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US 10,480,872 B2Granted
Turbulators in enhanced tubes
AssigneeTrane International Inc.
InventorsH. Kenneth Ring, Jr., Jon P. Hartfield, Todd A. Michael
Life of this patent
Estimating the term…
Abstract
A heat exchange tube combines an external surface feature, for example having crushed fins and cavities, which can have very high boiling enhancement characteristics, with an internal surface feature, for example having high performing intersecting helices, e.g. “cross hatched” with an intersecting helix angle. The new tube can provide a high performing tube in a shell and tube evaporator that can be relatively smaller, more efficient, and that can use relatively lower refrigerant charge.
Claims15
A heat exchange tube comprising:
- inner surface features on an inner surface of the heat exchange tube including a rib structure that is rifled and includes two or more helices that cross over each other;
- and
- a turbulator that extends in a longitudinal direction inside the heat exchange tube,
- at least a portion of the turbulator is positioned on the inner surface features,
- the inner surface features and the turbulator have a relative structure and arrangement to synergistically improve a heat transfer coefficient relative to a heat exchange tube without both the inner surface features and the turbulator, and in an operation condition where the working fluid flow is in an intermediate regime, and
- the intermediate regime is defined as including Reynolds numbers including lower than a transition point before a turbulent flow regime, including the transition point, and including a relatively smaller portion of the turbulent flow regime,
- wherein a ratio of turbulator pitch P1 to a tube inner diameter Dt, P1/Dt, is from 1 to 2.5, and
- a ratio of a turbulator diameter Dw to the tube inner diameter Dt, Dw/Dt, is from 0.04 to 0.1.
5 more elements
A fluid chiller comprising:
- a heat exchanger including a shell with an internal volume;
- and
- multiple heat exchange tubes disposed within the internal volume of the shell,
- one or more of the multiple heat exchange tubes comprise
- inner surface features on an inner surface of the heat exchange tube including a rib structure that is rifled and includes two or more helices that cross over each other;
- and
- a turbulator that extends in a longitudinal direction inside the heat exchange tube,
- at least a portion of the turbulator is positioned on the inner surface features,
- the inner surface features and the turbulator have a relative structure and arrangement to synergistically improve a heat transfer coefficient relative to a heat exchange tube without both the inner surface features and the turbulator, and in an operation condition where the working fluid flow is in an intermediate regime, and
- the intermediate regime is defined as including Reynolds numbers including lower than a transition point before a turbulent flow regime, including the transition point, and including a relatively smaller portion of the turbulent flow regime,
- wherein a ratio of turbulator pitch P1 to a tube inner diameter Dt, P1/Dt, is from 1 to 2.5, and
- a ratio of a turbulator diameter Dw to the tube inner diameter Dt, Dw/Dt, is from 0.04 to 0.1.
9 more elements
A method of making a heat exchange tube comprising:
- providing inner surface features on an inner surface of the heat exchange tube including a rib structure that is rifled and includes two or more helices that cross over each other;
- and
- providing a turbulator that extends in a longitudinal direction inside the heat exchange tube,
- positioning at least a portion of the turbulator on the inner surface features;
- and
- arranging the inner surface features and the turbulator to synergistically improve a heat transfer coefficient relative to a heat exchange tube without both the inner surface features and the turbulator, and in an operation condition where the working fluid flow is in an intermediate regime,
- the intermediate regime is defined as including Reynolds numbers including lower than a transition point before a turbulent flow regime, including the transition point, and including a relatively smaller portion of the turbulent flow regime,
- wherein a ratio of turbulator pitch P1 to a tube inner diameter Dt, P1/Dt, is from 1 to 2.5, and
- a ratio of a turbulator diameter Dw to the tube inner diameter Dt, Dw/Dt, is from 0.04 to 0.1.
6 more elements
Dependencies are inferred from the claim text.