HEAT EXCHANGER

摘要

In a heat exchanger, each of flat tubes (31) has an end portion inserted in a header-collecting pipe (70). When the heat exchanger functions as an evaporator, a refrigerant in a gas-liquid two-phase state upwardly flows in a subspace (71a) located in the header-collecting pipe (70). An effective cross-sectional area A of the subspace (71a) in the header-collecting pipe (70) is set based on a mass flow rate of the refrigerant flowing into the subspace (71a) in the header-collecting pipe (70). The effective cross-sectional area A is obtained by subtracting a projected area A1 which corresponds to a portion of each flat tube (31) located in the subspace (71a) and is projected onto a plane perpendicular to an axial direction of the header-collecting pipe (70) from an area A0 of a cross section of the subspace (71a) which is perpendicular to the axial direction of the header-collecting pipe (70).

主权项

1. A heat exchanger comprising:
a plurality of flat tubes; a first header-collecting pipe having inserted therein an end portion of each of the flat tubes; a second header-collecting pipe having inserted therein the other end portion of each of the flat tubes; and a plurality of fins joined to the flat tubes, the heat exchanger provided in a refrigerant circuit configured to perform a refrigerating cycle, wherein the second header-collecting pipe forms flow spaces which communicate with the plurality of flat tubes and in which a refrigerant being in a gas-liquid two-phase state flows upwardly when the heat exchanger functions as an evaporator, an effective cross-sectional area of the flow spaces is an area obtained by subtracting a projected area which corresponds to a portion of each flat tube located in a corresponding one of the flow spaces and which is projected onto a plane perpendicular to an axial direction of the second header-collecting pipe, from an area of a cross section of the corresponding one of the flow spaces which is perpendicular to the axial direction of the second header-collecting pipe, and the effective cross-sectional area of the flow spaces is set based on a mass flow rate at which the refrigerant flows into the flow spaces when the heat exchanger functions as the evaporator.