Traffic determination method, apparatus, device, storage medium, and product
By dividing the complex water pipeline of the vehicle thermal management system into loops and simplifying the Navier-Stokes equations, the problem of large computational load was solved, and faster flow rate calculation was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING CO WHEELS TECH CO LTD
- Filing Date
- 2024-10-29
- Publication Date
- 2026-08-04
AI Technical Summary
Existing technologies involve a large amount of computation when calculating the flow rate of complex water pipes in vehicle thermal management systems, resulting in low speed.
By dividing the target loop into multiple sub-loops and their connections, the loop flow resistance is calculated, and the Navier-Stokes equations for the simplified loop are established. The calculation process is simplified by using pump model information and total flow resistance.
It reduces the computational workload of calculating flow rates in complex water pipe systems and improves computational speed.
Smart Images
Figure CN120542286B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle thermal management technology, and in particular to a flow rate determination method, apparatus, device, storage medium, and product. Background Technology
[0002] The vehicle thermal management system can automatically adjust the cooling intensity to control the corresponding components in the vehicle to work within the optimal temperature range. Specifically, it can achieve the function of automatically adjusting the cooling intensity by controlling the flow rate of coolant in the complex water pipe system inside the vehicle.
[0003] In related technologies, commercial software is used to calculate the flow rate of complex water pipes in a vehicle's thermal management circuit. Specifically, the complex water pipes are divided into many small volumes by dividing the control volume in the middle. In each small volume, a set of equations is established based on constraints such as energy conservation, mass conservation, momentum conservation, and angular momentum conservation. This results in a complete set of equations for each small volume, i.e., the complete Navier-Stokes equations (NS equations). These equations are then discretized into linear equations for solution. When there are many small volumes, calculating the complete NS equations for each small volume is computationally intensive, which reduces the speed of calculating the flow rate of complex water pipes. Summary of the Invention
[0004] This application provides a flow rate determination method, apparatus, device, storage medium, and product, which can improve the speed of determining the flow rate in complex water pipelines.
[0005] The technical solution of this application embodiment is implemented as follows:
[0006] This application provides a method for determining traffic flow, the method comprising:
[0007] The target loop is divided into multiple sub-loops and the connection relationships between the multiple sub-loops;
[0008] Determine multiple sets of loop parameters corresponding to the multiple sub-loops, and determine the current resistance of multiple loops based on the multiple sets of loop parameters;
[0009] The total current resistance of the target loop is determined based on the multiple loop current resistances and the connection relationships.
[0010] Based on the pump model information corresponding to the pump in the target loop and the total flow resistance, a simplified loop corresponding to the target loop is established.
[0011] Establish the NS equation for the simplified loop, and determine the total loop flow of the target loop based on the NS equation.
[0012] In the above scheme, the step of dividing the target loop into multiple sub-loops and the connection relationships between the multiple sub-loops includes:
[0013] Identify the loop switches that control the target loop to form different loops;
[0014] Based on the circuit switch, the target circuit is divided into multiple sub-circuits and the connection relationships between the multiple sub-circuits are obtained.
[0015] In the above scheme, determining the multiple sets of loop parameters corresponding to the multiple sub-loops, and determining the multiple loop current resistances based on the multiple sets of loop parameters, includes:
[0016] Determine the flow rate, pressure drop, and fluid density of each of the multiple sub-loops;
[0017] The flow resistance of each of the multiple loops is determined based on the flow rate of the multiple loops, the pressure drop of the multiple loops, and the fluid density of the multiple loops.
[0018] In the above scheme, determining the total current resistance of the target loop based on the multiple loop current resistances and the connection relationships includes:
[0019] Determine the opening degree of multiple valves in the multiple sub-circuits;
[0020] The multiple loop flow resistances are updated according to the multiple valve openings to obtain multiple updated loop flow resistances;
[0021] According to the flow resistance fusion method corresponding to the connection relationship, the multiple updated loop flow resistances are fused to obtain the total flow resistance.
[0022] In the above scheme, updating the multiple loop flow resistances according to the multiple valve openings to obtain multiple updated loop flow resistances includes:
[0023] Obtain multiple sets of valve parameters from the multiple sub-circuits;
[0024] Based on the multiple sets of valve parameters and the multiple valve openings, determine the flow resistance of multiple valves;
[0025] The updated loop flow resistances are determined based on the multiple valve flow resistances and the multiple loop flow resistances.
[0026] In the above scheme, the connection relationship includes series connection and / or parallel connection; the step of fusing the multiple updated loop current resistances according to the current resistance fusion method corresponding to the connection relationship to obtain the total current resistance includes:
[0027] When the connection relationship is a series relationship, the sum of the multiple updated loop current resistances is determined to obtain the total current resistance;
[0028] When the connection relationship is in parallel, the multiple updated loop current resistances are merged according to the current resistance fusion method corresponding to the parallel relationship to obtain the total current resistance;
[0029] When the connection relationship includes both the series connection and the parallel connection, the multiple updated loop current resistances are merged according to the fusion method corresponding to the series connection and the parallel connection to obtain the total current resistance.
[0030] In the above scheme, the pump model information includes the correspondence between flow rate, speed, and pressure difference during the operation of the pump in the target loop. Establishing the Navier-Stokes equations for the simplified loop includes:
[0031] Establish the mass conservation equation and momentum conservation equation for the simplified circuit;
[0032] Substituting the mass conservation equation and the corresponding relationship into the momentum conservation equation, we obtain the Navier-Stokes equation.
[0033] In the above scheme, the method further includes:
[0034] Establish the primary relationship between pressure difference and flow rate when the rotational speed is at the rated speed;
[0035] When the rotational speed is not at the rated speed, a second relationship between the pressure difference and the flow rate is established based on the relationship between the rotational speed and the rated speed and the first relationship;
[0036] Based on the first relationship and the second relationship, determine the corresponding relationship;
[0037] The correspondence is determined as the water pump model information.
[0038] In the above scheme, after determining the total loop flow of the target loop according to the NS equation, the method further includes:
[0039] Based on the total loop flow, the sub-loop flow corresponding to the plurality of sub-loops is determined by reversing the steps of the flow determination method.
[0040] This application provides a flow rate determination device, including:
[0041] A partitioning unit is used to partition the target loop to obtain multiple sub-loops and the connection relationships between the multiple sub-loops;
[0042] The determining unit is used to determine multiple sets of loop parameters corresponding to the multiple sub-loops, and determine multiple loop flow resistances based on the multiple sets of loop parameters; determine the total flow resistance of the target loop based on the multiple loop flow resistances and the connection relationship; and determine the total loop flow rate of the target loop based on the Navier-Stokes equations.
[0043] The unit is used to establish a simplified loop corresponding to the target loop based on the pump model information corresponding to the pump in the target loop and the total flow resistance; and to establish the NS equation for the simplified loop.
[0044] In the above scheme, the determining unit is used to determine the loop switch that controls the target loop to form different loops;
[0045] The partitioning unit is used to partition the target circuit according to the circuit switch, thereby obtaining multiple sub-circuits and the connection relationships between the multiple sub-circuits.
[0046] In the above scheme, the determining unit is used to determine the multiple loop flow rates, multiple loop pressure drops, and loop fluid densities corresponding to the multiple sub-loops; and to determine the multiple loop flow resistances based on the multiple loop flow rates, the multiple loop pressure drops, and the loop fluid densities.
[0047] In the above scheme, the device further includes an update unit and a fusion unit;
[0048] The determining unit is used to determine the opening degree of multiple valves in the plurality of sub-circuits;
[0049] The updating unit is used to update the multiple loop flow resistances according to the multiple valve openings, so as to obtain multiple updated loop flow resistances.
[0050] The fusion unit is used to fuse the multiple updated loop current resistances according to the current resistance fusion method corresponding to the connection relationship to obtain the total current resistance.
[0051] In the above scheme, the device further includes an acquisition unit;
[0052] The acquisition unit is used to acquire multiple sets of valve parameters in the multiple sub-circuits;
[0053] The determining unit is used to determine multiple valve flow resistances based on the multiple sets of valve parameters and the multiple valve openings; and to determine multiple updated loop flow resistances based on the multiple valve flow resistances and the multiple loop flow resistances.
[0054] In the above scheme, the connection relationship includes series connection and / or parallel connection;
[0055] The determining unit is used to determine the sum of the multiple updated loop current resistances when the connection relationship is a series relationship, so as to obtain the total current resistance;
[0056] The fusion unit is used to fuse the multiple updated loop current resistances to obtain the total current resistance when the connection relationship is a parallel relationship, according to the current resistance fusion method corresponding to the parallel relationship; and to fuse the multiple updated loop current resistances to obtain the total current resistance when the connection relationship includes both the series relationship and the parallel relationship, according to the fusion method corresponding to the series relationship and the parallel relationship.
[0057] In the above scheme, the pump model information includes the correspondence between the flow rate, speed and pressure difference of the pump in the target loop during operation; the device also includes a substitution unit.
[0058] The establishment unit is used to establish the mass conservation equation and momentum conservation equation of the simplified circuit.
[0059] The substitution unit is used to substitute the mass conservation equation and the corresponding relationship into the momentum conservation equation to obtain the Navier-Stokes equation.
[0060] In the above scheme, the establishing unit is used to establish a first relationship between pressure difference and flow rate when the rotation speed is at the rated speed; and to establish a second relationship between pressure difference and flow rate when the rotation speed is not at the rated speed, based on the relationship between the rotation speed and the rated speed and the first relationship.
[0061] The determining unit is used to determine a corresponding relationship based on the first relationship and the second relationship; and to determine the corresponding relationship as the water pump model information.
[0062] In the above scheme, the determining unit is used to determine the sub-circuit flow corresponding to the plurality of sub-circuit based on the total circuit flow and by performing the reverse execution steps of the flow determination method.
[0063] This application provides a flow rate determination method device, the flow rate determination method device comprising:
[0064] Memory is used to store executable instructions for a computer;
[0065] A processor, when executing computer-executable instructions stored in the memory, implements the method provided in the embodiments of this application.
[0066] This application provides a computer-readable storage medium storing a computer program or computer-executable instructions for implementing the flow determination method provided in this application when executed by a processor.
[0067] This application provides a computer program product, including a computer program or computer executable instructions. When the computer program or computer executable instructions are executed by a processor, they implement the traffic determination method provided in this application.
[0068] The embodiments of this application have the following beneficial effects: The flow determination device divides the target loop into multiple self-loops and the connection relationships between multiple sub-loops, and determines multiple loop flow groups corresponding to multiple self-loops. Then, it uses the connection relationships between multiple sub-loops to fuse multiple loop flow groups to obtain the total flow resistance of the target loop. Then, it transforms the target loop with complex water pipe form into a simplified loop that only includes the pump model information corresponding to the water pump in the target loop and the total flow resistance. By establishing and solving the NS equations of the simplified loop, the total loop flow of the target loop is finally obtained. This reduces the number of NS equations established when calculating the flow of complex water pipes. Only the NS equations of the simplified loop need to be established and solved to obtain the total loop flow, thereby reducing the computational load when calculating the total loop flow, that is, reducing the speed when calculating the flow of complex water pipes. Attached Figure Description
[0069] Figure 1 This is a flowchart of a flow determination method provided in an embodiment of this application;
[0070] Figure 2 This is an exemplary simplified circuit diagram provided in an embodiment of this application;
[0071] Figure 3 This is an exemplary comparison of traffic determination results provided in an embodiment of this application. Figure 1 ;
[0072] Figure 4 This is an exemplary comparison of traffic determination results provided in an embodiment of this application. Figure 2 ;
[0073] Figure 5 This is a schematic diagram of the composition structure of a flow determination device provided in an embodiment of this application;
[0074] Figure 6 This is a schematic diagram of the composition structure of a flow determination device provided in an embodiment of this application. Detailed Implementation
[0075] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0076] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.
[0077] In this application embodiment, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.
[0078] Unless otherwise defined, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the embodiments of this application is for the purpose of describing the embodiments of this application only and is not intended to limit this application.
[0079] In the implementation of this application, the collection and processing of relevant data should strictly comply with the requirements of relevant national laws and regulations, obtain the informed consent or separate consent of the personal information subject, and carry out subsequent data use and processing within the scope of laws and regulations and the authorization of the personal information subject.
[0080] This application provides a flow rate determination method, which is applied to a flow rate determination device. Figure 1 A flowchart of a flow determination method provided in an embodiment of this application is shown below. Figure 1 As shown, flow rate determination methods may include:
[0081] S101. Divide the target loop into multiple sub-loops and the connection relationships between the multiple sub-loops.
[0082] The flow rate determination method provided in this application embodiment is applicable to scenarios where the flow rate of complex water pipelines in an on-board thermal management system is determined.
[0083] In the embodiments of this application, the traffic determination device can be implemented in various forms. For example, the traffic determination device described in this application may include, for example, a vehicle controller, a vehicle system, or a cloud that controls the vehicle system. The specific traffic determination device can be determined according to the actual situation, and the embodiments of this application do not limit it in this regard.
[0084] In this embodiment, the target loop can be a complex water pipeline in an on-board thermal management system. The target loop can also be a loop in other systems; the specific target loop can be determined based on actual circumstances, and this embodiment does not limit this.
[0085] In the embodiments of this application, the connection relationship refers to the connection relationship between multiple sub-circuits. For example, if the multiple sub-circuits are parallel circuits, the connection relationship is parallel; if the multiple sub-circuits are series circuits, the connection relationship is series; if the multiple sub-circuits include both series and parallel circuits, the connection relationship is both series and parallel.
[0086] In this embodiment of the application, the process of the flow determination device dividing a target loop into multiple sub-loops and the connection relationships between the multiple sub-loops includes: determining a loop switch that controls the target loop to form different loops; and dividing the target loop into multiple sub-loops and the connection relationships between the multiple sub-loops according to the loop switch.
[0087] In this embodiment of the application, the number of circuit switches can be multiple, and the specific number of circuit switches can be determined according to the actual situation. This embodiment of the application does not limit this.
[0088] In this embodiment of the application, the target circuit includes a circuit switch and a water pump. The different flow directions caused by the opening and closing of different circuit switches can be defined according to different circuit definitions, based on the direction of the water pump from high pressure to low pressure. This divides the target circuit into multiple sub-circuits and determines the connection relationship between the multiple sub-circuits.
[0089] In this embodiment of the application, the target loop can also be divided into multiple sub-loops and the connection relationships between the multiple sub-loops in other ways. The specific implementation method can be determined according to the actual situation, and this embodiment of the application does not limit it.
[0090] S102. Determine multiple sets of loop parameters corresponding to the multiple sub-loops, and determine multiple loop current resistances based on the multiple sets of loop parameters.
[0091] In this embodiment of the application, after the flow determination device divides the target loop into multiple sub-loops, it can determine multiple sets of loop parameters corresponding to the multiple sub-loops, and determine the multiple loop flow resistances based on the multiple sets of loop parameters.
[0092] In the embodiments of this application, multiple sub-circuits correspond one-to-one with multiple loop current resistances, that is, one sub-circuit corresponds to one loop current resistance.
[0093] In this embodiment of the application, the process of determining multiple sets of loop parameters corresponding to the multiple sub-loops and determining multiple loop flow resistances based on the multiple sets of loop parameters includes: determining multiple loop flow rates, multiple loop pressure drops, and loop fluid densities corresponding to the multiple sub-loops; and determining the multiple loop flow resistances based on the multiple loop flow rates, the multiple loop pressure drops, and the loop fluid densities.
[0094] In this embodiment of the application, the loop fluid density is the density of the fluid (e.g., water) in the complex water pipeline.
[0095] In the embodiments of this application, multiple sub-circuits correspond one-to-one with multiple loop flow rates, that is, one sub-circuit corresponds to one loop flow rate. Multiple sub-circuit circuits also correspond one-to-one with multiple loop voltage drops, that is, one sub-circuit corresponds to one loop voltage drop.
[0096] In this embodiment, the voltage drop of multiple loops can be measured, and the voltage drop of multiple loops can also be obtained in other ways. The specific method by which the flow determination device determines the voltage drop of multiple loops can be determined according to the actual situation, and this embodiment does not limit it.
[0097] It should be noted that the flow determination device can first determine multiple voltage drop identifiers corresponding to multiple loop voltage drops and multiple loop flow symbols corresponding to multiple loop flow rates, thereby determining the multiple loop flow rates and multiple loop voltage drops corresponding to multiple sub-loops. That is, the multiple loop current resistances are specifically expressions for the multiple loop current resistances. The multiple loop flow rates are identifiers used to represent the loop flow rates, such as Q.
[0098] In this embodiment of the application, the flow resistance of each of the multiple loops can be determined using the formula in formula (1) based on the multiple loop flow rates, the multiple loop pressure drops, and the loop fluid density:
[0099]
[0100] In formula (1), ΔP is any one of the multiple loop pressure drops, f is the loop flow resistance of the loop corresponding to any one of the multiple loop flow resistances, U is the loop flow rate of the loop corresponding to any one of the multiple loop flow resistances, and ρ is the loop fluid density.
[0101] S103. Determine the total current resistance of the target loop based on the multiple loop current resistances and the connection relationships.
[0102] In this embodiment of the application, after the flow determination device determines multiple sets of loop parameters corresponding to the multiple sub-loops and determines multiple loop flow resistances based on the multiple sets of loop parameters, it can determine the total flow resistance of the target loop based on the multiple loop flow resistances and the connection relationship.
[0103] In this embodiment of the application, the process of determining the total flow resistance of the target loop based on the multiple loop flow resistances and the connection relationship includes: determining the opening degree of multiple valves in the multiple sub-loops; updating the multiple loop flow resistances according to the multiple valve opening degrees to obtain multiple updated loop flow resistances; and fusing the multiple updated loop flow resistances according to the flow resistance fusion method corresponding to the connection relationship to obtain the total flow resistance.
[0104] In this embodiment, the flow determination device can detect multiple valve openings, obtain multiple valve openings from other devices, or obtain multiple valve openings through other means. The specific method by which the flow determination device obtains multiple valve openings can be determined according to the actual situation, and this embodiment does not limit this.
[0105] In this embodiment of the application, the process of the flow determination device updating the multiple loop flow resistances according to the multiple valve openings to obtain multiple updated loop flow resistances includes: acquiring multiple sets of valve parameters in the multiple sub-loops; determining multiple valve flow resistances according to the multiple sets of valve parameters and the multiple valve openings; and determining the multiple updated loop flow resistances according to the multiple valve flow resistances and the multiple loop flow resistances.
[0106] In the embodiments of this application, multiple sub-circuits correspond one-to-one with multiple sets of valve parameters, that is, one sub-circuit corresponds to one set of valve parameters.
[0107] In the embodiments of this application, any one of the multiple sets of valve parameters is the valve parameter to be identified in the sub-circuit. The relationship between the valve opening degree and flow resistance of the valve can be fitted by adjusting any one set of valve parameters.
[0108] In this embodiment, the method for determining the flow resistance of multiple valves based on the multiple sets of valve parameters and the multiple valve openings is as shown in formula (2):
[0109]
[0110] Among them, f valve For any one of multiple valve flow resistances, Va k1 and k2 are a set of valve parameters corresponding to the flow resistance of any given valve.
[0111] In this embodiment, when multiple valves and multiple sub-circuits are connected in series, the flow resistance of multiple valves and the sum of the flow resistance of the multiple circuits are determined to obtain multiple updated circuit flow resistances; when multiple valves and multiple sub-circuits are connected in parallel, the flow resistance of multiple valves and the flow resistance of the multiple circuits are merged according to the flow resistance fusion method corresponding to the parallel connection to obtain multiple updated circuit flow resistances.
[0112] In this embodiment, the connection relationship includes a series connection and / or a parallel connection. The flow determination device fuses the multiple updated loop flow resistances according to the flow resistance fusion method corresponding to the connection relationship to obtain the total flow resistance, including: when the connection relationship is a series connection, determining the sum of the multiple updated loop flow resistances to obtain the total flow resistance; when the connection relationship is a parallel connection, fusing the multiple updated loop flow resistances according to the flow resistance fusion method corresponding to the parallel connection to obtain the total flow resistance; when the connection relationship includes both the series connection and the parallel connection, fusing the multiple updated loop flow resistances according to the fusion methods corresponding to the series connection and the parallel connection to obtain the total flow resistance.
[0113] It should be noted that, in order to facilitate subsequent calculations, this application adopts two simplification principles: Principle 1: The impact of area change on flow is uniformly calculated into the flow resistance change, therefore it is assumed that the area is equal everywhere in the pipeline; Principle 2: The local flow resistance is evenly distributed to the friction flow resistance.
[0114] In this embodiment, when multiple sub-loops are connected in series, the flow rate remains constant, therefore the total flow resistance is the sum of the series flow resistances, and the flow rates are equal. That is, when the connection relationship is a series relationship, the sum of the multiple updated loop flow resistances is determined to obtain the total flow resistance as shown in formula (3):
[0115]
[0116] It should be noted that f is the total current resistance. i Let be the i-th updated loop current resistance.
[0117] In this embodiment of the application, when multiple sub-loops are connected in parallel, the pressures at both ends of different branches are equal, and the total flow rate is the sum of the flow rates of each sub-loop. That is, when the connection relationship is parallel, the flow resistances of the multiple updated loops are merged according to the flow resistance fusion method corresponding to the parallel relationship, and the total flow resistance is obtained as shown in formula (4):
[0118]
[0119] It should be noted that f is the total current resistance.i Let be the i-th updated loop current resistance.
[0120] S104. Based on the pump model information corresponding to the pump in the target circuit and the total flow resistance, establish the corresponding simplified circuit of the target circuit.
[0121] In this embodiment of the application, after the flow determination device determines the total flow resistance of the target loop based on the multiple loop flow resistances and the connection relationship, it can establish a simplified loop corresponding to the target loop based on the pump model information corresponding to the pump in the target loop and the total flow resistance.
[0122] In this embodiment, the flow determination device maps the total flow resistance to a flow resistance device that affects the target loop. The loop obtained by connecting the water pump in series with the flow resistance device is the simplified loop corresponding to the target loop. That is, the simplified loop of the target loop is obtained based on the water pump model information and the total flow resistance.
[0123] For example, such as Figure 2 As shown, the circuit obtained by connecting the water pump in series with a flow resistance device whose flow resistance is the total flow resistance is the simplified circuit. In this simplified circuit, the water flows from bottom to top, and the pressure stabilizing box is used to control the pressure of the water pump source to remain constant, which is p0.
[0124] S105. Establish the NS equation for the simplified loop, and determine the total loop flow of the target loop based on the NS equation.
[0125] In this embodiment of the application, after the flow determination device establishes the corresponding simplified loop of the target loop based on the pump model information corresponding to the pump in the target loop and the total flow resistance, it can establish the NS equation for the simplified loop and determine the total loop flow of the target loop based on the NS equation.
[0126] In this embodiment of the application, the total loop flow of the target loop can be obtained by solving the Navier-Stokes equations.
[0127] In this embodiment of the application, the pump model information includes the correspondence between flow rate, rotational speed and pressure difference during the operation of the pump in the target loop. The process of the flow rate determination device establishing the NS equation for the simplified loop includes: establishing the mass conservation equation and momentum conservation equation of the simplified loop; substituting the mass conservation equation and the correspondence into the momentum conservation equation to obtain the NS equation.
[0128] In this embodiment of the application, the process by which the flow rate determining device substitutes the mass conservation equation and the corresponding relationship into the momentum conservation equation to obtain the NS equation includes: simplifying the mass conservation equation according to the incompressible fluid to obtain a simplified result; and substituting the simplified result and the corresponding relationship into the momentum conservation equation to obtain the NS equation.
[0129] In this embodiment, the flow rate determination device can establish a first relationship between pressure difference and flow rate when the rotation speed is at the rated rotation speed; when the rotation speed is not at the rated rotation speed, it can establish a second relationship between pressure difference and flow rate based on the relationship between the rotation speed and the rated rotation speed and the first relationship; it can determine a corresponding relationship based on the first relationship and the second relationship; and it can determine the corresponding relationship as the water pump model information.
[0130] In this embodiment, a pump model is established based on the relationship between pump pressure difference, flow rate, and rotational speed. Under known relationships, when the pressure difference remains constant, the flow rate is directly proportional to the rotational speed; when the flow rate remains constant, the pressure difference is directly proportional to the square of the rotational speed.
[0131] First, establish the relationship between pressure difference and flow rate at rated speed as shown in formulas (5)-(6):
[0132] P e =P e,0 -k3Q e (5)
[0133]
[0134] It should be noted that P e Q is the pressure difference at rated speed. e Q is the flow rate at rated speed. e，0 It is the flow rate when the pressure difference is 0, P e,0 It is the pressure difference when the flow rate is 0, and k3 is the parameter to be identified, which is related to the structure of the water pump.
[0135] Next, the pressure difference-flow rate relationship at different speeds is established, as shown in formulas (7)-(8):
[0136]
[0137] It should be noted that n is the rotational speed, n e Since the speed is the rated speed, the undetermined slope k at speed n can be obtained as shown in formula (9):
[0138]
[0139] Finally, the flow rate at rotational speed n can be determined as shown in formula (10):
[0140] P n =P n,0 -k n Q n (10)
[0141] In this embodiment of the application, to simplify the calculation, the fluid is regarded as an incompressible fluid, and formula (11) can be obtained based on the mass conservation equation:
[0142]
[0143] Since it is an incompressible fluid, the second term on the left side of the formula is 0 (i.e., ...). Since the value of Q is 0, the differential of the flow rate Q with respect to position x is 0, and the flow rate is the same everywhere in the loop.
[0144] In this embodiment of the application, based on the momentum conservation equation, formula (12) can be established:
[0145]
[0146] In formula (12), s is the circumference of the pipe. Since it is an incompressible fluid, the two terms on the left side of the formula are 0. By rearranging the terms of the formula and dividing by A (the cross-sectional area of the pipe), the result is shown in formula (13):
[0147]
[0148] Integrating both sides of the equal sign in formula (13) with respect to x, we obtain formula (14):
[0149]
[0150] When x = 0, the pressure is P. T +P n , is the pumping pressure from PT. When x = L (loop length), the pressure is PT. Substituting these two conditions into formula (14), we get formulas (15)-(16):
[0151] P0=C(t=P n,0 -k n Q n +P T (15)
[0152]
[0153] By combining equations (15) and (16), eliminating PT, and integrating with respect to t, we can obtain equation (17):
[0154]
[0155] in,
[0156] The data flow rate at the previous moment.
[0157] In this embodiment of the application, after the flow determination device determines the total loop flow of the target loop according to the NS equation, it can also determine the sub-loop flow corresponding to the plurality of sub-loops according to the total loop flow and the reverse execution steps of the flow determination method.
[0158] It is understandable that by performing the reverse steps of the flow determination method, the flow rates of multiple sub-circuit corresponding to the total circuit flow resistance are determined, so that the flow determination method in this application can not only determine the total circuit flow rate of the target circuit, but also the flow rates of different sub-circuit corresponding to the target circuit, thereby improving the reliability of determining the flow rate of the target circuit.
[0159] In this embodiment of the application, the comparison result between the flow rate (simulated data) of the target loop determined by the flow rate determination method in this application and the flow rate (test data) of the target loop obtained by testing is as follows: Figure 3 and Figure 4 As shown, the simulated data is close to the test data, thus confirming the accuracy of the flow rate determined by the flow rate determination device. Among other things, Figure 3 The target loop and Figure 4 The target loops are different.
[0160] Understandably, the flow determination device divides the target loop into multiple self-loops and the connection relationships between multiple sub-loops, and determines multiple loop flow groups corresponding to multiple self-loops. Then, it uses the connection relationships between multiple sub-loops to merge multiple loop flow groups to obtain the total flow resistance of the target loop. After that, the target loop with complex water pipe form is transformed into a simplified loop that only includes the pump model information corresponding to the water pump in the target loop and the total flow resistance. By establishing and solving the Navier-Stokes equations of the simplified loop, the total loop flow of the target loop is finally obtained. This reduces the number of Navier-Stokes equations established when calculating the flow of complex water pipes. Only establishing and solving the Navier-Stokes equations of the simplified loop is needed to obtain the total loop flow, thereby reducing the computational load when calculating the total loop flow, that is, reducing the speed of calculating the flow of complex water pipes.
[0161] Based on the same inventive concept as the above-described flow determination method, this application provides a flow determination device 1, corresponding to a flow determination method; Figure 5 This is a schematic diagram of the composition of a flow determination device provided in an embodiment of this application. The flow determination device 1 may include:
[0162] The partitioning unit 11 is used to partition the target loop to obtain multiple sub-loops and the connection relationships between the multiple sub-loops;
[0163] The determining unit 12 is used to determine multiple sets of loop parameters corresponding to the multiple sub-loops, and determine multiple loop flow resistances based on the multiple sets of loop parameters; determine the total flow resistance of the target loop based on the multiple loop flow resistances and the connection relationship; and determine the total loop flow rate of the target loop based on the Navier-Stokes equations.
[0164] Establishment unit 13 is used to establish a simplified loop corresponding to the target loop based on the pump model information corresponding to the pump in the target loop and the total flow resistance; and to establish the NS equation for the simplified loop.
[0165] In some embodiments of this application, the determining unit 12 is used to determine the loop switch that controls the target loop to form different loops;
[0166] The partitioning unit 11 is used to partition the target circuit according to the circuit switch to obtain multiple sub-circuits and the connection relationship between the multiple sub-circuits.
[0167] In some embodiments of this application, the determining unit 12 is used to determine the multiple loop flow rates, multiple loop pressure drops, and loop fluid densities corresponding to the multiple sub-loops; and to determine the multiple loop flow resistances based on the multiple loop flow rates, the multiple loop pressure drops, and the loop fluid densities.
[0168] In some embodiments of this application, the apparatus further includes an updating unit and a fusion unit;
[0169] The determining unit 12 is used to determine the opening degree of multiple valves in the plurality of sub-circuits;
[0170] The updating unit is used to update the multiple loop flow resistances according to the multiple valve openings, so as to obtain multiple updated loop flow resistances.
[0171] The fusion unit is used to fuse the multiple updated loop current resistances according to the current resistance fusion method corresponding to the connection relationship to obtain the total current resistance.
[0172] In some embodiments of this application, the apparatus further includes an acquisition unit;
[0173] The acquisition unit is used to acquire multiple sets of valve parameters in the multiple sub-circuits;
[0174] The determining unit 12 is used to determine multiple valve flow resistances based on the multiple sets of valve parameters and the multiple valve openings; and to determine multiple updated loop flow resistances based on the multiple valve flow resistances and the multiple loop flow resistances.
[0175] In some embodiments of this application, the connection relationship includes a series connection and / or a parallel connection;
[0176] The determining unit 12 is used to determine the sum of the multiple updated loop current resistances when the connection relationship is a series relationship, so as to obtain the total current resistance;
[0177] The fusion unit is used to fuse the multiple updated loop current resistances to obtain the total current resistance when the connection relationship is a parallel relationship, according to the current resistance fusion method corresponding to the parallel relationship; and to fuse the multiple updated loop current resistances to obtain the total current resistance when the connection relationship includes both the series relationship and the parallel relationship, according to the fusion method corresponding to the series relationship and the parallel relationship.
[0178] In some embodiments of this application, the pump model information includes the correspondence between flow rate, rotational speed, and differential pressure during the operation of the pump in the target circuit; the device also includes a substitution unit;
[0179] The establishment unit 13 is used to establish the mass conservation equation and momentum conservation equation of the simplified circuit.
[0180] The substitution unit is used to substitute the mass conservation equation and the corresponding relationship into the momentum conservation equation to obtain the Navier-Stokes equation.
[0181] In some embodiments of this application, the establishing unit 13 is used to establish a first relationship between pressure difference and flow rate when the rotation speed is at the rated rotation speed; and to establish a second relationship between pressure difference and flow rate when the rotation speed is not at the rated rotation speed, based on the relationship between the rotation speed and the rated rotation speed and the first relationship.
[0182] The determining unit 12 is used to determine a corresponding relationship based on the first relationship and the second relationship; and to determine the corresponding relationship as the water pump model information.
[0183] In some embodiments of this application, the determining unit 12 is used to determine the sub-circuit flow corresponding to the plurality of sub-circuit based on the total circuit flow and in reverse execution steps of the flow determination method.
[0184] It should be noted that, in practical applications, the aforementioned partitioning unit 11, determining unit 12, and establishing unit 13 can be implemented by the processor 14 on the flow determination device, specifically by a CPU (Central Processing Unit), MPU (Microprocessor Unit), DSP (Digital Signal Processor), or Field Programmable Gate Array (FPGA), etc.; the aforementioned data storage can be implemented by the memory 15 on the flow determination device.
[0185] This application also provides a flow rate determination device, such as... Figure 6 As shown, the flow determination device includes a processor 14, a memory 15, and a communication bus 16. The memory 15 communicates with the processor 14 through the communication bus 16. The memory 15 stores programs executable by the processor 14. When the program is executed, the flow determination method described above is performed by the processor 14.
[0186] In practical applications, the aforementioned memory 15 can be volatile memory, such as random-access memory (RAM); or non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); or a combination of the above types of memory, and provide instructions and data to the processor 14.
[0187] This application provides a computer program product including a computer program or computer-executable instructions stored in a computer-readable storage medium. A processor of a flow determination device reads the computer-executable instructions from the computer-readable storage medium and executes the computer-executable instructions, causing the flow determination device to perform the flow determination method described in this application.
[0188] This application provides a computer-readable storage medium storing computer-executable instructions. When these computer-executable instructions are executed by a processor, they cause the processor to execute the flow determination method provided in this application. For example, ... Figure 1 The method for determining flow rate is shown.
[0189] In some embodiments, the computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEP ROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or it may be a variety of devices including one or any combination of the above-mentioned memories.
[0190] In some embodiments, computer-executable instructions may take the form of programs, software, software modules, scripts, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as stand-alone programs or as modules, components, subroutines, or other units suitable for use in a computing environment.
[0191] As an example, computer-executable instructions may, but do not necessarily, correspond to files in a file system. They may be stored as part of a file that holds other programs or data, for example, in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple co-located files (e.g., files that store one or more modules, subroutines, or code sections).
[0192] Understandably, the flow determination device divides the target loop into multiple self-loops and the connection relationships between multiple sub-loops, and determines multiple loop flow groups corresponding to multiple self-loops. Then, it uses the connection relationships between multiple sub-loops to merge multiple loop flow groups to obtain the total flow resistance of the target loop. After that, the target loop with complex water pipe form is transformed into a simplified loop that only includes the pump model information corresponding to the water pump in the target loop and the total flow resistance. By establishing and solving the Navier-Stokes equations of the simplified loop, the total loop flow of the target loop is finally obtained. This reduces the number of Navier-Stokes equations established when calculating the flow of complex water pipes. Only establishing and solving the Navier-Stokes equations of the simplified loop is needed to obtain the total loop flow, thereby reducing the computational load when calculating the total loop flow, that is, reducing the speed of calculating the flow of complex water pipes.
[0193] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.
[0194] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0195] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0196] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0197] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.
Claims
1. A flow rate determination method characterized by, The method includes: The target loop is divided into multiple sub-loops and the connection relationships between the multiple sub-loops; Determine multiple sets of loop parameters corresponding to the multiple sub-loops, and determine the current resistance of multiple loops based on the multiple sets of loop parameters; The total current resistance of the target loop is determined based on the multiple loop current resistances and the connection relationships. Based on the pump model information corresponding to the pump in the target loop and the total flow resistance, a simplified loop corresponding to the target loop is established. Establish the Navier-Stokes equations for the simplified loop, and determine the total loop flow of the target loop based on the Navier-Stokes equations; The method for determining the NS equation and solving for the total loop flow is as follows: Treating the fluid as incompressible, we obtain the following formula 11 based on the mass conservation equation: ； Since it is an incompressible fluid, the second term on the left side of the formula... The value of is 0, therefore the differential of the flow rate Q with respect to position x is 0, and the flow rate is the same everywhere in the loop. The density of the fluid in the loop; Based on the momentum conservation equation, we obtain the following formula 12: ； Where s is the circumference of the pipeline, For the total flow resistance, since it is an incompressible fluid, the two terms on the left side of the formula are 0. By rearranging the formula and dividing it by the cross-sectional area A of the pipe, we obtain the result shown in Formula 13 below: ； Integrating both sides of the equation with respect to x in Equation 13, we obtain Equation 14: ； When x=0, the pressure is It is the water pump from The pump outlet pressure, when x=L, is... Let L be the loop length. Substituting these two conditions into Equation 14, we obtain Equations 15-16: ； ； For the pending slope at speed n, solve equations 15-16 simultaneously, eliminate and integrate with respect to t to obtain equation 17: ； in, , , , , , Let n be the flow rate at the previous moment, and n be the rotational speed. It is the pressure difference when the flow rate is 0. For the rated speed, The parameters to be identified are related to the structure of the water pump.
2. The method of claim 1, wherein, The step of dividing the target loop into multiple sub-loops and the connection relationships between the multiple sub-loops includes: Identify the loop switches that control the target loop to form different loops; Based on the circuit switch, the target circuit is divided into multiple sub-circuits and the connection relationships between the multiple sub-circuits are obtained.
3. The method of claim 1, wherein, The step of determining multiple sets of loop parameters corresponding to the multiple sub-loops, and determining multiple loop current resistances based on the multiple sets of loop parameters, includes: Determine the flow rate, pressure drop, and fluid density of each of the multiple sub-loops; The flow resistance of each of the multiple loops is determined based on the flow rate of the multiple loops, the pressure drop of the multiple loops, and the fluid density of the multiple loops.
4. The method of claim 1, wherein, Determining the total current resistance of the target loop based on the multiple loop current resistances and the connection relationships includes: Determine the opening degree of multiple valves in the multiple sub-circuits; The multiple loop flow resistances are updated according to the multiple valve openings to obtain multiple updated loop flow resistances; According to the flow resistance fusion method corresponding to the connection relationship, the multiple updated loop flow resistances are fused to obtain the total flow resistance.
5. The method of claim 4, wherein, The step of updating the multiple loop flow resistances according to the multiple valve openings to obtain multiple updated loop flow resistances includes: Obtain multiple sets of valve parameters from the multiple sub-circuits; Based on the multiple sets of valve parameters and the multiple valve openings, determine the flow resistance of multiple valves; The updated loop flow resistances are determined based on the multiple valve flow resistances and the multiple loop flow resistances.
6. The method of claim 4, wherein, The connection relationships include series and / or parallel relationships; the method of fusing the multiple updated loop current resistances according to the flow resistance fusion method corresponding to the connection relationships to obtain the total flow resistance includes: When the connection relationship is a series relationship, the sum of the multiple updated loop current resistances is determined to obtain the total current resistance; When the connection relationship is in parallel, the multiple updated loop current resistances are merged according to the current resistance fusion method corresponding to the parallel relationship to obtain the total current resistance; When the connection relationship includes both the series connection and the parallel connection, the multiple updated loop current resistances are merged according to the fusion method corresponding to the series connection and the parallel connection to obtain the total current resistance.
7. The method of claim 1, wherein, The pump model information includes the correspondence between flow rate, rotational speed, and pressure difference during pump operation in the target loop. Establishing the Navier-Stokes equations for the simplified loop includes: Establish the mass conservation equation and momentum conservation equation for the simplified circuit; Substituting the mass conservation equation and the corresponding relationship into the momentum conservation equation, we obtain the Navier-Stokes equation.
8. The method of claim 1, wherein, The method further includes: Establish the primary relationship between pressure difference and flow rate when the rotational speed is at the rated speed; When the rotational speed is not at the rated speed, a second relationship between the pressure difference and the flow rate is established based on the relationship between the rotational speed and the rated speed and the first relationship; Based on the first relationship and the second relationship, determine the corresponding relationship; The correspondence is determined as the water pump model information.
9. The method of claim 1, wherein, After determining the total loop flow of the target loop according to the NS equation, the method further includes: Based on the total loop flow, the sub-loop flow corresponding to the plurality of sub-loops is determined by reversing the steps of the flow determination method.
10. A flow determining device, characterized in that The device includes: A partitioning unit is used to partition the target loop to obtain multiple sub-loops and the connection relationships between the multiple sub-loops; The determining unit is used to determine multiple sets of loop parameters corresponding to the multiple sub-loops, and determine multiple loop flow resistances based on the multiple sets of loop parameters; determine the total flow resistance of the target loop based on the multiple loop flow resistances and the connection relationship; and determine the total loop flow rate of the target loop based on the Navier-Stokes equations. The unit is configured to establish a simplified loop corresponding to the target loop based on the pump model information corresponding to the pump in the target loop and the total flow resistance; and to establish the NS equation for the simplified loop. Specifically, the establishing unit is used to determine the NS equation and solve for the total loop flow rate in the following manner: Treating the fluid as incompressible, we obtain the following formula 11 based on the mass conservation equation: ； Since it is an incompressible fluid, the second term on the left side of the formula... The value of is 0, therefore the differential of the flow rate Q with respect to position x is 0, and the flow rate is the same everywhere in the loop. The density of the fluid in the loop; Based on the momentum conservation equation, we obtain the following formula 12: ； Where s is the circumference of the pipeline, For the total flow resistance, since it is an incompressible fluid, the two terms on the left side of the formula are 0. By rearranging the formula and dividing it by the cross-sectional area A of the pipe, we obtain the result shown in Formula 13 below: ； Integrating both sides of the equation with respect to x in Equation 13, we obtain Equation 14: ； When x=0, the pressure is It is the water pump from The pump outlet pressure, when x=L, is... Let L be the loop length. Substituting these two conditions into Equation 14, we obtain Equations 15-16: ； ； For the pending slope at speed n, solve equations 15-16 simultaneously, eliminate and integrate with respect to t to obtain equation 17: ； in, , , , , , Let n be the flow rate at the previous moment, and n be the rotational speed. It is the pressure difference when the flow rate is 0. For the rated speed, The parameters to be identified are related to the structure of the water pump.
11. A flow determining device, characterized in that The device includes: Memory is used to store executable instructions for a computer; A processor, when executing computer-executable instructions stored in the memory, implements the flow determination method according to any one of claims 1 to 9.
12. A computer-readable storage medium storing computer-executable instructions, characterized in that, When the computer-executable instructions are executed by a processor, they implement the method described in any one of claims 1 to 9.
13. A computer program product comprising computer-executable instructions or a computer program, characterized in that, When the computer-executable instructions or computer program are executed by a processor, they implement the method according to any one of claims 1 to 9.