A float glass electric heating fully automatic ramp temperature control system and control method

Abstract

The invention discloses a fully automatic ramp-up temperature control system and a control method for electric heating of float glass, and relates to the field of automatic control of electric heating of float glass. The control system and a control method comprise a curve input module, an automatic ramp-up module, a sensor fault identification module, a time calculation module, and a pause and resume function module. The temperature ramp-up and down slope of each curve segment is calculated by providing a temperature ramp-up curve in advance, and the theoretical temperature of electric heating at each time point is obtained thereby. The ramp parameters are calculated in real time, and the ramp parameters are controlled to be within a reasonable range by controlling a PID set value. The PID set value serves as a guide for a power controller to control the temperature. Thus, the temperature is steadily increased or decreased within the adjustment range, and the problem of automatic electric heating of float glass is solved thereby.

Description

Technical Field

[0001] The invention belongs to the field of electric heating of float glass and relates to automatic control technology, in particular to a full-automatic ramp-up temperature control system and a control method for electric heating of float glass. Background Art

[0002] The process characteristics of float glass cannot be separated from the electric heating system. Taking the annealing furnace process as an example, the annealing temperature is crucial to the quality of the glass. Therefore, before starting the plate drawing, the temperature of the annealing furnace must be raised to the appropriate temperature in advance to allow the process equipment to expand in advance, and then cooled and inspected. After the inspection is completed, the temperature is raised to the temperature required for the plate drawing, and then the annealing furnace is kept warm. This process generally takes 7 to 10 days. The temperature increase / lowering work during this period must be strictly carried out in accordance with the equipment characteristics of the annealing furnace, otherwise it will cause uneven expansion of the annealing furnace, which will directly affect the quality of the annealing furnace equipment and may even cause equipment damage in severe cases. The traditional annealing furnace temperature increase / lowering is manually operated, and the temperature is set every half an hour to an hour according to the curve drawn in advance. The workload is large and the error rate is high;

[0003] Therefore, a float glass electric heating fully automatic ramping temperature control system and control method are proposed. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a fully automatic ramp temperature control system and control method for electric heating of float glass, which calculates the temperature rise and fall slope of each curve segment by providing a temperature ramp curve in advance; thereby obtaining the theoretical temperature of electric heating at each time point; and calculating the ramp parameters in real time, and controlling the ramp parameters within a reasonable range by controlling the PID set value; and the PID set value serves as a guide for the power controller to control the temperature; thereby, the temperature is steadily raised and lowered within the adjustment range; thereby solving the problem of automatic electric heating of float glass.

[0005] To achieve the above object, according to an embodiment of the first aspect of the present invention, a float glass electric heating fully automatic ramp temperature control system is provided, comprising a curve entry module, an automatic ramp module, a sensor fault identification module, a time calculation module, and a pause and continue function module; wherein the modules are electrically connected to each other;

[0006] Among them, the curve input module is used to input the temperature ramp curve and calculate the unit target temperature according to the temperature ramp curve;

[0007] Each inflection point (T1, t1), (T2, t2) ... (TN, tN) of the temperature ramp curve is set manually according to the actual conditions of different heating furnaces; the line segment from (Tn, tn) to (T(n+1), t(n+1)) constitutes a curve segment; Tn is the starting temperature, and T(n+1) is the ending temperature; wherein n = 1, 2 ... N; N represents the number of ramp curve stages;

[0008] When the curve data is entered into the curve entry module, the control system automatically calculates the speed slope of the temperature increase / decrease according to the curve data. Then, the target temperature per second from time t0 to time tN is calculated using the obtained speed slope Vn, that is, the target temperature per second in each curve segment is calculated with a resolution of 1 second; the curve input module sends the temperature data per second to the automatic ramp module;

[0009] Wherein, the automatic ramp module is used to control the temperature of the annealing kiln according to the set temperature curve using the pre-ramp program;

[0010] The pre-ramp program includes a set of PID set value pre-ramp algorithms; the PID set value pre-ramp algorithm controls a pulse signal with a duty cycle of 0.5, and calculates a ramp parameter γ through the edge signal of the pulse signal; the minimum temperature value fed back by the sensor is marked as M; the PID set value calculated by the automatic ramp program according to the curve is marked as N; the interval time between the edge signals of the two pulse signals is marked as b; the ramp parameter γ is calculated as follows: The sensors are several temperature sensors used to monitor the real-time temperature in the annealing kiln;

[0011] Determine whether the value of the slope parameter γ is within the interval of 1 times the speed slope Vn of the automatic calculation curve for temperature increase / decrease and 2 times the speed slope Vn of the automatic calculation curve for temperature increase / decrease. If not within the interval, modify the PID set value N to ensure that the slope parameter γ is always within the interval; control the temperature in the annealing furnace by the PID control power controller; ensure that the temperature rises and falls steadily within the adjustment range; and simultaneously control the pulse signal with a duty cycle of 0.5 to calculate and update the slope parameter γ in real time; the power controller is used to control the power output of the electric heating of the float glass; that is, the power controller controls the temperature rise and fall in the annealing furnace by controlling the electric power;

[0012] When the automatic ramp module is started, it sends a start signal to the time calculation module; when the automatic ramp module completes the temperature ramp of all curve segments, it sends a re-timing signal to the time calculation module;

[0013] The sensor fault identification module is mainly used to determine whether a sensor fault occurs; the sensor includes a voltage sensor, a current sensor and a temperature sensor;

[0014] When the voltage sensor, the current sensor and the temperature sensor all fail, the sensor failure identification module sends a sensor failure signal to the pause and continue function module;

[0015] Among them, the time calculation module is mainly used to calculate the running time; when the time calculation module receives a start signal, the timing is started; when the time calculation module receives a stop signal, the timing is stopped; the time calculation module sends the running time to the pause and continue function module in real time; when the time calculation module receives a re-timing signal, the time calculation module resets the running time;

[0016] The pause and continue function module is mainly used to pause the temperature ramp when a sensor failure or external failure occurs, and to continue the temperature ramp after the failure is repaired;

[0017] Wherein, the external faults include power controller communication interruption fault, interface fault and communication fault;

[0018] When a sensor failure or external failure occurs, the pause and continue function module sends a pause signal to the automatic climbing module, and the automatic climbing module controls the power controller to shut down, and records the current power controller state, PID setting value and current running time data; and sends a termination signal to the time calculation module;

[0019] When the sensor fault or external fault is repaired, the pause and resume function module sends a resume signal to the automatic climbing module; the automatic climbing module controls the power controller to start; and restarts the temperature climbing according to the power controller state at the time of pause, the PID setting value and the slope calculated according to the running time at the time of pause; and sends a start signal to the time calculation module;

[0020] When the sensor fails or the external fault cannot be repaired, the automatic climbing program is manually turned off; and a re-timing signal is sent to the time calculation module.

[0021] According to an embodiment of the second aspect of the present invention, a float glass electric heating fully automatic ramp temperature control method is provided, comprising the following steps:

[0022] Step 1: The curve input module inputs the temperature ramp curve and calculates the unit target temperature according to the temperature ramp curve;

[0023] Step 2: The automatic ramp module calculates the ramp parameters according to the temperature ramp curve and controls the range of the ramp parameters to adjust the temperature to rise and fall steadily within the adjustment range; and starts timing when the power controller is started; ends timing after the temperature ramp is completed, and resets the running time;

[0024] Step 3: The sensor fault identification program monitors whether the sensor is faulty and the validity of the data in real time; and when the current sensor, voltage sensor and temperature sensor fault are sensed, a pause signal is sent to the pause and continue function module;

[0025] Step 4: The pause and continue function module monitors the system in real time whether an external fault occurs, and promptly pauses the temperature ramp when an external fault or sensor fault occurs; and continues the temperature ramp when the sensor fault or external fault is resolved.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention provides a temperature ramp curve in advance, calculates the temperature rise and fall slope of each curve segment, thereby obtaining the theoretical temperature of electric heating at each time point, and calculates the ramp parameters in real time, and controls the ramp parameters within a reasonable range by controlling the PID set value. The PID set value serves as a guide for the power controller to control the temperature, thereby achieving steady temperature rise and fall within the adjustment range, and thereby solving the problem of automatic electric heating of float glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the principle diagram of the present invention;

[0029] Figure 2 This is an example of a temperature curve diagram of an embodiment of the present invention;

[0030] Figure 3 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] like Figure 1 As shown, a float glass electric heating fully automatic ramp-up temperature control system includes a curve entry module, an automatic ramp-up module, a sensor fault identification module, a time calculation module, and a pause and continue function module; wherein each module is electrically connected;

[0033] Among them, the curve input module is used to input the temperature ramp curve and calculate the unit target temperature according to the temperature ramp curve;

[0034] Wherein, the temperature climbing curve is as follows: Figure 2As shown, T represents temperature and t represents time; each inflection point (T1, t1), (T2, t2)…(TN, tN) of the curve is set manually according to the actual conditions of different heating furnaces; the line segment from (Tn, tn) to (T(n+1), t(n+1)) constitutes a curve segment; Tn is the starting temperature and T(n+1) is the ending temperature; wherein n=1, 2…N; wherein N represents the number of ramp curve stages; as shown Figure 2 The number of curve stages N in is 8;

[0035] When the starting temperature of each curve segment is equal to the target temperature, the curve entry module determines that the process requirement is insulation;

[0036] When the curve data is entered into the curve entry module, the control system automatically calculates the speed slope of the temperature increase / decrease according to the curve data. Then, the target temperature per second from time t0 to time tN is calculated using the obtained speed slope Vn, that is, the target temperature per second in each curve segment is calculated with a resolution of 1 second; the curve input module sends the temperature data per second to the automatic ramp module;

[0037] Wherein, the automatic ramp module is used to control the temperature of the annealing kiln according to the set temperature curve using the pre-ramp program;

[0038] The pre-ramp program includes a set of PID set value pre-ramp algorithms; the PID set value pre-ramp algorithm controls a pulse signal with a duty cycle of 0.5, and calculates a ramp parameter γ through the edge signal of the pulse signal; the minimum temperature value fed back by the sensor is marked as M; the PID set value calculated by the automatic ramp program according to the curve is marked as N; the interval time between the edge signals of the two pulse signals is marked as b; the ramp parameter γ is calculated as follows: The sensors are several temperature sensors used to monitor the real-time temperature in the annealing kiln;

[0039] Determine whether the value of the slope parameter γ is within the interval of 1 times the speed slope Vn of the automatic calculation curve for temperature increase / decrease and 2 times the speed slope Vn of the automatic calculation curve for temperature increase / decrease. If not within the interval, modify the PID set value N to ensure that the slope parameter γ is always within the interval; control the temperature in the annealing furnace by the PID control power controller to ensure that the actual value does not deviate too much from the set value; ensure that the temperature rises and falls steadily within the adjustment range; and simultaneously control the pulse signal with a duty cycle of 0.5 to calculate and update the slope parameter γ in real time; the power controller is used to control the power output of the electric heating of the float glass; that is, the power controller controls the temperature rise and fall in the annealing furnace by controlling the electric power;

[0040] When the automatic ramp module is started, it sends a start signal to the time calculation module; when the temperature ramp of all curve segments is completed, the automatic ramp module sends a re-timing signal to the time calculation module; the minimum time unit of the time calculation module is 500 milliseconds, that is, the time calculation module uses the method of timing once every 500 milliseconds to effectively improve the timing accuracy;

[0041] The sensor fault identification module is mainly used to determine whether a sensor fault occurs; the sensor includes a voltage sensor, a current sensor and a temperature sensor;

[0042] When the voltage sensor, the current sensor and the temperature sensor all fail, the sensor failure identification module sends a sensor failure signal to the pause and continue function module;

[0043] Among them, the time calculation module is mainly used to calculate the running time; when the time calculation module receives a start signal, the timing is started; when the time calculation module receives a stop signal, the timing is stopped; the time calculation module sends the running time to the pause and continue function module in real time; when the time calculation module receives a re-timing signal, the time calculation module resets the running time;

[0044] The pause and continue function module is mainly used to pause the temperature ramp when a sensor failure or external failure occurs, and to continue the temperature ramp after the failure is repaired;

[0045] Wherein, the external faults include power controller communication interruption fault, interface fault and communication fault;

[0046] When a sensor failure or external failure occurs, the pause and continue function module sends a pause signal to the automatic climbing module, and the automatic climbing module controls the power controller to shut down, and records the current power controller state, PID setting value and current running time data; and sends a termination signal to the time calculation module;

[0047] When the sensor fault or external fault is repaired, the pause and resume function module sends a resume signal to the automatic climbing module; the automatic climbing module controls the power controller to start; and restarts the temperature climbing according to the power controller state at the time of pause, the PID setting value and the slope calculated according to the running time at the time of pause; and sends a start signal to the time calculation module;

[0048] When the sensor fails or the external fault cannot be repaired, the automatic climbing program is manually turned off; and a re-timing signal is sent to the time calculation module.

[0049] like Figure 3 As shown, a float glass electric heating fully automatic ramp temperature control method comprises the following steps:

[0050] Step 1: The curve input module inputs the temperature ramp curve and calculates the unit target temperature according to the temperature ramp curve;

[0051] Step 2: The automatic ramp module calculates the ramp parameters according to the temperature ramp curve and controls the range of the ramp parameters to adjust the temperature to rise and fall steadily within the adjustment range; and starts timing when the power controller is started; ends timing after the temperature ramp is completed, and resets the running time;

[0052] Step 3: The sensor fault identification program monitors whether the sensor is faulty and the validity of the data in real time; and when the current sensor, voltage sensor and temperature sensor fault are sensed, a pause signal is sent to the pause and continue function module;

[0053] Step 4: The pause and continue function module monitors the system in real time whether an external fault occurs, and promptly pauses the temperature ramp when an external fault or sensor fault occurs; and continues the temperature ramp when the sensor fault or external fault is resolved.

[0054] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A float glass electric heating fully automatic ramp temperature control system, characterized in that: It includes a curve entry module, an automatic climbing module, a sensor fault identification module, a time calculation module, and a pause and continue function module; wherein each module is electrically connected; The curve entry module is used to enter the temperature ramp curve and calculate the unit target temperature based on the temperature ramp curve; the curve entry module sends the temperature data per second to the automatic ramp module; The automatic ramp module is used to control the temperature of the annealing furnace according to the set temperature curve using the pre-ramp program; when the automatic ramp module is started, it sends a start signal to the time calculation module; when the temperature ramp of all curve segments is completed, the automatic ramp module sends a re-timing signal to the time calculation module; The sensor fault identification module is used to determine whether a sensor fault occurs; the sensor fault identification module sends a sensor fault signal to the pause and continue function module when the sensor fails; The time calculation module is used to calculate the time the temperature ramp has been running; The pause and continue function module is used to notify the automatic climbing module to pause the temperature climbing when a sensor failure or an external failure occurs, and to notify the automatic climbing module to continue the temperature climbing after the failure is repaired; Each inflection point (T1, t1), (T2, t2) ... (TN, tN) of the temperature ramp curve is manually set according to the actual conditions of different heating furnaces; the line segment from (Tn, tn) to (T(n+1), t(n+1)) constitutes a curve segment; Tn is the starting temperature, and T(n+1) is the ending temperature; wherein n=1, 2 ... N; T represents temperature, t represents time; and N represents the number of ramp curve segments; When the curve data is entered into the curve entry module, the control system automatically calculates the speed slope of the temperature increase / decrease according to the curve data. ; Then use the obtained speed slope Vn to calculate the target temperature per second from time t0 to time tN; the curve entry module sends the temperature data per second to the automatic climbing module; The automatic ramp module is used to control the temperature of the annealing kiln according to the set temperature curve using the pre-ramp program; The pre-ramp program includes a set of PID set value pre-ramp algorithms; the PID set value pre-ramp algorithm controls a pulse signal with a duty cycle of 0.5, and calculates the ramp parameter γ through the edge signal of the pulse signal; the minimum temperature value fed back by the temperature sensor is marked as M; the PID set value calculated by the automatic ramp program according to the curve is marked as A; the interval time between two pulse edge signals is marked as a; the ramp parameter γ is calculated as follows: ; The PID set value pre-ramp algorithm determines whether the value of the ramp parameter γ is within the interval of 1 and 2 times the speed slope Vn of the automatic calculation curve temperature increase / decrease. If it is not within the interval, the PID set value A is modified to ensure that the ramp parameter γ is always within the interval; the temperature in the annealing furnace is regulated by the PID control power controller; the temperature is ensured to rise and fall steadily within the adjustment range without deviating from the set value; at the same time, a pulse signal with a duty cycle of 0.5 is controlled to calculate and update the ramp parameter γ in real time; the power controller is used to control the power output of the electric heating of the float glass; that is, the temperature rise and fall in the annealing furnace is controlled by the power controller.

2. A float glass electric heating fully automatic ramp temperature control system according to claim 1, characterized in that: The sensor failure refers to failure of all the voltage sensors, current sensors and temperature sensors.

3. The float glass electric heating fully automatic ramp-up temperature control system according to claim 1, characterized in that: When the time calculation module receives a start signal, it starts timing; when the time calculation module receives a stop signal, it stops timing; the time calculation module sends the running time to the pause and continue function module in real time; when the time calculation module receives a re-timing signal, the time calculation module resets the running time.

4. The float glass electric heating fully automatic ramp-up temperature control system according to claim 1, characterized in that: When a sensor failure or external failure occurs, the pause and continue function module sends a pause signal to the automatic climbing module, and the automatic climbing module controls the power controller to shut down, and records the current power controller state, PID setting value and current running time data; and sends a termination signal to the time calculation module; When the sensor fault or external fault is repaired, the pause and resume function module sends a resume signal to the automatic climbing module; the automatic climbing module controls the power controller to start; and restarts the temperature climbing according to the power controller state at the time of pause, the PID setting value and the slope calculated according to the running time at the time of pause; and sends a start signal to the time calculation module; When the sensor fails or the external fault cannot be repaired, the automatic climbing program is manually turned off; and a re-timing signal is sent to the time calculation module.

5. A control method for the float glass electric heating fully automatic ramp temperature control system as claimed in claim 1, characterized in that: The following steps are involved: Step 1: The curve input module inputs the temperature ramp curve and calculates the unit target temperature according to the temperature ramp curve; Step 2: The automatic ramp module calculates the ramp parameters according to the temperature ramp curve and controls the range of the ramp parameters to adjust the temperature to rise and fall steadily within the adjustment range; and starts timing when the power controller is started; ends timing after the temperature ramp is completed, and resets the running time; Step 3: The sensor fault identification program monitors whether the sensor is faulty and the validity of the data in real time; and when the current sensor, voltage sensor and temperature sensor fault are sensed, a pause signal is sent to the pause and continue function module; Step 4: The pause and continue function module monitors the system in real time whether an external fault occurs, and promptly pauses the temperature ramp when an external fault or sensor fault occurs; and continues the temperature ramp when the sensor fault or external fault is resolved.

Images