Fluid sand falling type circulating fluidized bed boiler with a plurality of risers and method of operating the same

Patent metadata

Field	Value
Publication number	US-2020025366-A1
Application number	US-201916401465-A
Country	US
Kind code	A1
Filing date	May 2, 2019
Priority date	Jul 19, 2018
Publication date	Jan 23, 2020
Grant date	—

Abstract

Disclosed herein are a fluid sand falling type circulating fluidized bed boiler with a plurality of risers for preventing erosion and corrosion of water tubes and increasing combustion efficiency, and a method of operating the same. The fluid sand falling type circulating fluidized bed boiler with a plurality of risers includes a boiler section into which fuel and oxidizer are injected, a riser section connected to the boiler section so that the fuel and fluid sand supplied from the boiler section are introduced from the bottom of the riser section and flow up, and a relay section provided on the boiler section to supply the fluid sand having passed through the riser section to the boiler section, wherein the fuel is injected from the top of the boiler section and burned while flowing down therein.

First claim

What is claimed is:

1 . A fluid sand falling type circulating fluidized bed boiler with a plurality of risers, comprising:
a boiler section into which fuel and oxidizer are injected; a riser section connected to the boiler section so that the fuel and fluid sand supplied from the boiler section are introduced from the bottom of the riser section and flow up; and a relay section provided on the boiler section to supply the fluid sand having passed through the riser section to the boiler section, wherein the fuel is injected from the top of the boiler section and burned while flowing down therein.

2 . The fluid sand falling type circulating fluidized bed boiler according to claim 1 , further comprising a plurality of water tube sections provided on an outer wall and in an internal space of the boiler section and extending in a height direction of the boiler section.

3 . The fluid sand falling type circulating fluidized bed boiler according to claim 1 , further comprising a plurality of oxidizer injection sections spaced apart from each other in a height direction of the boiler section and further provided in the lower portion of the riser section,
wherein each output of the oxidizer injection sections is individually controlled to control descending rates of the fluid sand and the fuel and combustion of the fuel.

4 . The fluid sand falling type circulating fluidized bed boiler according to claim 1 , further comprising a first fuel injection section provided at one side of the upper portion of the boiler section to inject the fuel into the boiler section.

5 . The fluid sand falling type circulating fluidized bed boiler according to claim 1 , further comprising a second fuel injection section provided at one side of the lower portion of the riser section to inject fuel, having a combustion rate higher than the fuel supplied into the boiler section, to the riser section.

6 . The fluid sand falling type circulating fluidized bed boiler according to claim 1 , wherein the riser section consists of a plurality of riser sections arranged along the circumference of the boiler section or in the inner portion of the boiler section.

7 . The fluid sand falling type circulating fluidized bed boiler according to claim 1 , further comprising a heat exchange section connected to the boiler section and the riser section to perform heat exchange using combustion gas produced by burning fuel.

8 . The fluid sand falling type circulating fluidized bed boiler according to claim 7 , further comprising a first cyclone section provided between the riser section and the relay section,
wherein the first cyclone section is provided to transfer the combustion gas heated while passing through the riser section to a final superheater or a repeater of the heat exchange section.

9 . The fluid sand falling type circulating fluidized bed boiler according to claim 7 , further comprising a second cyclone section connected to the upper portion of the boiler section,
wherein the second cyclone section serves to transfer the combustion gas produced in the boiler section to a convection heat exchanger of the heat exchange section.

10 . A method of operating the fluid sand falling type circulating fluidized bed boiler with a plurality of risers according to claim 1 , comprising:
a) a step of determining an operation mode or operation of each of a plurality of riser sections; b) a step of injecting fuel and oxidizer into the boiler section to burn the fuel; c) a step of transferring the fuel and fluid sand supplied from the boiler section to each of the riser sections to a first cyclone section; d) a step of transferring heated combustion gas transferred to the first cyclone section to a repeater of a heat exchange section and transferring the fluid sand to the relay section; and e) a step of resupplying the fluid sand transferred to the relay section to the boiler section, wherein the fuel is burned while flowing down in the boiler section, and the fuel is burned while flowing up in the riser section.

11 . The method according to claim 10 , wherein in the b) step, the combustion gas produced by burning the fuel in the boiler section is transferred to a convection heat exchanger of the heat exchange section through a second cyclone section.

12 . The method according to claim 10 , wherein in the b) step, each output of a plurality of oxidizer injection sections for injecting oxidizer into the boiler section is individually controlled to control descending rates of the fluid sand and the fuel and combustion of the fuel.

13 . The method according to claim 10 , wherein in the c) step, fuel, having a combustion rate higher than the fuel supplied into the boiler section, is further supplied to the riser section.

14 . The method according to claim 10 , wherein in the a) step, the operation mode is a pure oxygen combustion mode and an air combustion mode.

15 . A power generation plant using the fluid sand falling type circulating fluidized bed boiler with a plurality of risers according to claim 1 .

16 . A power generation system for oxidizer thermal power generation using a method of operating the fluid sand falling type circulating fluidized bed boiler with a plurality of risers according to claim 1 .

Assignees

• Korea Inst Ind Tech
• Korea Inst Energy Res
• Korea Inst Mach & Materials

Inventors

• Lee Uen Do
• Bang Byeong Ryeol
• Kim Young Doo
• Jeong Soo Hwa
• Yang Chang Won
• Lee Jae Goo
• Mun Tae Young
• Seo Myung Won
• Moon Ji Hong
• Park Hyun Seol
• Shim Joon Mok
• Park Young Cheol
• Shun Do Won
• Moon Jong Ho
• Bae Dal Hee
• Jo Sung Ho
• Hwang Yun Tae
• Keel Sang In
• Yun Jin Han
• Lee Chungkyu
• Heo Pil Woo

Classifications

• F23C2206/10

  Circulating fluidised bed · CPC title

• F23G2203/501

  with external recirculation of entrained bed material · CPC title

• F22B31/0084 Primary

  with recirculation of separated solids or with cooling of the bed particles outside the combustion bed · CPC title

• F23C10/20

  Inlets for fluidisation air, e.g. grids; Bottoms · CPC title

• F23C10/22

  Fuel feeders specially adapted for fluidised bed combustion apparatus (F23C10/26 takes precedence) · CPC title