JP4918639B2 - Measuring device, measuring system, measuring program, and recording medium recording the measuring program - Google Patents

Description

  The present invention relates to a measuring apparatus, a measuring method, a measuring system, a measuring program, and a recording medium recording the measuring program for analyzing a gas-liquid two-phase flow used in, for example, a light water power reactor.

  Today, gas-liquid two-phase flow is used in a wide variety of industrial equipment such as light water type power reactors, heat storage / refrigeration / refrigeration systems, electronic circuit cooling systems, and bubble reaction towers in the chemical industry. In these devices and systems, the behavior of the gas-liquid two-phase flow has a great influence on operating characteristics, efficiency, economy, safety, and the like.

  For example, in a light water power reactor, the behavior of a gas-liquid two-phase flow has a great influence on core cooling, and becomes a dominant factor in an accident due to a core cooling malfunction. In boiling water reactors (BWR), the behavior of gas-liquid two-phase flow greatly affects the core characteristics not only during an accident but also during normal operation. It becomes a factor of. Furthermore, in the new nuclear reactor, understanding the heat flow phenomenon associated with the operation of the passive safety system is an important issue that determines the design performance. In other nuclear and thermal power generation systems that use the Rankine cycle, gas-liquid two-phase flow is an important factor related to the operating characteristics and energy efficiency of steam generators, boilers, steam turbines, and the like.

  In recent years, in the design of these devices and systems, both higher safety and economy are required, and optimization is required. For this reason, in order to satisfy the design requirements of these devices and systems, it is necessary to obtain more detailed knowledge of gas-liquid two-phase flow.

  In analyzing gas-liquid two-phase flow, recognizing the existence of the interface and its change is the most important process and greatly contributes to the transport of momentum, heat, and mass. In particular, the interface change is related to the generation of fluid friction loss and the generation of fluid-induced noise. Therefore, in order to analyze gas-liquid two-phase flow and apply the analysis results, research on the interface is very important.

  Interface analysis methods include multi-sensor electrical / optical probing, ultrasonic Doppler, laser Doppler velocimetry (LDV), particle image velocimetry (Particle Image Velometry, PIV), and And various related photographic methods.

  In the fluid, when the number of bubbles or the void ratio is very low, the interface can be accurately analyzed by using the ultrasonic Doppler method, LDV, PIV, and various photographic methods. However, if the number of bubbles or the void ratio in the liquid increases and a sound wave or light beam has to pass through a large number of interfaces before reaching the object to be measured, There is a problem that it becomes difficult to distinguish the interface and the state of the interface cannot be accurately grasped.

  The electrical / optical probe method using a plurality of sensors is a method of measuring a spatial distribution state of an interface in a local region of a gas-liquid two-phase flow. In this method, measurement is performed based on the time taken for the interface to move from one sensor to another. This required time is mainly related to the interfacial velocity. Specifically, a very small number of sensors that perform electrical or optical sensing are placed in a two-phase flow, and the behavior of the interface is measured by measuring the output from the sensors with high accuracy. . Thereby, the instantaneous interface direction, interface speed, time average value of void ratio, time average value of interface area concentration, and the like can be measured. In addition, research on the time average value of the void ratio and the time average value of the interface area concentration has been actively conducted in the last few decades.

  Examples of the electrical / optical probe method using a plurality of sensors include a measurement method using a double sensor probe and a measurement method using a four sensor probe.

  In the measurement method using a double sensor probe, measurement is performed by arranging two sensors in a gas-liquid two-phase flow (for example, see Non-Patent Documents 1 and 2). According to this double sensor probe, (1) void fraction, (2) bubble frequency, (3) interface area concentration of one-dimensional bubble flow, (4) interface velocity of one-dimensional bubble flow, and (5) one-dimensional bubble It is possible to measure the bubble code length of the bubble flow.

In addition, the measurement method using a four-sensor probe is performed by arranging four sensors in a gas-liquid two-phase flow (see, for example, Patent Document 1 and Non-Patent Documents 3 to 4). According to this 4-sensor probe, (1) void fraction, (2) bubble frequency, (3) interfacial area concentration of multidimensional bubble flow, (4) interface velocity of one-dimensional bubble flow, and (5) primary It is possible to measure the bubble code length of the original bubble flow.
JP 2000-136962 A (published May 16, 2000) Kataoka, I., Ishii, M. & Serizawa, A., 1986. Local formulation and measurements of interfacial area concentration in two-phase flow. Int. J. Multiphase Flow 12, 505-529 Hibiki, T., Hogsett, T. & Ishii, M., 1998.Local measurement of interfacial area, interfacial velocity and turbulence in two-phase flow.J. Nucl. Engng. & Design 184, 287-304 Revankar, ST & Ishii, M., 1993. Theory and measurement of local interfacial area using a four sensor probe in two-phase flow. Int. J. Heat Mass Transfer. 36 (12), 2997-3007. Shen, X., Saito, Y., Mishima, K., Nakamura, H., Improved measurement method for interfacial area concentration in a large diameter tube, in: Proceeding of the 6th ASME-JSME Thermal Engineering Joint Conference, Hawaii Island, Hawaii, 2003, Paper no. TED-AJ03-389

  As described above, various apparatuses using gas-liquid two-phase flow have various channel shape changes and flow direction changes, and often involve phase changes. Therefore, the flow in the gas-liquid two-phase flow is multidimensional and has undeveloped flow characteristics.

  In contrast, the double sensor probe and the four sensor probe described above can only measure the interface velocity and bubble code length in a one-dimensional bubble flow, and are insufficient for analysis of a multi-dimensional bubble flow.

  The present invention has been made in view of the above problems, and its purpose is to provide a measuring device, a measuring method, a measuring system, a measuring program, and a measuring device capable of elucidating the interface microstructure and transport mechanism of a complex gas-liquid two-phase flow. And providing a recording medium on which a measurement program is recorded.

  In order to solve the above-described problems, the measuring apparatus according to the present invention is arranged in a gas-liquid two-phase flow, and receives an output signal from a sensor that detects a gas phase and a liquid phase in the gas-liquid two-phase flow. A measuring unit that calculates a physical characteristic related to an interface between a gas phase and a liquid phase in the gas-liquid two-phase flow based on an output signal received by the output receiving unit; The receiving unit receives output signals for at least three sensor sets of at least four sensors, each sensor set includes different combinations of sensors, and the measurement calculation means is based on the output signals. Thus, the three-dimensional velocity of the interface is calculated.

  Further, in order to solve the above problems, the measurement method according to the present invention is based on an output signal from a sensor that is arranged in a gas-liquid two-phase flow and detects a gas phase and a liquid phase in the gas-liquid two-phase flow. A measurement calculation step for calculating a physical characteristic relating to an interface between a gas phase and a liquid phase in the gas-liquid two-phase flow, wherein the output signal corresponds to at least three sets of a sensor set including at least four sensors. It is an output signal, and each sensor set includes different combinations of sensors. In the measurement calculation step, the three-dimensional velocity of the interface is calculated based on the output signal.

  In the above configuration and method, the physical characteristics relating to the interface between the gas phase and the liquid phase are calculated based on the received output signal. At this time, the physical characteristics of the interface are calculated based on the output signals for three sets of the sensor set including four sensors. Note that it is not necessary that the sensors included in each sensor set are different from the three sensor sets of four sensors, and a certain sensor may be included in a plurality of sensor sets. However, even in this case, each sensor set needs to include different combinations of sensors.

  Here, based on the output signal of the sensor set composed of four sensors, it is possible to calculate the normal direction component of the interface velocity as in the case of using the four-sensor probe described above. Then, the three-dimensional velocity of the interface can be calculated by considering the normal direction component of the velocity of the interface obtained based on the output signal of one set of sensor sets for three sets. As a result, it is possible to provide a measuring apparatus and a measuring method that enable more accurate analysis of a multidimensional bubble flow.

  Therefore, according to the measurement apparatus and the measurement method according to the present invention, the interface microstructure and transport mechanism of a complicated gas-liquid two-phase flow can be clarified, so that the safety and economical efficiency of various industrial apparatuses as described above can be improved. It is expected to contribute to improvement.

  Further, in the measurement apparatus according to the present invention, in the above configuration, the measurement calculation unit calculates the velocity of the interface normal direction component and the unit vector of the interface normal direction based on the output signal of each sensor set. In addition to the calculation, the three-dimensional velocity of the interface may be calculated based on the assumption that the unit vectors in the normal direction of the interface obtained based on the output signal of each sensor set are equal.

  According to the above configuration, it is possible to accurately calculate the three-dimensional velocity of the interface by considering the normal direction component of the velocity of the interface obtained based on the output signal of each sensor set for three sets. .

  Further, in the measurement apparatus according to the present invention, in the above configuration, the measurement calculation means assumes that the bubble surrounded by the interface is spherical, and the diameter of the bubble based on the three-dimensional velocity of the interface. It is good also as a structure which calculates.

  According to the above configuration, the three-dimensional velocity at the time when a bubble first contacts a specific location, the three-dimensional velocity at the time when the bubble leaves the specific location, and the time interval between these two times are calculated. Is possible. Here, assuming that the bubble is spherical, the bubble diameter can be calculated using the above three values.

  Further, in the measurement apparatus according to the present invention, in the above-described configuration, the measurement calculation unit measures all the normal direction components of each interface at all the measurable speeds at a specific position on the interface, and performs measurement. A configuration may be adopted in which the three-dimensional velocity of the interface is calculated using a law that the size of the normal component of the interface at the possible speed is equal to the normal component of the velocity of the interface.

  Here, the above measurable speed is a speed in a direction that can be measured based on an output from each sensor when the interface is measured by each sensor set. According to said structure, it becomes possible to calculate the normal direction component of the interface velocity with the output signal from the sensor which detects a gaseous phase and a liquid phase.

  Moreover, in order to solve the above-described problems, the measurement system according to the present invention includes at least three sensor sets each including at least four sensors and the measurement device according to the present invention, and the sensor sets are different from each other. It is characterized by including a combination of sensors.

  According to said structure, the measurement system which makes it possible to analyze a multidimensional bubble flow more correctly by calculating the three-dimensional velocity of an interface can be provided.

  Moreover, the measurement system according to the present invention may be configured such that, in the above configuration, the three sensor sets are configured by six sensors.

  When six sensors are provided, it is possible to set three sensor sets including four sensors in a state in which different combinations of sensors are included. That is, according to the above configuration, it is possible to set three sensor sets including four sensors independently of each other with the number of sensors minimized. Therefore, the size of the sensor portion can be minimized, and the cost and measurement error can be reduced.

  As described above, the measuring apparatus, the measuring method, and the measuring system according to the present invention calculate the three-dimensional velocity of the interface based on the output signals for at least three sets of the sensor set including at least four sensors. It has become. Therefore, there is an effect that the analysis of the multidimensional bubble flow can be performed more accurately.

  An embodiment of the present invention will be described below with reference to FIGS.

(System configuration)
FIG. 2 shows a schematic configuration of the measurement system according to the present embodiment. As shown in the figure, the measurement system includes a measurement device 1 and a sensor device 2.

  The sensor device 2 is a device that outputs detection results detected by a plurality of sensors arranged in a gas-liquid two-phase flow in the flow channel tube 3. FIG. 3 shows a schematic configuration of the sensor device 2. As shown in the figure, the sensor device 2 includes an output unit 2A and a probe unit 2B. In addition, the dimension shown in the figure is an example to the last, and is not limited to this dimension.

  The probe unit 2B is composed of a plurality of sensors, and the probe unit 2B is disposed in the gas-liquid two-phase flow. Each sensor detects a gas phase and a liquid phase in a gas-liquid two-phase flow by an electric or optical method. The electrical sensor performs phase detection based on the difference in electrical conductivity between the gas phase and the liquid phase. The optical sensor performs phase detection based on the difference in optical refractive index between the gas phase and the liquid phase. The output unit 2A outputs the result detected by each sensor in the probe unit 2B as an electric signal or an optical signal.

  The measuring device 1 is a device that analyzes the behavior of the gas-liquid two-phase flow based on the sensing result sent from the sensor device 2. Specifically, the measurement apparatus 1 includes a sensor output reception unit 4, a measurement calculation unit 5, and a measurement result output unit 6.

  The sensor output receiving unit 4 receives an electrical signal or an optical signal as a sensing result sent from the sensor device 2. The received electrical signal is A / D converted and sent to the measurement calculation unit 5. The received optical signal is converted into an electrical signal via a photoelectric converter, further A / D converted, and sent to the measurement calculation unit 5. The measurement calculation unit 5 performs analysis calculation processing of various parameters in the gas-liquid two-phase flow based on the sensing data sent from the sensor output reception unit 4. Details of processing contents in the measurement calculation unit 5 will be described later. The measurement result output unit 6 outputs the calculation result by the measurement calculation unit 5. The measurement result output unit 6 includes, for example, a display unit that displays the measurement result and a printing unit that prints the measurement result.

  The measuring device 1 may be any device as long as it has the configuration and functions described above. For example, the measuring device 1 can be realized by a general PC (Personal Computer). it can. In this case, the sensor output receiving unit 4 is realized by an interface board or the like with the sensor device 2 in the PC, and the measurement result output unit 6 is realized by a display or a printer provided in the PC. Moreover, the measurement calculation part 5 is implement | achieved by running the program which described the calculation process which this measurement calculation part 5 performs.

(Gas-liquid two-phase flow analysis method)
Next, the contents of the calculation process in the measurement calculation unit 5 will be described. Here, the analysis method using the double sensor probe and the analysis method using the four sensor probe are first described, and then the analysis method using three sets of the four sensor probe according to the present embodiment is described.

(Double sensor probe)
First, an interface measurement method (double sensor probe) when two sensors are arranged in a gas-liquid two-phase flow will be described. FIG. 5A shows an outline of measurement by a double sensor probe. As shown in the figure, in the double sensor probe, two sensors S0 and S1 are arranged in a gas-liquid two-phase flow. Incidentally, it is actually arranged sensor for sensing the respective lower end portions of the sensor S0 · S1, to the distance between the sensors and the vector s _01. In the example shown in the drawing, bubbles B is first contacts the sensor S0 at time _{t f0} (position of the air bubble _{B f0),} in contact with the sensor S1 at time _{t f1} (position of the air bubble _{B f1),} the time _{t r0} At a distance from the sensor S0 (the position of the bubble _Br0 ).

In the above case, the output signals from the two sensors S0 and S1 are signals as shown in FIG. Two types of information are basically included in the two output signals obtained from the two sensors S0 and S1. That is, (1) the time difference Δt ₀₁₁ (= t _f1 −t _f0 ) between the points specifying the phases in the two sensors and (2) the residence time Δt _0b (= t _r0 −t _f0 ) of the gas phase. .

The residence time Δt _0b indicates the time from passing through a sensor (sensor S0) having an interface that changes from liquid to gas until the interface changing from gas to liquid passes through this sensor. That is, the residence time Δt _0b indicates the transit time of the gas phase with respect to a certain sensor (sensor S0). Therefore, the void ratio α is obtained by the following equation based on the residence time Δt _0b .

In the above formula, Omega time requested measurement, N _B denotes the number of bubbles that are measured in the sensor S0 in Omega.

  Further, the bubble frequency f is obtained as follows.

Further, the time difference Δt ₀₁₁ indicates the time from when the interface l of the bubble B comes into contact with a sensor (sensor S0) until it comes into contact with another sensor (sensor S1). Therefore, the moving speed (interface speed) of the interface of the one-dimensional bubble flow can be measured by this time difference Δt ₀₁₁ . That is, the interface velocity vector V _i is expressed by the following equation.

  Further, the interfacial area concentration a1 of the one-dimensional bubble flow is obtained as follows.

Here, ω ₀ represents the maximum value of the angle w formed by the interface speed and the main flow direction. The maximum angle ω ₀ is determined by the fluctuation of the interface speed.

  The bubble code length Lch as a passing distance when a certain sensor (sensor S0 or sensor S1) passes through the bubble B is expressed by the following equation.

  Here, the calculation method of the interface velocity and the bubble code length is based on the premise that the bubble B travels in a linear direction from the tip of the sensor S0 to the tip of the sensor S1. That is, the calculation of the interface velocity and the bubble code length by the double sensor probe is effective only in the one-dimensional bubble flow, and the bubble moves obliquely with respect to the linear direction from the tip of the sensor S0 to the tip of the sensor S1. In such a case, the reliability of the calculation method is low.

  Thus, according to the double sensor probe, (1) void fraction, (2) bubble frequency, (3) interface area concentration of one-dimensional bubble flow, (4) interface velocity of one-dimensional bubble flow, and (5) primary It is possible to measure the bubble code length of the original bubble flow.

(4 sensors / probes)
Next, an interface analysis method when four sensors are used will be described. FIG. 6 schematically shows how an interface change is detected by four sensors S0, S1, S2, and S3. In the example shown in the figure, the sensor S0 detects the interfacial l at time _{t 0l,} sensor S1 detects the interfacial l at time _{t 1l,} sensor S2 detects the surface l at time _{t 2l,} at time _{t 3l} Sensor S0 detects interface l. That is, the interface K0 interface l is at time _{t 0l,} the interface K1 at time _{t 1l,} the interface K2 at time _{t 2l,} and becomes the interface K3 at time _{t 3l,} that is moving as shown in FIG. become. In the figure, it is assumed that sensors are provided at the lower ends of the sensors S0, S1, S2, and S3.

  Regarding the analysis of the interface behavior by the four-sensor probe, Shen et al. (2002) derives the “law of interface measurement”. This law shows the general relationship between local instantaneous interface velocity and locally measurable velocity. According to the law of interface measurement, the size of each interface normal direction component is equal for all measurable velocities at a specific position on the interface. Further, the magnitude of the interface normal direction component at the measurable speed is equal to the interface normal direction component of the local instantaneous interface speed. Here, the measurable speed is a speed in the distance direction between the sensors that can be measured based on an output from each sensor when the interface is measured by the multi-sensor probe. In the case of a 4-sensor probe, there are three measurable speeds. This interface measurement law is expressed by the following equation.

In the above equation, the vector n _il indicates a unit vector in the interface normal direction at a specific point 0 (x ₀ , t _0l ) (measurement position by the sensor S 0) of the l-th interface at time t _0l . . The vector V _il indicates the _speed at which the l-th interface at time t _0l passes a specific point 0 (x ₀ , t _0l ) (measurement position by the sensor S 0), and is expressed by the following equation: .

In _Equation 6, the vector V _m0kl indicates the measurable speed of the l-th interface. Each distance vector s _0-k from the tip of the sensor S0 to the tip of the sensor Sk (k = 1, 2, 3) and the lth interface from the tip of the sensor S0 to the sensor Sk (k = 1, 2) The vector V _m0kl is defined as follows using the time t _kl −t _0l required to move to the tip of 3).

Further, the distance vector s _0-k is expressed by the following equation.

Further, in Equation 6, the vector n _il is defined as the following equation by the three angles shown in FIG.

In _Equation 6, V _nl indicates the magnitude of the interface normal direction component of the interface velocity at the point 0 (x ₀ , t _0l ).

As described above, by applying the interface measurement law to the four-sensor probe method, the point (point 0 (x ₀ )) when the tip of the front sensor (sensor S0 in the above example) penetrates the interface. , T _0l )), the local instantaneous interface normal direction unit vector n _il and the interface normal direction component V _{nl of} the local instantaneous interface velocity are obtained. From this result, the following equation is derived.

Here, A _01l , A _02l and A _03l are directional determinants. Here, this directional determinant is used to determine the interface direction. The direction determinant itself is determined by the direction measurable by the four sensors and the measurable speed in the corresponding direction. This directional determinant is given by:

A ₀ is a basic determinant of the 4-sensor probe, and is determined by the above measurable direction, that is, the probe arrangement shape. This _A0 is given by the following equation.

Note that at any point on the interface, there are two directions of the interface normal, outward and inward. Accordingly, cos η _xi , cos η _yi , and cos η _zi in Equations 11 to 13 have two square roots, positive and negative, respectively, and two of η _xi , η _yi , and η _zi in [0, π], respectively. Corresponds to the remainder angle. A positive cosine value indicates an acute angle and a negative cosine value indicates an obtuse angle. The two residual angles are shown in FIGS. 7B and 7C for the interface approaching the sensor S and the interface approaching the sensor S, taking η _zi as an example. Usually, the normal direction of the outward interface is the positive interface direction, and only one angle is the correct solution for each interface. In Equations 6 to 8, whether to select a positive cosine or a negative cosine value for cos η _xi , cos η _yi , and cos η _{zi depends on} the signs of A _01l , A _02l , and A _03l It depends on. Direction of the vector V _nl, how even the interface is the same as the direction of the vector n _i.

  Note that when sensing is performed by inserting the sensor into a gas-liquid two-phase flow, as in the case of a 4-sensor probe, the local shape of the interface that is being closed by the probe in which the sensor is provided is actually measured. The problem of deformation and the problem that both the magnitude and direction of the interface speed change are unavoidable. Therefore, in the insertion type multi-sensor probe measurement, it is necessary to make the following assumptions regarding the interface shape, interface speed, and probe size. (1) In the contact process between the interface and the sensor, the bending effect of the interface is ignored by assuming that the interface is a curved surface that is continuous and does not deform. (2) In the contact process between the interface and the sensor, the normal direction at a fixed point on a curved surface that is continuous and does not deform is constant. (3) In the contact process between the interface and the sensor, the speed of the interface is also constant. (4) The insertion probe is smaller in size than the interface.

In general, in a system including four sensors, four sets of four-sensor / probe measurement systems are conceivable depending on which of the sensors Sk (k = 0, 1, 2, 3) is selected as the front sensor. Therefore, when Expressions 11 to 14 are applied to all four sets of four-sensor probe measurement systems, four instantaneous instantaneous interface direction unit vectors n _ikl (k = 0, 1, 2, 3) are different interfaces. _Four velocity normal direction component vectors V _nkl (x _k , t _kl ) (k = 0, 1, 2, 3) are obtained. Here, the four local instantaneous interface direction unit vectors n _ikl (k = 0, 1, 2, 3) at different sensor ends are not independent and are identical to each other, that is, the following equation is established. That can be proved theoretically.

Also, the interface normal direction components V _nk1 (x _k , t _kl ) (k = 0, 1, 2, 3) of the four local instantaneous interface velocities are not independent of each other and pass through the four-sensor probe. The same state as the l-th interface continues. That is, the following equation is established.

  The above Equations 19 and 20 are the results of assumptions introduced at the time of measurement. Thus, in the actual measurement calculation of the local instantaneous interface direction unit vector and the interface normal direction component of the local instantaneous interface velocity, the sensor Sk (k = 0, 1, 2, 3) in the 4-sensor probe is used. ) May be selected as the front sensor and the rest may be the rear sensor.

From the above, according to the 4-sensor probe, (1) void ratio, (2) bubble frequency, (3) interface area concentration of multidimensional bubble flow, and (4) interface normal direction component V of local instantaneous interface velocity _nl and (5) the bubble code length of the one-dimensional bubble flow can be measured. That is, (1) void ratio and (2) bubble frequency can be measured in the same manner as the double sensor probe.

(3) The interfacial area concentration a _i of the multidimensional bubbly flow is obtained by the following equation using the result of the interface normal direction component of the δ function and the above interface velocity.

  In the above equation, N indicates the number of interfaces to be measured.

(4) The interface normal direction component V _nl of the local instantaneous interface velocity is as described above.

  (5) The bubble code length of the one-dimensional bubble flow is obtained by the following equation.

Here, the calculation of the interface velocity of the one-dimensional bubble flow is performed by using the interface on the front side of the bubble and selecting the time (t _fk ) of the rear sensor Sk (k = 1, 2, or 3).

(Interfacial velocity measurement using 3 sets of 4 sensors and probes)
Since the interface velocity is composed of three independent velocity components, at least three equations are required to obtain the interface velocity from the equation. Therefore, as shown in FIG. 8, if the same interface can be measured at three different points a, b, and c using three independent sets of four sensors, probes SPa, SPb, and SPc, each of the four sensors From the probe, one independent local instantaneous interface normal direction unit vector and one interface normal direction component of an independent local instantaneous interface velocity are obtained. When the three points on the interface are very close and the interface normal vector is common, the locality of the l-th interface is solved by solving three independent equations obtained from the interface measurement law. Theoretical interfacial velocity is theoretically required. Of the three sets of four sensors, probes SPa, SPb, and SPc, one (for example, SPa) functions as a main probe, and the other two (for example, SPb and SPc) function as auxiliary probes.

As described above, the local instantaneous interface normal direction unit is obtained by using the interface measurement law at independent points a, b, and c on the interface for three sets of four-sensor probes SPa, SPb, and SPc. The vector n _ikl (x _k , t _kl ) (k = a, b, c) and the interface normal direction component V _nkl (x _k , t _kl ) (k = a, b, c) of the local instantaneous interface velocity and Is obtained and expressed by the following equation.

Here, cos η _kxi , cos η _kyi , and cos η _kzi (k = a, b, c) are the same as cos η _xi , cos η _yi , and cos η _zi in Equations 11 to 13, respectively, and A _k1l , A _k2l , A _k3l (k = a, b, c) is a directional determinant similar to A _01l , A _02l , A _{03l in Equations} 15 to 17, and A _k (k = a, b, c) is , Which is the same basic determinant as the above equation (18).

To know the local instantaneous interface velocity vector of the l-th interface, the following equation is obtained by _{reusing the} interface measurement law at (x _k , t _kl ) (k = a, b, c).

Here, the vector _{V ikl (x k, t kl} ) (k = a, b, c) is of the l-th interface _{(x k, t kl) (} k = a, b, c) local instantaneous at the interface It is a velocity vector.

Since the interface velocity is assumed to be constant in the contact process between the interface and the sensor, the above three local instantaneous interface velocity vectors V _ikl (x _k , t _kl ) (k = a, b, c) are Equal to each other. That is, the following equation holds.

Here, the vector V _il represents a local instantaneous interface velocity vector at the measurement point (x _a , t _al ), and is defined by the above-described Expression 7.

With the probe in x _a main _probe, based on the (x _{a, t al)} vector _{V il} solutions of several 25 to several 27 in, is determined as follows.

In the above equation, Δ, Δ _x , Δ _y , Δ _z are given by the following equations.

  The magnitude of the local instantaneous interface velocity at the measurement point, that is, the point where the tip of the 0th sensor S0 in the ath probe SPa contacts the lth interface is expressed by the following equation.

  Moreover, the direction of the interface velocity at the measurement point is expressed by the following equation.

(Local angle between interface velocity vector and interface normal vector)
When the interface measurement law is applied to the a-th probe SPa in consideration of V _il in the above-described equations 29 to 31, the following equation is obtained.

Here, the vector n _ial is a local instantaneous interface normal direction unit vector at the position a on the l-th interface, and is expressed by the following equation.

A vector V _am0kl (k is any one of 1, 2, and 3) indicates a measurable speed between the 0th sensor S0 and the kth sensor Sk in the _ath probe SPa. . The distance _Sa0-k between the 0th sensor S0 and the kth sensor Sk, and the time Δt required when the lth interface moves between the two sensors. _Using the ratio with _a0kl , the vector V _am0kl is defined as:

  Therefore, when the local instantaneous value is expressed in terms of the angle between the local instantaneous interface velocity and the local instantaneous interface normal direction unit vector, the following formula is obtained.

(Diameter of spherical bubbles)
The gas region in the liquid surrounded by the interface is called a bubble. Here, if the bubbles in the gas-liquid two-phase flow are spherical, the diameter D _k of the bubbles is expressed by the following equation.

Here, D _chk is a cord length corresponding to the distance from the point at which the front sensor starts to contact the kth bubble to the point at which the front sensor leaves the bubble. Further, Δt _FRk is a time _during which the k-th bubble is in contact with the front sensor, that is, a residence time, and Vi _(2k) is a velocity of the interface of the front hemisphere in the k-th bubble. That is, let V _{i (2k + 1) be} the velocity at the interface of the rear hemisphere in the kth bubble, that is, the front sensor is the velocity at the point at which the front sensor starts to contact the kth bubble. _{Assuming the} velocity at the point away from the kth bubble, D _chk is expressed by the following equation.

In Equation 44, θ _k is defined as the local instantaneous interface velocity and the local instantaneous interface normal direction unit vector at the interface of the front hemisphere in the k-th bubble, that is, the 2k-th interface. Is an angle.

  From the above, according to three sets of four-sensor probes, (1) void ratio, (2) bubble frequency, (3) interface area concentration of multidimensional bubble flow, (4) interface velocity of multidimensional bubble flow, and (5) Bubble diameter can be measured. That is, (1) void ratio, (2) bubble frequency (3), and interfacial area concentration of multidimensional bubble flow can be measured in the same manner as in the 4-sensor probe. Further, (4) the interfacial velocity of the multidimensional bubble flow and (5) the bubble diameter are determined by the above-described method.

(6 sensors / probes)
In the interface velocity measurement method using three sets of the four sensor probes described above, a total of 12 sensors are required. Here, considering that the sensor is shared, it is possible to perform the same analysis process as described above by using a 6-sensor probe including 6 sensors. This will be described below.

Among the 4-sensor probes, 1 (= C ¹ ₁ ) sets of independent 4-sensor probes are included. Here, the 5-sensor probe with one more sensor includes 4 (= C ³ ₄ ) sets of 4-sensor probes. However, due to the shared sensor, there are only two sets of four independent sensor probes for a five sensor probe.

A 6-sensor probe obtained by adding one sensor to the 5-sensor probe includes 10 (= C ³ ₅ ) sets of 4-sensor probes. In this case, considering sensor sharing as described above, three sets of four independent sensor probes are included in the six sensor probes. That is, the 6-sensor probe can realize an interface velocity measurement method using 3 sets of 4 sensor probes.

  Here, a method for selecting six sensors for constituting three sets of four independent sensor probes in the six sensor probe will be described.

  First, a number from 0 to 5 is assigned to each of the six sensors. Then, four sensors numbered 0 to 3 are selected as main four-sensor probes. This is a set of four independent sensor probes.

Next, the sensor numbered 4 and any three of the four sensors numbered 0-3 are selected as the second 4-sensor probe. There are 4 (= C ³ ₄ ) combinations of variations of the second 4-sensor probe combination.

Next, sensor No. 5 and any three of the five sensors numbered 0-4 are selected as the third four-sensor probe. There are 10 (= C ³ ₅ ) combinations of combinations of the third four-sensor probes.

From the above, the number of variations for selecting three sets of four independent sensor probes among the six sensor probes is 40 (= C ¹ ₁ C ³ ₄ C ³ ₅ ).

  Note that there is a condition that the basic determinant must not be equal to 0 for each of the three sets of four sensor probes selected from the six sensor probes.

FIG. 4 shows an example of the arrangement state of each sensor in a 6-sensor probe provided with 6 sensors S0 to S5. In the figure, when the lower end of the sensor S0 is located at the origin O in the xyz coordinate space, examples of the positions of the lower ends of the sensors S1 to S5 are as follows.
Sensor S1: (0.35, 0, 0.8)
Sensor S2: (0.175, -0.3031, 0.4)
Sensor S3: (-0.175, -0.3031, 0.8)
Sensor S4: (-0.175, 0.3031, 0.8)
Sensor S5: (0.175, 0.3031, 0.4)
In the above coordinates, the unit is mm. The arrangement state of each sensor is not limited to the above example.

(Flow of gas-liquid two-phase flow analysis process)
Next, the flow of processing in the above measurement system using six sensors and probes will be described below with reference to the flowchart shown in FIG. Although an example in the case of using 6 sensor probes will be described here, substantially the same processing is performed even in a configuration using 3 sets of 4 sensor probes each having 7 to 12 sensors.

  First, in step 1 (hereinafter simply referred to as S1), it is determined how to select three sets of four independent sensor probes from the six sensors. This selection is performed as described above. Note that this step is not necessary in the case of a configuration using three sets of four-sensor probes having twelve sensors.

  Next, in S2, the distance between each of the six sensors and the other sensors is calculated. This distance is calculated by Equation 9 described above. Note that the processing in S1 and S2 corresponds to the initial value setting processing in the measurement system, and therefore does not need to be performed every time the operation is performed. For example, the value obtained in advance may be stored in the measurement apparatus 1. That's fine.

  Next, in S3, sensing processing is actually performed by the six sensors in the gas-liquid two-phase flow. In S <b> 4, the measurement results obtained by the sensors are transmitted from the sensor device 2 to the measurement device 1.

  When the measurement apparatus 1 receives the measurement result, the measurement calculation unit 5 performs calculation processing from S5 to S9 based on the received measurement result. Note that the processing from S5 to S9 need not be performed in this order, and may be performed in any order, or may be performed in parallel. Further, only necessary arithmetic processing may be performed.

  In S5, the void ratio is calculated. This void ratio is calculated based on the above-described equation (1). In S6, the bubble frequency is calculated. The bubble frequency is calculated based on the above-described formula 2. In S7, the interfacial area concentration is calculated. This interfacial area concentration is calculated based on Equation 21 described above. In S8, the interface speed is calculated. This interface speed is calculated based on the above-described equations 29 to 31. In S9, the bubble diameter is calculated. The bubble diameter is calculated based on the above-described equation 44.

  When the void ratio, bubble frequency, interface area concentration, interface velocity, and bubble diameter are calculated as described above, the calculation results are output as measurement results by the measurement result output unit 6.

  In addition, the measurement calculation part 5 of the said embodiment is realizable when calculation means, such as CPU, run the program memorize | stored in memory | storage means, such as ROM (Read Only Memory) and RAM. Therefore, the computer having these means can realize the various functions and various processes of the measurement calculation unit 5 simply by reading the recording medium storing the program and executing the program. In addition, by recording the program on a removable recording medium, the various functions and various processes described above can be realized on an arbitrary computer.

  As this recording medium, a program medium such as a memory (not shown) such as a ROM may be used for processing by the microcomputer, or a program reader is provided as an external storage device (not shown). It may be a program medium that can be read by inserting a recording medium therein.

  In any case, the stored program is preferably configured to be accessed and executed by the microprocessor. Furthermore, it is preferable that the program is read out, and the read program is downloaded to a program storage area of the microcomputer and the program is executed. It is assumed that this download program is stored in advance in the main unit.

  In addition, if the system configuration is capable of connecting to a communication network including the Internet, the recording medium is preferably a recording medium that fluidly carries the program so as to download the program from the communication network.

  Further, when the program is downloaded from the communication network as described above, it is preferable that the download program is stored in the main device in advance or installed from another recording medium.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The measuring device, measuring method, and measuring system according to the present invention can be used for analysis of gas-liquid two-phase flow in various industrial devices using gas-liquid two-phase flow. Examples of such industrial equipment include light water type power reactors, heat storage / freezing / refrigeration systems, electronic circuit cooling systems, and bubble reaction towers in the chemical industry.

It is a flowchart which shows the flow of a process in the measurement system which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the said measurement system. It is a figure which shows schematic structure of the sensor apparatus with which the said measurement system is provided. It is a figure which shows the example of the arrangement state of each sensor in 6 sensor probe. FIG. 4A is a diagram showing an outline of measurement by a double sensor probe, and FIG. 4B is a diagram showing an example of output signals from two sensors. It is a figure which shows typically a mode that the change of an interface is detected by four sensors. FIG. 4A is a diagram showing angles defining unit vectors of the interface normal direction component. FIGS. 2B and 2C show the direction of the interface normal and the direction of the interface normal. It is a figure which shows the relationship. It is a figure which shows typically a mode that an interface is measured with three sets of 4 sensor probes which became independent.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 2 Sensor apparatus 3 Channel pipe 4 Sensor output receiving part (output receiving part)
5 Measurement calculation unit (measurement calculation means)
6 Measurement result output section

Claims (6)

An output receiving unit that is disposed in the gas-liquid two-phase flow and receives an output signal from a sensor that detects a gas phase and a liquid phase in the gas-liquid two-phase flow;
Based on the output signal received by the output receiving unit, comprising a measurement calculation means for calculating physical characteristics relating to the interface between the gas phase and the liquid phase in the gas-liquid two-phase flow,
The output receiving unit receives output signals for at least three sets of sensor sets including at least four sensors, and each sensor set includes different combinations of sensors,
The measurement calculation means considers three sets of the normal component of the interface velocity and the unit vector in the normal direction of the interface obtained from the output signal of the sensor set for one set. In addition, in all the measurable velocities at a specific position on the interface, the magnitude of the normal component of each interface is the same, and the magnitude of the normal component of the interface in the measurable speed is the speed of the interface. Using the law of interface measurement to be equal to the normal direction component, calculate the local instantaneous interface velocity vector of the interface in each sensor set,
Based on the assumption that the velocity of the interface is constant in the contact process between the interface and the sensor, using the relationship that the local instantaneous interface velocity vectors of the interface in each sensor set are equal to each other, A three-dimensional velocity is calculated. The measurement apparatus according to claim 1, wherein the diameter of the bubble is calculated based on a three-dimensional velocity of the interface assuming that the bubble surrounded by the interface is spherical. At least three sensor sets comprising at least four sensors;
A measuring device according to claim 1 or 2 ,
Each of the sensor sets includes a different combination of sensors. Measurement system according to claim 3, wherein the sensor set of the three sets is constituted by six sensors. Claim 1 or the measurement program characterized by executing the measuring operation means performs processing measuring apparatus has according to the computer 2. A computer-readable recording medium on which the measurement program according to claim 5 is recorded.

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