Ultrasonic water meter flow measurement and outdoor water leak detection method using temperature distribution and pressure change, and thereof the ultrasonic water meter

Abstract

The present invention relates to a method for measuring flow rate in an ultrasonic water meter, and more specifically, to a method for measuring flow rate and detecting outdoor leakage in an ultrasonic water meter using temperature distribution and pressure changes, which analyzes the flow pattern of water and measures the flow rate using an average flow velocity corresponding to the flow pattern of water. The method for measuring flow rate and detecting outdoor leakage of an ultrasonic water meter according to the present invention enables the measurement of a flow rate that takes into account the flow pattern of water using a temperature distribution. By considering that the velocity distribution and average velocity vary according to the flow pattern of water, and by determining the flow pattern of water using a Reynolds number to which the average temperature is applied, and calculating the average velocity according to the flow pattern of water, the flow rate can be calculated using this, thereby enabling accurate calculation of the flow rate.

Description

Technology Field

[0001] The present invention relates to a method for measuring flow rate in an ultrasonic water meter, and more specifically, to a method for measuring flow rate in an ultrasonic water meter and detecting outdoor leakage using temperature distribution and pressure change, which analyzes the flow pattern of water and measures the flow rate using an average flow velocity corresponding to the flow pattern of water. Background Technology

[0002] Impeller water meters have disadvantages such as pressure loss due to physical friction, inability to detect low-speed water flow, and errors caused by impeller floating and durability issues. , Recently, ultrasonic meters that overcome these disadvantages are being used.

[0003] An ultrasonic meter is a device that measures flow rate by detecting the fluid flow within a pipe using ultrasound. Since the ultrasonic sensor can be installed outside the pipe and the flow rate can be measured simply, it is widely used in water meters.

[0004] However, ultrasonic water meters also cannot accurately measure flow rates based solely on central velocity measurements due to the diverse water flows of laminar, transitional, and turbulent states; furthermore, errors in velocity measurement occur as the temperature distribution within the water pipes changes with the seasons.

[0005] Korean Registered Patent No. 10-2116651, "Method for measuring flow rate of an ultrasonic water meter and the ultrasonic water meter said," is intended to improve the precision of accurate ultrasonic flow rate measurement by calculating a flow rate correction coefficient to correct the error when calculating the flow rate using linear velocity. It calculates the ratio of the frictional force and the inertial force between water and a pipe, and corrects the linear velocity to an average velocity using a function thereof, thereby enabling the measurement of an accurate flow rate value.

[0006] In other words, the flow rate measurement method of such an ultrasonic water meter calculates the water temperature by utilizing the fact that the propagation time of ultrasound varies with water temperature, determines the water viscosity coefficient according to the temperature, and uses this to set a flow rate correction factor value to correct the error in flow rate measurement. (Error correction considering the laminar flow characteristics of water)

[0007] However, as shown in Fig. 1, the temperature of the water inside the water pipe varies depending on the surrounding environment and the measurement location.

[0008] Therefore, since changes in the internal temperature distribution of water pipes occur due to the difference with the external temperature, the accurate temperature distribution of the water cannot be determined solely from the central flow velocity. Consequently, inaccurate temperature measurements lead to errors in the calculation of the water viscosity coefficient, which in turn causes errors in flow rate measurement.

[0009] Ultrasonic water meters, which are significantly affected by water temperature, inevitably generate large errors in flow rate measurements due to the failure to account for water temperature or inaccurate temperature measurements. (The speed of ultrasound varies with water temperature.)

[0010] Figure 1 is a diagram showing the state of temperature distribution change according to the temperature difference between the inside and outside of a water pipe.

[0011] In addition, as shown in FIGS. 2 and 3, water flows laminarly or turbulently within a water pipe (there is also transitional flow, which is a combination of laminar and turbulent flow), and accordingly, a difference in flow velocity occurs between the surface and the center of the water pipe. If this is not taken into account, an error occurs in the flow rate measurement.

[0012] The above-described method for measuring the flow rate of an ultrasonic water meter does not consider the flow pattern of water and sets a correction factor value by assuming that the water flow is laminar flow as in Fig. 2, so an error in flow rate measurement occurs when there is turbulent flow or transitional flow as in Fig. 3.

[0013] Figures 2 and 3 are diagrams showing the flow distribution of water, Figure 2 shows laminar flow, and Figure 3 shows turbulent flow.

[0014] As such, conventional flow rate measurement methods cause significant errors in flow rate measurement due to failure to consider the temperature distribution of water or inaccurate water temperature measurements.

[0015] Meanwhile, while water leaks inside the home can be detected through real-time monitoring of water usage, there is a need for a method to monitor water leaks outside the home in real-time at a low cost.

[0016] Korean Registered Patent No. 10-1888188, an ultrasonic water meter capable of leak detection, a leak detection system equipped with the same, and a leak location detection method using the same, determine whether a leak has occurred and its location by analyzing the signal of a leak sound detection sensor.

[0017] However, such leak detection systems require the use of expensive leak sound detection sensors. Furthermore, since water meters utilize ultra-low capacity, low-power communication networks, they are unsuitable for transmitting high-capacity data such as leak sound detection signals; therefore, a separate leak sound detection system must be established, requiring a person to visit the site in person to determine the presence of a leak.

[0018] In addition, by identifying leakage sounds Accurate detection is difficult due to the influence of groundwater sounds, ambient noise, etc., when detecting the leak location.

[0019] Although water meters are designed to correct errors in minimum, maximum, and transition flow rates before shipment, water flow patterns in real-world environments—rather than laboratory settings—varie depending on the surrounding environment, water temperature distribution, and flow velocity; conventional flow measurement methods cannot account for all these variables to correct for errors.

[0020] In addition, due to the absence of a real-time monitoring system for outdoor leaks, there are many actual leak cases and slow response, resulting in a decrease in water efficiency. The problem to be solved

[0021] The present invention aims to provide a method for measuring the flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure changes, which distinguishes the flow of water within a water pipe, calculates the average flow velocity according to the water flow, and measures the flow rate using the calculated average flow velocity to enable accurate flow rate measurement in the ultrasonic water meter. means of solving the problem

[0022] To classify the flow type and calculate the accurate average velocity, the Reynolds number must be known, and to calculate the Reynolds number, the average velocity must be known. Furthermore, the Reynolds number varies with water temperature. Therefore, a method is required to measure flow rate by distinguishing between laminar, transitional, and turbulent flows and applying the appropriate average velocity.

[0023] The method for measuring flow rate and detecting outdoor leakage of an ultrasonic water meter according to the present invention determines the flow pattern of water by calculating the temperature distribution and average temperature, velocity distribution and average flow velocity of water within a water pipe, and calculating the Reynolds number, while considering changes in temperature according to the surrounding environment, and calculates the flow rate accordingly.

[0024] In addition, when determining the water flow pattern in this invention, it is essential to check for leakage in order to prevent errors caused by leakage by using a pressure sensor. Therefore, in the absence of flow velocity, leakage can be detected by continuously checking for a pressure decrease that deviates from the error range by comparing it with the pressure measured at the time of initial installation.

[0025] The present invention’s method for measuring flow rate and detecting outdoor water leakage using an ultrasonic water meter is characterized by the ability to measure the flow rate while considering the flow pattern of water using a temperature distribution, and by considering that the velocity distribution and average velocity vary according to the flow pattern of water, determining the flow pattern of water using a Reynolds number to which the average temperature is applied, calculating the average velocity according to the flow pattern of water, and calculating the flow rate using this, thereby enabling accurate calculation of the flow rate.

[0026] The method for measuring the flow rate and detecting outdoor leakage of an ultrasonic water meter according to the present invention comprises an ultrasonic time measurement process for measuring ultrasonic time for each ultrasonic sensor path in the same direction as the fluid flow direction and in the opposite direction to the fluid flow direction, and

[0027] A flow velocity calculation process that calculates the central flow velocity within a water pipe using the ultrasonic time calculated in the above ultrasonic time measurement process and the time difference of the ultrasonic time, and

[0028] An ultrasonic velocity calculation process that calculates the ultrasonic velocity using the ultrasonic time obtained in the above ultrasonic time measurement process, and

[0029] A water temperature calculation process that calculates the center temperature T (0) of the water using the ultrasonic velocity obtained in the above ultrasonic velocity calculation process, and

[0030] A surface water temperature measurement process that measures the temperature (Ts) of the water surface of a water pipe using a temperature sensor, and

[0031] A temperature distribution calculation process for obtaining the temperature distribution T(r) inside the water pipe using the above-mentioned measured surface water temperature, water center temperature T(0), and water pipe diameter information, and

[0032] A process for determining the flow pattern of water by comparing a first Reynolds number calculated using the average velocity and a velocity distribution calculated according to each water shape using the water temperature distribution T(r) and the value measured by the ultrasonic sensor, and a second Reynolds number calculated according to the pressure change obtained using the pressure sensor, and

[0033] It is characterized by including a flow rate calculation process that calculates the flow rate using the average flow velocity according to the water flow pattern determined through a water flow pattern determination process.

[0034] And the method for measuring the flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure change according to the present invention is

[0035] In the above process of determining the flow pattern of water,

[0036] Water temperature distribution T(r) and angular velocity distribution u(r) and average velocity V according to laminar and turbulent flow avg The method is characterized by comprising a first process of calculating an average temperature Tm for each of the laminar flow and turbulent flow, deriving a first Reynolds number using the calculated average temperature Tm, deriving an average velocity and a second Reynolds number according to the pressure change obtained using a pressure sensor, and determining whether the flow is laminar or turbulent by comparing the first Reynolds number and the second Reynolds number, and a second process of determining the flow form of water as a transitional flow when it does not correspond to either laminar flow or turbulent flow through the first process.

[0037] And in the method for measuring flow rate of an ultrasonic water meter and detecting outdoor leakage using temperature distribution and pressure change of the present invention,

[0038] In the above process of determining the flow pattern of water,

[0039] If the first Reynolds number and the second Reynolds number are Re≤2300 and the difference between the first and second Reynolds numbers is within a preset error range, the water flow type is determined to be laminar flow.

[0040] If the first Reynolds number and the second Reynolds number are Re≥4000 and the difference between the first Reynolds number and the second Reynolds number is within a preset error range, the water flow pattern is determined to be turbulent flow.

[0041] The method is characterized by changing the value of n and performing calculations until the difference between the first and second Reynolds numbers is within a preset error range, while the first Reynolds number and the second Reynolds number are 2300 < Re < 4000, and when the value of the first Reynolds number and the second Reynolds number are compared, it is determined to be a transitional flow.

[0042] And the method for measuring the flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure change according to the present invention is

[0043] The method is further characterized by including an outdoor leak monitoring process that monitors cases where there is no flow velocity based on the water flow velocity obtained from the above flow velocity calculation process, compares the pressure measured when there is no flow velocity during initial installation with the pressure measured by the pressure sensor when there is no flow velocity, determines whether there is a decrease in pressure that deviates from a preset reference error value as a result of the comparison, generates leak occurrence monitoring information if there is a decrease in pressure, and transmits the generated leak occurrence monitoring information to a control server.

[0044] The ultrasonic water meter of the present invention is,

[0045] The ultrasonic water meter for a water meter comprises: an ultrasonic sensor for transmitting and receiving ultrasonic waves through a water pipe; a pressure sensor for detecting pressure within the water pipe; a temperature sensor for detecting surface water temperature within the water pipe; a control means for determining the temperature distribution and water flow pattern using values ​​obtained from the ultrasonic sensor and the pressure sensor to calculate the flow rate; and a display means for displaying the flow rate obtained from the control means.

[0046] The above control means comprises: an ultrasonic time measuring means for measuring ultrasonic time for each ultrasonic sensor path in the same direction as the fluid flow direction and in the opposite direction to the fluid flow direction; a flow velocity calculating means for calculating the flow velocity within the water pipe using the ultrasonic time calculated by the ultrasonic time measuring means and the time difference between the ultrasonic time; an ultrasonic velocity calculating means for calculating the ultrasonic velocity using the ultrasonic time obtained from the ultrasonic time measuring means; a water temperature calculating means for calculating the center temperature T(0) of the water using the ultrasonic velocity obtained in the ultrasonic velocity calculation process; a temperature distribution calculating means for measuring the temperature (Ts) of the water surface of the water pipe from the value input from the temperature sensor, and calculating the temperature distribution T(r) within the water pipe using the center temperature T(0) of the water and the water pipe diameter information; a water flow pattern determining means for determining the water flow pattern by comparing the first Reynolds number calculated using the average velocity and the velocity distribution calculated according to each water shape using the water temperature distribution T(r) and the value measured by the ultrasonic sensor, and the second Reynolds number calculated according to the pressure change obtained using the pressure sensor. It is characterized by being configured to include a flow rate calculation means that calculates a flow rate using an average velocity and cross-sectional area obtained according to the water flow pattern determined by a water flow pattern determination means.

[0047] And in the water meter of the present invention,

[0048] The above-mentioned means for determining the flow pattern of water is,

[0049] The method is characterized by calculating the velocity distribution u(r) and average velocity Vavg according to the temperature distribution T(r) of the water and the laminar and turbulent flows, calculating the average temperature Tm for each of the laminar and turbulent flows, deriving a first Reynolds number using the calculated average temperature Tm, deriving a second Reynolds number according to the pressure change obtained using a pressure sensor, comparing the first Reynolds number and the second Reynolds number to determine whether the flow is laminar or turbulent, and determining the water flow type as transitional flow when it does not correspond to either laminar or turbulent flow.

[0050] And the ultrasonic water meter of the present invention is,

[0051] The above control means further comprises an outdoor leakage monitoring means that monitors cases where there is no flow rate based on the water flow rate obtained from the flow rate calculation means, compares the pressure measured when there is no flow rate at the time of initial installation with the pressure measured by the pressure sensor when there is no flow rate, determines whether there is a decrease in pressure that deviates from a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generates leakage occurrence monitoring information and transmits the generated leakage occurrence monitoring information to a control server. Effects of the invention

[0052] According to the present invention, accurate flow rate calculation is possible by determining the flow pattern of water inside a water pipe before estimating the average flow velocity for calculating the flow rate, and calculating the flow rate by determining the average flow velocity according to the flow pattern of the water. Brief explanation of the drawing

[0053] FIG. 1 is a diagram showing the state of temperature distribution change according to the temperature difference inside and outside a water pipe. FIG. 2 and FIG. 3 are diagrams showing the flow distribution of water inside a water pipe, where FIG. 2 shows laminar flow and FIG. 3 shows turbulent flow. FIG. 4 and FIG. 5 illustrate a method for measuring flow rate and detecting outdoor leaks using an ultrasonic water meter utilizing temperature distribution and pressure change according to the present invention; FIG. 4 is a flowchart showing the process of measuring the flow rate of an ultrasonic water meter, and FIG. 5 is a flowchart showing the process of detecting outdoor leaks. FIG. 6 is a diagram showing the viscosity / density / kinematic viscosity of water according to temperature. FIG. 7 is a block diagram showing the configuration of the ultrasonic water meter according to the present invention. FIG. 8 is a diagram showing an embodiment of the configuration inside a water pipe according to the present invention. Specific details for implementing the invention

[0054] First, the terms used in this specification and claims have been selected based on general terms considering their functions in various embodiments of the present invention. However, these terms may vary depending on the intent of those skilled in the art, legal or technical interpretations, or the emergence of new technologies. Additionally, some terms may be arbitrarily selected by the applicant. Such terms may be interpreted according to the meanings defined in this specification; in the absence of specific definitions, they may be interpreted based on the overall content of this specification and common technical knowledge in the relevant field.

[0055] Terms and words used in the detailed description and claims of the present invention shall not be interpreted as being limited to their ordinary or dictionary meanings, but rather shall be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that "the inventor may appropriately define the concept of the terms to best describe his invention."

[0056] In addition, the embodiments described in this specification and the configurations illustrated in the drawings are merely preferred embodiments of the present invention and do not represent all technical aspects of the present invention; therefore, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0057] In addition, the same reference numbers or symbols described in each drawing attached to this specification represent parts or components that perform substantially the same function. For convenience of explanation and understanding, the same reference numbers or symbols are used in different embodiments as well. That is, even if components having the same reference number are all depicted in multiple drawings, the multiple drawings do not imply a single embodiment.

[0058] Additionally, in this specification and claims, terms including ordinal numbers, such as 'first', 'second', etc., may be used to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from one another, and the meaning of the terms should not be limited by the use of such ordinal numbers. For example, the order of use or arrangement of components combined with such ordinal numbers should not be limited by the number. If necessary, each ordinal number may be used interchangeably.

[0059] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as 'comprising' or 'composing' are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0060] Hereinafter, the method for measuring the flow rate of an ultrasonic water meter and detecting outdoor leakage using temperature distribution and pressure change according to the present invention will be specifically described with reference to the embodiment illustrated in the attached drawing Fig. 4.

[0061] FIG. 4 is a flowchart showing the process of measuring the flow rate of an ultrasonic water meter in the method for measuring the flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure change of the present invention, and FIG. 5 is a flowchart showing the process of detecting outdoor leaks.

[0062] The method for measuring the flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure changes according to the present invention is

[0063] An ultrasonic time measurement process for measuring ultrasonic time for each ultrasonic sensor path in the same direction as the fluid flow direction and in the opposite direction to the fluid flow direction, and

[0064] A flow velocity calculation process that calculates the flow velocity within a water pipe using the ultrasonic time calculated in the above ultrasonic time measurement process and the time difference of the ultrasonic time, and

[0065] An ultrasonic velocity calculation process that calculates the ultrasonic velocity using the ultrasonic time obtained in the above ultrasonic time measurement process, and

[0066] A water temperature calculation process that calculates the center temperature T (0) of the water using the ultrasonic speed obtained in the above ultrasonic speed calculation process, and

[0067] The process of measuring surface water temperature using a temperature sensor to measure the water temperature (Ts) on the surface of the water pipe, and

[0068] A temperature distribution calculation process for obtaining the temperature distribution T(r) inside the water pipe using the above-mentioned measured surface water temperature, water center temperature T(0), and water pipe diameter information, and

[0069] A water flow pattern determination process that determines the water flow pattern by comparing a first Reynolds number calculated using the velocity distribution and average velocity (flow rate) calculated according to each water shape using the water temperature distribution T(r) and the value measured by the ultrasonic sensor, and a second Reynolds number calculated according to the pressure change obtained using the pressure sensor;

[0070] It is performed by including a flow rate calculation process that calculates the flow rate using the average velocity according to the water flow pattern determined through the water flow pattern determination process.

[0071] And the above process for determining the water flow pattern is,

[0072] It comprises a first process of calculating the velocity distribution u(r) and average velocity Vavg according to the temperature distribution T(r) of the water and laminar or turbulent flow, calculating the average temperature Tm for each of the laminar and turbulent flow, deriving a first Reynolds number using the calculated average temperature Tm, deriving a second Reynolds number based on the pressure change obtained using a pressure sensor, and determining whether the flow is laminar or turbulent by comparing the first Reynolds number and the second Reynolds number; and a second process of determining the water flow type as transitional flow when it does not correspond to either laminar or turbulent flow through the first process.

[0073] In addition, the outdoor leak monitoring process may further include monitoring cases where there is no flow rate from the water flow rate obtained from the above flow rate calculation process, comparing the pressure (P1) measured when there is no flow rate at the time of initial installation with the pressure (P2) measured by the pressure sensor when there is no flow rate, determining whether there is a decrease in pressure that deviates from a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generating leak occurrence monitoring information and transmitting the generated leak occurrence monitoring information to the control server.

[0074] The method for measuring flow rate and detecting outdoor leaks using an ultrasonic water meter based on temperature distribution and pressure changes achieved through the above process is explained in detail below with reference to the attached drawings.

[0075] The water flow velocity can be measured by propagating ultrasound in the forward and reverse directions relative to the water flow and utilizing the difference in arrival times.

[0076] At this time, the central temperature T(0) can be measured through the speed of the ultrasound by utilizing the fact that the speed of the ultrasound varies depending on the temperature of the water.

[0077] And the temperature (Ts) of the water on the surface of the water pipe can be measured using a temperature sensor.

[0078] Using the measured center temperature T (0), surface water temperature (Ts), and water pipe diameter information, the temperature distribution T (r) inside the water pipe is calculated as in the following mathematical formula 1.

[0079]

[0080] Here, r0 is the radius of the water pipe.

[0081] Subsequently, the water flow pattern is determined, and the flow rate is calculated according to each flow pattern: laminar flow, turbulent flow, and transitional flow.

[0082] Here, the Reynolds number is used to determine the water flow pattern. To calculate the Reynolds number, the average temperature Tm is required.

[0083] To calculate the above average temperature Tm, the velocity distribution u(r) and the average velocity Vavg are required.

[0084] In this case, since the velocity distribution u(r) and average velocity Vavg vary depending on the water flow pattern, the velocity distribution and average velocity are calculated for each water flow pattern, and the average temperature Tm is calculated using these.

[0085] That is, the average temperature Tm is calculated using the temperature distribution T(r), velocity distribution u(r), and average velocity Vavg obtained above, and the first Reynolds number Re is derived using this.

[0086] Subsequently, the average flow velocity and the second Reynolds number Re are calculated using the pressure change and compared with the first Reynolds number Re obtained above, and the flow pattern of the water can be determined based on the comparison value.

[0087] Here, the process of determining the water flow type involves first calculating the first Reynolds number and the second Reynolds number by assuming it is laminar or turbulent flow, comparing the first Reynolds number and the second Reynolds number to determine whether it is laminar or turbulent flow based on the comparison value, and when the water flow type does not correspond to either laminar or turbulent flow, the water flow type can be determined as transitional flow.

[0088] First, when the flow pattern of water is laminar flow, the velocity distribution u(r) can be obtained through the following mathematical equation 2.

[0089]

[0090] At this time, the average velocity Vavg is half the central velocity of water u0. (u0 = u max = 2Vavg)

[0091] Subsequently, using the average velocity Vavg, temperature distribution T(r), and velocity distribution u(r), the average temperature Tm is calculated as in Equation 3, and the kinematic viscosity coefficient of water is calculated using this, and the first Reynolds number Re for laminar flow can be derived as in Equation 4.

[0092]

[0093]

[0094] Here, Vavg: average velocity, υ: kinematic viscosity, D: water pipe diameter

[0095] The kinematic viscosity υ of water at 4℃ is about 95% higher than that of water at 30℃.

[0096] Figure 6 shows the kinematic viscosity coefficient υ.

[0097] Figure 6 is a graph showing the viscosity / density / kinematic viscosity of water according to temperature.

[0098] And verify whether the water flow pattern is laminar flow.

[0099] To verify whether the water flow pattern is indeed laminar flow, the Bernoulli equation as in Equation 5 ) The average velocity is calculated using the pressure change based on the principle, the second Reynolds number is calculated using the calculated average velocity, and the calculated second Reynolds number is compared with the first Reynolds number calculated using the velocity distribution above.

[0100] Mathematical Equation 5 represents the process of calculating the average velocity and the second Reynolds number using pressure change.

[0101]

[0102] Vavg: average flow velocity, μ : viscosity coefficient, υ: ​​kinematic viscosity coefficient, D: water pipe diameter, L: water pipe length

[0103] P1-P2: The difference between the pressure when there is no flow and the pressure when there is flow

[0104] The above P1 and P2 are pressures measured by pressure sensors, and the pressure when there is no flow is the value measured with the valve closed during the initial installation.

[0105] Here, if the first Reynolds number and the second Reynolds number are Re≤2300, and the difference between the first Reynolds number calculated using the velocity distribution and the second Reynolds number calculated using the pressure change is within a preset error range, the flow pattern of water can be determined as laminar flow.

[0106] Subsequently, assuming that the water flow pattern is laminar, the flow rate is calculated using the average velocity associated with laminar flow and the cross-sectional area of ​​the water pipe. (Flow rate = Average velocity Vavg × Cross-sectional area)

[0107] Meanwhile, when assuming the flow pattern of water is turbulent flow, the velocity distribution u(r) and average velocity Vavg are calculated using the following mathematical equations 6 and 7.

[0108]

[0109]

[0110] Then, using the average velocity Vavg, temperature distribution T(υ), and velocity distribution u(r), the average temperature Tm is calculated as in Equation 3, and the first Reynolds number Re is derived using this.

[0111] To verify whether the flow pattern of water is turbulent flow, the average flow velocity is calculated using the pressure change based on Bernoulli's principle as in Equation 5, the second Reynolds number is derived using the calculated average flow velocity, and the derived second Reynolds number is compared with the first Reynolds number calculated using the velocity distribution through Equations 6 and 7.

[0112] If the first Reynolds number and the second Reynolds number are Re≥4000 and the difference between the first and second Reynolds numbers is within a preset error range, the flow pattern of the water is determined to be turbulent flow and the flow rate is calculated. (Flow rate = Average velocity Vavg × Cross-sectional area)

[0113] Here, in the case of turbulent flow, the surface roughness of the water pipe must be considered when developing mathematical equations using pressure changes. However, since the surface of typical water pipes is very smooth and has almost no effect from surface roughness, the same method used for laminar flow is applied even in the case of turbulent flow.

[0114] Through the process described above, if the water flow pattern does not correspond to either laminar or turbulent flow, the water flow pattern is determined to be transitional flow.

[0115] In the case of transitional flow, the velocity distribution u(r) and average velocity Vavg are calculated using the following mathematical equations 6 and 7, just as in turbulent flow, where n is n < 7 (n is an integer).

[0116] Using the average velocity Vavg, temperature distribution T(r), and velocity distribution u(r), the average temperature Tm is calculated as in Equation 3, and the first Reynolds number Re is derived using this.

[0117] Bernoulli as in mathematical formula 5 ( Bernoulli) An average velocity is calculated using the pressure change based on the principle, and a second Reynolds number Re is derived using the calculated average velocity, and the derived second Reynolds number is compared with the first Reynolds number Re.

[0118] The first Reynolds number and the second Reynolds number are calculated by changing the value of n until the difference between the first Reynolds number and the second Reynolds number is within a preset error range, while the first Reynolds number and the second Reynolds number are 2300 < Re < 4000.

[0119] Once the value of n is derived, the flow rate is calculated using transient flow. (Flow rate = Average velocity Vavg × Cross-sectional area)

[0120] Meanwhile, outdoor leak detection monitors cases where there is no flow rate based on the water flow rate obtained using the ultrasonic sensor above, and in cases where there is no flow rate, compares the pressure (P1) measured when there is no flow rate at the time of initial installation with the pressure (P2) measured by the pressure sensor.

[0121] Based on the comparison results, continuously monitor whether there is a pressure reduction that deviates from the preset standard error value.

[0122] If a decrease in pressure occurs at this time, a leak at the outskirts of the water meter can be suspected. This information is transmitted to the control server as leak monitoring data to compare and analyze it with the measured pressure values ​​of water meters supplied at the same pressure, thereby enabling the determination of the actual leak.

[0123] At this time, the information transmitted to the control server is the pressure value measured by the pressure sensor and may include water flow velocity information.

[0124] As described above, when monitoring information regarding a leak is received from a water meter, the control server can remotely close the valve of the relevant water meter and re-measure the pressure, and then determine whether an actual leak has occurred by comparing and analyzing the measured pressure values ​​with those of water meters in the same area that are supplied with the same water pressure.

[0125] Meanwhile, an ultrasonic water meter for performing the method of measuring flow rate and detecting outdoor leakage using the temperature distribution and pressure change of the present invention is configured as follows.

[0126] FIG. 7 is a block diagram showing the configuration of the ultrasonic water meter of the present invention, and FIG. 8 is a drawing showing an embodiment of the configuration inside a water pipe in the present invention.

[0127] The ultrasonic water meter of the present invention is,

[0128] The ultrasonic water meter for a water meter comprises: an ultrasonic sensor (10) for transmitting and receiving ultrasonic waves through a water pipe; a pressure sensor (20) for detecting pressure within the water pipe; a temperature sensor (30) for detecting surface water temperature within the water pipe; a control means (40) for determining the temperature distribution and water flow pattern using values ​​obtained from the ultrasonic sensor (10) and the pressure sensor (20) to calculate the flow rate; and a display means (50) for displaying the flow rate obtained from the control means (40).

[0129] The above control means (40) comprises: an ultrasonic time measuring means (41) for measuring ultrasonic time for each path of the ultrasonic sensor (10) in the same direction as the fluid flow direction and in the opposite direction to the fluid flow direction; a flow velocity calculating means (42) for calculating the flow velocity in the water pipe using the ultrasonic time calculated by the ultrasonic time measuring means (41) and the time difference between the ultrasonic time; an ultrasonic velocity calculating means (43) for calculating the ultrasonic velocity using the ultrasonic time obtained from the ultrasonic time measuring means (41); a water temperature calculating means (44) for calculating the center temperature T(0) of the water using the ultrasonic velocity obtained from the ultrasonic velocity calculating means (43); a temperature distribution calculating means (45) for measuring the temperature (Ts) of the water surface of the water pipe from the value input from the temperature sensor (30), and for calculating the temperature distribution T(r) inside the water pipe using the center temperature T(0) of the water and the water pipe diameter information; and a speed calculated according to each water type using the water temperature distribution T(r) and the value measured by the ultrasonic sensor (10). It comprises a water flow pattern determination means (46) that determines the water flow pattern by comparing a first Reynolds number calculated using a distribution and average velocity with a second Reynolds number calculated according to a pressure change obtained using a pressure sensor (20), and a flow rate calculation means (47) that calculates the flow rate using the average velocity and cross-sectional area obtained according to the water flow pattern determined by the water flow pattern determination means (46).

[0130] And the above water flow pattern determination means (46) is,

[0131] The temperature distribution T(r) of the water and the velocity distribution u(r) and average velocity Vavg are calculated according to laminar flow and turbulent flow, and the average temperature Tm is calculated for each of the laminar flow and turbulent flow, and the first Reynolds number is derived using the calculated average temperature Tm, and the second Reynolds number is derived according to the pressure change obtained using the pressure sensor (20), and the first Reynolds number and the second Reynolds number are compared to determine whether it is laminar flow or turbulent flow, and when it does not correspond to both laminar flow and turbulent flow, the flow type of the water can be determined as transitional flow.

[0132] And the above control means (40) may further include an outdoor leak monitoring means (48) that monitors the case where there is no flow rate from the water flow rate obtained from the flow rate calculation means (42), compares the pressure (P1) measured when there is no flow rate at the time of initial installation with the pressure (P2) measured by the pressure sensor, determines whether there is a decrease in pressure that deviates from a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generates leak occurrence monitoring information and transmits the generated leak occurrence monitoring information to a control server.

[0133] An ultrasonic water meter having such a configuration is,

[0134] The above control means (40) measures the center temperature T (0) through the speed of the ultrasound and measures the temperature (Ts) of the water on the surface of the water pipe using the value input from the temperature sensor (30).

[0135] Using the measured center temperature T(0), surface water temperature (Ts), and water pipe diameter information, the temperature distribution T(r) inside the water pipe is calculated as in Equation 1 above.

[0136] Subsequently, the Reynolds number is used to determine the flow pattern of the water, and the flow rate is calculated according to each flow pattern: laminar flow, turbulent flow, and transitional flow.

[0137] To calculate the above Reynolds number, the average temperature Tm is required, and to calculate the above average temperature Tm, the velocity distribution u(r) and the average velocity Vavg are required.

[0138] The velocity distribution and average velocity can be calculated according to each water flow pattern, and the average temperature Tm can be calculated using this.

[0139] Using the temperature distribution and velocity distribution average velocity obtained above, the average temperature Tm is calculated, and the first Reynolds number Re is derived using this.

[0140] Subsequently, the average velocity and the second Reynolds number Re are calculated using the pressure change and compared with the first Reynolds number Re obtained above, and the flow pattern of water can be determined based on the comparison value.

[0141] Here, the determination of the water flow type is made by first assuming it is laminar flow or turbulent flow and calculating the first Reynolds number and the second Reynolds number, comparing the first Reynolds number and the second Reynolds number to determine whether it is laminar flow or turbulent flow based on the comparison value, and when the water flow type does not correspond to either laminar flow or turbulent flow, the water flow type can be determined as transitional flow.

[0142] First, when the flow pattern of water is laminar flow, the velocity distribution u(r) can be obtained through the above mathematical equation 2.

[0143] At this time, the average velocity Vavg is half the central velocity of water u0. (u0 = u max = 2Vavg)

[0144] Subsequently, the average temperature Tm can be calculated as in Equation 3 using the average velocity Vavg, temperature distribution T(r), and velocity distribution u(r), and the first Reynolds number Re according to laminar flow can be derived as in Equation 4 using this.

[0145] And verify whether the water flow pattern is laminar flow.

[0146] To verify whether the flow pattern of water is laminar flow, the average flow velocity is calculated using the pressure change based on Bernoulli's principle as in Equation 5 above, the second Reynolds number is calculated using the calculated average flow velocity, and the calculated second Reynolds number is compared with the first Reynolds number calculated using the velocity distribution above.

[0147] Here, if the first Reynolds number and the second Reynolds number are Re≤2300, and the difference between the first Reynolds number calculated using the velocity distribution and the second Reynolds number calculated using the pressure change is within a preset error range, the flow pattern of water can be determined as laminar flow.

[0148] Subsequently, the water flow pattern is determined to be laminar, and the flow rate is calculated using the average velocity associated with laminar flow and the cross-sectional area of ​​the water pipe. (Flow rate = Average velocity Vavg × Cross-sectional area)

[0149] Meanwhile, when assuming the flow pattern of water is turbulent flow, the velocity distribution u(r) and average velocity Vavg are calculated using the above mathematical equations 6 and 7.

[0150] Then, using the average velocity Vavg, temperature distribution T(r), and velocity distribution u(r), the average temperature Tm is calculated as in Equation 3, and the first Reynolds number Re is derived for turbulent flow.

[0151] To verify whether the flow pattern of water is turbulent flow, the average flow velocity is calculated using the pressure change based on Bernoulli's principle as in Equation 5, the second Reynolds number is derived using the calculated average flow velocity, and the derived second Reynolds number is compared with the first Reynolds number calculated using the velocity distribution through Equations 6 and 7.

[0152] If the first Reynolds number and the second Reynolds number are Re≥4000 and the difference between the first and second Reynolds numbers is within a preset error range, the flow pattern of the water is determined to be turbulent flow and the flow rate is calculated. (Flow rate = Average velocity Vavg × Cross-sectional area)

[0153] In the above cases, if the water flow pattern does not correspond to either laminar or turbulent flow, the water flow pattern is determined to be transitional flow.

[0154] In the case of transitional flow, the velocity distribution u(r) and average velocity Vavg are calculated using the following mathematical equations 6 and 7, just as in turbulent flow, where n is n < 7 (n is an integer).

[0155] Using the average velocity Vavg, temperature distribution T(r), and velocity distribution u(r), the average temperature Tm is calculated as in Equation 3, and the first Reynolds number Re is derived according to the transition flow.

[0156] The average flow velocity is calculated using the pressure change based on Bernoulli's principle as in Equation 5, the second Reynolds number is derived using the calculated average velocity, and the derived second Reynolds number is compared with the first Reynolds number calculated using the velocity distribution through Equations 6 and 7.

[0157] The first Reynolds number and the second Reynolds number are calculated by changing the value of n until the difference between the first Reynolds number and the second Reynolds number is within a preset error range, while the first Reynolds number and the second Reynolds number are 2300 < Re < 4000.

[0158] If a value of n is derived, it is determined to be transitional flow, and the flow rate is calculated. (Flow rate = Average velocity Vavg × Cross-sectional area)

[0159] In calculating the flow rate through the average velocity that varies according to the flow pattern of water, the flow pattern of water—laminar flow, turbulent flow, and transitional flow—is determined, and the average velocity is calculated according to each flow pattern of water to calculate the flow rate, thereby enabling the calculation of an accurate flow rate.

[0160] And in the outdoor leakage monitoring means (48) of the control means (40), the case where there is no flow rate is monitored from the water flow rate obtained using the ultrasonic sensor above, and when there is no flow rate, the pressure (P1) measured when there is no flow rate at the time of initial installation is compared with the pressure (P2) measured by the pressure sensor, and the comparison result is continuously monitored to see if there is a decrease in pressure that deviates from a preset reference error value.

[0161] If a decrease in pressure occurs at this time, a leak at the outskirts of the water meter can be suspected. This information is transmitted to the control server as leak monitoring data to compare and analyze it with the measured pressure values ​​of water meters supplied at the same pressure, thereby enabling the determination of the actual leak.

[0162] As described above, when monitoring information regarding a leak is received from a water meter, the control server can remotely close the valve of the relevant water meter and re-measure the pressure, and then determine whether an actual leak has occurred by comparing and analyzing the measured pressure values ​​with those of water meters in the same area that are supplied with the same water pressure.

[0163] An outdoor water leakage management system using the ultrasonic water meter of the present invention can be configured as described above.

[0164] The ultrasonic water meter comprises an outdoor leak monitoring means that includes a flow velocity calculation means for calculating the flow velocity within a water pipe by measuring ultrasonic time, a pressure sensor for measuring pressure within a water pipe, and an outdoor leak monitoring means that monitors cases where there is no flow velocity from the water flow velocity obtained from the flow velocity calculation means, compares the pressure (P1) measured when there is no flow velocity at the time of initial installation with the pressure (P2) measured by the pressure sensor when there is no flow velocity, determines whether there is a decrease in pressure that deviates from a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generates leak occurrence monitoring information and transmits the generated leak occurrence monitoring information to a control server, and is composed of a control server for the ultrasonic water meter.

[0165] The above control server may be configured to include means for determining whether an actual leak has occurred in the ultrasonic water meter by comparing and analyzing the pressure information received from the ultrasonic water meter with the measured pressure values ​​of ultrasonic water meters supplied with the same water pressure in the same area when leak occurrence monitoring information received from the ultrasonic water meter is received, by transmitting a remote control signal to the ultrasonic water meter to close the valve and re-measure from the pressure sensor, and by comparing and analyzing the pressure information received from the ultrasonic water meter with the measured pressure values ​​of ultrasonic water meters supplied with the same water pressure in the same area.

[0166] The present invention is not limited to an ultrasonic water meter according to an embodiment that calculates an accurate flow rate through an average velocity that varies according to the form of water flow, and can detect outdoor leakage by utilizing pressure changes in an ultrasonic sensor including a pressure sensor.

[0167] The method for measuring the flow rate of such an ultrasonic water meter and detecting outdoor leaks is,

[0168] The method may include an ultrasonic time measurement process for measuring ultrasonic time for each ultrasonic sensor path in the same direction as the fluid flow direction and in the opposite direction to the fluid flow direction; a flow velocity calculation process for calculating the flow velocity within the water pipe using the ultrasonic time calculated in the ultrasonic time measurement process and the time difference between the ultrasonic times; a flow rate calculation process for calculating the flow rate using the flow velocity; and an outdoor leak monitoring process that monitors cases where there is no flow velocity from the water flow velocity obtained from the flow velocity calculation process, compares the pressure (P1) measured when there is no flow velocity at the time of initial installation with the pressure (P2) measured by the pressure sensor when there is no flow velocity, determines whether there is a decrease in pressure that deviates from a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generates leak occurrence monitoring information and transmits the generated leak occurrence monitoring information to a control server.

[0169] In addition, an ultrasonic water meter to which the above-mentioned flow measurement and outdoor leak detection methods are applied is,

[0170] The ultrasonic water meter for a water meter comprises: an ultrasonic sensor for transmitting and receiving ultrasonic waves through a water pipe; a pressure sensor for detecting pressure within the water pipe; a control means for measuring ultrasonic time using a value obtained from the ultrasonic sensor, calculating the flow velocity within the water pipe using the ultrasonic time calculated during the ultrasonic time measurement process, and calculating the flow rate using the flow velocity; and a display means for displaying the flow rate obtained from the control means.

[0171] The above control means may further include an outdoor leak monitoring means that monitors the case where there is no flow rate from the water flow rate obtained from the flow rate calculation means, compares the pressure (P1) measured when there is no flow rate at the time of initial installation with the pressure (P2) measured by the pressure sensor when there is no flow rate, determines whether there is a decrease in pressure that deviates from a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generates leak occurrence monitoring information and transmits the generated leak occurrence monitoring information to a control server.

[0172] Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. Various modifications are possible by those skilled in the art without departing from the essence of the invention as claimed in the claims, and such modifications should not be understood individually from the technical spirit or perspective of the present invention. Explanation of the symbols

[0173] 10: Ultrasonic sensor 20: Pressure sensor 30: Temperature sensor 40: Control means 50 : Display means 41 : Ultrasonic time measuring means 42: Flow velocity calculation means 43: Ultrasonic velocity calculation means 44: Water temperature calculation means 45: Temperature distribution calculation means 46: Means for determining water flow pattern 47: Means for calculating flow rate 48: Outdoor leak monitoring means

Claims

Claim 1 An ultrasonic time measurement process for measuring ultrasonic time for each ultrasonic sensor path in the same direction as the fluid flow direction and in the opposite direction to the fluid flow direction; a flow velocity calculation process for calculating the flow velocity within the water pipe using the ultrasonic time calculated in the ultrasonic time measurement process and the time difference between the ultrasonic times; an ultrasonic velocity calculation process for calculating the ultrasonic velocity using the ultrasonic time obtained in the ultrasonic time measurement process; a water temperature calculation process for calculating the center temperature T(0) of the water using the ultrasonic velocity obtained in the ultrasonic velocity calculation process; a surface water temperature measurement process for measuring the temperature (Ts) of the water surface of the water pipe using a temperature sensor; a temperature distribution calculation process for calculating the temperature distribution T(r) within the water pipe using the measured surface water temperature, the center temperature T(0) of the water, and the water pipe diameter information; and a first Reynolds number calculated using the average velocity and the velocity distribution calculated according to each water shape using the water temperature distribution T(r) and the value measured by the ultrasonic sensor, and a second Reynolds number calculated according to the pressure change obtained using a pressure sensor to determine the flow pattern of the water. A method for measuring the flow rate of an ultrasonic water meter and detecting outdoor leakage using temperature distribution and pressure change, characterized by comprising a flow pattern determination process and a flow rate calculation process that calculates the flow rate using the average flow velocity according to the water flow pattern determined through the water flow pattern determination process. Claim 2 In claim 1, the process for determining the flow pattern of the water comprises, depending on the temperature distribution T(r) of the water and laminar or turbulent flow, each velocity distribution u(r) and average velocity V avg A method for measuring flow rate of an ultrasonic water meter and detecting outdoor leakage using temperature distribution and pressure change, characterized by comprising: a first process of calculating an average temperature Tm for each of the laminar flow and turbulent flow, deriving a first Reynolds number using the calculated average temperature Tm, deriving an average velocity and a second Reynolds number according to the pressure change obtained using a pressure sensor, and determining whether it is laminar flow or turbulent flow by comparing the first Reynolds number and the second Reynolds number; and a second process of determining the flow form of water as transitional flow when it does not correspond to both laminar flow and turbulent flow through the first process. Claim 3 A method for measuring the flow rate of an ultrasonic water meter and detecting an outdoor leak using temperature distribution and pressure change, characterized in that, in claim 1, the method further includes an outdoor leak monitoring process in which the water flow rate obtained from the above flow rate calculation process is monitored for cases where there is no flow rate, and in cases where there is no flow rate, the pressure (P1) measured when there is no flow rate at the time of initial installation is compared with the pressure (P2) measured by the pressure sensor, and the comparison result determines whether there is a decrease in pressure that deviates from a preset reference error value, and if there is a decrease in pressure, leak occurrence monitoring information is generated and the generated leak occurrence monitoring information is transmitted to a control server. Claim 4 In paragraph 1, the temperature distribution calculation process above, the temperature distribution T(r) inside the water pipe is, A method for measuring flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure changes, characterized by being calculated as follows. Claim 5 In paragraph 1 or 2, in the process of determining the flow pattern of water, the average temperature Tm is, It is calculated through, and the first Reynolds number Re is, It is calculated through, where, V avg A method for measuring flow rate and detecting outdoor leakage of an ultrasonic water meter using temperature distribution and pressure change, characterized in that : average flow velocity, υ: kinematic viscosity coefficient, D: water pipe diameter. Claim 6 In paragraph 1 or 2, in the process of determining the flow pattern of water, the average velocity according to the pressure change and the second Reynolds number Re are, It is computed through, and V avg : Average flow velocity, μ A method for measuring flow rate and detecting outdoor leakage using an ultrasonic water meter utilizing temperature distribution and pressure change, characterized in that : viscosity coefficient, υ: ​​kinematic viscosity coefficient, D: water pipe diameter, L: water pipe length, P1-P2: the difference between the pressure when there is no flow velocity and the pressure when there is flow velocity. Claim 7 In paragraph 5, when the flow pattern of water is laminar flow, the velocity distribution u(r) is, Calculated through, average speed V avg is half of the central velocity of water u0 (u0 = u max = 2V avg A method for measuring flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure change, characterized by ). Claim 8 In paragraph 5, when the water flow pattern is turbulent flow, the velocity distribution u(r) is, Calculated through , n=7, and the average speed Vavg is, A method for measuring flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure change, characterized by being calculated through. Claim 9 In paragraph 5, when the flow pattern of water is transitional flow, the velocity distribution u(r) is, , calculated through n < 7 (n is an integer), and the average speed Vavg is, A method for measuring flow rate of an ultrasonic water meter and detecting outdoor leaks using temperature distribution and pressure change, characterized by being calculated through. Claim 10 A method for measuring the flow rate of an ultrasonic water meter and detecting outdoor leakage using temperature distribution and pressure change, characterized in that, in claim 1 or 2, if the first Reynolds number and the second Reynolds number are Re≤2300 and the difference between the two values ​​is within a preset error range when comparing the first Reynolds number and the second Reynolds number, the water flow type is determined to be laminar flow; if the first Reynolds number and the second Reynolds number are Re≥4000 and the difference between the values ​​when comparing the first Reynolds number and the second Reynolds number is within a preset error range, the water flow type is determined to be turbulent flow; if the first Reynolds number and the second Reynolds number are 2300<Re<4000 and the difference between the values ​​when comparing the first Reynolds number and the second Reynolds number is within a preset error range, the value of n is changed and calculations are performed until the difference is within a preset error range, and when the value of n is derived, the water flow is determined to be transient flow. Claim 11 The ultrasonic water meter for a water meter comprises: an ultrasonic sensor for transmitting and receiving ultrasonic waves through a water pipe; a pressure sensor for detecting pressure within the water pipe; a temperature sensor for detecting surface water temperature within the water pipe; a control means for determining the temperature distribution and water flow pattern using values ​​obtained from the ultrasonic sensor and the pressure sensor to calculate the flow rate; and a display means for displaying the flow rate obtained from the control means. The control means comprises: an ultrasonic time measuring means for measuring ultrasonic time for each ultrasonic sensor path in the same direction as the fluid flow direction and in the opposite direction to the fluid flow direction; a flow rate calculating means for calculating the flow rate within the water pipe using the ultrasonic time calculated by the ultrasonic time measuring means and the time difference between the ultrasonic time; an ultrasonic speed calculating means for calculating the ultrasonic speed using the ultrasonic time obtained from the ultrasonic time measuring means; a water temperature calculating means for calculating the center temperature T(0) of the water using the ultrasonic speed obtained from the ultrasonic speed calculating means; and a water temperature calculating means for measuring the temperature (Ts) of the water surface of the water pipe from a value input from the temperature sensor, and using the center temperature T(0) of the water and water pipe diameter information to determine the flow rate within the water pipe An ultrasonic water meter characterized by comprising: a temperature distribution calculation means for calculating a temperature distribution T(r); a water flow pattern determination means for determining the water flow pattern by comparing a first Reynolds number calculated using the average speed and the temperature distribution calculated according to each water shape using the temperature distribution T(r) of the water and the measured value of the ultrasonic sensor, and a second Reynolds number calculated according to the pressure change obtained using the pressure sensor; and a flow rate calculation means for calculating a flow rate using the average speed and cross-sectional area obtained according to the water flow pattern determined by the water flow pattern determination means. Claim 12 In claim 11, the means for determining the flow pattern of water is characterized by calculating the velocity distribution u(r) and average velocity Vavg according to the temperature distribution T(r) of the water and laminar flow and turbulent flow, calculating the average temperature Tm for each of the laminar flow and turbulent flow, deriving a first Reynolds number using the calculated average temperature Tm, deriving a second Reynolds number according to the pressure change obtained using a pressure sensor, comparing the first Reynolds number and the second Reynolds number to determine whether it is laminar flow or turbulent flow, and determining the flow pattern of water as transitional flow when it does not correspond to both laminar flow and turbulent flow. Claim 13 An ultrasonic water meter according to claim 11, wherein the control means further comprises an outdoor leak monitoring means that monitors the case where there is no flow rate from the water flow rate obtained from the flow rate calculation means, compares the pressure (P1) measured when there is no flow rate at the time of initial installation with the pressure (P2) measured by the pressure sensor when there is no flow rate, determines whether there is a decrease in pressure that deviates from a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generates leak occurrence monitoring information and transmits the generated leak occurrence monitoring information to a control server. Claim 14 In claim 11, the temperature distribution calculation means comprises, the temperature distribution T(r) within the water pipe, An ultrasonic water meter characterized by performing calculations through Claim 15 In paragraph 11 or 12, the means for determining the flow pattern of water is, average temperature Tm, Calculate through, and the first Reynolds number Re is, An ultrasonic water meter characterized by performing calculations through, where Vavg: average flow velocity, υ: kinematic viscosity, D: water pipe diameter. Claim 16 In paragraph 11 or 12, the means for determining the flow pattern of water comprises an average velocity according to pressure change and a second Reynolds number Re, Calculate through, and V avg : Average flow velocity, μ: Viscosity coefficient , υ An ultrasonic water meter characterized by: kinematic viscosity, D: water pipe diameter, L: water pipe length, P1-P2: the difference between the pressure when there is no flow and the pressure when there is a flow. Claim 17 In paragraph 15, when the flow pattern of water is laminar flow, the velocity distribution u(r) is, It is calculated through, and the average velocity Vavg is half of the central velocity of water u0 (u0 = u max = 2V avg An ultrasonic water meter characterized by being ). Claim 18 In paragraph 15, the means for determining the flow pattern of water is, when the flow pattern of water is turbulent flow, the velocity distribution u(r), Calculated using , n=7, and the average speed Vavg is, An ultrasonic water meter characterized by performing calculations through Claim 19 In paragraph 15, the means for determining the flow pattern of water is, when the flow pattern of water is transitional flow, the velocity distribution u(r), , perform calculations using n < 7 (n is an integer), and the average speed Vavg, An ultrasonic water meter characterized by performing calculations through Claim 20 An ultrasonic water meter according to claim 11 or 12, wherein the means for determining the flow pattern of water is characterized by determining the flow pattern of water as laminar flow when the first Reynolds number and the second Reynolds number are Re≤2300 and the difference between the two values ​​is within a preset error range when comparing the first Reynolds number and the second Reynolds number, determining the flow pattern of water as turbulent flow when the first Reynolds number and the second Reynolds number are Re≥4000 and the difference between the values ​​of the first Reynolds number and the second Reynolds number is within a preset error range, and changing and calculating the value of n until the difference between the first Reynolds number and the second Reynolds number is within a preset error range when the first Reynolds number and the second Reynolds number are 2300〈Re<4000 and the difference between the values ​​of the first Reynolds number and the second Reynolds number is within a preset error range, and determining the flow pattern as transitional flow when the value of n is derived. Claim 21 delete Claim 22 delete

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