US-12625042-B2 - Method for checking quality of heat exchanger

US12625042B2US 12625042 B2US12625042 B2US 12625042B2US-12625042-B2

Abstract

A method for checking quality of a heat exchanger includes the steps of: performing a liquid pressure test for the heat exchanger including a first flow path and a second flow path adjacent to the first flow path by filling the first flow path and the second flow path with a liquid in a pressurized state; discharging the liquid from the first flow path and the second flow path; and promoting evaporation of the liquid remaining in the first flow path and the second flow path by reducing pressure inside each of the first flow path and the second flow path using a vacuum pump. The step of promoting evaporation of the liquid is performed to feed heated gas into the first flow path and the second flow path.

Inventors

Hiroaki Kanazawa
Kentaro Tanaka
Hideki TAKAFUJI
Tadashi Ikeuchi

Assignees

KOBE STEEL, LTD.

Dates

Publication Date: 20260512
Application Date: 20230719
Priority Date: 20220808

Claims (6)

1 . A method for checking quality of a heat exchanger comprising: performing a liquid pressure test for the heat exchanger including a first flow path and a second flow path adjacent to the first flow path by filling the first flow path and the second flow path with a liquid in a pressurized state; discharging the liquid from the first flow path and the second flow path; and promoting evaporation of the liquid remaining in the first flow path and the second flow path by reducing pressure inside each of the first flow path and the second flow path using a vacuum pump; wherein the promoting evaporation of the liquid includes a first step of reducing pressure inside the first flow path and at the same time feeding heated gas into the second flow path, and a second step of reducing pressure inside the second flow path and at the same time feeding heated gas into the first flow path, wherein the second step is performed before or after the first step.
2 . The method for checking quality of a heat exchanger according to claim 1 , wherein the first step is ended on condition that a decrease in pressure to a predetermined pressure or less in the first flow path is detected, and the second step is ended on condition that a decrease in pressure to a predetermined pressure or less in the second flow path is detected.
3 . The method for checking quality of a heat exchanger according to claim 1 , wherein the heat exchanger is heated when evaporation of the liquid is promoted.
4 . The method for checking quality of a heat exchanger according to claim 1 , wherein the heat exchanger is a heat exchanger of a stacked type.
5 . A method for checking quality of a heat exchanger comprising: performing a liquid pressure test for the heat exchanger including a first flow path and a second flow path adjacent to the first flow path by filling the first flow path and the second flow path with a liquid in a pressurized state; discharging the liquid from the first flow path and the second flow path; promoting evaporation of the liquid remaining in the first flow path and the second flow path by reducing pressure inside each of the first flow path and the second flow path using a vacuum pump; and checking to determine whether liquid remains in the first flow path and the second flow path by filling each of the first and second flow paths with a gas having a reference dew point below a predetermined value, causing the gas to flow out of each of the first and second flow paths, and comparing a dew point of the gas flowing out to the reference dew point.
6 . A method for checking quality of a heat exchanger comprising: performing a liquid pressure test for the heat exchanger including a first flow path and a second flow path adjacent to the first flow path by filling the first flow path and the second flow path with a liquid in a pressurized state; discharging the liquid from the first flow path and the second flow path; and promoting evaporation of the liquid remaining in the first flow path and the second flow path by reducing pressure inside each of the first flow path and the second flow path using a vacuum pump; wherein the promoting evaporation of the liquid includes a first step of reducing pressure inside the first flow path and at the same time heating the heat exchanger, and a second step of reducing pressure inside the second flow path and at the same time heating the heat exchanger, and wherein the second step is performed before or after the first step.

Description

FIELD OF INVENTION The present invention relates to a method for checking quality of a heat exchanger. BACKGROUND ART As disclosed in JP S61-118643 A, performing a pressure resistance test of a heat exchanger after assembling the heat exchanger has been conventionally known. In JP S61-118643 A, a pressure resistance test after completion of assembly of a heat exchanger is performed by filling the heat exchanger with an aqueous solution (aqueous solution of ammonium carbonate and ammonium hydrogen carbonate) under a pressure of 45 kg/cm2, for example, to pressurize the inside of the heat exchanger. Performing the pressure resistance test enables quality of the heat exchanger to be checked. After the pressure resistance test, processing of blowing hot air at 230° C. with an air volume of 14 m3/min into the heat exchanger is also performed to dry the inside of the heat exchanger. The method disclosed in JP S61-118643 A uses hot air at 230° C. to perform hot air drying, and it takes four to five hours to complete the drying. This method requires a large amount of hot air to complete a quality check, so that cost for performing the quality check increases. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for checking quality of a heat exchanger that does not need to use a large amount of hot air. A method for checking quality of a heat exchanger according to an aspect of the present invention includes the steps of: performing a liquid pressure test for the heat exchanger including a first flow path and a second flow path adjacent to the first flow path by filling the first flow path and the second flow path with a liquid in a pressurized state; discharging the liquid from the first flow path and the second flow path; and promoting evaporation of the liquid remaining in the first flow path and the second flow path by reducing pressure inside each of the first flow path and the second flow path using a vacuum pump. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a heat exchanger of a stacked type to be checked using a method for checking quality; FIG. 2 is a diagram for describing a flow path structure of the heat exchanger; FIG. 3 is a diagram for describing each step of the method for checking quality; FIG. 4 is a diagram illustrating a heat exchanger when a first step is performed in the method for checking quality; FIG. 5 is a diagram illustrating a heat exchanger when a second step is performed in the method for checking quality; and FIG. 6 is a diagram illustrating a heat exchanger when a first step is performed in a method for checking quality according to another embodiment. DETAILED DESCRIPTION Embodiments of the present invention will hereinafter be described in detail with reference to the drawings. A method for checking quality according to the present embodiment is for a heat exchanger 10 of a stacked type illustrated in FIGS. 1 and 2. The method for checking quality is performed after manufacturing the heat exchanger 10 and before shipping the heat exchanger 10 to a customer. Before the method for checking quality is specifically described, a configuration of the heat exchanger 10 will be first described. The heat exchanger 10 to be checked for quality is not limited to the heat exchanger 10 illustrated in FIGS. 1 and 2 as long as it is a heat exchanger of a stacked type, and may be, for example, a plate heat exchanger including many stacked plates and a gap between the corresponding plates formed as a flow path. Alternatively, the heat exchanger 10 may be a microchannel heat exchanger configured such that many plates having surfaces provided with many grooves are stacked each other to form many flow paths between corresponding plates adjacent to each other by bonding the corresponding plates to each other. The heat exchanger 10 may be made of an aluminum material, or may be made of stainless steel, titanium, or the like. The heat exchanger 10 illustrated in FIGS. 1 and 2 is a plate fin heat exchanger configured to perform heat exchange between a first fluid and a second fluid. The heat exchanger 10 is provided with headers 11 and 12 for the first fluid, and headers 13 and 14 for the second fluid, which are attached. The headers 11 and 12 for the first fluid include a first distribution header 11 through which the first fluid passes before flowing into the heat exchanger 10, and a first collection header 12 through which the first fluid having flowed out of the heat exchanger 10 passes. Then, the headers 13 and 14 for the second fluid include a second distribution header 13 through which the second fluid passes before flowing into the heat exchanger 10, and a second collection header 14 through which the second fluid having flowed out of the heat exchanger 10 passes. The heat exchanger 10 includes many partition plates 21 each formed of a flat plate, and fin plates 22 that are each in a corrugated shape and disposed between the corresponding partiti