AU2020223669B2

AU2020223669B2 - Non-invasive thermal dispersion flow meter with chronometric monitor or fluid leak detection and freeze burst prevention

Info

Publication number: AU2020223669B2
Application number: AU2020223669A
Authority: AU
Inventors: Scott Shaw; Robert Trescott
Original assignee: Sentinel Hydrosolutions LLC
Current assignee: Sentinel Hydrosolutions LLC
Priority date: 2014-05-21
Filing date: 2020-08-25
Publication date: 2022-07-07
Anticipated expiration: 2034-05-21
Also published as: JP6483812B2; IL249052A0; CA2949757C; CA2949757A1; WO2015178904A1; JP2017517013A; AU2020223669A1; IL249052B; EP3146305A1; AU2014395163A1

Abstract

A non-invasive thermal dispersion flow meter with chronometric monitor for fluid leak detection includes a heater, an ambient temperature sensor and a flow 5 rate sensor which are configured to sense the temperature of a fluid in a conduit, and then monitor the flow of that fluid through the conduit. The fluid flow sensor is incorporated into a Wheatstone bridge circuit which is used to provide increased sensitivity to the outputs of the sensors. Based upon the ambient temperature sensor readings, the flow rate sensor and heater may be io adjusted to optimize the operation of the system to detect leaks. An alternative embodiment utilizes a single sensor and separate heater which work together to determine heat propagation times which in turn is used to calculate flow rate. Based on the sensor readings, the flow may be adjusted to prevent damage and leaks by relieving the system of excess pressure. 15

Description

TITLE: NON-INVASIVE THERMAL DISPERSION FLOW METER WITH CHRONOMETRIC MONITOR OR FLUID LEAK DETECTION AND FREEZE BURST PREVENTION

INVENTOR: ROBERT TRESCOTT and SCOTT SHAW

RELATED APPLICATIONS

This Application claims the benefit of priority to United States Utility

Patent Application No. 13/342,961 filed January 3, 2012 entitled "Noninvasive

Thermal Dispersion Flow Meter with Chronometric Monitor for Fluid Leak

io Detection," which in tum claims benefit of priority to United States Provisional

Patent Application Serial No. 61/429,242 filed January 3, 2011 entitled

"Noninvasive Thermal Dispersion Flow Meter with Chronometric Monitor for

Fluid Leak Detection", and to United States Provisional Patent Application

Serial No. 61/542,793 filed on October 3, 2011 entitled "Direct Pipe Clamp on

Flow Meter Leak Detector".

FIELD OF THE INVENTION

The present invention relates generally to the field of fluid leakage

detection. More particularly, the present invention relates to devices useful for

the monitoring and evaluation of fluid flow rates. The present invention is more

particularly, though not exclusively, useful as a non-invasive leak detection

system capable of detecting even the smallest fluid leakage within a fluid

conduit system, terminating fluid flow in response to the leak, and providing

other indication, alert, and control functions.

1 18801590_1(GHMatters) P104898.AU.1

BACKGROUND OF THE INVENTION

In the process of residential or commercial building construction, builders

will frequently pre-plumb water supply pipes, and then encase the foundation

level plumbing within a concrete mixture creating a floor slab. The plumbing will

remain in use for the existence of the structure until it fails and leaks. Slab leaks

typically start when a pinhole size rupture forms in a pipe or fitting from a period

of constant pressure, friction with the slab material, and thermal expansion and

contraction. As more water passes through the opening, in time, the size of the

rupture increases. Undetected, the escaping water will eventually flood the

foundation, damage floors and walls and ultimately undermine the ground

beneath the structure due to erosion. The control of water has challenged man

since the beginning. The world today benefits and suffers from the conveyance

and containment of this life giving fluid. No matter the culture, the class, or the

location, similar issues are considered, such as materials, installation,

pressures, maintenance, effects of internal and external conditions, including

water quality, climactic conditions, electrolysis, etc. Issues with any one of

these may result in undesirable effects and damages.

Leaks can be slow and gradual, taking years to detect until significant

property damage occurs, or there can be large leaks that quickly produce a

variety of damaging results. Significant costs are expended everyday all over

the world from these water-related damages. The costs are so extensive and

pervasive, that nearly everyone in our modem world has been personally

affected.

Leaks occur at all phases of water system function, both during and after

2 18801590_1 (GHMatters) P104898.AU.1 construction. During construction leaks result from improper installation, faulty materials, testing, unintentional trade damage, and vandalism--to name a few.

Once a water system is installed, formation of leaks occur due to corrosion,

environmental effects, and improper maintenance. An exemplary example of

environmental effects causing leaks is during periods of extended below zero

temperatures. When water is below its freezing point, the water turns from a

liquid phase into a solid phase resulting in an increase of volume. An increase

in volume in a closed system increases the system pressure causing strain and

compromising the structural integrity of the system, eventually causing a leak.

io Costs are spread between responsible parties, insurance companies and

often to those not responsible who cannot prove otherwise, or because

responsible parties have no ability to pay the frequently large damages.

Virtually anyone in the construction industry can tell you horror stories about

water damage during their most recent project. Most in the industry accept

these damages simply as part of the construction world and never consider

there may actually be a solution to eliminate or minimize these damages.

Once a building, home or facility becomes occupied, the risks of leaks

may shift, but still remain as a liability, as any insurance underwriter can attest.

The repair and refurbishment resulting from leaks is an enormous industry,

most recently exacerbated by the scares and realities of mold. Slow, hard to

detect leaks within walls, ceilings or concealed areas often result in the most

damage, as they introduce moisture into a warm, stable atmosphere of a

controlled environment, resulting in mold growth that can cause extensive

damage and may include condemnation of the home or building.

3 18801590_1 (GHMatters) P104898.AU.1

Large leaks or ruptures can be catastrophic within a very short amount of

time, sometimes within minutes. In commercial structures, leaks can damage

computer systems resulting in untold losses of computer data. These risks are

not simply limited to property damage, but include personal injury and even

death. Toxic mold has verifiably taken a number of lives. Leaks also

substantially increase the risk of electrical shock, not to mention medically

sensitive risks caused by leaks. Leaks are indiscriminate of time, occurring

when occupants are present or away.

Until recently the prevention of leaks and/or mitigation of leak damages

io have been very limited. The "Loss Prevention" programs of insurance

companies have focused primarily on minimizing the underwriting of clients with

a history of previous leak claims rather than providing any true measure of

"Loss Prevention".

It is known that existing water meters are capable of detecting and

reporting water consumption, but these systems, which employ paddle wheels,

turbines, or other such impellers, suffer from mechanical limitations which allow

for small flow amounts to slip past the meter undetected and do not monitor

water temperatures.

SUMMARY OF THE INVENTION

Disclosed is a leak detection system that is a water flow monitor and

alarm system for detecting water leaking from the pressurized pipes or fixtures

in residential and commercial building structures. The sensor probes have no

moving parts to wear out and can detect water flow as little as a few ounces of

4 18801590_1 (GHMatters) P104898.AU.1 water per hour. If water flows continuously for a preset time without stopping, it triggers an alarm. It may also trigger other functions associated with the system such as a display change and valve control. The alarm function can be set to alert the homeowner or a surveillance company monitoring the premises.

Integrated into the system are user guides and features to aid the homeowner

or a professional in detecting a leak.

Such an alarm condition could indicate a faulty valve or a more serious

condition known as a "slab leak". An undetected slab leak (a broken pipe in or

under a concrete slab floor) can cause extreme structural damage in excess of

io thousands of dollars, and render the property uninsurable from the resulting

insurance claim.

Two separate sensor probes may be clamped directly onto the outside of

a pipe or thermally conductive heat transfer medium between the fluid and the

system to allow detection of all flow conditions. Not just water loss under the

hot water heater or dishwasher or an icemaker like other point of leak detection

competitive devices, but water loss for the entire structure. A comprehensive

system may include moisture sensors together with the leak detection system.

This will ensure both immediate and long-term protection of the structure and its

contents and detect leaks from the pressurized supply side as well as the drain

and waste systems, appliances, and water intrusion from the outside

environment. Resource conservation and water cost savings are also promoted

by detecting unknown water loss long before thousands of gallons escape

down the drain or into the structure's foundation.

The system works by measuring the temperature at the upstream and

5 18801590_1 (GHMatters) P104898.AU.1 downstream clamps. The downstream clamp contains both a temperature sensor and a heating element. The two temperature sensors form part of the sensing portion of a Wheatstone Bridge where the amount of heat energy added by the heating element to keep the bridge circuit in balance is proportional to the flow rate of fluid in the pipe.

A single temperature sensor and a separate heating element may be

clamped onto a pipe. The heating element is located a few inches downstream

from the temperature sensor. The sensor and the heating element are both

wrapped with insulation thereby isolating the sensor and heating element from

io ambient conditions and increasing the accuracy of the measurements and the

sensitivity of the system. This system works by measuring temperature before

the heater is energized, then energizing the heater for a predetermined period

of time. The temperature is continuously monitored to determine the amount of

time for the heat energy added by the heater to propagate to the temperature

sensor. That amount of time is used to determine the flow rate in the pipe. The

longer the time for the heat energy to reach the sensor, the higher the flow rate

is within the pipe. The shorter the time for the heat energy to reach the sensor,

the lower the flow rate is within the pipe. After the propagation time is

determined, the heater is deenergized to allow it and the sensor to return to

ambient conditions so a new test can be performed.

The addition of an external environment sensor probe and temperature

sensor package to a leak detection system creates a more comprehensive

system able to prevent and detect leaks. This works by taking the temperature

at the temperature sensor package of the leak detection system, the external

6 18801590_1 (GHMatters) P104898.AU.1 environment temperature sensor, and the additional temperature sensor package and feeding the data to a microprocessor where they are analyzed to determine whether the fluid is expanding by comparing the temperature data to the user inputted data stored in a control ROM and flash memory. If expansion is occurring, the microprocessor will open a relief valve and cause fluid to flow, releasing excess pressure and preventing damage to the structure's pipe system. In extreme conditions, the microprocessor will shut off the isolation valve to prevent additional fluid from entering the system and open a relief valve and cause fluid to flow, releasing excess pressure in the system. The io microprocessor will then open an air valve to aid the evacuation of the fluid in the system.

The control panel is easy to use and attractive. Its display provides real

time system and flow status. The Panel will indicate an alarm condition; the

flow level when the alarm occurred, and sound a built-in beeper, then if no

action is taken it will activate an industrial quality motor-driven ball valve to shut

off the water to the structure. The control panel will then display information to

guide the homeowner through the process of detecting simple leaks such as a

dripping faucet. The panel can also be used to select other operating modes or

select other features of the leak detection system such as monitoring the fluid

temperature and external environment temperature to prevent overpressure of

the structure's pipe system.

When the leak detection system is connected to an auto-dialer telephone

device, it can alert anyone with a telephone that a problem exists. When

connected to an electric water valve, which is the design for the initial product, it

7 18801590_1 (GHMatters) P104898.AU.1 can shut-off the water automatically until the system is manually reset. Other devices may be connected to the leak detection system to coordinate moisture and over-pressure sensors and leak detection throughout the entire structure.

In accordance with a first aspect of the present invention, there is

provided a device for interrupting the flow of fluid through a fluid conduit upon

the detection of expansion of water due to freezing, comprising: a primary

temperature sensor in thermal communication with said fluid conduit located

near the inlet of said fluid conduit configured to generate an analogue

temperature signal corresponding to said fluid temperature; a secondary

io temperature sensor in thermal communication with said fluid conduit and

located near the end of said fluid conduit configured to generate an analogue

temperature signal corresponding to said fluid temperature; an external

temperature sensor in thermal communication with external environment of said

fluid conduit configured to generate an analogue temperature signal

corresponding to said external temperature; a controller in electrical

communication with said primary temperature sensor, said secondary

temperature sensor, and said external environmental temperature sensor, said

controller sensing said analogue temperature signals from said primary

temperature sensor, said secondary temperature sensor, and said external

environmental temperature sensor; a first trigger point comprising a first trigger

point temperature predetermined and stored in a memory associated with the

controller; a second trigger point comprising a second trigger point temperature

lower than said first trigger point temperature, said second trigger point

temperature predetermined and stored in a memory associated with said

8 18801590_1 (GHMatters) P104898.AU.1 controller; a means for comparing said primary temperature sensor temperature signal, said secondary temperature sensor temperature signal, and said external environmental temperature sensor signal to predetermined user inputted values and generating an open or close signal in response thereto; an isolation valve located near the inlet of said fluid conduit in communication with said controller to receive said close signal from said controller to close said valve in response thereto; a relief valve located towards the end of said fluid conduit in communication with said controller to receive an open signal from said controller to open said valve allowing said fluid to flow io through a drainage pipe in response thereto; wherein said controller is configured to generate a close signal for said isolation valve when the signal of a sensor selected from the group comprising said primary temperature sensor, said secondary temperature sensor, and said external temperature sensor indicates a temperature below said first trigger point temperature; and wherein said controller is configured to generate an open signal for said relief valve when said signal of a sensor selected from the group comprising said primary temperature sensor, said secondary temperature sensor, and said external temperature sensor indicates a temperature below said second trigger point temperature.

In accordance with a second aspect of the present invention, there is

provided a device for evacuating fluid upon the detection of expansion of water

due to freezing in a pressurized fluid conduit, the device comprising: a primary

temperature sensor in thermal communication with said fluid conduit located

near the inlet of said fluid conduit configured to generate an analogue

9 18801590_1 (GHMatters) P104898.AU.1 temperature signal corresponding to said fluid temperature; a secondary temperature sensor in thermal communication with said fluid conduit and located near the end of said fluid conduit configured to generate an analogue temperature signal corresponding to said fluid temperature; an external temperature sensor in thermal communication with external environment of said fluid conduit configured to generate an analogue temperature signal corresponding to said external temperature; a controller in electrical communication with said primary temperature sensor, said secondary temperature sensor, and said external environmental temperature sensor, said io controller sensing said analogue temperature signals from said primary temperature sensor, said secondary temperature sensor, and said external environmental temperature sensor; a means for comparing said primary temperature sensor temperature signal, said secondary temperature sensor temperature signal, and said external environmental temperature sensor signal to predetermined user-inputted values and generating an open or close signal in response thereto; an isolation valve located near the inlet of said fluid conduit in communication with said controller to receive said close signal from said controller to close said valve in response thereto; a relief valve located towards the end and at a low point of said fluid conduit in communication with said controller to receive said open signal from said controller to open said valve allowing said fluid to flow through a drainage pipe in response thereto; an air valve located at a high point in said fluid conduit in communication with said controller to receive said open signal from said controller to open said valve to allow atmospheric air to enter said fluid conduit in response thereto; a first

10 18801590_1 (GHMatters) P104898.AU.1 trigger point comprising a first trigger point temperature predetermined and stored in a memory associated with said controller; and a second trigger point comprising a second trigger point temperature lower than said first trigger point temperature, said second trigger point temperature predetermined and stored in a memory associated with said controller; wherein said controller is configured to generate said open signal to open said relief valve when said signal of a sensor selected from the group comprising said primary temperature sensor, said secondary temperature sensor, and said external temperature sensor indicates a temperature below said first trigger point temperature; and wherein io said controller is configured to generate said close signal to close said isolation valve and said open signal to open said air valve when the signal of a sensor selected from the group comprising said primary temperature sensor, said secondary temperature sensor, and said external temperature sensor indicates a temperature below said second trigger point temperature.

In accordance with a third aspect of the present invention, there is

provided a method for evacuating a closed fluid conduit when expansion of

water due to freezing is occurring, comprising: providing a primary temperature

sensor capable of sensing fluid temperature and producing corresponding

analogue temperature signals; providing a secondary temperature sensor

capable of sensing fluid temperature and producing corresponding analogue

temperature signals; providing an external temperature sensor capable of

sensing fluid temperature and producing corresponding analogue temperature

signals; providing a signal processor capable of converting said analogue

temperature signals to digital temperature signals; converting said analogue

11 18801590_1(GHMatters) P104898.AU.1 temperature signals to said digital temperature signals; providing a memory which is able to store a series of look-up tables corresponding to said digital temperature signals with fluid expansion data, a predetermined first trigger point temperature, and a predetermined second trigger point temperature that is lower than said first trigger point temperature; providing a means for comparing said digital temperature signals with said data from said look-up tables, said first trigger point temperature, and said second trigger point temperature; providing a microprocessor capable of producing a drive signal in response to said first trigger point temperature and said second trigger point temperature; io providing an isolation valve located at the inlet of said fluid conduit capable of closing in response to receiving said drive signal in response to said second trigger point temperature; providing a relief valve located near the end of said fluid conduit at a low point capable of opening in response to receiving said drive signal in response to said first trigger point temperature; providing an air valve located at a high point of said fluid conduit capable of opening in response to receiving said drive signal in response to said second trigger point temperature; whereby said fluid conduit will evacuate said fluid in said fluid conduit by first closing said isolation valve, then open said relief valve, then open said air valve when said fluid is expanding.

BRIEF DESCRIPTION OF THE FIGURES

The novel features of this invention, as well as the invention itself, both

as to its structure and its operation, will be best understood from the

accompanying drawings, taken in conjunction with the accompanying

12 18801590_1 (GHMatters) P104898.AU.1 description, in which reference characters refer to similar parts, and in which:

Figure 1 Is an exemplary view of the controller of the present

invention as integrated with a structure, and showing the status panel of

the system including an alarm indicator, an auxiliary indicator, a flow

indicator, and a power indicator;

Figure 2 contains three perspective views of the noninvasive

io sensors when clamped onto a metal pipe;

Figure 2A is a perspective view of the sensors and heater when

clamped onto a plastic pipe through in-molding thermal carriers;

Figure 3 is a basic electrical schematic diagram showing the

implementation of a Wheatstone bridge used to sense the energy required to

balance the bridge, and to energize an LED when the detected flow rate is

above an adjustable level;

Figure 4 is a flow diagram of an exemplary operation of the system of

the present invention, and includes a sequence of operation when employing

a microprocessor controller to monitor the trip level and timer settings;

Figure 5 is a flow diagram of an exemplary operation of the system of

the present invention, and includes a sequence of operation when employing

a microprocessor controller to cycle heater power to conserve energy and

prevent excessive heating of the pipe section;

Figure 6 is an electrical schematic showing the placement of the

temperature sensors on the pipe and amplifiers configured to detect the flow

13 18801590_1 (GHMatters) P104898.AU.1 signal;

Figure 7 is an exemplary operational flowchart showing the overall

operation of the system of the present invention;

Figure 8 is a block diagram of an alternative embodiment of the present

invention showing dual temperature sensors coupled to analogue and digital

circuitry, a user interface display and a valve for interrupting fluid flow through

a conduit;

Figure 9 is a block diagram of an alternative embodiment of the

present invention showing a single sensor upstream from a heating element

io and having a central control unit with various inputs and outputs, alarm and

mode control, and timer control. Additionally, the diagram illustrates the

interface between the central control unit, the temperature sensor, and the

heater;

Figures 10A and 10B consist of a graph and its associated data points

respectively. The figures show temperature changes over time for no flow,

low flow, and medium flow conditions in response to turning on the heater

for a predetermined period of time when the ambient temperature is

approximately 75°F;

Figure 11A and 11B consist of a graph with its associated data

points which shows temperature changes over time for no flow, low flow,

and medium flow conditions in response to turning on the heater for a

predetermined period of time when the ambient temperature is

approximately 37°F;

Figure 12 is a diagram showing two temperature sensor packages 14 18801590_1 (GHMatters) P104898.AU.1 attached to a fluid conduit system and an external environment temperature sensor connected to a signal processor to form a circuit to detect changes in fluid temperature, fluid flow rate, and external environment temperatures;

Figure 13 is a block diagram of an alternative embodiment of the

present invention shown in Figure 12 showing an external environment

temperature sensor and two temperature sensor packages coupled to

analogue and digital circuitry, a user interface display and three valves for

controlling fluid flow.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

This invention relates to an electronic thermal monitor system

intended to measure fluid flow within a conduit or pipe, by clamping directly

to the outside of a pipe or onto a thermally conductive heat transfer

medium between the fluid and the system. Referring to Figure 1, the

present invention is suitable for application of leak detection technology

into a structure 100 having a water inlet 101, a water leak monitor 102,

and a shut off valve 120. The water leak monitor 102 includes a power

indicator 104, a timer set 105 with an indicator 106, and a trip level set 108

with an indicator 110. Sensitivity adjustment 109 provides a user the

ability to adjust the sensitivity of the device. A reset button 107 is

provided to allow for the system to be reset after an alarm condition has

been generated.

In an exemplary embodiment, this invention is discussed in

conjunction with a typical thin wall copper pipe section commonly found in

15 18801590_1 (GHMatters) P104898.AU.1 commercial and residential plumbing systems that form the water supply line" Since copper is an excellent conductor of temperature, this meter infers the water temperature by measuring the outside skin temperature of the pipe section. Another embodiment is to measure fluid flow within a confined conduit whereby the thermally conductive transfer medium is embedded within the conduit and allows for unimpeded and low heat measurements of fluids such as gasoline, diesel oil, liquid slurries, as well as gases such as air or nitrogen.

The thermal conduction means in the exemplary embodiment are clamps

which mount to the pipe and form not only a mechanical connection between

the meter and the pipe, but a thermal connection as well. The clamps are

designed to transfer heat to and from the meter and the water within the pipe.

The pipe may be any shape to contain the fluid and allow a thermal conduction

means to the fluid within.

In the exemplary embodiment there is one upstream temperature

reference clamp that contains an integrated temperature sensing element, such

as a thermistor, thermocouple, or resistance temperature detector ("RTD"),

which reads the current temperature of the pipe and fluid within. A second

sensor clamp, mounted downstream from the reference, also contains an

integrated temperature sensing element and a resistive heater which transfers

heat energy into the pipe and the water within. This damp performs the actual

flow rate measurement.

Referring to Figure 2, the clamps are comprised of a heat sink mount or

"shoe" 202 and 207 which partially wraps around the outside diameter of the 16 18801590_1 (GHMatters) P104898.AU.1 copper pipe 200, and are retained by spring clips 203 and 206 to keep them firmly pressed onto the pipe 200. The sensor/heat shoe 207 has mounting holes for both the thermistor 205 and the heater 204. The reference temperature shoe 202 has mounting holes for the reference thermistor 201.

Since copper pipe 200 comes in various diameters, the shoes 202 and 207 may

be configured in varying sizes and widths depending on the amount of surface

area that is required to perform effective temperature coupling and heater

loading.

While Figure 2 depicts an exemplary embodiment of the electronic

io components 201, 204, and 205 with unconnected leads, it should be noted that

either a single printed circuit board will be connected to these leads or

additional wires will be added to these leads to form a remote control operation.

Additionally, Figure 2A depicts a means to transfer heat through plastic

pipe 225 by in-molding thermal carriers 226 and 227 and mounting the

thermistors 201 and 205 and heater 204 directly to these thermal carriers 226

and 227. This method allows this invention to operate using non-thermally

conductive materials such as plastic, Teflon, ABS, PVC, etc.

Referring to Figure 3, as the heater R17 increases in temperature, the

thermally coupled thermistor R11 senses the temperature change and adjusts

the servo amp UA to maintain the equilibrium of the Wheatstone Bridge circuit

by modulating the power transistor Q1. The power transistor Q1 will either add

or subtract power to the heater R17 to maintain the Wheatstone Bridge in

balance. This system forms a closed loop feedback when the servo amp U1A

reads the reference temperature thermistor R10, adds in the sensitivity bias 17 18801590_1 (GHMatters) P104898.AU.1 voltage U1D, and then compares it to the current flow R11 temperature. This operation allows the reference thermistor R10 to adjust the circuit for any changes in incoming water temperature and allows the heater R17 to provide a constant temperature above the incoming water main as set by the sensitivity adjustment R5. Greater water flows require more heat to maintain this temperature difference and it is the amount of power consumed by the heater, to balance the bridge, which is read by the comparator U1C, to establish a flow trip threshold which is adjustable via resistor R1. If heater power increases above the preset trip threshold, the comparator U1C will activate and glow the TRIP

LED 02 which, in other embodiments, may also be connected to a micro

controller to monitor flow and time.

Figure 4 is a flowchart that describes an embodiment with a sequence of

operations when employing a microprocessor controller to monitor the trip level

and timer settings. When the trip level is exceeded, a counter is continuously

incremented until it matches the timeout setting at which time the alarm output is

activated. In this example, the alarm will automatically cancel once the trip value

falls below the trip threshold, however some installations require latching the

alarm on when tripped so it will remain active after the flow has been shut-off by

employing an electric water shut-off valve 120 (not shown). The alarm output

can be hard wired to existing commercial alarm panels. The alarm output signal

may also drive a low power RF transmitter and pass its status via wireless

signal.

Referring to Figure 5, the micro-controller may also be configured to cycle

18 18801590_1 (GHMatters) P104898.AU.1 heater power to conserve energy and prevent excessive heating of the copper pipe section. Detection of the leak will still occur when the unit powers up and performs its leak tests over time. After the system wakes up and applies power to the heaters, the system will go into normal operation.

Figure 6 is an electrical schematic showing the placement of the flow

sensor 610 clamped to a water pipe (conduit) 611, and amplifiers 614 and 616

configured to form a circuit to detect the variations in the resistance of the flow

sensor 610 produced by the flow of fluid 625 through the conduit 211. The

amplifiers 614 and 616 feed their signals into Analogue to Digital Converters 619

io and 620 to create a digital representation of the flow signals. The digital

representations are then fed to a microprocessor 621 where they are analyzed

to determine the flow rate by comparing the flow data to the data stored in the

control ROM and flash memory 622. The microprocessor 621 wiil then perform

various functions 624, such as energize a relay, illuminate an LED, or create an

audible alarm, based on the measured flow rate as compared to the data stored

in memory 622. The microprocessor 621 will also sense the amount of current

flow through the flow sensor 610 and adjust it as necessary to maintain a

constant electrical current through the flow sensor 610.

Figure 7 is an exemplary operational flowchart showing the overall

operation of the system of the present invention and is generally referred to as

item 250. At the start of the operation 252, the sensor is deenergized to allow it

to cool to ambient temperature and establish a baseline temperature for use in

future calculations 254. The sensor is then heated to a reference temperature

plus an offset temperature 256. 19 18801590_1 (GHMatters) P104898.AU.1

If the temperature has not been calibrated 258, then the system will reset

the accumulator and alarms 260 and to check to see if the flow timer has

expired 262. If the flow timer has expired 262, the system will reset the flow

timer 264 then restart the process 254. If the flow timer has not expired 262,

the system will go to step 256 to heat the sensor 256.

If the temperature has been calibrated 258, then the system will check for

the presence of a time delay 266. If the delay time value has not been reached,

the system will return to step 256 to continue heating the RTD. If the delay time

value has been reached 266, the system will add time to the accumulator and

io record flow 268. If the accumulator has not reached its maximum value 270, the

system will return to step 256 where it will continue to heat the RTD. If the

accumulator has reached its maximum value 270, the system will compare the

calculated flow to the flow trip point 272. If the trip point has not been reached

272, the system will return to step 268 where it will add time to the accumulator

and record flow. If the trip point has been reached 272, the system will activate

functions such as an alarm, an indicator, and automatic valve closure 274. It

should be appreciated by someone skilled in the art that many different

functions may be controlled by the system and the functions listed above are not

the exclusive functions of the system.

Figure 8 is a diagram of an alternative embodiment of the present

invention and is generally designated 300. This diagram shows a clamp on

temperature sensor package 306 which includes dual temperature sensors 324

and 326 separated by a known distance 328. The temperature sensor package

306 is coupled to a controller 302 having both analogue 318 and digital 312 20 18801590_1 (GHMatters) P104898.AU.1 circuitry, and equipped with a user interface display 304 and a valve 308 for interrupting the flow of water through a pipe or conduit 310 should a leak be detected. The controller 302 has an internal power supply 321, a microprocessor 314 with memory 316, and interface circuits to control such things as the isolation valve 308, temperature sensor package 306, and the display unit 304. The display 304 utilizes a microcontroller 331 to control the user display panel 330, and external interfaces 332 such as telephone, internet and alarm.

io An Alternative Embodiment

Now referring to Figure 9, an alternative embodiment of the present

invention is shown and is generally designated 500. This embodiment consists of

one temperature sensor 520, such as a RTD, thermistor, or thermocouple, clamped

onto a pipe or conduit 524 and a heating element 518 mounted a distance 522

downstream from the temperature sensor 520. The temperature sensor 520 and

heating element 518 are both wrapped or covered with an insulation material

516 thereby increasing the accuracy and sensitivity of the system.

This alternative embodiment uses heat conduction, propagation, and time

to determine if there is liquid flow within an enclosed metallic conduit 524.

Figures 10A, 10B, 11A, and 11B consist of graphs and the associated data

points of temperature response to a known amount of heat energy added to a

conduit having a no flow, low flow, and medium flow condition. The graphs and

data points are for a warm test and cold test respectively. Two elements are

required to electrically perform this function. One is a temperature sensor 520, 21 18801590_1 (GHMatters) P104898.AU.1 either analogue or digital, and the other is a resistive heater band 518 which wraps around the outside diameter of the conduit 524. It should be noted that the heater 518 and sensor 520 are separated by a short distance 522, such as

1"to 3", in order to create more average heating across the conduit 524 cross

section, and also allow the internal flowing liquid 534 to carry away the

conducted heat via convection cooling of the conduit 524 itself.

In normal operation, this embodiment works in an intermittent

operation. After a calibrated time has elapsed, the heater 518 becomes

energized, which forces heat energy into the conduit 524. The controller

502 would read the temperature sensor 520 just prior to heater 518

activation, and stored that value for further calculations. Conducted heat

from the metallic conduit 524 will readily propagate from the center of the

heat source 518 and outward eventually reaching the temperature sensor

522. The amount of time it takes for the heat to propagate to the

temperature sensor 520 is recorded in the controller 502 and is a direct

function of the liquid flow 534 within the conduit 524. Long propagation

times reflect large effective flow rates.

The heater power is removed after a predetermined "no-flow"

condition timer expires. The controller 502 will continue to read the

temperature sensor 520 to continually analyze the heat propagation and

lock onto a value that represents the peak temperature attained. This

value is also a direct function of the liquid flow 534 within the conduit 524.

Higher peak temperatures represent low effective flow rates, as the heater

518 is simply creating a no flow "pocket" of liquid, with little to no 22 18801590_1 (GHMatters) P104898.AU.1 convective forces to carry away the applied heat energy.

Finally, after a predetermined amount of time has elapsed, the

controller 502 acquires one final reading from the temperature sensor 520

and compares it to the previously saved value before the heater 518 was

activated. The ratio of the before and after temperature readings is also a

direct function of the liquid flow 534 within the conduit 524. The closer the

two values are, the greater the effective flow rate is within the conduit 524

as the flowing liquid 534 is restoring the ambient fluid temperature to nullify

the effects of the previously added heat energy.

All of the calculated temperature and time variables are scored

within an algorithm that normalizes the effective flow rate with respect to

ambient temperature and conduit/heater 524/518 thermal conductivity. The

calculated score determines the liquid flow 534 rate, then the controller

502 records that rate, powers down for a short period of time as

determined by the Master Time value 526, and allows the heater 518 and

temperature sensor 520 to return to ambient conditions through natural

convection.

As the system continues to move through heating and cooling

cycles, the running status is accumulated. If the flow rate over all the

cycles has not provided a single "no-flow" score, the system will enter an

alarm state where it will either activate a relay 514, create an audible alert

512, or do both. The alarm may be cancelled by stopping the fluid flow or

by switching to another mode of operation 510, either HOME or AWAY,

which effectively resets all timers and scoring status results. 23 18801590_1 (GHMatters) P104898.AU.1

The heater 518 and temperature sensor 520 must be properly

affixed to the conduit 524 to ensure consistent results over a long period

of time measured in years. The heater 518 is a flexible silicone band

which can wrap around the conduit 524 and be held in place with a self

adhesive vulcanizing wrapping tape specifically designed to seal out

moisture and provide continuous pressure on the heater 518 ensuring

optimal thermal conductivity over time. It is to be appreciated by someone

skilled in the art that many heater 518 designs exist that will satisfy the

requirements of the system. The temperature sensor 520 also requires the

io same treatment during installation to ensure that the conduit 524

temperature is properly reported. It is also imperative that the entire

heater/sensor 518/520 section, and a few inches beyond, be enclosed in

thermal insulation 516. This prevents ambient or environmental air

currents from affecting the calibrated flow readings by heating or cooling

effects that are not the direct result of the fluid flow 534 within the conduit

524.

Intermittent operation of the heater 518 is required to provide the

extended "no-flow" time period with an opportunity equilibrate with ambient

conditions. Otherwise, the heater 518 and temperature sensor 520 would

create a localized "hot water heater" within the test section of the conduit

524. Therefore, this device may not be used to measure flow rate or flow

total as do other technologies, such as Thermal Mass Flow Meters. While

this system is currently described to operate through a dosed section of

copper tubing/pipe 524, it may also operate through plastic conduit 24 18801590_1 (GHMatters) P104898.AU.1 provided that the test section has in-molded metal plates or "shoes" within.

The heater 518 and temperature sensor 520 requires direct thermal

conduction of the fluid within in order to perform the same operation of an

all-metal design.

An AC/DC power supply 504 may be used since the heater 518

requires significant energy output (>12 Watts) to perform its tests

accurately and reliably. Alarm panel interfacing may also be expanded to

include both wired and/or wireless operation for command/control facilities.

io Installation and Calibration

This alternative embodiment of the present invention requires about

8"-10" of clean copper pipe 524 to properly assemble the test section. The

section of water pipe 524 selected should pass all incoming supply to the

entire structure and should not be located outside where protecting the

heater 518 and temperature sensor 520 elements would be impossible.

Once the heater 518 and temperature sensor 520 have been properly

installed and the wiring and power have been completed, the device must

be calibrated to the particular installation. Before activating the calibration

function. all water flow in the test section must be halted.

The calibration function can be activated by an on-board switch. or

wireless command, or a unique mode selection. During calibration, the

unit wiH activate the heater 518. When the temperature sensor 520

records a temperature increase of 4"F - 10°F, the time which passes during

this test is recorded by the controller 502 and stored for all future heater

25 18801590_1 (GHMatters) P104898.AU.1 timing variables. Calibration finishes automatically and the system will be able to alert the installer if there is a problem or start performing normal operations if all is well.

This invention is a fluid flow meter with many applications and

embodiments incorporating a unique method of flow measurement utilizing

noninvasive thermal anemometry. The use of a Wheatstone Bridge

greatly increases the system sensitivity and accuracy allowing it to be used

in many applications.

io Freeze Burst Detection and Prevention

Figure 12 is a diagram of an alternative embodiment of the present

invention and is generally designated 700. The diagram shows a primary

temperature sensor package 702, attached near the inlet of a fluid conduit

system 720, secondary temperature sensor package 706 attached to the

fluid conduit 720 near the termination point, and an external environment

temperature sensor 704, all connected to a signal processor 710 to form a

circuit to detect variations in the resistance of the sensors. The resistance

measurements of the temperature sensor packages 702 and 706 can be

used to determine fluid temperature and fluid flow rate simultaneously. It is

appreciated by those skilled in the art that alternative temperature sensor

packages 702 and 706 may be used utilizing alternative temperature

sensing elements such as a thermistor, thermocouple, or resistance

temperature detector. The resistance measurements are fed into the signal

processor 710 and converted into digital signals representing flow and

temperature data. The digital signals are then fed to a microprocessor 712

26 18801590_1 (GHMatters) P104898.AU.1 where they are analyzed to determine the flow rate by comparing the flow data to the data stored in the control ROM and flash memory 716, the temperature by comparing the temperature data to the data stored in the control ROM and flash memory 716, and the temperature difference between the conduit system's 720 inlet and outlet fluid temperatures by comparing the temperature data of temperature sensor packages 702 and

706.

The external environment temperature sensor 704 detects

temperature changes in the external environment. The sensor 704 feeds

io the resistance measurements to the signal processor 710 to create a digital

signal of the temperature data which is fed to a microprocessor 712 where

it is analyzed to determine the temperature by comparing the temperature

data to the data stored in the control ROM and flash memory 716.

The flow and temperature data from the sensors are further analyzed

by the microprocessor 712 to determine the state of the fluid by comparing

the flow and temperature data of the sensors to the user inputted data

stored in the control ROM and flash memory 716, The microprocessor 712

will perform various functions 714, such as open a valve, energize a relay,

illuminate an LED, or create an audible alarm, when the measured flow and

temperature data triggers a response based on the user data stored in

memory 716.

The diagram shows an isolation valve 722 for interrupting fluid flow

into the conduit system 720, a relief valve 724 for releasing the flow of fluid

in the system through a drainage pipe 726, and an air valve 728 to allow

atmospheric air to enter into the system. Air valve 728 is located at a high

point in the system and relief valve 724 is located at a low point near the 27 18801590_1 (GHMatters) P104898.AU.1 end of the system. The microprocessor 712 will open relief valve 724 when a value stored in control ROM or flash memory 716 is reached by the sensors 702, 704, and/or 706. For example, at 32 degrees Fahrenheit water freezes and expands, increasing its volume. Therefore if the fluid is water and the temperature is at 32 degrees Fahrenheit a determination that the water is expanding will be made and the relief valve 724 will be opened.

If the value is at or below a secondary value stored in control ROM or flash

memory 716, such as severe freezing conditions for water, microprocessor

712 will close isolation valve 722 to prevent water from entering the system

io and open relief valve 724 to evacuate the water in the system. The air

valve 726 is then opened to allow atmospheric air to enter the system to aid

the evacuation of fluid and prevent the formation of a vacuum. The valves

will be installed in locations to allow the most efficient fluid flow through the

system. The control ROM and flash memory 716 can store several values

for different trigger points such as the temperature difference between inlet

and outlet fluid temperatures.

Figure 13 is a diagram of an alternative embodiment of the present

invention shown in Figure 12 and is generally designated 800. This

diagram shows primary clamp on temperature sensor package 806 which

includes dual temperature sensors 824 and 826 separated by a known

distance, secondary temperature sensor package 840 which includes dual

temperature sensors 842 and 844 separated by a known distance, and an

external environment temperature sensor 827. The primary temperature

sensor package 806, secondary temperature sensor package 840, and

external environment temperature sensor 827 is coupled to a controller 802

having both analogue 818 and digital 812 circuitry, and equipped with a 28 18801590_1 (GHMatters) P104898.AU.1 user interface display 804 and an isolation valve 808 for interrupting the flow of water through a pipe or conduit system 810 should a leak be detected, a relief valve 809 for releasing the flow of water in a pipe or conduit system 810 through a drainage pipe 807 should excess pressure be detected, and an air valve 846 to open the system to the atmosphere.

Isolation valve 808 is installed near the inlet of the conduit system 810, air

valve 846 is installed at a high point in the system, and relief valve 809 is at

a low point near the end of the system. The location of the valves win allow

the most efficient fluid flow through the system.

io The controller 802 has an internal power supply 821, a

microprocessor 814 with memory 816, and interface circuits to control such

things as the isolation valve 808, relief valve 809, air valve 846, primary

temperature sensor package 806, secondary temperature sensor package

840, external environment temperature sensor 827, and the display unit

804. The display unit 804 utilizes a microcontroller 831 to control the user

display panel 830, and external interfaces 832 such as telephone, internet,

and alarm. While there have been shown what are presently considered to

be preferred embodiments of the present invention, it will be apparent to

those skilled in the art that various changes and modifications can be made

herein without departing from the scope and spirit of the invention.

In the claims which follow and in the preceding description of the

invention, except where the context requires otherwise due to express

language or necessary implication, the word "comprise" or variations such

as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify

the presence of the stated features but not to preclude the presence or

addition of further features in various embodiments of the invention. 29 18801590_1 (GHMatters) P104898.AU.1

In the claims which follow and in the preceding description of the

invention, except where the context requires otherwise due to express

language or necessary implication, the word "comprise" or variations such

as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify

the presence of the stated features but not to preclude the presence or

addition of further features in various embodiments of the invention.

30 18801590_1 (GHMatters) P104898.AU.1

Claims

1. A device for interrupting the flow of fluid through a fluid conduit upon the

detection of expansion of water due to freezing, comprising:

a primary temperature sensor in thermal communication with said fluid

conduit located near the inlet of said fluid conduit configured to generate an

analogue temperature signal corresponding to said fluid temperature;

a secondary temperature sensor in thermal communication with said fluid

io conduit and located near the end of said fluid conduit configured to generate an

analogue temperature signal corresponding to said fluid temperature;

an external temperature sensor in thermal communication with external

environment of said fluid conduit configured to generate an analogue

temperature signal corresponding to said external temperature;

a controller in electrical communication with said primary temperature

sensor, said secondary temperature sensor, and said external environmental

temperature sensor, said controller sensing said analogue temperature signals

from said primary temperature sensor, said secondary temperature sensor, and

said external environmental temperature sensor;

a first trigger point comprising a first trigger point temperature

predetermined and stored in a memory associated with the controller;

a second trigger point comprising a second trigger point temperature

lower than said first trigger point temperature, said second trigger point

temperature predetermined and stored in a memory associated with said

controller; 31 18801590_1 (GHMatters) P104898.AU.1 a means for comparing said primary temperature sensor temperature signal, said secondary temperature sensor temperature signal, and said external environmental temperature sensor signal to predetermined user inputted values and generating an open or close signal in response thereto; an isolation valve located near the inlet of said fluid conduit in communication with said controller to receive said close signal from said controller to close said valve in response thereto; a relief valve located towards the end of said fluid conduit in communication with said controller to receive an open signal from said io controller to open said valve allowing said fluid to flow through a drainage pipe in response thereto; wherein said controller is configured to generate a close signal for said isolation valve when the signal of a sensor selected from the group comprising said primary temperature sensor, said secondary temperature sensor, and said external temperature sensor indicates a temperature below said first trigger point temperature; and wherein said controller is configured to generate an open signal for said relief valve when said signal of a sensor selected from the group comprising said primary temperature sensor, said secondary temperature sensor, and said external temperature sensor indicates a temperature below said second trigger point temperature.

2. The device of claim 1, wherein said controller further comprises:

a microprocessor;

32 18801590_1 (GHMatters) P104898.AU.1 a signal processor in communication with said microprocessor capable of converting said analogue temperature signals from said primary temperature sensor, said secondary temperature sensor, and said external environmental temperature sensor to digital temperature signals; and a memory in communication with said microprocessor.

3. The device of claim 2, wherein said memory further comprises:

a look-up table having said digital temperature sensor signals and

corresponding fluid temperature and fluid expansion data;

io an EEPROM in communication with said microprocessor and configured

to provide said user-inputted values and look-up data to said microprocessor.

4. A device for evacuating fluid upon the detection of expansion of water

due to freezing in a pressurized fluid conduit, the device comprising:

a primary temperature sensor in thermal communication with said fluid

conduit located near the inlet of said fluid conduit configured to generate an

analogue temperature signal corresponding to said fluid temperature;

a secondary temperature sensor in thermal communication with said fluid

conduit and located near the end of said fluid conduit configured to generate an

analogue temperature signal corresponding to said fluid temperature;

an external temperature sensor in thermal communication with external

environment of said fluid conduit configured to generate an analogue

temperature signal corresponding to said external temperature;

a controller in electrical communication with said primary temperature

33 18801590_1 (GHMatters) P104898.AU.1 sensor, said secondary temperature sensor, and said external environmental temperature sensor, said controller sensing said analogue temperature signals from said primary temperature sensor, said secondary temperature sensor, and said external environmental temperature sensor; a means for comparing said primary temperature sensor temperature signal, said secondary temperature sensor temperature signal, and said external environmental temperature sensor signal to predetermined user inputted values and generating an open or close signal in response thereto; an isolation valve located near the inlet of said fluid conduit in io communication with said controller to receive said close signal from said controller to close said valve in response thereto; a relief valve located towards the end and at a low point of said fluid conduit in communication with said controller to receive said open signal from said controller to open said valve allowing said fluid to flow through a drainage pipe in response thereto; an air valve located at a high point in said fluid conduit in communication with said controller to receive said open signal from said controller to open said valve to allow atmospheric air to enter said fluid conduit in response thereto; a first trigger point comprising a first trigger point temperature predetermined and stored in a memory associated with said controller; and a second trigger point comprising a second trigger point temperature lower than said first trigger point temperature, said second trigger point temperature predetermined and stored in a memory associated with said controller;

34 18801590_1 (GHMatters) P104898.AU.1 wherein said controller is configured to generate said open signal to open said relief valve when said signal of a sensor selected from the group comprising said primary temperature sensor, said secondary temperature sensor, and said external temperature sensor indicates a temperature below said first trigger point temperature; and wherein said controller is configured to generate said close signal to close said isolation valve and said open signal to open said air valve when the signal of a sensor selected from the group comprising said primary temperature sensor, said secondary temperature sensor, and said external temperature io sensor indicates a temperature below said second trigger point temperature.

5. The device of claim 4, wherein said controller further comprises:

a microprocessor;

a signal processor in communication with said microprocessor capable of

converting said analogue temperature signals from said primary temperature

sensor, said secondary temperature sensor, and said external environmental

temperature sensor to digital temperature signals; and

a memory in communication with said microprocessor.

6. The device of claim 5, wherein said memory further comprises:

a look-up table having said digital temperature sensor signals and

corresponding fluid temperature and fluid expansion data;

an EEPROM in communication with said microprocessor and configured

to provide said user-inputted values and look-up data to said microprocessor.

35 18801590_1 (GHMatters) P104898.AU.1

7. A method for evacuating a closed fluid conduit when expansion of water

due to freezing is occurring, comprising:

providing a primary temperature sensor capable of sensing fluid

temperature and producing corresponding analogue temperature signals;

providing a secondary temperature sensor capable of sensing fluid

temperature and producing corresponding analogue temperature signals;

providing an external temperature sensor capable of sensing fluid

temperature and producing corresponding analogue temperature signals;

io providing a signal processor capable of converting said analogue

temperature signals to digital temperature signals;

converting said analogue temperature signals to said digital temperature

signals;

providing a memory which is able to store a series of look-up tables

corresponding to said digital temperature signals with fluid expansion data, a

predetermined first trigger point temperature, and a predetermined second

trigger point temperature that is lower than said first trigger point temperature;

providing a means for comparing said digital temperature signals with

said data from said look-up tables, said first trigger point temperature, and said

second trigger point temperature;

providing a microprocessor capable of producing a drive signal in

response to said first trigger point temperature and said second trigger point

temperature;

providing an isolation valve located at the inlet of said fluid conduit

36 18801590_1 (GHMatters) P104898.AU.1 capable of closing in response to receiving said drive signal in response to said second trigger point temperature; providing a relief valve located near the end of said fluid conduit at a low point capable of opening in response to receiving said drive signal in response to said first trigger point temperature; providing an air valve located at a high point of said fluid conduit capable of opening in response to receiving said drive signal in response to said second trigger point temperature; whereby said fluid conduit will evacuate said fluid in said fluid conduit by io first closing said isolation valve, then open said relief valve, then open said air valve when said fluid is expanding.

37 18801590_1 (GHMatters) P104898.AU.1