JP2017142130A - Nitrogen concentration measurement system and method for measuring nitrogen concentration - Google Patents

Nitrogen concentration measurement system and method for measuring nitrogen concentration Download PDF

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JP2017142130A
JP2017142130A JP2016022964A JP2016022964A JP2017142130A JP 2017142130 A JP2017142130 A JP 2017142130A JP 2016022964 A JP2016022964 A JP 2016022964A JP 2016022964 A JP2016022964 A JP 2016022964A JP 2017142130 A JP2017142130 A JP 2017142130A
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nitrogen concentration
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裕行 武藤
Hiroyuki Muto
裕行 武藤
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Azbil Corp
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Abstract

PROBLEM TO BE SOLVED: To provide a nitrogen concentration measurement system with which it is possible to easily measure the concentration of nitrogen included in a gas.SOLUTION: Provided is a nitrogen concentration measurement system comprising: a measurement unit 301 for measuring the measured value of an electric signal from a heat generating element that is in contact with a mixed gas to be measured, at each of a plurality of heat generation temperatures; a normalization unit 306 for normalizing the measured values of electric signals so that the values of electric signals from a heat generating element that is in contact with a reference gas not including nitrogen and in contact with a calibration gas are constant irrespective of heat generation temperatures; an expression storage unit 402 for preserving a nitrogen concentration calculation expression where normalized electric signals from heat generating elements at three heat generation temperatures at the least are an independent variable and a nitrogen concentration is a dependent variable; and a nitrogen concentration calculation unit 307 for assigning the measured values of normalized electric signals to the independent variables of the nitrogen concentration calculation expression, and calculating the concentration of nitrogen included in the mixed gas to be measured.SELECTED DRAWING: Figure 23

Description

本発明はガス検査技術に係り、窒素濃度測定システム及び窒素濃度の測定方法に関する。   The present invention relates to a gas inspection technique, and relates to a nitrogen concentration measurement system and a nitrogen concentration measurement method.

従来、混合ガスの発熱量を求める際には、高価なガスクロマトグラフィ装置等を用いて混合ガスの成分を分析する必要がある。また、混合ガスの熱伝導率及び混合ガスにおける音速を測定することにより、混合ガスに含まれるメタン(CH4)、プロパン(C38)、窒素(N2)、及び炭酸ガス(CO2)の成分比率を算出し、混合ガスの発熱量を求める方法も提案されている(例えば、特許文献1参照。)。 Conventionally, when determining the calorific value of a mixed gas, it is necessary to analyze the components of the mixed gas using an expensive gas chromatography apparatus or the like. Further, by measuring the thermal conductivity of the mixed gas and the speed of sound in the mixed gas, methane (CH 4 ), propane (C 3 H 8 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ) contained in the mixed gas. ) Has been proposed (see, for example, Patent Document 1).

しかし、特許文献1に開示された方法は、熱伝導率を測定するためのセンサの他に、音速を測定するための高価な音速センサが必要である。そこで、音速センサを用いずに、複数の発熱温度で発熱する発熱素子を用いて、混合ガスの発熱量を求める方法も提案されている(例えば、特許文献2、3、4、5参照。)。   However, the method disclosed in Patent Document 1 requires an expensive sound speed sensor for measuring sound speed in addition to the sensor for measuring thermal conductivity. In view of this, there has also been proposed a method for obtaining a heat generation amount of a mixed gas using a heat generating element that generates heat at a plurality of heat generation temperatures without using a sonic sensor (see, for example, Patent Documents 2, 3, 4, and 5). .

特表2004−514138号公報JP-T-2004-514138 特許第5075986号公報Japanese Patent No. 5075986 特許第5781968号公報Japanese Patent No. 5781968 特開2013−205109号公報JP2013-205109A 特許第5759780号公報Japanese Patent No. 5759780

混合ガスに窒素ガスが含まれている場合、窒素ガスは不燃成分であり、発熱量がゼロである。したがって、混合ガスの発熱量を正確に知るために、窒素ガスの濃度が測定できることが好ましい。そこで、本発明は、ガスに含まれる窒素の濃度を容易に測定可能な窒素濃度測定システム及び窒素濃度の測定方法を提供することを目的の一つとする。   When nitrogen gas is contained in the mixed gas, the nitrogen gas is an incombustible component and the calorific value is zero. Therefore, it is preferable that the concentration of nitrogen gas can be measured in order to accurately know the calorific value of the mixed gas. Accordingly, an object of the present invention is to provide a nitrogen concentration measurement system and a nitrogen concentration measurement method that can easily measure the concentration of nitrogen contained in a gas.

本発明の態様によれば、(a)複数の発熱温度のそれぞれにおいて測定対象混合ガスに接する発熱素子からの電気信号の測定値を測定する測定部と、(b)炭化水素を校正成分とする窒素を含まない基準ガス及び校正ガスに接する発熱素子からの電気信号の値が発熱温度に関わらずそれぞれ一定となるよう、電気信号の測定値を正規化する正規化部と、(c)少なくとも3つの発熱温度における発熱素子からの正規化された電気信号を独立変数とし、窒素濃度を従属変数とする窒素濃度算出式を保存する式記憶装置と、(d)窒素濃度算出式の独立変数に、正規化された電気信号の測定値を代入し、測定対象混合ガスに含まれる窒素の濃度を算出する窒素濃度算出部と、を備える、窒素濃度測定システムが提供される。   According to the aspect of the present invention, (a) a measurement unit that measures a measured value of an electric signal from a heating element that is in contact with a measurement target mixed gas at each of a plurality of exothermic temperatures, and (b) a hydrocarbon as a calibration component. A normalization unit that normalizes the measurement value of the electrical signal so that the value of the electrical signal from the heating element in contact with the reference gas not containing nitrogen and the calibration gas is constant regardless of the heating temperature; and (c) at least 3 A formula storage device for storing a nitrogen concentration calculation formula having normalized electric signals from the heating elements at two exothermic temperatures as independent variables and a nitrogen concentration as a dependent variable, and (d) an independent variable of the nitrogen concentration calculation formula, There is provided a nitrogen concentration measurement system comprising: a nitrogen concentration calculation unit that substitutes a measured value of a normalized electric signal and calculates a concentration of nitrogen contained in a measurement target mixed gas.

上記の窒素濃度測定システムにおいて、窒素濃度算出部が、発熱温度の第1の差における正規化された電気信号の測定値の第1の差に、補正係数を掛けた補正された第1の差と、発熱温度の第2の差における正規化された電気信号の測定値の第2の差と、の差である評価値に基づいて、測定対象混合ガスに含まれる窒素の濃度を算出し、上記補正係数が、窒素を含まないガスが発熱素子に接している場合に、評価値が0に近づくよう設定されていてもよい。   In the above nitrogen concentration measurement system, the nitrogen concentration calculation unit corrects the first difference of the measured value of the normalized electrical signal in the first difference of the exothermic temperature by the correction coefficient and the corrected first difference. And the concentration of nitrogen contained in the measurement target mixed gas based on the evaluation value that is the difference between the second difference in the measured value of the normalized electrical signal in the second difference in the exothermic temperature, The correction coefficient may be set so that the evaluation value approaches 0 when a gas not containing nitrogen is in contact with the heating element.

上記の窒素濃度測定システムにおいて、窒素濃度算出部が、評価値に第2の補正係数を掛けて窒素の濃度を算出し、第2の補正係数が、無次元数である前記評価値を濃度単位に換算するよう設定されていてもよい。   In the nitrogen concentration measurement system, the nitrogen concentration calculation unit multiplies the evaluation value by a second correction coefficient to calculate a nitrogen concentration, and the second correction coefficient is a dimensionless number. It may be set to convert to.

上記の窒素濃度測定システムにおいて、基準ガスがメタンガスであってもよい。また、正規化部が、基準ガスに接する発熱素子からの電気信号の値が発熱温度に関わらず0となるよう、電気信号の測定値を正規化してもよい。   In the above nitrogen concentration measurement system, the reference gas may be methane gas. Further, the normalization unit may normalize the measured value of the electric signal so that the value of the electric signal from the heating element in contact with the reference gas becomes 0 regardless of the heat generation temperature.

上記の窒素濃度測定システムにおいて、校正ガスが混合ガスであってもよい。校正ガスがスパンガスであってもよい。正規化部が、校正ガスに接する発熱素子からの電気信号の値が発熱温度に関わらず1となるよう、電気信号の測定値を正規化してもよい。   In the above nitrogen concentration measurement system, the calibration gas may be a mixed gas. The calibration gas may be a span gas. The normalization unit may normalize the measured value of the electrical signal so that the value of the electrical signal from the heating element in contact with the calibration gas becomes 1 regardless of the heating temperature.

上記の窒素濃度測定システムにおいて、式記憶装置が、複数の発熱温度における発熱素子からの電気信号を独立変数とし、発熱量を従属変数とする発熱量算出式をさらに保存し、上記の窒素濃度測定システムが、発熱量算出式の独立変数に、発熱素子からの電気信号の測定値を代入し、測定対象混合ガスの発熱量の値を算出する発熱量算出部をさらに備えていてもよい。   In the above nitrogen concentration measurement system, the formula storage device further stores a calorific value calculation formula having the electrical signals from the heating elements at a plurality of exothermic temperatures as independent variables and the calorific value as a dependent variable, and measuring the above nitrogen concentration The system may further include a calorific value calculation unit that calculates the value of the calorific value of the measurement target mixed gas by substituting the measured value of the electrical signal from the heat generating element into the independent variable of the calorific value calculation formula.

上記の窒素濃度測定システムにおいて、複数の発熱温度の数が、少なくとも、測定対象混合ガスに含まれる複数種類のガス成分の数から1を引いた数であってもよい。   In the above nitrogen concentration measurement system, the number of the plurality of exothermic temperatures may be at least one obtained by subtracting 1 from the number of the plurality of types of gas components contained in the measurement target mixed gas.

また、本発明の態様によれば、(a)複数の発熱温度のそれぞれにおいて測定対象混合ガスに接する発熱素子からの電気信号の測定値を測定することと、(b)炭化水素を校正成分とする窒素を含まない基準ガス及び校正ガスに接する発熱素子からの電気信号の値が発熱温度に関わらずそれぞれ一定となるよう、電気信号の測定値を正規化することと、(c)少なくとも3つの発熱温度における発熱素子からの正規化された電気信号を独立変数とし、窒素濃度を従属変数とする窒素濃度算出式を用意することと、(d)窒素濃度算出式の独立変数に、正規化された電気信号の測定値を代入し、測定対象混合ガスに含まれる窒素の濃度を算出することと、を備える、窒素濃度の測定方法が提供される。   Further, according to the aspect of the present invention, (a) measuring a measured value of an electric signal from a heating element in contact with the measurement target mixed gas at each of a plurality of exothermic temperatures, and (b) using hydrocarbon as a calibration component Normalizing the measured value of the electric signal so that the value of the electric signal from the heating element in contact with the reference gas not containing nitrogen and the calibration gas is constant regardless of the heating temperature, and (c) at least three Prepared a nitrogen concentration calculation formula using the normalized electric signal from the heating element at the heat generation temperature as an independent variable and the nitrogen concentration as a dependent variable; and (d) normalized to an independent variable of the nitrogen concentration calculation formula. And a method of measuring the nitrogen concentration, comprising substituting the measured value of the electrical signal and calculating the concentration of nitrogen contained in the measurement target mixed gas.

上記の窒素濃度の測定方法の窒素の濃度を算出することにおいて、発熱温度の第1の差における電気信号の正規化測定値の第1の差に、補正係数を掛けた補正された第1の差と、発熱温度の第2の差における電気信号の正規化測定値の第2の差と、の差である評価値に基づいて、測定対象混合ガスに含まれる窒素の濃度を算出し、補正係数が、窒素を含まないガスが発熱素子に接している場合に、評価値が0に近づくよう設定されていてもよい。   In calculating the nitrogen concentration in the above nitrogen concentration measurement method, the corrected first value obtained by multiplying the first difference in the normalized measurement value of the electrical signal in the first difference in the exothermic temperature by the correction coefficient is used. Based on the evaluation value that is the difference between the difference and the second difference in the normalized measurement value of the electrical signal in the second difference in the heat generation temperature, the concentration of nitrogen contained in the measurement target mixed gas is calculated and corrected The coefficient may be set so that the evaluation value approaches 0 when a gas not containing nitrogen is in contact with the heating element.

上記の窒素濃度の測定方法の窒素の濃度を算出することにおいて、評価値に第2の補正係数を掛けて窒素の濃度を算出し、第2の補正係数が、無次元数である前記評価値を濃度単位に換算するよう設定されていてもよい。   In calculating the nitrogen concentration of the nitrogen concentration measurement method, the evaluation value is multiplied by a second correction coefficient to calculate the nitrogen concentration, and the evaluation value is a dimensionless number. May be set to be converted into a density unit.

上記の窒素濃度の測定方法において、基準ガスがメタンガスであってもよい。また、基準ガスに接する発熱素子からの電気信号の値が発熱温度に関わらず0となるよう、電気信号の測定値を正規化してもよい。   In the above method for measuring the nitrogen concentration, the reference gas may be methane gas. Further, the measured value of the electric signal may be normalized so that the value of the electric signal from the heating element in contact with the reference gas becomes 0 regardless of the heat generation temperature.

上記の窒素濃度の測定方法において、校正ガスが混合ガスであってもよい。校正ガスがスパンガスであってもよい。また、校正ガスに接する発熱素子からの電気信号の値が発熱温度に関わらず1となるよう、電気信号の測定値を正規化してもよい。   In the above nitrogen concentration measurement method, the calibration gas may be a mixed gas. The calibration gas may be a span gas. Further, the measurement value of the electric signal may be normalized so that the value of the electric signal from the heating element in contact with the calibration gas becomes 1 regardless of the heating temperature.

上記の窒素濃度の測定方法が、複数の発熱温度における発熱素子からの電気信号を独立変数とし、発熱量を従属変数とする発熱量算出式を用意することと、発熱量算出式の独立変数に、発熱素子からの電気信号の測定値を代入し、測定対象混合ガスの発熱量の値を算出することと、をさらに備えていてもよい。   The above-mentioned nitrogen concentration measurement method prepares a calorific value calculation formula using an electrical signal from a heating element at a plurality of exothermic temperatures as an independent variable and the calorific value as a dependent variable, and as an independent variable of the calorific value calculation formula. The method further includes substituting the measured value of the electrical signal from the heating element to calculate the value of the calorific value of the measurement target mixed gas.

上記の窒素濃度の測定方法において、複数の発熱温度の数が、少なくとも、測定対象混合ガスに含まれる複数種類のガス成分の数から1を引いた数であってもよい。   In the above nitrogen concentration measurement method, the number of the plurality of exothermic temperatures may be a number obtained by subtracting 1 from the number of the plurality of types of gas components contained in the measurement target mixed gas.

本発明によれば、ガスに含まれる窒素の濃度を容易に測定可能な窒素濃度測定システム及び窒素濃度の測定方法を提供可能である。   According to the present invention, it is possible to provide a nitrogen concentration measuring system and a nitrogen concentration measuring method capable of easily measuring the concentration of nitrogen contained in a gas.

本発明の実施の形態に係る第1のマイクロチップの斜視図である。It is a perspective view of the 1st microchip concerning an embodiment of the invention. 本発明の実施の形態に係る第1のマイクロチップの図1のII−II方向から見た断面図である。It is sectional drawing seen from the II-II direction of FIG. 1 of the 1st microchip which concerns on embodiment of this invention. 本発明の実施の形態に係る第2のマイクロチップの斜視図である。It is a perspective view of the 2nd microchip concerning an embodiment of the invention. 本発明の実施の形態に係る第2のマイクロチップの図3のIV−IV方向から見た断面図である。It is sectional drawing seen from the IV-IV direction of FIG. 3 of the 2nd microchip which concerns on embodiment of this invention. 本発明の実施の形態に係る熱伝導率と、放熱係数と、の関係を示すグラフである。It is a graph which shows the relationship between the thermal conductivity which concerns on embodiment of this invention, and a thermal radiation coefficient. 本発明の実施の形態に係る発熱素子の温度と、ガスの放熱係数の関係を示すグラフである。It is a graph which shows the relationship between the temperature of the heat generating element which concerns on embodiment of this invention, and the thermal radiation coefficient of gas. 本発明の実施の形態に係る熱伝導率と、発熱素子の抵抗と、の関係を示す第1のグラフである。It is a 1st graph which shows the relationship between the thermal conductivity which concerns on embodiment of this invention, and resistance of a heat generating element. 本発明の実施の形態に係る熱伝導率と、発熱素子の抵抗と、の関係を示す第2のグラフである。It is a 2nd graph which shows the relationship between the thermal conductivity which concerns on embodiment of this invention, and resistance of a heat generating element. 本発明の実施の形態に係る熱伝導率と、発熱素子の抵抗と、の関係を示す第3のグラフである。It is a 3rd graph which shows the relationship between the heat conductivity which concerns on embodiment of this invention, and resistance of a heat generating element. 本発明の実施の形態に係る熱伝導率と、発熱素子の抵抗と、の関係を示す第4のグラフである。It is a 4th graph which shows the relationship between the heat conductivity which concerns on embodiment of this invention, and resistance of a heat generating element. 本発明の実施の形態に係る熱伝導率と、発熱素子の駆動電力と、の関係を示す第1のグラフである。It is a 1st graph which shows the relationship between the thermal conductivity which concerns on embodiment of this invention, and the drive power of a heat generating element. 本発明の実施の形態に係る熱伝導率と、発熱素子の駆動電力と、の関係を示す第2のグラフである。It is a 2nd graph which shows the relationship between the thermal conductivity which concerns on embodiment of this invention, and the drive power of a heat generating element. 本発明の実施の形態に係る発熱素子の発熱温度と、ガスの熱伝導率と、の関係を示すグラフである。It is a graph which shows the relationship between the heat generation temperature of the heat generating element which concerns on embodiment of this invention, and the thermal conductivity of gas. 本発明の実施の形態に係る発熱素子の発熱温度と、ガスの正規化された熱伝導率と、の関係を示すグラフである。It is a graph which shows the relationship between the heat generation temperature of the heat generating element which concerns on embodiment of this invention, and the normalized thermal conductivity of gas. 本発明の実施の形態に係る発熱素子の発熱温度と、窒素濃度が0%のガスの正規化された熱伝導率と、の関係を示すグラフである。It is a graph which shows the relationship between the heat_generation | fever temperature of the heat generating element which concerns on embodiment of this invention, and the normalized thermal conductivity of the gas whose nitrogen concentration is 0%. 本発明の実施の形態に係る発熱素子の発熱温度と、窒素濃度が3%又は4%のガスの正規化された熱伝導率と、の関係を示すグラフである。It is a graph which shows the relationship between the heat_generation | fever temperature of the heat generating element which concerns on embodiment of this invention, and the normalized thermal conductivity of gas whose nitrogen concentration is 3% or 4%. 本発明の実施の形態に係る発熱素子の発熱温度と、窒素濃度が5%又は6%のガスの正規化された熱伝導率と、の関係を示すグラフである。It is a graph which shows the relationship between the heat_generation | fever temperature of the heat generating element which concerns on embodiment of this invention, and the normalized thermal conductivity of the gas whose nitrogen concentration is 5% or 6%. 本発明の実施の形態に係る発熱温度の第1の差における正規化された電気信号の測定値の第1の差を示すグラフである。It is a graph which shows the 1st difference of the measured value of the normalized electrical signal in the 1st difference of the exothermic temperature which concerns on embodiment of this invention. 本発明の実施の形態に係る発熱温度の第2の差における正規化された電気信号の測定値の第2の差を示すグラフである。It is a graph which shows the 2nd difference of the measured value of the normalized electrical signal in the 2nd difference of the exothermic temperature which concerns on embodiment of this invention. 本発明の実施の形態に係る評価値を示すグラフである。It is a graph which shows the evaluation value which concerns on embodiment of this invention. 本発明の実施の形態に係る補正された評価値と、実際の窒素濃度と、の関係を示すグラフである。It is a graph which shows the relationship between the corrected evaluation value which concerns on embodiment of this invention, and actual nitrogen concentration. 本発明の実施の形態に係る窒素濃度の測定値の誤差を示すグラフである。It is a graph which shows the error of the measured value of nitrogen concentration concerning an embodiment of the invention. 本発明の実施の形態に係る窒素濃度測定システムの模式図である。It is a mimetic diagram of a nitrogen concentration measuring system concerning an embodiment of the invention. 本発明の実施の形態に係る発熱量算出式の作成方法を示すフローチャートである。It is a flowchart which shows the preparation method of the emitted-heat amount calculation formula which concerns on embodiment of this invention. 本発明の実施の形態に係る窒素濃度算出式の作成方法を示すフローチャートである。It is a flowchart which shows the preparation method of the nitrogen concentration calculation formula which concerns on embodiment of this invention.

以下に本発明の実施の形態を説明する。以下の図面の記載において、同一又は類似の部分には同一又は類似の符号で表している。但し、図面は模式的なものである。したがって、具体的な寸法等は以下の説明を照らし合わせて判断するべきものである。また、図面相互間においても互いの寸法の関係や比率が異なる部分が含まれていることは勿論である。   Embodiments of the present invention will be described below. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

まず、斜視図である図1、及びII−II方向から見た断面図である図2を参照して、実施の形態に係る窒素濃度測定システムに用いられるマイクロチップ8について説明する。マイクロチップ8は、キャビティ66が設けられた基板60、及び基板60上にキャビティ66を覆うように配置された絶縁膜65を備える。基板60の厚みは、例えば0.5mmである。また、基板60の縦横の寸法は、例えばそれぞれ1.5mm程度である。絶縁膜65のキャビティ66を覆う部分は、断熱性のダイアフラムをなしている。さらにマイクロチップ8は、絶縁膜65のダイアフラムの部分に設けられた発熱素子61と、発熱素子61を挟むように絶縁膜65のダイアフラムの部分に設けられた第1の測温素子62及び第2の測温素子63と、基板60上に設けられた保温素子64と、を備える。   First, the microchip 8 used in the nitrogen concentration measurement system according to the embodiment will be described with reference to FIG. 1 which is a perspective view and FIG. 2 which is a cross-sectional view seen from the II-II direction. The microchip 8 includes a substrate 60 provided with a cavity 66, and an insulating film 65 disposed on the substrate 60 so as to cover the cavity 66. The thickness of the substrate 60 is, for example, 0.5 mm. The vertical and horizontal dimensions of the substrate 60 are, for example, about 1.5 mm. A portion of the insulating film 65 covering the cavity 66 forms a heat insulating diaphragm. Furthermore, the microchip 8 includes a heating element 61 provided in the diaphragm portion of the insulating film 65, a first temperature measuring element 62 and a second temperature measuring element 62 provided in the diaphragm portion of the insulating film 65 so as to sandwich the heating element 61. The temperature measuring element 63 and a heat retaining element 64 provided on the substrate 60 are provided.

ダイアフラムには、複数の孔が設けられている。ダイアフラムに複数の孔を設けることにより、キャビティ66内のガスの置換が速くなる。あるいは、絶縁膜65は、図3、及びIV−IV方向から見た断面図である図4に示すように、キャビティ66をブリッジ状に覆うように、基板60上に配置されてもよい。これによっても、キャビティ66内が露出し、キャビティ66内のガスの置換が速くなる。   The diaphragm is provided with a plurality of holes. By providing a plurality of holes in the diaphragm, gas replacement in the cavity 66 is accelerated. Alternatively, the insulating film 65 may be disposed on the substrate 60 so as to cover the cavity 66 in a bridge shape as shown in FIG. 3 and FIG. 4 which is a cross-sectional view seen from the IV-IV direction. Also by this, the inside of the cavity 66 is exposed, and the replacement of the gas in the cavity 66 is accelerated.

図1及び図2に示す発熱素子61は、キャビティ66を覆う絶縁膜65のダイアフラムの部分の中心に配置されている。発熱素子61は、例えば抵抗器であり、電力を与えられて発熱し、発熱素子61に接する雰囲気ガスを加熱する。第1の測温素子62及び第2の測温素子63は、例えば抵抗器等の受動素子等の電子素子であり、雰囲気ガスのガス温度に依存した電気信号を出力する。以下においては、第1の測温素子62の出力信号を利用する例を説明するが、これに限定されず、例えば第1の測温素子62の出力信号及び第2の測温素子63の出力信号の平均値を、測温素子の出力信号として利用してもよい。   The heating element 61 shown in FIGS. 1 and 2 is arranged at the center of the diaphragm portion of the insulating film 65 covering the cavity 66. The heating element 61 is a resistor, for example, and generates heat when power is applied to heat the atmospheric gas in contact with the heating element 61. The first temperature measuring element 62 and the second temperature measuring element 63 are electronic elements such as passive elements such as resistors, for example, and output electric signals depending on the gas temperature of the atmospheric gas. In the following, an example in which the output signal of the first temperature measuring element 62 is used will be described. However, the present invention is not limited to this. For example, the output signal of the first temperature measuring element 62 and the output of the second temperature measuring element 63 are described. You may utilize the average value of a signal as an output signal of a temperature measuring element.

保温素子64は、例えば抵抗器であり、電力を与えられて発熱し、基板60の温度を一定に保つ。基板60の材料としては、シリコン(Si)等が使用可能である。絶縁膜65の材料としては、酸化ケイ素(SiO2)等が使用可能である。キャビティ66は、異方性エッチング等により形成される。また発熱素子61、第1の測温素子62、第2の測温素子63、及び保温素子64のそれぞれの材料には白金(Pt)等が使用可能であり、リソグラフィ法等により形成可能である。また、発熱素子61、第1の測温素子62、及び第2の測温素子63は、同一の部材からなっていてもよい。 The heat retaining element 64 is a resistor, for example, and generates heat when supplied with electric power, and keeps the temperature of the substrate 60 constant. As a material of the substrate 60, silicon (Si) or the like can be used. As a material of the insulating film 65, silicon oxide (SiO 2 ) or the like can be used. The cavity 66 is formed by anisotropic etching or the like. Further, platinum (Pt) or the like can be used as the material of the heating element 61, the first temperature measuring element 62, the second temperature measuring element 63, and the heat retaining element 64, and can be formed by a lithography method or the like. . Further, the heating element 61, the first temperature measuring element 62, and the second temperature measuring element 63 may be made of the same member.

マイクロチップ8は、マイクロチップ8の底面に配置された断熱部材18を介して、雰囲気ガスが充填されるチャンバ等の容器に固定される。断熱部材18を介してマイクロチップ8を容器に固定することにより、マイクロチップ8の温度が、容器の内壁の温度変動の影響を受けにくくなる。   The microchip 8 is fixed to a container such as a chamber filled with atmospheric gas via a heat insulating member 18 disposed on the bottom surface of the microchip 8. By fixing the microchip 8 to the container via the heat insulating member 18, the temperature of the microchip 8 becomes less susceptible to the temperature fluctuation of the inner wall of the container.

発熱素子61には、複数の電圧が段階的に印加される。発熱素子61に3段階の電圧が印加されると、発熱素子61は、印加電圧に応じて、3段階の温度で発熱する。あるいは、発熱素子61に5段階の電圧が印加されると、発熱素子61は、印加電圧に応じて、5段階の温度で発熱する。以下、第1の電圧VL1を印加された発熱素子61の温度をTH1、第2の電圧VL2を印加された発熱素子61の温度をTH2、第3の電圧VL3を印加された発熱素子61の温度をTH3、第4の電圧VL4を印加された発熱素子61の温度をTH4、第5の電圧VL5を印加された発熱素子61の温度をTH5とする。ただし、段階的に加えられる電圧の数は、これらに限定されない。 A plurality of voltages are applied to the heating element 61 in stages. When three levels of voltage are applied to the heating element 61, the heating element 61 generates heat at three levels of temperature according to the applied voltage. Alternatively, when a five-step voltage is applied to the heating element 61, the heating element 61 generates heat at a five-step temperature according to the applied voltage. Hereinafter, the temperature of the heating element 61 to which the first voltage V L1 is applied is T H1 , the temperature of the heating element 61 to which the second voltage V L2 is applied is T H2 , and the third voltage V L3 is applied. The temperature of the heating element 61 is T H3 , the temperature of the heating element 61 to which the fourth voltage V L4 is applied is T H4 , and the temperature of the heating element 61 to which the fifth voltage V L5 is applied is T H5 . However, the number of voltages applied stepwise is not limited to these.

第1の測温素子62には、第1の測温素子62が自己発熱しない程度の弱い電圧が加えられる。   A weak voltage is applied to the first temperature measuring element 62 so as not to cause the first temperature measuring element 62 to self-heat.

発熱素子61の抵抗値は、発熱素子61の温度によって変化する。発熱素子61の温度THと、発熱素子61の抵抗値RHと、の関係は、下記(1)式で与えられる。
RH = RH-STD×[1+αH (TH-TH-STD) + βH (TH-TH-STD)2] ・・・(1)
ここで、TH-STDは発熱素子61の標準温度を表し、例えば20℃である。RH-STDは標準温度TH-STDにおける予め測定された発熱素子61の抵抗値を表す。αHは1次の抵抗温度係数を表す。βHは2次の抵抗温度係数を表す。
The resistance value of the heating element 61 varies depending on the temperature of the heating element 61. The relationship between the temperature TH of the heating element 61 and the resistance value R H of the heating element 61 is given by the following equation (1).
R H = R H-STD × [1 + α H (T H -T H-STD ) + β H (T H -T H-STD ) 2 ] (1)
Here, T H-STD represents the standard temperature of the heating element 61, and is 20 ° C., for example. R H-STD represents the resistance value of the heating element 61 measured in advance at the standard temperature T H-STD . α H represents a first-order resistance temperature coefficient. β H represents a second-order resistance temperature coefficient.

発熱素子61の抵抗値RHは、発熱素子61の駆動電力PHと、発熱素子61の通電電流IHから、下記(2)式で与えられる。
RH = PH / IH 2 ・・・(2)
あるいは発熱素子61の抵抗値RHは、発熱素子61にかかる電圧VHと、発熱素子61の通電電流IHから、下記(3)式で与えられる。
RH = VH / IH ・・・(3)
The resistance value R H of the heating element 61 is given by the following equation (2) from the drive power P H of the heating element 61 and the energization current I H of the heating element 61.
R H = P H / I H 2 (2)
Alternatively, the resistance value R H of the heating element 61 is given by the following equation (3) from the voltage V H applied to the heating element 61 and the energization current I H of the heating element 61.
R H = V H / I H (3)

ここで、発熱素子61の温度THは、発熱素子61と雰囲気ガスの間が熱的に平衡になったときに安定する。なお、熱的に平衡な状態とは、発熱素子61の発熱と、発熱素子61から雰囲気ガスへの放熱と、が釣り合っている状態をいう。下記(4)式に示すように、平衡状態における発熱素子61の駆動電力PHを、発熱素子61の温度THと雰囲気ガスの温度TIとの差ΔTHで割ることにより、雰囲気ガスの放熱係数MIが得られる。なお、放熱係数MIの単位は、例えばW/℃である。
MI = PH / (TH - TI)
= PH /ΔTH = (VH 2 / RH) /ΔTH ・・・(4)
Here, the temperature TH of the heating element 61 is stabilized when the heating element 61 and the ambient gas are in thermal equilibrium. The thermally balanced state is a state where the heat generation of the heating element 61 and the heat dissipation from the heating element 61 to the atmospheric gas are balanced. (4) below, as shown in the expression, the driving power P H of the heater element 61 at equilibrium, by dividing the difference [Delta] T H between the temperature T I of the temperature T H and the ambient gas of the heater element 61, the atmospheric gas A heat dissipation coefficient M I is obtained. The unit of the heat dissipation coefficient M I is, for example, W / ° C.
M I = P H / (T H -T I )
= P H / ΔT H = (V H 2 / R H ) / ΔT H・ ・ ・ (4)

上記(1)式より、発熱素子61の温度THは下記(5)式で与えられる。
TH = (1 / 2βH)×[-αH+ [αH 2 - 4βH (1 - RH / RH-STD)]1/2] + TH-STD ・・・(5)
したがって、発熱素子61の温度THと雰囲気ガスの温度TIとの差ΔTHは、下記(6)式で与えられる。
ΔTH=(1 / 2βH)×[-αH+ [αH 2 - 4βH (1 - RH / RH-STD)]1/2] + TH-STD - TI ・・・(6)
From the above equation (1), the temperature T H of the heater element 61 is given by the following equation (5).
T H = (1 / 2β H ) × [-α H + [α H 2 - 4β H (1 - R H / R H-STD)] 1/2] + T H-STD ···(Five)
Therefore, the difference ΔT H between the temperature T H of the heating element 61 and the temperature T I of the atmospheric gas is given by the following equation (6).
ΔT H = (1 / 2β H ) × [-α H + [α H 2 - 4β H (1 - R H / R H-STD)] 1/2] + T H-STD - T I ··· ( 6)

雰囲気ガスの温度TIは、自己発熱しない程度の電力を与えられる第1の測温素子62の温度TIに近似する。第1の測温素子62の温度TIと、第1の測温素子62の抵抗値RIと、の関係は、下記(7)式で与えられる。
RI = RI-STD×[1+αI (TI-TI-STD) + βI (TI-TI-STD)2] ・・・(7)
I-STDは第1の測温素子62の標準温度を表し、例えば20℃である。RI-STDは標準温度TI-STDにおける予め測定された第1の測温素子62の抵抗値を表す。αIは1次の抵抗温度係数を表す。βIは2次の抵抗温度係数を表す。上記(7)式より、第1の測温素子62の温度TIは下記(8)式で与えられる。
TI = (1 / 2βI)×[-αI+ [αI 2 - 4βI (1 - RI / RI-STD)]1/2] + TI-STD ・・・(8)
The temperature T I of the atmospheric gas approximates the temperature T I of the first temperature measuring element 62 to which power that does not generate heat is given. The relationship between the temperature T I of the first temperature measuring element 62 and the resistance value R I of the first temperature measuring element 62 is given by the following equation (7).
R I = R I-STD × [1 + α I (T I -T I-STD ) + β I (T I -T I-STD ) 2 ] (7)
T I-STD represents the standard temperature of the first temperature measuring element 62 and is, for example, 20 ° C. R I-STD represents the resistance value of the first temperature measuring element 62 measured in advance at the standard temperature T I-STD . α I represents the first-order resistance temperature coefficient. β I represents a second-order resistance temperature coefficient. From the above equation (7), the temperature T I of the first temperature measuring element 62 is given by the following equation (8).
T I = (1 / 2β I ) × [-α I + [α I 2 - 4β I (1 - R I / R I-STD)] 1/2] + T I-STD ··· (8)

よって、雰囲気ガスの放熱係数MIは、下記(9)式で与えられる。
MI = PH /ΔTH
=PH/[(1/2βH)[-αH+[αH 2-4βH (1-RH/RH-STD)]1/2]+TH-STD-(1/2βI)[-αI+[αI 2-4βI (1-RI/RI-STD)]1/2]-TI-STD] ・・・(9)
Therefore, the radiation coefficient M I of the atmospheric gas is given by the following equation (9).
M I = P H / ΔT H
= P H / [(1 / 2β H ) [-α H + [α H 2 -4β H (1-R H / R H-STD )] 1/2 ] + T H- STD-(1 / 2β I ) [-α I + [α I 2 -4β I (1-R I / R I-STD )] 1/2 ] -T I-STD ] ... (9)

発熱素子61の通電電流IHと、駆動電力PH又は電圧VHは測定可能であるため、上記(2)式又は(3)式から発熱素子61の抵抗値RHを算出可能である。同様に、第1の測温素子62の抵抗値RIも算出可能である。よって、マイクロチップ8を用いて、上記(9)式から雰囲気ガスの放熱係数MIが算出可能である。 Since the energizing current I H and the driving power P H or voltage V H of the heating element 61 can be measured, the resistance value R H of the heating element 61 can be calculated from the above equation (2) or (3). Similarly, the resistance value R I of the first temperature measuring element 62 can also be calculated. Therefore, by using the microchip 8, the heat radiation coefficient M I of the atmospheric gas can be calculated from the above equation (9).

なお、保温素子64で基板60の温度を一定に保つことにより、発熱素子61が発熱する前のマイクロチップ8の近傍の雰囲気ガスの温度が、基板60の一定の温度と近似する。そのため、発熱素子61が発熱する前の雰囲気ガスの温度の変動が抑制される。温度変動が一度抑制された雰囲気ガスを発熱素子61でさらに加熱することにより、より高い精度で放熱係数MIを算出することが可能となる。 Note that, by keeping the temperature of the substrate 60 constant by the heat retaining element 64, the temperature of the ambient gas in the vicinity of the microchip 8 before the heat generating element 61 generates heat approximates the constant temperature of the substrate 60. For this reason, fluctuations in the temperature of the atmospheric gas before the heat generating element 61 generates heat are suppressed. By temperature variation further heated by the heating element 61 to the atmosphere gas is once suppressed, it is possible to calculate the radiation coefficient M I with high accuracy.

ここで、雰囲気ガスが混合ガスであり、混合ガスが、ガスA、ガスB、ガスC、及びガスDの4種類のガス成分からなっているとする。ガスAの体積率VA、ガスBの体積率VB、ガスCの体積率VC、及びガスDの体積率VDの総和は、下記(10)式で与えられるように、1である。
VA+VB+VC+VD=1 ・・・(10)
Here, it is assumed that the atmospheric gas is a mixed gas, and the mixed gas is composed of four types of gas components: gas A, gas B, gas C, and gas D. The sum of the volume ratio V A of gas A , the volume ratio V B of gas B , the volume ratio V C of gas C , and the volume ratio V D of gas D is 1, as given by the following equation (10). .
V A + V B + V C + V D = 1 (10)

また、ガスAの単位体積当たりの発熱量をKA、ガスBの単位体積当たりの発熱量をKB、ガスCの単位体積当たりの発熱量をKC、ガスDの単位体積当たりの発熱量をKDとすると、混合ガスの単位体積当たりの発熱量Qは、各ガス成分の体積率に、各ガス成分の単位体積当たりの発熱量を乗じたものの総和で与えられる。したがって、混合ガスの単位体積当たりの発熱量Qは、下記(11)式で与えられる。なお、単位体積当たりの発熱量の単位は、例えばMJ/m3である。
Q = KA×VA+ KB×VB+ KC×VC+KD×VD ・・・(11)
The calorific value per unit volume of gas A is K A , the calorific value per unit volume of gas B is K B , the calorific value per unit volume of gas C is K C , and the calorific value per unit volume of gas D is Is K D , the calorific value Q per unit volume of the mixed gas is given by the sum of the volume ratio of each gas component multiplied by the calorific value per unit volume of each gas component. Therefore, the calorific value Q per unit volume of the mixed gas is given by the following equation (11). The unit of the calorific value per unit volume is, for example, MJ / m 3 .
Q = K A × V A + K B × V B + K C × V C + K D × V D ... (11)

さらに、ガスAの単位体積当たりの熱伝導率をCA、ガスBの単位体積当たりの熱伝導率をCB、ガスCの単位体積当たりの熱伝導率をCC、ガスDの単位体積当たりの熱伝導率をCDとすると、混合ガスの単位体積当たりの熱伝導率CIは、各ガス成分の体積率に、各ガス成分の単位体積当たりの熱伝導率を乗じたものの総和で与えられる。したがって、混合ガスの単位体積当たりの熱伝導率CIは、下記(12)式で与えられる。なお、単位体積当たりの熱伝導率の単位は、例えばW/(mK)である。
CI = CA×VA+ CB×VB+ CC×VC+CD×VD ・・・(12)
Furthermore, the thermal conductivity per unit volume of gas A is C A , the thermal conductivity per unit volume of gas B is C B , the thermal conductivity per unit volume of gas C is C C , and the per unit volume of gas D is When the thermal conductivity and C D, thermal conductivity C I of the mixed gas per unit volume is the volume ratios of the gas components, given by the sum of the values obtained by multiplying the thermal conductivity per unit volume of the gas components It is done. Accordingly, the thermal conductivity C I per unit volume of the mixed gas is given by the following equation (12). The unit of thermal conductivity per unit volume is, for example, W / (mK).
C I = C A × V A + C B × V B + C C × V C + C D × V D ... (12)

図5は、発熱素子61に第1の電圧V1、第1の電圧V1より大きい第2の電圧V2、及び第2の電圧V2より大きい第3の電圧V3を加えた場合の、熱伝導率と、放熱係数と、の関係を示すグラフである。図5に示すように、熱伝導率と、放熱係数と、は、一般に、比例関係にある。したがって、ガスAの放熱係数をMA、ガスBの放熱係数をMB、ガスCの放熱係数をMC、ガスDの放熱係数をMDとすると、混合ガスの放熱係数MIは、各ガス成分の体積率に、各ガス成分の放熱係数を乗じたものの総和で与えられる。よって、混合ガスの放熱係数MIは、下記(13)式で与えられる。
MI = MA×VA+ MB×VB+ MC×VC+MD×VD ・・・(13)
5, the first voltages V 1 to the heating element 61, when the first voltage V 1 is greater than the second voltage V 2, and a second voltage V 2 is greater than the third voltage V 3 was added It is a graph which shows the relationship between thermal conductivity and a heat dissipation coefficient. As shown in FIG. 5, the thermal conductivity and the heat dissipation coefficient are generally in a proportional relationship. Therefore, the radiation coefficient M A gas A, the radiation coefficient of gas B M B, when the radiation coefficient of gas C M C, the radiation coefficient of the gas D and M D, the radiation coefficient M I of the mixed gas, the It is given as the sum of the volume fraction of the gas component multiplied by the heat dissipation coefficient of each gas component. Therefore, the heat dissipation coefficient M I of the mixed gas is given by the following equation (13).
M I = M A × V A + M B × V B + M C × V C + M D × V D ... (13)

さらに、ガスの放熱係数は発熱素子61の温度THに依存するので、混合ガスの放熱係数MIは、発熱素子61の温度THの関数として、下記(14)式で与えられる。
MI (TH)= MA(TH)×VA+ MB(TH)×VB+ MC(TH)×VC+MD(TH)×VD ・・・(14)
Further, since the radiation coefficient of gas depends on the temperature T H of the heater element 61, the radiation coefficient M I of the mixed gas, as a function of the temperature T H of the heater element 61 is given by the following equation (14).
M I (T H ) = M A (T H ) × V A + M B (T H ) × V B + M C (T H ) × V C + M D (T H ) × V D・ ・ ・ ( 14)

したがって、発熱素子61の温度がTH1のときの混合ガスの放熱係数MI1(TH1)は下記(15)式で与えられる。また、発熱素子61の温度がTH2のときの混合ガスの放熱係数MI2(TH2)は下記(16)式で与えられ、発熱素子61の温度がTH3のときの混合ガスの放熱係数MI3(TH3)は下記(17)式で与えられる。
MI1 (TH1)= MA(TH1)×VA+ MB(TH1)×VB+ MC(TH1)×VC+MD(TH1)×VD ・・・(15)
MI2 (TH2)= MA(TH2)×VA+ MB(TH2)×VB+ MC(TH2)×VC+MD(TH2)×VD ・・・(16)
MI3 (TH3)= MA(TH3)×VA+ MB(TH3)×VB+ MC(TH3)×VC+MD(TH3)×VD ・・・(17)
Therefore, the heat dissipation coefficient M I1 (T H1 ) of the mixed gas when the temperature of the heating element 61 is T H1 is given by the following equation (15). The heat dissipation coefficient M I2 (T H2 ) of the mixed gas when the temperature of the heating element 61 is T H2 is given by the following equation (16), and the heat dissipation coefficient of the mixed gas when the temperature of the heating element 61 is T H3 : M I3 (T H3 ) is given by the following equation (17).
M I1 (T H1 ) = M A (T H1 ) × V A + M B (T H1 ) × V B + M C (T H1 ) × V C + M D (T H1 ) × V D・ ・ ・ ( 15)
M I2 (T H2 ) = M A (T H2 ) × V A + M B (T H2 ) × V B + M C (T H2 ) × V C + M D (T H2 ) × V D・ ・ ・ ( 16)
M I3 (T H3 ) = M A (T H3 ) × V A + M B (T H3 ) × V B + M C (T H3 ) × V C + M D (T H3 ) × V D・ ・ ・ ( 17)

ここで、発熱素子61の温度THに対して各ガス成分の放熱係数MA(TH),MB(TH),MC(TH),MD(TH)が非線形性を有する場合、上記(15)から(17)式は、線形独立な関係を有する。また、発熱素子61の温度THに対して各ガス成分の放熱係数MA(TH),MB(TH),MC(TH),MD(TH)が線形性を有する場合でも、発熱素子61の温度THに対する各ガス成分の放熱係数MA(TH),MB(TH),MC(TH),MD(TH)の変化率が異なる場合は、上記(15)から(17)式は、線形独立な関係を有する。さらに、(15)から(17)式が線形独立な関係を有する場合、(10)及び(15)から(17)式は線形独立な関係を有する。 Here, the heat dissipation coefficients M A (T H ), M B (T H ), M C (T H ), and M D (T H ) of each gas component are non-linear with respect to the temperature T H of the heating element 61. If so, the above equations (15) to (17) have a linearly independent relationship. Further, the heat dissipation coefficients M A (T H ), M B (T H ), M C (T H ), and M D (T H ) of each gas component have linearity with respect to the temperature T H of the heating element 61. Even in the case where the rate of change of the heat radiation coefficient M A (T H ), M B (T H ), M C (T H ), M D (T H ) of each gas component with respect to the temperature T H of the heating element 61 is different. (15) to (17) have a linearly independent relationship. Further, when the equations (15) to (17) have a linearly independent relationship, the equations (10) and (15) to (17) have a linearly independent relationship.

図6は、天然ガスに含まれるメタン(CH4)、プロパン(C38)、窒素(N2)、及び二酸化炭素(CO2)の放熱係数と、発熱抵抗体である発熱素子61の温度との関係を示すグラフである。発熱素子61の温度に対して、メタン(CH4)、プロパン(C38)、窒素(N2)、及び二酸化炭素(CO2)のそれぞれのガス成分の放熱係数は線形性を有する。しかし、発熱素子61の温度に対する放熱係数の変化率は、メタン(CH4)、プロパン(C38)、窒素(N2)、及び二酸化炭素(CO2)のそれぞれで異なる。したがって、混合ガスを構成するガス成分がメタン(CH4)、プロパン(C38)、窒素(N2)、及び二酸化炭素(CO2)であるである場合、上記(15)から(17)式は、線形独立な関係を有する。 FIG. 6 shows the heat release coefficients of methane (CH 4 ), propane (C 3 H 8 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ) contained in natural gas, and the heating element 61 that is a heating resistor. It is a graph which shows the relationship with temperature. The heat release coefficient of each gas component of methane (CH 4 ), propane (C 3 H 8 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ) has linearity with respect to the temperature of the heating element 61. However, the rate of change of the heat dissipation coefficient with respect to the temperature of the heating element 61 is different for each of methane (CH 4 ), propane (C 3 H 8 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ). Therefore, when the gas components constituting the mixed gas are methane (CH 4 ), propane (C 3 H 8 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ), the above (15) to (17 ) Has a linearly independent relationship.

(15)から(17)式中の各ガス成分の放熱係数MA(TH1),MB(TH1),MC(TH1),MD(TH1),MA(TH2),MB(TH2),MC(TH2),MD(TH2),MA(TH3),MB(TH3),MC(TH3),MD(TH3)の値は、測定等により予め得ることが可能である。したがって、(10)及び(15)から(17)式の連立方程式を解くと、ガスAの体積率VA、ガスBの体積率VB、ガスCの体積率VC、及びガスDの体積率VDのそれぞれが、下記(18)から(21)式に示すように、混合ガスの放熱係数MI1(TH1),MI2(TH2),MI3(TH3)の関数として与えられる。なお、下記(18)から(21)式において、nを自然数として、fnは関数を表す記号である。
VA=f1[MI1 (TH1), MI2 (TH2), MI3 (TH3)] ・・・(18)
VB=f2[MI1 (TH1), MI2 (TH2), MI3 (TH3)] ・・・(19)
VC=f3[MI1 (TH1), MI2 (TH2), MI3 (TH3)] ・・・(20)
VD=f4[MI1 (TH1), MI2 (TH2), MI3 (TH3)] ・・・(21)
The radiation coefficient M A (T H1 ), M B (T H1 ), M C (T H1 ), M D (T H1 ), M A (T H2 ) of each gas component in the equations (15) to (17) , M B (T H2 ), M C (T H2 ), M D (T H2 ), M A (T H3 ), M B (T H3 ), M C (T H3 ), M D (T H3 ) The value can be obtained in advance by measurement or the like. Therefore, when the simultaneous equations of (10) and (15) to (17) are solved, the volume ratio V A of gas A , the volume ratio V B of gas B , the volume ratio V C of gas C , and the volume of gas D Each of the rates V D is given as a function of the heat release coefficient M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 ) of the mixed gas as shown in the following equations (18) to (21). It is done. In the following formulas (18) to (21), n is a natural number and f n is a symbol representing a function.
V A = f 1 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )] (18)
V B = f 2 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )] (19)
V C = f 3 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )] (20)
V D = f 4 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )] (21)

ここで、上記(11)式に(18)から(21)式を代入することにより、下記(22)式が得られる。
Q = KA×VA + KB×VB + KC×VC + KD×VD
= KA×f1[MI1 (TH1), MI2 (TH2), MI3 (TH3)]
+ KB×f2[MI1 (TH1), MI2 (TH2), MI3 (TH3)]
+ KC×f3[MI1 (TH1), MI2 (TH2), MI3 (TH3)]
+ KD×f4[MI1 (TH1), MI2 (TH2), MI3 (TH3)] ・・・(22)
Here, the following equation (22) is obtained by substituting the equations (18) to (21) into the above equation (11).
Q = K A × V A + K B × V B + K C × V C + K D × V D
= K A × f 1 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )]
+ K B × f 2 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )]
+ K C × f 3 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )]
+ K D × f 4 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )] (22)

上記(22)式に示すように、混合ガスの単位体積当たりの発熱量Qは、発熱素子61の温度がTH1,TH2,TH3である場合の混合ガスの放熱係数MI1(TH1),MI2(TH2),MI3(TH3)を変数とする方程式で与えられる。したがって、混合ガスの発熱量Qは、g1を関数を表す記号として、下記(23)式で与えられる。
Q = g1[MI1 (TH1), MI2 (TH2), MI3 (TH3)] ・・・(23)
As shown in the above equation (22), the calorific value Q per unit volume of the mixed gas is the heat dissipation coefficient M I1 (T H1 ) of the mixed gas when the temperature of the heating element 61 is T H1 , T H2 , T H3. ), M I2 (T H2 ), M I3 (T H3 ) are given as equations. Therefore, the calorific value Q of the mixed gas is given by the following equation (23), where g 1 is a symbol representing a function.
Q = g 1 [M I1 (T H1 ), M I2 (T H2 ), M I3 (T H3 )] (23)

よって、ガスA、ガスB、ガスC、及びガスDからなる混合ガスについて、予め上記(23)式を得れば、ガスAの体積率VA、ガスBの体積率VB、ガスCの体積率VC、及びガスDの体積率VDが未知の測定対象混合ガスの単位体積当たりの発熱量Qを容易に算出可能であることを、本発明者は見出した。具体的には、上記(9)式を用いて、発熱素子61の発熱温度がTH1,TH2,TH3である場合の測定対象混合ガスの放熱係数MI1(TH1),MI2(TH2),MI3(TH3)を測定し、(23)式に代入することにより、測定対象混合ガスの発熱量Qを一意に求めることが可能となる。 Therefore, if the above equation (23) is obtained in advance for a mixed gas composed of gas A, gas B, gas C, and gas D, the volume ratio V A of gas A , the volume ratio V B of gas B , and the gas C The present inventor has found that the calorific value Q per unit volume of the measurement target mixed gas whose volume ratio V C and the volume ratio V D of the gas D are unknown can be easily calculated. Specifically, using the above equation (9), the heat release coefficients M I1 (T H1 ), M I2 (M I2 ) of the measurement target mixed gas when the heat generation temperature of the heat generating element 61 is T H1 , T H2 , T H3. By measuring T H2 ) and M I3 (T H3 ) and substituting them into the equation (23), the calorific value Q of the measurement target mixed gas can be determined uniquely.

以上説明した方法では、マイクロチップ8の発熱素子61と、第1の測温素子62と、を用いて、測定対象混合ガスの放熱係数MI1(TH1),MI2(TH2),MI3(TH3)を測定し、発熱量Qを求める。これに対し、以下の方法によれば、マイクロチップ8の第1の測温素子62を用いることなく、発熱素子61のみを用いて、混合ガスの発熱量Qを求めることが可能となる。 In the method described above, using the heat generating element 61 of the microchip 8 and the first temperature measuring element 62, the heat dissipation coefficients M I1 (T H1 ), M I2 (T H2 ), M of the measurement target mixed gas are used. Measure I3 (T H3 ) to determine calorific value Q. On the other hand, according to the following method, the calorific value Q of the mixed gas can be obtained using only the heating element 61 without using the first temperature measuring element 62 of the microchip 8.

上記(4)式に示すように、ガスの放熱係数MIは、発熱素子61の抵抗RHの逆数(1/RH)に比例する。また、上述したように、放熱係数と、熱伝導率と、は比例関係にある。そのため、発熱素子61の抵抗RHの逆数(1/RH)と、熱伝導率と、は比例関係にある。図7は、発熱素子61に第1の電圧V1、第2の電圧V2、及び第3の電圧V3を加えた場合の、熱伝導率と、発熱素子61の抵抗RHの逆数(1/RH)と、の関係を示すグラフである。図7及び図8に示すように、熱伝導率と、発熱素子61の抵抗RHの逆数(1/RH)と、は、発熱素子61への印加電圧が一定であれば、比例関係にある。また、図9及び図10に示すように、熱伝導率と、発熱素子61の抵抗RHと、は、発熱素子61への印加電圧が一定であれば、相関する。さらに、図11及び図12に示すように、熱伝導率と、発熱素子61の駆動電力と、は、発熱素子61への印加電圧が一定であれば、相関する。 As shown in the above equation (4), the heat dissipation coefficient M I of the gas is proportional to the reciprocal (1 / R H ) of the resistance R H of the heating element 61. Further, as described above, the heat dissipation coefficient and the thermal conductivity are in a proportional relationship. For this reason, the reciprocal (1 / R H ) of the resistance R H of the heating element 61 and the thermal conductivity are in a proportional relationship. FIG. 7 illustrates the thermal conductivity and the reciprocal of the resistance RH of the heating element 61 when the first voltage V 1 , the second voltage V 2 , and the third voltage V 3 are applied to the heating element 61. 1 / R H ). As shown in FIGS. 7 and 8, the thermal conductivity and the reciprocal (1 / R H ) of the resistance R H of the heating element 61 are proportional to each other as long as the voltage applied to the heating element 61 is constant. is there. As shown in FIGS. 9 and 10, the thermal conductivity and the resistance RH of the heating element 61 are correlated if the voltage applied to the heating element 61 is constant. Furthermore, as shown in FIGS. 11 and 12, the thermal conductivity and the driving power of the heating element 61 are correlated if the voltage applied to the heating element 61 is constant.

したがって、ガスAに接する場合の発熱素子61の抵抗RHの逆数を1/RHA、ガスBに接する場合の発熱素子61の抵抗RHの逆数を1/RHB、ガスCに接する場合の発熱素子61の抵抗RHの逆数を1/RHC、ガスDに接する場合の発熱素子61の抵抗RHの逆数を1/RHDとすると、上記(12)式を変形して、混合ガスに接する発熱素子61の抵抗RHの逆数(1/RHI)は、各ガス成分の体積率に、各ガス成分に接する場合の発熱素子61の抵抗RHの逆数を乗じたものの総和で与えられる。よって、一定の電圧が印可され、混合ガスに接する発熱素子61の抵抗RHの逆数(1/RHI)は、下記(24)式で与えられる。
1/RHI = 1/RHA×VA+ 1/RHB×VB+ 1/RHC×VC+1/RHD×VD ・・・(24)
Therefore, the resistance R H reciprocal 1 / R HA of the heater element 61 when in contact with the gas A, the resistance R H reciprocal 1 / R HB of the heater element 61 when in contact with the gas B, when in contact with the gas C resistor R H reciprocal 1 / R HC in the heater element 61, when the 1 / R HD reciprocal of the resistance R H of the heater element 61 when in contact with the gas D, by modifying the equation (12), a gas mixture reciprocal of the resistance R H of the heater element 61 coming into contact with the (1 / R HI) is given by the sum the volume ratios of the gas components, but multiplied by the reciprocal of the resistance R H of the heater element 61 when in contact with the gas components It is done. Therefore, a constant voltage is applied, and the reciprocal (1 / R HI ) of the resistance RH of the heating element 61 in contact with the mixed gas is given by the following equation (24).
1 / R HI = 1 / R HA × V A + 1 / R HB × V B + 1 / R HC × V C + 1 / R HD × V D ... (24)

また、発熱素子61の抵抗RHは、発熱素子61の温度THに依存するので、混合ガスに接する場合の発熱素子61の抵抗RHの逆数(1/RHI)は、発熱素子61の温度THの関数として、下記(25)式で与えられる。
1/RHI (TH)
= 1/RHA(TH) × VA+ 1/RHB(TH) × VB+ 1/RHC(TH) × VC+1/RHD(TH) × VD ・・・(25)
Further, since the resistance R H of the heating element 61 depends on the temperature T H of the heating element 61, the reciprocal (1 / R HI ) of the resistance R H of the heating element 61 in contact with the mixed gas is the resistance of the heating element 61. As a function of the temperature T H, the following equation (25) is given.
1 / R HI (T H )
= 1 / R HA (T H ) × V A + 1 / R HB (T H ) × V B + 1 / R HC (T H ) × V C + 1 / R HD (T H ) × V D・ ・·(twenty five)

したがって、発熱素子61の温度がTH1のときの混合ガスに接する発熱素子61の抵抗RHの逆数(1/RHI1)は下記(26)式で与えられる。また、発熱素子61の温度がTH2のときの混合ガスに接する発熱素子61の抵抗RHの逆数(1/RHI2)は下記(27)式で与えられ、発熱素子61の温度がTH3のときの混合ガスに接する発熱素子61の抵抗RHの逆数(1/RHI3)は下記(28)式で与えられる。
1/RHI1 (TH1)
= 1/RHA(TH1) × VA+ 1/RHB(TH1) × VB+ 1/RHC(TH1) × VC+1/RHD(TH1) × ・・・(26)
1/RHI2 (TH2)
= 1/RHA(TH2) × VA+ 1/RHB(TH2) × VB+ 1/RHC(TH2) × VC+1/RHD(TH2) × VD ・・・(27)
1/RHI3 (TH3)
= 1/RHA(TH3) × VA+ 1/RHB(TH3) × VB+ 1/RHC(TH3) × VC+1/RHD(TH3) × VD ・・・(28)
Therefore, the reciprocal (1 / R HI1 ) of the resistance R H of the heating element 61 in contact with the mixed gas when the temperature of the heating element 61 is T H1 is given by the following equation (26). Further, the reciprocal (1 / R HI2 ) of the resistance R H of the heating element 61 in contact with the mixed gas when the temperature of the heating element 61 is T H2 is given by the following equation (27), and the temperature of the heating element 61 is T H3. In this case, the reciprocal (1 / R HI3 ) of the resistance RH of the heating element 61 in contact with the mixed gas is given by the following equation (28).
1 / R HI1 (T H1 )
= 1 / R HA (T H1 ) × V A + 1 / R HB (T H1 ) × V B + 1 / R HC (T H1 ) × V C + 1 / R HD (T H1 ) × ... (26)
1 / R HI2 (T H2 )
= 1 / R HA (T H2 ) × V A + 1 / R HB (T H2 ) × V B + 1 / R HC (T H2 ) × V C + 1 / R HD (T H2 ) × V D・ ・・ (27)
1 / R HI3 (T H3 )
= 1 / R HA (T H3 ) × V A + 1 / R HB (T H3 ) × V B + 1 / R HC (T H3 ) × V C + 1 / R HD (T H3 ) × V D・ ・・ (28)

(26)式から(28)式中の各ガス成分に接する場合の発熱素子61の抵抗RHA(TH1)、RHB(TH1)、RHC(TH1)、RHD(TH1)、RHA(TH2)、RHB(TH2)、RHC(TH2)、RHD(TH2)、RHA(TH3)、RHB(TH3)、RHC(TH3)、RHD(TH3)の値は、測定等により予め得ることが可能である。したがって、(10)及び(26)から(28)式の連立方程式を解くと、ガスAの体積率VA、ガスBの体積率VB、ガスCの体積率VC、及びガスDの体積率VDのそれぞれが、下記(29)から(32)式に示すように、混合ガスに接する発熱素子61の抵抗RHI1(TH1)、RHI2(TH2)、RHI3(TH3)の関数として与えられる。なお、下記(29)から(32)式において、nを自然数として、fnは関数を表す記号である。
VA=f5[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)] ・・・(29)
VB=f6[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)] ・・・(30)
VC=f7[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)] ・・・(31)
VD=f8[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)] ・・・(32)
The resistances R HA (T H1 ), R HB (T H1 ), R HC (T H1 ), R HD (T H1 ) of the heating element 61 when contacting each gas component in the formulas (26) to (28) , R HA (T H2 ), R HB (T H2 ), R HC (T H2 ), R HD (T H2 ), R HA (T H3 ), R HB (T H3 ), R HC (T H3 ), The value of R HD (T H3 ) can be obtained in advance by measurement or the like. Therefore, when the simultaneous equations of (10) and (26) to (28) are solved, the volume ratio V A of gas A , the volume ratio V B of gas B , the volume ratio V C of gas C , and the volume of gas D As shown in the following equations (29) to (32), the rates V D are the resistances R HI1 (T H1 ), R HI2 (T H2 ), R HI3 (T H3 ) of the heating element 61 in contact with the mixed gas. Is given as a function of In the following formulas (29) to (32), n is a natural number and f n is a symbol representing a function.
V A = f 5 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )] (29)
V B = f 6 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )] (30)
V C = f 7 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )] (31)
V D = f 8 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )] (32)

ここで、上記(11)式に(29)から(32)式を代入することにより、下記(33)式が得られる。
Q = KA×VA+ KB×VB+ KC×VC+KD×VD
= KA×f5[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)]
+ KB×f6[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)]
+ KC×f7[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)]
+ KD×f8[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)] ・・・(33)
Here, the following equation (33) is obtained by substituting the equations (29) to (32) into the above equation (11).
Q = K A × V A + K B × V B + K C × V C + K D × V D
= K A × f 5 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )]
+ K B × f 6 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )]
+ K C × f 7 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )]
+ K D × f 8 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )] ・ ・ ・ (33)

上記(33)式に示すように、混合ガスの単位体積当たりの発熱量Qは、発熱素子61の温度がTH1,TH2,TH3である場合の発熱素子61の抵抗RHI1(TH1)、RHI2(TH2)、RHI3(TH3)を変数とする方程式で与えられる。したがって、混合ガスの発熱量Qは、g2、g3を関数を表す記号として、下記(34)式で与えられる。
Q = g2[1/RHI1 (TH1), 1/RHI2 (TH2), 1/RHI3 (TH3)]
= g3[RHI1 (TH1), RHI2 (TH2), RHI3 (TH3)] ・・・(34)
As shown in the above equation (33), the calorific value Q per unit volume of the mixed gas is the resistance R HI1 (T H1) of the heating element 61 when the temperature of the heating element 61 is T H1 , T H2 , T H3. ), R HI2 (T H2 ), R HI3 (T H3 ). Therefore, the calorific value Q of the mixed gas is given by the following equation (34), where g 2 and g 3 are symbols representing functions.
Q = g 2 [1 / R HI1 (T H1 ), 1 / R HI2 (T H2 ), 1 / R HI3 (T H3 )]
= g 3 [R HI1 (T H1 ), R HI2 (T H2 ), R HI3 (T H3 )] (34)

よって、ガスA、ガスB、ガスC、及びガスDからなる混合ガスについて、予め上記(34)式を得れば、ガスAの体積率VA、ガスBの体積率VB、ガスCの体積率VC、及びガスDの体積率VDが未知の測定対象混合ガスの単位体積当たりの発熱量Qを容易に算出可能であることを、本発明者は見出した。具体的には、発熱温度がTH1,TH2,TH3である場合の発熱素子61の抵抗値RHI1(TH1)、RHI2(TH2)、RHI3(TH3)を測定し、(34)式に代入することにより、測定対象混合ガスの発熱量Qを一意に求めることが可能となる。また、この場合、マイクロチップ8の第1の測温素子62を用いることなく、発熱素子61のみを用いて、混合ガスの発熱量Qを求めることが可能となる。 Therefore, if the above equation (34) is obtained in advance for the mixed gas composed of gas A, gas B, gas C, and gas D, the volume ratio V A of gas A , the volume ratio V B of gas B , and the gas C The present inventor has found that the calorific value Q per unit volume of the measurement target mixed gas whose volume ratio V C and the volume ratio V D of the gas D are unknown can be easily calculated. Specifically, the resistance values R HI1 (T H1 ), R HI2 (T H2 ), and R HI3 (T H3 ) of the heating element 61 when the heat generation temperatures are T H1 , T H2 , and T H3 are measured. By substituting into the equation (34), the calorific value Q of the measurement target mixed gas can be uniquely obtained. In this case, the calorific value Q of the mixed gas can be obtained using only the heating element 61 without using the first temperature measuring element 62 of the microchip 8.

さらに、抵抗Rと、電流Iと、は相関するから、混合ガスの単位体積当たりの発熱量Qは、g4を関数を表す記号として、発熱素子61の温度がTH1,TH2,TH3である場合の発熱素子61の通電電流IH1(TH1),IH2(TH2),IH3(TH3)を変数とする下記(35)式で与えられる。
Q = g4[IH1 (TH1), IH2 (TH2), IH3 (TH3)] ・・・(35)
Furthermore, since the resistance R and the current I are correlated, the calorific value Q per unit volume of the mixed gas is such that the temperature of the heating element 61 is T H1 , T H2 , T H3 , with g 4 as a symbol representing a function. When the currents I H1 (T H1 ), I H2 (T H2 ), and I H3 (T H3 ) of the heating element 61 are used as variables, the following equation (35) is given.
Q = g 4 [I H1 (T H1 ), I H2 (T H2 ), I H3 (T H3 )] (35)

また、発熱素子61の抵抗Rと、発熱素子61に接続されたアナログ−デジタル変換回路(以下において「A/D変換回路」という。)の出力信号ADと、は相関するから、混合ガスの単位体積当たりの発熱量Qは、g5を関数を表す記号として、発熱素子61の温度がTH1,TH2,TH3である場合のA/D変換回路の出力信号ADH1(TH1),ADH2(TH2),ADH3(TH3)を変数とする下記(36)式で与えられる。
Q = g5[ADH1 (TH1), ADH2 (TH2), ADH3 (TH3) ] ・・・(36)
Further, since the resistance R of the heating element 61 and the output signal AD of the analog-digital conversion circuit (hereinafter referred to as “A / D conversion circuit”) connected to the heating element 61 are correlated, the unit of the mixed gas The calorific value Q per volume is expressed by the output signal AD H1 (T H1 ) of the A / D conversion circuit when the temperature of the heating element 61 is T H1 , T H2 , T H3 , where g 5 is a symbol representing a function. It is given by the following equation (36) with AD H2 (T H2 ) and AD H3 (T H3 ) as variables.
Q = g 5 [AD H1 (T H1 ), AD H2 (T H2 ), AD H3 (T H3 )] (36)

よって、混合ガスの単位体積当たりの発熱量Qは、下記(37)式に示すように、g6を関数を表す記号として、発熱素子61の発熱温度がTH1,TH2,TH3である場合の発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3)を変数とする方程式で与えられる。
Q = g6[SH1 (TH1), SH2 (TH2), SH3 (TH3)] ・・・(37)
Therefore, the calorific value Q per unit volume of the mixed gas is represented by the following equation (37), and the heat generation temperature of the heat generating element 61 is T H1 , T H2 , T H3, where g 6 is a symbol representing a function. In this case, the electric signals S H1 (T H1 ), S H2 (T H2 ), and S H3 (T H3 ) from the heating element 61 are given by equations.
Q = g 6 [S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 )] (37)

なお、混合ガスのガス成分は、4種類に限定されることはない。例えば、混合ガスがn種類のガス成分からなる場合、g7を関数を表す記号として、下記(38)式で与えられる、少なくともn−1種類の発熱温度TH1,TH2,TH3,・・・,THn-1における発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),・・・,SHn-1(THn-1)を変数とする方程式を予め取得する。そして、n−1種類の発熱温度TH1,TH2,TH3,・・・,THn-1における、n種類のガス成分のそれぞれの体積率が未知の測定対象混合ガスに接する発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),・・・,SHn-1(THn-1)の値を測定し、(38)式に代入することにより、測定対象混合ガスの単位体積当たりの発熱量Qを一意に求めることが可能となる。なお、下記(38)式を、混合ガス(雰囲気ガス)の温度ごとに複数用意してもよい。
Q = g7[SH1 (TH1), SH2 (TH2), SH3 (TH3), ・・・, SHn-1 (THn-1)] ・・・(38)
The gas components of the mixed gas are not limited to four types. For example, if the mixed gas comprises n types of gas components, as a symbol that represents the the g 7 function given by the following equation (38), at least n-1 kinds of the heating temperatures T H1, T H2, T H3 , · ..., electric signals from the heater element 61 in the T Hn-1 S H1 (T H1), S H2 (T H2), S H3 (T H3), ···, S Hn-1 (T Hn-1) An equation having as a variable is acquired in advance. Then, the heating element 61 in contact with the measurement target mixed gas whose volume ratio of each of the n types of gas components at the n-1 types of heat generation temperatures T H1 , T H2 , T H3 ,. , Measured the values of electrical signals SH1 ( TH1 ), SH2 ( TH2 ), SH3 ( TH3 ),..., SHn-1 ( THn-1 ) from the equation (38). By substituting, the calorific value Q per unit volume of the measurement target mixed gas can be uniquely obtained. In addition, you may prepare two or more following (38) formulas for every temperature of mixed gas (atmosphere gas).
Q = g 7 [S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), ..., S Hn-1 (T Hn-1 )] (38)

例えば、測定対象混合ガスが、メタン(CH4)、エタン(C25)、プロパン(C38)、ブタン(C410)、二酸化炭素(CO2)、及び窒素(N2)の6種類のガスからなる場合、少なくとも5種類の発熱温度TH1,TH2,TH3,TH4,TH5における発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)を変数とする方程式を予め取得する。そして、5種類の発熱温度TH1,TH2,TH3,TH4,TH5における、6種類のガス成分のそれぞれの体積率が未知の測定対象混合ガスに接する発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の値を測定し、下記(39)式に代入することにより、測定対象混合ガスの単位体積当たりの発熱量Qを一意に求めることが可能である。
Q = g7[SH1(TH1), SH2(TH2), SH3(TH3), SH4(TH4), SH5(TH5)] ・・・(39)
For example, the measurement target mixed gas is methane (CH 4 ), ethane (C 2 H 5 ), propane (C 3 H 8 ), butane (C 4 H 10 ), carbon dioxide (CO 2 ), and nitrogen (N 2 ). If it made of six types of gases), at least five of the heating temperature T H1, T H2, T H3 , T H4, electric signals from the heater element 61 in the T H5 S H1 (T H1) , S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), and S H5 (T H5 ) as variables. Then, the electric signal S from the heating element 61 in contact with the measurement target mixed gas whose volume ratio of each of the six types of gas components at the five types of heat generation temperatures T H1 , T H2 , T H3 , T H4 , T H5 is unknown. By measuring the values of H1 ( TH1 ), SH2 ( TH2 ), SH3 ( TH3 ), SH4 ( TH4 ), SH5 ( TH5 ) and substituting them into the following equation (39), It is possible to uniquely determine the calorific value Q per unit volume of the measurement target mixed gas.
Q = g 7 [S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), S H5 (T H5 )] ・ ・ ・ (39)

ただし、混合ガスが、ガス成分としてメタン(CH4)、プロパン(C38)に加えて、jを自然数として、メタン(CH4)とプロパン(C38)以外のアルカン(Cj2j+2)を含む場合、メタン(CH4)とプロパン(C38)以外のアルカン(Cj2j+2)を、メタン(CH4)とプロパン(C38)の混合物とみなして(38)式を算出してもよい。例えば、エタン(C26)、ブタン(C410)、ペンタン(C512)、ヘキサン(C614)を、下記(40)から(43)式に示すように、それぞれ所定の係数を掛けられたメタン(CH4)とプロパン(C38)の混合物とみなして(38)式を算出してもかまわない。
C2H6 = 0.5 CH4 + 0.5 C3H8 ・・・(40)
C4H10 = -0.5 CH4 + 1.5 C3H8 ・・・(41)
C5H12 = -1.0 CH4 + 2.0 C3H8 ・・・(42)
C6H14 = -1.5 CH4 + 2.5 C3H8 ・・・(43)
However, the mixed gas, methane (CH 4) as a gas component in addition to the propane (C 3 H 8), a j is a natural number, methane (CH 4) and other than propane (C 3 H 8) alkane (C j H 2j + 2 ), alkanes other than methane (CH 4 ) and propane (C 3 H 8 ) (C j H 2j + 2 ), and mixtures of methane (CH 4 ) and propane (C 3 H 8 ) (38) may be calculated. For example, ethane (C 2 H 6 ), butane (C 4 H 10 ), pentane (C 5 H 12 ), and hexane (C 6 H 14 ) are respectively represented by the following formulas (40) to (43): The equation (38) may be calculated by regarding the mixture as methane (CH 4 ) and propane (C 3 H 8 ) multiplied by a predetermined coefficient.
C 2 H 6 = 0.5 CH 4 + 0.5 C 3 H 8 ... (40)
C 4 H 10 = -0.5 CH 4 + 1.5 C 3 H 8 ... (41)
C 5 H 12 = -1.0 CH 4 + 2.0 C 3 H 8 ... (42)
C 6 H 14 = -1.5 CH 4 + 2.5 C 3 H 8 ... (43)

したがって、zを自然数として、n種類のガス成分からなる混合ガスが、ガス成分としてメタン(CH4)、プロパン(C38)に加えて、メタン(CH4)とプロパン(C38)以外のz種類のアルカン(Cj2j+2)を含む場合、少なくともn−z−1種類の発熱温度における発熱素子61からの電気信号SHを変数とする方程式を求めてもよい。 Accordingly, the z as a natural number, a mixed gas consisting of n kinds of gas components methane (CH 4) as a gas component in addition to the propane (C 3 H 8), methane (CH 4) and propane (C 3 H 8 ) if it contains z kinds of alkane (C j H 2j + 2) other than, or an equation that the electrical signal S H and the variables from the heater element 61 in at least n-z-1 different heat producing temperatures.

また、(38)式の算出に用いられた混合ガスのガス成分の種類と、単位体積当たりの発熱量Qが未知の測定対象混合ガスのガス成分の種類が同じ場合に、測定対象混合ガスの発熱量Qの算出に(38)式を利用可能であることはもちろんである。さらに、測定対象混合ガスがn種類より少ない種類のガス成分からなり、かつ、n種類より少ない種類のガス成分が、(38)式の算出に用いられた混合ガスに含まれている場合も、(38)式を利用可能である。例えば、(38)式の算出に用いられた混合ガスが、メタン(CH4)、プロパン(C38)、窒素(N2)、及び二酸化炭素(CO2)の4種類のガス成分を含む場合、測定対象混合ガスが、窒素(N2)を含まず、メタン(CH4)、プロパン(C38)、及び二酸化炭素(CO2)の3種類のガス成分のみを含む場合も、測定対象混合ガスの発熱量Qの算出に(38)式を利用可能である。 Further, when the type of the gas component of the mixed gas used in the calculation of the equation (38) is the same as the type of the gas component of the measurement target mixed gas whose calorific value Q per unit volume is unknown, the measurement target mixed gas Of course, the equation (38) can be used to calculate the calorific value Q. Further, when the measurement target mixed gas is composed of less than n kinds of gas components and less than n kinds of gas components are included in the mixed gas used in the calculation of the equation (38), Equation (38) can be used. For example, the mixed gas used in the calculation of the equation (38) has four types of gas components, methane (CH 4 ), propane (C 3 H 8 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ). When it is included, the measurement target mixed gas may not contain nitrogen (N 2 ) but may contain only three types of gas components, methane (CH 4 ), propane (C 3 H 8 ), and carbon dioxide (CO 2 ). The equation (38) can be used to calculate the calorific value Q of the measurement target mixed gas.

さらに、(38)式の算出に用いられた混合ガスが、ガス成分としてメタン(CH4)とプロパン(C38)を含む場合、測定対象混合ガスが、(38)式の算出に用いられた混合ガスに含まれていないアルカン(Cj2j+2)を含んでいても、(38)式を利用可能である。これは、上述したように、メタン(CH4)とプロパン(C38)以外のアルカン(Cj2j+2)を、メタン(CH4)とプロパン(C38)の混合物とみなしてもよいためである。 Further, when the mixed gas used for calculating the equation (38) contains methane (CH 4 ) and propane (C 3 H 8 ) as gas components, the measurement target mixed gas is used for calculating the equation (38). Even if alkane (C j H 2j + 2 ) that is not contained in the mixed gas is included, the equation (38) can be used. This is because, as described above, the methane (CH 4) and propane (C 3 H 8) other than the alkane (C j H 2j + 2) , a mixture of methane (CH 4) and propane (C 3 H 8) This is because it may be considered.

次に、窒素濃度の測定方法について説明する。図13に示すように、発熱素子61の発熱温度に応じて、ガスの熱伝導率は変化する。ここで、メタン、エタン、プロパン、及びブタンのような炭化水素ガスに対して、窒素ガスは、発熱温度に対する熱伝導率の変化率が小さいことに、本発明者は着目した。   Next, a method for measuring the nitrogen concentration will be described. As shown in FIG. 13, the thermal conductivity of the gas changes according to the heat generation temperature of the heat generating element 61. Here, the inventor has paid attention to the fact that nitrogen gas has a smaller rate of change in thermal conductivity with respect to the exothermic temperature than hydrocarbon gases such as methane, ethane, propane, and butane.

図14は、発熱素子61の発熱温度に関わらずメタンの熱伝導率が0になり、発熱素子61の発熱温度に関わらずプロパンの熱伝導率が1になるよう、熱伝導率の値を正規化したときのグラフである。正規化する際には、各熱伝導率の値から同じ発熱温度におけるメタンの熱伝導率の値を引いた値を、同じ発熱温度におけるプロパンの熱伝導率の値から同じ発熱温度におけるメタンの熱伝導率の値を引いた値で割った。図14に示すように、炭化水素ガスと窒素ガスの間における、発熱温度に対する熱伝導率の変化率の違いは、熱伝導率の値を正規化すると、より顕著になる。   In FIG. 14, the thermal conductivity value is normalized so that the thermal conductivity of methane is 0 regardless of the heating temperature of the heating element 61 and the thermal conductivity of propane is 1 regardless of the heating temperature of the heating element 61. It is a graph when it is converted. When normalizing, the value obtained by subtracting the value of thermal conductivity of methane at the same exothermic temperature from the value of each thermal conductivity is used as the value of heat conductivity of methane at the same exothermic temperature from the value of propane thermal conductivity at the same exothermic temperature. The conductivity value was divided by the subtracted value. As shown in FIG. 14, the difference in the rate of change in thermal conductivity with respect to the exothermic temperature between hydrocarbon gas and nitrogen gas becomes more prominent when the value of thermal conductivity is normalized.

上述したように、発熱素子61からの電気信号の値は、発熱素子61に接するガスの熱伝導率の値を反映している。図15は、メタンガス、並びにメタン、エタン、プロパン、及びブタンの少なくともいずれかを含み、窒素を含まない14種類の混合ガスのそれぞれに接する発熱素子61からの電気信号の値を、発熱温度に関わらずメタンガスに接触時の電気信号の値が0となり、特定の混合ガスに接触時の電気信号の値が1となるよう、電気信号の値を正規化したときのグラフである。窒素ガスを含まない混合ガスは、発熱温度に対する正規化された電気信号の値の変化率が小さい。   As described above, the value of the electrical signal from the heating element 61 reflects the value of the thermal conductivity of the gas in contact with the heating element 61. FIG. 15 shows the value of the electrical signal from the heating element 61 in contact with each of the 14 types of mixed gas containing methane gas and at least one of methane, ethane, propane, and butane and not containing nitrogen. It is a graph when the value of the electrical signal is normalized so that the value of the electrical signal at the time of contact with methane gas becomes 0 and the value of the electrical signal at the time of contact with a specific mixed gas becomes 1. A mixed gas that does not contain nitrogen gas has a small rate of change in the value of the normalized electrical signal with respect to the exothermic temperature.

図16は、メタン、エタン、プロパン、及びブタンの少なくともいずれかを含み、窒素を3vol%又は4vol%含む4種類の混合ガスのそれぞれに接する発熱素子61からの電気信号の値を、図15と同じ条件で正規化したときのグラフである。図15と図16を比較すると、窒素ガスを含む混合ガスは、窒素ガスを含まない混合ガスに対して、発熱温度に対する正規化された電気信号の値の変化率が大きい。   FIG. 16 shows values of electric signals from the heating element 61 in contact with each of four types of mixed gas containing at least one of methane, ethane, propane, and butane and containing 3 vol% or 4 vol% nitrogen. It is a graph when normalized under the same conditions. Comparing FIG. 15 and FIG. 16, the mixed gas containing nitrogen gas has a larger change rate of the value of the normalized electric signal with respect to the heat generation temperature than the mixed gas not containing nitrogen gas.

図17は、メタン、エタン、プロパン、及びブタンの少なくともいずれかを含み、窒素を5vol%又は6vol%含む5種類の混合ガスのそれぞれに接する発熱素子61からの電気信号の値を、図15と同じ条件で正規化したときのグラフである。図16と図17を比較すると、窒素ガスを多く含む混合ガスは、発熱温度に対する正規化された電気信号の値の変化率が大きい。   FIG. 17 shows values of electrical signals from the heating element 61 in contact with each of five kinds of mixed gas containing at least one of methane, ethane, propane, and butane and containing 5 vol% or 6 vol% nitrogen. It is a graph when normalized under the same conditions. When FIG. 16 is compared with FIG. 17, the change rate of the value of the normalized electric signal with respect to the heat generation temperature is large in the mixed gas containing a large amount of nitrogen gas.

したがって、少なくとも2つの、窒素を含まない炭化水素含有ガスのそれぞれに接触時の電気信号の値がそれぞれ一定となるように、発熱素子61からの電気信号の値を正規化した際の、発熱温度に対する正規化された電気信号の値の変化率の大きさは、混合ガスに含まれる窒素の濃度を反映している。   Accordingly, the heat generation temperature when the value of the electric signal from the heating element 61 is normalized so that the value of the electric signal at the time of contact with each of at least two hydrocarbon-containing gases not containing nitrogen is constant. The magnitude of the rate of change in the value of the normalized electrical signal with respect to the value reflects the concentration of nitrogen contained in the mixed gas.

図18は、31種類のガスのそれぞれを発熱素子61に接触させ、発熱素子61を5段階で発熱させた場合の、最も高い発熱温度における電気信号の正規化値SH5N(TH5)と、最も高い発熱温度の次に高い発熱温度における電気信号の正規化値SH4N(TH4)と、の第1の差に100を掛けた値d1と、31種類のガスのそれぞれの実際の窒素濃度の値(vol%)と、をプロットしたグラフである。図19は、最も高い発熱温度の次に高い発熱温度における電気信号の正規化値SH4N(TH4)と、最も高い発熱温度の次の次に高い発熱温度における電気信号の正規化値SH3N(TH3)と、の第2の差に100を掛けた値d2と、実際の窒素濃度の値(vol%)と、をプロットしたグラフである。 FIG. 18 shows normalized values S H5N (T H5 ) of electric signals at the highest heat generation temperature when 31 kinds of gas are brought into contact with the heat generation element 61 and the heat generation element 61 generates heat in five stages. The normalized value S H4N (T H4 ) of the electrical signal at the next highest exothermic temperature, the value d 1 obtained by multiplying the first difference by 100, and the actual nitrogen of each of the 31 gases It is the graph which plotted the value (vol%) of the density | concentration. FIG. 19 shows the normalized value S H4N (T H4 ) of the electrical signal at the next highest heating temperature after the highest heating temperature, and the normalized value S H3N of the electrical signal at the next highest heating temperature after the highest heating temperature. and (T H3), and the value d 2 multiplied by 100 to the second difference is a graph plotting the actual nitrogen concentration value (vol%), the.

図18及び図19において、電気信号の正規化値の第1及び第2の差に100を掛けているのは、無次元数である第1及び第2の差のスケールを、窒素濃度に近づけるためである。そのため、第1及び第2の差のスケールを窒素濃度に近づけるために、第1及び第2の差に掛けられる値は、100に限定されない。   In FIG. 18 and FIG. 19, multiplying the first and second differences of the normalized values of the electrical signal by 100 brings the first and second difference scales, which are dimensionless numbers, closer to the nitrogen concentration. Because. Therefore, the value multiplied by the first and second differences in order to bring the first and second difference scales closer to the nitrogen concentration is not limited to 100.

図18及び図19に示すように、2つの発熱温度の間における電気信号の正規化値の差の値に100を掛けた値d1,d2は、概ね窒素濃度を反映しているが、実際には窒素濃度が0%である1番から15番までのガスにおいて、電気信号の正規化値の差の値に100を掛けた値d1,d2が0ではないものがある。 As shown in FIG. 18 and FIG. 19, values d 1 and d 2 obtained by multiplying the difference between the normalized values of the electrical signals between the two exothermic temperatures by 100 generally reflect the nitrogen concentration. Actually, in gases No. 1 to No. 15 having a nitrogen concentration of 0%, values d 1 and d 2 obtained by multiplying the difference value of the normalized value of the electric signal by 100 are not zero.

そこで、下記(44)式に示すように、第1の差の値d1に第1の補正係数A1を掛けた補正された第1の差dC1と、第2の差の値d2と、の差に、スケールを補正するためのスケール補正係数ASを掛けた値である評価値Eを設定する。
E=(A1×d1-d2)×AS
=(dC1-d2)×AS ・・・(44)
Therefore, as shown in the following equation (44), the corrected first difference d C1 obtained by multiplying the first difference value d 1 by the first correction coefficient A 1 and the second difference value d 2. When a difference in, sets an evaluation value E is a value obtained by multiplying the scale correction factor a S for correcting the scale.
E = (A 1 × d 1 -d 2 ) × A S
= (d C1 -d 2 ) × A S ... (44)

さらに、図18及び図19に示す実際には窒素濃度が0%である1番から15番までのガスにおいて、評価値Eが0に近づくような第1の補正係数A1の値を算出する。図18及び図19に示す例においては、第1の補正係数A1の値を1.87にすると、窒素濃度が0%である1番から15番までのガスにおいて、評価値Eが0に最も近づいた。なお、第1の補正係数A1の値1.87は、一例であり、これに限定されない。図20は、第1の補正係数A1の値を1.87にした場合の、31種類のガスのそれぞれの評価値Eと、31種類のガスのそれぞれの実際の窒素濃度の値(vol%)と、をプロットしたグラフである。 Further, the first correction coefficient A 1 is calculated so that the evaluation value E approaches 0 in the gases No. 1 to No. 15 in which the nitrogen concentration is actually 0% shown in FIGS. . In the examples shown in FIGS. 18 and 19, when the value of the first correction coefficient A 1 is 1.87, the evaluation value E is 0 in the gases No. 1 to No. 15 having a nitrogen concentration of 0%. Approached most. Note that the value 1.87 of the first correction coefficient A 1 is an example and is not limited to this. FIG. 20 shows the evaluation value E of each of the 31 types of gas and the actual nitrogen concentration value (vol%) of each of the 31 types of gas when the value of the first correction coefficient A 1 is 1.87. ) And are plotted.

図20に示すように、評価値Eは、概ね窒素濃度を反映しているが、16番から31番のガスの実際の窒素濃度と、評価値Eと、の間には、誤差がある。   As shown in FIG. 20, the evaluation value E generally reflects the nitrogen concentration, but there is an error between the actual nitrogen concentration of the 16th to 31st gases and the evaluation value E.

そこで、下記(45)式に示すように、評価値Eに第2の補正係数A2を掛けた補正された評価値ECを、混合ガスに含まれる窒素の濃度の測定値として設定する。
EC=A2×E ・・・(45)
Therefore, as shown in the following equation (45), a corrected evaluation value E C obtained by multiplying the evaluation value E by the second correction coefficient A 2 is set as a measured value of the concentration of nitrogen contained in the mixed gas.
E C = A 2 × E (45)

さらに、図20に示す24番から31番までの窒素濃度が4%から6%のガスにおいて、窒素濃度の実際の値と窒素濃度の測定値ECと間の誤差が0に近づくような第2の補正係数A2の値を算出する。図20に示す例においては、第2の補正係数A2の値を1.27にすると、窒素濃度が4%から6%のガスにおいて、窒素濃度の実際の値と窒素濃度の測定値ECと間の誤差が0に最も近づいた。なお、第2の補正係数A2の値1.27は、一例であり、これに限定されない。また、全てのガスにおいて、窒素濃度の実際の値と窒素濃度の測定値ECと間の誤差が0に近づくような第2の補正係数A2の値を算出してもよい。図21は、第2の補正係数A2の値を1.27にした場合の、31種類のガスのそれぞれの窒素濃度の実際の値(vol%)と、31種類のガスのそれぞれの窒素濃度の測定値(補正された評価値)ECと、をプロットしたグラフである。31種類のガスのそれぞれの窒素濃度の測定値ECは、窒素濃度の実際の値とほぼ一致した。 Further, in the gas having a nitrogen concentration of 4% to 6% from No. 24 to No. 31 shown in FIG. 20, the error between the actual value of the nitrogen concentration and the measured value E C of the nitrogen concentration approaches zero. The value of the correction coefficient A 2 of 2 is calculated. In the example shown in FIG. 20, when the value of the second correction coefficient A 2 is 1.27, the actual value of nitrogen concentration and the measured value E C of nitrogen concentration in a gas having a nitrogen concentration of 4% to 6%. The error between and was closest to 0. Note that the value 1.27 of the second correction coefficient A 2 is an example, and the present invention is not limited to this. Alternatively, the value of the second correction coefficient A 2 may be calculated so that the error between the actual value of the nitrogen concentration and the measured value E C of the nitrogen concentration approaches zero for all gases. FIG. 21 shows the actual values (vol%) of the nitrogen concentrations of the 31 kinds of gases and the nitrogen concentrations of the 31 kinds of gases when the value of the second correction coefficient A 2 is 1.27. Is a graph in which measured values (corrected evaluation values) E C are plotted. The measured value E C of the nitrogen concentration of each of the 31 kinds of gases almost coincided with the actual value of the nitrogen concentration.

図22は、窒素濃度の実際の値に対する、窒素濃度の測定値ECの誤差を示すグラフである。1番から31番までの全てのガスにおいて、窒素濃度の測定値ECの誤差は、0.2%以下であった。 FIG. 22 is a graph showing an error of the measured value E C of the nitrogen concentration with respect to the actual value of the nitrogen concentration. In all the gases from No. 1 to No. 31, the error in the measured value E C of the nitrogen concentration was 0.2% or less.

したがって、予め第1の補正係数A1及び第2の補正係数A2を、上述したように窒素濃度の実際の値が既知の複数のガスを用いて算出しておけば、窒素濃度が未知の測定対象混合ガスに接し、複数の発熱温度で発熱する発熱素子61からの電気信号の測定値を測定すれば、測定対象混合ガスに含まれる窒素の濃度を算出可能であることを、本発明者は見出した。 Therefore, if the first correction coefficient A 1 and the second correction coefficient A 2 are calculated in advance using a plurality of gases whose actual values of nitrogen concentration are known as described above, the nitrogen concentration is unknown. It is the present inventor that the concentration of nitrogen contained in the measurement target mixed gas can be calculated by measuring the measured value of the electrical signal from the heating element 61 that contacts the measurement target mixed gas and generates heat at a plurality of heat generation temperatures. Found.

具体的には、下記(46)式に示すような、少なくとも3つの発熱温度における発熱素子61からの正規化された電気信号を独立変数とし、窒素濃度を従属変数とする窒素濃度算出式を予め用意する。
EC=(A1×(SH5N(TH5)-SH4N(TH4))-(SH4N(TH4)-SH3N(TH3)))×AS×A2
=(A1×d1-d2)×AS×A2
=(dC1-d2)×AS×A2
= E×A2 ・・・(46)
なお、上記(46)式においては、少なくとも3つの発熱温度における発熱素子からの正規化された電気信号として、SH3N(TH3)、SH4N(TH4)、SH5N(TH5)を用いる例を示しているが、いずれの発熱温度を用いるかは任意であり、SH1N(TH1)、SH2N(TH2)が用いられてもよい。
Specifically, as shown in the following equation (46), a nitrogen concentration calculation formula having a normalized electric signal from the heating element 61 at at least three heat generation temperatures as an independent variable and a nitrogen concentration as a dependent variable is previously set. prepare.
E C = (A 1 × (S H5N (T H5 ) -S H4N (T H4 ))-(S H4N (T H4 ) -S H3N (T H3 ))) × A S × A 2
= (A 1 × d 1 -d 2 ) × A S × A 2
= (d C1 -d 2 ) × A S × A 2
= E × A 2 ... (46)
In the equation (46), S H3N (T H3 ), S H4N (T H4 ), and S H5N (T H5 ) are used as normalized electrical signals from the heating elements at at least three heating temperatures. Although an example is shown, it is arbitrary which heat generation temperature is used, and S H1N (T H1 ) and S H2N (T H2 ) may be used.

また、スケール補正係数ASを省略しても、第2の補正係数A2’によってスケール補正することが可能である。したがって、下記(47)式に示すように、第1の補正係数A1及び第2の補正係数A2’を含み、少なくとも3つの発熱温度における発熱素子61からの正規化された電気信号SH3N(TH3),SH4N(TH4),SH5N(TH5)を独立変数とし、窒素濃度ECを従属変数とする窒素濃度算出式を予め用意してもよい。
EC=(A1×(SH5N(TH5)-SH4N(TH4))-(SH4N(TH4)-SH3N(TH3)))×A2'
=(A1×d1-d2)S×A2'
=(dC1-d2)×A2' ・・・(47)
以下においては、スケール補正可能な第2の補正係数A2’も、第2の補正係数A2と表記する。
Even if the scale correction coefficient A S is omitted, the scale correction can be performed using the second correction coefficient A 2 ′. Therefore, as shown in the following equation (47), the normalized electric signal S H3N from the heating element 61 including at least three heating temperatures includes the first correction coefficient A 1 and the second correction coefficient A 2 ′. A nitrogen concentration calculation formula may be prepared in advance, where (T H3 ), S H4N (T H4 ), and S H5N (T H5 ) are independent variables and the nitrogen concentration E C is a dependent variable.
E C = (A 1 × (S H5N (T H5 ) -S H4N (T H4 ))-(S H4N (T H4 ) -S H3N (T H3 ))) × A 2 '
= (A 1 × d 1 -d 2 ) S × A 2 '
= (d C1 -d 2 ) × A 2 '(47)
In the following, the second correction coefficient A 2 ′ capable of scale correction is also expressed as a second correction coefficient A 2 .

次に、含有窒素濃度が未知の測定対象混合ガスを発熱素子61に接触させ、少なくとも3つの発熱温度における発熱素子61からの電気信号の測定値を測定し、それぞれの測定値を正規化する。さらに、上記(46)式又は(47)式で与えられる窒素濃度算出式の独立変数に、正規化された電気信号の測定値を代入することによって、測定対象混合ガスに含まれる窒素の濃度を算出することが可能である。   Next, the measurement object mixed gas whose nitrogen concentration is unknown is brought into contact with the heating element 61, the measured values of the electrical signals from the heating element 61 at at least three heating temperatures are measured, and the measured values are normalized. Furthermore, by substituting the measured value of the normalized electrical signal into the independent variable of the nitrogen concentration calculation formula given by the above equation (46) or (47), the concentration of nitrogen contained in the measurement target mixed gas is calculated. It is possible to calculate.

ここで、図23に示す実施の形態に係る窒素濃度測定システム20は、窒素を含まない基準ガス、窒素を含まない校正ガス、複数の窒素非含有混合ガス、及び複数の窒素含有混合ガスのそれぞれが注入される容器であるチャンバ101を備える。   Here, the nitrogen concentration measurement system 20 according to the embodiment shown in FIG. 23 includes a reference gas not containing nitrogen, a calibration gas not containing nitrogen, a plurality of nitrogen-free mixed gases, and a plurality of nitrogen-containing mixed gases, respectively. Is provided with a chamber 101 which is a container to be injected.

炭化水素を校正成分とする基準ガスとしては、メタンガスが使用可能である。校正ガスは、複数種類のガス成分を含む混合ガスであり、例えばメタン(CH4)、エタン(C26)、プロパン(C38)、及びブタン(C410)の4種類のガス成分のいずれか又は全部を含む。炭化水素を校正成分とする校正ガスは、例えば天然ガス又は液化天然ガス(LNG)と同じ成分からなる。校正ガスとしては、スパンガスが使用可能である。 Methane gas can be used as a reference gas having hydrocarbon as a calibration component. The calibration gas is a mixed gas containing a plurality of types of gas components, for example, four types of methane (CH 4 ), ethane (C 2 H 6 ), propane (C 3 H 8 ), and butane (C 4 H 10 ). Any or all of the gas components are included. The calibration gas containing hydrocarbon as a calibration component is composed of, for example, the same components as natural gas or liquefied natural gas (LNG). A span gas can be used as the calibration gas.

複数の窒素非含有混合ガスのそれぞれは、複数種類のガス成分を含む。複数の混合ガスのそれぞれは、例えばメタン(CH4)、エタン(C26)、プロパン(C38)、及びブタン(C410)の4種類のガス成分のいずれか又は全部を含む。複数の混合ガスのいずれか又は全部は、天然ガス又はLNGである。 Each of the plurality of nitrogen-free mixed gases includes a plurality of types of gas components. Each of the plurality of mixed gases is, for example, any or all of four kinds of gas components such as methane (CH 4 ), ethane (C 2 H 6 ), propane (C 3 H 8 ), and butane (C 4 H 10 ). including. Any or all of the plurality of mixed gases is natural gas or LNG.

複数の窒素含有混合ガスのそれぞれは、複数種類のガス成分を含む。複数の混合ガスのそれぞれは、例えばメタン(CH4)、エタン(C26)、プロパン(C38)、ブタン(C410)、及び窒素(N2)の5種類のガス成分のいずれか又は全部を含む。複数の混合ガスのいずれか又は全部は、天然ガス又はLNGである。 Each of the plurality of nitrogen-containing mixed gases includes a plurality of types of gas components. Each of the plurality of mixed gases includes, for example, five kinds of gases such as methane (CH 4 ), ethane (C 2 H 6 ), propane (C 3 H 8 ), butane (C 4 H 10 ), and nitrogen (N 2 ). Contains any or all of the ingredients. Any or all of the plurality of mixed gases is natural gas or LNG.

窒素濃度測定システム20は、さらに、チャンバ101に配置され、複数の発熱温度THで発熱する図1又は図3に示した発熱素子61を含むマイクロチップ8を備える。以下においては、窒素濃度測定システム20が図1に示したマイクロチップ8を備えている例を説明するが、窒素濃度測定システム20が図3に示したマイクロチップ8を備えていても、図23に示す窒素濃度測定システム20の動作は同様である。 The nitrogen concentration measurement system 20 further includes a microchip 8 disposed in the chamber 101 and including the heating element 61 shown in FIG. 1 or 3 that generates heat at a plurality of heat generation temperatures T H. Hereinafter, an example in which the nitrogen concentration measurement system 20 includes the microchip 8 illustrated in FIG. 1 will be described. However, even if the nitrogen concentration measurement system 20 includes the microchip 8 illustrated in FIG. The operation of the nitrogen concentration measurement system 20 shown in FIG.

マイクロチップ8は、断熱部材18を介してチャンバ101内に配置されている。チャンバ101には、基準ガス、校正ガス、複数の窒素非含有混合ガス、及び複数の窒素含有混合ガスのそれぞれをチャンバ101に送るための流路102と、基準ガス、校正ガス、複数の窒素非含有混合ガス、及び複数の窒素含有混合ガスのそれぞれをチャンバ101から外部に排出するための流路103と、が接続されている。   The microchip 8 is disposed in the chamber 101 via the heat insulating member 18. The chamber 101 includes a reference gas, a calibration gas, a plurality of nitrogen-free mixed gases, and a flow path 102 for sending each of the plurality of nitrogen-containing mixed gases to the chamber 101, a reference gas, a calibration gas, and a plurality of nitrogen-free gases. A flow path 103 for discharging each of the contained mixed gas and each of the plurality of nitrogen-containing mixed gases from the chamber 101 is connected.

窒素濃度測定システム20は、さらに、基準ガスに接し、複数の発熱温度THのそれぞれで発熱する発熱素子61からの基準電気信号SHA(TH)の測定値と、校正ガスに接し、複数の発熱温度THのそれぞれで発熱する発熱素子61からの校正用電気信号SHB(TH)の測定値と、複数の窒素非含有混合ガスのそれぞれに接し、複数の発熱温度THのそれぞれで発熱する発熱素子61からの窒素非含有時電気信号SH(TH)の測定値と、複数の窒素含有混合ガスのそれぞれに接し、複数の発熱温度THのそれぞれで発熱する発熱素子61からの窒素含有時電気信号SH(TH)の測定値と、を測定する測定部301を備える。 The nitrogen concentration measurement system 20 is further in contact with the reference gas and the measurement value of the reference electrical signal S HA (T H ) from the heating element 61 that generates heat at each of the plurality of heat generation temperatures T H and the calibration gas. Each of the plurality of exothermic temperatures T H in contact with the measured value of the calibration electric signal S HB (T H ) from the heating element 61 that generates heat at each exothermic temperature T H and each of the plurality of nitrogen-free mixed gases. The measured value of the electrical signal S H (T H ) when nitrogen is not contained from the heating element 61 that generates heat at the temperature and the heating element 61 that is in contact with each of the plurality of nitrogen-containing mixed gases and generates heat at each of the plurality of heating temperatures T H. The measurement part 301 which measures the measured value of the electrical signal SH ( TH ) at the time of nitrogen containing from is measured.

窒素濃度測定システム20は、さらに、基準ガス、校正ガス、複数の窒素非含有混合ガス、及び複数の窒素含有混合ガスのそれぞれの既知の発熱量Qの値、並びに複数の発熱温度THにおける発熱素子61からの基準電気信号SHA(TH)の測定値、校正用電気信号SHB(TH)の測定値、窒素非含有時電気信号SH(TH)の測定値、及び窒素含有時電気信号SH(TH)の測定値に基づいて、複数の発熱温度THにおける発熱素子61からの電気信号SH(TH)を独立変数とし、発熱量Qを従属変数とする発熱量算出式を作成する式作成部302を備える。 Nitrogen concentration measurement system 20 further includes reference gas, calibration gas, each of the known calorific value Q of a plurality of nitrogen-free mixed gas, and a plurality of nitrogen-containing gas mixture, and heating at a plurality of heat producing temperatures T H The measured value of the reference electrical signal S HA (T H ) from the element 61, the measured value of the calibration electrical signal S HB (T H ), the measured value of the electrical signal S H (T H ) when nitrogen is not included, and the nitrogen content when based on the measurement values of the electric signals S H (T H), the electrical signals from the heater element 61 at a plurality of heat producing temperatures T H S H a (T H) as independent variables and the calorific value Q as a dependent variable heating An expression creating unit 302 for creating an amount calculation expression is provided.

窒素濃度測定システム20は、さらに、窒素を含まない基準ガスに接する発熱素子61からの基準電気信号SHA(TH)の測定値が、発熱素子61の発熱温度に関わらず一定となり、かつ、窒素を含まない校正ガスに接する発熱素子61からの校正用電気信号SHB(TH)の測定値が、発熱素子61の発熱温度に関わらず一定となるよう、基準電気信号SHA(TH)の測定値、校正用電気信号SHB(TH)の測定値、窒素非含有時電気信号SH(TH)の測定値、及び窒素含有時電気信号SH(TH)の測定値を正規化する正規化部306を備える。 The nitrogen concentration measurement system 20 further has a measured value of the reference electrical signal S HA (T H ) from the heating element 61 in contact with the reference gas not containing nitrogen, regardless of the heating temperature of the heating element 61, and The reference electrical signal S HA (T H ) is set so that the measured value of the calibration electrical signal S HB (T H ) from the heating element 61 in contact with the calibration gas not containing nitrogen is constant regardless of the heating temperature of the heating element 61. ) Measurement value, calibration electric signal SHB ( TH ) measurement value, nitrogen-free electrical signal SH ( TH ) measurement value, and nitrogen-containing electrical signal SH ( TH ) measurement value Is provided with a normalization unit 306.

式作成部302は、基準ガス、校正ガス、複数の窒素非含有混合ガス、及び複数の窒素含有混合ガスのそれぞれの既知の窒素濃度の値、並びに複数の発熱温度THにおける発熱素子61からの基準電気信号SHA(TH)の測定値、校正用電気信号SHB(TH)の測定値、窒素非含有時電気信号SH(TH)の測定値、及び窒素含有時電気信号SH(TH)の測定値に基づいて、少なくとも3つの発熱温度THにおける発熱素子61からの正規化された電気信号SHN(TH)を独立変数とし、窒素濃度を従属変数とする窒素濃度算出式をも作成する。 The formula creation unit 302 includes the reference gas, the calibration gas, the plurality of nitrogen-free mixed gases, and the known nitrogen concentration values of the plurality of nitrogen-containing mixed gases, and the heating element 61 at the plurality of heat generation temperatures T H. The measured value of the reference electrical signal S HA (T H ), the measured value of the calibration electrical signal S HB (T H ), the measured value of the electrical signal S H (T H ) when not containing nitrogen, and the electrical signal S when containing nitrogen Based on the measured value of H (T H ), the normalized electrical signal S HN (T H ) from the heating element 61 at at least three exothermic temperatures T H is an independent variable, and the nitrogen concentration is a dependent variable. Also create a concentration formula.

チャンバ101に基準ガスが供給されると、図1及び図2に示す発熱素子61は、図23に示す駆動回路303から駆動電力PH1,PH2,PH3,PH4,PH5を順次与えられる。駆動電力PH1,PH2,PH3,PH4,PH5を与えられた場合、基準ガスに接する発熱素子61は、5段階の温度TH1、TH2、TH3、TH4、TH5で発熱し、発熱温度TH1における基準電気信号SH1A(TH1)、発熱温度TH2における基準電気信号SH2A(TH2)、発熱温度TH3における基準電気信号SH3A(TH3)、発熱温度TH4における基準電気信号SH4A(TH4)、及び発熱温度TH5における基準電気信号SH5A(TH5)を出力する。 When the reference gas is supplied to the chamber 101, the heater element 61 shown in FIGS. 1 and 2 sequentially supplies driving power P H1, P H2, P H3 , P H4, P H5 from the driving circuit 303 shown in FIG. 23 It is done. When the driving powers P H1 , P H2 , P H3 , P H4 , and P H5 are given, the heating element 61 in contact with the reference gas has five levels of temperatures T H1 , T H2 , T H3 , T H4 , and T H5 . fever, reference electrical signal S H1A at the heat producing temperature T H1 (T H1), the reference electric signal S H2A at the heat producing temperature T H2 (T H2), the reference electrical signal at the heat producing temperature T H3 S H3A (T H3) , heating temperature reference electrical signal S H4A at T H4 (T H4), and outputs a reference electric signal S H5A (T H5) at a heat producing temperature T H5.

チャンバ101から基準ガスが除去された後、校正ガスがチャンバ101に供給される。チャンバ101に校正ガスが供給されると、校正ガスに接する発熱素子61は、5段階の温度TH1、TH2、TH3、TH4、TH5で発熱し、発熱温度TH1における校正用電気信号SH1B(TH1)、発熱温度TH2における校正用電気信号SH2B(TH2)、発熱温度TH3における校正用電気信号SH3B(TH3)、発熱温度TH4における校正用電気信号SH4B(TH4)、及び発熱温度TH5における校正用電気信号SH5B(TH5)を出力する。 After the reference gas is removed from the chamber 101, calibration gas is supplied to the chamber 101. When the calibration gas is supplied to the chamber 101, the heating element 61 in contact with the calibration gas generates heat at five stages of temperatures T H1 , T H2 , T H3 , T H4 , T H5 , and the calibration electricity at the heat generation temperature T H1 . signal S H1B (T H1), the heat producing temperature T calibration electrical signal S H2B in H2 (T H2), calibration electrical signal S H3B at the heat producing temperature T H3 (T H3), an electrical signal for calibration at the heat producing temperature T H4 S The calibration electric signal S H5B (T H5 ) at H4B (T H4 ) and the heat generation temperature T H5 is output.

チャンバ101から校正ガスが除去された後、複数の窒素非含有混合ガスのそれぞれがチャンバ101に順次供給される。チャンバ101に複数の窒素非含有混合ガスの内の第1の窒素非含有混合ガスが供給されると、第1の窒素非含有混合ガスに接する図1及び図2に示す発熱素子61は、発熱温度TH1における窒素非含有時電気信号SH1(TH1)、発熱温度TH2における窒素非含有時電気信号SH2(TH2)、発熱温度TH3における窒素非含有時電気信号SH3(TH3)、発熱温度TH4における窒素非含有時電気信号SH4(TH4)、及び発熱温度TH5における窒素非含有時電気信号SH5(TH5)を出力する。他の窒素非含有混合ガスのそれぞれについても、発熱素子61は、発熱温度TH1における窒素非含有時電気信号SH1(TH1)、発熱温度TH2における窒素非含有時電気信号SH2(TH2)、発熱温度TH3における窒素非含有時電気信号SH3(TH3)、発熱温度TH4における窒素非含有時電気信号SH4(TH4)、及び発熱温度TH5における窒素非含有時電気信号SH5(TH5)を出力する。 After the calibration gas is removed from the chamber 101, each of the plurality of nitrogen-free mixed gases is sequentially supplied to the chamber 101. When the first nitrogen-free mixed gas among the plurality of nitrogen-free mixed gases is supplied to the chamber 101, the heating element 61 shown in FIGS. 1 and 2 in contact with the first nitrogen-free mixed gas generates heat. temperature T H1 nitrogen-free time of the electric signal S in H1 (T H1), the heat producing temperature T nitrogen-free time of the electric signal S H2 in H2 (T H2), heating temperature T at nitrogen-free in H3 electric signal S H3 (T H3 ), an electric signal S H4 (T H4 ) when nitrogen is not contained at an exothermic temperature T H4 , and an electric signal S H5 (T H5 ) when no nitrogen is contained at an exothermic temperature T H5 . For each well of other nitrogen-containing gas mixture, heating element 61, heating temperature T nitrogen-free time of an electrical signal at a H1 S H1 (T H1), fever producing temperature T H2, nitrogen-free time of the electric signal S H2 in (T H2), nitrogen-free time of an electrical signal at a heat producing temperature T H3 S H3 (T H3) , heating nitrogen-free time of the electric signal S H4 (T H4 at the temperature T H4), and nitrogen-free time electricity at the heat producing temperature T H5 The signal S H5 (T H5 ) is output.

図23に示すチャンバ101から複数の窒素非含有混合ガスのそれぞれが除去された後、複数の窒素含有混合ガスのそれぞれがチャンバ101に順次供給される。チャンバ101に複数の窒素含有混合ガスの内の第1の窒素含有混合ガスが供給されると、第1の窒素含有混合ガスに接する図1及び図2に示す発熱素子61は、発熱温度TH1における窒素含有時電気信号SH1(TH1)、発熱温度TH2における窒素含有時電気信号SH2(TH2)、発熱温度TH3における窒素含有時電気信号SH3(TH3)、発熱温度TH4における窒素含有時電気信号SH4(TH4)、及び発熱温度TH5における窒素含有時電気信号SH5(TH5)を出力する。他の窒素含有混合ガスのそれぞれについても、発熱素子61は、発熱温度TH1における窒素含有時電気信号SH1(TH1)、発熱温度TH2における窒素含有時電気信号SH2(TH2)、発熱温度TH3における窒素含有時電気信号SH3(TH3)、発熱温度TH4における窒素含有時電気信号SH4(TH4)、及び発熱温度TH5における窒素含有時電気信号SH5(TH5)を出力する。 After each of the plurality of nitrogen-free mixed gases is removed from the chamber 101 illustrated in FIG. 23, each of the plurality of nitrogen-containing mixed gases is sequentially supplied to the chamber 101. When the first nitrogen-containing mixed gas among the plurality of nitrogen-containing mixed gases is supplied to the chamber 101, the heating element 61 shown in FIGS. 1 and 2 in contact with the first nitrogen-containing mixed gas has a heating temperature T H1. Nitrogen-containing electrical signal S H1 (T H1 ), exothermic temperature T H2 nitrogen-containing electrical signal S H2 (T H2 ), exothermic temperature T H3 nitrogen-containing electrical signal S H3 (T H3 ), exothermic temperature T An electrical signal S H4 (T H4 ) when nitrogen is contained in H4 and an electrical signal S H5 (T H5 ) when nitrogen is contained at an exothermic temperature T H5 are output. For each well of other nitrogen-containing gas mixture, heating element 61, the nitrogen-containing time an electrical signal at a heat producing temperature T H1 S H1 (T H1) , fever producing temperature T H2, nitrogenous during electric signal S H2 in (T H2), heat producing temperature T H3 nitrogenous during electric signal S H3 in (T H3), heating temperature at the time the nitrogen content in T H4 electric signal S H4 (T H4), and the heating temperature T nitrogenous during electric signal S H5 in H5 (T H5 ) Is output.

なお、図23に示すチャンバ101に供給されるガスの順番は任意である。例えば、複数の窒素非含有混合ガスの間に、校正ガスがチャンバ101に供給されてもよい。   Note that the order of gases supplied to the chamber 101 shown in FIG. 23 is arbitrary. For example, the calibration gas may be supplied to the chamber 101 between a plurality of nitrogen-free mixed gases.

マイクロチップ8は、測定部301を含む中央演算処理装置(CPU)300に接続されている。CPU300には、電気信号記憶装置401が接続されている。測定部301は、基準ガスに接する発熱素子61からの発熱温度TH1における基準電気信号SH1A(TH1)、発熱温度TH2における基準電気信号SH2A(TH2)、発熱温度TH3における基準電気信号SH3A(TH3)、発熱温度TH4における基準電気信号SH4A(TH4)、及び発熱温度TH5における基準電気信号SH5A(TH5)の測定値を測定し、測定値を電気信号記憶装置401に保存する。 The microchip 8 is connected to a central processing unit (CPU) 300 that includes a measurement unit 301. An electrical signal storage device 401 is connected to the CPU 300. Measuring unit 301, the reference electrical signal S H1A at a heat producing temperature T H1, from the heater element 61 in contact with the reference gas (T H1), the reference electric signal S H2A at the heat producing temperature T H2 (T H2), the reference in the heat producing temperature T H3 electrical signal S H3A (T H3), measures the measurement value of the reference electrical signal S H4A at the heat producing temperature T H4 (T H4), and the reference electrical signal S H5A at the heat producing temperature T H5 (T H5), electrical measurements Save in the signal storage device 401.

また、測定部301は、校正ガスに接する発熱素子61からの発熱温度TH1における校正用電気信号SH1B(TH1)、発熱温度TH2における校正用電気信号SH2B(TH2)、発熱温度TH3における校正用電気信号SH3B(TH3)、発熱温度TH4における校正用電気信号SH4B(TH4)、及び発熱温度TH5における校正用電気信号SH5B(TH5)の測定値を測定し、測定値を電気信号記憶装置401に保存する。 The measurement unit 301, calibration electrical signal S H1B at a heat producing temperature T H1, from the heater element 61 in contact with the calibration gas (T H1), calibration electrical signal S H2B at the heat producing temperature T H2 (T H2), heating temperature calibration electrical signal S H3B at T H3 (T H3), calibration electrical signal S H4B at the heat producing temperature T H4 (T H4), and the measured values of the calibration electrical signal S H5B (T H5) at a heat producing temperature T H5 Measure and store the measured value in the electrical signal storage device 401.

さらに、測定部301は、複数の窒素非含有混合ガスのそれぞれに接する発熱素子61からの発熱温度TH1における窒素非含有時電気信号SH1(TH1)、発熱温度TH2における窒素非含有時電気信号SH2(TH2)、発熱温度TH3における窒素非含有時電気信号SH3(TH3)、発熱温度TH4における窒素非含有時電気信号SH4(TH4)、及び発熱温度TH5における窒素非含有時電気信号SH5(TH5)の測定値を測定し、測定値を電気信号記憶装置401に保存する。 Further, the measurement unit 301 is configured to display the electric signal S H1 (T H1 ) when no heat is generated from the heating element 61 in contact with each of the plurality of nitrogen-free mixed gases, and the non-nitrogen content when the heat generation temperature is T H2 . electric signal S H2 (T H2), nitrogen-free time of an electrical signal at a heat producing temperature T H3 S H3 (T H3) , nitrogen-free time of the electric signal S H4 at the heat producing temperature T H4 (T H4), and the heating temperature T H5 The measured value of the electrical signal S H5 (T H5 ) when nitrogen is not contained in is measured, and the measured value is stored in the electrical signal storage device 401.

またさらに、測定部301は、複数の窒素含有混合ガスのそれぞれに接する発熱素子61からの発熱温度TH1における窒素含有時電気信号SH1(TH1)、発熱温度TH2における窒素含有時電気信号SH2(TH2)、発熱温度TH3における窒素含有時電気信号SH3(TH3)、発熱温度TH4における窒素含有時電気信号SH4(TH4)、及び発熱温度TH5における窒素含有時電気信号SH5(TH5)の測定値を測定し、測定値を電気信号記憶装置401に保存する。 Furthermore, measuring unit 301, the heat generation temperature T when the nitrogen content in H1 electric signal S H1 (T H1) from the heater element 61 coming into contact with the each of the plurality of nitrogen-containing mixed gas, nitrogen-containing time electrical signal at the heat producing temperature T H2, S H2 (T H2), the heat producing temperature T nitrogenous when an electrical signal at a H3 S H3 (T H3), heat producing temperature T H4 nitrogenous during electric signal S H4 in (T H4), and when the nitrogen containing at the heat producing temperature T H5 The measured value of the electrical signal S H5 (T H5 ) is measured, and the measured value is stored in the electrical signal storage device 401.

発熱素子61からの電気信号SHとは、発熱素子61の抵抗値RH、発熱素子61の通電電流IH、及び発熱素子61に接続されたA/D変換回路304の出力信号ADHのいずれであってもよい。 The electric signals S H from the heater element 61, the heater element 61 the resistance value R H, of the energizing current I H, and the output signal AD H of the connected A / D conversion circuit 304 to the heater element 61 of the heater element 61 Either may be sufficient.

CPU300に含まれる式作成部302は、例えば基準ガス、校正ガス、複数の窒素非含有混合ガス、及び複数の窒素含有混合ガスのそれぞれの既知の発熱量Qの値と、発熱素子61からの基準電気信号SH1A(TH1),SH2A(TH2),SH3A(TH3),SH4A(TH4),SH5A(TH5)の測定値、校正用電気信号SH1B(TH1),SH2B(TH2),SH3B(TH3),SH4B(TH4),SH5B(TH5)の測定値、窒素非含油時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値、及び窒素含油時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値と、を収集する。 The formula creation unit 302 included in the CPU 300 includes, for example, the known calorific value Q of each of the reference gas, the calibration gas, the plurality of nitrogen-free mixed gases, and the plurality of nitrogen-containing mixed gases, and the reference from the heating element 61. electrical signal S H1A (T H1), S H2A (T H2), S H3A (T H3), S H4A (T H4), the measured value of S H5A (T H5), calibration electrical signal S H1B (T H1) , S H2B (T H2 ), S H3B (T H3 ), S H4B (T H4 ), S H5B (T H5 ) measured values, nitrogen non-oil- free electrical signals S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), S H5 (T H5 ), and the nitrogen oil-containing electrical signals S H1 (T H1 ), S H2 (T H2 ), S H3 A plurality of measured values of (T H3 ), S H4 (T H4 ), and S H5 (T H5 ) are collected.

さらに式作成部302は、収集した発熱量Qの値と、基準電気信号SHAの測定値、校正用電気信号SHBの測定値、窒素非含油時電気信号SHの測定値、及び窒素含油時電気信号SHの測定値に基づいて、多変量解析により、発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)を独立変数とし、発熱量Qを従属変数とする発熱量算出式を算出する。 Further formula creation module 302, the value of the collected calorific value Q, the measured value of the reference electrical signal S HA, measurements of the calibration electrical signal S HB, measurement of nitrogen-oil-containing time electric signal S H, and a nitrogen oil-containing Based on the measured value of the time electrical signal S H , electrical signals S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ) from the heating element 61 are obtained by multivariate analysis. ), S H5 (T H5 ) is an independent variable, and a calorific value calculation formula is calculated with a calorific value Q as a dependent variable.

「多変量解析」とは、A.J Smola及びB.Scholkopf著の「A Tutorial on Support Vector Regression」(NeuroCOLT Technical Report (NC−TR−98−030)、1998年)に開示されているサポートベクトル回帰、重回帰分析、及び特開平5−141999号公報に開示されているファジィ数量化理論II類等を含む。   “Multivariate analysis” means A. J Smol and B.M. In support vector regression, multiple regression analysis, and Japanese Patent Application Laid-Open No. 5-141999, disclosed in Scholkopf's “A Tutor on Support Vector Regression” (NeuroCOLt Technical Report (NC-TR-98-030), 1998). Includes the disclosed fuzzy quantification theory class II.

正規化部306は、同一ゲインにおける、発熱素子61からの基準電気信号SH3A(TH3),SH4A(TH4),SH5A(TH5)の測定値、校正用電気信号SH3B(TH3),SH4B(TH4),SH5B(TH5)の測定値、窒素非含油時電気信号SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値、及び窒素含油時電気信号SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値を収集する。 The normalizing unit 306 uses the measured values of the reference electrical signals S H3A (T H3 ), S H4A (T H4 ), S H5A (T H5 ) and the calibration electrical signal S H3B (T H3), S H4B (T H4 ), the measured value of S H5B (T H5), nitrogen-oil-containing time electric signal S H3 (T H3), S H4 (T H4), a plurality of measurements of S H5 (T H5) value, and nitrogen oilless when the electric signal S H3 (T H3), S H4 (T H4), collecting a plurality of measured values of S H5 (T H5).

また、正規化部306は、複数の発熱温度のそれぞれにおいて、例えば下記(48)式に示すように、電気信号SH(TH)の測定値と基準電気信号SHA(TH)の測定値との差を、校正用電気信号SHB(TH)の測定値と基準電気信号SHA(TH)の測定値との差で割って、正規化された電気信号の測定値SHN(TH)を算出する
SHN(TH)= (SH(TH)-SHA(TH))/(SHB(TH)-SHA(TH)) ・・・(48)
上記(48)式を用いると、正規化された基準電気信号の測定値SHAN(TH)は、発熱温度に関わらず、0になる。また、正規化された校正用電気信号の測定値SHBN(TH)は、発熱温度に関わらず、1になる。
Further, the normalization unit 306 measures the measured value of the electrical signal S H (T H ) and the reference electrical signal S HA (T H ) at each of the plurality of heat generation temperatures, for example, as shown in the following equation (48). The difference between the two values is divided by the difference between the measured value of the calibration electrical signal S HB (T H ) and the measured value of the reference electrical signal S HA (T H ), and the normalized measured value S HN of the electrical signal Calculate (T H )
S HN (T H ) = (S H (T H ) -S HA (T H )) / (S HB (T H ) -S HA (T H )) (48)
When the above equation (48) is used, the measured value S HAN (T H ) of the normalized reference electrical signal becomes 0 regardless of the heat generation temperature. Further, the measured value S HBN (T H ) of the normalized electrical signal for calibration is 1 regardless of the heat generation temperature.

式作成部302は、正規化された窒素非含油時電気信号の複数の測定値SH3N(TH3),SH4N(TH4),SH5N(TH5)、及び正規化された窒素含油時電気信号の複数の測定値SH3N(TH3),SH4N(TH4),SH5N(TH5)を収集する。 The formula creation unit 302 has a plurality of measured values S H3N (T H3 ), S H4N (T H4 ), S H5N (T H5 ) of the normalized nitrogen- free oil signal and the normalized nitrogen- containing oil signal. Collect a plurality of measured values S H3N (T H3 ), S H4N (T H4 ), and S H5N (T H5 ) of the electrical signal.

式作成部302は、複数の窒素非含有混合ガスのそれぞれについて、下記(49)式に示すように、発熱温度TH5と発熱温度TH4の差を、発熱温度の第1の差として、発熱温度TH5における正規化された窒素非含油時電気信号SH5N(TH5)と、発熱温度TH4における正規化された窒素非含油時電気信号SH4N(TH4)と、差である、正規化された窒素非含有時電気信号の第1の差の値d1を算出する。
d1= SH5(TH5)-SH4(TH5) ・・・(49)
For each of the plurality of nitrogen-free mixed gases, the formula creating unit 302 generates the heat by using the difference between the heat generation temperature T H5 and the heat generation temperature T H4 as the first heat generation temperature difference as shown in the following formula (49). a normalized nitrogen-oil-containing time electric signal S H5N (T H5) at a temperature T H5, a normalized nitrogen-oil-containing time electric signal S H4N at the heat producing temperature T H4 (T H4), which is the difference, normalized The first difference value d 1 of the converted nitrogen-free electrical signal is calculated.
d 1 = S H5 (T H5 ) -S H4 (T H5 ) (49)

式作成部302は、複数の窒素含有混合ガスのそれぞれについても、発熱温度TH5における正規化された窒素含油時電気信号SH5N(TH5)と、発熱温度TH4における正規化された窒素含油時電気信号SH4N(TH4)と、差である、正規化された窒素含有時電気信号の第1の差の値d1を算出する。 For each of the plurality of nitrogen-containing mixed gases, the formula creation unit 302 also uses the normalized nitrogen oil- containing electric signal S H5N (T H5 ) at the exothermic temperature T H5 and the normalized nitrogen oil- containing at the exothermic temperature T H4 . A first difference value d 1 between the hourly electrical signal S H4N (T H4 ) and the normalized nitrogen-containing hourly electrical signal is calculated.

また、式作成部302は、複数の窒素非含有混合ガスのそれぞれについて、下記(50)式に示すように、発熱温度TH4と発熱温度TH3の差を、発熱温度の第2の差として、発熱温度TH4における正規化された窒素非含油時電気信号SH4N(TH4)と、発熱温度TH3における正規化された窒素非含油時電気信号SH3N(TH3)と、差である、正規化された窒素非含有時電気信号の第2の差の値d2を算出する。
d2= SH4(TH4)-SH3(TH3) ・・・(50)
In addition, as shown in the following formula (50), the formula creation unit 302 sets the difference between the heat generation temperature T H4 and the heat generation temperature T H3 as the second difference in the heat generation temperature for each of the plurality of nitrogen-free mixed gases. , the heating temperature normalized nitrogen-oil-containing time an electrical signal at a T H4 S H4N (T H4) , the heating temperature T normalized nitrogen-oil-containing time an electrical signal at a H3 S H3N (T H3), is the difference Then, a second difference value d 2 of the normalized electric signal without nitrogen is calculated.
d 2 = S H4 (T H4 ) -S H3 (T H3 ) (50)

式作成部302は、複数の窒素含有混合ガスのそれぞれについても、発熱温度TH4における正規化された窒素含油時電気信号SH4N(TH4)と、発熱温度TH3における正規化された窒素含油時電気信号SH3N(TH3)と、差である、正規化された窒素含有時電気信号の第2の差の値d2を算出する。 For each of the plurality of nitrogen-containing mixed gases, the formula creating unit 302 also normalizes the nitrogen-containing oil signal S H4N (T H4 ) at the exothermic temperature T H4 and the normalized nitrogen-containing oil at the exothermic temperature T H3 . A second difference value d 2 between the hourly electrical signal S H3N (T H3 ) and the normalized nitrogen-containing hourly electrical signal is calculated.

式作成部302は、複数の窒素非含有混合ガスのそれぞれについて、下記(51)式に示すように、第1の差の値d1に第1の補正係数A1を掛けた補正された第1の差dC1と、第2の差の値d2と、の差の値である評価値Eを設定する。さらに、式作成部302は、複数の窒素非含有混合ガスのそれぞれについて、評価値Eが0に近づくような第1の補正係数A1の値を算出する。
E=A1×d1-d2
=dC1-d2 ・・・(51)
For each of the plurality of nitrogen-free mixed gases, the equation creating unit 302 corrects the first difference value d 1 multiplied by the first correction coefficient A 1 as shown in the following equation (51). An evaluation value E that is a difference value between the difference d C1 of 1 and the value d 2 of the second difference is set. Further, the formula creation unit 302 calculates a value of the first correction coefficient A 1 such that the evaluation value E approaches 0 for each of the plurality of nitrogen-free mixed gases.
E = A 1 × d 1 -d 2
= d C1 -d 2 ... (51)

さらに、式作成部302は、例えば、下記(52)式に示すように、評価値Eに第2の補正係数A2を掛けた補正された評価値ECを、混合ガスに含まれる窒素の濃度の測定値として設定する。さらに、式作成部302は、複数の窒素含有混合ガスのそれぞれにおいて、窒素濃度の既知の実際の値と、窒素濃度の測定値ECと、の間の誤差が0に近づくような第2の補正係数A2の値を算出する。第2の補正係数A2を掛けることにより、無次元数である評価値Eが、濃度単位に変換される。
EC=E×A2 ・・・(52)
Further, for example, as shown in the following formula (52), the formula creating unit 302 uses a corrected evaluation value E C obtained by multiplying the evaluation value E by the second correction coefficient A 2 to the nitrogen contained in the mixed gas. Set as a measured value of concentration. Further, the formula creating unit 302 performs the second operation such that the error between the known actual value of the nitrogen concentration and the measured value E C of the nitrogen concentration approaches zero in each of the plurality of nitrogen-containing mixed gases. The value of the correction coefficient A 2 is calculated. By multiplying the second correction coefficient A 2, is a dimensionless number evaluation value E is converted into concentration units.
E C = E × A 2 ... (52)

式作成部302は、算出された第1の補正係数A1、及び第2の補正係数A2を用いて、上記(47)式に示すような、少なくとも3つの発熱温度における発熱素子61からの正規化された電気信号SH3N(TH3),SH4N(TH4),SH5N(TH5)を独立変数とし、窒素濃度ECを従属変数とする窒素濃度算出式を作成する。 The formula creation unit 302 uses the calculated first correction coefficient A 1 and second correction coefficient A 2 to generate the current from the heating element 61 at at least three heating temperatures as shown in the above formula (47). A nitrogen concentration calculation formula is created with the normalized electrical signals S H3N (T H3 ), S H4N (T H4 ), and S H5N (T H5 ) as independent variables and the nitrogen concentration E C as a dependent variable.

窒素濃度測定システム20は、CPU300に接続された式記憶装置402をさらに備える。式記憶装置402は、式作成部302が作成した発熱量算出式を保存する。また、式記憶装置402は、式作成部302が作成した窒素濃度算出式を保存する。さらにCPU300には、入力装置312及び出力装置313が接続される。入力装置312としては、例えばホストコンピュータ、通信機器、キーボード、及びマウス等のポインティングデバイス等が使用可能である。出力装置313には液晶ディスプレイ、アナログ出力受信機、モニタ等の画像表示装置、及びプリンタ等が使用可能である。   The nitrogen concentration measurement system 20 further includes a formula storage device 402 connected to the CPU 300. The formula storage device 402 stores the calorific value calculation formula created by the formula creation unit 302. The formula storage device 402 stores the nitrogen concentration calculation formula created by the formula creation unit 302. Further, an input device 312 and an output device 313 are connected to the CPU 300. As the input device 312, for example, a host computer, a communication device, a keyboard, and a pointing device such as a mouse can be used. As the output device 313, a liquid crystal display, an analog output receiver, an image display device such as a monitor, a printer, and the like can be used.

次に、図24に示すフローチャートを用いて実施の形態に係る発熱量算出式の作成方法について説明する。   Next, a method for creating a calorific value calculation formula according to the embodiment will be described using the flowchart shown in FIG.

(a)ステップS100で、図23に示すチャンバ101内に基準ガスを導入する。ステップS101で、駆動回路303は、図1及び図2に示す発熱素子61に駆動電力PH1を与え、発熱素子61を発熱温度TH1で発熱させる。図23に示す測定部301は、発熱温度TH1で発熱する発熱素子61からの基準電気信号SH1A(TH1)の測定値を測定し、電気信号記憶装置401に保存する。 (A) In step S100, a reference gas is introduced into the chamber 101 shown in FIG. In step S101, the drive circuit 303 applies drive power P H1 to the heat generating element 61 shown in FIGS. 1 and 2, and causes the heat generating element 61 to generate heat at the heat generation temperature T H1 . 23 measures the measured value of the reference electrical signal S H1A (T H1 ) from the heating element 61 that generates heat at the heating temperature T H1 , and stores it in the electrical signal storage device 401.

(b)ステップS102で、駆動回路303は、図1及び図2に示す発熱素子61の温度の切り替えが完了したか否か判定する。発熱温度TH2、TH3、TH4、TH5への切り替えが完了していない場合には、ステップS101に戻り、図23に示す駆動回路303は、図1及び図2に示す発熱素子61を発熱温度TH2で発熱させる。図23に示す測定部301は、基準ガスに接し、発熱温度TH2で発熱する発熱素子61からの基準電気信号SH2A(TH2)の測定値を測定し、電気信号記憶装置401に保存する。 (B) In step S102, the drive circuit 303 determines whether or not the temperature switching of the heating element 61 shown in FIGS. 1 and 2 has been completed. If the switching to the heat generation temperatures T H2 , T H3 , T H4 , and T H5 has not been completed, the process returns to step S101, and the drive circuit 303 shown in FIG. Heat is generated at an exothermic temperature TH2 . 23 measures the measured value of the reference electrical signal S H2A (T H2 ) from the heating element 61 that is in contact with the reference gas and generates heat at the heating temperature T H2 , and stores it in the electrical signal storage device 401. .

(c)以後、ステップS101とステップS102のループを繰り返し、図23に示す測定部301は、基準ガスに接し、発熱温度TH3で発熱する発熱素子61からの基準電気信号SH3A(TH3)の測定値、発熱温度TH4で発熱する発熱素子61からの基準電気信号SH4A(TH4)の測定値、及び発熱温度TH5で発熱する発熱素子61からの基準電気信号SH5A(TH5)の測定値を電気信号記憶装置401に保存する。 (C) Thereafter, the loop of step S101 and step S102 is repeated, and the measurement unit 301 shown in FIG. 23 is in contact with the reference gas and generates the reference electrical signal S H3A (T H3 ) from the heating element 61 that generates heat at the heating temperature T H3. measurements, exothermic temperature reference from the heater element 61 that generates heat at T H4 electric signal S H4A measurements of (T H4), and the reference electrical signal S H5A from the heater element 61 that generates heat at a heat producing temperature T H5 (T H5 ) Is stored in the electrical signal storage device 401.

(d)発熱素子61の温度の切り替えが完了した場合には、ステップS102からステップS103に進む。ステップS103で、ガスの切り替えが完了したか否かを判定する。基準ガスから校正ガスへの切り替えが完了していない場合には、ステップS100に戻る。ステップS100で、図23に示すチャンバ101内に校正ガスを導入する。   (D) When the switching of the temperature of the heating element 61 is completed, the process proceeds from step S102 to step S103. In step S103, it is determined whether or not the gas switching has been completed. If switching from the reference gas to the calibration gas has not been completed, the process returns to step S100. In step S100, a calibration gas is introduced into the chamber 101 shown in FIG.

(e)基準ガスがチャンバ101に導入されたときと同様に、ステップS101からステップS102のループが繰り返される。測定部301は、校正ガスに接し、発熱温度TH1、TH2、TH3、TH4、TH5で発熱する発熱素子61からの校正用電気信号SH1B(TH1),SH2B(TH2),SH3B(TH3),SH4B(TH4),SH5B(TH5)の測定値を測定し、電気信号記憶装置401に保存する。 (E) The loop from step S101 to step S102 is repeated in the same manner as when the reference gas is introduced into the chamber 101. The measurement unit 301 is in contact with the calibration gas, and the calibration electric signals S H1B (T H1 ) and S H2B (T H2 ) from the heating element 61 that generates heat at the heat generation temperatures T H1 , T H2 , T H3 , T H4 , T H5. ), S H3B (T H3 ), S H4B (T H4 ), and S H5B (T H5 ) are measured and stored in the electrical signal storage device 401.

(f)発熱素子61の温度の切り替えが完了した場合には、ステップS102からステップS103に進む。ステップS103で、ガスの切り替えが完了したか否かを判定する。校正ガスから複数の窒素非含有混合ガスのそれぞれへの切り替えが完了していない場合には、ステップS100に戻る。ステップS100で、図23に示すチャンバ101内に複数の窒素非含有混合ガスの内の第1の窒素非含有混合ガスを導入する。   (F) When the switching of the temperature of the heating element 61 is completed, the process proceeds from step S102 to step S103. In step S103, it is determined whether or not the gas switching has been completed. If switching from the calibration gas to each of the plurality of nitrogen-free mixed gases has not been completed, the process returns to step S100. In step S100, the first nitrogen-free mixed gas among the plurality of nitrogen-free mixed gases is introduced into the chamber 101 shown in FIG.

(g)基準ガスがチャンバ101に導入されたときと同様に、ステップS101からステップS102のループが繰り返される。測定部301は、第1の窒素非含有混合ガスに接し、発熱温度TH1、TH2、TH3、TH4、TH5で発熱する発熱素子61からの窒素非含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の測定値を測定し、電気信号記憶装置401に保存する。 (G) The loop from step S101 to step S102 is repeated in the same manner as when the reference gas is introduced into the chamber 101. The measurement unit 301 is in contact with the first non-nitrogen-containing mixed gas, and the non-nitrogen-containing electric signal S H1 (T H (T) from the heating element 61 that generates heat at the exothermic temperatures T H1 , T H2 , T H3 , T H4 , T H5. The measured values of H1 ), SH2 ( TH2 ), SH3 ( TH3 ), SH4 ( TH4 ), SH5 ( TH5 ) are measured and stored in the electrical signal storage device 401.

(h)その後、ステップS100からステップS103のループが繰り返される。これにより、他の窒素非含有混合ガスのそれぞれに接し、発熱温度TH1、TH2、TH3、TH4、TH5で発熱する発熱素子61からの窒素非含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の測定値が電気信号記憶装置401に保存される。 (H) Thereafter, the loop from step S100 to step S103 is repeated. Thus, the non-nitrogen containing electrical signal S H1 (T H1) from the heating element 61 in contact with each of the other non-nitrogen containing mixed gases and generating heat at the exothermic temperatures T H1 , T H2 , T H3 , T H4 , T H5. ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), and S H5 (T H5 ) are stored in the electrical signal storage device 401.

(i)発熱素子61の温度の切り替えが完了した場合には、ステップS102からステップS103に進む。ステップS103で、ガスの切り替えが完了したか否かを判定する。複数の窒素非含有混合ガスから複数の窒素含有混合ガスのそれぞれへの切り替えが完了していない場合には、ステップS100に戻る。ステップS100で、図23に示すチャンバ101内に複数の窒素含有混合ガスの内の第1の窒素含有混合ガスを導入する。   (I) When the switching of the temperature of the heating element 61 is completed, the process proceeds from step S102 to step S103. In step S103, it is determined whether or not the gas switching has been completed. If switching from the plurality of nitrogen-free mixed gases to each of the plurality of nitrogen-containing mixed gases has not been completed, the process returns to step S100. In step S100, the first nitrogen-containing mixed gas among the plurality of nitrogen-containing mixed gases is introduced into the chamber 101 shown in FIG.

(j)基準ガスがチャンバ101に導入されたときと同様に、ステップS101からステップS102のループが繰り返される。測定部301は、第1の窒素含有混合ガスに接し、発熱温度TH1、TH2、TH3、TH4、TH5で発熱する発熱素子61からの窒素含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の測定値を測定し、電気信号記憶装置401に保存する。 (J) The loop from step S101 to step S102 is repeated in the same manner as when the reference gas is introduced into the chamber 101. The measurement unit 301 is in contact with the first nitrogen-containing mixed gas, and the nitrogen-containing electric signal S H1 (T H1 ) from the heating element 61 that generates heat at the heat generation temperatures T H1 , T H2 , T H3 , T H4 , T H5. , S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), and S H5 (T H5 ) are measured and stored in the electrical signal storage device 401.

(k)その後、ステップS100からステップS103のループが繰り返される。これにより、他の窒素含有混合ガスのそれぞれに接し、発熱温度TH1、TH2、TH3、TH4、TH5で発熱する発熱素子61からの窒素含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の測定値が電気信号記憶装置401に保存される。 (K) Thereafter, the loop from step S100 to step S103 is repeated. As a result, the nitrogen-containing electrical signal S H1 (T H1 ), which is in contact with each of the other nitrogen-containing mixed gases and is generated from the heating element 61 that generates heat at the heat generation temperatures T H1 , T H2 , T H3 , T H4 , T H5 , The measured values of S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), and S H5 (T H5 ) are stored in the electrical signal storage device 401.

(l)ステップS104で、入力装置312から式作成部302に、基準ガス、校正ガス、複数の窒素非含有混合ガス、及び複数の窒素含有混合ガスのそれぞれの既知の発熱量Qの値を入力する。また、式作成部302は、電気信号記憶装置401から、発熱素子61からの基準電気信号SH1A(TH1),SH2A(TH2),SH3A(TH3),SH4A(TH4),SH5A(TH5)の測定値、校正用電気信号SH1B(TH1),SH2B(TH2),SH3B(TH3),SH4B(TH4),SH5B(TH5)の測定値、窒素非含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値、及び窒素含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値を読み出す。 (L) In step S104, the value of the known calorific value Q of each of the reference gas, the calibration gas, the plurality of nitrogen-free mixed gases, and the plurality of nitrogen-containing mixed gases is input from the input device 312 to the formula creating unit 302. To do. Further, the formula creating unit 302 receives the reference electrical signals S H1A (T H1 ), S H2A (T H2 ), S H3A (T H3 ), S H4A (T H4 ) from the electrical signal storage device 401. , the measured value of S H5A (T H5), calibration electrical signal S H1B (T H1), S H2B (T H2), S H3B (T H3), S H4B (T H4), S H5B of (T H5) A plurality of measured values of electrical signals SH1 ( TH1 ), SH2 ( TH2 ), SH3 ( TH3 ), SH4 ( TH4 ), SH5 ( TH5 ) when nitrogen is not contained, and A plurality of measured values of the electrical signals SH1 ( TH1 ), SH2 ( TH2 ), SH3 ( TH3 ), SH4 ( TH4 ), SH5 ( TH5 ) when nitrogen is contained are read.

(m)ステップS105で、基準ガス、校正ガス、複数の窒素非含有混合ガス、及び複数の窒素含有混合ガスのそれぞれの既知の発熱量Qの値と、発熱素子61からの基準電気信号SH1A(TH1),SH2A(TH2),SH3A(TH3),SH4A(TH4),SH5A(TH5)の測定値、校正用電気信号SH1B(TH1),SH2B(TH2),SH3B(TH3),SH4B(TH4),SH5B(TH5)の測定値、窒素非含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値、及び窒素含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値と、に基づいて、式作成部302は、サポートベクトル回帰などの多変量解析を行う。サポートベクトル回帰などの多変量解析により、式作成部302は、発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)を独立変数とし、発熱量Qを従属変数とする発熱量算出式を算出する。その後、ステップS106で、式作成部302は作成した発熱量算出式を式記憶装置402に保存し、実施の形態に係る発熱量算出式の作成方法が終了する。 (M) In step S105, the known calorific value Q of each of the reference gas, the calibration gas, the plurality of nitrogen-free mixed gases, and the plurality of nitrogen-containing mixed gases, and the reference electrical signal S H1A from the heating element 61 (T H1), S H2A ( T H2), S H3A (T H3), S H4A (T H4), the measured value of S H5A (T H5), calibration electrical signal S H1B (T H1), S H2B ( T H2), S H3B (T H3), S H4B (T H4), the measured value of S H5B (T H5), nitrogen-free time of the electric signal S H1 (T H1), S H2 (T H2), S H3 (T H3 ), S H4 (T H4 ), a plurality of measured values of S H5 (T H5 ), and electrical signals SH 1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ) when nitrogen is contained , S H4 (T H4 ), S H5 (T H5 ), and the formula creation unit 302 performs multivariate analysis such as support vector regression. By multivariate analysis such as support vector regression, the formula creating unit 302 generates electrical signals S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ) from the heating element 61. , S H5 (T H5 ) is an independent variable, and a calorific value calculation formula is calculated with a calorific value Q as a dependent variable. Thereafter, in step S106, the formula creation unit 302 stores the created calorific value calculation formula in the formula storage device 402, and the calorific value calculation formula creation method according to the embodiment ends.

以上示したように、実施の形態に係る発熱量算出式の作成方法によれば、測定対象混合ガスの発熱量Qの値を一意に算出可能な発熱量算出式を作成することが可能となる。   As described above, according to the method for creating the calorific value calculation formula according to the embodiment, it is possible to create a calorific value calculation formula that can uniquely calculate the calorific value Q of the measurement target mixed gas. .

次に、図25に示すフローチャートを用いて実施の形態に係る窒素濃度算出式の作成方法について説明する。   Next, a method of creating a nitrogen concentration calculation formula according to the embodiment will be described using the flowchart shown in FIG.

(a)ステップS201で、正規化部306は、電気信号記憶装置401から、発熱素子61からの基準電気信号SH1A(TH1),SH2A(TH2),SH3A(TH3),SH4A(TH4),SH5A(TH5)の測定値、校正用電気信号SH1B(TH1),SH2B(TH2),SH3B(TH3),SH4B(TH4),SH5B(TH5)の測定値、窒素非含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値、及び窒素含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値を読み出す。 (A) In step S201, the normalization unit 306 receives the reference electrical signals S H1A (T H1 ), S H2A (T H2 ), S H3A (T H3 ), S from the electrical signal storage device 401. H4A (T H4), the measured value of S H5A (T H5), calibration electrical signal S H1B (T H1), S H2B (T H2), S H3B (T H3), S H4B (T H4), S H5B (T H5 ) measured value, electric signal SH 1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), S H5 (T H5 ) when not containing nitrogen And a plurality of measured values of electrical signals SH1 ( TH1 ), SH2 ( TH2 ), SH3 ( TH3 ), SH4 ( TH4 ), SH5 ( TH5 ) when nitrogen is contained read out.

(b)ステップS202で、正規化部306は、例えば、上記(48)式を用いて、正規化された基準電気信号の測定値SHAN(TH)が発熱温度に関わらず0となり、正規化された校正用電気信号の測定値SHBN(TH)が発熱温度に関わらず1となるよう、窒素非含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値、及び窒素含有時電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の複数の測定値のそれぞれを正規化し、正規化された窒素非含有時電気信号の測定値SH1N(TH1),SH2N(TH2),SH3N(TH3),SH4N(TH4),SH5N(TH5)、及び正規化された窒素含有時電気信号の測定値SH1N(TH1),SH2N(TH2),SH3N(TH3),SH4N(TH4),SH5N(TH5)を算出する。 (B) In step S202, the normalization unit 306, for example, using the above equation (48), the measured value S HAN (T H ) of the normalized reference electrical signal becomes 0 regardless of the heat generation temperature, The non-nitrogen containing electrical signals S H1 (T H1 ), S H2 (T H2 ), S H3 (so that the measured value S HBN (T H ) of the calibrated electrical signal becomes 1 regardless of the heat generation temperature. A plurality of measured values of T H3 ), S H4 (T H4 ), S H5 (T H5 ), and electric signals SH 1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), Each of a plurality of measured values of S H4 (T H4 ) and S H5 (T H5 ) is normalized, and the measured values of the normalized electrical signal when no nitrogen is contained S H1N (T H1 ), S H2N (T H2 ) , S H3N (T H3), S H4N (T H4), S H5N (T H5), and the measured value S h1N (T H1) of the normalized nitrogenous time electrical signals, S H2N (T H2 , S H3N (T H3), S H4N (T H4), calculates the S H5N (T H5).

(c)ステップ203で、式作成部302は、正規化部306から、複数の窒素非含有混合ガスのそれぞれについての正規化された窒素非含有時電気信号の測定値SH3N(TH3),SH4N(TH4),SH5N(TH5)、及び複数の窒素含有混合ガスのそれぞれについての正規化された窒素含有時電気信号の測定値SH3N(TH3),SH4N(TH4),SH5N(TH5)を受け取る。 (C) In step 203, the formula creation unit 302 receives from the normalization unit 306 the normalized measured value S H3N (T H3 ) of the non-nitrogen containing electric signal for each of the plurality of non-nitrogen containing mixed gases. S H4N (T H4 ), S H5N (T H5 ), and normalized nitrogen-containing electrical signal measurements S H3N (T H3 ), S H4N (T H4 ) for each of the plurality of nitrogen-containing mixed gases , S H5N (T H5 ).

(d)ステップ204で、式作成部302は、例えば上記(49)式を用いて、複数の窒素非含有混合ガスのそれぞれについて、発熱温度の第1の差における、正規化された窒素非含有時電気信号の第1の差の値d1を算出する。また、式作成部302は、複数の窒素含有混合ガスのそれぞれについても、発熱温度の第1の差における、正規化された窒素含有時電気信号の第1の差の値d1を算出する。 (D) In step 204, the formula creating unit 302 uses the formula (49), for example, and normalizes nitrogen-free in the first difference in the exothermic temperature for each of the plurality of nitrogen-free mixed gases. A first difference value d 1 of the hourly electrical signal is calculated. In addition, the formula creating unit 302 also calculates the first difference value d 1 of the normalized electrical signal when containing nitrogen in the first difference in the exothermic temperature for each of the plurality of nitrogen-containing mixed gases.

(e)ステップ205で、式作成部302は、例えば上記(50)式を用いて、複数の窒素非含有混合ガスのそれぞれについて、発熱温度の第2の差における、正規化された窒素非含有時電気信号の第2の差の値d2を算出する。また、式作成部302は、複数の窒素含有混合ガスのそれぞれについても、発熱温度の第2の差における、正規化された窒素含有時電気信号の第2の差の値d2を算出する。 (E) In step 205, the formula creation unit 302 uses the above formula (50), for example, for each of the plurality of nitrogen-free mixed gases, normalized nitrogen-free in the second difference in the exothermic temperature A second difference value d 2 of the hourly electrical signal is calculated. In addition, the formula creating unit 302 also calculates the second difference value d 2 of the normalized nitrogen-containing electrical signal in the second difference in the exothermic temperature for each of the plurality of nitrogen-containing mixed gases.

(f)ステップ206で、式作成部302は、複数の窒素非含有混合ガス及び複数の窒素含有混合ガスのそれぞれについて、上記(51)式に示すように、第1の差の値d1に第1の補正係数A1を掛けた補正された第1の差dC1と、第2の差の値d2と、の差の値である評価値Eを設定する。さらに、式作成部302は、複数の窒素非含有混合ガスのそれぞれについて、評価値Eが0に近づくような第1の補正係数A1の値を算出する。 (F) In step 206, the formula creation unit 302 sets the first difference value d 1 for each of the plurality of nitrogen-free mixed gases and the plurality of nitrogen-containing mixed gases, as shown in the formula (51) above. An evaluation value E which is a difference value between the corrected first difference d C1 multiplied by the first correction coefficient A 1 and the second difference value d 2 is set. Further, the formula creation unit 302 calculates a value of the first correction coefficient A 1 such that the evaluation value E approaches 0 for each of the plurality of nitrogen-free mixed gases.

(g)ステップS207で、式作成部302は、例えば、上記(52)式に示すように、評価値Eに第2の補正係数A2を掛けた補正された評価値ECを、混合ガスに含まれる窒素の濃度の測定値として設定する。さらに、式作成部302は、複数の窒素含有混合ガスのそれぞれにおいて、窒素濃度の実際の値と、窒素濃度の測定値ECと、の間の誤差が0に近づくような第2の補正係数A2の値を算出する。 (G) In step S207, for example, as shown in the above equation (52), the equation creating unit 302 uses the evaluation value E C obtained by multiplying the evaluation value E by the second correction coefficient A 2 as a mixed gas. Is set as a measured value of the concentration of nitrogen contained in. Further, the formula creation unit 302 uses the second correction coefficient such that the error between the actual value of the nitrogen concentration and the measured value E C of the nitrogen concentration approaches zero in each of the plurality of nitrogen-containing mixed gases. to calculate the value of a 2.

(h)ステップS208で、式作成部302は、算出された第1の補正係数A1、及び第2の補正係数A2を用いて、上記(47)式に示すような、少なくとも3つの発熱温度における発熱素子61からの正規化された電気信号を独立変数とし、窒素濃度を従属変数とする窒素濃度算出式を作成する。その後、ステップS209で、式作成部302は作成した窒素濃度算出式を式記憶装置402に保存し、実施の形態に係る窒素濃度算出式の作成方法が終了する。 (H) In step S208, the formula creation unit 302 uses the calculated first correction coefficient A 1 and second correction coefficient A 2 to generate at least three heat generations as shown in the formula (47). A nitrogen concentration calculation formula is created with the normalized electrical signal from the heating element 61 at the temperature as an independent variable and the nitrogen concentration as a dependent variable. Thereafter, in step S209, the formula creation unit 302 stores the created nitrogen concentration calculation formula in the formula storage device 402, and the nitrogen concentration calculation formula creation method according to the embodiment ends.

以上示したように、実施の形態に係る窒素濃度算出式の作成方法によれば、測定対象混合ガスの窒素濃度の値を一意に算出可能な窒素濃度算出式を作成することが可能となる。   As described above, according to the method for creating a nitrogen concentration calculation formula according to the embodiment, it is possible to create a nitrogen concentration calculation formula that can uniquely calculate the nitrogen concentration value of the measurement target mixed gas.

次に、発熱量Q及び窒素濃度が未知の測定対象混合ガスの発熱量Qの値及び窒素濃度を測定する際の、実施の形態に係る図23に示す窒素濃度測定システム20の機能を説明する。   Next, functions of the nitrogen concentration measuring system 20 shown in FIG. 23 according to the embodiment when measuring the calorific value Q and the nitrogen concentration of the measurement target mixed gas whose calorific value Q and nitrogen concentration are unknown will be described. .

例えば未知の体積率でメタン(CH4)、エタン(C26)、プロパン(C38)、ブタン(C410)、窒素(N2)、及び二酸化炭素(CO2)等を含む、発熱量Q及び窒素濃度が未知の天然ガス等の測定対象混合ガスが、チャンバ101に導入される。図1及び図2に示すマイクロチップ8の発熱素子61は、図23に示す駆動回路303から駆動電力PH1,PH2,PH3,PH4,PH5を順次与えられる。駆動電力PH1,PH2,PH3,PH4,PH5を与えられた場合、測定対象混合ガスに接する発熱素子61は、例えば、5段階の発熱温度で順次発熱し、発熱温度TH1における電気信号SH1(TH1)、発熱温度TH2における電気信号SH2(TH2)、発熱温度TH3における電気信号SH3(TH3)、発熱温度TH4における電気信号SH4(TH4)、及び発熱温度TH5における電気信号SH5(TH5)を出力する。 For example, methane (CH 4 ), ethane (C 2 H 6 ), propane (C 3 H 8 ), butane (C 4 H 10 ), nitrogen (N 2 ), carbon dioxide (CO 2 ), etc. at unknown volume ratios A measurement target mixed gas such as natural gas whose calorific value Q and nitrogen concentration are unknown is introduced into the chamber 101. The heating element 61 of the microchip 8 shown in FIGS. 1 and 2 is sequentially supplied with driving powers P H1 , P H2 , P H3 , P H4 , and P H5 from the driving circuit 303 shown in FIG. When the driving powers P H1 , P H2 , P H3 , P H4 , and P H5 are given, the heating element 61 in contact with the measurement target mixed gas sequentially generates heat at, for example, five levels of heating temperature, and at the heating temperature T H1 . electric signals S H1 (T H1), an electric signal S H2 at heating temperatures T H2 (T H2), the electric signal S H3 at the heat producing temperature T H3 (T H3), the electric signal S H4 at the heat producing temperature T H4 (T H4) And an electric signal S H5 (T H5 ) at the heat generation temperature T H5 is output.

測定部301は、測定対象混合ガスに接する発熱素子61からの発熱温度TH1における電気信号SH1(TH1)、発熱温度TH2における電気信号SH2(TH2)、発熱温度TH3における電気信号SH3(TH3)、発熱温度TH4における電気信号SH4(TH4)、及び発熱温度TH5における電気信号SH5(TH5)の測定値を測定し、測定値を電気信号記憶装置401に保存する。 The measuring unit 301 has an electric signal S H1 (T H1 ) at the heat generation temperature T H1 from the heat generating element 61 in contact with the measurement target mixed gas, an electric signal S H2 (T H2 ) at the heat generation temperature T H2, and an electricity at the heat generation temperature T H3 . signal S H3 (T H3), the electric signal S H4 at the heat producing temperature T H4 (T H4), and the measured values of the electric signals S H5 (T H5) at a heat producing temperature T H5 measured, electric signal storage device measurements Save to 401.

上述したように、式記憶装置402は、電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)を独立変数とし、発熱量Qを従属変数とする発熱量算出式を保存している。 As described above, the expression storage device 402 uses the electrical signals S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), and S H5 (T H5 ) as independent variables. And a calorific value calculation formula having the calorific value Q as a dependent variable is stored.

実施の形態に係る窒素濃度測定システム20は、発熱量算出部305をさらに備える。発熱量算出部305は、式記憶装置402から発熱量算出式を読み出す。さらに、発熱量算出部305は、発熱量算出式の発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の独立変数に、電気信号記憶装置401から読み出した発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の測定値をそれぞれ代入し、測定対象混合ガスの発熱量Qの測定値を算出する。CPU300には、測定結果記憶装置403がさらに接続されている。発熱量算出部305は、算出した測定対象混合ガスの発熱量Qの値を、測定結果記憶装置403に保存する。 The nitrogen concentration measurement system 20 according to the embodiment further includes a calorific value calculation unit 305. The calorific value calculation unit 305 reads the calorific value calculation formula from the formula storage device 402. Further, the calorific value calculation unit 305 is configured to output the electric signals S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H4 ), S H from the heating element 61 of the calorific value calculation formula. Electric signals S H1 (T H1 ), S H2 (T H2 ), S H3 (T H3 ), S H4 (T H (T H5 )) read from the electric signal storage device 401 are added to the independent variables of H5 (T H5 ). The measured values of H4 ) and S H5 (T H5 ) are substituted, and the measured value of the calorific value Q of the measurement target mixed gas is calculated. A measurement result storage device 403 is further connected to the CPU 300. The calorific value calculation unit 305 stores the calculated value of the calorific value Q of the measurement target mixed gas in the measurement result storage device 403.

また、正規化部306は、発熱素子61からのSH3(TH3),SH4(TH4),SH5(TH5)の測定値を電気信号記憶装置401から読み出し、正規化された電気信号の測定値SH3N(TH3),SH4N(TH4),SH5N(TH5)を算出する。 In addition, the normalization unit 306 reads the measured values of S H3 (T H3 ), S H4 (T H4 ), and S H5 (T H5 ) from the heating element 61 from the electric signal storage device 401, and normalizes the electric The signal measurement values S H3N (T H3 ), S H4N (T H4 ), and S H5N (T H5 ) are calculated.

実施の形態に係る窒素濃度測定システム20は、窒素濃度算出部307をさらに備える。窒素濃度算出部307は、式記憶装置402から窒素濃度算出式を読み出す。また、窒素濃度算出部307は、正規化部306から、正規化された電気信号の測定値SH3N(TH3),SH4N(TH4),SH5N(TH5)を受け取る。さらに、窒素濃度算出部307は、例えば(47)式で与えられる窒素濃度算出式の正規化された電気信号SH3N(TH3),SH4N(TH4),SH5N(TH5)の独立変数に、正規化された電気信号の測定値SH3N(TH3),SH4N(TH4),SH5N(TH5)をそれぞれ代入し、測定対象混合ガスに含まれる窒素の濃度を算出する。窒素濃度算出部307は、算出した測定対象混合ガスに含まれる窒素の濃度の値を、測定結果記憶装置403に保存する。 The nitrogen concentration measurement system 20 according to the embodiment further includes a nitrogen concentration calculation unit 307. The nitrogen concentration calculation unit 307 reads the nitrogen concentration calculation formula from the formula storage device 402. Further, the nitrogen concentration calculation unit 307 receives the normalized electric signal measurement values S H3N (T H3 ), S H4N (T H4 ), and S H5N (T H5 ) from the normalization unit 306. Further, the nitrogen concentration calculation unit 307 is independent of the normalized electrical signals S H3N (T H3 ), S H4N (T H4 ), and S H5N (T H5 ) of the nitrogen concentration calculation formula given by, for example, the equation (47). The measured values S H3N (T H3 ), S H4N (T H4 ), and S H5N (T H5 ) of the normalized electrical signal are substituted for the variables, and the concentration of nitrogen contained in the measurement target mixed gas is calculated. . The nitrogen concentration calculation unit 307 stores the calculated concentration value of nitrogen contained in the measurement target mixed gas in the measurement result storage device 403.

なお、実施の形態に係る窒素濃度測定システム20の各構成要素は、同じ筐体に収まっている必要は無く、各構成要素の少なくとも一部が分離されて配置されていてもよい。   In addition, each component of the nitrogen concentration measurement system 20 according to the embodiment does not need to be housed in the same casing, and at least a part of each component may be arranged separately.

以上説明した実施の形態に係る窒素濃度測定システム20によれば、高価なガスクロマトグラフィ装置や音速センサを用いることなく、測定対象混合ガスに接する発熱素子61からの電気信号SH1(TH1),SH2(TH2),SH3(TH3),SH4(TH4),SH5(TH5)の測定値から、測定対象混合ガスの混合ガスの発熱量Qの値と窒素濃度の値を測定することが可能となる。 According to the nitrogen concentration measurement system 20 according to the embodiment described above, the electrical signal S H1 (T H1 ), the heat signal from the heating element 61 in contact with the measurement target mixed gas can be used without using an expensive gas chromatography apparatus or sound velocity sensor. S H2 (T H2), S H3 (T H3), S H4 (T H4), from the measured values of S H5 (T H5), values of the nitrogen concentration of the calorific value Q of the mixed gas to be measured mixed gas Can be measured.

天然ガスは、産出ガス田によって炭化水素の成分比率が異なる。また、天然ガスには、炭化水素の他に、窒素(N2)や炭酸ガス(CO2)等が含まれる。そのため、産出ガス田によって、天然ガスに含まれるガス成分の体積率は異なり、ガス成分の種類が既知であっても、天然ガスの発熱量Qは未知であることが多い。また、同一のガス田由来の天然ガスであっても、発熱量Qが常に一定であるとは限らず、採取時期によって変化することもある。 Natural gas has a different component ratio of hydrocarbons depending on the gas field. Natural gas includes nitrogen (N 2 ), carbon dioxide (CO 2 ) and the like in addition to hydrocarbons. Therefore, the volume ratio of the gas component contained in the natural gas differs depending on the output gas field, and the calorific value Q of the natural gas is often unknown even if the type of the gas component is known. Moreover, even if it is the natural gas derived from the same gas field, the calorific value Q is not always constant and may change depending on the sampling time.

従来、天然ガスの使用料金を徴収する際には、天然ガスの使用熱量Qでなく、使用体積に応じて課金する方法がとられている。しかし、天然ガスは由来する産出ガス田によって発熱量Qが異なるため、使用体積に課金するのは公平でない。これに対し、実施の形態に係る窒素濃度測定システム20を用いれば、ガス成分の種類が既知であるが、ガス成分の体積率が未知であるために発熱量Qが未知の天然ガス等の混合ガスの発熱量Qを、簡易に算出することが可能となる。そのため、公平な使用料金を徴収することが可能となる。   Conventionally, when collecting the usage fee of natural gas, a method has been used in which charging is performed according to the volume of use, not the amount of heat Q used for natural gas. However, since the calorific value Q differs depending on the production gas field from which natural gas is derived, it is not fair to charge the volume used. On the other hand, if the nitrogen concentration measurement system 20 according to the embodiment is used, the type of gas component is known, but the volume ratio of the gas component is unknown. The calorific value Q of the gas can be easily calculated. Therefore, it becomes possible to collect a fair usage fee.

また、LNGを原料とするガス事業においては、エネルギー有効活用の観点から、ボイルオフガス(BOG)を捨てずに都市ガスに混入させる傾向にある。ボイルオフガスにおいては、メタンが主成分であるが、低沸点成分である窒素が高濃度で含まれる場合がある。窒素は不燃成分であり、発熱量がゼロであるから、混合ガスの発熱量を正確に把握するためにも、混合ガスに含まれる窒素濃度を測定可能であることは有用である。   In the gas business using LNG as a raw material, from the viewpoint of effective energy utilization, boil-off gas (BOG) tends to be mixed into city gas without being discarded. In the boil-off gas, methane is the main component, but nitrogen, which is a low boiling point component, may be contained at a high concentration. Since nitrogen is an incombustible component and the calorific value is zero, it is useful to be able to measure the concentration of nitrogen contained in the mixed gas in order to accurately grasp the calorific value of the mixed gas.

(その他の実施の形態)
上記のように、本発明は実施の形態によって記載したが、この開示の一部をなす記述及び図面はこの発明を限定するものであると理解するべきではない。この開示から当業者には様々な代替実施の形態、実施の形態及び運用技術が明らかになるはずである。本発明はここでは記載していない様々な実施の形態等を包含するということを理解すべきである。
(Other embodiments)
As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, embodiments, and operation techniques should be apparent to those skilled in the art. It should be understood that the present invention includes various embodiments and the like not described herein.

8 マイクロチップ
18 断熱部材
20 窒素濃度測定システム
60 基板
61 発熱素子
62 第1の測温素子
63 第2の測温素子
64 保温素子
65 絶縁膜
66 キャビティ
101 チャンバ
102、103 流路
300 中央演算処理装置
301 測定部
302 式作成部
303 駆動回路
304 変換回路
305 発熱量算出部
306 正規化部
307 窒素濃度算出部
312 入力装置
313 出力装置
401 電気信号記憶装置
402 式記憶装置
403 測定結果記憶装置
8 Microchip 18 Heat insulation member 20 Nitrogen concentration measurement system 60 Substrate 61 Heating element 62 First temperature measuring element 63 Second temperature measuring element 64 Heat insulating element 65 Insulating film 66 Cavity 101 Chamber 102, 103 Flow path 300 Central processing unit 301 Measurement unit 302 Formula creation unit 303 Drive circuit 304 Conversion circuit 305 Heat generation amount calculation unit 306 Normalization unit 307 Nitrogen concentration calculation unit 312 Input device 313 Output device 401 Electric signal storage device 402 Formula storage device 403 Measurement result storage device

Claims (20)

複数の発熱温度のそれぞれにおいて測定対象混合ガスに接する発熱素子からの電気信号の測定値を測定する測定部と、
炭化水素を校正成分とする窒素を含まない基準ガス及び校正ガスに接する前記発熱素子からの電気信号の値が発熱温度に関わらずそれぞれ一定となるよう、前記電気信号の測定値を正規化する正規化部と、
少なくとも3つの発熱温度における前記発熱素子からの正規化された電気信号を独立変数とし、窒素濃度を従属変数とする窒素濃度算出式を保存する式記憶装置と、
前記窒素濃度算出式の前記独立変数に、前記正規化された電気信号の測定値を代入し、前記測定対象混合ガスに含まれる窒素の濃度を算出する窒素濃度算出部と、
を備える、窒素濃度測定システム。
A measuring unit for measuring a measured value of an electric signal from a heating element in contact with the measurement target mixed gas at each of a plurality of heating temperatures;
Normalization that normalizes the measured value of the electric signal so that the value of the electric signal from the heating element in contact with the reference gas not containing nitrogen and the calibration gas containing hydrocarbon as a calibration component is constant regardless of the heat generation temperature. And
A formula storage device for storing a nitrogen concentration calculation formula having normalized electric signals from the heating elements at at least three heating temperatures as independent variables and a nitrogen concentration as a dependent variable;
Substituting the normalized measured value of the electrical signal into the independent variable of the nitrogen concentration calculation formula, and calculating a concentration of nitrogen contained in the measurement target mixed gas;
A nitrogen concentration measurement system.
前記窒素濃度算出部が、発熱温度の第1の差における前記正規化された電気信号の測定値の第1の差に、補正係数を掛けた補正された第1の差と、発熱温度の第2の差における前記正規化された電気信号の測定値の第2の差と、の差である評価値に基づいて、前記測定対象混合ガスに含まれる窒素の濃度を算出し、前記補正係数が、窒素を含まないガスが前記発熱素子に接している場合に、前記評価値が0に近づくよう設定されている、請求項1に記載の窒素濃度測定システム。   The nitrogen concentration calculator is configured to multiply the first difference of the measured value of the normalized electrical signal in the first difference of the exothermic temperature by a correction coefficient and the first difference of the exothermic temperature. A concentration of nitrogen contained in the measurement target gas mixture is calculated based on an evaluation value that is a difference between the second difference of the measured values of the normalized electrical signal in the difference of 2, and the correction coefficient is The nitrogen concentration measurement system according to claim 1, wherein the evaluation value is set to approach 0 when a gas not containing nitrogen is in contact with the heating element. 前記窒素濃度算出部が、前記評価値に第2の補正係数を掛けて前記窒素の濃度を算出し、前記第2の補正係数が、無次元数である前記評価値を濃度単位に換算する、請求項2に記載の窒素濃度測定システム。   The nitrogen concentration calculator multiplies the evaluation value by a second correction coefficient to calculate the nitrogen concentration, and the second correction coefficient converts the evaluation value, which is a dimensionless number, into a concentration unit. The nitrogen concentration measurement system according to claim 2. 前記基準ガスがメタンガスである、請求項1から3のいずれか1項に記載の窒素濃度測定システム。   The nitrogen concentration measurement system according to any one of claims 1 to 3, wherein the reference gas is methane gas. 前記正規化部が、前記基準ガスに接する前記発熱素子からの電気信号の値が発熱温度に関わらず0となるよう、前記電気信号の測定値を正規化する、請求項1から4のいずれか1項に記載の窒素濃度測定システム。   The said normalization part normalizes the measured value of the said electrical signal so that the value of the electrical signal from the said heat generating element which contact | connects the said reference gas may become 0 irrespective of heat_generation | fever temperature. The nitrogen concentration measurement system according to item 1. 前記校正ガスが混合ガスである、請求項1から5のいずれか1項に記載の窒素濃度測定システム。   The nitrogen concentration measurement system according to any one of claims 1 to 5, wherein the calibration gas is a mixed gas. 前記校正ガスがスパンガスである、請求項1から6のいずれか1項に記載の窒素濃度測定システム。   The nitrogen concentration measurement system according to any one of claims 1 to 6, wherein the calibration gas is a span gas. 前記正規化部が、前記校正ガスに接する前記発熱素子からの電気信号の値が発熱温度に関わらず1となるよう、前記電気信号の測定値を正規化する、請求項1から7のいずれか1項に記載の窒素濃度測定システム。   The said normalization part normalizes the measured value of the said electric signal so that the value of the electric signal from the said heat generating element which contacts the said calibration gas may become 1 irrespective of heat_generation | fever temperature. The nitrogen concentration measurement system according to item 1. 前記式記憶装置が、前記複数の発熱温度における前記発熱素子からの電気信号を独立変数とし、発熱量を従属変数とする発熱量算出式を更に保存し、
前記発熱量算出式の前記独立変数に、前記前記発熱素子からの電気信号の測定値を代入し、前記測定対象混合ガスの発熱量の値を算出する発熱量算出部を更に備える、請求項1から8のいずれか1項に記載の窒素濃度測定システム。
The equation storage device further stores a calorific value calculation formula having an electrical signal from the heating element at the plurality of exothermic temperatures as an independent variable and a calorific value as a dependent variable,
The heating value calculation part which calculates the value of the emitted-heat amount of the said measuring object mixed gas further by substituting the measured value of the electric signal from the said heat generating element for the said independent variable of the said emitted-heat amount calculation formula, The nitrogen concentration measuring system according to any one of 1 to 8.
前記複数の発熱温度の数が、少なくとも、前記測定対象混合ガスに含まれる複数種類のガス成分の数から1を引いた数である、請求項9に記載の窒素濃度測定システム。   10. The nitrogen concentration measurement system according to claim 9, wherein the number of the plurality of heat generation temperatures is at least a number obtained by subtracting 1 from the number of the plurality of types of gas components contained in the measurement target mixed gas. 複数の発熱温度のそれぞれにおいて測定対象混合ガスに接する発熱素子からの電気信号の測定値を測定することと、
炭化水素を校正成分とする窒素を含まない基準ガス及び校正ガスに接する前記発熱素子からの電気信号の値が発熱温度に関わらずそれぞれ一定となるよう、前記電気信号の測定値を正規化することと、
少なくとも3つの発熱温度における前記発熱素子からの正規化された電気信号を独立変数とし、窒素濃度を従属変数とする窒素濃度算出式を用意することと、
前記窒素濃度算出式の前記独立変数に、前記正規化された電気信号の測定値を代入し、前記測定対象混合ガスに含まれる窒素の濃度を算出することと、
を備える、窒素濃度の測定方法。
Measuring a measured value of an electrical signal from a heating element in contact with a measurement target mixed gas at each of a plurality of heating temperatures;
Normalize the measured value of the electric signal so that the value of the electric signal from the heating element in contact with the reference gas not containing nitrogen and the calibration gas containing hydrocarbon as a calibration component is constant regardless of the heating temperature. When,
Preparing a nitrogen concentration calculation formula with normalized electric signals from the heating elements at at least three exothermic temperatures as independent variables and nitrogen concentration as a dependent variable;
Substituting the normalized measured value of the electrical signal into the independent variable of the nitrogen concentration calculation formula, and calculating the concentration of nitrogen contained in the measurement target mixed gas;
A method for measuring nitrogen concentration.
前記窒素の濃度を算出することにおいて、発熱温度の第1の差における前記電気信号の正規化測定値の第1の差に、補正係数を掛けた補正された第1の差と、発熱温度の第2の差における前記電気信号の正規化測定値の第2の差と、の差である評価値に基づいて、前記測定対象混合ガスに含まれる窒素の濃度を算出し、前記補正係数が、窒素を含まないガスが前記発熱素子に接している場合に、前記評価値が0に近づくよう設定されている、請求項11に記載の窒素濃度の測定方法。   In calculating the concentration of nitrogen, the corrected first difference obtained by multiplying the first difference of the normalized measurement value of the electrical signal in the first difference of the exothermic temperature by a correction coefficient, and the exothermic temperature Based on an evaluation value that is a difference between the second difference of the normalized measurement value of the electrical signal in the second difference, a concentration of nitrogen contained in the measurement target mixed gas is calculated, and the correction coefficient is The method for measuring a nitrogen concentration according to claim 11, wherein the evaluation value is set to approach 0 when a gas not containing nitrogen is in contact with the heating element. 前記窒素の濃度を算出することにおいて、前記評価値に第2の補正係数を掛けて前記窒素の濃度を算出し、前記第2の補正係数が、無次元数である前記評価値を濃度単位に換算する、請求項12に記載の窒素濃度の測定方法。   In calculating the concentration of nitrogen, the nitrogen concentration is calculated by multiplying the evaluation value by a second correction coefficient, and the evaluation value is a dimensionless unit of the evaluation value where the second correction coefficient is a dimensionless number. The method for measuring a nitrogen concentration according to claim 12, which is converted. 前記基準ガスがメタンガスである、請求項11から13のいずれか1項に記載の窒素濃度の測定方法。   The method for measuring a nitrogen concentration according to any one of claims 11 to 13, wherein the reference gas is methane gas. 前記基準ガスに接する前記発熱素子からの電気信号の値が発熱温度に関わらず0となるよう、前記電気信号の測定値を正規化する、請求項11から14のいずれか1項に記載の窒素濃度の測定方法。   15. The nitrogen according to claim 11, wherein the measured value of the electrical signal is normalized so that the value of the electrical signal from the heating element in contact with the reference gas becomes 0 regardless of the heating temperature. Concentration measurement method. 前記校正ガスが混合ガスである、請求項11から15のいずれか1項に記載の窒素濃度の測定方法。   The method for measuring a nitrogen concentration according to claim 11, wherein the calibration gas is a mixed gas. 前記校正ガスがスパンガスである、請求項11から16のいずれか1項に記載の窒素濃度の測定方法。   The method for measuring a nitrogen concentration according to any one of claims 11 to 16, wherein the calibration gas is a span gas. 前記校正ガスに接する前記発熱素子からの電気信号の値が発熱温度に関わらず1となるよう、前記電気信号の測定値を正規化する、請求項11から17のいずれか1項に記載の窒素濃度の測定方法。   18. The nitrogen according to claim 11, wherein the measured value of the electrical signal is normalized so that the value of the electrical signal from the heating element in contact with the calibration gas becomes 1 regardless of the heating temperature. Concentration measurement method. 前記複数の発熱温度における前記発熱素子からの電気信号を独立変数とし、発熱量を従属変数とする発熱量算出式を用意することと、
前記発熱量算出式の前記独立変数に、前記前記発熱素子からの電気信号の測定値を代入し、前記測定対象混合ガスの発熱量の値を算出することと、
を更に備える、請求項11から18のいずれか1項に記載の窒素濃度の測定方法。
Preparing a calorific value calculation formula having an electrical signal from the heating element at the plurality of heat generation temperatures as an independent variable and a calorific value as a dependent variable;
Substituting the measured value of the electric signal from the heating element into the independent variable of the calorific value calculation formula, and calculating the calorific value of the measurement object mixed gas;
The method for measuring a nitrogen concentration according to any one of claims 11 to 18, further comprising:
前記複数の発熱温度の数が、少なくとも、前記測定対象混合ガスに含まれる複数種類のガス成分の数から1を引いた数である、請求項19に記載の窒素濃度の測定方法。   The method of measuring a nitrogen concentration according to claim 19, wherein the number of the plurality of exothermic temperatures is at least a number obtained by subtracting 1 from the number of a plurality of types of gas components contained in the measurement target mixed gas.
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CN111771119A (en) * 2018-02-06 2020-10-13 乔治洛德方法研究和开发液化空气有限公司 Method for in situ monitoring of the quality of gas delivered to an industrial user site using thermal conductivity technology

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111771119A (en) * 2018-02-06 2020-10-13 乔治洛德方法研究和开发液化空气有限公司 Method for in situ monitoring of the quality of gas delivered to an industrial user site using thermal conductivity technology
CN111771119B (en) * 2018-02-06 2023-11-17 乔治洛德方法研究和开发液化空气有限公司 Method for in situ monitoring of the quality of a gas delivered to an industrial consumer site using thermal conductivity technology

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