Method for measuring flow rate in ultrasonic water meter and detecting outdoor water leakage using temperature distribution and pressure change and ultrasonic water meter

Abstract

The present invention relates to a method for measuring the flow rate in an ultrasonic water meter and, more specifically, to a method for measuring the flow rate in an ultrasonic water meter and detecting outdoor water leakage using temperature distribution and pressure change, wherein the flow pattern of water is analyzed and the flow rate is measured by using an average flow velocity suitable for the flow pattern of water. The method for measuring the flow rate in an ultrasonic water meter and detecting outdoor water leakage according to the present invention can measure the flow rate in consideration of the flow pattern of water by using a temperature distribution. The method takes into consideration that velocity distribution and average velocity vary according to the flow pattern of water and determines the flow pattern of water by using a Reynolds number accounting for average temperature, obtains the average velocity according to the flow pattern of water, and calculates the flow rate using the average velocity, thus enabling accurate calculation of the flow rate.

Description

Flow measurement and outdoor water leak detection method using temperature distribution and pressure change of ultrasonic water meter and its ultrasonic water meter

[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 water leaks using temperature distribution and pressure changes, which analyzes the flow pattern of water and measures the flow rate using an average flow velocity suitable for the flow pattern of water.

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

[0003] An ultrasonic meter is a device that measures the flow rate by detecting the flow of fluid in a pipe using ultrasonic waves. The ultrasonic sensor can be installed on the outside of the pipe, and the flow rate can be easily measured, so it is widely used in water meters.

[0004] However, ultrasonic water meters cannot accurately measure flow rate by measuring only the central velocity due to the various types of water flow, such as laminar / transitional / turbulent flow. In addition, the temperature distribution of water in the water pipe changes with the seasons, which causes errors in velocity measurement.

[0005] Korean Patent No. 10-2116651, a method for measuring flow rate of an ultrasonic water meter and the ultrasonic water meter, is intended to improve the precision of accurate ultrasonic flow rate measurement by obtaining a flow rate correction coefficient to correct errors when calculating flow rate using linear velocity, and to obtain the ratio of frictional force and inertial force between water and pipes, and to correct linear velocity to average velocity from this function, thereby enabling accurate flow rate measurement.

[0006] In other words, the flow measurement method of this type of ultrasonic water meter calculates the water temperature by using the fact that the propagation time of ultrasonic waves varies depending on the water temperature, calculates the viscosity of water according to the water temperature, and uses this to set the flow correction coefficient value to correct the error in the flow measurement. (Error correction considering the laminar flow characteristics of water)

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

[0008] Therefore, changes in the temperature distribution within a water pipe due to differences in external temperatures occur, making it impossible to accurately determine the water temperature distribution based solely on the central velocity of the water. Consequently, inaccurate temperature measurements lead to errors in calculating the water viscosity, which in turn leads to errors in flow rate measurements.

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

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

[0011] Furthermore, as illustrated in Figures 2 and 3, water flows laminarly or turbulently within water pipes (there is also transitional flow, which is a combination of laminar and turbulent flow), resulting in a velocity difference between the surface and center of the pipe. Failure to take this into account will result in errors in flow rate measurements.

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

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

[0014] In this way, conventional flow measurement methods cause a large amount of error in flow measurement due to not considering the temperature distribution of water or inaccurate water temperature measurement.

[0015] Meanwhile, while it is possible to detect water leaks inside the home through real-time monitoring of water usage, a low-cost method for real-time monitoring of water leaks outside the home is needed.

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

[0017] However, such a water leak detection system requires the use of an expensive water leak detection sensor, and since water meters use ultra-low-capacity, low-power communication networks, they are not suitable for transmitting high-volume data such as water leak detection signals. Therefore, a separate water leak detection system must be built and a person must visit the site in person to determine whether there is a water leak.

[0018] In addition, since the location of the leak is detected by determining the leak sound, accurate detection is difficult due to the influence of groundwater noise, surrounding noise, etc.

[0019] Water meters are designed to correct errors in minimum / maximum / transition flow rates before shipping, but in real environments, not laboratory environments, the flow of water varies depending on the surrounding environment, water temperature distribution, and flow rate. Conventional flow measurement methods cannot correct errors by taking all of these variables into account.

[0020] Additionally, due to the lack of a real-time monitoring system for outdoor water leaks, there are many actual water leak cases and the response is slow, which reduces the water flow rate.

[0021] The present invention provides a method for measuring flow rate and detecting outdoor water leaks using temperature distribution and pressure changes of an ultrasonic water meter, which enables accurate flow rate measurement in an ultrasonic water meter by distinguishing the flow of water in a water pipe, calculating an average flow rate according to the water flow, and measuring the flow rate using the calculated average flow rate.

[0022] To accurately determine the average velocity by distinguishing the flow type, the Reynolds number must be known. To determine the Reynolds number, the average velocity must be known. Furthermore, the Reynolds number varies depending on the water temperature. Therefore, a method is needed to measure flow rate by distinguishing between laminar, transitional, and turbulent flow types and applying the appropriate average velocity.

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

[0024] Furthermore, when determining the flow pattern of water in the present invention, it is essential to check for leaks to prevent errors due to leakage by using a pressure sensor. Therefore, in the absence of flow, leaks can be detected by continuously checking for pressure decreases that exceed the error threshold compared to the pressure measured during initial installation.

[0025] The method for measuring flow rate and detecting outdoor water leaks of an ultrasonic water meter of the present invention is capable of measuring flow rate considering the flow pattern of water using temperature distribution, and considering that the velocity distribution and average velocity vary depending on the flow pattern of water, the flow pattern of water is determined using the Reynolds number to which the average temperature is applied, and the average velocity is obtained depending on the flow pattern of water, and the flow rate is calculated using this, thereby enabling accurate calculation of flow rate, as its technical feature.

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

[0027] A velocity calculation process for calculating the central velocity in a water pipe by using the ultrasonic time calculated in the above ultrasonic time measurement process and the time difference between the ultrasonic times,

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

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

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

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

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

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

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

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

[0036] Temperature distribution T(r) of water and velocity distribution u(r) and average velocity V depending on laminar and turbulent flow avg The method is characterized by comprising a first process of calculating a first Reynolds number, calculating an average temperature Tm for each of 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 a pressure change obtained using a pressure sensor, and comparing the first Reynolds number and the second Reynolds number to determine whether the flow is laminar or turbulent, and a second process of determining the flow form of water as transitional flow when neither laminar flow nor turbulent flow is found through the first process.

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

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

[0039] If the first and second Reynolds numbers are Re≤2300 and the difference between the first and second Reynolds numbers is within a predetermined error range, the flow pattern of water is judged 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 flow pattern of water is determined to be turbulent flow.

[0041] 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 calculated by changing the value of n until it is within a preset error range, and when the value of n is derived, it is determined that it is a transition flow.

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

[0043] It is characterized by further including an outdoor water leak monitoring process of monitoring a case where there is no water flow rate from the water flow rate obtained from the above water flow rate calculation process, comparing the pressure measured when there is no water flow rate at the time of initial installation with the pressure measured by a pressure sensor, determining whether there is a decrease in pressure that exceeds a preset standard error value as a result of the comparison, and generating water leak occurrence monitoring information and transmitting the generated water leak occurrence monitoring information to a control server.

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

[0045] An ultrasonic water meter for a water meter comprising an ultrasonic sensor for transmitting and receiving ultrasonic waves through a water pipe, a pressure sensor for detecting pressure inside the water pipe, a temperature sensor for detecting surface water temperature inside the water pipe, a control means for calculating flow rate by judging temperature distribution and water flow pattern using values ​​obtained from the ultrasonic sensor and the pressure sensor, 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 the 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 velocity calculating means for calculating the flow velocity in the water pipe using the ultrasonic time calculated by the ultrasonic time measuring means and the time difference between the ultrasonic times, an ultrasonic velocity calculating means for calculating the ultrasonic velocity with the ultrasonic time obtained by the ultrasonic time measuring means, a water temperature calculating means for calculating the central temperature T(0) of the water using the ultrasonic velocity obtained in the ultrasonic velocity calculating process, a temperature distribution calculating means for measuring the temperature (Ts) of the water surface on the water pipe from a value input from a temperature sensor and calculating the temperature distribution T(r) in the water pipe using the central temperature T(0) of the water and the water pipe diameter information, and a water flow form for determining the water flow form by comparing the first Reynolds number calculated using the average velocity and the second Reynolds number calculated according to the pressure change obtained using the pressure sensor with the water temperature distribution T(r) and the measured value of the ultrasonic sensor. It is characterized by comprising a judgment means and a flow rate calculation means for calculating a flow rate using an average velocity and a cross-sectional area obtained according to the flow pattern of water determined by the water flow pattern judgment means.

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

[0048] The means for determining the flow pattern of the above water is:

[0049] The method is characterized in that the temperature distribution T(r) of water and the velocity distribution u(r) and the average velocity Vavg are calculated according to laminar flow and turbulent flow, the average temperature Tm is calculated for each of laminar flow and turbulent flow, the first Reynolds number is derived using the calculated average temperature Tm, the second Reynolds number is derived according to the pressure change obtained using a pressure sensor, the first Reynolds number and the second Reynolds number are compared to determine whether the flow is laminar or turbulent, and when neither laminar flow nor turbulent flow is applicable, the flow form of the water is determined to be transitional flow.

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

[0051] The above control means is characterized in that it further includes an outdoor water leakage monitoring means that monitors when there is no water velocity from the water velocity obtained from the water velocity calculation means, compares the pressure measured when there is no water velocity at the time of initial installation with the pressure measured by the pressure sensor, determines whether there is a decrease in pressure that exceeds a preset standard error value as a result of the comparison, and generates water leakage monitoring information when there is a decrease in pressure, and transmits the generated water leakage monitoring information to the control server.

[0052] According to the present invention, before estimating the average velocity for calculating the flow rate, the flow pattern of water inside the water pipe is determined, and the average velocity is obtained according to the flow pattern of the water to calculate the flow rate, thereby enabling accurate calculation of the flow rate.

[0053] Figure 1 is a drawing showing the change in temperature distribution according to the temperature difference inside and outside the water pipe.

[0054] Figures 2 and 3 are drawings showing the flow distribution of water in a water pipe, with Figure 2 showing laminar flow and Figure 3 showing turbulent flow.

[0055] Figures 4 and 5 illustrate a method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change of the present invention. Figure 4 is a flow chart illustrating a process for measuring flow rate of an ultrasonic water meter, and Figure 5 is a flow chart illustrating a process for detecting outdoor water leaks.

[0056] Figure 6 is a diagram showing the viscosity / density / dynamic viscosity of water according to temperature.

[0057] Fig. 7 is a block diagram showing the configuration of the ultrasonic water meter of the present invention.

[0058] Figure 8 is a drawing showing one embodiment of the configuration within a water pipe according to the present invention.

[0059] First, the terms used in this specification and claims are general terms selected based on their functions in various embodiments of the present invention. However, these terms may vary depending on the intentions of those skilled in the art, legal or technical interpretations, and the emergence of new technologies. Furthermore, some terms may be arbitrarily selected by the applicant. These terms may be interpreted according to the meanings defined herein. In the absence of a specific definition, they may be interpreted based on the overall content of this specification and common technical knowledge in the relevant technical field.

[0060] The terms and words used in the detailed description and claims of the present invention should not be interpreted based on their usual or dictionary meanings, but should be interpreted based on the principle that 'an inventor may appropriately define the concept of a term to best explain his or her invention.' They should be interpreted with meanings and concepts that conform to the technical spirit of the present invention.

[0061] In addition, it should be understood that 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 of the technical ideas of the present invention, and therefore, there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0062] Additionally, the same reference numbers or symbols in each drawing attached to this specification represent parts or components that perform substantially the same functions. For convenience of explanation and understanding, the same reference numbers or symbols are used in different embodiments. In other words, even if components with the same reference numbers are depicted in multiple drawings, they do not necessarily represent a single embodiment.

[0063] Additionally, terms including ordinal numbers, such as "first," "second," etc., may be used in this specification and claims to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from each other, and the use of these ordinal numbers should not be interpreted in a limited way. For example, components associated with these ordinals should not be interpreted in a limited way with respect to the order of use or arrangement, etc., due to their numbers. If necessary, each ordinal number may be used interchangeably.

[0064] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "comprise" or "comprises" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0065] Hereinafter, the method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change of the present invention will be specifically described with reference to the embodiment illustrated in the attached drawing 4.

[0066] Fig. 4 is a flow chart showing a process of measuring the flow rate of an ultrasonic water meter in a method of measuring the flow rate of an ultrasonic water meter and detecting an outdoor water leak using temperature distribution and pressure change of the present invention, and Fig. 5 is a flow chart showing an outdoor water leak detection process.

[0067] The method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change of the present invention is as follows:

[0068] An ultrasonic time measurement process that measures the 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,

[0069] A velocity calculation process for calculating the velocity in a water pipe by using the time difference between the ultrasonic time and the ultrasonic time calculated in the above ultrasonic time measurement process,

[0070] An ultrasonic velocity calculation process for calculating the ultrasonic velocity using the ultrasonic time obtained in the above ultrasonic time measurement process,

[0071] A water temperature calculation process that calculates the central temperature T(0) of water using the ultrasonic velocity obtained in the above ultrasonic velocity calculation process,

[0072] The process of measuring the surface water temperature (Ts) of the water pipe surface using a temperature sensor,

[0073] A temperature distribution calculation process for obtaining the temperature distribution T(r) inside the water pipe using the measured surface water temperature, the center temperature T(0) of the water, and the diameter information of the water pipe,

[0074] A process for determining the flow form of water by comparing the first Reynolds number calculated using the temperature distribution T(r) of water and the velocity distribution and average velocity (flow rate) calculated according to each water type using the measured values ​​of the ultrasonic sensor and the second Reynolds number calculated according to the pressure change obtained using the pressure sensor,

[0075] It is comprised of a flow rate calculation process that calculates the flow rate using the average velocity according to the flow rate determined through the water flow rate determination process.

[0076] And the process of judging the flow pattern of the water is as follows:

[0077] The method comprises the following steps: a first step of calculating the temperature distribution T(r) of water and the velocity distribution u(r) and the average velocity Vavg according to laminar flow and turbulent flow, calculating the average temperature Tm for each of laminar flow and turbulent flow, deriving the first Reynolds number using the calculated average temperature Tm, deriving the second Reynolds number according to the pressure change obtained using a pressure sensor, and comparing the first Reynolds number and the second Reynolds number to determine whether the flow is laminar or turbulent; and a second step of determining the flow form of water as transitional flow when neither laminar flow nor turbulent flow is found through the first step.

[0078] And, from the water flow rate obtained from the above flow rate calculation process, the outdoor water leak monitoring process may further include monitoring a case where there is no flow rate, 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, determining whether there is a decrease in pressure that exceeds a preset standard error value as a result of the comparison, and generating water leak monitoring information and transmitting the generated water leak monitoring information to the control server.

[0079] The method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change through a process like this is described in detail with reference to the attached drawings.

[0080] Ultrasound can be transmitted forward and backward along the water flow, and the difference in arrival time can be used to measure the water flow rate.

[0081] At this time, the central temperature T(0) can be measured through the speed of ultrasonic waves by using the speed of ultrasonic waves that changes depending on the temperature of the water.

[0082] And the temperature sensor can be used to measure the temperature (Ts) of the water on the surface of the water pipe.

[0083] Using the measured central temperature T(0), surface water temperature (Ts) and water pipe diameter information, the temperature distribution T(r) within the water pipe is calculated as in the following mathematical equation 1.

[0084]

[0085] (Ts: surface temperature, T(0): center temperature)

[0086] Here, r0 is the radius of the water pipe.

[0087] Afterwards, the flow pattern of water is determined, and the flow rate is calculated according to each water flow pattern (laminar flow, turbulent flow, and transitional flow).

[0088] Here, the Reynolds number is used to determine the flow pattern of water. To determine the Reynolds number, the average temperature Tm is required.

[0089] To obtain the above average temperature Tm, the velocity distribution u(r) and the average velocity Vavg are required.

[0090] At this time, since the velocity distribution u(r) and the average velocity Vavg vary depending on the flow pattern of the water, the velocity distribution and average velocity are obtained according to each flow pattern of the water, and the average temperature Tm is obtained using this.

[0091] 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.

[0092] Afterwards, 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 the water can be determined based on the comparison value.

[0093] Here, the process of determining the flow form of water is assuming that it is laminar flow or turbulent flow, first calculating the first Reynolds number and the second Reynolds number, comparing the first Reynolds number and the second Reynolds number, and determining laminar flow or turbulent flow based on the comparison value, and when the flow form of water does not correspond to either laminar flow or turbulent flow, the flow form of water can be determined as transitional flow.

[0094] First, if the flow pattern of water is laminar flow, the velocity distribution u(r) can be obtained through the following mathematical equation 2.

[0095]

[0096] At this time, the average velocity Vavg is half of the central velocity u0 of the water. (u0= u max = 2Vavg)

[0097] Afterwards, 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 using this, the kinematic viscosity coefficient of water can be obtained, and the first Reynolds number Re in the case of laminar movement can be derived as in Equation 4.

[0098]

[0099]

[0100] Here, Vavg: average velocity, υ: coefficient of kinematic viscosity, D: diameter of water pipe

[0101] The kinematic viscosity υ of water at 4°C is approximately 95% higher than that of water at 30°C.

[0102] Figure 6 shows the coefficient of viscosity υ.

[0103] Figure 6 is a diagram showing the viscosity / density / dynamic viscosity of water according to temperature.

[0104] And verify that the water flow pattern is laminar flow.

[0105] In order to verify whether the flow pattern of water is laminar flow, the average velocity is calculated using the pressure change according to Bernoulli's principle as in Equation 5, the second Reynolds number is calculated using the obtained average velocity, and the calculated second Reynolds number is compared with the first Reynolds number obtained using the velocity distribution above.

[0106] Mathematical expressions 5 to 7 represent the process of obtaining the average velocity and the second Reynolds number using pressure changes.

[0107]

[0108]

[0109]

[0110] Vavg: average velocity, μ: viscosity coefficient, υ: ​​kinematic viscosity coefficient, D: pipe diameter, L: pipe length

[0111] P1-P2: Pressure difference when there is no flow and when there is flow

[0112] The above P1 and P2 are the pressures measured by the pressure sensor, and the pressure when there is no flow is the value measured when the valve is closed at the initial stage of installation.

[0113] Here, if the first Reynolds number and the second Reynolds number are Re≤2300, and the difference between the first Reynolds number obtained using the velocity distribution and the second Reynolds number obtained using the pressure change is within a preset error range, the flow form of the water can be determined to be laminar flow.

[0114] Afterwards, it is determined that the water flow pattern is laminar flow, and the flow rate is calculated using the average velocity according to laminar flow and the cross-sectional area of ​​the water pipe. (Flow rate = average velocity Vavg × cross-sectional area)

[0115] Meanwhile, when the flow pattern of water is assumed to be turbulent, the velocity distribution u(r) and the average velocity Vavg are obtained using the following mathematical equations 8 and 9.

[0116]

[0117] Here, n=7

[0118]

[0119] Afterwards, 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.

[0120] In order to verify whether the flow form of water is turbulent flow, the average velocity is obtained by using the pressure change according to Bernoulli's principle as in Equations 5 to 7, the second Reynolds number is derived using the obtained average velocity, and the derived second Reynolds number is compared with the first Reynolds number obtained using the velocity distribution through Equations 8 and 9.

[0121] If 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, the flow pattern of water is determined to be turbulent flow and the flow rate is calculated. (Flow rate = average velocity Vavg × cross-sectional area)

[0122] Here, when developing mathematical equations using pressure changes in turbulent flow, the surface roughness of the water pipe must be taken into account. However, the surface of typical water pipes is very smooth, so the influence of surface roughness is minimal. Therefore, the same method as for laminar flow is used in turbulent flow.

[0123] Through the process described above, if the flow pattern of water does not correspond to either laminar flow or turbulent flow, the flow pattern of water is determined to be transitional flow.

[0124] In the case of transitional flow, the velocity distribution u(r) and the average velocity Vavg are obtained using Equations 8 and 9, as in the case of turbulent flow, where n is n<7 (n is an integer).

[0125] 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.

[0126] The average velocity is obtained by using the pressure change according to Bernoulli's principle as in Equations 5 to 7, and the second Reynolds number Re is derived using the obtained average velocity, and the derived second Reynolds number is compared with the first Reynolds number Re.

[0127] 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 calculated by changing the value of n until it is within a preset error range.

[0128] Once the n value is derived, the flow rate is calculated using the transition flow. (Flow rate = average velocity Vavg × cross-sectional area)

[0129] Meanwhile, outdoor water leak detection monitors the case where there is no flow from the water flow rate obtained using the ultrasonic sensor above, and compares the pressure (P1) measured when there is no flow rate during initial installation with the pressure (P2) measured by the pressure sensor.

[0130] The comparison results continuously monitor whether there is a decrease in pressure that exceeds the preset standard error value.

[0131] If there is a decrease in pressure at this time, a leak may be suspected in front of the water meter (outdoors), and the information is transmitted to the control server as leak monitoring information, and compared and analyzed with the measured pressure values ​​of water meters supplied with the same water pressure to determine whether there is an actual leak.

[0132] At this time, the information transmitted to the control server is the pressure value measured by the pressure sensor and may include water flow rate information.

[0133] As described above, when water leakage monitoring information is received from a water meter, the control server can remotely lock the valve of the water meter, re-measure the pressure, and then compare and analyze the measured pressure values ​​with those of water meters supplied with the same water pressure in the same area to determine whether an actual water leakage has occurred.

[0134] Meanwhile, an ultrasonic water meter for performing a method of measuring flow rate and detecting outdoor water leaks using the temperature distribution and pressure change of the present invention is configured as follows.

[0135] 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 one embodiment of the configuration within a water pipe according to the present invention.

[0136] The ultrasonic water meter of the present invention is,

[0137] An ultrasonic water meter for a water meter comprising an ultrasonic sensor (10) for transmitting and receiving ultrasonic waves through a water pipe, a pressure sensor (20) for detecting pressure inside the water pipe, a temperature sensor (30) for detecting surface water temperature inside the water pipe, a control means (40) for calculating a flow rate by judging a temperature distribution and a water flow pattern using values ​​obtained from the ultrasonic sensor (10) and the pressure sensor (20), and a display means (50) for displaying the flow rate obtained from the control means (40).

[0138] The above control means (40) comprises an ultrasonic time measuring means (41) for measuring the ultrasonic time for each path of an ultrasonic sensor (10) in the same direction as the flow direction of the fluid and in the opposite direction to the flow direction of the fluid, a velocity calculation 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 times, an ultrasonic velocity calculation means (43) for calculating the ultrasonic velocity with the ultrasonic time obtained by the ultrasonic time measuring means (41), a water temperature calculation means (44) for calculating the center temperature T(0) of the water using the ultrasonic velocity obtained by the ultrasonic velocity calculation means (43), a temperature distribution calculation 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 calculating the temperature distribution T(r) in the water pipe using the center temperature T(0) of the water and the water pipe diameter information, and a temperature distribution calculation means (45) for calculating the temperature distribution T(r) of the water and the measured value of the ultrasonic sensor (10) according to each type of water. It is configured to include a water flow form determination means (46) for determining the water flow form by comparing the first Reynolds number calculated using the calculated velocity distribution and average velocity with the second Reynolds number calculated according to the pressure change obtained using the pressure sensor (20), and a flow rate calculation means (47) for calculating the flow rate using the average velocity and cross-sectional area obtained according to the water flow form determined by the water flow form determination means (46).

[0139] And the means for determining the flow pattern of the water (46) is

[0140] The temperature distribution T(r) of water and the velocity distribution u(r) and the average velocity Vavg are calculated according to laminar flow and turbulent flow, the average temperature Tm is calculated for each of laminar flow and turbulent flow, the first Reynolds number is derived using the calculated average temperature Tm, 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 the flow is laminar or turbulent, and when neither laminar flow nor turbulent flow corresponds to the flow, the flow form of the water can be determined to be a transitional flow.

[0141] And the above control means (40) may further include an outdoor water leakage monitoring means (48) that monitors when there is no water velocity from the water velocity obtained from the water velocity calculation means (42), compares the pressure (P1) measured when there is no water velocity 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 standard error value as a result of the comparison, and, if there is a decrease in pressure, generates water leakage monitoring information and transmits the generated water leakage monitoring information to the control server.

[0142] An ultrasonic water meter having this configuration is

[0143] In the above control means (40), the central temperature T(0) is measured through the speed of ultrasonic waves, and the temperature (Ts) of the water on the surface of the water pipe is measured using the value input from the temperature sensor (30).

[0144] Using the measured central temperature T(0), surface water temperature (Ts) and water pipe diameter information, the temperature distribution T(r) within the water pipe is calculated as in the above mathematical expression 1.

[0145] Afterwards, the Reynolds number is used to determine the flow pattern of water, and the flow rate is calculated according to each flow pattern of water: laminar flow, turbulent flow, and transitional flow.

[0146] To obtain the above Reynolds number, the average temperature Tm is required, and to obtain the above average temperature Tm, the velocity distribution u(r) and the average velocity Vavg are required.

[0147] Depending on the flow pattern of each water, the velocity distribution and average velocity can be obtained, and the average temperature Tm can be obtained using these.

[0148] 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.

[0149] Afterwards, 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 the water can be determined based on the comparison value.

[0150] Here, to determine the flow form of water, first, assuming that it is laminar flow or turbulent flow, the first Reynolds number and the second Reynolds number are obtained, the first Reynolds number and the second Reynolds number are compared, and laminar flow or turbulent flow is determined based on the comparison value. When the flow form of water does not correspond to either laminar flow or turbulent flow, the flow form of water can be determined to be transitional flow.

[0151] First, if the flow pattern of water is laminar flow, the velocity distribution u(r) can be obtained through the above mathematical equation 2.

[0152] At this time, the average velocity Vavg is half of the central velocity u0 of the water. (u0= u max = 2Vavg)

[0153] Afterwards, 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 using this, the first Reynolds number Re according to laminar flow can be derived as in Equation 4.

[0154] And verify that the water flow pattern is laminar flow.

[0155] In order to verify whether the flow pattern of water is laminar flow, the average velocity is obtained using the pressure change according to Bernoulli's principle as in the above mathematical equation 5, the second Reynolds number is calculated using the obtained average velocity, and the calculated second Reynolds number is compared with the first Reynolds number obtained using the velocity distribution above.

[0156] Here, if the first Reynolds number and the second Reynolds number are Re≤2300, and the difference between the first Reynolds number obtained using the velocity distribution and the second Reynolds number obtained using the pressure change is within a preset error range, the flow form of the water can be determined to be laminar flow.

[0157] Afterwards, the water flow pattern is determined to be laminar flow, and the flow rate is calculated using the average velocity according to laminar flow and the cross-sectional area of ​​the water pipe. (Flow rate = average velocity Vavg × cross-sectional area)

[0158] Meanwhile, when the flow form of water is assumed to be turbulent flow, the velocity distribution u(r) and the average velocity Vavg are obtained using the above mathematical equations 8 and 9.

[0159] Afterwards, 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 this is used to derive the first Reynolds number Re according to the turbulent flow.

[0160] In order to verify whether the flow form of water is turbulent flow, the average velocity is obtained by using the pressure change according to Bernoulli's principle as in Equations 5 to 7, the second Reynolds number is derived using the obtained average velocity, and the derived second Reynolds number is compared with the first Reynolds number obtained using the velocity distribution through Equations 8 and 9.

[0161] If 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, the flow pattern of water is determined to be turbulent flow and the flow rate is calculated. (Flow rate = average velocity Vavg × cross-sectional area)

[0162] In the above case, if the water flow pattern does not correspond to either laminar flow or turbulent flow, the water flow pattern is determined to be transitional flow.

[0163] In the case of transitional flow, the velocity distribution u(r) and the average velocity Vavg are obtained using the following mathematical equations 8 and 9, as in the case of turbulent flow, where n is n<7 (n is an integer).

[0164] 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 according to the transition flow is derived using this.

[0165] The average velocity is obtained by using the pressure change according to Bernoulli's principle as in Equations 5 and 7, the second Reynolds number is derived using the obtained average velocity, and the derived second Reynolds number is compared with the first Reynolds number obtained using the velocity distribution through Equations 8 and 9.

[0166] 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 calculated by changing the value of n until it is within a preset error range.

[0167] Once the n value is derived, the flow rate is calculated by judging it as a transition flow. (Flow rate = average velocity Vavg × cross-sectional area)

[0168] In calculating the flow rate through the average velocity that varies according to the flow pattern of water, by determining the flow pattern of water, whether it is laminar flow, turbulent flow, or transitional flow, and calculating the flow rate by obtaining the average velocity according to each flow pattern of water, an accurate flow rate can be calculated.

[0169] And the outdoor water leak monitoring means (48) of the control means (40) monitors the case where there is no flow rate from the water flow rate obtained using the ultrasonic sensor above, and in the case where there is no flow rate, compares the pressure (P1) measured when there is no flow rate during initial installation with the pressure (P2) measured by the pressure sensor, and continuously monitors whether there is a decrease in pressure that deviates from the preset standard error value as a result of the comparison.

[0170] If there is a decrease in pressure at this time, a leak may be suspected in front of the water meter (outdoors), and the information is transmitted to the control server as leak monitoring information, and compared and analyzed with the measured pressure values ​​of water meters supplied with the same water pressure to determine whether there is an actual leak.

[0171] As described above, when water leakage monitoring information is received from a water meter, the control server can remotely lock the valve of the water meter, re-measure the pressure, and then compare and analyze the measured pressure values ​​with those of water meters supplied with the same water pressure in the same area to determine whether an actual water leakage has occurred.

[0172] An outdoor water leak management system can be configured using the ultrasonic water meter of the present invention.

[0173] An ultrasonic water meter comprising a flow rate calculation means for calculating a flow rate in a water pipe by measuring an ultrasonic time, and a pressure sensor for measuring a pressure in a water pipe, and an outdoor water leak monitoring means for monitoring a case where there is no flow rate from the flow rate of water obtained from the flow rate calculation means, comparing the pressure (P1) measured when there is no flow rate during initial installation with the pressure (P2) measured by the pressure sensor, determining whether there is a decrease in pressure that exceeds a preset standard error value as a result of the comparison, and generating water leak occurrence monitoring information and transmitting the generated water leak occurrence monitoring information to a control server, and a control server of the ultrasonic water meter.

[0174] The above control server may be configured to include a means for, when water leakage monitoring information received from the ultrasonic water meter is received, transmitting a remote control signal to the ultrasonic water meter to close the valve and re-measure from the pressure sensor, and 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 to determine whether an actual water leakage has occurred in the ultrasonic water meter.

[0175] In this way, the ultrasonic water meter according to the embodiment of the present invention, which calculates an accurate flow rate through an average speed that varies according to the flow pattern of water, can detect outdoor water leaks by using pressure changes in an ultrasonic sensor including a pressure sensor.

[0176] The method of measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter is as follows:

[0177] The method may include an ultrasonic time measurement process for measuring the ultrasonic time for each ultrasonic sensor path in the same direction as the direction of fluid flow and in the opposite direction to the direction of fluid flow, a velocity calculation process for calculating the velocity of flow in a water pipe using the time difference between the ultrasonic time calculated in the ultrasonic time measurement process and the ultrasonic time, a flow calculation process for calculating the flow rate using the velocity, and an outdoor water leak monitoring process for monitoring the case where there is no velocity from the velocity of water obtained from the velocity calculation process, and comparing the pressure (P1) measured when there is no velocity at the time of initial installation with the pressure (P2) measured by the pressure sensor, and determining whether there is a decrease in pressure that exceeds a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generating water leak monitoring information, and transmitting the generated water leak monitoring information to a control server.

[0178] In addition, the ultrasonic water meter to which the above ultrasonic water meter's flow measurement and outdoor water leak detection method are applied,

[0179] An ultrasonic water meter for a water meter comprising an ultrasonic sensor for transmitting and receiving ultrasonic waves through a water pipe, a pressure sensor for detecting pressure inside the water pipe, a control means for measuring ultrasonic time using a value obtained from the ultrasonic sensor, calculating flow velocity inside the water pipe using the ultrasonic time calculated in the ultrasonic time measurement process, and calculating flow rate using the flow rate, and a display means for displaying the flow rate obtained from the control means.

[0180] The above control means may further include an outdoor water leak monitoring means that monitors when there is no water flow rate from the water flow rate obtained from the water flow rate calculation means, compares the pressure (P1) measured when there is no water 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 exceeds a preset standard error value as a result of the comparison, and, if there is a decrease in pressure, generates water leak monitoring information and transmits the generated water leak monitoring information to the control server.

[0181] Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and various modifications may be made by a person skilled in the art to which the invention pertains without departing from the gist of the present invention as claimed in the claims. Furthermore, such modifications should not be understood individually from the technical idea or prospect of the present invention.

Claims

1. Ultrasonic time measurement process that measures the 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 velocity calculation process for calculating the velocity in a water pipe by using the ultrasonic time calculated in the above ultrasonic time measurement process and the time difference between the ultrasonic times, An ultrasonic velocity calculation process that calculates the ultrasonic velocity using the ultrasonic time obtained in the above ultrasonic time measurement process, A water temperature calculation process that calculates the central temperature T(0) of water using the ultrasonic velocity obtained in the above ultrasonic velocity calculation process, The surface water temperature measurement process in which a temperature sensor measures the temperature (Ts) of the water surface of the water pipe, A temperature distribution calculation process for obtaining the temperature distribution T(r) inside the water pipe using the measured surface water temperature, the center temperature T(0) of the water, and the water pipe diameter information, A process for determining the flow form of water by comparing the first Reynolds number calculated using the velocity distribution and average velocity calculated according to each water type using the temperature distribution T(r) of the water and the measured values ​​of the ultrasonic sensor, and the second Reynolds number calculated according to the pressure change obtained using the pressure sensor, and A method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure changes, characterized in that it includes a flow rate calculation process for calculating flow rate using an average velocity according to the flow pattern of water determined through a water flow pattern judgment process.

2. In paragraph 1, the process of determining the flow pattern of the water is as follows: A method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change, characterized by comprising a first step of calculating each velocity distribution u(r) and average velocity Vavg according to temperature distribution T(r) of water and laminar flow and turbulent flow, calculating average temperature Tm for each of 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 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 step of determining the flow form of the water as transitional flow when neither laminar flow nor turbulent flow is found through the first step.

3. A method for measuring flow rate and detecting outdoor water leaks using temperature distribution and pressure change of an ultrasonic water meter, characterized in that the method further includes an outdoor water leak monitoring process of monitoring a case where there is no flow rate from the water flow rate obtained from the flow rate calculation process in the first paragraph, comparing the pressure (P1) measured when there is no flow rate during initial installation with the pressure (P2) measured by a pressure sensor, determining whether there is a decrease in pressure that exceeds a preset standard error value as a result of the comparison, and generating water leak monitoring information if there is a decrease in pressure, and transmitting the generated water leak monitoring information to a control server.

4. In the first paragraph, the temperature distribution calculation process is as follows: The temperature distribution T(r) inside the water pipe is A method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change, characterized in that the temperature distribution and pressure change are calculated as (Ts: surface temperature, T(0): center temperature).

5. In the process of determining the flow pattern of water in paragraph 1 or 2, The average temperature Tm is, The first Reynolds number Re is, It is calculated through, Here, V avg : average velocity, υ: coefficient of kinematic viscosity, D: diameter of water pipe, A method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change, characterized by being.

6. In the process of determining the flow pattern of water in paragraph 1 or 2, The average velocity and the second Reynolds number Re according to the pressure change are given by Equations 5 to 7. , , is calculated through, V avg : average velocity, μ: viscosity coefficient, υ: ​​kinematic viscosity coefficient, D: pipe diameter, L: pipe length P1-P2: Pressure difference when there is no flow and pressure when there is flow A method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change, characterized by being.

7. In paragraph 5, If the flow pattern of water is laminar flow, The velocity distribution u(r) is, is calculated through, Average speed V avg is half of the central velocity of water u0 (u0 = u max = 2V avg ) is characterized by a temperature distribution and pressure change, and a method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter.

8. In paragraph 5, If the flow pattern of water is turbulent, The velocity distribution u(r) is, It is calculated through n=7, The average speed Vavg is, It is operated through, A method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change characterized by the above.

9. In paragraph 5, if the water flow form is a transitional flow, The velocity distribution u(r) is, , is calculated through n〈7 (n is an integer), The average speed Vavg is, It is operated through, A method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change characterized by the above.

10. In paragraph 1 or 2, If the first and second Reynolds numbers are Re≤2300 and the difference between the first and second Reynolds numbers is within the preset error range, the flow pattern of the water is judged to be laminar flow. 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 the preset error range, the flow pattern of the water is judged to be turbulent flow. A method for measuring flow rate and detecting outdoor water leaks using an ultrasonic water meter using temperature distribution and pressure change, characterized in that the first Reynolds number and the second Reynolds number are 2300〈Re〈4000, and the difference between the values ​​obtained by comparing the first Reynolds number and the second Reynolds number is within a preset error range, and the value of n is changed and calculated, and when the value of n is derived, it is determined that there is transitional flow.

11. An ultrasonic water meter for a water meter comprising an ultrasonic sensor for transmitting and receiving ultrasonic waves through a water pipe, a pressure sensor for detecting pressure inside the water pipe, a temperature sensor for detecting surface water temperature inside the water pipe, a control means for calculating flow rate by judging temperature distribution and water flow pattern using values ​​obtained from the ultrasonic sensor and pressure sensor, and a display means for displaying the flow rate obtained from the control means. The above control means comprises an ultrasonic time measuring means for measuring the ultrasonic time for each ultrasonic sensor path in the same direction as the flow direction of the fluid and in the opposite direction to the flow direction of the fluid, a velocity calculation means for calculating the flow velocity in the water pipe using the time difference between the ultrasonic time calculated by the ultrasonic time measuring means and the ultrasonic time, an ultrasonic velocity calculation means for calculating the ultrasonic velocity with the ultrasonic time obtained by the ultrasonic time measuring means, a water temperature calculation 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 calculation 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) in the water pipe using the center temperature T(0) of the water and the water pipe diameter information, and a water flow form for determining the flow form of the water by comparing the first Reynolds number calculated using the velocity distribution and average velocity calculated according to each water form with the measured value of the ultrasonic sensor and the second Reynolds number calculated according to the pressure change obtained using the pressure sensor. An ultrasonic water meter characterized by comprising a judgment means and a flow rate calculation means for calculating a flow rate using an average velocity and a cross-sectional area obtained according to a water flow pattern judged by a water flow pattern judgment means.

12. In paragraph 11, The above means for determining the flow pattern of water is: An ultrasonic water meter characterized in that it calculates the temperature distribution T(r) of water and the velocity distribution u(r) and the average velocity Vavg according to laminar flow and turbulent flow, calculates the average temperature Tm for each of laminar flow and turbulent flow, derives the first Reynolds number using the calculated average temperature Tm, derives the second Reynolds number according to the pressure change obtained using a pressure sensor, determines whether the flow is laminar or turbulent by comparing the first Reynolds number and the second Reynolds number, and determines the flow form of the water as transitional flow when it does not correspond to either laminar flow or turbulent flow.

13. In the 11th paragraph, the control means monitors a case where there is no flow rate from the flow rate of water obtained from the flow rate calculation means, compares the pressure (P1) measured when there is no flow rate during initial installation with the pressure (P2) measured by the pressure sensor, determines whether there is a decrease in pressure that exceeds a preset reference error value as a result of the comparison, and generates water leak occurrence monitoring information if there is a decrease in pressure, and further includes an outdoor water leak monitoring means for transmitting the generated water leak occurrence monitoring information to a control server.

14. In paragraph 11, the temperature distribution calculation means, The temperature distribution T(r) inside the water pipe, (Ts: surface temperature, T(0): center temperature) An ultrasonic water meter characterized by operating through .

15. In paragraph 11 or 12, the means for determining the flow pattern of water is: The average temperature Tm, the average temperature Tm, Operate through, The first Reynolds number Re is, Operates through, Here, Vavg: average velocity, υ: coefficient of kinematic viscosity, D: diameter of water pipe, An ultrasonic water meter characterized by:

16. In paragraph 11 or 12, the means for determining the flow pattern of water is: The average velocity and the second Reynolds number Re according to the pressure change are given in Equations 5 to 7. , , Operate through, V avg : average velocity, μ: viscosity coefficient, υ: ​​kinematic viscosity coefficient, D: pipe diameter, L: pipe length, P1-P2: pressure difference when there is no velocity and when there is velocity An ultrasonic water meter characterized by:

17. In paragraph 15, If the flow pattern of water is laminar flow, The velocity distribution u(r) is, is calculated through, The average velocity Vavg is half of the central velocity u0 of the water (u0 = u max = 2V avg ) is characterized by an ultrasonic water meter.

18. In paragraph 15, the means for determining the flow pattern of water is: If the flow pattern of water is turbulent, The velocity distribution u(r), Operate through n=7, The average speed Vavg is, It is operated through, An ultrasonic water meter characterized by:

19. In paragraph 15, the means for determining the flow pattern of water is: If the flow form of water is transitional flow, The velocity distribution u(r), , , n〈7(n is an integer) is used for calculation, The average speed Vavg is, It is operated through, An ultrasonic water meter characterized by:

20. In paragraph 11 or 12, The above means for determining the flow pattern of water is: If the first and second Reynolds numbers are Re≤2300 and the difference between the first and second Reynolds numbers is within the preset error range, the flow pattern of the water is judged to be laminar flow. 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 the preset error range, the flow pattern of the water is judged to be turbulent flow. An ultrasonic water meter characterized in that 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 calculated while changing the n value until it is within a preset error range, and when the n value is derived, it is determined that the flow is transitional.

21. An ultrasonic time measurement process that measures the 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 velocity calculation process for calculating the velocity in a water pipe by using the ultrasonic time calculated in the above ultrasonic time measurement process and the time difference between the ultrasonic times, A flow rate calculation process that calculates the flow rate using the flow rate, A method for measuring flow rate and detecting outdoor water leaks using temperature distribution and pressure change of an ultrasonic water meter, characterized by including an outdoor water leak monitoring process of monitoring a case where there is no flow rate from the water flow rate obtained from the above-mentioned flow rate calculation process, comparing the pressure (P1) measured when there is no flow rate during initial installation with the pressure (P2) measured by a pressure sensor, determining whether there is a decrease in pressure that exceeds a preset reference error value as a result of the comparison, and generating water leak monitoring information if there is a decrease in pressure, and transmitting the generated water leak monitoring information to a control server.

22. An ultrasonic water meter for a water meter, comprising an ultrasonic sensor for transmitting and receiving ultrasonic waves through a water pipe, a pressure sensor for detecting pressure inside the water pipe, a control means for measuring ultrasonic time using a value obtained from the ultrasonic sensor, calculating flow velocity inside the water pipe using the ultrasonic time calculated in the ultrasonic time measurement process, and calculating flow rate using the flow rate, and a display means for displaying the flow rate obtained from the control means. The above control means monitors the case where there is no flow rate from the water flow rate obtained from the flow rate calculation means, and if there is no flow rate, compares the pressure (P1) measured when there is no flow rate during the initial installation with the pressure (P2) measured by the pressure sensor, determines whether there is a decrease in pressure that exceeds a preset reference error value as a result of the comparison, and if there is a decrease in pressure, generates water leak occurrence monitoring information, and transmits the generated water leak occurrence monitoring information to the control server. It is characterized in that the outdoor water leak monitoring means further includes:

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