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

A ultrasound water meter, comprising:

• an ultrasound sensor for transmitting and receiving ultrasound waves through a water pipe,
• a pressure sensor for detecting pressure in the water pipe,
• a temperature sensor for detecting water surface temperature in the water pipe, and
• a controller for determining water temperature distribution and water movement pattern using information obtained from the ultrasound sensor and the pressure sensor to calculate a water flow rate,
• wherein the controller includes:
• a ultrasound measurement device that measures a ultrasound time, wherein the ultrasound time includes a forward ultrasound time and a backward ultrasound time, wherein the forward ultrasound time detects ultrasound in the same direction as a water flowing direction, wherein the backward ultrasound time detects ultrasound in the opposite direction to the water flowing direction;
• a water flow rate calculator that calculates the water flow rate in the water pipe using a difference between the forward ultrasound time and the backward ultrasound time;
• a ultrasound speed calculator that calculates a ultrasound speed using the forward ultrasound time and the backward ultrasound time obtained in the ultrasound measurement device;
• a center water temperature calculator that calculates water temperature T(0) of water located in a center of the water pipe using the ultrasound speed, wherein the ultrasound speed is obtained in the ultrasound speed calculation process and varies depending on water temperature;
• a temperature distribution calculator that (i) detects a water surface temperature (Ts) of water located in a surface of the water pipe using a temperature sensor, and (ii) calculates a water temperature distribution T(r) in the water pipe using the water surface temperature (Ts), the center water temperature T(0), and a water pipe diameter;
• a water movement pattern determination device that determines a water movement pattern using the water temperature distribution T(r), a water flow rate distribution, and comparison between a first Reynolds number and a second Reynolds number, wherein the water flow rate distribution is obtained using the ultrasound time and varies depending on the water movement pattern, wherein the first Reynolds number is calculated using an average water flow rate, wherein the second Reynolds number is calculated using a pressure change in the water pipe, wherein the pressure change is obtained using a pressure sensor;
• and
• a water flow amount calculator that calculates a water flow amount using a average water flow rate, wherein the average water flow rate varies depending on the water movement pattern,
• wherein the water temperature distribution T(r) is calculated from the following Formula 1:
• T
• ⁡
• (
• r
• )
• =
• qr
• 0
• 2
• 4
• ⁢
• K
• ⁢
• (
• 1
• -
• r
• 2
• r
• o
• 2
• )
• +
• Ts
• 〈
• Formula
• ⁢
• 1
• 〉
• wherein Ts is the water surface temperature,
• wherein r0 is the radius of the water pipe,
• wherein, when r=0, the center water temperature T(0) is presented by the following formula:
• T
• ⁡
• (
• 0
• )
• =
• qr
• 0
• 2
• 4
• ⁢
• K
• +
• T
• s
• wherein q is heat generation rate,
• wherein K is thermal conductivity,
• wherein the ultrasound water meter further comprises:
• an outdoor water leakage monitor;
• and a control server,
• wherein the outdoor water leakage monitor (i) monitors whether there is no water flow in the water pipe using the water flow rate obtained in the water flow rate calculator, (ii) compares a first pressure (P1) and a second pressure (P2) detected, wherein the first pressure (P1) is measured when there is no water flow in the water pipe at the time of initial installation, wherein the second pressure (P2) is measured by a pressure sensor when there is no water flow in the water pipe at a given point of time;
• (iii) determines whether there is a pressure drop that exceeds a preset reference error value:
• (iv) generates water leak monitoring information when pressure drop exceeds the preset reference error value;
• and (v) transmits the water leak monitoring information to a control server,
• wherein control server receives the water leak monitoring information and remotely locks a valve of the ultrasound water meter.