KR102219049B1 - Low Pressure Selective Catalytic Reduction Reactor - Google Patents

Abstract

The present invention relates to a low-pressure SCR reactor for removing NOx, which is an exhaust gas air pollutant of a large diesel engine for ships, and is particularly configured to increase space utilization inside a ship through miniaturization and weight reduction.
In addition, in the low-pressure SCR reactor of the present invention for achieving the above object, exhaust gas is introduced into the interior through the exhaust gas inlet pipe 101 connected to one side, and the exhaust gas is discharged through the exhaust gas discharge pipe 102 connected to the other side. The discharged housing 110, the reinforcing partition wall 120 fixed inside the housing 110 in the flow direction of the exhaust gas, and the inner surface of the housing 110 with a plurality of layers spaced inside the housing 110 The frames 131 fixed to the reinforcing partition wall 120, the catalyst module layers 130 mounted on each frame 131 and on which the catalyst modules 130C are mounted, and a housing at a position higher than the uppermost catalyst module layer It is located between the door 105 formed in the upper part of 110 or in the exhaust gas discharge pipe 102, and the catalyst module layer of the lowest layer among the catalyst module layers 130 located in a plurality of layers and the exhaust gas inlet pipe 101 It is characterized in that it comprises a dispersion plate 140 for uniformly dispersing the exhaust gas introduced through the exhaust gas inlet pipe 101.

Description

Low Pressure Selective Catalytic Reduction Reactor

The present invention relates to a low-pressure SCR reactor for removing NOx, which is an exhaust gas air pollutant of a large diesel engine for ships, and is particularly configured to increase space utilization inside a ship through miniaturization and weight reduction.

As part of efforts to reduce the emission of air pollutants at home and abroad, the revised regulations of related laws and the enforcement regulations of the Air Environment Conservation Act have been revised and supplemented, thereby strengthening the pollution control.

These legal amendments were very effective in regulating the emission of air pollutants and played a role in drastically reducing the emission of major air pollutants. However, despite the implementation of legal and regulatory measures for such a long time, the reduction of nitrogen oxide emissions remains a part where satisfactory results have not been obtained.

The biggest factor that caused this situation is that the control of nitrogen oxides among the various air pollutants generated in the combustion process is technically not easy compared to other pollutants.

However, despite this situation, the emission limit standards for nitrogen oxides are expected to be strengthened step by step, and the pollutant emission regulation, which was applied mainly to large pollutant facilities, is being applied to small emission facilities such as ships, small and medium boilers, and automobiles.

As a post-treatment facility that treats nitrogen oxides contained in exhaust gas, the SCR (selected catalytic reduction) system and the SNCR (selective non-catalytic reduction) system are typically adopted and used.

The SNCR system is advantageous in its constructional simplicity, such as no need for a catalyst layer. However, since the reducing agent has to react in the high-temperature reaction zone, it is practically impossible to apply it outside the furnace where it is difficult to create a high-temperature state required for the reaction.

The SCR system also has a disadvantage in that the initial equipment cost and operation cost by introducing a reducing agent are high, but it is widely applied because it has the advantage of being able to operate the system with stable exhaust gas and high reduction efficiency.

The SCR system is mainly applied to large-sized discharge facilities due to the high facility operation cost, but the scope of application of the nitrogen oxide regulation is gradually expanding to small-sized discharge facilities, making it an economical and efficient SCR system applicable to small-sized discharge facilities. The development needs of the company are increasing.

On the other hand, the exhaust gas temperature of HP-SCR (High Pressure Selective Catalytic Reduction) installed in front of the turbo charger (TC) is about 330 to 450 degrees and the pressure is 1.0 to 5.0 bar, so the reactor is used under high temperature and high pressure conditions. While the design is cylindrical, the LP-SCR (Low Pressure Selective Catalytic Reduction) for large engines is installed at the rear end of the turbocharger.

The exhaust gas temperature at the rear end of the turbocharger is about 190 to 300 degrees and the pressure is at a low pressure of 1.5 bar or less, and the LP-SCR reactor has a rectangular cylindrical structure.

As such, the reason why the LP-SCR reactor has a square cylinder structure is that the working pressure is low, and due to the characteristics of the LP-SCR reactor having a square cylinder structure, it takes up a lot of space, and thus there is a disadvantage in that the space utilization inside the hull is deteriorated.

In the drawings, FIG. 1 is a conceptual diagram showing an LP-SCR reactor having a rectangular cylindrical structure according to the prior art.

As shown in FIG. 1, the LP-SCR reactor 10 includes a reactor housing 20 having a rectangular structure, and doors 21H and 21L installed in the housing 20 so that an operator can enter the interior of the housing 20. ), a vane 40 for guiding the traveling direction of the exhaust gas flowing into the lower portion of the housing 20, and catalyst module layers 30 located in a plurality of layers inside the housing 20.

Here, in the catalyst module layer 30, the frame 31 for supporting and fixing the catalyst is horizontally fixed in a plurality of layers with an upper and lower interval, and the catalyst modules 30C are arranged and disposed on the upper part of the frame 31, The exhaust gas guided upward through the vanes 40 located below the housing 20 passes through the catalyst modules 30C of each catalyst module layer 30 and is exhausted to the upper portion of the housing 20 after a catalytic reaction.

In the LP-SCR reactor configured as described above, the door (21H, 21L) enters the interior of the housing 20 in order for the operator to replace the catalyst modules (30C) inside the LP-SCR reactor 10 or to maintain other facilities. It is formed to be capable of, and in order for an operator to enter the interior of the housing 20 through the doors 21H and 21L and work, the door must have a height of at least the average height of an adult.

In addition, the catalyst module layers 30 must have a height equal to or greater than the average height of an adult so that the worker can move and work along the frame 31.

For this reason, the doors 21H and 21L formed in the housing 20 as shown in FIG. 1 are divided into an upper door 21H and a lower door 21L corresponding to each catalyst module layer 30, The operator enters the housing 20 through the doors 21H and 21L corresponding to the catalyst module layer 30 to be installed and maintained to perform the work.

As such, the height of the door and the spacing between the catalyst module layers are limited, thereby causing the disadvantage that the height of the housing, that is, the LP-SCR reactor, is inevitably increased.

In order to solve the problem of increasing the height of the LP-SCR reactor, there is a method of relatively increasing the cross-sectional area of the housing, but this also causes a problem of lowering the space utilization inside the ship.

Korean Patent Publication No. 10-1561260 (October 19, 2015)

The present invention was invented to solve the problems of the prior art as described above, and the space utilization can be increased by reducing the height of the reactor by reducing the spacing of the catalyst module layers, and also miniaturizing the reactor by increasing the internal rigidity. An object thereof is to provide an LP-SCR reactor configured to be lightweight.

The low-pressure SCR reactor according to the present invention for achieving the above object includes a housing through which exhaust gas is introduced into the interior through an exhaust gas inlet pipe connected to one side and exhaust gas is discharged through an exhaust gas discharge pipe connected to the other side, and exhaust gas. The reinforcing bulkhead fixed inside the housing in the flow direction of the housing, the frames fixed to the inner side of the housing and the reinforcing bulkhead with a plurality of layers spaced inside the housing, and a catalyst module layer mounted on each frame and on which catalyst modules are mounted It is characterized by a technical feature that includes them.

Further, according to a preferred embodiment of the present invention, there are a plurality of reinforcing partition walls, and the inside of the housing is divided into a plurality of regions, and passage holes are formed in the reinforcing partition walls so as to be movable to both regions based on the reinforcing partition walls.

Further, according to a preferred embodiment of the present invention, the frame includes a fixing frame fixed to the inner side of the housing and the reinforcing partition wall, and a reinforcing beam for reinforcing the fixing frame.

In addition, according to a preferred embodiment of the present invention, the catalyst module layer covers the catalyst support frame on which the catalyst modules are mounted and the outer edge of the catalyst support frame to compensate for the expansion of the catalyst support frame by contacting the inner side of the housing or the side of the reinforcing partition wall. It includes a sealing mat, and the catalyst module layer is technically characterized in that it is seated on the fixed frame.

In addition, the low-pressure SCR reactor according to the present invention is located between the catalyst module layer of the lowest layer and the exhaust gas inlet pipe among the catalyst module layers located in a plurality of layers, and a dispersion plate that uniformly distributes the exhaust gas introduced through the exhaust gas inlet pipe. It includes more.

Further, according to a preferred embodiment of the present invention, the dispersion plate has a porous plate structure.

In addition, the low-pressure SCR reactor of the present invention includes a housing through which exhaust gas is introduced through an exhaust gas inlet pipe connected to one side and exhaust gas is discharged through an exhaust gas discharge pipe connected to the other side, and a plurality of layers inside the housing are spaced apart. It is characterized in that it comprises a frame to be placed and fixed, catalyst module layers mounted on each frame and on which catalyst modules are mounted, and a door formed on an upper portion of the housing or in an exhaust gas discharge pipe at a position higher than that of the uppermost catalyst module layer. .

In addition, according to a preferred embodiment of the present invention, a hoist beam for mounting a hoist is fixed to an upper portion of the housing in which the door is formed or the exhaust gas discharge pipe.

In addition, the low-pressure SCR reactor of the present invention for achieving the above object includes a housing through which exhaust gas is introduced into the interior through an exhaust gas inlet pipe connected to one side and exhaust gas is discharged through an exhaust gas discharge pipe connected to the other side, and exhaust gas. Reinforcing bulkheads fixed inside the housing in the direction of gas flow, frames fixed to the inner side of the housing and the reinforcing bulkheads with a plurality of layers spaced inside the housing, and a catalyst module mounted on each frame and equipped with catalyst modules It is located between the layers, the uppermost of the housing or the exhaust gas discharge pipe at a position higher than the uppermost catalyst module layer, and the lowermost catalyst module layer among the plurality of layers of the catalyst module layer and the exhaust gas inlet pipe. It is characterized in that it comprises a dispersion plate uniformly dispersing the exhaust gas introduced through the gas inlet pipe.

As described above, the LP-SCR reactor according to the present invention forms a door in the upper part of the housing or in the exhaust gas discharge pipe so that the operator can enter through the door formed on the upper part and enter the catalyst module layer to be worked together. By constructing the support frame of the module layer in a prefabricated manner, the spacing between the catalyst module layers is reduced. Therefore, there is an advantage that the height of the LP-SCR reactor can be reduced.

In addition, the LP-SCR reactor according to the present invention has the advantage of being able to reduce weight by reinforcing internal components of the reactor by configuring a reinforcing partition wall connecting the catalyst module layers.

In addition, according to the characteristics of the structure of the LP-SCR reactor according to the present invention to reduce size and weight, the existing vane that guides the inflow of exhaust gas can be changed into a porous distribution plate structure, thereby reducing the size and weight of the reactor. .

1 is a conceptual diagram showing an LP-SCR reactor having a rectangular cylindrical structure according to the prior art.
2 is a conceptual diagram showing an LP-SCR reactor according to the present invention,
Figure 3 is a partial cross-sectional view of the LP-SCR reactor shown in Figure 2,
4 is an exploded view showing the support frame of the catalyst module layer shown in FIG. 3.
5 is an image showing the result of analyzing the flow uniformity of the LP-SCR reactor according to the present invention.

Hereinafter, a preferred embodiment of the LP-SCR reactor according to the present invention will be described in detail with reference to the accompanying drawings.

In the drawings, FIG. 2 is a conceptual diagram showing an LP-SCR reactor according to the present invention, FIG. 3 is a partial cross-sectional view of the LP-SCR reactor shown in FIG. 2, and FIG. 4 is a support frame of the catalyst module layer shown in FIG. It is an exploded view showing. And Figure 5 is an image showing the result of analyzing the flow uniformity of the LP-SCR reactor according to the present invention.

As shown in FIG. 2, the LP-SCR reactor 100 has an exhaust gas inlet pipe 101 connected to the lower part and an exhaust gas discharge pipe 102 connected to the upper part of the housing 110, and the vertical housing 110 Reinforcing partitions 120 intersecting in the longitudinal and transverse directions in the direction, and catalyst modules located in the space between the reinforcing partitions 120 and the housing 110 and arranged at intervals in the vertical direction of the housing 110 Layer 130.

In addition, a door 105 is formed on the top of the housing 110 or in the exhaust gas discharge pipe 102 located above the catalyst module layer 130 of the uppermost layer, and the catalyst module layer 130 includes a reinforcing partition wall 120 and a housing. (110) The fixed frame 131 fixed in the space between the inner side, the catalyst support frame 133 seated on the fixed frame 131, and the catalyst support frame 133 located outside the catalyst support frame 133 ) And a sealing mat 135 to compensate for the displacement caused by the expansion.

Hereinafter, the LP-SCR reactor configured as described above will be described in detail.

2 and 3, the housing 110 has a rectangular cylindrical structure, and the upper and lower portions of the rectangular cylindrical structure are formed in a hopper structure, so that the exhaust gas discharge pipe 102 is connected to the upper part, and the exhaust gas inlet pipe is connected to the lower part. 101 is connected.

On the other hand, the door 105 to which the operator can enter and exit is installed in the exhaust gas discharge pipe 102 or the upper hopper part 111. That is, the operator enters the interior of the housing 110 through the door 105 formed on the uppermost catalyst module layer 130. 2 and 3 show that the door 105 is formed in the exhaust gas discharge pipe 102, it may be formed in the upper hopper part 111 of the housing 110 below it.

In addition, a hoist beam is mounted inside the exhaust gas discharge pipe 102 so that materials and parts, etc. that enter and exit through the door 105 may be moved to the hoist 109 mounted on the hoist beam. Here, the hoist 109 is mounted on the hoist beam only during maintenance and repair of the LP-SCR reactor, and is removed from the hoist beam during normal operation.

The material and parts, etc., which are mounted through the door 105 and the door 105, can be moved through the hoist 109.

In addition, a reinforcing partition wall 120 is formed in the interior of the housing 110 in a vertical direction, that is, corresponding to the flow direction of the exhaust gas, and the reinforcing partition wall 120 crosses the vertical reinforcing partition wall and the transverse reinforcing partition at a right angle. It is a structure, and the intersection point is preferably located at the vertical center of the housing (110).

In this way, the reinforcing bulkheads in the longitudinal direction and the reinforcing bulkheads in the transverse direction are fixed inside the housing 110, so that the inner space of the housing 110 is divided into four zones, and introduced through the exhaust gas inlet pipe 101. The exhaust gas flows upward through four zones.

In each zone, the catalyst module layer 130 is located in a plurality of layers, and the levels of the plurality of catalyst module layers 130 formed in each zone are fixed to match each layer.

In addition, in the reinforcing partition wall 120 divided into four areas, a passage hole 121 is formed in the reinforcing partition wall 120 so that a worker can move to the catalyst module layer 130 located at the same level. That is, the passage holes 121 are formed in the reinforcing partition wall 120 to correspond to the catalyst module layer 130 of the same level, so that the operator moves the catalyst module layer 130 of the same level, and maintenance and replacement are possible.

Meanwhile, as shown in FIG. 4, the catalyst module layers 130 located in each zone have a fixed frame 131 fixed to the side of the reinforcing partition wall 120 and the inner side of the housing 110, and the fixed frame 131. ) And is divided into a catalyst support frame 133 on which the catalyst module 130C is mounted on the upper surface.

Here, the fixing frame 131 is fixed to the side surface of the reinforcing partition wall 120 and the inner surface of the housing 110 by welding or the like, and the catalyst support frame 133 is mounted on the upper surface of the fixing frame 131. The fixed frame 131 is fixed to the reinforcing beam 131S inside the fixed frame 131 so as to support the load of the catalyst support frame 133 seated on the upper part even at a high temperature.

On the other hand, the catalyst support frame 133 has a structure that is simply seated on the upper surface of the fixing frame 131 without welding and fixing the reinforcing partition wall 120 and the inner surface of the housing 110.

This is because the operator located on the upper part of the catalyst module layer 130 lifts the catalyst support frame 133 and moves to the catalyst module layer 130 below, and does not restrict expansion and contraction, so that thermal stress does not accumulate, It is configured to stably support the catalyst module.

In this way, the sealing mat 135 is fixed to the outer surface of the catalyst support frame 133 to facilitate expansion and contraction of the catalyst support frame 133, and the sealing mat 135 is fixed to the side of the catalyst support frame 133 It is seated on the upper surface of the fixed frame 131 in the state. In this state, when the catalyst support frame 133 expands by temperature, the sealing mat 135 is pressed and compressed to compensate for expansion.

The catalyst support frame 133 is positioned by inserting the catalyst module 130C in a space divided into squares in a checkerboard shape.

In this way, the catalyst module layer 130 is located in a plurality of layers in the four areas partitioned by the reinforcing barrier ribs 120 in the housing 110, and each catalyst module layer 130 located on both sides of the reinforcing barrier ribs 120 ) Is configured to match the level, and a passage hole 121 is formed in the reinforcing partition wall 120 so that the catalyst module layer 130 of the level match can be moved.

Further, at the lower end of the reinforcing partition wall 120, a distribution plate 140 having a porous plate structure is positioned perpendicular to the inflow direction of the exhaust gas. In the past, as vanes (40 in FIG. 1) guiding the inflow direction of the exhaust gas under the housing 110 are positioned in the direction of the exhaust gas, the length of the lower part of the housing is relatively longer, but the lower part of the housing 110 In addition to the function of uniformly distributing the exhaust gas flowing into the housing 110 from the exhaust gas inlet pipe 101 to the entire flat sectional area of the catalyst module layer 130 by placing the dispersion plate 140 on the housing 110 The lower length of the can be reduced.

As shown in Figures 5 (a) and (b), in a conventional LP-SCR reactor equipped with a vane, the exhaust gas passing through the vanes forms a laminar flow (Figure 5 (a)), but according to the present invention In the LP-SCR reactor 100 equipped with the dispersion plate 140, it can be seen that turbulence is formed in front of the dispersion plate 140 (FIG. 5(b)). As described above, although turbulent flow of exhaust gas is formed in front of the distribution plate 140, the exhaust gas is guided in a laminar flow while passing through the distribution plate 140 and the catalyst module 130C, and is discharged through the exhaust gas discharge pipe 102.

In the design structure of SCR, one of the important factors to be considered is the pressure difference between the exhaust gas inlet and the outlet. In terms of the pressure difference, the LP-SCR reactor equipped with a vane according to the prior art is 91mmWC, and the LP-SCR reactor equipped with a dispersion plate according to the present invention is 109mmWC, and the pressure difference has increased by 16.5% relative to the vane, but the housing (110 The length of) has the advantage of being relatively reduced.

As described above, in the LP-SCR reactor according to the present invention, the door 105 for the operator to enter into the housing 110 is located above the catalyst module layer 130 and the housing 110 is formed as a reinforcing partition wall 120. ) There is an advantage in that the housing 110 can be miniaturized and lightweight by reinforcing the catalyst module layer 130 inside and dispersing the exhaust gas uniformly with the dispersion plate 140.

100: LP-SCR reactor
101: exhaust gas inlet pipe
102: exhaust gas discharge pipe
105: door
109: hoist
110: housing
111: hopper part
120: reinforcing bulkhead
121: passage hall
130: catalyst module layer
131: fixed frame
131S: reinforcing beam
133: catalyst support frame
135: sealing mat
140: dispersion plate

Claims (11)

A housing 110 through which exhaust gas is introduced into the interior through an exhaust gas inlet pipe 101 connected to one side and exhaust gas is discharged through an exhaust gas discharge pipe 102 connected to the other side,
A reinforcing partition wall 120 fixed inside the housing 110 in the flow direction of the exhaust gas,
Frames fixed to the inner side of the housing 110 and the reinforcing partition wall 120 with a plurality of layers spaced inside the housing 110,
It is seated on each frame and includes catalyst module layers 130 on which catalyst modules 130C are mounted,
As a plurality of reinforcing partition walls 120, the inside of the housing 110 is divided into a plurality of zones, and passage holes 121 are formed in the reinforcing partition walls 120 so as to be movable to both regions based on the reinforcing partition walls 120. Low pressure SCR reactor, characterized in that.
delete The method of claim 1,
The frame is a low-pressure SCR reactor, characterized in that it comprises a fixed frame 131 fixed to the inner side of the housing 110 and the reinforcing partition wall 120, and a reinforcing beam 131S for reinforcing the fixed frame 131.
The method of claim 3,
The catalyst module layer 130 includes a catalyst support frame 133 on which the catalyst modules 130C are mounted,
It includes a sealing mat 135 that surrounds the outer periphery of the catalyst support frame 133 and contacts the inner side of the housing 110 or the side of the reinforcing partition wall 120 to compensate for the expansion of the catalyst support frame 133,
The catalyst module layer 130 is a low pressure SCR reactor, characterized in that seated on the fixed frame (131).
The method of claim 4,
A dispersion plate that is located between the catalyst module layer at the lowest layer and the exhaust gas inlet pipe 101 among the catalyst module layers 130 positioned in a plurality of layers, and uniformly distributes the exhaust gas introduced through the exhaust gas inlet pipe 101 Low pressure SCR reactor, characterized in that it further comprises (140).
The method of claim 5,
The dispersion plate 140 is a low-pressure SCR reactor, characterized in that the porous plate structure.
The method of claim 1,
A low-pressure SCR reactor comprising a door 105 formed on the top of the housing 110 or in the exhaust gas discharge pipe 102 at a position higher than the uppermost catalyst module layer.
The method of claim 7,
A low-pressure SCR reactor, characterized in that a hoist beam for mounting the hoist 109 is fixed to the top of the housing 110 or the exhaust gas discharge pipe 102 in which the door 105 is formed.
The method according to claim 7 or 8,
It is located between the catalyst module layer 130 at the lowest layer and the exhaust gas inlet pipe 101 among the catalyst module layers 130 located in a plurality of layers, and uniformly distributes the exhaust gas introduced through the exhaust gas inlet pipe 101 Low-pressure SCR reactor, characterized in that it further comprises a distribution plate (140).
The method of claim 9,
The dispersion plate 140 is a low-pressure SCR reactor, characterized in that the porous plate structure.
delete

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