JP3678618B2 - Multiphase fluid flow meter and multiphase fluid flow rate calculation method - Google Patents

Description

ここで
ρ_mp：流体密度
υ_mp：流体速度
Ｇ_mp：流体の質量流量
ξ_mp：回転トルク比
【００３７】
従って、三相流の質量流量 Ｇ_mpは
Ｇ_mp ＝ｋ・δ・Ａ／〔ξ_mp・Ｑ_mp・Ｒ_A〕 …（４）
また、液相密度ρ_Lは
ρ_L ＝Ｇ_mp ／〔（１−β）・Ｑ_mp 〕 …（５）
と表わされる。
一方、油の密度ρ_o及び水の密度ρ_Wは、一般的に温度Ｔの関数であるから、流体の温度を測定することによって計算でき、
ρ_O＝ｆ₃（Ｔ） …（６）
ρ_W＝ｆ₄（Ｔ） …（７）
と表わされる。
水分率αは、液相密度ρ_Lとの関係で次式が成り立つ。
ρ_L＝αρ_W＋（１−α）ρ_O …（８）
【００３８】
従って、水分率αは
α＝（ρ_L−ρ_O）／（ρ_W−ρ_O） …（９）
よって、液相の体積流量Ｑ_Lは
Ｑ_L＝（１−β）Ｑ_mp …（１０）
なので、油の体積流量Ｑ_O及び水の体積流量Ｑ_Wは
Ｑ_O＝（１−α）Ｑ_L …（１１）
Ｑ_W＝α・Ｑ_L …（１２）
と表すことが出来る。
液相流の質量流量Ｇ_L、油の質量流量Ｇ_O、及び水の質量流量Ｇ_Wは、それぞれ、
Ｇ_L＝ρ_L・Ｑ_L …（１３）
Ｇ_O＝ρ_O・Ｑ_O …（１４）
Ｇ_W＝ρ_W・Ｑ_W …（１５）
と表わされる。
【００３９】
以上（１）〜（１５）式を、演算部１８で、繰り返しのループ計算方式により自動的に計算する。
図３は、この繰り返しのループ計算方式の処理手順を示すフローチャート図である。
これらの式において最も重要なファクタは、回転比ε_mpと回転トルク比ξ_mpであるが、これらは一義的に決まる定数ではなく、実験の結果、ガスボイド率βと水分率α（Ｗ／Ｃ）の複雑な関数であることが分かった。
図４及び図５は、ガス−油−水からなる三相流の回転比ε_mpと回転トルク比ξ_mp それぞれの水分率α（Ｗ／Ｃ）をパラメータとしたガスボイド率βの特性の測定例を示す図である。
この図から分かるように、回転比ε_mpと回転トルク比ξ_mpは、両方ともボイド率βの上昇に伴ってスリップが大きくなってくると言える。しかも、水分率α（Ｗ／Ｃ）が、パラメータとなって上下している。 これは、油と水の混相では、油中水と水中油で劇的な粘度変化があり、それにガスがからまった三相粘度が、複雑に翼車の軸と軸受けの摩擦係数に影響を与えているからと推察される。
しかしながら、ガスボイド率βと水分率α（Ｗ／Ｃ）の関数として表せないことはない。したがって、便宜的に
ε_mp＝ｆ₁（α，β） …（１６）
ξ_mp＝ｆ₂（α，β） …（１７）
として表すことにする。
【００４０】
本発明に係るループ計算方式を若干説明すると、ボイド率βと水分率α（Ｗ／Ｃ）が、全ての流量値に絡んでくるため、液相密度決定のための大ループ計算と、その中に含まれるボイド率決定のための小ループ計算から構成されている。これは数学的に表現すれば、ｉ×ｊ個のマトリックス計算をしていることになる。
図６は、液相密度ρ_Lとボイド率βの関係のマトリックスを示す図である。
即ち１計測ポイントにおいて、図６のごとく液相密度のキャンディデートｉ個とボイド率のキャンディデートｊ個の中から例えば斜線部に示す最良値１組が選ばれる手法である。
【００４１】
以下、図３のフローチャートを、詳細に説明する。
まず、翼車の平均半径Ｒ_A、流路断面積Ａ、バネ定数ｋ、スプリング初期トルクＭ_O及び以後の計算に必要な円周率（π）の値、重力加速度（ｇ）の値など定数設定を予め演算部１６に入力する（ステップＳ１）。
計測時間ｔの間に、計測された翼車の回転数Ｎと、複数回計測され伝送された前記測定値である時間差△ｔ、圧力損失△Ｐ、流体温度Ｔの平均値を計算する（ステップＳ２）。
流体温度Ｔの平均値Ｔ_Aの多項式から、油成分の密度ρ_O及び水の密度ρ_Wを計算し、前記回転数Ｎと計測時間ｔから、回転角速度ωを計算し、時間差△ｔの平均値△ｔ_A、計測時間ｔ、回転数Ｎ及びバネ定数ｋから見掛けの回転トルクＭを計算し、これより初期トルクＭ₀を減じて回転トルクＭ_Sを計算する（ステップＳ３）。
【００４２】
ある密度階差△ρをもって、階差液相密度を計算するエリアで、初期値ρ_L1＝ρ_Oを与え、ρ_L2＝ρ_O＋△ρを計算する（ステップＳ４）。
水分率計算エリアで、初期値液相密度ρ_L1から、α₁を計算するステップＳ５）。
あるボイド率階差（△β）をもって階差ボイド率を計算する階差ボイド率計算エリアで、初期値β₁＝β_m1nを与え、次にβ₂＝β_m1n＋△βを計算する（ステップＳ６）。
水分率α（Ｗ／Ｃ）とボイド率βの関数であるところの回転比ε_mpの式からε_mp1、ε_mp2を計算し、計算総体積流量Ｑ_mp1、Ｑ_mp2を、前記回転角速度ω₁，ω₂に流路断面積Ａ、翼車の平均半径Ｒ_Aを乗じ、それぞれε_mp1、ε_mp2で除して求め、総体積流量Ｑ_mp、液相密度ρ_Lと圧力損失△Ｐの関数である計算ボイド率β_E1、β_E2を求め、この計算ボイド率β_E1、β_E2と階差ボイド率β₁、β₂との差の絶対値△β_E1、△β_E2を求める（ステップＳ７）。
【００４３】
次に、求められた△β_E1と△β_E2を比較し、△β_E2≦△β_E1なら、β_E2とＱ_mp2が記憶され、△β_E2＞△β_E1なら、β_E1とＱ_mp1が残り、次のβ_E3とＱ_mp3とを計算するために、ステップＳ６に戻り、ステップＳ７を介し、再び△β_E3と△β_E2又は、△β_E3と△β_E1が比較される（ステップＳ８）。
このようにｊ＝１〜ｎにわたって、この計算ループが、ｎ回繰り返され、最後まで勝ち残ったＱ_mpjとβ_Ejが、チャンピオン（最良値）Ｑ_mpbjとβ_Ebjとして残る（ステップＳ９）。
次に、このチャンピオン（最良値）Ｑ_mpbjとβ_Ebjを用いて、水分率α（Ｗ／Ｃ）とボイド率βの関数である回転トルク比ξ_mpに、α₁とβ_Ebjを代入して、先に求めた回転トルクＭ_Sに流路断面積Ａを乗じ、回転トルク比ξ_mpと最良総体積流量Ｑ_mpbj及び翼車の平均半径Ｒ_Aで除して総質量流量Ｇ_mp1を求め、この総質量流量Ｇ_mp1を最良総体積流量Ｑ_mpbjと最良液相率（１−β_Ebj）で除して、計算液相密度ρ_LE1を計算し、ρ_L1とρ_LE1との差の絶対値△ρ_LE1を計算し、初期値とする（ステップＳ１０）。
【００４４】
そして、次のρ_Liの計算のため、ステップＳ４に戻り、ステップＳ５〜Ｓ１０を経て、△ρ_LE2と△ρ_LE1が比較され、△ρ_LE2≦△ρ_LE1なら、ρ_LE2とＧ_mp2が記憶され、△ρ_LE2＞△ρ_LE1なら、ρ_LE1とＧ_mp1が残り、次のρ_LE3とＧ_mp3とを計算するために、ステップＳ４に戻り、ステップＳ５〜Ｓ１０を介し、再び△ρ_E3と△ρ_E2又は、△ρ_E3と△ρ_E1が比較される（ステップＳ１１）。
このように比較値が小さい方のＧ_mp及びρ_LEが、記憶データとして残り、大きい方のＧ_mp及びρ_LEは捨てられ、ｉ＝１〜ｎのｎ回循環計算が行われ、最後まで残ったチャンピオン（最良値）が最良総質量流量Ｇ_mpbと最良液相密度ρ_Lbとして選ばれ（ステップＳ１２）、それを使って 最終的な水分率α_Eが計算される（ステップＳ１３）。
【００４５】
そして、最後まで生き残った最良総体積流量Ｑ_mpb、最良ボイド率β_Eb、最良総質量流量Ｇ_mpb、最良液相密度ρ_Lb、最終的な水分率α_Eが出力される（ステップＳ１４）。
この出力された各最良値を用いて、多相流体の体積流量Ｑ_MPと液体質量流量Ｇ_Lおよび気体体積流量Ｑ_G，油体積流量Ｑ_O，水分体積流量Ｑ_W等を演算部１８で演算し、出力部１９から出力する。
このようにして求められた各流量は、実体にあったもので、十分に実用に耐える精度を有することが証明された。
【００４６】
図７は、本発明のホモジナイザの他の実施例を示す図である。図７（Ａ）は、正面図、図７（Ｂ）は、左側面図、図７（Ｃ）は、捻れフィンエレメントの構成を示す図である。
本実施例に係るホモジナイザは、図２のものと比べ全体構成は、同じであるが、捻れフィンエレメントの構成が相違する。図７（Ｃ）に示すように、各捻れフィンエレメントに円形の透孔ｄ₁〜ｄ_N（Ｎは任意数）が、並べて設けられている。
本実施例の特性も、図２のものとほとんど変わらないが、ホモジナイザ下流の気・液混合流体に含有される気泡の大きさは、捻れフィンエレメントｂ′₁〜ｂ′₁₉に開けられた透孔ｄ₁〜ｄ_Nにより、気泡の切断が促進され、図２のものに比べて、さらに細かく且つ均一になることが分かった。
この実施例に係るホモジナイザを使用することにより、より測定精度の向上をはかることができる。
【００４７】
図８は、本発明の多相流体流量計の差圧を取り出すための圧力計の設置箇所の他の例を示す図である。
図１の実施例では、多相流体流量計の差圧を取り出すための圧力計の設置箇所を、ホモジナイザ１４の上流側２ａとタービン質量流量計１の下流側２ｄに配置し、差圧ΔＰを採用したが、多相流体流量計が設置された流管２内に配置された前記ホモジナイザ１４、前記タービン質量流量計１の各構成要素に因る圧力損失を計測できる箇所ならどこでもよく、例えば、図８に示すようにホモジナイザ１４の上流２ａ、ホモジナイザ１４とタービン質量流量計１の間２ｂ、タービン質量流量計１の第１翼車７と第２翼車８の間２ｃ、タービン質量流量計１の下流２ｄのうちの任意の２カ所を選択し、その差圧△Ｐ、△Ｐ₁〜△Ｐ₅を演算に採用すればよい。
【００４８】
【発明の効果】
本発明によれば、上流側に測定対象の油・水・ガスからなる多相流体の混合効率が高く、気泡の微細化、均質化に優れているホモジナイザ、下流側にタービン質量流量計を設け、ホモジナイザの上流とタービン質量流量計の下流の間の圧力損失を生ずる任意の箇所の差圧を計測するようにしたので、遠隔移送された油・水・ガスからなる多相流体を相分離することなく安価に正確な油体積流量，水体積流量およびガス体積流量を計測することができる。
【００４９】
さらに、本発明によれば、ホモジナイザは、下流に旋回流を発生しないので、間に整流器を設けなくてもタービン質量流量計の測定精度に影響を与えなく、高精度な質量流量および体積流量を計測することができる。
【００５０】
さらに、本発明によれば、検出された測定値から各流量を計算で求める際、体積流量にボイド率に加え、水分率を考慮し、質量流量については、ボイド率及び水分率をも考慮するようにして、その上、回転比と、回転トルク比のボイド率及び水分率との複雑な関数関係をベスト値選択方式を採用し取り込むようにし、より実体に即した油・水・ガスの多相流の各相の体積流量および質量流量を得ることができる。
また、ベスト値選択方式による計算は、繰り返し演算は必要であるものの演算そのものは簡単で、演算部のマイクロコンピュータなら短時間で計算可能で、オンラインで各流量を求めることができる。
【図面の簡単な説明】
【図１】 本発明の多相流体流量計の一実施例の構成を示す図である。
【図２】 図１の多相流体流量計に用いられるホモジナイザの一実施例の構成を示す図である。
【図３】 本発明の多相流体流量計において実施される多相流体流量を求める演算処理手順を示すフローチャート図である。
【図４】 ガス−油−水からなる三相流の回転比ε_mp の水分率α（Ｗ／Ｃ）をパラメータとしたガスボイド率βの特性の測定例を示す図である。
【図５】 ガス−油−水からなる三相流の回転トルク比ξ_mpの水分率α（Ｗ／Ｃ）をパラメータとしたガスボイド率βの特性の測定例を示す図である。
【図６】 本発明の多相流体流量を求める演算処理の一部を説明するための液相密度ρ_Lとボイド率βの関係のマトリックスを示す図である。
【図７】 図１の多相流体流量計に用いられるホモジナイザの他の実施例を示す図である。
【図８】 本発明の多相流体流量計の差圧を取り出すための圧力計の設置個所の他の例を示す図である。
【図９】 先願発明に係る多相流体流量計の構成を示す図である。
【符号の説明】
１…タービン質量流量計、２…流管（タービン質量流量計管体）、３，４…サポートフィン、３′，４′…整流器、５，６…軸受、７…第１翼車、８…第２翼車、９，１０…回転軸、１１…スプリング、１２，１３…ピックアップ、１４…ホモジナイザ、１４′…ラインミキサ、１５，１６…圧力計、１７…差圧計、１８…演算部、１９…出力部、２０…温度計、２１…流管。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-phase fluid flow meter, and more specifically, a multi-phase fluid composed of a mixture of oil / water and gas produced from an oil / gas field or the like using a turbine mass flow meter. The present invention relates to a multiphase fluid flow meter that individually obtains the flow rate without phase separation.
[0002]
[Prior art]
Oil and natural gas are currently the main energy sources as well as hydropower and nuclear power, but they are finite earth resources, and about half of the recoverable reserves belong to deep seas or ice seas where the development environment is severe, Oil and gas fields are becoming smaller, and rationalization for cost reduction is achieved in the separation and refining process of multiphase flow (hereinafter referred to as multiphase flow) of oil, water, and gas produced from these wells. Is required. For this purpose, the multiphase fluid produced from wells in the deep sea area, etc. is transferred to the land at high pressure without being phase-separated, separated and refined through the extraction well collection process, and oil and gas are delivered to the destination. Oil and gas are sent to the water, and water is drained. In this case, the flow rate of the multiphase fluid that has been transferred to the oil collection well collecting process at high pressure is first measured for the management of the oil collection well, the sampling process, or the shipment. Usually, in the flow measurement of a multiphase flow, the gas flow rate and the respective flow rates of oil and water are measured after a single-phase flow of gas, oil, water, etc. through a phase separation step. However, this method has the problem of increasing the cost of equipment for phase separation, so it is possible to measure the flow rate of gas and liquid oil and water in the state of a multiphase fluid. Technology is required.
[0003]
For this reason, many attempts have been made to measure a multiphase fluid without phase separation of the multiphase fluid. For example, a multiphase fluid flow measurement method without moving parts is based on a cross-correlation method using a density meter and an ultrasonic flow meter, and a gas-liquid two-phase flow is measured using a γ-ray density meter as a density meter. In this method, the average density is measured, the void rate is obtained from the average density, and the respective flow rates are obtained from the void rate and the volume flow rate of the multiphase fluid measured by an ultrasonic flowmeter. In this case, the flow rate of oil and water can be measured by adding an element for measuring the moisture content, but there is a problem that an expensive sensor such as a γ-ray density meter is required and the cost is increased.
[0004]
As described in Archer et al., “Software Technology for Flow Rate Measurement in Horizontal Two-Phase Flow” (SPE Production Engneering August 1991), it is defined in the axial direction of a straight pipe through which gas-liquid two-phase fluid flows. The pressure value and cross-sectional average void fraction were measured at several locations, and each of the gas-liquid two-phase flow was measured using the measured pressure, the statistical characteristics of the differential pressure fluctuation waveform, and the statistical characteristics of the void ratio. There is a method for determining the fluid flow rate of the phase.
[0005]
Also, "Simultaneous measurement method for volume flow of each phase of gas-liquid two-phase flow with turbine flow meter" (The Japan Society of Mechanical Engineers, Proceedings B, Vol.62, No.593 (1996-1), Paper No.95-0135) Proposed a method for simultaneously measuring the volume flow of each phase of a two-phase fluid by measuring the rotational speed of the impeller of the turbine flow meter and the differential pressure before and after the turbine flow meter. That is, in the characteristics when a gas-liquid two-phase flow is passed through the turbine flow meter, the flow passage cross-sectional area A and the impeller average radius R of the turbine flow meter_AThe rotation ratio ε as a dimensionless number, which is the ratio of the volumetric flow rate Q to the product of the rotational angular velocity ω, is the same as the case where the friction torque of the impeller bearing is a single-phase flow, but the flow of gas-liquid two-phase flow The impeller torque due to physical strength varies depending on the void ratio α. By using a homogenizer, the gas-liquid volume flow ratio β is approximately equal to the actual void ratio in the gas-liquid two-phase flow. It applies that the relationship of the flow rate ratio β is required.
[0006]
Further, the present applicant previously connected two impellers (hereinafter referred to as impellers) having different blade mounting angles coaxially with springs, and the torsional displacement proportional to the fluid torque difference between the two impellers. An application has been filed for measuring the volumetric flow rate and mass flow rate of each phase of a multiphase flow of oil, water, and gas using a turbine mass flow meter that measures the mass flow rate in proportion to the time difference of No. 10-281845, hereinafter referred to as “prior application”).
[0007]
[Problems to be solved by the invention]
The method of measuring the flow rate of each phase of the gas-liquid two-phase flow described above using a density meter and an ultrasonic flow meter cannot discriminate between water and oil, and a liquid phase containing moisture in addition to oil in oil mining. It cannot be applied to multiphase fluid flow measurement.
[0008]
The method proposed by Archer et al. For probabilistically processing the pressure waveform and void fraction waveform to determine the flow velocity (apparent flow velocity) of each phase from statistical characteristics is measured online for multiphase flow ejected from the oilfield wellhead. In this case as well, it is impossible to determine the flow rates of the liquid phase oil and water. Furthermore, pressure and void rate waveforms are correctly detected by sensors such as pressure gauges, differential pressure gauges and void rate meters with the gas-liquid two-phase flow in the flow tube made uniform, and bending upstream of the flow tube is detected. In order to eliminate the flow fluctuation due to the gradient, a long flow tube and a large number of sensors are required, resulting in a high cost.
[0009]
Furthermore, even in the simultaneous measurement method of each phase volume flow rate of gas-liquid two-phase flow using a turbine flow meter, if the gas-liquid two-phase flow is a multi-phase flow consisting of oil, water and gas, the oil and moisture are distinguished. It is not possible to determine the volume and mass flow rates of oil and water, respectively.
[0010]
Further, two impellers (hereinafter referred to as “impellers”) having different blade mounting angles as turbine flow meters are connected coaxially by springs, and the time difference of torsional displacement is proportional to the fluid torque difference between the two impellers. The invention of the prior application that measures the volumetric flow rate and mass flow rate of each phase of oil, water, and gas multiphase flow using a method that measures mass flow rate in proportion to the However, due to the lack of calculation methods and specific means, such as how to calculate the rotation ratio and rotation torque ratio, and how to calculate each flow rate, it is actually difficult to measure multiphase flow rates. there were. The multiphase fluid flow meter of the prior invention will be described below.
[0011]
FIG. 9 is a diagram showing a configuration of a multiphase fluid flow meter according to the invention of the prior application.
In the figure, 1 is a turbine mass flow meter, 2 is a flow tube (multiphase fluid flow meter tube), 3 'and 4' are rectifiers, 5 and 6 are bearings, 7 is a first impeller, and 8 is a second blade. Car, 9 and 10 are rotating shafts, 11 are springs, 12 and 13 are pickups, 14 'is a line mixer, 15 and 16 are pressure gauges, 17 is a differential pressure gauge, 18' is a calculation unit, 19 is an output unit, and 20 is A thermometer 21 is a flow tube.
[0012]
As shown in the figure, the multiphase fluid flow meter according to the invention of the prior application is inserted with a line mixer 14 ′ for evenly mixing the inflowing multiphase flow on the upstream side of the turbine mass flow meter 1, and the turbine mass flow rate is A flow tube 21 into which a thermometer 20 for measuring the temperature of the multiphase fluid is inserted is joined to the downstream of the total 1.
The line mixer 14 'is formed of a static mixer in which a plurality of static mixer elements formed by baffle plates that intersect and are fixed in the 45 ° direction are connected in series with a 90 ° phase shift.
[0013]
In order to measure the pressure, the pressure gauge 15 is measured 2a upstream of the line mixer 14 ', the pressure gauge 16 is measured downstream 2d of the turbine mass flow meter 1, and the pressure loss ΔP obtained from the pressure gauges 15 and 16 is measured. The differential pressure gauge 17 and the volume flow rate Q of the multiphase fluid measured by the turbine mass flow meter 1._MPAnd liquid mass flow rate G_LAnd gas volume flow Q_G, Oil volume flow Q_O, Moisture volume flow Q_WA converter 18 ′ for outputting and the like and an output unit 19 are provided.
Hereinafter, these components and the calculation method of the output will be described.
[0014]
The turbine mass flow meter 1 is a known one, and the first impeller 7 having a blade attachment angle θ1 and the attachment angle θ2 (θ1> θ2) connected coaxially by a spring 11 on the downstream side of the first impeller 7. The second impeller 8 is supported on the upstream rectifier 3 ′ having the bearing 5 and the downstream rectifier 4 ′ having the bearing 6 so as to be rotatable by the rotating shaft 9 and the rotating shaft 10. The number of blades of the first impeller 7 and the second impeller 8 is equal, and the rotation of the impeller is electromagnetically caused by pickups 12 and 13 arranged in the axial direction in the circumferential direction of the respective impellers of the flow tube 2. Detected.
[0015]
When a fluid having a mass flow rate G flows into the turbine mass flow meter 1 configured as described above at a flow velocity υ, the respective impellers connected by the springs 11 become an angular velocity proportional to the flow velocity υ. Rotates at ω. Further, since the first impeller 7 and the second impeller 8 are connected by the spring 11, the spring constant of the spring 11 is proportional to the torque difference received by the first impeller 7 and the second impeller 8 from the fluid. A torsional deviation angle δ determined by k is generated.
Further, since the entire impeller rotates at a rotational angular velocity ω proportional to the flow velocity υ, the time t required for the impeller to rotate by the deviation angle δ is detected from the detection signals of the pickups 12 and 13, and the torsional deviation is detected. The position angle δ is obtained.
[0016]
In the above description, it has been described that the rotational angular velocity ω of the impeller is proportional to the flow velocity υ in the turbine flowmeter that measures a single-phase fluid. However, this proportional relationship is established in a high Reynolds (Re number) region in an actual turbine flow meter, but is not established in a low Re number region, and a nonlinear region occurs. This is because the viscous resistance coefficient of the single-phase flow acting on the blades of the impeller has Re number characteristics, and the viscous resistance coefficient changes in the middle region between laminar flow and laminar flow and turbulent flow. Another reason is that the bearing friction torque is negligible in the high Re number region compared to the rotational force of the impeller, but the influence of the bearing friction torque cannot be ignored in the bearing friction region in the low flow velocity region.
[0017]
In turbine flowmeters, dimensionless characteristic formulas are used to analyze such characteristics, and as dimensionless values,
Rotation ratio ε = AR_Aω / Q
Where A: passage cross-sectional area of flow tube, R_A: Average radius of impeller, Q: Volume flow rate
Is required. The rotation ratio ε is the sum of the term determined by only the slip coefficient corresponding to the shape of the impeller and the delay of the outlet fluid with the fluid to be measured as the ideal fluid, and the term of the delay element due to the bearing friction torque and fluid resistance. Dimensionalized and calculated separately.
[0018]
In the case of a two-phase fluid, the rotation ratio can be obtained by the same method._TPThe value of the slip coefficient of the impeller does not change, and the void ratio α and the gas phase flow velocity υ_GAnd liquid flow velocity υ_LIs assumed to be constant in the radius r direction,_TPAnd the mass flow rate G is determined as follows.
[0019]
1. First, the mass flow rate G is obtained from the torsional deviation angle δ of the first impeller 7 and the second impeller 8.
2. Next, as described above, by using a homogenizer, in the gas-liquid two-phase flow, the gas-liquid volume flow ratio β is substantially equal to the actual void ratio, and the rotation ratio ε_TPAnd the gas-liquid volume flow ratio β is required, the two-phase volume flow rate Q_TPIs the angular velocity ω of the impeller and the rotation ratio ε for two-phase flow._TP Ask from.
3. The pressure loss ΔP is measured from the differential pressure of the pressure gauges 15 and 16 obtained by the differential pressure gauge 17, the void ratio β is obtained, and the liquid amount (oil amount + water amount) and the gas amount (gas amount) are calculated.
4.1. 2. Determine the mass flow rate G obtained in step 2 above. Volume flow rate Q obtained by_TPLiquid flow rate Q multiplied by liquid phase ratio (1-β)_TPDivide by (1-β), calculate the average density, determine the moisture content, and calculate the oil amount and the moisture amount.
[0020]
Above 1. ~ 4. As a factor that each flow rate obtained according to
(1) On the upstream side, the impeller blade angle θ1 was larger than the downstream impeller blade angle θ2.
(2) The calculation formula used for the calculation is theoretically obtained by assuming that the multiphase flow flowing into the mass flow meter 1 is uniformly mixed, and therefore, a line mixer consisting only of a static mixer. In the case of 14 ', in particular, when the object is a gas-liquid fluid, a sufficient degree of mixing cannot be obtained, the bubbles contained therein are large, and each obtained flow rate includes an error.
(3) Furthermore, although the calculation formula for obtaining the volume flow rate Q is assumed to be a function of only the void fraction, it has been found that it is also related to the moisture fraction, and the mass flow rate G is the phase difference between the front and rear impellers. It was assumed that the angle was obtained from the deviation angle δ, but it was clarified that it depends on the void ratio and the moisture ratio, but it was not taken into account in the above calculation process.
(4) The rotation ratio ε is not a constant that is uniquely determined, but is a complex function of the void fraction and moisture content.
It was found by repeating the experiment and analysis that the above four items exist.
[0021]
The present invention relates to an improvement of the invention of the prior application, and has been made in view of the above situation. In two impellers having different blade mounting angles, the blade angle of the downstream impeller is made larger than the upstream impeller blade angle. Using a turbine mass flowmeter that connects the impeller coaxially with a spring and measures the mass flow rate in proportion to the time difference of torsional deviation proportional to the difference in fluid torque between the two impellers, a new upstream is used. A homogenizer that sufficiently mixes the multiphase fluids devised in Fig. 2 is provided, and the measured values obtained from the turbine mass flowmeter are more in line with the theoretical formula. In addition to the rate, the moisture content is taken into account, and the mass flow rate is also taken into account the void rate and the moisture rate, so that the rotation ratio and the void rate of the rotational torque ratio newly introduced in the present invention By adopting the best value selection method to capture the complex function relationship with the fraction, the volume flow rate and mass flow rate of each phase of the oil, water, gas multiphase flow that is more realistic are improved and the accuracy is improved. The purpose is to measure.
[0022]
[Means for Solving the Problems]
The present invention is a multi-phase fluid flow meter, comprising a blade rotatably supported in parallel to a flow direction coaxially connected by a spring in a flow pipe through which a multi-phase fluid composed of gas, oil and water flows. In two impellers having different attachment angles, a impeller in which the blade angle of the downstream impeller is larger than the upstream impeller blade angle, and 2 in the axial direction in the circumferential direction of the two impellers of the flow tube. A turbine mass flow meter comprising two pickups, a high-efficiency homogenizer inserted in the upstream side of the impeller, and a pressure loss due to each component arranged in the flow tube is measured. Two pressure gauges for measuring a fluid pressure at a predetermined location, a differential pressure gauge for measuring a differential pressure between the two pressure gauges, and a thermometer for measuring the temperature of the multiphase fluid. To do.
Furthermore, the present invention provides a static mixer section and a strip-shaped plate in which a plurality of static mixer elements formed by baffle plates that intersect and are fixed in the 45 ° direction are connected in series with a 90 ° phase shift as the homogenizer. It is characterized in that a homogenizer is used in which a twisted fin bundle part obtained by bundling and joining twisted fin elements twisted at right angles to the longitudinal direction is bundled over the entire pipe cross section.
Furthermore, the present invention is characterized in that a through hole is provided in the plate surface of the twisted fin element.
Further, according to the present invention, the predetermined portion is located upstream of the homogenizer, between the homogenizer and the turbine mass flow meter, between two impellers of the turbine mass flow meter, and downstream of the turbine mass flow meter. It is characterized by.
[0023]
Furthermore, the present invention provides each of the multiphase fluid flow meters, wherein the rotational speed N of the impeller measured during the measurement time t and the deviation angle generated between the two impellers measured and transmitted a plurality of times. a step of calculating a rotation time difference Δt of δ, a pressure loss ΔP which is an output of the differential pressure gauge, and an average value of the temperature T of the multiphase fluid;
Average value T of fluid temperature T_AFrom the polynomial of_OAnd water density ρ_WFrom the rotation speed N and the measurement time t, the rotation angular velocity ω is calculated, and the average value Δt of the time differences Δt_A, The apparent rotational torque M is calculated from the measurement time t, the rotational speed N, and the spring constant k.₀Is reduced to the rotational torque M_SA step of calculating
In the area where the difference liquid phase density is calculated with a certain density difference Δρ, the initial value ρ_L1= Ρ_OAnd ρ_L2= Ρ_OCalculating + Δρ;
In the moisture content calculation area, the initial liquid phase density ρ_L1From α₁A step of calculating
In the difference void ratio calculation area that calculates the difference void ratio with a certain void ratio difference (△ β), the initial value β₁= Β_m1nAnd then β₂= Β_m1nCalculating + Δβ;
Rotational ratio ε as a function of moisture content α (W / C) and void rate β_mpFrom the equation_mp1, Ε_mp2And calculate the total volume flow Q_mp1, Q_mp2, The rotational angular velocity ω₁, Ω₂The cross-sectional area of the channel A, the average radius R of the impeller_AMultiplied by_mp1, Ε_mp2Divided by the total volume flow Q_mpLiquid phase density ρ_LCalculated void fraction β as a function of pressure loss ΔP_E1, Β_E2This void ratio β_E1, Β_E2And difference void ratio β₁, Β₂Absolute value of difference from △ β_E1, △ β_E2A step of seeking
△ β found_E1And △ β_E2△ β_E2≦ △ β_E1Then β_E2And Q_mp2Is stored, △ β_E2> △ β_E1Then β_E1And Q_mp1Is left and the next β_E3And Q_mp3And return to the previous step to calculate △ β again._E3And △ β_E2Or △ β_E3And △ β_E1A step in which
Thus, this calculation loop is repeated n times over j = 1 to n, and the remaining Q_mpjAnd β_EjBut champion (best value) Q_mpbjAnd β_EbjAnd the remaining steps as
This champion (best value) Q_mpbjAnd β_EbjRotational torque ratio ξ which is a function of moisture content α (W / C) and void rate β_mpAnd α₁And β_EbjIs substituted, and the rotational torque M obtained previously is_SIs multiplied by the flow path cross-sectional area A to obtain a rotational torque ratio ξ_mpAnd the best total volume flow Q_mpbjAnd the average radius R of the impeller_ADivided by the total mass flow rate G_mp1This total mass flow rate G_mp1The best total volume flow Q_mpbjAnd the best liquid phase ratio (1-β_Ebj) To calculate the calculated liquid density ρ_LE1To calculate ρ_L1And ρ_LE1Absolute value of difference from △ ρ_LE1Calculating the initial value, and
Next ρ_LiReturn to the previous step to calculate_LE2And △ ρ_LE1Are compared and Δρ_LE2≦ △ ρ_LE1Then ρ_LE2And G_mp2Is stored, △ ρ_LE2> △ ρ_LE1Then ρ_LE1And G_mp1And the next ρ_LE3And G_mp3And return to the previous step and again Δρ_E3And △ ρ_E2Or Δρ_E3And △ ρ_E1A step in which
In this way, the G with the smaller comparison value_mpAnd ρ_LEIs left as stored data, and the larger G_mpAnd ρ_LEIs discarded, the circulation calculation is performed n times from i = 1 to n, and the last remaining champion (best value) is the best total mass flow rate G_mpbAnd the best liquid density ρ_LbSelected as and using it, the final moisture content α_EA step in which
Best total volume flow Q that survived to the end_mpb, Best void ratio β_Eb, Best total mass flow G_mpb, Best liquid density ρ_LbFinal moisture content α_EA step that outputs
Using each output best value, the volume flow rate Q of the multiphase fluid_MPAnd liquid mass flow rate G_LAnd gas volume flow Q_G, Oil volume flow Q_O, Moisture volume flow Q_WA step of calculating
Is a method for obtaining a multiphase fluid flow rate.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing an embodiment of the configuration of the multiphase fluid flow meter of the present invention. In addition, the same code | symbol is attached | subjected to the component same as prior invention.
Turbine mass flow meter 1, flow tube (multiphase fluid flow meter tube) 2, bearings 5 and 6, first impeller 7, second impeller 8, rotating shafts 9 and 10, spring 11, pickups 12 and 13, The pressure gauges 15 and 16, the differential pressure gauge 17, the calculation unit 18, the output unit 19, the thermometer 20, and the flow tube 21 are common to the prior invention.
Reference numerals 3 and 4 are support fins which simply support the bearings 5 and 6 and do not require special rectifying action.
14 is an alternative to the line mixer 14 'according to the invention of the prior application. The static mixer section 14-1 comprising a static mixer having the same structure as the line mixer 14' according to the prior application invention, and the twisted fin bundle section having a structure unique to the present invention. 14-2.
[0025]
In the multiphase fluid flow meter of the present invention, a homogenizer 14 for homogeneously mixing an inflowing multiphase flow is inserted upstream of the turbine mass flow meter 1, and the temperature of the multiphase fluid is downstream of the turbine mass flow meter 1. A flow tube 21 in which a thermometer 20 for measuring is inserted is joined.
Further, a pressure gauge 15 is arranged on the upstream side 2a of the homogenizer 14 and a pressure gauge 16 is arranged on the downstream side 2d of the turbine mass flow meter 1, and the pressure loss ΔP (P1-P2) obtained from the pressure gauges 15 and 16 is measured. The differential pressure gauge 17 and the volume flow rate Q of the multiphase fluid measured by the turbine mass flow meter 1._MPAnd liquid mass flow rate G_LAnd gas volume flow Q_G, Oil volume flow Q_O, Moisture volume flow Q_WAn arithmetic unit 18 and an output unit 19 for calculating and outputting the above are provided.
These components and the output calculation method of the present invention will be described in detail below.
[0026]
The turbine mass flow meter 1 is known as described above. However, the blade mounting angle θ1 of the first impeller 7 and the blade mounting angle θ2 of the second impeller 7 are θ1 <θ2, and the blades of the first impeller 7 and the second impeller 8 are not equal in arbitrary numbers. It is also good.
[0027]
The homogenizer 14 is composed of a static mixer section 14-1 and a twisted fin bundle section 14-2, and the static mixer section 14-1 crosses and is fixed in the 45 ° direction used in the conventional line mixer 14 ′. A plurality of static mixer elements formed of baffle plates are connected in series with a 90 ° phase shift. The twisted fin bundle portion 14-2 is obtained by bundling and joining twisted fin elements obtained by twisting a strip-shaped plate at a right angle to the longitudinal direction thereof over the entire pipe cross section.
[0028]
FIG. 2 is a diagram showing an embodiment of the homogenizer of the present invention. 2A is a front view, FIG. 2B is a left side view, and FIG. 2C is a diagram showing a configuration of a twisted fin element.
A homogenizer 14 comprising a static mixer section 14-1 and a twisted fin bundle section 14-2 is inserted into the flow pipe 2 on the upstream side of the turbine mass flow meter 1. a₁, A₂Is a static mixer element of the static mixer section 14-1, b₁~ B₁₉Is a twisted fin element constituting the twisted fin bundle portion 14-2, and c₁~ C₁₉Is the twisted fin element b₁~ B₁₉It is a ring to fix.
[0029]
The static mixer section 14-1 on the upstream side of the homogenizer 14 includes a static element a made of a baffle plate obtained by intersecting a plurality of flat plates in the 45 ° direction.₁, A₂Are connected by shifting the phase by 90 °. In addition, the twisted fin bundle portion 14-2 is a twisted fin element b obtained by twisting a strip-shaped plate once in a direction perpendicular to the longitudinal direction.₁~ B₁₉The ends of ring c₁~ C₁₉As shown in the side view of FIG. 2B, approximately 19 rings are bundled and joined to the entire pipe cross section.
[0030]
The homogenizer 14 has a smaller resistance coefficient and pressure loss than the line mixer 14 ′ in the prior invention, and the twisted fin bundle portion 14-2 hardly receives pressure loss. When the multiphase fluid passes through the twisted fin bundle portion 14-2, each twisted fin element b₁~ B₁₉As the fluid flows along the surface of the fluid, the fluid is rotated and shearing force is applied, and the bubbles contained in the multiphase fluid are successively cut and refined one after another, and the outlet of the homogenizer 14 Then, the size of the bubbles is fine and uniform. It works in the same way across the cross section of the flow tube, and in multiphase fluids, especially gas-liquid two-phase flow in question, the gas and liquid are sufficiently homogeneously mixed to give characteristics as if they were single phase fluids. I found out that Therefore, by using this homogenizer, the multiphase flow meter measures the gas-liquid volume flow rate ratio as the void ratio, and the flow rate measurement accuracy of each phase is improved.
[0031]
Further, since the line mixer 14 'in the prior invention generates a swirling flow downstream, it must be rectified before flowing into the turbine mass flow meter. However, the homogenizer 14 of the present invention is twisted as described above. Fin element b₁~ B₁₉However, a rotational motion is given to the fluid flowing along it, and the rotational motion is generated independently by dividing the cross section of the flow tube for each twisted fin element, so that the centrifugal forces due to the rotational motion cancel each other, Since there is no centrifugal force (no swirl flow) and no swirl flow is generated downstream, the present invention eliminates the need for the rectifiers 3 and 4 employed in the invention of the prior application, and makes the structure simpler. Just do it.
[0032]
The action of the turbine mass flow meter 1 when the fluid of the mass flow rate G flows in the direction of the arrow at the flow velocity υ into the multiphase fluid flow meter of the present invention configured as described above is the same as that of the prior invention. The impellers connected with each other are rotated together at an angular velocity ω proportional to the flow velocity υ. Further, since the first impeller 7 and the second impeller 8 are connected by the spring 11, the spring constant of the spring 11 is proportional to the torque difference received by the first impeller 7 and the second impeller 8 from the fluid. A torsional deviation angle δ determined by k is generated. This torsional deviation angle δ is the mass flow rate G of the multiphase flow._mpAnd volume flow Q_mpIt depends on.
[0033]
Since the entire impeller rotates at a rotational angular velocity ω proportional to the flow velocity υ, the time Δt required for the impeller to rotate by the deviation angle δ is detected from the detection signals of the pickups 12 and 13, and the torsion is detected. The deviation angle δ is obtained.
This time difference Δt is the total mass flow rate G_mpThe rotational angular velocity ω of the entire impeller is the total volume flow Q_mpUsed to determine. The fluid temperature T measured by the thermometer is the density of the liquid ρ_LUsed to correct.
This multiphase fluid flow meter determines the flow rate of a three-phase fluid consisting of oil, water and gas by measuring the rotational angular velocity ω, time difference Δt, fluid temperature T and pressure loss ΔP of the impeller. is there.
[0034]
Total volume flow Q_mpIs a rotation ratio ε which is a dimensionless value in the dimensionless characteristic equation._mpIs expressed by the following equation.
Q_mp= AR_Aω / ε_mp                            ... (1)
Where A: flow tube cross-sectional area = π (R_a ²-R_b ²)
here
R_a: Outside radius of wing wheel
R_b: Wing car radius
R_A: Average radius of impeller
(= {(R_a ²+ R_b ²) / 2}^1/2  )
[0035]
Further, the pressure loss ΔP is expressed by the following equation.
ΔP = c₁ρ_L(1-β)^2-Z  Q_mp ²                  ... (2)
here
ρ_L: Liquid phase density
β: Gas void ratio
c₁: Constant determined by experiment
Z: Index determined by experiment
[0036]
The deviation angle δ generated between the two impellers 7 and 8 and the rotational torque M received by the impeller from the fluid energy._SIn the meantime, the following balanced relational expression is obtained.

here
ρ_mp: Fluid density
υ_mp: Fluid velocity
G_mp: Mass flow rate of fluid
ξ_mp: Rotational torque ratio
[0037]
Therefore, the three-phase flow mass flow G_mpIs
G_mp = K ・ δ ・ A / [ξ_mp・ Q_mp・ R_A] (4)
In addition, liquid phase density ρ_LIs
ρ_L  = G_mp  / [(1-β) · Q_mp ] (5)
It is expressed as
On the other hand, oil density ρ_oAnd water density ρ_WIs generally a function of temperature T, so it can be calculated by measuring the temperature of the fluid,
ρ_O= F_Three(T) ... (6)
ρ_W= F_Four(T) (7)
It is expressed as
Moisture content α is the liquid phase density ρ_LThe following equation holds in relation to:
ρ_L= Αρ_W+ (1-α) ρ_O                    ... (8)
[0038]
Therefore, the moisture content α is
α = (ρ_L−ρ_O) / (Ρ_W−ρ_O(9)
Therefore, the volume flow rate Q of the liquid phase_LIs
Q_L= (1-β) Q_mp                          (10)
So, oil volume flow Q_OAnd water volume flow Q_WIs
Q_O= (1-α) Q_L                            ... (11)
Q_W= Α ・ Q_L                                  (12)
Can be expressed as
Mass flow rate G of liquid phase flow_L, Oil mass flow rate G_O, And mass flow rate G of water_WRespectively
G_L= Ρ_L・ Q_L                       ... (13)
G_O= Ρ_O・ Q_O                                  ... (14)
G_W= Ρ_W・ Q_W                                  ... (15)
It is expressed as
[0039]
The above equations (1) to (15) are automatically calculated by the calculation unit 18 by a repeated loop calculation method.
FIG. 3 is a flowchart showing the processing procedure of this repeated loop calculation method.
The most important factor in these equations is the rotation ratio ε_mpAnd torque ratio ξ_mpHowever, these are not constants that are uniquely determined. As a result of experiments, it has been found that these are complex functions of the gas void ratio β and the moisture ratio α (W / C).
4 and 5 show the rotation ratio ε of the three-phase flow composed of gas-oil-water._mpAnd torque ratio ξ_mp It is a figure which shows the example of a measurement of the characteristic of the gas void ratio (beta) which used each moisture content (alpha) (W / C) as a parameter.
As can be seen from this figure, the rotation ratio ε_mpAnd torque ratio ξ_mpIn both cases, it can be said that slip increases as the void ratio β increases. Moreover, the moisture content α (W / C) increases and decreases as a parameter. This is because, in the mixed phase of oil and water, there is a dramatic change in viscosity between water-in-oil and oil-in-water. It is guessed that it is given.
However, it cannot be expressed as a function of the gas void ratio β and the moisture ratio α (W / C). Therefore, for convenience
ε_mp= F₁(Α, β) (16)
ξ_mp= F₂(Α, β) (17)
Let's represent it as
[0040]
The loop calculation method according to the present invention will be described briefly. Since the void ratio β and the moisture ratio α (W / C) are related to all the flow values, the large loop calculation for determining the liquid phase density, Is composed of a small loop calculation for determining the void ratio included in the. This can be expressed mathematically as i × j matrix calculations.
FIG. 6 shows the liquid phase density ρ_LIt is a figure which shows the matrix of the relationship of void ratio (beta).
That is, at one measurement point, as shown in FIG. 6, for example, one set of the best values shown in the shaded area is selected from i liquid phase density candy dates and j void ratio candy dates.
[0041]
Hereinafter, the flowchart of FIG. 3 will be described in detail.
First, the average radius R of the impeller_A, Channel cross-sectional area A, spring constant k, spring initial torque M_OIn addition, constant settings such as the value of the circumferential ratio (π) and the value of gravitational acceleration (g) necessary for the subsequent calculation are input to the calculation unit 16 in advance (step S1).
During the measurement time t, the rotation speed N of the measured impeller and the average value of the time difference Δt, pressure loss ΔP, and fluid temperature T, which are the measurement values measured and transmitted a plurality of times, are calculated (step) S2).
Average value T of fluid temperature T_AFrom the polynomial of_OAnd water density ρ_WFrom the rotation speed N and the measurement time t, the rotation angular velocity ω is calculated, and the average value Δt of the time differences Δt_A, The apparent rotational torque M is calculated from the measurement time t, the rotational speed N, and the spring constant k.₀Is reduced to the rotational torque M_SIs calculated (step S3).
[0042]
In the area where the difference liquid phase density is calculated with a certain density difference Δρ, the initial value ρ_L1= Ρ_OAnd ρ_L2= Ρ_O+ Δρ is calculated (step S4).
In the moisture content calculation area, the initial liquid phase density ρ_L1From α₁Is calculated in step S5).
In the difference void ratio calculation area that calculates the difference void ratio with a certain void ratio difference (△ β), the initial value β₁= Β_m1nAnd then β₂= Β_m1n+ Δβ is calculated (step S6).
Rotational ratio ε as a function of moisture content α (W / C) and void rate β_mpFrom the equation_mp1, Ε_mp2And calculate the total volume flow Q_mp1, Q_mp2, The rotational angular velocity ω₁, Ω₂The cross-sectional area of the channel A, the average radius R of the impeller_AMultiplied by_mp1, Ε_mp2Divided by the total volume flow Q_mpLiquid phase density ρ_LCalculated void fraction β as a function of pressure loss ΔP_E1, Β_E2This void ratio β_E1, Β_E2And difference void ratio β₁, Β₂Absolute value of difference from △ β_E1, △ β_E2Is obtained (step S7).
[0043]
Next, the calculated Δβ_E1And △ β_E2△ β_E2≦ △ β_E1Then β_E2And Q_mp2Is stored, △ β_E2> △ β_E1Then β_E1And Q_mp1Is left and the next β_E3And Q_mp3To return to step S6 and again through step S7, Δβ_E3And △ β_E2Or △ β_E3And △ β_E1Are compared (step S8).
Thus, this calculation loop is repeated n times over j = 1 to n, and the remaining Q_mpjAnd β_EjBut champion (best value) Q_mpbjAnd β_Ebj(Step S9).
Next, this champion (best value) Q_mpbjAnd β_EbjRotational torque ratio ξ which is a function of moisture content α (W / C) and void rate β_mpAnd α₁And β_EbjIs substituted, and the rotational torque M obtained previously is_SIs multiplied by the flow path cross-sectional area A to obtain a rotational torque ratio ξ_mpAnd the best total volume flow Q_mpbjAnd the average radius R of the impeller_ADivided by the total mass flow rate G_mp1This total mass flow rate G_mp1The best total volume flow Q_mpbjAnd the best liquid phase ratio (1-β_Ebj) To calculate the calculated liquid density ρ_LE1To calculate ρ_L1And ρ_LE1Absolute value of difference from △ ρ_LE1Is calculated as an initial value (step S10).
[0044]
And the following ρ_LiTherefore, the process returns to step S4, and after steps S5 to S10, Δρ_LE2And △ ρ_LE1Are compared and Δρ_LE2≦ △ ρ_LE1Then ρ_LE2And G_mp2Is stored, △ ρ_LE2> △ ρ_LE1Then ρ_LE1And G_mp1And the next ρ_LE3And G_mp3To return to step S4 and again through steps S5 to S10, Δρ_E3And △ ρ_E2Or Δρ_E3And △ ρ_E1Are compared (step S11).
In this way, the G with the smaller comparison value_mpAnd ρ_LEIs left as stored data, and the larger G_mpAnd ρ_LEIs discarded, the circulation calculation is performed n times from i = 1 to n, and the last remaining champion (best value) is the best total mass flow rate G_mpbAnd the best liquid density ρ_Lb(Step S12), and using it, the final moisture content α_EIs calculated (step S13).
[0045]
And the best total volume flow Q that survived to the end_mpb, Best void ratio β_Eb, Best total mass flow G_mpb, Best liquid density ρ_LbFinal moisture content α_EIs output (step S14).
Using each output best value, the volume flow rate Q of the multiphase fluid_MPAnd liquid mass flow rate G_LAnd gas volume flow Q_G, Oil volume flow Q_O, Moisture volume flow Q_WAre calculated by the calculation unit 18 and output from the output unit 19.
Each flow rate obtained in this way was suitable for the substance, and it was proved that the flow rate was sufficiently accurate for practical use.
[0046]
FIG. 7 is a view showing another embodiment of the homogenizer of the present invention. 7A is a front view, FIG. 7B is a left side view, and FIG. 7C is a diagram showing the configuration of a twisted fin element.
The homogenizer according to the present embodiment has the same overall configuration as that of FIG. 2, but the configuration of the twisted fin element is different. As shown in FIG. 7C, each twisted fin element has a circular through hole d.₁~ D_N(N is an arbitrary number) are provided side by side.
The characteristics of this embodiment are almost the same as those of FIG. 2, but the size of the bubbles contained in the gas / liquid mixed fluid downstream of the homogenizer is determined by the twisted fin element b ′.₁~ B '₁₉Through hole d₁~ D_NTherefore, it was found that the cutting of the bubbles was promoted and became finer and more uniform than that of FIG.
By using the homogenizer according to this embodiment, the measurement accuracy can be further improved.
[0047]
FIG. 8 is a diagram showing another example of the place where the pressure gauge for taking out the differential pressure of the multiphase fluid flow meter of the present invention is installed.
In the embodiment of FIG. 1, the pressure gauge installation locations for taking out the differential pressure of the multiphase fluid flow meter are arranged on the upstream side 2 a of the homogenizer 14 and the downstream side 2 d of the turbine mass flow meter 1, and the differential pressure ΔP is Although adopted, it may be anywhere that can measure pressure loss due to each component of the homogenizer 14 and the turbine mass flow meter 1 arranged in the flow pipe 2 in which a multiphase fluid flow meter is installed, for example, As shown in FIG. 8, the upstream 2a of the homogenizer 14, 2b between the homogenizer 14 and the turbine mass flow meter 1, 2c between the first impeller 7 and the second impeller 8 of the turbine mass flow meter 1, and the turbine mass flow meter 1 Select any two of the downstream 2d and the differential pressures ΔP, ΔP₁~ △ P_FiveMay be adopted for the calculation.
[0048]
【The invention's effect】
According to the present invention, a homogenizer having high mixing efficiency of a multiphase fluid composed of oil, water, and gas to be measured on the upstream side and excellent in micronization and homogenization of bubbles, and a turbine mass flow meter on the downstream side are provided. Since the differential pressure at any point causing pressure loss between the upstream of the homogenizer and the downstream of the turbine mass flowmeter is measured, the multiphase fluid consisting of oil, water and gas transferred remotely is phase-separated. The accurate oil volume flow rate, water volume flow rate, and gas volume flow rate can be measured at low cost.
[0049]
Further, according to the present invention, since the homogenizer does not generate a swirling flow downstream, it does not affect the measurement accuracy of the turbine mass flowmeter even if a rectifier is not provided, and a high-precision mass flow rate and volume flow rate can be obtained. It can be measured.
[0050]
Furthermore, according to the present invention, when calculating each flow rate from the detected measurement value, in addition to the void rate in addition to the volume flow rate, the moisture content is considered, and for the mass flow rate, the void rate and the moisture rate are also considered. In addition, a complicated function relationship between the rotation ratio, the void ratio and the moisture ratio of the rotation torque ratio is adopted by adopting the best value selection method, and more oil, water, and gas more in line with the substance. The volume flow rate and mass flow rate of each phase of the phase flow can be obtained.
The calculation using the best value selection method requires repeated calculation, but the calculation itself is simple. If the microcomputer of the calculation unit is used, the calculation can be performed in a short time, and each flow rate can be obtained online.
[Brief description of the drawings]
FIG. 1 is a diagram showing the configuration of an embodiment of a multiphase fluid flow meter of the present invention.
FIG. 2 is a diagram showing a configuration of an embodiment of a homogenizer used in the multiphase fluid flow meter of FIG. 1;
FIG. 3 is a flowchart showing a calculation processing procedure for obtaining a multiphase fluid flow rate implemented in the multiphase fluid flowmeter of the present invention.
Fig. 4 Rotational ratio ε of three-phase flow consisting of gas-oil-water_mp It is a figure which shows the example of a measurement of the characteristic of the gas void ratio (beta) which used the moisture content (alpha) (W / C) of this as a parameter.
Fig. 5 Rotational torque ratio ξ of three-phase flow consisting of gas, oil and water_mpIt is a figure which shows the example of a measurement of the characteristic of the gas void ratio (beta) which used the moisture content (alpha) (W / C) of this as a parameter.
FIG. 6 is a liquid phase density ρ for explaining a part of the arithmetic processing for obtaining the multiphase fluid flow rate of the present invention._LIt is a figure which shows the matrix of the relationship of void ratio (beta).
7 is a view showing another embodiment of a homogenizer used in the multiphase fluid flow meter of FIG. 1. FIG.
FIG. 8 is a diagram showing another example of the location where the pressure gauge for taking out the differential pressure of the multiphase fluid flow meter of the present invention is installed.
FIG. 9 is a view showing a configuration of a multiphase fluid flow meter according to the invention of the prior application.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Turbine mass flowmeter, 2 ... Flow pipe (turbine mass flowmeter tube), 3, 4 ... Support fin, 3 ', 4' ... Rectifier, 5, 6 ... Bearing, 7 ... First impeller, 8 ... Second impeller, 9, 10 ... Rotating shaft, 11 ... Spring, 12,13 ... Pickup, 14 ... Homogenizer, 14 '... Line mixer, 15,16 ... Pressure gauge, 17 ... Differential pressure gauge, 18 ... Calculation unit, 19 ... output part, 20 ... thermometer, 21 ... flow tube.

Claims (5)

The blade angle of the downstream impeller in two rotatable impellers with different attachment angles of the blades connected coaxially by a spring and supported in the flow direction in a flow tube through which a multiphase fluid consisting of gas, oil and water flows. A turbine mass flow meter comprising an impeller larger than an upstream impeller blade angle, and two pickups arranged in the axial direction in a circumferential direction of the two impellers of the flow tube, and an upstream of the impeller A low pressure loss and high-efficiency homogenizer inserted on the side, the homogenizer disposed in the flow tube, and fluid pressure at a predetermined location for measuring pressure loss due to each component of the turbine mass flow meter A multi-phase fluid flow meter comprising: two pressure gauges for measuring the pressure, a differential pressure gauge for measuring a differential pressure between the two pressure gauges, and a thermometer for measuring the temperature of the multi-phase fluid. As the homogenizer, a static mixer section in which a plurality of static mixer elements formed by baffle plates intersecting and fixed in the 45 ° direction and connected in series by shifting the phase by 90 ° and a strip-shaped plate are perpendicular to the longitudinal direction. 2. The multiphase fluid flow meter according to claim 1, wherein a homogenizer is used in which a twisted fin bundle portion obtained by bundling and joining twisted fin elements twisted to the entire surface of a pipe is joined. The multiphase fluid flow meter according to claim 2, wherein a through hole is provided in a plate surface of the twisted fin element. The predetermined portion is located upstream of the homogenizer, between the homogenizer and the turbine mass flow meter, between two impellers of the turbine mass flow meter, and downstream of the turbine mass flow meter. The multiphase fluid flow meter according to 1 or 2. In the multiphase fluid flow meter according to any one of claims 1 to 4,
The rotation speed N of the impeller measured during the measurement time t, the rotation time difference Δt based on the deviation angle generated between the two impellers measured and transmitted a plurality of times, and the output of the differential pressure gauge. calculating the pressure loss △ P, an average value T _a of the temperature T of the multiphase fluid,
From polynomial mean T _A fluid temperature T, and calculate the density [rho _O and density [rho _W water of the oil component, from the rotational speed N and the measured time t, and calculates the rotational angular velocity omega, the average time difference △ t _{A step} of calculating the apparent rotational torque M from the value Δt _A , the measurement time t, the rotational speed N and the spring constant k, subtracting the initial torque M ₀ from this, and calculating a rotational torque M _S ; In the area where the difference liquid phase density is calculated with ρ, the initial value ρ _L1 = ρ _O is given, and in the step for calculating ρ _L2 = ρ _O + Δρ and the moisture content calculation area, the initial value liquid phase density ρ _L1 From the step of calculating α ₁ and the difference void rate calculation area for calculating the difference void rate with a certain void rate difference ( _Δβ) , the initial value β ₁ = β _m1n is given, and then β ₂ = calculating β _m1n + _Δβ ;
Ε _mp1 and ε _mp2 are calculated from the equation of the rotation ratio ε _mp which is a function of the moisture content α (W / C) and the void rate β, and the calculated total volume flow rates Q _mp1 and Q _mp2 are calculated as the rotational angular velocity ω _1. , omega ₂ in the flow path cross-sectional area a, multiplied by the average radius R _a of the wheel, respectively epsilon _mp1, calculated by dividing the epsilon _mp2, a total volume flow Q _mp, a function of the liquid phase density [rho _L and the pressure loss △ P a step calculating the void fraction beta _E1, seeking beta _E2, for determining the absolute value △ β _E1, △ β _E2 of the difference between the calculated void fraction beta _E1, beta _E2 and differencing void ratio beta _1, beta ₂ is,
The obtained △ comparing beta _E1 and △ beta _E2, if _{△ β E2 ≦ △ β E1,} β E2 and Q _mp2 are stored, △ beta _E2> if △ beta _E1, remainder beta _E1 and Q _mp1, following to calculate the beta _E3 and Q _mp3 of the steps returns to the previous step, again △ beta _E3 and △ beta _E2 or, where △ beta _E3 and △ beta _E1 are compared,
Thus, this calculation loop is repeated n times over j = 1 to n, and Q _mpj and β _{Ej that} have been won to the end remain as champion (best values) Q _mpbj and β _Ebj ,
The Champion (best value) using a Q _Mpbj and beta _EBJ, the moisture content alpha (W / C) and the rotation torque ratio xi] _mp is a function of void fraction beta, by substituting the alpha ₁ and beta _EBJ, previously Multiply the calculated rotational torque M _S by the channel cross-sectional area A, and _divide by the rotational torque ratio ξ _mp , the best total volume flow Q _mpbj and the average radius R _A of the impeller to obtain the total mass flow G _mp1 , _{Divide the} flow rate G _{m p1} by the best total volume flow rate Q _mpbj and the best liquid phase rate (1-β _Ebj ) to calculate the calculated liquid phase density ρ _LE1 , and the absolute value _Δρ of the difference between ρ _L1 and ρ _LE1 Calculating _{LE1 and} setting it as an initial value;
For the next calculation of ρ _Li , return to the previous step, _{Δρ LE2} and _{Δρ LE1} are compared, and if _{Δρ LE2} ≦ _{Δρ LE1} , ρ _LE2 and G _mp2 are stored, and _{Δρ LE2} > Δρ if _LE1, rest [rho _LE1 and G _mp1, in order to calculate the next [rho _LE3 and G _mp3, returns to the previous step, again △ [rho _E3 and △ [rho _E2 or, △ [rho _E3 and △ [rho _E1 comparison And steps
In this way, G _mp and ρ _LE with the smaller comparison value remain as stored data, and the larger G _mp and ρ _LE are discarded, n = 1 to n cyclic calculations are performed, and the remaining is left to the end. The champion (best value) is chosen as the best total mass flow rate G _mpb and the best liquid phase density ρ _Lb and using it, the final moisture content α _E is calculated,
A step of _outputting the best total volume flow rate Q _mpb , the best void rate β _Eb , the best total mass flow rate G _mpb , the best liquid phase density ρ _Lb , and the final moisture content α _E that survived to the end;
Calculating the volume flow rate Q _MP , the liquid mass flow rate G _{L, the} gas volume flow rate Q _G , the oil volume flow rate Q _O , and the water volume flow rate Q _W of the multiphase fluid using each of the output best values;
A multiphase fluid flow rate calculation method characterized by comprising:

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