| abstract |
(57) [Abstract] [Object] An object of the present invention is to provide a heat transfer tube with a cross groove having high heat transfer performance to a mixed refrigerant, and a heat exchanger using the same. [Structure] In a heat transfer tube with a cross groove, a sub-groove 1b is provided in parallel with the tube axis, or a burr 3 is provided on a three-dimensional projection to induce a refrigerant flow into the sub-groove 1b. Further, in the heat exchanger using this heat transfer tube, the number of refrigerant paths is changed on the way so that the number of outlets is smaller than the number of inlets. [Effect] The concentration boundary layer formed on the three-dimensional projection is thinned, and a heat transfer tube with a cross groove having high heat transfer performance can be provided. Furthermore, by changing the refrigerant path, the mass velocity can be kept as high as possible, which results in A heat exchanger for mixed refrigerant having high heat transfer performance can be provided. |