Clamp-On Thermal Meter for Non-Intrusive Flow Measurement in a Conduit

A non-intrusive thermal flow measurement device for quantitatively determining fluid flow in a conduit, comprising:

• a clamp structure configured to externally conform to and maintain continuous circumferential thermal contact with conduits of varying diameters, the flexible clamp structure comprises two half-shells, wherein the 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 a 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 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 between multiple distinct points along the conduit wall, wherein spacing between adjacent sensors is up to approximately 1.5 inches or approximately 38 millimeters;
• 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 up to approximately 15 minutes.

A non-intrusive thermal flow measurement device for quantitatively determining fluid flow in a conduit, comprising:

• a clamp structure configured to externally conform to and maintain continuous circumferential thermal contact with conduits of varying diameters, the clamp structure comprises two half-shells, wherein the 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 a conduit wall, a 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 a portion of a conduit wall without directly heating 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 differentials between multiple distinct points along the conduit wall, wherein spacing between adjacent sensors is up to approximately 1.5 inches or approximately 38 millimeters;
• 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 up to approximately 15 minutes.