JPH07326470A - Heat input control device of billet heater - Google Patents

Abstract

PURPOSE:To enhance the accuracy of controlled temperature by computing and determining a controlled output on the basis of an input side tracking temperature, an input side measured temperature, an output side measured temperature, a desired heating temperature, and total electric power, etc., and subjecting a heating power source to feedback control. CONSTITUTION:A billet 3 is heated using heating coils 2a, 2b to which power is supplied from a heating power source 1. In this case, a controlled output computing portion 16 calculates and determines a controlled output Ea on the basis of an input side tracking temperature thetan determined by a shift portion 14 to which a temperature theta0 measured by an input side thermometer 4a is supplied, the temperature theta0, a temperature thetaa measured by an output side thermometer 4b, a desired heating temperature thetaR, and the total electric power Pn of the power source 1 as measured by an output power integrating portion 15, etc., and the power source 1 is subjected to feedback control according to the output Ea. This actual increase in temperature and the total electric power are used to determine the controlled output, thereby enhancing the accuracy of controlled temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat input controller for a heater, and more particularly to a heat input controller for a pellet heater effective for induction heating.

[0002]

2. Description of the Related Art FIG. 2 shows a heat input control device for a conventional pellet heater used for an induction heating device or the like. In FIG. 2, 1 is an inverter as a heating power source, and 2a is an input power output from the inverter 1. 1 heating coil, 2b is a second heating coil which also receives the output power of the inverter 1, 3 is a billet which is inserted into the heating coils 2a and 2b and flows in the direction of the arrow, 4a is the temperature on the inlet side of the pyret A first thermometer for measurement 4b is a second thermometer for measuring the temperature on the outlet side of the pellet.

Further, reference numeral 10 in FIG. 2 is an arithmetic and control unit, which is composed of a main setting arithmetic unit 11, a correction setting arithmetic unit 12, and a control output arithmetic unit 13. The main setting calculation unit 11 measures the measured temperature θ _O of the first thermometer 4a, the pellet diameter D _w , the billet transfer speed S _p, and the target heating temperature θ _R.
The calculation of equation (1) is executed by inputting.

P _a = f {(θ _R −θ _O ), D _W , S _p } (1) The correction setting calculator 12 calculates the inlet side measured temperature θ _O and the billet by the second thermometer 4 b. The corrected set power amount ΔP is executed by the calculation of the equation (2) with the output side actual measurement temperature θ _a of the above.

ΔP = K × {θ _R −θ _O ) − (θ _a −θ _O ) ... (2) Here, K is a constant, and the control output operation unit 13 is the main setting operation unit 11. The main set power amount P _a , which is the calculation output, and the correction set power amount ΔP, which is the calculation output of the correction setting calculation unit 12.
Is input and the operation of equation (3) is executed.

E _a = P _a + ΔP (3) According to the billet heater heat input control device of FIG. 2, the temperature on the heating coil input side is measured and the target temperature rise amount (target temperature θ _R −input side From the measured temperature θ _O ), the billet diameter, and the billet transport speed, the main set power amount P _a is calculated by the power formula including the heat radiation amount.
To decide. Furthermore, measure the temperature on the outlet side of the heating coil,
The correction set power amount ΔP is determined from the difference between the actual temperature rise amount (measured temperature θ _a on the outlet side−measured temperature θ _O on the inlet side) and the target temperature rise amount. The control output E _a is determined from the main set power amount P _a and the correction set power amount ΔP and is fed back to the thyristor inverter 1.

[0007]

Since the temperature is measured by the inlet side thermometer and the outlet side thermometer at the same time, and the difference between them is used as the actual temperature rise amount, the distance to the measurement position when the actual temperature rise amount is calculated. There is. (The actual amount of temperature rise at a certain billet position cannot be calculated).

Further, since the actual input electric energy (the integrated value of the electric energy) is not calculated when the set electric energy is calculated, the actual input electric energy and the temperature rise amount are not matched. Therefore, the accuracy of the control temperature is lowered.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a high-performance billet heater heat input control device with improved control temperature accuracy.

[0010]

In order to achieve the above object, a heat input control device for a billet heater according to the present invention supplies electric power from a heating power source to a heating coil and heats the billet by the heating coil. In the heat input control device of the billet heater that measures the temperature of the heated billet with a thermometer and controls the heating power supply by the calculation control device based on this measurement data, the calculation control unit controls the heating of the billet. A temperature data shift unit for sequentially shifting the input side measured temperature of the coil to output the input side tracking temperature; and an output power amount integrating unit for integrating the output power amount of the heating power source as an input and outputting an integrated power amount. , The integrated power amount of the output power amount integration unit, the tracking temperature of the temperature data shift unit, the measured inlet temperature and the outlet temperature of the billet, and Characterized by being configured by the control output calculation section for controlling the heating power running operation as an input at least the target heating temperature.

[0011]

Function: The input side tracking temperature θ _n becomes the input side temperature of the output side temperature measuring unit at the current time. The integrated power amount P _n is an integrated value of the power actually input to the outlet temperature measurement unit at the current time. In the control output calculation unit 16, the actual temperature rise amount (outside measured temperature θ _a −inlet side tracking temperature θ _n ), the target temperature rise amount (target heating temperature θ _R −inlet side measured temperature θ _O ), the billet transport speed S _p , The billet diameter D _W and the integrated electric energy P _n determine the control output E _a and feed it back to the inverter.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows a heat input control device for a billet heater according to an embodiment of the present invention. The same or corresponding members as those in FIG.
0A is a temperature data shift unit 14 to which the actually measured temperature data θ _O by the first thermometer 4a is input, an output power amount integration unit 15 to which the output power amount P _o of the inverter 1 is input, and a control output calculation unit. It is composed of 16.

In the heat input control device having the above-mentioned structure, the temperature data shift unit 14 inputs θ ₁ = θ ₀ , θ ₂ = the input side measured temperature θ _O of the billet 3 by the first thermometer 4 a.
θ ₁ , ... θ _n-1 = θ _n-2 , θ _n = θ _n-1 are sequentially shifted to output the input side tracking temperature θ _n as a shift output. The output power amount integration unit 15 receives the output power amount P _o of the inverter 1 as input, and P ₁ = P ₀ , P ₂ = P ₁ + P ₀ , ...
·, And outputs the integrated electricity P _n by performing the operation of the _{P n-1 = P n-} 2 + P 0, P n = P n-1 + P 0.

The control output calculator 16 controls the inlet side tracking temperature θn, the integrated electric energy P _n , the inlet side measured temperature θ _o, the outlet side measured temperature θ _a of the billet 3 by the second thermometer 4b, and the billet conveying speed S _p. , The billet diameter D _W and the target heating temperature θ _R are input, the calculation of the equation (4) is executed to output the control output E _a , and the control output E _a is input to the inverter 1.

E _a = f {(θ _a −θ _n ), (θ _R −θ _O ), S _p , D _W } (4) That is, the billet from the inverter 1 via the heating coils 2 a and 2 b. Power is supplied to 3. The second thermometer (inlet thermometer) 4a measures the inlet temperature of the billet 3,
The thermometer (outgoing side thermometer) 4b measures the outgoing temperature of the billet 3. The input side temperature data is shifted by the input side temperature data shift unit 14 at a constant time interval in synchronization with the billet transport speed. The output electric power amount is accumulated in the output electric power accumulating unit 15 at a constant time interval in synchronization with the conveyance speed.

The incoming tracking temperature θ _n is the incoming temperature of the outgoing temperature measuring unit at the current time. The integrated electric energy P _n is
It is the integrated value of the electric power actually input to the outlet temperature measurement unit at the current time. In the control output calculation unit 16, the actual temperature rise amount (outside measured temperature θ _a −inlet side tracking temperature θ _n ), the target temperature rise amount (target heating temperature θ _R −inlet side measured temperature θ _O ), the billet transport speed S _p , The billet diameter D _W and the integrated electric energy P _n determine the control output E _a and feed it back to the inverter.

[0018]

As described above, the present invention is provided with the inlet side temperature data shift section and the data is tracked so that the actual temperature rise is obtained from the difference between the inlet side temperature and the outlet side temperature at the same point of the billet. It is possible to obtain the amount of electricity, and by providing the output power integration unit, it is possible to obtain the integrated value of the power input to the point where the billet exists, and the actual temperature rise amount and the power integration when determining the control output. Values can be used. Therefore, the temperature accuracy is improved, and the heat input control device for the billet heater with high accuracy and high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a heat input control device for a pellet heater according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional pellet heater heat input control device.

[Explanation of symbols]

 1 ... An inverter that is a heating power supply. 2a ... 1st heating coil (inlet heating coil) 2b ... 2nd heating coil (outlet heating coil) 3 ... Billet 4a ... 1st thermometer (inlet thermometer) 4b ... 2nd thermometer ( Output side thermometer) 10A ... Arithmetic control device 14 ... Temperature data shift unit 15 ... Output electric energy integrating unit 16 ... Control output arithmetic unit

Claims (1)

[Claims] 1. A heating power supply supplies electric power to a heating coil to heat the billet, and
In the heat input control device of the billet heater, which measures the temperature of the heated billet with a thermometer and controls the heating power supply by the calculation control device based on this measurement data, the calculation control unit controls the heating of the billet. A temperature data shift unit for sequentially shifting the input side measured temperature of the coil to output the input side tracking temperature; and an output power amount integrating unit for integrating the output power amount of the heating power source as an input and outputting an integrated power amount. , The integrated power amount of the output power amount integration unit, the tracking temperature of the temperature data shift unit,
A heat input control device for a billet heater, comprising a control output calculation unit that executes a calculation by inputting a measured input temperature and an output temperature of the billet, and at least a target heating temperature, and controls the heating power source.