JP2008111632A - Heat treatment furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power control device of a heat treatment furnace that can efficiently heat a treated material. <P>SOLUTION: An electric power function generating part 11 of a control part 6 generates electric power waveform for controlling power transistors G11, G12 which a PAM converter 4 has so that the heat generation spectrum of a load 2 coincides with the heat absorption spectrum of the treated material. Output power from the electric power function generating part 11 is pulse-converted by a pulse converter 13 and then converted into pulses for performing ON-OFF control of the power transistors G11, G12 of the PAM converter 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power control apparatus that controls power supplied to a heat source of a heat treatment furnace.

  Conventionally, when a heat source such as a halogen lamp in a heat treatment furnace is a single-phase load, a single-phase AC power source is used as a power source, and PWM system voltage control is directly performed without smoothing the output from the single-phase AC power source (for example, patent In general, the power supplied to the heat source is controlled by the power, voltage, and current control (see, for example, Patent Document 2) by phase control and cycle control. Further, the power feedback is detected in units of half cycle of the power output of PWM voltage control. Phase and cycle control do not add this function.

JP-A-8-171992 JP 2000-77345 A

  According to the technique described above, direct control of a single-phase power supply is simply control of heat output to a heat source. However, in the heat source, when the supplied power changes, not only the heat output changes, but also the heat source spectrum. Here, the relationship between the heat output and the heat source spectrum in the halogen lamp as the heat source will be described with reference to FIG. As shown in FIG. 7, when the heat output in the halogen lamp is 100%, when the heat source spectrum wavelength is at a peak of 10 μm, the heat output spectrum changes in the direction of increasing the wavelength as the heat output decreases. (Refer to (a) to (c) in the figure). On the other hand, the treatment material has a unique heat absorption spectrum. For example, when the treatment material has a heat absorption spectrum with a wavelength of 8 to 12 μm (see (d) in the figure), the heat source generally has a heat source spectrum at 100% heat output and the heat of the treatment material. It is determined so that the absorption spectrum matches. For this reason, the heat source spectrum when the heat source has a heat output of 100% or less does not match the heat absorption spectrum of the treatment material. In this case, radiant heat from the heat source is not efficiently absorbed by the treatment material, and the treatment material is heated by radiant heat, resulting in a slow thermal response. The treatment materials may be distributed individually when the whole treatment is the same substance.

  Then, an object of this invention is to provide the electric power control apparatus in the heat processing furnace which can heat a processing material efficiently.

  The power control apparatus in the heat treatment furnace according to the present invention matches the heat generation spectrum and the heat absorption spectrum of the treatment material by function-controlling the heat source of the heat treatment furnace.

  According to the present invention, since the heat generation spectrum of the heat source matches the heat absorption spectrum of the treatment material, the radiant heat from the heat source is efficiently absorbed by the treatment material. Thereby, the thermal response of a processing material becomes quick, a processing material can be heated efficiently, and productivity and quality can be improved. Furthermore, power saving in the heat treatment furnace can be achieved.

  In the present invention, it is preferable to perform feedback control of any one of voltage, current, and power supplied to the heat source. According to this, the electric power supplied to the heat source can be accurately controlled. Moreover, when the load is short-circuited, the roller can respond to the load instantaneously, and the power element can be safely protected.

  In the present invention, power supplied to the plurality of heat sources may be generated from a three-phase power source. According to this, since the phase balance and the power factor can be improved, further power saving in the heat treatment furnace can be achieved.

  Furthermore, in the present invention, it is more preferable to feed-forward control the power supplied to the heat source in response to a change in the material of the treatment material, a change in conveyance speed, and insertion of the treatment material into a discontinuous heat treatment furnace. According to this, a processing material can be heated appropriately (optimally).

  The present invention may further include receiving means for receiving an instruction from the outside and transmitting means for transmitting the internal data to the outside. According to this, the power function generator and various parameters can be set and controlled at a single location for a plurality of power control devices. Data such as settings and load power can be transmitted.

  In addition, the present invention may include a switching element and a microprocessor that controls the switching element. According to this, the multi-group electric power supplied to the heat source can be finely averaged to improve the phase balance and power factor of the three-phase power source.

  In the present invention, the treatment material may be a solar cell.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic block diagram of a power control apparatus in a heat treatment furnace according to an embodiment of the present invention. This heat treatment furnace is a heat treatment furnace for solar cells using a solar cell as a treatment material. The power control device 1 is a device for controlling the power supplied to a halogen heater (hereinafter referred to as a load) 2 as a heat source in a heat treatment furnace for heat-treating a treatment material. As shown in FIG. A plurality of AC power supplies are connected in parallel. Note that the load 2 is determined such that when the output is 100%, the heat generation spectrum of the load 2 matches the heat absorption spectrum of the treatment material. Therefore, it is possible to select or use a xenon lamp, a nichrome heater, a silicon carbide heater or the like having a different heat generation spectrum depending on the type of treatment material. Each power control device 1 can control power supplied to a plurality of loads 2, a power conversion unit 3 connected to each load 2, and a control unit 6 that controls each power conversion unit 3. have. The power supplied from the three-phase AC power supply is converted to DC power via the filter 7, the rectifier 8 and the capacitor (smoothing capacitor) C 1, and then supplied to each power conversion unit 3. Then, the power conversion unit 3 controlled by the control unit 6 generates desired power, and the generated power is supplied to the load 2. The capacitor C1 may be deleted when the input is a three-phase power source and the load 2 is a resistive load.

  The power conversion unit 3 includes a PAM converter 4 and a polarity conversion inverter 5. The PAM converter 4 converts DC power into PAM (Pulse Amplitude Modulation), and includes two power transistors G11 and G12 such as an IGBT (Insulated Gate Bipolar Transistor), a coil L11, and a capacitor C11. The PAM converter 4 generates power having a desired output waveform by alternately turning on and off the power transistors G11 and G12 at a constant ratio (see FIG. 4). The polarity conversion inverter 5 converts the polarity every time the power converted by the PAM converter 4 becomes zero. It is necessary to reverse the polarity of the power supplied to the load 2 at a predetermined cycle (see t11 in FIG. 3) determined by the heat source time constant of the load 2. For this reason, the PAM converter 4 generates an output waveform in which the power becomes 0 in a predetermined cycle. Thereby, the polarity conversion inverter 5 generates electric power having an output waveform in which the polarity is inverted at a predetermined cycle. The electric power generated by the polarity conversion inverter 5 is supplied to the load 2.

  The controller 6 will be described with further reference to FIGS. FIG. 2 is a functional block diagram of the control unit 6. FIG. 3 is a power waveform diagram generated by the power function generator 11 of the controller 6. FIG. 4 is a waveform diagram of power supplied to the load 2. In the following description, only the relationship between the control unit 6 and one power conversion unit 3 will be described. The controller 6 controls the operation of the PAM converter 4. As shown in FIGS. 1 and 2, the control unit 6 includes a power function generation unit 11, a gain adjustment unit 12, a pulse converter 13, a photocoupler 14, a power converter 15, an upper limit current setting unit 16, and a comparator. 17. A coefficient setting block 18 for K01 and a coefficient setting block 19 for K02, a main power command signal generation unit 20, a feedforward power command signal generation unit 21, and a feedforward start signal generation unit 22 surrounded by a dotted line are shown. K01 and K02 may have a plurality of values. Further, a portion surrounded by a dotted line may be installed outside the control unit 6.

  The power function generation unit 11 generates a power function waveform to be output to the polarity conversion inverter 5 by being operated from outside via wireless or wired. As shown in FIG. 3A, the power to be supplied to the load 2 needs to be inverted in polarity at a predetermined period t11 determined by the heat source time constant of the load. A power function waveform is output so that the power becomes zero every t11. The power function generator 11 determines the power supplied to the load 2 based on the addition of the main power command signal and the feedforward power command signal, and increases or decreases the time when the power supplied to the load 2 becomes 100%. For example, in FIG. 3B, the power supplied to the load 2 is 100% during t21, and the power supplied to the load 2 is 30% during t22. At this time, as long as the relationship between the time when the power supplied to the load 2 is 100% and the time when it is 30% is maintained, the generated power waveform may be an arbitrary pattern. For example, as shown in FIG. 3C, the time t31 and t33 when the power supplied to the load 2 becomes 100% and the time t32 when the power supplied to the load 2 becomes 30% may be combined. (Note that t31 + t32 × 2 = t21, t32 × 3 = t22). At this time, it is preferable to secure a long time when the power supplied to the load 2 becomes 100% so that the time when the heat generation spectrum of the load 2 coincides with the heat absorption spectrum of the treatment material becomes the longest. Further, when the treatment material moves and the treatment material temperature adversely affects the movement time, as shown in FIGS. 3B, 3C, 5A, 5B, and 6, heat is applied. This synchronization can be eliminated by changing the output and advancing or delaying the phase of the heat output with respect to the time axis.

  The power converter 15 converts the current I11 output to the polarity conversion inverter 5 detected by the current detection 42 and the voltage E1 output to the polarity conversion inverter 5, and outputs the power output to the polarity conversion inverter 5. Is detected. The power detected by the power converter 15 is fed back to the output terminal of the power function generator 11. Then, the gain adjustment unit 12 outputs power obtained by multiplying the deviation between the output result of the power function generation unit 11 and the detection result of the power converter 15 by the gain K. The upper limit current setting unit 16 sets an upper limit current I0 when starting current limitation when the load 2 is short-circuited. The comparator 17 compares the drain current I10 of the power transistor G12 detected by the current detection 41 with a predetermined upper limit current I0, and when the drain current I10 exceeds the upper limit current I0, the pulse converter 13 By adjusting the output from the gain adjusting unit 12 so that the power input to the power supply is always I0, current limitation when the load 2 is short-circuited can be performed.

  The pulse converter 13 generates a pulse signal for ON / OFF control of the power transistors G11 and G12 according to the input power. The photocoupler 14 is for transmitting the pulse signal from the pulse converter 13 to the gate voltages GE11 and GE12. The system configuration of these control units 6 is configured by a microprocessor.

  In addition, although the control part 6 demonstrated the structure which controls the electric power supplied to the load 2 so that it may change with a rectangular pulse as shown in FIG. 3, as shown to Fig.5 (a), each rectangular pulse is demonstrated. The electric power supplied to the load 2 may be controlled so that becomes a sine wave (see FIG. 4B). In this case, it is preferable that the output of each rectangular pulse matches the execution output of the corresponding sine wave. Further, as shown in FIGS. 5B and 5C, at least a part of the waveform pattern may be temporally exchanged and many frequencies may be introduced. Further, FIG. 6 shows a method for securing a heat source output spectrum with a sine wave output. As shown in FIG. 6, when the heat source output spectrum due to a sine wave flickers, the frequency of the sine wave is increased to eliminate the flicker. Thus, the power function generator can generate a power function waveform corresponding to the heat absorption spectrum required by the load.

  As described above, according to the present embodiment described above, the control unit 6 controls the power supplied by the load 2 so that the heat generation spectrum of the load 2 and the heat absorption spectrum of the treatment material coincide with each other. Is efficiently absorbed by the treatment material. Thereby, the thermal response of a processing material becomes quick, a processing material can be heated efficiently, and productivity and quality can be improved. Furthermore, power saving in the heat treatment furnace can be achieved.

  In addition, since the control unit 6 performs feedback control on the power supplied to the load 2, the power supplied to the load 2 can be accurately controlled.

  Furthermore, since the control unit 6 generates power to be supplied to each load 2 from the three-phase power source, the phase balance and the power factor can be improved, so that further power saving in the heat treatment furnace can be achieved. .

  In addition, the control unit 6 performs function control based on the main power command signal and the feedforward command signal, whereby the heat source heat generation spectrum and the absorption spectrum of the processing material can be matched, and the processing material can be efficiently heated. Thus, in order to determine the power to be supplied to the load 2 that heats the treatment material to a temperature to be heat-treated with respect to the material change of the treatment material, the change of the conveyance speed, and the charging of the treatment material into the discontinuous furnace. The treatment material can be heated appropriately.

  Moreover, since the control part 6 has a communication means which transmits / receives data between the exterior, the some power control apparatus 1 can be controlled in one place.

  Furthermore, since the control unit 6 includes a microprocessor, the power supplied to the load 2 can be controlled to be finely averaged. The circuit configuration of the control unit 6 can be realized by hardware as well as software.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the embodiment described above, the control unit 6 is configured to feedback control the power supplied to the load 2, but may be configured to feedback control the current or voltage supplied to the load 2.

  In the above-described embodiment, the control unit 6 is configured to generate the power supplied to each load 2 from the three-phase power source, but may be configured to generate from a single-phase power source.

  Furthermore, in the above-described embodiment, when a rectangular wave is used in function control (when the waveform is discontinuous up and down in any part), S-shaped curves may be inserted at the rise and fall of the function. Thereby, generation | occurrence | production of a surge can be suppressed.

  In embodiment mentioned above, although the example which applied this invention about the power control apparatus 1 of the heat processing furnace for solar cells whose processing material is a solar cell was demonstrated, the heat processing which uses members other than a solar cell as a processing material The present invention is also applicable to a furnace power device.

  Moreover, in embodiment mentioned above, although the processing material was demonstrated as a single member, a solar cell may be comprised from a multiple types of member. For example, a solar cell includes a substrate and a terminal disposed on the surface of the substrate. In this case, in the heat treatment step, when it is required to heat only the terminals arranged on the surface of the solar cell, the power supplied to the load 2 is controlled so that the heat generation spectrum matches the heat absorption spectrum of the terminals. Is preferred. Thereby, only a terminal can be heated efficiently and the thermal load added to a base material can be reduced.

It is a schematic block diagram of the electric power control apparatus which is embodiment which concerns on this invention. It is a functional block diagram of the control apparatus shown in FIG. FIG. 3 is a power waveform diagram generated by a power function generation unit shown in FIG. 2. It is an electric power waveform diagram supplied to the load shown in FIG. It is a modification of the electric power waveform diagram supplied to the load shown in FIG. It is a modification of the electric power waveform diagram supplied to the load shown in FIG. It is the figure which showed the relationship between the heat output in the halogen lamp which is a heat source, and a heat source spectrum.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power controller 2 Load 3 Power conversion unit 4 PAM converter 5 Polarity conversion inverter 6 Control part 7 Filter 8 Rectifier 11 Power function generation part 12 Gain adjustment part 13 Pulse converter 14 Photocoupler 15 Power converter 16 Upper limit current setting part 17 Comparator 18 Coefficient Setting Block 19 Coefficient Setting Block 20 Main Power Command Signal Generation Unit 21 Feedforward Power Command Signal Generation Unit 22 Feedforward Start Signal Generation Units 41 and 42 Current Detection G11 Power Transistor G12 Power Transistor

Claims (7)

  A power control apparatus for a heat treatment furnace, wherein a heat source of the heat treatment furnace is function-controlled to make the heat generation spectrum coincide with the heat absorption spectrum of the treatment material.   2. The power control apparatus for a heat treatment furnace according to claim 1, wherein any one of a voltage, a current, and power supplied to the heat source is feedback-controlled.   The power control apparatus for a heat treatment furnace according to claim 1 or 2, wherein power to be supplied to the plurality of heat sources is generated from a three-phase power source.   The power supplied to the heat source is feedforward controlled with respect to a change in the material of the treatment material, a change in conveyance speed, and insertion of the treatment material into a discontinuous heat treatment furnace. A power control apparatus for the heat treatment furnace according to claim 1. Receiving means for receiving instructions from the outside;
The power control apparatus for a heat treatment furnace according to any one of claims 1 to 4, further comprising transmission means for transmitting internal data to the outside.   The power control apparatus for a heat treatment furnace according to any one of claims 1 to 5, further comprising a switching element and a microprocessor for controlling the switching element.   The said control material is a solar cell, The power control apparatus in the heat processing furnace in any one of Claims 1-6 characterized by the above-mentioned.

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