| 摘要 |
PROBLEM TO BE SOLVED: To improve heat exchange efficiency with a water tube prevented from clogging up due to adhered (precipitated) calcium, in a heat exchanger which effects heat exchange between supply hot water and a refrigerant (carbon dioxide). SOLUTION: A refrigerant tube 221 and a water tube 223 (a water tube body 223a) are disposed in an orthogonal crossing state, and an inner fin 223f is disposed in the water tube 223. This constitution increases heat transfer area between supply hot water and the water tube 223, and brings supply hot water flowing through the water tube 223, into a turbulent flow state as a result of the supply hot water being disturbed by the inner fin 223f and increases the heat transfer efficiency between water and the water tube 223. Thereby, since even if the passage cross section of the water tube 223 is set to a large value, a heat exchange efficiency is prevented from large decrease, the passage cross section of the water tube 223 can be set to large, anticipating the amount of adhered calcium. |
