JP6332853B2 - Induction heating device - Google Patents
Induction heating deviceInfo
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- JP6332853B2 JP6332853B2 JP2014101957A JP2014101957A JP6332853B2 JP 6332853 B2 JP6332853 B2 JP 6332853B2 JP 2014101957 A JP2014101957 A JP 2014101957A JP 2014101957 A JP2014101957 A JP 2014101957A JP 6332853 B2 JP6332853 B2 JP 6332853B2
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- 238000010438 heat treatment Methods 0.000 title claims description 72
- 230000006698 induction Effects 0.000 title claims description 64
- 238000004364 calculation method Methods 0.000 claims description 196
- 238000004804 winding Methods 0.000 claims description 147
- 230000004907 flux Effects 0.000 claims description 70
- 238000001514 detection method Methods 0.000 claims description 47
- 230000036760 body temperature Effects 0.000 claims description 38
- 238000012937 correction Methods 0.000 claims description 33
- 230000007246 mechanism Effects 0.000 claims description 32
- 230000002093 peripheral effect Effects 0.000 claims description 28
- 230000005284 excitation Effects 0.000 claims description 27
- 239000000463 material Substances 0.000 claims description 25
- 230000035699 permeability Effects 0.000 claims description 20
- 230000006870 function Effects 0.000 claims description 19
- 230000007704 transition Effects 0.000 claims description 15
- 238000005259 measurement Methods 0.000 claims description 13
- 239000007788 liquid Substances 0.000 claims description 11
- 230000006866 deterioration Effects 0.000 claims description 6
- 239000004065 semiconductor Substances 0.000 claims description 5
- 230000005484 gravity Effects 0.000 claims description 2
- 230000008859 change Effects 0.000 description 19
- 230000009467 reduction Effects 0.000 description 13
- 229910000975 Carbon steel Inorganic materials 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 9
- 239000010962 carbon steel Substances 0.000 description 9
- 230000035515 penetration Effects 0.000 description 9
- 230000000630 rising effect Effects 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 230000001052 transient effect Effects 0.000 description 5
- 238000013500 data storage Methods 0.000 description 4
- 230000020169 heat generation Effects 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 230000001131 transforming effect Effects 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910000976 Electrical steel Inorganic materials 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
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- General Induction Heating (AREA)
Description
本発明は、誘導発熱加熱装置に関するものである。 The present invention relates to an induction heating apparatus.
誘導加熱装置において、特許文献1に示すように、被加熱体に温度検出素子を取り付けて直接温度を測定するものがある。 As an induction heating apparatus, as shown in Patent Document 1, there is an induction heating apparatus in which a temperature detection element is attached to a heated object and the temperature is directly measured.
ところが、被加熱体への温度検出素子の取り付け作業は煩わしく、また、加熱後の被加熱体から温度検出素子を取り外す場合などにおいて危険が伴う。さらに、温度検出素子を被加熱体に取り付ける場合には、個別に温度検出素子と被加熱体との接触状況が異なり、検出温度の誤差となることがある。 However, the operation of attaching the temperature detection element to the heated body is troublesome, and there is a danger in removing the temperature detection element from the heated heated body. Furthermore, when attaching a temperature detection element to a to-be-heated body, the contact state of a temperature detection element and a to-be-heated body differs separately, and it may become an error of detection temperature.
なお、輻射式温度計等の非接触式温度検出手段を用いて被加熱体の温度を検出する方法も考えられるが、検出精度が低かったり、被加熱体の表面輻射率(放射率)に影響されたりして、正確な温度検出が困難な場合が多い。 In addition, although the method of detecting the temperature of a to-be-heated body using non-contact-type temperature detection means, such as a radiation-type thermometer, can also be considered, detection accuracy is low or it influences the surface emissivity (emissivity) of a to-be-heated body. In many cases, accurate temperature detection is difficult.
そこで本発明は、上記問題点を解決するためになされたものであり、誘導加熱装置において、被加熱体の温度を測定する温度検出素子を不要にすることをその主たる課題とするものである。 Accordingly, the present invention has been made in order to solve the above-described problems, and it is a main object of the present invention to eliminate the need for a temperature detection element for measuring the temperature of the object to be heated in the induction heating apparatus.
すなわち本発明に係る誘導加熱装置は、磁束発生機構の巻き線に接続されるとともに、交流電流又は交流電圧を制御する制御素子が設けられた電源回路を備え、前記磁束発生機構により被加熱体を誘導加熱する誘導加熱装置であって、前記巻き線を流れる交流電流を検出する交流電流検出部から得られる交流電流値と、前記巻き線に印加される交流電圧を検出する交流電圧検出部から得られる交流電圧値と、前記被加熱体及び前記磁束発生機構からなる誘導加熱ユニットの力率を検出する力率検出部から得られる力率と、前記巻き線の巻き線抵抗値と、前記磁束発生機構により生じる磁束密度と前記磁束発生機構及び前記被加熱体から構成される磁気回路の励磁抵抗との関係特性から得られる励磁抵抗値とをパラメータとして、前記被加熱体の温度を算出する被加熱体温度算出部を備えることを特徴とする。なお、前記磁束発生機構により生じる磁束密度と前記被加熱体及び前記磁束発生機構から構成される磁気回路の励磁抵抗との関係特性は、予め測定したものを用いることができる。また、巻き線の巻き線抵抗値は、巻き線の巻き線抵抗を検出する巻き線抵抗検出部を設けて、当該巻き線抵抗検出部により直接的に検出するようにしても良いし、後述するように、巻き線の温度を検出する巻き線温度検出部を設けて、当該巻き線温度検出部から得られる巻き線の温度から巻き線抵抗値を算出しても良いし、巻き線に間欠的に直流電圧を印加して、その際に流れる直流電流を検出することにより、巻き線抵抗値を算出するようにしても良い。 That is, the induction heating device according to the present invention includes a power supply circuit that is connected to a winding of a magnetic flux generation mechanism and is provided with a control element that controls an alternating current or an alternating voltage. An induction heating device for induction heating, obtained from an alternating current value obtained from an alternating current detection unit that detects an alternating current flowing through the winding and an alternating voltage detection unit that detects an alternating voltage applied to the winding. An AC voltage value, a power factor obtained from a power factor detection unit that detects a power factor of an induction heating unit including the heated object and the magnetic flux generation mechanism, a winding resistance value of the winding, and the magnetic flux generation The heated object using as parameters the magnetic flux density generated by the mechanism and the excitation resistance value obtained from the relationship between the magnetic flux generation mechanism and the exciting resistance of the magnetic circuit composed of the heated object Characterized in that it comprises a heated body temperature calculating unit for calculating the temperature. As a relational characteristic between the magnetic flux density generated by the magnetic flux generation mechanism and the excitation resistance of the magnetic circuit composed of the heated body and the magnetic flux generation mechanism, those measured in advance can be used. Further, the winding resistance value of the winding may be directly detected by the winding resistance detecting unit provided with a winding resistance detecting unit for detecting the winding resistance of the winding, which will be described later. As described above, a winding temperature detection unit for detecting the winding temperature may be provided, and the winding resistance value may be calculated from the winding temperature obtained from the winding temperature detection unit, or intermittently in the winding. A winding resistance value may be calculated by applying a direct current voltage to the current and detecting a direct current flowing at that time.
このようなものであれば、巻き線の電流値と、巻き線の電圧値と、誘導加熱ユニットの力率と、巻き線の抵抗値と、磁気回路の励磁抵抗値とをパラメータとして被加熱体の温度を算出する被加熱体温度算出部を有するので、被加熱体に温度検出素子を設けることなく、被加熱体の温度を算出することができる。 If this is the case, the object to be heated is set with the parameters of the current value of the winding, the voltage value of the winding, the power factor of the induction heating unit, the resistance value of the winding, and the excitation resistance value of the magnetic circuit. Therefore, the temperature of the object to be heated can be calculated without providing a temperature detecting element in the object to be heated.
具体的には、前記被加熱体温度算出部が、前記電流検出部から得られる電流値と、前記電圧検出部から得られる電圧値と、前記力率検出部から得られる力率と、前記巻き線抵抗値と、前記磁束密度及び前記磁気回路の磁気抵抗の関係特性から得られる励磁抵抗値とをパラメータとして前記被加熱体の抵抗値を算出し、前記被加熱体の抵抗値と前記被加熱体の比透磁率とを用いて、前記被加熱体の温度を算出することが望ましい。 Specifically, the heated object temperature calculation unit includes a current value obtained from the current detection unit, a voltage value obtained from the voltage detection unit, a power factor obtained from the power factor detection unit, and the winding. The resistance value of the object to be heated is calculated using the line resistance value and the excitation resistance value obtained from the relational characteristics of the magnetic flux density and the magnetic resistance of the magnetic circuit as parameters, and the resistance value of the object to be heated and the object to be heated are calculated. It is desirable to calculate the temperature of the heated object using the relative permeability of the body.
より具体的には、誘導加熱装置が、前記電流検出部から得られる電流値と、前記電圧検出部から得られる電圧値と、前記力率検出部から得られる力率とにより前記誘導加熱ユニットのインピーダンス(以下、ユニットインピーダンスという。)を算出するインピーダンス算出部を備えており、さらに前記インピーダンス算出部が、前記ユニットインピーダンスと前記巻き線抵抗値と前記励磁抵抗値とをパラメータとして、前記被加熱体の抵抗値を算出するものである。 More specifically, the induction heating device includes a current value obtained from the current detection unit, a voltage value obtained from the voltage detection unit, and a power factor obtained from the power factor detection unit. An impedance calculation unit for calculating an impedance (hereinafter referred to as a unit impedance), and the impedance calculation unit further uses the unit impedance, the winding resistance value, and the excitation resistance value as parameters. The resistance value is calculated.
ここで、被加熱体及び磁束発生機構からなる誘導加熱ユニットの等価回路を図5に示す。電源回路による交流電圧の通電時において、巻き線に印加される入力交流電圧Vを、巻き線を流れる交流電流Iで除し、且つ、誘導加熱ユニットの力率cosφを乗じると、巻き線の抵抗r1、励磁抵抗r0、及び被加熱体の抵抗r2からなる合成抵抗rcombが算出される。この合成抵抗rcombは、以下の式により示される。
rcomb=(V/I)×cosφ [Ω]
rcomb=(r1r2+r1r0+r2r0)/(r2+r0) [Ω]
Here, FIG. 5 shows an equivalent circuit of an induction heating unit including a heated object and a magnetic flux generation mechanism. When the AC voltage is applied by the power supply circuit, the input AC voltage V applied to the winding is divided by the AC current I flowing through the winding, and multiplied by the power factor cosφ of the induction heating unit. A combined resistance r comb consisting of r 1 , excitation resistance r 0 , and resistance r 2 of the object to be heated is calculated. This combined resistance r comb is expressed by the following equation.
r comb = (V / I) × cos φ [Ω]
r comb = (r 1 r 2 + r 1 r 0 + r 2 r 0 ) / (r 2 + r 0 ) [Ω]
被加熱体の抵抗r2を求める式に書き換えると、以下となる。
r2=r0(r1−rcomb)/(rcomb−r1−r0) [Ω]
Rewriting into the equation for obtaining the resistance r 2 of the heated object is as follows.
r 2 = r 0 (r 1 −r comb ) / (r comb −r 1 −r 0 ) [Ω]
この被加熱体の抵抗r2の式において、励磁抵抗r0は、磁束発生機構により生じる磁束密度との関係から求めることができる。この関係は、磁束発生機構の鉄心の材質及び厚さ等の形状と、被加熱体の材質との組み合わせによって決まる。図6には、磁束発生機構の鉄心が厚さ0.23mmの方向性珪素鋼板であって、被加熱体の材質が炭素鋼S45Cの熱処理材である場合の、磁束発生機構により生じる磁束密度と励磁抵抗との特性を示している。 In the equation for the resistance r 2 of the heated object, the excitation resistance r 0 can be obtained from the relationship with the magnetic flux density generated by the magnetic flux generation mechanism. This relationship is determined by a combination of the shape and thickness of the iron core of the magnetic flux generation mechanism and the material of the object to be heated. FIG. 6 shows the magnetic flux density generated by the magnetic flux generation mechanism when the iron core of the magnetic flux generation mechanism is a directional silicon steel sheet having a thickness of 0.23 mm and the material of the object to be heated is a heat treatment material of carbon steel S45C. The characteristic with excitation resistance is shown.
磁束密度Bmは、入力交流電圧Vから巻き線のリアクタンスl1及び巻き線の抵抗r1による電圧降下分を引くベクトル算出の電圧をVmとすると、以下の式により算出できる。なお、以下の式は、筒形状をなす被加熱体における式である。 The magnetic flux density Bm is, when Vm a voltage vector calculation subtracting the voltage drop due to the resistance r 1 of the reactance l 1 and winding of the winding from the input AC voltage V, can be calculated by the following equation. In addition, the following formula | equation is a formula in the to-be-heated body which makes | forms a cylinder shape.
l1=[1.975×D×N2×κ{d+(a+σ)/3}/πLh]×10−9 [H]
ここで、Dは磁束発生機構及び被加熱体の電流浸透部の平均直径[mm]であるが、形状がn角形の場合は平均周長/πの値とする。また、Nは巻き線の巻き数、aはコイル厚さ[mm]、Lhは巻き線幅[mm]、dは巻き線及び被加熱体の間の距離[mm]である。
さらに、σは被加熱体の電流浸透深さ[mm]であり、被加熱体の材質の固有抵抗をρ[μΩ・cm]、被加熱体の比透磁率をμs、周波数をf[Hz]とすると、σ={5.03√(ρ/μs×f)}×10[mm]により示される。
κはロゴスキー係数であり、κ={1−(a+σ+d)/πLh}により示される。
Vm=√{(cosφ×V−I×r1)2+(sinφ×V−2πf×l1×I)2} [V]
Bm=Vm×108/(4.44×f×N×Sm) [G]
ここで、Smは鉄心の磁路断面積[cm2]である。
l 1 = [1.975 × D × N 2 × κ {d + (a + σ) / 3} / πLh] × 10 −9 [H]
Here, D is the average diameter [mm] of the magnetic flux generation mechanism and the current permeation part of the heated object, and when the shape is an n-gon, the value is the average circumference / π. N is the number of turns of the winding, a is the coil thickness [mm], Lh is the winding width [mm], and d is the distance [mm] between the winding and the object to be heated.
Further, σ is the current penetration depth [mm] of the heated body, the specific resistance of the material of the heated body is ρ [μΩ · cm], the relative permeability of the heated body is μs, and the frequency is f [Hz]. Then, σ = {5.03√ (ρ / μs × f)} × 10 [mm].
κ is a Rogowski coefficient and is represented by κ = {1− (a + σ + d) / πLh}.
Vm = √ {(cos φ × V−I × r 1 ) 2 + (sin φ × V−2πf × l 1 × I) 2 } [V]
Bm = Vm × 10 8 /(4.44×f×N×Sm) [G]
Here, Sm is a magnetic path cross-sectional area [cm 2 ] of the iron core.
上記の式において、比透磁率μsは、材質ごとに磁束密度との固有の変化特性を示すので、材質ごとに前もって測定した変化特性から求める。被加熱体の材質が例えば炭素鋼S45Cの場合、磁束密度と比透磁率との関係は、図7に示すものとなる。 In the above formula, the relative permeability μs indicates a characteristic change characteristic with the magnetic flux density for each material, and is thus obtained from the change characteristic measured in advance for each material. When the material of the object to be heated is, for example, carbon steel S45C, the relationship between the magnetic flux density and the relative magnetic permeability is as shown in FIG.
上記の式の計算段階では、磁束密度Bmが確定していないので、入力交流電圧Vを磁束密度Bmを求める式に代入して、その磁束密度Bmと図7の関係とから比透磁率μsを求めて電流浸透度σを算出する。さらにこの算出結果を用いて磁束密度Bmを再演算し、図7の関係から比透磁率μsを用いて電流浸透度σを再演算する。このように繰り返し演算することによって、それぞれの値が収束していき、確定した磁束密度Bmが得られる。 Since the magnetic flux density Bm is not determined at the calculation stage of the above formula, the input AC voltage V is substituted into the formula for obtaining the magnetic flux density Bm, and the relative permeability μs is calculated from the magnetic flux density Bm and the relationship shown in FIG. The current penetration degree σ is calculated. Further, the magnetic flux density Bm is recalculated using this calculation result, and the current permeability σ is recalculated using the relative permeability μs from the relationship of FIG. By repeatedly calculating in this way, each value converges and a determined magnetic flux density Bm is obtained.
この磁束密度Bmと、図6に示される磁束密度Bm及び励磁抵抗r0の関係から励磁抵抗r0を求める。 And the magnetic flux density Bm, obtains the excitation resistor r 0 from the relationship between the magnetic flux density Bm and the excitation resistor r 0 shown in Fig.
前記被加熱体の抵抗r2の式において、巻き線の抵抗r1は、巻き線を構成する電線の材質、長さ、断面積及び巻き線の温度によって決まり、上述したように、電線の材質が例えば銅であれば、次式により算出することができる。
r1=kL/100Sc [Ω]
k=2.1(234.5+θC)/309.5
ここで、Lは電線の長さ[m]であり、SCは電線の断面積[mm2]であり、θCは巻き線の温度[℃]である。
In the formula of the resistance r 2 of the object to be heated, the resistance r 1 of the winding is determined by the material, length, cross-sectional area and winding temperature of the wire constituting the winding, and as described above, the material of the wire If is, for example, copper, it can be calculated by the following equation.
r 1 = kL / 100 Sc [Ω]
k = 2.1 (234.5 + θ C ) /309.5
Here, L is the length of the wire [m], S C is the cross-sectional area of the wire [mm 2], the theta C is the temperature of the windings [° C.].
具体的には、巻き線に温度センサ(温度検出部)を埋設して、当該温度センサが検出した巻き線の温度から抵抗値を算出することができる。また、後述するように、巻き線に短時間の直流電圧を印加してそのときに流れる直流電流を検出することにより、巻き線の抵抗値を直接検出することもできる。 Specifically, a temperature sensor (temperature detection unit) is embedded in the winding, and the resistance value can be calculated from the temperature of the winding detected by the temperature sensor. Further, as will be described later, the resistance value of the winding can be directly detected by applying a short-time DC voltage to the winding and detecting the direct current flowing at that time.
また、直流電源を制御して、前記巻き線に間欠的に直流電圧を印加する直流電圧印加部と、前記直流電圧印加部により印加される直流電圧と当該直流電圧を印加したときに前記巻き線に流れる直流電流とから前記巻き線の抵抗値を算出する抵抗値算出部とを備え、前記被加熱体温度算出部が、前記抵抗値算出部から得られる前記巻き線の抵抗値を用いて前記被加熱体の温度を算出することが望ましい。具体的には、前記被加熱体温度算出部が、前記インピーダンス算出部により得られたユニットインピーダンスと、前記抵抗値算出部により得られた巻き線抵抗値と、前記磁気回路の励磁抵抗値とによって、前記被加熱体の温度を算出することが望ましい。 A DC voltage application unit that intermittently applies a DC voltage to the winding by controlling a DC power source; a DC voltage applied by the DC voltage application unit; and the winding when the DC voltage is applied. A resistance value calculation unit that calculates a resistance value of the winding from a direct current flowing through the heating element, and the heated object temperature calculation unit uses the resistance value of the winding obtained from the resistance value calculation unit. It is desirable to calculate the temperature of the object to be heated. Specifically, the to-be-heated body temperature calculation unit is configured by the unit impedance obtained by the impedance calculation unit, the winding resistance value obtained by the resistance value calculation unit, and the excitation resistance value of the magnetic circuit. It is desirable to calculate the temperature of the heated object.
通電によって1次コイルである巻き線の温度が変化すると、図5に示す単相の誘導加熱ユニットの等価回路におけるr1が変化するので、回路インピーダンスも変化することになり、すなわち、rcombも変わることになる。したがって、被加熱体の抵抗r2の再計算が必要である。ところが、この変化は、被加熱体の発熱部温度の変化には無関係であるので、その変化分を補正する必要がある。 When the temperature of the winding that is the primary coil changes due to energization, r 1 in the equivalent circuit of the single-phase induction heating unit shown in FIG. 5 changes, so that the circuit impedance also changes, that is, r comb also Will change. Therefore, it is necessary to recalculate the resistance r 2 of the heated object. However, this change is irrelevant to the change in the temperature of the heat generating part of the heated body, and it is necessary to correct the change.
巻き線の抵抗率と温度とは、およそ絶対温度に比例する関係があるが、その材質によって固有の変化特性を示す。電線の材質が例えば銅であれば、下記式の関係になるので、巻き線の温度が分かれば巻き線の抵抗値r1が算出できる。
r1=kL/100S[Ω]
k=2.1(234.5+θC)/309.5
ここで、Lは電線長[m]であり、Sは電線断面積[mm2]であり、θCは巻き線温度[℃]である。
The resistivity and temperature of the winding have a relationship that is approximately proportional to the absolute temperature, but shows inherent change characteristics depending on the material. If the material is, for example, copper wire, since the relationship of the following equation, the resistance value r 1 of the winding if the temperature of the winding is known can be calculated.
r 1 = kL / 100S [Ω]
k = 2.1 (234.5 + θ C ) /309.5
Here, L is the wire length [m], S is the wire cross-sectional area [mm 2 ], and θ C is the winding temperature [° C.].
ここで、巻き線が被加熱体の外部にある場合を考えると、被加熱体の外径をΦ[cm]、電流浸透深さをσ[cm]、電流浸透深さの内面部断面積をSi[cm2]、被加熱体の発熱内面長(巻き線幅に等しい)をlS[cm]とすれば、r2は、巻き線側から見た一次換算値なので、r2を被加熱体側から見た二次換算値にし、単位をμΩとした値をR2とすると、R2は以下の式で示される。
R2=(r2/N2)×106 [μΩ]
R2=ρπ(Φ−σ)/Si
Si=σlS
したがって、
R2σlS=ρπ(Φ−σ)
Here, considering the case where the winding is outside the heated body, the outer diameter of the heated body is Φ [cm], the current penetration depth is σ [cm], and the inner surface cross-sectional area of the current penetration depth is If S i [cm 2 ] and the heating inner surface length (equal to the winding width) of the heated body is l S [cm], r 2 is a primary conversion value viewed from the winding side, so r 2 is the secondary conversion value as viewed from the heating side, the value obtained by the μΩ the unit When R 2, R 2 is expressed by the following equation.
R 2 = (r 2 / N 2 ) × 10 6 [μΩ]
R 2 = ρπ (Φ−σ) / S i
S i = σl S
Therefore,
R 2 σl S = ρπ (Φ−σ)
ここで、電流浸透深さσは、比透磁率をμs、周波数をfとすると、次の式となる。
σ=5.03√(ρ/μs×f) [cm]
このσを前述の式に代入すると、
5.03√(ρ/μs×f)R2lS=ρπΦ−5.03ρπ√(ρ/μs×f)
両辺を5.03√(ρ/μs×f)で除して、
R2lS=ρπΦ/{5.03√(ρ/μs×f)}−ρπ
この式を変形して、
R2lS+ρπ=ρπΦ/{5.03√(ρ/μs×f)}
両辺を二乗して、
(R2lS)2+2R2lSρπ+(ρπ)2
=(ρπΦ)2/(5.032ρ/μs×f)
この式を変形して、
(5.03R2lS)2+2×5.032R2lSρπ+(5.03ρπ)2
=ρμs×f(πΦ)2
さらに、この式を変形して、
(5.03π)2×ρ2+{2×5.032πR2lS−(πΦ)2μs×f}ρ
+(5.03R2lS)2=0
この方程式を解くと、
ρ=「−{2×5.032πR2lS−(πΦ)2μs×f}
−√[{2×5.032πR2lS−(πΦ)2μs×f}2
−4×5.03 4(πR2lS)2]」/{2×(5.03π)2}
固有抵抗ρは材質ごとに温度との固有の特性を示すが、例えば炭素鋼S45Cの固有抵抗ρの場合は、被加熱体の被加熱面の温度をθS[℃]とすると、以下の式となる。
ρ=14.3×(1+2.0×10−3×θS) [μΩ・cm]
この式を変形して、
ρ=14.3+2.86×10−2×θS
ρを消去して、
14.3+2.86×10−2×θS
=「−{2×5.032πR2lS−(πΦ)2μs×f}
−√[{2×5.032πR2lS−(πΦ)2μs×f}2
−4×5.03 4(πR2lS)2]」/{2×(5.03π)2}
θSを求める式に書き換えると、
θS=|−「{2×5.032πR2lS−(πΦ)2μs×f}
−√[{2×5.032πR2lS−(πΦ)2μs×f}2
−4×5.03 4(πR2lS)2]」/{2×(5.03π)2}
−14.3|/(2.86×10−2) [℃]
上述したように、比透磁率μsは、材質ごとに磁束密度との固有の変化特性を示し、被加熱体の材質が例えば炭素鋼S45Cであれば、磁束密度と比透磁率との関係は、図7に示すものとなる。
Here, the current penetration depth σ is expressed by the following equation where the relative permeability is μs and the frequency is f.
σ = 5.03√ (ρ / μs × f) [cm]
Substituting this σ into the above equation,
5.03√ (ρ / μs × f) R 2 l S = ρπΦ−5.03ρπ√ (ρ / μs × f)
Divide both sides by 5.03√ (ρ / μs × f)
R 2 l S = ρπΦ / {5.03√ (ρ / μs × f)} − ρπ
By transforming this equation,
R 2 l S + ρπ = ρπΦ / {5.03√ (ρ / μs × f)}
Square both sides,
(R 2 l S ) 2 + 2R 2 l S ρπ + (ρπ) 2
= (ΡπΦ) 2 /(5.03 2 ρ / μs × f)
By transforming this equation,
(5.03R 2 l S ) 2 + 2 × 5.03 2 R 2 l S ρπ + (5.03ρπ) 2
= Ρμs × f (πΦ) 2
Furthermore, by transforming this formula,
(5.03π) 2 × ρ 2 + {2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f} ρ
+ (5.03R 2 l S ) 2 = 0
Solving this equation gives
ρ = “− {2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f}
−√ [{2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f} 2
−4 × 5.03 4 (πR 2 l S ) 2 ] ”/ {2 × (5.03π) 2 }
The specific resistance ρ shows a characteristic specific to temperature for each material. For example, in the case of the specific resistance ρ of carbon steel S45C, if the temperature of the heated surface of the heated body is θ S [° C.], the following equation It becomes.
ρ = 14.3 × (1 + 2.0 × 10 −3 × θ S ) [μΩ · cm]
By transforming this equation,
ρ = 14.3 + 2.86 × 10 −2 × θ S
delete ρ,
14.3 + 2.86 × 10 −2 × θ S
= “− {2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f}
−√ [{2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f} 2
−4 × 5.03 4 (πR 2 l S ) 2 ] ”/ {2 × (5.03π) 2 }
Rewriting the equation for theta S,
θ S = | − “{2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f}
−√ [{2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f} 2
−4 × 5.03 4 (πR 2 l S ) 2 ] ”/ {2 × (5.03π) 2 }
−14.3 | / (2.86 × 10 −2 ) [° C.]
As described above, the relative magnetic permeability μs shows a unique change characteristic with the magnetic flux density for each material. If the material of the heated object is, for example, carbon steel S45C, the relationship between the magnetic flux density and the relative magnetic permeability is The result is shown in FIG.
また、巻き線が、被加熱体の内部にある場合は、被加熱体の内径をφとして、R2を次式として計算することになる。
R2=ρπ(Φ+σ)/Si
このとき、被加熱体の被加熱面の温度θS[℃]は、以下の式となる。
θS=|「{2×5.032πR2lS+(πΦ)2μs×f}
−√[{2×5.032πR2lS+(πΦ)2μs×f}2
−4×5.03 4(πR2lS)2]」/{2×(5.03π)2}
−14.3|/(2.86×10−2) [℃]
When the winding is inside the heated object, the inner diameter of the heated object is φ and R 2 is calculated as the following equation.
R 2 = ρπ (Φ + σ) / S i
At this time, the temperature θ S [° C.] of the heated surface of the heated body is expressed by the following equation.
θ S = | “{2 × 5.03 2 πR 2 l S + (πΦ) 2 μs × f}
−√ [{2 × 5.03 2 πR 2 l S + (πΦ) 2 μs × f} 2
−4 × 5.03 4 (πR 2 l S ) 2 ] ”/ {2 × (5.03π) 2 }
−14.3 | / (2.86 × 10 −2 ) [° C.]
磁束発生機構の巻き線と対向する被加熱体の被加熱面が発熱部となるが、当該発熱部から距離を置いた箇所の温度の算出には、補正が必要となる。
被加熱体が、発熱部の面積と発熱部から距離を置いた箇所の面積とが異なる中空円筒形状をなすものの場合と、それらの面積を実質的に同一と見なすことができる平板形状をなすものの場合と、各側壁が平板形状をなす中空多角筒形状をなすものの場合とで、それぞれに合った補正式を採用することになる。
The heated surface of the heated object that faces the winding of the magnetic flux generation mechanism becomes a heat generating portion, but correction is required for calculating the temperature at a location away from the heat generating portion.
The object to be heated has a hollow cylindrical shape in which the area of the heat generating part and the area of the part spaced from the heat generating part are different, and a flat plate shape in which those areas can be regarded as substantially the same. Depending on the case and the case where each side wall is in the shape of a hollow polygonal cylinder having a flat plate shape, a correction formula suitable for each is adopted.
前記被加熱体が、中空円筒形状をなし、前記磁束発生機構が、前記被加熱体を外周側又は内周側から誘導加熱するものの場合には、被加熱体温度算出部が次のように温度算出面の温度を算出する。
つまり、前記巻き線に対向する前記被加熱体の被加熱面と温度を算出する面である温度算出面との温度差をθ[℃]としたときに、前記被加熱体温度算出部が、前記インピーダンスと前記関係データとから得られた前記被加熱体の温度を、以下の式を用いて得られる温度差θを用いて補正して、前記温度算出面の温度を算出する。
θ=kP/[2π/{ln(d2/d1)/λ}]
ここで、d1は前記被加熱面の直径[m]であり、d2は前記温度算出面の直径[m]であり、λは前記被加熱面及び前記温度算出面の間の平均温度における熱伝導率[W/m・℃]であり、Pは熱流速[W/m]であり、kは、実測値から算出した補正係数である。
When the object to be heated has a hollow cylindrical shape and the magnetic flux generating mechanism heats the object to be heated from the outer peripheral side or the inner peripheral side, the temperature of the heated object temperature calculation unit is as follows: Calculate the temperature of the calculation surface.
That is, when the temperature difference between the heated surface of the heated object facing the winding and the temperature calculating surface which is a surface for calculating the temperature is θ [° C.], the heated object temperature calculating unit, The temperature of the object to be heated obtained from the impedance and the relational data is corrected using a temperature difference θ obtained using the following equation to calculate the temperature of the temperature calculation surface.
θ = kP / [2π / {ln (d 2 / d 1 ) / λ}]
Here, d 1 is the diameter [m] of the heated surface, d 2 is the diameter [m] of the temperature calculating surface, and λ is an average temperature between the heated surface and the temperature calculating surface. The thermal conductivity [W / m · ° C.], P is the heat flow rate [W / m], and k is a correction coefficient calculated from the actual measurement value.
なお、熱伝導率λは、被加熱体の材質及び温度によって変化し、例えば温度と炭素鋼の熱伝導率の特性を図8に示す。また、数十〜数百kHzの高周波では被加熱体の電流浸透度は数μmであるが、50〜1000Hzの中周波では数mm〜数十mmの電流浸透度が得られる。例えば炭素鋼では、60Hz・500℃において電流浸透度が10mm程度である。つまり、中周波誘導加熱では電流浸透度が深いため、発熱部温度(被加熱面の温度)と温度算出面の温度との差が高周波に比べて小さくなる。 The thermal conductivity λ varies depending on the material and temperature of the object to be heated. For example, the characteristics of temperature and thermal conductivity of carbon steel are shown in FIG. Further, the current penetration degree of the object to be heated is several μm at a high frequency of several tens to several hundreds kHz, but a current penetration degree of several mm to several tens mm is obtained at a medium frequency of 50 to 1000 Hz. For example, carbon steel has a current penetration of about 10 mm at 60 Hz and 500 ° C. That is, since current penetration is deep in medium frequency induction heating, the difference between the temperature of the heat generating portion (temperature of the heated surface) and the temperature of the temperature calculation surface is smaller than that of the high frequency.
ある1つの条件の発熱密度かつ到達温度の温度上昇計測を行い、被加熱体の温度算出面の温度とインピーダンスとの関係を近似式化して、その近似式によってインピーダンスから被加熱体の温度算出面の温度を求める。発熱密度が変われば、肉厚t(被加熱面と温度算出面との距離t)における温度差θも変わり、また、被加熱体の温度算出面の到達温度が変われば平均温度が変わることで熱伝導率も変化する。それらを換算式で演算すれば、被加熱体の温度算出面の温度が得られ、インピーダンスによる被加熱体の温度算出面の温度の算出が可能となる。 Measure the temperature rise of the heat generation density and the reached temperature under a certain condition, approximate the relationship between the temperature of the temperature calculation surface of the heated object and the impedance, and calculate the temperature calculation surface of the heated object from the impedance using the approximate expression Find the temperature of If the heat generation density changes, the temperature difference θ in the wall thickness t (distance t between the heated surface and the temperature calculation surface) also changes, and if the temperature reached by the temperature calculation surface of the heated object changes, the average temperature changes. Thermal conductivity also changes. If they are calculated using a conversion formula, the temperature of the temperature calculation surface of the object to be heated can be obtained, and the temperature of the temperature calculation surface of the object to be heated can be calculated by impedance.
前記被加熱体の側周壁に気液二相の熱媒体が封入されるジャケット室が形成されていることが望ましい。このジャケット室は、封入された気液二相の熱媒体による熱輸送によって被加熱体の温度を均一にするものであり、被加熱体の温度算出面の温度も同時に均一化する。
つまり、インピーダンスによる被加熱体の温度の検出は被加熱面の温度の平均温度を検出するものであるから、ジャケット室によって均一化された被加熱体の各部の温度算出面の温度は、インピーダンスによって検出した温度に必要な補正を加えて温度算出面の温度に換算した値と等価であるといえる。
It is desirable that a jacket chamber in which a gas-liquid two-phase heat medium is enclosed is formed on a side peripheral wall of the object to be heated. The jacket chamber makes the temperature of the heated object uniform by heat transport by the enclosed gas-liquid two-phase heat medium, and the temperature of the temperature calculation surface of the heated object is also made uniform at the same time.
That is, the detection of the temperature of the object to be heated by impedance detects the average temperature of the surface to be heated, so the temperature of the temperature calculation surface of each part of the object to be heated that is made uniform by the jacket chamber depends on the impedance. It can be said that this is equivalent to a value obtained by adding necessary correction to the detected temperature and converting it to the temperature of the temperature calculation surface.
ここで、前記被加熱面及び前記温度算出面の間の断面積をS[m2]とし、前記被加熱面及び前記温度算出面の間のジャケット室の断面積の総和をSj[m2]とし、前記被加熱面及び前記温度算出面の間の距離をt[m]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、前記被加熱体温度算出部が、前記被加熱面の直径d1を、dj1=d1±t{1−α(1−Sj/S)}とし、前記温度算出面の直径d2を、dj2=d2±t{1−α(1−Sj/S)}として得られる温度差θを用いて、前記被加熱体の温度を補正することが望ましい。
なお、dj1は、ジャケット室による距離(肉厚)低下分を考慮した被加熱面の仮想直径であり、dj2は、ジャケット室による距離(肉厚)低下分を考慮した温度算出面の仮想直径である。また、上記dj1の式において、±部分は、d1>d2のときは、マイナスであり、d1<d2のときは、プラスである。一方、上記dj2の式において、±部分は、d1>d2のときは、プラスであり、d1<d2のときは、マイナスである。
Here, the cross-sectional area between the heated surface and the temperature calculating surface is S [m 2 ], and the sum of the cross-sectional areas of the jacket chamber between the heated surface and the temperature calculating surface is S j [m 2]. When the distance between the heated surface and the temperature calculation surface is t [m], and the variable indicating the ratio of the function deterioration of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop is α, The heated body temperature calculation unit sets the diameter d 1 of the heated surface as d j1 = d 1 ± t {1−α (1−S j / S)}, and sets the diameter d 2 of the temperature calculated surface to , D j2 = d 2 ± t {1-α (1-S j / S)} is preferably used to correct the temperature of the object to be heated.
D j1 is the virtual diameter of the heated surface considering the distance (thickness) reduction due to the jacket chamber, and d j2 is the virtual temperature calculation plane considering the distance (thickness) reduction due to the jacket chamber. Diameter. Further, in the formula of d j1 , the ± part is negative when d 1 > d 2 and is positive when d 1 <d 2 . On the other hand, in the formula of d j2 , the ± part is positive when d 1 > d 2 , and is negative when d 1 <d 2 .
中空円筒形状をなす被加熱体の中心軸に直交する断面積をSとし、ジャケット室の前記中心軸に直交する断面積の総和をSjとし、被加熱面及び温度算出面の間の距離をtとしたときに、熱的に換算した距離tjは、以下の式となる。
tj=α×t(S−Sj)/S (α>1)
ここで、αは、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数である。α−θの関係は、熱媒体の種類と、ジャケット室内の不純物濃度とによって特性が定まる。
Let S be the cross-sectional area perpendicular to the central axis of the object to be heated having a hollow cylindrical shape, S j be the sum of the cross-sectional areas perpendicular to the central axis of the jacket chamber, and the distance between the heated surface and the temperature calculation surface When t, the thermally converted distance t j is expressed by the following equation.
t j = α × t (S−S j ) / S (α> 1)
Here, α is a variable indicating the rate of deterioration of the function of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop. The α-θ relationship is determined by the type of heat medium and the impurity concentration in the jacket chamber.
距離tと熱的換算距離tjとの差異は、
t−tj=t−α×t(S−Sj)/S
=t{1−α(S−Sj)/S}
=t{1−α(1−Sj/S)}
The difference between the distance t and the thermal conversion distance t j is
t−t j = t−α × t (S−S j ) / S
= T {1-α (S−S j ) / S}
= T {1-α (1-S j / S)}
したがって、熱的に換算した被加熱面の仮想直径dj1及び温度算出面の仮想直径dj2は、以下になる。
dj1=d1±t{1−α(1−Sj/S)}
dj2=d2±t{1−α(1−Sj/S)}
なお、上記dj1の式において、±部分は、d1>d2のときは、マイナスであり、d1<d2のときは、プラスである。一方、上記dj2の式において、±部分は、d1>d2のときは、プラスであり、d1<d2のときは、マイナスである。
つまり、計算上の被加熱面及び温度算出面の距離が小さくなり、温度差θは小さくなるので、温度計測誤差も小さくなる。
Therefore, the virtual diameter d j1 of the heated surface and the virtual diameter d j2 of the temperature calculation surface, which are thermally converted, are as follows.
d j1 = d 1 ± t {1-α (1-S j / S)}
d j2 = d 2 ± t {1-α (1-S j / S)}
In the formula of d j1 , the ± part is negative when d 1 > d 2 , and is positive when d 1 <d 2 . On the other hand, in the formula of d j2 , the ± part is positive when d 1 > d 2 , and is negative when d 1 <d 2 .
That is, the calculated distance between the heated surface and the temperature calculation surface is reduced, and the temperature difference θ is reduced, so that the temperature measurement error is also reduced.
前記被加熱体が、平板形状をなし、前記磁束発生機構が、前記被加熱体を片面側から誘導加熱するものの場合には、被加熱体温度算出部が次のように温度算出面の温度を算出する。
つまり、前記巻き線に対向する前記被加熱体の被加熱面と温度を算出する面である温度算出面との温度差をθ[℃]としたときに、前記被加熱体温度算出部が、前記インピーダンスと前記関係データとから得られた前記被加熱体の温度を、以下の式を用いて得られる温度差θを用いて補正して、前記温度算出面の温度を算出する。
θ=kQ/(λS/t)
ここで、tは前記被加熱面及び前記温度算出面の間の距離[m]であり、Sは前記被加熱面及び前記温度算出面の間の断面積[m2]であり、λは前記被加熱面及び前記温度算出面の間の平均温度[℃]における前記被加熱体の熱伝導率[W/m・℃]であり、Qは前記被加熱面の発熱量[W]であり、kは、実測値から算出した補正係数である。
When the object to be heated has a flat plate shape and the magnetic flux generating mechanism heats the object to be heated from one side, the temperature calculation unit of the object to be heated calculates the temperature of the temperature calculation surface as follows. calculate.
That is, when the temperature difference between the heated surface of the heated object facing the winding and the temperature calculating surface which is a surface for calculating the temperature is θ [° C.], the heated object temperature calculating unit, The temperature of the object to be heated obtained from the impedance and the relational data is corrected using a temperature difference θ obtained using the following equation to calculate the temperature of the temperature calculation surface.
θ = kQ / (λS / t)
Here, t is a distance [m] between the heated surface and the temperature calculating surface, S is a cross-sectional area [m 2 ] between the heated surface and the temperature calculating surface, and λ is the above-mentioned It is the thermal conductivity [W / m · ° C.] of the heated body at the average temperature [° C.] between the heated surface and the temperature calculation surface, and Q is the calorific value [W] of the heated surface, k is a correction coefficient calculated from an actual measurement value.
前記被加熱体が、高さがh[m]、n辺の長さがそれぞれa1、a2、・・・an[m]の中空n角筒形状をなし、前記磁束発生機構が、前記被加熱体を外周側又は内周側から誘導加熱するものの場合には、被加熱体温度算出部が次のように温度算出面の温度を算出する。なお、以下は、各側壁部それぞれで被加熱面と温度算出面との距離が同一の場合を示している。 The to-be-heated body has a hollow n-square cylindrical shape with a height h [m] and n side lengths a 1 , a 2 ,..., A n [m], and the magnetic flux generation mechanism includes: In the case where the object to be heated is induction-heated from the outer peripheral side or the inner peripheral side, the heated object temperature calculation unit calculates the temperature of the temperature calculation surface as follows. The following shows a case where the distance between the heated surface and the temperature calculation surface is the same in each side wall.
つまり、前記巻き線に対向する前記被加熱体の被加熱面と温度を算出する面である温度算出面との温度差をθ[℃]とし、前記被加熱体の各辺における前記被加熱面及び前記温度算出面の間の距離をt[m]としたときに、前記被加熱体温度算出部が、前記インピーダンスと前記関係データとから得られた前記被加熱体の温度を、以下の式を用いて得られる温度差θを用いて補正して、前記温度算出面の温度を算出する。
θ=kQ/λ[{(a1+a2+・・・+an)h/t}+mn×n×h]
ここで、nは1から始まる自然数であり、λは前記被加熱面及び前記温度算出面の間の平均温度[℃]における前記被加熱体の熱伝導率[W/m・℃]であり、Qは前記被加熱面の発熱量[W]であり、kは、実測値から算出した補正係数であり、mnはnにおける定数である。
That is, the temperature difference between the heated surface of the heated object facing the winding and the temperature calculating surface which is a surface for calculating the temperature is θ [° C.], and the heated surface on each side of the heated object When the distance between the temperature calculation surfaces is t [m], the heated object temperature calculation unit calculates the temperature of the heated object obtained from the impedance and the relational data as follows: The temperature of the temperature calculation surface is calculated by correcting using the temperature difference θ obtained by using.
θ = kQ / λ [{(a 1 + a 2 +... + a n ) h / t} + m n × n × h]
Here, n is a natural number starting from 1, and λ is the thermal conductivity [W / m · ° C.] of the heated object at an average temperature [° C.] between the heated surface and the temperature calculating surface, Q is the calorific value [W] of the surface to be heated, k is a correction coefficient calculated from actual measurement values, and mn is a constant at n.
上記のような平板形状又は中空n角筒形状をなす被加熱体の肉厚内に気液二相の熱媒体が封入されるジャケット室が形成されている場合には、前記被加熱面及び前記温度算出面の間の断面積をS[m2]とし、前記被加熱面及び前記温度算出面の間のジャケット室の断面積の総和をSj[m2]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、前記被加熱体温度算出部が、前記被加熱面及び前記温度算出面の間の距離tを、tj=αt(S−Sj)/Sとして得られる温度差θを用いて、前記被加熱体の温度を補正することが望ましい。 In the case where a jacket chamber in which a gas-liquid two-phase heat medium is enclosed is formed in the thickness of the heated object having a flat plate shape or a hollow n-square tube shape as described above, the heated surface and the The cross-sectional area between the temperature calculation surfaces is S [m 2 ], the sum of the cross-sectional areas of the jacket chamber between the heated surface and the temperature calculation surface is S j [m 2 ], and the heat medium accompanying the temperature decrease When the variable indicating the rate of reduction in the function of the jacket chamber due to the pressure drop is α, the heated object temperature calculation unit sets the distance t between the heated surface and the temperature calculation surface to t j = αt It is desirable to correct the temperature of the object to be heated using the temperature difference θ obtained as (S−S j ) / S.
一方で、上記の中空n角筒形状をなす被加熱体において、各側壁部それぞれの被加熱面と温度算出面との距離が異なる場合には、被加熱体温度算出部が次のように温度算出面の温度を算出する。 On the other hand, in the object to be heated having the above-described hollow n-square tube shape, when the distance between the surface to be heated and the temperature calculation surface of each side wall portion is different, the temperature of the object to be heated is calculated as follows. Calculate the temperature of the calculation surface.
つまり、前記被加熱体の各側壁部それぞれの前記巻き線に対向する前記被加熱体の被加熱面と温度を算出する面である温度算出面との温度差をθn[℃]とし、前記被加熱体の各側壁部それぞれの前記被加熱面及び前記温度算出面の間の距離をt1、t2、・・・tn[m]としたときに、前記被加熱体温度算出部が、前記インピーダンスと前記関係データとから得られた前記被加熱体の温度を、以下の式を用いて得られる温度差θnを用いて補正して、前記温度算出面の温度を算出する。
θn=knQn/(λnSn/tn)
ここで、tnはn番目の側壁部における前記被加熱面及び前記温度算出面の間の距離[m]であり、Snはn番目の側壁部における前記被加熱面及び前記温度算出面の間の断面積[m2]であり、λnはn番目の側壁部における前記被加熱面及び前記温度算出面の間の平均温度[℃]における前記被加熱体の熱伝導率[W/m・℃]であり、Qnはn番目の側壁部における前記被加熱面の発熱量[W]であり、knは、実測値から算出した補正係数である。
That is, the temperature difference between the heated surface of the heated body facing the winding of each side wall portion of the heated body and the temperature calculation surface that is a surface for calculating the temperature is θ n [° C.], and When the distance between the heated surface and the temperature calculation surface of each side wall portion of the heated object is t 1 , t 2 ,... T n [m], the heated object temperature calculating unit is Then, the temperature of the object to be heated obtained from the impedance and the relational data is corrected using a temperature difference θ n obtained using the following equation to calculate the temperature of the temperature calculation surface.
θ n = k n Q n / (λ n S n / t n)
Here, t n is the distance between the heated surface and the temperature calculated surface at the n-th sidewall part [m], S n is the heated surface and the temperature calculated surface at the n-th sidewall part the cross-sectional area [m 2] between, lambda n is n th said at side wall portions of the heated surface and thermal conductivity of the object to be heated at an average temperature [℃] between the temperature calculated surface [W / m a · ° C.], Q n is the heat value of the heated surface of the n-th sidewall part [W], k n is a correction coefficient calculated from the measured value.
このとき、前記被加熱体の肉厚内に気液二相の熱媒体が封入されるジャケット室が形成されている場合には、n番目の側壁部における前記被加熱面及び前記温度算出面の間のジャケット室の断面積の総和をSnj[m2]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、前記被加熱体温度算出部が、n番目の側壁部における前記被加熱面及び前記温度算出面の間の距離tnを、tnj=αtn(Sn−Snj)/Snとして得られる温度差θnを用いて、前記被加熱体の温度を補正することが望ましい。 At this time, in the case where a jacket chamber in which a gas-liquid two-phase heat medium is sealed is formed within the thickness of the heated body, the heated surface and the temperature calculating surface of the nth side wall portion. When the sum of the cross-sectional areas of the jacket chamber is S nj [m 2 ], and the variable indicating the rate of decrease in the function of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop is α, the temperature of the heated object The calculation unit calculates a temperature difference θ n obtained by setting the distance t n between the heated surface and the temperature calculation surface in the n th side wall as t nj = αt n (S n −S nj ) / S n. It is desirable to correct the temperature of the object to be heated.
前記制御素子が半導体の場合には、通電角によって電圧及び電流の波形形状が変わるが、それはそれぞれ違った形状に変わるので、それぞれのインピーダンスの分担電圧が変わることで、励磁インピーダンスの電圧が変化して磁束密度が変わり、励磁インピーダンス及び比透磁率も変化する。このとき、制御素子と通電角と負荷が決まれば、電圧及び電流はそれぞれ一定の形状になるため、通電角による補正係数が決まる。 When the control element is a semiconductor, the waveform shape of the voltage and current changes depending on the energization angle, but it changes to a different shape, so that the voltage of the excitation impedance changes by changing the shared voltage of each impedance. Thus, the magnetic flux density changes, and the excitation impedance and relative permeability also change. At this time, if the control element, the energization angle, and the load are determined, the voltage and the current each have a fixed shape, and thus the correction coefficient according to the energization angle is determined.
ここで、前記インピーダンス算出部により得られたインピーダンスを、前記制御素子の通電角により補正するインピーダンス補正部を更に備え、前記被加熱体温度算出部が、前記インピーダンス補正部により補正された補正インピーダンスと前記関係データとから前記被加熱体の温度を算出するものであることが望ましい。 Here, an impedance correction unit that corrects the impedance obtained by the impedance calculation unit based on an energization angle of the control element is further provided, and the heated object temperature calculation unit includes the corrected impedance corrected by the impedance correction unit and It is desirable to calculate the temperature of the object to be heated from the relation data.
制御素子がサイリスタであり、検証した被加熱体(外径Φ×深さL×側壁部の厚さtを有する円筒形金属製釜)の場合は、波形歪による高調波成分の変化によって、等価回路におけるリアクタンス成分のl1及びl2にかかる電圧が変化することになる。したがって、励磁インピーダンスに印加される電圧が変化して、磁束密度も変わることになる。つまり、磁束密度によって励磁インピーダンス及び比透磁率が変化するため、その影響を補正する必要がある。
サイリスタの位相角変化による影響を補正した補正インピーダンスR2は、下記となる。
R2=a×RX
ここで、C=V/Vinとすると、
a=anCn+an−1Cn−1+an−2Cn−2+,・・・,+a2C2+a1C+a0
ここで、anは各誘導加熱装置により定まる実測値に基づく係数であり、a0は定数である。
また、RXは、補正前のインピーダンスであり、Vinは、サイリスタの受電電圧であり、Vは、サイリスタの出力電圧である。
When the control element is a thyristor and the object to be heated (cylindrical metal kettle with outer diameter Φ x depth L x side wall thickness t) is equivalent due to a change in harmonic components due to waveform distortion The voltage applied to the reactance components l 1 and l 2 in the circuit will change. Therefore, the voltage applied to the excitation impedance changes and the magnetic flux density also changes. That is, since the excitation impedance and the relative permeability change depending on the magnetic flux density, it is necessary to correct the influence.
Correction impedance R 2 obtained by correcting the influence of the phase angle change of the thyristor becomes below.
R 2 = a × R X
Here, if C = V / V in ,
a = a n C n + a n-1 C n-1 + a n-2 C n-2 +, ···, + a 2 C 2 + a 1 C + a 0
Here, a n is a coefficient based on the measured value determined by the induction heating device, a 0 is a constant.
Also, R X is a correction before the impedance, V in is the receiving voltage of the thyristor, V is an output voltage of the thyristor.
巻き線抵抗値は、巻き線に数秒以内の短時間に一定の直流電圧を印加して、当該直流電圧を巻き線に流れる直流電流で除せば算出できる。ここで、直流電圧であれば誘導作用は無いので、直流電流は、被加熱体の影響は受けず、巻き線抵抗値のみとの関係となる。なお、巻き線温度は急激には変化しないことから、周期的且つ短時間の測定値を採用しても、大きな測定誤差を生むことは無い。 The winding resistance value can be calculated by applying a constant DC voltage to the winding in a short time within a few seconds and dividing the DC voltage by the DC current flowing through the winding. Here, since there is no inductive action in the case of a DC voltage, the DC current is not affected by the heated object, and has only a relationship with the winding resistance value. Since the winding temperature does not change abruptly, even if periodic and short-time measurement values are used, no large measurement error is produced.
また、間欠的な直流電圧の印加とは、数秒以内の印加時間を数秒から数十分の例えば一定の周期で行うことである。このような間欠的な印加であれば、直流成分から受ける偏磁作用を小さくするとともに、誘導発熱させるための交流回路への影響も最小限に抑えることができる。さらに、誘導加熱装置の巻き線は一般的に熱慣性が大きく、且つ、通常の一定負荷条件下の運転では巻き線の温度の変化はさほど大きい値にはならない。したがって、数秒以内の短時間の印加時間によってなされる温度検出を、数秒から数十分単位、好ましくは、数十秒から数分単位で実施されれば、被加熱体の温度制御にとっては十分といえる。 Further, intermittent application of the DC voltage means that the application time within a few seconds is performed at a constant period of several seconds to several tens of minutes, for example. With such intermittent application, it is possible to reduce the demagnetizing action received from the DC component and to minimize the influence on the AC circuit for induction heating. Further, the winding of the induction heating device generally has a large thermal inertia, and the change in the temperature of the winding does not become a large value in the operation under a normal constant load condition. Therefore, if temperature detection performed by a short application time within several seconds is performed in units of several seconds to several tens of minutes, preferably in units of several tens of seconds to several minutes, it is sufficient for temperature control of the object to be heated. I can say that.
前記電源回路に設けられた制御素子により、前記交流電流又は交流電圧を遮断又は最小限とした状態で、前記抵抗値算出部が前記巻き線に直流電圧を印加して巻き線抵抗値を算出するものであることが望ましい。 The resistance value calculation unit applies a DC voltage to the winding and calculates a winding resistance value in a state where the AC current or the AC voltage is cut off or minimized by a control element provided in the power supply circuit. It is desirable to be a thing.
交流電圧が印加されている巻き線に直流電圧を印加して、交流電流と直流電流とが重畳した電流から直流成分(直流電流)だけを検出するには、複雑な検出回路が必要となってしまう。ここで、通常の誘導加熱装置では、被加熱体の温度を制御するための交流電流又は交流電圧を制御する制御素子などの制御回路部を有する電源回路を備えている。このため、制御素子により、直流電圧を印加する印加時間のみ、交流電流又は交流電圧を遮断又は最小限の値にすれば、交流電流(交流成分)の影響を抑えることができ、直流電流(直流成分)の検出を容易に行うことができる。ここで、交流電流又は交流電圧の遮断又は最小限の値とするのは、数秒以内の短時間であって、数秒から数十分の時間間隔であり、誘導発熱作用の障害にはならない。 In order to detect only the DC component (DC current) from the current in which the AC current and DC current are superimposed by applying DC voltage to the winding to which AC voltage is applied, a complicated detection circuit is required. End up. Here, the normal induction heating apparatus includes a power supply circuit having a control circuit unit such as a control element for controlling an alternating current or an alternating voltage for controlling the temperature of the object to be heated. For this reason, if the AC current or the AC voltage is cut off or set to a minimum value only during the application time for applying the DC voltage by the control element, the influence of the AC current (AC component) can be suppressed. Component) can be easily detected. Here, the interruption or the minimum value of the AC current or AC voltage is a short time within a few seconds, and is a time interval of several seconds to several tens of minutes, and does not hinder the induction heating action.
交流電流又は交流電圧の遮断又は最小限の値にする実施態様としては、制御素子が例えば電磁接触器等のスイッチ機器を有する場合は、当該スイッチ機器を遮断する態様、又は、制御回路部が例えばサイリスタ等の半導体素子(電力制御素子)を有する場合は、当該半導体素子の通電位相角を最小にする態様が考えられる。 As an embodiment in which the alternating current or the alternating voltage is cut off or set to a minimum value, when the control element has a switch device such as an electromagnetic contactor, the switch device is cut off, or the control circuit unit has, for example, In the case where a semiconductor element (power control element) such as a thyristor is included, a mode in which the energization phase angle of the semiconductor element is minimized can be considered.
被加熱体の昇温過渡期又は降温過渡期における被加熱体の温度算出面の温度を正確に算出するためには、前記被加熱体温度算出部が、前記被加熱面の温度を算出するとともに、当該被加熱面の温度から定常状態における前記温度算出面の計算値を算出し、以下の式を用いて得られるΔT[h]時間後に前記温度算出面が前記計算値に到達することを基準に、過渡期における前記温度算出面の温度を算出することが望ましい。
ΔT=k×w×c×t2/(2λ) [h]
ここで、wは前記被加熱体の材質の比重[kg/m3]であり、cは前記被加熱体の材質の比熱[kcal/kg・℃]であり、tは前記被加熱面及び前記温度算出面の間の距離[m]であり、λは被加熱体の材質の熱伝導率[kcal/m・h・℃]であり、kは実測値から求めた補正係数である。
In order to accurately calculate the temperature of the temperature calculation surface of the heated object in the temperature rising transition period or the temperature falling transition period of the heated object, the heated object temperature calculation unit calculates the temperature of the heated surface. The calculated value of the temperature calculation surface in a steady state is calculated from the temperature of the heated surface, and the temperature calculation surface reaches the calculated value after ΔT [h] time obtained using the following equation: In addition, it is desirable to calculate the temperature of the temperature calculation surface in the transition period.
ΔT = k × w × c × t 2 / (2λ) [h]
Here, w is the specific gravity [kg / m 3 ] of the material of the heated object, c is the specific heat [kcal / kg · ° C.] of the material of the heated object, and t is the heated surface and the The distance [m] between the temperature calculation surfaces, λ is the thermal conductivity [kcal / m · h · ° C.] of the material of the object to be heated, and k is a correction coefficient obtained from the measured value.
図9に昇温過渡期の被加熱体の温度変化を示しており、図10に降温過渡期の被加熱体の温度変化を示している。図9及び図10において、実線は被加熱体の被加熱面温度を示し、点線は、被加熱面温度から算出した定常状態に至った時の温度算出面の計算値を示し、一点鎖線は、過渡期の温度算出面の温度を示している。 FIG. 9 shows the temperature change of the heated object during the temperature rising transition period, and FIG. 10 shows the temperature change of the heated object during the temperature falling transient period. 9 and 10, the solid line indicates the heated surface temperature of the heated object, the dotted line indicates the calculated value of the temperature calculation surface when the steady state calculated from the heated surface temperature is reached, and the alternate long and short dash line is: The temperature on the temperature calculation surface in the transition period is shown.
過渡期における温度算出面の温度は定常状態に至った時の温度算出面の温度よりも低く、昇温時においては、ΔT時間後(Tn+ΔT)に、その時点Tnで算出した定常状態における温度算出面の計算値に温度算出面の温度が到達することになり、降温時においては、ΔT時間前(Tn−ΔT)に、温度算出面の温度が、その時点Tnで算出した定常状態の温度算出面の計算値であったことになる。 Temperature of the temperature calculating surface in the transition period is lower than the temperature of the temperature calculation surface when reaching a steady state, at the time of Atsushi Nobori, after [Delta] T time (T n + [Delta] T), steady-state calculated at the time T n The temperature of the temperature calculation surface will reach the calculated value of the temperature calculation surface at the time, and when the temperature falls, the temperature of the temperature calculation surface is calculated at the time T n before ΔT time (T n −ΔT). This is the calculated value of the temperature calculation surface in the steady state.
したがって、昇温時及び降温時で分けて温度算出面の温度を算出する必要があり、時間Tnの時の被加熱面温度θi(n)が、時間T(n−1)すなわちΔT時間前の被加熱面温度θi(n−1)と比較して、昇温過渡期か降温過渡期かを判断する。すなわち、θi(n)>θi(n−1)であれば昇温過渡期であり、θi(n)<θi(n−1)であれば降温過渡期である。
比較する時間周期は、被加熱体の肉厚や保有している加熱容量によって、制御に問題にならない値を決定するが、数ミリ秒から数十秒、望ましくは、数百ミリ秒から数秒の値である。
Therefore, it is necessary to calculate the temperature of the temperature calculation surfaces divided in a time and during cooling heating, the heated surface temperature θ i (n) at time T n is time T (n-1) i.e. ΔT time Compared with the previous heated surface temperature θ i (n−1) , it is determined whether the temperature is in a temperature rising transient period or a temperature falling transient period. That is, if θ i (n) > θ i (n−1) , it is a temperature rising transient period, and if θ i (n) <θ i (n−1) , it is a temperature falling transient period.
The time period to be compared is determined to be a value that does not pose a problem for control depending on the thickness of the object to be heated and the heating capacity held, but it is several milliseconds to several tens of seconds, preferably several hundred milliseconds to several seconds. Value.
θi(n)>θi(n−1)、すなわち昇温過渡期である時間Tn時点の被加熱面温度θi(n)から算出した、その時点の定常状態に至ったときの温度算出面の温度をθnとすると、昇温過渡期における実際の温度算出面の温度は、TnよりΔT時間経過したT(n+1)において温度θnに到達することになる。
ここで、T(n+1)−Tn=ΔTであるから、時間ΔTだけ経過した時点で温度θnを表示させれば、その時点での温度算出面の温度を表示していることと等価となる。
θ i (n)> θ i (n-1), that is, the temperature calculation when heated transition time that is calculated from the heated surface temperature Tn when θ i (n), leading to a steady state at that time Assuming that the surface temperature is θ n , the actual temperature calculation surface temperature in the temperature rising transition period reaches the temperature θ n at T (n + 1) after ΔT time has elapsed from T n .
Here, since T (n + 1) −T n = ΔT, if the temperature θ n is displayed when the time ΔT has elapsed, it is equivalent to displaying the temperature of the temperature calculation surface at that time. Become.
θi(n)<θi(n−1)、すなわち降温過渡期である時間Tn時点の被加熱面温度θi(n)から算出した、その時点の定常状態に至ったときの温度算出面の温度をθnとすると、降温過渡期における実際の温度算出面の温度は、TnよりΔT時間前のT(n−1)において温度θnに到達していたことになる。つまり、温度算出面の温度は、Tn時点ではθnよりも低い温度になっているが、正確な温度算出は困難である。したがって、概算値として、θi(n−1)−θinだけ温度低下したと考えて温度表示すれば、大きく外れた値とはならない。つまり、温度算出面の温度θEは、下記の式で示される。
θE≒θn−{θi(n−1)−θin}
θ i (n) <θ i (n−1) , that is, the temperature calculation when the temperature reaches the steady state at that time, calculated from the heated surface temperature θ i (n) at the time T n in the temperature-falling transition period Assuming that the surface temperature is θ n , the actual temperature calculation surface temperature during the temperature-falling transition period has reached the temperature θ n at T (n−1) before ΔT time from T n . That is, the temperature of the temperature calculation plane is at T n time has become a temperature lower than the theta n, accurate temperature calculation is difficult. Accordingly, as an approximate value, if the temperature is displayed assuming that the temperature has decreased by θ i (n−1) −θ in , the value does not deviate greatly. That is, the temperature θ E on the temperature calculation surface is expressed by the following equation.
θ E ≈θ n − {θ i (n−1) −θ in }
過渡期における温度算出面の温度は、誘導加熱装置が定常運転になれば、いずれ定常状態計算温度に収束する。被加熱体の温度が昇降状態で、製品生産のために稼働することは原則として考えにくいため、被加熱体の温度算出面の温度は概算値として把握できれば十分である。 The temperature of the temperature calculation surface in the transition period will eventually converge to the steady state calculated temperature if the induction heating device is in steady operation. In principle, it is unlikely to operate for product production when the temperature of the object to be heated is raised or lowered, so it is sufficient if the temperature of the temperature calculation surface of the object to be heated can be grasped as an approximate value.
このように構成した本発明によれば、被加熱体に温度検出素子を設けることなく、被加熱体の温度を算出することができる。 According to the present invention configured as described above, the temperature of the heated object can be calculated without providing the temperature detecting element in the heated object.
<第1実施形態>
以下に本発明に係る誘導加熱装置の第1実施形態について図面を参照して説明する。
<First Embodiment>
A first embodiment of an induction heating apparatus according to the present invention will be described below with reference to the drawings.
本実施形態に係る誘導加熱装置100は、図1に示すように、処理対象物を熱処理するために加熱される被加熱体2と、当該被加熱体2を誘導加熱するための鉄心31及び巻き線32からなる磁束発生機構3と、巻き線32に接続されるとともに、電流又は電圧を制御する制御素子4が設けられた電源回路5とを備えている。 As shown in FIG. 1, the induction heating apparatus 100 according to this embodiment includes a heated body 2 that is heated to heat-treat a processing target, an iron core 31 and a winding for induction heating the heated body 2. A magnetic flux generation mechanism 3 composed of a wire 32 and a power supply circuit 5 connected to the winding 32 and provided with a control element 4 for controlling current or voltage are provided.
本実施形態の被加熱体2は、図2に示すように、処理対象物を収容する収容部を有するものであり、高さがh[m]、外径がφ[m]、側壁部の厚さがt[m]の中空円筒形状をなす金属製釜である。この被加熱体2の側周壁の肉厚内には、気液二相の熱媒体が封入される複数のジャケット室2Sが、中心軸に沿って周方向に等間隔に形成されている。 As shown in FIG. 2, the heated body 2 of the present embodiment has a housing portion that houses the object to be processed, and has a height of h [m], an outer diameter of φ [m], and a side wall portion. It is a metal pot having a hollow cylindrical shape with a thickness of t [m]. A plurality of jacket chambers 2S in which a gas-liquid two-phase heat medium is enclosed are formed at equal intervals in the circumferential direction along the central axis in the wall thickness of the side peripheral wall of the body 2 to be heated.
また、本実施形態の巻き線32は、中空円筒形状をなす被加熱体2の外側周面の周りに離間して巻回された概略円筒形状をなすものである。これにより、被加熱体2の外側周面が、巻き線32に対向して加熱される被加熱面2hとなる。 In addition, the winding wire 32 of the present embodiment has a substantially cylindrical shape that is wound around the outer peripheral surface of the heated body 2 having a hollow cylindrical shape. Thereby, the outer peripheral surface of the heated body 2 becomes a heated surface 2 h that is heated to face the winding 32.
さらに、本実施形態の制御素子4は、半導体により交流電流又は交流電圧の通電角を制御するものであり、具体的にはサイリスタである。 Furthermore, the control element 4 of this embodiment controls the conduction angle of an alternating current or an alternating voltage with a semiconductor, and is specifically a thyristor.
そして、本実施形態の誘導発熱ローラ装置100を制御する制御装置6は、巻き線32を流れる交流電流値と、巻き線32に印加される交流電圧値と、被加熱体2及び磁束発生機構(巻き線32)からなる誘導加熱ユニット200の力率と、巻き線32の巻き線抵抗値と、被加熱体2及び磁束発生機構(巻き線32)から構成される磁気回路の励磁抵抗値とをパラメータとして、被加熱体2の温度算出面2xの温度を算出する温度算出機能を有する。本実施形態の温度算出面2xは、被加熱体2の側壁部において被加熱面2hから厚さ方向に離間した温度を算出する面であり、具体的には、被加熱体2の内側周面である。 And the control apparatus 6 which controls the induction heating roller apparatus 100 of this embodiment is the alternating current value which flows through the winding 32, the alternating voltage value applied to the winding 32, the to-be-heated body 2, and magnetic flux generation mechanism ( The power factor of the induction heating unit 200 composed of the winding 32), the winding resistance value of the winding 32, and the excitation resistance value of the magnetic circuit composed of the heated body 2 and the magnetic flux generation mechanism (winding 32). As a parameter, it has a temperature calculation function for calculating the temperature of the temperature calculation surface 2x of the body 2 to be heated. The temperature calculation surface 2x of the present embodiment is a surface for calculating the temperature separated from the heated surface 2h in the thickness direction at the side wall portion of the heated body 2, and specifically, the inner peripheral surface of the heated body 2 It is.
具体的に制御装置6は、CPU、内部メモリ、A/Dコンバータ、D/Aコンバータ、入出力インターフェイス等を備えた専用乃至汎用のコンピュータであり、内部メモリに予め記憶させた所定プログラムにしたがって前記CPUや周辺機器が動作することにより、図3に示すように、インピーダンス算出部61、インピーダンス補正部62、温度算出用データ格納部63、被加熱体温度算出部64、被加熱体温度制御部65等としての機能を発揮する。 Specifically, the control device 6 is a dedicated or general-purpose computer including a CPU, an internal memory, an A / D converter, a D / A converter, an input / output interface, and the like. The control device 6 is configured according to a predetermined program stored in the internal memory. When the CPU and peripheral devices operate, as shown in FIG. 3, an impedance calculation unit 61, an impedance correction unit 62, a temperature calculation data storage unit 63, a heated body temperature calculation unit 64, and a heated body temperature control unit 65. Demonstrate the function as such.
以下、各部について、図3とともに、図4の温度算出フローチャートを参照して説明する。 Hereinafter, each part will be described with reference to the temperature calculation flowchart of FIG. 4 together with FIG. 3.
インピーダンス算出部61は、巻き線32を流れる交流電流Iを検出する交流電流検出部7から得られる交流電流値と、巻き線32に印加される交流電圧Vを検出する交流電圧検出部8から得られる交流電圧値と、力率検出部10から得られる力率とから、誘導加熱ユニット200のインピーダンス(ユニットインピーダンス)Z1(=V×cosφ/I=rcomb)を算出する(図4の(1))。 The impedance calculation unit 61 is obtained from the AC voltage value obtained from the AC current detection unit 7 that detects the AC current I flowing through the winding 32 and the AC voltage detection unit 8 that detects the AC voltage V applied to the winding 32. The impedance (unit impedance) Z 1 (= V × cos φ / I = r comb ) of the induction heating unit 200 is calculated from the AC voltage value obtained and the power factor obtained from the power factor detection unit 10 ((FIG. 4 ( 1)).
さらに、インピーダンス算出部61は、インピーダンスrcombと、巻き線32の温度を検出する温度検出部9から得られる巻き線温度θC[℃]により求めた巻き線抵抗r1と、予め測定しておいた磁束密度及び磁気回路の磁気抵抗の関係特性(図6参照)から求めた励磁抵抗r0によって、被加熱体2の抵抗(被加熱体インピーダンス)r2を算出する(図4の(2))。なお、温度検出部9は、巻き線32に埋設されている。 Furthermore, the impedance calculation unit 61 measures in advance the impedance r comb and the winding resistance r 1 obtained from the winding temperature θ C [° C.] obtained from the temperature detection unit 9 that detects the temperature of the winding 32. The resistance (heated body impedance) r 2 of the heated body 2 is calculated from the exciting resistance r 0 obtained from the relational characteristic of the magnetic flux density and the magnetic resistance of the magnetic circuit (see FIG. 6) ((2 in FIG. 4). )). The temperature detection unit 9 is embedded in the winding 32.
具体的にインピーダンス算出部61は、以下の式により、巻き線抵抗r1を算出して、被加熱体2の抵抗r2を算出する。
r1=kL/100S[Ω]
k=2.1(234.5+θC)/309.5
ここで、Lは電線長[m]であり、Sは電線断面積[mm2]であり、θCは巻き線温度[℃]である。
Specifically, the impedance calculation unit 61 calculates the winding resistance r 1 by the following formula, and calculates the resistance r 2 of the heated body 2.
r 1 = kL / 100S [Ω]
k = 2.1 (234.5 + θ C ) /309.5
Here, L is the wire length [m], S is the wire cross-sectional area [mm 2 ], and θ C is the winding temperature [° C.].
また、インピーダンス算出部61は、被加熱体2の抵抗r2を、被加熱体2側から見た二次換算した値に変換する。二次換算して、単位をμΩにした被加熱体2の抵抗をR2、巻き線の巻き数をNとすると、以下の式で示される。
R2=(r2/N2)×106
The impedance calculation unit 61 converts the resistance r 2 of the object to be heated 2, the secondary-converted value as viewed from the heated body 2 side. When the resistance of the heated body 2 in units of μΩ in terms of secondary is R 2 and the number of windings is N, the following equation is obtained.
R 2 = (r 2 / N 2 ) × 10 6
インピーダンス補正部62は、二次換算した被加熱体2の抵抗R2を、制御素子(サイリスタ)4の通電角(位相角)により補正する(図4の(3))。
具体的にインピーダンス補正部62は、以下の式により、インピーダンスR2を補正する。
R2=a×RX
ここで、C=V/Vinとすると、
a=anCn+an−1Cn−1+an−2Cn−2+,・・・,+a2C2+a1C+a0
ここで、anは各誘導加熱装置により定まる実測値に基づく係数であり、a0は定数である。
また、RXは、補正前のインピーダンスであり、Vinは、サイリスタの受電電圧であり、Vは、サイリスタの出力電圧である。
The impedance correction unit 62 corrects the second-order converted resistance R 2 of the heated body 2 by the energization angle (phase angle) of the control element (thyristor) 4 ((3) in FIG. 4).
Specifically impedance correction unit 62, according to the following equation to correct the impedance R 2.
R 2 = a × R X
Here, if C = V / V in ,
a = a n C n + a n-1 C n-1 + a n-2 C n-2 +, ···, + a 2 C 2 + a 1 C + a 0
Here, a n is a coefficient based on the measured value determined by the induction heating device, a 0 is a constant.
Also, R X is a correction before the impedance, V in is the receiving voltage of the thyristor, V is an output voltage of the thyristor.
温度算出用データ格納部63は、被加熱体2の被加熱面2hの温度を算出するのに必要な温度算出用データを格納している。具体的に温度算出用データは(a)誘導加熱ユニットにおける磁気回路の磁束密度と励磁抵抗との関係を示す磁束密度−励磁抵抗関係データ、(b)材質ごとに測定された磁束密度と比透磁率との関係(図6参照)を示す磁束密度−比透磁率関係データ等を含むデータである。 The temperature calculation data storage unit 63 stores temperature calculation data necessary for calculating the temperature of the heated surface 2 h of the heated body 2. Specifically, the temperature calculation data includes (a) magnetic flux density-excitation resistance relationship data indicating the relationship between the magnetic flux density of the magnetic circuit and the excitation resistance in the induction heating unit, and (b) magnetic flux density and specific permeability measured for each material. It is data including magnetic flux density-relative permeability relationship data indicating the relationship with magnetic permeability (see FIG. 6).
被加熱体温度算出部64は、インピーダンス補正部62により補正された補正インピーダンスと、前記温度算出用データ格納部63に格納された温度算出用データとを用いて、被加熱体2の被加熱面2hの温度を算出する(図4の(4))。 The heated object temperature calculation unit 64 uses the corrected impedance corrected by the impedance correction unit 62 and the temperature calculation data stored in the temperature calculation data storage unit 63 to be heated on the heated surface of the heated object 2. The temperature for 2 h is calculated ((4) in FIG. 4).
具体的に被加熱体温度算出部64は、以下の式を用いて、被加熱体2の被加熱面2hの温度θSを算出する。
θS=|−「{2×5.032πR2lS−(πΦ)2μs×f}
−√[{2×5.032πR2lS−(πΦ)2μs×f}2
−4×5.03 4(πR2lS)2]」/{2×(5.03π)2}
−14.3|/(2.86×10−2) [℃]
Specifically, the heated body temperature calculation unit 64 calculates the temperature θ S of the heated surface 2h of the heated body 2 using the following formula.
θ S = | − “{2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f}
−√ [{2 × 5.03 2 πR 2 l S − (πΦ) 2 μs × f} 2
−4 × 5.03 4 (πR 2 l S ) 2 ] ”/ {2 × (5.03π) 2 }
−14.3 | / (2.86 × 10 −2 ) [° C.]
このとき、被加熱体温度算出部64は、上記の被加熱面2hの温度θSの式において、R2を以下の式により算出する。
r2=r0(r1−rcomb)/(rcomb−r1−r0)
R2=(r2/N2)×106
At this time, the heated object temperature calculation section 64, in Formula temperature theta S above the heated surface 2h, calculated by the following equation R 2.
r 2 = r 0 (r 1 -r comb ) / (r comb -r 1 -r 0 )
R 2 = (r 2 / N 2 ) × 10 6
ここで、合成抵抗rcombは、rcomb=(V/I)×cosφにより示されるため、交流電圧検出部8により得られた交流電圧値と、交流電流検出部7により得られた交流電流値と、力率検出部10により得られた力率と、抵抗検出部により得られた巻き線抵抗値又は温度検出部9の巻き線温度から求めた巻き線抵抗値と、磁束密度及び磁気回路の励磁抵抗の関係特性から得られる励磁抵抗値とにより算出される。 Here, since the combined resistance r comb is represented by r comb = (V / I) × cos φ, the AC voltage value obtained by the AC voltage detector 8 and the AC current value obtained by the AC current detector 7 are used. And the power factor obtained by the power factor detection unit 10, the winding resistance value obtained by the resistance detection unit or the winding resistance value obtained from the winding temperature of the temperature detection unit 9, the magnetic flux density and the magnetic circuit It is calculated by the excitation resistance value obtained from the relational characteristic of the excitation resistance.
励磁抵抗r0は、誘導加熱ユニット200における磁気回路の磁束密度Bmと励磁抵抗r0との関係を示す磁束密度−励磁抵抗関係データから求められる。具体的には、被加熱体2の磁束密度Bmを以下の式により算出して、得られた磁束密度Bmと磁束密度−励磁抵抗関係データとから、励磁抵抗r0を求める。
Bm=Vm×108/(4.44×f×N×Sm) [G]
ここで、Vmは、入力交流電圧Vから巻き線32のリアクタンスl1及び巻き線32の抵抗r1による電圧降下分を引いたベクトル算出の電圧値[V]である。fは周波数[Hz]であり、Nは巻き線32の巻数であり、Smは鉄心31の磁路断面積[cm3]である。
Exciting resistor r 0 is the magnetic flux density shows the relation between the magnetic flux density Bm of the magnetic circuit and the excitation resistor r 0 in the induction heating unit 200 - obtained from the excitation resistor relationship data. Specifically, the magnetic flux density Bm of the body to be heated 2 is calculated by the following formula, and the exciting resistance r 0 is obtained from the obtained magnetic flux density Bm and the magnetic flux density-exciting resistance relation data.
Bm = Vm × 10 8 /(4.44×f×N×Sm) [G]
Here, Vm is a vector-calculated voltage value [V] obtained by subtracting the voltage drop due to the reactance l 1 of the winding 32 and the resistance r 1 of the winding 32 from the input AC voltage V. f is the frequency [Hz], N is the number of turns of the winding 32, and Sm is the magnetic path cross-sectional area [cm 3 ] of the iron core 31.
巻き線32の抵抗r1は、巻き線32を構成する電線の材質、長さ、断面積及び巻き線の温度によって決まり、電線の材質が例えば銅であれば、次式により算出することができる。
r1=kL/100Sc [Ω]
k=2.1(234.5+θC)/309.5
ここで、Lは電線の長さ[m]であり、SCは電線の断面積[mm2]であり、θCは巻き線の温度[℃]である。
Resistance r 1 of the winding 32, the material of the wires forming the windings 32, the length, determined by the temperature of the cross-sectional area and winding, if the material of the wire is, for example, copper, can be calculated by the following formula .
r 1 = kL / 100 Sc [Ω]
k = 2.1 (234.5 + θ C ) /309.5
Here, L is the length of the wire [m], S C is the cross-sectional area of the wire [mm 2], the theta C is the temperature of the windings [° C.].
これらにより、合成抵抗rcomb、励磁抵抗r0、巻き線の抵抗r1を求めることによって、被加熱体2の抵抗r2を算出して、さらには被加熱体2側から見た二次換算且つ単位をμΩとしたR2を算出することができる。
することができる。
Thus, by calculating the combined resistance r comb , the excitation resistance r 0 , and the winding resistance r 1 , the resistance r 2 of the heated body 2 is calculated, and further the secondary conversion as viewed from the heated body 2 side. R 2 with the unit of μΩ can be calculated.
can do.
また、被加熱体温度算出部64は、図7に示す比透磁率と磁束密度との関係を示す比透磁率−磁束密度関係データと前記被加熱体2の磁束密度(仕様により求まる値)とから、比透磁率μsを求める。 Further, the heated object temperature calculation unit 64 includes the relative permeability-magnetic flux density relationship data indicating the relationship between the relative permeability and the magnetic flux density shown in FIG. 7, and the magnetic flux density (value determined by the specification) of the heated object 2. From this, the relative permeability μs is obtained.
そして、被加熱体温度算出部64は、上記により求めた被加熱体2の抵抗R2及び比透磁率μsを上記の式に代入して、被加熱体2の被加熱面2hの温度θSを算出する。 And the to-be-heated body temperature calculation part 64 substitutes resistance R2 of the to-be-heated body 2 and relative permeability (micro | micron | mu) s which were calculated | required by the above into the said Formula, and is the temperature (theta) S of the to-be-heated surface 2h of the to-be-heated body 2. Is calculated.
具体的に被加熱体温度算出部64は、被加熱体2の被加熱面2hの温度θSと当該被加熱面2hから離間した温度を算出する面である温度算出面2xの温度との温度差をθ[℃]としたときに、以下の式から得られる温度差θを用いて、被加熱面2hの温度θSを補正して温度算出面2xの温度を算出する(図4の(5))。
θ=kP/[2π/{ln(d2/d1)/λ}]
ここで、d1は被加熱面2hの直径[m]であり、d2は温度算出面2xの直径[m]であり、λは被加熱面2h及び温度算出面2xの間の平均温度における熱伝導率[W/m・℃]であり、Pは熱流速[W/m]であり、kは、実測値から算出した補正係数である。熱流速P[W/m]は、ここでは被加熱体2の外面の発熱量[W]を発熱外面長[m](巻き線幅に等しい)で除した値であり、熱流速[W/m]を求めるに当たって、被加熱体温度算出部64は、電流検出部7、電圧検出部8及び力率検出部10のそれぞれの測定値から計算して得られる電力値を用いる。すなわち、誘導加熱ユニットの電力をPとすると、P=I×V×cosφとなり、このユニット電力Pからコイル電力PCと鉄損Pfとを引いた値が被加熱体2の電力PSとなる。
Specifically, the heated body temperature calculation unit 64 is a temperature between the temperature θ S of the heated surface 2h of the heated body 2 and the temperature of the temperature calculating surface 2x that is a surface that calculates the temperature separated from the heated surface 2h. When the difference is θ [° C.], the temperature difference θ calculated from the following equation is used to correct the temperature θ S of the heated surface 2 h to calculate the temperature of the temperature calculation surface 2 x (FIG. 4 ( 5)).
θ = kP / [2π / {ln (d 2 / d 1 ) / λ}]
Here, d 1 is the diameter [m] of the heated surface 2h, d 2 is the diameter [m] of the temperature calculating surface 2x, and λ is an average temperature between the heated surface 2h and the temperature calculating surface 2x. The thermal conductivity [W / m · ° C.], P is the heat flow rate [W / m], and k is a correction coefficient calculated from the actual measurement value. Here, the heat flow rate P [W / m] is a value obtained by dividing the heat generation amount [W] of the outer surface of the heated body 2 by the heat generation outer surface length [m] (equal to the winding width). m], the to-be-heated body temperature calculation unit 64 uses power values obtained by calculating from the measured values of the current detection unit 7, the voltage detection unit 8, and the power factor detection unit 10. That is, when the power of the induction heating unit and P, and P = I × V × cosφ and the value obtained by subtracting a coil power P C and the core loss P f from the unit power P is heated body 2 power P S Become.
ここで、コイル電力PCは、PC=r1×(kI)2(kは、電線内に発生する渦電流分の割り増し定数で、巻き線及び電線の形状によって定まる値である。)であり、鉄損Pfは、Pf={(Vm/r0)2}×r0/2=Vm2/(2×r0)となる。鉄損Pfの算出において、励磁電流の2乗に励磁抵抗を乗じて1/2としているのは、磁束発生機構3の鉄心31における鉄損分と被加熱体2における鉄損分とを半々として計算しているためである。
つまり、被加熱体2の電力PSは、以下の式となる。
PS=P−PC−Pf
=I×V×cosφ−r1×(kI)2−Vm2/(2×r0)
Here, the coil power P C is P C = r 1 × (kI) 2 (k is an additional constant for the eddy current generated in the electric wire and is a value determined by the shape of the winding and the electric wire). There, iron loss P f becomes P f = {(Vm / r 0) 2} × r 0/2 = Vm 2 / (2 × r 0). Half and half in the calculation of the core loss P f, are you 1/2 by multiplying the excitation resistance to the square of the exciting current, and a core loss in core loss and the body to be heated 2 of the iron core 31 of the magnetic flux generating mechanism 3 It is because it is calculating as.
That is, the power P S of the object to be heated 2 can be expressed as the following formula.
P S = P−P C −P f
= I × V × cos φ−r 1 × (kI) 2 −Vm 2 / (2 × r 0 )
また、被加熱体温度算出部64は、被加熱体2に形成されたジャケット室2Sによる肉厚低下分を考慮して、被加熱体2の温度算出面2xの温度を算出する。 The heated body temperature calculation unit 64 calculates the temperature of the temperature calculation surface 2x of the heated body 2 in consideration of the thickness reduction due to the jacket chamber 2S formed in the heated body 2.
具体的に被加熱体温度算出部64は、被加熱面2h及び温度算出面2xの間の断面積をS[m2]とし、被加熱面2h及び温度算出面2xの間のジャケット室の断面積の総和をSj[m2]とし、被加熱面2h及び温度算出面2xの間の距離をt[m]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、被加熱面2hの直径d1を、肉厚低下分を考慮した仮想直径dj1(=d1−t{1−α(1−Sj/S)})とし、温度算出面2xの直径d2を、肉厚低下分を考慮した仮想直径dj2(=d2+t{1−α(1−Sj/S)})として、上記温度差θの式から得られる温度差θを用いて、被加熱体2の被加熱面2hの温度を補正することにより、被加熱体2の温度算出面2xの温度を算出する。 Specifically, the to-be-heated body temperature calculation unit 64 sets S [m 2 ] as the cross-sectional area between the heated surface 2h and the temperature calculating surface 2x, and cuts the jacket chamber between the heated surface 2h and the temperature calculating surface 2x. The sum of the areas is S j [m 2 ], the distance between the heated surface 2h and the temperature calculation surface 2x is t [m], and the rate of decrease in the function of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop is When the variable shown is α, the diameter d 1 of the heated surface 2h is assumed to be a virtual diameter d j1 (= d 1 −t {1−α (1−S j / S)}) in consideration of the thickness reduction. And the diameter d 2 of the temperature calculation surface 2x is a virtual diameter d j2 (= d 2 + t {1−α (1−S j / S)}) in consideration of the thickness reduction, The temperature calculation of the heated body 2 is performed by correcting the temperature of the heated surface 2h of the heated body 2 using the temperature difference θ obtained from To calculate the temperature of the surface 2x.
以上にように被加熱体温度算出部64により得られた被加熱体2の温度算出面2xの温度に基づいて、被加熱体温度制御部65が、電源回路の制御素子4を制御して、被加熱体2の温度算出面2xの温度を所定の設定温度となるように制御する。 Based on the temperature of the temperature calculation surface 2x of the heated object 2 obtained by the heated object temperature calculating unit 64 as described above, the heated object temperature control unit 65 controls the control element 4 of the power supply circuit, The temperature of the temperature calculation surface 2x of the heated body 2 is controlled to be a predetermined set temperature.
このように構成した本実施形態の誘導加熱装置100によれば、巻き線32の交流電流値と、巻き線32の交流電圧値と、誘導加熱ユニット200の力率と、巻き線32の巻き線抵抗値と、被加熱体2及び磁束発生機構(巻き線32)から構成される磁気回路の励磁抵抗値とをパラメータとして被加熱体2の温度を算出する被加熱体温度算出部64を有するので、被加熱体2に温度検出素子を設けることなく、被加熱体2の温度を算出することができる。 According to the induction heating apparatus 100 of the present embodiment configured as described above, the alternating current value of the winding 32, the alternating voltage value of the winding 32, the power factor of the induction heating unit 200, and the winding of the winding 32. Since it has the to-be-heated body temperature calculation part 64 which calculates the temperature of the to-be-heated body 2 using a resistance value and the exciting resistance value of the magnetic circuit comprised from the to-be-heated body 2 and a magnetic flux generation mechanism (winding 32) as a parameter. The temperature of the heated body 2 can be calculated without providing the temperature detection element in the heated body 2.
また、インピーダンス算出部61により得られたインピーダンスを、インピーダンス補正部62により、サイリスタ4の通電角を用いて補正しているので、被加熱体2の温度を精度良く算出することができる。 Further, since the impedance obtained by the impedance calculation unit 61 is corrected by the impedance correction unit 62 using the energization angle of the thyristor 4, the temperature of the heated object 2 can be calculated with high accuracy.
さらに、被加熱体温度算出部64が、被加熱体2の被加熱面2hの温度と温度算出面2xの温度との温度差θにより、温度算出面2xの温度を算出しているので、被加熱体2の温度算出面2xの温度を精度良く算出することができる。また、昇降温時の過渡期における温度到達時間遅れも、被加熱体温度算出部64が算出し補正しているので、被加熱体2の温度算出面2xの温度を精度良く算出することができる。 Further, the heated object temperature calculation unit 64 calculates the temperature of the temperature calculation surface 2x based on the temperature difference θ between the temperature of the heated surface 2h of the heated object 2 and the temperature of the temperature calculation surface 2x. The temperature of the temperature calculation surface 2x of the heating body 2 can be calculated with high accuracy. In addition, the temperature arrival time delay in the transition period during the temperature rise and fall is also calculated and corrected by the heated object temperature calculation unit 64, so that the temperature of the temperature calculation surface 2x of the heated object 2 can be calculated with high accuracy. .
<第2実施形態>
次に本発明に係る第2実施形態について説明する。第2実施形態に係る誘導加熱装置は、前記第1実施形態とは、被加熱体2の構成及び被加熱体温度算出部64の機能が異なる。
Second Embodiment
Next, a second embodiment according to the present invention will be described. The induction heating apparatus according to the second embodiment is different from the first embodiment in the configuration of the heated body 2 and the function of the heated body temperature calculation unit 64.
第2実施形態に係る被加熱体2は、図11に示すように、一方面(図11では上面)が処理対象物に熱を作用させる作用面となる厚さt[m]の平板形状をなす金属製加熱プレートである。この被加熱体2の肉厚内には、気液二相の熱媒体が封入される複数のジャケット室2Sが、格子状に形成されている。 As shown in FIG. 11, the heated body 2 according to the second embodiment has a flat plate shape with a thickness t [m], which is a working surface in which one surface (upper surface in FIG. 11) acts on the object to be processed. It is a metal heating plate. A plurality of jacket chambers 2S in which a gas-liquid two-phase heat medium is enclosed are formed in a lattice shape within the thickness of the heated body 2.
また、巻き線32は、被加熱体2の他方面(図11では下面)に、当該他方面から離間して設けられた概略平板形状をなすものである。これにより、被加熱体2の他方面が、巻き線32により加熱される被加熱面2hとなり、磁束発生機構である巻き線32が、被加熱体2を片面側から誘導加熱する構成となる。 The winding 32 has a substantially flat plate shape provided on the other surface (the lower surface in FIG. 11) of the heated body 2 so as to be separated from the other surface. Thereby, the other surface of the to-be-heated body 2 becomes the to-be-heated surface 2h heated with the winding 32, and the winding 32 which is a magnetic flux generation mechanism becomes the structure which induction-heats the to-be-heated body 2 from one side.
そして、被加熱体温度算出部64は、前記実施形態と同様に求めた被加熱体2の被加熱面2hの温度と、当該被加熱面2hから厚さ方向に離間した温度を算出する面である温度算出面2x(例えば上面である作用面の温度)との温度差をθ[℃]としたときに、以下の式から得られる温度差θを用いて被加熱面2hの温度を補正して温度算出面2xの温度を算出する。
θ=kQ/(λS/t)
ここで、tは被加熱面2h及び温度算出面2xの間の距離[m]であり、Sは被加熱面2h及び温度算出面2xの間の断面積[m2]であり、λは被加熱面2h及び前記温度算出面2xの間の平均温度[℃]における前記被加熱体の熱伝導率[W/m・℃]であり、Qは前記被加熱面2hの発熱量[W]であり、kは、実測値から算出した補正係数である。
And the to-be-heated body temperature calculation part 64 is a surface which calculates the temperature separated from the to-be-heated surface 2h in the thickness direction, and the temperature of the to-be-heated surface 2h calculated | required similarly to the said embodiment. When the temperature difference with a certain temperature calculation surface 2x (for example, the temperature of the working surface which is the upper surface) is θ [° C.], the temperature difference of the heated surface 2h is corrected using the temperature difference θ obtained from the following equation. To calculate the temperature of the temperature calculation surface 2x.
θ = kQ / (λS / t)
Here, t is the distance [m] between the heated surface 2h and the temperature calculating surface 2x, S is the cross-sectional area [m 2 ] between the heated surface 2h and the temperature calculating surface 2x, and λ is the covered surface. The thermal conductivity [W / m · ° C.] of the heated body at the average temperature [° C.] between the heating surface 2h and the temperature calculation surface 2x, and Q is the calorific value [W] of the heated surface 2h. Yes, k is a correction coefficient calculated from actual measurement values.
また、被加熱体温度算出部64は、被加熱体2に形成されたジャケット室2Sによる肉厚低下分を考慮して、被加熱体2の温度算出面2xの温度を算出する。 The heated body temperature calculation unit 64 calculates the temperature of the temperature calculation surface 2x of the heated body 2 in consideration of the thickness reduction due to the jacket chamber 2S formed in the heated body 2.
具体的に被加熱体温度算出部64は、被加熱面2h及び温度算出面2xの間の断面積をS[m2]とし、被加熱面2h及び温度算出面2xの間のジャケット室の断面積の総和をSj[m2]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、被加熱面2h及び温度算出面2xの間の距離tを、肉厚低下分を考慮した仮想距離tj(=αt(S−Sj)/S)として、上記温度差θの式から得られる温度差θを用いて、被加熱体2の被加熱面2hの温度を補正することにより、被加熱体2の温度算出面2xの温度を算出する。 Specifically, the to-be-heated body temperature calculation unit 64 sets S [m 2 ] as the cross-sectional area between the heated surface 2h and the temperature calculating surface 2x, and cuts the jacket chamber between the heated surface 2h and the temperature calculating surface 2x. When the sum of the areas is S j [m 2 ], and the variable indicating the rate of reduction in the function of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop is α, the space between the heated surface 2h and the temperature calculation surface 2x Is used as a virtual distance t j (= αt (S−S j ) / S) in consideration of the thickness reduction, using the temperature difference θ obtained from the above temperature difference θ formula, By correcting the temperature of the heated surface 2h, the temperature of the temperature calculating surface 2x of the heated body 2 is calculated.
<第3実施形態>
次に本発明に係る第3実施形態について説明する。第3実施形態に係る誘導加熱装置は、前記第1、2実施形態とは、被加熱体2の構成及び被加熱体温度算出部64の機能が異なる。
<Third Embodiment>
Next, a third embodiment according to the present invention will be described. The induction heating apparatus according to the third embodiment is different from the first and second embodiments in the configuration of the heated body 2 and the function of the heated body temperature calculation unit 64.
第3実施形態に係る被加熱体2は、図12に示すように、処理対象物を収容する収容部又は処理対象物が通過する通過部を有するものであり、高さがh[m]、n辺の長さがそれぞれa1、a2、・・・an[m]の中空n角筒形状(図12では中空四角形筒形状)をなす金属製筒体である。この被加熱体2の側周壁の肉厚内には、気液二相の熱媒体が封入される複数のジャケット室2Sが、中心軸に沿って周方向に等間隔に形成されている。 As shown in FIG. 12, the heated object 2 according to the third embodiment has a housing part that houses the processing object or a passage part through which the processing object passes, and the height is h [m], a 1 length of n sides, respectively, a 2, a metallic cylindrical body forming the (hollow square tubular shape in FIG. 12) hollow n rectangular tube shape ··· a n [m]. A plurality of jacket chambers 2S in which a gas-liquid two-phase heat medium is enclosed are formed at equal intervals in the circumferential direction along the central axis in the wall thickness of the side peripheral wall of the body 2 to be heated.
また、本実施形態の巻き線32は、中空n角筒形状をなす被加熱体2の外側周面の周りに離間して巻回された概略中空n角筒形状をなすものである。これにより、被加熱体2の外側周面が、巻き線32により加熱される被加熱面2hとなる。 In addition, the winding wire 32 of the present embodiment has a substantially hollow n-square tube shape that is wound around the outer peripheral surface of the heated body 2 having a hollow n-square tube shape. Thereby, the outer peripheral surface of the heated body 2 becomes the heated surface 2h heated by the winding 32.
そして、被加熱体温度算出部64は、前記実施形態と同様に求めた被加熱体2の被加熱面2hの温度と、当該被加熱面2hから離間した温度を算出する面である温度算出面2xとの温度差をθ[℃]としたときに、以下の式から得られる温度差θを用いて被加熱面2hの温度を補正して温度算出面2xの温度を算出する。なお、第3実施形態では、各側壁部それぞれで被加熱面2hと温度算出面2xとの厚さ方向の距離は同一である。
θ=kQ/λ[{(a1+a2+・・・+an)h/t}+mn×n×h]
ここで、nは1から始まる自然数であり、λは被加熱面2h及び温度算出面2xの間の平均温度[℃]における被加熱体の熱伝導率[W/m・℃]であり、Qは被加熱面2hの発熱量[W]であり、kは、実測値から算出した補正係数であり、mnはnにおける定数である。なお、例えばn=4の場合、k4=0.54である。
And the to-be-heated body temperature calculation part 64 is a temperature calculation surface which is a surface which calculates the temperature of the to-be-heated surface 2h of the to-be-heated body 2 calculated | required similarly to the said embodiment, and the temperature away from the said to-be-heated surface 2h. When the temperature difference from 2x is θ [° C.], the temperature of the heated surface 2h is corrected using the temperature difference θ obtained from the following equation to calculate the temperature of the temperature calculation surface 2x. In the third embodiment, the distance in the thickness direction between the heated surface 2h and the temperature calculation surface 2x is the same in each side wall portion.
θ = kQ / λ [{(a 1 + a 2 +... + a n ) h / t} + m n × n × h]
Here, n is a natural number starting from 1, λ is the thermal conductivity [W / m · ° C.] of the heated body at the average temperature [° C.] between the heated surface 2h and the temperature calculation surface 2x, and Q Is the calorific value [W] of the heated surface 2h, k is a correction coefficient calculated from the actual measurement value, and mn is a constant at n. For example, when n = 4, k 4 = 0.54.
また、被加熱体温度算出部64は、被加熱体2に形成されたジャケット室2Sによる肉厚低下分を考慮して、被加熱体2の温度算出面2xの温度を算出する。 The heated body temperature calculation unit 64 calculates the temperature of the temperature calculation surface 2x of the heated body 2 in consideration of the thickness reduction due to the jacket chamber 2S formed in the heated body 2.
具体的に被加熱体温度算出部64は、被加熱面2h及び前記温度算出面2xの間の断面積をS[m2]とし、前記被加熱面2h及び前記温度算出面2xの間のジャケット室の断面積の総和をSj[m2]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、被加熱面2h及び温度算出面2xの間の距離tを、肉厚低下分を考慮した仮想距離tj(=αt(S−Sj)/S)として、上記温度差θの式から得られる温度差θを用いて、被加熱体2の被加熱面2hの温度を補正することにより、被加熱体2の温度算出面2xの温度を算出する。 Specifically, the to-be-heated body temperature calculation unit 64 sets S [m 2 ] as a cross-sectional area between the heated surface 2h and the temperature calculating surface 2x, and a jacket between the heated surface 2h and the temperature calculating surface 2x. When the sum of the cross-sectional areas of the chamber is S j [m 2 ], and the variable indicating the rate of function deterioration of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop is α, the heated surface 2h and the temperature calculation surface The distance t between 2x is defined as a virtual distance t j (= αt (S−S j ) / S) in consideration of the thickness reduction, using the temperature difference θ obtained from the above temperature difference θ formula, By correcting the temperature of the heated surface 2h of the heated body 2, the temperature of the temperature calculating surface 2x of the heated body 2 is calculated.
<第4実施形態>
次に本発明に係る第4実施形態について説明する。第4実施形態に係る誘導加熱装置は、前記第1〜3実施形態とは、被加熱体2の構成及び被加熱体温度算出部64の機能が異なる。
<Fourth embodiment>
Next, a fourth embodiment according to the present invention will be described. The induction heating apparatus according to the fourth embodiment is different from the first to third embodiments in the configuration of the heated body 2 and the function of the heated body temperature calculation unit 64.
第4実施形態に係る被加熱体2は、図13に示すように、処理対象物を収容する収容部又は処理対象物が通過する通過部を有するものであり、高さがh[m]、n辺の長さがそれぞれa1、a2、・・・an[m]の中空n角筒形状(図13では中空四角形筒形状)をなす金属製筒体である。この被加熱体2の側周壁の肉厚内には、気液二相の熱媒体が封入される複数のジャケット室2Sが、中心軸に沿って周方向に等間隔に形成されている。 As shown in FIG. 13, the heated object 2 according to the fourth embodiment has a housing part that houses the processing object or a passage part through which the processing object passes, and the height is h [m], a 1, a 2 length of n sides, respectively, is a metal cylindrical body forming the (hollow square tubular shape in FIG. 13) hollow n rectangular tube shape ··· a n [m]. A plurality of jacket chambers 2S in which a gas-liquid two-phase heat medium is enclosed are formed at equal intervals in the circumferential direction along the central axis in the wall thickness of the side peripheral wall of the body 2 to be heated.
また、本実施形態の巻き線32は、中空n角筒形状をなす被加熱体2の外側周面の周りに離間して巻回された概略中空n角筒形状をなすものである。これにより、被加熱体2の外側周面が、巻き線32により加熱される被加熱面2hとなる。 In addition, the winding wire 32 of the present embodiment has a substantially hollow n-square tube shape that is wound around the outer peripheral surface of the heated body 2 having a hollow n-square tube shape. Thereby, the outer peripheral surface of the heated body 2 becomes the heated surface 2h heated by the winding 32.
そして、被加熱体温度算出部64は、前記第1実施形態と同様に求めた各側壁部それぞれにおける、被加熱体2の被加熱面2hの温度と、当該被加熱面2hから離間した温度を算出する面である温度算出面2xとの温度差をθn[℃]とし、前記被加熱体の各側壁部それぞれの被加熱面2h及び温度算出面2xの間の厚さ方向の距離をt1、t2、・・・tn[m]としたときに、以下の式から得られる温度差θnを用いて、各側壁部の被加熱面2hの温度を補正して、各側壁部の温度算出面2xの温度を算出する。
θn=knQn/(λnSn/tn)
ここで、tnはn番目の側壁部における被加熱面2h及び温度算出面2xの間の距離[m]であり、Snはn番目の側壁部における被加熱面2h及び温度算出面2xの間の断面積[m2]であり、λnはn番目の側壁部における被加熱面2h及び温度算出面2xの間の平均温度[℃]における被加熱体の熱伝導率[W/m・℃]であり、Qnはn番目の側壁部における被加熱面2hの発熱量[W]であり、knは、実測値から算出した補正係数である。
And the to-be-heated body temperature calculation part 64 calculates the temperature separated from the to-be-heated surface 2h and the temperature of the to-be-heated body 2 in each side wall part calculated | required similarly to the said 1st Embodiment. A temperature difference from the temperature calculation surface 2x, which is a surface to be calculated, is θ n [° C.], and a distance in the thickness direction between the heated surface 2h and the temperature calculation surface 2x of each side wall portion of the heated object is t. 1 , t 2 ,... T n [m], the temperature difference θ n obtained from the following equation is used to correct the temperature of the heated surface 2 h of each side wall portion, and each side wall portion The temperature of the temperature calculation surface 2x is calculated.
θ n = k n Q n / (λ n S n / t n)
Here, t n is the distance [m] between the n-th sidewall heated surface 2h and temperature calculation surfaces in section 2x, S n is the n th side wall heated surface 2h and temperature calculation surfaces in section 2x the cross-sectional area [m 2] between, lambda n is the average temperature thermal conductivity of the heated object at [℃] between the n-th sidewall heated surface 2h and temperature calculation surfaces in section 2x [W / m · ℃] a and, Q n is the heat value of the heated surface 2h at n-th sidewall part [W], k n is a correction coefficient calculated from the measured value.
また、被加熱体温度算出部64は、被加熱体2に形成されたジャケット室2Sによる肉厚低下分を考慮して、被加熱体2の各側壁部の温度算出面2xの温度を算出する。 The heated body temperature calculation unit 64 calculates the temperature of the temperature calculation surface 2x of each side wall portion of the heated body 2 in consideration of the thickness reduction due to the jacket chamber 2S formed in the heated body 2. .
具体的に被加熱体温度算出部64は、n番目の側壁部における前記被加熱面2h及び前記温度算出面2xの間の断面積をSn[m2]とし、n番目の側壁部における前記被加熱面2h及び前記温度算出面2xの間のジャケット室の断面積の総和をSnj[m2]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、n番目の側壁部における被加熱面2h及び温度算出面2xの間の距離tnを、肉厚低下分を考慮した仮想距離tnj(=αtn(Sn−Snj)/Sn)として、上記温度差θの式から得られる温度差θを用いて、被加熱体2の各側壁部の被加熱面2hの温度を補正することにより、被加熱体2の各側壁部の温度算出面2xの温度を算出する。 Specifically, the to-be-heated body temperature calculation unit 64 sets S n [m 2 ] as the cross-sectional area between the heated surface 2h and the temperature calculation surface 2x in the nth side wall, and the nth side wall in the nth side wall. The sum of the cross-sectional areas of the jacket chamber between the heated surface 2h and the temperature calculation surface 2x is S nj [m 2 ], and a variable indicating the rate of decrease in the function of the jacket chamber due to the decrease in the pressure of the heat medium accompanying the temperature decrease. When α is α, the distance t n between the heated surface 2h and the temperature calculation surface 2x in the nth side wall portion is assumed to be a virtual distance t nj (= αt n (S n −S nj) in consideration of the thickness reduction. ) / S n ), by using the temperature difference θ obtained from the equation of temperature difference θ, the temperature of the heated surface 2h of each side wall portion of the heated body 2 is corrected, thereby The temperature of the temperature calculation surface 2x of the side wall is calculated.
なお、本発明は前記実施形態に限られるものではない。 The present invention is not limited to the above embodiment.
例えば、前記第1実施形態では、巻き線32の温度を検出する温度検出部9を巻き線32に埋設する構成としているが、以下のように構成しても良い。
つまり、図14及び図15に示すように、制御装置6が、被加熱体2を誘導発熱させて被加熱物を処理する加熱運転中において周期的に巻き線32の温度を検出する温度検出動作を行うように構成しても良い。より詳細には、制御装置6が、直流電圧印加部66、抵抗値算出部67としての機能を発揮する。
For example, in the first embodiment, the temperature detection unit 9 that detects the temperature of the winding 32 is embedded in the winding 32, but may be configured as follows.
That is, as shown in FIGS. 14 and 15, the temperature detection operation in which the control device 6 periodically detects the temperature of the winding 32 during the heating operation in which the object to be heated 2 is induced to generate heat to process the object to be heated. You may comprise so that it may perform. More specifically, the control device 6 functions as a DC voltage application unit 66 and a resistance value calculation unit 67.
直流電圧印加部66は、巻き線32に電気的に接続された直流電源12を制御して、巻き線32に間欠的に直流電圧を印加するものである。具体的に直流電圧印加部66は、巻き線32に対して、一定の直流電圧を、数秒以内の印加時間を数秒から数十分の一定周期で印加するものである。 The DC voltage application unit 66 controls the DC power supply 12 electrically connected to the winding 32 and applies a DC voltage to the winding 32 intermittently. Specifically, the direct-current voltage application unit 66 applies a constant direct-current voltage to the winding 32 at a constant period of several seconds to several tens of minutes with an application time within several seconds.
ここで、直流電圧印加部66によって巻き線32に直流電圧が印加される印加時間内では、制御装置6の被加熱体温度制御部65が制御素子4を制御して、交流電流又は交流電圧を遮断又は最小限とした状態としている。なお、被加熱体温度制御部65は、被加熱体2の温度を所定の設定温度とするために、電源回路5に設けられた制御素子4を制御して交流電圧又は交流電流を制御するものである。 Here, within the application time during which the DC voltage is applied to the winding 32 by the DC voltage application unit 66, the heated body temperature control unit 65 of the control device 6 controls the control element 4 to generate an AC current or an AC voltage. Blocked or minimized. The heated body temperature control unit 65 controls the AC voltage or the AC current by controlling the control element 4 provided in the power supply circuit 5 in order to set the temperature of the heated body 2 to a predetermined set temperature. It is.
抵抗値算出部67は、直流電圧印加部66により印加される直流電圧と、巻き線32に直流電圧を印加したときに巻き線32に流れる直流電流とから巻き線32の巻き線抵抗値を算出するものである。具体的に抵抗値算出部67は、予め入力された直流電源12の直流電圧と、巻き線32及び直流電源12から構成される直流回路に設けられた直流電流検出部13により得られる直流電流とから、巻き線32の巻き線抵抗値を算出する。 The resistance value calculation unit 67 calculates the winding resistance value of the winding 32 from the DC voltage applied by the DC voltage application unit 66 and the DC current flowing through the winding 32 when a DC voltage is applied to the winding 32. To do. Specifically, the resistance value calculation unit 67 includes a DC voltage of the DC power source 12 input in advance, and a DC current obtained by the DC current detection unit 13 provided in the DC circuit composed of the winding 32 and the DC power source 12. From this, the winding resistance value of the winding 32 is calculated.
このとき、上述した通り、直流電圧を印加して直流電流を検出するタイミングでは、交流電流又は交流電圧を遮断又は最小限とした状態としているので、交流電流(交流成分)の影響を抑えることができ、直流電流(直流成分)の検出を容易に行うことができ、抵抗値を精度良く算出することができる。 At this time, as described above, at the timing of detecting the DC current by applying the DC voltage, the AC current or AC voltage is cut off or minimized, so that the influence of the AC current (AC component) can be suppressed. Therefore, it is possible to easily detect a direct current (DC component) and to calculate a resistance value with high accuracy.
さらに、前記第1、3、4実施形態では、巻き線32を被加熱体2の外側周面の周りに配置して被加熱体2を外周側から誘導加熱するものであったが、巻き線32を被加熱体2の中空内に配置して被加熱体2を内周側から誘導加熱するものであっても良い。なお、この場合、被加熱体2の内側周面が被加熱面となる。また、前記第2実施形態では、温度算出面2xが被加熱体2の作用面(上面)であったが、肉厚内に設定された仮想面であっても良い。さらに、前記第3、4実施形態では、温度算出面2xが被加熱体2の側壁部の肉厚内に設定された仮想面であったが、被加熱体2の内側周面であっても良い。 Further, in the first, third, and fourth embodiments, the winding 32 is disposed around the outer peripheral surface of the heated body 2 and the heated body 2 is induction-heated from the outer peripheral side. 32 may be disposed in the hollow of the heated body 2 and the heated body 2 may be induction heated from the inner peripheral side. In this case, the inner peripheral surface of the heated body 2 becomes the heated surface. Moreover, in the said 2nd Embodiment, although the temperature calculation surface 2x was the action surface (upper surface) of the to-be-heated body 2, the virtual surface set in the thickness may be sufficient. Further, in the third and fourth embodiments, the temperature calculation surface 2x is a virtual surface set within the thickness of the side wall portion of the heated object 2, but even if it is the inner peripheral surface of the heated object 2. good.
その他、本発明は前記実施形態に限られず、その趣旨を逸脱しない範囲で種々の変形が可能であるのは言うまでもない。また、各計算過程において実測値と計算値とに差異が生じる場合には、実測値から算出した補正係数を用いて補正を行うことも言うまでも無いことである。 In addition, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In addition, when there is a difference between the actual measurement value and the calculation value in each calculation process, it goes without saying that correction is performed using a correction coefficient calculated from the actual measurement value.
100・・・誘導加熱装置
200・・・誘導加熱ユニット
2・・・被加熱体
2S・・・ジャケット室
3・・・磁束発生機構
32・・・巻き線
4・・・制御素子
5・・・電源回路
6・・・制御装置
61・・・インピーダンス算出部
62・・・インピーダンス補正部
63・・・温度算出用データ格納部
64・・・被加熱体温度算出部
7・・・電流検出部
8・・・電圧検出部
9・・・温度検出部
10・・・力率検出部
DESCRIPTION OF SYMBOLS 100 ... Induction heating apparatus 200 ... Induction heating unit 2 ... To-be-heated body 2S ... Jacket chamber 3 ... Magnetic flux generation mechanism 32 ... Winding 4 ... Control element 5 ... Power supply circuit 6 ... Control device 61 ... Impedance calculation unit 62 ... Impedance correction unit 63 ... Temperature calculation data storage unit 64 ... Substrate temperature calculation unit 7 ... Current detection unit 8 ... Voltage detector 9 ... Temperature detector 10 ... Power factor detector
Claims (13)
前記巻き線を流れる交流電流を検出する交流電流検出部から得られる交流電流値と、前記巻き線に印加される交流電圧を検出する交流電圧検出部から得られる交流電圧値と、前記被加熱体及び前記磁束発生機構からなる誘導加熱ユニットの力率を検出する力率検出部から得られる力率と、前記巻き線の巻き線抵抗値と、前記磁束発生機構により生じる磁束密度と前記磁束発生機構及び前記被加熱体から構成される磁気回路の励磁抵抗との関係特性から得られる励磁抵抗値とをパラメータとして、前記被加熱体の温度を算出する被加熱体温度算出部を備える誘導加熱装置。 An induction heating device that is connected to a winding of a magnetic flux generation mechanism and includes a power supply circuit provided with a control element that controls an alternating current or an alternating voltage, and induction-heats an object to be heated by the magnetic flux generation mechanism,
An AC current value obtained from an AC current detection unit that detects an AC current flowing through the winding, an AC voltage value obtained from an AC voltage detection unit that detects an AC voltage applied to the winding, and the object to be heated And a power factor obtained from a power factor detector that detects a power factor of an induction heating unit comprising the magnetic flux generation mechanism, a winding resistance value of the winding, a magnetic flux density generated by the magnetic flux generation mechanism, and the magnetic flux generation mechanism An induction heating apparatus comprising: a heated body temperature calculating unit that calculates the temperature of the heated body using, as a parameter, an excitation resistance value obtained from a relational characteristic with an excitation resistance of a magnetic circuit including the heated body.
前記巻き線温度検出部から得られる前記巻き線の温度から前記巻き線抵抗値を算出する抵抗値算出部とを備え、
前記被加熱体温度算出部が、前記抵抗値算出部から得られる前記巻き線抵抗値を用いて前記被加熱体の温度を算出する請求項1又は2記載の誘導加熱装置。 A winding temperature detector for detecting the temperature of the winding;
A resistance value calculation unit that calculates the winding resistance value from the temperature of the winding obtained from the winding temperature detection unit;
The induction heating apparatus according to claim 1 or 2, wherein the heated body temperature calculation unit calculates the temperature of the heated body using the winding resistance value obtained from the resistance value calculation unit.
前記直流電圧印加部により印加される直流電圧と当該直流電圧を印加したときに前記巻き線に流れる直流電流とから前記巻き線抵抗値を算出する抵抗値算出部とを備え、
前記被加熱体温度算出部が、前記抵抗値算出部から得られる巻き線抵抗値を用いて前記被加熱体の温度を算出する請求項1又は2記載の誘導加熱装置。 A DC voltage application unit that controls a DC power supply and intermittently applies a DC voltage to the winding;
A resistance value calculation unit that calculates the winding resistance value from a DC voltage applied by the DC voltage application unit and a DC current that flows through the winding when the DC voltage is applied;
The induction heating apparatus according to claim 1, wherein the heated body temperature calculation unit calculates the temperature of the heated body using a winding resistance value obtained from the resistance value calculation unit.
前記磁束発生機構が、前記被加熱体を外周側又は内周側から誘導加熱するものであり、
前記被加熱体温度算出部が、前記被加熱体の被加熱面の温度を算出するとともに、
前記巻き線に対向する前記被加熱体の被加熱面と温度を算出する面である温度算出面との温度差をθ[℃]としたときに、前記被加熱体温度算出部が、前記被加熱体の被加熱面の温度を、以下の式を用いて得られる温度差θを用いて補正して、前記温度算出面の温度を算出する請求項1乃至4の何れかに記載の誘導加熱装置。
θ=kP/[2π/{ln(d2/d1)/λ}]
ここで、d1は前記被加熱面の直径[m]であり、d2は前記温度算出面の直径[m]であり、λは前記被加熱面及び前記温度算出面の間の平均温度における熱伝導率[W/m・℃]であり、Pは熱流速[W/m]であり、kは、実測値から算出した補正係数である。 The heated body has a hollow cylindrical shape,
The magnetic flux generation mechanism is to induction heat the object to be heated from the outer peripheral side or the inner peripheral side,
The heated body temperature calculating unit calculates the temperature of the heated surface of the heated body,
When the temperature difference between the heated surface of the heated object facing the winding and the temperature calculating surface, which is a surface for calculating the temperature, is θ [° C.], the heated object temperature calculating unit includes the heated object temperature calculating unit. The induction heating according to any one of claims 1 to 4, wherein the temperature of the heated surface of the heating body is corrected using a temperature difference θ obtained using the following equation to calculate the temperature of the temperature calculating surface. apparatus.
θ = kP / [2π / {ln (d 2 / d 1 ) / λ}]
Here, d 1 is the diameter [m] of the heated surface, d 2 is the diameter [m] of the temperature calculating surface, and λ is an average temperature between the heated surface and the temperature calculating surface. The thermal conductivity [W / m · ° C.], P is the heat flow rate [W / m], and k is a correction coefficient calculated from the actual measurement value.
前記被加熱面及び前記温度算出面の間の断面積をS[m2]とし、前記被加熱面及び前記温度算出面の間のジャケット室の断面積の総和をSj[m2]とし、前記被加熱面及び前記温度算出面の間の距離をt[m]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、
前記被加熱体温度算出部が、前記被加熱面の直径d1を、dj1=d1±t{1−α(1−Sj/S)}とし、前記温度算出面の直径d2を、dj2=d2±t{1−α(1−Sj/S)}として得られる温度差θを用いて、前記被加熱体の温度を補正する請求項5記載の誘導加熱装置。
なお、前記dj1の式において、±部分は、d1>d2のときは、マイナスであり、d1<d2のときは、プラスである。一方、前記dj2の式において、±部分は、d1>d2のときは、プラスであり、d1<d2のときは、マイナスである。 A jacket chamber in which a gas-liquid two-phase heat medium is enclosed is formed on the side peripheral wall of the heated body,
The cross-sectional area between the heated surface and the temperature calculation surface is S [m 2 ], and the total cross-sectional area of the jacket chamber between the heated surface and the temperature calculation surface is S j [m 2 ], When the distance between the surface to be heated and the temperature calculation surface is t [m], and the variable indicating the rate of function deterioration of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop is α,
The heated body temperature calculation unit sets the diameter d 1 of the heated surface as d j1 = d 1 ± t {1−α (1−S j / S)}, and sets the diameter d 2 of the temperature calculated surface to The induction heating apparatus according to claim 5, wherein the temperature of the object to be heated is corrected using a temperature difference θ obtained as d j2 = d 2 ± t {1−α (1−S j / S)}.
In the formula of d j1 , the ± part is negative when d 1 > d 2 , and is positive when d 1 <d 2 . On the other hand, in the formula of d j2 , the ± part is positive when d 1 > d 2 , and is negative when d 1 <d 2 .
前記磁束発生機構が、前記被加熱体を片面側から誘導加熱するものであり、
前記被加熱体温度算出部が、前記被加熱体の被加熱面の温度を算出するとともに、
前記巻き線に対向する前記被加熱体の被加熱面と温度を算出する面である温度算出面との温度差をθ[℃]としたときに、前記被加熱体温度算出部が、前記被加熱体の被加熱面の温度を以下の式を用いて得られる温度差θを用いて補正して、前記温度算出面の温度を算出する請求項1乃至4の何れかに記載の誘導加熱装置。
θ=kQ/(λS/t)
ここで、tは前記被加熱面及び前記温度算出面の間の距離[m]であり、Sは前記被加熱面及び前記温度算出面の間の断面積[m2]であり、λは前記被加熱面及び前記温度算出面の間の平均温度[℃]における前記被加熱体の熱伝導率[W/m・℃]であり、Qは前記被加熱面の発熱量[W]であり、kは、実測値から算出した補正係数である。 The heated object has a flat plate shape,
The magnetic flux generation mechanism is to induction-heat the object to be heated from one side,
The heated body temperature calculating unit calculates the temperature of the heated surface of the heated body,
When the temperature difference between the heated surface of the heated object facing the winding and the temperature calculating surface, which is a surface for calculating the temperature, is θ [° C.], the heated object temperature calculating unit includes the heated object temperature calculating unit. The induction heating apparatus according to claim 1, wherein the temperature of the heated surface of the heating body is corrected using a temperature difference θ obtained by using the following equation to calculate the temperature of the temperature calculation surface. .
θ = kQ / (λS / t)
Here, t is a distance [m] between the heated surface and the temperature calculating surface, S is a cross-sectional area [m 2 ] between the heated surface and the temperature calculating surface, and λ is the above-mentioned It is the thermal conductivity [W / m · ° C.] of the heated body at the average temperature [° C.] between the heated surface and the temperature calculation surface, and Q is the calorific value [W] of the heated surface, k is a correction coefficient calculated from an actual measurement value.
前記磁束発生機構が、前記被加熱体を外周側又は内周側から誘導加熱するものであり、
前記被加熱体温度算出部が、前記被加熱体の被加熱面の温度を算出するとともに、
前記巻き線に対向する前記被加熱体の被加熱面と温度を算出する面である温度算出面との温度差をθ[℃]とし、前記被加熱体の各辺における前記被加熱面及び前記温度算出面の間の距離をt[m]としたときに、前記被加熱体温度算出部が、前記被加熱体の被加熱面の温度を以下の式を用いて得られる温度差θを用いて補正して、前記温度算出面の温度を算出する請求項1乃至4の何れかに記載の誘導加熱装置。
θ=kQ/λ[{(a1+a2+・・・+an)h/t}+mn×n×h]
ここで、nは1から始まる自然数であり、λは前記被加熱面及び前記温度算出面の間の平均温度[℃]における前記被加熱体の熱伝導率[W/m・℃]であり、Qは前記被加熱面の発熱量[W]であり、kは、実測値から算出した補正係数であり、mnはnにおける定数である。 The heated body has a hollow n-square tube shape with a height of h [m] and n side lengths of a 1 , a 2 ,... A n [m], respectively.
The magnetic flux generation mechanism is to induction heat the object to be heated from the outer peripheral side or the inner peripheral side,
The heated body temperature calculating unit calculates the temperature of the heated surface of the heated body,
The temperature difference between the heated surface of the heated object facing the winding and the temperature calculating surface that is a surface for calculating the temperature is θ [° C.], and the heated surface on each side of the heated object and the temperature When the distance between the temperature calculation surfaces is t [m], the heated body temperature calculation unit uses the temperature difference θ obtained by using the following equation for the temperature of the heated surface of the heated body. The induction heating apparatus according to any one of claims 1 to 4, wherein the temperature of the temperature calculation surface is calculated by correction.
θ = kQ / λ [{(a 1 + a 2 +... + a n ) h / t} + m n × n × h]
Here, n is a natural number starting from 1, and λ is the thermal conductivity [W / m · ° C.] of the heated object at an average temperature [° C.] between the heated surface and the temperature calculating surface, Q is the calorific value [W] of the surface to be heated, k is a correction coefficient calculated from actual measurement values, and mn is a constant at n.
前記被加熱面及び前記温度算出面の間の断面積をS[m2]とし、前記被加熱面及び前記温度算出面の間のジャケット室の断面積の総和をSj[m2]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、
前記被加熱体温度算出部が、前記被加熱面及び前記温度算出面の間の距離tを、tj=αt(S−Sj)/Sとして得られる温度差θを用いて、前記被加熱体の被加熱面の温度を補正する請求項7又は8記載の誘導加熱装置。 A jacket chamber in which a gas-liquid two-phase heat medium is enclosed in the thickness of the heated object is formed,
The cross-sectional area between the heated surface and the temperature calculation surface is S [m 2 ], and the total cross-sectional area of the jacket chamber between the heated surface and the temperature calculation surface is S j [m 2 ], When the variable indicating the ratio of the function deterioration of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop is α,
The heated body temperature calculation unit uses the temperature difference θ obtained by setting the distance t between the heated surface and the temperature calculating surface as t j = αt (S−S j ) / S, and The induction heating apparatus according to claim 7 or 8, wherein the temperature of the heated surface of the body is corrected.
前記磁束発生機構が、前記被加熱体を外周側又は内周側から誘導加熱するものであり、
前記被加熱体温度算出部が、前記被加熱体の被加熱面の温度を算出するとともに、
前記被加熱体の各側壁部それぞれの前記巻き線に対向する前記被加熱体の被加熱面と温度を算出する面である温度算出面との温度差をθn[℃]とし、前記被加熱体の各側壁部それぞれの前記被加熱面及び前記温度算出面の間の距離をt1、t2、・・・tn[m]としたときに、前記被加熱体温度算出部が、前記被加熱体の被加熱面の温度を以下の式を用いて得られる温度差θnを用いて補正して、前記温度算出面の温度を算出する請求項1乃至4の何れかに記載の誘導加熱装置。
θn=knQn/(λnSn/tn)
ここで、tnはn番目の側壁部における前記被加熱面及び前記温度算出面の間の距離[m]であり、Snはn番目の側壁部における前記被加熱面及び前記温度算出面の間の断面積[m2]であり、λnはn番目の側壁部における前記被加熱面及び前記温度算出面の間の平均温度[℃]における前記被加熱体の熱伝導率[W/m・℃]であり、Qnはn番目の側壁部における前記被加熱面の発熱量[W]であり、knは、実測値から算出した補正係数である。 The heated body has a hollow n-square tube shape with a height of h [m] and n side lengths of a 1 , a 2 ,... A n [m], respectively.
The magnetic flux generation mechanism is to induction heat the object to be heated from the outer peripheral side or the inner peripheral side,
The heated body temperature calculating unit calculates the temperature of the heated surface of the heated body,
A temperature difference between the heated surface of the heated body facing the winding of each side wall portion of the heated body and a temperature calculation surface which is a surface for calculating the temperature is θ n [° C.], and the heated When the distance between the heated surface and the temperature calculation surface of each side wall portion of the body is t 1 , t 2 ,... T n [m], the heated body temperature calculation unit The induction according to any one of claims 1 to 4, wherein the temperature of the heated surface of the heated body is corrected using a temperature difference θ n obtained using the following equation to calculate the temperature of the temperature calculating surface. Heating device.
θ n = k n Q n / (λ n S n / t n)
Here, t n is the distance between the heated surface and the temperature calculated surface at the n-th sidewall part [m], S n is the heated surface and the temperature calculated surface at the n-th sidewall part the cross-sectional area [m 2] between, lambda n is n th said at side wall portions of the heated surface and thermal conductivity of the object to be heated at an average temperature [℃] between the temperature calculated surface [W / m a · ° C.], Q n is the heat value of the heated surface of the n-th sidewall part [W], k n is a correction coefficient calculated from the measured value.
n番目の側壁部における前記被加熱面及び前記温度算出面の間の断面積をSn[m2]とし、n番目の側壁部における前記被加熱面及び前記温度算出面の間のジャケット室の断面積の総和をSnj[m2]とし、温度低下に伴う熱媒体の圧力低下によるジャケット室の機能低下の割合を示す変数をαとしたときに、
前記被加熱体温度算出部が、n番目の側壁部における前記被加熱面及び前記温度算出面の間の距離tnを、tnj=αtn(Sn−Snj)/Snとして得られる温度差θnを用いて、前記被加熱体の被加熱面の温度を補正する請求項10記載の誘導加熱装置。 A jacket chamber in which a gas-liquid two-phase heat medium is enclosed in the thickness of the heated object is formed,
Let S n [m 2 ] be the cross-sectional area between the heated surface and the temperature calculation surface in the nth side wall portion, and the jacket chamber between the heated surface and the temperature calculation surface in the nth side wall portion. When the sum of the cross-sectional areas is S nj [m 2 ] and the variable indicating the rate of function deterioration of the jacket chamber due to the pressure drop of the heat medium accompanying the temperature drop is α,
The heated object temperature calculation unit obtains the distance t n between the heated surface and the temperature calculation surface in the nth side wall part as t nj = αt n (S n −S nj ) / S n. The induction heating device according to claim 10, wherein the temperature of the heated surface of the heated body is corrected using the temperature difference θ n .
前記被加熱体のインピーダンスを算出するインピーダンス算出部と、
前記インピーダンス算出部により得られたインピーダンスを、前記制御素子の通電角により補正するインピーダンス補正部を更に備え、
前記被加熱体温度算出部が、前記インピーダンス補正部により補正された補正インピーダンスを用いて前記被加熱体の温度を算出する請求項1乃至11の何れかに記載の誘導加熱装置。 The control element controls a conduction angle of an alternating current or an alternating voltage with a semiconductor,
An impedance calculation unit for calculating the impedance of the object to be heated;
An impedance correction unit that corrects the impedance obtained by the impedance calculation unit based on a conduction angle of the control element;
The induction heating apparatus according to any one of claims 1 to 11, wherein the heated object temperature calculating unit calculates the temperature of the heated object using the corrected impedance corrected by the impedance correcting unit.
ΔT=k×w×c×t2/(2λ)
ここで、wは前記被加熱体の材質の比重[kg/m3]であり、cは前記被加熱体の材質の比熱[kcal/kg・℃]であり、tは前記被加熱面及び前記温度算出面の間の距離[m]であり、λは前記被加熱体の材質の熱伝導率[kcal/m・h・℃]であり、kは実測値から求めた補正係数である。 The heated object temperature calculating unit calculates the temperature of the heated surface, calculates the calculated value of the temperature calculating surface in a steady state from the temperature of the heated surface, and obtains ΔT obtained using the following equation: The induction heating device according to any one of claims 5 to 11 , wherein the temperature of the temperature calculation surface in a transition period is calculated based on the fact that the temperature calculation surface reaches the calculated value after [h] time.
ΔT = k × w × c × t 2 / (2λ)
Here, w is the specific gravity [kg / m 3 ] of the material of the heated object, c is the specific heat [kcal / kg · ° C.] of the material of the heated object, and t is the heated surface and the It is the distance [m] between the temperature calculation surfaces, λ is the thermal conductivity [kcal / m · h · ° C.] of the material of the object to be heated, and k is a correction coefficient obtained from the measured value.
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