Clamp-on thermal meter for non-intrusive flow measurement in a conduit
Compact, non-intrusive thermal flow measurement devices, systems and methods configured to clamp externally onto a pipe, tube, or conduit and quantitatively determine fluid flow without penetrating the conduit or disturbing the internal fluid. Flow rate of fluid includes gas and liquid flows of fluid. The devices, systems and methods include a compact flexible clamp structure housing at least one low-power heater and a plurality of temperature sensors positioned upstream, downstream, and at the heater location along the conduit wall. The conformal clamp enables rapid, one-handed installation on conduits of varying diameters. During operation, the heater raises the pipe wall temperature at the point of measurement, and the flow of fluid induces a directional thermal gradient detected by the sensors. An electronic processor calculates fluid flow rate based on steady-state temperature differences using phase-specific empirical calibrations. The devices, systems and methods accommodate both gas and liquid flows using the same sensor configuration. Additional features include an integrated digital display, wireless communication, and support for portable, battery-powered use. The devices, systems and methods enable precise flow measurement across a range of applications, without pressure drop or fluid access, and supports field deployment, diagnostics, and integration into external monitoring platforms.
1 . A non-intrusive thermal flow measurement device for quantitatively determining fluid flow in a conduit, comprising:
a flexible clamp structure configured to externally conform to and maintain continuous circumferential thermal contact with conduits of varying diameters without requiring interchangeable inserts;
at least one heater configured to provide a heat flux of approximately 10 Watts per square inch to approximately 20 Watts per square inch, the heater configured to externally heat only a portion of a conduit wall at a measurement location, without directly heating bulk fluid inside the conduit wall, thereby avoiding vaporization and enabling portable, battery-powered operation;
a plurality of temperature sensors positioned along the conduit wall and configured to measure temperature differentials between multiple distinct points along the conduit wall; and
an electronic processor configured to calculate and determine a fluid flow rate in the conduit based on steady-state temperature differentials which are the temperature differentials measured by said sensors when the temperature differentials have reached a steady-state within a time of approximately 3 minutes to approximately 15 minutes.
2 . The device of claim 1 , wherein the flexible clamp structure comprises two half-shells configured to flexibly adapt and snugly conform to conduit diameters between a range between approximately ¼ inch to approximately ⅝ inch.
3 . The device of claim 1 , wherein the plurality of temperature sensors includes at least one sensor positioned upstream of the heater, at least one sensor positioned directly on the heater, and at least one sensor positioned downstream of the heater.
4 . The device of claim 1 , further comprising a communication medium configured to transmit measured temperature and flow rate data through a wired connection.
5 . The device of claim 1 , further comprising a communication medium configured to transmit measured temperature and flow rate data through at least one wireless connection selected, from the group consisting of Bluetooth, Wi-Fi Direct, NFC, Zigbee, and Z-Wave.
6 . The device of claim 1 , further comprising:
a digital display integrated directly into the clamp structure, configured to locally display measured temperatures and calculated fluid flow rates without requiring an external meter.
7 . The device of claim 1 , wherein the calculation of the fluid flow rate is performed empirically from said steady-state temperature differentials by using calibration constants specific to fluid phases, thereby enabling the determination of a fluid flow of either a gas or a liquid in the conduit using same sensor configuration.
8 . The device of claim 2 , wherein for an approximately ¼″ pipe, the time frame is within approximately 3 minutes.
9 . The device of claim 2 , wherein for an approximately ⅜″ pipe, the time frame is within approximately 6 minutes.
10 . The device of claim 2 , wherein for an approximately ⅝″ pipe, the time frame is within approximately 15 minutes.
11 . The device of claim 2 , wherein overall weight of the device is up to approximately 1 pound or approximately 454 grams, overall length of the device is up to approximately 7.6″ or approximately 193 millimeters, and overall width of the device is up to approximately 1.7″ or approximately 43 millimeters.
12 . The device of claim 2 , wherein spacing between adjacent sensors is up to approximately 1.5 inches or 38 millimeters.
13 . The device of claim 2 , wherein an upper half-shell of the two half-shells, includes:
an upper flexible pad pliable support between the upper half-shell and an upper half heater temperature sensor, and an upper half heater pad between the upper half heater temperature sensor and an upper half heater element, and
wherein a lower half-shell of the two half shells includes
a lower flexible pad pliable support between the lower half-shell and lower half-heater temperature sensor, and a lower half heater pad between the lower half heater temperature sensor and a lower half heater pad between the lower half heater temperature sensor and a lower half heater element.
14 . The device of claim 1 , wherein the flexible clamp structure includes:
an upper arm having a grip end and a distal end with a concave lower surface;
a lower arm having a grip end and a distal end with a concave upper surface;
a spring-loaded member for allowing the upper arm to pivot relative to the lower arm, wherein the concave lower surface on the distal end of the upper arm and the concave upper surface on the distal end of the lower arm grip about a conduit wall.
15 . The device of claim 1 , wherein the flexible clamp structure includes a fixed mechanical clamp assembly that includes:
an upper shell having a lower facing concave surface; and
a lower shell having an upper facing concave surface, wherein the upper shell and the lower shell wrap about a section of the conduit wall.
16 . The device of claim 15 , wherein the fixed mechanical clamp assembly includes:
fasteners selected from at least one of screws and bolts for locking the upper shell to the lower shell.
17 . The device of claim 16 , wherein the fixed mechanical clamp assembly includes:
securing members selected from at least one of: magnets, latches, ties, spring clips, and latch clamps for securing the upper shell to the lower shell.
18 . A non-intrusive thermal flow measurement device for quantitatively determining fluid flow in a conduit, comprising:
a flexible clamp structure configured to externally conform to and maintain continuous circumferential thermal contact with conduits of varying diameters without requiring interchangeable inserts, the flexible clamp structure comprises two half-shells configured to flexibly adapt and snugly conform to conduit diameters between a range between approximately ¼ inch to approximately ⅝ inch, wherein the flexible clamp structure includes an upper arm having a grip end and a distal end with a concave lower surface, and a lower arm having a grip end and a distal end with a concave upper surface, and a spring loaded member for allowing the upper arm to pivot relative to the lower arm, wherein the concave lower surface on the distal end of the upper arm and the concave upper surface on the distal end of the lower arm grip about conduit wall;
at least one heater configured to provide a heat flux of approximately 10 Watts per square inch to approximately 20 Watts per square inch, the heater configured to externally heat only a portion of the conduit wall at a measurement location, without directly heating the bulk fluid inside the conduit wall, thereby avoiding vaporization and enabling portable, battery-powered operation;
a plurality of temperature sensors positioned along the conduit wall and configured to measure temperature differentials at distinct points along the conduit wall, the plurality of temperature sensors includes at least one sensor positioned upstream of the heater, at least one sensor positioned directly on the heater, and at least one sensor positioned downstream of the heater, wherein spacing between adjacent sensors is approximately 1.5 inches or 38 millimeters;
wherein an upper half-shell of the two half-shells, includes:
an upper flexible pad pliable support between the upper half-shell and an upper half heater temperature sensor, and an upper half heater pad between the upper half heater temperature sensor and an upper half heater element, and
wherein a lower half-shell of the two half shells includes;
a lower flexible pad pliable support between the lower half-shell and lower half-heater temperature sensor, and a lower half heater pad between the lower half heater temperature sensor and a lower half heater element:
and
an electronic processor configured to calculate and determine a fluid flow rate in the conduit based on steady-state temperature differentials which are the temperature differentials measured by said sensors when the temperature differentials have reached a steady state within a time frame of approximately 3 minutes to approximately 15 minutes, wherein overall weight of the device is up to approximately 1 pound or approximately 454 grams, overall width of the device is approximately 1.7 inches or approximately 43 millimeters, and overall length of the device is approximately 7.6 inches or approximately 193 millimeters.
19 . A non-intrusive thermal flow measurement device for quantitatively determining fluid flow in a conduit, comprising:
a flexible clamp structure configured to externally conform to and maintain continuous circumferential thermal contact with conduits of varying diameters without requiring interchangeable inserts, the flexible clamp structure comprises two half-shells configured to flexibly adapt and snugly conform to conduit diameters between a range between approximately ¼ inch to approximately ⅝ inch, wherein the flexible clamp structure includes a fixed mechanical clamp assembly with an upper shell having a lower facing concave surface, and a lower shell having an upper facing concave surface, wherein the upper shell and the lower shell wrap about a section of the conduit wall, the fixed clamp assembly is assembled by either fasteners selected from at least one of screws and bolts for locking the upper shell to the lower shell, or is assembled by securing members selected from at least one of: magnets, latches, ties, spring clips, and latch clamps for securing the upper shell to the lower shell;
at least one heater configured to provide a heat flux of approximately 10 Watts per square inch to approximately 20 Watts per square inch, the at least one heater configured to externally heat only a portion of a conduit wall at a measurement location, without directly heating the bulk fluid inside the conduit, thereby avoiding vaporization and enabling portable, battery-powered operation;
a plurality of temperature sensors positioned along the conduit wall and configured to measure temperature differential between distinct points, the plurality of temperature sensors includes at least one sensor positioned upstream of the heater, at least one sensor positioned directly on the heater, and at least one sensor positioned downstream of the heater, wherein spacing between adjacent sensors is approximately 1.5 inches or approximately 38 millimeters;
wherein an upper half-shell of the two half-shells, includes:
an upper flexible pad pliable support between the upper half-shell and an upper half heater temperature sensor, and an upper half heater pad between the upper half heater temperature sensor and an upper half heater element;
wherein a lower half-shell of the two half shells includes:
a lower flexible pad pliable support between the lower half-shell and lower half-heater temperature sensor, and a lower half heater pad between the lower half heater temperature sensor and a lower half heater element;
and
an electronic processor configured to calculate and determine a flow rate in the conduit based on steady-state temperature differentials which are the temperature differentials measured by said sensors when the temperature differentials have reached a steady-state within a time frame of approximately 3 minutes to approximately 15 minutes, wherein overall weight of the device is up to approximately 1 pound or approximately 454 grams, overall width of the device is approximately 1.7 inches or approximately 43 millimeters, and overall length of the device is approximately 7.6 inches or approximately 193 millimeters.