Heater exchangers for water heaters

Abstract

Improved heat exchanges for a water heater are provided. The heat exchangers are designed to be optimized for size, manufacturing cost, and performance. The heat exchanger include a central diverter tube and a coil tube that provide for efficient dissipation of heat from the heat exchanger to the water stored in the water tank and provides for a more uniform distribution of thermal energy within the water tank. The designs allow for this maximal thermal efficiency to be accomplished while simultaneously minimizing the manufacturing complexity and cost for the heat exchangers. For example, the heat exchanger designs minimize the number of individual components that together form the heat exchanger, thereby reducing the number of joints in the heat exchangers, resulting in fewer welds being required, among other manufacturing benefits.

Description

HEATER EXCHANGERS FOR WATER HEATERSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and benefit of U.S. provisional patent application no. 63 / 689,560 filed August 30, 2024, which is herein incorporated by reference.FIELD

[0002] This application relates generally to water heaters, and more particularly to heat exchangers for water heaters.BACKGROUND

[0003] Typical fuel-fired water heaters use fuels, such as natural gas, propane or oil, to heat water contained in a water tank of such water heaters. With such water heaters, a heat exchanger associated with the tank is typically used to heat the water. In some water heaters, hot gas passes through a heat exchanger once to heat the water. In other water heaters, the heat exchanger may include multiple branches, and the hot gas passes through the heat exchanger multiple times to heat the water. The multiple-branched heat exchanger can result in improved thermal efficiency. However, the arrangement of the multiple branches of the heat exchanger in the tank can present challenges to providing a top water outlet without degrading the thermal efficiency of the water heater.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The detailed description is set forth with reference to the accompanying drawings. In some instances, the use of the same reference numerals may indicate similar or identical items. Various embodiments may utilize elements and / or components other than those illustrated in the drawings, and some elements and / or components may not be present in various embodiments. Throughout this disclosure, depending on the context, singular and plural terminology may be used interchangeably.

[0005] FIG. 1 shows a water heater, in accordance with one or more embodiments of the disclosure.

[0006] FIG. 2A shows a heat exchanger included within a water heater, in accordance with one or more embodiments of the disclosure.

[0007] FIG. 2B shows the heat exchanger of FIG. 2A, in accordance with one or more embodiments of the disclosure.

[0008] FIG. 2C shows a cross-section of the heat exchanger of FIG 2B, in accordance with one or more embodiments of the disclosure.

[0009] FIG. 2D shows another cross-section of the heat exchanger of FIG. 2B depicting a flow of gas through the heat exchanger, in accordance with one or more embodiments of the disclosure.

[0010] FIG. 2E shows a heat map of the cross-section of FIG. 2D, in accordance with one or more embodiments of the disclosure.

[0011] FIG. 3 A shows another heat exchanger, in accordance with one or more embodiments of the disclosure.

[0012] FIG. 3B shows a cross-section of the heat exchanger of FIG. 3A, in accordance with one or more embodiments of the disclosure.

[0013] FIG. 4A shows another heat exchanger, in accordance with one or more embodiments of the disclosure.

[0014] FIG. 4B shows a cross-section of the heat exchanger of FIG. 4A, in accordance with one or more embodiments of the disclosure.

[0015] FIG. 4C shows gas flow through the heat exchanger of FIG. 4A, in accordance with one or more embodiments of the disclosure.

[0016] FIG. 4D shows a top-dow n view of the heat exchanger of FIG. 4A, in accordance with one or more embodiments of the disclosure.

[0017] FIG. 5A shows another heat exchanger, in accordance with one or more embodiments of the disclosure.

[0018] FIG. 5B shows a cross-section of the heat exchanger of FIG. 5A, in accordance with one or more embodiments of the disclosure.

[0019] FIG. 6A shows another heat exchanger, in accordance with one or more embodiments of the disclosure.

[0020] FIG. 6B shows a cross-section of the heat exchanger of FIG. 6A, in accordance with one or more embodiments of the disclosure.

[0021] FIG. 7A shows another heat exchanger, in accordance with one or more embodiments of the disclosure.

[0022] FIG. 7B shows gas flow through the heat exchanger of FIG. 7A, in accordance with one or more embodiments of the disclosure.

[0023] FIG. 7C shows a cross-section of the heat exchanger of FIG. 7C, in accordance with one or more embodiments of the disclosure.

[0024] FIG. 8-11 show additional heat exchangers, in accordance with one or more embodiments of the disclosure.

[0025] FIG. 12A shows another heat exchanger, in accordance with one or more embodiments of the disclosure.

[0026] FIG. 12B shows a cross-section of the heat exchanger of FIG. 12A, in accordance with one or more embodiments of the disclosure.

[0027] FIG. 13 shows a top-down view of the heat exchanger of FIG. 12A, in accordance with one or more embodiments of the disclosure.

[0028] FIG. 14-24 show additional heat exchangers, in accordance with one or more embodiments of the disclosure.

[0029] FIGS. 25A-25J show diverter tube configurations and corresponding thermal maps, in accordance with one or more embodiments of the disclosure.

[0030] FIG. 26A shows another diverter for a heat exchanger, in accordance with one or more embodiments of the disclosure.

[0031] FIGS. 26B-26C show thermal maps for a heat exchanger including the diverter of FIG. 26 A, in accordance with one or more embodiments of the disclosure.

[0032] FIGS. 27-36 show additional diverters for heat exchangers, in accordance with one or more embodiments of the disclosure.DETAILED DESCRIPTION

[0033] Disclosed herein are improved heat exchangers for a water heater. The water heater may include a water tank that may be any suitable size, shape, or configuration (for example, generally cylindrical in some instances). The heat exchanger may be provided within the water tank and is used to heat the water stored within the water tank. That is, a combustion system of the water heater produces hot gases that are directed into flue tubes of the heat exchanger. As the hot gases traverse the flue tubes of the heat exchanger within the water tank, thermal transfer occurs between the flue tubes and the water in the water tank to heat the water in the water tank. The hot water stored in the water tank may then be routed for usage for various residential and / or commercial purposes, such as water for a shower, a sink, etc.

[0034] Some heat exchangers may be multi-pass heat exchangers that include multiple passes of flue tubes through which hot gases from the combustion system flow. For example, a multi-pass heat exchanger may include first, second, and third-pass flue tubes, which are provided in the water tank of the water heater. The first-pass flue tube may be connected to the combustion system of the water heater such that hot gas produced by the combustion system flows into the first-pass flue tube. Multiple second-pass flue tubes may be connected to the first-pass flue tube and multiple third-pass flue tubes are connected to the second-pass flue tubes. Accordingly, the hot gas that passes through the first-pass flue tube subsequently passes from the first-pass flue tube into the second-pass flue tubes, and then finally from the second-pass flue tubes into the third-pass flue tubes. Thus, the hot gas may be used to heat the water in the water tank while being reduced to a threshold temperature after passing through all three sets of tubes.

[0035] In contrast with this and other existing heat exchanger designs, the heat exchangers described herein are designed to be optimized for size, manufacturing cost, and performance. The heat exchanger designs described herein include a central diverter tube and a coil tube that provide for efficient dissipation of heat from the heat exchanger to the water stored in the water tank and provide for a more uniform distribution of thermal energy within the water tank. The designs allow for this maximal thermal efficiency to be accomplished while simultaneously minimizing the manufacturing complexity and cost for the heat exchangers. For example, the heat exchanger designs minimize the number of individual components that together form the heat exchanger, thereby reducing the number of joints in the heat exchangers, resulting in fewer welds being required, among other manufacturing benefits.

[0036] While reference is specifically made herein to heat exchangers provided in water heaters, this is not intended to be limiting and the heat exchangers may also be provided in other types of heating appliances that use heat exchangers. Additionally, while reference is made herein to multi-pass heat exchangers including three passes of flue tubes, this is merely exemplary and other configurations may also be possible (e.g., any other number of passes including any other number of flue tubes of any sizes and shapes).

[0037] More generally, the heat exchangers described herein may be used in any type of vapor compression cycle system. A “vapor compression cycle system” may broadly encompass any system that is configured to heat and / or cool a conditioned space, heat and / or cool a fluid that is provided to a load, and / or perform any other actions associatedwith a vapor compression cycle. Non-limiting examples of types of a vapor compression cycle systems can include air conditioners (e.g., no reversing valve, only provides cooling mode), heat pumps (e.g., air source or geothermal; has a reversing valve and operates in both heating and cooling modes), heat pump water heaters, integrated heat pump water heaters, split system heat pump water heaters, heat pump water heaters with a circulation pump and a brazed plate heat exchanger, split systems, packaged systems, mini-splits, PTACs, window units, vertical packaged systems, VRF systems, etc.

[0038] Turning to the figures, FIG. 1 illustrates a perspective view of a water heater 100 that includes a water tank 102. a top cover assembly 104, and a bottom assembly 106. The water heater 100 also includes a combustion system 108 at the top end of the water heater 100. The combustion system 108 may include a down- fired burner, where hot gas flows downw ard into a multi-pass heat exchanger (shown in further detail in FIGS. 2-12) disposed in the water tank 102. The water heater 100 also includes a water inlet 112 that may be disposed, for example, closer to the bottom end of the water tank 102. The water tank 102 also includes a top water outlet 110 through the top cover assembly 104.

[0039] During the operation of the water heater 100, unheated water enters the water tank 102 through the water inlet 112, and gas is heated by the combustion system 108. The unheated water gets heated inside the water tank 102 by hot gas flowing through the heat exchanger. The resulting heated water exits the water tank 102 through the top water outlet 110 in the top cover assembly 104. The hot gas that flows through the heat exchanger may exit the water tank through a hot gas outlet in the bottom assembly 106.

[0040] The water heater 100 provides a top water outlet location along with the high efficiency of a multi-pass heat exchanger. By providing the top water outlet 1 10, the water heater 100 provides a fuel-fired water heater with a top w ater outlet location that is preferable in some installations.

[0041] FIG. 2A shows a heat exchanger 208 included within a water heater 200 (which may be the same as, or similar to, w ater heater 100 shown in FIG. 1 or any other water heater described herein or otherwise). Similar to w ater heater 100, water heater 200 includes a w ater tank 204, a top cover assembly 206, and a bottom assembly 205. The water heater 200 also includes a combustion system 202 at the top end of the water heater 200 (such as down-fired burner).

[0042] Provided within the w ater tank 204 is a heat exchanger 208. FIG. 2B show-s an illustration of the heat exchanger 208 w ithout the w ater tank 204. During operation of thewater heater 200, the combustion system 202 produces hot gases that are directed down into the heat exchanger 208. The hot gases then traverse within the tubing of the heat exchanger 208 and any water within the water tank 204 is heated by thermal dissipation through the tubes of the heat exchanger 208.

[0043] The heat exchanger 208 is advantageously configured for ease of manufacturing relative to other heat exchanger designs while maintaining maximal thermal efficiency (for example, 95% thermal efficiency or greater). For example, the heat exchanger 208 (as well as other heat exchangers described herein) may be more efficient than existing heat exchangers by allowing the heat of combustion gases within the heat exchanger 208 to be reduced from approximately 2100°F to approximately 120°F (or any other temperature values resulting) when the combustion gases are exhausted from the heat exchanger 208. In various implementations, the heat exchanger 208 is a condensing heat exchanger (e.g., combustion gases condense within the heat exchanger 208). Some existing heat exchangers may also provide for high thermal efficiency, but may include more complex tubing configurations that are more difficult to manufacture and replace.

[0044] In embodiments, the heat exchanger 208 includes a diverter tube 210 and a coil tube 212 that is provided around the diverter tube 210. As shown in FIG. 2 A, the diverter tube 210 may be centrally aligned within the water tank 204, however, this configuration is not intended to be limiting and the diverter tube 210 may also be positioned in any other manner within the water tank 204.

[0045] The diverter tube 210 is aligned with the combustion system 202 such that the hot gases expelled by the combustion system 202 are directed down into the diverter tube 210 before entering the coil tube 212. That is, the hot gases traverse into the diverter tube 210 and into the coil tube 212 via an inlet 214 of the coil tube 212. The inlet 214 may be provided at a top portion 216 of the coil tube 212. As the gases traverse through the coil tube 212 and heat dissipation occurs, the gases cool and ultimately exit the coil tube 212 at an outlet 218 of the coil tube 212. The outlet 218 may be provided at a bottom portion 222 of the coil tube 212. The outlet 218 is aligned with an opening 220 in the water tank 204 such that the cooled gases exit the water heater 200 such that the gases are not trapped within the heat exchanger 208. Condensate from the cooled gases may also exit the water heater 200 from the outlet 218 and be collected in a condensate boot (e.g.. shown in FIG. 2B) for neutralization and disposal.

[0046] Although the heat exchanger 208 is illustrated as being provided in a specific size and shape, this illustration is not necessarily intended to be limiting. For example, the size of the diverter tube 210 and the coil tube 212 may vary. As another example, the coil tube 212 may also include a number of coils around the diverter tube 210 and the coils may be provided at different spacings than the spacings represented in FIG. 2A. Further non-limiting examples of heat exchanger configurations are shown in FIGS. 3A-12B and are described in further detail below.

[0047] FIG. 2C is a cross-section of the heat exchanger 208 that shows the internal cavity of the diverter tube 210. Particularly, the diverter tube 210 is shown as including an inner tube 220 and an outer tube 222, with the outer tube 222 being provided around at least a portion of the inner tube 220. The inner tube 220 is connected to, and is in fluid communication with, the combustion system 202. The outer tube 222 is connected to and is in fluid communication with the inlet 214 of the coil tube 212.

[0048] To allow for hot gases received from the combustion system 202 to traverse from the inner tube 220 to the outer tube 222 (and ultimately into the coil tube 212), one or more openings (for example, first opening 224, second opening 226. third opening 228, etc.) are provided at various intervals down the length of the inner tube 220. The one or more openings provide passages through hot gases from the combustion system 202 may traverse from the inner tube 220 to the outer tube 222.

[0049] FIG. 2D provides an illustration of the flow of hot gases produced by the combustion system 202 (not shown in FIG. 2D) through the heat exchanger 208. As the combustion system 202 produces hot gases, the hot gases are directed down into the inner tube 220 of the diverter tube 210. The gases flow through the inner tube 220 and transition from the inner tube 220 to the outer tube 222 via the one or more openings in the inner tube 220. The gases then flow through the outer tube 222 and into the inlet 214 of the coil tube 212. Some of the thermal energy’ from the hot gases dissipates through the outer tube 222 into the water in the water tank 204. As the gases flow through the coil tube 212, additional thermal energy7from the hot gases dissipates through the coil tube 212 into the water tank 204. The cooled gas then exits the coil tube 212 at the outlet of the coil tube 212 at the bottom of the heat exchanger 208.

[0050] While conventional diverter tubes seek to have a long path length for combustion gases to travel through an outer tube (e.g., by providing a solid inner tube with a flow path to the outer tube at the bottom), despite having a shorter path length for someof the combustion gases, the heat exchanger 208 improves heat exchange with the surrounding water. By providing the plurality of openings along the length of the inner tube 220, hot spots are created along the length of the outer tube 222 that increase the rate of heat exchange with the water compared to conventional diverter tube arrangements. Additionally, because more heat is exchanged with the water through the outer tube 222, the temperature of the combustion gases entering the inlet 214 of the coil tube 212 is lower with conventional diverter tubes, thereby reducing thermal stresses at the joint between the diverter tube 210 and the coil tube 212. The reduced thermal stress at the joint improves the reliability of the heat exchanger 208.

[0051] As aforementioned, the heat exchanger configuration shown in FIGS. 2A-2E is merely exemplary' and other configurations may also be used. FIGS. 3A-12B provide examples of further heat exchanger configurations.

[0052] Beginning with FIGS. 3A-3B, an exemplary heat exchanger 308 is shown. FIGS. 3 A shows a perspective view of the heat exchanger 308 and FIG. 3B shows a crosssection of the heat exchanger 308. Similar to the heat exchanger 208 shown in FIGS. 2A- 2B, the heat exchanger 308 includes a diverter tube 310. The diverter tube 310 also includes an inner tube 320 and an outer tube 322 provided around the inner tube 320. The inner tube 320 is formed as a funnel that extends into the outer tube 322 and includes an opening 323 at the bottom of the inner tube 320. Coil tube 312 is connected to the outer tube 322 at inlet 314 at the top 316 of the coil tube 312. Hot gases produced by the combustion system 302 flow through the inner tube 320, into the outer tube 322, into the coil tube 312 through the inlet 314 and exit the coil tube 312 through the outlet 318 at the bottom 322 of the coil tube 312.

[0053] FIGS. 4A-4B show another exemplary heat exchanger 408. FIGS. 4A shows a perspective view' of the heat exchanger 408 and FIG. 4B shows a cross-section of the heat exchanger 408. The heat exchanger 408 also includes a diverter tube 410. Similar to the heat exchanger 208 shown in FIGS. 2A-2E and the heat exchanger 308 shown in FIGS. 3A-3B, the diverter tube 410 includes an inner tube 420 and an outer tube 422 provided around the inner tube 420. The inner tube 420 also includes the one or more openings that allow for gas received by the inner tube 420 via the combustion system (not shown in the figure) to flow into the outer tube 422. The heat exchanger 408 also includes a coil tube 412 attached to the diverter tube 410, where the coil tube 412 includes an inlet 414 and an outlet 418.

[0054] In contrast with the heat exchangers 208 and 308, however, the inlet 414 of the heat exchanger 408 is provided below the top portion 416 of the coil tube 412. That is, rather than the top of the coil tube 412 connecting into the diverter tube 410 at the top of the coil tube 412, a j-tube 411 is provided that extends down between the diverter tube 410 and the coil tube 412. Although a j-tube 411 is shown, any other shape of tube may be used as well.

[0055] This configuration in which the inlet 414 is provided at a point further dow n the diverter tube 410 may be used when a shorter diverter tube 410 is used in the heat exchanger 408 (that is, the diverter tube 410 shown in FIGS. 4A-4B is shorter than the diverter tubes 210 and 310 shown in FIGS. 2A-3B). For example, the diverter tube 410 may need to be shortened to fit within a smaller-capacity water tank (as a non-limiting example, an 80 gallon tank).

[0056] FIGS. 5A-5B show another exemplary heat exchanger 508. FIGS. 5A shows a perspective view of the heat exchanger 508 and FIG. 5B shows a cross-section of the heat exchanger 508. The heat exchanger 508 also includes a diverter tube 510. Similar to the heat exchanger 408 shown in FIGS. 4A-4B, the diverter tube 510 includes an inner tube 520 and an outer tube 522 provided around the inner tube 520. The inner tube 520 also includes the one or more openings that allow for gas received by the inner tube 522 via the combustion system (not shown in the figure) to flow into the outer tube 522. The heat exchanger 508 also includes a coil tube 512 attached to the diverter tube 510, where the coil tube 512 includes an inlet 514 and an outlet 518.

[0057] Similar to the heat exchanger 408 shown in FIGS. 4A-4B, the heat exchanger 508 of FIGS. 5A-5B includes an inlet 514 that is provided below the top portion 516 of the coil tube 512. Also similar to the heat exchanger 508, the heat exchanger 508 includes aj- tube 511 is provided that extends down between the diverter tube 510 and the coil tube 512. Although a j-tube 511 is shown, any other shape of tube may be used as well.However, in contrast with the heat exchanger 508, the coil tube 512 of the heat exchanger 508 is provided around more of the length of the diverter tube 510. The embodiment shown in FIGS. 4A-4B uses a j-tube to have the top of the coil at an intermediate position between the top of the tank and the inlet of the j-tube, whereas the embodiment shown in FIGS. 5A-5B extends the j-tube to the top of the tank.

[0058] FIGS. 6A-6B show another exemplary heat exchanger 608. FIGS. 6A shows a perspective view of the heat exchanger 608 and FIG. 6B shows a cross-section of the heatexchanger 608. The heat exchanger 608 also includes a diverter tube 610. Similar to the heat exchanger 508 shown in FIGS. 5A-5B, the diverter tube 610 includes an inner tube 620 and an outer tube 622 provided around the inner tube 620. The inner tube 620 also includes the one or more openings that allow for gas received by the inner tube 622 via the combustion system (not shown in the figure) to flow into the outer tube 622. The heat exchanger 608 also includes a coil tube 612 attached to the diverter tube 610, where the coil tube 612 includes an inlet 614 and an outlet 618.

[0059] In contrast with the heat exchangers shown in FIGS. 2A-5B, the heat exchanger 608 includes multiple coil tubes that are provided around the diverter tube 610. For example, FIGS. 6A-6B show a first coil tube 611 and a second coil tube 612. The first coil tube 611 is shown as being provided above the second coil tube 612 along the length of the diverter tube 610.

[0060] The first coil tube 611 and the second coil tube 612 include inlets that are provided at the bottom portion 623 of the diverter tube 610. For example, the first coil tube 611 includes an inlet 614 provided at the bottom portion of the diverter tube 610 and the second coil tube 612 includes inlet 618 provided at the bottom portion 623 of the diverter tube 610. However, while the first coil tube 611 and the second coil tube 612 are shown as including separate inlets, the first coil tube 611 and second coil tube 612 may share a common outlet 621.

[0061] This specific configuration of inlets and outlets of the first coil tube 611 and the second coil tube 612 is merely exemplary and each of the individual coil tubes may share inlets and / or outlets with any of the other coil tubes or some or all of the coil tubes may have their own individual inlets and / or outlets connecting the coil tubes to the diverter tube 610. As non-limiting examples, the first coil tube 611 and the second coil tube 612 may instead share a single inlet, may have separate outlets, etc.

[0062] FIGS. 6A-6B are merely intended to illustrate that multiple coil tubes may be used on a heat exchanger instead of a single coil tube and the specific configuration shown in the figures is not intended to be limiting. For example, although the first coil tube 611 and the second coil tube 612 are show n as being similar in size and including a similar number of individual coils around the diverter tube 611, one of the coils may be larger in size than the other and may include more individual coils. The tubing of the two coil tubes does not necessarily need to be the same diameter. Any other parameters relating to the size and shape of the coil tubes may also differ. Additionally. The spacing between thetwo coil tubes may also vary and some or all of the individual coils of the coil tubes may also overlap as well. For example, some or all of the individual coils of the first coil tube 611 may be provided between the individual coils of the second coil tube 612 and the diverter tube 610 (or vice versa). Likewise, some or all of the individual coils of the first coil tube 611 may be provided between coils of the second coil tube 612 (or vice versa). Further, more than two coil tubes may be provided around the heat exchanger 608 as well. For example, there may be three coil tubes, four coil tubes, etc. Some further non-limiting examples of configurations involving multiple coil tubes are shown in subsequent figures.

[0063] FIGS. 7A-7C show another exemplary heat exchanger 708. FIGS. 7A shows a perspective view of the heat exchanger 708 and FIG. 7B shows an exemplary flow of hot gases through the heat exchanger 708. FIG. 7C shows a cross-section of the heat exchanger 708. The heat exchanger 708 also includes a diverter tube 710. Similar to the heat exchanger 608 shown in FIGS. 6A-6B, the diverter tube 710 includes an inner tube 720 and an outer tube 722 provided around the inner tube 720. The inner tube 720 also includes the one or more openings that allow for gas received by the inner tube 722 via the combustion system (not shown in the figure) to flow into the outer tube 722. The heat exchanger 708 also includes a coil tube 712 attached to the diverter tube 710, where the coil tube 712 includes an inlet 714 and an outlet 718.

[0064] Similar to heat exchanger 608 shown in FIGS. 6A-6B, heat exchanger 708 also includes multiple coil tubes. For example, the heat exchanger 708 is shown as including first coil tube 711 and second coil tube 712. How- ever, the first coil tube 711 and the second coil tube 712 are provided in a different configuration than the first coil tube 611 and the second coil tube 612 of the heat exchanger 608. Particularly, the inlet 714 for the first coil tube 711 and the inlet 718 for the second coil tube 712 are provided between the position of the first coil tube 711 and the second coil tube 712 rather than being provided at the bottom 722 of the diverter tube 710. Additional spacing is also provided between the first coil tube 711 and the second coil tube 712 relative to the spacing between the first coil tube 611 and the second coil tube 612 in the heat exchanger 608. Similar to the heat exchanger 608, the first coil tube 711 and the second coil tube 712 include a common outlet 721. However, as mentioned with respect to FIGS. 6A-6B, any other configuration of inlet(s) and / or outlet(s) may also be used.

[0065] FIG. 8 shows another exemplary heat exchanger 808. The heat exchanger 808 also includes a diverter tube 810. Similar to the heat exchanger 708 shown in FIGS. 7A-7C, the diverter tube 810 includes an inner tube 820 and an outer tube 822 provided around the inner tube 820. The inner tube 820 also includes the one or more openings that allow for gas received by the inner tube 822 via the combustion system (not shown in the figure) to flow into the outer tube 722. The heat exchanger 808 also includes a coil tube 812 attached to the diverter tube 810, where the coil tube 812 includes an inlet 814 and an outlet 818.

[0066] Similar to heat exchanger 708 shown in FIGS. 7A-7C, heat exchanger 808 also includes multiple coil tubes. For example, the heat exchanger 808 is shown as including first coil tube 811 and second coil tube 812. However, the first coil tube 811 and the second coil tube 812 are provided in a different configuration than the first coil tube 711 and the second coil tube 712 of the heat exchanger 708. Particularly, the inlet 814 for the first coil tube 811 and the inlet 818 for the second coil tube 812 are provided between the position of the first coil tube 811 and the second coil tube 812 and the common outlet 821 is provided, however, the routing of the tubing of the first coil tube 81 1 and the second coil tube 812 differs from the routing of the first coil tube 711 and the second coil tube 712 shown in FIGS. 7A-7C.

[0067] FIG. 9 shows another exemplary heat exchanger 908. The heat exchanger 908 also includes a diverter tube 910. Similar to the heat exchanger 808 shown in FIG. 8, the diverter tube 910 includes an inner tube and an outer tube provided around the inner tube (not shown in the figure). The inner tube also includes the one or more openings that allow for gas received by the inner tube via the combustion system (not shown in the figure) to flow into the outer tube. The heat exchanger 908 also includes a coil tube 12 attached to the diverter tube 910, where the coil tube 912 includes an inlet 914 and an outlet 918.

[0068] FIGS. 10-24 show even further heat exchanger configurations. Beginning with FIGS. 10-11, heat exchangers 1000 and 1100 are shown. Heat exchangers 1000 and 1100 also include a central tube (for example, central tubes 1002 and 1102) and a coil tube (for example, coil tubes 1004 and 1104). However, heat exchangers 1000 and 1100 also include one or more additional flue tubes. For example, heat exchanger 1000 includes first additional flue tube 1006, second additional flue tube 1008, third additional flue tube 1010, and fourth additional flue tube (not shown in the figure). Likewise, heat exchanger includes first additional flue tube 1106. second additional flue tube 1108, third additional flue tube 1110, fourth additional flue tube 1112, fifth additional flue tube 1114, sixth additional flue tube 1116, seventh additional flue tube 1118, and eighth additional fluetube (not shown in the figure). During operation, hot gases from the combustion system (not shown in FIGS. 10-11) flow down the central tubes 1002 and 1102, down into the additional flue tubes, back into the diverter tube 1002 at a bottom portion 1030 and 1130 of the diverter tube, back up through the central tube 1002, and into the coil tubes 1004 and 1104. The hot gases then flow through the coil tube 1004 and 1104 and exit the coil tube at outlet 1032 and 1132.

[0069] The heat exchangers 1000 and 1100 show two exemplary' configurations including additional flue tubes and any other configurations are also possible. For example, any other number of additional flue tubes may be provided, the additional flue tubes may be any other size, provided in any other arrangement, etc.

[0070] FIGS. 12A-13 show another exemplary' heat exchanger 1200. FIG. 12A shows a perspective view' of the heat exchanger 1200, FIG. 12B show s a cross-section view of the heat exchanger 1200, and FIG. 13 shows a top-down view of the heat exchanger 1200.

[0071] Particularly, the heat exchanger are further exemplary heat exchangers that include multiple, separate coil tubes (for example, coil tube 1204 and coil tube 1206). However, in contrast with the heat exchangers shown in FIGS. 6A-8, the coil tubes shown in FIGS. 12A-12C are provided in the same area relative to the diverter tube 1202. Although the coil tube 1204 is shown as smaller than the coil tube 1206, this is merely exemplary' and not intended to limit the configuration of the coil tubes.

[0072] Hot gases from the combustion system (not shown in the figure) flow' down the diverter tube 1202, into the inlets 1203 and 1205 of the coil tube 1204 and 1206, through the coil tubes 1204 and 1206. and exit the coil tubes via outlets 1207 and 1208.

[0073] FIGS. 14-18 show' heat exchangers 1400-1800 (FIG. 16 is a top-down view of heat exchanger 1500 of FIG. 15 and FIG. 18 is a top-down view' of heat exchanger 1700 of FIG. 17) that, similar to the heat exchangers shown in FIGS. 4A-4B, include coil tubes that include “J-tubes” (or tubes of other shapes) that cause the inlet of the coil tubes to be located further down the diverter tube (e.g., below the top portion of the coil tube). FIGS. 19-21 show' further examples of heat exchangers 1900, 2000, and 2100 that includes tw o separate coil tubes. FIGS. 22-24 show' yet further examples of heat exchangers 2200, 2300, and 2400. The heat exchangers 2200 and 2300 of FIGS. 22-23 also include coil tubes 2202 and 2302. however, a portion (for example portion 2204 and 2304) of the top of the coil tubes 2202 and 2302 may be initially routed to a top portion of the tank such that the w arm gases are routed proximate to the outlets 2206 and 2306 of the tanks. FIG.24 shows a heat exchanger 2400 that includes a larger central diverter tube 2402. This configuration may be advantageous in smaller capacity water tanks. That is, rather than having a longer coil tube with more turns, the heat exchanger 2400 may instead include the larger diameter central diverter tube so provide similar surface area of the heat exchanger with respect to the water in the water tank.

[0074] FIGS. 25A-25J show configurations of diverter tubes and corresponding thermal maps. Specifically, FIGS. 25A-25J show various exemplary' configurations of the inner tubes (the inner tubes are shown as including openings of differing sizes, spacing, etc.). The configurations of the inner tubes shown in FIGS. 25A-25J are not intended to be limiting but instead are simply intended to show various exemplary configurations and other configurations are also possible.

[0075] Beginning with FIGS. 25A-25B, diverter tube 2500 including inner tube 2502 and outer tube 2504 is shown. The inner tube 2502 has a diameter of 3.5 inches and the holes are 40mm in diameter. Thermal map 2506 is shown for the diverter tube 2500. FIGS. 25C-25D show diverter tube 2508 including inner tube 2510 and outer tube 2512. The inner tube 2510 has a diameter of 2.5 inches and the holes are 30mm in diameter.Thermal map 2514 is shown for the diverter tube 2508. FIGS. 25E-25F show diverter tube 2516 including inner tube 2518 and outer tube 2520. The inner tube 2518 has a diameter of 3.5 inches and the holes are 30mm in diameter. Thermal map 2522 is shown for the diverter tube 2516. FIGS. 25G-25H show' diverter tube 2524 including inner tube 2526 and outer tube 2528. The inner tube 2526 has a diameter of 3.5 inches and the holes are 50mm in diameter. Thermal map 2530 is shown for the diverter tube 2524. FIGS. 25I-25J show diverter tube 2532 including inner tube 2534 and outer tube 2536. The inner tube 2534 has a diameter of 4.5 inches and the holes are 30mm in diameter. Thermal map 2538 is shown for the diverter tube 2532.

[0076] FIGS. 26A-39 show further examples of diverters that may be used in any of the heat exchangers described herein. Beginning with FIG. 26A, diverter tube 2600 is shown. FIGS. 26B-26C show' thermal maps 2620 and 2630 for a heat exchanger including the diverter tube 2600 of FIG. 26A.

[0077] Whereas diverter tube 210 of FIGS. 2A-2B includes an inner tube 320 and an outer tube 322, diverter tube 2600 of FIG. 26A includes a diverter plate 2602 provided within the diverter tube 2600. The separating plate includes an angled top surface 2604 that contacts an inner surface of the diverter tube 2600 and directs hot gases from thecombustion system (not shown in the figure) down a first side 2608 of the diverter plate 2604. The diverter plate 2602 also includes an opening 2606 at the bottom of the diverter plate 2602. The hot gases flow down the first side 2608, through the opening 2606, and up through the second side 2610 of the diverter tube 2600. A coil tube 2612 (only a portion of the coil tube 2612 is shown in FIG. 26A) is connected to the diverter tube 2600 such that the inlet 2611 of the coil tube 2612 is located at the second side 2610 of the diverter tube 2600. Thus, the hot gases flowing up through the second side 2610 and then enter the coil tube 2612 through the inlet 2611.

[0078] FIGS. 27-36 show cross-sections of additional diverter configurations for heat exchangers. FIG. 27 shows one configuration for a diverter tube 2700 including an inner tube 2702 (similar to the funnel shown in FIG. 3B). Hot gases from the combustion system (not shown in any of FIGS. 27-31) flow through the diverter tube 2700, into the funnel 2702, out of the inner tube 2702 through opening 2704, into an outer tube 2706 (the portion of the diverter tube 2700 directly surrounding the funnel 2702), and ultimately into a coil tube connected to the diverter tube 2700. Although reference may be made to a single coil tube with respect to FIGS. 27-31, this is not intended to be limiting, and as mentioned elsewhere herein, multiple coil tubes may be provided in a heat exchanger as well.

[0079] FIG. 28 shows another diverter tube 2800. Similar to the diverter tube 2600 shown in FIGS. 26 A, diverter tube 2700 includes a diverter plate 2802. The diverter plate 2802 includes an angled top surface 2804 and an opening 2807. Hot gases from the combustion system flow down the diverter tube 2800 and are directed down a first side 2806 of the diverter plate 2802, through the opening 2807, into a second side 2808 of the diverter plate 2802, and into the coil tube 2810.

[0080] FIG. 29 shows a slightly different configuration of diverter tube 2900 relative to the diverter tube 2800 shown in FIG. 28. Diverter tube 2900 also includes a diverter plate 2902, however, diverter plate 2902 includes a first surface 2904, second surface 2906, and third surface 2908. Therefore, hot gases from the combustion system flow down the diverter tube 2900 and are directed down a first area 2910, through first opening 2911, into a second area 2912, through second opening 2913, into a third area 2914, and into the coil tube 2916. It should be noted that the diverter plate configurations shown in FIGS. 28- 29 are merely exemplary and other configurations of diverter plates (sizes, shapes, etc.) are also possible.

[0081] FIG. 30 shows another diverter tube 3000. The diverter tube 3000 includes an inner structure 3002 and one or more baffles 3006 surrounding the inner structure 3002. Hot gases from the combustion system are directed down through the diverter tube 3000, around the inner structure 3002, down through the baffles 3006, into a bottom portion 3004 of the diverter tube 3000, and into the coil tube 3008. The baffles 3006 shown in FIG. 30 are merely exemplary and the baffles 3006 may also be provided in any other configuration (size, shape, number of baffles, spacing of baffles, etc.).

[0082] FIG. 31 shows another heat exchanger 3100. The heat exchanger includes two coils (for example, first coil 31002 and second coil 3104) that extend downward from the burner 3106.

[0083] FIG. 32A shows another diverter tube 3200. The diverter tube 3200 includes a diverter plate 3202 (an example of a diverter plate 3202 by itself is shown in FIG. 32B) that is provided within the diverter tube 3200. The diverter plate 3202 extends across the inner diameter of the diverter tube 3200 such that the hot gases from the combustion system (not shown in FIGS. 32-38) are only able to pass through the diverter plate 3202 through one or more openings 3204 provided on the diverter plate 3202. As shown in FIG. 32B, the one or more openings 3204 may be provided as “slots’" on the diverter plate 3202, however, the one or more openings 3204 may also be provided as any other shape. The number and arrangement of the one or more openings 3204 may also vary. Further, although the diverter plate 3202 is shown as being provided at a particular angle within the diverter tube 3200, this is merely exemplary and the diverter plate 3202 may be provided at any other angle. Additionally, the diverter plate 3202 may be any other shape. After the hot gases pass through the one or more openings 3204, the hot gases may then flow into the coil tube 3206.

[0084] FIG. 33 shows another diverter tube 3300. The diverter tube 3300 includes an inner tube 3302 and an outer tube 3303. The coil tube 3306 extends into the outer tube3303 such that the inner tube 3302 extends down through the coil tube 3306. An opening3304 is provided through the coil tube 3306. Accordingly, hot gases from the combustion system flow through the inner tube 3302 and into the coil tube 3306 through the opening 3304.

[0085] FIG. 34 shows another diverter tube 3400. The diverter tube 3400 includes an inner tube 3402 and an outer tube 3403. Similar to the configuration shown in FIG. 33, the coil tube 3404 extends within the diverter tube 3400. The coil tube 3404 includes one ormore openings 3406. Accordingly, hot gases from the combustion system flow down through the inner tube 3402 and into the coil tube 3404 through the one or more openings 3406.

[0086] FIG. 35 shows another diverter tube 3500. The diverter tube 3500 includes an inner tube 3502 and an outer tube 3503. Similar to the configuration shown in FIG. 34, the coil tube 3506 extends within the diverter tube 3500. The coil tube 3506 includes one or more openings 3508. How ever, in contrast with the configuration shown in FIG. 34, the inner tube 3502 in FIG. 35 also includes one or more openings 3504. Accordingly, hot gases from the combustion system flow down through the inner tube 3502, out of the one or more openings 3502 in the inner tube 3502, and into the coil tube 3506 through the one or more openings 3508.

[0087] FIG. 36 shows another diverter tube 3600. Provided within the diverter tube 3600 are one or more baffles 3602 that are provided at various intervals within the diverter tube 3600. The one or more baffles 2603 direct the flow of hot gas from the combustion system through the diverter tube 3600 until the hot gases flow into the coil tube 3604. Any other number of baffles may be provided and the baffles may be provided in any other arrangement.

[0088] It should be apparent that the foregoing relates only to certain embodiments of the present application and that numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the disclosure.

[0089] Although specific embodiments of the disclosure have been described, numerous other modifications and alternative embodiments are within the scope of the disclosure. For example, any of the functionality described with respect to a particular device or component may be performed by another device or component. Further, while specific device characteristics have been described, embodiments of the disclosure may relate to numerous other device characteristics. Further, although embodiments have been described in language specific to structural features and / or methodological acts, it is to be understood that the disclosure is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments. Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments couldinclude, while other embodiments may not include, certain features, elements, and / or steps. Thus, such conditional language is not generally intended to imply that features, elements, and / or steps are in any way required for one or more embodiments.

[0090] Example Embodiments

[0091] Embodiment l.A fluid heater comprising: a combustion system; a fluid tank; a heat exchanger provided in the fluid tank, the heat exchanger comprising: a diverter tube comprising: an inner tube comprising a plurality of openings provided at intervals along a length of the diverter tube and configured to receive gas expelled by the combustion system; an outer tube configured to receive the gas from the inner tube via the plurality of openings, wherein the inner tube is provided within the outer tube; and a first coil tube provided around the diverter tube and configured to receive the gas from the outer tube.

[0092] Embodiment 2. The fluid heater of Embodiment 1, wherein the diverter tube is provided centrally within the fluid tank.

[0093] Embodiment 3. The fluid heater of Embodiment 2, wherein the first coil tube comprises an inlet provided at a top portion of the first coil tube that connects to the outer tube of the diverter tube.

[0094] Embodiment 4. The fluid heater of any of Embodiments 1-3. wherein the first coil tube comprises an inlet provided below a top portion of the first coil tube that connects to the outer tube of the diverter tube.

[0095] Embodiment 5. The fluid heater of any of Embodiments 1-4, wherein the first coil tube comprises an outlet provided at a bottom portion of the first coil tube that connects to an opening in the fluid tank.

[0096] Embodiment 6. The fluid heater of any of Embodiments 1 -5, further comprising a second coil tube provided at a second location within the fluid tank.

[0097] Embodiment 7. The fluid heater of any of Embodiments 1-6, wherein the second coil tube is provided around the diverter tube.

[0098] Embodiment 8. A heat exchanger comprising a diverter tube comprising: an inner tube comprising a plurality of openings provided at intervals along a length of the inner tube and configured to receive gas expelled by a combustion system of a fluid heater; an outer tube configured to receive the gas from the inner tube via the plurali ty of openings, wherein the inner tube is provided within the outer tube; and a first coil tube provided around the diverter tube and configured to receive the gas from the outer tube, wherein the heat exchanger is provided within a fluid tank of the fluid heater.

[0099] Embodiment 9. The heat exchanger of Embodiment 8, wherein the diverter tube is provided centrally within the fluid tank.

[0100] Embodiment 10. The heat exchanger of Embodiment 9, wherein the first coil tube comprises an inlet provided at a top portion of the first coil tube that connects to the outer tube of the diverter tube.

[0101] Embodiment 11. The heat exchanger of any of Embodiments 8-10, wherein the first coil tube comprises an inlet provided below a top portion of the first coil tube that connects to the outer tube of the diverter tube.

[0102] Embodiment 12. The heat exchanger of any of Embodiments 8-11. wherein the first coil tube comprises an outlet provided at a bottom portion of the first coil tube that connects to an opening in the fluid tank.

[0103] Embodiment 13. The heat exchanger of any of Embodiments 8-12. further comprising a second coil tube provided at a second location within the fluid tank.

[0104] Embodiment 14. The heat exchanger of any of Embodiments 8-13, wherein the second coil tube is provided around the diverter tube.

[0105] Embodiment 15. A heating appliance comprising: a combustion system; and a heat exchanger, the heat exchanger comprising: a diverter tube comprising: an inner tube comprising a plurality of openings provided at intervals along a length of the diverter tube and configured to receive gas expelled by the combustion system; an outer tube configured to receive the gas from the inner tube via the plurality of openings, wherein the inner tube is provided within the outer tube; and a first coil tube provided around the diverter tube and configured to receive the gas from the outer tube.

[0106] Embodiment 16. The heating appliance of Embodiment 15, wherein the first coil tube comprises an inlet provided at a top portion of the first coil tube that connects to the outer tube of the diverter tube.

[0107] Embodiment 17. The heating appliance of Embodiment 16, wherein the first coil tube comprises an inlet provided below a top portion of the first coil tube that connects to the outer tube of the diverter tube.

[0108] Embodiment 18. The heating appliance of any of Embodiments 15-17, wherein the first coil tube comprises an outlet provided at a bottom portion of the first coil tube that connects to an opening in the heating appliance.

[0109] Embodiment 19. The heating appliance of any of Embodiments 15-18, further comprising a second coil tube provided at a second location within a fluid tank.

[0110] Embodiment 20. The heating appliance of any of Embodiments 15-19, further comprising a second coil tube provided around the diverter tube.

Claims

CLAIMSThat which is claimed is:

1. A fluid heater comprising:A combustion system; a fluid tank; a heat exchanger provided in the fluid tank, the heat exchanger comprising: a diverter tube comprising: an inner tube comprising a plurality of openings provided at intervals along a length of the diverter tube and configured to receive gas expelled by the combustion system; an outer tube configured to receive the gas from the inner tube via the plurality of openings, wherein the inner tube is provided within the outer tube; and a first coil tube provided around the diverter tube and configured to receive the gas from the outer tube.

2. The fluid heater of claim 1, wherein the diverter tube is provided centrally within the fluid tank.

3. The fluid heater of claim 2, wherein the first coil tube comprises an inlet provided at a top portion of the first coil tube that connects to the outer tube of the diverter tube.

4. The fluid heater of any of claims 1 -3, wherein the first coil tube comprises an inlet provided below a top portion of the first coil tube that connects to the outer tube of the diverter tube.

5. The fluid heater of any of claims 1-4, wherein the first coil tube comprises an outlet provided at a bottom portion of the first coil tube that connects to an opening in the fluid tank.

6. The fluid heater of any of claims 1-5. further comprising a second coil tube provided at a second location within the fluid tank.

7. The fluid heater of any of claims 1-6, wherein the second coil tube is provided around the diverter tube.

8. A heat exchanger comprising: a diverter tube comprising: an inner tube comprising a plurality of openings provided at intervals along a length of the inner tube and configured to receive gas expelled by a combustion system of a fluid heater; an outer tube configured to receive the gas from the inner tube via the plurality of openings, wherein the inner tube is provided within the outer tube; and a first coil tube provided around the diverter tube and configured to receive the gas from the outer tube, wherein the heat exchanger is provided within a fluid tank of the fluid heater.

9. The heat exchanger of claim 8, wherein the diverter tube is provided centrally within the fluid tank.

10. The heat exchanger of claim 9, wherein the first coil tube comprises an inlet provided at a top portion of the first coil tube that connects to the outer tube of the diverter tube.

11. The heat exchanger of any of claims 8- 10, wherein the first coil tube comprises an inlet provided below a top portion of the first coil tube that connects to the outer tube of the diverter tube.

12. The heat exchanger of any of claims 8-11, wherein the first coil tube comprises an outlet provided at a bottom portion of the first coil tube that connects to an opening in the fluid tank.

13. The heat exchanger of any of claims 8-12, further comprising a second coil tube provided at a second location within the fluid tank.

14. The heat exchanger of any of claims 8-13, wherein the second coil tube is provided around the diverter tube.

15. A heating appliance comprising: a combustion system; and a heat exchanger, the heat exchanger comprising: a diverter tube comprising: an inner tube comprising a plurality of openings provided at intervals along a length of the diverter tube and configured to receive gas expelled by the combustion system; an outer tube configured to receive the gas from the inner tube via the plurality of openings, wherein the inner tube is provided within the outer tube; and a first coil tube provided around the diverter tube and configured to receive the gas from the outer tube.

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