Heat exchanger and water heating device including same

Abstract

Provided is a heat exchanger which includes a plurality of meandering heat transfer pipes that includes first and second heat transfer pipes, as the plurality of heat transfer pipes, which are adjacent to each other in a predetermined y direction and are misaligned with each other in a z direction such that a plurality of straight pipe parts are in a non-overlapping state in the y direction, in which a first recessed part recessed in the y direction is provided in each curved pipe part of the first heat transfer pipe, and a part of each curved pipe part of the second heat transfer pipe is fitted into the first recessed part.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the priority benefit of Japan application serial no. 2020-068371, filed on Apr. 6, 2020. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.BACKGROUNDTechnical Field[0002]The disclosure relates to a type of heat exchanger that is used as a component of a water heating device such as a hot water supply device and recovers heat from a heating medium such as combustion gas by using a heat transfer pipe, and a water heating device including the same.Description of Related Art[0003]As an example of a heat exchanger, there is one described in Patent Document 1.[0004]In the heat exchanger described in the same document, a meandering heat transfer pipe is used for a heat transfer pipe for recovering heat from combustion gas. The meandering heat transfer pipe has a configuration in which a plurality of straight pipe parts are connected to ea...

AI Technical Summary

Benefits of technology

The patent is about a type of heat exchanger that helps recover heat from combustion gas to heat water. The technical effect of this invention is to improve the efficiency of water heating devices by using a more efficient heat transfer system.

Problems solved by technology

First, since the entire curved pipe parts of the meandering heat transfer pipes are formed in flat shapes, there is a disadvantage that the resistance (flow path resistance) when a fluid to be heated flows through the inside of the heat transfer pipe increases.

Secondly, since an amount of processing for forming the entirety of each curved pipe part into a flat shape is large, a residual stress increases.

This causes stress cracking in the heat transfer pipe, which is not preferable.

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