JP2009085769A - Apparatus for measuring fluid in pipe and clogging diagnosis system for pressure guiding pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for measuring fluid inside a pipe line and a clogging diagnosing system, capable of accurately diagnosing clogging in a connecting pipe at all times, without being affected by process flow rates or process states. <P>SOLUTION: In the system, a differential pressure ΔP and pressures PH, PL which are detected via two connecting pipes 53H, 53L connected to the upstream and downstream sides of an orifice 52, and pressures P1, P2 of the fluid in the pipe line which are measured without using the connecting pipes 53H, 53L, are compared as time-series variation patterns by using a data-collecting section 21 and an arithmetic section 22, and then a clogged state of the connecting pipe 53H, 53L is diagnosed, based on this comparison result by using a diagnosis section 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a device for measuring a fluid in a pipe, such as a differential pressure / pressure transmitter, which measures a predetermined physical quantity of the fluid in the pipe using the pressure guide, and diagnoses a clogged state of the pressure pipe. The present invention relates to a clogging diagnosis system for a pressure guiding tube.

  A differential pressure transmitter or the like is known as a device for measuring a flow rate of a fluid in a pipe line in a plant or the like. The differential pressure transmitter guides the fluid in the pipeline from the front and back of a throttling mechanism (hereinafter referred to as an orifice) installed in the pipeline to the detection unit via the two pressure guidance tubes. The differential pressure of the fluid in the pipeline is detected and the differential pressure signal is transmitted to a higher-level control device, or the flow rate of the fluid in the pipeline is obtained from the detected differential pressure and a signal indicating this flow rate value is obtained. Or transmit to a higher-level control device.

  The pressure guiding tube is made of, for example, a thin metal tube, and is configured to fill the fluid in the conduit in the pressure guiding tube and transmit the pressure of the fluid in the conduit to the detection unit of the differential pressure transmitter.

  In the differential pressure transmitter, not only the differential pressure before and after the orifice, but also the static pressure of the fluid in the pipe line via the upstream pressure guide pipe and the static pressure of the fluid in the pipe line via the downstream pressure guide pipe Some of them have a function of measuring these static pressure signals and transmitting them to a host control device.

  As described above, in a measuring instrument using a pressure guiding tube, there is a possibility that an accurate measurement result may not be obtained when the pressure guiding tube is clogged. Therefore, there are some conventional techniques for detecting clogging of the pressure guiding tube. Proposals have been made.

  For example, Patent Document 1 discloses a technique for determining that a pressure guiding tube is clogged and outputting a warning when a temporal change amount of pressure fluctuation through the pressure guiding tube deviates from a reference value. Patent Document 2 describes a case where the average value of a pressure signal or a differential pressure signal and a variance value of a temporal variation (also called fluctuation or ripple noise) are calculated and the variance value falls below a predetermined threshold value. A technique is disclosed in which it is determined that the pressure guiding tube is clogged, or when the dispersion value is a very small value or the average value is not within the predetermined range, the pressure guiding tube clogging diagnosis is impossible and the diagnosis is not performed. .

In Patent Document 3, the ratio between the dispersion value of the pressure fluctuation measured through the pressure guiding pipe upstream of the orifice and the dispersion value of the pressure fluctuation measured through the pressure guiding pipe downstream of the orifice is shown. A technique for calculating and determining clogging of a pressure guiding tube based on this ratio is disclosed.
US Pat. No. 6,654,697 JP 2006-329847 A JP 2006-105707 A

  However, the conventional techniques for diagnosing clogging of a pressure guiding tube have the following problems. For example, the technique of Patent Document 1 requires a complicated operation of learning and storing data such as pressure fluctuation during normal operation as reference data in advance. Further, the techniques disclosed in Patent Documents 1 and 2 have a problem that the accuracy of clogging diagnosis greatly depends on the process state, and accurate clogging diagnosis cannot be performed when the pressure fluctuation of the fluid in the pipeline is originally small. Also, in a plant where the process flow rate increases or decreases due to changes in the pump operating status over time, the pressure fluctuation amount of the fluid in the pipe line differs greatly between a large flow rate and a small flow rate. There is a problem that accurate clogging diagnosis cannot be performed.

  Further, in the technique of Patent Document 1, there is a possibility that the pressure guiding pipe is clogged when the process fluid stops, and in the technique of Patent Document 2, in order to avoid such a misdiagnosis, an error may occur. Although clogging diagnosis is not performed in a process state where there is a possibility of diagnosis, there is a problem that clogging diagnosis is not executed in a specific process state.

  In addition, the technique of Patent Document 3 calculates a pressure distribution value of two systems via two pressure guiding pipes so as not to be affected by the process flow rate, and compares them to perform a highly accurate clogging diagnosis. However, since the turbulent flow generated in the fluid in the pipe line is different between the upstream side and the downstream side of the orifice, the diagnosis accuracy is so high only by comparing the two pressure dispersion points. There is a problem that cannot be obtained.

  An object of the present invention is that complicated processing such as learning and storage processing of pressure data during normal operation is unnecessary, and it is always possible to diagnose clogging of a pressure guiding tube with high accuracy without being affected by process flow rate or process state. It is to provide a measuring device and a clogging diagnosis system.

  Another object of the present invention is to enable detection of a clogged state of a pressure guiding tube from an early stage before the pressure guiding tube is completely clogged.

  In order to achieve the above-described object, the invention according to claim 1 is configured to guide the fluid in the pipe line from the upstream side and the downstream side of the throttle mechanism installed in the pipe line to the detection unit via at least two pressure guiding pipes. In a device for measuring fluid in a pipe that measures a predetermined physical quantity of fluid in the pipe based on the output of the detection unit, a measurement signal is input from the pressure measuring device that measures the pressure of the fluid in the pipe without using the pressure guiding pipe And a comparison means for comparing the time-series change pattern of the pressure value represented by the input measurement signal with the time-series change pattern of the measurement value obtained by the output of the detection section, and the comparison means And an evaluation means for evaluating the degree of clogging of the pressure guiding tube based on the comparison result.

  According to a second aspect of the present invention, in the apparatus for measuring an in-pipe fluid according to the first aspect, the signal input unit includes a first pressure measuring device that measures the pressure of the in-pipe fluid upstream of the throttling mechanism. A first signal input unit configured to input a measurement signal; and the detection unit includes a first pressure detection unit configured to detect the pressure of the fluid in the pipe line via the pressure guiding pipe connected to the upstream side of the throttle mechanism. And the comparison means is configured to compare a time-series change pattern between the pressure value represented by the measurement signal of the first signal input unit and the pressure value represented by the output of the first pressure detection unit. It is said.

  According to a third aspect of the present invention, in the apparatus for measuring an in-pipe fluid according to the first or second aspect, the signal input unit measures the pressure of the in-pipe fluid downstream of the throttling mechanism. A second signal input unit configured to input a measurement signal from the apparatus; and the detection unit detects a pressure of fluid in the pipe line via the pressure guiding pipe connected to a downstream side of the throttle mechanism. And the comparison means is configured to compare a time-series change pattern between the pressure value represented by the measurement signal of the second signal input unit and the pressure value represented by the output of the second pressure detection unit. It is characterized by.

  According to a fourth aspect of the present invention, in the apparatus for measuring an in-pipe fluid according to the first aspect, the detection unit includes the in-pipe fluid via the pressure guide pipe on the upstream side of the throttling mechanism and the downstream guide. The differential means is configured to detect a differential pressure with respect to the fluid in the pipe line via the pressure pipe, and the comparing unit is configured to detect a pressure value represented by the measurement signal of the signal input unit and a differential pressure value represented by the output of the detection unit. It is characterized by the configuration for comparing the change patterns of the series.

  According to a fifth aspect of the present invention, in the apparatus for measuring a fluid in a pipe line according to any one of the first to third aspects, the comparing means includes time-series pressure data represented by a measurement signal of the signal input unit. The cross-correlation value with the time-series measurement data represented by the output of the detection unit is calculated.

  According to a sixth aspect of the present invention, in the pipe fluid measuring device according to the fifth aspect, data of a distance along the pipe line from the connection position of the pressure measurement device to the connection position of the pressure guiding pipe can be stored. Data storage means, and the comparison means obtains the flow velocity of the fluid in the pipeline based on the output of the detection unit, and the time value required for the fluid in the pipeline to travel the distance from the data of the flow velocity and the distance And the cross-correlation value is calculated using the time value as the phase difference of the cross-correlation function.

  The invention described in claim 7 is a clogging diagnosis system that diagnoses a clogged state of a pressure guiding pipe that is installed between a pipe and a measuring instrument and guides fluid in the pipe from the pipe to the detection unit of the measuring instrument. The pressure guiding pipe is configured to guide the fluid in the pipe line from the upstream side and the downstream side of the throttle mechanism installed in the pipe line to the detection unit, respectively. Pressure detection means for detecting pressure, comparison means for comparing time-series change patterns of the pressure value detected by the pressure detection means and the measured value for the fluid in the pipe line guided through the pressure guiding pipe; And an evaluation means for evaluating the degree of clogging of the pressure guiding tube based on the result of the comparison means.

  According to an eighth aspect of the present invention, in the pressure guiding tube blockage diagnosing system according to the seventh aspect, the pressure detecting means is a pipe that is directly connected to the pipe without detecting the pressure guiding pipe and detects the pressure of the fluid in the pipe. It is a direct connection type pressure detector.

  According to the present invention, the pressure measurement value of the fluid in the pipe line measured without going through the pressure guiding pipe to be subjected to the clogging diagnosis, and the pressure or the differential pressure of the fluid in the pipe line measured through the pressure guiding pipe Compares the time-series change pattern with the value and diagnoses the clogged state of the pressure guiding tube, so there is no need to learn or memorize the fluid pressure, which is the basis for comparison, and it hardly depends on the process flow rate or process state. In addition, it is always possible to diagnose clogging of a pressure guiding tube with high accuracy.

  In addition, by calculating the cross-correlation value in consideration of the flow velocity and performing clogging diagnosis based on this cross-correlation value, for example, a partial clogging state before the pressure guiding tube is completely clogged, such as a half-clogging state It is also possible to detect this.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a configuration diagram showing an example of a system in which a differential pressure transmitter 1 according to a first embodiment of the present invention is connected to a pipeline.

  The differential pressure transmitter 1 according to the first embodiment is an embodiment of a fluid measurement device in a pipe according to the present invention, and measures the flow rate of the fluid flowing in the pipe 51 and sends the measurement signal to a host controller or the like. It is a device to transmit to. The differential pressure transmitter 1 is connected to the front and rear of an orifice 52 as a throttle mechanism installed in the pipe line 51 via pressure guide pipes 53H and 53L, respectively, and the fluid in the pipe line is connected to the pressure guide pipes 53H and 53L. The inside is filled and the pressure is guided to the detection unit 11.

  The differential pressure transmitter 1 receives the pressure of the fluid filled in the pressure guiding pipes 53H and 53L and detects the static pressures PH and PL and the differential pressure ΔP, and receives the differential pressure signal and converts it into digital form. Data sampling section 12, calculation section 13 that calculates flow rate and flow velocity from sampled differential pressure data, analog output section 14 that outputs an analog signal corresponding to the flow rate, and clogging diagnosis of pressure guiding pipes 53H and 53L A pressure guiding tube clogging diagnosis block 20 or the like is provided.

  In addition, the differential pressure transmitter 1 is installed upstream of the orifice 52 and measures the pressure P1 of the fluid in the pipeline. The differential pressure transmitter 1 is installed downstream of the orifice 52 and the fluid in the pipeline. A pressure signal is input from the pressure transmitter 62 for measuring the pressure P2 through the external input terminals T1 and T2 (first and second signal input units). These pressure signals are used for diagnosing clogging of the pressure guiding pipes 53H and 53L, and even when the pressure guiding pipes 53H and 53L are clogged, the portions for introducing the fluid in the pressure transmitters 61 and 62 are not clogged. Therefore, as the pressure transmitters 61 and 62, for example, a pressure transmitter of a pipe direct connection type that measures the pressure of the fluid in the pipe line without using a pressure guiding pipe or the like may be used.

The detection unit 11, the data sampling unit 12, the calculation unit 13, and the analog output unit 14 are the same as those provided in a general differential pressure transmitter. For example, the detection unit 11 detects the static pressure PH of the fluid in the pipe line via the pressure guiding pipe 53H based on the sum of the oscillation frequencies of the two vibrators formed on the diaphragm of one vibration semiconductor sensor (first step). 1 pressure detection unit), and detects the differential pressure ΔP based on the difference in oscillation frequency, and also determines the static pressure PL of the fluid in the pipe line via the pressure guiding pipe 53L based on the difference between the static pressure PH and the differential pressure ΔP. Detection (second pressure detection unit). The data sampling unit 12 converts the analog differential pressure signal from the detection unit 11 into digital data at a predetermined sampling frequency, and the calculation unit 13 substitutes this digital data into the following calculation formulas (1) and (2). calculating a mass flow rate q _m and the flow velocity v or the like in the line fluid with. Data of the mass flow rate q _m calculated by the calculation unit 13 is supplied to the analog output unit 14, and data of the flow velocity v is supplied to the data sampling & data collection unit 21 of the pressure guiding tube blockage diagnosis block 20. The analog output section 14 transmits to the host controller converts the data of mass flow rate _{q m} for example into an analog current signal of 4mA to 20mA.

  The pressure tube clogging diagnosis block 20 digitizes signals necessary for clogging diagnosis and collects these data for a predetermined time, and calculates a cross-correlation value to be described later from these data. A calculation unit 22, a diagnosis unit 23 for diagnosing the clogged state of the pressure guiding tubes 53H and 53L based on the calculation result of the calculation unit 22, a digital output unit 24 for generating and outputting digital alarm information based on the diagnosis result, A non-volatile memory 25 and the like for holding setting data necessary for correlation value calculation and clogging diagnosis are provided.

  Among the above configurations, the data sampling unit 12, the calculation unit 13, the data sampling and data collection unit 21, the calculation unit 22, and the diagnosis unit 23 are realized by, for example, an AD converter or a central processing unit of a microcomputer. It is a functional block.

  The data sampling & data collection unit 21 digitizes and samples the following four signals at a predetermined sampling frequency. That is, a signal indicating the static pressure PH upstream of the orifice 52 detected by the detection unit 11 via the pressure guiding pipe 53H, and the static pressure PL downstream of the orifice 52 detected by the detection unit 11 via the pressure guiding pipe 53L. , A signal of the pressure P1 upstream of the orifice 52 input from the external pressure transmitter 61, and a signal of the pressure P2 downstream of the orifice 52 input from the external pressure transmitter 62.

Further, the data sampling & data collecting unit 21 collects the sampled signal as the following discrete data for a certain period of time. That is,
For the signal of the pressure P1, N discrete data {P1 _i : i = 1, 2,... N} from the time t every sampling interval Δt
For the signal of the static pressure PH, N discrete data {PH _i : i = 1, 2,... N} every sampling interval Δt from time t + τ ₁
With respect to the signal of the static pressure PL, N discrete data {PL _i : i = 1, 2,... N} every sampling interval Δt from time t
The signals of the pressure P2, the time t + tau ₂ from each sampling interval Delta] t N pieces of discrete data: a _{{P2 i i = 1,2 ... N} }.

  Here, the sampling period is, for example, several tens of milliseconds, and the number N of discrete data to be collected is, for example, several hundred points (for example, 300 points). A discrete data having such a number of data can represent a time-series change pattern such as the pressure of the fluid in the pipeline.

The offset times τ ₁ and τ ₂ are values shown in the following equations (3) and (4).

That is, by taking the offset time τ ₁ into consideration, the collected discrete data of the pressure P1 and the static pressure PH is obtained when an arbitrary point of the fluid in the pipe reaches the connection point of the pressure transmitter 61. The same index value i is added to the data measured by the pressure transmitter 61 and the data detected via the pressure guiding tube 53H when the arbitrary point reaches the connection point of the pressure guiding tube 53H. Are to be collected. Similarly, by taking the offset time τ ₂ into consideration, the collected discrete data of the static pressure PL and the pressure P2 is obtained when an arbitrary point of the fluid in the pipe reaches the connection point of the pressure guiding pipe 53L. The static pressure PL data detected via the pressure guiding pipe 53L and the pressure P2 data measured by the pressure transmitter 62 when the arbitrary point reaches the connection location of the pressure transmitter 62 are: The same index value i is added and collected.

Data of the flow velocity v necessary to obtain the offset times τ ₁ and τ ₂ is supplied from the calculation unit 13, and the distances l ₁ , between the pressure transmitters 61 and 62 and the connection portions of the pressure guiding pipes 53H and 53L are supplied. The l ₂ is written in advance in the nonvolatile memory 25 as data storage means by the system setter, and is read out by the data sampling & data collection unit 21. The setting data can be written to the nonvolatile memory 25 by, for example, communication via a transmission line connected to the host controller, or directly connected to the differential pressure transmitter 1 by a data writer or the like. Alternatively, the data may be written to the nonvolatile memory 25. The number of discrete data “N” is also set by being written in the nonvolatile memory 25. The setting change of the N value may be performed, for example, by a method of adding or subtracting an arbitrary fluctuation value to a standard N value (for example, 300).

  The data sampling & data collection unit 21 discards the oldest data for each sampling period and newly samples the discrete data collected as described above, like a FIFO (fast-in / fast-out) buffer. The above-described set of discrete data is updated at every sampling period by adding one piece of data.

The computing unit 22 computes the cross-correlation values RH and RL as in the following equations (5) and (6) using the discrete data set collected as described above.

The cross-correlation value RH obtained from the equation (5) is obtained by calculating the static pressure PH detected through the upstream pressure guiding tube 53H and the pressure P1 measured by the upstream pressure transmitter 61 as functions of time. It is a value representing the correlation of the waveform for the time of sampling period Δt × N. Here, the time function and the time function of the pressure P1 of the hydrostatic PH, which is what the phase is shifted by ₁ minute offset time tau. The cross-correlation value RH is normalized so as to take a value of “0 to 1”. The cross-correlation value RH represents the degree of approximation of these data by comparing time series data of the static pressure PH and the pressure P1.

The cross-correlation value RL obtained from Equation (6) is obtained by calculating the static pressure PL detected via the downstream pressure guiding tube 53L and the pressure P2 measured by the downstream pressure transmitter 62 as functions of time. It is a value representing the correlation of the waveform for the time of sampling period Δt × N. Here, the time function of the time function and the pressure P2 of the hydrostatic PL, has become one offset time τ only ₂ minutes phases are shifted. Further, the cross-correlation value RL is normalized so as to take a value of “0 to 1”. The cross-correlation value RL represents time series data of the static pressure PL and the pressure P2, and represents the degree of approximation of these data.

In other words, the cross-correlation values RH and RL are obtained by using the following equations (7) and (8), the cross-correlation functions C _P1PH (τ ₁ ) and C _PLP2 (τ ₂ ), and the offset times τ ₁ and τ ₂ . The phase difference is normalized so that the value takes “0 to 1”, and is represented by discrete data.

The fluid in the pipe line is pumped by the pressure that fluctuates in time by a pump provided on the upstream side of the pipe line, and the pressure changes by changing the amount of fluid stored in the storage tank etc. on the downstream side of the pipe line. To do. In addition, bubbles and vortices are generated in the fluid, which changes the amount of pressure transmitted. For this reason, the fluid in the pipe is always in a state in which a temporal change in pressure (also referred to as oscillation or ripple noise) has occurred. Therefore, if the pressure guiding tube 53H is not clogged, the waveforms of P1 (t) and PH (t + τ ₁ ) are approximated when the phase difference τ ₁ reaches the value of Equation (3), and the cross-correlation function C _P1PH ( τ ₁ ) takes the maximum value. On the other hand, when the pressure guiding tube 53H is clogged, the process state is not transmitted to PH (t + τ ₁ ) detected via the pressure guiding tube 53H, and the waveforms of P1 (t) and PH (t + τ ₁ ) are not approximated. The cross-correlation function C _P1PH (τ ₁ ) shows a small value. In addition, when the pressure guiding tube 53H is clogged, the value of the flow velocity v required to obtain τ ₁ becomes inaccurate, so that the cross-correlation function C _P1PH (τ ₁ ) shows a smaller value. It becomes. The same _{applies to the} cross-correlation function C _PLP2 (τ ₂ ) related to the downstream pressure.

  Therefore, the degree of clogging of the pressure guiding tubes 53H and 53L is diagnosed by evaluating the cross-correlation values RH and RL in the equations (5) and (6) corresponding to the normalized values of these cross-correlation functions. Is possible.

  FIG. 2 shows an example of the cross-correlation value RH and the clogging diagnosis and alarm contents related to the pressure upstream of the orifice. FIG. 3 shows an example of the cross-correlation value RL and the clogging diagnosis and alarm contents related to the pressure downstream of the orifice.

  For example, if the cross-correlation value RH calculated by the calculation unit 22 is in the range of “0.5 to 1”, the diagnosis unit 23 diagnoses that the pressure guiding tube 53H is normal, and “0.2 to 0.5”. If it is within the range, it is diagnosed that it is clogged, and if it is within the range of “0 to 0.2”, it is diagnosed that it is clogged. Similarly, if the cross-correlation value RL calculated by the calculation unit 22 is in the range of “0.5 to 1”, it is diagnosed that the pressure guiding tube 53L is normal, and is in the range of “0.2 to 0.5”. When it becomes, it is diagnosed that it is clogged, and when it is in the range of “0 to 0.2”, it is diagnosed that it is clogged. If it is diagnosed that it is clogged, it outputs a command to output warning alarm information to the digital output unit 24. If it is diagnosed that it is clogged, it outputs a command to output alarm alarm information to the digital output unit 24. To do.

  Such threshold values of the three types of diagnosis results are written in the nonvolatile memory 25, and the diagnosis unit 23 reads them and compares them with the calculated cross-correlation values RH and RL. Diagnosis is made. Such a cross-correlation value threshold value can be appropriately changed by a system setter by rewriting the value in the nonvolatile memory 25.

  When the digital output unit 24 receives a warning warning output command from the diagnosis unit 23 or receives an alarm warning output command, the digital output unit 24 generates a digital signal representing the warning information. The signal is digitally output by being superimposed on a transmission line for transmitting the signal to the host controller. Further, a warning or warning display is output to a display (not shown) provided in the differential pressure transmitter 1.

  As described above, according to the differential pressure transmitter 1 of this embodiment, the built-in pressure guiding tube blockage diagnosis block 20 and the pressure of the in-pipe fluid measured and guided without the pressure guiding tubes 53H and 53L are introduced. The clogged state of the pressure guiding pipes 53H and 53L is diagnosed by comparing the time-series change pattern with the pressure of the fluid in the pipe line detected through the pressure pipes 53H and 53L, and therefore almost depends on the process flow rate and the process state. Therefore, the clogging diagnosis of the pressure guiding pipes 53H and 53L with high accuracy can always be performed. In addition, it is not necessary to learn or store data as a reference for comparison and can diagnose a clogged state in real time.

  Further, the measurement value of the upstream pressure transmitter 61 is used for diagnosing clogging of the pressure guiding pipe 53H upstream of the orifice 52, and the measurement of the downstream pressure transmitter 62 is used for diagnosing clogging of the downstream pressure guiding pipe 53L. Since the time series change pattern of each pressure is compared using the value, the difference in pressure fluctuation between the upstream side and the downstream side generated by the orifice 52 is a big error in the clogging diagnosis of the pressure guiding pipes 53H and 53L. Can be avoided.

  In addition, since the cross-correlation values RH and RL in consideration of the flow velocity v of the fluid in the pipe line are calculated and clogging is diagnosed, it is possible to accurately diagnose even the partial clogging of the pressure guiding pipes 53H and 53L. Therefore, for example, it is possible to detect a stage before the pressure guiding tube is completely clogged, such as a clogged state.

  In the first embodiment, the alarm information indicating the diagnosis result of the pressure guiding tube blockage diagnosis block 20 is transmitted by superimposing the digital signal on the analog signal. For example, the transmission line has an analog of 4 mA to 20 mA. If it is a standard for signal transmission, warning information or alarm information for clogging diagnosis may be expressed by outputting an analog signal with a lower limit or upper limit such as 3.6 mA or 22 mA.

For example, when applied to a full digital transmission line such as a foundation or field bus, the differential pressure ΔP and the flow rate q _m are displayed together with the digital data representing the differential pressure ΔP and the flow rate q _m , and the warning information and alarm information for clogging diagnosis are also digital data. It is also possible to configure to transmit from the device 1 to a higher-level control device (host controller or the like). Further, in the case of a full digital transmission line, not only warning information and alarm information, but also the data of the cross-correlation values RH and RL calculated by the calculation unit 22 may be transmitted to the host controller one by one. it can.

Other information outputted from the impulse line blockage diagnosis block 20, or to transmit to the host controller and the transmission line for transmitting signal of the differential pressure ΔP and flow rate q _m using the transmission line of another system, or Alternatively, it may be transmitted to the host controller using a radio signal.

In the first embodiment, the flow velocity v of the fluid in the pipe and the offset times τ ₁ and τ ₂ corresponding to the distances l ₁ and l ₂ are used in the calculation of the cross correlation value as the phase difference of the cross correlation function. However, for example, when the period of process fluctuation is long and the pressure fluctuation of the fluid in the pipe line is very small in the period of sampling interval Δt × sampling number N, detection of static pressure PH and pressure transmission via the pressure guiding pipe 53H. since the measurement of the pressure P1 by vessel 61 can be regarded as having been subjected substantially at the same point, ignoring the offset time tau _1, it is also possible to perform the calculation of cross-correlation values. The same applies to the offset time τ ₂ on the downstream side. In addition, the offset times τ ₁ and τ ₂ are not determined only by the flow velocity v of the fluid in the pipeline and the distances l ₁ and l ₂ , but for example, the velocity of the sound wave, the velocity of the shock wave, and the pressure in the fluid in the pipeline The offset time during which the temporal fluctuation waveform of the pressure is shifted may be determined in consideration of the content of bubbles and vortex flow that affect the transmission of the pressure.

[Second Embodiment]
FIG. 4 shows a system configuration example in which the differential pressure transmitter 1B according to the second embodiment of the present invention is connected to a pipeline.

  In the differential pressure transmitter 1B of the second embodiment, only one pressure transmitter 61 in which an externally connected pressure transmitter is installed on the upstream side of the orifice 52 is used. Also in this case, the cross-correlation value RH of the time-series change pattern between the pressure P1 measured by the pressure transmitter 61 and the static pressure PH detected via the upstream pressure guiding tube 53H is expressed by the above equation (5). ) And comparing this value RH with a set threshold value, the clogged state of the upstream guiding tube 53H can be diagnosed in the same manner as in the first embodiment.

In addition, there is a certain strong correlation between the time-series change pattern of the pressure P1 measured upstream of the orifice 52 and the static pressure PL detected via the pressure guiding pipe 53L downstream of the orifice 52. In this case, by calculating the cross-correlation value R1L between the pressure P1 and the static pressure PL by the calculation unit 22, although the accuracy slightly decreases, it is possible to diagnose the clogged state of the downstream pressure guiding tube 53L. . In this case, the cross-correlation value R1L can be obtained as in the following equation (9).

  In the second embodiment, the measurement signal of the pressure P1 is externally input from only one pressure transmitter 61 installed on the upstream side of the orifice 52, and the upstream and downstream pressure guiding pipes 53H and 53L are input. Although it was configured to perform the clogging diagnosis, conversely, the measurement signal of the pressure P2 is externally input from only one pressure transmitter 62 (see FIG. 1) installed on the downstream side of the orifice 52, and downstream using this. It is good also as a structure which performs the clogging diagnosis of the side pressure guiding pipe 53L similarly to 1st Embodiment.

  At this time, the time-series change pattern of the pressure P2 measured on the downstream side of the orifice 52 and the static pressure PH detected on the upstream side of the orifice 52 via the pressure guiding pipe 53H is somewhat strong. When there is a correlation, the cross-correlation value between the pressure P2 and the static pressure PH is calculated by the calculation unit 22 in the same manner as described above, so that the accuracy is slightly reduced, but the clogged state of the upstream pressure guiding tube 53H is also diagnosed. It becomes possible to do.

[Third Embodiment]
FIG. 5 shows a system configuration example in which the differential pressure transmitter 1C according to the third embodiment of the present invention is connected to a pipeline.

  In the differential pressure transmitter 1C of the third embodiment, the detection unit 11C independently detects each pressure of the upstream static pressure PH and the downstream static pressure PL guided through the pressure guiding pipes 53H and 53L. This is an example of a case where only the differential pressure ΔP (= PH-PL) can be detected. Further, even when the static pressures PH and PL on the upstream side and the downstream side can be detected independently, when it is desired to easily perform the clogging diagnosis without distinguishing both the pressure guiding pipes 53H and 53L. This embodiment can also be applied.

In this embodiment, the upstream pressure P1 measured by the pressure transmitter 61 has a strong correlation with the static pressure PH detected via the upstream pressure guiding tube 53H, and the downstream pressure guiding tube 53L is The cross-correlation value R of the time function between the pressure P1 and the differential pressure ΔP is calculated using the fact that there is a weak correlation with the static pressure PL detected via the pressure, and the pressure guiding pipes 53H and 53L are clogged by the calculated value. The condition is diagnosed. Since there is a correlation as described above between the upstream pressure P1 and the static pressures PH and PL via the pressure guiding pipes 53H and 53L, the differential pressure ΔP (= PH-PL) and the upstream pressure A relatively strong correlation also remains with the pressure P1, and an equation such as the following equation (10) can be adopted as the cross-correlation value R in this case.

  Then, when such a cross-correlation value R is calculated by the calculation unit 22, the diagnosis unit 23 compares the calculation result with a threshold value to diagnose the clogged state of the pressure guiding tubes 53H and 53L.

  Even with such a cross-correlation value R, although the accuracy is slightly lower than that of the first embodiment, the clogged state of the pressure guiding tubes 53H and 53L can be similarly diagnosed.

[Fourth Embodiment]
FIG. 6 is a configuration diagram showing a pressure guiding tube blockage diagnosing system according to a fourth embodiment of the present invention.

  The fourth embodiment shows an embodiment of a pressure guiding tube clogging diagnosis system according to the present invention. In order to diagnose clogging of the pressure guiding tubes 53H and 53L of the differential pressure transmitter 63, the differential pressure transmitter 63 and Is a separate clogging diagnosis device 2 added to the system.

  The system of this embodiment measures a differential pressure transmitter 63 that measures the differential pressure ΔP upstream and downstream of the orifice 52 via the pressure guiding pipes 53H and 53L, and measures the pressure P1 of the fluid in the pipe upstream of the orifice 52. A first pressure transmitter 61 as a pressure detecting means, a second pressure transmitter 62 as a pressure detecting means for measuring the pressure P2 of the fluid in the pipe downstream of the orifice 52, and a differential pressure transmitter 63. The clogging diagnosis device 2 for diagnosing the clogging state of the pressure guiding pipes 53H and 53L and the measurement data and alarm information etc. from the differential pressure transmitter 63 and the clogging diagnosis device 2 via the transmission path 65 are used to control the entire system. A host controller 70 and the like are provided.

  The pressure transmitters 61 and 62 measure the pressure P1 on the upstream side and the pressure P2 on the downstream side of the fluid in the pipe line in order to diagnose clogging of the pressure guiding pipes 53H and 53L of the differential pressure transmitter 63. Since it is desirable that the pressure transmitters 61 and 62 can measure an accurate pressure value of the fluid in the pipe line even in a situation where the pressure guide pipes 53H and 53L of the differential pressure transmitter 63 are clogged, the pipe line is not connected via the pressure pipe. A pipe direct connection type that measures the pressure of the internal fluid may be applied. The measurement signals of both pressure transmitters 61 and 62 are configured to be directly transmitted to the diagnostic device 2, for example. In addition, these signals may be clogged and supplied to the diagnostic device 2 via the transmission path 65.

  The differential pressure transmitter 63 measures the differential pressure ΔP between the upstream side and the downstream side of the orifice 52 and transmits a signal representing the differential pressure ΔP to the host controller 70, or the flow rate of the fluid in the pipe line, etc. A signal representing this is calculated and transmitted to the host controller 70. In addition, the differential pressure transmitter 63 calculates the static pressure PH on the upstream side of the orifice and the static pressure PL on the downstream side detected through the pressure guiding pipes 53H and 53L, respectively, for diagnosis of clogging of the pressure guiding pipes 53H and 53L. A signal indicating the flow velocity v of the fluid in the pipeline calculated from the differential pressure ΔP and the signal indicating the differential pressure ΔP are transmitted to the clogging diagnosis device 2.

In addition to the I / O interface 27 that inputs and outputs signals via the transmission path 65, the clogging diagnosis device 2 is similar to the data sampling and data collecting unit 21 described in the clogging diagnosis block 20 of the first embodiment. , A calculation unit 22 for calculating a cross-correlation value, a diagnosis unit 23 for comparing a calculation result with a threshold value to perform a clogging diagnosis, a digital output unit 24 for outputting alarm information corresponding to a clogging state, and data writing from outside A non-volatile memory 25 that can set l ₁ , l ₂ , N value, alarm threshold value, and the like is provided.

  To the I / O interface 27, the signals of the pressures P1, P2, PH, PL and the flow velocity v described above are input from the pressure transmitters 61 and 62 and the differential pressure transmitter 63, or the host controller via the transmission path 65. Or send alarm information.

  Even when the clogging diagnosis device 2 is provided separately, the clogging diagnosis device 2 samples and collects necessary data in the same manner as the clogging diagnosis block 20 of the differential pressure transmitter 1 described in the first embodiment. Thus, the cross-correlation value of the pressure waveform is calculated, and the state where the pressure guiding tubes 53H and 53L are clogged or clogged can be diagnosed according to the calculated value. When it is determined that the device is clogged or clogged, warning and alarm information can be transmitted to the host controller 70 via the I / O interface 27 and the transmission path 65.

[Fifth Embodiment]
In FIG. 7, the block diagram of the clogging diagnosis system of the pressure guiding tube of 5th Embodiment of this invention is shown.

  The fifth embodiment shows an embodiment of a pressure guiding tube clogging diagnosis system according to the present invention. A pressure guiding tube clogging diagnosis block 72 is provided in the host controller 70, and the pressure guiding tubes 53H and 53L are clogged on the host controller 70 side. The diagnosis is performed. The pressure tube clogging diagnosis block 72 is the same as the pressure tube clogging diagnosis block 20 of the differential pressure transmitter 1 shown in the first embodiment, for example.

  Even in such a configuration, the data of the static pressure PH and PL and the data of the flow velocity v are transmitted from the differential pressure transmitter 63 via the transmission path 65 to the pressure guiding tube blockage diagnosis block 72 of the host controller 70. By transmitting the pressure P1 and P2 data of the fluid in the pipe line from the pressure transmitters 61 and 62 to the pressure guiding tube blockage diagnosis block 72 of the host controller 70 via the transmission line 65, the pressure guiding tube blockage diagnosis block 72 performs the first operation. It is possible to perform cross-correlation calculation in the same manner as in the first embodiment, and to diagnose clogging of the pressure guiding tubes 53H and 53L based on the value.

  In the fourth embodiment, the block for diagnosing clogging of the pressure guiding tubes 53H and 53L is shown as an independent device separated from each measuring device, and in the fifth embodiment, this block is provided in the host controller 70. In the same manner, this clogging diagnosis block may be provided in the pressure transmitters 61 and 62 or in another measuring device.

  Further, in the fourth and fifth embodiments showing the clogging diagnosis system according to the present invention, the static pressure PH of the fluid in the pipe line via the upstream pressure guiding pipe 53H and the upstream pressure transmitter 61 are shown. The calculation of the cross-correlation value with the measured value of the pressure P1 by the pressure, the static pressure PL of the fluid in the pipe line through the downstream pressure guiding pipe 53L, and the measured value of the pressure P2 by the downstream pressure transmitter 62 Although it has been described that each of the pressure guiding tubes 53H and 53L is diagnosed by calculating the cross-correlation value, the measurement data for obtaining the cross-correlation is various modifications as shown in the second embodiment and the third embodiment. It can also be adopted.

  Further, in the first to fifth embodiments, the pipe direct connection type measuring instrument is shown as the pressure transmitters 61 and 62, but the two pressure guiding pipes may be rarely clogged in the same state at the same time. For example, as the pressure transmitters 61 and 62, a measuring device of a type that measures pressure via a pressure guiding tube may be applied.

  In the first to fifth embodiments, the differential pressure transmitter is exemplified as the fluid measuring device in the pipe and the pressure transmitter is exemplified as the pressure measuring means. However, the information is transmitted to the host controller for centralized management. If the system is not necessary, a differential pressure measuring device or a pressure measuring device that performs only measurement without transmitting a measurement signal can be applied.

It is a block diagram which shows an example of the system which connected the differential pressure transmitter of 1st Embodiment of this invention to the pipe line. It is a table | surface which shows an example of the cross-correlation value RH which concerns on the pressure upstream from an orifice, the content of the clogging diagnosis of a pressure guiding tube, and the content of alarm. It is a table | surface which shows an example of the cross-correlation value RL which concerns on the pressure downstream from an orifice, the content of the clogging diagnosis of a pressure guiding tube, and the content of alarm. It is a block diagram which shows an example of the system which connected the differential pressure transmitter of 2nd Embodiment of this invention to the pipe line. It is a block diagram which shows an example of the system which connected the differential pressure transmitter of 3rd Embodiment of this invention to the pipe line. It is a block diagram which shows the clogging diagnosis system of the pressure guiding tube of 4th Embodiment of this invention. It is a block diagram which shows the clogging diagnosis system of the pressure guiding tube of 5th Embodiment of this invention.

Explanation of symbols

1, 1B, 1C Differential Pressure Transmitter 2 Clogging Diagnosis Device 11 Detection Unit 20 Impulse Tube Clogging Diagnosis Block 21 Data Sampling & Data Collection Unit 22 Calculation Unit 23 Diagnosis Unit 24 Digital Output Unit 25 Non-Volatile Memory 51 Pipeline 52 Orifice 53H, 53L Pressure tube 61, 62 Pressure transmitter 63 Differential pressure transmitter 70 Host controller 72 Pressure tube clogging diagnosis block

Claims (8)

The fluid in the pipeline is guided to the detection unit via at least two pressure guiding pipes from the upstream side and the downstream side of the throttle mechanism installed in the pipeline, and a predetermined physical quantity of the fluid in the pipeline is calculated based on the output of the detection unit. In the measuring device for the fluid in the pipeline to be measured,
A signal input unit that inputs a measurement signal from a pressure measuring device that measures the pressure of the fluid in the pipe without passing through the pressure guiding pipe;
Comparison means for comparing the time-series change pattern of the pressure value represented by the input measurement signal and the time-series change pattern of the measurement value obtained by the output of the detection unit;
Evaluation means for evaluating the degree of clogging of the pressure guiding tube based on the comparison result of the comparison means;
An apparatus for measuring a fluid in a pipe line. The signal input unit is
A first signal input unit that inputs a measurement signal from a first pressure measurement device that measures the pressure of the fluid in the pipe upstream of the throttle mechanism;
The detector is
A first pressure detection unit that detects the pressure of fluid in the pipe line through the pressure guiding pipe connected to the upstream side of the throttle mechanism;
The comparison means is configured to compare a time-series change pattern between a pressure value represented by a measurement signal of the first signal input unit and a pressure value represented by an output of the first pressure detection unit. Item 1. The apparatus for measuring a fluid in a pipeline according to Item 1. The signal input unit is
A second signal input unit that inputs a measurement signal from a second pressure measurement device that measures the pressure of the fluid in the pipe downstream of the throttle mechanism;
The detector is
A second pressure detector that detects the pressure of the fluid in the pipe line through the pressure guiding pipe connected to the downstream side of the throttle mechanism;
The comparison means is configured to compare a time-series change pattern between a pressure value represented by a measurement signal of the second signal input unit and a pressure value represented by an output of the second pressure detection unit. Item 3. The apparatus for measuring a fluid in a pipeline according to Item 1 or 2. The detector is
It is configured to detect a differential pressure between the fluid in the pipe line through the pressure guiding pipe on the upstream side of the throttling mechanism and the fluid in the pipe line through the pressure guiding pipe on the downstream side,
2. The comparison means according to claim 1, wherein the comparison means compares a time-series change pattern between a pressure value represented by a measurement signal of the signal input unit and a differential pressure value represented by an output of the detection unit. Measuring device for fluid in pipe. The comparison means includes
4. The structure according to claim 1, wherein the cross-correlation value between the time-series pressure data represented by the measurement signal of the signal input unit and the time-series measurement data represented by the output of the detection unit is calculated. The apparatus for measuring a fluid in a pipe line according to any one of the above items. Data storage means capable of storing data of distance along the pipe line from the connection position of the pressure measuring device to the connection position of the pressure guiding pipe;
The comparison means obtains a flow velocity of the fluid in the pipeline based on the output of the detection unit, obtains a time value required for the fluid in the pipeline to travel the distance from the data of the flow velocity and the distance, and calculates the time value. 6. The apparatus for measuring fluid in a pipe line according to claim 5, wherein a cross-correlation value is calculated as a phase difference of the cross-correlation function. A clogging diagnosis system for diagnosing a clogged state of a pressure guiding pipe that is installed between a pipe and a measuring instrument and guides fluid in the pipe from the pipe to the detection unit of the measuring instrument,
The pressure guiding pipe is configured to guide the fluid in the pipeline from the upstream side and the downstream side of the throttle mechanism installed in the pipeline to the detection unit, respectively.
Pressure detecting means for detecting the pressure of the fluid in the pipeline without going through the pressure guiding pipe;
Comparing means for comparing a time-series change pattern between the pressure value detected by the pressure detecting means and the measured value for the fluid in the pipe line guided through the pressure guiding pipe;
Evaluation means for evaluating the degree of clogging of the pressure guiding tube based on the result of the comparison means;
A pressure guiding tube blockage diagnosis system comprising: The pressure detecting means includes
8. The pressure guiding tube clogging diagnosis system according to claim 7, wherein the pressure guiding tube clogging diagnosis system is a directly connected piping type pressure detector that is directly connected to a conduit without using a pressure guiding tube and detects the pressure of fluid in the conduit.

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