A water heater can include a baffle and a slab heat exchanger with at least two rows of heat exchanger tubes, each row comprising a plurality of heat exchanger tubes. At least one of the heat exchanger tubes comprises a tube and a plurality of fins on the exterior of the tube circumscribing the tube, wherein the outer edge of each fin of the plurality of fins is bent at least at the same three areas of each fin such that the bends form at least three flat or concave areas running along the length of the heat exchanger tube.

The present invention provides a heat transfer equipment at rapid rate of thermal diffusion across the temperature gradient. The present invention further provides a method of manufacturing of a heat transfer equipment. The various embodiments of the present invention provide various methods for manufacturing of heat transfer equipment by affixing the loop or a solid member (201) containing crests and troughs on the surface of the central hollow member (101) by use of laser weld (301). The invention would provide much higher strength to the equipment and have much higher temperature sensitivity.

The present invention provides a heat transfer equipment at rapid rate of thermal diffusion across the temperature gradient. The present invention further provides a method of manufacturing of a heat transfer equipment. The various embodiments of the present invention provide various methods for manufacturing of heat transfer equipment by affixing the loop or a solid member (201) containing crests and troughs on the surface of the central hollow member (101) by use of laser weld (301). The invention would provide much higher strength to the equipment and have much higher temperature sensitivity.

Embodiments include various water heaters. In one example, a water heater includes a burner, an exhaust vent, a corrugated baffle having a first slit having a first length and a second slit having a second length that is less than the first length, and a heat exchanger. The heat exchanger includes a first set of heat exchanger tubes arranged in a first row, and a second set of heat exchanger tubes arranged in a second row, the second set of heat exchanger tubes having a third tube having a first angled surface and a second angled surface, where the first angled surface and the second angled surface together form a fin. The third tube can be arranged such that the fin is disposed at least partially between the first curved outer surface and the second curved outer surface.

A flow-guiding rod includes a cooling channel provided in a rod portion of the flow-guiding rod, and a coolant inlet pipe and a coolant outlet pipe provided on end(s) of the flow-guiding rod. The coolant inlet pipe and the coolant outlet pipe are communicated with the cooling channel.

Polymeric tube-in-shell heat exchangers with twisted tubes are provided. The heat exchanger may include one or more polymeric tube bundles, wherein each of the one or more polymeric tube bundles includes at least one tube twisted about its length or at least one pair of tubes twisted or wound around each other. The presently disclosed polymeric tube-in-shell heat exchangers with twisted tubes may be especially suited for applications where the use of polymer tubes offers advantages, such as in the case of acid solutions, food and beverage fluids, and carbon capture applications where the use of metal heat exchangers destroy the amines used for capture.

A finned tube having a tube main body, on the outside of which, in particular separate or integral, fins are arranged, preferably circumferentially, wherein the fins and/or the tube main body are of a multi-layer material.

A finned tube having a tube main body, on the outside of which, in particular separate or integral, fins are arranged, preferably circumferentially, wherein the fins and/or the tube main body are of a multi-layer material.

An outer finned tube includes a tube body, an outer wall of the tube body is provided with outer fins spirally arranged in an extension direction of the tube body; grid fins are arranged between two adjacent spiral parts of the outer fins correspondingly; two ends of each grid fin are connected to the two adjacent spiral parts of the corresponding outer fin respectively; a gap is kept between each grid fin and the outer wall of the tube body; and the plurality of grid fins are spaced in the extension direction of the tube body. An enhancing cavity is formed in an area defined by the outer wall of the tube body, inner walls of the grid fins and the outer fins in an encircling way, which can form a larger degree of superheat, provides a nucleation point for a boiling/condensation process and improves a heat exchange performance.

Fins are formed monolithically from the material of a tube body. The fins extend from the tube body outer surface, and include a fin base and a fin top. Wings extending from a fin side surface between the fin base and fin top can produce upper and lower channels between adjacent fins. Depressions can be formed in the fin top with platforms below the depressions. The tube can also include helical ridges on an inner surface of the tube. The tubes are used for heat transfer, and can be included in shell and tube heat exchangers.