JP2004125736A - Method and device for measuring enthalpy of saturated water, latent evaporation heat of saturated water, enthalpy of superheated steam and dryness fraction of wet steam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for measuring enthalpy of saturated water, which can improve the measurement accuracy of information for measuring the dryness fraction of wet steam and reduce the measurement cost. <P>SOLUTION: The device comprises a wet steam pressure detecting means 5 which detects the pressure of the wet steam to be measured, a wet steam index value deriving means 81 which, based on the information detected by the wet steam pressure detecting means 5, multiplies the fourth root of the absolute pressure of the wet steam by a coefficient to obtain a wet steam index value, and a saturated water enthalpy deriving means 82 which obtains enthalpy i1 of saturated water using a n-th formula for deriving the enthalpy of saturated water, having the wet steam index value as a variable. <P>COPYRIGHT: (C)2004,JPO

Description

係数ｋ_１は、例えば、１０００の４乗根に設定する。
【００２９】
飽和水エンタルピ導出手段８２について説明を加えると、飽和水エンタルピ導出手段８２は、飽和水のエンタルピｉ１（ｋＪ／ｋｇ）を、上記の数６にて求めた湿り蒸気指標値ｐを変数とする下記の数７にて示される飽和水エンタルピ導出用の２次式にて求める。
【００３０】
【数７】
ｉ１＝ｋ_２×ｐ^２＋ｋ_３×ｐ＋ｋ_４
ｋ_２、ｋ_３、ｋ_４は定数であり、例えば、以下のように設定する。
ｋ_２＝−１．８８７１
ｋ_３＝１５６．０１
ｋ_４＝−５４．８４６
【００３１】
飽和水蒸発潜熱導出手段８３について説明を加えると、飽和水蒸発潜熱導出手段８３は、飽和水の蒸発潜熱ｒ（ｋＪ／ｋｇ）を、上記の数６にて求めた湿り蒸気指標値ｐを変数とする下記の数８にて示される飽和水蒸発潜熱導出用の２次式にて求める。
【００３２】
【数８】
ｒ＝ｋ_５×ｐ^２＋ｋ_６×ｐ＋ｋ_７
ｋ_５、ｋ_６、ｋ_７は定数であり、例えば、以下のように設定する。
ｋ_５＝−３．６５９０
ｋ_６＝−６５．７４６
ｋ_７＝２５００．２９
【００３３】
過熱蒸気指標値導出手段８４について説明を加えると、過熱蒸気指標値導出手段８４は、過熱蒸気圧力センサ６にて検出される過熱蒸気のゲージ圧力をＰ_２（ＭＰａＧ）とすると、係数用指標値ａを、過熱蒸気の圧力Ｐ_２を変数とする下記の数９の係数用指標値導出用の一次式にて求め、並びに、定数項用指標値ｂを、過熱蒸気の圧力Ｐ_２を変数とする下記の数１０の定数項用指標値導出用の一次式にて求める。
【００３４】
【数９】
ａ＝ｋ_８×Ｐ_２＋ｋ_９
【００３５】
【数１０】
ｂ＝ｋ_１０×Ｐ_２＋ｋ_１１
ｋ_８、ｋ_９、ｋ_１０、ｋ_１１は定数であり、例えば、以下のように設定する。
ｋ_８＝０．１７０２
ｋ_９＝０．４７６２５
ｋ_１０＝−４４．４６４
ｋ_１１＝５９１．６２５
【００３６】
過熱蒸気エンタルピ導出手段８５について説明を加えると、過熱蒸気エンタルピ導出手段８５は、過熱蒸気のエンタルピｉ２（ｋＪ／ｋｇ）を、係数用指標値ａを過熱蒸気の温度Ｔ（°Ｃ）を変数とする項の係数とし且つ定数項用指標値ｂを定数項とする下記の数１１の過熱蒸気エンタルピ導出用の一次式により求める。
【００３７】
【数１１】
ｉ２＝４．１８６０５×（ａ×Ｔ_２＋ｂ）
【００３８】
そして、乾き度導出手段８６は、湿り蒸気の乾き度ｘを、上述のようにして求められた飽和水のエンタルピｉ１、飽和水の蒸発潜熱ｒ及び過熱蒸気のエンタルピｉ２に基づいて、上記の数５により求める。
【００３９】
操作部９は、飽和水のエンタルピｉ１、飽和水の蒸発潜熱ｒ、過熱蒸気のエンタルピｉ２及び湿り蒸気の乾き度ｘのうちから、測定するものを選択自在に指令することができるように構成してあり、処理部８は、操作部９から指令されたものを測定するように機能すると共に、その測定結果を表示部１０に表示させる。
【００４０】
つまり、飽和水のエンタルピｉ１の測定が指令されると、湿り蒸気指標値導出手段８１及び飽和水エンタルピ導出手段８２が作動して飽和水のエンタルピｉ１が測定され、その測定された飽和水のエンタルピｉ１が表示部１０に表示され、飽和水の蒸発潜熱ｒの測定が指令されると、湿り蒸気指標値導出手段８１及び飽和水蒸発潜熱導出手段８３が作動して、飽和水の蒸発潜熱ｒが測定され、その測定された飽和水の蒸発潜熱ｒが表示部１０に表示される。
又、過熱蒸気のエンタルピｉ２の測定が指令されると、過熱蒸気指標値導出手段８４及び過熱蒸気エンタルピ導出手段８５が作動して過熱蒸気のエンタルピｉ２が測定され、その測定された過熱蒸気のエンタルピｉ２が表示部１０に表示される。
又、湿り蒸気の乾き度ｘの測定が指令されると、湿り蒸気指標値導出手段８１、飽和水エンタルピ導出手段８２、飽和水蒸発潜熱導出手段８３、過熱蒸気指標値導出手段８４、過熱蒸気エンタルピ導出手段８５及び乾き度導出手段８６が作動して、湿り蒸気の乾き度ｘが測定され、その測定された乾き度ｘが表示部１０に表示される。
【００４１】
上記のように構成した湿り蒸気の乾き度測定装置によれば、飽和水のエンタルピｉ１、飽和水の蒸発潜熱ｒ、過熱蒸気のエンタルピｉ２及び湿り蒸気の乾き度ｘを連続して測定することが可能である。
【００４２】
〔別実施形態〕
次に別実施形態を説明する。
（イ）　上記の実施形態においては、湿り蒸気の乾き度測定装置の実施形態について説明したが、以下、図１に基づいて、飽和水のエンタルピ測定装置、飽和水の蒸発潜熱測定装置、及び、過熱蒸気のエンタルピ測定装置夫々の実施形態について説明する。
飽和水のエンタルピ測定装置は、上記の実施形態において説明した湿り蒸気の乾き度測定装置のうちの、測定用蒸気供給路１、湿り蒸気圧力センサ５、処理部８、操作部９及び表示部１０を備えて構成し、処理部８には、湿り蒸気指標値導出手段８１及び飽和水エンタルピ導出手段８２を備える。
【００４３】
飽和水の蒸発潜熱測定装置は、上記の実施形態において説明した湿り蒸気の乾き度測定装置のうちの、測定用蒸気供給路１、湿り蒸気圧力センサ５、処理部８、操作部９及び表示部１０を備えて構成し、処理部８には、湿り蒸気指標値導出手段８１及び飽和水蒸発潜熱導出手段８３を備える。
【００４４】
過熱蒸気のエンタルピ測定装置は、上記の実施形態において説明した湿り蒸気の乾き度測定装置のうちの、測定用蒸気供給路１、断熱膨張器２、蒸気排出路３、流量調整弁４、過熱蒸気圧力センサ６、過熱蒸気温度センサ７、処理部８、操作部９及び表示部１０を備えて構成し、処理部８には、過熱蒸気指標値導出手段８４及び過熱蒸気エンタルピ導出手段８５を備える。
【００４５】
（ロ）　上記の実施形態において、飽和水エンタルピ導出用のｎ次式及び飽和水蒸発潜熱導出用のｎ次式として、夫々、２次の多項式を設定したが、１次の多項式を設定したり、３次以上の多項式を設定しても良い。但し、１次の多項式では誤差が大きくなるので、２次以上の多項式に設定するのが好ましい。
【００４６】
（ハ）　飽和水のエンタルピｉ１を、上記の数６にて示される湿り蒸気指標値導出用の式及び数７にて示される飽和水エンタルピ導出用の２次式により、人為的に演算して求めても良い。
飽和水の蒸発潜熱ｒを、上記の数６にて示される湿り蒸気指標値導出用の式及び数８にて示される飽和水蒸発潜熱導出用の２次式により、人為的に演算して求めても良い。
過熱蒸気のエンタルピｉ２を、上記の数９にて示される係数用指標値導出用の一次式、数１０にて示される定数項用指標値導出用の一次式及び数１１にて示される過熱蒸気エンタルピ導出用の一次式により、人為的に演算して求めても良い。
湿り蒸気の乾き度ｘを、以下のように、人為的に演算することにより求めても良い。即ち、上述のように飽和水のエンタルピｉ１、飽和水の蒸発潜熱ｒ及び過熱蒸気のエンタルピｉ２を演算して求めると共に、それら飽和水のエンタルピｉ１、飽和水の蒸発潜熱ｒ及び過熱蒸気のエンタルピｉ２に基づいて、上記の数５により、湿り蒸気の乾き度ｘを求める。
【００４７】
（ニ）　定数ｋ_１，ｋ_２，ｋ_３，ｋ_４，ｋ_５，ｋ_６，ｋ_７，ｋ_８，ｋ_９，ｋ_１０，ｋ_１１の具体値は、上記の実施形態において例示した値に限定されるものではなく、導出目的の各値を精度良く求めることができるようにすべく、種々に設定することができる。例えば、湿り蒸気の乾き度を０〜１００％の間で複数の範囲に分けて、各範囲毎に、乾き度を精度良く測定することができるように、前記各定数を設定すると、湿り蒸気の乾き度の測定精度を一段と向上することが可能となる。
【図面の簡単な説明】
【図１】本発明の実施形態にかかる湿り蒸気の乾き度測定装置を示すブロック図
【符号の説明】
２　　断熱膨張器
５　　湿り蒸気圧力検出手段
６　　過熱蒸気圧力検出手段
７　　過熱蒸気温度検出手段
８１　湿り蒸気指標値導出手段
８２　飽和水エンタルピ導出手段
８３　飽和水蒸発潜熱導出手段
８４　過熱蒸気指標値導出手段
８５　過熱蒸気エンタルピ導出手段
８６　乾き度導出手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for measuring enthalpy of saturated water, latent heat of evaporation of saturated water, enthalpy of superheated steam, and dryness of wet steam.
[0002]
[Prior art]
The management of the steam used in each processing such as the processing and sterilization of the workpiece is performed by measuring the mass ratio of the dry saturated steam in the wet steam, that is, the dryness.
Then, as a method of measuring the dryness of the wet steam, the wet steam to be measured is adiabatically expanded to superheated steam, and the enthalpy and latent heat of evaporation of the saturated water before the adiabatic expansion, and the superheated steam after the adiabatic expansion. The enthalpy is measured as information for determining the dryness of the wet steam, and the enthalpy i1 of the saturated water, the latent heat of evaporation r, and the enthalpy i2 of the superheated steam are used to calculate the dryness x of the wet steam in Equation 1 above. The method of seeking is known.
Conventionally, as a wet steam dryness measuring apparatus that measures the dryness of wet steam using the above method, a wet steam pressure sensor that detects the pressure of the wet steam to be measured, a superheated steam after adiabatic expansion, A superheated steam temperature sensor that detects the temperature of the superheated steam and a superheated steam pressure sensor that detects the pressure of the superheated steam after adiabatic expansion are provided.The pressure of the wet steam detected by the wet steam pressure sensor is detected by the superheated steam temperature sensor. In some cases, the dryness of wet steam is calculated based on the temperature of the superheated steam and the pressure of the superheated steam detected by the superheated steam pressure sensor (for example, see Patent Document 1).
Note that this conventional wet steam dryness measuring apparatus may be referred to as a first conventional technique in the following description.
In the first prior art, there is no description of a method of calculating the dryness of wet steam based on the pressure of wet steam, the temperature of superheated steam, and the pressure of superheated steam, but the dryness is calculated as follows. Is calculated.
That is, a saturated steam table indicating the relationship between the pressure of wet steam, enthalpy, and latent heat of vaporization, and a superheated steam table indicating the relationship between temperature, pressure, and enthalpy of superheated steam are stored in storage means, and the wet steam is stored. The enthalpy and latent heat of vaporization of the saturated water are determined based on the measured pressure of the superheated steam and the saturated steam table stored in the storage means, and the measured temperature and measured pressure of the superheated steam and the superheated steam stored in the storage means are obtained. Based on the table, the enthalpy of the superheated steam is obtained, and the dryness of the wet steam is calculated by the above equation (1) from the enthalpy of the saturated water and the latent heat of vaporization thus obtained, and the enthalpy of the superheated steam. it is conceivable that.
[0003]
Conventionally, as a wet steam dryness measuring apparatus for measuring the dryness of wet steam, there has been a second prior art described below in addition to the above first prior art (for example, see Patent Document 2). ).
This second conventional technique supplies wet steam to be measured to a measuring container that stores a predetermined amount of liquid, detects the amount of the supplied wet steam, and detects a temperature change of the liquid in the measuring container. From the detected amount of wet steam and the temperature change of the liquid, the enthalpy of the supplied wet steam is calculated as information for calculating the dryness of the wet steam based on the calorific value conversion, and the dryness of the wet steam is calculated from the enthalpy. Was composed.
That is, the relationship between the dryness of the wet steam and the enthalpy of the dry steam is defined as 100% of the dryness of the dry saturated steam and 0% of the dryness of the saturated water at each pressure. Since the value is uniquely determined by proportionally distributing the values, the relationship between the dryness and the enthalpy for each pressure is stored in the storage means, and the dryness is calculated from the calculated enthalpy of the wet steam to be measured. It is configured as follows.
[0004]
[Patent Document 1]
JP-A-2002-174578
[Patent Document 2]
JP-A-2002-243676
[0005]
[Problems to be solved by the invention]
However, in the first prior art, since each of the enthalpy of saturated water and the latent heat of evaporation of saturated water is measured based on the saturated steam table, it is necessary to store a large amount of data such as the saturated steam table in the storage means. Therefore, a high-priced storage device having a large storage capacity is required as the storage means, which leads to an increase in measurement cost, and when the detection pressure of the wet steam to be measured is not included in the saturated steam table, that is, when the detection pressure is In the case of a value between adjacent pressures in the saturated steam table, there is a problem that the measurement accuracy of the enthalpy of the saturated water and the latent heat of vaporization of the saturated water is reduced.
In other words, when the detected pressure is a value between adjacent pressures in the saturated steam table, it is conceivable that the enthalpy and latent heat of vaporization corresponding to the adjacent pressures are simply obtained by proportionally distributing. , The relationship between pressure and enthalpy, and the relationship between pressure and latent heat of vaporization are not simply relationships expressed by a linear function. Lower.
By the way, in order to eliminate the problem that the measurement accuracy of the enthalpy of saturated water and the latent heat of evaporation of saturated water is reduced due to the fact that the detection pressure of the wet steam to be measured is not included in the saturated steam table, It is conceivable to acquire the data in the table at as narrow a pressure interval as possible, but it is necessary to spend time and effort in acquiring the data, and as a storage means for storing the data, the price of a large storage capacity is higher. However, the cost of measuring the enthalpy of saturated water and the latent heat of vaporization of saturated water is further increased.
[0006]
Further, in the first prior art, since the enthalpy of the superheated steam is measured based on the superheated steam table, it is necessary to store a large amount of data such as the superheated steam table in the storage means. A large and expensive product is required, which leads to an increase in measurement cost.In addition, if the detected temperature and pressure of the superheated steam to be measured are not included in the superheated steam table, that is, the detected temperature is adjacent to the superheated steam table In the case where the detected pressure is a value between the temperatures of the superheated steam and the detected pressure is a value between the adjacent pressures in the superheated steam table, the measurement accuracy of the enthalpy of the superheated steam is reduced.
In other words, since the relationship between pressure and enthalpy, and the relationship between temperature and enthalpy are not simply relationships represented by linear functions, the detected temperature is a value between adjacent temperatures in the superheated steam table. In the case where the detected pressure is a value between the adjacent pressures in the superheated steam table, if the adjacent enthalpies are simply obtained by proportionally distributing, the accuracy is reduced.
By the way, in order to eliminate the problem that the measurement temperature and pressure of the superheated steam to be measured are not included in the superheated steam table, the measurement accuracy of the enthalpy of the superheated steam is reduced, the data in the superheated steam table are used. It is conceivable to obtain the data at as narrow a temperature and pressure as possible.However, it is necessary to spend time and effort to obtain the data, and as a storage means for storing the data, a storage device having a larger storage capacity and a higher price is required. This necessitates a problem that the cost of measuring the enthalpy of the superheated steam further increases.
[0007]
In the first prior art, as described above, since the measurement accuracy of the enthalpy of the saturated water and the enthalpy of the latent heat of vaporization and the enthalpy of the superheated steam as the information for determining the dryness of the wet steam is poor, the enthalpy of the saturated water is low. , The accuracy of the dryness of the wet steam obtained based on the latent heat of vaporization and the enthalpy of the superheated steam becomes low.
[0008]
In the second prior art, the enthalpy of the wet steam is obtained based on the amount of the wet steam and the temperature of the wet steam. However, the amount of the wet steam is complicated and it is difficult to measure it with high accuracy. There has been a problem that the measurement accuracy of the enthalpy of steam is low.
In the second prior art, since the measurement accuracy of the enthalpy of the wet steam as information for obtaining the dryness of the wet steam is low, the accuracy of the dryness of the wet steam obtained based on the enthalpy of the wet steam is low. Become.
In addition, since the configuration for measuring the amount of wet steam becomes complicated, there is a problem that the cost of the apparatus rises and the cost of measuring the enthalpy of the wet steam rises.
In short, conventionally, information for measuring the dryness of wet steam, for example, enthalpy of saturated water, latent heat of evaporation of saturated water, enthalpy of superheated steam, enthalpy of wet steam, etc. In addition, there is a problem that it is difficult to reduce the measurement cost.
[0009]
The present invention has been made in view of the above circumstances, and has as its object to improve the measurement accuracy of information for measuring the dryness of wet steam and to reduce the cost of measuring the enthalpy and saturation of saturated water. It is an object of the present invention to provide a method and apparatus for measuring latent heat of vaporization of water, enthalpy of superheated steam, and dryness of wet steam.
[0010]
[Means for Solving the Problems]
[Invention of claim 1]
A method for measuring the enthalpy of saturated water according to claim 1 is to obtain a wet steam index value by multiplying a coefficient by a fourth root of the absolute pressure of the wet steam to be measured, and to use the wet steam index value as a variable. The feature is that the enthalpy i1 of the saturated water is obtained by the n-th order equation for derivation.
That is, the absolute pressure of the wet steam to be measured is measured, the fourth root of the absolute pressure is obtained, and the obtained fourth root of the absolute pressure is multiplied by a coefficient to obtain a wet steam index value. The enthalpy i1 of the saturated water is obtained by substituting the steam index value into the n-th order equation for deriving the saturated water enthalpy using the wet steam index value as a variable.
In other words, the inventor of the present invention has intensively studied the measurement of the enthalpy of the saturated water in order to improve the measurement accuracy and reduce the cost of the measurement. The enthalpy of the saturated water is the fourth root of the absolute pressure of the wet steam. Has been found to be able to be accurately approximated by an n-th order equation in which the wet steam index value obtained by multiplying by a predetermined coefficient is a variable.
The enthalpy of the saturated water can be accurately approximated using the wet steam index value obtained by multiplying the fourth root of the absolute pressure of the wet steam by a predetermined coefficient as a variable, in other words, using the absolute pressure of the wet steam as a variable. The enthalpy of the saturated water is obtained by substituting the measured value of the absolute pressure of the wet steam to be measured into the n-th order equation for deriving the enthalpy of the saturated water, so that the enthalpy of the saturated water can be accurately measured.
Further, since a saturated steam table is not used, it is not necessary to obtain accurate saturated steam table data in order to improve measurement accuracy, which is required in the above-mentioned first conventional technique. The enthalpy of the saturated water can be measured with a simple configuration such as measuring the pressure of steam, so that the measurement cost can be reduced.
Accordingly, it is possible to provide a method for measuring the enthalpy of the saturated water, which can improve the measurement accuracy of the enthalpy of the saturated water as information for measuring the dryness of the wet steam and reduce the measurement cost.
[0011]
[Invention of claim 2]
The enthalpy measuring device for saturated water according to claim 2 is a wet steam pressure detecting means for detecting the pressure of the wet steam to be measured,
A wet steam index value deriving means for obtaining a wet steam index value by multiplying a coefficient by a fourth root of the absolute pressure of the wet steam based on the detection information of the wet steam pressure detecting means;
There is provided a saturated water enthalpy deriving means for obtaining an enthalpy of saturated water i1 by an n-th order equation for deriving saturated water enthalpy using the wet steam index value as a variable.
That is, the wet steam pressure detecting means detects the pressure of the wet steam to be measured, and the wet steam index value deriving means calculates the absolute pressure of the wet steam on the basis of the detection information of the wet steam pressure detecting means. The wet steam index value is obtained by multiplying the coefficient by a coefficient, and the saturated water enthalpy derivation means uses the wet steam index value obtained by the wet steam index value derivation means as a variable for the saturated water enthalpy using the wet steam index value as a variable. The enthalpy i1 of the saturated water is obtained by substituting into the n-th order equation.
That is, as described above, the enthalpy of the saturated water is determined by multiplying the fourth root of the absolute pressure of the wet steam by a predetermined coefficient to the nth order using the wet steam index value as a variable. It is found that the approximation can be made with high accuracy by the formula, and the wet steam index value obtained by multiplying the fourth root of the absolute pressure of the wet steam by a predetermined coefficient is used as a variable, in other words, the absolute value of the wet steam. Using the pressure as a variable and substituting the measured value of the absolute pressure of the wet steam to be measured into the nth order equation for deriving the saturated water enthalpy set as that which can accurately approximate the enthalpy of the saturated water, Since it is determined, the enthalpy of the saturated water can be accurately measured.
Further, since the enthalpy of the saturated water is obtained by a simple formula without using a saturated steam table having a large amount of information, it is possible to use an inexpensive memory having a small storage capacity as a storage means. Since the enthalpy of saturated water can be measured with a simple configuration such as measuring pressure, the cost of equipment can be reduced, and the cost of measuring the enthalpy of saturated water can be reduced. Becomes possible.
Therefore, it has become possible to provide an apparatus for measuring the enthalpy of saturated water that can improve the measurement accuracy of the enthalpy of saturated water as information for measuring the dryness of wet steam and reduce the cost of measurement.
[0012]
[Invention of claim 3]
The method for measuring the latent heat of vaporization of saturated water according to claim 3, wherein a coefficient of the fourth root of the absolute pressure of the wet steam to be measured is multiplied by a coefficient to obtain a wet steam index value, and the saturated steam index value is used as a variable. It is characterized in that the latent heat of evaporation r of saturated water is obtained by the n-th order equation for deriving latent heat of evaporation.
That is, the absolute pressure of the wet steam to be measured is measured, the fourth root of the absolute pressure is obtained, and the obtained fourth root of the absolute pressure is multiplied by a coefficient to obtain a wet steam index value. By substituting the steam index value into the n-th order equation for deriving the latent heat of evaporation of saturated water using the wet steam index value as a variable, the latent heat of evaporation r of the saturated water is obtained.
In other words, the inventor of the present invention has studied diligently in measuring the latent heat of vaporization of saturated water in order to improve the measurement accuracy and reduce the cost of the measurement. The latent heat of vaporization of the saturated water is 4 times the absolute pressure of the wet steam. It has been found that the approximation can be made with high accuracy by an n-th order equation using the wet steam index value obtained by multiplying the root by a predetermined coefficient as a variable.
Then, using the wet steam index value obtained by multiplying the fourth root of the absolute pressure of the wet steam by a predetermined coefficient as a variable, in other words, using the absolute pressure of the wet steam as a variable, the latent heat of evaporation of the saturated water is accurately approximated. By substituting the measured value of the absolute pressure of the wet steam to be measured into the n-th equation for deriving the latent heat of evaporation of saturated water, the latent heat of evaporation of the saturated water is obtained. It becomes possible.
Further, since a saturated steam table is not used, it is not necessary to obtain accurate saturated steam table data in order to improve measurement accuracy, which is required in the above-mentioned first conventional technique. Since the latent heat of evaporation of saturated water can be measured with a simple configuration such as measuring the pressure of steam, the measurement cost can be reduced.
Therefore, it is possible to provide a method for measuring the latent heat of evaporation of saturated water, which can improve the measurement accuracy of the latent heat of evaporation of saturated water as information for measuring the dryness of wet steam and reduce the cost of measurement. Was.
[0013]
[Invention of claim 4]
An apparatus for measuring the latent heat of vaporization of saturated water according to claim 4, comprising: a wet steam pressure detecting means for detecting the pressure of the wet steam to be measured;
A wet steam index value deriving means for obtaining a wet steam index value by multiplying a coefficient by a fourth root of the absolute pressure of the wet steam based on the detection information of the wet steam pressure detecting means;
A characteristic feature is that there is provided a saturated water evaporation latent heat deriving means for obtaining an evaporation latent heat r of saturated water by an n-th order expression for deriving saturated water evaporation latent heat using the wet steam index value as a variable.
That is, the wet steam pressure detecting means detects the pressure of the wet steam to be measured, and the wet steam index value deriving means calculates the absolute pressure of the wet steam on the basis of the detection information of the wet steam pressure detecting means. The wet steam index value is obtained by multiplying the coefficient by the coefficient, and the saturated water evaporation latent heat derivation means derives the saturated steam evaporation latent heat using the wet steam index value obtained by the wet steam index value derivation means as a variable. The latent heat of evaporation r of the saturated water is obtained by substituting into the following n-th order equation.
That is, as described above, the latent heat of evaporation of the saturated water is obtained by multiplying the fourth root of the absolute pressure of the wet steam by a predetermined coefficient, and using the wet steam index value as a variable. It has been found that the approximation can be made with high accuracy by the following equation, and the wet steam index value obtained by multiplying the fourth root of the absolute pressure of the wet steam by a predetermined coefficient is used as a variable, in other words, Using the absolute pressure as a variable, the measured value of the absolute pressure of the wet steam to be measured is substituted into the n-th order equation for deriving the latent heat of evaporation of saturated water, which is set as a value that can accurately approximate the latent heat of vaporization of saturated water. Since the latent heat of vaporization of the saturated water is obtained, the latent heat of vaporization of the saturated water can be accurately measured.
Further, since the latent heat of evaporation of the saturated water is obtained by a simple formula without using a saturated steam table having a large amount of information, an inexpensive storage device having a small storage capacity can be used. It is possible to measure the latent heat of vaporization of saturated water with a simple configuration, such as measuring the pressure of water, so that the cost of the apparatus can be reduced and the cost of measuring the latent heat of vaporization of saturated water can be reduced. Can be achieved.
Therefore, it is possible to provide an apparatus for measuring the latent heat of evaporation of saturated water, which can improve the measurement accuracy of the latent heat of evaporation of saturated water as information for measuring the dryness of wet steam and reduce the cost of measurement. Was.
[0014]
[Invention according to claim 5]
The method for measuring the enthalpy of superheated steam according to claim 5 obtains an index value for the coefficient by a linear expression for deriving an index value for the coefficient using the pressure of the superheated steam to be measured as a variable, and obtains the pressure of the superheated steam to be measured. The index value for the constant term is determined by a linear expression for deriving the index value for the constant term with the variable as the variable, and the index value for the coefficient is set as the coefficient of the term with the temperature of the superheated steam as a variable, and the index value for the constant term The characteristic feature is that the enthalpy i2 of the superheated steam is obtained by a linear equation for deriving the superheated steam enthalpy as a constant term.
That is, the pressure and temperature of the superheated steam to be measured are measured, and the measured pressure is substituted into a linear expression for deriving the index value for the coefficient with the pressure of the superheated steam to be measured as a variable, and the index value for the coefficient is obtained. Obtain, and, the measured pressure, by substituting the pressure of the superheated steam of the measurement target into a linear expression for deriving an index value for a constant term as a variable, to obtain an index value for a constant term, and then measuring the measurement temperature, The enthalpy i2 of the superheated steam is obtained by substituting the index value for the coefficient as a coefficient of a term using the temperature of the superheated steam as a variable and deriving a linear equation for deriving the enthalpy of superheated steam using the index value for the constant term as a constant term.
In other words, the inventor of the present invention, when measuring the enthalpy of superheated steam, conducts intensive research to improve the measurement accuracy and reduce the cost of measurement, and the enthalpy of the superheated steam to be measured is used to derive the superheated steam enthalpy. The primary expression, that is, the coefficient index value obtained by the linear expression for deriving the index value for the coefficient using the pressure of the superheated steam to be measured as a variable, as the coefficient of the primary term using the temperature of the superheated steam as a variable, In addition, it can be accurately approximated by a linear expression in which the constant term index value obtained by the linear expression for deriving the constant term index value using the pressure of the superheated steam to be measured as a variable is a constant term. I found it.
Then, the pressure and temperature of the superheated steam are used as variables, and the three primary expressions for deriving the index value for the coefficient, deriving the index value for the constant term, and deriving the superheated steam enthalpy set as those that can accurately approximate the enthalpy of the superheated steam are given. Since the enthalpy of the superheated steam is obtained by substituting the measured values of the pressure and the temperature of the superheated steam to be measured, the enthalpy of the superheated steam can be accurately measured.
Further, since the superheated steam table is not used, it is not necessary to acquire accurate data of the superheated steam table in order to improve the measurement accuracy, which is required in the first prior art. Since the enthalpy of the superheated steam can be measured with a simple configuration such as measuring the pressure and the temperature of the steam, the measurement cost can be reduced.
Therefore, it has become possible to provide a method for measuring the enthalpy of superheated steam which can improve the measurement accuracy of the enthalpy of superheated steam as information for measuring the dryness of wet steam and reduce the measurement cost.
[0015]
[Invention of claim 6]
An apparatus for measuring the enthalpy of superheated steam according to claim 6, wherein superheated steam pressure detecting means for detecting the pressure of the superheated steam to be measured and superheated steam temperature detecting means for detecting the temperature are provided.
Based on the detection information of the superheated steam pressure detecting means, a coefficient index value is obtained by a linear expression for deriving a coefficient index value using the pressure of the superheated steam as a variable, and a constant using the pressure of the superheated steam as a variable. Superheated steam index value deriving means for obtaining a constant term index value by a linear expression for term index value derivation,
Based on the detection information of the superheated steam temperature detecting means, the primary value for deriving the superheated steam enthalpy using the index value for the coefficient as a coefficient of a term using the temperature of the superheated steam as a variable and the index value for the constant term as a constant term A feature is that a superheated steam enthalpy deriving means for obtaining the enthalpy i2 of the superheated steam by an equation is provided.
That is, the pressure of the superheated steam to be measured is detected by the superheated steam pressure detection means, the temperature of the superheated steam to be measured is measured by the superheated steam temperature detection means, and the superheated steam pressure value detection means is detected by the superheated steam index value derivation means. Based on the detection information, the index value for the coefficient is obtained by a linear expression for deriving the index value for the coefficient using the pressure of the superheated steam as a variable, and for deriving the index value for the constant term using the pressure of the superheated steam as a variable. An index value for a constant term is obtained by a linear expression, and the coefficient of the term using the temperature of the superheated steam as a variable is determined by the superheated steam enthalpy deriving means based on the detection information of the superheated steam temperature detecting means. Then, the enthalpy i2 of the superheated steam is obtained by a linear expression for deriving the superheated steam enthalpy using the index value for the constant term as a constant term.
That is, as described above, the enthalpy of the superheated steam to be measured is a linear expression for deriving the superheated steam enthalpy, that is, the index for the coefficient having the pressure of the superheated steam to be measured as a variable. Derivation of the index value for the coefficient obtained by the linear expression for deriving the value as the coefficient of the primary term with the temperature of the superheated steam as a variable, and the derivation of the index value for the constant term with the pressure of the superheated steam to be measured as a variable It is found that the approximation can be accurately approximated by a linear expression that uses the index value for the constant term obtained by the linear expression for the constant term as a constant term, and the enthalpy of the superheated steam is accurately determined using the pressure and temperature of the superheated steam as variables. Substituting the measured values of the pressure and temperature of the superheated steam to be measured into three linear equations for deriving the index value for the coefficient set as a good approximation, deriving the index value for the constant term, and deriving the superheated steam enthalpy Superheated steam Since obtaining the enthalpy, it becomes possible to accurately measure the enthalpy of the superheated steam.
In addition, the enthalpy of the superheated steam is obtained by a simple formula without using a superheated steam table having a large amount of information, so that an inexpensive one having a small storage capacity can be used as a storage means. It is possible to measure the enthalpy of the superheated steam with a simple configuration such as measuring the pressure and the temperature, so that the cost of the apparatus can be reduced and the cost of measuring the enthalpy of the superheated steam can be reduced. It becomes possible to plan.
Therefore, it has become possible to provide an enthalpy measurement apparatus for superheated steam that can improve the measurement accuracy of enthalpy of superheated steam as information for measuring the dryness of wet steam and reduce the measurement cost.
[0016]
[Invention of claim 7]
The method for measuring the dryness of wet steam according to claim 7, wherein a wet steam index value is obtained by multiplying a coefficient by a fourth root of the absolute pressure of the wet steam to be measured, and the saturated water having the wet steam index value as a variable. An enthalpy of saturated water i1 is obtained by an nth-order equation for deriving enthalpy, and a latent heat of evaporation r of the saturated water is obtained by an nth-order equation for deriving a latent heat of evaporation of saturated water using the wet steam index value as a variable.
Determine the index value for the coefficient by a linear expression for deriving the index value for the coefficient with the pressure of the superheated steam generated by adiabatically expanding the wet steam of the measurement target, and obtain a constant term using the pressure of the superheated steam as a variable. An index value for a constant term is determined by a linear expression for deriving an index value for the superheated steam, wherein the index value for the coefficient is a coefficient of a term having the temperature of the superheated steam as a variable, and the index value for the constant term is a constant term. The enthalpy i2 of the superheated steam is obtained by a linear equation for deriving the enthalpy,
Based on the enthalpy i1 of the saturated water, the latent heat of evaporation r of the saturated water, and the enthalpy i2 of the superheated steam, the dryness x of the wet steam is calculated as follows:
[0017]
(Equation 3)
x = (i2-i1) ÷ r
[0018]
The feature obtained at is defined as a feature configuration.
That is, the absolute pressure of the wet steam to be measured is measured, the fourth root of the absolute pressure is obtained, and the obtained fourth root of the absolute pressure is multiplied by a coefficient to obtain a wet steam index value. The enthalpy i1 of the saturated water is obtained by substituting the steam index value into an n-th order equation for deriving the saturated water enthalpy using the wet steam index value as a variable.
Further, by substituting the wet steam index value into the n-th order equation for deriving the latent heat of evaporation of saturated water using the wet steam index value as a variable, the evaporation latent heat r of the saturated water is obtained.
Further, the pressure and temperature of the superheated steam generated by adiabatically expanding the wet steam to be measured are measured, and the measured pressure is substituted into a linear expression for deriving an index value for a coefficient having the pressure of the superheated steam as a variable. The index value for the coefficient is obtained, and the measured pressure is substituted into a linear expression for deriving the index value for the constant term using the pressure of the superheated steam as a variable to obtain the index value for the constant term. By substituting the temperature into a linear equation for deriving the superheated steam enthalpy using the index value for the coefficient as a coefficient of a term using the temperature of the superheated steam as a variable and using the index value for the constant term as a constant term, the enthalpy of the superheated steam is obtained. Find i2.
Then, the dryness x of the wet steam is obtained by substituting the enthalpy of saturated water i1, the latent heat of evaporation r of the saturated water, and the enthalpy i2 of the superheated steam measured as described above into the above equation (3).
That is, as described above with respect to the first aspect of the present invention, it is possible to measure the enthalpy i1 of the saturated water while improving the measurement accuracy and reducing the measurement cost by using the n-th order equation for deriving the saturated water enthalpy. In addition, as described above with respect to the third aspect of the present invention, it is possible to improve the measurement accuracy of the saturated water evaporation latent heat r and reduce the measurement cost by using the n-th order equation for deriving the saturated water evaporation latent heat. It is possible to measure while planning, and as described above in the description of claim 5, three linear expressions for deriving an index value for a coefficient, deriving an index value for a constant term, and deriving an overheated steam enthalpy. This makes it possible to measure the enthalpy of the superheated steam while improving the measurement accuracy and reducing the measurement cost, and thereby improving the measurement accuracy and the measurement cost of the wet steam dryness. It is possible to measure while achieving cost reduction.
Accordingly, the accuracy of measurement of the enthalpy of saturated water, the latent heat of evaporation of saturated water, and the enthalpy of superheated steam as information for measuring the dryness of wet steam, and the measurement cost are reduced, and the dryness of wet steam is reduced. It has become possible to provide a method for measuring the dryness of wet steam which can improve the measurement accuracy and reduce the measurement cost.
[0019]
[Invention of claim 8]
A wet steam dryness measuring apparatus according to claim 8, wherein a wet steam pressure detecting means for detecting a pressure of the wet steam to be measured;
An adiabatic expander that adiabatically expands the wet steam to be measured to superheated steam,
Superheated steam pressure detection means for detecting the pressure of the superheated steam generated by the adiabatic expander,
Superheated steam temperature detecting means for detecting the temperature of the superheated steam is provided,
Wet steam index value deriving means for obtaining a wet steam index value by multiplying a fourth root of the absolute pressure of the wet steam by a coefficient based on the detection information of the wet steam pressure detecting means,
Saturated water enthalpy deriving means for obtaining an enthalpy of saturated water i1 by an n-th order equation for deriving saturated water enthalpy with the wet steam index value as a variable,
A saturated water evaporation latent heat deriving means for obtaining an evaporation latent heat r of the saturated water by an n-th equation for deriving the saturated water evaporation latent heat having the wet steam index value as a variable;
Based on the detection information of the superheated steam pressure detecting means, a coefficient index value is obtained by a linear expression for deriving a coefficient index value using the pressure of the superheated steam as a variable, and a constant using the pressure of the superheated steam as a variable. Superheated steam index value deriving means for obtaining a constant term index value by a linear expression for term index value derivation,
Based on the detection information of the superheated steam temperature detecting means, the primary value for deriving the superheated steam enthalpy using the index value for the coefficient as a coefficient of a term using the temperature of the superheated steam as a variable and the index value for the constant term as a constant term A superheated steam enthalpy deriving means for obtaining the enthalpy i2 of the superheated steam by the formula is provided,
Based on the enthalpy i1 of the saturated water, the latent heat of evaporation r of the saturated water, and the enthalpy i2 of the superheated steam,
[0020]
(Equation 4)
x = (i2-i1) ÷ r
[0021]
And a dryness deriving means for obtaining a dryness x of the wet steam by the following method.
That is, the wet steam pressure detecting means detects the pressure of the wet steam to be measured, the superheated steam pressure detecting means detects the pressure of the superheated steam generated by the adiabatic expander, and the superheated steam temperature detecting means The temperature of the superheated steam generated by the adiabatic expander is detected.
The wet steam index value deriving means obtains the wet steam index value by multiplying the fourth root of the absolute pressure of the wet steam by a coefficient based on the detection information of the wet steam pressure detecting means, and obtains the wet steam enthalpy deriving means. The enthalpy i1 of the saturated water is obtained by substituting the wet steam index value obtained by the steam index value deriving means into the nth order equation for deriving the saturated water enthalpy using the wet steam index value as a variable. The latent heat of evaporation r of the saturated water is obtained by substituting the wet steam index value into an n-th order equation for deriving the latent water evaporation latent heat using the wet steam index value as a variable by the evaporation latent heat deriving means.
The superheated steam index value deriving means obtains a coefficient index value by a linear expression for deriving a coefficient index value using the pressure of the superheated steam as a variable based on the detection information of the superheated steam pressure detecting means, and An index value for the constant term is obtained by a linear expression for deriving the index value for the constant term using the steam pressure as a variable, and the superheated steam enthalpy derivation means determines the index value for the coefficient based on the detection information of the superheated steam temperature detection means. The enthalpy i2 of the superheated steam is obtained by a linear equation for deriving the superheated steam enthalpy using the index value as a coefficient of a term using the temperature of the superheated steam as a variable and the index value for the constant term as a constant term.
Then, the dryness deriving means substitutes the enthalpy of saturated water i1, the latent heat of evaporation r of saturated water, and the enthalpy of superheated steam i2, which are measured as described above, into the above equation (4) to obtain the dryness x of the wet steam. Is required.
That is, as described above, the enthalpy i1 of the saturated water is measured by the wet steam index value deriving means and the saturated water enthalpy deriving means while improving the measurement accuracy and reducing the measurement cost. In addition, as described above, the accuracy of measuring the latent heat of evaporation r of the saturated water is improved by the wet steam index value deriving means and the saturated water evaporation latent heat deriving means. In addition, it is possible to perform the measurement while reducing the measurement cost, and as described above, the enthalpy of the superheated steam is obtained by the superheated steam index value deriving means and the superheated steam enthalpy deriving means. Measurement while improving the measurement accuracy and reducing the measurement cost, thereby improving the measurement accuracy of the dryness of wet steam. It is possible to measure while achieving cost reduction of the fine measurement costs.
Accordingly, the accuracy of measurement of the enthalpy of saturated water, the latent heat of evaporation of saturated water, and the enthalpy of superheated steam as information for measuring the dryness of wet steam, and the measurement cost are reduced, and the dryness of wet steam is reduced. It has become possible to provide a wet steam dryness measuring device capable of improving measurement accuracy and reducing measurement cost.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 1, the wet steam dryness measuring device is configured to adiabaticly expand a measurement steam supply path 1 for guiding the wet steam to be measured and the wet steam supplied in the measurement steam supply path 1. Adiabatic expander 2 for converting superheated steam, a steam discharge path 3 for discharging steam from the adiabatic expander 2, and a flow rate adjustment for adjusting an amount of wet steam supplied to the adiabatic expander 2 through a measurement steam supply path 1. A valve 4, a wet steam pressure sensor 5 (corresponding to wet steam pressure detecting means) for detecting the pressure of the wet steam at a location upstream of the flow control valve 4 in the measurement steam supply path 1, and an adiabatic expander. A superheated steam pressure sensor 6 (corresponding to superheated steam pressure detecting means) for detecting the pressure of superheated steam in the superheated steam 2 and a superheated steam temperature sensor 7 (superheated steam temperature detection) for detecting the temperature of the superheated steam in the adiabatic expander 2 Equivalent to the means) and those wet A processing unit 8 for calculating the dryness of the wet steam based on the detection information of the steam pressure sensor 5, the superheated steam pressure sensor 6, and the superheated steam temperature sensor 7, and an operation unit 9 for instructing the processing unit 8 to process the information. And a display unit 10 for displaying the calculation result of the processing unit 8.
[0023]
Since the adiabatic expander 2 is well known and will not be described in detail and not shown, the wet steam supplied through the measurement steam supply path 1 is throttled to be jetted into the adiabatic expander 2 to adiabatic expansion ( By changing the enthalpy, superheated steam is formed.
[0024]
The processing unit 8 is configured using a microcomputer, and based on the detection information of the wet steam pressure sensor 5, the processing unit 8 multiplies the fourth root of the absolute pressure of the wet steam by a coefficient to obtain a wet steam. Wet steam index value deriving means 81 for obtaining the index value p, saturated water for obtaining the enthalpy i1 of the saturated water by an n-th order equation (n is a positive integer) for deriving the saturated water enthalpy using the wet steam index value p as a variable An enthalpy deriving means 82; a saturated water evaporation latent heat deriving means 83 for obtaining an evaporation latent heat r of the saturated water by an n-th order equation (n is a positive integer) for deriving a saturated water evaporation latent heat using the wet steam index value p as a variable; Based on the detection information of the superheated steam pressure sensor 6, a coefficient index value a is obtained by a linear expression for deriving a coefficient index value using the pressure of the superheated steam as a variable, and a constant using the pressure of the superheated steam as a variable. In the linear expression for deriving the index value for the term The superheated steam index value deriving means 84 for obtaining the index value b for the number term, based on the detection information of the superheated steam temperature sensor 7, sets the index value a for the coefficient as a coefficient of a term having the temperature of the superheated steam as a variable, and the constant Superheated steam enthalpy deriving means 85 for obtaining enthalpy i2 of superheated steam by a linear expression for deriving superheated steam enthalpy having term index value b as a constant term, enthalpy i1 of the saturated water, latent heat of evaporation of the saturated water r And a dryness deriving means 86 for obtaining the dryness x of the wet steam from the following equation 5 based on the enthalpy i2 of the superheated steam.
[0025]
(Equation 5)
x = (i2-i1) ÷ r
[0026]
Specifically, each of the wet steam index value deriving means 81, the saturated water enthalpy deriving means 82, the saturated water evaporation latent heat deriving means 83, the superheated steam index value deriving means 84, the superheated steam enthalpy deriving means 85, and the dryness deriving means 86 The means are each configured by a program for causing the processing unit 8 to function as each unit, and the programs are stored in a storage unit (not shown) of the processing unit 8.
[0027]
The wet steam index value deriving means 81 will be described. The wet steam index value deriving means 81 sets the gauge pressure of the wet steam to be measured detected by the wet steam pressure sensor 5 to P.₁(MPaG), the wet steam index value p is obtained by the following equation (6).
[0028]
(Equation 6)

Coefficient k₁Is set to, for example, the fourth root of 1000.
[0029]
The saturated water enthalpy deriving means 82 will be described below. The saturated water enthalpy deriving means 82 determines the enthalpy i1 (kJ / kg) of the saturated water as a variable using the wet steam index value p obtained by the above equation (6). Is obtained by a quadratic equation for deriving the saturated water enthalpy represented by the equation (7).
[0030]
(Equation 7)
i1 = k₂× p²+ K₃× p + k₄
k₂, K₃, K₄Is a constant, and is set, for example, as follows.
k₂= -1.8871
k₃= 156.01
k₄= -54.846
[0031]
The saturated water evaporation latent heat deriving means 83 will be described. The saturated water evaporation latent heat deriving means 83 calculates the evaporation latent heat r (kJ / kg) of the saturated water by using the wet steam index value p obtained by the above equation 6 as a variable. The following equation (8) is used to derive the latent heat of evaporation of saturated water.
[0032]
(Equation 8)
r = k₅× p²+ K₆× p + k₇
k₅, K₆, K₇Is a constant, and is set, for example, as follows.
k₅= -3.6590
k₆= -65.746
k₇= 250.29
[0033]
The superheated steam index value deriving means 84 will be described. The superheated steam index value deriving means 84 sets the gauge pressure of the superheated steam detected by the superheated steam pressure sensor 6 to P.₂(MPaG), the index value a for the coefficient is represented by the pressure P of the superheated steam.₂Is determined by a linear expression for deriving an index value for the coefficient of the following equation 9 with the variable as the variable, and the index value b for the constant term is determined by the pressure P of the superheated steam.₂Is obtained by the following linear expression for deriving an index value for a constant term of the following Expression 10 using a variable as a variable.
[0034]
(Equation 9)
a = k₈× P₂+ K₉
[0035]
(Equation 10)
b = k₁₀× P₂+ K₁₁
k₈, K₉, K₁₀, K₁₁Is a constant, and is set, for example, as follows.
k₈= 0.1702
k₉= 0.47625
k₁₀= -44.464
k₁₁= 591.625
[0036]
The superheated steam enthalpy deriving means 85 will be described in further detail. The superheated steam enthalpy deriving means 85 uses the enthalpy i2 (kJ / kg) of the superheated steam as a coefficient index value a and the temperature T (° C) of the superheated steam as a variable. The superheated steam enthalpy of the following equation 11 is obtained by using a linear equation for deriving the superheated steam enthalpy as the coefficient of the term to be set and the index value b for the constant term as a constant term.
[0037]
[Equation 11]
i2 = 4.18605 × (a × T₂+ B)
[0038]
Then, the dryness deriving means 86 calculates the dryness x of the wet steam on the basis of the enthalpy i1 of the saturated water, the latent heat of evaporation r of the saturated water, and the enthalpy i2 of the superheated steam, as described above. Determined by 5.
[0039]
The operation unit 9 is configured to be capable of selectively instructing what to measure among the enthalpy of saturated water i1, the latent heat of evaporation of saturated water r, the enthalpy of superheated steam i2, and the dryness x of wet steam. The processing unit 8 functions to measure what is instructed from the operation unit 9 and causes the display unit 10 to display the measurement result.
[0040]
That is, when the measurement of the enthalpy i1 of the saturated water is instructed, the wet steam index value deriving means 81 and the enthalpy deriving means 82 of the saturated water are operated to measure the enthalpy i1 of the saturated water, and the enthalpy of the measured saturated water is measured. When i1 is displayed on the display unit 10 and the measurement of the latent heat of evaporation r of the saturated water is commanded, the wet steam index value deriving means 81 and the latent water evaporating latent heat deriving means 83 operate, and the latent heat of evaporation r of the saturated water is reduced. The measured latent heat of vaporization r of the saturated water is displayed on the display unit 10.
Further, when the measurement of the enthalpy i2 of the superheated steam is instructed, the superheated steam index value deriving means 84 and the superheated steam enthalpy deriving means 85 are operated to measure the enthalpy i2 of the superheated steam, and the measured enthalpy i of the superheated steam is measured. i2 is displayed on the display unit 10.
When the measurement of the dryness x of the wet steam is commanded, the wet steam index value deriving means 81, the saturated water enthalpy deriving means 82, the saturated water evaporation latent heat deriving means 83, the superheated steam index value deriving means 84, the superheated steam enthalpy The derivation unit 85 and the dryness derivation unit 86 operate to measure the dryness x of the wet steam, and the measured dryness x is displayed on the display unit 10.
[0041]
According to the wet steam dryness measuring device configured as described above, it is possible to continuously measure the enthalpy of saturated water i1, the latent heat of evaporation r of saturated water, the enthalpy of superheated steam i2, and the dryness x of wet steam. It is possible.
[0042]
[Another embodiment]
Next, another embodiment will be described.
(A) In the above embodiment, the embodiment of the wetness steam dryness measuring device has been described. Hereinafter, based on FIG. 1, the saturated water enthalpy measuring device, the saturated water evaporation latent heat measuring device, and Each embodiment of the enthalpy measuring device for superheated steam will be described.
The enthalpy measuring device for the saturated water is the measuring steam supply path 1, the wet steam pressure sensor 5, the processing unit 8, the operating unit 9, and the display unit 10 of the wet steam dryness measuring device described in the above embodiment. The processing unit 8 includes a wet steam index value deriving unit 81 and a saturated water enthalpy deriving unit 82.
[0043]
The apparatus for measuring the latent heat of evaporation of saturated water is the measuring steam supply path 1, the wet steam pressure sensor 5, the processing section 8, the operating section 9, and the display section of the wet steam dryness measuring apparatus described in the above embodiment. The processing unit 8 includes a wet steam index value deriving unit 81 and a saturated water evaporation latent heat deriving unit 83.
[0044]
The apparatus for measuring the enthalpy of superheated steam is the measuring steam supply path 1, the adiabatic expander 2, the steam discharge path 3, the flow control valve 4, the superheated steam, and the wet steam dryness measuring apparatus described in the above embodiment. The processing unit 8 includes a pressure sensor 6, a superheated steam temperature sensor 7, a processing unit 8, an operation unit 9, and a display unit 10. The processing unit 8 includes a superheated steam index value deriving unit 84 and a superheated steam enthalpy deriving unit 85.
[0045]
(B) In the above embodiment, a quadratic polynomial was set as the n-th order equation for deriving the saturated water enthalpy and the n-th order equation for deriving the saturated water evaporation latent heat. A third-order or higher polynomial may be set. However, since an error increases in a first-order polynomial, it is preferable to set a second-order or higher polynomial.
[0046]
(C) エ ン The enthalpy i1 of the saturated water is artificially calculated by the equation for deriving the wet steam index value shown in the above equation 6 and the quadratic equation for deriving the saturated water enthalpy shown in the above equation 7 You may ask.
The latent heat of evaporation r of the saturated water is artificially calculated by the equation for deriving the wet steam index value shown in the above equation 6 and the quadratic equation for deriving the latent water of evaporation of the saturated water shown in equation 8 above. May be.
The enthalpy i2 of the superheated steam is obtained by calculating the linear expression for deriving the index value for the coefficient shown by the above equation 9, the linear equation for deriving the index value for the constant term shown by the above equation 10, and the superheated steam shown by the above equation 11. The enthalpy may be artificially calculated using a linear equation for deriving the enthalpy.
The dryness x of the wet steam may be obtained by artificially calculating as follows. That is, as described above, the enthalpy of saturated water i1, the latent heat of evaporation of saturated water r, and the enthalpy of superheated steam i2 are calculated, and the enthalpy of saturated water, latent heat of evaporation of saturated water r, and enthalpy of superheated steam i2 are calculated. Is used to determine the dryness x of the wet steam from the above equation (5).
[0047]
(D) constant k₁, K₂, K₃, K₄, K₅, K₆, K₇, K₈, K₉, K₁₀, K₁₁Is not limited to the values exemplified in the above embodiment, but can be variously set so that each value for the purpose of derivation can be obtained with high accuracy. For example, when the dryness of the wet steam is divided into a plurality of ranges from 0 to 100%, and the above constants are set so that the dryness can be accurately measured for each range, the wet steam is It becomes possible to further improve the measurement accuracy of the dryness.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an apparatus for measuring dryness of wet steam according to an embodiment of the present invention.
[Explanation of symbols]
2 adiabatic expander
5 Wet steam pressure detection means
6 Superheated steam pressure detection means
7 Superheated steam temperature detection means
81 Wet steam index value derivation means
82 Saturated water enthalpy derivation means
83 ° means for deriving latent heat of evaporation of saturated water
84 Superheated steam index value derivation means
Derivation means for 85 ° superheated steam enthalpy
86 Dryness derivation means

Claims (8)

The enthalpy i1 of the saturated water is calculated by multiplying the fourth root of the absolute pressure of the wet steam to be measured by a coefficient to obtain a wet steam index value, and using the wet steam index value as a variable to derive the saturated water enthalpy n-th order equation. The desired enthalpy measurement method for saturated water. Wet steam pressure detecting means for detecting the pressure of the wet steam to be measured,
A wet steam index value deriving means for obtaining a wet steam index value by multiplying a coefficient by a fourth root of the absolute pressure of the wet steam based on the detection information of the wet steam pressure detecting means;
A saturated water enthalpy deriving means for obtaining a saturated water enthalpy i1 by an n-th order equation for deriving the saturated water enthalpy using the wet steam index value as a variable. A coefficient is multiplied by the fourth root of the absolute pressure of the wet steam to be measured to obtain a wet steam index value, and the latent heat of vaporization of saturated water is calculated by an n-th order equation for deriving latent heat of vaporization of saturated water using the wet steam index value as a variable. A method for measuring latent heat of vaporization of saturated water for determining r. Wet steam pressure detecting means for detecting the pressure of the wet steam to be measured,
A wet steam index value deriving means for obtaining a wet steam index value by multiplying a coefficient by a fourth root of the absolute pressure of the wet steam based on the detection information of the wet steam pressure detecting means;
A saturated water evaporative latent heat deriving means for obtaining a saturated water evaporative latent heat r by an n-th order equation for deriving the saturated water evaporative latent heat using the wet steam index value as a variable. A linear expression for deriving an index value for the coefficient using a linear expression for deriving an index value for the coefficient using the pressure of the superheated steam to be measured as a variable, and an index value for the constant term using the pressure of the superheated steam for the variable as the variable The index value for the constant term is obtained at, and the index value for the coefficient is a coefficient of a term using the temperature of the superheated steam as a variable, and the linear expression for deriving the superheated steam enthalpy with the index value for the constant term as a constant term. Enthalpy measurement method of superheated steam for obtaining enthalpy i2 of superheated steam. Superheated steam pressure detection means for detecting the pressure of the superheated steam to be measured, and superheated steam temperature detection means for detecting the temperature are provided,
Based on the detection information of the superheated steam pressure detecting means, a coefficient index value is obtained by a linear expression for deriving a coefficient index value using the pressure of the superheated steam as a variable, and a constant using the pressure of the superheated steam as a variable. Superheated steam index value deriving means for obtaining a constant term index value by a linear expression for term index value derivation,
Based on the detection information of the superheated steam temperature detecting means, the primary value for deriving the superheated steam enthalpy using the index value for the coefficient as a coefficient of a term using the temperature of the superheated steam as a variable and the index value for the constant term as a constant term An apparatus for measuring the enthalpy of superheated steam provided with superheated steam enthalpy deriving means for obtaining the enthalpy i2 of superheated steam by an equation. The enthalpy of the saturated water i1 is calculated by multiplying the fourth root of the absolute pressure of the wet steam to be measured by a coefficient to obtain a wet steam index value, and using the wet steam index value as a variable to derive the saturated water enthalpy n-th order equation. Calculating the latent heat of evaporation of saturated water r by the n-th order equation for deriving latent water of evaporation of saturated water using the wet steam index value as a variable,
Determine the index value for the coefficient by a linear expression for deriving the index value for the coefficient with the pressure of the superheated steam generated by adiabatically expanding the wet steam of the measurement target, and obtain a constant term using the pressure of the superheated steam as a variable. An index value for a constant term is determined by a linear expression for deriving an index value for the superheated steam, wherein the index value for the coefficient is a coefficient of a term having the temperature of the superheated steam as a variable, and the index value for the constant term is a constant term. The enthalpy i2 of the superheated steam is obtained by a linear equation for deriving the enthalpy,
Based on the enthalpy i1 of the saturated water, the latent heat of evaporation r of the saturated water, and the enthalpy i2 of the superheated steam, the dryness x of the wet steam is calculated as follows:

The method for measuring the dryness of wet steam as determined by Wet steam pressure detecting means for detecting the pressure of the wet steam to be measured,
An adiabatic expander that adiabatically expands the wet steam to be measured to superheated steam,
Superheated steam pressure detection means for detecting the pressure of the superheated steam generated by the adiabatic expander,
Superheated steam temperature detecting means for detecting the temperature of the superheated steam is provided,
Wet steam index value deriving means for obtaining a wet steam index value by multiplying a coefficient by a fourth root of the absolute pressure of the wet steam based on the detection information of the wet steam pressure detecting means,
Saturated water enthalpy deriving means for obtaining an enthalpy of saturated water i1 by an n-th order equation for deriving saturated water enthalpy with the wet steam index value as a variable,
Saturated water evaporation latent heat deriving means for obtaining the evaporation latent heat r of saturated water by an n-th order equation for deriving the latent water evaporation latent heat having the wet steam index value as a variable,
Based on the detection information of the superheated steam pressure detecting means, a coefficient index value is obtained by a linear expression for deriving a coefficient index value using the pressure of the superheated steam as a variable, and a constant using the pressure of the superheated steam as a variable. Superheated steam index value deriving means for obtaining a constant term index value by a linear expression for term index value derivation,
Based on the detection information of the superheated steam temperature detecting means, the primary value for deriving the superheated steam enthalpy using the index value for the coefficient as a coefficient of a term using the temperature of the superheated steam as a variable and the index value for the constant term as a constant term A superheated steam enthalpy deriving means for obtaining the enthalpy i2 of the superheated steam by the formula is provided,
Based on the enthalpy i1 of the saturated water, the latent heat of evaporation r of the saturated water, and the enthalpy i2 of the superheated steam,

A wetness steam dryness measuring device provided with a dryness derivation means for obtaining a wetness steam dryness x by means of:

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