JP3152797B2 - Temperature control device for circulating medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control device for a circulating medium used in a cooling system of a continuous process line or the like, and more particularly to a temperature control device for a circulating medium having a heat removal control function and a heater heating control function. It relates to improvement of a temperature control device.

[0002]

2. Description of the Related Art Conventionally, a circulating gas temperature controller as shown in FIG. 2 is used for cooling equipment such as a continuous process line. In this cooling equipment, a gas circulation path 3 is provided so as to extend from the upstream side to the downstream side of the cooling furnace 2 in which the coil 1 to be controlled in cooling temperature travels. Cooler equipment 4 for cooling, this cooler equipment 4
A blower 5 for discharging the gas cooled by the blower into the furnace, a heater device 6 for heating the gas discharged from the blower 5 to a predetermined temperature, and a cooler outlet so as to bypass the cooler equipment 4. Heat bypass 7
Is provided.

Next, the circulating gas temperature control system is turned on by the output of the coil tracking calculator 10 in response to changes in the thickness of the coil running in the furnace, the line speed, etc., and changes the plate thickness, line speed, etc. The set temperature determined by the coil information is the cooler side circulating gas temperature control device 1
1. It is supplied to the heater-side circulating gas temperature control device 12 and the deviation calculation means 13.

[0004] The cooler side circulating gas temperature control device 11
Performs an adjustment operation based on the changed set temperature, outputs an adjustment signal, and further corrects the linearity with the cooler characteristic corrector 14 and the bypass characteristic corrector 15, and adjusts the corresponding cooler valve 16 and bypass. The control valve 17 is controlled.
It should be noted that the control is performed such that the cooler valve 16 is opened when the normal cooling temperature is controlled, and the cooler valve 16 is closed and the bypass valve 17 is opened when the temperature needs to be increased in accordance with the change of the set temperature.

On the other hand, in the heating control on the heater side, the deviation calculation means 13 sets the set value α by changing the set temperature.
And the bypass valve 17 is fully open, an override determination is made by the override determination means 18 and the adjustment signal of the heater-side circulating gas temperature control device 12 is taken in to obtain the heater thyristor characteristic corrector 19. Through which the conduction angle of the thyristor 20 is controlled and the required power is applied to the heater device 6 to perform heater heating control.

[0006]

However, the circulating gas temperature control apparatus described above has a problem in that when the coil 1 passing through the furnace transitions from a thick material to a thin material, the coil 1 is stretched and broken. Although it is necessary to quickly raise the temperature in the furnace from the viewpoint of preventing the
Performs an over-ride determination as to whether or not the heater is in the fully open state, and if the heating amount is still necessary, the system switches to heater heating. The risk of breakage of the coil 1 during the transfer of the material is extremely high, which is a problem in control.

[0007] The present invention has been made in view of the above circumstances, and when the thickness of a coil to be controlled, for example, a coil, changes.
It is an object of the present invention to provide a temperature control device for a circulating medium that improves transient control accuracy and prevents coil breakage.

[0008]

In order to solve the above-mentioned problems, an invention according to claim 1 is provided so as to extend from an upstream side to a downstream side of a temperature control region in which a temperature-controlled object travels. A circulating medium path, a cooler facility for cooling the circulating medium taken from the temperature control area, a medium discharge device for returning the circulating medium cooled by the cooler facility to the temperature control area, and a circulating medium discharged from the circulating medium path. In a process line facility provided with a heater device for heating to a temperature of the predetermined temperature, and provided with a cooler heat removal bypass path so as to bypass the cooler facility, when the set temperature due to the temperature controlled object is changed, the circulation is performed. A cooler-side heat removal control system for controlling the medium temperature control and the pre-blower temperature control in a cascade control configuration and performing cooler-side heat removal control of the cooler heat removal bypass path; The heater-side heating control system for controlling the heater heating amount of the heater device simultaneously with the cooler-side heat removal control by the cooler-side heat removal control system, and the cooler-side heat removal control system and the heater-side heating control system are almost balanced. When the connection of the cascade control is disconnected, the cooler side heat removal control is performed by gradually increasing the pre-blower set temperature at a predetermined rate of change, while the heater side heating control system is controlled in a direction to reduce the heater heating amount. And a control unit for controlling the temperature of the circulating medium.

Next, according to a second aspect of the present invention, a circulating medium path extending from the upstream side to the downstream side of the temperature control region in which the temperature controlled object travels is taken from the temperature control region. Cooler equipment for cooling the circulating medium, a medium discharging device for returning the circulating medium cooled by the cooler equipment to the temperature control region, and a heater device for heating the discharged circulating medium to a predetermined temperature are installed, Further, in a process line facility provided with a bypass path for heat removal from the cooler so as to bypass the cooler facility, when the set temperature due to the temperature controlled object is changed, the changed set temperature and the temperature in the temperature control area are changed. Cooler-side heat removal temperature control device that outputs a control signal based on the temperature and a target value as an adjustment signal of the cooler-side heat removal temperature control device and a temperature before blower. A pre-blower temperature control device that performs heat removal control on the cooler side of the cooler heat removal bypass path, and controls a heater heating amount of the heater device based on the changed set temperature and the temperature in the temperature control region. A heater-side heating temperature controller, a judging means for judging whether or not the pre-blower temperature controller and the heater-side heating temperature controller are substantially in a balanced state; Disconnecting the cooler-side heat removal temperature control device from the pre-blower temperature control device, gradually increasing the pre-blower set temperature at a predetermined rate of change, and applying the pre-blower temperature control device to the pre-blower temperature control device. It is a temperature control device of the provided circulating medium.

[0010]

Therefore, the invention corresponding to claim 1 adopts the above-mentioned means, so that, for example, when the coil to be temperature-controlled shifts from a thick material to a thin material, a higher set temperature is obtained by the tracking process. However, at this time, the cooler-side heat removal control system smoothly rises in the upper limit direction of the allowable temperature before blower by executing the cooler-side heat removal control of the cooler heat removal bypass path by the cascade control configuration, At this time, the heating control on the heater side is also executed at the same time, so that the responsiveness of the heating control on the heater side appears with respect to the change of the set temperature, and the risk of the coil breaking when transferring the thin material is reduced due to the improvement of the transient control accuracy. Become.

After that, after the cooler side heat removal control and the heater side heating control are substantially balanced, the connection of the cascade control is disconnected, and the pre-blower temperature control is executed according to a predetermined rate of change. It operates in a direction to reduce the heater heating amount, and the heater heating amount can be reduced.

Next, according to the invention corresponding to claim 2, when a coil to be controlled, for example, a coil shifts from a thick material to a thin material, the temperature is changed to a higher set temperature by a tracking process. The switching by the override determination as described above is removed, and the cooler-side heat removal temperature control device and the heater-side heating temperature control device are simultaneously operated. The cooler-side heat removal temperature control device outputs an adjustment signal based on the high set temperature and the temperature in the temperature control region, and applies this to the pre-blower temperature control device as the set temperature. The pre-blower temperature control device executes the cooler-side heat removal control of the cooler heat removal bypass path based on the target value as the adjustment signal of the cooler-side heat removal temperature control device and the temperature before the blower. On the other hand, the heater-side heating temperature control device executes heating control of the heater device based on the high set temperature and the temperature in the temperature control region. Therefore, when the set temperature changes due to the temperature controlled object,
The responsiveness of the heater-side heating control appears, and the risk of breakage of the temperature-controlled object is eliminated by the transient improvement in control accuracy.

[0013] Thereafter, the balance state between the pre-blower temperature control device and the heater-side heating control device is determined by the determination means, and when it is determined that the balance state has been entered, the pre-blower set temperature control means performs the control from the pre-blower temperature control device. By disconnecting the cooler side heat removal temperature control device and gradually increasing the pre-blower set temperature at a predetermined rate of change, the pre-blower temperature control device accordingly maintains the balance state while maintaining the cooler heat removal bypass path. Since the cooler side heat removal control is executed, the heater heating amount of the heater side heating control device is reduced by that amount, and the heater heating amount can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. 2, the same parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. Hereinafter, improved parts will be described.

First, the cooler-side circulating gas temperature control device 11
Is provided with a pre-blower set temperature control means 21 for determining a pre-blower set temperature (target value). When the in-furnace coil 1 shifts from a thick material to a thin material, the cooler-side circulating gas temperature control device 11 receives a high set temperature by tracking processing. The control signal from the circulating gas temperature control device 11 at the beginning of the reception is output as it is within a range not reaching the upper limit of the allowable temperature before blower, while when a certain condition described later is satisfied, the blower is gradually set with a predetermined change rate β. The control for increasing the output of the temperature is performed.

Further, between the pre-blower set temperature control means 21 and the characteristic correctors 14 and 15, a blower for performing temperature control before blower based on the pre-blower set temperature from the pre-blower set temperature control means 21. A pre-temperature control device 22 is provided. The pre-blower temperature control device 22 performs an adjustment calculation based on a deviation between the pre-blower set temperature sent from the pre-blower set temperature control means 21 and the detected-before-blower temperature (control variable) from the pre-blower temperature detector 23. And performs the heat removal control on the cooler side by using the obtained adjustment calculation signal.

Therefore, in the cooler-side heat removal control system, the cooler-side circulating gas temperature controller 11 and the pre-blower temperature controller 2
2 has a cascade control connection configuration, and executes cooler side heat removal control by cascade within the allowable upper limit temperature before blower.

On the other hand, in the heater-side heating control system, the conventional override switching is removed, and the heater-side circulating gas temperature controller 12 executes the heater heating control completely freely based on the set temperature set by the tracking process. Therefore, when the furnace coil 1 shifts from a thick material to a thin material,
By controlling the opening of the cooler bypass valve 17 simultaneously with the opening control of the cooler bypass valve 17, the heater-side circulating gas temperature control device 12 controls the heater heating amount to increase, thereby promptly improving the heater-side heating control, and transiently improving the control accuracy. Can be planned.

Further, there is provided an override judging means 24 for judging the balance between the cooler side heat removal control and the heater side heat control by the pre-blower temperature control device 22. In this override determination means 24, the following 3
It is necessary to satisfy two conditions.

A. Temperature control by both control devices 22 and 12 is balanced. That is, the control device (TIC1) 1
The control deviation α of 1 has a relationship of −γ <α <γ. B. The heater device 6 is being controlled at the present time.
That is, the adjustment signal MV of the control device (TIC2) 12 is MV>
0 relationship.

C. The control device (TIC2) 12 is performing control other than manual control. Therefore, when the above condition is satisfied, the override judging unit 24 sends a switching control signal to the pre-blower set temperature control unit 21.

Upon receiving the switching control signal, the pre-blower set temperature control means 21 disconnects the cascade control connection, and gradually raises the pre-blower set temperature to the upper limit of the pre-blower allowable temperature at a rate of change β. Accordingly, the opening of the bypass valve 17 is gradually opened. As a result, on the contrary, the heater heating amount by the heater-side circulating gas temperature control device 12 gradually decreases. That is, the configuration is such that the amount of heating of the heater is reduced.

Next, the operation of the above device will be described. Now, when the in-furnace coil 1 shifts from a thick material to a thin material, a higher set temperature than the previous thick material is given to the control devices 11 and 12 by the tracking process.

As a result, the cooler-side circulating gas temperature control device 11 outputs an adjustment signal to make the deviation between the higher set temperature and the temperature detected by the temperature detector 25 downstream of the heater device zero, and this adjustment is performed. Set signal before blower temperature (target value)
Is applied to the pre-blower temperature controller 22. here,
The pre-blower temperature control device 22 closes the cooler valve 16 in accordance with the deviation between the pre-blower set temperature and the pre-blower detected temperature from the pre-blower temperature detector 23, and opens the bypass valve 17 by opening the bypass valve 17. Go. However, this bypass valve 1
The temperature inside the furnace does not increase rapidly only by controlling the heat removal from the cooler by opening 7.

Therefore, in the present apparatus, the conventional override switching is removed, and simultaneously with the opening control of the bypass valve 17, the heater-side circulating gas temperature controller 12 also detects the deviation between the high set temperature and the temperature detected by the temperature detector 25. The heating amount of the heater is raised by the
Transient control accuracy can be greatly improved, and the coil breakage at the time of transfer to a thin material can be prevented.

Thereafter, the temperature inside the furnace is rapidly increased by the heat removal control on the cooler side and the control on the heater heating side, and the control deviation between the set temperature in the circulating gas temperature control device 11 and the temperature detected by the temperature detector 25 is small. Then, the cooler side heat removal control and the heater heating side control are performed by the bypass valve 17.
Balance at any open position. However, if the heater-side heating control is left as it is even after this balance, the energy saving effect is inferior to the conventional device.

Therefore, in the present apparatus, the upper limit of the allowable temperature before the blower determined by the blower main body is set, and opening the opening of the bypass valve 17 to the upper limit of the allowable temperature before the blower means that it stops. The cooler-side circulating gas temperature controller 11 outputs the pre-blower set temperature subject to the upper limit of the allowable temperature before blower, and the pre-blower temperature controller 22
Is applied to the cascade control.

The balance between the heat removal control on the cooler side and the heating control on the heater side is checked by the override judging means 24, and the control deviation α of the cooler side circulating gas temperature control device 11 falls within a certain range. When the circulating gas temperature controller 12 is actually performing the heater heating side control (output of TIC2> 0) and the heater heating side control is performing the automatic or cascade control, it is determined that the state is in the balance state, and the switching is performed. The control signal is sent to the pre-blower set temperature control means 21.

The pre-blower set temperature control means 21 receives a switching control signal from the override determination means 24,
The connection of the cascade control is disconnected, and an arbitrary change rate β
, The set temperature of the pre-blower temperature control device 22 is gradually increased to the pre-blower allowable temperature upper limit. Accordingly, the furnace temperature is increased while the opening of the bypass valve 17 is gradually opened, so that the output of the heater-side circulating gas temperature controller 12 gradually reduces the heater heating amount in the energy saving direction while maintaining a balanced state. In this way, the heater can be operated in the steady state by finally reducing the heating amount to the minimum amount, and the energy-saving control can be realized.

In the above embodiment, the temperature control of the coil 1 has been described. However, any temperature control having the cooler equipment 4, the heater device 6, and the cooler bypass path 3 does not particularly specify the temperature control target. . Further, the present apparatus was applied to the cooling furnace 2 for cooling the coil,
Other furnaces may be used. Further, in the above-described embodiment, the configuration in which the gas temperature in the furnace of the cooling furnace is controlled has been described, but a gas or liquid other than gas may be used. Further, three conditions are set as the judgment conditions of the override judgment means 24. At least the control deviation α of the control device (TIC1) 11 is −γ
<Α <γ may be satisfied, and the other conditions can be appropriately increased or decreased. In addition, the present invention can be implemented with various modifications without departing from the scope of the invention.

[0031]

As described above, according to the present invention, when the set temperature of the control target in the furnace is changed, the heat removal control on the cooler side by the cooler bypass and the control on the heater heating side are performed at the same time. Control accuracy can be greatly improved, and breakage of a thin object at the time of transfer to a controlled object can be avoided. In the steady state after the balance between the cooler side heat removal control and the heater heating side control, the set value of the pre-blower temperature control is gradually increased while maintaining the balance state based on the override determination, so that the heater heating side control is minimized. The steady state can be maintained by the heater heating amount, and energy-saving control can be realized. Therefore, highly accurate controllability can be obtained for the temperature load.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a circulating medium temperature control device according to the present invention.

FIG. 2 is a diagram showing a configuration of a conventional device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Coil (control object), 2 ... Furnace, 4 ... Cooler equipment, 5
... Blower, 6 ... heater device, 7 ... cooler bypass path,
11: cooler-side circulating gas temperature controller, 12: heater heating-side circulating gas temperature controller, 21: pre-blower preset temperature control means, 22: pre-blower temperature controller, 23: pre-blower temperature detector, 24: override determination means.

Claims (2)

(57) [Claims] 1. A cooler facility for cooling a circulating medium taken from the temperature control area through a circulating medium path provided so as to extend from an upstream side to a downstream side of a temperature control area in which a temperature-controlled object travels. A medium discharge device for returning the circulating medium cooled by the cooler equipment to the temperature control region and a heater device for heating the discharged circulating medium to a predetermined temperature are installed, and the cooling device is bypassed. In a process line facility provided with a bypass path for heat removal from the cooler, the temperature control of the circulating medium and the temperature control before the blower are configured in a cascade control configuration when the set temperature is changed due to the temperature controlled object. A heat removal control system that performs heat removal control on the cooler side of the bypass path for use, and the heater device simultaneously with the heat removal control on the cooler side by the cooler heat removal control system. When the heater-side heating control system that controls the heater heating amount, and the cooler-side heat removal control system and the heater-side heating control system are substantially balanced, the connection of the cascade control is disconnected, and the blower is gradually blown at a predetermined rate. Means for controlling the heat removal on the cooler side by increasing a preset temperature, and means for controlling the heating control system on the heater side in a direction to reduce the heating amount of the heater. apparatus. 2. A cooler facility for cooling a circulating medium taken from the temperature control area through a circulating medium path provided so as to extend from the upstream side to the downstream side of the temperature control area in which the temperature controlled object travels. A medium discharge device for returning the circulating medium cooled by the cooler facility to the temperature control region, a heater device for heating the discharged circulating medium to a predetermined temperature, and a cooler for bypassing the cooler facility are provided. In a process line facility provided with a heat removal bypass path, a cooler that outputs an adjustment signal based on the changed set temperature and the temperature in the temperature control region when the set temperature is changed due to the temperature controlled object. Side heat removal temperature control device and the cooler heat removal bypass passage based on a target value as an adjustment signal of the cooler side heat removal temperature control device and the temperature before the blower. A pre-blower temperature control device that performs heat removal control on the cooler side, and a heater-side heating temperature control device that controls a heater heating amount of the heater device based on the changed set temperature and the temperature in the temperature control region. Determining means for determining whether or not the pre-blower temperature control device and the heater-side heating temperature control device are substantially in a balanced state; A circulation device, wherein the cooler side heat removal temperature control device is separated, and a pre-blower set temperature control means for gradually increasing the pre-blower set temperature at a predetermined rate of change and applying the temperature to the pre-blower temperature control device is provided. Medium temperature control device.