| 摘要 |
PURPOSE:To improve the average heating operation efficiency and reduce the uncomfortable feeling during the defrosting operation by disposing tubular or columnar objects on the upstream side of the fin leading edge on the air flow upstream side of a heat transmission pipe, said tubular or columnar objects being so situated as to include the fin leading edge in their dead water area. CONSTITUTION:Dummy pipes 14 are fastened to the end plates 15 on the upstream side of the fin leading edge 13 which is located on the air flow upstream side. during the heating operation, as there is less fresh air flow supply to the fin leading edge 13 located in the dead water area of the dummy pipes 14, and the ratio of heat exchange by means of the humidity gradient is increased, the frosting rate is significantly reduced in comparison with the case where the dummy pipes are not provided. The fin leading edge 15 located between the heat transmission pipes 13 experiences an increased rate of heat exchange due to the accelerated air flow by the dummy pipes 14 as well as the increased frosting. However, because the air speed is increased, the frosting lengthwise of the fin 11 becomes more uniform, and does not reduce the minimum width of the air flow passage. |
