CN211098423U

CN211098423U - SCR denitration heating device

Info

Publication number: CN211098423U
Application number: CN201922060161.0U
Authority: CN
Inventors: 陈俊立; 郑书文; 郑力玮; 李乾实; 许庆斌
Original assignee: Laiwu Anbang Metallurgical Equipment Co ltd
Current assignee: Laiwu Anbang Metallurgical Equipment Co ltd
Priority date: 2019-11-23
Filing date: 2019-11-23
Publication date: 2020-07-28
Anticipated expiration: 2029-11-23

Abstract

The utility model discloses a rising temperature device of SCR denitration relates to flue gas denitration's technical field, has solved when internal coal-fired unit is in the low-load function, and SCR device's entry smoke temperature can be less than the best reaction temperature of SCR catalyst, causes the unsatisfactory problem of device denitration effect. The SCR catalytic device is characterized by comprising a main flue, a warming device and an SCR catalytic device, wherein the warming device comprises a temperature detector, a gas heater and a driving mechanism, the temperature detector is fixedly connected to the side wall of the main flue and is close to the warming device, the gas heater is arranged on the driving mechanism, and the driving mechanism is arranged on the side wall of one side of the main flue. When the internal combustion engine unit operates at a low load, if the temperature of the flue gas detected by the temperature detector is lower than 314 ℃, an electric signal is transmitted to the driving mechanism, so that the driving mechanism drives the gas heater to slide towards the middle of the main flue, the flue gas is sufficiently heated, and the flue gas reacts with the SCR device.

Description

SCR denitration heating device

Technical Field

The utility model belongs to the technical field of flue gas denitration's technique and specifically relates to a rising temperature device of SCR denitration is related to.

Background

At present, with the development of the electric power industry in China, the emission of NOX is increased day by day, and NOX in the atmosphere is not only a main source of photochemical smog formation, but also a main formation reason of acid rain around the country. Therefore, the state is forced to control the NOX emission of the thermal power plant by the regulation. In order to reduce the discharge amount of NOX, denitration devices are additionally arranged in power plants to treat flue gas, wherein the SCR denitration technology has high denitration efficiency and is applied to the high attention and wide application of the power industry due to the fact that the SCR denitration technology meets the current environmental protection requirement, and a large number of thermal power plants begin to adopt selective denitration devices (SCR). The optimal reaction temperature range of the SCR device is 320-400 ℃, and when the SCR device is operated at low load, namely the load is lower than 450MW, the temperature of the smoke at the inlet of the SCR device does not reach the requirement of the lowest allowable operation temperature (314 ℃) of the SCR device. In a 210-250 MW load interval, the flue gas temperature at the SCR inlet is even only 260-270 ℃, and the denitration system cannot be put into operation at all.

Chinese utility model patent publication No. CN108380044A discloses a selective catalytic reduction SCR denitration device, which comprises a nitrogen injection device and an SCR reactor with a catalyst, wherein the nitrogen injection device is connected with a boiler flue and used for injecting a reducing agent into the boiler flue so as to sufficiently mix flue gas and the reducing agent, and the SCR reactor with the catalyst is connected to a junction of the nitrogen injection device and the boiler flue and used for receiving a mixed gas of the flue gas and the reducing agent; the SCR reactor is configured to generate microwave radiation beams capable of completely covering the inner area of the SCR reactor when the mixed gas enters the SCR reactor, and the catalyst and the mixed gas are rapidly heated through the microwave radiation beams, so that the temperature of flue gas in the mixed gas reaches a preset temperature value, and the reducing agent and nitrogen oxides in the flue gas rapidly generate oxidation-reduction reaction.

The above prior art solutions have the following drawbacks: when the domestic coal-fired unit operates at low load, the inlet smoke temperature of the SCR device is often lower than the optimal reaction temperature of the SCR catalyst, sometimes even lower than the normal reaction temperature, so that the denitration effect of the device is not ideal, and the smoke gas still difficultly reaches the emission standard after the denitration of the device.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a SCR takes off round pin device has the effect that improves the entrance cigarette temperature, makes catalyst and flue gas fully react.

The above object of the present invention can be achieved by the following technical solutions:

the utility model provides a rising temperature device of SCR denitration, includes the flue stack, sets up rising temperature device and fixed connection in the SCR catalytic unit of flue stack afterbody on flue stack one end lateral wall, rising temperature device includes thermodetector, gas heater and actuating mechanism, thermodetector fixed connection is on the lateral wall of flue stack to be close to rising temperature device, actuating mechanism sets up on the lateral wall of flue stack one side, gas heater sets up on actuating mechanism.

Through adopting above-mentioned technical scheme, when the temperature detector detected the temperature of flue gas and is greater than 134 ℃, then can not start actuating mechanism, when the internal-combustion engine group was in the underload operation, the temperature detector detected the temperature of flue gas and was less than 314 ℃ then give actuating mechanism with electric signal transmission, and actuating mechanism begins to rotate to the slip of drive gas heater makes the temperature of gas heater heating flue gas, thereby makes flue gas and SCR catalytic unit react.

Further: the lateral wall of flue duct one side has been seted up and has been held the chamber, gas heater sliding connection holds the intracavity.

Through adopting above-mentioned technical scheme, with gas heater sliding connection in hold the intracavity purpose, when using gas heater, can make gas heater slide out and hold the chamber and heat the flue gas. When the flue gas is not heated, the gas heater slides into the accommodating cavity.

Further: the driving mechanism comprises a motor, the motor is fixed on the side wall of the main flue, a first lead screw is coaxially and fixedly connected to an output shaft at one end of the motor, a first lead screw is connected with a first nut fixing seat in a threaded mode, a horizontal baffle is fixedly connected to the lower surface of the first nut fixing seat, and the baffle can completely shield the accommodating cavity.

Through adopting above-mentioned technical scheme, when the motor rotates, can drive the rotation of lead screw one, the rotation of lead screw one can drive the sideslip of its upper screw fixing base for baffle on the screw fixing base can cover or open holding the chamber, thereby can play the guard action to gas heater.

Further: the gas heater is characterized in that a first chain wheel is coaxially and fixedly connected to an output shaft of the other end of the motor, a second chain wheel is arranged right above the first chain wheel, the second chain wheel and the first chain wheel are in chain transmission, a worm is coaxially and fixedly connected to the second chain wheel, a worm wheel is arranged on one side of the worm, the worm wheel is meshed with the worm, a second lead screw is coaxially and threadedly connected to the worm wheel, and one end, far away from the worm wheel, of the second lead screw extends to the accommodating cavity and is fixedly connected with the.

Through adopting above-mentioned technical scheme, the rotation of motor other end output shaft can drive the rotation of sprocket one, and the rotation of sprocket one passes through the rotation that the chain drove sprocket two, and the rotation of sprocket two can drive the rotation of worm, and the rotation of worm can drive the rotation of worm wheel, and the rotation of worm wheel can drive two vertical slides of lead screw to make two drive gas heater of lead screw slide holding the intracavity.

Further: the lateral wall of the main flue is fixedly connected with a vertical supporting rod, and the worm is rotatably connected with the supporting rod.

Through adopting above-mentioned technical scheme, the bracing piece plays the supporting role to the worm, because the worm rotates with the bracing piece to be connected, so the worm is when rotating, and the rotation of worm wheel can not be influenced to the bracing piece.

Further: the lower end of the SCR catalytic device is fixedly connected with an economizer, and the lower end of the economizer is fixedly connected with an air preheater.

By adopting the technical scheme, the temperature of the discharged flue gas is reduced after the flue gas discharged from the SCR catalytic device is subjected to heat exchange between the economizer and the air preheater.

Further: the lower end of the first screw rod and the lower end of the motor are fixedly connected with a protective cover, and the protective cover is fixedly connected with the side wall of the main flue.

Through adopting above-mentioned technical scheme, at the lower extreme fixed connection protection casing of lead screw one and motor, the purpose alleviates the flue gas and causes the corruption to lead screw one and motor.

Further: the protective cover is made of polytetrafluoroethylene.

By adopting the technical scheme, the polytetrafluoroethylene is selected as the material of the protective cover, so that the polytetrafluoroethylene is high-temperature resistant and corrosion resistant, and the service life of the protective cover can be prolonged.

To sum up, the utility model discloses a beneficial technological effect does:

1. the SCR catalytic device is fixedly connected to the tail of the main flue, the heating device comprises a temperature detector, a gas heater and a driving mechanism, the temperature detector is fixedly connected to one side of the heating device, the gas heater is connected with the driving mechanism in a sliding mode, and the driving mechanism is arranged on the side wall of one side of the main flue. When the temperature detector detects that the temperature of the flue gas is higher than 134 ℃, the driving mechanism cannot be started, when the internal combustion engine set is in low-load operation, the temperature detector detects that the temperature of the flue gas is lower than 314 ℃, an electric signal is transmitted to the driving mechanism, the driving mechanism starts to rotate, and therefore the gas heater is driven to slide, the gas heater heats the temperature of the flue gas, and the flue gas reacts with the SCR catalytic device;

2. the first chain wheel is fixedly connected to the output shaft of the other end of the motor in a coaxial mode, the second chain wheel is arranged right above the first chain wheel and is in chain transmission with the first chain wheel, the worm is fixedly connected to the second chain wheel in a coaxial mode, a worm wheel is arranged on one side of the worm and is meshed with the worm, the second lead screw is connected to the worm wheel in a threaded connection in a coaxial mode, and one end, far away from the worm wheel, of the second lead screw extends to the containing cavity and is fixedly. When an output shaft at the other end of the motor rotates, the first chain wheel is driven to rotate, the first chain wheel drives the second chain wheel to rotate through a chain, the second chain wheel drives the worm to rotate, the worm rotates to drive the worm wheel to rotate, and the worm wheel rotates to drive the second lead screw to vertically slide, so that the second lead screw drives the gas heater to slide in the accommodating cavity;

3. the side wall of the main flue is fixedly connected with a vertical supporting rod, and the worm is rotatably connected with the supporting rod. The support rod plays a supporting role for the worm, and the worm is rotationally connected with the support rod, so that the support rod cannot influence the rotation of the worm wheel when the worm rotates.

Drawings

FIG. 1 is a schematic view of the overall structure of the present embodiment;

fig. 2 is a partially enlarged schematic view of a in fig. 1.

The reference symbols: 1. a main flue; 2. a temperature raising device; 21. a temperature detector; 22. a gas heater; 23. a drive mechanism; 231. a motor; 232. a first lead screw; 233. a baffle plate; 234. a chain wheel I; 235. a second chain wheel; 236. a worm; 237. a worm gear; 238. a second screw rod; 25. a protective cover; 26. an accommodating chamber; 3. an SCR catalytic device; 4. a low temperature superheater; 5. a coal economizer; 6. an air preheater; 7. a nut fixing seat; 8. a support rod.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

An SCR denitration device is shown in FIG. 1 and comprises a main flue 1, a temperature rising device 2 (shown in FIG. 2) and an SCR catalytic device 3. The temperature rising device 2 is fixedly connected to the side wall of one side of the main flue 1 and used for heating flue gas in front of an inlet of the SCR catalytic device 3 to rise the temperature of the flue gas to reach the reaction temperature. The SCR catalytic device 3 is fixedly connected to the tail part of the main flue 1 and used for carrying out catalytic reaction on the flue gas.

As shown in fig. 2, a low-temperature superheater 4 is fixedly connected to an inlet of the main flue 1, and when flue gas enters the low-temperature superheater 4, saturated steam in the flue gas is heated into superheated steam, so that loss of flue gas is reduced, and thermal efficiency of the boiler is improved. The lower end of the low-temperature superheater 4 is fixedly connected with an economizer 5, and after the flue gas enters the economizer 5, the temperature of the flue gas is reduced through heat exchange of the economizer 5, so that the efficiency is improved. At SCR denitrification facility's lower extreme fixedly connected with air preheater 6, after the flue gas enters into SCR catalytic device 3, carry out catalytic reaction, discharge from SCR catalytic device 3's tail end afterwards, enter into and carry out the heat transfer in the air preheater 6 to reduce the temperature from the exhaust flue gas in the air preheater 6, the energy saving.

As shown in fig. 2, the temperature increasing device 2 is provided between the economizer 5 and the SCR catalytic device 3 (see fig. 1), and the temperature increasing device 2 includes a temperature detector 21, a gas heater 22, and a drive mechanism 23. An accommodating cavity 26 is formed in the side wall of the main flue 1, and the gas heater 22 is vertically and slidably connected in the accommodating cavity 26. The temperature detector 21 is fixedly connected to the side wall of the main flue 1 near the accommodating cavity 26. The driving mechanism 23 is disposed on a side wall of the main flue 1, and is used for driving the gas heater 22 to slide. When the temperature detector 21 detects that the temperature of the flue gas is too low, an electric signal is transmitted to the driving mechanism 23, and the driving mechanism 23 receives the electric signal and starts to drive the gas heater to slide towards the outside of the accommodating cavity 26, so that the flue gas is heated.

As shown in fig. 2, the driving mechanism 23 includes a motor 231 and a first lead screw 232, the motor 231 is fixedly connected to the side wall of the flue stack 1, and the first lead screw 232 is coaxially and fixedly connected to an output shaft at one end of the motor 231. The first lead screw 232 is in threaded connection with a nut fixing seat 7, a horizontal baffle 233 is fixedly connected to the nut fixing seat 7, and the accommodating cavity 26 can be completely blocked by the baffle 233.

As shown in fig. 2, a vertical second lead screw 238 is fixedly connected to the bottom end of the gas heater 22, and a worm wheel 237 is coaxially and threadedly connected to one end of the second lead screw 23 extending out of the accommodating cavity 26. A support rod 8 is vertically and fixedly connected to the side wall of the main flue 1, and a horizontal worm 236 is rotatably connected to the support rod 8. One end of the worm 236, which is far away from the worm wheel 237, is coaxially and fixedly connected with a second chain wheel 235, the output shaft at the other end of the motor 231 is coaxially and fixedly connected with a first chain wheel 234, and the second chain wheel 235 and the first chain wheel 234 are in chain transmission. When thermodetector 21 detected the temperature of flue gas lower, the signal of telecommunication gives motor 231 for the both ends output shaft of motor 231 begins to rotate simultaneously, sprocket 234 rotates with lead screw 232 simultaneously, sprocket 234 drives the rotation of sprocket two 235 through the chain, thereby drives the rotation of worm 236, and then drives the rotation of worm wheel 237, makes two 238 drive gas heater 22 with the lead screw of worm wheel 237 threaded connection slide outside holding chamber 26, and screw fixing base 7 drives the sideslip of baffle 233 simultaneously.

As shown in fig. 2, when the baffle 233 slides to the side edge of the accommodating chamber 26, the accommodating chamber 26 is completely opened, and the gas heater 22 slides vertically to the outlet edge of the accommodating chamber 26. The motor 231 then continues to rotate, causing the gas heater 22 to continue to slide out of the receiving cavity 26 until the gas heater 22 has completely slid out of the receiving cavity 26. The gas heater 22 starts to heat the flue gas, thereby raising the temperature of the flue gas so that the flue gas can reach the temperature of the catalytic reaction after entering the SCR catalytic device 3. The lower end of the first lead screw 232 and the lower end of the motor 231 are fixedly connected with the protective cover 25, the protective cover 25 is made of polytetrafluoroethylene, and due to the fact that the polytetrafluoroethylene is high-temperature resistant and corrosion resistant, corrosion of smoke to the first lead screw 232 and the motor 231 is reduced, and the service life of the protective cover 25 is prolonged.

The specific working process of this embodiment: when the internal combustion engine set is in low-load operation, the temperature of the flue gas is lower than the normal temperature. After the heat transfer of flue gas process low temperature over heater 4 and economizer 5, enter into main flue 1, temperature detector 21 detects the temperature of flue gas and is less than catalytic reaction's optimum temperature, and the transmission signal of telecommunication gives motor 231, and two output shafts of motor 231 begin to rotate to drive a lead screw 232 and rotate with a sprocket 234 simultaneously, the rotation of a lead screw 232 can make screw fixing base 7 drive baffle 233 and remove to the edge that holds chamber 26. Meanwhile, the rotation of the first sprocket 234 drives the second sprocket 235 to rotate through the chain, so as to drive the worm 236 to rotate, the rotation of the worm 236 drives the worm wheel 237 to rotate, and the rotation of the worm wheel 237 enables the second lead screw 238 to drive the gas heater 22 to slide out of the accommodating cavity 26. When the baffle 233 slides to the side edge of the receiving chamber 26 to fully open it, the gas heater 22 slides to the outlet edge of the receiving chamber 26. The motor 231 continues to rotate, and the gas heater 22 continues to slide out of the accommodating cavity 26 until completely sliding out of the accommodating cavity 26. The gas heater 22 then begins to heat the flue gas, thereby increasing the temperature of the flue gas so that the flue gas can undergo a catalytic reaction after entering the SCR catalytic device 3. After the catalytic reaction, the temperature of the flue gas discharged from the SCR catalytic device 3 is reduced after the heat exchange of the air preheater 6, so that the energy is saved.

Claims

1. The utility model provides a rising temperature device of SCR denitration, includes flue (1), sets up rising temperature device (2) and fixed connection in SCR catalytic unit (3) of flue (1) afterbody on flue (1) one end lateral wall, its characterized in that: the heating device (2) comprises a temperature detector (21), a gas heater (22) and a driving mechanism (23), wherein the temperature detector (21) is fixedly connected to the side wall of the main flue (1) and is close to the heating device (2), the driving mechanism (23) is arranged on the side wall of one side of the main flue (1), and the gas heater (22) is arranged on the driving mechanism (23).

2. The temperature raising device for SCR denitration according to claim 1, characterized in that: the lateral wall of main flue (1) one side has been seted up and has been held chamber (26), gas heater (22) sliding connection holds in chamber (26).

3. The temperature raising device for SCR denitration according to claim 1, characterized in that: actuating mechanism (23) includes motor (231), motor (231) fixed connection is on the lateral wall of flue stack (1), coaxial fixedly connected with lead screw (232) on the output shaft of motor (231) one end, threaded connection has screw fixing base (7) on lead screw (232), the lower fixed surface of screw fixing base (7) is connected with horizontally baffle (233), baffle (233) can shield holding chamber (26) completely.

4. The temperature raising device for SCR denitration according to claim 3, characterized in that: coaxial fixedly connected with sprocket (234) on the output shaft of motor (231) other end, be provided with sprocket two (235) directly over sprocket one (234), sprocket two (235) and sprocket one (234) pass through chain drive, coaxial fixedly connected with worm (236) on sprocket two (235), one side of worm (236) is provided with worm wheel (237), worm wheel (237) and worm (236) meshing, coaxial threaded connection has lead screw two (238) on worm wheel (237), the one end that worm wheel (237) was kept away from to lead screw two (238) extends to and holds in chamber (26) and gas heater (22) bottom fixed connection.

5. The temperature raising device for SCR denitration according to claim 4, characterized in that: the side wall of the main flue (1) is fixedly connected with a vertical supporting rod (8), and the worm (236) is rotatably connected with the supporting rod (8).

6. The temperature raising device for SCR denitration according to claim 1, characterized in that: the lower end of the SCR catalytic device (3) is fixedly connected with an economizer (5), and the lower end of the economizer (5) is fixedly connected with an air preheater (6).

7. The temperature raising device for SCR denitration according to claim 3, characterized in that: the lower end of the first lead screw (232) and the lower end of the motor (231) are fixedly connected with a protective cover (25), and the protective cover (25) is fixedly connected with the side wall of the main flue (1).

8. The temperature raising device for SCR denitration according to claim 7, characterized in that: the protective cover (25) is made of polytetrafluoroethylene.