In-layer heat transfer pipe of fluidized bed furnace and fluidized bed furnace

Abstract

Provided is an in-bed heat transfer tube for a fluidized bed boiler, which has a sufficient heat transfer effect, and with which molten salt corrosion can be suppressed, thereby limiting the reduction in the thickness of the tube and providing excellent durability. This in-bed heat transfer tube (5) is configured from: an inner tube (6), in the interior of which a fluid (water, saturated water, steam, a binary fluid, or the like) flows; inner tube fins (37) provided on the outer circumference of the inner tube (6) as a securing part; and a protector (8), which is provided on the outer circumferential side of the inner tube (6) so as to form a 0.25-0.75 mm gap (7) therebetween, and which protects the inner tube (6). A pair of the inner tube fins (37) is affixed to the outer circumferential surface of the inner tube (6) by welding, and the protector (8) is affixed to the inner tube fins (37) by welding in the same manner. Multiple slits (81) with a width of 0.5 mm are formed in the protector (8) at 50 mm intervals.

Description

technical field [0001] The present invention relates to an inner layer heat pipe for burning fuels such as RDF (Refuse Derived Fuel: Garbage Derived Fuel) containing biomass or plastics with high calorific value and waste, and a fluidized bed furnace having the inner heat pipe. And recovery of combustion heat. Background technique [0002] In recent years, efficient use of energy has been pursued in response to rising prices of fossil fuels and global warming. Therefore, as a system functioning as a heat recovery (thermal recycle), a system that utilizes heat generated by combustion of RDF and waste to generate power has become increasingly important. As a heat recovery system of this power generation system, there is a system in which thermal energy generated by combustion of RDF and waste is recovered in a fluidized bed furnace through an in-layer heat transfer pipe. Since RDF and waste contain chlorine, in this method, when RDF and waste are burned in a fluidized bed fu...

AI Technical Summary

Problems solved by technology

However, if a shield is provided outside the heat pipe, there is a problem of hindering heat conduction.

In addition, if the heat transfer pipe itself is formed of high-chromium steel or stainless steel, although the thickness reduction due to wear is reduced, there is a concern that the durability will not be sufficient in an environment where the molten salt is corroded at the same time as the wear.

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