System and method capable of carrying out flue gas denitration and efficiency increasing through ozone

[0024] Example 1:

[0025] Such as figure 1 As shown, a system that uses ozone for flue gas denitration and efficiency enhancement includes a circulating fluidized bed boiler 1 and an online monitoring system. The gas outlet pipe of the circulating fluidized bed boiler 1 is connected with a cyclone separator 2, and the main part of the cyclone separator 2 The function is to remove the solid particles carried in the flue gas as much as possible. The gas outlet pipe of the cyclone separator 2 is connected with a flue 6, and the flue 6 is sequentially provided with a high temperature economizer 3, a denitration catalyst 4, and a medium/low temperature coal saving The outlet pipe of the circulating fluidized bed boiler 1 is connected with an ozone generating system. The ozone generating system can generate ozone and deliver the ozone to the outlet pipe of the circulating fluidized bed boiler 1, and the inlet pipe of the cyclone separator 2 and Ammonia water supply system is connected to the air outlet pipe. The ammonia water supply system can produce ammonia water and deliver the ammonia water to the inlet and outlet of the cyclone separator 2. The flue 6 is provided with a soot blowing system for cleaning the surface of the denitration catalyst 4 , The setting of the soot blowing system can ensure that the denitration catalyst 4 plays an effective role. The entire system is controlled by the DCS system. When the entire system is running, the high oxidizing property of ozone is used to couple the SNCR+SCR method to improve the denitration efficiency, thereby Meet high NO x It requires only one layer of denitration catalyst 4, which is arranged between the high temperature economizer 3 and the medium/low temperature economizer 5, which can save space and investment; among them, the medium/low temperature economizer 5 refers to You can use medium temperature economizer or low temperature economizer.

[0026] The ozone generation system includes an ozone generator 71, an ozone supply valve 72 and an ozone spray gun 73 connected in sequence. The various components are connected by pipelines to deliver ozone to a set position. The ozone spray gun 73 is arranged at the outlet of the circulating fluidized bed , Arrange 2-4 on both sides respectively, arranged vertically, the two spray guns on both sides are opposite, and each spray gun is inserted vertically into the outlet pipe of circulating fluidized bed boiler 1, which can ensure the sufficient supply of ozone. The ozone supply valve 72 is a pneumatic valve, which can easily control the delivery of ozone.

[0027] The ammonia water supply system includes an ammonia water storage tank 81, an ammonia water metering pump 82, and an ammonia water spray gun 83 which are connected in sequence. The various components are connected by pipelines. The ammonia water spray gun 83 is respectively arranged on the air inlet pipe and the air outlet pipe of the cyclone 2, thereby connecting The ammonia is delivered to the set position. Two to four ammonia spray guns 83 are arranged on both sides of the inlet of the cyclone 2 respectively, which are arranged along the vertical direction. The ammonia spray guns 83 on both sides are opposed to each other, and two ammonia spray guns 83 are arranged at the outlet. Each ammonia spray gun 83 is vertically inserted into the pipeline to ensure a sufficient supply of ammonia, and the ammonia metering pump 82 is a variable frequency pump, which can facilitate the control of the delivery of ammonia.

[0028] The online monitoring system includes a first pressure transmitter 91 disposed between the denitration catalyst 4 and the high temperature economizer 3, a second pressure transmitter 92 disposed between the denitration catalyst 4 and the medium/low temperature economizer 5, The ammonia leak detector 93 and the NOx/O2 analyzer 94, the first pressure transmitter 91 and the second pressure transmitter 92, which are arranged at the outlet end of the flue 6, can measure the pressure of the flue gas in the pipe and transmit the pressure signal To the DCS system, the settings of the ammonia leak detector 93 and the NOx/O2 analyzer 94 can monitor the NH in the flue gas 3 , NO x And O 2 The signal is transmitted to the DCS system, which is convenient for controlling the operation of the entire system through these signals.

[0029] The soot blowing system includes a compressed air tank 101, a pressure reducing valve 102, a third pressure transmitter 103, a solenoid valve 104 and a soot blower 105 which are connected in sequence. The various components are connected by pipelines. The compressed air tank 101 is compressed The air can be blown out from the outlet of the soot blower 105, so that the dust on the surface of the denitration catalyst 4 can be removed.

[0030] The outlet end of the soot blower 105 is connected with a protective device 106, such as figure 2 As shown, the protective device 106 includes a housing 212 with a ventilation cavity 201, one end of the housing 212 is provided with an air inlet 202 for connecting with the outlet end of the soot blower 105, and an air outlet plate 211 is slidingly connected in the ventilation cavity 201, The air outlet plate 211 is provided with an air outlet 207, one end of the air outlet plate 211 close to the air inlet 202 is provided with a return spring 203 connected to the side wall of the housing 212, and the other end of the air outlet plate 211 is provided with a plurality of support rods 208, The same dust-proof cover 206 is connected to the multiple support rods 208. Because the soot blower 105 is used in a very dusty environment, the nozzle hole at the outlet end of the soot blower 105 is often blocked, which affects the soot blower 105 Therefore, the outlet end of the soot blower 105 is connected with the air inlet 202 of the housing 212. When the compressed air is blown from the outlet end of the soot blower 105, the compressed air will blow onto the dust cover 206 and then overcome the return spring 203 The air outlet plate 211 is driven by the support rod 208 to slide in the ventilation chamber 201 after the spring force of the pressure, so that the compressed air can be smoothly discharged from the air outlet 207. When no compressed air is discharged, under the action of the return spring 203, the air outlet plate 211 The support rod 208 drives the dust cover 206 to move, thereby closing the opening of the ventilation cavity 201 to prevent dust from entering the ventilation cavity 201 and blocking the outlet hole 207 or the spray hole on the soot blower 105.

[0031] The end of the housing 212 away from the air inlet 202 is provided with an inner closed ring 204. The dust cover 206 is provided with an outer closed ring 205 corresponding to the inner closed ring 204. The diameter of the inner closed ring 204 is smaller than the diameter of the outer closed ring 205. When the dust cover 206 moves under the action of the return spring 203, the outer closed ring 205 just covers the inner closed ring 204, which can effectively prevent dust.

[0032] The outer surface of the inner closed ring 204 is provided with a first closed slope 210, so that the wall thickness of the inner closed ring 204 gradually decreases toward the outer closed ring 205, and the inner surface of the outer closed ring 205 is provided with a first closed slope The second closed slope 209 matched with 210 makes the wall thickness of the outer closed ring 205 gradually increase away from the outer closed ring 205. The arrangement of the first closed slope 210 and the second closed slope 209 can improve the outer closed ring 205 and the inner closed ring 205. The degree of adhesion between the closed rings 204 improves the sealing effect.