A fire pump set and a method for flow control thereon

Abstract

This invention discloses a fire pump set and a method for controlling its flow. The fire pump set includes a flow control module, a fire pump parameter processing module, and a motor speed detection module. The flow control module is connected to the fire pump parameter processing module, which is in turn connected to the motor speed detection module. The motor speed detection module detects the motor speed. The fire pump parameter processing module acquires and calculates the parameter relationship between relevant fire pump parameters and motor speed, and preprocesses the parameter relationship to obtain correlation parameters. The flow control module determines the flow parameters based on the correlation parameters and controls the flow rate of the fire pump set based on these flow parameters. By establishing the relationship between motor speed and various relevant parameters, the degree to which changes in motor speed affect relevant parameters is determined, thereby ensuring that changes in each parameter remain within a set range and meeting the various performance requirements of the fire pump.

Description

Technical Field

[0001] This invention relates to the field of fire pump technology, and more specifically to a fire pump set and a method for controlling its flow. Background Technology

[0002] Fire pumps are required to operate without failure during firefighting operations and must be designed for automatic, unmanned operation. However, the inlet and outlet valves of the pumps are generally fully open, and the water consumption of end-point firefighting equipment (such as fire hydrants) is often difficult to effectively control. Furthermore, in a multi-pump parallel water supply system, the first pump to start is likely to bear the full load for a short period, but firefighting pumps cannot be overloaded or allowed to shut down, or experience cavitation (if the first pump stops, the subsequent water consumption will be even greater, making it easier for the standby pumps to overload or cavitate, leading to system collapse).

[0003] In addition to the requirements mentioned above, the following issues also need to be addressed in practical applications:

[0004] A. When the inlet and outlet valves of the fire pump are fully open and the system pressure is low, the fire pump may start under full load. Therefore, the motor is required to have high starting torque and low starting current (so that the power distribution system does not trip).

[0005] B. Using excessive water flow without cavitation (reducing flow velocity);

[0006] C. In line with the low-carbon economy, under the above technical conditions, the driving power and energy consumption of the fire pump set should be reduced (due to the reduction of motor power, the consumption of steel, non-ferrous metals and energy is reduced).

[0007] Traditional solutions:

[0008] A. Centrifugal pumps with special flow channels and impellers require a redesign of the pump casing and impeller to meet the requirements. The non-general series of products not only have complex modeling (hydraulic model) and long design cycle, but also result in high product prices.

[0009] B. Synchronous control of the variable speed motor to meet the above technical requirements, such as the technology in patent: CN108700899 A "Self-adjusting open-circuit pump unit". This technology is very complex to control, and the introduction of electronic speed control devices into its main electrical control circuit leads to a decrease in the reliability of the equipment. Therefore, its use is not recommended in practical applications. Summary of the Invention

[0010] This invention provides a fire pump set and a method for controlling its flow, in order to solve the above-mentioned problems existing in the prior art.

[0011] This invention provides a fire pump set, including: a flow control module, a fire pump parameter processing module, and a motor speed detection module; the flow control module is connected to the fire pump parameter processing module, and the fire pump parameter processing module is connected to the motor speed detection module;

[0012] The motor speed detection module is used to detect the motor speed, and the fire pump parameter processing module is used to acquire and calculate the parameter relationship between the fire pump and the motor speed, and to preprocess the parameter relationship to obtain the correlation parameters.

[0013] The flow control module is used to determine the flow parameters based on the correlation parameters, and to control the flow of the fire pump set based on the flow parameters.

[0014] Preferably, the fire pump parameter processing module includes:

[0015] The first relationship determination unit is used to determine the first relationship between the water pump flow rate and the motor speed;

[0016] The second relationship determination unit is used to determine the second relationship between the pump head and the motor speed;

[0017] The third relationship determination unit is used to determine the third relationship between the pump shaft power and the motor speed;

[0018] The correlation parameter determination unit is used to determine the correlation between motor speed and water pump flow rate, water pump head and water pump shaft power based on the first relationship, the second relationship and the third relationship, and form correlation parameters.

[0019] Preferably, the first relationship includes: the change in water pump flow rate is directly proportional to the change in motor speed;

[0020] The second relationship includes: the pump head is directly proportional to the square of the change in motor speed;

[0021] The third relationship includes: the pump shaft power is directly proportional to the cube of the change in motor speed;

[0022] The correlation is as follows: when the motor speed is changed, the change in the power of the water pump shaft is greater than or equal to the set value.

[0023] Preferably, when the water consumption exceeds the designed rated flow rate and the power of the water pump shaft exceeds 75% of the maximum shaft power of the motor, the rate of decrease in motor speed increases, and the rate of decrease in water pump shaft power is the cube of the rate of decrease in motor speed.

[0024] The flow control module includes:

[0025] The first equivalent parameter determination unit is used to determine the first equivalent parameter based on the maximum power of the water pump shaft as a constraint and a third relationship. The first equivalent parameter includes: a first proportional coefficient and a first equivalent coefficient; the first proportional coefficient when the water pump shaft power is proportional to the cube of the change in motor speed; the first equivalent coefficient is: within the constraint of ensuring the maximum power of the water pump shaft, the range of change in motor speed is determined as the first equivalent parameter.

[0026] The second equivalent parameter determination unit is used to determine the second equivalent parameter based on the limitation of the rated head of the water pump and the second relationship. The second equivalent parameter includes: a second proportional coefficient and a second equivalent coefficient; the second proportional coefficient is proportional to the square of the change in the water pump head and the motor speed. The second equivalent coefficient is: under the limitation of the rated head of the water pump, the range of change in the motor speed is determined as the second equivalent parameter.

[0027] The control unit is used to determine the range of motor speed variation based on the first equivalent parameter and the second equivalent parameter, and then determine the motor speed. Based on the determined range of motor speed and the first relationship between motor speed and water pump flow rate, the flow rate of the fire pump set is controlled.

[0028] Preferably, it also includes a liquid level marking module for calibrating the liquid level;

[0029] The liquid level marking module includes:

[0030] The acquisition unit is used for real-time image acquisition from an industrial camera on a liquid level gauge.

[0031] The liquid level height determination unit is used to calibrate the ratio between the image pixel size and the actual liquid level scale size in real time, and to segment the image into regions of interest. The size of the segmented float indicator height image is calculated according to the pixel ratio and the actual ratio to obtain the scale value mapped on the float liquid level scale, that is, the liquid level height.

[0032] The calculation and adjustment unit is used to perform logical calculations based on the real-time flow rate of the water pump and the liquid level height to predict the liquid level change data; adjust the flow control parameters of the water pump according to the liquid level change data, or, if the liquid level change data is greater than or equal to a set change threshold, send an alarm message to the alarm module to remind the user to adjust the water pump flow rate or add water.

[0033] The present invention also provides a method for flow control of a fire pump set, comprising:

[0034] S100 includes a flow control module, a fire pump parameter processing module, and a motor speed detection module; the flow control module is connected to the fire pump parameter processing module, and the fire pump parameter processing module is connected to the motor speed detection module.

[0035] S200, the motor speed detection module is used to detect the motor speed, and the fire pump parameter processing module is used to obtain and calculate the parameter relationship between the relevant parameters of the fire pump and the motor speed, and to preprocess the parameter relationship to obtain the correlation parameters;

[0036] S300, the flow control module is used to determine the flow parameters according to the correlation parameters, and control the flow of the fire pump set based on the flow parameters.

[0037] Preferably, S200 includes:

[0038] S201, determine the primary relationship between pump flow rate and motor speed;

[0039] S202, determine the second relationship between pump head and motor speed;

[0040] S203, determine the third relationship between the pump shaft power and the motor speed;

[0041] S204. Based on the first relationship, the second relationship, and the third relationship, the correlation between motor speed and water pump flow rate, water pump head, and water pump shaft power is determined, forming correlation parameters.

[0042] Preferably, the first relationship includes: the change in water pump flow rate is directly proportional to the change in motor speed;

[0043] The second relationship includes: the pump head is directly proportional to the square of the change in motor speed;

[0044] The third relationship includes: the pump shaft power is directly proportional to the cube of the change in motor speed;

[0045] The correlation is as follows: when the motor speed is changed, the change in the power of the water pump shaft is greater than or equal to the set value.

[0046] Preferably, S300 includes: determining that when the water consumption exceeds the designed rated flow rate; when the water pump shaft power exceeds 75% of the maximum shaft power of the motor, the rate of decrease in motor speed increases; and the rate of decrease in water pump shaft power is the cube of the rate of decrease in motor speed.

[0047] The S300 includes:

[0048] S301, based on the maximum power of the water pump shaft as a constraint, and based on the third relationship, a first equivalent parameter is determined. The first equivalent parameter includes: a first proportional coefficient and a first equivalent coefficient; the first proportional coefficient when the water pump shaft power is proportional to the cube of the change in motor speed, and the first equivalent coefficient is: within the constraint of the maximum power of the water pump shaft, the range of change in motor speed is determined as the first equivalent parameter.

[0049] S302, under the limitation of the rated head of the water pump, and based on the second relationship, determine the second equivalent parameter. The second equivalent parameter includes: a second proportional coefficient and a second equivalent coefficient; a second proportional coefficient that is proportional to the square of the change in the water pump head and the motor speed. The second equivalent coefficient is: under the limitation of the rated head of the water pump, the range of change in the motor speed is determined as the second equivalent parameter.

[0050] S303, the range of motor speed variation is determined based on the first equivalent parameter and the second equivalent parameter, and then the motor speed is determined. Based on the determined range of motor speed and the first relationship between motor speed and water pump flow rate, the flow rate of the fire pump set is controlled.

[0051] Preferably, the method further includes step S400, which involves calibrating the liquid level;

[0052] The S400 includes:

[0053] S401 uses an industrial camera to capture images of the liquid level gauge in real time.

[0054] S402 calibrates the ratio of image pixel size to actual liquid level scale size in real time, and performs region of interest segmentation on the image. The size of the segmented float indicator height image is calculated according to the pixel ratio to obtain the scale value mapped on the float liquid level scale, that is, the liquid level height.

[0055] S403, perform logical calculations based on the real-time flow rate of the water pump and the liquid level height to predict the liquid level change data; adjust the flow control parameters of the water pump according to the liquid level change data, or, if the liquid level change data is greater than or equal to the set change threshold, send an alarm message to the alarm module to remind the user to adjust the water pump flow rate or add water.

[0056] Compared with the prior art, the present invention has the following advantages:

[0057] This invention provides a fire pump set and a method for controlling its flow. The fire pump set includes a flow control module, a fire pump parameter processing module, and a motor speed detection module. The flow control module is connected to the fire pump parameter processing module, which is also connected to the motor speed detection module. The motor speed detection module detects the motor speed. The fire pump parameter processing module acquires and calculates the parameter relationship between relevant fire pump parameters and the motor speed, and preprocesses the parameter relationship to obtain correlation parameters. The flow control module determines the flow parameters based on the correlation parameters and controls the flow rate of the fire pump set based on these flow parameters. This solution uses the motor speed detection module to detect the motor speed, and the fire pump parameter processing module to determine the relationship between the motor speed and relevant parameters, thus identifying the correlation parameters. The flow control parameters are then determined based on these correlation parameters, thereby controlling the flow rate of the fire pump set. By establishing the relationship between the motor speed and various relevant parameters, the degree to which changes in motor speed affect these parameters is determined, ensuring that changes in each parameter remain within a set range and meeting the various performance requirements of the fire pump.

[0058] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0059] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0060] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0061] Figure 1 This is a schematic diagram of the structure of a fire pump set according to an embodiment of the present invention;

[0062] Figure 2 This is a schematic diagram of the liquid level marking module in an embodiment of the present invention;

[0063] Figure 3 This is a flowchart of a method for flow control of a fire pump set according to an embodiment of the present invention. Detailed Implementation

[0064] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0065] This invention provides a fire pump set, please refer to... Figure 1 The fire pump set includes: a flow control module, a fire pump parameter processing module, and a motor speed detection module; the flow control module is connected to the fire pump parameter processing module, and the fire pump parameter processing module is connected to the motor speed detection module.

[0066] The motor speed detection module is used to detect the motor speed, and the fire pump parameter processing module is used to acquire and calculate the parameter relationship between the fire pump and the motor speed, and to preprocess the parameter relationship to obtain the correlation parameters.

[0067] The flow control module is used to determine the flow parameters based on the correlation parameters, and to control the flow of the fire pump set based on the flow parameters.

[0068] The working principle of the above technical solution is as follows: The solution adopted in this embodiment is a flow control module, a fire pump parameter processing module, and a motor speed detection module; the flow control module is connected to the fire pump parameter processing module, and the fire pump parameter processing module is connected to the motor speed detection module; the motor speed detection module is used to detect the motor speed, and the fire pump parameter processing module is used to obtain and calculate the parameter relationship between the relevant parameters of the fire pump and the motor speed, and preprocess the parameter relationship to obtain the correlation parameters; the flow control module is used to determine the flow parameters according to the correlation parameters, and control the flow of the fire pump group based on the flow parameters.

[0069] The beneficial effects of the above technical solution are as follows: The solution provided in this embodiment detects the motor speed through the motor speed detection module and determines the relationship between the motor speed and related parameters based on the fire pump parameter processing module. It then determines the correlation parameters and determines the flow control parameters based on the correlation parameters, thereby controlling the flow of the fire pump group. By establishing the relationship between the motor speed and various related parameters, it determines the degree to which changes in the motor speed will affect the related parameters, and thus ensures that the changes in each parameter are within the set range, thereby ensuring that they meet the various index requirements of the fire pump.

[0070] In another embodiment, the fire pump parameter processing module includes:

[0071] The first relationship determination unit is used to determine the first relationship between the water pump flow rate and the motor speed;

[0072] The second relationship determination unit is used to determine the second relationship between the pump head and the motor speed;

[0073] The third relationship determination unit is used to determine the third relationship between the pump shaft power and the motor speed;

[0074] The correlation parameter determination unit is used to determine the correlation between motor speed and water pump flow rate, water pump head and water pump shaft power based on the first relationship, the second relationship and the third relationship, and form correlation parameters.

[0075] The working principle of the above technical solution is as follows: The solution adopted in this embodiment is that the fire pump parameter processing module includes: a first relationship determination unit, used to determine the first relationship between the pump flow rate and the motor speed; a second relationship determination unit, used to determine the second relationship between the pump head and the motor speed; a third relationship determination unit, used to determine the third relationship between the pump shaft power and the motor speed; and a correlation parameter determination unit, used to determine the correlation between the motor speed and the pump flow rate, pump head, and pump shaft power based on the first, second, and third relationships, thereby forming correlation parameters.

[0076] In another embodiment, the first relationship includes: the water pump flow rate is directly proportional to the change in motor speed;

[0077] The second relationship includes: the pump head is directly proportional to the square of the change in motor speed;

[0078] The third relationship includes: the pump shaft power is directly proportional to the cube of the change in motor speed;

[0079] The correlation is as follows: when the motor speed is changed, the change in the power of the water pump shaft is greater than or equal to the set value.

[0080] Specifically, the formulas relating pump flow rate, pump head, pump shaft power, and motor speed are as follows:

[0081]

[0082]

[0083]

[0084] Where Q, H, P, and n represent the pump flow rate, pump head, pump shaft power, and motor speed, respectively.

[0085] The change in the pump's flow rate Q is directly proportional to the change in its rotational speed n; α is the proportionality coefficient for the first relationship.

[0086] The pump head H is directly proportional to the square of the rotational speed n; β is the second proportionality coefficient.

[0087] The shaft power P of the water pump is directly proportional to the cube of the rotational speed n; γ is the first proportionality coefficient.

[0088] Therefore, changing the rotational speed n can significantly change the shaft power P of the water pump.

[0089] When the water consumption of the fire pump exceeds the designed rated flow rate and its pump shaft power exceeds 75% of the maximum motor power, the motor speed n drops rapidly. At this time, the flow rate Q, head H and shaft power P of the driven centrifugal pump will change according to the above relationship formula.

[0090] At 1.5 times the rated flow rate, its head must not be less than 0.65 of the rated head. Furthermore, as the system continues to increase the water flow rate, the fire pump's drive power (drive power = flow rate * head / efficiency) will reach an inflection point (the head decreases significantly as the water flow rate increases) without causing overload.

[0091] In another embodiment, the flow control module includes:

[0092] The first equivalent parameter determination unit is used to determine the first equivalent parameter based on the maximum power of the water pump shaft as a constraint and a third relationship. The first equivalent parameter includes: a first proportional coefficient and a first equivalent coefficient; the first proportional coefficient when the water pump shaft power is proportional to the cube of the change in motor speed; the first equivalent coefficient is: within the constraint of ensuring the maximum power of the water pump shaft, the range of change in motor speed is determined as the first equivalent parameter.

[0093] The second equivalent parameter determination unit is used to determine the second equivalent parameter based on the limitation of the rated head of the water pump and the second relationship. The second equivalent parameter includes: a second proportional coefficient and a second equivalent coefficient; the second proportional coefficient is proportional to the square of the change in the water pump head and the motor speed. The second equivalent coefficient is: under the limitation of the rated head of the water pump, the range of change in the motor speed is determined as the second equivalent parameter.

[0094] The control unit is used to determine the range of motor speed variation based on the first equivalent parameter and the second equivalent parameter, and then determine the motor speed. Based on the determined range of motor speed and the first relationship between motor speed and water pump flow rate, the flow rate of the fire pump set is controlled.

[0095] Therefore, based on the above relationship, the range of motor speed can be calculated under the set limiting conditions. Then, the water pump flow rate can be determined and controlled based on this speed range. The set limiting conditions are: at 1.5 times the rated flow rate, its head cannot be less than 0.65 of the rated head. When the system continues to increase the water flow rate, the fire pump's drive power (drive power = flow rate * head / efficiency) will reach an inflection point (the head decreases significantly as the water flow rate increases) without causing overload.

[0096] Based on the set constraints and the relationship between the pump head, pump shaft power, and motor speed, the range of motor speed can be determined. Once the motor speed range is determined, the set constraints can be maintained within this range. Furthermore, based on the proportional relationship between the pump flow rate and the motor speed, the pump flow rate can be controlled.

[0097] In another embodiment, please refer to Figure 2 It also includes a liquid level marking module, used to calibrate the liquid level of the liquid storage device;

[0098] The liquid level marking module includes:

[0099] The acquisition unit is used for long-distance, real-time acquisition of images from liquid level gauges by industrial cameras;

[0100] The liquid level height determination unit is used to calibrate the ratio between the image pixel size and the actual liquid level scale size in real time, and to segment the image into regions of interest. The size of the segmented float indicator height image is calculated according to the pixel ratio and the actual ratio to obtain the scale value mapped on the float liquid level scale, that is, the liquid level height.

[0101] The calculation and adjustment unit is used to perform logical calculations based on the real-time flow rate of the water pump and the liquid level height to predict the liquid level change data; adjust the flow control parameters of the water pump according to the liquid level change data, or send an alarm message to the alarm module if the liquid level change data is greater than or equal to a set change threshold, reminding the user to adjust the water pump flow rate or add water.

[0102] The working principle of the above technical solution is as follows: The solution adopted in this embodiment also includes a liquid level marking module for calibrating the liquid level; the liquid level marking module includes: a data acquisition unit for acquiring images on the liquid level scale in real time using an industrial camera; a liquid level height determination unit for calibrating the ratio of the image pixel size to the actual liquid level scale size in real time, and performing region of interest segmentation on the image, calculating the scale value mapped on the float liquid level scale based on the pixel and actual ratio of the segmented float indication height image, i.e., the liquid level height; a calculation and adjustment unit for performing logical calculations based on the real-time flow rate of the water pump and the liquid level height to predict the liquid level change data; adjusting the flow control parameters of the water pump based on the liquid level data change data, or, if the liquid level data change data is greater than or equal to a set change threshold, sending an alarm message to the alarm module to remind the user to adjust the water pump flow rate or add water.

[0103] The beneficial effects of the above technical solution are as follows: the solution provided in this embodiment uses a vision plus control algorithm to realize real-time liquid level adjustment, simulates manual control logic, and further limits the control of flow rate.

[0104] In another embodiment, the present invention also provides a method for flow control of a fire pump set, please refer to... Figure 3 The flow control method includes:

[0105] S100 includes a flow control module, a fire pump parameter processing module, and a motor speed detection module; the flow control module is connected to the fire pump parameter processing module, and the fire pump parameter processing module is connected to the motor speed detection module.

[0106] S200, the motor speed detection module is used to detect the motor speed, and the fire pump parameter processing module is used to obtain and calculate the parameter relationship between the relevant parameters of the fire pump and the motor speed, and to preprocess the parameter relationship to obtain the correlation parameters;

[0107] S300, the flow control module is used to determine the flow parameters according to the correlation parameters, and control the flow of the fire pump set based on the flow parameters.

[0108] The working principle of the above technical solution is as follows: The solution adopted in this embodiment includes a flow control module, a fire pump parameter processing module, and a motor speed detection module; the flow control module is connected to the fire pump parameter processing module, and the fire pump parameter processing module is connected to the motor speed detection module; the motor speed detection module is used to detect the motor speed, and the fire pump parameter processing module is used to obtain and calculate the parameter relationship between the relevant parameters of the fire pump and the motor speed, and preprocess the parameter relationship to obtain the correlation parameters; the flow control module is used to determine the flow parameters according to the correlation parameters, and control the flow of the fire pump group based on the flow parameters.

[0109] The beneficial effects of the above technical solution are as follows: The solution provided in this embodiment includes a flow control module, a fire pump parameter processing module, and a motor speed detection module. The flow control module is connected to the fire pump parameter processing module, which in turn is connected to the motor speed detection module. The motor speed detection module detects the motor speed, and the fire pump parameter processing module acquires and calculates the parameter relationship between relevant fire pump parameters and motor speed, preprocesses the parameter relationship, and obtains correlation parameters. The flow control module determines the flow parameters based on the correlation parameters and controls the flow rate of the fire pump group based on these flow parameters. By detecting the motor speed through the motor speed detection module and determining the relationship between the motor speed and relevant parameters based on the fire pump parameter processing module, correlation parameters are determined. Then, flow control parameters are determined based on these correlation parameters, thereby controlling the flow rate of the fire pump group. By establishing the relationship between the motor speed and various relevant parameters, the degree to which changes in motor speed affect relevant parameters is determined, ensuring that changes in each parameter remain within the set range and meeting the various performance requirements of the fire pump.

[0110] In another embodiment, S200 includes:

[0111] S201, determine the primary relationship between pump flow rate and motor speed;

[0112] S202, determine the second relationship between pump head and motor speed;

[0113] S203, determine the third relationship between the pump shaft power and the motor speed;

[0114] S204. Based on the first relationship, the second relationship, and the third relationship, the correlation between motor speed and water pump flow rate, water pump head, and water pump shaft power is determined, forming correlation parameters.

[0115] The working principle of the above technical solution is as follows: The solution adopted in this embodiment is to determine the first relationship between the water pump flow rate and the motor speed; to determine the second relationship between the water pump head and the motor speed; to determine the third relationship between the water pump shaft power and the motor speed; and to determine the correlation between the motor speed and the water pump flow rate, the water pump head and the water pump shaft power based on the first, second and third relationships, thus forming correlation parameters.

[0116] The beneficial effects of the above technical solution are as follows: the solution provided in this embodiment determines the first relationship between the pump flow rate and the motor speed; determines the second relationship between the pump head and the motor speed; determines the third relationship between the pump shaft power and the motor speed; and determines the correlation between the motor speed and the pump flow rate, pump head and pump shaft power based on the first, second and third relationships, thus forming correlation parameters.

[0117] In another embodiment, the first relationship includes: the water pump flow rate is directly proportional to the change in motor speed;

[0118] The second relationship includes: the pump head is directly proportional to the square of the change in motor speed;

[0119] The third relationship includes: the pump shaft power is directly proportional to the cube of the change in motor speed;

[0120] The correlation is as follows: when the motor speed is changed, the change in the power of the water pump shaft is greater than or equal to the set value.

[0121] The working principle of the above technical solution is as follows: The solution adopted in this embodiment is that the first relationship includes: the change of water pump flow rate is directly proportional to the change of motor speed; the second relationship includes: the water pump head is directly proportional to the square of the change of motor speed; the third relationship includes: the water pump shaft power is directly proportional to the cube of the change of motor speed; the correlation is: when the motor speed is changed, the change in water pump shaft power is greater than or equal to the set value.

[0122] In another embodiment, S300 includes: determining that when the water consumption exceeds the designed rated flow rate; when the water pump shaft power exceeds 75% of the maximum shaft power of the motor, the rate of decrease in motor speed increases; and the rate of decrease in water pump shaft power is the cube of the rate of decrease in motor speed.

[0123] The S300 includes:

[0124] S301, based on the maximum power of the water pump shaft as a constraint, and based on the third relationship, a first equivalent parameter is determined. The first equivalent parameter includes: a first proportional coefficient and a first equivalent coefficient; the first proportional coefficient when the water pump shaft power is proportional to the cube of the change in motor speed, and the first equivalent coefficient is: within the constraint of the maximum power of the water pump shaft, the range of change in motor speed is determined as the first equivalent parameter.

[0125] S302, under the limitation of the rated head of the water pump, and based on the second relationship, determine the second equivalent parameter. The second equivalent parameter includes: a second proportional coefficient and a second equivalent coefficient; a second proportional coefficient that is proportional to the square of the change in the water pump head and the motor speed. The second equivalent coefficient is: under the limitation of the rated head of the water pump, the range of change in the motor speed is determined as the second equivalent parameter.

[0126] S303, the range of motor speed variation is determined based on the first equivalent parameter and the second equivalent parameter, and then the motor speed is determined. Based on the determined range of motor speed and the first relationship between motor speed and water pump flow rate, the flow rate of the fire pump set is controlled.

[0127] The working principle of the above technical solution is as follows: The solution adopted in this embodiment includes S300: S301, determining that the flow control module is activated when the water consumption exceeds the designed rated flow; S302, when the power of the water pump shaft exceeds 75% of the maximum shaft power of the motor, the rate of decrease in motor speed increases; S303, the rate of decrease in water pump shaft power is the cube of the rate of decrease in motor speed.

[0128] Specifically, the formulas relating pump flow rate, pump head, pump shaft power, and motor speed are as follows:

[0129]

[0130]

[0131]

[0132] Where Q, H, P, and n represent the pump flow rate, pump head, pump shaft power, and motor speed, respectively.

[0133] The change in the flow rate Q of the water pump is directly proportional to the change in the rotational speed n;

[0134] The change in the pump head H is directly proportional to the square of the rotational speed n;

[0135] The shaft power P of a water pump is directly proportional to the cube of its rotational speed n;

[0136] Therefore, changing the rotational speed n can significantly change the shaft power P of the water pump.

[0137] When the water consumption of the fire pump exceeds the designed rated flow rate and its pump shaft power exceeds 75% of the maximum motor power, the motor speed n drops rapidly. At this time, the flow rate Q, head H and shaft power P of the driven centrifugal pump will change according to the above relationship formula.

[0138] At 1.5 times the rated flow rate, its head must not be less than 0.65 of the rated head. Furthermore, as the system continues to increase the water flow rate, the fire pump's drive power (drive power = flow rate * head / efficiency) will reach an inflection point (the head decreases significantly as the water flow rate increases) without causing overload.

[0139] In another embodiment, step S400 is also included to calibrate the liquid level;

[0140] The S400 includes:

[0141] S401 uses an industrial camera to capture images of the liquid level gauge in real time.

[0142] S402 calibrates the ratio of image pixel size to actual liquid level scale size in real time, and performs region of interest segmentation on the image. The size of the segmented float indicator height image is calculated according to the pixel ratio to obtain the scale value mapped on the float liquid level scale, that is, the liquid level height.

[0143] S403, perform logical calculations based on the real-time flow rate of the water pump and the liquid level height to predict the liquid level change data; adjust the flow control parameters of the water pump according to the liquid level change data, or, if the liquid level change data is greater than or equal to the set change threshold, send an alarm message to the alarm module to remind the user to adjust the water pump flow rate or add water.

[0144] The working principle of the above technical solution is as follows: The solution adopted in this embodiment further includes step S400, which calibrates the liquid level; S400 includes: S401, using a telephoto lens to acquire an image on the liquid level scale in real time from a distance; S402, calibrating the ratio of the image pixel size to the actual liquid level scale size in real time, and segmenting the image into regions of interest, calculating the scale value mapped onto the float liquid level scale based on the pixel and actual ratio of the segmented float indication height image, i.e., the liquid level height; S403, performing logical calculations based on the real-time flow rate of the water pump and the liquid level height to predict the liquid level change data; adjusting the flow control parameters of the water pump according to the liquid level change data, or, if the liquid level change data is greater than or equal to a set change threshold, sending an alarm message to the alarm module to remind the user to adjust the water pump flow rate or add water.

[0145] The beneficial effects of the above technical solution are as follows: the solution provided in this embodiment uses a vision plus control algorithm to realize real-time liquid level adjustment, simulates manual control logic, and further limits the control of flow rate.

[0146] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A fire pump assembly, comprising: include: The system includes a flow control module, a fire pump parameter processing module, and a motor speed detection module; the flow control module is connected to the fire pump parameter processing module, and the fire pump parameter processing module is connected to the motor speed detection module. The motor speed detection module is used to detect the motor speed, and the fire pump parameter processing module is used to acquire and calculate the parameter relationship between the fire pump and the motor speed, and to preprocess the parameter relationship to obtain the correlation parameters. The fire pump parameter processing module includes: The first relationship determination unit is used to determine the first relationship between the water pump flow rate and the motor speed; The second relationship determination unit is used to determine the second relationship between the pump head and the motor speed; The third relationship determination unit is used to determine the third relationship between the pump shaft power and the motor speed; The correlation parameter determination unit is used to determine the correlation between motor speed and water pump flow rate, water pump head and water pump shaft power based on the first relationship, the second relationship and the third relationship, and form correlation parameters; The first relationship includes: the water pump flow rate is directly proportional to the change in motor speed; The second relationship includes: the pump head is directly proportional to the square of the change in motor speed; The third relationship includes: the pump shaft power is directly proportional to the cube of the change in motor speed; The correlation is as follows: when the motor speed is changed, the change in the power of the water pump shaft is greater than or equal to the set value. When the water consumption of the fire pump exceeds the designed rated flow, and its pump shaft power exceeds 75% of the maximum motor power, the motor speed drops rapidly. When the flow rate is 1.5 times the rated flow, its head cannot be lower than 0.65 of the rated head. In addition, when the system continues to increase the water flow, the drive power of the fire pump will reach an inflection point without overload. The flow control module is used to determine the flow parameters based on the correlation parameters, and to control the flow of the fire pump set based on the flow parameters; When the water consumption exceeds the designed rated flow rate, and the power of the water pump shaft exceeds 75% of the maximum shaft power of the motor, the rate of decrease in motor speed increases. The rate of decrease in water pump shaft power is the cube of the rate of decrease in motor speed.

2. The method of claim 1, wherein, The flow control module includes: The first equivalent parameter determination unit is used to determine the first equivalent parameter based on the maximum power of the water pump shaft as a constraint and a third relationship. The first equivalent parameter includes: a first proportional coefficient and a first equivalent coefficient; the first proportional coefficient when the water pump shaft power is proportional to the cube of the change in motor speed; the first equivalent coefficient is: within the constraint of ensuring the maximum power of the water pump shaft, the range of change in motor speed is determined as the first equivalent parameter. The second equivalent parameter determination unit is used to determine the second equivalent parameter based on the limitation of the rated head of the water pump and the second relationship. The second equivalent parameter includes: a second proportional coefficient and a second equivalent coefficient; the second proportional coefficient is proportional to the square of the change in the water pump head and the motor speed. The second equivalent coefficient is: under the limitation of the rated head of the water pump, the range of change in the motor speed is determined as the second equivalent parameter. The control unit is used to determine the range of motor speed variation based on the first equivalent parameter and the second equivalent parameter, and then determine the motor speed. Based on the determined range of motor speed and the first relationship between motor speed and water pump flow rate, the flow rate of the fire pump set is controlled.

3. The method of claim 1, wherein, It also includes a liquid level marking module, used to calibrate the liquid level of the liquid storage device; The liquid level marking module includes: The acquisition unit is used to acquire images of the liquid level gauge in real time using an industrial camera; The liquid level height determination unit is used to calibrate the ratio between the image pixel size and the actual liquid level scale size in real time, and to segment the image into regions of interest. The size of the segmented float indicator height image is calculated according to the pixel ratio and the actual ratio to obtain the scale value mapped on the float liquid level scale, that is, the liquid level height. The calculation and adjustment unit is used to perform logical calculations based on the real-time flow rate of the water pump and the liquid level height to predict the liquid level change data; adjust the flow control parameters of the water pump according to the liquid level change data, or send an alarm message to the alarm module if the liquid level change data is greater than or equal to a set change threshold, reminding the user to adjust the water pump flow rate or add water.

4. A method of flow control of a fire pump group, characterized by, include: S100 includes a flow control module, a fire pump parameter processing module, and a motor speed detection module; the flow control module is connected to the fire pump parameter processing module, and the fire pump parameter processing module is connected to the motor speed detection module. S200, the motor speed detection module is used to detect the motor speed, and the fire pump parameter processing module is used to obtain and calculate the parameter relationship between the relevant parameters of the fire pump and the motor speed, and to preprocess the parameter relationship to obtain the correlation parameters; S200 includes: S201, determine the primary relationship between pump flow rate and motor speed; S202, determine the second relationship between pump head and motor speed; S203, determine the third relationship between the pump shaft power and the motor speed; S204, based on the first relationship, the second relationship and the third relationship, determine the correlation between motor speed and water pump flow rate, water pump head and water pump shaft power, and form correlation parameters; The first relationship includes: the water pump flow rate is directly proportional to the change in motor speed; The second relationship includes: the pump head is directly proportional to the square of the change in motor speed; The third relationship includes: the pump shaft power is directly proportional to the cube of the change in motor speed; The correlation is as follows: when the motor speed is changed, the change in the power of the water pump shaft is greater than or equal to the set value. When the water consumption of the fire pump exceeds the designed rated flow and the pump shaft power exceeds 75% of the maximum power of the motor, the motor speed drops rapidly. When the flow rate is 1.5 times the rated flow rate, its head must not be less than 0.65 of the rated head. In addition, when the water flow rate of the system continues to increase, the drive power of the fire pump will reach an inflection point without overload. S300, the flow control module is used to determine the flow parameters according to the correlation parameters, and control the flow of the fire pump set based on the flow parameters; Specifically, S300 includes: determining that when the water consumption exceeds the designed rated flow rate; when the water pump shaft power exceeds 75% of the maximum shaft power of the motor, the rate of decrease in motor speed increases; and the rate of decrease in water pump shaft power is the cube of the rate of decrease in motor speed.

5. The method of flow control of a fire pump group according to claim 4, wherein, The S300 includes: S301, based on the maximum power of the water pump shaft as a constraint, and based on the third relationship, a first equivalent parameter is determined. The first equivalent parameter includes: a first proportional coefficient and a first equivalent coefficient; the first proportional coefficient when the water pump shaft power is proportional to the cube of the change in motor speed, and the first equivalent coefficient is: within the constraint of the maximum power of the water pump shaft, the range of change in motor speed is determined as the first equivalent parameter. S302, under the limitation of the rated head of the water pump, and based on the second relationship, determine the second equivalent parameter. The second equivalent parameter includes: a second proportional coefficient and a second equivalent coefficient; a second proportional coefficient that is proportional to the square of the change in the water pump head and the motor speed. The second equivalent coefficient is: under the limitation of the rated head of the water pump, the range of change in the motor speed is determined as the second equivalent parameter. S303, the range of motor speed variation is determined based on the first equivalent parameter and the second equivalent parameter, and then the motor speed is determined. Based on the determined range of motor speed and the first relationship between motor speed and water pump flow rate, the flow rate of the fire pump set is controlled.

6. The method for flow control of a fire pump set according to claim 4, characterized in that, It also includes step S400, which calibrates the liquid level; The S400 includes: S401 uses an industrial camera to capture images of the liquid level gauge in real time. S402 calibrates the ratio of image pixel size to actual liquid level scale size in real time, and performs region of interest segmentation on the image. The size of the segmented float indicator height image is calculated according to the pixel ratio to obtain the scale value mapped on the float liquid level scale, that is, the liquid level height. S403, perform logical calculations based on the real-time flow rate of the water pump and the liquid level height to predict the liquid level change data; adjust the flow control parameters of the water pump according to the liquid level change data, or, if the liquid level change data is greater than or equal to the set change threshold, send an alarm message to the alarm module to remind the user to adjust the water pump flow rate or add water.

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