JP2004237211A - Device and method for controlling warmup of drying oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for controlling a warmup of a drying oven that can exactly raise a temperature in the drying oven to the desired temperature by the desired starting time of operation by controlling a heating/temperature rise with a high precision. <P>SOLUTION: The device for controlling the warmup of the drying oven comprises a warmup curve processing unit 5 that corrects a preset warmup curve for the drying oven 1 based on an open-air temperature, a completion time of warmup and the desired temperature in the oven at the completion time of warmup, and a controlling unit 8 for heating the drying oven that initiates the heating of the drying oven at the starting time of heating calculated by an oven temperature processing unit 7 based on an oven temperature and the above corrected warmup curve and controls a temperature rise in the oven based on the corrected warmup curve. The method for controlling the warmup of the drying oven is practiced by using the above device. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for controlling a temperature rise of a drying furnace in a coating line and a method for controlling a temperature rise of a drying furnace by the apparatus.
[0002]
[Prior art]
In a painting line of an automobile manufacturing plant, a painted vehicle body is placed on a truck and transported, and is subjected to baking and drying by hot air convection in a drying furnace provided in the middle of the transport path.
[0003]
In this drying furnace, the heating by the heating device is started before the operation of the coating line is started, and the temperature rise in the furnace is controlled so that the furnace temperature becomes a predetermined temperature at the operation start time. The time when heating is performed to start raising the temperature inside the drying furnace (hereinafter, referred to as “heating start time”) depends on the seasonal temperature of the drying furnace, the outside air temperature, the outside air humidity, etc. before the start of the heating. , Due to the weather, etc., it has been difficult to determine appropriately and accurately according to the fluctuation. Therefore, the furnace temperature does not reach the predetermined temperature even when the operation time of the coating line is reached, and the operation start of the coating line is delayed, causing a decrease in the operation rate. There was a problem that the temperature in the furnace reached a predetermined temperature and unnecessary fuel cost was incurred due to unnecessary heating.
[0004]
Therefore, a temperature detecting means for detecting the outside air temperature and the furnace temperature, a detected value of the temperature detecting means, a heating completion time at the setting means, a set value of the furnace temperature at the heating completion time, and a heating of the heating means From the output, a heating start time required for setting the furnace temperature at the heating completion time to the set furnace temperature is obtained, and heating of the drying furnace by the heating means is started at the obtained heating start time. There has been proposed a heating-up control device for a drying furnace provided with a heating start control means (see Patent Document 1).
[0005]
[Patent Document 1]
Japanese Patent Publication No. 7-10368
[0006]
[Problems to be solved by the invention]
However, in the conventional control device or control method, the heating start time is determined by accurately reflecting the influence of the fluctuation of the outside air humidity and the like, and the heating / heating of the drying furnace from the heating start time to the heating completion time is further determined. The temperature could not be properly controlled, and the temperature raising completion time could not be set to an appropriate time in time for the operation start time of the coating line. For this reason, wasteful heating of the heating device may cause waste of fuel, or delay in the start of operation may cause a decrease in the operating rate of the coating line. Therefore, for the purpose of reducing the fuel cost of the drying furnace, improving the operation rate of the coating line, etc., the heating / heating of the drying furnace is controlled with higher precision than before so that the desired operation start time can be more accurately determined. There is a need for an apparatus or method for adjusting the temperature in a drying oven to a desired temperature.
[0007]
In view of the above problems, the present invention can control the heating / heating of the drying furnace with high precision, and can accurately raise the temperature in the furnace of the drying furnace to a desired temperature by a desired operation start time. An object of the present invention is to provide a temperature raising control device and a temperature raising control method for a drying furnace.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, an invention according to claim 1 is a temperature increase control device for a temperature in a furnace of a drying furnace heated by a heating device, wherein the temperature rising control start time t of the drying furnace is set to t. ₀ , The temperature rise completion time t in the drying furnace ₄ And the desired furnace temperature T at the time when the temperature rise is completed. ₄ A setting unit for setting an expected temperature rise curve in advance; an outside air humidity measuring device provided outside the drying furnace for measuring the outside air humidity H; the outside air humidity H; and the temperature rise completion time t ₄ And desired furnace temperature T ₄ A temperature rise curve calculation unit for correcting the expected temperature rise curve to obtain a corrected temperature rise curve based on _S And a furnace temperature T measured by the furnace temperature measuring device. _S An in-furnace temperature calculating unit for obtaining a heating start time ts of the drying furnace based on the corrected temperature rising curve; and starting the heating of the drying furnace by the heating device at the heating start time ts; A drying furnace heating control section for controlling heating by a heating device so that the furnace temperature rises based on the curve; and the temperature rise control start time t ₀ Further, an apparatus for controlling a temperature rise of a drying furnace, comprising: a temperature rise curve calculation section, an in-furnace temperature calculation section, and a device activation section for activating the drying furnace heating control section.
[0009]
In this temperature rise control device, an outside air humidity H measured by an outside air humidity measuring device and a preset temperature rise completion time t ₄ And desired furnace temperature T ₄ , A preset expected temperature rise curve is corrected to obtain a corrected temperature rise curve. The heating of the drying furnace is started at the heating start time ts of the drying furnace determined based on the corrected temperature rising curve and the furnace temperature measured by the furnace temperature measuring device, and based on the corrected temperature rising curve. The temperature rise in the furnace is controlled.
[0010]
According to a second aspect of the present invention, in the temperature rise control device according to the first aspect, the in-furnace temperature calculator is measured at least twice by the in-furnace temperature measuring device before the heating by the heating device is started. Furnace temperature T _S And determining a heating start time ts by calculating a time at which the furnace temperature falling curve intersects with the corrected temperature rising curve in the drying furnace before heating based on I do.
[0011]
In this temperature rise control device, the time at which the furnace temperature fall curve and the corrected temperature rise curve obtained based on the furnace temperature measured by the furnace temperature measuring device intersect is defined as the heating start time ts.
[0012]
According to a third aspect of the present invention, in the temperature rise control device according to the first aspect, the furnace temperature calculating unit continuously measures the furnace temperature T by the furnace temperature measuring device. _S And the furnace temperature T _S Scheduled furnace temperature T read from the corrected temperature rise curve for the measurement time _T The heating start time ts is determined in comparison with the above.
[0013]
In this temperature rise control device, the furnace temperature T continuously measured. _S And scheduled furnace temperature T _T Is equal to the heating start time ts.
[0014]
Further, the invention according to claim 4 is a method for controlling the temperature rise of the temperature inside the drying furnace heated by the heating device, wherein the temperature rising control start time t of the drying furnace is controlled. ₀ , Temperature rise completion time t ₄ And desired furnace temperature T at the time of completion of temperature rise ₄ Setting an expected temperature increase curve in advance, and the temperature increase control start time t ₀ Starting the temperature rise control, the outside air humidity H measured by an outside air humidity meter provided outside the drying furnace, and the temperature rise completion time t. ₄ And desired furnace temperature T ₄ Calculating a corrected temperature rise curve by correcting the expected temperature rise curve based on the temperature of the furnace, and measuring a furnace temperature T measured by a furnace temperature measuring device disposed in the drying furnace. _S Determining the heating start time ts of the drying furnace based on the corrected temperature rising curve; and starting the heating of the drying furnace by the heating device at the heating start time ts. Controlling the heating by the heating device so as to raise the temperature in the furnace based on the temperature of the drying furnace.
[0015]
In this temperature rise control method, the outside air humidity H measured by the outside air humidity measurement device and a preset temperature rise completion time t ₄ And desired furnace temperature T ₄ , A preset expected temperature rise curve is corrected to obtain a corrected temperature rise curve. Then, the heating of the drying furnace is started at the heating start time ts of the drying furnace determined based on the corrected temperature rising curve and the furnace temperature measured by the furnace temperature measuring device, and based on the corrected temperature rising curve. The temperature rise in the furnace is controlled.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a schematic diagram showing a configuration of a temperature increase control device for a drying furnace according to an embodiment of the present invention.
[0017]
The temperature rise control device shown in FIG. 1 includes a setting unit 2, a timer 3 (device activation unit), an outside air humidity sensor 4 (outside air humidity measuring device), a temperature rise curve calculation unit 5 (temperature rise curve calculation unit). , An in-furnace temperature sensor 6 (in-furnace temperature measuring device), an in-furnace temperature calculating unit 7 and a drying furnace heating control unit 8.
[0018]
The setting unit 2 sets the temperature rising control start time t of the drying furnace 1. ₀ , Temperature rise completion time t ₄ , The temperature completion time t ₄ Desired furnace temperature T at ₄ , And an expected temperature rise curve can be set in advance by an operator.
[0019]
The setting unit 2 includes a preset temperature increase control start time t ₀ Transmission line 2a for transmitting the time to the timer 3, and the temperature increase completion time t ₄ , Desired furnace temperature T ₄ , And a signal transmission line 2 b for transmitting an expected temperature rise curve to the temperature rise curve calculation unit 5.
[0020]
The timer 3 (apparatus start-up unit) is used to set the temperature increase control start time t set by the setting unit 2. ₀ In addition, a signal (start signal) for starting each of the temperature rising curve calculation unit 5, the in-furnace temperature calculation unit 7, and the drying furnace heating control unit 8 is output. The timer 3 is connected to the setting unit 2 by a signal transmission line 2a, and is connected to the temperature rise curve calculation unit 5, the in-furnace temperature calculation unit 7, and the drying furnace heating control unit 8 by signal transmission lines 3a, 3b, and 3c. ing.
[0021]
The timer 3 uses the temperature increase control start time t set by the setting unit 2. ₀ Is input and stored through the signal transmission line 2a. Then, the temperature increase control start time t ₀ Then, a start signal is output to each of the temperature rise curve calculation unit 5, the furnace temperature calculation unit 7, and the drying furnace heating control unit 8 through the signal transmission lines 3a, 3b, and 3c.
[0022]
The outside air humidity sensor 4 (outside air humidity measuring device) is provided outside the drying furnace 1 and is connected to the temperature rise curve calculation unit 5 by a signal transmission line 4a. The outside air humidity sensor 4 measures the outside air humidity H, and outputs a signal related to the outside air humidity H to the temperature rise curve calculation unit 5 through the signal transmission line 4a. As a specific example of the outside air humidity sensor 4, MgCr ₂ O ₄ -TiO ₂ Ceramics, TiO ₂ -V ₂ O ₅ Ceramics, ZnCr ₂ O ₄ -LiZnVO ₄ Various humidity sensors such as a ceramic humidity sensor using a system ceramic, a polymer film humidity sensor using a conductive polymer, an electrolyte humidity sensor such as a lithium chloride humidity sensor, and a heat conduction type humidity sensor using a thermistor are exemplified.
[0023]
The temperature rise curve calculation unit 5 is started by a start signal from the timer 3, and the outside air humidity H measured by the outside air humidity sensor 4 and the temperature rise completion time t set by the setting unit 2. ₄ And the desired furnace temperature T ₄ , A predicted temperature increase curve preset by the setting unit 2 is corrected to obtain a corrected temperature increase curve C. The calculated correction temperature rise curve C is based on the outside air humidity H and is set at a temperature rise completion time t. ₄ Exactly the desired furnace temperature T ₄ Is calculated as described below so as to reach. The obtained corrected temperature increase curve C is output to the furnace temperature calculating section 7.
[0024]
The temperature rise curve calculation unit 5 is activated when a start signal is input from the timer 3 through the signal transmission line 3a. Also, a signal relating to the outside air humidity is input from the outside air humidity sensor 4 through the signal transmission line 4a, and the temperature rise completion time t from the setting unit 2 through the signal transmission line 2b. ₄ , Desired furnace temperature T ₄ , And an expected heating curve are input. Then, information on the corrected heating curve C obtained by the heating curve calculating section 5 is output to the furnace temperature calculating section 7 through the signal transmission line 5a.
[0025]
The in-furnace temperature sensor 6 (in-furnace temperature measuring device) is provided in the drying furnace 1 and is connected to the in-furnace temperature calculation unit 7 via a signal transmission line 6a. The in-furnace temperature sensor 6 detects the in-furnace temperature T of the drying furnace 1. _S Is measured, and the measured furnace temperature T _S The signal relating to the temperature is output to the furnace temperature calculating section 7 through the signal transmission line 6a. Specific examples of the in-furnace temperature sensor 6 include a sensor using a thermocouple, a platinum resistance temperature detector, a thermistor, or the like as a temperature-sensitive element.
[0026]
The in-furnace temperature calculation unit 7 is started by a start signal from the timer 3, and the in-furnace temperature T measured by the in-furnace temperature sensor 6. _S The heating start time ts of the drying furnace 1 is obtained based on the correction temperature raising curve C obtained by the temperature raising curve calculator 5. The obtained heating start time ts is output to the drying furnace heating control unit 8.
[0027]
In the in-furnace temperature calculation unit 7, a start signal is input from the timer 3 through the signal transmission line 3b. The information on the corrected heating curve C input from the heating curve calculation unit 5 through the signal transmission line 5a and the signal on the furnace temperature input from the in-furnace temperature sensor 6 through the signal transmission line 6a provide the drying furnace. A heating start time ts of 1 is obtained. Then, a signal related to the obtained heating start time ts is output to the drying furnace heating control unit 8 through the signal transmission line 7a.
[0028]
The in-furnace temperature calculator 7 is configured to obtain the heating start time ts according to the flowchart shown in FIG. 3 or FIG.
The in-furnace temperature calculating unit 7 for obtaining the heating start time ts in accordance with the flowchart shown in FIG. _S Is determined based on the above equation, and the time at which the in-furnace temperature drop curve D intersects with the corrected temperature rise curve C is calculated to determine the heating start time ts. Is configured.
[0029]
Further, according to the flowchart shown in FIG. 4, the furnace temperature calculating section 7 calculates the furnace temperature T continuously measured by the furnace temperature sensor 6. _S And the furnace temperature T _S Scheduled furnace temperature T read from the corrected temperature rise curve C for the measurement time _T And the heating start time ts is determined.
The calculation of the heating start time ts shown in the flowcharts shown in FIGS. 3 and 4 will be described in detail in the description of the temperature rise control method described later.
[0030]
The drying furnace heating control unit 8 ignites the burner 9 (heating device) provided in the drying furnace 1 at the heating start time ts obtained by the in-furnace temperature calculating unit 7 to start heating the drying furnace 1; Further, the temperature of the furnace is controlled to rise according to the corrected temperature rise curve C. Further, the drying furnace heating control unit 8 circulates hot air provided in the drying furnace 1 in order to blow hot air into the drying furnace 1 to stir the atmosphere inside the drying furnace 1 and make the temperature inside the drying furnace 1 uniform. It is configured to control the on / off of the fan 10.
[0031]
Further, in the drying furnace heating control section 8, the temperature raising completion time t ₄ Time t before a predetermined time from ₃ Then, the combustion output of the burner 9 is reduced, and the furnace temperature of the drying furnace 1 is controlled so as to rise in accordance with the curved portion of the corrected heating curve C. t ₃ Is usually t ₄ 30 minutes before (see FIG. 5).
[0032]
In the drying furnace heating control unit 8, a start signal is input from the timer 3 through the signal transmission line 3c, and a signal regarding the heating start time ts is input from the in-furnace temperature calculation unit 7 through the signal transmission line 7a. Then, at the input heating start time ts, a signal for igniting the burner 9 is output via the signal transmission line 8a, and a signal for turning on / off the hot air circulation fan 10 is output via the signal transmission line 8b.
[0033]
It should be noted that the “heating temperature control start time t ₀ "Means the components constituting the temperature rise control device, that is, the temperature rise curve calculation unit 5, the furnace temperature calculation unit 7, the outside air humidity sensor 4, the furnace temperature sensor 6, the drying furnace heating control unit 8 Is the time at which the operation of each part is started. This temperature rise control start time t ₀ As will be described later, the drying furnace 1 calculated from the maximum combustion output of the heating device (burner 9), the heat capacity of the drying furnace 1, the heat capacity of the air in the drying furnace 1, the outside air introduced into the drying furnace 1, and the like. In consideration of the required heating time, the heating completion time t ₄ Is set to a time that is about 30 minutes before the longest required heating time of the drying oven.
[0034]
In addition, the temperature raising completion time t ₄ Means that the furnace temperature of the drying furnace is the desired furnace temperature T ₄ , And the time at which the temperature increase in the furnace by heating is completed. This temperature rise completion time t ₄ Is set to a time that is a predetermined time before the operation start time of the drying furnace 1. Also, the “desired furnace temperature” T ₄ Is the temperature rise completion time t ₄ Means the temperature inside the drying furnace 1 at the time of completion, and the temperature rise completion time t before the operation start time ₄ Temperature T of the drying furnace 1 _S Is the desired furnace temperature T ₄ , The heating / heating of the drying furnace 1 is controlled.
[0035]
Further, the “temperature-raising curve” refers to a curve indicating a change over time in the furnace temperature of the drying furnace 1 which is heated and heated by the combustion in the burner 9 (heating device) controlled by the drying furnace heating controller 8. . Further, the “heating gradient” refers to the slope of the heating curve, and corresponds to the heating rate of the furnace temperature after the start of heating.
[0036]
Further, the expected temperature rising curve is the heating amount of the burner 9 provided in the drying furnace 1, the heat capacity of the drying furnace 1, the heat capacity of the air in the drying furnace 1, the external air introduced into the drying furnace 1 (outside air). Is a preset temperature rise curve for the temperature rise behavior of the drying furnace 1 in consideration of the heat capacity of the drying furnace 1 and the like. The predicted temperature increase curve is set in advance according to the season, for example, as indicated by dotted lines C1 and C2 in FIG.
[0037]
Next, a method for controlling the temperature rise of the drying furnace 1 by the temperature rise control device will be described with reference to FIG.
FIG. 2 is a flowchart illustrating a temperature raising control method by the temperature raising controller according to the embodiment of the present invention.
In this temperature rise control method, the temperature rise control of the drying furnace 1 is performed by the operator using the temperature rise control start time t in the setting unit 2. ₀ , Temperature rise completion time t ₄ , Temperature rise completion time t ₄ Desired furnace temperature T at ₄ , And an expected temperature rise curve (step S1).
[0038]
In step S1, the temperature increase control start time t ₀ Is the temperature increase control start time t ₀ And the temperature rise completion time t ₄ Is the furnace temperature T _S Is set so as to be longer than the longest required heating time derived from the fluctuation of the temperature and the maximum amount of heat generated by the combustion of the burner 9.
[0039]
In the first step S1, the estimated temperature rise curve set by the setting unit 2 is such that the furnace temperature rises linearly in a substantially proportional manner as shown by the temperature rise curves C1 and C2 indicated by dotted lines in FIG. Linear heating section C1 ₁ , C2 ₁ And this linear heating portion C1 ₁ , C2 ₁ Curve rising part C1 that continues continuously ₂ , C2 ₂ It is composed of
[0040]
Linear heating section C1 ₁ , C2 ₁ Immediately after the start of heating, that is, after ignition, the burner 9 is burned at the maximum combustion output to indicate the temperature rise gradient of the in-furnace temperature in a time zone in which the drying furnace 1 is heated. This linear heating portion C1 ₁ , C2 ₁ Then, as shown in FIG. 5, the furnace temperature T _S Rise, and the temperature rising gradient, that is, the temperature rising rate is maintained at a constant value.
[0041]
In addition, a curve heating portion C1 ₂ , C2 ₂ Is the heating completion time t to prevent overbaking. ₄ Time t before the given time ₃ Thus, the output of the burner 9 is controlled as needed to an output previously obtained by calculation, and the temperature rising gradient becomes smaller with time.
[0042]
Next, the temperature rise control start time t set in the setting unit 2 ₀ Is input to the timer 3 through the signal transmission line 2a, and the temperature increase control start time t ₀ , A start signal is output to the temperature rise curve calculation unit 5, the in-furnace temperature calculation unit 7, and the drying furnace heating control unit 8 through the signal transmission lines 3a, 3b, and 3c, respectively (see FIG. 1). Is started (step S2).
[0043]
Next, in the temperature rise curve calculation unit 5 started by the start signal from the timer 3, the temperature rise completion time t from the setting unit 2 through the signal transmission line 2a. ₄ And desired furnace temperature T ₄ , And expected temperature rise curves (C1, C2, etc.) are input, and further, a signal relating to the outside air humidity H measured by the outside air humidity sensor 4 through the signal transmission line 4a (step S3) (see FIG. 1). Then, the temperature rise curve calculation unit 5 inputs the outside air humidity H and the temperature rise completion time t. ₄ And desired furnace temperature T ₄ Is corrected based on the above, a corrected temperature rise curve C shown in FIG. 5 is obtained (step S4).
[0044]
In the correction of the expected temperature rise curves (C1, C2, etc.) in step S4, the outside air humidity H measured by the outside air humidity sensor 4 is the furnace temperature T due to the heating of the drying furnace 1 by the burner 9. _S Is a factor that has a large effect on the temperature rise gradient. That is, when the outside air humidity H is high, the specific heat of the air becomes large, so that the temperature rising gradient becomes small. On the other hand, when the outside air humidity is low, the specific heat becomes small, so that the temperature rise gradient becomes large.
[0045]
Accordingly, in the present invention, in step S4, a coefficient obtained from the outside air humidity H is added to the expected temperature rising curve C1 (or C2) set in the setting section 2 to obtain a true temperature rising curve (corrected temperature rising curve). The curve C) is calculated. This coefficient can be determined in advance based on a temperature rise curve obtained by actual measurement for air having different humidities and based on the temperature rise curve.
[0046]
Next, the in-furnace temperature calculation unit 7 activated by the activation signal input from the timer 3 through the signal transmission line 3b supplies the in-furnace temperature of the drying furnace 1 before heating measured by the in-furnace temperature sensor 6 (step S5). Temperature T _S Is input through the signal transmission line 6a (see FIG. 1). The in-furnace temperature calculating unit 7 calculates the in-furnace temperature T _S And the heating start time ts of the drying furnace is obtained based on the corrected temperature rise curve C (step S6).
[0047]
The calculation of the heating start time ts in step S6 is performed according to the flowchart shown in FIG. In this calculation, first, the furnace temperature of the drying furnace 1 before heating is measured at least twice by the furnace temperature sensor 6 (step S61). For example, as shown in FIG. ₁ And its furnace temperature measurement time t ₁ Time t 10 minutes after ₂ The furnace temperature T ₁ , T ₂ Are respectively measured. The measured furnace temperature (T ₁ , T ₂ ) And measurement time (t ₁ , T ₂ ) Is input to the in-furnace temperature calculator 7 through the signal transmission line 6a (see FIG. 1).
[0048]
The in-furnace temperature calculating unit 7 calculates an in-furnace temperature decrease curve D based on the in-furnace temperature of the drying furnace measured at least twice by the in-furnace temperature sensor 6 (step S62).
[0049]
Here, the “furnace temperature decrease curve” refers to the furnace temperature T of the drying furnace 1 in a non-heated state. _S Means a curve showing a change with time. The “furnace temperature falling gradient” refers to the slope of the furnace temperature falling curve, and the furnace temperature T of the drying furnace 1 in a non-heated state. _S Corresponds to the descending speed of For example, as shown in FIG. ₁ The furnace temperature measured at ₁ At time t ₁ Time t after a lapse of a predetermined time Δt from ₂ The furnace temperature measured at ₂ , The furnace temperature drop gradient θ = (T ₂ -T ₁ ) / Δt, and has a slope corresponding to the furnace temperature drop gradient, and the point (t ₁ , T ₁ ) Is a furnace temperature drop curve D. In the drying furnace at the time of non-heating, the furnace temperature T _S Goes down. For example, as shown in FIG. ₁ And the time t 10 minutes later ₂ Temperature T measured in the furnace ₁ , T ₂ Thus, the furnace temperature drop curve D having the furnace temperature drop gradient θ (see FIG. 5) in the drying furnace 1 is calculated.
[0050]
Next, as shown in FIG. 3, a time t at which the determined furnace temperature drop curve D and the corrected temperature rise curve C intersect. _C Is obtained (step S63). This time t _C Is determined as the heating start time ts (step S64). The heating start time ts is output to the drying furnace heating control unit 8.
[0051]
The calculation of the heating start time ts in step 6 can also be performed according to the flowchart shown in FIG.
[0052]
In the calculation shown in FIG. _D (Time ts in FIG. 5 ₁ , Ts ₂ ), The furnace temperature T is detected by the furnace temperature sensor 6. _S (TS1, TS2 in FIG. 5) were actually measured, and the furnace temperature T _S Is input to the in-furnace temperature calculator 7 through the signal transmission line 6a (step S641).
[0053]
At this time, at the same time, the reading signal is always output from the timer 3 to the heating curve calculating section 5 through the signal transmission line 3a in the heating curve calculating section 5, and the time t is calculated from the corrected heating curve C. _D (Ts in FIG. 5 ₁ , Ts ₂ Planned furnace temperature T) _T (TT1, TT2 in FIG. 5) are read and input to the in-furnace temperature calculator 7 (step S642). Here, the “scheduled furnace temperature” refers to the furnace temperature read from the corrected temperature rise curve C at a certain time.
[0054]
Next, as shown in FIG. 4, the furnace temperature T actually measured by the furnace temperature sensor 6 is measured. _S And the furnace temperature T _S Measurement time t _D Planned furnace temperature T read from the corrected temperature rise curve C _T Are compared with each other (step S643). And T _S ≠ T _T (Step S643, NO), that is, if it is TS1 (≠ TT1) shown in FIG. 5, the process returns to step S641, and steps S642 and S643 are repeated. Also, T _S = T _T If it is (step S643, YES), if it is TS2 (= TT2) shown in FIG. 5, the process proceeds to step S644, and the furnace temperature measurement time t _D (Ts2 shown in FIG. 5) is determined as the heating start time ts.
[0055]
A signal relating to the heating start time ts of the drying furnace 1 determined by the calculation in the in-furnace temperature calculating section 7 is input to the drying furnace heating control section 8, and the drying furnace heating control section 8 ignites the burner 9 and subsequently. The combustion output of the burner 9 is controlled (Step S7). As a result, the temperature inside the drying furnace 1 becomes the heating completion time t. ₄ The desired furnace temperature T ₄ Thus, the coating line can be operated at the scheduled operation start time. At this time, in order to prevent overbaking of the drying furnace 1, the heating completion time t ₄ Time t before the given time ₃ From this, the output of the burner 9 is controlled as needed to an output obtained in advance by calculation, so that the temperature rising gradient is controlled to decrease with time.
[0056]
Further, in the present embodiment, the temperature raising control device of the drying furnace is described as an independent device. However, the temperature raising control device of the present invention may be configured as a part of an integrated control system of a coating line. With such a configuration, the start-up of the temperature increase control device of the drying furnace is controlled by the integrated control system instead of the timer 3, and further, the temperature increase curve calculation unit 5, the furnace temperature calculation unit 7, and If the drying furnace heating control unit 8 is provided in the integrated control system, integrated control including not only the drying furnace 1 but also other devices in the coating line can be performed. Thereby, more efficient operation of the drying furnace can be realized in consideration of not only the drying furnace but also the entire coating line or a higher-order system.
[0057]
【The invention's effect】
According to the temperature rise control device according to the first to third aspects of the present invention, the outside air humidity H and the preset temperature rise completion time t ₄ And desired furnace temperature T ₄ The heating of the drying furnace is started at the heating start time ts of the drying furnace determined by the corrected heating curve and the furnace temperature based on the corrected heating curve and the furnace is calculated based on the corrected heating curve. The rise of the internal temperature is controlled. Therefore, the heating / heating of the drying furnace can be controlled with high accuracy, and the furnace temperature of the drying furnace can be accurately raised to a desired temperature by a desired operation start time.
[0058]
According to the second aspect of the invention, the time at which the furnace temperature drop curve and the corrected temperature rise curve obtained based on the measurement of the furnace temperature intersect can be determined as the heating start time ts. Then, the heating of the drying furnace is started at the heating start time ts, and further, the heating / heating of the drying furnace is controlled with high accuracy based on the corrected temperature rising curve, so that the heating operation is accurately performed by the desired operation start time. The temperature in the drying furnace can be raised to a desired temperature.
[0059]
According to the third aspect of the present invention, the time when the furnace temperature TS actually measured by the furnace temperature measuring device and the scheduled furnace temperature TT become equal to each other is defined as the heating start time ts. Can be. Then, the heating of the drying furnace is started at the heating start time ts, and further, the heating / heating of the drying furnace is controlled with high accuracy based on the corrected temperature rising curve, so that the heating operation is accurately performed by the desired operation start time. The temperature in the drying furnace can be raised to a desired temperature.
[0060]
According to the invention as set forth in claim 4, a method for controlling the heating / heating of the drying furnace with high accuracy to accurately raise the temperature in the furnace of the drying furnace to a desired temperature by a desired operation start time. Can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration of a temperature increase control device according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a temperature raising control method in the temperature raising control device according to the embodiment of the present invention.
FIG. 3 is a flowchart showing an example of a method of calculating a heating start time ts in a furnace temperature calculating unit in the temperature raising control device according to the embodiment of the present invention.
FIG. 4 is a flowchart illustrating another example of a method of calculating the heating start time ts in the furnace temperature calculating unit in the temperature raising control device according to the embodiment of the present invention.
FIG. 5 is a graph showing a relationship between a temperature decrease curve in the drying furnace during non-heating and a temperature rising curve in the drying furnace.
[Explanation of symbols]
1 Drying furnace
2 Setting section
3 timer (device starter)
4 Outside air humidity sensor (outside air humidity meter)
5 Heating curve calculator
6 Furnace temperature sensor (furnace temperature measuring device)
7 Furnace temperature calculator
8 Drying furnace heating controller
9 Burner (heating device)
10 Hot air circulation fan

Claims (4)

A heating control apparatus for controlling the temperature inside the drying furnace heated by the heating device,
A setting unit that previously sets a temperature increase control start time t _{0 of} the drying furnace, a temperature increase completion time t ₄ in the drying oven, a desired furnace temperature T _{4 at} the temperature increase completion time, and an expected temperature increase curve;
An outside air humidity measuring device disposed outside the drying oven and measuring outside air humidity H;
And outside air humidity H, and on the basis of the Atsushi Nobori completion time t ₄ and the desired furnace temperature T _4, the estimated corrected heating curve to obtain a correction heating curve heating curve calculation unit,
An in-furnace temperature measuring device disposed in the drying furnace and measuring an in-furnace temperature T _S ;
An in-furnace temperature calculating unit that determines a heating start time ts of the drying furnace based on the in-furnace temperature T _S measured by the in-furnace temperature measuring device and the corrected temperature rising curve;
A drying furnace heating control unit that controls heating by the heating device so that the heating device starts heating the drying furnace by the heating device at the heating start time ts and the furnace temperature rises based on the corrected temperature rise curve. ,
At the time of the temperature increase control start time t ₀ , a temperature increase control of a drying furnace, comprising: a temperature increase curve operation unit, an in-furnace temperature operation unit, and a device activation unit that activates the drying oven heating control unit. apparatus. The in-furnace temperature calculating unit obtains an in-furnace temperature decrease curve in the drying furnace before heating based on the in-furnace temperature T _S measured at least twice by the in-furnace temperature measuring device before the heating by the heating device is started. The heating temperature control device for a drying furnace according to claim 1, wherein the heating start time ts is determined by calculating a time at which the in-furnace temperature falling curve intersects with the corrected temperature rising curve. The in-furnace temperature calculation unit is configured to read the in-furnace temperature T _S continuously measured by the in-furnace temperature measuring device and the scheduled in-furnace temperature read from the corrected temperature rise curve for the measurement time of the in-furnace temperature T _S. by comparison with the T _T, drying oven Atsushi Nobori control unit according to claim 1, characterized in that to determine the heating start time ts. A method for controlling an increase in the temperature inside the drying furnace heated by the heating device,
A step of previously setting a temperature rise control start time t _{0 of} the drying furnace, a desired temperature T ₄ in the temperature rise completion time t ₄ and a desired temperature T _{4 at the} time of completion of the temperature rise, and an expected temperature rise curve;
Wherein the temperature increase control start time t _0, a step of starting the temperature increase control,
The drying furnace outside measured by disposed outside air humidity measuring device outside air humidity H of, and on the basis of the Atsushi Nobori completion time t ₄ and the desired furnace temperature T _4, by correcting the predicted Atsushi Nobori curve Determining a corrected heating curve;
Determining a heating start time ts of the drying furnace based on the furnace temperature T _S measured by a furnace temperature measuring device disposed in the drying furnace and the corrected temperature rising curve;
Starting heating of the drying furnace by the heating device at the heating start time ts, and controlling heating by the heating device such that the temperature in the furnace increases based on the corrected temperature increase curve. Temperature rise control method.

Images