KR102550080B1 - Combined sncr and scr system - Google Patents

Abstract

A selective non-catalytic reduction and selective catalytic reduction composite system for reducing nitrogen oxides contained in exhaust gas discharged from a combustion chamber according to an embodiment of the present invention includes an exhaust passage for discharging exhaust gas generated from the combustion chamber, and the exhaust passage A reactor installed on the top of the reactor and having a built-in catalyst for reducing nitrogen oxides contained in the exhaust gas, a first injection unit installed on the exhaust passage upstream of the reactor, and a second injection unit installed in the combustion chamber; A rear branch passage branched from the exhaust passage downstream of the reactor, a decomposition chamber connected to the branch passage, a reducing agent supply passage connecting the decomposition chamber and the first injector, and the decomposition chamber and the second injector and a urea supply unit for supplying urea to at least one of them.

Description

Selective non-catalytic reduction and selective catalytic reduction combined system {COMBINED SNCR AND SCR SYSTEM}

The present invention relates to a selective non-catalytic reduction and a selective catalytic reduction system, and more particularly, to a selective non-catalytic reduction and a selective catalytic reduction system used to reduce nitrogen oxides (NOx) contained in exhaust gas.

As industrialization progresses rapidly, the use of various fossil fuels such as petroleum and coal has increased. As a result, various harmful gases discharged during the combustion of fossil fuels cause serious air pollution. Representative examples include smog and acid rain.

The main cause of air pollution is sulfur oxides (SOx) or nitrogen oxides (NOx) of exhaust gas discharged from engines of vehicles and ships or thermal power plants or factories. Among them, representative facilities for reducing nitrogen oxides include a selective non-catalytic reduction (SNCR) system and a selective catalytic reduction (SCR) system.

The selective non-catalytic reduction (SNCR0 system) is a method of reducing nitrogen oxides (NOx) by reacting with nitrogen oxides (NOx) by directly injecting an aqueous solution of urea or ammonia as a reducing agent into the exhaust gas having a high temperature generated in the combustion chamber. At this time, the exhaust gas generated in the combustion chamber may have a temperature within the range of 800 degrees Celsius to 1100 degrees Celsius.

A selective catalytic reduction (SCR) system is a method of reducing nitrogen oxides (NOx) by reacting a reducing agent with nitrogen oxides (NOx) in a reactor in which a catalyst is installed. In the selective catalytic reduction system, an aqueous urea solution or an aqueous ammonia solution, which is a reducing agent, is injected into exhaust gas having a relatively low temperature, or an aqueous urea solution is decomposed into ammonia gas in a separately provided decomposition chamber or vaporizer, and then injected into the exhaust gas. . The injected reducing agent flows into the reactor in which the catalyst is installed together with the exhaust gas. And the temperature of the exhaust gas flowing into the reactor may have a temperature within the range of 200 degrees Celsius to 500 degrees Celsius.

Although the selective non-catalytic reduction system has a nitrogen oxide (NOx) reduction rate of 40% to 60%, it has been widely used because it is more advantageous than the selective catalytic reduction system in terms of installation cost and maintenance. The use of selective catalytic reduction systems with a NOx) reduction rate of up to 95% or more is greatly increasing, and a combination system in which a selective non-catalytic reduction system and a selective catalytic reduction system are applied together is also widely used.

In a conventional composite system in which a selective non-catalytic reduction system and a selective catalytic reduction system are applied together, an aqueous urea solution is directly injected into exhaust gas to be used for selective non-catalytic reduction, and the aqueous urea solution is decomposed into ammonia gas in a separately provided decomposition chamber or vaporizer. After that, it was injected into the exhaust gas and used for selective catalytic reduction.

However, in order to separately operate the decomposition chamber or vaporizer, a heating device such as an electric heater, steam, or a burner is required to supply heat energy to the decomposition chamber or vaporizer, and additional costs are incurred for operating the heating device. In addition, it takes time to decompose urea, and the decomposed ammonia gas must be stored and supplied.

In addition, when the temperature of the exhaust gas discharged from the combustion chamber is variable depending on the type of the combustion chamber or the surrounding environment, a situation in which the selective non-catalytic reduction system and the selective catalytic reduction system are used together may occur.

Specifically, in a situation where the temperature of the exhaust gas discharged from the combustion chamber does not reach the temperature suitable for the selective non-catalytic reduction reaction, the urea aqueous solution directly injected into the exhaust gas for selective non-catalytic reduction may not smoothly reduce nitrogen oxides. there is.

In addition, even when the temperature of the exhaust gas discharged from the combustion chamber is a temperature suitable for decomposing urea into ammonia in the decomposition chamber or vaporizer, a heating device is unnecessarily operated to supply heat energy to the decomposition chamber or vaporizer, resulting in waste of energy. It can be.

In addition, when the temperature of the exhaust gas discharged from the combustion chamber is higher than the temperature suitable for decomposing urea into ammonia in the decomposition chamber or vaporizer, the decomposition efficiency of urea may be lowered and the overall efficiency of the system may be lowered.

In this way, when the temperature of the exhaust gas passing through the position where the reducing agent is injected fluctuates due to various factors, the reducing agent injected into the exhaust gas is not completely decomposed depending on the situation, resulting in reduced nitrogen oxide reduction efficiency or deposits. There is a problem in that energy is generated or unnecessarily wasted.

In addition, in the conventional composite system in which the selective non-catalytic reduction system and the selective catalytic reduction system are applied together, the reducing agent supply device for supplying the reducing agent required for the selective non-catalytic reduction system and the reducing agent supply for supplying the reducing agent required for the selective catalytic reduction system The device was isolated and operated independently. Accordingly, since the configuration of the overall system becomes complicated, there are problems in that installation and maintenance are cumbersome and space is wasted.

Embodiments of the present invention provide a combined selective non-catalytic reduction and selective catalytic reduction system capable of efficiently supplying a reducing agent.

According to an embodiment of the present invention, a selective non-catalytic reduction and selective catalytic reduction complex system for reducing nitrogen oxides contained in exhaust gas discharged from a combustion chamber includes an exhaust passage for discharging exhaust gas generated from the combustion chamber, and the exhaust gas. A reactor installed on a passage and having a built-in catalyst for reducing nitrogen oxides contained in the exhaust gas, a first injection unit installed on the exhaust passage upstream of the reactor, and a second injection unit installed in the combustion chamber; , a rear branch passage branched from the exhaust passage downstream of the reactor, a decomposition chamber connected to the branch passage, a reducing agent supply passage connecting the decomposition chamber and the first injection unit, and the decomposition chamber and the second branch passage and a urea supply section for supplying urea to at least one of the sand sections.

The selective non-catalytic reduction and selective catalytic reduction combined systems include a heating device installed on the rear branch passage to control the temperature of the exhaust gas moving along the rear branch passage, and a heating device installed on the rear branch passage to control the exhaust gas. A blower for moving a portion of the exhaust gas moving along the passage to the rear branch passage may be further included.

In addition, the selective non-catalytic reduction and selective catalytic reduction composite systems described above include an oxygen concentration sensor installed on the rear branch passage, a fuel supply unit for supplying fuel to the heating device, and supplying air for combustion to the heating device. It may further include an air supply unit for combustion.

In addition, the selective non-catalytic reduction and selective catalytic reduction combined systems include an economizer installed on the exhaust passage between the combustion chamber and the reactor to recover thermal energy from exhaust gas moving along the exhaust passage; The urea supply unit may further include a urea storage unit for storing urea to be supplied.

The selective non-catalytic reduction and selective catalytic reduction combined system may further include an additional reducing agent supply passage connecting the decomposition chamber and the second injection unit. And the urea supply unit may supply urea only to the decomposition chamber.

In addition, the selective non-catalytic reduction and selective catalytic reduction composite systems described above include a third injection unit installed on the exhaust passage upstream of the first injection unit, a fourth injection unit installed in the combustion chamber, and the decomposition chamber and the An additional reducing agent supply passage connecting the second injection unit may be further included. In addition, the urea supply unit may supply urea to the decomposition chamber, the third injection unit, and the fourth injection unit.

In addition, according to another embodiment of the present invention, a selective non-catalytic reduction and selective catalytic reduction composite system for reducing nitrogen oxides contained in exhaust gas discharged from a combustion chamber includes an exhaust passage for discharging exhaust gas generated from the combustion chamber and , a reactor installed on the exhaust passage and having a built-in catalyst for reducing nitrogen oxides contained in the exhaust gas, a first injection unit installed on the exhaust passage upstream of the reactor, and a second injection unit installed in the combustion chamber. An injection unit, a front branch passage branched from the exhaust passage upstream of the reactor, a decomposition chamber connected to the branch passage, a reducing agent supply passage connecting the decomposition chamber and the first injection part, and the decomposition chamber and the decomposition chamber. and a urea supply unit for supplying urea to at least one of the second injection units.

The selective non-catalytic reduction and selective catalytic reduction complex systems described above include a heating device installed on the front branch passage to control the temperature of the exhaust gas moving along the front branch passage, and a heating device installed on the front branch passage to the exhaust gas. A blower may be further included to move some of the exhaust gas moving along the passage to the front branch passage.

In addition, the selective non-catalytic reduction and selective catalytic reduction complex systems may further include an outside air supply unit for temperature control that supplies outside air to the front branch passage and controls the temperature of the exhaust gas moving along the front branch passage.

In addition, the selective non-catalytic reduction and selective catalytic reduction composite systems described above include an oxygen concentration sensor installed on the front branch passage, a fuel supply unit for supplying fuel to the heating device, and supplying air for combustion to the heating device. It may further include an air supply unit for combustion.

In addition, the selective non-catalytic reduction and selective catalytic reduction combined systems include an economizer installed on the exhaust passage between the combustion chamber and the reactor to recover thermal energy from exhaust gas moving along the exhaust passage; The urea supply unit may further include a urea storage unit for storing urea to be supplied.

The selective non-catalytic reduction and selective catalytic reduction combined system may further include an additional reducing agent supply passage connecting the decomposition chamber and the second injection unit. And the urea supply unit may supply urea only to the decomposition chamber.

In addition, the selective non-catalytic reduction and selective catalytic reduction composite systems described above include a third injection unit installed on the exhaust passage upstream of the first injection unit, a fourth injection unit installed in the combustion chamber, and the decomposition chamber and the An additional reducing agent supply passage connecting the second injection unit may be further included. In addition, the urea supply unit may supply urea to the decomposition chamber, the third injection unit, and the fourth injection unit.

According to an embodiment of the present invention, the combined system of selective non-catalytic reduction and selective catalytic reduction can efficiently supply a reducing agent.

1 is a block diagram of a combined system for selective non-catalytic reduction and selective catalytic reduction according to a first embodiment of the present invention.
2 is a block diagram of a combined selective non-catalytic reduction and selective catalytic reduction system according to a second embodiment of the present invention.
3 is a block diagram of a combined selective non-catalytic reduction and selective catalytic reduction system according to a third embodiment of the present invention.
4 is a block diagram of a combined system for selective non-catalytic reduction and selective catalytic reduction according to a fourth embodiment of the present invention.
5 is a block diagram of a combined system for selective non-catalytic reduction and selective catalytic reduction according to a fifth embodiment of the present invention.
6 is a block diagram of a combined selective non-catalytic reduction and selective catalytic reduction system according to a sixth embodiment of the present invention.
7 is a configuration diagram of a heating device usable in the selective non-catalytic reduction and selective catalytic reduction combined systems according to the first to sixth embodiments of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

In addition, in various embodiments, components having the same configuration are typically described in the first embodiment using the same reference numerals, and in other embodiments, only configurations different from those of the first embodiment will be described. do.

It is advised that the drawings are schematic and not drawn to scale. Relative dimensions and proportions of parts in the drawings are shown exaggerated or reduced in size for clarity and convenience in the drawings, and any dimensions are illustrative only and not limiting. And like structures, elements or parts appearing in two or more drawings, like reference numerals are used to indicate like features.

The embodiments of the present invention specifically represent ideal embodiments of the present invention. As a result, various variations of the diagram are expected. Therefore, the embodiment is not limited to the specific shape of the illustrated area, and includes, for example, modification of the shape by manufacturing.

Hereinafter, a selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) combination system 101 according to a first embodiment of the present invention will be described with reference to FIG. 1 .

The selective non-catalytic reduction and selective catalytic reduction composite system 101 according to the first embodiment of the present invention reduces nitrogen oxides (NOx) contained in exhaust gas discharged from the combustion chamber 100 . Here, the combustion chamber 100 may be an engine used in a ship or vehicle, or an internal combustion engine or furnace used in a plant. For example, the exhaust gas discharged from the combustion chamber 100 may have a temperature within a range of 200 degrees Celsius to 1100 degrees Celsius.

As shown in FIG. 1, the selective non-catalytic reduction and selective catalytic reduction combined system 101 according to the first embodiment of the present invention includes an exhaust passage 610, a reactor 300, a first injection unit 510, It includes a second injection part 520, a rear branch passage 680, a decomposition chamber 500, a reducing agent supply passage 651, and a urea supply part 810.

In addition, the selective non-catalytic reduction and selective catalytic reduction complex system 101 according to the first embodiment of the present invention includes a heating device 400, a blower 450, an economizer 900, and a urea storage unit 880 may further include.

The exhaust passage 610 moves exhaust gas containing nitrogen oxides (NOx) discharged from the combustion chamber 100 . And the exhaust passage 610 is connected to the reactor 300 to be described later.

The reactor 300 is installed on the exhaust passage 610 . That is, the reactor 300 receives exhaust gas discharged from the combustion chamber 100 through the exhaust passage 610 . And the reactor 300 has a built-in catalyst 350 for reducing nitrogen oxides (NOx) contained in the exhaust gas. The catalyst 350 promotes the reaction of nitrogen oxides (NOx) contained in exhaust gas with a reducing agent to reduce nitrogen oxides (NOx) to nitrogen and water vapor.

In addition, in the first embodiment of the present invention, the catalyst 350 installed inside the reactor 300 may be installed in the form of a module. A plurality of catalyst modules may be loaded in a direction crossing the direction in which the exhaust gas moves inside the reactor 300 to form a plurality of catalyst layers. The plurality of catalyst layers may be spaced apart based on a direction in which exhaust gas moves inside the reactor 300 .

In addition, the catalyst 350 may be made of various materials known to those skilled in the art, such as zeolite, vanadium, and platinum. In one example, the catalyst 350 may have an activation temperature in the range of 250 degrees Celsius to 350 degrees Celsius. Here, the activation temperature refers to a temperature at which the catalyst 350 is not poisoned and can stably reduce nitrogen oxides. If the catalyst 350 reacts outside the activation temperature range, the catalyst 350 is poisoned and efficiency is reduced.

For example, when a reduction reaction to reduce nitrogen oxides contained in exhaust gas occurs at a relatively low temperature of 150 degrees Celsius or more and less than 250 degrees Celsius, sulfur oxides (SOx) of the exhaust gas and ammonia (NH ₃ ) as a reducing agent reacts to produce a catalyst poisoning substance. Specifically, the poisoning substance that poisons the catalyst 350 may include at least one of ammonium sulfate ((NH ₄ ) ₂ SO ₄ ) and ammonium bisulfate (NH ₄ HSO ₄ ). These catalyst poisoning substances are adsorbed on the catalyst 350 to lower the activity of the catalyst 350 . Since the catalyst poisoning material is decomposed at a relatively high temperature, that is, a temperature within the range of 350 degrees Celsius to 450 degrees Celsius, the poisoned catalyst 350 may be regenerated by raising the temperature of the catalyst 350 in the reactor 300 .

The first injection unit 510 is installed on the exhaust passage 610 upstream of the reactor 300 . And the second injection unit 520 is installed in the combustion chamber 100 . In the first embodiment of the present invention, the first injection unit 510 injects ammonia (NH ₃ ) gas generated in the decomposition chamber 500 to be described later, and the second injection unit 520 is a urea supply unit to be described later ( 810) can spray the urea aqueous solution supplied directly.

The rear branch passage 680 is branched from the exhaust passage 610 downstream of the reactor 300 and connected to the decomposition chamber 500 to be described later.

The decomposition chamber 500 receives a portion of the exhaust gas that has passed through the reactor 300 through the rear branch passage 680 . In addition, the decomposition chamber 500 is supplied with urea (urea, CO(NH ₂ ) ₂ ) from a urea supply unit 810 to be described later. The urea storage unit 880 stores urea to be supplied by the urea supply unit 810 . At this time, the urea storage unit 880 may store urea in the form of an aqueous solution, and the urea supply unit 810 may supply an aqueous urea solution. A reducing agent that directly reacts with nitrogen oxides (NOx) is ammonia (NH ₃ ), but since ammonia itself is a pollutant and is not easy to store and transport, a stable aqueous solution of urea is stored in the urea storage unit 880 and then decomposed to ammonia. produce gas That is, urea corresponds to a reducing agent precursor. Specifically, the urea aqueous solution supplied from the urea supply unit 810 to the decomposition chamber 500 is decomposed to produce ammonia (NH ₃ ) and isocyanic acid (HNCO). And isocyanic acid (HNCO) is again decomposed into ammonia (NH ₃ ) and carbon dioxide (CO ₂ ). That is, urea is decomposed to produce ammonia, a reducing agent that reacts with nitrogen oxides.

The reducing agent supply passage 651 connects the decomposition chamber 500 and the first injection unit 510 . Therefore, the ammonia gas generated in the decomposition chamber 500 may be transferred to the first injection unit 510 through the reducing agent supply passage 651 and injected.

As described above, ammonia gas, which is a reducing agent injected through the first injection unit 510, is used for the selective catalytic reduction reaction.

The blower 450 is installed on the rear branch passage 680 to move some of the exhaust gas moving along the exhaust passage 610 to the rear branch passage 680 . That is, a part of the exhaust gas moving along the exhaust passage 610 by the blower 450 is directed to the decomposition chamber 500 . Also, the blower 450 may adjust the flow rate of the exhaust gas moving along the rear branch passage 680 .

The heating device 400 is installed on the rear branch passage 680 to adjust the temperature of the exhaust gas moving along the rear branch passage 680 . In the first embodiment of the present invention, the reactor 300 is maintained above the activation temperature of the catalyst 350 for the selective catalytic reduction reaction. That is, the inside of the reactor 300 may be maintained at a temperature in the range of 250 degrees Celsius to 350 degrees Celsius or higher. Accordingly, the exhaust gas passing through the reactor 300 has significant thermal energy.

In the first embodiment of the present invention, by supplying a portion of the exhaust gas that has passed through the reactor 300 to the decomposition chamber 500, the thermal energy of the exhaust gas can be utilized for decomposition of urea. Therefore, when the temperature of the exhaust gas supplied to the decomposition chamber 500 through the rear branch passage 680 is within a temperature range capable of decomposing urea, the heating device 400 does not need to be operated. At this time, the decomposition temperature range of urea may belong to the range of 250 degrees Celsius to 600 degrees Celsius.

That is, according to the first embodiment of the present invention, the heating device 400 is used as an auxiliary according to the temperature of the exhaust gas supplied to the decomposition chamber 500 through the rear branch passage 680, so that the decomposition chamber 500 will regulate the temperature.

Specifically, in the first embodiment of the present invention, if the temperature of the exhaust gas supplied to the decomposition chamber 500 through the rear branch passage 680 is within the decomposition temperature range of urea, the heating device 400 is not operated. . Conversely, if it does not reach the decomposition temperature range of urea, the heating device 400 raises the temperature of the exhaust gas moving along the rear branch passage 680 to the temperature range at which urea can be decomposed.

In this way, according to the first embodiment of the present invention, the heating device 400 is not always operated and is used auxiliaryly depending on the temperature of the exhaust gas supplied to the decomposition chamber 500 through the rear branch passage 680. , the operation rate of the heating device 400 can be minimized. That is, the consumption of fuel or other energy according to the use of the heating device 400 can be reduced.

In addition, the fact that the operating rate of the heating device 400 is minimized means that the time required for the heating device 400 to operate to raise the temperature of the decomposition chamber to the decomposition temperature of urea can be reduced. As a result, the overall time required to generate ammonia by decomposing urea in the decomposition chamber 500 can be reduced. That is, the residence time required to convert urea into ammonia can be reduced, and thus the size of the decomposition chamber 500 or the length of the reducing agent supply passage 651 can be reduced.

In addition, the urea supply unit 810 supplies the urea aqueous solution to the second injection unit 520 together with the decomposition chamber 500 . That is, the second injection unit 520 injects the urea aqueous solution directly supplied from the urea supply unit 810 into the combustion chamber 520 .

As described above, the urea injected from the second injection unit 520 is decomposed into ammonia due to the relatively high temperature inside the combustion chamber 100 and reacts with nitrogen oxides. That is, the urea injected from the second injection unit 520 is used for a selective non-catalytic reduction reaction.

An economizer 900 is installed on the exhaust passage 610 between the combustion chamber 100 and the reactor 300 . The economizer 900 recovers and recycles thermal energy from the exhaust gas moving along the exhaust passage 610 . Accordingly, the temperature of the exhaust gas is lowered while passing through the economizer 900 . That is, even if the temperature of the exhaust gas discharged from the combustion chamber 100 is high at 800 degrees Celsius or more, the temperature of the exhaust gas passing through the economizer 900 and reaching the reactor 300 may be 500 degrees Celsius or less.

With this configuration, according to the first embodiment of the present invention, the combined selective non-catalytic reduction and selective catalytic reduction system 101 can efficiently supply the reducing agent.

Specifically, energy and time consumed for decomposing urea into ammonia in the decomposition chamber 500 can be minimized by utilizing thermal energy of exhaust gas that has passed through the reactor 300 .

In addition, a reducing agent to be used for the selective non-catalytic reduction reaction and a reducing agent to be used for the selective catalytic reduction reaction may be simultaneously supplied using one urea supply unit 810 . Through this, the total amount of the reducing agent required for the selective non-catalytic reduction and selective catalytic reduction composite system 101 can be managed in an integrated manner.

In addition, by simplifying the overall configuration of the combined selective non-catalytic reduction and selective catalytic reduction system 101, it is possible to increase ease of installation and maintenance and improve space utilization.

In addition, since the form of the reducing agent is appropriately converted and used according to the temperature of the exhaust gas, it is possible to prevent a phenomenon in which urea is not completely converted into ammonia and deposits are formed inside the system.

Hereinafter, a selective non-catalytic reduction and selective catalytic reduction system 102 according to a second embodiment of the present invention will be described with reference to FIG. 2 .

As shown in FIG. 2, the selective non-catalytic reduction and selective catalytic reduction system 102 according to the second embodiment of the present invention is an additional reducing agent connecting the decomposition chamber 5000 and the second injection unit 520. A supply passage 652 is further included. And the urea supply unit 810 supplies urea only to the decomposition chamber 500 . That is, unlike the first embodiment, in the second embodiment of the present invention, the second injection unit 520 does not receive and spray the urea aqueous solution directly from the urea supply unit 810, but ammonia generated in the decomposition chamber 500 will inject gas.

With this configuration, the combined selective non-catalytic reduction and selective catalytic reduction system 102 according to the second embodiment of the present invention can stably supply the reducing agent.

Specifically, ammonia generated in the decomposition chamber 500 even when the temperature of the exhaust gas generated in the combustion chamber 100 fluctuates due to the type of the combustion chamber 100 or the surrounding environment, making it inappropriate to directly decompose urea into ammonia. By using the gas for the selective non-catalytic reduction reaction, a reducing agent for the selective non-catalytic reduction reaction can be stably supplied.

Hereinafter, a selective non-catalytic reduction and selective catalytic reduction system 103 according to a third embodiment of the present invention will be described with reference to FIG. 3 .

As shown in FIG. 3, the selective non-catalytic reduction and selective catalytic reduction system 103 according to the third embodiment of the present invention is installed on the exhaust passage 610 upstream of the first injection unit 510. It further includes an injection part 530, a fourth injection part 540 installed in the combustion chamber 100, and an additional reducing agent supply passage 652 connecting the decomposition chamber 500 and the second injection part 520. .

Also, in the third embodiment of the present invention, the urea supply unit 810 supplies urea to the decomposition chamber 500, the third injection unit 530, and the fourth injection unit 540. That is, unlike the first embodiment, in the third embodiment of the present invention, the second injection unit 520 receives the urea aqueous solution directly from the urea supply unit 810 and does not inject the ammonia generated in the decomposition chamber 500. will inject gas.

In addition, according to the third embodiment of the present invention, the first injection unit 510 and the third injection unit 530 inject the reducing agent to be used for the selective catalytic reduction reaction, and the second injection unit 520 and the fourth injection unit 520 The master 540 injects a reducing agent to be used for the selective non-catalytic reduction reaction. Also, the first injection unit 510, the third injection unit 530, the second injection unit 520, and the fourth injection unit 540 may be selectively used.

Specifically, when the temperature of the exhaust gas generated in the combustion chamber 100 fluctuates depending on the type of the combustion chamber 100 or the surrounding environment, so that urea is suitable for directly decomposing into ammonia, the urea aqueous solution is supplied through the fourth injection unit 540. is sprayed, and it can be used as a reducing agent for a selective non-catalytic reduction reaction.

Conversely, when the temperature of the exhaust gas generated in the combustion chamber 100 fluctuates and is inappropriate to directly decompose urea into ammonia, the ammonia gas generated in the decomposition chamber 500 is injected through the second injection unit 520, and , it can be used as a reducing agent for a selective non-catalytic reduction reaction.

As such, by selectively using the second injector 520 and the fourth injector 540 according to the temperature of the exhaust gas generated in the combustion chamber 100, a reducing agent suitable for the temperature of the current exhaust gas is supplied to provide stable and selective It becomes possible to carry out a non-catalytic reduction reaction.

In addition, when the temperature of the exhaust gas flowing into the reactor 300 fluctuates and it is suitable to directly decompose urea into ammonia, the third injection unit 530 passes through the exhaust passage 610 upstream of the reactor 300. The sprayed urea aqueous solution can be used as a reducing agent for a selective catalytic reduction reaction. In this case, since there is no need to operate the heating device 400 and the blower 450, energy consumed unnecessarily in operating the system can be reduced.

Conversely, when the temperature of the exhaust gas flowing into the reactor 300 fluctuates and is inappropriate to decompose urea into baro ammonia, the ammonia gas generated in the decomposition chamber 500 is injected through the first injection unit 510. And it can be used as a reducing agent for a selective catalytic reduction reaction.

In this way, by selectively using the first injector 510 and the third injector 530 according to the temperature of the exhaust gas flowing into the reactor 300, a reducing agent suitable for the temperature of the current exhaust gas is supplied to provide stable and selective In addition to performing the catalytic reduction reaction, by minimizing the operation of the heating device 400 and the blower 450, consumption of energy and time according to the operation of the heating device 400 and the blower 450 can be reduced.

With this configuration, the combined selective non-catalytic reduction and selective catalytic reduction system 103 according to the third embodiment of the present invention can more efficiently and stably supply the reducing agent.

Hereinafter, a selective non-catalytic reduction and selective catalytic reduction system 104 according to a fourth embodiment of the present invention will be described with reference to FIG. 4 .

As shown in FIG. 4 , the selective non-catalytic reduction and selective catalytic reduction system 104 according to the fourth embodiment of the present invention further includes a front branch passage 640 . The front branch passage 640 branches from the exhaust passage 610 upstream of the reactor 300 . Also, the rear branch passage 680 used in the first embodiment is omitted in the fourth embodiment. The rest of the configuration is the same as that of the first embodiment.

In addition, the front branch passage 640 may branch from the exhaust passage 610 upstream of the economizer 900 .

Further, in the fourth embodiment of the present invention, the decomposition chamber 500 is connected to the front branch passage 640, and the heating device 400 and the blower 450 are installed on the front branch passage 640. Therefore, the heating device 400 controls the temperature of the exhaust gas moving along the front branch passage 640, and the blower 450 transfers a portion of the exhaust gas moving along the exhaust passage 610 to the front branch passage 640. ) to move That is, the heating device 400 is used auxiliary according to the temperature of the exhaust gas supplied to the decomposition chamber 500 through the front branch passage 640 to adjust the temperature of the decomposition chamber 500, and the blower 450 A flow rate of the exhaust gas moving along the front branch passage 640 may be adjusted.

Specifically, in the fourth embodiment of the present invention, if the temperature of the exhaust gas supplied to the decomposition chamber 500 through the front branch passage 640 is within the decomposition temperature range of urea, the heating device 400 is not operated. . Conversely, if the temperature of the exhaust gas does not reach the temperature range in which urea can be decomposed, the heating device 400 raises the temperature of the exhaust gas moving along the front branch passage 640 to the temperature range in which urea can be decomposed.

However, in the fourth embodiment of the present invention, by supplying the exhaust gas branched from the exhaust passage 610 upstream of the reactor 300 to the decomposition chamber 500, the temperature is relatively higher than that of the first embodiment. Exhaust gas can be used for decomposition of urea. In addition, when the temperature of the exhaust gas supplied to the decomposition chamber 500 through the front branch passage 640 is within the decomposition temperature range of urea, there is no need to operate the heating device 400, so the operation rate of the heating device can be greatly reduced. there is.

In addition, the selective non-catalytic reduction and selective catalytic reduction system 104 according to the fourth embodiment of the present invention supplies outside air to the front branch passage 640 to increase the temperature of the exhaust gas moving along the front branch passage 640. An external air supply unit 460 for controlling temperature may be further included.

The temperature of the exhaust gas supplied to the decomposition chamber 500 along the front branch passage 640 may be higher than the decomposition temperature range of urea. For example, the decomposition temperature range of urea is 250 degrees Celsius to 600 degrees Celsius, and if the temperature of the exhaust gas supplied to the decomposition chamber 500 through the front branch passage 640 is 800 degrees Celsius or more, the decomposition chamber ( In 500), urea may not be smoothly decomposed.

At this time, the outside air supply unit 460 for temperature control supplies outside air to the front branch passage 640 so that the temperature of the exhaust gas supplied to the decomposition chamber 500 through the front branch passage 640 is in the range of 250 degrees Celsius to 600 degrees Celsius can be adjusted with

Specifically, the outside air supply unit 460 for temperature control may include an outside air supply pipe for supplying outside air and a blower for supplying outside air installed in the outside air supply pipe.

As such, according to the fourth embodiment of the present invention, the heating device 400 is not always operated and is used auxiliaryly depending on the temperature of the exhaust gas supplied to the decomposition chamber 500 through the front branch passage 640. , the operation rate of the heating device 400 can be greatly reduced. That is, the consumption of fuel or other energy according to the use of the heating device 400 can be reduced.

In addition, according to the fourth embodiment of the present invention, the temperature of the exhaust gas supplied to the decomposition chamber 500 through the front branch passage 640 using the outside air supply unit 460 for temperature control is higher than the urea decomposition possible temperature range. When the temperature is high, the temperature of the exhaust gas may be lowered by supplying outside air to the front branch passage 640 .

With this configuration, the combined selective non-catalytic reduction and selective catalytic reduction system 104 according to the fourth embodiment of the present invention can more efficiently supply the reducing agent.

Hereinafter, a selective non-catalytic reduction and selective catalytic reduction system 105 according to a fifth embodiment of the present invention will be described with reference to FIG. 5 .

As shown in FIG. 5, the selective non-catalytic reduction and selective catalytic reduction system 105 according to the fifth embodiment of the present invention is the decomposition chamber 500 0 and the second injection unit 520 in the above-described fourth embodiment. ) It further includes an additional reducing agent supply passage 652 connecting the. And the urea supply unit 810 supplies urea only to the decomposition chamber 500 . That is, unlike the fourth embodiment, in the fourth embodiment of the present invention, the second injection unit 520 does not receive and spray the urea aqueous solution directly from the urea supply unit 810, but ammonia generated in the decomposition chamber 500. will inject gas.

With this configuration, the combined selective non-catalytic reduction and selective catalytic reduction system 105 according to the fifth embodiment of the present invention can stably supply the reducing agent.

Specifically, ammonia generated in the decomposition chamber 500 even when the temperature of the exhaust gas generated in the combustion chamber 100 fluctuates due to the type of the combustion chamber 100 or the surrounding environment, making it inappropriate to directly decompose urea into ammonia. By using the gas for the selective non-catalytic reduction reaction, a reducing agent for the selective non-catalytic reduction reaction can be stably supplied.

Hereinafter, a selective non-catalytic reduction and selective catalytic reduction system 106 according to a sixth embodiment of the present invention will be described with reference to FIG. 6 .

As shown in FIG. 6, the selective non-catalytic reduction and selective catalytic reduction system 103 according to the sixth embodiment of the present invention has an exhaust passage 610 upstream of the first injection unit 510 in the fourth embodiment. The third injection part 530 installed on the top, the fourth injection part 540 installed in the combustion chamber 100, and an additional reducing agent supply passage 652 connecting the decomposition chamber 500 and the second injection part 520. ) is further included.

Also, in the sixth embodiment of the present invention, the urea supply unit 810 supplies urea to the decomposition chamber 500, the third injection unit 530, and the fourth injection unit 540. That is, unlike the fourth embodiment, in the sixth embodiment of the present invention, the second injection unit 520 does not receive and spray the urea aqueous solution directly from the urea supply unit 810, but ammonia generated in the decomposition chamber 500. will inject gas.

In addition, according to the sixth embodiment of the present invention, the first injection unit 510 and the third injection unit 530 inject the reducing agent to be used for the selective catalytic reduction reaction, and the second injection unit 520 and the fourth injection unit 520 The master 540 injects a reducing agent to be used for the selective non-catalytic reduction reaction. Also, the first injection unit 510, the third injection unit 530, the second injection unit 520, and the fourth injection unit 540 may be selectively used.

Specifically, when the temperature of the exhaust gas generated in the combustion chamber 100 fluctuates depending on the type of the combustion chamber 100 or the surrounding environment, so that urea is suitable for directly decomposing into ammonia, the urea aqueous solution is supplied through the fourth injection unit 540. is sprayed, and it can be used as a reducing agent for a selective non-catalytic reduction reaction.

Conversely, when the temperature of the exhaust gas generated in the combustion chamber 100 fluctuates and is inappropriate to directly decompose urea into ammonia, the ammonia gas generated in the decomposition chamber 500 is injected through the second injection unit 520, and , it can be used as a reducing agent for a selective non-catalytic reduction reaction.

As such, by selectively using the second injector 520 and the fourth injector 540 according to the temperature of the exhaust gas generated in the combustion chamber 100, a reducing agent suitable for the temperature of the current exhaust gas is supplied to provide stable and selective It becomes possible to carry out a non-catalytic reduction reaction.

In addition, when the temperature of the exhaust gas flowing into the reactor 300 fluctuates and it is suitable to directly decompose urea into ammonia, the third injection unit 530 passes through the exhaust passage 610 upstream of the reactor 300. The sprayed urea aqueous solution can be used as a reducing agent for a selective catalytic reduction reaction. In this case, since there is no need to operate the heating device 400 and the blower 450, energy consumed unnecessarily in operating the system can be reduced.

Conversely, when the temperature of the exhaust gas flowing into the reactor 300 fluctuates and is inappropriate to decompose urea into baro ammonia, the ammonia gas generated in the decomposition chamber 500 is injected through the first injection unit 510. And it can be used as a reducing agent for a selective catalytic reduction reaction.

In this way, by selectively using the first injector 510 and the third injector 530 according to the temperature of the exhaust gas flowing into the reactor 300, a reducing agent suitable for the temperature of the current exhaust gas is supplied to provide stable and selective In addition to performing the catalytic reduction reaction, by minimizing the operation of the heating device 400 and the blower 450, consumption of energy and time according to the operation of the heating device 400 and the blower 450 can be reduced.

With this configuration, the combined selective non-catalytic reduction and selective catalytic reduction system 106 according to the sixth embodiment of the present invention can more efficiently and stably supply the reducing agent.

Hereinafter, the heating device 400 used in the first to sixth embodiments of the present invention will be described in detail with reference to FIG. 7 .

As described above, the heating device 400 is installed in the rear branch oil 680 or on the front branch oil passage 640 to raise the temperature of the exhaust gas moving along the rear branch oil passage 680 or the front branch oil passage 640. can make it

At this time, the heating device 400 may be a burner. However, when a burner is used as the heating device 400, the exhaust gas moving along the rear branch passage 680 or the front branch passage 640 may not have sufficient oxygen content, so that the burner may not burn smoothly.

Accordingly, an oxygen concentration sensor 407 is installed on the rear branch passage 680 or the front branch passage 640, and fuel is supplied to the heating device 400 according to the measured value of the oxygen concentration sensor 407 for combustion. The combustion air supply unit 405 supplying combustion air to the fuel supply unit 403 and the heating device 400 can be controlled. At this time, the combustion air supply unit 405 may be a blower.

As such, when the combustion air supply unit 405 is applied to the fourth to sixth embodiments, the selective non-catalytic reduction and selective catalytic reduction complex systems 104, 105, and 106 include at least three blowers 450 and 460 , 405) can be used to control the flow of exhaust gas and air.

Meanwhile, a burner is not necessarily used as the heating device 400, and various devices known to those skilled in the art, such as an electric heater, may be used as the heating device 400.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. will be.

Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting, and the scope of the present invention is indicated by the following detailed description of the claims, the meaning and scope of the claims, and All changes or modified forms derived from the equivalent concept should be construed as being included in the scope of the present invention.

101, 102, 103, 104, 105, 106: selective non-catalytic reduction and selective catalytic reduction complex systems
100: combustion chamber
300: reactor
350 Catalyst
400: heating device
403: fuel supply unit for combustion
405: air supply for combustion
407: oxygen concentration sensor
450: blower
500: decomposition chamber
510: first injection unit
520: second injection unit
530: third injection unit
540: fourth injection unit
610: exhaust flow path
640: front quarter passage
651: reducing agent supply flow path
652: additional reducing agent supply flow path
680: rear branch flow
810: urea supply unit
880: urea storage unit
900: economizer

Claims (13)

In a selective non-catalytic reduction and selective catalytic reduction composite system for reducing nitrogen oxides contained in exhaust gas discharged from a combustion chamber,
an exhaust passage through which exhaust gas generated in the combustion chamber is discharged;
a reactor installed on the exhaust passage and having a built-in catalyst for reducing nitrogen oxides contained in the exhaust gas;
a first injection unit installed on the exhaust passage upstream of the reactor;
a second injection unit installed in the combustion chamber;
a rear branch passage branched from the exhaust passage downstream of the reactor;
a decomposition chamber connected to the rear branch passage;
A reducing agent supply passage connecting the decomposition chamber and the first injection unit;
a urea supply unit supplying urea to at least one of the decomposition chamber and the second injection unit;
a heating device installed on the rear branch passage to control the temperature of the exhaust gas moving along the rear branch passage;
a blower installed on the rear branch passage to move a portion of the exhaust gas moving along the exhaust passage to the rear branch passage;
an oxygen concentration sensor installed on the rear branch passage;
a fuel supply unit for supplying fuel to the heating device; and
Combustion air supply unit supplying combustion air to the heating device
Selective non-catalytic reduction and selective catalytic reduction composite system comprising a. delete delete According to claim 1,
an economizer installed on the exhaust passage between the combustion chamber and the reactor to recover thermal energy from exhaust gas moving along the exhaust passage;
Urea storage unit for storing urea to be supplied by the urea supply unit
Selective non-catalytic reduction and selective catalytic reduction composite system, characterized in that it further comprises. According to claim 1 or 4,
Further comprising an additional reducing agent supply passage connecting the decomposition chamber and the second injection unit,
The urea supply unit supplies urea only to the decomposition chamber. In a selective non-catalytic reduction and selective catalytic reduction composite system for reducing nitrogen oxides contained in exhaust gas discharged from a combustion chamber,
an exhaust passage through which exhaust gas generated in the combustion chamber is discharged;
a reactor installed on the exhaust passage and having a built-in catalyst for reducing nitrogen oxides contained in the exhaust gas;
a first injection unit installed on the exhaust passage upstream of the reactor;
a second injection unit installed in the combustion chamber;
a rear branch passage branched from the exhaust passage downstream of the reactor;
a decomposition chamber connected to the rear branch passage;
A reducing agent supply passage connecting the decomposition chamber and the first injection unit;
a urea supply unit supplying urea to at least one of the decomposition chamber and the second injection unit;
a third injection unit installed on the exhaust passage upstream of the first injection unit;
a fourth injection unit installed in the combustion chamber; and
Additional reducing agent supply passage connecting the decomposition chamber and the second injection unit
Including,
The urea supply unit supplies urea to the decomposition chamber, the third injection unit, and the fourth injection unit. In a selective non-catalytic reduction and selective catalytic reduction composite system for reducing nitrogen oxides contained in exhaust gas discharged from a combustion chamber,
an exhaust passage through which exhaust gas generated in the combustion chamber is discharged;
a reactor installed on the exhaust passage and having a built-in catalyst for reducing nitrogen oxides contained in the exhaust gas;
a first injection unit installed on the exhaust passage upstream of the reactor;
a second injection unit installed in the combustion chamber;
a front branch passage branched from the exhaust passage upstream of the reactor;
a decomposition chamber connected to the front branch passage;
A reducing agent supply passage connecting the decomposition chamber and the first injection unit;
a urea supply unit supplying urea to at least one of the decomposition chamber and the second injection unit; and
A temperature control outside air supply unit supplying outside air to the front branch passage to adjust the temperature of the exhaust gas moving along the front branch passage
Selective non-catalytic reduction and selective catalytic reduction composite system comprising a. According to claim 7,
a heating device installed on the front branch passage and regulating the temperature of the exhaust gas moving along the front branch passage;
A blower installed on the front branch passage to move a part of the exhaust gas moving along the exhaust passage to the front branch passage
Selective non-catalytic reduction and selective catalytic reduction composite system, characterized in that it further comprises. delete According to claim 8,
an oxygen concentration sensor installed on the front branch passage;
a fuel supply unit for supplying fuel to the heating device; and
Combustion air supply unit supplying combustion air to the heating device
Selective non-catalytic reduction and selective catalytic reduction composite system, characterized in that it further comprises. According to claim 7,
an economizer installed on the exhaust passage between the combustion chamber and the reactor to recover thermal energy from exhaust gas moving along the exhaust passage;
Urea storage unit for storing urea to be supplied by the urea supply unit
Selective non-catalytic reduction and selective catalytic reduction composite system, characterized in that it further comprises. The method of any one of claims 7, 8, 10, and 11,
Further comprising an additional reducing agent supply passage connecting the decomposition chamber and the second injection unit,
The urea supply unit supplies urea only to the decomposition chamber. In a selective non-catalytic reduction and selective catalytic reduction composite system for reducing nitrogen oxides contained in exhaust gas discharged from a combustion chamber,
an exhaust passage through which exhaust gas generated in the combustion chamber is discharged;
a reactor installed on the exhaust passage and having a built-in catalyst for reducing nitrogen oxides contained in the exhaust gas;
a first injection unit installed on the exhaust passage upstream of the reactor;
a second injection unit installed in the combustion chamber;
a front branch passage branched from the exhaust passage upstream of the reactor;
a decomposition chamber connected to the front branch passage;
A reducing agent supply passage connecting the decomposition chamber and the first injection unit;
a urea supply unit supplying urea to at least one of the decomposition chamber and the second injection unit;
a third injection unit installed on the exhaust passage upstream of the first injection unit;
a fourth injection unit installed in the combustion chamber; and
Additional reducing agent supply passage connecting the decomposition chamber and the second injection unit
Including,
The urea supply unit supplies urea to the decomposition chamber, the third injection unit, and the fourth injection unit.

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