CN108590817A - Switchable type SCR denitration system behind the preceding whirlpool in whirlpool - Google Patents

Abstract

The present disclosure provides a switchable SCR denitrification system before and after the vortex, including: a turbine; an SCR system; and a switching device before and after the vortex; The rear switching device guides the engine exhaust gas to first push the turbine to do work, and then passes through the SCR system for denitrification treatment; The SCR system performs denitrification treatment, and the treated airflow drives the turbine to do work. The switchable SCR denitrification system provided by the present disclosure switches the intake sequence of the turbine and the SCR system by setting a switching device before and after the vortex, so as to ensure that the engine exhaust gas entering the SCR system reaches a temperature sufficient for catalytic reduction reaction, so that The catalytic reduction reaction proceeds smoothly, improving the purification effect of engine exhaust gas.

Description

Switchable SCR denitrification system before and after the vortex

technical field

The disclosure relates to the technical field of engine exhaust gas treatment, in particular to a switchable SCR denitrification system before and after the vortex.

Background technique

Ship transportation is an important part of the world's transportation industry. In the process of transportation, it not only consumes a lot of energy but also produces a lot of pollutants, which brings serious environmental problems. The TIER 3 Convention announced by the International Maritime Organization requires that the pollutants from ships must be reduced to a certain level, which puts forward certain requirements for post-discharge treatment technologies. SCR-Selective Catalytic Reduction technology (SCR-Selective Catalytic Reduction) is an efficient exhaust gas treatment technology, which can achieve high NO _X conversion rate on the basis of minor changes to the machine, and has good economic efficiency. It is currently the most recognized in the world. Effective exhaust emission control means.

The SCR system in the prior art is generally installed behind the turbine, and the exhaust gas generated by engine combustion pushes the turbine and enters the SCR system for reaction to realize exhaust gas treatment. At present, most ships often use high-sulfur fuel oil in order to reduce operation and maintenance costs. High-sulfur fuel oil will produce a large amount of SO ₃ in the exhaust gas, and sulfuric acid or sulfurous acid will be formed at a lower exhaust gas temperature. The chemical reaction between sulfuric acid or sulfurous acid and ammonia in the SCR system is likely to block the channel. Therefore, there are certain requirements for the temperature at which the exhaust gas enters the SCR system.

However, the applicant found that in the process of implementing the present disclosure, under relatively high load conditions, the temperature of the exhaust gas after driving the turbine is still sufficient to drive the SCR system, and the sufficient mixing of ammonia and exhaust gas can be achieved without affecting the treatment efficiency of exhaust gas. But when the load is small, the temperature behind the turbine is not enough to drive the SCR system, and it is difficult to meet the requirements of exhaust gas treatment.

Contents of the invention

(1) Technical problems to be solved

Based on the above technical problems, the present disclosure provides a switchable SCR denitrification system in the front of the vortex and behind the vortex to alleviate the SCR system in the prior art. When the temperature behind the vortex is low, the engine exhaust gas is not enough to drive the SCR system. Technical issues to meet the requirements of tail gas treatment.

(2) Technical solution

The disclosure provides a switchable SCR denitrification system before and after the vortex, including: a turbine, which is driven by airflow to do work; an SCR system, connected in series with the turbine, for treating engine exhaust gas; and a switching device before and after the vortex, It switches the intake sequence of the SCR system and the turbine according to the initial temperature of the engine exhaust gas; wherein, when the initial temperature of the airflow is higher than the set value, the switching device guides the engine exhaust gas to first push the The turbine works, and then denitrification treatment is carried out through the SCR system; when the initial temperature of the airflow is lower than the set value, the vortex front and vortex rear switching device guides the engine exhaust gas to first pass through the SCR system for denitrification treatment, and the treated airflow Push the turbine to do work.

In some embodiments of the present disclosure, the SCR denitrification system switchable before and after the vortex further includes: a main pipeline connected to the exhaust port of the engine, and the turbine is arranged in series in front of the SCR system through the main pipeline; the first branch The main road communicates with the main pipeline, its inlet is set in front of the turbine, and its outlet is set between the turbine and the SCR system; the second branch communicates with the main pipeline, and its inlet is set at the After the SCR system, its outlet is set between the inlet of the first branch and the turbine; and the third branch communicates with the main pipeline, and its inlet is set between the turbine and the first branch Between the outlets of the pipeline; where, when the initial temperature of the airflow is higher than the set value, the engine exhaust gas is discharged into the environment after passing through the turbine and the SCR system in turn along the main pipeline; when the initial temperature of the airflow is lower than the set value value, the engine exhaust gas first enters the SCR system through the first branch for denitrification treatment, and the treated air flows into the turbine along the second branch to perform work, and then is discharged to the environment through the third branch middle.

In some embodiments of the present disclosure, the switching device for swirl before and after swirl includes: a temperature sensor for monitoring the airflow temperature at the inlet of the main pipeline; On the main pipeline, it is used to open or close the main pipeline; the second solenoid valve group is connected with the temperature sensor signal, and is respectively arranged in the first branch, the second branch and the third branch On the road, it is used to open or close the first branch, the second branch and the third branch; when the initial temperature of the air flow is higher than the set value, the first electromagnetic valve group is opened, and the second electromagnetic valve group is opened. The valve group is closed; when the initial temperature of the airflow is lower than the set value, the first solenoid valve group is closed and the second solenoid valve group is opened.

In some embodiments of the present disclosure, the first solenoid valve group includes: a first solenoid valve, disposed on the main main road, between the inlet of the first branch and the outlet of the second branch ; The second solenoid valve is set on the main road, between the entrance of the third branch and the outlet of the first branch; the third solenoid valve is set on the main road, located in the first branch Downstream of the entrance of the second branch.

In some embodiments of the present disclosure, the second solenoid valve group includes: a fourth solenoid valve disposed on the first branch; a fifth solenoid valve disposed on the second branch; and a sixth solenoid valve A valve is arranged on the third branch.

In some embodiments of the present disclosure, the SCR system includes: a urea storage injection system connected to the main pipeline for storing and supplying urea solution; a mixing chamber arranged along the main pipeline at the urea storage injection system; The downstream of the system is used for mixing the ammonia gas generated by the urea solution and the engine exhaust gas; and the catalytic reduction reaction device is arranged downstream of the mixing chamber along the main pipeline, and is used for catalytic reduction of the engine exhaust gas.

In some embodiments of the present disclosure, the urea storage injection system includes: a urea storage device for storing urea solution; a urea pump connected with the urea storage device for pumping urea solution from the urea storage device extraction; and a urea nozzle, connected to the urea pump and the main pipeline, for spraying the urea solution drawn out by the urea pump into the main pipeline.

In some embodiments of the present disclosure, the urea storage and injection system further includes: a liquid level sensor, disposed in the urea storage device, for monitoring the liquid level of the urea solution in the urea storage device.

In some embodiments of the present disclosure, the urea storage injection system further includes: two _NOx sensors, signal-connected to the urea pump, respectively arranged upstream of the urea nozzle in the main pipeline and the catalytic reduction reaction downstream of the device; wherein the _NOx sensor respectively detects the concentration of _NOx in the upstream of the urea nozzle in the main pipeline and the downstream of the catalytic reduction reaction device, and adjusts the supply of urea solution according to the concentration of _NOx .

In some embodiments of the present disclosure, the switchable SCR denitrification system is matched with the diesel engine.

(3) Beneficial effects

It can be seen from the above technical solutions that the switchable SCR denitrification system provided by the present disclosure has one or part of the following beneficial effects:

(1) Switch the intake sequence of the turbine and the SCR system by setting the switching device before the vortex and the vortex, so as to ensure that the engine exhaust gas entering the SCR system reaches a temperature sufficient for the catalytic reduction reaction, so that the catalytic reduction reaction can proceed smoothly and improve the purification of the engine exhaust gas Effect;

(2) By changing the trajectory of the airflow in the main pipeline, the first branch, the second branch and the third branch to achieve the purpose of switching the intake sequence of the turbine and the SCR system, the modification of the existing equipment is relatively small. Small, easy to manufacture or modify;

(3) The air flow is controlled by the temperature sensor, the first solenoid valve group and the second solenoid valve group, which improves the degree of automation of the system, and has low difficulty in implementation and high reliability;

(4) By arranging a liquid level sensor in the urea storage device, it is possible to detect the remaining amount of urea solution, which is convenient for replenishing urea raw material in time, and avoids the decrease of purification effect due to insufficient amount of urea solution;

(5) By installing two _NOx sensors upstream of the urea nozzle and downstream of the catalytic reduction reaction device in the main pipeline, the catalytic reduction reaction effect can be monitored in real time, and the supply of urea solution can be adjusted according to the actual situation to improve the purification effect. At the same time avoid waste.

Description of drawings

FIG. 1 is a schematic structural diagram of a switchable SCR denitrification system of the present disclosure.

Fig. 2 is a schematic structural diagram of a vortex front and vortex rear switching device in the vortex front and vortex rear switchable SCR denitrification system shown in Fig. 1 .

FIG. 3 is a schematic structural diagram of the SCR system in the switchable SCR denitrification system shown in FIG. 1 .

[Description of main component symbols of the embodiment of the present disclosure in the accompanying drawings]

100-turbine; 200-SCR system; 300-vortex front and rear switching device;

400-main road; 500-first branch road; 600-second branch road;

700-the third branch;

210-urea storage injection system; 220-mixing chamber; 230-catalytic reduction reaction device;

310-temperature sensor; 320-the first solenoid valve; 330-the second solenoid valve;

340-the third solenoid valve; 350-the fourth solenoid valve; 360-the fifth solenoid valve;

370-the sixth solenoid valve;

211-urea storage device; 212-urea pump; 213-urea nozzle;

214-liquid level sensor; 215-NO _X sensor.

Detailed ways

In the switchable SCR denitrification system provided by the embodiments of the present disclosure, the reaction temperature of the catalytic reduction reaction in the SCR system is ensured by switching the intake sequence of the turbine and the SCR system, thereby ensuring the treatment efficiency of engine exhaust gas.

In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a switchable SCR denitrification system of the present disclosure.

The present disclosure provides a switchable SCR denitrification system before and after the vortex, as shown in Figure 1, including: a turbine 100, which is driven by airflow to do work; an SCR system 200, connected in series with the turbine 100, for treating engine exhaust gas; and The pre-vortex and post-swirl switching device 300, which switches the intake sequence of the SCR system 200 and the turbine 100 according to the initial temperature of the engine exhaust gas; wherein, when the initial temperature of the airflow is higher than the set value, the swirl before and after the switching device 300 guides the engine The exhaust gas first drives the turbine 100 to do work, and then goes through the SCR system 200 for denitrification treatment; when the initial temperature of the airflow is lower than the set value, the vortex front vortex rear switching device 300 guides the engine exhaust gas to first pass through the SCR system 200 for denitrification treatment, and the treated The air flow pushes the turbine 100 to do work, and the intake sequence of the turbine 100 and the SCR system 200 is switched by setting the vortex front and vortex rear switching device 300, so as to ensure that the engine exhaust gas entering the SCR system 200 reaches a temperature at which the catalytic reduction reaction can fully proceed, so that the catalytic reduction reaction goes smoothly To improve the purification effect of engine exhaust gas.

Fig. 2 is a schematic structural diagram of a vortex front and vortex rear switching device in the vortex front and vortex rear switchable SCR denitrification system shown in Fig. 1 .

In some embodiments of the present disclosure, as shown in FIG. 1 to FIG. 2 , it also includes: a main pipeline 400 connected to the exhaust port of the engine, and the turbine 100 is arranged in series before the SCR system 200 through the main pipeline 400; the first branch 500 communicates with the main pipeline 400, its inlet is set before the turbine 100, and its outlet is set between the turbine 100 and the SCR system 200; the second branch 600 communicates with the main pipeline 400, and its inlet is set after the SCR system 200, Its outlet is arranged between the inlet of the first branch 500 and the turbine 100; and the third branch 700 communicates with the main pipeline 400, and its inlet is arranged between the turbine 100 and the outlet of the first branch 500; wherein, when When the initial temperature of the airflow is higher than the set value, the engine exhaust gas passes through the turbine 100 and the SCR system 200 along the main pipeline 400 and then is discharged to the environment; when the initial temperature of the airflow is lower than the set value, the engine exhaust gas first passes through the first Road 500 enters the SCR system 200 for denitrification treatment, the treated air flow enters the turbine 100 along the second branch 600 to do work, and then is discharged into the environment through the third branch 700, and the air flows through the main pipe 400 and the first branch 500 by changing the air flow , the running track in the second branch 600 and the third branch 700, in order to achieve the purpose of switching the intake sequence of the turbine 100 and the SCR system 200, the modification to the existing equipment is small, and it is convenient for manufacturing or refitting.

In some embodiments of the present disclosure, as shown in FIG. 1 to FIG. 2 , the switching device 300 of the swirl before and after the swirl includes: a temperature sensor 310 for monitoring the airflow temperature at the inlet of the main pipeline 400; a first electromagnetic valve group, and The signal connection of the temperature sensor 310 is arranged on the main pipeline 400 for opening or closing the main pipeline 400; the second solenoid valve group is connected with the signal of the temperature sensor 310 and is respectively arranged on the first branch 500, the second branch 600 and the first branch 600. On the third branch 700, it is used to open or close the first branch 500, the second branch 600 and the third branch 700; when the initial temperature of the air flow is higher than the set value, the first electromagnetic valve group is opened, and the second The second electromagnetic valve group is closed, and the air flow passes through the main pipeline 400, and then passes through the turbine 100 and the SCR system 200 in turn; After passing through the first branch 500, the second branch 600 and the third branch 700, it first passes through the SCR system 200, then passes through the turbine 100, and realizes the control of the air flow through the temperature sensor 310, the first solenoid valve group and the second solenoid valve group. control, which improves the degree of automation of the system, and has low difficulty in realization and high reliability.

In some embodiments of the present disclosure, as shown in FIGS. 1 to 2 , the first solenoid valve group includes: a first solenoid valve 320 disposed on the main pipeline 400 , located at the entrance of the first branch 500 and the second branch between the outlets of the road 600; the second solenoid valve 330 is arranged on the main pipe 400, between the entrance of the third branch 700 and the outlet of the first branch 500; the third solenoid valve 340 is arranged on the main pipe 400 on, downstream of the entrance of the second branch 600 .

In some embodiments of the present disclosure, as shown in FIGS. 1 to 2 , the second solenoid valve group includes: a fourth solenoid valve 350 disposed on the first branch 500 ; a fifth solenoid valve 360 disposed on the second branch on the branch 600 ; and the sixth solenoid valve 370 is arranged on the third branch 700 .

FIG. 3 is a schematic structural diagram of the SCR system in the switchable SCR denitrification system shown in FIG. 1 .

In some embodiments of the present disclosure, as shown in FIG. 1 and FIG. 3 , the SCR system 200 includes: a urea storage injection system 210 connected to the main pipeline 400 for storing and supplying urea solution; a mixing chamber 220 along the main pipeline 400 is set downstream of the urea storage injection system 210 for mixing the ammonia generated by the urea solution with engine exhaust gas; and the catalytic reduction reaction device 230 is set downstream of the mixing chamber 220 along the main pipeline 400 for catalytic reduction of engine exhaust gas.

In some embodiments of the present disclosure, as shown in FIG. 1 and FIG. 3 , the urea storage injection system 210 includes: a urea storage device 211 for storing urea solution; a urea pump 212 connected with the urea storage device 211 for The urea solution is drawn from the urea storage device 211 ; and the urea nozzle 213 is connected with the urea pump 212 and the main pipeline 400 , and is used to spray the urea solution drawn out by the urea pump 212 into the main pipeline 400 .

In some embodiments of the present disclosure, as shown in FIGS. 1 and 3 , the urea storage injection system 210 further includes: a liquid level sensor 214 disposed in the urea storage device 211 for monitoring the level of the urea solution in the urea storage device 211 For liquid level, by installing a liquid level sensor 214 in the urea storage device 211, the remaining amount of urea solution can be detected, which is convenient for replenishing urea raw material in time, and avoids the decrease of purification effect due to insufficient amount of urea solution.

In some embodiments of the present disclosure, as shown in FIG. 1 and FIG. 3 , the urea storage and injection system 210 further includes: two _NOx sensors 215 , which are signal-connected to the urea pump 212 , respectively arranged in the urea nozzle 213 in the main pipeline 400 The upstream of the catalytic reduction reaction device 230 and the downstream of the catalytic reduction reaction device 230; wherein, the NO _X sensor 215 respectively detects the concentration of NO _X in the upstream of the urea nozzle 213 in the main pipeline 400 and the downstream of the catalytic reduction reaction device 230, and adjusts the urea according to the concentration of NO _X For the supply of solution, by setting two _NOx sensors 215 upstream of the urea nozzle 213 and downstream of the catalytic reduction reaction device 230 in the main pipeline, the catalytic reduction reaction effect can be monitored in real time, and the supply of urea solution can be adjusted according to the actual situation , Improve the purification effect while avoiding waste.

In some embodiments of the present disclosure, the switchable SCR denitrification system is matched with the diesel engine.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that, in the accompanying drawings or in the text of the specification, implementations that are not shown or described are forms known to those of ordinary skill in the art, and are not described in detail. In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and those skilled in the art can easily modify or replace them.

Based on the above description, those skilled in the art should have a clear understanding of the switchable SCR denitrification system provided by the present disclosure.

To sum up, the switchable SCR denitrification system provided by the present disclosure ensures the temperature of the catalytic reduction reaction by changing the intake sequence of the SCR system relative to the turbine, thereby improving the purification effect of engine exhaust gas.

It should also be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "back", "left", "right", etc., are only referring to the directions of the drawings, not Used to limit the protection scope of this disclosure. Throughout the drawings, the same elements are indicated by the same or similar reference numerals. Conventional structures or constructions are omitted when they may obscure the understanding of the present disclosure.

And the shape and size of each component in the figure do not reflect the actual size and proportion, but only illustrate the content of the embodiment of the present disclosure. Furthermore, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Similarly, it should be appreciated that in the above description of exemplary embodiments of the disclosure, in order to streamline the disclosure and to facilitate an understanding of one or more of the various disclosed aspects, various features of the disclosure are sometimes grouped together into a single embodiment, figure, or its description. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the foregoing claims reflect, disclosed aspects lie in less than all features of a single foregoing disclosed embodiment. Thus the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present disclosure in detail. It should be understood that the above descriptions are only specific embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims (10)

1. switchable type SCR denitration system behind a kind of preceding whirlpool in whirlpool, including：

Turbine pushes its acting using air-flow；

SCR system is connect with the turbines in series, for handling engine exhaust；And

Switching device behind the preceding whirlpool in whirlpool, according to the initial temperature of engine exhaust switch the SCR system and the turbine into Gas sequence；

Wherein, when the initial temperature of air-flow is higher than setting value, switching device guiding engine exhaust first pushes away behind the preceding whirlpool in whirlpool The dynamic turbine acting, after pass through the SCR system and carry out denitration process；

When the initial temperature of air-flow is less than setting value, switching device guiding engine exhaust first passes through described behind the preceding whirlpool in whirlpool SCR system carries out denitration process, and treated, and air-flow pushes turbine acting.

2. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to claim 1, further includes：

Main line is connect with engine exhaust port, before the turbine is arranged in series in the SCR system by main line；

The first branch is connected to the main line, and entrance is arranged before the turbine, and outlet is arranged in the turbine and institute It states between SCR system；

The second branch is connected to the main line, and entrance is arranged after the SCR system, and outlet is arranged described first Between the entrance of branch and the turbine；And

Third branch is connected to the main line, and entrance is arranged between the turbine and the outlet of the first branch；

Wherein, when the initial temperature of air-flow is higher than setting value, engine exhaust passes sequentially through the turbine and institute along main line It is discharged into environment after stating SCR system；

When the initial temperature of air-flow is less than setting value, engine exhaust first passes through the first branch and enters the SCR system Denitration process is carried out, treated, and air-flow does work along the second branch into the turbine, then is arranged by the third branch It is put into environment.

3. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to claim 2, switching device packet behind the preceding whirlpool in whirlpool It includes：

Temperature sensor, the gas flow temperature for monitoring the main line inlet；

First solenoid valve block is connect with the temperature sensor signal, is arranged on the main line, for being turned on and off master Pipeline；

Second solenoid valve group is connect with the temperature sensor signal, is separately positioned on the first branch, the second branch On the road with the third branch, for being turned on and off the first branch, the second branch and the third branch；

When the initial temperature of air-flow is higher than setting value, the first solenoid valve block is opened, and second solenoid valve group is closed；

When the initial temperature of air-flow is less than setting value, the first solenoid valve block is closed, and second solenoid valve group is opened.

4. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to claim 3, first solenoid valve block include：

First solenoid valve is arranged on the main line, is located at the outlet of the entrance and the second branch of the first branch Between；

Second solenoid valve is arranged on the main line, is located at the outlet of the entrance and the first branch of the third branch Between；

Third solenoid valve is arranged on the main line, is located at the downstream of the entrance of the second branch.

5. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to claim 3, the second solenoid valve group include：

4th solenoid valve is arranged in the first branch；

5th solenoid valve is arranged in the second branch；And

6th solenoid valve is arranged on third branch road.

6. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to claim 2, the SCR system include：

Urea storage spraying system is connect with the main line, for storing and supplying urea liquid；

Mixing chamber is arranged in the downstream of the urea storage spraying system along the main line, is generated for mixing urea solution Ammonia and engine exhaust；And

Catalytic reduction reaction device is arranged along the main line in the downstream of the mixing chamber, useless for being catalyzed reduction engine Gas.

7. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to claim 6, the urea storage spraying system packet It includes：

Urea storage device is used for stored urea solution；

Urea pump is connect with the urea storage device, for extracting urea liquid out from the urea storage device；And

Urea nozzle is connect with the urea pump and the main line, for spraying the urea liquid of the urea pumped Into main line.

8. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to claim 7, the urea storage spraying system also wrap It includes：Liquid level sensor is arranged in the urea storage device, the liquid for monitoring urea liquid in the urea storage device Position.

9. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to claim 7, the urea storage spraying system also wrap It includes：Two NO_XSensor is connect with the urea pump signal, be separately positioned in the main line upstream of urea nozzle and The downstream of the catalytic reduction reaction device；

Wherein, the NO_XSensor detects the upstream of urea nozzle and the catalytic reduction reaction device in the main line respectively Downstream in NO_XConcentration, and according to NO_XConcentration adjust urea liquid supply amount.

It, can behind the preceding whirlpool in the whirlpool 10. switchable type SCR denitration system behind the preceding whirlpool in whirlpool according to any one of claim 1 to 9 Suitching type SCR denitration system matches setting with diesel engine.