KR102111227B1 - Exhaust gas denitrification device and control method for exhaust gas denitrification device - Google Patents

Abstract

An exhaust gas denitration device for reducing nitrogen oxides contained in engine exhaust gas discharged from a main engine mounted on a ship, the exhaust flow path through which the engine exhaust gas discharged from the main engine flows, a reducing agent storage tank, and a reducing agent injection nozzle, , A denitrification reactor having a denitrification catalyst, a boiler exhaust gas conduit for flowing boiler exhaust gas discharged from a boiler mounted on a ship to an upstream side of a denitrification reactor in an exhaust flow path, and a boiler in a boiler exhaust gas conduit A boiler exhaust gas control valve for controlling the flow of the exhaust gas, and a blower for blowing the boiler exhaust gas flowing through the boiler exhaust gas flow path downstream.

Description

Exhaust gas denitrification device and control method for exhaust gas denitrification device

The present disclosure relates to an exhaust gas denitration device and a control method of the exhaust gas denitration device.

Reduction of nitrogen oxides (NOx) contained in the exhaust gas of engines is also required in a two-stroke diesel engine for ships that is used as a cycle of a ship under the trend of strengthening environmental regulations in recent years. As a method of reducing the NOx contained in the engine exhaust gas, for example, by spraying a reducing agent in the engine exhaust gas, nitrogen oxide (NOx) is converted into nitrogen (N ₂ ) and water (H ₂ O by the action of the SCR catalyst. ), A selective catalytic reduction method (SCR method) is known conventionally.

In general, the SCR catalyst in circulation is premised on continuous use and at an active temperature (for example, 300 ° C or higher), but the temperature of the engine exhaust gas discharged from the above-described marine 2-stroke diesel engine is Since it is low, it may not be possible to exhibit efficient denitrification performance. Particularly, during the start-up of the cycle-during the low-load operation, since the flow rate of the engine exhaust gas discharged from the marine 2-stroke diesel engine is also small, the temperature of the engine exhaust gas is significantly lowered due to heat radiation from the exhaust pipe. Moreover, in the engine provided with the supercharger, since the supercharger is driven by the engine exhaust gas, the temperature of the engine exhaust gas discharged from the supercharger decreases more remarkably.

Furthermore, if the temperature of the engine exhaust gas decreases to 250 ° C. or lower, for example, acidic ammonium sulfate (NH ₄ HSO ₄ ) is generated by reaction with fuel-derived sulfur oxides (SOx), resulting in a decrease in catalyst performance. I have a concern.

In order to cope with such a problem, the marine exhaust gas denitration apparatus of patent document 1 is equipped with a supporting burner for heating the engine exhaust gas discharged from the engine. When the denitrification performance of the denitration catalyst is less than a predetermined level, it is configured to increase the temperature of the engine exhaust gas supplied to the denitration catalyst by this supporting burner.

In addition, the low-temperature denitrification apparatus of Patent Document 2 is capable of supplying an engine exhaust gas discharged from a diesel engine for power generation formed separately from a diesel main engine to a denitration catalyst. Then, by supplying a high-temperature engine exhaust gas discharged from a diesel engine for power generation to a denitration catalyst, the denitration catalyst poisoned by the production of acidic ammonium sulfate and deteriorated in performance is configured to be regenerated.

Japanese Patent Application Publication No. 2012-82804 Japanese Patent Publication No. 2009-222005

However, the ship exhaust gas denitration apparatus for patent document 1 has a problem in that the engine exhaust gas is heated with a dedicated burner burner, which requires installation and fuel cost.

In addition, the low-temperature denitrification device of Patent Document 2 introduces the engine exhaust gas discharged from the diesel engine for power generation, which is formed separately from the diesel main engine, into the exhaust passage, but the diesel engine for power generation is the engine exhaust discharged according to the load. Since the flow rate and temperature of the gas fluctuate, there is a problem that it is difficult to stably supply the engine exhaust gas at a temperature required for regeneration of the denitration catalyst. In addition, as shown in FIG. 1 of Patent Document 2, when there are a plurality of diesel engines for power generation, a plurality of pipes for connecting these diesel engines for power generation and a denitrification catalyst are required, and there is a problem that the apparatus configuration is complicated. .

At least one embodiment of the present invention is an invention made in view of the problems of the prior art described above, and the object thereof is an exhaust gas capable of stably supplying a high-temperature exhaust gas to a denitration catalyst with a simple device configuration. It is to provide a control method of a denitrification device and an exhaust gas denitrification device.

(1) An exhaust gas denitration apparatus according to at least one embodiment of the present invention,

An exhaust passage through which engine exhaust gas discharged from the ship's cycle engine flows;

A reducing agent storage tank for storing a reducing agent,

A reducing agent injection nozzle that injects the reducing agent stored in the reducing agent storage tank into the engine exhaust gas flowing through the exhaust passage;

A denitrification reactor formed on the exhaust flow path and reducing nitrogen oxide contained in the engine exhaust gas,

A boiler exhaust gas flow path that flows boiler exhaust gas discharged from the boiler mounted on the ship to an upstream side of the denitrification reactor in the exhaust flow path,

A boiler exhaust gas control valve for controlling the flow of the boiler exhaust gas in the boiler exhaust gas flow path;

A blower that blows the boiler exhaust gas flowing through the boiler exhaust gas conduit downstream

It is provided.

According to the embodiment described in the above (1), the exhaust gas denitration device includes a boiler exhaust gas flow path and a boiler that flows boiler exhaust gas discharged from a boiler mounted on a ship to an upstream side of a denitrification reactor in an exhaust flow path. A boiler exhaust gas control valve for controlling the flow of boiler exhaust gas in the exhaust gas flow path and a blower for blowing the boiler exhaust gas flowing in the boiler exhaust gas flow path downstream are provided.

Accordingly, in an operating state in which the temperature of the engine exhaust gas discharged from the cycle engine is low, such as when the main engine is started or during low load operation, the boiler exhaust gas discharged from the boiler is passed through the boiler exhaust gas flow path to the denitrification reactor. By distillation, the denitration catalyst can be heated.

In addition, the boiler mounted on the ship supplies, for example, a heat source required for the ship, and the combustion state is substantially constant and stable compared to a diesel engine for power generation.

Therefore, according to the embodiment described in (1) above, compared with the low-temperature denitrification device described in Patent Document 2, it is possible to stably supply a high-temperature exhaust gas to the denitration catalyst.

In addition, while a plurality of diesel engines for power generation are usually provided, the number of boilers installed is often only one, and the number of installations is smaller than that of a diesel engine for power generation.

Therefore, according to the embodiment described in (1) above, compared to the low-temperature denitrification device described in Patent Document 2, the number of boiler exhaust gas flow paths for flowing the boiler exhaust gas discharged from the boiler to the denitrification catalyst is at least. In view of this, it is possible to supply the boiler exhaust gas discharged from the boiler to the denitration catalyst with a simple device configuration.

However, the pressure of the boiler exhaust gas discharged from the boiler is usually lower than the pressure of the engine exhaust gas discharged from the main engine. For this reason, when the exhaust flow path of the boiler and the main engine is connected through the boiler exhaust gas flow path, the pressure of the exhaust flow path propagates to the boiler, and the pressure on the downstream side of the boiler exhaust gas flow in the boiler rises to combust the boiler. There is a possibility of affecting the condition.

Regarding this problem, in the embodiment described in (1) above, a blower is provided to blow the boiler exhaust gas flowing through the boiler exhaust gas flow path downstream. Thereby, it is possible to prevent the pressure of the exhaust passage from propagating to the boiler and affecting the combustion state of the boiler.

(2) In some embodiments, in the exhaust gas denitration device according to (1), the boiler exhaust gas control valve is based on the temperature of the engine exhaust gas, the temperature of the boiler exhaust gas, and the temperature of the denitration reactor. It is further provided with a control device for controlling the opening or closing of the valve and ON / OFF of the operation of the blower.

According to the embodiment described in (2) above, based on the temperature of the engine exhaust gas, the temperature of the boiler exhaust gas, and the temperature of the denitrification reactor, the valve opening or closing of the boiler exhaust gas control valve and the operation of the blower are performed. ON / OFF can be controlled by a control device.

(3) In some embodiments, in the exhaust gas denitration device according to (2) above, the control device has a denitrification reactor temperature less than a first prescribed temperature when the main engine is started or at a low load operation. When the temperature of the engine exhaust gas is less than the second prescribed temperature, and the temperature of the boiler exhaust gas is higher than the temperature of the engine exhaust gas, the valve of the boiler exhaust gas control valve is opened and the operation of the blower is turned ON. Thus, it is configured to supply the boiler exhaust gas discharged from the boiler to the denitrification reactor.

According to the embodiment described in (3) above, when the temperature of the denitrification reactor is lower than the first prescribed temperature, and when the temperature of the boiler exhaust gas is higher than the temperature of the engine exhaust gas, the boiler exhaust gas is denitrified reactor. By supplying to the denitration catalyst, the denitration catalyst can be heated by a high-temperature boiler exhaust gas.

Here, the term "at the start of the main engine" means that the engine discharged from the main engine is for a period of time after the start of the main engine in the stationary state until a predetermined time has elapsed or until a predetermined load is reached. It means that the temperature of the exhaust gas has not reached the second prescribed temperature. In addition, "at the time of low-load operation of a main engine" means a state in which the temperature of the engine exhaust gas discharged from the main engine is below the second prescribed temperature and the main engine continues to operate.

In addition, for example, the 1st prescribed temperature mentioned above is the active temperature of a denitration catalyst. In addition, the above-mentioned second prescribed temperature is the temperature of the engine exhaust gas required to heat the denitration catalyst to the first prescribed temperature when the engine exhaust gas discharged from the main engine is supplied to the denitration reactor. 1 The temperature is equal to or higher than the specified temperature.

(4) In some embodiments, in the exhaust gas denitration apparatus described in (2) or (3) above, the control apparatus has a temperature of the denitration reactor that is less than the third prescribed temperature during regeneration of the denitration catalyst, and When the temperature of the engine exhaust gas discharged from the main engine is less than the fourth prescribed temperature and the temperature of the boiler exhaust gas is higher than the temperature of the engine exhaust gas, the valve of the boiler exhaust gas control valve is opened and the blower is operated. It is configured to turn ON to supply boiler exhaust gas to the denitrification reactor.

According to the embodiment described in (4) above, when the temperature of the denitration reactor is lower than the third prescribed temperature, and when the temperature of the boiler exhaust gas is higher than the temperature of the engine exhaust gas, the boiler exhaust gas is denitrified reactor. By supplying to the denitration catalyst, the poisoned denitration catalyst can be regenerated by heating the denitration catalyst with a hot boiler exhaust gas.

In addition, the term "when regenerating a denitration catalyst" means a state in which measures are taken to restore the performance of a denitration catalyst whose performance has been lowered by poisoning, and specifically, acidic sulfuric acid attached to the surface of the denitration catalyst. In order to remove ammonium by heating, it means a state in which the denitration catalyst is heated above a third prescribed temperature. Whether the denitration catalyst is poisoned or not is determined, for example, when the front and rear differential pressures of the denitration reactor are higher than or equal to a predetermined value. In addition, for example, when the difference in NOx concentration before and after the denitrification reactor becomes less than a predetermined value, it is determined that the denitration catalyst is poisoned. In addition, regeneration of the denitration catalyst is performed assuming that poisoning of the denitration catalyst is in progress when the main engine is continuously operated for a predetermined time or longer, or when the elapsed time from the previous regeneration exceeds a predetermined time. You may do it.

In addition, for example, the above-mentioned third prescribed temperature is a temperature required to regenerate the denitration catalyst. In addition, for example, the above-mentioned fourth prescribed temperature is the temperature of the engine exhaust gas required to heat the denitration catalyst to the third specified temperature when the engine exhaust gas is supplied to the denitrification reactor, and the third It is equal to or higher than the specified temperature.

(5) In some embodiments, in the exhaust gas denitration apparatus according to any one of (1) to (4) above, it branches off from the upstream side of the position where the reducing agent is injected from the reducing agent injection nozzle in the exhaust flow path. , A bypass flow path joining on the downstream side of the denitrification reactor in the exhaust flow path, an exhaust flow path side branch valve formed on the exhaust flow path side in the branch portion where the bypass flow path diverges from the exhaust flow path, and in the branch portion The bypass flow path side branch valve formed on the bypass flow path side of the exhaust pipe, the exhaust flow path side confluence valve formed on the exhaust flow path side in the confluence section where the exhaust flow path and the bypass flow path converge, and the bypass in the confluence section. A bypass flow path side confluence valve formed on the flow path side is further provided.

According to the embodiment described in (5), the flow of the engine exhaust gas is switched by opening and closing each of the exhaust flow path side branch valve, the bypass flow path side branch valve, the exhaust flow path side confluence valve, and the bypass flow path side confluence valve. , It can be switched between the exhaust flow path side and the bypass flow path side.

Therefore, for example, when the ship is passing through a sea area where environmental regulations are strict, the engine exhaust gas flow is switched to the exhaust flow path side, and when a normal sea area is being navigated, the engine exhaust gas flow is switched to the bypass flow path side. It is also possible to switch the flow of the engine exhaust gas in accordance with the environmental regulation values of the sailing area and the like.

(6) In some embodiments, in the exhaust gas denitration device according to (5), a purge gas for supplying a purge gas to a section between an exhaust flow path side branch valve and an exhaust flow path side confluence valve in the exhaust flow path It is further equipped with a supply device.

According to the embodiment described in (6), the purge gas supply device can supply purge gas to a section between the exhaust flow path side branch valve and the exhaust flow path side confluence valve in the exhaust flow path.

(7) In some embodiments, in the exhaust gas denitration device according to (6) above, the control device is in a non-operation of an exhaust gas denitration system comprising a reducing agent storage tank, a reducing agent injection nozzle, and a denitrification reactor, The exhaust flow path side branch valve is closed, the bypass flow path side branch valve is opened, the exhaust flow path side confluence valve is closed, and the bypass flow path side confluence valve is opened. The purge gas supply device is configured to control the purge gas supply device so as to supply a purge gas to a section between the exhaust flow path side branch valve and the exhaust flow path side confluence valve in the exhaust flow path.

According to the embodiment described in (7) above, a purge gas can be sealed in the section between the exhaust flow path side branch valve and the exhaust flow path side confluence valve in the exhaust flow path by the control device. Thereby, for example, when the exhaust gas denitrification system is inoperative, the engine exhaust gas flowing out from the branch passage valve on the exhaust flow path side or the confluence valve on the exhaust flow path side in the valve closed state to the exhaust flow path side contacts the denitrification catalyst, and nitric acid (HNO ₃ ) Can be reliably prevented from being generated.

(8) In some embodiments, in the exhaust gas denitration device according to any one of (5) to (7) above, the control device includes an exhaust gas containing a reducing agent storage tank, a reducing agent injection nozzle, and a denitrification reactor. After the denitrification system is completed, the exhaust flow path side branch valve is closed, the bypass flow path side branch valve is opened, the exhaust flow path side confluence valve is opened, and the bypass flow path side confluence valve is opened. And, it is configured to supply the boiler exhaust gas control valve to the denitrification reactor for a predetermined time by opening the valve and turning on the operation of the blower.

According to the embodiment described in (8) above, after completion of the operation of the exhaust gas denitration system, boiler exhaust gas is supplied to the denitration reactor over a predetermined time. Thereby, the progress of poisoning in the denitration catalyst can be suppressed, and the regeneration interval of the denitration catalyst can be lengthened.

(9) In some embodiments, in the exhaust gas denitration device according to any one of (5) to (8), an exhaust gas economizer disposed on the downstream side of the confluence section in the exhaust flow passage is further provided. .

According to the embodiment described in (9) above, even when the engine exhaust gas passes through either the exhaust passage or the bypass passage by the exhaust gas economizer disposed on the downstream side of the confluence section in the exhaust passage, the engine exhaust gas Heat recovery can be performed.

(10) A control method of an exhaust gas denitration apparatus according to at least one embodiment of the present invention,

An exhaust passage through which engine exhaust gas discharged from the main engine flows;

A reducing agent storage tank for storing a reducing agent,

A reducing agent injection nozzle that injects the reducing agent stored in the reducing agent storage tank into engine exhaust gas flowing through the exhaust flow passage,

A denitrification reactor having a catalyst formed on the exhaust flow path and reducing nitrogen oxide contained in the engine exhaust gas,

A boiler exhaust gas flow path for flowing boiler exhaust gas discharged from a boiler mounted on a ship to an upstream side of the denitrification reactor in the exhaust flow path,

A boiler exhaust gas control valve for controlling the flow of the boiler exhaust gas in the boiler exhaust gas flow path;

As a control method of an exhaust gas denitration device having a blower for blowing the boiler exhaust gas flowing in the boiler exhaust gas flow path to the downstream side,

A step of opening or closing the valve of the boiler exhaust gas control valve and a step of controlling ON / OFF of the operation of the blower are provided.

According to the embodiment described in (10), in the control method of an exhaust gas denitration device for reducing nitrogen oxides contained in engine exhaust gas discharged from a main engine mounted on a ship, the valve of the boiler exhaust gas control valve is opened Alternatively, a step of closing the valve and a step of controlling ON / OFF of the operation of the blower are provided. Accordingly, if necessary, the boiler exhaust gas discharged from the boiler can be supplied to the denitrification reactor and the denitration catalyst can be heated, if necessary.

According to at least one embodiment of the present invention, it is possible to provide an exhaust gas denitration device and a control method for an exhaust gas denitration device capable of stably supplying a high temperature exhaust gas to a denitration catalyst with a simple device configuration.

1 is an overall configuration diagram of an exhaust gas denitration apparatus according to an embodiment of the present invention.
2 is an overall configuration diagram of an exhaust gas denitration apparatus according to an embodiment of the present invention.
3 is a block diagram of a control device according to an embodiment of the present invention.
4 is a block diagram of a control device according to an embodiment of the present invention.
5 is a control flow diagram of a control apparatus according to an embodiment of the present invention, and is a diagram showing a flow of heating control of a denitration catalyst at the time of starting a main engine or at a low load operation.
6 is a control flow diagram of a control apparatus according to an embodiment of the present invention, and is a diagram showing a flow of regeneration control of a denitration catalyst during regeneration of the denitration catalyst.
7 is a timing chart showing a supply timing of a boiler exhaust gas and an operation timing of an exhaust gas denitration system in an exhaust gas denitration apparatus according to an embodiment of the present invention.
8 is a view showing a state in which a purge gas is supplied to a section between an exhaust flow path side branch valve and an exhaust flow path side confluence valve in an exhaust flow path.
9 is a timing chart for explaining the supply timing of the purge gas.
10 is a view showing a state in which a boiler exhaust gas is supplied to a denitrification reactor after the operation of the exhaust gas denitrification system.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, and are merely illustrative examples.

For example, expressions that indicate relative or absolute placement, such as "in any direction", "in any direction", "parallel", "orthogonal", "center", "concentric" or "coaxial", are strictly such In addition to showing the arrangement, it is also assumed that the state is relatively displaced with tolerances or angles or distances that achieve the same function.

For example, expressions indicating that objects such as "equal," "equal," and "homogeneous" are in an equal state not only represent a strictly equivalent state, but also have tolerances or differences in the degree to which the same function is obtained. It is also assumed that the state is present.

For example, an expression representing a shape such as a square shape or a cylindrical shape not only represents a shape such as a square shape or a cylindrical shape in a geometrically strict sense, but also includes irregularities, chamfers, and the like in a range where the same effect is obtained. It shall also be shown the shape to be said.

On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" the components of 1 are not exclusive expressions excluding the existence of other components.

1 and 2 are overall configuration diagrams of an exhaust gas denitration apparatus according to an embodiment of the present invention.

The exhaust gas denitration apparatus according to an embodiment of the present invention is an exhaust gas denitration apparatus 10 for reducing nitrogen oxides contained in engine exhaust gas discharged from a cycle engine 2 mounted on a ship 1. Then, the exhaust gas denitration apparatus 10 (10A, 10B) according to one embodiment of the present invention, as shown in Figs. 1 and 2, the exhaust flow path 11, the exhaust gas denitration system 20, It is equipped with the boiler exhaust gas flow path 12, the boiler exhaust gas control valve 13, and the blower 14.

The main engine 2 is, for example, a two-stroke diesel engine for a ship mounted on the ship 1, and is an engine for providing propulsion for navigating the ship 1. In the illustrated embodiment, the main engine 2 has a cylinder portion (not shown), an exhaust manifold 3, a supercharger 4, an exhaust valve (not shown), and the like. The main engine 2 is configured to discharge the engine exhaust gas from the combustion chamber inside the cylinder by opening the exhaust valve. The exhausted engine exhaust gas is first introduced into the exhaust manifold 3, converted into a static pressure, and then introduced into the turbine portion 4a of the supercharger 4. And after rotating the turbine rotor blade (not shown) arrange | positioned inside the turbine part 4a, it is discharged | emitted from the turbine part 4a.

The exhaust flow path 11 is a tubular flow path through which the engine exhaust gas discharged from the main engine 2 flows. One end side of the exhaust flow path 11 is connected to the outlet side of the turbine portion 4a of the main engine 2. The other end side of the exhaust flow path 11 is connected to a chimney for discharging the engine exhaust gas to the outside.

The exhaust gas denitrification system 20 is a denitrification system for reducing nitrogen oxides (NOx) contained in the engine exhaust gas discharged from the main engine. The exhaust gas denitration system 20 of this embodiment is, for example, a selective catalytic reduction (SCR) system, as shown in Figs. 1 and 2, a reducing agent storage tank 22 for storing a reducing agent, and a reducing agent storage tank ( 22) a reducing agent injection nozzle 24 for injecting the reducing agent stored in the exhaust gas 11 into the engine exhaust gas flowing through the exhaust flow passage 11 and the exhaust flow passage 11 to reduce nitrogen oxide contained in the engine exhaust gas And a denitrification reactor 26 having a denitration catalyst 26a.

The reducing agent storage tank 22 stores, for example, urea water as a reducing agent. Then, when the reducing agent pump 23a is driven, the reducing agent stored in the reducing agent storage tank 22 through the reducing agent flow passage 23 connecting the reducing agent storage tank 22 and the reducing agent injection nozzle 24 is reduced agent injection nozzle (24). Then, the reducing agent is injected from the reducing agent injection nozzle 24 toward the inside of the exhaust passage 11. The denitrification reactor 26 is disposed downstream of the reducing agent injection nozzle 24 in the exhaust flow path 11. The denitrification reactor 26 is a normal member configured to allow the engine exhaust gas to pass through the inside thereof, and is connected to an exhaust pipe in which the inlet side and the outlet side respectively constitute the exhaust flow passage 11. In other words, the denitrification reactor 26 forms a part of the exhaust flow path 11 therein.

The boiler 8 is, for example, an auxiliary boiler mounted on the ship 1, and is used for operation of an auxiliary machine other than the main engine driving on the ship 1, for use in aboard air conditioning equipment, kitchens, and other duties. It is for supplying thermal energy of the lamp on board. In this embodiment, one boiler 8 is mounted on the ship 1. Such a boiler 8 is mounted in most ships having a scale of a predetermined degree or more.

The boiler exhaust gas flow path 12 flows the boiler exhaust gas discharged from the boiler 8 mounted on the ship 1 described above to the upstream side of the denitrification reactor 26 in the exhaust flow path 11. It is a tubular flow path for. In the illustrated embodiment, the connecting portion 12a of the exhaust flow path 11 and the boiler exhaust gas flow path 12 is an upstream side of the denitrification reactor 26, and is located on the downstream side of the reducing agent injection nozzle 24. have.

Moreover, in another embodiment not shown, the connecting portion 12a of the exhaust flow path 11 and the boiler exhaust gas flow path 12 is an upstream side of the denitrification reactor 26, and the reducing agent injection nozzle 24 is also used. It is located upstream. By doing in this way, since the reducing agent can be injected directly to the exhaust gas in which the engine exhaust gas and the boiler exhaust gas are mixed (hereinafter sometimes referred to as "engine-boiler mixed exhaust gas"), it is included in the engine exhaust gas. Not only nitrogen oxides, but also nitrogen oxides contained in the boiler exhaust gas can be efficiently reduced by the denitration catalyst 26a.

The boiler exhaust gas control valve 13 is a valve for controlling the flow of the boiler exhaust gas in the boiler exhaust gas flow path. As the type of the boiler exhaust gas control valve 13, for example, by adjusting the valve opening degree, a control valve for controlling the flow rate of the boiler exhaust gas passing through, or a valve body is opened (for example, deployed). Alternatively, an opening / closing valve or the like that controls the flow rate of the boiler exhaust gas passing through to 0% (does not pass) or 100% (total amount is passed) by closing the valve (for example, completely closing) can be adopted.

In the illustrated embodiment, two boiler exhaust gas control valves 13A and 13B are arranged in the boiler exhaust gas shunt 12. The boiler exhaust gas control valve 13A is disposed on the downstream side of the connecting portion 12a of the exhaust flow path 11 and the boiler exhaust gas flow path, and also on the upstream side of the blower 14 to be described later, and the boiler exhaust gas flow The flow of the boiler exhaust gas flowing through the furnace 12 is controlled. The boiler exhaust gas control valve 13B is a downstream side of the flow of the boiler exhaust gas of the boiler 8, and is arranged in the branch 12b of the boiler exhaust gas duct 12 and the boiler exhaust gas outlet 19 The flow of the boiler exhaust gas discharged from the boiler 8 is switched to the boiler exhaust gas flow path 12 (valve open side) and the boiler exhaust gas discharge path 19 side (valve closed side). However, at least one boiler exhaust gas control valve 13 may be provided, and the number of installations is not particularly limited.

The blower 14 is a device for blowing the boiler exhaust gas flowing in the boiler exhaust gas flow path 12 to the downstream side, and is made of, for example, an attracting fan. The blower 14 resists the pressure of the engine exhaust gas flowing through the exhaust flow path 11 by sucking the boiler exhaust gas flowing upstream of the boiler exhaust gas flow path 12 and discharging it to the downstream side, thereby preventing the boiler exhaust gas Boiler exhaust gas flowing through the flow path 12 is discharged to the exhaust flow path 11. In the illustrated embodiment, the blower 14 is disposed between the two boiler exhaust gas control valves 13A and 13B described above.

Further, in the illustrated embodiment, the main engine 2 is arranged on the bottom surface of the engine room, and the reducing agent injection nozzle 24 and the denitrification reactor 26 are arranged on the floor surface of the 3rd deck, which is one level higher than the bottom surface of the engine room. It is. Moreover, the boiler 8 is arrange | positioned on the floor surface of the 2nd deck 1 level higher than the floor surface of the 3rd deck in which the denitrification reactor 26 is arrange | positioned. The exhaust flow path 11 extends from the bottom surface of the engine room where the main engine 2 is disposed toward the floor surface of the upper deck which is one level higher than the floor surface of the 2nd deck where the boiler 8 is disposed, and the engine exhaust gas It is connected to a chimney for discharging it to the outside. In addition, in the illustrated embodiment, the distance between the reducing agent injection nozzle 24 and the denitrification reactor 26 is secured to a distance required for the injected reducing agent to be sufficiently mixed with the engine exhaust gas.

According to such an embodiment, the exhaust gas denitration apparatus 10 upstream of the denitrification reactor 26 in the exhaust flow path 11 uses the exhaust gas of the boiler exhausted from the boiler 8 mounted on the ship 1. Boiler exhaust gas flow path 12 flowing to the side, boiler exhaust gas control valves 13A, 13B for controlling the flow of boiler exhaust gas in the boiler exhaust gas flow path 12, and boiler exhaust gas flow path ( 12) A blower 14 is provided to blow the boiler exhaust gas flowing therethrough to the downstream side.

Therefore, the boiler exhaust gas discharged from the boiler 8 is discharged from the boiler 8 in the operating state in which the engine exhaust gas discharged from the cycle engine 2, such as when the main engine 2 is started or during low load operation, is low. The denitrification catalyst 26a can be heated by flowing through the gas flow path 12 to the denitrification reactor 26.

Further, the boiler 8 mounted on the ship 1 has a relatively constant combustion state and is stable compared to a diesel engine for power generation.

Therefore, according to such embodiment, compared with the low-temperature denitration apparatus described in the above-mentioned patent document 2, high-temperature exhaust gas can be stably supplied to the denitration catalyst 26a.

Here, as a kind of high-temperature exhaust gas supplied to the denitrification reactor 26, three of (a)-(c) are mentioned below as demonstrated in embodiment mentioned later.

(a) Exhaust gas in which high-temperature boiler exhaust gas is mixed with engine exhaust gas (engine / boiler mixed exhaust gas)

(b) Engine exhaust only (when engine exhaust is hot)

(c) Boiler exhaust gas only (in this case, the engine exhaust gas bypasses the denitrification reactor 26 through the bypass flow passage 15 described later)

In addition, while a plurality of diesel engines for power generation are usually provided, the number of boiler installations is often only one, and the number of installations is smaller than that of a diesel engine for power generation.

Therefore, according to this embodiment, compared with the low-temperature denitrification apparatus described in the above-mentioned Patent Document 2, boiler exhaust gas flow for flowing the boiler exhaust gas discharged from the boiler 8 to the denitration catalyst 26a Since the number of installations of the furnace 12 is at least, it is possible to supply the boiler exhaust gas discharged from the boiler 8 to the denitration catalyst 26a with a simple device configuration.

By the way, the pressure of the boiler exhaust gas discharged from the boiler 8 is usually lower than the pressure of the engine exhaust gas discharged from the main engine 2. For this reason, when the boiler 8 and the exhaust flow path 11 of the main engine 2 are connected through the boiler exhaust gas flow path 12, the pressure of the exhaust flow path 11 propagates to the boiler 8, There is a possibility that the pressure on the downstream side of the boiler exhaust gas flow in the boiler 8 rises and affects the combustion state of the boiler 8.

Regarding this problem, in the above-described embodiment, a blower 14 is provided to blow the boiler exhaust gas flowing through the boiler exhaust gas flow path 12 to the downstream side. Thereby, it is possible to suppress the pressure of the exhaust passage 11 from propagating to the boiler 8 and affecting the combustion state of the boiler 8.

In some embodiments, as shown in FIG. 2, the exhaust gas denitration device 10B branches from the upstream side of the position where the reducing agent is injected from the reducing agent injection nozzle 24 in the exhaust flow path 11 and exhausts Exhaust in the bypass passage 15 joining on the downstream side of the denitrification reactor 26 in the flow passage 11 and in the branch 16 where the bypass flow passage 15 branches from the exhaust passage 11 The exhaust flow path side branch valve 16A formed on the flow path 11 side, the bypass flow path side branch valve 16B formed on the bypass flow path 15 side in the branch portion 16, and the exhaust flow path ( 11) The exhaust flow path side confluence valve 17A formed in the exhaust flow path 11 side in the confluence part 17 in which the bypass flow path 15 joins, and the bypass flow path in the confluence part 17 (15) The bypass flow path side confluence valve (17B) formed on the side is additionally obtained. Compare

In addition, in FIG. 2 and FIGS. 8 and 10 described later, the exhaust flow path side branch valve 16A, the bypass flow path side branch valve 16B, the exhaust flow path side confluence valve 17A, and the bypass flow path side confluence In the valve symbol indicating the valve 17B, the white paint indicates the valve open state, and the black paint indicates the valve closed state.

According to such an embodiment, each of the exhaust flow path side branch valve 16A, the bypass flow path side branch valve 16B, the exhaust flow path side confluence valve 17A, and the bypass flow path side confluence valve 17B is opened and closed, respectively. By doing so, the flow of the engine exhaust gas discharged from the main engine 2 can be switched to the exhaust flow path 11 side and the bypass flow path 15 side.

Therefore, for example, when the ship 1 passes through the sea area where environmental regulations are strict, the engine exhaust gas flow is switched to the exhaust flow path 11 side, and when the general sea area is being navigated, the engine exhaust gas flow is reduced. It is also possible to switch the flow of the engine exhaust gas according to the environmental regulation value of the navigating sea area, such as switching to the bypass channel 15 side.

In some embodiments, as shown in FIG. 2, a purge gas supply for supplying a purge gas to a section between the exhaust flow path side branch valve 16A and the exhaust flow path side confluence valve 17A in the exhaust flow path 11 The device 18 is further provided.

In the illustrated embodiment, the purge gas supply device 18 includes a purge gas generator 18A for generating a purge gas, and the generated purge gas with an exhaust flow path side branch valve 16A in the exhaust flow path 11 The purge gas flow path 18B flowing in the section between the exhaust flow path side confluence valve 17A and the purge gas flow path 18B side at the connection between the exhaust flow path 11 and the purge gas flow path 18B It consists of the purge gas supply valve 18C arrange | positioned. As the purge gas, in addition to an inert gas such as nitrogen (N ₂ ), a gas having a NOx concentration and a SOx concentration of a predetermined concentration or less and a moisture content of a predetermined amount or less can be used. Further, in the illustrated embodiment, the purge gas generator is arranged on the floor surface of the 2nd deck having the same height as the boiler 8 is arranged.

According to this embodiment, the purge gas supply device 18 supplies the purge gas to the section between the exhaust flow path side branch valve 16A and the exhaust flow path side confluence valve 17A in the exhaust flow path 11. Can be.

Therefore, as will be described later, for example, during the non-operation of the exhaust gas denitration system 20, the section between the exhaust flow path side branch valve 16A and the exhaust flow path side confluence valve 17A in the exhaust flow path 11 is performed. By supplying the purge gas, the engine exhaust gas flowing from the exhaust flow path side branch valve 16A or the exhaust flow path side confluence valve 17A in the valve closed state to the exhaust flow path 11 side comes into contact with the denitration catalyst 26a. The production of nitric acid (HNO ₃ ) can be reliably prevented.

In some embodiments, as shown in FIG. 2, an exhaust gas economizer 60 disposed on the downstream side of the confluence section 17 in the exhaust flow path 11 is further provided.

The exhaust gas economizer 60 is a device for recovering the heat energy of the engine exhaust gas flowing through the exhaust flow path 11 and for heat exchange with a heating medium such as water. In the illustrated embodiment, the exhaust gas economizer 60 is arranged on the floor surface of the 2nd deck having the same height as the boiler 8. The boiler water heated by the exhaust gas economizer 60 is configured to be supplied to the boiler 8.

According to this embodiment, the engine exhaust gas discharged from the main engine 2 by the exhaust gas economizer 60 disposed on the downstream side of the confluence section 17 in the exhaust passage 11 is the exhaust passage ( 11) Even when it passes through any of the bypass flow paths 15, heat can be recovered from the engine exhaust gas. That is, heat recovery can be performed from both the engine exhaust gas flowing through the exhaust flow path 11 and the engine exhaust gas flowing through the bypass flow path 15 by one exhaust gas economizer 60.

<Control device 40>

3 and 4 are block diagrams of a control device according to an embodiment of the present invention. 5 is a control flow diagram of a control apparatus according to an embodiment of the present invention, and is a diagram showing a flow of control at the time of starting a main engine or at a low load operation. 6 is a control flow diagram of a control device according to an embodiment of the present invention, and is a view showing a flow of control at the time of starting a main engine or at a low load operation.

The control device 40 according to an embodiment of the present invention includes, for example, a microcomputer comprising a central processing unit (CPU), a random access memory (RAM), a read-only memory (ROM), and an I / O interface. It is configured as.

1 and 2, the exhaust gas denitration apparatus 10 according to the embodiment of the present invention includes an engine exhaust gas pressure sensor 31, a boiler exhaust gas pressure sensor 32, and an engine exhaust gas. Various sensors, such as the temperature sensor 33, the boiler exhaust gas temperature sensor 34, and the denitrification reactor temperature sensor 35, are mounted.

The engine exhaust gas pressure sensor 31 is a sensor that measures the pressure of the engine exhaust gas discharged from the main engine 2. In the illustrated embodiment, the engine exhaust gas pressure sensor 31 is connected to the upstream side of the denitrification reactor 26 in the exhaust flow path 11, and also the connection portion between the exhaust flow path 11 and the bypass flow path 15 ( 12a), or between the denitrification reactor 26 and the connection portion 12a.

The boiler exhaust gas pressure sensor 32 is a sensor that measures the pressure of the boiler exhaust gas discharged from the boiler 8. In the illustrated embodiment, the boiler exhaust gas pressure sensor 32 is provided on the downstream side of the boiler 8 and also on the branch portion 12b of the boiler exhaust gas flow path 12 and the boiler exhaust gas discharge path 19. It is arranged on the upstream side.

The engine exhaust gas temperature sensor 33 is a sensor that measures the temperature of the engine exhaust gas discharged from the main engine 2. In the illustrated embodiment, the engine exhaust gas temperature sensor 33 is located on the upstream side of the position where the reducing agent is injected from the reducing agent injection nozzle 24, and in the exhaust gas denitration device 10 shown in FIG. 2, the exhaust passage ( 11) is arranged on the upstream side of the branch 16 where the bypass flow path 15 branches.

The boiler exhaust gas temperature sensor 34 is a sensor that measures the temperature of the boiler exhaust gas discharged from the boiler 8. In the illustrated embodiment, the boiler exhaust gas temperature sensor 34 is disposed downstream of the branch portion 12b of the boiler exhaust gas flow path 12 and further upstream of the blower 14. The denitrification reactor temperature sensor 35 is a sensor that measures the temperature of the denitrification reactor 26. In the illustrated embodiment, it is arranged at the inlet of the denitrification reactor 26, and the ambient temperature at the inlet of the denitrification reactor 26 is measured.

The data measured by these various sensors are transmitted to the control device 40 through wired or wireless communication means.

In some embodiments, in the exhaust gas denitration apparatus 10 (10A, 10B) shown in FIGS. 1 and 2, as shown in FIGS. 3 and 4, the exhaust gas of the engine exhausted from the main engine 2 Based on the temperature, the temperature of the boiler exhaust gas discharged from the boiler 8, and the temperature of the denitrification reactor 26, the valve opening or closing of the boiler exhaust gas control valve 13 and the operation of the blower 14 A control device 40 for controlling ON / OFF is further provided.

FIG. 3 is a block diagram of the control device 40 showing the configuration in particular when the main engine 2 is started or operated during low load operation. And, as shown in FIG. 3, the control device 40 includes an operation unit 41, a heating execution determination unit 42, a heating necessity determination unit 44, a boiler exhaust gas / engine exhaust gas comparison unit 46 , Boiler exhaust temperature comparison unit (47), Boiler exhaust gas regulation temperature setting unit (48), Engine exhaust gas regulation temperature setting unit (49), Engine exhaust gas temperature comparison unit (50), Denitrification reactor regulation temperature setting unit ( 51).

Here, the term "at the start of the main engine" means that the main engine 2 in the stopped state is for a period of time until a predetermined time has elapsed or until a predetermined load is reached. 2) refers to a state in which the temperature of the engine exhaust gas discharged from (the temperature of the engine exhaust gas measured by the engine exhaust gas temperature sensor 33 described above in this embodiment) does not reach the second prescribed temperature described later. do. In addition, "at the time of low-load operation of the cycle engine" means a state in which the temperature of the engine exhaust gas discharged from the cycle engine 2 is below the second prescribed temperature and the cycle engine 2 continues to operate. do.

The heating necessity determining unit 44 includes a temperature of the denitration reactor 26 input from the denitration reactor temperature sensor 35 (atmosphere temperature at the inlet of the denitration reactor 26) and a denitration reactor prescribed temperature setting unit It is a judgment part which compares the preset temperature set in (51) and determines whether or not it is necessary to heat the denitration catalyst 26a. For example, when the temperature of the denitration reactor 26 is less than the first prescribed temperature that is the active temperature of the denitration catalyst 26a, it is determined that heating of the denitration catalyst 26a is necessary. When the temperature of the denitration reactor 26 is equal to or higher than the first prescribed temperature, it is determined that heating of the denitration catalyst 26a is unnecessary. And it is comprised so that the determination result may be output to the heating execution determination part 42 mentioned later.

When the heating execution determination unit 42 determines that the denitration catalyst 26a is required to be heated in the above-described heating necessity determination unit 44, whether or not to actually heat the denitration catalyst 26a is performed. It is a judging section for judging. The heating execution determination unit 42 is based on the output from the boiler exhaust gas temperature comparison unit 47 and the engine exhaust gas temperature comparison unit 50, and the denitrification catalyst 26a by the boiler exhaust gas. It is determined whether or not to perform heating.

For example, although the temperature of the engine exhaust gas discharged from the cycle engine 2 is often lower than the second prescribed temperature, depending on the operating state of the cycle engine 2, the temperature of the engine exhaust gas is the second regulation. It may be higher than the temperature. In such a case, since the denitration catalyst 26a can be heated to the first prescribed temperature by the engine exhaust gas discharged from the main engine 2, it is determined that heating by the boiler exhaust gas is not performed.

Further, for example, when the temperature of the boiler exhaust gas discharged from the boiler 8 is lower than the temperature of the engine exhaust gas discharged from the cycle engine 2, the heating by the boiler exhaust gas cannot be performed. , It is judged that heating by the boiler exhaust gas is not performed.

Further, for example, when the temperature of the boiler exhaust gas discharged from the boiler 8 is supplied to the denitration reactor 26 when the boiler exhaust gas is supplied, it is necessary to heat the denitration catalyst 26a to a first specified temperature. Even in cases such as lowering the temperature, it may be configured to determine that heating is not performed.

In other cases, it is determined that the denitration catalyst 26a is heated by the boiler exhaust gas.

Here, the second prescribed temperature means that when the engine exhaust gas discharged from the main engine 2 is supplied to the denitration reactor 26, the denitration catalyst 26a is heated to the first specified temperature, which is its active temperature. It is the temperature of the engine exhaust gas required to. This second prescribed temperature is set as a temperature equal to or higher than the first prescribed temperature. For example, as in the case of this embodiment, as the case where the temperature of the engine exhaust gas is measured by the engine exhaust gas temperature sensor 33, in the section from the engine exhaust gas temperature sensor 33 to the denitrification reactor 26 In the case where the temperature drop due to heat dissipation or the like from the exhaust pipe cannot be ignored, the second prescribed temperature is set as a temperature higher than the first prescribed temperature in view of the temperature drop due to the heat dissipation. In the case where the temperature drop due to heat dissipation from the exhaust pipe from the engine exhaust gas temperature sensor 33 to the denitration reactor 26 can be neglected, the second specified temperature is set to the same temperature as the first specified temperature.

The operation unit 41 is a control unit for controlling ON / OFF of the blower 14 and its rotational speed while controlling the opening degree of the boiler exhaust gas control valve 13. On the basis of the determination result of whether or not heating execution is required from the heating execution determination unit 42, the operation unit 41 opens the valve or opens the valve of the boiler exhaust gas control valve 13, and blowers 14 It controls ON / OFF of operation. When it is determined that the execution of heating is &quot; needed &quot;, the boiler exhaust gas control valve 13 is opened, and the operation of the blower 14 is turned ON. When it is determined that heating is not necessary, the boiler exhaust gas control valve 13 is closed, and the blower 14 is turned off. Moreover, the operation part 41 is the pressure of the engine exhaust gas discharged from the main engine 2 and the pressure of the boiler exhaust gas discharged from the boiler 8, which is output from the boiler exhaust gas / engine exhaust gas comparison part 46. Based on the comparison result (differential pressure), the number of revolutions of the blower 14 is controlled. The number of revolutions of the blower 14 is controlled by the number of revolutions necessary to resist the pressure of the engine exhaust gas discharged from the main engine 2 and to discharge the boiler exhaust gas into the exhaust flow path 11. Specifically, the greater the differential pressure between the pressure of the engine exhaust gas discharged from the main engine 2 and the pressure of the boiler exhaust gas discharged from the boiler 8, the higher the rotational speed is controlled. The rotation speed is calculated based on, for example, a map defining the relationship between the differential pressure and the rotation speed. In addition, for controlling the temperature of the denitrification reactor 26 measured by the denitrification reactor temperature sensor 35 to a target temperature (for example, the first prescribed temperature), for example, feedback control, or of the periodic engine 2 It may be configured to control the number of revolutions of the blower 14 by feed forward control that compensates for disturbances including output fluctuations.

The boiler exhaust gas / engine exhaust gas comparison unit 46 is a comparison unit that compares the pressure of the engine exhaust gas discharged from the main engine 2 and the pressure of the boiler exhaust gas discharged from the boiler 8. In the boiler exhaust gas / engine exhaust gas comparison section 46, the pressure of the engine exhaust gas discharged from the cycle engine 2 measured by the engine exhaust gas pressure sensor 31 and the boiler exhaust gas pressure sensor 32 are measured. The pressure of the boiler exhaust gas discharged from the boiler 8 is input. Then, the differential pressure between the pressure of the engine exhaust gas discharged from the main engine 2 and the pressure of the boiler exhaust gas discharged from the boiler 8 is configured to be output to the operation unit 41.

The boiler exhaust gas temperature comparison unit 47 compares the temperature of the boiler exhaust gas input from the boiler exhaust gas temperature sensor 34 and the preset temperature set in the boiler exhaust gas prescribed temperature setting unit 48 Wealth. The set temperature set in the boiler exhaust gas prescribed temperature setting unit 48 is, for example, when the boiler exhaust gas is supplied to the denitrification reactor 26, for heating the denitration catalyst 26a to the first prescribed temperature. It is the temperature of the exhaust gas required for the boiler. Then, the comparison result of the temperature of the boiler exhaust gas discharged from the boiler 8 and the temperature of the boiler exhaust gas and the set temperature set by the boiler exhaust gas prescribed temperature setting unit 48 is sent to the heating execution determination unit 42. It is configured to output.

The engine exhaust gas temperature comparison unit 50 compares the temperature of the engine exhaust gas input from the engine exhaust gas temperature sensor 33 and the preset temperature set in the engine exhaust gas prescribed temperature setting unit 49 Wealth. The set temperature set in the engine exhaust gas prescribed temperature setting section 49 is, for example, when the engine exhaust gas discharged from the main engine 2 is supplied to the denitration reactor 26, the denitration catalyst 26a Is the above-mentioned second prescribed temperature which is the temperature of the engine exhaust gas required to heat to the first prescribed temperature. Then, the comparison result of the temperature of the engine exhaust gas discharged from the cycle engine 2 and the temperature of the engine exhaust gas discharged from the cycle engine 2 and the set temperature set in the engine exhaust gas prescribed temperature setting section 49 , It is configured to output to the heating execution determination unit 42.

The control flow of the control device 40 shown in FIG. 3 will be described in FIG. 5 to be described later.

4 is a block diagram of the control device 40 showing the configuration in particular when it is operated during regeneration of the denitration catalyst 26a. And, as shown in Fig. 4, the control device 40 includes an operation unit 41, a regeneration execution determination unit 43, a regeneration necessity determination unit 45, a boiler exhaust gas / engine exhaust gas comparison unit 46 , Boiler exhaust gas temperature comparison unit 47, Boiler exhaust gas regulation temperature setting unit 48, Engine exhaust gas regulation temperature setting unit 49, Engine exhaust gas temperature comparison unit 50, Denitrification reactor differential pressure calculation unit 52 ), A denitration catalyst regeneration comparison section 53, a continuous operation time count section 54, and a denitration catalyst regeneration interval count section 55.

The regeneration necessity determination unit 45 is based on the comparison result of the front and rear differential pressure of the denitration reactor 26 input from the denitration reactor differential pressure sensor 36 and the differential pressure calculated by the denitration reactor differential pressure calculation unit 52, It is a judging section that determines whether or not it is necessary to regenerate the denitration catalyst 26a. In the denitrification reactor differential pressure calculation unit 52, an appropriate differential pressure in the operation state (denitrification catalyst 26a) based on the engine operation load signal 37 regarding engine speed, torque, and the like output from an ECU (not shown) ) Is calculated. And, for example, when the front and rear differential pressures of the denitration reactor 26 are equal to or greater than the calculated differential pressure calculated by the denitration reactor differential pressure calculation unit 52, it is determined that poisoning of the denitration catalyst 26a is in progress, and the denitration catalyst ( 26a) is judged to be necessary. When the front-rear differential pressure of the denitrification reactor 26 is less than the calculated differential pressure, it is determined that regeneration of the denitration catalyst 26a is unnecessary. Then, the result of the determination is configured to be output to the reproduction execution determination unit 43 to be described later.

Further, the regeneration necessity determination unit 45 determines whether it is necessary to regenerate the denitration catalyst 26a based on the output from the denitration catalyst regeneration comparison unit 53. The denitration catalyst regeneration comparison unit 53 compares the continuous operation time output from the continuous operation time counting unit 54 with the specified continuous operation time, and the last regeneration output from the denitration catalyst regeneration interval count unit 55 It is a comparison unit that compares the elapsed time from the specified reproduction interval. Then, when the counted continuous operation time exceeds the specified continuous operation time, and when the elapsed time from the counted previous reproduction exceeds the specified reproduction interval, the comparison result is compared. It outputs it to the determination part 45 which needs to be reproduced. The regeneration necessity determination unit 45 that has received such an output from the denitration catalyst regeneration comparison unit 53 needs to regenerate the denitration catalyst 26a even if, for example, the front and rear differential pressure of the denitration reactor 26 is less than the calculated differential pressure. It is judged that there is.

Here, "when regenerating the denitration catalyst" means a state in which measures are taken to restore the performance of the denitration catalyst 26a whose performance has been lowered by poisoning, and specifically, on the surface of the denitration catalyst 26a. It means a state in which the denitration catalyst 26a is heated above the third prescribed temperature, which is the temperature (regeneration temperature) required to regenerate the denitration catalyst 26a in order to heat and remove the attached acidic ammonium sulfate. Whether or not the denitration catalyst 26a is poisoned, for example, when the front and rear differential pressures of the denitration reactor 26 are equal to or higher than a predetermined value, it is determined that the denitration catalyst 26a is poisoned. In addition, for example, when the NOx concentration difference between the front and rear of the denitration reactor 26 becomes less than a predetermined value, the denitration catalyst 26a may be configured to be poisoned.

When the regeneration execution determination unit 43 determines that regeneration of the denitration catalyst 26a is necessary in the regeneration necessity determination unit 45 described above, whether or not to actually regenerate the denitration catalyst 26a is performed. It is a judging section for judging. The regeneration execution determination unit 43 is based on the output from the boiler exhaust gas temperature comparison unit 47 and the output from the engine exhaust gas temperature comparison unit 50, of the denitration catalyst 26a by the boiler exhaust gas. A needless judgment is made as to whether or not reproduction is to be performed.

For example, when the temperature of the denitrification reactor 26 is higher than the third prescribed temperature, it is determined that heating by the boiler exhaust gas is not performed because the denitration catalyst 26a is already considered to be in the regenerated state. .

Further, for example, the temperature of the engine exhaust gas discharged from the cycle engine 2 is often lower than the fourth prescribed temperature, but depending on the operating state of the cycle engine 2, the temperature of the engine exhaust gas is It may be higher than the fourth prescribed temperature. In such a case, since the denitration catalyst 26a can be heated to the third prescribed temperature by the engine exhaust gas discharged from the main engine 2, it is determined not to perform regeneration by the boiler exhaust gas.

Further, for example, when the temperature of the boiler exhaust gas discharged from the boiler 8 is lower than the temperature of the engine exhaust gas discharged from the cycle engine 2, the heating by the boiler exhaust gas cannot be performed. , It is judged that regeneration by the boiler exhaust gas is not performed.

Further, for example, when the temperature of the boiler exhaust gas discharged from the boiler 8 is supplied to the denitration reactor 26 when the boiler exhaust gas is supplied, it is necessary to heat the denitration catalyst 26a to a third prescribed temperature. Even in cases such as lowering the temperature, it may be configured to determine that regeneration is not performed.

In other cases, it is determined to regenerate the denitration catalyst 26a by the boiler exhaust gas.

Here, the fourth prescribed temperature means the amount of engine exhaust gas required to heat the denitration catalyst 26a to the third specified temperature when the engine exhaust gas discharged from the main engine is supplied to the denitration reactor 26. Temperature. This fourth prescribed temperature is set as a temperature equal to or higher than the third prescribed temperature. For example, as in this embodiment, when the temperature of the engine exhaust gas is measured by the engine exhaust gas temperature sensor 33, in the section of the denitrification reactor 26 from the engine exhaust gas temperature sensor 33 In the case where the temperature drop due to heat dissipation from the exhaust pipe cannot be ignored, the fourth prescribed temperature is set as a temperature higher than the third prescribed temperature in view of the temperature drop due to the heat radiation. In the case where the temperature drop due to heat dissipation from the exhaust pipe from the engine exhaust gas temperature sensor 33 to the denitration reactor 26 can be neglected, the fourth prescribed temperature is set to the same temperature as the third specified temperature.

The operation unit 41 is a control unit for controlling ON / OFF of the blower 14 and its rotational speed while controlling the opening degree of the boiler exhaust gas control valve 13. On the basis of the result of the determination as to whether or not heating execution is required from the regeneration execution determination unit 43, the operation unit 41 opens the valve or closes the valve of the boiler exhaust gas control valve, and blowers 14 It controls ON / OFF of operation. When it is determined that regeneration is "needed", the boiler exhaust gas control valve 13 is opened, and the operation of the blower 14 is turned ON. When it is determined that regeneration is "not necessary", the boiler exhaust gas control valve 13 is closed, and the operation of the blower 14 is turned off. Moreover, the operation part 41 is the pressure of the engine exhaust gas discharged from the main engine 2 and the pressure of the boiler exhaust gas discharged from the boiler 8, which is output from the boiler exhaust gas / engine exhaust gas comparison part 46. Based on the comparison result (differential pressure), the number of revolutions of the blower 14 is controlled. The number of revolutions of the blower 14 is controlled by the number of revolutions necessary to resist the pressure of the engine exhaust gas discharged from the main engine 2 and to discharge the boiler exhaust gas into the exhaust flow path 11. Specifically, the greater the differential pressure between the pressure of the engine exhaust gas discharged from the main engine 2 and the pressure of the boiler exhaust gas discharged from the boiler 8, the higher the rotational speed is controlled. The rotation speed is calculated based on, for example, a map defining the relationship between the differential pressure and the rotation speed. Also, for example, in order to control the temperature of the denitrification reactor 26 measured by the denitrification reactor temperature sensor 35 to a target temperature (for example, the third prescribed temperature), feedback control, or of the periodic engine 2 It may be configured to control the number of revolutions of the blower 14 by feed forward control in which output fluctuation is disturbance.

The boiler exhaust gas temperature comparator 47 is similar to the embodiment shown in FIG. 3, to the temperature of the boiler exhaust gas input from the boiler exhaust gas temperature sensor 34 and the boiler exhaust gas prescribed temperature setting unit 48 Therefore, it is a comparison unit that compares a preset temperature. The set temperature set in the boiler exhaust gas prescribed temperature setting section 48 is, for example, when the boiler exhaust gas is supplied to the denitrification reactor 26, the denitration catalyst 26a is heated to a third prescribed temperature. It is necessary temperature. Then, the comparison result of the temperature of the boiler exhaust gas discharged from the boiler 8 and the temperature of the boiler exhaust gas and the set temperature set by the boiler exhaust gas prescribed temperature setting unit 48 is returned to the regeneration execution determination unit 43. It is configured to output.

The engine exhaust gas temperature comparator 50 is similar to the embodiment shown in FIG. 3, in the temperature of the engine exhaust gas input from the engine exhaust gas temperature sensor 33 and the engine exhaust gas prescribed temperature setting unit 49 Therefore, it is a comparison unit that compares a preset temperature. The set temperature set in the engine exhaust gas prescribed temperature setting unit 49 is, for example, when the engine exhaust gas discharged from the main engine 2 is supplied to the denitration reactor 26, the denitration catalyst 26a Is the above-mentioned fourth prescribed temperature which is the temperature of the engine exhaust gas required to heat to the third specified temperature. Then, the comparison result of the temperature of the engine exhaust gas discharged from the cycle engine 2 and the temperature of the engine exhaust gas discharged from the cycle engine 2 and the set temperature set in the engine exhaust gas prescribed temperature setting section 49 , It is configured to output to the reproduction execution determination unit 43.

The control flow of the control device 40 shown in FIG. 4 will be described in FIG. 6 to be described later.

5 is a control flow diagram of a control device according to an embodiment of the present invention, and is a view showing a flow of heating control of a denitration catalyst at the time of starting a main engine or at a low load operation.

As shown in Fig. 5, at the time of starting the main engine or at the time of low-load operation (S51), the temperature of the denitrification reactor 26 input from the denitrification reactor temperature sensor 35 in the heating necessity determination unit 44 is shown. The set temperature (first prescribed temperature) set in advance in the denitrification reactor prescribed temperature setting unit 51 is compared. Then, when the temperature of the denitration reactor 26 is less than the first prescribed temperature that is the active temperature of the denitration catalyst 26a ("YES" in S52), the process proceeds to the next step (S53). When the temperature of the denitration reactor 26 is higher than or equal to the first prescribed temperature that is the active temperature of the denitration catalyst 26a ("YES" in S53), heating of the denitration catalyst 26a is unnecessary, and thus the boiler exhaust gas is used. Heating control of the denitration catalyst 26a is not performed, and the control ends.

Next, in the heating execution determination unit 42, it is compared whether the temperature of the engine exhaust gas discharged from the main engine 2 is less than the second prescribed temperature (S53). When the temperature of the engine exhaust gas discharged from the main engine 2 is less than the second prescribed temperature ("YES" in S53), the process proceeds to the next step S54. When the temperature of the engine exhaust gas is equal to or higher than the second prescribed temperature ("NO" in S53), the temperature of the denitrification reactor 26 can be heated up to the first specified temperature only by the engine exhaust gas. Heating control of the denitration catalyst 26a is not carried out, and the control ends.

Further, next, in the heating execution determination unit 42, the temperature of the boiler exhaust gas discharged from the boiler 8 is compared with the temperature of the engine exhaust gas discharged from the cycle engine 2 (S54). When the temperature of the boiler exhaust gas is equal to or higher than the temperature of the engine exhaust gas discharged from the cycle engine 2 ("YES" in S54), the process proceeds to the next step S55. When the temperature of the boiler exhaust gas is less than the temperature of the engine exhaust gas discharged from the cycle engine 2 ("NO" in S54), the heating by the boiler exhaust gas is in a state where the heating is not possible. Heating control of the denitration catalyst 26a is not performed, and the control ends.

In addition, for convenience of description, although it was described as executing S54 after S53, the order of S53 and S54 is not limited to this. S54 may be executed before S53, or both steps may be executed simultaneously.

Then, in the operation unit 41, the boiler exhaust gas control valve 13 is opened, and the blower 14 is started (S55). Then, the boiler exhaust gas is supplied to the denitrification reactor 26 (S56), and the denitration reactor 26 is heated by the high-temperature boiler exhaust gas.

In more detail, when the boiler exhaust gas control valve 13 is opened and the blower 14 is started, the boiler exhaust gas discharged from the boiler 8 is exhausted through the boiler exhaust gas flow path 12. It flows to the upstream side of the denitrification reactor 26 in the flow path 11. Then, the engine exhaust gas flowing through the exhaust passage 11 and the boiler exhaust gas are mixed to generate an exhaust gas (engine / boiler mixed exhaust gas) higher than the engine exhaust gas. Then, this high-temperature exhaust gas (engine-boiler mixed exhaust gas) is supplied to the denitration reactor 26 (S56), so that the denitration reactor 26 is heated.

Further, the engine exhaust gas may be bypassed through the bypass flow passage 15 described above, and only the high-temperature boiler exhaust gas may be supplied to the denitration reactor 26 (S56) to control the denitration reactor 26 to be heated.

Then, until the temperature of the denitrification reactor 26 reaches the first prescribed temperature, the boiler exhaust gas is continuously supplied to the denitrification reactor 26 (S57).

Further, even after the temperature of the denitrification reactor 26 reaches the first prescribed temperature, while the temperature of the engine exhaust gas discharged from the main engine 2 rises above the second prescribed temperature, the boiler exhaust gas May be continuously supplied to the denitrification reactor 26 (S58).

Then, when the temperature of the denitrification reactor 26 reaches the first prescribed temperature, and the temperature of the engine exhaust gas discharged from the main engine 2 rises above the second prescribed temperature (in S57, S58, YES ), The condition that the denitration catalyst 26a can be stably operated is provided, the boiler exhaust gas control valve 13 is abolished, the blower 14 is stopped (S59), and a series of boiler exhausts The heating control of the denitration catalyst 26a by gas ends.

6 is a control flow diagram of a control device according to an embodiment of the present invention, and is a diagram showing a flow of regeneration control of a denitration catalyst during regeneration of the denitration catalyst.

As shown in Fig. 6, at the time of regeneration of the denitration catalyst 26a (S61), in the regeneration necessity determination unit 45, the front and rear differential pressures of the denitration reactor 26 input from the denitration reactor differential pressure sensor 36 and , The calculated differential pressure calculated in the denitrification reactor differential pressure calculation unit 52 is compared (S62). And when the front-rear differential pressure of the denitrification reactor 26 is less than a calculated differential pressure ("YES" in S62), it progresses to the next step.

Next, in the denitration catalyst regeneration comparison unit 53, the continuous operation time output from the continuous operation time counting unit 54 is compared with the prescribed continuous operation time (S63). Then, when the continuous operation time output from the continuous operation time count unit 54 is less than the specified continuous operation time ("YES" in S63), the process proceeds to the next step.

Next, in the denitration catalyst regeneration comparison section 53, the elapsed time from the previous regeneration output from the denitration catalyst regeneration interval count section 55 is compared with the specified regeneration interval (S64). Then, when the elapsed time from the previous regeneration outputted from the denitration catalyst regeneration interval count section 55 is less than the specified regeneration interval ("YES" in S64), regeneration of the denitration catalyst 26a is not performed (S65) , Ends control.

In addition, for convenience of description, although it was described as being executed in the order of S62, S63 and S64, the order of S62 to S64 is not limited to this. The order of S62 to S64 may be changed, or S62 to S64 may be executed simultaneously.

When it is determined as "NO" in at least one step in S62 to S64, regeneration of the denitration catalyst 26a is performed (S66).

In the regeneration execution determination unit 43, it is compared whether the temperature of the denitrification reactor 26 is less than the third prescribed temperature (S67). When the temperature of the denitration reactor 26 is less than the third prescribed temperature ("YES" in S67), the process proceeds to the next step (S68). When the temperature of the denitrification reactor 26 is higher than or equal to the third prescribed temperature ("NO" in S67), the denitration catalyst 26a is already considered to be in a regenerated state, and thus the denitration catalyst 26a by the boiler exhaust gas The reproduction control is not performed, and the control ends.

Next, in the regeneration execution determination unit 43, it is compared whether the temperature of the engine exhaust gas discharged from the main engine 2 is less than the fourth prescribed temperature (S68). When the temperature of the engine exhaust gas discharged from the main engine 2 is less than the fourth prescribed temperature ("YES" in S68), the process proceeds to the next step S69. When the temperature of the engine exhaust gas discharged from the main engine 2 is equal to or higher than the fourth prescribed temperature ("NO" in S68), the temperature of the denitrification reactor 26 is heated to the third specified temperature only by the engine exhaust gas. Because it is possible, the regeneration control of the denitration catalyst 26a by the boiler exhaust gas is not carried out, and the control ends.

Further, next, in the regeneration execution determination unit 43, the temperature of the boiler exhaust gas discharged from the boiler 8 and the temperature of the engine exhaust gas discharged from the cycle engine 2 are compared (S69). When the temperature of the boiler exhaust gas is equal to or higher than the temperature of the engine exhaust gas discharged from the main engine 2 ("YES" in S69), the process proceeds to the next step S610. When the temperature of the boiler exhaust gas is less than the temperature of the engine exhaust gas discharged from the cycle engine 2 ("NO" in S69), the heating by the boiler exhaust gas is in a state where the heating is not possible. Regeneration control of the denitration catalyst 26a is not performed, and control is ended.

Then, in the operation unit 41, the boiler exhaust gas control valve 13 is opened, and the blower 14 is started (S610). Then, the boiler exhaust gas is supplied to the denitrification reactor (S611), and the denitration reactor 26 is heated by the high-temperature boiler exhaust gas to regenerate the denitration catalyst 26a.

In more detail, when the boiler exhaust gas control valve 13 is opened and the blower 14 is started, the boiler exhaust gas discharged from the boiler 8 is exhausted through the boiler exhaust gas flow path 12. It flows to the upstream side of the denitrification reactor 26 in the flow path 11. Then, the engine exhaust gas flowing through the exhaust passage 11 and the boiler exhaust gas are mixed to generate an exhaust gas (engine / boiler mixed exhaust gas) higher than the engine exhaust gas. Then, this high-temperature exhaust gas (engine-boiler mixed exhaust gas) is supplied to the denitration reactor 26 (S611), so that the denitration reactor 26 is heated to regenerate the denitration catalyst 26a.

Further, the engine exhaust gas may be bypassed through the bypass flow passage 15 described above, and only the high-temperature boiler exhaust gas is supplied to the denitration reactor 26 (S611), so that the denitrification reactor 26 may be controlled to be heated.

Then, the boiler exhaust gas is continuously supplied to the denitration reactor 26 until the temperature of the denitration reactor 26 reaches the third prescribed temperature (S612).

Further, even after the temperature of the denitrification reactor 26 reaches the third prescribed temperature, the boiler exhaust gas may be continuously supplied to the denitration reactor 26 until a prescribed regeneration time has elapsed (S613). .

Then, when the temperature of the denitration reactor 26 reaches the third prescribed temperature and the specified regeneration time has elapsed ("YES" in S612 and S613), it is assumed that the denitration catalyst 26a regeneration is completed. The boiler exhaust gas control valve 13 is closed, the blower 14 is stopped (S614), and the regenerative control of the denitration catalyst 26a by a series of boiler exhaust gases is ended.

7 is a timing chart showing a supply timing of a boiler exhaust gas and an operation timing of an exhaust gas denitration system in an exhaust gas denitration apparatus according to an embodiment of the present invention.

In some embodiments, as shown in FIG. 7, almost simultaneously with the start of operation of the main engine 2, the valve of the boiler exhaust gas control valve 13 is opened, and the operation of the blower 14 is turned ON. The supply of boiler exhaust gas is started (time t1). Thereby, the high-temperature exhaust gas (engine-boiler mixed exhaust gas) in which the engine exhaust gas and the boiler exhaust gas are mixed is supplied to the denitration reactor 26, the temperature of the denitration reactor 26 gradually rises, and at time t2. In this case, the deactivation catalyst 26a is at least the first specified temperature that is the active temperature. And almost simultaneously with this, the operation of the exhaust gas denitration system 20 is started. Then, at the time t3, when the engine exhaust gas temperature reaches the second prescribed temperature or higher, the boiler exhaust gas control valve 13 is closed, and the operation of the blower 14 is turned OFF, and the exhaust gas of the boiler is exhausted. Stop supply.

That is, in the present embodiment, the temperature of the denitrification reactor 26 reaches the first prescribed temperature when the main engine 2 is started (or during low load operation), and is discharged from the main engine 2 as well. The supply of the boiler exhaust gas to the denitrification reactor 26 is continued until the temperature of the engine exhaust gas to be reached is equal to or higher than the second prescribed temperature. Thus, the denitration catalyst 26a can be raised to the active temperature early, and after the engine exhaust gas temperature reaches the second prescribed temperature, the supply of the boiler exhaust gas to the denitration reactor 26 is stopped, It is intended to prevent wasteful operation of the blower 14.

As described above, according to the above-described embodiment, the boiler is based on the temperature of the engine exhaust gas discharged from the main engine 2, the temperature of the boiler exhaust gas discharged from the boiler 8, and the temperature of the denitrification reactor 26. A control device 40 for controlling opening / closing of the valve of the exhaust gas control valve 13 and ON / OFF of the operation of the blower 14 is further provided. Accordingly, based on the temperature of the engine exhaust gas discharged from the main engine 2, the temperature of the boiler exhaust gas discharged from the boiler 8, and the temperature of the denitrification reactor 26, the boiler exhaust gas control valve 13 The valve opening or closing of the valve and ON / OFF of the operation of the blower 14 can be controlled by the control device 40.

Further, according to the above-described embodiment, when the temperature of the denitrification reactor 26 is lower than the first prescribed temperature, the temperature of the boiler exhaust gas discharged from the boiler 8 is discharged from the cycle engine 2 When the temperature of the engine exhaust gas to be higher is higher, the denitration catalyst 26a can be heated by the hot boiler exhaust gas by supplying the boiler exhaust gas discharged from the boiler 8 to the denitration reactor 26.

Further, according to the above-described embodiment, the temperature of the denitration reactor 26 is lower than the third prescribed temperature, and the temperature of the boiler exhaust gas discharged from the boiler 8 is discharged from the cycle engine 2 When the temperature is higher than the engine exhaust gas, the boiler exhaust gas discharged from the boiler 8 is supplied to the denitrification reactor 26 to heat the denitrification catalyst 26a by the high-temperature boiler exhaust gas and poison it. The denitration catalyst 26a can be regenerated.

8 is a view showing a state in which a purge gas is supplied to a section between an exhaust flow path side branch valve and an exhaust flow path side confluence valve in an exhaust flow path. 9 is a timing chart for explaining the supply timing of the purge gas.

In some embodiments, as shown in FIG. 8, the control device 40 closes the exhaust flow path side branch valve 16A when the exhaust gas denitration system 20 is inactive, and bypass bypass flow side branch The valve 16B is opened to the valve, the exhaust flow path side confluence valve 17A is closed, and the bypass flow path side confluence valve 17B is opened. The purge gas supply device 18 is configured to control the purge gas supply device 18 so as to supply a purge gas to the section between the exhaust flow path side branch valve 16A and the exhaust flow path side confluence valve 17A in the exhaust flow path 11. At this time, the boiler exhaust gas control valve 13 remains closed.

In addition, here, the state in which the exhaust gas denitration system 20 is operating means that the reducing agent is being injected into the exhaust passage 11 from the reducing agent injection nozzle 24, and the reducing agent from the reducing agent injection nozzle 24 is Although not being jetted, high-temperature exhaust gas (engine-boiler mixed exhaust gas, engine exhaust gas, or boiler exhaust gas) is supplied to the denitrification reactor 26, and the denitrification reactor 26 is heated to a third prescribed temperature to denitrify It is assumed that both catalysts 26a are being regenerated.

Timings for supplying the purge gas to the section between the exhaust flow path side branch valve 16A and the exhaust flow path side confluence valve 17A in the exhaust flow path 11 are shown in FIGS. 9 (a) to 9 (c). There are three timings.

In Fig. 9A, after the operation of the exhaust gas denitration system 20 is completed, the purge gas is injected only once.

In Fig. 9B, after the operation of the exhaust gas denitration system 20 is completed, the purge gas is injected a plurality of times at predetermined intervals.

In Fig. 9C, after the operation of the exhaust gas denitration system 20 is completed, the purge gas is continuously supplied.

According to this embodiment, the purge gas can be sealed in the section between the exhaust flow path side branch valve 16A and the exhaust flow path side confluence valve 17A in the exhaust flow path 11 by the control device 40. have. Thus, for example, when the exhaust gas denitrification system 20 is inoperative, the engine flows out from the exhaust flow path side branch valve 16A or the exhaust flow path side confluence valve 17A in the valve closed state to the exhaust flow path 11 side. It is possible to reliably prevent the production of nitric acid (HNO ₃ ) when the exhaust gas contacts the denitration catalyst 26a.

10 is a view showing a state in which a boiler exhaust gas is supplied to a denitrification reactor after the denitrification system is completed.

In some embodiments, as shown in FIG. 10, after completion of the operation of the exhaust gas denitration system 20, the control device 40 closes the exhaust flow path side branch valve 16A and closes the bypass flow path side. The branch valve 16B is opened by a valve, the exhaust flow path side confluence valve 17A is opened, and the bypass flow path side confluence valve 17B is opened. Then, the valve of the boiler exhaust gas control valve 13 is opened, and the operation of the blower 14 is turned ON, so that the boiler exhaust gas discharged from the boiler 8 is supplied to the denitration reactor 26 for a predetermined time. do.

According to this embodiment, after the operation of the exhaust gas denitration system 20, the boiler exhaust gas is supplied to the denitration reactor 26 over a predetermined time. Thereby, the progress of poisoning in the denitration catalyst 26a can be suppressed, and the regeneration interval of the denitration catalyst 26a can be lengthened.

In addition, the control method of the exhaust gas denitration apparatus according to at least one embodiment of the present invention is an exhaust gas for reducing nitrogen oxides contained in engine exhaust gas discharged from a cycle engine 2 mounted on a ship 1 It is a control method of the denitrification apparatus 10 (10A, 10B). The exhaust gas denitration apparatus 10 (10A, 10B) includes an exhaust passage 11 through which engine exhaust gas discharged from the main engine 2 flows, a reducing agent storage tank 22 for storing a reducing agent, and a reducing agent storage tank ( 22) a reducing agent injection nozzle 24 for injecting the reducing agent stored in the engine exhaust gas flowing through the exhaust passage 11, and the exhaust passage 11 to reduce nitrogen oxide contained in the engine exhaust gas The exhaust gas denitration system 20 including the denitration reactor 26 having the denitration catalyst 26a and the boiler exhaust gas discharged from the boiler 8 mounted on the ship 1 are provided in the exhaust flow path 11. A boiler exhaust gas flow path 12 that flows upstream of the denitrification reactor 26, and a boiler exhaust gas control valve 13 that controls the flow of boiler exhaust gas in the boiler exhaust gas flow path 12, Boiler ship And a blower 14 for blowing the boiler exhaust gas flowing through the gas doryu 12 to the downstream side. The control method of the exhaust gas denitration device includes a step of opening or closing the valve of the boiler exhaust gas control valve 13 and a step of controlling ON / OFF of the operation of the blower 14.

According to this embodiment, in the control method of the exhaust gas denitration apparatus 10 (10A, 10B) for reducing nitrogen oxide contained in the engine exhaust gas discharged from the main engine 2 mounted on the ship 1 In this case, a step of opening or closing the valve of the boiler exhaust gas control valve 13 and a step of controlling ON / OFF of the operation of the blower 14 are provided. Therefore, if necessary, the boiler exhaust gas discharged from the boiler 8 can be supplied to the denitrification reactor 26, if necessary, and the denitration catalyst 26a can be heated.

In some embodiments, the boiler exhaust gas control is based on the temperature of the engine exhaust gas discharged from the cycle engine 2, the temperature of the boiler exhaust gas discharged from the boiler 8, and the temperature of the denitrification reactor 26. The step of opening the valve 13 or closing the valve 13 and the step of controlling ON / OFF of the operation of the blower 14 are further provided.

In some embodiments, the temperature of the denitrification reactor 26 is less than the first specified temperature, and the exhaust gas of the engine exhaust gas discharged from the cycle engine 2 during start-up or low load operation of the cycle engine 2 Boiler exhaust gas control valve 13 when the temperature is less than the second prescribed temperature and the temperature of the boiler exhaust gas discharged from the boiler 8 is higher than the temperature of the engine exhaust gas discharged from the cycle engine 2 The step of supplying the boiler exhaust gas discharged from the boiler 8 to the denitrification reactor 26 is further provided by turning on the valve and turning on the operation of the blower 14.

In some embodiments, in regeneration of the denitration catalyst 26a, the temperature of the denitration reactor 26 is less than the third prescribed temperature, and the temperature of the engine exhaust gas discharged from the cycle engine 2 is less than the fourth prescribed temperature Also, when the temperature of the boiler exhaust gas discharged from the boiler 8 is higher than the temperature of the engine exhaust gas discharged from the cycle engine 2, the boiler exhaust gas control valve 13 is opened with a valve and blower The step of supplying the boiler exhaust gas discharged from the boiler 8 to the denitration reactor 26 is further provided by turning ON the operation of (14).

In some embodiments, during the non-operation of the exhaust gas denitration system 20, the exhaust flow path side branch valve 16A is closed, the bypass flow path side branch valve 16B is opened, and the exhaust flow path side confluence valve is opened. Between the step of closing the valve 17A and opening the bypass flow path side confluence valve 17B, and between the exhaust flow path side branch valve 16A and the exhaust flow path side confluence valve 17A in the exhaust flow path 11 A step of controlling the purge gas supply device 18 is further provided to supply the purge gas to the section of.

In some embodiments, after completion of the operation of the exhaust gas denitration system 20, the exhaust flow path side branch valve 16A is closed, the bypass flow path side branch valve 16B is opened, and the exhaust flow path side joins. The step of opening the valve 17A to open the valve, opening the bypass flow path side confluence valve 17B, opening the boiler exhaust gas control valve 13, and turning on the operation of the blower 14 are turned ON. The step of supplying the boiler exhaust gas discharged from the boiler 8 to the denitrification reactor 26 for a predetermined time is further provided.

Although some embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the object of the present invention.

1 ship
2 cycle engine
3 exhaust manifold
4 supercharger
4a turbine section
5 exhaust valve
8 boiler
10 (10A, 10B) exhaust gas denitrification system
11 exhaust flow path
12 Boiler Exhaust Furnace
12a connection
12b branch
13 (13A, 13B) boiler exhaust gas control valve
14 blowers
15 Bypass Euro
16 quarters
16A exhaust flow path branch valve
16B bypass flow path branch valve
17 confluence
17A exhaust flow path side confluence valve
17B bypass flow path confluence valve
18 purge gas supply
18A purge gas generator
18B purge gas conduit
18C purge gas supply valve
19 Boiler exhaust
20 exhaust denitrification system
22 reducing agent storage tank
23 reducing agent euro
23a reducing agent pump
24 reducing agent injection nozzle
26 Denitrification reactor
26a denitrification catalyst
31 Engine exhaust pressure sensor
32 boiler exhaust gas pressure sensor
33 Engine exhaust temperature sensor
34 boiler exhaust temperature sensor
35 Denitrification reactor temperature sensor
36 Denitrification reactor differential pressure sensor
37 Engine operating load signal
40 control unit
41 Control panel
42 Heating execution judgment unit
43 Playback execution judgment section
44 Whether heating is necessary
45 Whether playback is necessary
46 Boiler exhaust / engine exhaust comparison
47 Boiler exhaust temperature comparison section
48 Boiler exhaust gas regulation temperature setting part
49 Engine exhaust gas regulation temperature setting part
50 engine exhaust temperature comparison section
51 Denitrification reactor prescribed temperature setting part
52 Denitrification reactor differential pressure calculation unit
53 Denitrification catalyst regeneration comparison section
54 continuous operation time count
55 Denitrification catalyst regeneration interval count section
60 exhaust gas economizer

Claims (10)

An exhaust passage through which engine exhaust gas discharged from the ship's cycle engine flows;
A reducing agent storage tank for storing a reducing agent,
A reducing agent injection nozzle that injects the reducing agent stored in the reducing agent storage tank into the engine exhaust gas flowing through the exhaust passage;
A denitrification reactor formed on the exhaust flow path and reducing nitrogen oxide contained in the engine exhaust gas,
A boiler exhaust gas flow path that flows boiler exhaust gas discharged from the boiler mounted on the ship to an upstream side of the denitrification reactor in the exhaust flow path,
A boiler exhaust gas control valve for controlling the flow of the boiler exhaust gas in the boiler exhaust gas flow path;
And a blower for blowing the boiler exhaust gas flowing through the boiler exhaust gas flow path downstream. According to claim 1,
Control to control the valve opening or closing of the boiler exhaust gas control valve and ON / OFF of the operation of the blower based on the temperature of the engine exhaust gas, the temperature of the boiler exhaust gas, and the temperature of the denitrification reactor. An exhaust gas denitration device further comprising a device. According to claim 2,
The control device, at the start of the cycle engine or at a low load operation,
When the temperature of the denitrification reactor is less than the first specified temperature, and the temperature of the engine exhaust gas is less than the second specified temperature, and the temperature of the boiler exhaust gas is higher than the temperature of the engine exhaust gas, the boiler exhaust An exhaust gas denitration apparatus, configured to supply the boiler exhaust gas to the denitration reactor by opening a gas control valve and turning on the operation of the blower. The method according to claim 2 or 3,
The control device in the regeneration of the denitration catalyst of the denitration reactor,
When the temperature of the denitrification reactor is less than the third specified temperature, and the temperature of the engine exhaust gas is less than the fourth specified temperature, and the temperature of the boiler exhaust gas is higher than the temperature of the engine exhaust gas, the boiler exhaust An exhaust gas denitration apparatus, configured to supply the boiler exhaust gas to the denitration reactor by opening a gas control valve and turning on the operation of the blower. According to claim 2,
A bypass flow path branching from the upstream side of the position where the reducing agent is injected from the reducing agent injection nozzle in the exhaust flow path, and joining on the downstream side of the denitrification reactor in the exhaust flow path,
An exhaust flow path side branch valve formed on the exhaust flow path side in the branch portion where the bypass flow path branches from the exhaust flow path,
A bypass flow path side branch valve formed on the bypass flow path side in the branch portion,
An exhaust flow path side confluence valve formed on the exhaust flow path side in a confluence section where the exhaust flow path and the bypass flow path converge;
An exhaust gas denitration device further comprising a bypass flow path side confluence valve formed on the bypass flow path side in the confluence section. The method of claim 5,
And a purge gas supply device for supplying a purge gas to a section between the exhaust flow path side branch valve and the exhaust flow path side confluence valve in the exhaust flow passage. The method of claim 6,
The control device, during the non-operation of the exhaust gas denitrification system including the reducing agent storage tank, the reducing agent injection nozzle, and the denitrification reactor,
Close the valve on the exhaust flow path side branch valve,
The bypass valve on the side of the bypass flow path opens the valve,
The confluence valve on the exhaust flow path side is closed, and
The bypass flow path side confluence valve to open the valve,
And an exhaust gas denitration device configured to control the purge gas supply device so as to supply a purge gas to a section between the exhaust flow path side branch valve and the exhaust flow path side confluence valve in the exhaust flow passage. The method according to any one of claims 5 to 7,
The control device, after completion of the operation of the exhaust gas denitrification system including the reducing agent storage tank, the reducing agent injection nozzle, and the denitrification reactor,
Close the valve on the exhaust flow path side branch valve,
The bypass valve on the side of the bypass flow path opens the valve,
The confluence valve on the exhaust flow path side is opened to open the valve,
The bypass flow path side confluence valve to open the valve,
Exhaust gas denitration apparatus, configured to supply the boiler exhaust gas to the denitration reactor for a predetermined time by opening the valve of the boiler exhaust gas control valve and turning on the operation of the blower. The method according to any one of claims 5 to 7,
An exhaust gas denitration device further comprising an exhaust gas economizer disposed on the downstream side of the confluence section in the exhaust flow passage. An exhaust passage through which engine exhaust gas discharged from the main engine flows;
A reducing agent storage tank for storing a reducing agent,
A reducing agent injection nozzle that injects the reducing agent stored in the reducing agent storage tank into engine exhaust gas flowing through the exhaust flow passage,
A denitrification reactor having a catalyst formed on the exhaust flow path and reducing nitrogen oxide contained in the engine exhaust gas,
A boiler exhaust gas flow path for flowing boiler exhaust gas discharged from a boiler mounted on a ship to an upstream side of the denitrification reactor in the exhaust flow path,
A boiler exhaust gas control valve for controlling the flow of the boiler exhaust gas in the boiler exhaust gas flow path;
As a control method of an exhaust gas denitration device having a blower for blowing the boiler exhaust gas flowing in the boiler exhaust gas flow path to the downstream side,
And a step of opening or closing the valve of the boiler exhaust gas control valve and a step of controlling ON / OFF of the operation of the blower.

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