| 摘要 |
PURPOSE:To increase an inner surface area, generate some effects of evaporation and condensation cores and improve an efficiency of heat exchanging operation by a method wherein several inner fins are arranged at an inner wall of a coolant passage and a flat part is arranged between the adjoining inner fins. CONSTITUTION:Several inner fins 16 are arranged at an inner wall of a coolant passage 13 of a flat heat exchanging pipe 11 and a flat part 8 is arranged between the adjoining inner fins 16. Oil 17 circulating in a cooling system is accumulated on the flat part 8 and the inner fins 16 sufficiently project from the oil 17, thereby the effects of increasing of an inner surface area and forming of evaporation and condensation cores are sufficiently generated. |
