| 摘要 |
PURPOSE:To make it possible to use effectively the energy of a high temperature exhaust heat source as a low temperature heat source by a method wherein the steam generating from a steam generating device and water are sealed as heat medium into heat transfer tubes connected to the water supply side of the heat exchanger. CONSTITUTION:When a boiler is started, water is supplied from a water supply line 26 into a steam drum 27 up to a predetermined level. In this case, boiler water is also introduced from a water drum 27' into each of element tubes 5 within an air preheater A through a water filling pipe 32 and a water filling valve 33 by opening a main boiler water filling valve 31. Then a high pressure blower 1' is operated and after purging the interior of a combustion furnace 20, a burner 19 is ignited to thereby elevate the pressure in the furnace 20. Further, when the level of the water in each of the element tubes 5 lowers below a reference level, water is supplied into the tube 5 by opening the water filling valve 33 and when it rises above the reference level, the superfluous water is blown out from a water level adjust valve 11. In addition, with the elevation of the pressure in the steam drum 27, the pressure in each of the element tubes 5 also elevates and when it reaches a predetermined value, a safety valve 10 is operated. Thus, in the above condition, the pressure and the level of the water in each of the element tubes 5 are kept at the predetermined values, respectively, and the pressure in the boiler is increased to thereby increase the load. |
