A differential pressure online viscosity measurement method and heavy oil mixed phase mass flowmeter

Abstract

The present invention provides a differential pressure online viscosity measurement method and a heavy oil mixed phase mass flowmeter, and relates to the technical field of industrial mixed phase fluid measurement. After obtaining the first pressure difference value between the first pressure point and the second pressure point, and the second pressure difference value between the second pressure point and the third pressure point of the fluid to be measured in real time, the present invention deeply considers the influence of the flow pressure drop on the flow velocity of the fluid, and ensures that the final calculated fluid flow velocity and the actual fluid viscosity value can respectively truly reflect the real flow condition and the real viscosity condition of the fluid to be measured in the differential pressure flowmeter through the flow velocity iteration solution operation and the viscosity iteration solution operation, so as to improve the flow measurement accuracy and viscosity measurement accuracy of the fluid to be measured (especially high viscosity fluid), wherein the first pressure point is in the inlet straight pipe section, the second pressure point and the third pressure point are both in the throat straight pipe section, and the third pressure point is far away from the first pressure point relative to the second pressure point.

Description

Technical Field

[0001] The invention relates to the technical field of industrial mixed-phase fluid measurement, and in particular to a differential pressure online viscosity measurement method and a heavy oil mixed-phase mass flowmeter. Background Art

[0002] With the continuous development of science and technology, differential pressure flowmeters are widely used in metallurgy, electric power, coal, chemical industry, petroleum, transportation, construction, textile, food, medicine, agriculture, environmental protection and other fields because they can utilize the potential correlation between the pressure difference and flow rate generated when the fluid flows through the throttling device to achieve high-precision and reliable flow measurement function by measuring the pressure difference.

[0003] At present, in the actual use of differential pressure flowmeters, it is often necessary to measure the flow of complex fluids with complex flow shapes and high viscosity (for example, heavy oil, heavy oil, coal tar and other substances). When the fluid viscosity is high, friction will occur between the various media in the fluid in the differential pressure flowmeter, and the boundary part of the fluid will also rub against the inner wall of the differential pressure flowmeter, resulting in a significant pressure drop in the tube (i.e., flow pressure drop) during the fluid transmission process, which seriously affects the accuracy of flow measurement using pressure difference, resulting in the inability of traditional differential pressure flowmeters to achieve high-precision flow measurement effects for high-viscosity fluids. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a differential pressure online viscosity measurement method and a heavy oil mixed phase mass flowmeter, which can deeply consider the influence of flow pressure drop on fluid flow velocity, and combine theoretical viscosity calculation to perform flow velocity iterative solution and viscosity iterative solution, to ensure that the final calculated fluid flow velocity and actual fluid viscosity value can respectively truly reflect the actual flow condition and actual viscosity condition of the fluid to be measured in the differential pressure flowmeter, so as to achieve high-precision flow real-time measurement effect and high-precision viscosity real-time measurement effect for high-viscosity fluid when high-viscosity fluid (for example, heavy oil) is used as the fluid to be measured.

[0005] In order to achieve the above purpose, the technical solution adopted by the embodiment of the present invention is as follows:

[0006] In a first aspect, the present invention provides a differential pressure online viscosity measurement method, which is applied to a heavy oil mixed phase mass flow meter, wherein the heavy oil mixed phase mass flow meter comprises a measuring pipeline and at least one differential pressure transmitter, wherein the inlet straight pipe section of the measuring pipeline is connected to the throat straight pipe section via a contraction pipe section, and is used to transport the fluid to be measured to the throat straight pipe section; the at least one differential pressure transmitter is used to measure a first pressure difference between a first pressure point and a second pressure point and a second pressure difference between the second pressure point and a third pressure point, wherein the first pressure point is in the inlet straight pipe section, the second pressure point and the third pressure point are both in the throat straight pipe section, and the third pressure point is far away from the first pressure point relative to the second pressure point; the differential pressure online viscosity measurement method comprises:

[0007] Acquire a first pressure difference value and a second pressure difference value of the fluid to be measured in the measuring pipeline in real time;

[0008] Calculating a theoretical viscosity value of the fluid to be measured at the second pressure point without regard to the influence of the pressure drop in the pipe according to the actual fluid density, the actual flow state, the first pressure difference value and the second pressure difference value of the fluid to be measured;

[0009] According to the actual fluid density, the actual flow state, the first pressure difference value, the second pressure difference value and the actual installation mode of the measuring pipeline, the actual flow velocity and the actual fluid viscosity value of the measured fluid at the second pressure point affected by the pressure drop in the pipe are obtained through iterative calculation based on the theoretical viscosity value;

[0010] The actual flow velocity, the actual fluid density and the pipe cross-sectional area of ​​the throat straight pipe section are multiplied to obtain the current total fluid mass flow rate of the fluid to be measured.

[0011] In an optional embodiment, the step of calculating the theoretical viscosity value of the fluid to be measured at the second pressure point ignoring the influence of the pressure drop in the pipe according to the actual fluid density, the actual flow state, the first pressure difference value and the second pressure difference value of the fluid to be measured includes:

[0012] Substituting the first pressure difference value and the actual fluid density into the first ideal pressure difference flow rate correlation equation to solve the flow rate, so as to obtain the theoretical flow rate of the measured fluid at the second pressure point without considering the influence of the pressure drop in the pipe;

[0013] Substituting the theoretical flow rate, the second pressure difference value and the actual fluid density into the second ideal pressure difference flow rate correlation equation to solve the friction factor in the pipe, so as to obtain the theoretical friction factor of the fluid to be measured at the throat straight pipe section when the influence of the pressure drop in the pipe is ignored;

[0014] The theoretical friction factor, the theoretical flow rate and the actual fluid density are substituted into a fluid viscosity calculation equation matching the actual flow state to solve for viscosity, thereby obtaining the theoretical viscosity value.

[0015] In an optional embodiment, the first ideal pressure difference flow rate correlation equation is expressed by the following equation:

[0016] ;

[0017] The second ideal pressure difference flow rate correlation equation is expressed by the following equation:

[0018] ;

[0019] in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to express the density of the fluid transported in the measuring pipe. Used to indicate the equivalent pipe diameter ratio of the measuring pipe, , It is used to indicate the inner diameter of the inlet straight pipe section. It is used to indicate the inner diameter of the throat straight pipe section. It is used to indicate the theoretical flow rate of the fluid at the second pressure point. It is used to indicate the theoretical friction factor of the fluid in the throat straight pipe section when the pressure drop in the pipe is ignored. Used to indicate the length of the pipe section between the third pressure taking point and the second pressure taking point.

[0020] In an optional embodiment, when the actual flow state is a laminar flow state, the corresponding fluid viscosity calculation equation is expressed by the following equation:

[0021] ;

[0022] When the actual flow state is a turbulent state, the corresponding fluid viscosity calculation equation is expressed by the following equation:

[0023] ;

[0024] in, It is used to express the density of the fluid transported in the measuring pipe. It is used to represent the friction factor of the fluid in the straight pipe section of the throat. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the inner diameter of the throat straight pipe section. Used to indicate fluid viscosity. Used to represent the Reynolds number of a fluid.

[0025] In an optional embodiment, the step of obtaining the actual flow rate and the actual fluid viscosity value of the fluid to be measured affected by the pressure drop in the pipe at the second pressure taking point by iterative calculation based on the theoretical viscosity value according to the actual fluid density, the actual flow state, the first pressure difference value, the second pressure difference value and the actual installation mode of the measuring pipeline, comprises:

[0026] For each iteration operation, a target viscosity value of this iteration operation is determined, and the target viscosity value and the actual fluid density are substituted into a fluid viscosity calculation equation matching the actual flow state to obtain a friction factor flow velocity correlation equation of this iteration operation; wherein the target viscosity value of the first iteration operation is the theoretical viscosity value;

[0027] Substituting the first pressure difference value, the actual fluid density and the friction factor flow velocity correlation equation into a first pressure drop flow velocity correlation equation matching the actual installation mode to solve the flow velocity, and obtaining the target flow velocity of the fluid to be measured in this iterative operation;

[0028] Substituting the target flow rate, the second pressure difference value and the actual fluid density into a second pressure drop flow rate correlation equation matching the actual installation mode to solve the internal friction factor of the tube, thereby obtaining the target friction factor of this iterative operation;

[0029] Substituting the target friction factor, the target flow rate and the actual fluid density into a fluid viscosity calculation equation matching the actual flow state to solve for viscosity, thereby obtaining a viscosity value to be output for the fluid to be measured in this iterative operation;

[0030] Detecting whether the target flow rate meets an iteration end condition;

[0031] If it is detected that the target flow rate meets the iteration end condition, the target flow rate is directly used as the actual flow rate of the fluid to be measured at the second pressure point, and the viscosity value to be output is output as the actual fluid viscosity value of the fluid to be measured. Otherwise, the next iteration operation is executed, wherein the target viscosity value of the next iteration operation is the viscosity value to be output of this iteration operation.

[0032] In an optional embodiment, when the actual installation mode is a horizontal installation mode, the corresponding first pressure drop flow rate correlation equation is expressed by the following equation:

[0033] ;

[0034] The corresponding second pressure drop flow rate correlation equation is expressed by the following equation:

[0035] ;

[0036] in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to express the density of the fluid transported in the measuring pipe. Used to indicate the equivalent pipe diameter ratio of the measuring pipe, , It is used to indicate the inner diameter of the inlet straight pipe section. It is used to indicate the inner diameter of the throat straight pipe section. It is used to indicate the length of the pipe section between the third pressure point and the second pressure point. It is used to indicate the length of the pipe section between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the local form resistance pressure drop of the fluid between the second pressure point and the first pressure point. Used to express the local form resistance factor, It is used to indicate the friction factor of the fluid in the straight pipe section at the throat.

[0037] In an optional embodiment, when the actual installation mode is a vertical installation mode, the corresponding first pressure drop flow rate correlation equation is expressed by the following equation:

[0038] ;

[0039] The corresponding second pressure drop flow rate correlation equation is expressed by the following equation:

[0040] ;

[0041] in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to express the density of the fluid transported in the measuring pipe. Used to indicate the equivalent pipe diameter ratio of the measuring pipe, , It is used to indicate the inner diameter of the inlet straight pipe section. It is used to indicate the inner diameter of the throat straight pipe section. It is used to indicate the length of the pipe section between the third pressure point and the second pressure point. It is used to indicate the length of the pipe section between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the local form resistance pressure drop of the fluid between the second pressure point and the first pressure point. Used to express the local form resistance factor, It is used to represent the friction factor of the fluid in the straight pipe section of the throat. It is used to indicate the gravity pressure drop of the fluid between the second pressure point and the first pressure point. Used to represent the acceleration due to gravity, It is used to indicate the gravity pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the setting height of the first pressure point. It is used to indicate the setting height of the second pressure point. Used to indicate the setting height of the third pressure point, where , .

[0042] In an optional embodiment, the heavy oil mixed phase mass flowmeter further includes a multi-level photon source and a photon probe, wherein the multi-level photon source is arranged in the throat straight pipe section, and is used to emit photons of multiple energy levels according to a preset photon emission rate; the photon probe is arranged opposite to the multi-level photon source, and is used to detect the number of photon transmissions of each of the multiple energy levels; the differential pressure online viscosity measurement method further includes:

[0043] Real-time acquisition of the actual number of light quanta transmitted through the fluid to be measured at each of the multiple energy levels;

[0044] Calculating the volume fraction of each phase of the fluid medium in the fluid to be measured according to the actual number of light quantum transmissions obtained;

[0045] The actual mass flow rate of each phase of the fluid medium in the fluid to be measured is calculated according to the total fluid mass flow rate and the volume phase fraction of each phase of the fluid medium.

[0046] In a second aspect, the present invention provides a heavy oil mixed phase mass flow meter, the heavy oil mixed phase mass flow meter comprising a main control unit, a measuring pipeline and at least one differential pressure transmitter;

[0047] The inlet straight pipe section of the measuring pipeline is connected to the throat straight pipe section via the contraction pipe section, and is used to transport the fluid to be measured to the throat straight pipe section;

[0048] The at least one differential pressure transmitter is installed on the measuring pipeline, and is used for real-time measuring a first pressure difference between a first pressure point and a second pressure point, and a second pressure difference between the second pressure point and a third pressure point, wherein the first pressure point is located in the inlet straight pipe section, the second pressure point and the third pressure point are both located in the throat straight pipe section, and the third pressure point is far away from the first pressure point relative to the second pressure point;

[0049] The main control unit is communicatively connected to the at least one differential pressure transmitter and is used to control the working state of the at least one differential pressure transmitter, wherein the main control unit also stores a computer program and can run the computer program to implement the differential pressure online viscosity measurement method described in any one of the aforementioned embodiments.

[0050] In a third aspect, the present invention provides a heavy oil mixed phase mass flow meter, the heavy oil mixed phase mass flow meter comprising a main control unit, a measuring pipeline, a multi-level photon source, a photon probe and at least one differential pressure transmitter;

[0051] The inlet straight pipe section of the measuring pipeline is connected to the throat straight pipe section via the contraction pipe section, and is used to transport the fluid to be measured to the throat straight pipe section;

[0052] The at least one differential pressure transmitter is installed on the measuring pipeline, and is used for real-time measuring a first pressure difference between a first pressure point and a second pressure point, and a second pressure difference between the second pressure point and a third pressure point, wherein the first pressure point is located in the inlet straight pipe section, the second pressure point and the third pressure point are both located in the throat straight pipe section, and the third pressure point is far away from the first pressure point relative to the second pressure point;

[0053] The multi-energy-level photon source is arranged in the throat straight pipe section, and is used to emit photons of multiple energy levels according to a preset photon emission rate;

[0054] The photon probe is installed on the measuring pipe and is arranged in the throat straight pipe section facing the multi-energy-level photon source, and is used to detect the number of photons transmitted through the fluid to be measured at each of the multiple energy levels;

[0055] The main control unit is respectively connected in communication with the multi-level photon source, the photon probe and the at least one differential pressure transmitter, and is used to control the working states of the multi-level photon source, the photon probe and the at least one differential pressure transmitter, wherein the main control unit also stores a computer program and can run the computer program to implement the differential pressure online viscosity measurement method described in any one of the aforementioned embodiments.

[0056] In this case, the beneficial effects of the embodiments of the present invention may include the following:

[0057] The present invention calculates the theoretical viscosity value of the measured fluid at the second pressure point ignoring the influence of the pressure drop in the pipe according to the actual fluid density, actual flow state, the first pressure difference value and the second pressure difference value of the measured fluid, when obtaining in real time the first pressure difference value between the first pressure point and the second pressure difference value located in the inlet straight pipe section and the throat straight pipe section respectively, and the second pressure difference value between the second pressure point and the third pressure point located in the throat straight pipe section at the same time. Then, according to the actual fluid density, actual flow state, the first pressure difference value, the second pressure difference value and the actual installation method of the measuring pipeline, the actual flow rate of the measured fluid at the second pressure point affected by the pressure drop in the pipe is iteratively calculated based on the theoretical viscosity value. The actual flow rate, the actual fluid density and the pipe cross-sectional area of ​​the throat straight pipe section are multiplied to obtain the current total fluid mass flow rate of the fluid to be measured, so as to deeply consider the influence of the flow pressure drop on the fluid flow rate, and combine the theoretical viscosity calculation to perform the flow rate iteration solution, so as to ensure that the fluid flow rate finally calculated can truly reflect the actual flow condition of the fluid to be measured in the differential pressure flowmeter, so that the total fluid mass flow calculated using the fluid flow rate can effectively get rid of the interference of the flow pressure drop, so that when the high viscosity fluid is used as the fluid to be measured, the flow measurement accuracy of the high viscosity fluid can be effectively improved, so as to achieve the high-precision flow real-time measurement effect of the high viscosity fluid. In addition, the present invention will take into account the viscosity iteration solution operation in the process of flow rate iteration solution, so as to ensure that the actual fluid viscosity value output synchronously can truly reflect the actual viscosity condition of the fluid to be measured when the actual flow rate of the fluid to be measured is finally determined, and the viscosity measurement accuracy of the high viscosity fluid is improved, so as to achieve the high-precision viscosity real-time measurement effect of the fluid to be measured (especially the high viscosity fluid).

[0058] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0060] Figure 1 A schematic diagram of the overall structure of a heavy oil mixed phase mass flow meter provided by an embodiment of the present invention;

[0061] Figure 2 One of the cross-sectional schematic diagrams of the heavy oil mixed phase mass flowmeter provided by the embodiment of the present invention;

[0062] Figure 3 A second cross-sectional schematic diagram of a heavy oil mixed phase mass flow meter provided by an embodiment of the present invention;

[0063] Figure 4 The third cross-sectional schematic diagram of the heavy oil mixed phase mass flow meter provided by the embodiment of the present invention;

[0064] Figure 5 One of the flow diagrams of the differential pressure online viscosity measurement method provided in an embodiment of the present invention;

[0065] Figure 6 for Figure 5 A schematic flow chart of the sub-steps included in step 220;

[0066] Figure 7 for Figure 5 A flowchart of the sub-steps included in step 230;

[0067] Figure 8 The second schematic flow chart of the differential pressure online viscosity measurement method provided in an embodiment of the present invention.

[0068] Icons: 10-heavy oil mixed phase mass flowmeter; 11-main control unit; 12-measuring pipeline; 121-inlet straight pipe section; 122-contraction pipe section; 123-throat straight pipe section; 13-differential pressure transmitter; 14-valve group; 15-pressure transmitter; 16-multi-level photon source; 17-photon probe. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0070] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0072] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the invention is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0073] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] In addition, in the description of the present invention, it is understood that the relational terms such as the terms "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances.

[0075] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0076] Please refer to Figure 1 , Figure 2 and Figure 3 ,in Figure 1 is a schematic diagram of the overall structure of a heavy oil mixed phase mass flowmeter 10 provided in an embodiment of the present invention, Figure 2 is one of the cross-sectional schematic diagrams of the heavy oil mixed phase mass flowmeter 10 provided in the embodiment of the present invention, Figure 3 This is the second cross-sectional schematic diagram of the heavy oil mixed phase mass flow meter 10 provided in the embodiment of the present invention. In the embodiment of the present invention, the heavy oil mixed phase mass flow meter 10 may include a main control unit 11, a measuring pipeline 12 and at least one differential pressure transmitter 13.

[0077] In this embodiment, the measuring pipe 12 includes an inlet straight pipe section 121, a contraction pipe section 122, a throat straight pipe section 123 and an outlet pipe section. The inlet straight pipe section 121 is connected to the throat straight pipe section 123 via the contraction pipe section 122, and the throat straight pipe section 123 is connected to the outlet pipe section. The pipe opening size of the contraction pipe section 122 close to the inlet straight pipe section 121 is larger than the pipe opening size close to the throat straight pipe section 123, and the pipe opening size of the outlet pipe section close to the throat straight pipe section 123 is smaller than the pipe opening size away from the throat straight pipe section 123.

[0078] Optionally, in one implementation of the present embodiment, a first flange is provided at one end of the inlet straight pipe section 121 away from the contraction pipe section 122 to connect a fluid transport pipeline through the first flange, and a second flange is provided at one end of the outlet pipe section away from the throat straight pipe section 123 to connect another fluid transport pipeline through the second flange, so that the fluid to be measured can enter the inlet straight pipe section 121 and then flow out of the outlet pipe section through the contraction pipe section 122 and the throat straight pipe section 123.

[0079] In this embodiment, a first pressure point is provided in the inlet straight pipe section 121, and a second pressure point and a third pressure point are provided in the throat straight pipe section 123, wherein the second pressure point is between the third pressure point and the first pressure point, and the third pressure point is away from the first pressure point relative to the second pressure point. The at least one differential pressure transmitter 13 is installed on the outer wall of the measuring pipe 12 via a valve group 14, and measures the first pressure difference between the first pressure point and the second pressure point and the second pressure difference between the second pressure point and the third pressure point in real time through a measuring through hole connecting the inner wall and the outer wall of the measuring pipe 12, wherein the first pressure difference is obtained by subtracting the real-time pressure value at the first pressure point from the real-time pressure value at the second pressure point, and the second pressure difference is obtained by subtracting the real-time pressure value at the second pressure point from the real-time pressure value at the third pressure point.

[0080] Optionally, see Figure 2 Section view from AA perspective (i.e. Figure 2 ), in one implementation manner of the present embodiment, the total number of devices of the differential pressure transmitter 13 included in the heavy oil mixed phase mass flowmeter 10 is 1, and the differential pressure transmitter 13 is responsible for real-time measurement of the first pressure differential value and the second pressure differential value at the same time. At this time, the first pressure point, the second pressure point and the third pressure point corresponding to the differential pressure transmitter 13 are all on the inner wall of the same side of the measuring pipeline 12, and the differential pressure transmitter 13 can be directly implemented by an integrated differential pressure transmitter.

[0081] Optionally, see Figure 3 Section view from AA perspective (i.e. Figure 3), in another implementation manner of the present embodiment, the total number of devices of the differential pressure transmitter 13 included in the heavy oil mixed phase mass flowmeter 10 is 2, one of the differential pressure transmitters 13 is responsible for real-time measurement of the first differential pressure value, and the other differential pressure transmitter 13 is responsible for real-time measurement of the second differential pressure value, wherein the first pressure point and the second pressure point corresponding to the first differential pressure value are located on the inner wall of the pipe body on one side of the measuring pipe 12, the second pressure point and the third pressure point corresponding to the second differential pressure value are located on the inner wall of the pipe body on the other side of the measuring pipe 12, and the second pressure points corresponding to the first differential pressure value and the second differential pressure value are respectively located on the same pipe cross section of the throat straight pipe section 123.

[0082] In this embodiment, please refer to Figure 2 or Figure 3 The cross-sectional view from the BB perspective (i.e. Figure 2 or Figure 3 The main control unit 11 is installed on the outer wall of the measuring pipe 12 and is connected to the at least one differential pressure transmitter 13 for controlling the working state of the at least one differential pressure transmitter 13, and by running a specific computer program pre-stored in the main control unit 11, when the measuring pipe 12 is passed with the fluid to be measured, the first differential pressure value and the second differential pressure value collected in real time by the at least one differential pressure transmitter 13 are obtained, and based on the obtained first differential pressure value and the second differential pressure value, the influence of the flow pressure drop on the flow velocity of the fluid is deeply considered, and the flow velocity is calculated in combination with the theoretical viscosity. The speed iteration solution and viscosity iteration solution ensure that the finally calculated fluid flow rate and actual fluid viscosity value can respectively truly reflect the actual flow condition and actual viscosity condition of the measured fluid (especially high viscosity fluid) in the differential pressure flowmeter, so that the total fluid mass flow calculated using the fluid flow rate can effectively get rid of the interference of the flow pressure drop, so that when high viscosity fluid (for example, heavy oil) is used as the measured fluid, the flow measurement accuracy and viscosity measurement accuracy of the high viscosity fluid can be effectively improved, so as to achieve high-precision flow real-time measurement effect and high-precision viscosity real-time measurement effect of the high viscosity fluid.

[0083] Optionally, please refer to Figure 1 and Figure 4 ,in Figure 4 This is the third cross-sectional schematic diagram of the heavy oil mixed phase mass flow meter 10 provided in the embodiment of the present invention. In the embodiment of the present invention, the heavy oil mixed phase mass flow meter 10 may further include a multi-level photon source 16 and a photon probe 17 .

[0084] In this embodiment, refer to Figure 4 The cross-sectional view from the BB perspective (i.e. Figure 4As shown in the right side view in the figure, the multi-energy-level photon source 16 is arranged in the throat straight pipe section 123, and the photon emission direction of the multi-energy-level photon source 16 is perpendicular to the central axis of the throat straight pipe section 123, and is used to emit photons of multiple energy levels at a preset photon emission rate, wherein the actual photon emission rates corresponding to the multiple energy levels of the multi-energy-level photon source 16 are consistent and are all the preset photon emission rate (for example, one million photons are emitted per second), and the multi-energy-level photon source 16 can be a Ba-133 photon source.

[0085] In one implementation of this embodiment, the multiple energy levels may include a first energy level that satisfies the Compton effect and at least two second energy levels that satisfy the photoelectric effect, and the energy value corresponding to the first energy level is greater than the energy value corresponding to any one of the second energy levels, that is, the energy value of the first energy level is the largest among the multiple energy levels. The second energy level involved in the multi-level photon source 16 may include at least two energy levels of 31keV, 53keV, 81keV and 160keV, and the first energy level involved in the multi-level photon source 16 may be any one of 276keV, 302keV, 356keV and 383keV.

[0086] In this embodiment, the photon probe 17 is installed on the measuring pipe 12 and is arranged opposite to the multi-level photon source 16 in the throat straight pipe section 123, so as to detect the photon transmission quantities corresponding to the multiple energy levels, respectively. When the fluid to be measured exists in the throat straight pipe section 123, the photon probe 17 can effectively detect the actual photon transmission quantities of each of the multiple energy levels under the interference of the fluid to be measured; when there is no fluid medium (for example, gaseous hydrocarbon compounds, liquid hydrocarbon compounds, water and solid hydrocarbon compounds) in the throat straight pipe section 123, the photon probe 17 can directly detect the medium-free photon transmission quantities of each of the multiple energy levels in the throat straight pipe section 123.

[0087] In this embodiment, the main control unit 11 can be simultaneously communicated with the multi-level photon source 16 and the photon probe 17 to control the respective working states of the multi-level photon source 16 and the photon probe 17, so that when the fluid to be measured is passed into the measuring pipeline 12, the multi-level photon source 16 and the photon probe 17 are controlled to cooperate with each other to perform multi-level photon measurement on the fluid to be measured at the throat straight pipe section 123, and then based on the principle of photoelectric effect, the principle of Compton effect, the principle of mass conservation "the volume of the gas phase fluid medium before and after the throttling effect is variable but the mass remains unchanged, and the volume and mass of the non-gas phase fluid medium remain unchanged" and the principle of fluid continuity "the mass flow rate of any mixed phase fluid before and after the throttling effect remains consistent", the volume phase fraction of each phase fluid medium in the fluid to be measured is directly calculated, and then the calculated total fluid mass flow rate and the volume phase fraction of each phase fluid medium are used to achieve a high-precision mass flow real-time measurement effect for each phase fluid medium in the fluid to be measured.

[0088] Among them, the main control unit 11 can pre-store the number of medium-free light quantum transmissions of the multiple energy levels involved in the multi-level light quantum source 16 in the throat straight pipe section 123, and the main control unit 11 also stores a computer program, and can achieve high-precision real-time mass flow measurement effect for each phase fluid medium in the fluid to be measured by running the computer program.

[0089] It is understandable that the heavy oil mixed phase mass flowmeter 10 provided by the present invention may further include a pressure transmitter 15, so as to monitor the actual pressure value at the inlet straight pipe section 121 in real time through the pressure transmitter 15. The pressure collection position of the pressure transmitter 15 in the inlet straight pipe section 121 may be a first pressure point, and the first pressure point corresponding to the pressure transmitter 15 and the first pressure point corresponding to the first pressure difference value are on the same pipe cross section of the inlet straight pipe section 121.

[0090] In the present invention, in order to ensure that any of the above-mentioned heavy oil mixed phase mass flowmeters 10 can deeply consider the influence of flow pressure drop on fluid flow velocity, the flow velocity iterative solution and viscosity iterative solution are performed in combination with theoretical viscosity calculation to ensure that the final calculated fluid flow velocity and actual fluid viscosity value can respectively truly reflect the actual flow condition and actual viscosity condition of the measured fluid (especially high viscosity fluid) in the differential pressure flowmeter, so as to improve the flow measurement accuracy and viscosity measurement accuracy of high viscosity fluid (for example, heavy oil), and achieve high-precision flow real-time measurement effect and high-precision viscosity real-time measurement effect of high viscosity fluid. The embodiment of the present invention provides a differential pressure type online viscosity measurement method applied to the heavy oil mixed phase mass flowmeter 10 to achieve the above-mentioned purpose. The differential pressure type online viscosity measurement method provided by the present invention is described in detail below.

[0091] Please refer to Figure 5 , Figure 5 FIG. 1 is one of the flow charts of the differential pressure online viscosity measurement method provided in the embodiment of the present invention. In the embodiment of the present invention, Figure 5 The differential pressure online viscosity measurement method shown may include steps 210 to 240.

[0092] Step 210: acquiring in real time a first pressure difference value and a second pressure difference value of the fluid to be measured in the measuring pipeline.

[0093] In this embodiment, when the measured fluid passes into the measuring pipe 12 , the main control unit 11 can control the at least one differential pressure transmitter 13 to collect the first pressure difference value and the second pressure difference value of the measured fluid in the measuring pipe 12 in real time.

[0094] Step 220, calculating the theoretical viscosity value of the fluid to be measured at the second pressure point without regard to the influence of the pressure drop in the pipe according to the actual fluid density, the actual flow state, the first pressure difference value and the second pressure difference value of the fluid to be measured.

[0095] In this embodiment, the actual flow state of the fluid to be measured will affect the selection of the fluid viscosity calculation formula, and different flow states correspond to different fluid viscosity calculation formulas. For any fluid (especially high-viscosity fluid), the fluid transmission process from the inlet straight pipe section 121 to the throat straight pipe section 123 can be abstracted as the static pressure and dynamic pressure conversion process under the ideal Venturi tube when ignoring the pressure drop in the pipe (for example, the friction pressure drop caused by fluid flow friction, the local form resistance pressure drop caused by fluid energy loss, and the gravity pressure drop caused by the vertical installation of the pipeline). The differential pressure flowmeter works on the principle of calculating the theoretical flow rate of the measured fluid at the second pressure point regardless of the influence of the pressure drop in the pipe by detecting the increased dynamic pressure, and then the pressure reduction process of the fluid in the throat straight pipe section 123 is regarded as an ideal friction pressure drop process based on the theoretical flow rate, and the viscosity calculation formula of the fluid matching the actual flow state is called to calculate the viscosity, and the theoretical viscosity value of the measured fluid at the second pressure point is obtained, wherein the theoretical viscosity value is used to represent the estimated value of the fluid viscosity regardless of the influence of the pressure drop in the pipe, and the theoretical flow rate is used to represent the estimated value of the flow rate at the second pressure point regardless of the influence of the pressure drop in the pipe.

[0096] Optionally, see Figure 6 , Figure 6 yes Figure 5 Schematic diagram of the flow of sub-steps included in step 220. In this embodiment, step 220 may include sub-steps 221 to 223 to effectively calculate the estimated value of the fluid viscosity of the measured fluid at the second pressure point without considering the influence of the pressure drop in the pipe.

[0097] Sub-step 221, substituting the first pressure difference value and the actual fluid density into the first ideal pressure difference flow rate correlation equation to solve the flow rate, and obtaining the theoretical flow rate of the measured fluid at the second pressure point without considering the influence of the pressure drop in the pipe.

[0098] In this embodiment, the first ideal pressure difference flow rate correlation equation corresponds to the first pressure point and the second pressure point, and the first ideal pressure difference flow rate correlation equation can be used to characterize the conversion process between static pressure and dynamic pressure under the ideal venturi tube. The first ideal pressure difference flow rate correlation equation is expressed by the following equation:

[0099] ;

[0100] in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to indicate the density of the fluid transmitted in the measuring pipe 12, It is used to indicate the equivalent diameter ratio of the measuring pipe 12, , It is used to indicate the inner diameter of the inlet straight pipe section 121, It is used to indicate the inner diameter of the throat straight pipe section 123, Used to indicate the theoretical flow rate of the fluid at the second pressure point.

[0101] Sub-step 222, substitute the theoretical flow rate, the second pressure difference value and the actual fluid density into the second ideal pressure difference flow rate correlation equation to solve the friction factor in the pipe, and obtain the theoretical friction factor of the measured fluid at the throat straight pipe section when the pressure drop in the pipe is ignored.

[0102] In this embodiment, the second ideal pressure difference flow rate correlation equation corresponds to the second pressure point and the third pressure point, and the second ideal pressure difference flow rate correlation equation can be used to characterize the ideal friction pressure drop process based on the theoretical flow rate. The second ideal pressure difference flow rate correlation equation is expressed by the following equation:

[0103] ;

[0104] in, It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to indicate the density of the fluid transmitted in the measuring pipe 12, It is used to indicate the inner diameter of the inlet straight pipe section 121, It is used to indicate the theoretical flow rate of the fluid at the second pressure point. It is used to represent the theoretical friction factor of the fluid at the throat straight pipe section 123 when the pressure drop in the pipe is ignored. Used to indicate the length of the pipe section between the third pressure taking point and the second pressure taking point.

[0105] Sub-step 223, substituting the theoretical friction factor, theoretical flow velocity and actual fluid density into a fluid viscosity calculation equation matching the actual flow state to solve for viscosity and obtain a theoretical viscosity value.

[0106] In this embodiment, when the actual flow state is a laminar flow state, the corresponding fluid viscosity calculation equation is expressed by the following equation:

[0107] ;

[0108] in, It is used to indicate the density of the fluid transmitted in the measuring pipe 12, It is used to represent the friction factor of the fluid at the throat straight pipe section 123, It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the inner diameter of the throat straight pipe section 123, Used to indicate fluid viscosity. Used to represent the fluid Reynolds number, .

[0109] When the actual flow state is a turbulent state, the corresponding fluid viscosity calculation equation is expressed by the following equation:

[0110] ;

[0111] in, It is used to indicate the density of the fluid transmitted in the measuring pipe 12, It is used to represent the friction factor of the fluid at the throat straight pipe section 123, It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the inner diameter of the throat straight pipe section 123, Used to indicate fluid viscosity. Used to represent the fluid Reynolds number, .

[0112] Therefore, the present invention can effectively calculate the estimated value of the fluid viscosity of the fluid to be measured at the second pressure point without considering the influence of the pressure drop in the pipe by executing the above sub-steps 221 to 223.

[0113] Step 230, according to the actual fluid density, the actual flow state, the first pressure difference value, the second pressure difference value and the actual installation method of the measuring pipeline, based on the theoretical viscosity value, the actual flow rate and the actual fluid viscosity value of the fluid to be measured at the second pressure point affected by the pressure drop in the pipe are obtained through iterative calculation.

[0114] In this embodiment, different pipeline installation methods will result in different flow pressure drop components in the corresponding measuring pipeline 12 during the fluid transmission process from the inlet straight pipe section 121 to the throat straight pipe section 123. For example, when the pipeline installation method belongs to the horizontal installation method, the corresponding flow pressure drop component includes the friction pressure drop caused by the fluid flow friction and the local form resistance pressure drop caused by the fluid energy loss, and when the pipeline installation method belongs to the vertical installation method, the corresponding flow pressure drop component includes the friction pressure drop caused by the fluid flow friction, the local form resistance pressure drop caused by the fluid energy loss, and the gravity pressure drop caused by the fluid gravity potential energy.

[0115] In this embodiment, after calculating the theoretical viscosity value of the measured fluid at the second pressure point without regard to the influence of the pressure drop in the pipe, the influence of the flow pressure drop on the fluid flow velocity under different pipeline installation methods can be considered, and the flow velocity iterative solution and the fluid iterative solution are performed based on the theoretical viscosity value to ensure that the actual flow velocity and actual fluid viscosity values ​​finally solved can respectively truly reflect the actual flow condition and actual viscosity condition of the measured fluid in the differential pressure flowmeter, get rid of the interference of the flow pressure drop on the fluid flow velocity measurement, and improve the flow velocity measurement accuracy and viscosity measurement accuracy.

[0116] Optionally, see Figure 7 , Figure 7 yes Figure 5 Schematic diagram of the flow chart of the sub-steps included in step 230. In this embodiment, step 230 may include sub-steps 231 to 236 to accurately calculate the actual flow velocity of the fluid to be measured at the second pressure point under the flow pressure drop interference, and take into account the viscosity iteration solution operation during the actual flow velocity calculation process, so as to ensure that the actual fluid viscosity value output synchronously can truly reflect the actual viscosity condition of the fluid to be measured when the actual flow velocity is finally determined, so as to achieve a high-precision real-time viscosity measurement effect for the fluid to be measured (especially high-viscosity fluid).

[0117] Sub-step 231, for each iteration operation, determine the target viscosity value of this iteration operation, and substitute the target viscosity value and the actual fluid density into the fluid viscosity calculation equation matching the actual flow state to obtain the friction factor flow velocity correlation equation of this iteration operation.

[0118] In this embodiment, the target viscosity value used in the first iteration operation is the theoretical viscosity value; the friction factor flow rate correlation formula of each iteration operation is obtained by substituting the fluid viscosity calculation equation corresponding to the actual flow state into the corresponding target viscosity value and the actual fluid density and then deforming it.

[0119] Sub-step 232, substituting the first pressure difference value, the actual fluid density and the friction factor flow rate correlation equation into the first pressure drop flow rate correlation equation matching the actual installation mode to solve the flow rate and obtain the target flow rate of the fluid to be measured in this iterative operation.

[0120] In this embodiment, the first pressure drop flow velocity correlation equation corresponds to the first pressure taking point and the second pressure taking point; the first pressure drop flow velocity correlation equation is used to describe the parameter correlation relationship between the flow pressure drop composition and the fluid flow velocity in the fluid transmission process from the inlet straight pipe section 121 to the throat straight pipe section 123 under the actual installation method, and different pipeline installation methods correspond to different first pressure drop flow velocity correlation equations.

[0121] In this embodiment, when the actual installation mode is a horizontal installation mode, the corresponding first pressure drop flow rate correlation equation is expressed by the following equation:

[0122] ;

[0123] in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to indicate the density of the fluid transmitted in the measuring pipe 12, It is used to indicate the equivalent diameter ratio of the measuring pipe 12, , It is used to indicate the inner diameter of the inlet straight pipe section 121, It is used to indicate the inner diameter of the throat straight pipe section 123, It is used to indicate the length of the pipe section between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the second pressure point and the first pressure point. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the local form resistance pressure drop of the fluid between the second pressure point and the first pressure point. Used to express the local form resistance factor, It is used to represent the friction factor of the fluid at the throat straight pipe section 123. It is usually expressed as 0.1.

[0124] When the actual installation mode is a vertical installation mode, the first pressure drop flow rate correlation equation is expressed by the following equation:

[0125] ;

[0126] in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to indicate the density of the fluid transmitted in the measuring pipe 12, It is used to indicate the equivalent diameter ratio of the measuring pipe 12, , It is used to indicate the inner diameter of the inlet straight pipe section 121, It is used to indicate the inner diameter of the throat straight pipe section 123, It is used to indicate the length of the pipe section between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the second pressure point and the first pressure point. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the local form resistance pressure drop of the fluid between the second pressure point and the first pressure point. Used to express the local form resistance factor, It is used to represent the friction factor of the fluid at the throat straight pipe section 123, It is used to indicate the gravity pressure drop of the fluid between the second pressure point and the first pressure point. Used to represent the acceleration due to gravity, It is used to indicate the setting height of the first pressure point. It is used to indicate the setting height of the second pressure point, wherein .

[0127] Sub-step 233, substituting the target flow rate, the second pressure difference value and the actual fluid density into the second pressure drop flow rate correlation equation matching the actual installation mode to solve the friction factor in the pipe, and obtaining the target friction factor of this iterative operation.

[0128] In this embodiment, the second pressure drop flow velocity correlation equation corresponds to the second pressure taking point and the third pressure taking point; the second pressure drop flow velocity correlation equation is used to describe the parameter correlation relationship between the flow pressure drop component under the actual installation method and the fluid flow velocity during the fluid transmission process in the throat straight pipe section 123, and different pipeline installation methods correspond to different second pressure drop flow velocity correlation equations; wherein, when the pipeline installation method belongs to a horizontal installation method, the flow pressure drop component involved in the second pressure drop flow velocity correlation equation only includes the friction pressure drop caused by fluid flow friction, and when the pipeline installation method belongs to a vertical installation method, the flow pressure drop component involved in the second pressure drop flow velocity correlation equation includes the friction pressure drop caused by fluid flow friction, and the gravity pressure drop caused by the gravitational potential energy of the fluid.

[0129] In this embodiment, when the actual installation mode is a horizontal installation mode, the corresponding second pressure drop flow rate correlation equation is expressed by the following equation:

[0130] ;

[0131] in, It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to indicate the density of the fluid transmitted in the measuring pipe 12, It is used to indicate the inner diameter of the inlet straight pipe section 121, It is used to indicate the length of the pipe section between the third pressure point and the second pressure point. It is used to indicate the friction pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to represent the friction factor of the fluid in the throat straight pipe section 123.

[0132] When the actual installation mode is a vertical installation mode, the corresponding second pressure drop flow rate correlation equation is expressed by the following equation:

[0133] ;

[0134] in, It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to indicate the density of the fluid transmitted in the measuring pipe 12, It is used to indicate the inner diameter of the inlet straight pipe section 121, It is used to indicate the length of the pipe section between the third pressure point and the second pressure point. It is used to indicate the friction pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to represent the friction factor of the fluid at the throat straight pipe section 123, Used to represent the acceleration due to gravity, It is used to indicate the gravity pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the setting height of the second pressure point. Used to indicate the setting height of the third pressure point, where .

[0135] Sub-step 234, substitute the target friction factor, target flow rate and actual fluid density into the fluid viscosity calculation equation matching the actual flow state to solve for viscosity, and obtain the viscosity value to be output for the fluid to be tested in this iterative operation.

[0136] In this embodiment, when the target friction factor and target flow rate of each iterative operation are solved, the viscosity is solved by calling the fluid viscosity calculation equation that matches the actual flow state and combining the aforementioned target friction factor, the aforementioned target flow rate and the actual fluid density to obtain the output viscosity value of the fluid to be tested during this iterative operation.

[0137] Sub-step 235, detecting whether the target flow rate satisfies the iteration end condition.

[0138] In this embodiment, after the viscosity value to be output and the target flow rate of a certain iteration operation are solved, it can be confirmed whether the iteration operation can terminate the flow rate iteration solution process by detecting whether the target flow rate of the iteration operation meets the iteration end condition. The iteration end condition can be "the number of iteration calculations corresponding to the iteration operation exceeds the maximum number of iteration calculations" or "the flow rate difference between the target flow rate of the iteration operation and the target flow rate of the previous iteration operation is less than a preset value (for example, ), wherein the target flow rate of the previous iteration operation of the first iteration operation is represented by the theoretical flow rate".

[0139] If it is detected that the target flow rate of this iteration operation meets the iteration end condition, it means that the target flow rate of this iteration operation can stably reflect the real flow condition of the fluid to be measured in the differential pressure flowmeter, and the viscosity value to be output of this iteration operation can basically reflect the real viscosity condition of the fluid to be measured, and sub-step 236 will be executed accordingly. If it is detected that the target flow rate of this iteration operation does not meet the iteration end condition, it means that the target flow rate of this iteration operation cannot effectively reflect the real flow condition of the fluid to be measured, and sub-step 231 will be jumped to continue execution to start the next iteration operation until the target flow rate that meets the iteration end condition and the viscosity value to be output corresponding to the target flow rate are finally determined. Among them, the viscosity value to be output of this iteration operation can be used as the target viscosity value of the next iteration operation.

[0140] Sub-step 236 , directly taking the target flow rate as the actual flow rate of the fluid to be measured at the second pressure point, and outputting the viscosity value to be output as the actual fluid viscosity value of the fluid to be measured.

[0141] In this embodiment, when it is determined that the target flow rate of a certain iterative operation meets the iteration end condition, the target flow rate obtained by the iterative operation can be directly used as the actual flow rate of the fluid to be measured that is currently affected by the pressure drop in the pipe at the second pressure point. At this time, the viscosity value to be outputted by the iterative operation is used to characterize the actual fluid viscosity value of the fluid to be measured.

[0142] Therefore, the present invention can accurately calculate the actual flow rate of the fluid to be measured at the second pressure point under the interference of the flow pressure drop by executing the above-mentioned sub-steps 231 to 236, and take into account the viscosity iterative solution operation during the actual flow rate calculation process, so as to ensure that when the actual flow rate is finally determined, the actual fluid viscosity value output synchronously can truly reflect the actual viscosity condition of the fluid to be measured, thereby achieving a high-precision real-time viscosity measurement effect for the fluid to be measured (especially high-viscosity fluid).

[0143] Step 240 , multiplying the actual flow velocity, the actual fluid density and the pipe cross-sectional area of ​​the throat straight pipe section to obtain the current total fluid mass flow rate of the fluid to be measured.

[0144] Therefore, the present invention can deeply consider the influence of the flow pressure drop on the fluid flow velocity by executing the above steps 210 to 240, and perform iterative solutions of the flow velocity and the viscosity in combination with the theoretical viscosity calculation, so as to ensure that the fluid flow velocity and the actual fluid viscosity value finally calculated can truly reflect the real flow condition and the real viscosity condition of the fluid to be measured (especially the high viscosity fluid) in the differential pressure flowmeter, respectively, so that the total fluid mass flow calculated using the fluid flow velocity can effectively get rid of the interference of the flow pressure drop, so that when the high viscosity fluid is used as the fluid to be measured, the flow measurement accuracy and viscosity measurement accuracy of the high viscosity fluid can be effectively improved, so as to achieve a high-precision flow real-time measurement effect and a high-precision viscosity real-time measurement effect of the high viscosity fluid.

[0145] Optionally, see Figure 8 , Figure 8 This is the second flow chart of the differential pressure online viscosity measurement method provided by the embodiment of the present invention. In the embodiment of the present invention, when the heavy oil mixed phase mass flow meter 10 includes a multi-level photon source 16 and a photon probe 17, Figure 5 Compared with the differential pressure online viscosity measurement method shown, Figure 8 The differential pressure online viscosity measurement method shown may further include steps 250 to 270 to achieve a high-precision real-time mass flow measurement effect for each phase of the fluid medium in the fluid to be measured.

[0146] Step 250 , obtaining in real time the actual number of light quanta transmitted through the fluid to be tested at each of the multiple energy levels.

[0147] Step 260, calculating the volume fraction of each phase of the fluid medium in the fluid to be measured according to the actual light quantum transmission quantity obtained.

[0148] The volume fraction of each phase of the fluid medium in the fluid to be measured can be calculated with reference to the prior art (for example, the published patent documents CN109443466A, CN113984719B, etc.), which will not be described in detail here.

[0149] Step 270, calculating the actual mass flow rate of each phase of the fluid medium in the fluid to be measured according to the total fluid mass flow rate and the volume fraction of each phase of the fluid medium.

[0150] In this embodiment, the total fluid mass flow rate is obtained by adding the actual mass flow rates of the fluid media of each phase in the fluid to be measured. Therefore, the actual mass flow rates of the fluid media of each phase in the fluid to be measured can be solved based on the volume phase fraction of the fluid media of each phase and the principle of mass conservation, so that the flow rate iteration solution operation can ensure that the total fluid mass flow rate is free from the influence of flow pressure drop interference, and achieve high-precision real-time mass flow measurement effect for the fluid media of each phase in the fluid to be measured.

[0151] Therefore, the present invention can execute the above steps 250 to 270 and utilize the flow rate iterative solution operation to ensure that the total fluid mass flow rate is free from the influence of flow pressure drop interference, and achieve high-precision real-time mass flow measurement effect for each phase fluid medium in the fluid to be measured.

[0152] In summary, in a differential pressure online viscosity measurement method and a heavy oil mixed phase mass flowmeter provided by an embodiment of the present invention, the present invention can deeply consider the influence of flow pressure drop on the flow velocity of the fluid, and perform flow velocity iteration solution in combination with theoretical viscosity calculation, so as to ensure that the fluid flow velocity finally calculated can truly reflect the actual flow condition of the fluid to be measured in the differential pressure flowmeter, so that the total fluid mass flow calculated using the fluid flow velocity can effectively get rid of the interference of the flow pressure drop, so that when a high viscosity fluid is used as the fluid to be measured, the flow measurement accuracy of the high viscosity fluid can be effectively improved, so as to achieve a high-precision flow real-time measurement effect of the high viscosity fluid. In addition, the present invention will take into account the viscosity iteration solution operation in the process of flow velocity iteration solution, so as to ensure that when the actual flow velocity of the fluid to be measured is finally determined, the actual fluid viscosity value output synchronously can truly reflect the actual viscosity condition of the fluid to be measured, and improve the viscosity measurement accuracy of the high viscosity fluid, so as to achieve a high-precision viscosity real-time measurement effect of the fluid to be measured (especially the high viscosity fluid).

[0153] The above are only various embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A differential pressure online viscosity measurement method, characterized in that: Applicable to a mixed-phase mass flowmeter for heavy oil, the mixed-phase mass flowmeter for heavy oil comprises a measuring pipeline and at least one differential pressure transmitter, wherein the inlet straight pipe section of the measuring pipeline is connected to the throat straight pipe section via a contraction pipe section, and is used to transport the fluid to be measured to the throat straight pipe section; the at least one differential pressure transmitter is used to measure a first pressure difference between a first pressure point and a second pressure point and a second pressure difference between the second pressure point and a third pressure point, wherein the first pressure point is in the inlet straight pipe section, the second pressure point and the third pressure point are both in the throat straight pipe section, and the third pressure point is far away from the first pressure point relative to the second pressure point; The differential pressure type online viscosity measurement method comprises: Acquire a first pressure difference value and a second pressure difference value of the fluid to be measured in the measuring pipeline in real time; Calculating a theoretical viscosity value of the fluid to be measured at the second pressure point without regard to the influence of the pressure drop in the pipe according to the actual fluid density, the actual flow state, the first pressure difference value and the second pressure difference value of the fluid to be measured; According to the actual fluid density, the actual flow state, the first pressure difference value, the second pressure difference value and the actual installation mode of the measuring pipeline, the actual flow velocity and the actual fluid viscosity value of the measured fluid at the second pressure point affected by the pressure drop in the pipe are obtained through iterative calculation based on the theoretical viscosity value; Performing a multiplication operation on the actual flow velocity, the actual fluid density and the pipe cross-sectional area of ​​the throat straight pipe section to obtain a current total fluid mass flow rate of the fluid to be measured; In this process, the step of calculating the theoretical viscosity value of the fluid to be measured at the second pressure point without regard to the influence of the pressure drop in the pipe according to the actual fluid density, the actual flow state, the first pressure difference value and the second pressure difference value of the fluid to be measured includes: Substituting the first pressure difference value and the actual fluid density into the first ideal pressure difference flow rate correlation equation to solve the flow rate, so as to obtain the theoretical flow rate of the measured fluid at the second pressure point without considering the influence of the pressure drop in the pipe; Substituting the theoretical flow rate, the second pressure difference value and the actual fluid density into the second ideal pressure difference flow rate correlation equation to solve the friction factor in the pipe, and obtaining the theoretical friction factor of the measured fluid at the throat straight pipe section when the pressure drop in the pipe is ignored; wherein the second ideal pressure difference flow rate correlation equation is used to characterize the ideal friction pressure drop process achieved based on the theoretical flow rate; Substituting the theoretical friction factor, the theoretical flow rate and the actual fluid density into a fluid viscosity calculation equation matching the actual flow state to solve for viscosity, thereby obtaining the theoretical viscosity value; The step of obtaining the actual flow velocity and the actual fluid viscosity value of the fluid to be measured at the second pressure point affected by the pressure drop in the pipe through iterative calculation based on the theoretical viscosity value according to the actual fluid density, the actual flow state, the first pressure difference value, the second pressure difference value and the actual installation mode of the measuring pipeline comprises: For each iteration operation, a target viscosity value of this iteration operation is determined, and the target viscosity value and the actual fluid density are substituted into a fluid viscosity calculation equation matching the actual flow state to obtain a friction factor flow velocity correlation equation of this iteration operation; wherein the target viscosity value of the first iteration operation is the theoretical viscosity value; Substitute the first pressure difference value, the actual fluid density and the friction factor flow velocity correlation equation into the first pressure drop flow velocity correlation equation matching the actual installation mode to solve the flow velocity, and obtain the target flow velocity of the fluid to be measured in this iterative operation; wherein, the first pressure drop flow velocity correlation equation is used to describe the parameter correlation relationship between the flow pressure drop composition under the actual installation mode and the fluid flow velocity in the fluid transmission process from the inlet straight pipe section to the throat straight pipe section; the flow pressure drop composition of the first pressure drop flow velocity correlation equation when the actual installation mode is a horizontal installation mode includes the friction pressure drop caused by fluid flow friction and the local form resistance pressure drop caused by fluid energy loss; the flow pressure drop composition of the first pressure drop flow velocity correlation equation when the actual installation mode is a vertical installation mode includes the friction pressure drop caused by fluid flow friction, the local form resistance pressure drop caused by fluid energy loss and the gravity pressure drop caused by the gravitational potential energy of the fluid; Substituting the target flow rate, the second pressure difference value and the actual fluid density into the second pressure drop flow rate correlation equation matching the actual installation mode to solve the friction factor in the pipe, and obtaining the target friction factor of this iterative operation; wherein the second pressure drop flow rate correlation equation is used to describe the parameter correlation relationship between the flow pressure drop component under the actual installation mode and the fluid flow rate in the fluid transmission process in the throat straight pipe section; the flow pressure drop component of the second pressure drop flow rate correlation equation when the actual installation mode is a horizontal installation mode only includes the friction pressure drop caused by fluid flow friction; the flow pressure drop component of the second pressure drop flow rate correlation equation when the actual installation mode is a vertical installation mode includes the friction pressure drop caused by fluid flow friction and the gravity pressure drop caused by the gravitational potential energy of the fluid; Substituting the target friction factor, the target flow rate and the actual fluid density into a fluid viscosity calculation equation matching the actual flow state to solve for viscosity, thereby obtaining a viscosity value to be output for the fluid to be measured in this iterative operation; Detecting whether the target flow rate meets an iteration end condition; If it is detected that the target flow rate satisfies the iteration end condition, the target flow rate is directly used as the actual flow rate of the fluid to be measured at the second pressure point, and the viscosity value to be output is output as the actual fluid viscosity value of the fluid to be measured, otherwise the next iteration operation is performed, wherein the target viscosity value of the next iteration operation is the viscosity value to be output of the current iteration operation; The first ideal pressure difference flow rate correlation equation is expressed by the following equation: ； in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to express the density of the fluid transported in the measuring pipe. Used to indicate the equivalent pipe diameter ratio of the measuring pipe, , It is used to indicate the inner diameter of the inlet straight pipe section. It is used to indicate the inner diameter of the throat straight pipe section. Used to indicate the theoretical flow rate of the fluid at the second pressure point.

2. The differential pressure type online viscosity measurement method according to claim 1, characterized in that: The second ideal pressure difference flow rate correlation equation is expressed by the following equation: ； in, It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to express the density of the fluid transported in the measuring pipe. It is used to indicate the inner diameter of the inlet straight pipe section. It is used to indicate the theoretical flow rate of the fluid at the second pressure point. It is used to indicate the theoretical friction factor of the fluid in the throat straight pipe section when the pressure drop in the pipe is ignored. Used to indicate the length of the pipe section between the third pressure taking point and the second pressure taking point.

3. The differential pressure type online viscosity measurement method according to claim 1, characterized in that: When the actual flow state is a laminar flow state, the corresponding fluid viscosity calculation equation is expressed by the following equation: ； When the actual flow state is a turbulent state, the corresponding fluid viscosity calculation equation is expressed by the following equation: ； in, It is used to express the density of the fluid transported in the measuring pipe. It is used to represent the friction factor of the fluid in the straight pipe section of the throat. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the inner diameter of the throat straight pipe section. Used to indicate fluid viscosity. Used to represent the Reynolds number of a fluid.

4. The differential pressure type online viscosity measurement method according to claim 1, characterized in that: When the actual installation mode is a horizontal installation mode, the first pressure drop flow rate correlation equation is expressed by the following equation: ； The corresponding second pressure drop flow rate correlation equation is expressed by the following equation: ； in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to express the density of the fluid transported in the measuring pipe. Used to indicate the equivalent pipe diameter ratio of the measuring pipe, , It is used to indicate the inner diameter of the inlet straight pipe section. It is used to indicate the inner diameter of the throat straight pipe section. It is used to indicate the length of the pipe section between the third pressure point and the second pressure point. It is used to indicate the length of the pipe section between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the local form resistance pressure drop of the fluid between the second pressure point and the first pressure point. Used to express the local form resistance factor, It is used to indicate the friction factor of the fluid in the straight pipe section at the throat.

5. The differential pressure type online viscosity measurement method according to claim 1, characterized in that: When the actual installation mode is a vertical installation mode, the corresponding first pressure drop flow rate correlation equation is expressed by the following equation: ； The corresponding second pressure drop flow rate correlation equation is expressed by the following equation: ； in, It is used to indicate the pressure difference between the second pressure point and the first pressure point. It is used to indicate the pressure difference between the third pressure point and the second pressure point. It is used to express the density of the fluid transported in the measuring pipe. Used to indicate the equivalent pipe diameter ratio of the measuring pipe, , It is used to indicate the inner diameter of the inlet straight pipe section. It is used to indicate the inner diameter of the throat straight pipe section. It is used to indicate the length of the pipe section between the third pressure point and the second pressure point. It is used to indicate the length of the pipe section between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the second pressure point and the first pressure point. It is used to indicate the friction pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the flow rate of the fluid at the second pressure point. It is used to indicate the local form resistance pressure drop of the fluid between the second pressure point and the first pressure point. Used to express the local form resistance factor, It is used to represent the friction factor of the fluid in the straight pipe section of the throat. It is used to indicate the gravity pressure drop of the fluid between the second pressure point and the first pressure point. Used to represent the acceleration due to gravity, It is used to indicate the gravity pressure drop of the fluid between the third pressure point and the second pressure point. It is used to indicate the setting height of the first pressure point. It is used to indicate the setting height of the second pressure point. Used to indicate the setting height of the third pressure point, where , .

6. The differential pressure online viscosity measurement method according to any one of claims 1 to 5, characterized in that: The heavy oil mixed phase mass flowmeter further comprises a multi-level photon source and a photon probe, wherein the multi-level photon source is arranged in the throat straight pipe section, and is used to emit photons of multiple energy levels according to a preset photon emission rate; the photon probe is arranged opposite to the multi-level photon source, and is used to detect the transmission quantity of photons of each of the multiple energy levels; The differential pressure type online viscosity measurement method also includes: Real-time acquisition of the actual number of light quanta transmitted through the fluid to be measured at each of the multiple energy levels; Calculating the volume fraction of each phase of the fluid medium in the fluid to be measured according to the actual number of light quantum transmissions obtained; The actual mass flow rate of each phase of the fluid medium in the fluid to be measured is calculated according to the total fluid mass flow rate and the volume phase fraction of each phase of the fluid medium.

7. A heavy oil mixed phase mass flow meter, characterized in that: The heavy oil mixed phase mass flow meter comprises a main control unit, a measuring pipeline and at least one differential pressure transmitter; The inlet straight pipe section of the measuring pipeline is connected to the throat straight pipe section via the contraction pipe section, and is used to transport the fluid to be measured to the throat straight pipe section; The at least one differential pressure transmitter is installed on the measuring pipeline, and is used for real-time measuring a first pressure difference between a first pressure point and a second pressure point, and a second pressure difference between the second pressure point and a third pressure point, wherein the first pressure point is located in the inlet straight pipe section, the second pressure point and the third pressure point are both located in the throat straight pipe section, and the third pressure point is far away from the first pressure point relative to the second pressure point; The main control unit is communicatively connected to the at least one differential pressure transmitter and is used to control the working state of the at least one differential pressure transmitter, wherein the main control unit also stores a computer program and can run the computer program to implement the differential pressure online viscosity measurement method described in any one of claims 1-6.

8. A heavy oil mixed phase mass flow meter, characterized in that: The heavy oil mixed phase mass flow meter comprises a main control unit, a measuring pipeline, a multi-level photon source, a photon probe and at least one differential pressure transmitter; The inlet straight pipe section of the measuring pipeline is connected to the throat straight pipe section via the contraction pipe section, and is used to transport the fluid to be measured to the throat straight pipe section; The at least one differential pressure transmitter is installed on the measuring pipeline, and is used for real-time measuring a first pressure difference between a first pressure point and a second pressure point, and a second pressure difference between the second pressure point and a third pressure point, wherein the first pressure point is located in the inlet straight pipe section, the second pressure point and the third pressure point are both located in the throat straight pipe section, and the third pressure point is far away from the first pressure point relative to the second pressure point; The multi-energy-level photon source is arranged in the throat straight pipe section, and is used to emit photons of multiple energy levels according to a preset photon emission rate; The photon probe is installed on the measuring pipe and is arranged in the throat straight pipe section facing the multi-energy-level photon source, and is used to detect the number of photons transmitted through the fluid to be measured at each of the multiple energy levels; The main control unit is respectively connected to the multi-level photon source, the photon probe and the at least one differential pressure transmitter for controlling the respective working states of the multi-level photon source, the photon probe and the at least one differential pressure transmitter, wherein the main control unit also stores a computer program and can run the computer program to implement the differential pressure online viscosity measurement method described in any one of claims 1 to 6.

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