Heat exchanger

Abstract

A brazing material 315 in a paste form is applied in advance to dented portions 314 formed on the outer surface of a core pipe 31, and then a pipe 32 is disposed on the pipe 31, and brazing is carried out in a furnace. In this way, the brazing material 315 that was melted by the heat will be reliably poured into the dented portions 314 and bonded thereto after being cooled down. Thus, the dented portions 314 formed on the outer surface of the core pipe 31 can be reliably filled with the brazing material 33, which consequently eliminates a poor contact between the core pipe 31 and the winding pipe 32. In addition, even if the wall thickness of portions in which projections 313 are formed are made thinner in the process of forming the projections, the dented portions 314 formed on the outer surface are filled with the brazing material 33, so that the core pipe thickness can be reinforced, and the reduction in strength of the portions with the projections 313 can be prevented.

Description

technical field [0001] The present invention relates to a heat exchanger, and more particularly to a heat exchanger having a core tube formed with protrusions on the inner surface by pressing the outer surface and a coil tube wound on the outer surface of the core tube. Background technique [0002] Among the heat exchange devices used in air conditioners, water heaters, etc., some are provided with a heat exchanger having a core tube forming a flow path for the first fluid and a core tube wound on the outer surface of the core tube and forming a second fluid flow path. A coil of flow passages, the heat exchanger performs heat exchange between the first fluid and the second fluid. For example, as a heat exchanger for hot water supply such as a heat pump water heater, there is a double-tube heat exchanger disclosed in Patent Document 1, which consists of a core tube through which water flows and a disc through which refrigerant flows. The tube consists of a double tube, and ...

AI Technical Summary

Problems solved by technology

[0005] However, when using a core tube in which protrusions are provided on the inner surface of the core tube of the heat exchanger by pressing the outer surface, the outer surface of the core tube corresponding to the portion where the protrusion is formed on the inner surface form a depression

When the coiled tube is wound on the core tube in this state, and then wound into an oblong spiral shape, since the cross section of the core tube is uneven due to the protrusion, there may be a problem that the core tube and the core tube are separated. Poor contact of the coil, resulting in reduced heat transfer performance

In addition, during the processing of the protrusions, sometimes the wall thickness of the raised part of the core tube will be thinner than that of the part without the protrusions, and the strength of the raised part may be reduced.

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