Fluid addition method based on coupling feedback of a rotor pump and a mass flow meter

Abstract

This invention relates to the field of petroleum engineering equipment control technology, and in particular to a fluid addition method based on the coupled feedback of a rotary pump and a mass flow meter. This invention adjusts the rotary pump speed based on slip to regulate the flow rate and addition amount of high-viscosity fluid; and provides a slip calculation model. This invention is the first to introduce a slip model based on the pump's internal leakage mechanism, which can identify the time-varying slip of high-viscosity fluid within the pump in real time, solving the problem of uncontrollable slip caused by high viscosity and significantly improving flow accuracy.

Description

Technical Field

[0001] This invention relates to the field of petroleum engineering equipment control technology, and in particular to a fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter. Background Technology

[0002] With the development of automation technology, the closed-loop flow control method of rotor pump + mass flow meter + PID is widely used. This control scheme is based on real-time flow feedback of the fluid. The mass flow meter detects the mass flow rate of the fluid and transmits the signal to the controller. The controller dynamically adjusts the speed of the rotor pump according to the deviation between the set value and the actual value (referred to as slip), thereby achieving precise fluid addition.

[0003] However, the above methods cannot be applied to high-viscosity fluids because they lack mechanism modeling of slip in high-viscosity fluids and lack prediction and compensation for changes in physical properties, thus failing to meet the field control requirements of "high precision, low pulsation, predictability, and rapid response" for high-viscosity chemical agents.

[0004] The automated addition of high-viscosity fluids faces the following challenges:

[0005] (1) The viscosity of high-viscosity media is greatly affected by temperature, shear rate, and proportion, and its changes directly affect the volumetric efficiency of the pump, causing significant slip fluctuations. It is impossible to dynamically update compensation according to actual operating conditions, and the flow deviation increases with changes in operating conditions, leading to a continuous increase in cumulative error. Under micro-addition conditions, the metering error reaches over 10%. Currently, in the control of high-viscosity fluid addition, slip compensation remains at the empirical level and cannot be updated in real time with changes in viscosity.

[0006] (2) Conventional PID controllers suffer from large hysteresis and oscillations, making them unable to handle pulsation and nonlinear characteristics. High-viscosity fluids are prone to wall flow, backflow, and volumetric hysteresis in the pump inlet area, resulting in flow meter signal lag, significant flow pulsation, and nonlinear response characteristics between speed and flow rate. This easily leads to large control overshoot, long settling time, and difficulty in eliminating steady-state errors.

[0007] (3) In actual high viscosity pumping, the relationship between speed and flow rate will be severely disturbed by factors such as suction conditions, fluid temperature, real-time fluctuations of liquid, and changes in well site feeding conditions, which makes it impossible for the open-loop method to maintain stable accuracy in industrial sites.

[0008] (4) The volumetric efficiency variation law and slip change with the fluid viscosity and pressure difference under high viscosity. The quantitative relationship of rotor speed change under different working conditions and the pumping error mechanism under non-Newtonian fluid model are quite different. There is currently no available modeling mechanism. Summary of the Invention

[0009] To overcome the problem that existing technologies lack slip calculation models for high-viscosity media and cannot use automated addition, this invention proposes a fluid addition method based on the coupled feedback of a rotor pump and a mass flow meter. It realizes an adaptive slip compensation-closed-loop PID coupled control algorithm based on a high-viscosity fluid transport mechanism model, which can be used for stable flow control and precise adjustment of cumulative amount in positive displacement pumps for transporting high-viscosity slurry, additives and other media.

[0010] This invention proposes a fluid addition method based on the coupled feedback of a rotor pump and a mass flow meter. The rotor pump speed is adjusted based on slip to regulate the flow rate and addition amount of the high-viscosity fluid; slip is the deviation between the target instantaneous flow rate and the actual instantaneous flow rate of the high-viscosity fluid.

[0011] The formula for calculating slip S is:

[0012] ;

[0013] ;

[0014] Among them, Q th (n+Δn) represents the target instantaneous flow rate, where n+Δn is the rotor pump speed theoretically required to achieve the target instantaneous flow rate; n is the current speed, and Δn is the speed difference to be derived; Q th (n) represents the theoretical instantaneous flow rate, which is the product of the theoretical displacement D0 per unit speed and n; Q th (n+Δn) is defined as the product of D0 and n+Δn;

[0015] η v (n+Δn) is the transition parameter, Q leack (μ n+Δn ,ΔP n+Δn (n+Δn) represents the leakage flow rate when the measured instantaneous flow rate is Qth(n+Δn), μ n+Δn ΔP represents the viscosity at the measured instantaneous flow rate of Qth(n+Δn). n+Δn This represents the pressure difference when the measured instantaneous flow rate is Qth(n+Δn), where the pressure difference is the pressure difference between the inlet and outlet of the rotor pump.

[0016] Preferred:

[0017] ;

[0018] ;

[0019] Among them, C geom (n+Δn) represents the equivalent structural leakage coefficient when the measured instantaneous flow rate is Qth(n+Δn). The measured instantaneous flow rate is Q. th The measured rotational speed at (n+Δn).

[0020] Preferably, the viscosity used in the calculation process is the effective viscosity, and the formula for calculating the effective viscosity is: ;

[0021] Where K is the fluid consistency coefficient, Q is the measured instantaneous flow rate, b and h are the width and height of the equivalent parallel slit, and p is the flow index.

[0022] Preferably, the viscosity used in the calculation process is a real-time calculated value. ;

[0023] ;

[0024] Where ΔP is the pressure difference, I is the motor current, Q is the measured instantaneous flow rate, and k1, k2, k3 and k0 are experimental fitting parameters related to fluid materials.

[0025] Preferably, it includes the following steps:

[0026] S1: Receive the target cumulative addition amount and the target instantaneous flow rate Q th (n+Δn), initialize the basic speed n0 of the rotor pump;

[0027] S2: Real-time acquisition of the measured instantaneous flow rate Q, and simultaneous acquisition of the rotor pump speed n, motor current I, and pressure difference ΔP; the initial value of n is the rotor pump's base speed n0;

[0028] S3: Obtain the fluid viscosity μ and calculate the current slip S(t); the viscosity μ is taken as the effective viscosity μ. eff Or real-time calculated value ;

[0029] S4: Calculate the speed difference Δn based on the slip S(t), and perform filtering and smoothing on Δn to obtain the feedforward compensation amount Δn. ff ;

[0030] S5: Calculate the target instantaneous flow rate Q th The error e(t) between (n+Δn) and the measured instantaneous flow rate Q is used to generate the feedback compensation amount Δn by running a closed-loop PID controller based on e(t). pid ;

[0031] S6: Adjust the feedforward compensation amount Δn ff With feedback compensation amount Δn pid The final pump speed command n+Δn is formed by superposition. ff +Δn pid And execute;

[0032] S7: Repeat steps S2-S6 until the cumulative addition reaches the target value, then execute the stop-addition strategy.

[0033] Preferably, step S7 specifically involves: calculating the predicted response time t. remain If t remain If the value is less than or equal to the set value, the stop adding strategy is executed; otherwise, return to step S2.

[0034] ;

[0035] Among them, Q th (n+Δn) represents the target instantaneous flow rate, G leiji For the cumulative flow, Q(t) is the current measured instantaneous flow, and max indicates taking the maximum value.

[0036] Preferably, the formula for calculating the speed difference Δn is:

[0037] ;

[0038] Where D0 is the displacement per unit speed, n is the current speed, and Q act This represents the actual traffic volume. For Q act Partial derivative with respect to rotational speed n.

[0039] Preferred:

[0040] ;

[0041] ;

[0042] Among them, C geom Q is the equivalent structural leakage coefficient. th (n) represents the theoretical instantaneous flow rate, which is the product of the theoretical displacement D0 per unit speed and n.

[0043] Preferred strategies for stopping the addition include end deceleration, back suction angle calculation, and short-term reversal.

[0044] The present invention proposes a high-viscosity fluid addition system based on the coupling feedback of a rotor pump and a mass flow meter, comprising a memory and a processor. The memory stores a computer program, and the processor is connected to the memory. The processor is used to execute the computer program to realize the fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter.

[0045] The advantages of this invention are:

[0046] (1) The fluid addition method proposed in this invention is based on the coupling feedback of a rotor pump and a mass flow meter. It introduces a slip model based on the leakage mechanism inside the pump for the first time, which can identify the slip amount generated by high viscosity fluid in the pump over time in real time, solve the problem of uncontrollable slip caused by high viscosity, and significantly improve the flow accuracy.

[0047] (2) This invention combines multiple parameters such as “rotation speed n – pressure difference ΔP – electrode current I” to estimate viscosity. By using feedforward compensation, it corrects the flow deviation caused by sudden viscosity changes and pressure difference changes in advance. This allows the system to avoid problems such as flow lag and increased cumulative deviation that are common in traditional control methods. It effectively overcomes the problems of large pulsation and inaccurate metering that are easy to occur when traditional positive displacement pumps transport high viscosity fluids, and improves the system response speed and control accuracy.

[0048] (3) The dual-channel coupling mechanism of "slip compensation feedforward + closed-loop PID" adopted in this invention enables the rotor pump to still have millisecond-level flow response capability when facing high-viscosity media, non-Newtonian fluids or pressure fluctuations. The feedforward quickly suppresses the large error caused by the rotor pump itself, and the PID is responsible for fine adjustment and steady-state correction. The two effectively avoid the defects of large overshoot, slow response and residual steady-state error caused by single PID control, and significantly improve the dynamic response speed of flow control for high-viscosity fluids (such as polymer solutions, drilling fluids, oil-based mud, etc.).

[0049] (4) The flow prediction model established based on the actual pump control relationship and the viscosity calculation method using multiple parameters such as motor current, differential pressure, and pump speed can adapt to complex fluids such as high-viscosity drilling fluid additives, viscoelastic polymers, and barite slurries. It is unaffected by working conditions such as fluid temperature changes, pump chamber wear, and changes in sealing gaps, giving the control system stronger environmental adaptability. The cumulative addition amount control accuracy of the present invention is high, the control algorithm has strong robustness, and it has versatility and scalability.

[0050] (5) Compared with existing PID control, the present invention has a faster flow control response speed, which is beneficial to improving the accuracy of fluid accumulation control. In particular, the present invention can significantly improve the addition accuracy of high viscosity fluids, and is also applicable to low viscosity fluids (e.g., water). Attached Figure Description

[0051] Figure 1 This is a flowchart of a fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter proposed in this invention;

[0052] Figure 2 This is a frequency domain comparison diagram of the flow signals in the embodiment;

[0053] Figure 3 This is a time-domain comparison diagram of the flow signals in the embodiment. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0055] Definitions: The rotational speed referred to below is the rotational speed of the rotor of the rotary pump, the viscosity is the viscosity of the fluid transported by the rotary pump, and the flow rate is the instantaneous displacement of the rotary pump; the measured instantaneous flow rate (also called the measured flow rate) is obtained by the mass flow meter on the conveying path of the rotary pump, and the pressure is obtained by the pressure gauge.

[0056] like Figure 1 As shown, a method for precisely adding high-viscosity fluids based on the coupled feedback of a rotor pump and a mass flow meter is presented. The rotor pump speed is adjusted based on slip to regulate the flow rate and addition amount of the high-viscosity fluid. Slip is the deviation between the target instantaneous flow rate and the actual instantaneous flow rate of the high-viscosity fluid. The slip calculation process is as follows:

[0057] (1)

[0058] (2)

[0059] Q th (n) = D0·n (3)

[0060] Where S is slip; Q th (n+Δn) represents the target instantaneous flow rate, and n+Δn represents the rotor pump speed theoretically required to achieve the target instantaneous flow rate; Q th (n) represents the theoretical instantaneous flow rate, n represents the current rotational speed; Δn represents the rotational speed difference to be derived; η v (n+Δn) is the transition parameter, η v (μ n+Δn ,ΔP n+Δn (n+Δn) is a transition parameter function, representing η v (n+Δn) is the correlation μ n+Δn and ΔP n+Δn The mapping function; μ n+Δn ΔP represents the viscosity at the measured instantaneous flow rate of Qth(n+Δn). n+Δn The pressure difference represents the pressure difference between the inlet and outlet of the rotor pump when the measured instantaneous flow rate is Qth(n+Δn). D0 is the theoretical displacement per unit speed.

[0061] When the flow rate, viscosity, and pressure difference are n, μ, and ΔP, respectively, the leakage flow rate is denoted as Q. leack (μ,ΔP,n), transition parameter function η vThe formula for calculating (μ,ΔP,n) is as follows:

[0062] (4)

[0063] Right now:

[0064] (5)

[0065] Among them, Q leack (μ n+Δn ,ΔP n+Δn ,n+Δn) represents the leakage flow rate when the measured instantaneous flow rate is Qth(n+Δn).

[0066] In the case of low-viscosity fluids, the leakage flow rate Q leack Specifically, it can be characterized using the Poiseuille approximation model or the narrow-slit flow model, that is, the real leakage channel is equivalent to several "expanded tiny parallel slit channels". The characteristics of the parallel slit channels are: slit height Gap length L, flow Reynolds number 1. The main flow direction is singular (along the pressure difference direction). This indicates that the value is much smaller than the target value. The parallel slot structure is clear, computationally efficient, and easy to embed into feedforward control. In this embodiment, the specific parameters for the parallel slot are as follows: slot height h is the design gap; slot width is the equivalent unfolded width b≈α·πD (α is a correction coefficient, D is the equivalent diameter of the flow channel); and slot length L is equivalent to the average flow path length from the high-pressure zone to the low-pressure zone.

[0067] Specifically, in the case of low-viscosity fluids: ;

[0068] In the case of high-viscosity fluids, viscosity μ needs to be replaced with effective viscosity μ. eff This embodiment uses a power-law model. Derivation of effective viscosity, i.e. K is the consistency coefficient determined by the liquid material itself (i.e., the fluid), and γ is the shear rate. Therefore:

[0069] (6)

[0070] p is the flow index, which can be directly measured by a rheometer.

[0071] In the case of high-viscosity fluids, the formula for calculating leakage flow rate is:

[0072] (7)

[0073] (8)

[0074] Among them, Cgeom Q is the equivalent structural leakage coefficient, used to comprehensively characterize the influence of multiple tiny fitting clearances inside the rotor pump on its internal leakage capacity; Q is the measured instantaneous flow rate; Q th The theoretical instantaneous flow rate is calculated as the product of the actual rotational speed and the theoretical displacement per unit speed D0, i.e., Q when the rotor pump speed is n. th =D0·n, Q when the rotor pump speed is n+Δn th =D0·(n+Δn).

[0075] Thus, in formula (5):

[0076] (9)

[0077] The measured instantaneous flow rate is Q. th The measured rotational speed at (n+Δn).

[0078] In actual calculations, viscosity is related to flow rate and gap height, therefore μ is taken. n+Δn ≈μ eff Therefore, formula (9) can be transformed into the following formula (10):

[0079] (10)

[0080] Formulas 1, 2, 3, 5, 6, and 10 above constitute the slip mechanism model S=f(n, μ, ΔP).

[0081] This embodiment proposes a fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter, which includes the following steps:

[0082] S1: Receive the target cumulative addition amount and the target instantaneous flow rate, and initialize the rotor pump base speed n0;

[0083] S2: Real-time acquisition of the instantaneous mass flow rate Q (i.e., the measured instantaneous flow rate) output by the mass flow meter, and simultaneous acquisition of the rotor pump speed n, motor current I, and pressure difference ΔP (the pressure difference between the rotor pump inlet and outlet).

[0084] S3: Obtain the effective viscosity μ of the fluid eff And substitute it into the slip mechanism model S(t)=f(n, μ) eff ΔP) predicts the slip S(t);

[0085] Specifically, in this step, if the consistency coefficient K of the fluid is known, the effective viscosity μ can be calculated using formula (6). eff ;

[0086] If the fluid's consistency coefficient K is unknown, then n, I, and ΔP are substituted into a pre-built online viscosity assessment model to calculate the fluid's equivalent viscosity. As the effective viscosity μ eff ;

[0087] The online viscosity assessment model is as follows:

[0088] (11)

[0089] Among them, k1, k2, k3 and k0 are experimental fitting parameters. Taking the emulsifier in the previous experiment as an example, we can obtain k0=2, k1=8, k2=0.3 and k3=0.05. Let |.| denote the derivative of the measured instantaneous flow rate Q with respect to time t, and |.| denotes taking the absolute value.

[0090] S4: Calculate the speed difference Δn based on the slip S(t), and perform filtering and smoothing on Δn to obtain the feedforward compensation amount Δn. ff ;

[0091] (12)

[0092] (13)

[0093] Where S is slip; D0 is displacement per unit speed; Q act This represents the actual traffic volume. For Q act Partial derivative with respect to rotational speed n.

[0094] S5: Based on the target instantaneous flow rate Q th The error e(t) between (n+Δn) and the measured instantaneous flow rate Q is used to generate a feedback compensation quantity Δn by running a closed-loop PID controller. pid ;

[0095] (14)

[0096] Where, k p k i and k d These are the experimental fit coefficients;

[0097] S6: Adjust the feedforward compensation amount Δn ff With feedback compensation amount Δn pid The final pump speed command n+Δn is formed by superposition. ff +Δn pid And control the frequency of the rotor pump to execute the final pump speed command n+Δn ff +Δn pid ;

[0098] S7: Based on the mass flow meter output, the cumulative amount is integrated. When the cumulative amount added reaches the target value, the end deceleration, back suction angle calculation, and short-term reverse are performed to prevent dripping.

[0099] Specifically, step S7 consists of the following steps:

[0100] S71. Calculate the cumulative flow G leiji and predicted response time t remain ;

[0101] (15)

[0102] (16)

[0103] Q(t) represents the actual flow rate Q at time t, i.e., the current measured instantaneous flow rate; Q th (n+Δn) represents the target instantaneous flow rate, which can be specifically taken as the target addition amount and the cumulative flow rate G. leiji The ratio of the difference to the remaining addition time;

[0104] S72, Determine t remain Is it less than or equal to a set value, such as 5 seconds?

[0105] No, then return to step S2;

[0106] Yes, the system will reduce frequency and decelerate, stop the pump, reset to zero, and generate an addition completion signal.

[0107] The fluid addition method based on the coupling feedback of the rotor pump and the mass flow meter is verified below with reference to specific embodiments.

[0108] In this embodiment, the fluid is an emulsifier, and a mass flow meter is installed at the output end of the rotor pump to detect the flow rate. In this embodiment, the flow rate signal detected by the mass flow meter when using the existing PID control method is recorded as the original flow rate signal, and the flow rate signal detected by the mass flow meter when using the method of this invention is recorded as the corrected flow rate signal.

[0109] In this embodiment, under the same target addition amount, two original flow signals and corrected flow signals of equal time length are collected and compared. Figure 2 As shown in the figure, the flow rate is more stable when using the method of the present invention, proving that the method of the present invention can effectively suppress periodic flow rate fluctuations.

[0110] After performing Fourier frequency domain transforms on the original flow signal and the corrected flow signal respectively, the comparison results are as follows: Figure 3As shown, due to the characteristics of the rotor pump, the original flow signal exhibits significant harmonic pulsations at 40Hz and its harmonics, with periodic fluctuations in the time domain waveform and multiple discrete spectral peaks in the frequency domain. The energy distribution is dense, the amplitude is high, and the overall signal-to-noise ratio is low, making it difficult to directly observe the actual flow rate. However, after optimization and control using the method of this invention, the curve becomes smoother overall and converges stably to the true average flow rate (approximately 1.5 m³ / h). In the method of this invention, the high-frequency peaks decrease, and the energy distribution tends to become continuous.

[0111] The results show that the method of this invention can weaken harmonic energy and suppress periodic interference. Without affecting the cumulative flow rate, it reduces measurement uncertainty and improves the stability of flow measurement, making the liquid material quantitative addition system more accurate and reliable.

[0112] Of course, those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0113] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0114] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A fluid addition method based on the coupling feedback of a rotary pump and a mass flow meter, characterized in that, The rotor pump speed is adjusted based on slip, thereby regulating the flow rate and dosage of high-viscosity fluids; slip is the deviation between the target instantaneous flow rate and the actual instantaneous flow rate of the high-viscosity fluid. The formula for calculating slip S is: wherein Q th (n + Δn) is the target instantaneous flow rate, n + Δn is the rotor pump speed when the target instantaneous flow rate is theoretically achieved; n is the current speed, and Δn is the speed difference value to be derived; Q th (n) is the theoretical instantaneous flow rate, which is the product of the unit speed theoretical displacement D0 and n; Q th (n + Δn) is defined as the product of D0 and n + Δn; η v (n+Δn) is the transition parameter, Q leak (μ n+Δn ,ΔP n+Δn (n+Δn) represents the measured instantaneous flow rate as Q th Leakage flow rate at (n+Δn), μ n+Δn The measured instantaneous flow rate is Q. th The viscosity at (n+Δn), ΔP n+Δn The measured instantaneous flow rate is Q. th The pressure difference at (n+Δn) is the pressure difference between the inlet and outlet of the rotor pump. Among them, C geom (n+Δn) represents the equivalent structural leakage coefficient when the measured instantaneous flow rate is Qth(n+Δn). The measured instantaneous flow rate is Q. th The measured rotational speed at (n+Δn).

2. The fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter as described in claim 1, characterized in that, All viscosities used in the calculations are effective viscosities, and the formula for calculating effective viscosity is: ; Where K is the fluid consistency coefficient, Q is the measured instantaneous flow rate, b and h are the width and height of the equivalent parallel slit, and p is the flow index.

3. The fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter as described in claim 1, characterized in that, The viscosity used in the calculation process is the real-time calculated value. ; Where ΔP is the pressure difference, I is the motor current, Q is the measured instantaneous flow rate, and k1, k2, k3 and k0 are experimental fitting parameters related to fluid materials.

4. The fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter as described in any one of claims 1-3, characterized in that, Includes the following steps: S1: Receive the target cumulative addition amount and the target instantaneous flow rate Q th (n+Δn), initialize the basic speed n0 of the rotor pump; S2: Real-time acquisition of the measured instantaneous flow rate Q, and simultaneous acquisition of the rotor pump speed n, motor current I, and pressure difference ΔP; the initial value of n is the rotor pump's base speed n0; S3: Obtain the fluid viscosity μ and calculate the current slip S(t); the viscosity μ is taken as the effective viscosity μ. eff Or real-time calculated value ; S4: Calculate the speed difference Δn based on the slip S(t), and perform filtering and smoothing on Δn to obtain the feedforward compensation amount Δn. ff ; S5: Calculate the target instantaneous flow rate Q th The error e(t) between (n+Δn) and the measured instantaneous flow rate Q is used to generate the feedback compensation amount Δn by running a closed-loop PID controller based on e(t). pid ; S6: Adjust the feedforward compensation amount Δn ff With feedback compensation amount Δn pid The final pump speed command n+Δn is formed by superposition. ff +Δn pid And execute; S7: Repeat steps S2-S6 until the cumulative addition reaches the target value, then execute the stop-addition strategy.

5. The fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter as described in claim 4, characterized in that, Step S7 specifically involves: calculating the predicted response time t. remain If t remain If the value is less than or equal to the set value, the stop adding strategy is executed; otherwise, return to step S2. Among them, Q th (n+Δn) represents the target instantaneous flow rate, G leiji For the cumulative flow, Q(t) is the current measured instantaneous flow, and max indicates taking the maximum value.

6. The fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter as described in claim 4, characterized in that, The formula for calculating the speed difference Δn is: Where D0 is the displacement per unit speed, n is the current speed, and Q act This represents the actual traffic volume. For Q act Partial derivative with respect to rotational speed n.

7. The fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter as described in claim 6, characterized in that: Among them, C geom Q is the equivalent structural leakage coefficient. th (n) represents the theoretical instantaneous flow rate, which is the product of the theoretical displacement D0 per unit speed and n.

8. The fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter as described in claim 4, characterized in that, The stop-addition strategy includes end deceleration, back-suction angle calculation, and short-term reversal.

9. A high-viscosity fluid addition system based on the coupled feedback of a rotor pump and a mass flow meter, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, the processor is connected to the memory, and the processor is used to execute the computer program to implement the fluid addition method based on the coupling feedback of a rotor pump and a mass flow meter as described in any one of claims 1-8.

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