Water consumption estimation and measurement method, system and application based on intelligent fire hydrant

Abstract

The present invention proposes a water estimation and metering method, system and application based on intelligent fire hydrants, including establishing an ideal water discharge model, using the Bernoulli equation and the continuity equation to determine the basic calculation relationship; then constructing an actual water discharge model, considering factors such as the roughness of the inner wall of the pipeline, calculating the friction loss and local resistance loss according to the Darcy-Weisbach formula and the local resistance coefficient, determining the flow state by the Reynolds number to determine the correlation coefficient, and then correcting the water discharge speed; finally, combining the actual data on site for comparison, verification and optimization of the model. The present invention can realize the estimation and metering of municipal fire hydrant water without a flow meter, providing a low-cost solution for water supply companies to grasp the illegal water consumption and distribution.

Description

Technical Field

[0001] The present invention relates to the technical field of water estimation and metering for intelligent fire hydrants, and in particular to a water estimation and metering method and system based on intelligent fire hydrants and applications thereof. Background Art

[0002] Municipal fire hydrants, as an important part of urban public fire protection facilities, play a key role in ensuring fire safety. However, in actual application, municipal fire hydrants have the problem of unauthorized water use, and the main bodies of these unauthorized water use include sanitation, greening, construction sites, etc.

[0003] This unauthorized water use has brought many adverse effects to the water supply company. First, the water supply company loses the water fee income that should have been collected, which directly affects the company's economic benefits. Secondly, since the actual water consumption does not match the statistical water consumption, the operating costs of the water supply company are increased, and the water leakage rate of the water company is increased. In order to make up for these losses, the water supply company may have to take measures to increase the water price, which will undoubtedly affect the interests of all users.

[0004] At present, the current situation of illegal water use through municipal fire hydrants has always existed, but the water supply company cannot accurately grasp the actual illegal water use and distribution. This makes the water supply company face difficulties in decision-making, such as being unable to reasonably plan the allocation of water resources according to the actual water use situation, and unable to take effective management measures for areas with serious illegal water use. Although in theory, flow meters can be installed for all fire hydrants in the region for statistical measurement, this method is very costly and does not meet the water supply company's requirements for cost control. In addition, the main demand of the water supply company is to understand the overall municipal illegal water use and distribution in order to make macro decisions, and it is not necessarily necessary to accurately measure and charge for the water use of each fire hydrant.

[0005] In summary, the existing technology has obvious deficiencies in the management of municipal fire hydrant water use, which cannot meet the needs of water supply companies to grasp the illegal water use and distribution, and also faces the problem of high costs. Therefore, there is an urgent need for a technical solution that can estimate the water use of municipal fire hydrants at a low cost. Summary of the invention

[0006] The embodiments of the present invention provide a method, system and application of water consumption estimation and metering based on intelligent fire hydrants, which aims to solve the problems of the existing flow meter metering method with high cost and lack of low-cost technical solutions for estimating water consumption.

[0007] The core technology of the present invention is mainly based on intelligent fire hydrants, which realizes the estimation and measurement of water consumption of municipal fire hydrants through an ideal water discharge model (using the Bernoulli equation and the continuity equation) and an actual water discharge model that considers multiple factors (involving the Darcy-Weisbach formula, local resistance coefficient, etc. to calculate the friction loss and local resistance loss along the way).

[0008] In a first aspect, the present invention provides a method for estimating and measuring water consumption based on an intelligent fire hydrant, the method comprising the following steps:

[0009] S00. According to the established theoretical water discharge model, the initial water discharge velocity of the water outlet is obtained, and the initial velocity is used as the fluid velocity. The Reynolds number Re is calculated according to the fluid velocity and dynamic viscosity and the pipe diameter to determine the flow state, including laminar flow or turbulent flow; wherein the Reynolds number Re is a dimensionless number used to judge the flow state of the fluid; the theoretical water discharge model is established by determining the measurement point, measuring the pressure and height difference and determining the fluid properties, and defining the relevant variables based on the Bernoulli equation and the continuity equation for calculation;

[0010] S10, determining the friction coefficient according to the Reynolds number Re and the roughness of the inner wall of the pipeline;

[0011] S20, determining the local resistance coefficient according to the local obstacles in the fire hydrant system;

[0012] S30, measuring the internal pressure of the fire hydrant and recording the atmospheric pressure, thereby obtaining a pressure difference;

[0013] S40, based on the friction coefficient and the local resistance coefficient, respectively calculating the friction loss along the way and the local resistance loss; wherein the friction loss along the way and the local resistance loss are both expressed in the form of pressure loss, and the local resistance loss is used to describe the energy loss when the fluid passes through a local obstacle in the pipeline;

[0014] S50, based on the friction loss and local resistance along the way, the water release speed is corrected by the Bernoulli equation;

[0015] S60. Based on the corrected water discharge speed and the known water outlet diameter, the actual volume flow of water discharge is calculated, and then the cumulative water consumption in the corresponding time period is obtained by integrating or summing the volume flow in different time periods, thereby realizing the simulation and calculation of the actual water discharge situation and estimating the water consumption of the municipal fire hydrant.

[0016] Furthermore, in step S00, when the Reynolds number is less than 2300, the flow state is laminar flow; when the Reynolds number is greater than 4000, the flow state is turbulent flow.

[0017] Furthermore, in step S10, when the flow state is laminar flow, the friction coefficient f is calculated by the theoretical formula:

[0018] f=64 / Re

[0019] Where Re is the Reynolds number; 64 is a constant derived from theory, which is used to describe the relationship between the friction coefficient and the Reynolds number when the fluid flows under laminar conditions;

[0020] When the flow state is turbulent, the friction coefficient f is simplified by the Svedsen-Buckley formula:

[0021]

[0022] Among them, ε is the absolute roughness of the inner wall of the pipe; D is the diameter of the fire hydrant pipe.

[0023] Furthermore, in step S40, the friction loss along the way is calculated by the Darcy-Weisbach formula:

[0024]

[0025] Among them, f is the friction coefficient; D is the diameter of the fire hydrant pipe; ρ is the density of the fluid; Δp1 is the pressure loss through the pipe section, which is used to express the friction loss along the way; Δh is the height difference between the two measuring points; and v1 is the water flow velocity in the fire hydrant.

[0026] Furthermore, in step S40, the calculation formula of the local resistance loss is:

[0027]

[0028] Where Δp2 is the pressure drop caused by local resistance; ξ is the damping coefficient.

[0029] Furthermore, the establishment process of the theoretical water release model is as follows:

[0030] Determine the measuring points, with the bottom of the fire hydrant as the first measuring point and the water outlet of the fire hydrant as the second measuring point;

[0031] Measure the pressure at two measuring points respectively, measure the height difference between the two measuring points, and measure the pipe diameter and the outlet diameter of the fire hydrant;

[0032] Based on the known fluid density and gravitational acceleration, a theoretical water release model is established through the Bernoulli equation and the continuity equation.

[0033] Furthermore, the theoretical water release model Q is:

[0034]

[0035] Among them, V2 is the initial water discharge velocity of the outlet; D is the diameter of the fire hydrant pipe; d is the diameter of the outlet; ρ is the fluid density; g is the acceleration of gravity; Δh is the height difference between the two measuring points; and P is the pressure difference between the two measuring points.

[0036] In a second aspect, the present invention provides a water consumption estimation and metering system based on an intelligent fire hydrant, comprising:

[0037] Theoretical water discharge module obtains the initial water discharge velocity of the water outlet according to the established theoretical water discharge model. The initial velocity is used as the fluid velocity. The Reynolds number Re is calculated according to the fluid velocity and viscosity as well as the pipe diameter to determine the flow state, including laminar flow or turbulent flow. The Reynolds number Re is a dimensionless number used to determine the flow state of the fluid. The theoretical water discharge model determines the measurement points, measures the pressure and height difference, and determines the fluid properties. It is established by calculation based on the Bernoulli equation and the continuity equation after defining the relevant variables.

[0038] The actual water discharge module determines the friction coefficient according to the Reynolds number Re and the roughness of the inner wall of the pipe; determines the local resistance coefficient according to the local obstacles in the fire hydrant system; measures the internal pressure of the fire hydrant and records the atmospheric pressure to obtain the pressure difference; calculates the friction loss and local resistance loss along the way based on the friction coefficient and the local resistance coefficient; the friction loss and local resistance loss along the way are expressed in the form of pressure loss, and the local resistance loss is used to describe the energy loss when the fluid passes through the local obstacles in the pipeline;

[0039] The correction module corrects the water release speed based on the friction loss and local resistance along the way and then uses the Bernoulli equation;

[0040] The calculation module calculates the actual volume flow of water discharge based on the corrected water discharge speed and the known outlet diameter, and then obtains the cumulative water consumption in the corresponding time period by integrating or summing the volume flow in different time periods, thereby simulating and calculating the actual water discharge situation and estimating the water consumption of municipal fire hydrants.

[0041] In a third aspect, the present invention provides an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute the above-mentioned water consumption estimation and metering method based on smart fire hydrants.

[0042] In a fourth aspect, the present invention provides a readable storage medium storing a computer program, wherein the computer program includes a program code for controlling a process to execute a process, wherein the process includes the water consumption estimation and metering method based on the smart fire hydrant.

[0043] The main contributions and innovations of the present invention are as follows:

[0044] 1. Cost

[0045] In the existing technology, if water consumption of municipal fire hydrants is to be measured, the method of installing flow meters in the whole area is very costly. However, the present invention does not need to install flow meters, and estimates water consumption by building a water release model based on smart fire hydrants. Moreover, since water consumption measurement does not need to be very accurate, it can fully meet the demand and greatly reduce the cost investment of water supply companies in understanding water consumption.

[0046] 2. Understand water usage

[0047] The existing technology cannot effectively grasp the actual illegal water consumption and distribution of municipal fire hydrants, which is not conducive to the water supply company to make reasonable decisions. The present invention can estimate and measure the water consumption of municipal fire hydrants by establishing an ideal and actual water release model, and provide the water supply company with data support for the overall municipal illegal water consumption and distribution, which helps the water supply company to rationally plan water resource allocation and take effective management measures for areas with serious illegal water use.

[0048] 3. Accuracy and practicality

[0049] By comparing the actual data on site, the present invention can continuously adjust and optimize the model parameters and improve the accuracy of water consumption estimation and measurement. At the same time, the present invention fully considers various factors in the actual fluid flow, such as the roughness of the inner wall of the pipeline, local obstacles, etc., so that the model is more in line with the actual situation and has high practicality.

[0050] The details of one or more embodiments of the invention are set forth in the following drawings and description so that other features, objects, and advantages of the invention are more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0052] Figure 1 This is a process of a water consumption estimation and metering method based on an intelligent fire hydrant according to an embodiment of the present invention;

[0053] Figure 2 is a schematic diagram of the structure of an intelligent fire hydrant according to an embodiment of the present invention;

[0054] Figure 3 4 is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with one or more embodiments of this specification. Instead, they are merely examples of devices and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0056] It should be noted that: in other embodiments, the steps of the corresponding method are not necessarily performed in the order shown and described in this specification. In some other embodiments, the steps included in the method may be more or less than those described in this specification. In addition, a single step described in this specification may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this specification may be combined into a single step for description in other embodiments.

[0057] Unauthorized water use from municipal fire hydrants results in reduced water bill revenue, increased operating costs, and higher leakage rates for water supply companies, and it is impossible to grasp the actual amount and distribution of illegal water use.

[0058] Based on this, the present invention solves the problems existing in the prior art based on an ideal water release model and an actual water release model.

[0059] Embodiment 1

[0060] The present invention aims to propose a water consumption estimation and metering method based on intelligent fire hydrants. Figure 1 , the method comprising:

[0061] S00, obtaining the initial velocity of water discharge from the water outlet according to the established theoretical water discharge model, taking the initial velocity as the fluid velocity, and calculating the Reynolds number Re according to the fluid velocity and viscosity and the pipe diameter to determine the flow state, including laminar flow or turbulent flow; wherein the Reynolds number Re is a dimensionless number used to judge the flow state of the fluid;

[0062] In this embodiment, in order to simplify the calculation process during the actual establishment of the theoretical water release model, it is assumed that the water flow is in an ideal state (that is, viscosity and compressibility are not considered) and the head loss is ignored.

[0063] The theoretical basis is:

[0064] Bernoulli's equation: describes the relationship between pressure, velocity and height of a fluid at different locations in a pipe.

[0065] Continuity equation: ensures that the mass flow rate of the fluid in each cross section of the pipe is equal.

[0066] Model construction:

[0067] Determine the measuring points: one at the fire hydrant and the other at the fire hydrant outlet.

[0068] Measuring pressure: Use a pressure gauge to measure the pressure inside the fire hydrant and the atmospheric pressure

[0069] Measure Height Difference: Measure the height difference between two locations

[0070] Determine fluid properties: record the density ρ and viscosity of the fluid

[0071] The calculation steps are as follows:

[0072] S01. Define variables:

[0073] like Figure 2 As shown, p1 and p2 represent the detected pressure at the fire hydrant valve disc and the atmospheric pressure respectively; the pressure sensor measures the relative pressure value (the pressure difference relative to the atmospheric pressure), so p1-p2 is the measured value P of the pressure sensor; v1 and v2 represent the internal flow velocity of the pipeline and the flow velocity of the fire hydrant outlet (the initial speed of water discharge from the outlet), respectively; h1 and h2 are the heights of the fire hydrant outlet at the valve disc; Δh is the height difference between the valve disc and the fire hydrant outlet; ρ is the density of water; g is the acceleration of gravity.

[0074] Therefore, based on the Bernoulli equation we get:

[0075]

[0076] S02. Assuming that the fluid flow is stable and continuous, according to the continuity equation, the volume flow rate of the fluid through any cross section of the pipeline is constant. Based on the continuity equation, the following calculation can be performed:

[0077] The diameter of the fire hydrant pipe is D, the diameter of the water outlet is d, A1 is the cross-sectional area of ​​the fire hydrant body, and A2 is the cross-sectional area of ​​the water outlet.

[0078]

[0079] In this way, the water flow velocity at the fire hydrant outlet (initial water discharge velocity at the outlet) v2 is:

[0080]

[0081]

[0082] That is, the theoretical water release model Q is obtained.

[0083] S10, determining the friction coefficient according to the Reynolds number Re and the roughness of the inner wall of the pipeline;

[0084] S20, determining the local resistance coefficient according to the local obstacles in the fire hydrant system;

[0085] S30, measuring the internal pressure of the fire hydrant and recording the atmospheric pressure, thereby obtaining a pressure difference;

[0086] S40, based on the friction coefficient and the local resistance coefficient, respectively calculating the friction loss along the way and the local resistance loss; wherein the friction loss along the way and the local resistance loss are both expressed in the form of pressure loss, and the local resistance loss is used to describe the energy loss when the fluid passes through a local obstacle in the pipeline;

[0087] In this embodiment, steps S10-S40 are the process of establishing an actual waterproof model. In the actual fluid flow process, there is not only the ideal situation described by the Bernoulli equation, but also energy loss caused by factors such as the roughness of the inner wall of the pipe, fluid viscosity, and local obstacles. The theoretical basis is:

[0088] Darcy-Weisbach formula: calculates friction losses along the way.

[0089] Local resistance coefficient: describes the pressure loss caused by local obstacles (such as elbows, valves, etc.).

[0090] Among them, a pressure gauge is used to measure the pressure inside the fire hydrant and record the atmospheric pressure p. The friction coefficient f is found or calculated based on the Reynolds number of the pipeline material and the fluid. The local resistance coefficient K is found or estimated based on the specific conditions of the fire hydrant system (such as whether there are valves, elbows, etc.).

[0091] Specifically calculate the friction loss along the way and express it in the form of pressure loss:

[0092]

[0093] Where f is the friction coefficient; D is the diameter of the fire hydrant pipe; ρ is the density of the fluid; Δp1 is the pressure loss through the pipe section, which is used to express the friction loss along the way; Δh is the height difference between the two measuring points; v1 is the water flow velocity in the fire hydrant;

[0094] The friction coefficient f is a key parameter in the Darcy-Weisbach formula, and its value depends on the flow state of the fluid (laminar or turbulent) and the roughness of the inner wall of the pipe. The determination of the friction coefficient usually depends on the Reynolds number and the relative roughness of the inner wall of the pipe.

[0095] Here the Reynolds coefficient

[0096] Where v is the water velocity in the fire hydrant, D is the diameter of the fire hydrant pipe, μ is the dynamic viscosity of the fluid (unit: Pa·s), and ρ is the density of the fluid (unit: kg / m³).

[0097] When the Reynolds number is less than about 2300, laminar flow is used;

[0098] When the Reynolds number is greater than about 4000, it is turbulent;

[0099] Between 2300 and 4000, the flow may be in a transitional state, depending on the conditions.

[0100] S50, based on the friction loss and local resistance along the way, the water release speed is corrected by the Bernoulli equation;

[0101] S60. Based on the corrected water discharge speed and the known water outlet diameter, the actual volume flow of water discharge is calculated, and then the cumulative water consumption in the corresponding time period is obtained by integrating or summing the volume flow in different time periods, thereby realizing the simulation and calculation of the actual water discharge situation and estimating the water consumption of the municipal fire hydrant.

[0102] In this embodiment, when the Reynolds number is less than about 2300, laminar flow is performed, that is, the particles of the fluid move in an orderly linear manner and do not mix with each other. For laminar flow, the friction coefficient can be calculated by the theoretical formula f=64 / Re, where 64 is a constant derived based on theoretical derivation and is used to describe the relationship between the friction coefficient and the Reynolds number when the fluid flows under laminar flow conditions.

[0103] When the flow state is turbulent, the friction coefficient f is simplified by the Svedsen-Buckley formula:

[0104]

[0105] Among them, ε is the absolute roughness of the inner wall of the pipe; D is the diameter of the fire hydrant pipe.

[0106] For example, at 20°C, the kinematic viscosity of water (dynamic viscosity of a fluid divided by its density) is approximately 1.004*10 -6 m² / s, fire hydrant pipe diameter D=100mm, ρ=1*10 3 kg / m³

[0107] but

[0108] When Re>4000, the friction coefficient f should be calculated according to turbulence, that is, in a 100mm fire hydrant, when v>0.04m / s, the fluid is in a turbulent state. The friction coefficient is simplified by the Svedsen-Buckley formula:

[0109]

[0110] Among them, ε is the absolute roughness of the inner wall of the pipe; D is the diameter of the fire hydrant pipe. The absolute roughness here is shown in Table 1 below:

[0111] Table 1

[0112]

[0113] In this embodiment, the damping coefficient ξ is a way to measure the local resistance, which is used to describe the energy loss when the fluid passes through local obstacles such as valves, elbows, and expansion sections. The relationship between the damping coefficient and the flow velocity is as follows:

[0114]

[0115] Where Δp2 is the pressure drop caused by the local resistance; ξ is the damping coefficient, and the damping coefficient is an empirical value. Generally, for fire hydrants, it is 0.5 - 3, for right-angle elbows, it is 0.3 - 1.5, for 45° elbows, it is 0.1 - 0.2, and so on.

[0116] Preferably, there is also a situation where when the Reynolds number Re is between 2300 and 4000, the flow may be in a transitional state, and it needs to be determined according to specific conditions.

[0117] For example, when the flow is in a transitional state (2300 < Re < 4000), the following is a possible method for estimating the friction coefficient, but note that this is only a relatively complex way that needs to be adjusted according to the actual situation:

[0118] 1. Consider the influence weights of laminar flow and turbulent flow

[0119] Since the transitional state is between laminar flow and turbulent flow, the influence weights of laminar flow and turbulent flow can be roughly determined according to the relative position of the Reynolds number in this interval. For example, when Re is close to 2300, the influence weight of laminar flow is relatively large; when Re is close to 4000, the influence weight of turbulent flow is relatively large.

[0120] 2. Calculate by combining laminar flow and turbulent flow formulas

[0121] First, calculate the corresponding friction coefficients in the laminar flow and turbulent flow states respectively.

[0122] For laminar flow, calculate according to Calculate.

[0123] For turbulent flow, the turbulent friction coefficient formula or chart applicable to the corresponding pipe conditions (such as the inner wall roughness of the pipe, pipe diameter, etc.) can be referred to. For example, if it is a pipe with a certain specific pipe diameter and roughness, relevant empirical formulas or formulas fitted based on experimental data under similar pipe conditions can be found to calculate the friction coefficient f in the turbulent flow state 湍流 .

[0124] 3. Calculate the friction coefficient in the transitional state by weighted average

[0125] According to the determined laminar and turbulent influence weights, f 层流 and f 湍流 Perform weighted averaging. Let the laminar flow influence weight be w 层流 , the turbulence influence weight is w 层流 , and w 层流 +w 湍流 =1.

[0126] The friction coefficient f in the transition state is 过渡 =w 层流 *f 层流 +w 湍流 *f 湍流 .

[0127] 4. Adjust according to the actual situation of the pipeline

[0128] Considering the material properties of the pipe, the unevenness of the inner wall roughness, and other characteristics of the actual fluid (such as temperature, impurity content, and other factors that may affect the viscosity), the calculated f 过渡 Make appropriate adjustments. This may require reference to more actual engineering experience data or further experimental research results for reasonable corrections. For example, refer to the actual experience data of similar pipelines and fluid systems in the transition state in the past. If there is a large amount of experimental data or actual engineering cases showing that under certain specific conditions (such as specific pipe diameters, fluid types, temperatures, etc.), the tendency of laminar or turbulent flow is more obvious, then the weights can be adjusted based on this information. Refer to the actual experience data of similar pipelines and fluid systems in the transition state in the past. If there is a large amount of experimental data or actual engineering cases showing that under certain specific conditions (such as specific pipe diameters, fluid types, temperatures, etc.), the tendency of laminar or turbulent flow is more obvious, then the weights can be adjusted based on this information.

[0129] It is worth mentioning that in actual use, most situations are turbulent.

[0130] Embodiment 2

[0131] Based on the same concept, the present invention also proposes a water consumption estimation and metering system based on intelligent fire hydrants, comprising:

[0132] Theoretical water discharge module obtains the initial water discharge velocity of the water outlet according to the established theoretical water discharge model. The initial velocity is used as the fluid velocity. The Reynolds number Re is calculated according to the fluid velocity and viscosity as well as the pipe diameter to determine the flow state, including laminar flow or turbulent flow. The Reynolds number Re is a dimensionless number used to determine the flow state of the fluid. The theoretical water discharge model determines the measurement points, measures the pressure and height difference, and determines the fluid properties. It is established by calculation based on the Bernoulli equation and the continuity equation after defining the relevant variables.

[0133] The actual water discharge module determines the friction coefficient according to the Reynolds number Re and the roughness of the inner wall of the pipe; determines the local resistance coefficient according to the local obstacles in the fire hydrant system; measures the internal pressure of the fire hydrant and records the atmospheric pressure to obtain the pressure difference; calculates the friction loss and local resistance loss along the way based on the friction coefficient and the local resistance coefficient; the friction loss and local resistance loss along the way are expressed in the form of pressure loss, and the local resistance loss is used to describe the energy loss when the fluid passes through the local obstacles in the pipeline;

[0134] The correction module corrects the water release speed based on the friction loss and local resistance along the way and then uses the Bernoulli equation;

[0135] The calculation module calculates the actual volume flow of water discharge based on the corrected water discharge speed and the known outlet diameter, and then obtains the cumulative water consumption in the corresponding time period by integrating or summing the volume flow in different time periods, thereby simulating and calculating the actual water discharge situation and estimating the water consumption of municipal fire hydrants.

[0136] In this embodiment, the initial water discharge speed of the water outlet is obtained through the theoretical water discharge model:

[0137]

[0138] For example, the fire hydrant pipe diameter D = 100mm, the outlet diameter d = 65mm, the height difference between the two measuring points Δh = 0.5m, and the pressure difference between the two measuring points P = 100Kpa.

[0139] but

[0140] v 20 =15.981m / s,

[0141] Friction loss along the way :

[0142] Reynolds number

[0143]

[0144]

[0145] The local resistance loss is taken as 1.5 according to the actual situation and experience:

[0146]

[0147] Then use the Bernoulli equation to correct the water release speed v2:

[0148] Bernoulli equation

[0149]

[0150] The flow rate Q (which is not the same as the theoretical water release model Q) is:

[0151]

[0152] Among them, A2 is the cross-sectional area of ​​the drain outlet.

[0153] In this embodiment, a comparison with the flow meter water meter is also performed, and the initial parameters are as follows:

[0154] D=100, d=65, Δh=0.5m, ε is 0.5, the default value, which can be adjusted according to the actual situation, and ξ is 1.5 as the default value, which can be adjusted according to the actual situation. The results are shown in Table 2:

[0155] Table 2

[0156]

[0157] It can be seen that the error of using the system or method of the present invention is not large, which can fully meet the current usage requirements, and the cost is much lower than installing flow meters and water meters in large quantities.

[0158] Embodiment 3

[0159] This embodiment also provides an electronic device, referring to Figure 3 , comprises a memory 404 and a processor 402, wherein the memory 404 stores a computer program, and the processor 402 is configured to run the computer program to execute the steps in any of the above method embodiments.

[0160] Specifically, the processor 402 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiment of the present invention.

[0161] Among them, the memory 404 may include a large capacity memory 404 for data or instructions. For example, but not limitation, the memory 404 may include a hard disk drive (HDD), a floppy disk drive, a solid state drive (SSD), a flash memory, an optical disk, a magneto-optical disk, a tape, or a universal serial bus (USB) drive, or a combination of two or more of these. In appropriate cases, the memory 404 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 404 may be inside or outside the data processing device. In a specific embodiment, the memory 404 is a non-volatile memory. In a specific embodiment, the memory 404 includes a read-only memory (ROM) and a random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (Programmable Read-Only Memory, PROM for short), an erasable PROM (Erasable Programmable Read-Only Memory, EPROM for short), an electrically erasable PROM (Electrically Erasable Programmable Read-Only Memory, EEPROM for short), an electrically alterable ROM (Electrically Alterable Read-Only Memory, EAROM for short) or a flash memory (FLASH) or a combination of two or more of these. In appropriate circumstances, the RAM may be a static random access memory (SRAM) or a dynamic random access memory (DRAM), wherein the DRAM may be a fast page mode dynamic random access memory 404 (FPMDRAM), an extended data output dynamic random access memory (EDODRAM), a synchronous dynamic random access memory (SDRAM), etc.

[0162] The memory 404 may be used to store or cache various data files required for processing and / or communication, as well as possible computer program instructions executed by the processor 402 .

[0163] The processor 402 reads and executes the computer program instructions stored in the memory 404 to implement any one of the water consumption estimation and metering methods based on the smart fire hydrant in the above embodiments.

[0164] Optionally, the electronic device may further include a transmission device 406 and an input / output device 408 , wherein the transmission device 406 is connected to the processor 402 , and the input / output device 408 is connected to the processor 402 .

[0165] The transmission device 406 can be used to receive or send data via a network. Specific examples of the above-mentioned network may include a wired or wireless network provided by a communication provider of the electronic device. In one example, the transmission device includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 406 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0166] Input / output devices 408 are used to input or output information.

[0167] Embodiment 4

[0168] This embodiment also provides a readable storage medium, in which a computer program is stored. The computer program includes a program code for controlling a process to execute a process. The process includes a water consumption estimation and metering method based on a smart fire hydrant according to the first embodiment.

[0169] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and this embodiment will not be described in detail here.

[0170] In general, various embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software executed by a controller, microprocessor, or other computing device, but the invention is not limited thereto. Although various aspects of the invention may be shown and described as block diagrams, flow charts, or using some other graphical representation, it should be understood that, as non-limiting examples, the boxes, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0171] Embodiments of the present invention may be implemented by computer software that is executable by a data processor of a mobile device, such as in a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) including software routines, applets and / or macros may be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. A computer program product may include one or more computer executable components configured to perform an embodiment when the program is run. One or more computer executable components may be at least one software code or a portion thereof. In addition, at this point, it should be noted that, for example, Figure 1 Any block of the logic flow in the program may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on physical media such as memory chips or storage blocks implemented within the processor, magnetic media such as hard disks or floppy disks, and optical media such as, for example, DVDs and their data variants, CDs, etc. Physical media are non-transitory media.

[0172] Those skilled in the art should understand that the technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0173] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A water consumption estimation and metering method based on intelligent fire hydrants, characterized in that: The following steps are involved: S00. According to the established theoretical water discharge model, the initial water discharge velocity of the water outlet is obtained, and the initial velocity is used as the fluid velocity. The Reynolds number Re is calculated according to the fluid velocity and viscosity and the pipe diameter to determine the flow state, including laminar flow or turbulent flow; wherein the Reynolds number Re is a dimensionless number used to determine the flow state of the fluid; the theoretical water discharge model is established by determining the measurement point, measuring the pressure and height difference and determining the fluid properties, and defining the relevant variables based on the Bernoulli equation and the continuity equation for calculation; S10, determining the friction coefficient according to the Reynolds number Re and the roughness of the inner wall of the pipeline; S20, determining the local resistance coefficient according to the local obstacles in the fire hydrant system; S30, measuring the internal pressure of the fire hydrant and recording the atmospheric pressure, thereby obtaining a pressure difference; S40, based on the friction coefficient and the local resistance coefficient, respectively calculating the friction loss along the way and the local resistance loss; wherein the friction loss along the way and the local resistance loss are both expressed in the form of pressure loss, and the local resistance loss is used to describe the energy loss when the fluid passes through a local obstacle in the pipeline; S50, based on the friction loss along the way and the local resistance, correcting the water release speed by using the Bernoulli equation; S60. Based on the corrected water discharge speed and the known water outlet diameter, the actual volume flow of water discharge is calculated, and then the cumulative water consumption in the corresponding time period is obtained by integrating or summing the volume flow in different time periods, thereby realizing the simulation and calculation of the actual water discharge situation and estimating the water consumption of the municipal fire hydrant.

2. A water consumption estimation and metering method based on intelligent fire hydrants as claimed in claim 1, characterized in that: In step S00, when the Reynolds number is less than 2300, the flow state is laminar flow; when the Reynolds number is greater than 4000, the flow state is turbulent flow.

3. A water consumption estimation and metering method based on intelligent fire hydrants as claimed in claim 2, characterized in that: In step S10, when the flow state is laminar, the friction coefficient f is calculated by the theoretical formula: f=64 / Re Where Re is the Reynolds number; 64 is a constant derived from theory, which is used to describe the relationship between the friction coefficient and the Reynolds number when the fluid flows under laminar conditions; When the flow state is turbulent, the friction coefficient f is simplified by the Svedsen-Buckley formula: ； Among them, ε is the absolute roughness of the inner wall of the pipe; D is the diameter of the fire hydrant pipe.

4. The water consumption estimation and metering method based on intelligent fire hydrants according to claim 1 is characterized in that: In step S40, the friction loss along the way is calculated by the Darcy-Weisbach formula: ； Among them, f is the friction coefficient; D is the diameter of the fire hydrant pipe; ρ is the density of the fluid; Δp1 is the pressure loss through the pipe section, which is used to express the friction loss along the way; Δh is the height difference between the two measuring points; and v1 is the water flow velocity in the fire hydrant.

5. A water consumption estimation and metering method based on intelligent fire hydrants as claimed in claim 4, characterized in that: In step S40, the calculation formula of the local resistance loss is: ； Where Δp2 is the pressure drop caused by local resistance; ξ is the damping coefficient.

6. A water consumption estimation and metering method based on intelligent fire hydrants as described in any one of claims 1 to 5, characterized in that: The establishment process of the theoretical water release model is as follows: Determine the measuring points, with the bottom of the fire hydrant as the first measuring point and the water outlet of the fire hydrant as the second measuring point; Measure the pressure at two measuring points respectively, measure the height difference between the two measuring points, and measure the pipe diameter and the outlet diameter of the fire hydrant; Based on the known fluid density and gravitational acceleration, a theoretical water release model is established through the Bernoulli equation and the continuity equation.

7. A water consumption estimation and metering method based on intelligent fire hydrants as claimed in claim 6, characterized in that: The theoretical water release model Q is: ； Among them, V2 is the initial water discharge velocity of the outlet; D is the diameter of the fire hydrant pipe; d is the diameter of the outlet; ρ is the fluid density; g is the acceleration of gravity; Δh is the height difference between the two measuring points; and P is the pressure difference between the two measuring points.

8. A water consumption estimation and metering system based on intelligent fire hydrants, characterized in that: include: Theoretical water discharge module obtains the initial water discharge velocity of the water outlet according to the established theoretical water discharge model. The initial velocity is used as the fluid velocity. The Reynolds number Re is calculated according to the fluid velocity and viscosity as well as the pipe diameter to determine the flow state, including laminar flow or turbulent flow. The Reynolds number Re is a dimensionless number used to determine the flow state of the fluid. The theoretical water discharge model determines the measurement points, measures the pressure and height difference, and determines the fluid properties. It is established by calculation based on the Bernoulli equation and the continuity equation after defining the relevant variables. The actual water discharge module determines the friction coefficient according to the Reynolds number Re and the roughness of the inner wall of the pipe; determines the local resistance coefficient according to the local obstacles in the fire hydrant system; measures the internal pressure of the fire hydrant and records the atmospheric pressure to obtain the pressure difference; calculates the friction loss and local resistance loss along the way based on the friction coefficient and the local resistance coefficient; the friction loss and local resistance loss along the way are expressed in the form of pressure loss, and the local resistance loss is used to describe the energy loss when the fluid passes through the local obstacles in the pipeline; The correction module corrects the water release speed based on the friction loss and local resistance along the way and then uses the Bernoulli equation; The calculation module calculates the actual volume flow of water discharge based on the corrected water discharge speed and the known outlet diameter, and then obtains the cumulative water consumption in the corresponding time period by integrating or summing the volume flow in different time periods, thereby simulating and calculating the actual water discharge situation and estimating the water consumption of municipal fire hydrants.

9. An electronic device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to run the computer program to execute the water consumption estimation and metering method based on smart fire hydrants according to any one of claims 1 to 7.

10. A readable storage medium, characterized in that: A computer program is stored in the readable storage medium, and the computer program includes a program code for controlling a process to execute the process, and the process includes the water consumption estimation and metering method based on the smart fire hydrant according to any one of claims 1 to 7.

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