Wet flue gas desulfurization apparatus and operation method for wet flue gas desulfurization apparatus

Patent metadata

Field	Value
Publication number	US-2018200667-A1
Application number	US-201615745794-A
Country	US
Kind code	A1
Filing date	Jul 15, 2016
Priority date	Jul 23, 2015
Publication date	Jul 19, 2018
Grant date	—

Abstract

Flue gas generated when fuel is subjected to combustion by a combustor such as a boiler is supplied, and a sulfur oxide is reduced or removed from the supplied flue gas. A desulfurization apparatus 10 A includes an absorber 11 , a gas introduction unit 13 a , an absorbent jetting unit 15 , a plurality of water flow oxidation devices 20 , an absorbent supplying unit 25 , a demister 30 , a gas discharging unit 13 b , and a control device 40 that varies the number of water flow oxidation devices 20 that jet absorbent 14 and air 21 based on a rate of the sulfur compound in the absorbent 14 within an absorbent storage tank 11 A.

First claim

1 . A wet flue gas desulfurization apparatus comprising:
an absorber that includes an absorbent storage tank for storing absorbent and a flue gas passage through which flue gas discharged from a combustor passes, the absorber bringing the flue gas into contact with the absorbent to cause the absorbent to absorb a sulfur oxide included in the flue gas: a gas introduction unit that is arranged on an upper side wall of the absorber, and introduces the flue gas into the absorber; an absorbent jetting unit that is arranged in the flue gas passage and jets the absorbent into a space of the absorber; an absorbent circulation line that supplies the absorbent to the absorbent jetting unit from the absorbent storage tank; a plurality of water flow oxidation devices that jet part of the absorbent branched and introduced from the absorbent circulation line into an inside of the absorbent storage tank together with air; and a control device that adjusts any one or both of a jetting amount of the absorbent jetted from the water flow oxidation device and a supply amount of the air supplied to the water flow oxidation device based on any one or both of a rate of a sulfur compound included in the flue gas and a rate of a sulfur compound in the absorbent within the absorbent storage tank.

2 . The wet flue gas desulfurization apparatus according to claim 1 , wherein the control device executes any one or both of control for varying the number of operations of the water flow oxidation devices and control for varying a circulation amount of the absorbent circulated into the water flow oxidation device.

3 . The wet flue gas desulfurization apparatus according to claim 1 , wherein the control device executes control for varying an amount of the air supplied to the water flow oxidation device with a valve.

4 . The wet flue gas desulfurization apparatus according to claim 1 , wherein the control device reduces the number of operations of the water flow oxidation devices when the rate of the sulfur compound included in the flue gas or the rate of the sulfur compound in the absorbent within the absorbent storage tank is lower than a predetermined threshold set in advance.

5 . The wet flue gas desulfurization apparatus according to claim 1 , wherein
the absorbent circulation line includes a plurality of circulation pumps, and when the rate of the sulfur compound included in the flue gas or the rate of the sulfur compound in the absorbent within the absorbent storage tank is lower than the predetermined threshold set in advance, the control device stops operations of some of the circulation pumps to reduce the circulation amount of the absorbent.

6 . The wet flue gas desulfurization apparatus according to claim 1 , comprising:
a plurality of air supply lines that supply air to the respective water flow oxidation devices; and valves that are arranged in the respective air supply lines and adjust the supply amount of the air, wherein when the rate of the sulfur compound included in the flue gas or the rate of the sulfur compound in the absorbent within the absorbent storage tank is lower than the predetermined threshold set in advance, the control device executes closing some of the valves or adjusts a degree of opening of the valves to reduce the amount of the air supplied to the water flow oxidation device.

7 . The wet flue gas desulfurization apparatus according to claim 1 , wherein the water flow oxidation device comprises:
a connection part connected to an absorbent branch line that branches part of the absorbent from the absorbent circulation line; a liquid supply passage that communicates with the connection part and includes a flow channel narrow part formed inside; and an air supply passage having an opening in a downstream area of the flow channel narrow part within the liquid supply passage.

8 . The wet flue gas desulfurization apparatus according to claim 1 , wherein, in stopping the operations of the water flow oxidation devices, the control device stops the operations of any of the water flow oxidation devices at intervals of every predetermined number in an arrangement direction of the water flow oxidation devices.

9 . The wet flue gas desulfurization apparatus according claim 1 , comprising:
an oxidation-reduction potential meter that measures oxidation-reduction potential within the absorbent storage tank, wherein the control device obtains the rate of the sulfur compound in the absorbent within the absorbent storage tank based on a measured value of the oxidation-reduction potential measured with the oxidation-reduction potential meter.

10 . The wet flue gas desulfurization apparatus according to claim 1 , wherein the control device adjusts any one or both of the jetting amount of the absorbent jetted from the water flow oxidation device and the supply amount of the air supplied to the water flow oxidation device based on at least one of values of a boiler load, inlet SO 2 concentration, outlet SO 2 concentration, and a desulfurization ratio, and the rate of the sulfur compound in the absorbent within the absorbent storage tank.

11 . The wet flue gas desulfurization apparatus according to claim 1 , comprising:
a stirring device within the absorbent storage tank, wherein the stirring device is started/stopped by the control device.

12 . The wet flue gas desulfurization apparatus according to claim 1 , comprising:
a blower that supplies the air to the water flow oxidation device, wherein, when the rate of the sulfur compound included in the flue gas or the rate of the sulfur compound in the absorbent is higher than the threshold, the control device increases the supply amount of the air supplied from the blower to the water flow oxidation device.

13 . The wet flue gas desulfurization apparatus according to claim 3 , comprising:
a blower that supplies the air to the water flow oxidation device, wherein, in adjusting the supply amount of the air supplied to the water flow oxidation device, when the rate of the sulfur compound included in the flue gas or the rate of the sulfur compound in the absorbent is lower than a threshold, the control device reduces the supply amount of the air supplied from the blower to the water flow oxidation device.

14 . An operation method for a wet flue gas desulfurization apparatus, the method comprising,
in removing a sulfur oxide in flue gas discharged from a combustor by bringing absorbent into contact with the sulfur oxide, the absorbent circulating in an absorbent circulation line from an absorbent storage tank including a water flow oxidation device that jets the absorbent and air, adjusting any one or both of a jetting amount of the absorbent jetted from the water flow oxidation device and a supply amount of the air supplied to the water flow oxidation device based on a rate of a sulfur compound included in the flue gas or a rate of a sulfur compound in the absorbent in the absorbent storage tank.

Assignees

• Mitsubishi Hitachi Power Sys

Inventors

• Kagawa Seiji
• Kamiyama Naoyuki
• Yoshimoto Takashi
• Ushiku Tetsu
• Sugita Satoru

Classifications

• B01D53/1481

  Removing sulfur dioxide or sulfur trioxide · CPC title

• B01D2251/404

  of calcium · CPC title

• B01D53/185 Primary

  Liquid distributors · CPC title

• B01D53/18 Primary

  Absorbing units; Liquid distributors therefor (B01D3/16, B01D3/26, B01D3/30 take precedence; packing elements B01J19/30, B01J19/32) · CPC title

• B01D53/1412

  Controlling the absorption process · CPC title