Radiant Superheater

Abstract

A radiant superheater arranged to hang at the upper portion of a furnace of a boiler. The radiant superheater is substantially planar and includes a first vertical pass, a first connection pass, a second vertical pass, a third vertical pass, a second connection pass, and a fourth vertical pass. Each vertical pass includes an upper end and a lower end. The vertical passes are connected in series, so that steam to be superheated enters at the upper end of the first vertical pass and flows through the first vertical pass and from the lower end of the first vertical pass via the first connection pass to the lower end of the second vertical pass and through the second vertical pass and from the upper end of the second vertical pass to the upper end of the third vertical pass and through the third vertical pass and from the lower end of the third vertical pass via the second connection pass to the lower end of the fourth vertical pass and through the fourth vertical pass, to be discharged from the upper end of the fourth vertical pass. The first connection pass is arranged below the second connection pass so as to shield the second connection pass from radiation from the lower portion of the furnace.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a radiant superheater. More particularly, the present invention relates to a radiant superheater arranged to hang at the upper portion of a furnace of a boiler, especially, of a supercritical or ultra supercritical pulverized coal firing boiler.[0003]2. Description of the Related Art[0004]In practice, all power boilers of today have superheaters (SH), i.e., heat exchangers, in which the temperature of high pressure steam produced in an evaporator is raised above the saturation temperature. Superheated steam is then conducted to a high pressure steam turbine to produce steam power. Many boilers also comprise a reheater, in which the temperature of lower pressure steam released from the high pressure steam turbine is raised again, in order to produce more power by an intermediate pressure steam turbine. In the following, the term “superheater” may refer to either an actual superheater or a...

AI Technical Summary

Benefits of technology

[0009]An object of the present invention is to provide a radiant superheater by which the problems of the prior art mentioned above are minimized.

Problems solved by technology

Due to high flame temperature in the furnace, the durability of radiant superheaters may suffer from overheating.

The above-mentioned prior art solutions may adversely alter the heat duty among the superheating stages, and thus, lower the thermal efficiency of the boiler, or they address primarily convective dominant heat transfer.

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