JP7149852B2 - Selective catalytic reduction system and power unit provided with the same - Google Patents

Description

The present invention relates to a selective catalytic reduction system that reduces nitrogen oxides contained in exhaust gas using a selective catalytic reduction reaction, and a power plant having the same.

2. Description of the Related Art Generally, a power unit used in a ship or the like includes a diesel engine that generates power, a turbocharger that supplies scavenging air to the diesel engine, and a nitrogen oxide contained in exhaust gas discharged from the diesel engine. Selective Catalytic Reduction (SCR) systems for reducing substances and the like.

The selective catalytic reduction system reacts nitrogen oxides contained in the exhaust gas with the reducing agent while passing the exhaust gas and the reducing agent through a reactor in which a catalyst is installed, thereby reducing nitrogen and A process of reduction to water vapor is performed.

In the case of ships, the amount of nitrogen oxides (NOx) and sulfur oxides (SOx) emitted from ships is within the Emission Control Area (ECA) to prevent air pollution caused by engines. The performance and operation of diesel engines and selective catalytic reduction systems are required so that they can meet international Tier-III regulations (IMO Tier-III).

In order to operate marine diesel engines efficiently, different fuels are normally supplied to the diesel engines inside and outside the emission control sea area.

Specifically, high sulfur fuel oil (HFO) is used outside the emission control area, and low sulfur fuel oil (Marine Gas Oil, MGO) is used before the vessel enters the emission control area. ) are being exchanged for As an example, low-sulfur fuel oil is fuel oil that has been desulfurized so that the sulfur content is 0.1% or less.

However, in order to meet the regulation of nitrogen oxide (NOx) emissions in the emission control area, it is difficult to meet the regulation only by replacing the fuel supplied to the diesel engine.

In other words, in order to efficiently operate marine diesel engines and selective catalytic reduction systems, in addition to exchanging the fuel supplied to the diesel engines, effective operation control of the diesel engines and selective catalytic reduction systems must be performed. is required.

Embodiments of the present invention provide a selective catalytic reduction system and a power plant capable of efficient operation.

According to an embodiment of the present invention, fuel is selectively supplied from any one of a plurality of fuel tanks in which different types of fuel are respectively stored and discharged from an engine that generates power. A selective catalytic reduction system for reducing nitrogen oxides (NOx) in exhaust gas includes a fuel sensor that senses the type of fuel supplied to the engine and a fuel sensor contained in the exhaust gas discharged from the engine. A reactor installed with a catalyst for reducing nitrogen oxides, a catalyst preheating unit for preheating the catalyst installed in the reactor, and supplying a reducing agent to the exhaust gas flowing into the reactor. determining whether or not to change the fuel based on the sensing result of the reducing agent supply unit and the fuel sensing unit, and at least one of the catalyst preheating unit and the reducing agent supply unit according to the determination result; A control unit for determining whether one operation is necessary, a display unit, and a signal from a user for instructing whether or not to operate at least one of the catalyst preheating unit and the reducing agent supply unit are inputted. and a user input unit, wherein the control unit determines whether operation of at least one of the catalyst preheating unit and the reducing agent supply unit is necessary when it is determined that the fuel has been changed. displaying the determination result on the display unit, operating at least one of the catalyst preheating unit and the reducing agent supply unit according to the input result of the user input unit ; A sulfur concentration sensor that measures the sulfur concentration of fuel .

The fuel sensing unit includes a fuel information receiving unit that receives physical property information of the fuel supplied to the engine from the outside, and selects one of different types of fuel in the plurality of fuel tanks for the engine. and a valve information receiving section for receiving switching state information of the fuel switching valve for supplying fuel.

In the invention as a reference example of the present invention, the fuel sensor may include one or more sensors for measuring physical property values of the fuel supplied to the engine.

The physical property value may include at least one of temperature and viscosity of the fuel, and the sensor may include one or more of a temperature sensor and a viscosity sensor.

The above-described selective catalytic reduction system includes a display unit and a user input unit through which a user inputs a signal indicating whether to operate at least one of the catalyst preheating unit and the reducing agent supply unit. and further including Further, when it is determined that the fuel has been changed, the control unit displays a determination result as to whether or not at least one of the catalyst preheating unit and the reducing agent supply unit needs to be operated on the display unit. and operates at least one of the catalyst preheating unit and the reducing agent supply unit according to the input result of the user input unit .

The control unit may operate the catalyst preheating unit before operating the reducing agent supply unit.

The catalyst preheating unit includes a preheating channel that connects a rear end of the reactor and a front end of the reactor, and a heater that is provided above the preheating channel and raises the temperature of a fluid moving in the preheating channel. and a blower provided above the preheating channel for circulating the fluid heated by the heating device.

Further, according to the embodiment of the present invention, the power plant comprises a plurality of fuel tanks storing fuels of different components, an engine supplied with the fuel from the plurality of fuel tanks to generate power, and the plurality of a fuel supply line connecting the fuel tank and the engine; a fuel switching valve provided in the fuel supply line for changing the type of fuel supplied to the engine; and the type of fuel supplied to the engine a nitrogen oxide reduction device for reducing nitrogen oxides (NOx) contained in the exhaust gas of the engine; and changing the fuel based on the sensing result of the fuel sensor. a control unit for determining whether or not it is necessary to change the operating state of the engine or whether it is necessary to operate the nitrogen oxide reduction device according to the determination result; a display unit; an input unit for inputting whether or not to operate the nitrogen oxide reduction device from a user, the nitrogen oxide reduction device reducing nitrogen oxides contained in the exhaust gas discharged from the engine. a reactor provided with a catalyst for reducing nitrogen oxides contained in the exhaust gas discharged from the engine; and at least one of a selective catalytic reduction system having a reducing agent supply unit that supplies a reducing agent to the inflowing exhaust gas, wherein the control unit determines whether it is necessary to change the operating state of the engine. or whether at least one of the selective catalytic reduction system and the exhaust gas recirculation device needs to be operated on the display unit, and the engine state according to the input result of the input unit or operate at least one of the selective catalytic reduction system and the exhaust gas recirculation device, and the fuel sensing unit is a sulfur concentration sensor that measures the sulfur concentration of the fuel .

The fuel sensing unit includes at least one of a fuel information receiving unit that receives physical property value information of the fuel supplied to the engine from the outside, and a valve information receiving unit that receives switching state information of the fuel switching valve. or one receiver.

In the invention as a reference example of the present invention, the fuel sensor may include one or more sensors for measuring physical property values of the fuel supplied to the engine.

The physical property value may include at least one of temperature and viscosity of the fuel, and the sensor may include one or more of a temperature sensor and a viscosity sensor.

The nitrogen oxide reduction device includes an exhaust gas recirculation device provided in the engine for reducing nitrogen oxides contained in the exhaust gas discharged from the engine, A selective catalytic reduction system comprising a reactor installed with a catalyst for reducing contained nitrogen oxides and a reducing agent supply unit supplying a reducing agent to the exhaust gas flowing into the reactor including at least one of Also, the power unit may further include a display unit and an input unit through which a user inputs whether or not to operate the nitrogen oxide reduction device. Further, the control unit displays whether or not it is necessary to change the operating state of the engine or whether or not operation of at least one of the selective catalytic reduction system and the exhaust gas recirculation device is necessary. to change the engine state or to operate at least one of the selective catalytic reduction system and the exhaust gas recirculation device according to the input result of the input unit .

The nitrogen oxide reduction device includes an exhaust gas recirculation device provided in the engine for reducing nitrogen oxides contained in the exhaust gas discharged from the engine, A selective catalytic reduction system comprising a reactor installed with a catalyst for reducing contained nitrogen oxides and a reducing agent supply unit supplying a reducing agent to the exhaust gas flowing into the reactor at least any one of Further, when it is determined that it is necessary to change the operating state of the engine or to operate the nitrogen oxide reduction device, the control unit limits the output of the engine, or At least one of an exhaust gas recirculation device and the selective catalytic reduction system can be operated.

The selective catalytic reduction system includes a reactor equipped with a catalyst for reducing nitrogen oxides contained in the exhaust gas discharged from the engine, and reducing the exhaust gas flowing into the reactor. A reducing agent supply can be included for supplying a reducing agent. Also, the control unit may control whether to operate the reducing agent supply unit according to a change in a physical property value of the fuel supplied to the engine, which is measured by the fuel sensing unit .

The selective catalytic reduction system may further include a catalyst preheating unit for preheating the catalyst installed in the reactor. Also, the control unit can operate the catalyst preheating unit before operating the reducing agent supply unit.

The selective catalytic reduction system includes a reactor installed with a catalyst for reducing nitrogen oxides contained in the exhaust gas discharged from the engine, and preheating the catalyst installed in the reactor. A catalyst preheat section may be included. Also, the control unit may control whether to operate the catalyst preheating unit according to a change in physical properties of the fuel supplied to the engine, which is measured by the fuel sensing unit .

The catalyst preheating unit includes a preheating channel that connects a rear end of the reactor and a front end of the reactor, and a heater that is provided above the preheating channel and raises the temperature of a fluid moving in the preheating channel. and a blower provided above the preheating channel for circulating the fluid heated by the heating device.

ADVANTAGE OF THE INVENTION According to the Example of this invention, it is possible to operate a selective catalytic reduction system and a power plant provided with the same efficiently.

1 is a configuration diagram of a selective catalytic reduction system and a power plant having the same according to a first embodiment of the present invention; FIG. 4 is a graph showing changes in temperature of fuel due to replacement of fuel supplied to the engine; FIG. 2 is a configuration diagram of a selective catalytic reduction system and a power plant having the same according to a second embodiment of the present invention; FIG. 3 is a configuration diagram of a selective catalytic reduction system and a power plant having the same according to a third embodiment of the present invention;

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. The present invention can be implemented in various modifications and is not limited to the examples herein.

In these embodiments, constituent elements having similar configurations are denoted by the same reference numerals, and are typically described in the first embodiment, and other embodiments differ from the first embodiment. Only the configuration will be described.

The drawings are schematic representations and are not drawn to scale. Relative dimensions and proportions in the drawings are exaggerated or reduced in size for clarity and convenience, and any dimensions are illustrative only and are limiting. is not. Also, similar structures, elements or parts in more than one drawing are labeled with the same reference numerals to indicate similar characteristics.

The embodiments of the present invention specifically illustrate preferred embodiments of the present invention. And various drawing interpretations are possible. Accordingly, embodiments are not limited to the particular forms shown and include, for example, variations in form due to manufacture.
Hereinafter, a selective catalytic reduction system (abbreviated as "SCR") 301 and a power plant 101 including the same according to a first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1 , power plant 101 may include multiple fuel tanks 281 , 282 , fuel supply line 285 , fuel selector valve 270 , engine 200 , and selective catalytic reduction system 301 .

A plurality of fuel tanks 281 and 282 store fuels of different components. Specifically, the plurality of fuel tanks 281 , 282 can include a first fuel tank 281 and a second fuel tank 282 . Also, the first fuel tank 281 can store a first fuel, and the second fuel tank 282 can store a second fuel. For example, the first fuel can be High sulfur fuel oil (abbreviated as "HFO") and the second fuel is Marine Gas Oil ("MGO"). ) can be.

However, the first embodiment of the present invention is not limited to the above. That is, the plurality of fuel tanks 281, 282 can include more than two fuel tanks, and the first and second fuels can be various fuels known to those skilled in the art. can be done.

Fuel is supplied from the plurality of fuel tanks 281 and 282 to the engine 200 to generate power and exhaust exhaust gas. At this time, the exhaust gas discharged from the engine 200 contains sulfur oxides (SOx) and nitrogen oxides (NOx).

Specifically, engine 200 may be a two-stroke low speed diesel engine. However, the first embodiment of the present invention is not so limited, and the engine 200 can also be a four-stroke medium speed diesel engine. Also, multiple engines 200 may be used, in which case a mixture of two-stroke low-speed diesel engines and four-stroke medium-speed diesel engines may be used. At this time, the two-stroke low-speed diesel engine can be used as the main power source to generate propulsion power for the ship, and the four-stroke medium-speed diesel engine can be used for power generation or as an auxiliary power source. can.

Also, the engine 200 is not limited to a marine engine, and may be a vehicle engine. That is, engine 200 can be a variety of engines known to those skilled in the art.

Also, the power plant 101 may further include a turbocharger (not shown). The turbocharger is connected to the exhaust port of engine 200 . Specifically, the turbocharger may include a turbine rotated by the pressure of the exhaust gas discharged from the engine 200, and a compressor that receives power from the turbine and compresses the air that is supplied to the engine 200. can.

Fuel supply line 285 connects multiple fuel tanks 281 , 282 and engine 200 . That is, the fuel supply line 285 supplies fuel stored in the plurality of fuel tanks 281 and 282 to the engine 200 .

Fuel switching valve 270 is provided on fuel supply line 285 . Further, fuel switching valve 270 can change the type of fuel supplied to engine 200 . Specifically, the fuel switching valve 270 selects either one of the first fuel stored in the first fuel tank 281 and the second fuel stored in the second fuel tank 282. It can be selectively supplied to engine 200 .

That is, the fuel switching valve 270 is provided to supply the first fuel to the engine 200 when in the first position, and to supply the second fuel to the engine 200 when in the second position. ing. Here, the operating position of the fuel switching valve 270 is changed between the first position and the second position, and the position information of the fuel switching valve 270 is sent to the control unit 700, which will be described later, and the fuel sensor, which will be described later. It is provided to either one of the unit 810 or a valve information receiving unit (not shown). Although fuel switching valve 270 is shown to selectively supply two types of fuel to engine 200, it is possible to selectively supply three or more types of fuel to engine 200 as required. can. In this case, the fuel switching valve 270 can be composed of one or more valves.

Exhaust flow path 610 moves exhaust gases discharged from engine 200 . Also, when the power plant 101 includes a turbocharger, the exhaust flow path 610 sequentially connects the engine 200, the turbocharger, and the reactor 300 of the selective catalytic reduction system 301, which will be described later. That is, the exhaust gas discharged from the engine 200 moves along the exhaust passage 610 and flows into the reactor 300 .

A selective catalytic reduction (SCR) system 301 reduces nitrogen oxides (NOx) contained in exhaust gas emitted during power generation of the engine 200 .

A selective catalytic reduction system 301 according to the first embodiment of the present invention includes a fuel sensing unit 810 , a reactor 300 , a reducing agent supply unit 500 , a catalyst preheating unit 400 and a control unit 700 .

Reactor 300 is provided above exhaust channel 610 . Reactor 300 also includes a catalyst 350 for reducing nitrogen oxides (NOx) contained in the exhaust gas emitted from engine 200 . The catalyst 350 accelerates the reaction between the nitrogen oxides (NOx) contained in the exhaust gas and the reducing agent, and reduces the nitrogen oxides (NOx) to nitrogen and water vapor.

Also, the catalyst 350 installed inside the reactor 300 may be arranged in a multi-layered structure based on the moving direction of the exhaust gas. That is, the catalyst 350 can be installed in the form of a plurality of catalyst modules, and the plurality of catalyst modules can be arranged along the moving direction of the exhaust gas.

Catalyst 350 can be of various materials known to those skilled in the art, such as Zeolite, Vanadium, Platinum, and the like. As an example, catalyst 350 may have an activation temperature in the range of 250 degrees Celsius to 350 degrees Celsius. Here, the activation temperature is a temperature at which nitrogen oxides can be stably reduced without poisoning the catalyst 350 . If the catalyst 350 reacts in an environment outside of its active temperature range, poisoning of the catalyst 350 will occur and efficiency will be reduced.

For example, when a reduction reaction for reducing nitrogen oxides contained in the exhaust gas occurs at a relatively low temperature of 150 degrees Celsius or more and less than 250 degrees Celsius, sulfur oxides (SOx) and ammonia (NH ₃ ) in the exhaust gas ) react with each other to produce a catalyst poisoning substance.

Specifically, the poisoning substance that poisons the catalyst 350 is one or more of ammonium sulfate ((NH ₄ ) ₂ SO ₄ ) and ammonium bisulfate (NH ₄ HSO ₄ ). be able to. Such catalyst poisoning substances are adsorbed on the catalyst 350 and reduce the activity of the catalyst 350 . Since the catalyst poisoning substance decomposes at a relatively high temperature, that is, a temperature within the range of 350 degrees Celsius to 450 degrees Celsius, the temperature of the catalyst 350 in the reactor 300 is raised to remove the poisoned catalyst 350. can be played.

As a reducing agent, ammonia ( _NH3 ) or urea (Urea, CO( _NH2 ) ₂ ) can be used. When urea is used as the reducing agent, it hydrolyzes or thermally decomposes urea (Urea, CO( _NH2 ) ₂ ) to produce ammonia ( _NH3 ) and isocyanic acid (HNCO). Isocyanic acid (HNCO) is further decomposed into ammonia (NH ₃ ) and carbon dioxide (CO ₂ ). Thus, urea is decomposed and finally ammonia is produced. Ammonia (NH ₃ ) serves as the final reducing agent that directly reacts with nitrogen oxides. That is, urea (CO(NH ₂ ) ₂ ) and isocyanic acid (HNCO) correspond to reducing agent precursors.

In addition, the housing of the reactor 300 can be made of, for example, a stainless steel material having excellent heat resistance.
The reducing agent supply unit 500 supplies a reducing agent to the exhaust gas flowing into the reactor 300 . As an example, the reducing agent supply unit 500 supplies urea (CO(NH ₂ ) ₂ ) as a reducing agent precursor or ammonia as a reducing agent toward the exhaust gas over the exhaust flow path 600 in front of the reactor 300 . (NH ₃ ) can be injected. In the present specification, forward refers to an upward direction with respect to the direction of movement of the exhaust gas, and backward refers to a direction downward from the direction of movement of the exhaust gas.

Reducing agent supply unit 500 can supply an appropriate amount of urea in consideration of the required amount of reducing agent that varies according to the load of engine 200 .

Also, although not shown, the reducing agent supply 500 can include various configurations known to those skilled in the art, such as a storage tank, an atomizing compressed air supply, and the like.

Also, although not shown, the selective catalytic reduction system 301 may further include a mixing member. The mixing member is installed on the exhaust channel 610 to effectively mix the reducing agent or the reducing agent precursor injected from the reducing agent supply unit 500 with the exhaust gas before flowing into the reactor 300 .

The catalyst preheating unit 400 preheats the catalyst 350 installed in the reactor 300 .

Specifically, the catalyst preheating section 400 includes a preheating channel 480 that connects the rear end of the reactor 300 and the front end of the reactor 300, and is provided above the preheating channel 480. A heating device 410 that heats the moving fluid and a blower 450 that is provided above the preheating flow path 480 and circulates the fluid heated by the heating device 410 can be included.

As an example, the heating device 410 can be an oil burner or a plasma burner. Thus, if an oil burner or a plasma burner is used as heating device 410, oxygen is required for operation of heating device 410. FIG. Therefore, when an oil burner or a plasma burner is used as the heating device 410, an outside air supply unit (not shown) for supplying oxygen may be further included. That is, the outside air supply unit can supply the heating device 410 or the preheating channel 480 with enough air to supply oxygen necessary for operating the heating device 410 .

Blower 450 can control the flow rate and flow velocity of the fluid heated by heating device 410 .

However, the catalyst preheating section 400 is not limited to the above. Catalyst preheater 400 can be an electric heater that directly heats catalyst 350, and catalyst preheater 400 can preheat catalyst 350 in a variety of ways known to those skilled in the art.

Furthermore, the catalyst preheating unit 400 can heat and regenerate the catalyst 350 as necessary.

Fuel sensing unit 810 may sense the type of fuel supplied to engine 200 . Specifically, the fuel sensing unit 810 may sense the type of fuel based on the material properties of the fuel. In addition, the physical properties may include the temperature and viscosity of the fuel, the composition ratio of sulfur contained in the fuel, the composition ratio of the fuel components, and the like. In addition, any information that can determine the type of fuel corresponds to physical property value information.

Also, the fuel sensing unit 810 may include a sensor that measures physical properties of fuel. The sensors include a temperature sensor that measures the temperature of the fuel, a viscosity sensor that measures the viscosity of the fuel, and a sulfur concentration sensor that measures the sulfur concentration of the fuel. can do.

On the other hand, when the above-mentioned sensor is already installed in the ship on which the selective catalytic reduction system 301 is installed, the fuel sensing unit 810 is a fuel information receiving unit (not shown).

On the other hand, the fuel sensing unit 810 may include a valve information receiving unit (not shown) that receives switching state information of the fuel switching valve 810 of the ship engine 101 in which the selective catalytic reduction system 301 is installed. Fuel switching valve 810 is switched manually by an operator or automatically by an actuator (not shown). Here, the switching state information is operating position information of the fuel switching valve 270, and based on the operating position of the fuel switching valve 270, the type of fuel supplied to the engine 101 can be confirmed.

If necessary, the fuel sensor 810 may include both a sensor for measuring physical properties of fuel and a valve information receiver. That is, the control unit 700 can determine the type of fuel and whether or not the fuel has been changed by combining the physical property values of the fuel measured by the sensor and the information received from the valve information receiving unit. .

For example, when a temperature sensor is used as fuel sensing unit 810 , fuel sensing unit 810 measures the temperature of fuel supplied to engine 200 . Specifically, the temperature sensor is provided on fuel supply line 285 between fuel switching valve 270 and engine 200 . Note that a temperature sensor may be provided in engine 200 in some cases. At this time, the controller 700 controls whether to operate the reducing agent supply unit 500 according to the temperature change of the fuel measured by the temperature sensor, which is the fuel sensor 810 .

Specifically, the control unit 700 activates the reducing agent supply unit 500 when the temperature of the fuel measured by the temperature sensor falls below the set value. Also, the control unit 700 can stop the operation of the reducing agent supply unit 500 again when the temperature of the fuel measured by the fuel sensing unit 810 exceeds the set value. It should be noted that the set value can be set variously according to the type of fuel stored in the plurality of fuel tanks 281 and 282 .

The selective catalytic reduction system 301 can further include a display 780 and a user input 770, as shown in FIG.

Display unit 780 is controlled by control unit 700 . Display 780 may include various display modules such as a cathode ray tube (CRT) display, a liquid crystal display (LCD), an organic light emitting display (OLED), and the like.

The user inputs whether or not at least one of the catalyst preheating unit 400 and the reducing agent supply unit 500, which are components of the selective catalytic reduction system 301, needs to be operated through the user input unit 770. FIG. User input unit 770 includes various known input means such as keyboard, mouse, touch screen, touch pad, and electronic pen.

When it is determined that the fuel is changed from the sensing signal of the fuel sensor 810, the controller 700 determines whether at least one of the catalyst preheater 400 and the reducing agent supplier 500 needs to be operated. . Then, the judgment result is displayed on the display unit 780, and an input from the user is waited.

When there is an input from the user through the user input unit 770, at least one of the catalyst preheating unit 400 and the reducing agent supply unit 500 is operated according to the input result. That is, the control unit 700 can automatically operate at least one of the catalyst preheating unit 400 and the reducing agent supply unit 500 when it is determined that the fuel type has been changed. Display on the display unit 780 to determine whether or not to operate, and operate at least one of the catalyst preheating unit 400 and the reducing agent supply unit 500 only when there is an instruction from the user. You can also

As shown in FIG. 2 , the fuel supplied to engine 200 is switched from the first fuel, which is high-sulfur fuel oil, to the second fuel, which is low-sulfur fuel oil, by operating fuel switching valve 270 . In this case, it can be seen that the temperature of the fuel supplied to engine 200 changes.

According to the first embodiment of the present invention, based on the fuel temperature measured by the fuel sensing unit 810, the control unit 700 determines the timing of fuel replacement, and performs selective catalytic reduction according to the fuel replacement. A decision can be made whether to activate the system 301 or not.

Therefore, when entering an emission control sea area, the fuel is changed to meet the sulfur oxide (SOx) emission regulation, and the selective catalytic reduction system 301 is operated to control the nitrogen oxide (NOx) emission. can satisfy

In addition, the selective catalytic reduction system 301 can be operated only when necessary, rather than operating all the time. method can be easily determined.

That is, according to the first embodiment of the present invention, it is possible to operate the selective catalytic reduction system 301 efficiently.

Also, in the first embodiment of the present invention, the control unit 700 can operate the catalyst preheating unit 400 before operating the reducing agent supply unit 500 .

At this time, the operating time point of the catalyst preheating unit 400 may be set to a temperature higher than a preset temperature value, which is the reference of the operating time point of the reducing agent supply unit 500 . The temperature of the fuel is lowered by the fuel exchange, and the catalyst preheating section 400 can be operated before the reducing agent supply section 500 is operated.

In addition, the operating time of the catalyst preheating unit 400 may be based on the preliminary work for exchanging the fuel instead of the temperature of the fuel. For example, the catalyst preheating unit 400 can be operated in an inspection step performed before fuel replacement, or the catalyst preheating unit 400 can be operated when an operation signal is transmitted to the fuel switching valve 270 . In this way, after the fuel switching valve 270 operates and the fuel exchange is started, it takes a predetermined time for the temperature of the fuel to rise and the reducing agent supply unit 500 to operate. is transmitted, the catalyst preheating unit 400 can be operated prior to the operation of the reducing agent supply unit 500 .

With the above configuration, according to the first embodiment of the present invention, the selective catalytic reduction system 301 can be efficiently operated.

A modification of the first embodiment of the present invention will be described below.
According to a modification of the first embodiment of the present invention, the control unit 700 controls whether or not to operate the catalyst preheating unit 400 according to the temperature change of the fuel measured by the fuel sensing unit 810 . That is, in the modification of the first embodiment of the present invention, the control unit 700 controls whether or not to operate the catalyst preheating unit 400 in accordance with the temperature change of the fuel prior to the reducing agent supply unit 500. Other than that, it is the same as the first embodiment.

Specifically, control unit 700 activates catalyst preheating unit 400 when the temperature of the fuel measured by fuel sensing unit 810 falls below a set value.

The catalyst preheating unit 400 stops operating when the catalyst 350 is preheated by operation for a predetermined time.

At this time, the operating time of the catalyst preheating unit 400 varies according to the current temperature of the catalyst 350, the climate environment, and the performance of the heating device 410. FIG.

As an example, the temperature of the catalyst 350 is increased by 200 degrees Celsius or more by the catalyst preheating section 400 .

As described above, according to the modified example of the first embodiment of the present invention, based on the fuel physical property value measured by the fuel sensing unit 810 or the valve switching state information of the fuel switching valve 270, the control unit 270 The timing of fuel replacement can be determined and preheating for operation of the selective catalytic reduction system 301 can be initiated in conjunction with the fuel replacement. In addition, the physical properties of the fuel may include at least one of fuel temperature, fuel viscosity, fuel sulfur content ratio, and fuel composition ratio.

Therefore, when entering an emission control sea area, the fuel is changed to meet the sulfur oxide (SOx) emission regulation, and the selective catalytic reduction system 301 is operated to control the nitrogen oxide (NOx) emission. can satisfy

In addition, the selective catalytic reduction system 301 can be operated only when necessary instead of being operated all the time, and the preheating point of the catalyst 350 can be determined by directly measuring the physical property value of the fuel or indirectly by measuring the measured information. or the valve switching state information of the fuel switching valve 270 can be easily determined.

That is, according to the modification of the first embodiment of the present invention, the selective catalytic reduction system 301 can be efficiently operated.

Also, in the first embodiment of the present invention, the control unit 700 can operate the reducing agent supply unit 500 after operating the catalyst preheating unit 400 .

At this time, the operating point of the reducing agent supply unit 500 may be after the catalyst 350 is preheated.

According to the above configuration, it is possible to efficiently operate the selective catalytic reduction system 301 even in the modification of the first embodiment of the present invention.

A second embodiment of the present invention will be described below with reference to FIG.
As shown in FIG. 3, a power plant 102 according to a second embodiment of the invention includes a nitrogen oxide reduction device. Note that the nitrogen oxide reduction device includes the selective catalytic reduction system 301 and the exhaust gas recirculation device 240 . In some cases, the nitrogen oxides reduction device may include only one of selective catalytic reduction system 301 and exhaust gas recirculation system 240 .

In the power plant 102 according to the second embodiment of the present invention, the control unit 700 controls the operation of the engine 200 in accordance with changes in the fuel physical properties measured by the fuel sensing unit 810 . At this time, the fuel sensing unit 810 is the same as the fuel sensing unit 810 installed in the selective catalytic reduction system 301 in the first embodiment, so redundant description will be omitted.

Specifically, when the temperature of the fuel measured by the fuel sensor 810 is less than a set value, the control unit 700 detects one of the output (Power), rotation speed (RPM), and load (Load) of the engine 200. One or more can be limited or the exhaust gas recirculation (EGR) rate can be increased.

By controlling the operation of engine 200 as described above, the content of nitrogen oxides contained in the exhaust gas discharged from engine 200 is reduced. That is, when the output, rotation speed, or load of the engine 200 is decreased, or when the exhaust gas recirculation rate is increased, the nitrogen oxide content contained in the exhaust gas discharged from the engine 200 is decreased.

For example, the recirculated exhaust gas contains more carbon dioxide (CO ₂ ), which has a higher heat capacity than nitrogen (N ₂ ), so the rate of temperature rise is low even if the same amount of fuel is burned. In addition, since the exhaust gas, which contains less oxygen than air, participates in the combustion, the combustion speed is lowered and the maximum combustion temperature is lowered. This significantly reduces the amount of nitrogen oxides (NOx). Instead, the output of engine 200 is reduced.

Further, as shown in FIG. 3, the power plant 102 according to the second embodiment of the present invention includes a selective catalytic reduction system 302 as a nitrogen oxide reduction device, as well as an exhaust system for recirculating the exhaust gas. A gas recirculation device 240 may also be included.

The exhaust gas recirculation device 240 adjusts a recirculation passage 248 for re-introducing the exhaust gas discharged from the engine 200 into the engine 200 and the flow rate of the exhaust gas recirculated through the recirculation passage 248. A possible recirculation valve 247 can be included. Also, the recirculation valve 247 can be controlled by the controller 700 .

In addition, when the physical property value (e.g., temperature) of the fuel measured by the fuel sensor 810 exceeds a set value, the control unit 700 limits the engine power (Power), rotation speed (RPM), and load (Load). can be eliminated or the exhaust gas recirculation (EGR) rate can be reduced.

As shown in FIG. 2 , the fuel supplied to engine 200 is switched from the first fuel, which is high-sulfur fuel oil, to the second fuel, which is low-sulfur fuel oil, by operating fuel switching valve 270 . In this case, it can be seen that the temperature of the fuel supplied to engine 200 changes. It should be noted that FIG. 2 is an example showing a change in temperature due to a change in the type of fuel. The ratio will change.

According to the second embodiment of the present invention, the control unit 700 determines the timing of fuel replacement based on the physical property value (e.g., temperature) of the fuel measured by the fuel sensor 810, and determines the timing of the fuel replacement. By controlling the operation of the engine 200, when entering an emission control sea area, the fuel is changed to satisfy the sulfur oxide (SOx) emission regulation, and the nitrogen oxide (NOx) emission regulation is satisfied. can satisfy

That is, according to the second embodiment of the present invention, the engine 200 can be operated efficiently.

In addition, in the second embodiment of the present invention, the control unit 700 determines whether the nitrogen oxide reduction device needs to be operated according to the change in the physical property value (e.g., temperature) of the fuel measured by the fuel sensing unit 810. can be controlled. More specifically, the controller 700 can control at least one of the exhaust gas recirculation device 240 and the selective catalytic reduction system 302 . The controller 700 can also control only the exhaust gas recirculation device 240 or only the selective catalytic reduction system 302 . For example, when it is determined that the fuel type has changed through the fuel sensor 810, the controller 700 controls only the exhaust gas recirculation device 240, and the selective catalytic reduction system 302 controls the concentration of nitrogen oxides (NOx). , engine load, and other criteria.

When the control unit 700 attempts to control the exhaust gas recirculation device 240 , the control unit 700 can control the recirculation valve 247 of the exhaust gas recirculation device 240 .

When the control unit 700 controls the selective catalytic reduction system 302, the control unit 700 controls whether the reducing agent supply unit 500 and the catalyst preheating unit 400 of the selective catalytic reduction system 302 need to be operated. can be done. Here, the control unit 700 can operate the catalyst preheating unit 400 before the reducing agent supply unit 500 .

Further, when the control unit 700 determines that the fuel type has been changed, the control unit 700 can automatically control the nitrogen oxide reduction device directly. can be inquired of the user, and the nitrogen oxide reduction device can be operated based on the user's instructions. More specifically, the operation device 102 according to the second embodiment includes a display unit 780 for inquiring of the user whether or not to operate the nitrogen oxide reduction device, and a display unit 780 for allowing the user to operate the nitrogen oxide reduction device. and an input unit 770 for inputting whether or not. The control unit 700 can operate the nitrogen oxide reduction device, maintain the stopped state, or stop the operation according to the input result of the input unit 770 .

As described above, the control unit 700 selectively controls the reducing agent supply unit 500 and the catalyst preheating unit 400 based on the change information of the physical property value (e.g., temperature) of the fuel measured by the fuel sensing unit 810. The catalytic reduction system 302 is similar to the selective catalytic reduction system 301 in the first embodiment.

With the above configuration, according to the second embodiment of the present invention, the power plant 102 can be operated efficiently.

A third embodiment of the present invention will be described below with reference to FIG.
As shown in FIG. 4, in the power plant 103 according to the third embodiment of the present invention, the control unit 700 controls the change in the physical property value (for example, temperature) of the fuel measured by the fuel sensing unit 810. It controls the operation of the engine 200 and controls the selective catalytic reduction system 301 . As described in detail in the first embodiment, the fuel sensor 810 receives physical property value information of the fuel from the outside without directly measuring it, or receives valve switching state information of the fuel switching valve 270. It goes without saying that the type of fuel can also be detected by receiving the information.

At this time, the controller 700 may further include an engine controller 720 that controls the engine 200 and an aftertreatment controller 730 that controls the selective catalytic reduction system 301 . Aftertreatment control 730 may control one or more of reducing agent supply 500 or catalyst preheater 400 .

Engine control 720 controls exhaust gas recirculation device 240 and aftertreatment control 730 is tasked with controlling selective catalytic reduction system 301, as shown in FIG. Engine control unit 720 and aftertreatment control unit 730 may be able to communicate information with each other.

For example, aftertreatment control unit 730 can receive switching state information of fuel switching valve 720 from engine control unit 720 . Conversely, the engine control unit 720 can obtain operating state information of the selective catalytic reduction system 301 from the aftertreatment control unit 730 . The operating state information of the selective catalytic reduction system 301 is information regarding whether one or more of the reducing agent supply unit 500 and the catalyst preheating unit 400 need to be operated.

The power plant 103 according to the third embodiment can further include the display unit 780 and the input unit 770 detailed in the first and second embodiments. Note that the display unit 780 and the input unit 770 can be controlled by the post-processing control unit 730 . Of course, it may be controlled by the engine control unit 720 if necessary.

Note that the third embodiment of the present invention is not limited to the above, and one control unit 700 can control both the engine 200 and the selective catalytic reduction system 301 .

The operation of the engine control unit 720 can be the same as the operation of the control unit 700 described in the second embodiment, and the operation of the post-processing control unit 730 is similar to that of the first embodiment and the first embodiment. The operation can be the same as that of the control unit 700 described in the modified example.

Also, the selective catalytic reduction system 301 in the third embodiment can be the same as in the first embodiment.

Therefore, according to the third embodiment of the present invention, the control unit 300 determines the timing of fuel replacement based on the physical property value (e.g., temperature) of the fuel measured by the fuel sensing unit 810, and determines the fuel replacement time. In accordance with, control the operation of the engine 200 and determine whether to operate at least one of the selective catalytic reduction system 301 and the exhaust gas recirculation device 240, or the selective catalytic reduction system Preheating for operation of 301 can be initiated.

That is, according to the third embodiment of the present invention, it is possible to efficiently operate the engine 200 and the selective catalytic reduction system 301 and/or the exhaust gas recirculation device 240 which are nitrogen oxide reduction devices.

With the above configuration, according to the third embodiment of the present invention, the selective catalytic reduction system 301 and the power plant 103 including the same can be efficiently operated.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it will be appreciated by those skilled in the art to which the present invention pertains that the present invention may be modified in various ways without departing from its technical spirit or essential features. It will be understood that it can be implemented by changing to

The foregoing embodiments are illustrative only and not limiting, the scope of the invention being indicated by the foregoing detailed description of the invention and the following claims, given the meaning and scope of the claims. , and all modifications or variations derived from the equivalent concept thereof, are to be construed as included within the scope of the present invention.

According to the embodiment of the present invention, since the selective catalytic reduction system and the power plant having the same can be efficiently operated, energy can be saved in the operation of the selective catalytic reduction system and the power plant having the same. can be used for

Claims (11)

Nitrogen oxides (NOx) in exhaust gas emitted from an engine that generates power by selectively supplying fuel from any one of a plurality of fuel tanks storing different types of fuel respectively A selective catalytic reduction system that reduces
a fuel sensor that senses the type of fuel supplied to the engine;
a reactor equipped with a catalyst for reducing nitrogen oxides contained in the exhaust gas discharged from the engine;
a catalyst preheating unit that preheats the catalyst installed in the reactor;
a reducing agent supply unit that supplies a reducing agent to the exhaust gas flowing into the reactor;
determining whether or not to change the fuel based on the sensing result of the fuel sensing unit, and whether at least one of the catalyst preheating unit and the reducing agent supply unit needs to be operated according to the determination result; a control unit for determining whether
a display unit;
a user input unit into which a user inputs a signal indicating whether to operate at least one of the catalyst preheating unit and the reducing agent supply unit;
The control unit causes the display unit to display a determination result as to whether or not at least one of the catalyst preheating unit and the reducing agent supply unit needs to be operated when it is determined that the fuel has been changed; operating at least one of the catalyst preheating unit and the reducing agent supply unit according to the input result of the user input unit ;
The selective catalytic reduction system , wherein the fuel sensor is a sulfur concentration sensor that measures the sulfur concentration of the fuel . The fuel sensing unit includes a fuel information receiving unit that receives physical property information of the fuel supplied to the engine from the outside, and selects one of different types of fuel in the plurality of fuel tanks for the engine. 2. The selective catalytic reduction system according to claim 1, further comprising at least one of a valve information receiving section for receiving switching state information of a fuel switching valve for supplying fuel to the target. 2. The selective catalytic reduction system according to claim 1, wherein the control unit operates the catalyst preheating unit before operating the reducing agent supply unit. The catalyst preheating section is
a preheating channel connecting the rear end of the reactor and the front end of the reactor;
a heating device provided above the preheating channel for raising the temperature of the fluid moving in the preheating channel;
2. The selective catalytic reduction system according to claim 1, further comprising a blower provided above the preheating flow path and configured to circulate the fluid heated by the heating device. a plurality of fuel tanks each storing fuel of different composition;
an engine that receives fuel from the plurality of fuel tanks to generate power;
a fuel supply line connecting the plurality of fuel tanks and the engine;
a fuel switching valve provided in the fuel supply line for changing the type of fuel supplied to the engine;
a fuel sensor that senses the type of fuel supplied to the engine;
a nitrogen oxide reduction device for reducing nitrogen oxides (NOx) contained in exhaust gas of the engine;
determining whether or not to change the fuel based on the sensing result of the fuel sensor, and depending on the determination result, whether or not it is necessary to change the operating state of the engine, or operate the nitrogen oxide reduction device; a control unit for determining whether a
a display unit;
an input unit for inputting whether or not to operate the nitrogen oxide reduction device from the user,
The nitrogen oxide reduction device includes an exhaust gas recirculation device provided in the engine for reducing nitrogen oxides contained in the exhaust gas discharged from the engine, and the exhaust gas discharged from the engine. A selective catalytic reduction system comprising a reactor installed with a catalyst for reducing contained nitrogen oxides and a reducing agent supply unit supplying a reducing agent to the exhaust gas flowing into the reactor including at least one of
The control unit displays on the display unit whether it is necessary to change the operating state of the engine or whether it is necessary to operate at least one of the selective catalytic reduction system and the exhaust gas recirculation device. display, change the engine state according to the input result of the input unit, or operate at least one of the selective catalytic reduction system and the exhaust gas recirculation device ;
The power plant , wherein the fuel sensor is a sulfur concentration sensor that measures the sulfur concentration of the fuel . The fuel sensing unit includes at least one of a fuel information receiving unit that receives physical property value information of the fuel supplied to the engine from the outside, and a valve information receiving unit that receives switching state information of the fuel switching valve. 6. A power plant as claimed in claim 5 , comprising at least one receiver. The nitrogen oxide reduction device includes an exhaust gas recirculation device provided in the engine for reducing nitrogen oxides contained in the exhaust gas discharged from the engine, A selective catalytic reduction system comprising a reactor installed with a catalyst for reducing contained nitrogen oxides and a reducing agent supply unit supplying a reducing agent to the exhaust gas flowing into the reactor including at least one of
When it is determined that the operating state of the engine needs to be changed or the nitrogen oxide reduction device needs to be operated, the control unit limits the output of the engine or controls the exhaust gas. 6. A power plant according to claim 5 , wherein at least one of a recirculation device and said selective catalytic reduction system is operated. The selective catalytic reduction system includes a reactor equipped with a catalyst for reducing nitrogen oxides contained in the exhaust gas discharged from the engine, and reducing the exhaust gas flowing into the reactor. including a reducing agent supply unit that supplies a reducing agent;
3. The control unit controls whether or not to operate the reducing agent supply unit according to a change in physical properties of the fuel supplied to the engine measured by the fuel sensing unit. 7. The power plant according to 7. The selective catalytic reduction system further includes a catalyst preheating unit that preheats the catalyst installed in the reactor,
9. The power plant according to claim 8 , wherein the control unit operates the catalyst preheating unit before operating the reducing agent supply unit. The selective catalytic reduction system includes a reactor installed with a catalyst for reducing nitrogen oxides contained in the exhaust gas discharged from the engine, and preheating the catalyst installed in the reactor. including a catalyst preheating section,
8. The control unit controls whether or not to operate the catalyst preheating unit according to changes in the physical properties of the fuel supplied to the engine, which are measured by the fuel sensing unit. The power unit according to . The catalyst preheating section is
a preheating channel connecting the rear end of the reactor and the front end of the reactor;
a heating device provided above the preheating channel for raising the temperature of the fluid moving in the preheating channel;
11. The power unit according to claim 10 , further comprising a blower provided above the preheating flow path and configured to circulate the fluid heated by the heating device.

Images