| 摘要 |
PROBLEM TO BE SOLVED: To provide a feed water preheater which can improve the thermal efficiency of a water heater by recovering the sensible heat and latent heat of the waste gas from the water heater when the preheater is attached to the water heater. SOLUTION: The feed water preheater 33 has a water pipe composed of a stainless steel pipe, and a heat exchanger 34 which belongs to the water pipe and is constituted of stainless steel fins, and the preheater 33 is connected to the exhaust port of the main body of the water heater. Water is supplied to the water pipe of the heat exchanger 34 and the feed water flowing through the water pipe is supplied to the main body of the water heater. The feed water supplied to the main body is preheated through the heat exchange between the waste gas discharged from the main body and the feed water in the water pipe. In this case, the heat exchange is preformed sufficiently and the temperature of the waste gas discharged from the preheater 33 becomes the dew point of the waste gas or lower. Therefore, the steam in the waste gas condenses and the latent heat of the waste gas is utilized for preheating the feed water. The condensed water is discharged from a drainage discharge port 35. |
