CN108561887B - Control method for hearth temperature - Google Patents
Control method for hearth temperature Download PDFInfo
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- CN108561887B CN108561887B CN201810336155.0A CN201810336155A CN108561887B CN 108561887 B CN108561887 B CN 108561887B CN 201810336155 A CN201810336155 A CN 201810336155A CN 108561887 B CN108561887 B CN 108561887B
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- 238000000034 method Methods 0.000 title claims abstract description 17
- 239000000779 smoke Substances 0.000 claims description 18
- 238000002485 combustion reaction Methods 0.000 claims description 13
- 230000008878 coupling Effects 0.000 claims description 3
- 238000010168 coupling process Methods 0.000 claims description 3
- 238000005859 coupling reaction Methods 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 230000004044 response Effects 0.000 abstract description 4
- 238000006243 chemical reaction Methods 0.000 description 9
- 230000003750 conditioning effect Effects 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- 239000003546 flue gas Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000002912 waste gas Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000009191 jumping Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
- F23G5/50—Control or safety arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G2207/00—Control
- F23G2207/10—Arrangement of sensing devices
- F23G2207/101—Arrangement of sensing devices for temperature
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Incineration Of Waste (AREA)
Abstract
The invention relates to a control method of hearth temperature. The control method comprises the following specific steps: the first step is as follows: transfusion systemPre-stored data is input; the second step is that: determining the real-time temperature T (k) of the hearth k moment;
the third step: determining the rotating speeds n1 and n2 of 2 fans; comparing T (k) with Tc＝(Tb‑T0) 80% size, TbIs the target temperature of the hearth; if T (k) ≦ TcIf N1 is N1, N2 is N2; if not, then,
entering PID regulation control; Δ n (K) ═ Kp[e(k)‑e(k‑1)]+Ki·e(k)+Kd[e(k)‑2e(k‑1)+2e(k‑2)](ii) a Fourthly, driving 2 fans in the garbage disposal equipment according to the rotating speeds n1 and n 2. The invention solves the problems of constant temperature regulation of the hearth temperature and air flow control, and improves the response speed of the hearth temperature regulation.
Description
Technical Field
The invention belongs to the technical field of garbage treatment, and particularly relates to a hearth temperature control method.
Background
The combustion temperature control of the hearth of the existing garbage treatment furnace is realized by controlling the air flow entering the hearth through a manual switch valve, and the air flow in the hearth is realized by negative pressure generated by the rising of hot air flow, so the air flow entering the hearth is unstable and uncontrollable, the response speed of manual control of the furnace temperature is slow, the combustion temperature fluctuation in the hearth is large, and the generated harmful gas has more components, which is not beneficial to environmental protection.
Disclosure of Invention
The invention aims to provide a control method of hearth temperature, which realizes the dynamic controllability of the whole requirement of the garbage treatment furnace from ignition to stable combustion and at an ideal temperature point of flue gas emission, solves the problem of constant temperature regulation of the hearth temperature during the work of the garbage treatment furnace, achieves the reliable control of air flow and further improves the response speed of hearth temperature regulation.
The technical scheme of the invention is that 1, a control method of hearth temperature is characterized in that: the control method comprises the following specific steps:
the first step is as follows: inputting pre-stored data; the pre-stored data comprises a corresponding relation table of PID parameters and temperature difference, a target value of the temperature of the hearth and the maximum difference value between two adjacent acquired data of the same temperature sensorΔTmax；
The second step is that: judging whether the temperature in the hearth rises to 80% of a set value or not, and determining the real-time temperature T (k) of the hearth at the moment k;
in the formula: i is 0-n, wherein n is the number of temperature sensors in the hearth; beta is aiThe weight coefficient of the ith temperature sensor is 0-1; k is the current time; 1, 2, 3., and t (k) is a real-time temperature of the furnace at the time k; t is0The initial temperature of the hearth; the temperature units are degrees; t isi(k) The real-time temperature of the ith temperature sensor k in the hearth is obtained;
the third step: determining the rotating speeds n1 and n2 of 2 fans;
comparing T (k) with Tc＝(Tb-T0) 80% size, TbIs the target temperature of the hearth;
if T (k) ≦ TcIf N1 is N1, N2 is N2; in the formula, N1 is the highest rotating speed of the air inlet fan, and N2 is the highest rotating speed of the smoke exhaust fan; if not, then,
entering PID regulation control; wherein the content of the first and second substances,
Δn(k)＝Kp[e(k)-e(k-1)]+Kj·e(k)+Kd[e(k)-2e(k-1)+2e(k-2)](ii) a Δ n (k) is the fan speed PID control increment;
e(k)＝Tb-t (k); e (k) is the difference between the current temperature and the control target temperature;
PID parameter proportionality coefficient KpIntegral coefficient KiDifferential coefficient KdAnd determining according to a corresponding relation table of PID parameters and temperature differences stored in a memory in advance.
Fourthly, driving an inlet fan 8 and a smoke exhaust fan 9 in the garbage treatment equipment according to the determined 2 fan rotating speeds n1 and n2, so that the coupling adjustment of the air inlet fan 8 and the smoke exhaust fan 9 is realized, and the combustion temperature of the garbage in the hearth is adjusted.
ΔTmax1 degree.
The T isi(k) According to the following formula, if the difference value Delta T of the temperature data acquired by two adjacent temperature sensors is less than or equal to Delta TmaxThen T isi(k) Equal to the collection temperature, otherwise
Ti(k)＝Ti(k-1)+αΔTi(k-1)+(1-α)ΔTi(k-2), alpha is more than or equal to 0.5 and less than or equal to 1, alpha is an integral weight coefficient, and alpha is 0.65.
The invention has the advantages that 1) the whole process from ignition to constant-temperature stable combustion of the garbage treatment furnace is controllable, the temperature measurement precision is improved, and the measurement signal more truly reflects the temperature distribution condition in the hearth; 2) the invention ensures that the flow of air entering the hearth is accurately regulated, reduces the flow resistance of the flue gas discharge flue to the air flow, and improves the control response speed of the combustion temperature of the hearth; 3) the invention enables the garbage disposal furnace to realize self-adaptive constant temperature control on garbage combustion with different moisture contents and different components entering the hearth, so that the garbage disposal furnace works in an ideal state; 4) the higher the garbage treatment temperature is, the higher the garbage treatment efficiency is, and the invention realizes the control of the combustion temperature, thereby controlling the garbage treatment efficiency.
Drawings
FIG. 1 is a schematic diagram of a method for controlling the temperature of a furnace according to the present invention;
FIG. 2 is a schematic view showing the structure of a control device for a furnace temperature control method according to the present invention;
FIG. 3 is a schematic view showing the construction of a control cabinet in the control apparatus according to the present invention;
fig. 4 is a schematic view of an assembly structure of a control device using the present invention.
Detailed Description
As shown in FIG. 1, the control method of the hearth temperature of the invention comprises the following specific steps:
the first step is as follows: initializing and inputting pre-stored data. Pre-stored data is input to the controller through the input display device, namely a corresponding relation table of PID parameters and temperature difference, a target value of the temperature of the hearth and a maximum difference value delta T between two adjacent acquired data of the same temperature sensormax，ΔTmax1 degree.
The second step is that: judging whether the temperature in the hearth rises to 80% of a set value or not, and determining the real-time temperature T (k) of the hearth at the moment k.
In the formula: i is 0-n, wherein n is the number of temperature sensors in the hearth;
βithe weighting coefficient of the ith temperature sensor is 0-1, the distance between the temperature sensor and the center of the hearth is a large value, and the distance between the temperature sensor and the center of the hearth is a small value;
k is the current time; the k value is varied, meaning the warming process, k 1, 2, 3.
T (k) is the real-time temperature of the hearth at the moment k;
T0the initial temperature of the hearth; the temperature units are degrees;
Ti(k) is the real-time temperature T of the ith temperature sensor k in the hearthi(k) Is determined according to the following formula, namely if the difference value Delta T of the temperature data acquired by two adjacent temperature sensors is less than or equal to Delta TmaxThen T isi(k) Equal to the collection temperature, otherwise
Ti(k)＝Ti(k-1)+αΔTi(k-1)+(1-α)ΔTi(k-2), alpha is more than or equal to 0.5 and less than or equal to 1.α is an integral weight coefficient, and α is 0.65.
The third step: the rotational speeds n1 and n2 of the 2 fans are determined.
Comparing T (k) with Tc＝(Tb-T0) 80% size, TbIs the target temperature of the hearth;
if T (k) ≦ TcIf N1 is N1, N2 is N2; wherein N1 is the highest of the inlet fansAnd N2 is the highest rotating speed of the smoke exhaust fan, and the rotating speed unit is r/min. When the garbage treatment furnace starts to work, the temperature in the furnace has a larger chance of jumping, and the fan outputs at the highest rotating speed, so that the temperature in the furnace rises quickly.
If not, then,
the k value is changed, which means the heating process, and the PID regulation control is entered.
Wherein the content of the first and second substances,
Δn(k)＝Kp[e(k)-e(k-1)]+Ki·e(k)+Kd[e(k)-2e(k-1)+2e(k-2)](ii) a Δ n (k) is the fan speed PID control increment;
temperature difference e (k) Tb-t (k); e (k) is the difference between the current temperature and the control target temperature.
PID parameter proportionality coefficient KpIntegral coefficient KiDifferential coefficient KdAnd determining according to a corresponding relation table of PID parameters and temperature differences stored in a memory in advance.
Fourthly, the controller outputs control signals to control 2 fans to operate at the rotating speeds n1 and n2, and therefore the temperature in the furnace is automatically adjusted. According to the 2 fan rotating speeds n1 and n2 determined in the steps, the inlet fan 8 and the smoke exhaust fan 9 in the garbage disposal equipment are driven, the 2 fan rotating speeds are controlled, the coupling adjustment of the air inlet fan 8 and the smoke exhaust fan 9 is realized, and the air flow rate in the hearth of the garbage disposal furnace 1 is determined, so that the garbage combustion temperature in the hearth is adjusted, and the optimal process temperature requirement of garbage combustion is met.
As shown in fig. 2 and 4, the furnace temperature control device comprises a control cabinet 3, a touch screen, a plurality of temperature sensors, an air inlet pipe and 2 fans. The 2 fans are an air inlet fan 8 and a smoke exhaust fan 9. Touch-sensitive screen, a plurality of temperature sensor, air inlet fan 8 and smoke exhaust fan 9 all are connected with switch board 3 through the cable. 2 fans are all frequency-conversion speed-regulation fans.
The intake pipe is fixed in the furnace of refuse handling furnace 1, specifically arranges in the lateral wall of furnace and middle bottom, is provided with a plurality of ventholes in the intake pipe, and the venthole is located the below of intake pipe to axial distribution along the intake pipe. A plurality of temperature sensor fix respectively in refuse treatment furnace 1's furnace, fix respectively on refuse treatment furnace's furnace both sides inner wall and middle part riser promptly, and a plurality of furnace temperature sensor distribute along the direction of height of both sides inner wall and middle part riser, refuse treatment furnace 1's furnace both sides inner wall respectively fixes 3 temperature sensor along the direction of height, along the fixed 3 temperature sensor of direction of height on the riser in refuse treatment furnace 1's furnace middle part, a plurality of temperature sensor pass through the cable and are connected with switch board 3. The air inlet of the air inlet fan 8 is communicated with the atmosphere, and the air outlet of the air inlet fan 8 is communicated with the air inlet pipe through a pipeline 7. An air inlet of the smoke exhaust fan 9 is connected with an air outlet of a dust removal device in the garbage disposal equipment, and an air outlet of the smoke exhaust fan 9 is connected with an air inlet of a waste gas treatment device in the garbage disposal equipment.
The touch screen is connected with the control cabinet 3 through a power line and a signal line, receives the relation table of the initial temperature (namely room temperature) in the hearth, the target temperature of the hearth, the maximum difference value of the real-time temperature value and the target temperature and the temperature difference value and the PID control parameter input by an operator, the PID control parameter refers to a proportional coefficient, a differential coefficient and an integral coefficient, and displays the working temperature of the hearth output by the control cabinet 3 in real time.
A plurality of temperature sensor pass through cable junction to switch board 3, and temperature sensor detects the temperature of different positions in the furnace in real time to will detect the temperature and export for the switch board in real time.
The intake fan 8 and the exhaust fan 9 are connected to the control cabinet 3 by cables.
The control cabinet receives signals of the touch screen and the temperature sensors, processes the received signals, selects PID control parameters according to the received data so as to determine respective increment of the rotating speeds of the 2 fans, obtains the frequency or voltage of the rotating speed control signals of the fans, and respectively outputs the frequency or voltage of the rotating speed control signals of the fans to the frequency converters of the 2 fans through the control signals, thereby realizing the control of the rotating speeds of the two fans.
As shown in fig. 3, the control cabinet 3 includes a controller, a power processing module, a man-machine interface terminal, a hearth temperature signal conditioning module, an air inlet machine frequency conversion control module and an exhaust machine frequency conversion control module. The power supply processing module, the man-machine interface terminal, the hearth temperature signal conditioning module, the air inlet machine variable-frequency control module and the smoke exhaust machine variable-frequency control module are connected with the controller through cables.
The power supply processing module provides power supply, namely the power supply is supplied to the controller, the hearth temperature signal conditioning module, the air inlet machine frequency conversion control module, the smoke exhaust machine frequency conversion control module and 2 fans.
The hearth temperature signal conditioning module is connected with the plurality of temperature sensors through cables, receives signals output by the plurality of temperature sensors, filters, amplifies and shapes the received signals output by the plurality of temperature sensors to eliminate interference signals and meet the requirement of the controller for processing the signals, and outputs the processed signals to the controller.
The controller is connected with the control cabinet 3, the touch screen and the 2 fans through the man-machine interface terminal. The controller receives and stores data input by the touch screen. The controller reads an output signal of the hearth temperature signal conditioning module, calculates a difference value between a currently acquired real-time temperature value and a target temperature according to an initial temperature in the hearth and a target temperature of the hearth, selects a PID control parameter from a relation table of the temperature difference value and the PID control parameter, determines respective increment of 2 fan rotating speeds, obtains a fan rotating speed control signal (frequency or voltage), respectively outputs the control signal to the fan inlet frequency control module and the smoke exhaust fan frequency control module, controls the rotating speeds of the two fans, and controls the temperature of garbage combustion in the hearth of the garbage treatment furnace 1.
The air inlet machine frequency conversion control module and the smoke exhaust machine frequency conversion control module are connected with the controller and the corresponding fans through cables, and the air inlet machine frequency conversion control module and the smoke exhaust machine frequency conversion control module receive control signals (namely fan rotating speeds) of the controller, convert the control signals into corresponding voltages, and output the voltage values to frequency converters of 2 fans, so that the rotating speeds of the fans are controlled.
The invention is suitable for controlling the hearth temperature of the garbage treatment furnace 1 and the waste gas treatment heating electric furnace. When the garbage disposal furnace 1 works, the temperature in the hearth is adjusted, and the constant-temperature combustion of the hearth is controlled.
Claims (1)
1. A control method of hearth temperature is characterized in that: the control method comprises the following specific steps:
the first step is as follows: inputting pre-stored data; the pre-stored data comprises a corresponding relation table of PID parameters and temperature difference, a target value of the temperature of the hearth and a maximum difference value delta T between two adjacent acquired data of the same temperature sensormax；
The second step is that: judging whether the temperature in the hearth rises to 80% of a set value or not, and determining the real-time temperature T (k) of the hearth at the moment k;
in the formula: i is 0-n, wherein n is the number of temperature sensors in the hearth; beta is aiThe weight coefficient of the ith temperature sensor is 0-1; k is the current time; t (k) is the real-time temperature of the furnace at time k; t is0The initial temperature of the hearth; the temperature units are degrees; t isi(k) The real-time temperature of the ith temperature sensor k in the hearth is obtained;
the third step: determining the rotating speeds n1 and n2 of 2 fans;
comparing T (k) with Tc＝(Tb-T0) 80% size, TbIs the target temperature of the hearth;
if T (k) ≦ TcIf N1 is N1, N2 is N2; in the formula, N1 is the highest rotating speed of the air inlet fan, and N2 is the highest rotating speed of the smoke exhaust fan; if not, then,
entering PID regulation control; wherein the content of the first and second substances,
Δn(k)＝Kp[e(k)-e(k-1)]+Ki·e(k)+Kd[e(k)-2e(k-1)+2e(k-2)]；
Δ n (k) is the fan speed PID control increment;
e(k)＝Tb-t (k); e (k) is the current temperatureA difference from a control target temperature;
PID parameter proportionality coefficient KpIntegral coefficient KiDifferential coefficient KdDetermining according to a corresponding relation table of PID parameters and temperature differences stored in a memory in advance;
fourthly, driving an air inlet fan (8) and a smoke exhaust fan (9) in the garbage treatment equipment according to the determined 2 fan rotating speeds n1 and n2, so that the coupling adjustment of the air inlet fan (8) and the smoke exhaust fan (9) is realized, and the combustion temperature of the garbage in the hearth is adjusted;
ΔTmax1 degree;
the T isi(k) According to the following formula, if the difference value Delta T of the temperature data acquired by two adjacent temperature sensors is less than or equal to Delta TmaxThen T isi(k) Equal to the collection temperature, otherwise
Ti(k)＝Ti(k-1)+αΔTi(k-1)+(1-α)ΔTi(k-2), alpha is more than or equal to 0.5 and less than or equal to 1, and alpha is an integral weight coefficient.
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| CN109765948B (en) * | 2019-03-11 | 2019-10-11 | 广东明峰医疗科技有限公司 | Non-overshoot temperature control algorithm for CT detector |
| CN112181014A (en) * | 2020-08-21 | 2021-01-05 | 内蒙古航天金岗重工有限公司 | Temperature control method and device suitable for garbage pyrolysis furnace and electronic equipment |
| CN112000149B (en) * | 2020-08-31 | 2021-07-23 | 万华化学集团股份有限公司 | Method, storage medium and system for automatically controlling temperature of batch reactor |
| CN116293718A (en) * | 2023-05-24 | 2023-06-23 | 中城院(北京)环境科技股份有限公司 | Self-adaptive PID incinerator temperature control method and device based on snake optimization algorithm |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103123460A (en) * | 2011-11-21 | 2013-05-29 | 才秀君 | Temperature control system and temperature control method |
| CN103411234A (en) * | 2013-08-26 | 2013-11-27 | 罗泽云 | Quantitative air distribution economic combustion energy saving control system |
| CN105094177A (en) * | 2015-07-29 | 2015-11-25 | 南京汉之力化工科技有限公司 | High-precision constant-temperature controller and method based on fuzzy self-adaptive PID control |
| CN106871156A (en) * | 2015-12-13 | 2017-06-20 | 杨挺 | A kind of environmentally friendly combustion control system |
| CN106959007A (en) * | 2017-04-28 | 2017-07-18 | 大连重工机电设备成套有限公司 | Turnbarrel shaft furnace process control system |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103123460A (en) * | 2011-11-21 | 2013-05-29 | 才秀君 | Temperature control system and temperature control method |
| CN103411234A (en) * | 2013-08-26 | 2013-11-27 | 罗泽云 | Quantitative air distribution economic combustion energy saving control system |
| CN105094177A (en) * | 2015-07-29 | 2015-11-25 | 南京汉之力化工科技有限公司 | High-precision constant-temperature controller and method based on fuzzy self-adaptive PID control |
| CN106871156A (en) * | 2015-12-13 | 2017-06-20 | 杨挺 | A kind of environmentally friendly combustion control system |
| CN106959007A (en) * | 2017-04-28 | 2017-07-18 | 大连重工机电设备成套有限公司 | Turnbarrel shaft furnace process control system |
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