and method of the present invention;

[0037] Figure 2 This is a module diagram of an output link system of an embodiment of a heating PLC control device and method of the present invention;

[0038] Figure 3 This is a module diagram of a communication link system of an embodiment of a heating PLC control device and method of the present invention;

[0039] Figure 4 This is a flow chart of the steps of an embodiment of a heating PLC control device and method of the present invention.

[0040] The symbols of the main components are explained as follows: PLC main control module 101, input isolation module 102, output isolation module 103, intermediate relay group module 104, sensor group module 105, communication module 106, human-computer interaction interface 107, passive signal isolation unit 108, analog signal isolation unit 109, digital signal transfer unit 110, analog signal output unit 111, PLC digital input terminal 112, PLC analog input terminal 113, frequency converter 114, cloud server 115, mobile terminal 116, PLC digital output terminal 117, PLC analog output terminal 118. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the present invention, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts are within the scope of protection of the present invention.

[0042] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0044] like Figure 1 As shown, a heating PLC control device of the present invention includes a PLC main control module 101, an input isolation module 102, an output isolation module 103, an intermediate relay group module 104, a sensor group module 105, a communication module 106 and a human-computer interaction interface 107, wherein the input isolation module 102 is used for signal filtering or voltage isolation, and the input isolation module 102 is equipped with a passive signal isolation unit to prevent high-voltage interference, and the output isolation module 103 is equipped with an analog signal output unit 111, and the PLC main control module 101 includes a PLC analog input terminal 113, a PLC digital input terminal 112, a PLC digital output terminal 117 and a PLC analog output terminal 118;

[0045] It also includes an input link, an output link, and a communication link. In the input link, the sensor group module 105 is communicatively connected to the input isolation module 102, and the input isolation module 102 is communicatively connected to the analog input terminal or the digital input terminal of the PLC main control module 101; the passive signal isolation unit of the input isolation module 102 receives the field device status signal and is communicatively connected to the PLC digital input terminal 112;

[0046] In the output link, the PLC digital output terminal 117 is connected to the intermediate relay group module 104, which is connected to the field device; the PLC analog output terminal 118 is connected to the analog signal output unit 111 of the output isolation module 103, which is connected to the frequency converter 114; the PLC analog output terminal 118 is connected to the analog signal output unit 111 of the output isolation module 103, which is connected to the frequency converter 114; and the cloud server 115 and the mobile terminal 116 are also included.

[0047] The PLC main control module 101 of the communication link is connected to the communication module 106 , and the communication module 106 is connected to the cloud server 115 or the mobile terminal 116 .

[0048] In the actual application of this embodiment, the input isolation module 102 is used for signal protection and voltage isolation. The input isolation module 102 includes a passive signal isolation unit 108 and an analog signal isolation unit 109. The passive signal isolation unit 108 is used to receive digital signals, and the analog signal isolation unit 109 is used to receive analog signals.

[0049] In practical applications of this embodiment, the output isolation module 103 includes: a digital signal adapter unit 110 and an analog signal output unit 111. The digital signal adapter unit 110 is used to control the intermediate relay, and the analog signal output unit 111 is used to output execution instructions.

[0050] In the actual application of this embodiment, the PLC main control module 101 has a built-in control logic program, which includes an adaptive PID algorithm and a segmented self-optimizing control algorithm for adjusting the water pump speed and valve opening of the heating device.

[0051] In the actual application of this embodiment, the communication module 106 supports the Modbus RTU / TCP protocol, and the communication module 106 is used to exchange data with the cloud server 115 and the mobile terminal 116.

[0052] In practical applications of this embodiment, the sensor group module 105 includes a temperature sensor, a pressure sensor, and a flow sensor. The sensor group module 105 is used to collect operating parameters of the heat exchange station in real time.

[0053] In the practical application of this embodiment, each signal channel module of the device is independently packaged and replaced through hot plugging.

[0054] In the practical application of this embodiment, the segmented self-optimizing control algorithm divides the load range through fuzzy logic and dynamically optimizes the air-to-coal ratio and the pump frequency.

[0055] Specifically, according to the heat load rate Divide the intervals:

[0056] Low load (L ≤ 50%): Single pump operation;

[0057] Medium load (50% < L ≤ 80%): Two pumps in parallel;

[0058] High load (L > 80%): Two pumps in parallel + Valve opening adjustment.

[0059] A method for a heating PLC control device includes the following steps:

[0060] Step 1: Collect on-site device signals through the input isolation module 102;

[0061] Step 2: The PLC main control module 101 analyzes the data and generates control instructions;

[0062] Step 3: Drive the actuator through the output isolation module 103;

[0063] Step 4: When a fault occurs, start the built-in standby control logic of the PLC main control module 101 and upload alarm information.

[0064] In the practical application of this embodiment, the calculation formula of the adaptive PID algorithm of the PLC main control module 101 is as follows:

[0065]

[0066] Among them, e(t) = T set- T real : The deviation between the set temperature and the actual temperature; K p 、K i and K d are the basic PID parameters;

[0067] ΔK p (T out ) = 0.1×(T out +5): Outdoor temperature compensation term, used to dynamically adjust the proportional gain.

[0068] Embodiment 1: Application in small and medium-sized heat exchange stations

[0069] Scenario: A heat exchange station in a certain community, with a heating area of 100,000 square meters.

[0070] Configuration: Siemens S7-1200 PLC, 4 analog inputs (temperature, pressure), 2 analog outputs (circulation pump inverter).

[0071] Operation logic:

[0072] PLC dynamically adjusts the secondary network water supply temperature (target value T set =0.5×T out +45);

[0073] The frequency converter 114 receives the 4-20mA signal and adjusts the speed of the circulation pump.

[0074] Substitute the values:

[0075] When T out =-5℃, T set =0.5×(-5)+45=42.5°;

[0076] PLC outputs 4-20mA signal to the frequency converter 114 (corresponding to 0-50Hz). If the target frequency f set =35Hz, then the output current I=4+(35 / 50)×16=15.2mA.

[0077] Example 2: Large-scale regional heat exchange station

[0078] Scenario: Centralized heating in an industrial park, equipped with three circulation pumps (two in use and one in standby).

[0079] Control strategy: The segmented self-optimization algorithm optimizes the water pump combination. When the load is less than 50%, a single pump is operated. When the load is greater than 80%, two pumps are connected in parallel.

[0080] Segmented self-optimization logic:

[0081] Conditions: Total heat load Q = 1200kW, maximum power of single pump Q max =800kW;

[0082] Calculation: L = 1200 / 800 = 150%, triggering high load mode;

[0083] Action suggestion: Two pumps in parallel (total power 1600kW) + valve opening adjusted to 70%.

[0084] Example 3: Wireless Data Integration

[0085] Scenario: Renovation of an old heat exchange station where wiring is not possible.

[0086] Configuration: PLC is equipped with a LoRa wireless module, and sensor data is transmitted wirelessly to the control center.

[0087] LoRa wireless module communication parameters:

[0088] Frequency: 433MHz, transmission distance 1km;

[0089] Data packet format: [temperature: 25.3℃, pressure: 200kPa, status: normal], uploaded every 10 seconds.

[0090] Example 4: Multi-system linkage

[0091] Scenario: Linked with the peak and valley electricity prices of the municipal power grid.

[0092] Peak and valley electricity price strategy:

[0093] Off-peak hours (22:00-6:00): The target temperature of the hot water tank is increased to 85°C (originally set at 75°C);

[0094] Peak electricity period (10:00-14:00): the pump frequency is reduced from 45Hz to 35Hz,

[0095] Logic: Increase the temperature of the hot water tank during off-peak hours and reduce the pump frequency during peak hours, saving 20% of electricity costs.

[0096] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A heating PLC control device, characterized by: The invention comprises a PLC main control module (101), an input isolation module (102), an output isolation module (103), an intermediate relay group module (104), a sensor group module (105), a communication module (106) and a human-machine interaction interface (107); the input isolation module (102) is used for signal filtering or voltage isolation; the input isolation module (102) is equipped with a passive signal isolation unit for preventing high-voltage interference; the output isolation module (103) is equipped with an analog signal output unit (111); the PLC main control module (101) comprises a PLC analog input terminal (113), a PLC digital input terminal (112), a PLC digital output terminal (117) and a PLC analog output terminal (118); It also includes an input link, an output link, and a communication link. In the input link, the sensor group module (105) is communicatively connected to the input isolation module (102), and the input isolation module (102) is communicatively connected to the analog input terminal or the digital input terminal of the PLC main control module (101); the passive signal isolation unit of the input isolation module (102) receives a field device status signal and is communicatively connected to the PLC digital input terminal (112); In the output link, a PLC digital output terminal (117) is connected to an intermediate relay group module (104), which is connected to a field device; a frequency converter (114) is also included; a PLC analog output terminal (118) is connected to an analog signal output unit (111) of an output isolation module (103), which is connected to the analog signal output unit (111) of the frequency converter (114); and a cloud server (115) and a mobile terminal (116) are also included. The PLC main control module (101) of the communication link is connected to a communication module (106), and the communication module (106) is connected to a cloud server (115) or a mobile terminal (116).

2. A heating PLC control device according to claim 1, characterized in that: The input isolation module (102) is used for signal protection and voltage isolation. The input isolation module (102) comprises a passive signal isolation unit (108) and an analog signal isolation unit (109). The passive signal isolation unit (108) is used to receive digital signals, and the analog signal isolation unit (109) is used to receive analog signals.

3. A heating PLC control device according to claim 1, characterized in that: The output isolation module (103) comprises: a digital signal switching unit (110) and an analog signal output unit (111); the digital signal switching unit (110) is used to control an intermediate relay; and the analog signal output unit (111) is used to output an execution instruction.

4. A heating PLC control device according to claim 1, characterized in that: The PLC main control module (101) is equipped with a built-in control logic program, which includes an adaptive PID algorithm and a segmented self-optimizing control algorithm for adjusting the water pump speed and valve opening of the heating device.

5. A heating PLC control device according to claim 1, characterized in that: The communication module (106) supports the Modbus RTU / TCP protocol, and the communication module (106) is used for data interaction with the cloud server (115) and the mobile terminal (116).

6. A heating PLC control device according to claim 1, characterized in that: The sensor group module (105) includes a temperature sensor, a pressure sensor, and a flow sensor. The sensor group module (105) is used to collect operating parameters of the heat exchange station in real time.

7. A heating PLC control device according to claim 1, characterized in that: Each signal channel module of the device is independently packaged and can be replaced by hot plugging.

8. A heating PLC control method according to claim 4, characterized in that: The segmented self-optimizing control algorithm divides the load intervals by fuzzy logic and dynamically optimizes the air-coal ratio and water pump frequency; Specifically, the segmented self-optimizing control algorithm is based on the heat load rate to divide intervals: low load (L ≤ 50%): single pump operation; medium load (50% < L ≤ 80%): two pumps in parallel; high load (L > 80%): two pumps in parallel and valve opening adjustment.

9. A method based on the heating PLC control device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: collecting field device signals through the input isolation module (102); Step 2: The PLC main control module (101) analyzes the data and generates control instructions; Step 3: driving the actuator via the output isolation module (103); Step 4: When a fault occurs, the backup control logic built into the PLC main control module (101) is started and the alarm information is uploaded.

10. A heating PLC control method according to claim 9, characterized in that: The calculation formula of the adaptive PID algorithm of the PLC main control module (101) is as follows: Where, e(t) = T set- T real : Deviation between set temperature and actual temperature; K p , K i and K d As the basic PID parameters; ΔK p (T out )=0.1×(T out +5): Outdoor temperature compensation item, used to dynamically adjust the proportional gain.

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