Heat exchanger and tube for heat exchanger

Abstract

A heat exchanger and its tubes, wherein the heat exchanger includes a core 300a, having a lamination of flat tubes 301 for flowing a refrigerant and corrugated fins 302, and tanks 310 having slots for insertion of the ends of tubes, the core is configured to have the flat surfaces of the tubes in parallel with the airflow direction, and the tubes have their ends 301a twisted in the width direction by 90° with respect to the airflow direction. A heat exchanger for a supercritical refrigeration cycle has tanks 310a, 310c displaced in a direction orthogonal to the airflow direction on one side of plural cores 300a, 300b which are overlaid in the airflow direction, and an inlet 320 and an outlet 330 for the refrigerant are oriented toward the windward side or the downwind side of the airflow direction.

Description

TECHNICAL FIELD [0001] The present invention relates to a heat exchanger, which is provided with a core comprising flat tubes for flowing a refrigerant and corrugated fins, and tanks with slots for insertion of the ends of the tubes, and carries out heat exchange by flowing air to the core and transferring heat to the core. BACKGROUND ART [0002] A heat exchanger such as a radiator or an evaporator to be used for a refrigeration cycle is known that a core is comprised of plural flat tubes and plural corrugated fins, stacked alternately and the ends of the tubes are inserted into pipe-shape tanks. The flat surfaces of the tubes are configured to be parallel with an airflow direction. The refrigerant is introduced inside from the tank, flowed through the tubes while carrying out heat exchange with heat transferred to the core and discharged outside from the tank. [0003] As the refrigerant for the refrigeration cycle, a fluorocarbon refrigerant including a substitute fluorocarbon has be...

AI Technical Summary

Benefits of technology

[0008] Specifically, according to the present invention, there is an advantage that the width of the tubes can be determined appropriately because it is not restrained by the inner diameter of the tanks. Further, because the flat surfaces of the tubes do not face the passage of the refrigerant within the tanks, a situation where a high flow passage resistance is produced in the refrigerant passage can be avoided, and a pressure loss can be reduced. Besides, when the twist angle of the tube ends in the width direction is 90°, the slots are formed along the longitudinal direction of the tanks, and there is an advantage that they can be formed with ease. Specifically, in the case where the twist angle of the tube ends in the width direction is less than 900 and the slots are formed in a slanting direction to the longitudinal direction of the tanks, the fabrication of the tanks involves some difficulties, but according to the present invention such a disadvantage can be avoided. Further, the tubes can be assembled with ease in comparison with the case that the slots are formed in a slanting direction.

[0049] Specifically, with the present invention the two tanks on one side of the first core and of the second core are displaced in the direction orthogonal to the airflow direction, thereby to determine the diameters of the individual tanks to a prescribed size and also to prevent them from mutually interfering. Such a structure is very effective for the heat exchanger for the supercritical refrigeration cycle having a large difference between the outer and inner diameters of the tanks. By displacing the tanks as described above, the inlet and the outlet of the individual tanks can be oriented toward the windward side or the downwind side of the airflow direction, and the piping structure in the layout of the refrigeration cycle can be simplified.

Problems solved by technology

Here, when the tanks are made thick, there is a disadvantage that the width of the tubes to be inserted into the tanks must be made extremely small with respect to the outer diameter of the tanks.

In other words, the tank having a large thickness has a large difference between the outer diameter and the inner diameter, and has disadvantages that the width of the tube to the outer diameter of the tank is extremely small to insert the ends of the tube having a prescribed width along the longitudinal direction, resulting in unsatisfactory width of the core with respect to mounting space of the heat exchanger.

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