# US 2014/0196872 A1 · Heat exchanger with enhanced airflow > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196872 A1 - Document ID: US20140196872A1 - Status: Published application - Kind: A1 - Application number: 14/158,277 - Filed: 2014-01-17 - Published: 2014-07-17 - Earliest claimed: 2013-01-17 - Assignees: Trane International Inc. - Applicants: Trane International Inc. - Inventors: Fahad ANWAR - Web page: https://patentgrep.com/patent/US20140196872A1 ## CPC - F28F 13/12: by creating turbulence, e.g. by stirring, by increasing the force of circulation (F28F13/08 takes precedence) - F28D 1/0475: {the conduits having a single U-bend} - F28F 1/025: {with variable shape, e.g. with modified tube ends, with different geometrical features (F28F1/06, F28F1/08, F28F9/16, F28F9/18 take precedence)} - F28F 1/06: crimped or corrugated in cross-section - F28F 1/10: Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses (crimped or corrugated elements F28F1/06, F28F1/08) - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) ## Abstract Systems, apparatuses, and methods described herein are directed to a heat exchange tube structure and an arrangement of heat exchange tubes that enhance or help promote fluid flow through a heat exchanger. Bend portions of heat exchange tubes may be structured and configured to allow for gaps so that fluid may pass an assembly of the heat exchange tubes. The heat exchange tubes may be arranged to expose the air gaps at the bend portions of the heat exchange tubes to promote fluid flow. ## Claims ### Claim 1 A heat exchange tube, comprising: a first leg; a second leg; a bend portion connected to the first leg and the second leg, the bend portion disposed between the first leg and the second leg, the first and second legs are generally parallel to each other due to the connection with the bend portion, the bend portion is disposed at one end of the heat exchange tube, and the first and second legs have free ends disposed at an end opposite the bend portion; and a flow passage through the first leg, the bend portion, and the second leg, the flow passage suitable to pass a fluid therethrough to establish a heat exchange relationship with a fluid passing over outside the heat exchange tube, the bend portion includes a first bend that connects the first leg to the bend portion and a second bend that connects the bend portion to the second leg, the first and second bends create a fluid flow opening proximate the bend portion suitable to promote fluid flow therethrough and to pass outside the heat exchange tube. ### Claim 2 (depends on 1) The heat exchange tube of claim 1, wherein one of the first bend and the second bend includes an inner angle that is acute relative to an inner angle of the other of the first bend or the second bend, the other of the first bend or the second bend includes an inner angle that is obtuse relative to the inner angle that is acute. ### Claim 3 (depends on 2) The heat exchange tube of claim 2, wherein the first bend and the second bend of the bend portion form the fluid flow opening to resemble a triangle-like bend area. ### Claim 4 (depends on 1) The heat exchange tube of claim 1, wherein the second leg is oriented relatively above the first leg, the second leg having an internal and/or external surface suitable to promote turbulence of fluid flowing through the flow passage. ### Claim 5 (depends on 4) The heat exchange tube of claim 4, wherein the surface is one or more dimples. ### Claim 6 A heat exchanger, comprising: an arrangement of heat exchange tubes including a first heat exchange tube; a second heat exchange tube; and a fluid flow gap configured from an arrangement of the first heat exchange tube and the second heat exchange tube. the first heat exchange tube comprises: a first leg, a second leg, a bend portion connected to the first leg and the second leg, and a flow passage through the first leg, the bend portion, and the second leg, the bend portion disposed between the first leg and the second leg, the first and second legs are generally parallel to each other due to the connection with the bend portion, the bend portion is disposed at one end of the first heat exchange tube, and the first and second legs have free ends disposed at an end opposite the bend portion, the flow passage suitable to pass a fluid therethrough to establish a heat exchange relationship with a fluid passing over and outside the first heat exchange tube, the bend portion includes a first bend that connects the first leg to the bend portion and a second bend that connects the bend portion to the second leg, the first and second bends create a fluid flow opening proximate the bend portion suitable to promote fluid flow therethrough and to pass outside the first heat exchange tube, the second heat exchange tube respectively comprises: a first leg, a second leg, a bend portion connected to the first leg and the second leg, and a flow passage through the first leg, the bend portion, and the second leg, the bend portion disposed between the first leg and the second leg, the first and second legs are generally parallel to each other due to the connection with the bend portion, the bend portion is disposed at one end of the second heat exchange tube, and the first and second legs have free ends disposed at an end opposite the bend portion, the flow passage suitable to pass a fluid therethrough to establish a heat exchange relationship with a fluid passing over and outside the second heat exchange tube, the bend portion includes a first bend that connects the first leg to the bend portion and a second bend that connects the bend portion to the second leg, the first and second bends create a fluid flow opening proximate the bend portion suitable to promote fluid flow therethrough and to pass outside the second heat exchange tube, the fluid flow gap formed by a portion of the bend portion of one of the first heat exchange tube and the second heat exchange tube extending beyond a portion of the bend portion of the other of the first heat exchange tube or the second heat exchange tube, wherein the fluid flow gaps are defined by the fluid flow openings of the first heat exchange tube and the second heat exchange tube being at least partially exposed. ### Claim 7 (depends on 6) The heat exchanger of claim 6, wherein in one of the first heat exchange tube or the second heat exchange tube, the first bend includes an inner angle that is acute relative to an inner angle of the second bend, and the second bend includes an inner angle that is obtuse relative to the inner angle of the first bend, and wherein in the other of the first heat exchange tube or the second heat exchange tube, the first bend includes an inner angle that is obtuse relative to an inner angle of the second bend, and the second bend includes an inner angle that is acute relative to the inner angle of the first bend. ### Claim 8 (depends on 6) The heat exchanger of claim 6, wherein the first and second bends of the first and second heat exchange tubes respectively form the fluid flow openings to resemble a triangle-like bend area. ### Claim 9 (depends on 6) The heat exchanger of claim 6, wherein the second leg of the first heat exchange tube and of the second heat exchange tube are respectively oriented relatively above the first leg of the first heat exchange tube and the second heat exchange tube, the second legs having an internal and/or external surface suitable to promote turbulence of fluid flowing through the flow passage. ### Claim 10 (depends on 9) The heat exchanger of claim 9, wherein the surface is one or more dimples. ### Claim 11 (depends on 6) The heat exchanger of claim 6, wherein the arrangement of heat exchange tubes includes heat exchange tubes that are alternated to form a staggered configuration at ends of the heat exchange tubes so as to form multiple fluid flow gaps. ### Claim 12 (depends on 6) The heat exchanger of claim 6, wherein the arrangement of heat exchange tubes are a component of a unitary air conditioning and/or heating product. ### Claim 13 A method of fluid heat exchange through an assembly of heat exchange tubes, comprising: directing a fluid through an arrangement of heat exchange tubes; directing another fluid over and outside of the arrangement of heat exchange tubes, the arrangement of heat exchange tubes including a first heat exchange tube, a second heat exchange tube, and a fluid flow gap, a) the first heat exchange tube comprises: a first leg, a second leg, a bend portion connected to the first leg and the second leg, and a flow passage through the first leg, the bend portion, and the second leg, the bend portion disposed between the first leg and the second leg, the first and second legs are generally parallel to each other due to the connection with the bend portion, the bend portion is disposed at one end of the first heat exchange tube, and the first and second legs have free ends disposed at an end opposite the bend portion, the flow passage suitable to pass a fluid therethrough to establish a heat exchange relationship with a fluid passing over outside the first heat exchange tube, the bend portion includes a first bend that connects the first leg to the bend portion and a second bend that connects the bend portion to the second leg, the first and second bends create a fluid flow opening proximate the bend portion suitable to promote fluid flow therethrough and to pass outside the first heat exchange tube, b) the second heat exchange tube respectively comprises: a first leg, a second leg, a bend portion connected to the first leg and the second leg, and a flow passage through the first leg, the bend portion, and the second leg, the bend portion disposed between the first leg and the second leg, the first and second legs are generally parallel to each other due to the connection with the bend portion, the bend portion is disposed at one end of the second heat exchange tube, and the first and second legs have free ends disposed at an end opposite the bend portion, the flow passage suitable to pass a fluid therethrough to establish a heat exchange relationship with a fluid passing over outside the second heat exchange tube, the bend portion includes a first bend that connects the first leg to the bend portion and a second bend that connects the bend portion to the second leg, the first and second bends create a fluid flow opening proximate the bend portion suitable to promote fluid flow therethrough and to pass outside the second heat exchange tube, c) the fluid flow gap formed by a portion of the bend portion of one of the first heat exchange tube and the second heat exchange tube extending beyond a portion of the bend portion of the other of the first heat exchange tube or the second heat exchange tube, wherein the fluid flow gaps are defined by the fluid flow openings of the first heat exchange tube and the second heat exchange tube being at least partially exposed; directing the another fluid through the fluid flow gap at the ends of the heat exchange tubes where the bend portions are disposed; and limiting increase in pressure drop when the another fluid passes through the fluid flow gap. ### Claim 14 (depends on 13) The method of claim 13, wherein the directing the another fluid flow over and outside of the arrangement of heat exchange tubes includes directing the another fluid to flow horizontally. ### Claim 15 (depends on 13) The method of claim 13, wherein the directing the another fluid through the fluid flow gap includes directing the another fluid to flow horizontally.