CN211069625U

CN211069625U - Denitration urea injection system

Info

Publication number: CN211069625U
Application number: CN201920947984.2U
Authority: CN
Inventors: 郭祖光; 侯海军; 谭琦; 云川; 张浩军; 王建东; 赵士杰; 刘志林; 陈真; 阙培新
Original assignee: Douhe Power Plant Of Datang International Power Generation Co ltd
Current assignee: Douhe Power Plant Of Datang International Power Generation Co ltd
Priority date: 2019-06-21
Filing date: 2019-06-21
Publication date: 2020-07-24
Anticipated expiration: 2029-06-21

Abstract

The utility model provides a denitration urea injection system, which comprises a plurality of spray guns, a urea supply pipe and an atomization compressed air supply pipe, wherein the urea supply pipe and the atomization compressed air supply pipe are respectively composed of a main pipe and branch pipes connected with the spray guns, and are also provided with a purging pipe, the purging pipe is composed of an A pipe section and a B pipe section, and the A pipe section and the B pipe section are tightly connected through flanges; the atomized compressed air main pipe is provided with a first transition pipe with an inlet and a second outlet, the pipe section A is connected to one of the outlets, and the pipe section A is provided with an isolation valve; be equipped with two transition pipes two that advance one on the urea supply pipe, the B pipeline section is connected on one of them entry, is equipped with isolated valve on the B pipeline section, and this structure effectively solves the sparge water and stores up in the pipeline, freezes under the extremely cold weather and blocks up the pipeline, influences the input of ammonia system, leads to nitrogen oxide's the emission that exceeds standard, guarantees that the unit operation reaches the environmental protection requirement.

Description

Denitration urea injection system

Technical Field

The utility model discloses thermal power factory deNOx systems technique, concretely relates to denitration urea injection system of prevention pipe blockage.

Background

At present, in a selective catalytic reduction denitration (SCR) process, most reducing agents adopt a urea method ammonia preparation system, urea solution is conveyed to a storage tank and then conveyed to a urea solution metering module by a high-flow circulating pump, enters a urea spray gun through an adjusting valve and reacts in a pyrolysis furnace to generate ammonia gas, and then the ammonia gas enters a flue to react with nitrogen oxides in flue gas to generate nitrogen gas and water so as to reduce the concentration of the nitrogen oxides in the flue gas.

In the prior art, when a distribution and metering module of a denitration system is in a standby period, a pipeline is frozen and blocked in extremely cold weather, so that the denitration system breaks down when put into operation again, and the ammonia gas is frequently supplied to the denitration system. The reason for this is that the frozen urea solution pipeline washing water in the pipeline, and this part of washing water is input into the pipeline for urea washing after urea supply is stopped, and there is some washing water in the pipeline after the pump is stopped, and it can not be completely discharged.

The phenomenon of blockage caused by freezing of washing water causes the frequent occurrence of the accident of excessive discharge of nitrogen oxides, and the safe, economic and environment-friendly operation of a unit is seriously influenced.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a wash water stores up among the solution prior art urea pipeline, blocks up the problem of pipeline after freezing.

The utility model discloses a solve the solution that above-mentioned technical problem provided and be:

a denitration urea injection system comprises a plurality of spray guns, a urea supply pipe and an atomization compressed air supply pipe, wherein the urea supply pipe and the atomization compressed air supply pipe are respectively composed of a main pipe and branch pipes connected with the spray guns, the denitration urea injection system is also provided with a purging pipe, the purging pipe is composed of a pipe section A and a pipe section B, and the pipe section A and the pipe section B are tightly connected through flanges; the atomized compressed air main pipe is provided with a first transition pipe with an inlet and a second outlet, the pipe section A is connected to one of the outlets, and the pipe section A is provided with an isolation valve; the urea supply pipe is provided with a second transition pipe with two inlets and one outlet, the section B is connected to one of the inlets, and the section B is provided with an isolation valve.

Specifically, the first transition pipe, the second transition pipe, the pipe section A and the pipe section B are arranged in the small metering and distributing space of the denitration urea injection system in the whole process.

Specifically, the isolation valves of the section A and the section B are ball valves.

The second transition pipe is arranged at a position which is equivalent to the pipe pass distance of each spray gun and the flushing water valve.

The utility model discloses effectively solve the sparge water and store up in the pipeline, the freezing jam pipeline that blocks up under extremely cold weather, influence the input of ammonia system, lead to nitrogen oxide's emission that exceeds standard, guarantee that the unit operation reaches the environmental protection requirement.

Drawings

FIG. 1 is a layout diagram of the whole pipeline of the present invention;

FIG. 2 is a view showing the connection of a purge pipe and an atomized compressed air supply pipe;

FIG. 3 is a butt joint structure diagram of the pipe section A and the pipe section B.

In the figure: the device comprises a urea supply pipe 1, a washing water valve 2, a purging pipe 3, a pipe section A31, a pipe section B32, a flange 33, an atomized compressed air supply pipe 4, an atomized compressed air valve 5, a first transition pipe 6, a spray gun 7, an isolation valve 8 and a second transition pipe 9.

Detailed Description

The following detailed description of the embodiments of the present invention is made with reference to the accompanying drawings:

as shown in fig. 1-3, a denitration urea injection system comprises a plurality of spray guns 7, a urea supply pipe 1 and an atomized compressed air supply pipe 4, wherein the urea supply pipe 1 and the atomized compressed air supply pipe 4 are respectively composed of a main pipe and branch pipes passing through the spray guns, and a purging pipe 3 is further arranged, the purging pipe 3 is composed of an a pipe section 31 and a B pipe section 32, and the a pipe section 31 and the B pipe section 32 are tightly connected through a flange 33; the atomized compressed air main pipe is provided with a first transition pipe 6 with an inlet and a second outlet, the pipe section A31 is connected to one of the outlets, and the pipe section A31 is provided with an isolation valve 8; the urea supply pipe 1 is provided with a two-in one-out transition pipe II 9, a pipe B section 32 is connected to one of the inlets, and the pipe B section 32 is provided with an isolation valve 8.

Specifically, the first transition pipe 6, the second transition pipe 9, the A pipe section 31 and the B pipe section 32 are arranged in the denitration urea injection system metering and distributing chamber in the whole process.

Two DN20 stainless steel manual isolation doors are arranged on the section A pipe 31 and the section B pipe 32. The B-section pipe 32 and the three-way spray gun 7 front flushing water main pipe

The stainless steel pipe is in transitional connection with a washing water pipe, namely a urea supply pipeline main pipe.

The utility model discloses application method: a. in the ammonia supply denitration process, two sections of the blowing pipe 3 are in an off state, the two isolation valves 8 are guaranteed to be closed, and the original denitration work is normally carried out. b. When water washing is carried out, the urea supply pipe 1 is connected with a washing water pump, a washing water valve 2 is opened, and the pipeline is washed normally according to the original operation. c. After the washing is finished, the washing water pump is closed, the opening state of the washing water valve 2 is kept, the purging pipe 3 is connected, then the atomizing compressed air valve 5 and the two isolation valves 8 on the purging pipe 3 are opened, high-pressure air enters the urea supply pipe 1, washing water stored in the pipe is blown to each spray gun 7, and the water stored in the main pipe is flushed back to the back of the washing water valve 2.

Preferably, the second transition duct 9 is positioned at a distance from the respective lance 7 and the pipe side of the flush water valve 2.

The utility model discloses after washing finishing, close rinsing water main door and urea solution door, sweep each spray gun and pipeline with compressed air, do not have in the effective protection pipeline and deposit water, solved because of the problem of the freezing jam pipeline of rinsing water.

Claims

1. The utility model provides a denitration urea injection system, includes a plurality of spray guns, urea supply tube and atomizing compressed air supply tube, and urea supply tube and atomizing compressed air supply tube all comprise female pipe and the branch pipe of connecting each spray gun, characterized by: the device is also provided with a purging pipe, the purging pipe consists of a pipe section A and a pipe section B, and the pipe section A and the pipe section B are tightly connected through a flange; the atomized compressed air main pipe is provided with a first transition pipe with an inlet and a second outlet, the pipe section A is connected to one of the outlets, and the pipe section A is provided with an isolation valve; the urea supply pipe is provided with a second transition pipe with two inlets and one outlet, the section B is connected to one of the inlets, and the section B is provided with an isolation valve.

2. The denitration urea injection system according to claim 1, wherein: the first transition pipe, the second transition pipe, the pipe section A and the pipe section B are arranged in the small metering and distributing space of the denitration urea injection system in the whole process.

3. The denitration urea injection system according to claim 2, wherein: the isolation valves of the section A and the section B are ball valves.