Method and system for determining optimization range and energy consumption curve of variable-speed pump unit

Abstract

The invention belongs to the technical field of variable speed units, and discloses a variable speed pump unit optimization range and energy consumption curve determination method and system, the variable speed pump unit optimization range and energy consumption curve determination method comprises the following steps: fitting a rated speed curve of a pump to obtain a quartic equation; curves at other rotating speeds are obtained through the impeller cutting law; obtaining an energy consumption curve of the pump by utilizing a graphical method; the system for determining the optimization range and the energy consumption curve of the variable-speed pump unit comprises a curve fitting module, a rotating speed curve obtaining module and an energy consumption curve obtaining module. According to the optimization range and energy consumption curve determination method of the variable-speed pump unit, the energy consumption curve can be found, and the optimal energy consumption point can be found on the energy consumption curve. According to the definition of an energy consumption curve, the energy consumption curve of the rotating speed pump unit is that all points on the curve are a set of the points with the minimum energy consumption under a certain determined flow by adjusting the rotating speed under the condition that the system demand pressure is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of variable speed units, and in particular relates to a method and system for determining an optimization range and an energy consumption curve of a variable speed pump unit. Background Art

[0002] At present, in order to optimize the operating point of the pump and optimize its energy consumption, it is necessary to understand its energy consumption value under different working conditions (flow rates). Only in this way can the subsequent optimization be carried out.

[0003] For non-variable speed pumps, the relationship between flow rate and power can be calculated by directly querying its flow-pressure and flow-power curves in the operation database;

[0004] P=f(Q)[Q min ,Q max ]

[0005] The flow-power curve can be fitted using a single-variable 3-6 degree equation at most. However, the power curve of a variable frequency unit is completely different. Because the operating speed of a variable frequency unit is adjustable, the flow-head curve and flow-power curve corresponding to each speed are different. This makes it very difficult to find the optimal energy consumption point or energy consumption curve for a variable frequency pump. To date, there is no specific method.

[0006] The existing technology faces the following major problems and defects when optimizing the operating point of the variable speed pump unit to achieve energy consumption optimization:

[0007] 1. Increased complexity:

[0008] For non-variable speed pumps, their flow-pressure and flow-power curves can be directly retrieved from the operating database, and the relationship between flow and power can be derived using simple fitting methods (such as a univariate 3-6th order equation). However, due to the adjustable operating speed of variable speed pumps, the flow-head curve and flow-power curve corresponding to each speed are different. This greatly increases the complexity of the system, making traditional simple fitting methods unsuitable for energy consumption optimization of variable speed pumps.

[0009] 2. Difficulty in data acquisition and processing:

[0010] Because variable speed pumps have adjustable speeds, it's necessary to obtain flow-head and flow-power curves corresponding to each speed. This requires extensive experimental data and measurements, and each speed requires independent data processing and analysis. This complexity makes optimizing energy consumption for variable speed pumps extremely difficult, making it difficult to quickly and accurately identify the optimal operating point.

[0011] 3. Lack of unified optimization methods:

[0012] Currently, there's no specific, unified technical solution for determining the optimal range and energy consumption curve for variable-speed pumps. Existing technologies primarily focus on optimizing the energy consumption of non-variable-speed pumps. Research and technical solutions for variable-speed pumps are relatively limited, lacking systematic and targeted optimization methods. This results in a lack of effective guidance and tools for optimizing the energy consumption of variable-speed pumps in practical applications, making it difficult to achieve the expected energy savings.

[0013] 4. Real-time optimization is difficult:

[0014] The speed of a variable-frequency pump can be adjusted in real time based on system requirements, resulting in a constantly changing relationship between flow and power. Finding the optimal energy consumption point within this dynamic environment requires real-time monitoring and adjustment of the pump's operating status. This places high demands on the real-time performance and computing power of the optimization algorithm, and existing technologies struggle to meet these high-precision optimization requirements.

[0015] In summary, existing technologies for optimizing the energy consumption of variable-speed pump units face major challenges and drawbacks, including increased complexity, difficulties in data acquisition and processing, a lack of a unified optimization method, and the difficulty of real-time optimization. These issues severely limit the energy-saving potential of variable-speed pumps in practical applications, necessitating new technical solutions. Summary of the Invention

[0016] In view of the problems existing in the prior art, the present invention provides a method and system for determining the optimization range and energy consumption curve of a variable speed pump unit.

[0017] The present invention is implemented as follows: a method for determining an optimization range and an energy consumption curve of a variable speed pump unit, the method comprising:

[0018] The rated speed curve is obtained and fitted, and the energy consumption curve is obtained using the impeller cutting law and graphical method.

[0019] Furthermore, the method for determining the optimization range and energy consumption curve of the variable speed pump unit includes the following steps:

[0020] Step 1: Fit the rated speed curve of the pump to obtain a quartic equation;

[0021] Step 2: Obtain the curves at other speeds through the impeller cutting law;

[0022] Step three, use the graphical method to obtain the energy consumption curve of the pump.

[0023] Furthermore, the method for determining the optimization range and energy consumption curve of the variable speed pump unit further includes:

[0024] The centrifugal pump fully complies with the impeller cutting law, and does not conform to the centrifugal pump speed reduction formula during actual operation;

[0025]

[0026] Furthermore, in step 1, the initial curve of the pump at a certain speed is the rated speed curve.

[0027] By fitting the curve, we get a quartic equation:

[0028] H=f(Q)=gQ 6 +fQ 5 +eQ 4 +dQ 3 +cQ 2 +bQ+a;

[0029] In most cases, the flow-head curve uses the sixth power formula at most, and the coefficient is set to 12 decimal places at most. 2 =1.

[0030] Furthermore, in step 2, for different rotational speeds, the curves of the pump at other rotational speeds can be obtained through calculation and self-learning, and the parameter values ​​can be calibrated and corrected through the self-learning of the pump.

[0031] Furthermore, the forming of the energy consumption curve in step 3 includes:

[0032] (1) According to the definition of the energy consumption curve of a variable speed unit, the energy consumption curve is the set of operating points with the minimum power under the condition of meeting the system required pressure p at all speeds;

[0033] (2) According to the derivation of flow rate-specific work, the maximum flow rate point that meets the pressure conditions on the flow rate-head curve is the minimum energy consumption point under the speed. The minimum energy consumption points of each speed are connected to obtain the energy consumption curve;

[0034] (3) The analytical method for the different speed curves is:

[0035] p n1 =f(Q), n1=1480

[0036] p n2 =f(Q), n2=921.5

[0037] …

[0038] p n9 =f(Q), n9=630.5;

[0039] (4) Since p is known, find Q and use the inverse function to substitute into p to calculate Q;

[0040] Q n1 =g(p), n1=1480

[0041] Q n2 =g(p), n2=921.5

[0042] …

[0043] p n9 =f(Q), n9=630.5

[0044] When the head is brought into each speed, the flow rate relative to the pressure at each speed is calculated, which are Q n1 , Q n2 ,…Q n9 ;

[0045] (5) The intersection of the lift line and the flow-pressure line at each speed is the maximum flow allowable point Q under a certain speed condition. max，ni ; The analytical method is in p ni =f(Q) ni The inverse function Q max,ni =g(p) ni Substitute the system required pressure p into the equation and calculate the corresponding Q max，ni , n i For different speeds;

[0046] (6) By calculating Q at each speed max，ni Point, into the pump unit flow rate at each speed - power curve, calculate the power P under the flow rate ni ; In P ni =f(Q) ni Substitute Q max，ni , calculate P ni ;

[0047] (7) Connect all power points to form a curve, which is the minimum energy consumption line achieved by adjusting the pump speed under variable frequency conditions and the parameter conditions required by the system;

[0048] (8) In the analytical solution, list the flow rate Q max，ni and P ni , and fit the curve;

[0049] P min =f(Q);

[0050] Among them, the top point of the curve is the maximum point, which is the flow rate at maximum speed - the point on power; the bottom point of the curve is the minimum point.

[0051] Another object of the present invention is to provide a system for determining an optimization range and an energy consumption curve of a variable speed pump unit using the method for determining an optimization range and an energy consumption curve of a variable speed pump unit. The system for determining an optimization range and an energy consumption curve of a variable speed pump unit comprises:

[0052] Curve fitting module, used to fit the rated speed curve of the pump to obtain a quartic equation;

[0053] Speed ​​curve acquisition module, used to obtain curves at other speeds through the impeller cutting law;

[0054] The energy consumption curve acquisition module is used to obtain the energy consumption curve of the pump using a graphical method.

[0055] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps:

[0056] The rated speed curve is obtained and fitted, and the energy consumption curve is obtained using the impeller cutting law and graphical method.

[0057] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor performs the following steps:

[0058] The rated speed curve is obtained and fitted, and the energy consumption curve is obtained using the impeller cutting law and graphical method.

[0059] Another object of the present invention is to provide an information data processing terminal, which is used to implement the optimization range and energy consumption curve determination system of the variable speed pump unit.

[0060] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0061] First, the optimization range and energy consumption curve determination method for a variable-speed pump unit provided by this invention can identify the energy consumption curve and find the optimal energy consumption point on it. According to the definition of an energy consumption curve, the energy consumption curve of a variable-speed pump unit is the set of points on this curve that minimize energy consumption while meeting the system's required pressure by adjusting the speed at a given flow rate.

[0062] The method for determining the optimization range and energy consumption curve of a variable speed pump unit provided by the present invention fills the gap in the current technical solutions for determining the optimization range and energy consumption curve of a variable speed pump unit.

[0063] Second, this invention addresses the technical challenges of optimizing the operation and controlling energy consumption of variable-speed pump units in existing industrial applications. It proposes a method for determining the optimal range and energy consumption curve for variable-speed pump units. This method addresses the low operational efficiency and high energy consumption of conventional pump units.

[0064] First, the present invention accurately calculates the energy consumption curve for the pump unit by acquiring and fitting the rated speed curve, combining it with the impeller shear law and a graphical method. This method not only improves the accuracy of the pump unit's operation but also enables operators to adjust the pump's operating status according to actual needs, thereby achieving energy conservation and emission reduction.

[0065] Secondly, the optimization method proposed in this paper significantly improves the operating efficiency of the pump unit. By fitting the rated speed curve and obtaining curves at other speeds, the pump unit's efficient operating range can be accurately identified. This prevents the pump unit from operating in the inefficient range, thereby reducing energy consumption and improving overall operating efficiency.

[0066] Finally, this invention has achieved significant technological advancement in industrial applications. By determining the optimal range and energy consumption curve for variable-speed pump units, enterprises can more scientifically manage pump unit operations and achieve efficient energy utilization. This not only helps companies reduce operating costs but also plays a significant role in promoting green industrial development and achieving sustainable development goals.

[0067] Third, the present invention successfully solves a series of technical problems in the operation of variable speed pump units in the prior art by introducing key parameters, advanced algorithms and precise mathematical models.

[0068] First, this invention carefully selects key parameters, such as pump speed, flow rate, and power, which directly reflect the operating status and energy consumption of the pump unit. By accurately acquiring and analyzing these parameters, we can gain a deeper understanding of the pump unit's performance, providing a solid data foundation for subsequent optimization.

[0069] Secondly, the present invention uses advanced algorithms to fit the rated speed curve and calculates the curves at other speeds using the impeller cutting law. The use of these algorithms enables us to more accurately predict the performance of the pump unit and thus formulate more reasonable operation strategies.

[0070] Furthermore, the present invention constructs a precise mathematical model that comprehensively considers various pump unit parameters and operating conditions, accurately describing the pump unit's energy consumption characteristics. This model enables quantitative analysis of the pump unit's energy consumption, identifying the causes of high energy consumption and proposing targeted optimization measures.

[0071] In summary, this invention, through the selection of key parameters, the application of advanced algorithms, and the construction of precise mathematical models, successfully addresses the low operating efficiency and high energy consumption issues of variable-speed pump units in existing technologies, achieving significant technological progress. These innovations not only improve the operating efficiency and energy consumption control of pump units, but also provide strong support for the green development of industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0073] Figure 1 This is a flow chart of a method for determining an optimization range and energy consumption curve of a variable speed pump unit provided by an embodiment of the present invention;

[0074] Figure 2 This is a structural block diagram of a system for determining an optimization range and energy consumption curve of a variable speed pump unit provided by an embodiment of the present invention;

[0075] Figure 3 is a performance curve diagram of a pump provided by an embodiment of the present invention;

[0076] Figure 4 is a graph at different speeds provided by an embodiment of the present invention;

[0077] Figure 5 is a graph provided by an embodiment of the present invention;

[0078] Figure 6 This is a flow-power curve diagram of a pump unit provided by an embodiment of the present invention;

[0079] Figure 7 This is a schematic diagram of the shape of the speed regulation minimum energy consumption line of a certain type of pump provided by an embodiment of the present invention;

[0080] In the figure: 1. Curve fitting module; 2. Speed ​​curve acquisition module; 3. Energy consumption curve acquisition module. DETAILED DESCRIPTION

[0081] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0082] In view of the problems existing in the prior art, the present invention provides a method and system for determining the optimization range and energy consumption curve of a variable speed pump unit. The present invention is described in detail below with reference to the accompanying drawings.

[0083] like Figure 1 As shown, the method for determining the optimization range and energy consumption curve of a variable speed pump unit provided by an embodiment of the present invention includes the following steps:

[0084] S101, fitting the rated speed curve of the pump to obtain a quartic equation;

[0085] S102, obtain the curves at other speeds through the impeller cutting law;

[0086] S103, using a graphical method to obtain an energy consumption curve of the pump.

[0087] like Figure 2 As shown, the system for determining the optimization range and energy consumption curve of a variable speed pump unit provided by an embodiment of the present invention includes:

[0088] Curve fitting module 1, used for fitting the rated speed curve of the pump to obtain a quartic equation;

[0089] Speed ​​curve acquisition module 2, used to obtain curves at other speeds through the impeller cutting law;

[0090] The energy consumption curve acquisition module 3 is used to obtain the energy consumption curve of the pump using a graphical method.

[0091] The technical solution of the present invention is further described below with reference to specific embodiments.

[0092] 1. The optimization range and energy consumption curve determination method of the variable speed pump unit provided by the present invention can find the energy consumption curve and find the optimal energy consumption point on it. According to the definition of the energy consumption curve, the energy consumption curve of the variable speed pump unit is the set of points where the energy consumption is minimized by adjusting the speed under a certain flow rate while meeting the system's required pressure. The present invention assumes that the centrifugal pump fully complies with the impeller cutting law, and in actual operation, it does not conform to the centrifugal pump's speed reduction formula;

[0093]

[0094] 2. Content

[0095] 1. For any pump performance curve, there is an initial curve at a certain speed, which is also the rated speed curve (see Figure 3 ).

[0096] 2. By fitting this curve, a fourth-order equation can be obtained. In most cases, the flow-head curve can be calculated using a sixth-order formula with coefficients set to a maximum of 12 decimal places to meet the requirements.

[0097] H=f(Q)=gQ 6+fQ 5 +eQ 4 +dQ 3 +cQ 2 +bQ+a

[0098] The accuracy of the above pump using a quartic equation is sufficient (R 2 =1).

[0099] 3. For different speeds, the impeller cutting law can be used. Of course, the curves at other speeds can also be calculated and self-learned (see Figure 4 ).

[0100] 4. Let me reiterate here that, as can be seen from the graph, as the speed decreases, the flow head line decreases in parallel. The actual situation is quite different. The pump must be calibrated through self-learning and its parameters must be continuously corrected in subsequent work. The calculation data here is only used for data analysis and examples.

[0101] 5. Formation of energy consumption curve

[0102] 1) According to the definition of the energy consumption curve of the variable speed unit, the energy consumption curve is the set of operating points with minimum power under the condition of meeting the system required pressure p at all speeds.

[0103] 2) According to the derivation of flow rate-specific work, we only need to find the maximum flow point on the flow rate-head curve that meets the pressure conditions, which is the minimum energy consumption point at this speed. Connecting the minimum energy consumption points of each speed will give us the energy consumption curve.

[0104] 3) In the above case, the analytical expression of the different speed curves is:

[0105] p n1 =f(Q), n1=1480

[0106] p n2 =f(Q), n2=921.5

[0107] …

[0108] p n9 =f(Q), n9=630.5

[0109] 4) Since p is known, Q is calculated by substituting the inverse function of the above function into p.

[0110] Q n1 =g(p), n1=1480

[0111] Q n2 =g(p), n2=921.5

[0112] …

[0113] p n9 =f(Q), n9=630.5

[0114] When the head is brought into each speed, the flow rate relative to the pressure at each speed is calculated, which are Q n1 , Q n2 ,…Q n9 .

[0115] 5) For the graphical method, the curve is as follows Figure 5 shown.

[0116] Therefore, for the above curve graph, the present invention can mark the lift in the form of a red line in the above graph, and the curve part on the right side of the line is the range that can be met.

[0117] 6) The intersection of the lift line and the flow-pressure line at each speed is the maximum flow allowable point Q under a certain speed condition. max，ni .

[0118] The analytical method is to ni =f(Q) ni The inverse function Q max,ni =g(p) ni (n i For different speeds), substitute the system required pressure p and calculate the corresponding Q max，ni .

[0119] 7) By calculating the Q at each speed max，ni Point, into the pump unit flow rate at each speed - power curve, calculate the power P at this flow rate ni .

[0120] That is, in P ni =f(Q) ni Substitute Q max，ni , calculate P ni .

[0121] 8) If Figure 6 As shown, connect all the power points above to form a curve. This curve is the minimum energy consumption line that can be achieved by adjusting the pump speed under the variable frequency condition and the parameter conditions required by the system.

[0122] 9) In the analytical solution, the flow rate Q is listed max，ni and P ni , and then fit the curve.

[0123] Table 1 Curve fitting data

[0124] Serial number 1 2 3 4 … n <![CDATA[Flow rate (Q max，ni )]]> <![CDATA[Q max，1 ]]> <![CDATA[Q max，2 ]]> <![CDATA[Q max，3 ]]> <![CDATA[Q max，3 ]]> … <![CDATA[Q max，n ]]> <![CDATA[Power (P ni )]]> <![CDATA[P n1 ]]> <![CDATA[P n2 ]]> <![CDATA[P n3 ]]> <![CDATA[P n3 ]]> … <![CDATA[P nn ]]>

[0125] P min =f(Q)

[0126] Figure 7 It is the shape of the minimum energy consumption line for speed regulation of a certain type of pump.

[0127] 10) The top point of the curve, that is, the maximum point, must be the flow rate-power point at maximum speed (no deceleration).

[0128] 11) The lowest point on the curve, also known as the minimum point...

[0129] Example 1: Energy Consumption Optimization of Variable Speed ​​Pumps in Urban Water Supply Systems

[0130] In urban water supply systems, pumping stations must adjust water supply based on fluctuating user demand. Traditional, fixed-speed pumps struggle to flexibly respond to fluctuations in water demand, resulting in high energy consumption. Introducing variable-speed pumps and optimizing their energy consumption can significantly improve system energy efficiency and reduce operating costs.

[0131] 1. Data Collection and Analysis:

[0132] Collect flow-head curve and flow-power curve data of variable speed pumps at different speeds.

[0133] Using Internet of Things technology and sensors, the operating data of the pump station, including flow, pressure, power and other parameters, can be monitored in real time.

[0134] 2. Model building:

[0135] Based on the collected data, a multivariate regression model of flow-power relationship was established using a machine learning algorithm.

[0136] Simulation technology is used to simulate the operation of the pump under different working conditions and analyze its energy consumption characteristics.

[0137] 3. Optimization algorithm design:

[0138] Develop a control strategy based on dynamic programming and optimization algorithm to adjust the pump speed in real time to meet the optimal energy consumption point under different water demand.

[0139] Utilize deep reinforcement learning algorithms to automatically learn and optimize the operating strategies of water supply pumps, continuously improving energy efficiency.

[0140] 4. System integration and implementation:

[0141] Integrate the optimization algorithm into the pump station's automated control system to achieve real-time monitoring and dynamic adjustment.

[0142] In actual operation, the pump's energy consumption data is monitored and optimized over a long period of time through cloud platforms and big data analysis.

[0143] 5. Results and benefits:

[0144] Through optimization, the overall energy consumption of the water supply system is significantly reduced and the water supply efficiency is improved.

[0145] Operating costs are reduced while the reliability and stability of water supply are improved.

[0146] Example 2: Energy Consumption Optimization of Variable Speed ​​Pumps in Industrial Cooling Systems

[0147] In large industrial facilities, cooling systems require constant regulation of cooling water flow and pressure to maintain normal equipment operation. Variable speed pumps provide flexible adjustments to the cooling water supply in this application, but energy consumption remains high if not optimized. Through system optimization, efficient cooling system operation can be achieved.

[0148] 1. Data Collection and Analysis:

[0149] Install flow meters, pressure sensors and power meters to collect real-time data of variable speed pumps under different operating conditions.

[0150] Establish a database to store data such as flow, head, power, etc. under different working conditions, and perform data analysis and feature extraction.

[0151] 2. Model building:

[0152] Based on the collected data, a multiple regression model was established to describe the relationship between flow and power.

[0153] Use simulation software to simulate the operation of the pump at different speeds and analyze its energy consumption curve and performance characteristics.

[0154] 3. Optimization algorithm design:

[0155] Develop an optimization strategy based on linear programming and genetic algorithms to dynamically adjust the pump speed and achieve optimal energy consumption.

[0156] Applying predictive control algorithms, pump operating parameters are adjusted in advance based on future cooling demand estimates, improving system response speed and energy efficiency.

[0157] 4. System integration and implementation:

[0158] The optimization algorithm is embedded into the PLC (Programmable Logic Controller) of the cooling system to achieve automated control and real-time optimization.

[0159] The human-machine interface (HMI) and monitoring system display the pump's operating status and energy consumption in real time, facilitating operation and maintenance.

[0160] 5. Results and benefits:

[0161] The optimized cooling system significantly reduces energy consumption and improves cooling efficiency.

[0162] By reducing energy consumption, the operating costs of industrial facilities are reduced, the life of equipment is extended, and the environmental impact is reduced.

[0163] The above two examples demonstrate that energy consumption optimization for variable speed pumps has significant energy-saving and economic benefits across various industrial applications. These optimization methods and technologies not only improve system efficiency but also provide strong support for sustainable business development.

[0164] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. Those skilled in the art will appreciate that the above-mentioned devices and methods can be implemented using computer-executable instructions and / or contained in processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, or can be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0165] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for determining the optimization range and energy consumption curve of a variable speed pump unit, characterized in that: include: The rated speed curve is obtained and fitted, and the energy consumption curve is obtained using the impeller cutting law and graphical method.

2. The method for determining the optimization range and energy consumption curve of a variable speed pump unit according to claim 1, characterized in that: The method for determining the optimization range and energy consumption curve of the variable speed pump unit comprises the following steps: Step 1: Fit the rated speed curve of the pump to obtain a quartic equation; Step 2: Obtain the curves at other speeds through the impeller cutting law; Step three, use the graphical method to obtain the energy consumption curve of the pump.

3. The method for determining the optimization range and energy consumption curve of a variable speed pump unit according to claim 1, characterized in that: The method for determining the optimization range and energy consumption curve of the variable speed pump unit also includes: The centrifugal pump fully complies with the impeller cutting law, and does not conform to the centrifugal pump speed reduction formula during actual operation; 4. The method for determining the optimization range and energy consumption curve of a variable speed pump unit according to claim 2, wherein: In the step 1, the initial curve of the pump at a certain speed is the rated speed curve; By fitting the curve, we get a quartic equation: H=f(Q)=gQ 6 +fQ 5 +eQ 4 +dQ 3 +cQ 2 +bQ+a; In most cases, the flow-head curve uses the sixth power formula at most, and the coefficient is set to 12 decimal places at most. 2 =1.

5. The method for determining the optimization range and energy consumption curve of a variable speed pump unit according to claim 2, wherein: In the step 2, for different rotational speeds, the curves of the pump at other rotational speeds can be obtained through calculation and self-learning, and the parameter values ​​can be calibrated and corrected through the self-learning of the pump.

6. The method for determining the optimization range and energy consumption curve of a variable speed pump unit according to claim 2, characterized in that: The formation of the energy consumption curve in step 3 includes: (1) According to the definition of the energy consumption curve of a variable speed unit, the energy consumption curve is the set of operating points with the minimum power under the condition of meeting the system required pressure p at all speeds; (2) According to the derivation of flow rate-specific work, the maximum flow rate point that meets the pressure conditions on the flow rate-head curve is the minimum energy consumption point under the speed. The minimum energy consumption points of each speed are connected to obtain the energy consumption curve; (3) The analytical method for the different speed curves is: p n1 =f(Q),n1=1480 p n2 =f(Q), n2 =921.5 … p n9 =f(Q),n9=630.5; (4) Since p is known, find Q and use the inverse function to substitute into p to calculate Q; Q n1 =g(p),n1=1480 Q n2 =g(p),n2=921.5 … p n9 =f(Q),n9=630.5 When the head is brought into each speed, the flow rate relative to the pressure at each speed is calculated, which are Q n1 , Q n2 ,…Q n9 ; (5) The intersection of the lift line and the flow-pressure line at each speed is the maximum flow allowable point Q under a certain speed condition. max，ni ; The analytical method is in p ni =f(Q) ni The inverse function Q max,ni =g(p) ni Substitute the system required pressure p into the equation and calculate the corresponding Q max，ni , n i For different speeds; (6) By calculating Q at each speed max，ni Point, into the pump unit flow rate at each speed - power curve, calculate the power P under the flow rate ni ; In P ni =f(Q) ni Substitute Q max，ni , calculate P ni ; (7) Connect all power points to form a curve, which is the minimum energy consumption line achieved by adjusting the pump speed under variable frequency conditions and the parameter conditions required by the system; (8) In the analytical solution, list the flow rate Q max，ni and P ni , and fit the curve; P min =f(Q); Among them, the top point of the curve is the maximum point, which is the flow rate at maximum speed - the point on power; the bottom point of the curve is the minimum point.

7. A system for determining an optimization range and energy consumption curve of a variable speed pump unit using the method for determining an optimization range and energy consumption curve of a variable speed pump unit according to any one of claims 1 to 6, characterized in that: The system for determining the optimization range and energy consumption curve of the variable speed pump unit includes: Curve fitting module, used to fit the rated speed curve of the pump to obtain a quartic equation; Speed ​​curve acquisition module, used to obtain curves at other speeds through the impeller cutting law; The energy consumption curve acquisition module is used to obtain the energy consumption curve of the pump using a graphical method.

8. A computer device, characterized in that: The computer device includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps: The rated speed curve is obtained and fitted, and the energy consumption curve is obtained using the impeller cutting law and graphical method.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor performs the following steps: The rated speed curve is obtained and fitted, and the energy consumption curve is obtained using the impeller cutting law and graphical method.

10. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the optimization range and energy consumption curve determination system of the variable speed pump unit as described in claim 7.

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