Water pump apparatus and liquid flow determination method

Abstract

The application discloses a water pump device and a liquid flow determination method, and relates to the technical field of water pumps. The water pump device comprises a water pump motor and a controller connected with the water pump motor. The water pump motor is configured to convert electric energy into mechanical energy and transmit liquid based on the mechanical energy. The controller is configured to: acquire an actual rotating speed and an actual motor power of the water pump motor; determine a lift status of the water pump motor based on the actual rotating speed; the lift status is used to describe the ability of the water pump motor to lift liquid when working at the actual rotating speed; determine an actual equivalent lift of the water pump motor according to the lift status; and determine the liquid flow based on the actual equivalent lift and the actual motor power. Based on the above water pump device, the liquid flow can be determined without the aid of additional hardware devices such as flow meters and flow sensors, thereby reducing the hardware cost.

Description

Technical Field

[0001] This application relates to the field of water pump technology, and in particular to a water pump device and a method for determining liquid flow rate. Background Technology

[0002] In modern and civilian applications, water pumps are crucial equipment for transporting fluids, and accurate estimation of liquid flow rate and efficient control of the pumps are of paramount importance. For example, in scenarios such as water supply systems, cooling circulation, and agricultural irrigation, determining the liquid flow rate and rationally controlling the operating status of the water pumps are of great significance for ensuring stable system operation and improving energy efficiency.

[0003] Currently, accurate estimation of liquid flow rate in water pump equipment is typically achieved using additional hardware devices such as flow meters and flow sensors. However, installing multiple flow meters to monitor liquid flow at different locations increases hardware costs; furthermore, during long-term use, flow meters are susceptible to the effects of impurities and corrosion in the fluid, leading to decreased measurement accuracy or equipment failure, requiring frequent maintenance and component replacement. Summary of the Invention

[0004] This application provides a water pump device and a method for determining liquid flow rate, which can determine liquid flow rate without the need for additional hardware devices such as flow meters and flow sensors, thereby reducing hardware costs.

[0005] In a first aspect, a water pump device is provided, comprising:

[0006] A water pump motor is configured to convert electrical energy into mechanical energy and to transport liquid based on that mechanical energy.

[0007] The controller connected to the water pump motor is configured as follows:

[0008] Obtain the actual speed and actual power of the water pump motor;

[0009] The head state of the water pump motor is determined based on the actual rotational speed; the head state describes the ability of the water pump motor to lift liquid when operating at its actual rotational speed.

[0010] Determine the actual equivalent head of the pump motor based on the head condition;

[0011] The liquid flow rate is determined based on the actual equivalent head and the actual motor power.

[0012] In the above technical solution, the liquid flow rate is determined by directly obtaining the actual speed and power of the water pump motor. This avoids the problems of measurement errors and equipment damage caused by impurities and corrosion, which are common in traditional flow meter monitoring of liquid flow rate. This ensures data accuracy and reduces hardware costs. Furthermore, since the speed of the water pump motor typically varies under different head loads, the head state of the water pump motor at its actual speed can be determined based on the relationship between the motor speed and head, thus describing the pump motor's ability to lift liquid when operating at its actual speed. This allows for the calculation of the actual equivalent head of the water pump motor, revealing its actual load conditions. Consequently, determining the liquid flow rate based on the actual equivalent head and actual motor power comprehensively considers both the pump motor's load and its work capacity, improving the accuracy of liquid flow rate determination.

[0013] In one embodiment, the controller determines the pump motor head state based on the actual rotational speed and is configured as follows:

[0014] If the actual rotational speed is less than the preset rotational speed, the head state is determined to be high head state;

[0015] If the actual rotational speed is equal to the preset rotational speed, then the head state is determined to be low head state.

[0016] In the above technical solution, if the actual speed of the water pump motor cannot reach the preset speed during actual operation, it can be considered that the pump motor's head state is already in a high-head state, hindering the actual speed of the pump motor from rising to the preset speed. That is, the pump motor needs to output sufficient torque to overcome the high load. Conversely, if the actual speed reaches the preset speed, it can be considered that the pump motor's head state is in a low-head state, not hindering the actual speed of the pump motor from rising to the preset speed. That is, the pump motor does not need to overcome the high load. Furthermore, based on the comparison between the preset speed and the actual speed, the head state of the water pump motor can be conveniently and accurately determined, and the load condition of the water pump motor can be understood.

[0017] In one embodiment, the controller determines the actual equivalent head of the pump motor based on the head status and is configured as follows:

[0018] If the head condition is high head condition, then determine the first ratio of the actual speed to the preset speed;

[0019] The product of the first ratio and the preset equivalent head corresponding to the preset rotational speed is determined as the actual equivalent head.

[0020] In the above technical solution, in actual situations, if the actual speed has not yet reached the preset speed, it can be assumed that the water pump motor still has a certain output potential, and can overcome the additional resistance brought by the high head by outputting a larger load, thereby increasing the actual speed to the preset speed. Furthermore, according to the working principle of the water pump motor, within a certain range, the head of the water pump motor can increase with the increase of the speed. Therefore, by multiplying the ratio (first ratio) reflecting the current actual speed relative to the ideal preset speed by the preset equivalent head, the actual equivalent head that conforms to the actual working condition of the water pump motor in the current high head state and working scenario where the actual speed is lower than the preset speed can be determined.

[0021] In one embodiment, the controller determines the actual equivalent head of the pump motor based on the head status and is configured as follows:

[0022] If the head state is low head state, then determine the target power range where the actual motor power is located, and the initial equivalent head corresponding to the target power range;

[0023] The initial equivalent head is corrected based on the actual motor power and the target power range to determine the actual equivalent head.

[0024] In the above technical solution, since the actual motor power can reflect the working state of the water pump motor in real time, different power values ​​correspond to different operating intensities and conditions of the water pump motor. By comprehensively considering the specific position of the actual motor power within the target power range, as well as the system operating characteristics implied by the target power range, the initial equivalent head can be adjusted accordingly. Furthermore, based on the above correction method, the differences in actual operation can be fully considered, so that the final determined actual equivalent head closely matches the actual working condition of the water pump motor under low head conditions.

[0025] In one embodiment, the controller corrects the initial equivalent head based on the actual motor power and the target power range to determine the actual equivalent head, and is configured as follows:

[0026] Determine the power difference between the actual motor power and the minimum value in the target power range;

[0027] The difference between the initial equivalent head and the power difference is determined as the actual equivalent head.

[0028] In the above technical solution, the power difference can intuitively show the deviation between the actual motor power of the water pump motor and the lower limit of the target power range, reflecting situations such as the water pump motor exceeding or falling short of its work. Furthermore, the water pump motor typically needs to output a certain power to achieve a specific head. Therefore, obtaining the actual equivalent head by subtracting the initial equivalent head from the determined power difference allows the obtained actual equivalent head to better match actual operating conditions.

[0029] In one embodiment, the controller, which determines the liquid flow rate based on the actual equivalent head and the actual motor power, is configured as follows:

[0030] Based on the actual motor power, power efficiency factor, and torque efficiency factor, the actual effective energy of the water pump motor to drive the water flow is determined.

[0031] The liquid flow rate is determined based on the actual effective energy and the actual equivalent head.

[0032] In the above technical solution, the actual effective energy of the water pump motor driving the water flow is determined based on the actual motor power, power efficiency factor, and torque efficiency factor. This allows for an accurate assessment of the water pump motor's work capacity, taking into account the losses when the water pump motor converts electrical energy into mechanical energy. Therefore, when determining the liquid flow rate based on the actual effective energy and the actual equivalent head, the method of determining the liquid flow rate can be more scientific and reasonable, conforming to the principles of energy conservation and fluid mechanics.

[0033] In one embodiment, the liquid flow rate is determined based on the actual effective energy and the actual equivalent head, and is configured as follows:

[0034] The second ratio of effective energy to actual equivalent head is determined as the liquid flow rate.

[0035] In the above technical solution, the actual effective energy refers to the energy actually used by the pump motor to propel the water flow, and the actual equivalent head refers to the total resistance that the water needs to overcome during the flow process. Furthermore, the head is related to the kinetic energy of the water, which in turn is related to the liquid flow rate. Therefore, based on fluid mechanics principles, determining the liquid flow rate using the ratio of effective energy to actual equivalent head can achieve high accuracy and practicality.

[0036] In a second aspect, a method for determining liquid flow rate is provided, applied to a water pump device as described in the first aspect. The water pump device includes a water pump motor configured to convert electrical energy into mechanical energy and to transfer liquid based on the mechanical energy. The method for determining liquid flow rate includes:

[0037] Obtain the actual speed and actual power of the water pump motor;

[0038] The head state of the water pump motor is determined based on the actual rotational speed; the head state describes the ability of the water pump motor to lift liquid when operating at its actual rotational speed.

[0039] Determine the actual equivalent head of the pump motor based on the head condition;

[0040] The liquid flow rate is determined based on the actual equivalent head and the actual motor power.

[0041] Thirdly, a computer-readable storage medium is provided, which stores a computer program that, when run by a water pump device, causes the water pump device to perform the liquid flow determination method of the second aspect.

[0042] Fourthly, a computer program product is provided, comprising: a computer program that, when run by a water pump device, causes the water pump device to execute the liquid flow determination method of the second aspect.

[0043] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure of an air conditioning system provided in one embodiment of this application;

[0045] Figure 2 This is a timing interaction diagram of a liquid flow determination method in a water pump device according to an embodiment of this application;

[0046] Figure 3 This is a schematic diagram illustrating one implementation method for determining the actual equivalent head in a liquid flow determination method provided in an embodiment of this application;

[0047] Figure 4 This is a schematic diagram illustrating one implementation method for determining the actual equivalent head in a liquid flow determination method provided in another embodiment of this application. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; "and / or" in this text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0049] Hereinafter, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0050] Specific details, such as particular system architectures and techniques, are set forth for illustrative purposes and not for limitation, to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted to avoid unnecessary detail that could obscure the description of this application.

[0051] The water pump equipment provided in this application can be applied to various scenarios, such as water supply systems, cooling circulation, and agricultural irrigation. For example, the water pump equipment, water pipes, and water purification facilities can form a water supply system; the water pump equipment, cooling equipment, heat exchangers, pipes, valves, and mechanical devices requiring cooling can form a cooling circulation system; and the water pump equipment, water pipes, pressure regulating devices, valves, and sprinkler irrigation devices can form an irrigation system.

[0052] As an example, consider an air conditioning system within a cooling circulation system, see [link to relevant documentation]. Figure 1 , Figure 1 This is a schematic diagram of an air conditioning system provided in an embodiment of this application. The air conditioning system includes: a temperature control device 10 for controlling the operating mode of the air conditioner, which includes, but is not limited to, a compressor, an outdoor fan, and an indoor fan; and a water pump device 20 for discharging water generated during the operation of the air conditioner, which includes, but is not limited to, a controller, a water pump motor, a water receiving pan, a drain pipe, a high water level switch, and a low water level switch.

[0053] In the aforementioned scenarios, water pumps are key equipment for transporting fluids, and accurate estimation of liquid flow rate and efficient control of the pumps are crucial. For example, determining the liquid flow rate and rationally controlling the operating status of the pump motor are of great significance for ensuring stable system operation and improving energy efficiency.

[0054] Currently, accurate estimation of liquid flow rate in water pump equipment is typically achieved using additional hardware devices such as flow meters and flow sensors. However, installing multiple flow meters to monitor liquid flow at different locations increases hardware costs; furthermore, during long-term use, flow meters are susceptible to the effects of impurities and corrosion in the fluid, leading to decreased measurement accuracy or equipment failure, requiring frequent maintenance and component replacement.

[0055] Therefore, to determine liquid flow rate without the need for additional hardware such as flow meters and flow sensors, this application provides a water pump device and a method for determining liquid flow rate. By directly obtaining the actual rotational speed and actual motor power of the water pump motor to determine the liquid flow rate, it avoids the problems of measurement errors and equipment damage caused by impurities and corrosion, which are common in traditional flow meter monitoring of liquid flow rate. This ensures data accuracy and reduces hardware costs. Furthermore, since the rotational speed of the water pump motor usually changes under different head loads, the head state of the water pump motor at the actual rotational speed can be determined based on the relationship between the rotational speed and the head, thus describing the water pump motor's ability to lift liquid when operating at the actual rotational speed. In this way, the actual equivalent head of the water pump motor can be calculated, and the actual load condition of the water pump motor can be understood. Therefore, determining the liquid flow rate based on the actual equivalent head and actual motor power can comprehensively consider the load condition and work capacity of the water pump motor, thereby improving the accuracy of liquid flow rate determination.

[0056] To facilitate a further understanding of the technical solutions in some embodiments of this application, the technical solutions of the water pump equipment and the liquid flow determination method, as well as how these technical solutions solve the aforementioned technical problems, are described in detail below with reference to some specific embodiments and accompanying drawings. The embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application.

[0057] In one embodiment, the pump device may include a pump motor and a controller connected to the pump motor. The pump motor is configured to convert electrical energy into mechanical energy and to transport liquid based on the mechanical energy. For example, when the pump motor is running, it can pump water from the receiving pan to a drain pipe and discharge it through the drain pipe.

[0058] In one embodiment, the liquid is a fluid substance that can flow in a pipeline or other transport system under the action of a water pump motor. The liquid includes, but is not limited to, water, alcohol, milk, and pharmaceutical solutions.

[0059] Furthermore, the aforementioned controller can be based on a three-phase six-switch hardware inverter topology circuit to realize the variable frequency drive operation of the water pump equipment. For example, in terms of drive control strategy, the controller can adopt dual closed-loop control, which is further subdivided into power control and speed control, and the liquid flow rate is determined according to the actual situation of the water pump motor head.

[0060] Specifically, the three-phase six-switch hardware inverter topology circuit provides variable frequency drive power support for the water pump equipment. The controller can regulate power and speed according to a dual closed-loop control strategy to ensure stable operation of the water pump equipment. During this process, information such as the pump motor's current, power, and speed can be fed back to the controller in real time. Based on this information, the controller can monitor the current liquid flow rate.

[0061] To further describe the method for determining liquid flow rate, please refer to [link to relevant documentation]. Figure 2 , Figure 2 This is a timing interaction diagram of a liquid flow determination method in a water pump device according to an embodiment of this application, as shown below. Figure 2 As shown, the controller is configured to perform the following steps:

[0062] S210: Obtain the actual speed and actual power of the water pump motor.

[0063] In one embodiment, the aforementioned actual rotational speed refers to the number of revolutions per minute (r / min) of the rotor of the water pump motor during actual operation, typically expressed in revolutions per minute (r / min). The actual rotational speed reflects the operating speed of the water pump motor-driven equipment and can be used to measure the operating status of the water pump motor.

[0064] In one embodiment, the water pump equipment may be equipped with a speed sensor to obtain the actual speed; or, the actual speed may be determined based on the controller feedback function. In this embodiment, the method of obtaining the actual speed is not limited.

[0065] For example, a speed sensor can be installed on the shaft end of a water pump motor to detect changes in the magnetic field, photoelectric signals, or mechanical pulses generated when the water pump motor rotates. The detected signals are then converted into electrical signals and processed to obtain the actual rotational speed. For instance, a photoelectric speed sensor can calculate the rotational speed by detecting changes in the amount of light obstructed and transmitted when a code disk mounted on the water pump motor shaft rotates.

[0066] The aforementioned actual motor power refers to the electrical power consumed or the mechanical power output by the water pump motor during actual operation. The actual motor power reflects the energy conversion and utilization of the water pump motor during operation, and can be used to assess the pump motor's efficiency, load capacity, and energy consumption.

[0067] In one embodiment, the water pump equipment can determine the actual electrical power based on a power analyzer, or calculate the actual electrical power based on water pump motor parameters and operating data, without limitation.

[0068] For example, the measurement probe of a power analyzer can be connected to the power input terminal of a water pump motor to measure information such as the motor's voltage, current, and phase difference between them. The actual electrical power can then be calculated using this information.

[0069] S220. Determine the head status of the water pump motor based on the actual rotational speed.

[0070] In one embodiment, the aforementioned head state describes the pump motor's ability to lift liquid and its operating state when operating at its actual speed. Specifically, the head state reflects the pump motor's overall performance in overcoming liquid resistance and lifting the liquid to a certain height.

[0071] In one embodiment, the aforementioned head state includes, but is not limited to, normal head state, low head state, and high head state, etc., and there is no limitation thereto.

[0072] The normal head condition refers to the operating state of the water pump motor under its design conditions, where it can stably and efficiently lift the liquid to the expected height. At this time, all performance indicators of the water pump motor are within the ideal range. For example, flow rate and power meet design requirements, and the operation is smooth and highly efficient.

[0073] Low head condition means that the pump motor actually lifts the liquid to a height lower than the normal head during operation. Typically, under low head conditions, the pump motor's flow rate will increase, and the motor's power consumption may change accordingly.

[0074] High head operation means that the pump motor needs to overcome resistance higher than its design head to lift the liquid to a height exceeding the design expectation. Typically, under high head conditions, the flow rate of liquid transmitted by the pump motor will decrease, and the pump motor may be at risk of overload because it needs to output more power to overcome the resistance.

[0075] For ease of explanation, this embodiment will be described using high head and low head states as examples.

[0076] In one embodiment, the controller can determine the head status based on a pressure sensor. For example, a pressure sensor is installed at the outlet of the pump equipment or at the piping system to measure hydraulic pressure (e.g., water pressure). It is understood that, according to fluid mechanics principles, there is a direct relationship between water pressure and head: H = P / (ρg), where P is the pressure, ρ is the density of water, and g is the acceleration due to gravity.

[0077] Based on this, the actual water pressure P can be measured using a pressure sensor to calculate the actual head value. Finally, the head state is determined based on the difference between the actual head value and a preset value. For example, if the actual head value is less than the preset value, the head state is considered low. Otherwise, if the actual head value is greater than the preset value, the head state is determined to be high. And, if the actual head value equals the preset value, the head state is determined to be normal.

[0078] It should be noted that determining the head status using the above method requires the installation of additional hardware. Therefore, to reduce hardware costs, the controller can also determine the head status based on the actual rotational speed.

[0079] For example, since there is usually a certain correlation between the actual speed of a water pump motor and its head, the head state can be determined based on the water pump motor performance curve. For example, the actual speed of the water pump motor can be obtained, and the head corresponding to the actual speed can be determined from a preset water pump motor performance curve to determine the head state.

[0080] However, it should be noted that determining the head state using the aforementioned pump motor performance curve requires extensive prior experiments and data collection to establish the pump motor performance curve. The accuracy of this established performance curve depends heavily on the quality and coverage of the experimental data, and typically requires a significant amount of time.

[0081] Therefore, in order to conveniently and accurately determine the head status of the water pump motor, the controller can determine the head status as high head when the actual speed is less than the preset speed. Otherwise, when the actual speed is equal to the preset speed, the head status is determined as low head.

[0082] It should be noted that, unlike conventional judgment methods, in this embodiment, if the actual speed of the water pump motor cannot reach the preset speed during operation, it can be considered that the water pump motor's head state is already in a high-head state, preventing the actual speed of the water pump motor from rising to the preset speed. That is, the water pump motor needs to output sufficient torque to overcome the high load. Conversely, if the actual speed reaches the preset speed, it can be considered that the water pump motor's head state is in a low-head state, not preventing the actual speed of the water pump motor from rising to the preset speed. That is, the water pump motor does not need to overcome the high load. Therefore, based on the comparison between the preset speed and the actual speed, the head state of the water pump motor can be conveniently and accurately determined, and the load situation of the water pump motor can be understood.

[0083] The preset speed can be set according to actual conditions and is not limited thereto. For example, the preset speed can be the expected speed that the water pump motor will reach during normal operation. Based on this, in this case, when the actual speed of the water pump motor reaches the preset speed, the controller usually stops increasing the actual speed.

[0084] Understandably, during the operation of a water pump motor, the preset speed is an ideal operating speed value set based on actual working conditions. If the speed is further increased after the water pump motor reaches the preset speed, it will not only fail to bring any additional benefits to the operation of the water pump equipment, but may also cause energy waste, overheating, and other malfunctions.

[0085] Based on this, in this embodiment, the actual rotational speed is divided into two cases: less than the preset rotational speed or equal to the preset rotational speed.

[0086] S230. Determine the actual equivalent head of the pump motor based on the head condition.

[0087] In one embodiment, the aforementioned actual equivalent head is an actual head that takes into account many factors when the pump motor is working. It represents the effective lifting height of the pump motor after overcoming various resistances in the entire process from the inlet to the outlet.

[0088] The controller can determine the actual equivalent head based on the method for determining the head state in S220 above. For example, the actual head value (i.e., the actual equivalent head) can be calculated by measuring the actual water pressure P using a pressure sensor. Alternatively, the actual equivalent head can be determined based on the pump motor performance curve. In this embodiment, the method for determining the actual equivalent head is not limited.

[0089] Based on the above explanation of head conditions, it is clear that the load on the pump motor typically differs significantly under different head conditions. Furthermore, the head condition directly relates to the actual operating condition of the pump motor. Therefore, if the actual equivalent head is determined directly using the above method without considering the head condition, it is impossible to comprehensively consider the load characteristics of the pump motor under different lifting heights and resistance conditions. Consequently, it is difficult to accurately reflect the true operating state of the pump motor, thus affecting the accuracy of the actual equivalent head.

[0090] Therefore, in order to improve the accuracy of the actual equivalent head, the controller can determine the actual equivalent head using different methods for different head conditions. For example, the controller can determine the actual equivalent head based on, for instance, the following: Figure 3 The steps S310-S320 shown are used to determine the actual equivalent head. Details are as follows:

[0091] S310. If the head state is high head state, then determine the first ratio between the actual speed and the preset speed.

[0092] S320. The product of the first ratio and the preset equivalent head corresponding to the preset speed is determined as the actual equivalent head.

[0093] In one embodiment, the aforementioned preset equivalent head is a head-related value pre-set under specific conditions. These specific conditions include, but are not limited to, preset rotational speed, pipeline parameters, etc., which will not be described in detail.

[0094] It should be noted that at high head conditions, the resistance to water flow increases significantly, leading to a greater load on the pump motor. In this situation, the pump motor needs to output more torque to drive its operation. However, in practice, if the actual speed has not yet reached the preset speed, it can be assumed that the pump motor still has some output potential and can overcome the additional resistance caused by the high head by outputting a larger load, thereby increasing the actual speed to the preset speed.

[0095] Furthermore, based on the working principle of water pump motors, it is known that the rotational speed is closely related to the pump motor's head. For example, under normal circumstances, within a certain range, the pump motor's head can increase with the increase of rotational speed. Therefore, when the rotational speed is lower than the preset rotational speed, the actual equivalent head will also be lower than the preset equivalent head.

[0096] Based on this, by multiplying the ratio of the current actual speed to the ideal preset speed (the first ratio) with the preset equivalent head, the actual equivalent head that conforms to the actual working condition of the water pump motor can be determined in the current high head state and working scenario where the actual speed is lower than the preset speed.

[0097] In another embodiment, the controller can also be based on, for example... Figure 4 The steps S410-S420 shown are used to determine the actual equivalent head. Details are as follows:

[0098] S410. If the head state is low head state, then determine the target power range where the actual motor power is located, and the initial equivalent head corresponding to the target power range.

[0099] S420: Based on the actual motor power and the target power range, the initial equivalent head is corrected to determine the actual equivalent head.

[0100] In one embodiment, the controller can pre-set multiple power ranges and an initial equivalent head corresponding to each power range. In this case, the power range in which the actual motor power falls is the target power range. Dividing the actual motor power into specific ranges helps the controller more accurately analyze and process power-related parameters.

[0101] As an example, the power range mentioned above can be: [Pm1, Pmax], [Pm2, Pm1), [Pm3, Pm2). Where Pmax > Pm1 > Pm2 > Pm3, and the unit is W. The corresponding initial equivalent heads can be: Hm1 for [Pm1, Pmax], Hm2 for [Pm2, Pm1), and Hm3 for [Pm3, Pm2). The unit of the initial equivalent head can be cm.

[0102] Wherein, Pmax can be the maximum power that the water pump motor can achieve during operation, and Pm1, Pm2, and Pm3 can be set according to actual conditions, without limitation. For example, Pm3 can be the minimum power required for the water pump motor to operate.

[0103] In one embodiment, the above-mentioned correction method includes, but is not limited to, correction using mathematical models or empirical formulas. For example, the initial equivalent head can be adjusted according to the ratio between the actual motor power and the upper and lower limits of the target power range to obtain the actual equivalent head.

[0104] It should be noted that since the actual motor power reflects the working state of the pump motor in real time, different power values ​​correspond to different pump motor operating intensities and conditions. By comprehensively considering the specific position of the actual motor power within the target power range, as well as the system operating characteristics inherent in the target power range, the initial equivalent head can be adjusted accordingly. Furthermore, based on the above correction method, the differences in actual operation can be fully considered, ensuring that the final determined actual equivalent head closely matches the actual working condition of the pump motor under low head conditions.

[0105] It should be added that, under low head conditions, even if the actual speed equals the preset speed, the complexity of the actual operating conditions of the water pump motor makes it difficult to directly apply the correspondence between speed and head. For example, factors such as pipeline resistance and medium characteristics in the water pump equipment may change frequently under low head conditions, affecting the output characteristics of the water pump motor. As a result, even if the speed remains unchanged, the actual equivalent head of the water pump motor may change.

[0106] However, motor power typically provides a more direct and comprehensive reflection of the actual working state of a water pump motor, encompassing the combined impact of various factors on the pump motor during operation. Therefore, under low head conditions, determining the actual equivalent head using a method based on motor power is more reliable and effective.

[0107] Furthermore, under high-head conditions, the pump motor needs to overcome a significant pressure difference to raise the liquid level, leading to an increased load on the pump motor. Based on the characteristics of pump motors, it is known that the motor speed will decrease with increased load, resulting in a difference between the actual speed and the preset speed. Therefore, by calculating the ratio of the actual speed to the preset speed and multiplying it by the preset equivalent head corresponding to the preset speed, the actual equivalent head can be determined. This method fully considers the impact of speed changes on head, thus accurately reflecting the actual head capacity of the pump motor under high load and low speed conditions.

[0108] Furthermore, under low head conditions, the pressure difference faced by the pump motor is small, and the pump motor does not need to output excessive torque to maintain normal operation. The actual speed can usually stabilize at the preset speed. At this time, since the speed is relatively stable (actual speed equals preset speed), and the speed has little impact on the head, the pump motor does not need to consider the impact of speed changes on the head as it does under high head conditions. Therefore, the actual equivalent head can be determined directly based on the actual motor power, which reflects the pump motor's working state under low head conditions, thus improving the accuracy of the actual equivalent head determination.

[0109] In one embodiment, the controller can determine the power difference between the actual motor power and the minimum value in the target power range. Then, the difference between the initial equivalent head and the power difference is determined as the actual equivalent head.

[0110] For example, consider power ranges of [Pm1, Pmax], [Pm2, Pm1), and [Pm3, Pm2), with corresponding initial equivalent heads Hm1, Hm2, and Hm3, respectively. When the target power range is [Pm1, Pmax], the corresponding power difference is P – Pm1, and the corresponding actual equivalent head is Hmout (actual equivalent head) = Hm1 - (P – Pm1). When the target power range is [Pm2, Pm1), the corresponding power difference is P – Pm2, and the corresponding actual equivalent head is Hmout = Hm2 - (P – Pm2). And when the target power range is [Pm3, Pm2), the corresponding power difference is P – Pm3, and the corresponding actual equivalent head is Hmout = Hm3 - (P – Pm3). Where P is the actual motor power.

[0111] It should be noted that when subtracting the initial equivalent head from the power difference, both the initial equivalent head and the power difference are scalars. That is, only numerical mathematical operations are performed, without considering the dimensions between the two.

[0112] In practical engineering applications and analyses, determining the actual equivalent head of a water pump motor is often difficult because the initial equivalent head and the power difference have different dimensions, making direct calculations impossible. However, by acquiring multiple sets of data through extensive testing and performing fitting analysis, the specific formula described above can be obtained. This formula enables calculations based on the initial equivalent head and power difference with different dimensions; that is, by subtracting the power difference from the initial equivalent head, the final value of the actual equivalent head is obtained.

[0113] In one embodiment, the power difference can visually represent the deviation between the actual motor power of the water pump motor and the lower limit of the target power range, reflecting situations such as the water pump motor exceeding or falling short of its work requirements. Furthermore, the water pump motor typically needs to output a certain power to achieve a specific head. Therefore, obtaining the actual equivalent head by subtracting the initial equivalent head from the determined power difference allows the obtained actual equivalent head to better reflect actual operating conditions.

[0114] S240, determine the liquid flow rate based on the actual equivalent head and the actual motor power.

[0115] In one embodiment, the controller can establish a theoretical model of the water pump motor based on fluid mechanics principles to determine the aforementioned liquid flow rate. The theoretical model can comprehensively consider factors such as the geometric structure of the water pump motor, the physical properties of the fluid, and the flow state, and solve for the liquid flow rate through numerical calculation methods.

[0116] For example, after establishing the above theoretical model, the actual equivalent head and actual motor power can be input into the model as boundary conditions to obtain the liquid flow rate.

[0117] In another embodiment, the controller can determine the actual effective energy of the pump motor to drive the water flow based on the actual motor power, power efficiency factor, and torque efficiency factor. Then, based on the actual effective energy and the actual equivalent head, the liquid flow rate is determined.

[0118] In one embodiment, the aforementioned power efficiency factor is used to measure the efficiency of a water pump motor in converting electrical energy into mechanical energy. This power efficiency factor can take into account various energy losses during the operation of the water pump motor, such as copper losses, iron losses, and mechanical friction losses. Typically, the value of the power efficiency factor is between 0 and 1; the higher the value, the higher the efficiency of the water pump motor in converting electrical energy into mechanical energy.

[0119] Furthermore, the aforementioned torque efficiency factor is used to consider the efficiency of a water pump motor in converting its output torque into mechanical energy to propel water flow. It mainly involves the influence of factors such as the mechanical structure of the water pump motor, impeller design, and fluid resistance on torque transmission and energy conversion. Similarly, the value of the torque efficiency factor is between 0 and 1, reflecting the water pump motor's ability to effectively convert torque into energy to propel water flow.

[0120] Furthermore, the aforementioned actual effective energy refers to the electrical energy output by the water pump motor, which, after undergoing power conversion and torque conversion by the water pump motor itself, is used to propel the water flow. This actual effective energy is an energy value obtained by comprehensively considering the actual motor power, power efficiency, and torque efficiency, reflecting the effective energy of the water pump motor in performing work on the water flow during actual operation.

[0121] Typically, a controller can determine the actual effective energy by multiplying the actual motor power, power efficiency factor, and torque efficiency factor. Through this product, the actual electrical power input to the pump motor is corrected twice for efficiency, yielding the true effective energy used to drive the water flow.

[0122] Based on the above explanation, by determining the actual effective energy of the water pump motor in driving the water flow based on the actual motor power, power efficiency factor, and torque efficiency factor, the work capacity of the water pump motor can be accurately assessed, taking into account the losses when the water pump motor converts electrical energy into mechanical energy. Therefore, when determining the liquid flow rate based on the actual effective energy and the actual equivalent head, the method of determining the liquid flow rate can be more scientific and reasonable, conforming to the principles of energy conservation and fluid mechanics.

[0123] In one embodiment, after obtaining the actual effective energy, the second ratio of the effective energy to the actual equivalent head can be determined as the liquid flow rate.

[0124] It is understandable that the actual effective energy is the energy that the pump motor actually uses to propel the water flow, and the actual equivalent head refers to the total resistance that the water needs to overcome during the flow. Furthermore, the head is related to the kinetic energy of the water, which in turn is related to the liquid flow rate. Therefore, based on fluid mechanics principles, determining the liquid flow rate using the ratio of effective energy to actual equivalent head can achieve high accuracy and practicality.

[0125] As an example, the controller can calculate the above liquid flow rate using the following formula, detailed below:

[0126]

[0127] Where Qout is the liquid flow rate, P is the actual motor power, and η p For the power efficiency factor, η m For torque efficiency factor, Hmout is the actual equivalent head, and ω represents the coefficient introduced when converting power from KW to a unit relationship that matches physical quantities such as flow rate and head.

[0128] The value of ω varies depending on the liquid. For example, when the liquid is water, ω can be 367.

[0129] In this embodiment, the liquid flow rate is determined by directly acquiring the actual rotational speed and actual motor power of the water pump motor. This avoids the measurement errors and equipment damage caused by impurities and corrosion that are common in traditional flow meter monitoring, ensuring data accuracy and reducing hardware costs. Furthermore, since the rotational speed of the water pump motor typically varies under different head loads, the head state of the water pump motor at its actual rotational speed can be determined based on the relationship between the motor's rotational speed and head, thus describing the motor's ability to lift liquid when operating at its actual speed. This allows for the calculation of the actual equivalent head of the water pump motor, revealing its actual load conditions. Consequently, determining the liquid flow rate based on the actual equivalent head and actual motor power comprehensively considers both the motor's load and its work capacity, improving the accuracy of liquid flow rate determination.

[0130] In another embodiment, such as Figure 2 As shown, the water pump equipment can be used to implement the liquid flow rate determination method described in the above method embodiments.

[0131] The water pump device may include one or more memories storing programs that can be run by a controller to generate instructions that cause the controller to execute the liquid flow determination method described in the above method embodiments.

[0132] Optionally, the memory may also store data. Optionally, the controller may also read data stored in the memory, which may be stored at the same memory address as the program, or the data may be stored at a different memory address than the program.

[0133] The controller and memory can be set up separately or integrated together; for example, integrated on the system on chip (SOC) of the terminal device.

[0134] This application also provides a computer program product that, when executed by a controller, implements the liquid flow determination method of any method embodiment in this application.

[0135] The computer program product can be stored in memory, for example, as a program. The program is eventually converted into an executable object file that can be executed by the controller after processes such as preprocessing, compilation, assembly, and linking.

[0136] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a computer, implements the liquid flow determination method of any method embodiment of this application. The computer program may be a high-level language program or an executable object program.

[0137] The computer-readable storage medium is, for example, memory. Memory can be volatile or non-volatile, or it can include both volatile and non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), which serves as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0138] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0139] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0140] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0141] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0142] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for example, the division of modules is merely a logical functional division, and there may be other division methods in actual implementation; for example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0143] The modules described as separate components may or may not be physically separate. Similarly, the components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0144] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0145] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A water pump device, characterized in that, include: A water pump motor is configured to convert electrical energy into mechanical energy and to transport liquid based on said mechanical energy; A controller connected to the water pump motor is configured to: Obtain the actual speed and actual power of the water pump motor; The head state of the water pump motor is determined based on the actual rotational speed; the head state is used to describe the ability of the water pump motor to lift liquid when operating at the actual rotational speed. The actual equivalent head of the water pump motor is determined based on the head condition. The liquid flow rate is determined based on the actual equivalent head and the actual motor power.

2. The water pump equipment according to claim 1, characterized in that, The controller determines the head state of the water pump motor based on the actual rotational speed and is configured as follows: If the actual rotational speed is less than the preset rotational speed, then the head state is determined to be a high head state; If the actual rotational speed is equal to the preset rotational speed, then the head state is determined to be a low head state.

3. The water pump equipment according to claim 2, characterized in that, The controller determines the actual equivalent head of the water pump motor based on the head status and is configured as follows: If the head state is the high head state, then determine the first ratio of the actual rotational speed to the preset rotational speed; The product of the first ratio and the preset equivalent head corresponding to the preset rotational speed is determined as the actual equivalent head.

4. The water pump equipment according to claim 2, characterized in that, The controller determines the actual equivalent head of the water pump motor based on the head status and is configured as follows: If the head state is the low head state, then the target power range of the actual motor power and the initial equivalent head corresponding to the target power range are determined. The initial equivalent head is corrected based on the actual motor power and the target power range to determine the actual equivalent head.

5. The water pump equipment according to claim 4, characterized in that, The controller corrects the initial equivalent head based on the actual motor power and the target power range to determine the actual equivalent head, and is configured as follows: Determine the power difference between the actual motor power and the minimum value in the target power range; The difference between the initial equivalent head and the power difference is determined as the actual equivalent head.

6. The water pump equipment according to any one of claims 1-5, characterized in that, The controller determines the liquid flow rate based on the actual equivalent head and the actual motor power, and is configured as follows: Based on the actual motor power, power efficiency factor, and torque efficiency factor, the actual effective energy of the water pump motor in driving the water flow is determined. The liquid flow rate is determined based on the actual effective energy and the actual equivalent head.

7. The water pump equipment according to claim 6, characterized in that, The determination of liquid flow rate based on the actual effective energy and the actual equivalent head is configured as follows: The second ratio of effective energy to actual equivalent head is determined as the liquid flow rate.

8. A method for determining liquid flow rate, characterized in that, Applied to water pump equipment, the water pump equipment including a water pump motor configured to convert electrical energy into mechanical energy and to transport liquid based on the mechanical energy; The method for determining the liquid flow rate includes: Obtain the actual speed and actual power of the water pump motor; The head state of the water pump motor is determined based on the actual rotational speed; the head state is used to describe the ability of the water pump motor to lift liquid when operating at the actual rotational speed. The actual equivalent head of the water pump motor is determined based on the head condition. The liquid flow rate is determined based on the actual equivalent head and the actual motor power.

9. The method for determining liquid flow rate according to claim 8, characterized in that, Determining the head state of the water pump motor based on the actual rotational speed includes: If the actual rotational speed is less than the preset rotational speed, then the head state is determined to be a high head state; If the actual rotational speed is equal to the preset rotational speed, then the head state is determined to be a low head state.

10. The method for determining liquid flow rate according to claim 9, characterized in that, Determining the actual equivalent head of the water pump motor based on the head state includes: If the head state is the high head state, then determine the first ratio of the actual rotational speed to the preset rotational speed; The product of the first ratio and the preset equivalent head corresponding to the preset rotational speed is determined as the actual equivalent head.

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