Integrated device for dust removal, desulfurization and denitrification of ship exhaust gas and ship

Abstract

The present invention discloses an integrated device for dust removal, desulfurization and denitration of ship exhaust gas and a ship, comprising a metal DPF dust removal unit, a first air-cooled heat exchanger, a second air-cooled heat exchanger, an SCR denitration unit, an induced draft fan and a desulfurization unit, wherein the outlet of the metal DPF dust removal unit is connected to the inlet of the first air-cooled heat exchanger, the outlet of the first air-cooled heat exchanger is connected to the inlet of the SCR denitration unit, the outlet of the SCR denitration unit is connected to the inlet of the induced draft fan, the outlet of the induced draft fan is connected to the inlet of the second air-cooled heat exchanger, and the outlet of the second air-cooled heat exchanger is connected to the inlet of the desulfurization unit. The present invention can realize the integrated treatment of sulfur dioxide, nitrogen oxides and particulate matter in the tail gas when a diesel engine ship uses light diesel, heavy diesel, shale oil and fuel oil, and solve the problem of black smoke from ship exhaust and excessive emission of pollutants.

Description

Technical Field

[0001] The invention relates to dust removal, desulfurization and denitrification of ship exhaust gas, and in particular to an integrated device for dust removal, desulfurization and denitrification of ship exhaust gas and a ship. Background Art

[0002] Since ship engines are mainly diesel engines, the fuels used are light diesel, heavy diesel, shale oil, and fuel oil. Compared with other motor vehicle exhaust, the SO in ship exhaust is 2 (sulfur dioxide), NO x (nitrogen oxides) and particulate matter (black smoke) concentrations are high, posing a great threat to the human body and the environment.

[0003] In the existing technology, the exhaust gas post-treatment method (EGC) is generally adopted, that is, by installing an exhaust gas treatment device, SO 2 Most of the sulfur dioxide is removed, achieving the effect of emission reduction. However, when ships use light diesel, heavy diesel, shale oil, and fuel oil, their flue gas still contains a large amount of NO x (nitrogen oxides) and particulate matter (black smoke), these pollutants also need to be dealt with urgently. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide an integrated device for dust removal, desulfurization and denitrification of ship exhaust gas and a ship. The present invention can achieve SO in tail gas when the ship uses light diesel, heavy diesel, shale oil and fuel oil. 2 (sulfur dioxide), NO x The integrated treatment of nitrogen oxides (nitrogen oxides) and particulate matter (black smoke) solves the problem of black smoke and excessive pollutant emissions from ship exhaust.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An integrated device for dust removal, desulfurization and denitrification of ship exhaust gas comprises a metal DPF dust removal unit, a first air-cooled heat exchanger, a second air-cooled heat exchanger, an SCR denitrification unit, an induced draft fan and a desulfurization unit, wherein the outlet of the metal DPF dust removal unit is connected to the inlet of the first air-cooled heat exchanger, the outlet of the first air-cooled heat exchanger is connected to the inlet of the SCR denitrification unit, the outlet of the SCR denitrification unit is connected to the inlet of the induced draft fan, the outlet of the induced draft fan is connected to the inlet of the second air-cooled heat exchanger, and the outlet of the second air-cooled heat exchanger is connected to the inlet of the desulfurization unit.

[0007] Preferably, the desulfurization unit adopts a wet desulfurization unit, including a first desulfurization tower and a second desulfurization tower, the outlet of the second air-cooled heat exchanger is connected to the inlet of the first desulfurization tower, and the outlet of the first desulfurization tower is connected to the inlet of the second desulfurization tower.

[0008] Preferably, the metal DPF dust removal unit includes a filter housing, a metal DPF filter element and a back pressure gauge, wherein an air inlet pipe and an air outlet pipe are respectively installed at both ends of the filter housing, and the air outlet pipe on the filter housing is connected to the inlet of the first air-cooled heat exchanger; the back pressure gauge is placed in the air inlet pipe on the filter housing, and a plurality of mounting holes for installing the metal DPF filter element are opened on the side wall of the filter housing from one end of the filter housing to the other end, and the metal DPF filter element is inserted into the filter housing through the mounting holes, and the end of the metal DPF filter element is detachably connected to the filter housing.

[0009] Preferably, the axis of the metal DPF filter element is perpendicular to the airflow direction in the filter housing.

[0010] Preferably, the end of the metal DPF filter element is detachably connected to the filter housing via a clamp.

[0011] Preferably, the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas of the present invention also includes a flue gas emission continuous monitoring system, which includes a measuring device, an industrial computer, a gas sampling probe, a sampling pipeline and a sample gas pretreatment device. The measuring device is connected to the industrial computer, and the industrial computer is connected to the PLC of the control system of the SCR denitrification unit and the PLC of the control system of the desulfurization unit. The measuring device includes a particle detection probe, a temperature sensor, a pressure sensor, a flow rate measuring device, a humidity sensor and a gas analyzer. The gas analyzer is connected to the sample gas pretreatment device, and the sample gas pretreatment device is connected to the gas sampling probe through a sampling pipeline. The particle detection probe, temperature sensor, pressure sensor, flow rate measuring device and gas sampling probe are arranged at the outlet of the desulfurization unit, and the particle detection probe, temperature sensor, pressure sensor, flow rate measuring device and gas analyzer are all connected to the industrial computer.

[0012] Preferably, the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas of the present invention also includes a container, and the metal DPF dust removal unit, the first air-cooled heat exchanger, the second air-cooled heat exchanger, the SCR denitrification unit, the induced draft fan and the desulfurization unit are all arranged in the container and fixedly connected to the bottom plate of the container, the inlet of the metal DPF dust removal unit is provided with a flue gas inlet pipe, the outlet of the desulfurization unit is provided with a smoke exhaust pipe, and both ends of the container are arranged with open double doors.

[0013] Preferably, a base and lifting lugs are provided on the outside of the container.

[0014] The present invention also provides a ship, comprising a smoke exhaust device and the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas as described above, wherein the smoke outlet of the smoke exhaust device is connected to the inlet of the metal DPF dust removal unit.

[0015] Preferably, the smoke exhaust equipment includes a main engine, an auxiliary engine, a fuel oil boiler and a generator.

[0016] The present invention has the following beneficial effects:

[0017] The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas of the present invention can remove most of the particulate matter and black carbon in the flue gas generated by burning heavy oil in the ship by setting a metal DPF dust removal unit. By setting a first air-cooled heat exchanger, the temperature of the flue gas after dust removal by the metal DPF dust removal unit can be reduced, so that the flue gas temperature meets the treatment requirements of the SCR denitrification unit. The SCR denitrification unit can decompose the nitrogen oxides in the flue gas after the temperature is reduced by the first air-cooled heat exchanger into harmless nitrogen and water. The induced draft fan can pressurize the flue gas passing through the outlet of the SCR denitrification unit and send it to the second air-cooled heat exchanger. The second air-cooled heat exchanger can cool the flue gas so that the flue gas temperature meets the treatment requirements of the desulfurization unit. The desulfurization unit can decompose SO in the flue gas. 2 In summary, the present invention can achieve the removal of SO in tail gas when ships use light diesel, heavy diesel, shale oil and fuel oil. 2 (sulfur dioxide), NO x The integrated treatment of nitrogen oxides (nitrogen oxides) and particulate matter (black smoke) solves the problem of black smoke and excessive pollutant emissions from ship exhaust.

[0018] Furthermore, the desulfurization unit includes a first desulfurization tower and a second desulfurization tower, and the two desulfurization towers are connected in series, thereby being able to reduce the installation and use height of a single desulfurization tower.

[0019] Furthermore, a plurality of mounting holes for mounting a metal DPF filter element are provided on the side wall of the filter housing of the metal DPF dust removal unit from one end of the filter housing to the other end, and the metal DPF filter element is inserted into the filter housing through the mounting holes. This structural design enables as many metal DPF filter elements as possible to be installed on the filter housing to remove as much particulate matter and black carbon as possible.

[0020] Furthermore, the present invention is also provided with a flue gas emission continuous monitoring system, which uses a particulate matter detection probe, a temperature sensor, a pressure sensor, and a flow rate measuring device to respectively monitor in real time the particulate matter concentration, flue gas temperature, flue gas pressure, and flue gas flow rate in the flue gas discharged from the outlet of the desulfurization unit; uses a sampling probe pipeline to take real-time samples from the outlet of the desulfurization unit, and uses a gas analyzer and a humidity sensor to analyze in real time the sulfur dioxide concentration, nitrogen oxide concentration, oxygen content, and humidity of the flue gas discharged from the outlet of the desulfurization unit; and transmits the above-mentioned measurement signals to an industrial computer in real time, and the industrial computer feeds back the measurement signals to the PLC of the SCR denitrification unit and the PLC of the desulfurization unit in real time, thereby controlling the working status of the SCR denitrification unit and the desulfurization unit to ensure that the flue gas at the outlet of the desulfurization unit meets the emission standards.

[0021] Furthermore, the present invention sets a container, and the metal DPF dust removal unit, the first air-cooled heat exchanger, the second air-cooled heat exchanger, the SCR denitrification unit, the induced draft fan and the desulfurization unit are all set in the container. Then, the integrated device for ship exhaust gas dust removal, desulfurization and denitrification of the present invention is a skid-mounted device integrating ship flue gas dust removal, denitrification and desulfurization, which greatly facilitates the transportation of equipment and on-site installation and use, and can be widely used in exhaust gas treatment of various diesel engine ships and shipbuilding (repair) yards.

[0022] Since the ship of the present invention is provided with the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas, the ship of the present invention can greatly reduce the concentration of sulfur dioxide, nitrogen oxides and particulate matter in the exhaust gas when using light diesel, heavy diesel, shale oil and fuel oil, thereby solving the problem of black smoke emitting from ship exhaust and excessive emission of pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the main structure of the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to the present invention;

[0024] Figure 2 It is a schematic diagram of the top view of the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to the present invention;

[0025] Figure 3 This is a schematic structural diagram of a metal DPF (diesel particulate filter) dust removal unit used in the present invention;

[0026] Figure 4 It is a schematic diagram of the three-dimensional structure of the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to the present invention;

[0027] Figure 5 The present invention is a process route diagram for using the device of the present invention for dust removal, desulfurization and denitrification of ship exhaust gas.

[0028] In the figure, 1. metal DPF dust removal unit; 101. filter housing; 102. metal DPF filter element; 103. filter housing inlet; 104. filter housing outlet; 21. first air-cooled heat exchanger; 22. second air-cooled heat exchanger; 3. SCR denitrification unit; 4. induced draft fan; 51. first desulfurization tower; 52. second desulfurization tower; 6. container; 601. container bottom plate; 7. equipment connection pipeline bracket; 8. exhaust gas online monitoring equipment. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] Reference Figure 1 , Figure 2 and Figure 4The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas of the present invention comprises a metal DPF dust removal unit 1, a first air-cooled heat exchanger 21, a second air-cooled heat exchanger 22, an SCR denitrification unit 3, an induced draft fan 4 and a desulfurization unit, wherein the outlet of the metal DPF dust removal unit 1 is connected to the inlet of the first air-cooled heat exchanger 21, the outlet of the first air-cooled heat exchanger 21 is connected to the inlet of the SCR denitrification unit 3, the outlet of the SCR denitrification unit 3 is connected to the inlet of the induced draft fan 4, the outlet of the induced draft fan 4 is connected to the inlet of the second air-cooled heat exchanger 22, and the outlet of the second air-cooled heat exchanger 22 is connected to the inlet of the desulfurization unit.

[0031] As a preferred embodiment of the present invention, refer to Figure 1 , Figure 2 and Figure 4 The desulfurization unit adopts a wet desulfurization unit, including a first desulfurization tower 51 and a second desulfurization tower 52 , the outlet of the second air-cooled heat exchanger 22 is connected to the inlet of the first desulfurization tower 51 , and the outlet of the first desulfurization tower 51 is connected to the inlet of the second desulfurization tower 52 .

[0032] As a preferred embodiment of the present invention, refer to Figure 1 , Figure 3 and Figure 4 The metal DPF dust removal unit 1 includes a filter housing 101, a metal DPF filter element 102 and a back pressure gauge. An air inlet pipe and an air outlet pipe are respectively installed at both ends of the filter housing 101. The air outlet pipe on the filter housing 101 is connected to the inlet of the first air-cooled heat exchanger 21; the back pressure gauge is placed in the air inlet pipe on the filter housing 101, and a plurality of mounting holes for mounting the metal DPF filter element 102 are opened on the side wall of the filter housing 101 from one end of the filter housing 101 to the other end. The metal DPF filter element 102 is inserted into the filter housing 101 through the mounting holes, and the end of the metal DPF filter element 102 is detachably connected to the filter housing 101.

[0033] As a preferred embodiment of the present invention, refer to Figure 1 , Figure 2 and Figure 4 The axis of the metal DPF filter element 102 is perpendicular to the air flow direction in the filter housing 101 .

[0034] As a preferred embodiment of the present invention, the end of the metal DPF filter element 102 is detachably connected to the filter housing 101 via a clamp.

[0035] As a preferred embodiment of the present invention, the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas of the present invention also includes a flue gas emission continuous monitoring system, which includes a measuring device, an industrial computer, a gas sampling probe, a sampling pipeline and a sample gas pretreatment device. The measuring device is connected to the industrial computer, and the industrial computer is connected to the PLC of the control system of the SCR denitrification unit 3 and the PLC of the control system of the desulfurization unit. The measuring device includes a particle detection probe, a temperature sensor, a pressure sensor, a flow rate measuring device, a humidity sensor and a gas analyzer. The gas analyzer is connected to the sample gas pretreatment device, and the sample gas pretreatment device is connected to the gas sampling probe through a sampling pipeline. The particle detection probe, the temperature sensor, the pressure sensor, the flow rate measuring device and the gas sampling probe are arranged at the outlet of the desulfurization unit, and the particle detection probe, the temperature sensor, the pressure sensor, the flow rate measuring device and the gas analyzer are all connected to the industrial computer.

[0036] As a preferred embodiment of the present invention, refer to Figure 1 , Figure 2 and Figure 4 The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas of the present invention also includes a container, a metal DPF dust removal unit 1, a first air-cooled heat exchanger 21, a second air-cooled heat exchanger 22, an SCR denitrification unit 3, an induced draft fan 4 and a desulfurization unit are all arranged in the container and fixedly connected to the bottom plate of the container, a flue gas inlet pipe is provided at the inlet of the metal DPF dust removal unit 1, a smoke exhaust pipe is provided at the outlet of the desulfurization unit, and both ends of the container are set as open double doors.

[0037] As a preferred embodiment of the present invention, a base and lifting lugs are provided on the outside of the container.

[0038] The present invention also provides a ship, comprising a smoke exhaust device and the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas as described above, referring to Figure 5 The smoke outlet of the smoke exhaust device is connected to the inlet of the metal DPF dust removal unit 1.

[0039] As a preferred embodiment of the present invention, refer to Figure 5 The smoke exhaust equipment includes a main engine, an auxiliary engine, a fuel oil boiler and a generator.

[0040] The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas of the present invention is an integrated device for comprehensive treatment of dust removal, desulfurization and denitrification of ship exhaust gas, which can remove particulate matter, SO 2 It can effectively control pollutants such as NOx and black smoke from ship exhaust and excessive emissions of pollutants. It can also monitor the concentration of pollutant emissions in real time and optimize the operating parameters of the treatment equipment. It is also convenient for transportation and on-site installation and use.

[0041] Example

[0042] The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas in this embodiment mainly includes eight units: a metal DPF dust removal unit 1, an air-cooled heat exchanger (including a first air-cooled heat exchanger 21 and a second air-cooled heat exchanger 22), an SCR denitrification unit 3, an induced draft fan 4, a wet desulfurization unit (including a first desulfurization tower 51 and a second desulfurization tower 52), a container 6, a device connection pipeline support 7 and an exhaust gas online monitoring device 8. The outlet of the metal DPF dust removal unit 1 is connected to the inlet of the first air-cooled heat exchanger 21, the outlet of the first air-cooled heat exchanger 21 is connected to the inlet of the SCR denitrification unit 3, the outlet of the SCR denitrification unit 3 is connected to the induced draft fan 4, the induced draft fan 4 is connected to the inlet of the second air-cooled heat exchanger 22, the outlet of the second air-cooled heat exchanger 22 is connected to the inlet of the first desulfurization tower 51, the outlet of the first desulfurization tower 51 is connected to the inlet of the second desulfurization tower 52, the outlet of the second desulfurization tower 52 can be connected to an exhaust pipe, and the exhaust gas online monitoring device 8 is connected to the outlet pipe section of the second desulfurization tower 52.

[0043] The metal DPF dust removal unit 1 mainly includes: a filter housing 101, a metal DPF filter element 102 and a back pressure gauge. The back pressure gauge is placed in the air intake pipe of the metal DPF dust removal unit 1, such as Figure 3 As shown, six metal DPF filter elements 102 are placed in the filter housing 101. The particulate matter in the exhaust gas of the diesel engine passes through the six groups of metal DPF filter elements 102 from the outside to the inside, and the carbon particles are captured by the filter element wall; when the carbon particles on the outer surface of the metal DPF filter element 102 accumulate to a certain extent and the pressure measured by the back pressure gauge reaches a preset value, the metal DPF filter element 102 is cleaned, regenerated and reused. The SCR denitrification unit 3 mainly includes: an SCR reactor housing, an SCR mixing section, an SCR reaction section, a vanadium-based catalyst, a urea solution tank, a urea nozzle, a urea pump, a static mixer, a temperature / flow sensor, and an electronically controlled metering cabinet. Temperature sensors are provided before and after the SCR reaction section, and a flow sensor is also provided before the SCR reaction section. The urea solution injection amount of the urea pump can be automatically adjusted in real time according to the flue gas flow rate and the NOx concentration value fed back by the rear-end flue gas emission continuous monitoring system, thereby accurately controlling the flue gas NOx emission concentration. The wet desulfurization unit mainly includes: a first desulfurization tower 51 and a second desulfurization tower 52, which are connected in series. The first desulfurization tower 51 and the second desulfurization tower 52 include a desulfurization tower shell, a spray layer and a packing layer. The first desulfurization tower 51 and the second desulfurization tower 52 share a circulating slurry pool, a circulating pump, an alkali preparation tank, an alkali replenishment pump, an alkali stirring pump, and an electric control cabinet; wherein the second desulfurization tower 52 is also provided with a demisting layer above the spray layer. The exhaust gas enters the first desulfurization tower 51 and the second desulfurization tower 52 in turn, and is discharged from the top of the second desulfurization tower 52. SO 2After the gas is countercurrently absorbed by the absorbent, the absorbent flows into the circulating slurry pool through the bottom of the tower and is then pumped out and recycled by the circulating pump. The absorbent is configured in the alkali solution preparation tank, and after being stirred evenly by the alkali solution stirring pump, it is pumped into the circulating slurry pool by the alkali solution replenishment pump for use. In the offshore environment and during the period when the ship is moored at the shore, the desulfurization alkali solution can be recycled for a long time to avoid the discharge of wastewater. The flue gas emission continuous monitoring system adopts the exhaust gas online monitoring equipment 8 and adopts an integrated visual control method, which can monitor the SO in the exhaust gas in real time. 2 , NOx, particulate emission concentration, as well as exhaust gas temperature, pressure, flow, humidity, oxygen content and other parameters, and synchronously feed back measurement signals to the SCR desulfurization unit 3, the first desulfurization tower 51 and the second desulfurization tower 52, and then manually or automatically adjust the operating parameters of each unit to achieve the best pollutant removal effect. The above-mentioned device in the integrated device for ship exhaust gas dust removal, desulfurization and denitrification of this embodiment is arranged as a whole in the container 6, and the container 6 is provided with fixing bolts inside, and a base and lifting ears outside. The skid-mounted device integrating ship exhaust gas dust removal, denitrification and desulfurization is adopted, which greatly facilitates the transportation of equipment and on-site installation and use, and can be widely used in exhaust gas treatment of various diesel engine ships and shipbuilding (repair) yards.

[0044] The process route of treating ship exhaust gas by the integrated device for dust removal, desulfurization and denitrification of ship exhaust gas in this embodiment is as follows:

[0045] Exhaust gas collection + metal DPF dust removal + air-cooled heat exchanger + SCR denitrification + air-cooled heat exchanger + induced draft fan + sodium-alkali desulfurization + emission, that is: the exhaust gas generated by the ship's main engine, auxiliary engine, fuel boiler, generator and other equipment using heavy diesel, shale oil and other fuels is collected, first passed through the metal DPF dust removal unit 1 to remove most of the particulate matter and black carbon, and then the flue gas temperature is adjusted and cooled through the first air-cooled heat exchanger 21, and then passed through the SCR denitrification unit 3, reacting with urea under certain temperature and catalyst conditions to decompose nitrogen oxides (NOx) into harmless nitrogen (N 2 ) and water H 2 O, and then enter the second air-cooled heat exchanger 22 through the induced draft fan 4, the flue gas temperature is adjusted and cooled again, and finally enters the wet desulfurization unit, where caustic soda is used to remove SO in the flue gas. 2 The purified flue gas is discharged from the exhaust pipe through the connecting pipeline 7, and the pollutant emission concentration is monitored in real time by the exhaust gas online monitoring device 8, and then the operating parameters of the treatment equipment are adjusted to achieve the best treatment effect.

[0046] The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas in this embodiment is installed in a skid-mounted manner, and all equipment is fixedly installed in a high-cube container to facilitate transportation and on-site installation and use.

[0047] The metal DPF (diesel particulate filter) dust removal unit used in this embodiment is introduced as follows:

[0048] Working principle:

[0049] The exhaust gas emitted by the diesel engine enters the air inlet of the exhaust gas filtration system. The exhaust gas containing a large amount of carbon particles passes through the filter wall from the outside to the inside and enters the filter. The carbon particles are captured by the filter wall, and the clean gas is discharged into the atmosphere from the exhaust port. As the engine continues to run, the carbon particles on the outer surface of the filter accumulate continuously, and the back pressure of the exhaust gas filtration system increases; when the carbon particles on the outer surface of the filter accumulate to a certain value, the back pressure increases to a fixed value (generally 20Kpa), then the machine can be stopped, the clamp is removed, the filter element is pulled out, the filter element is placed under the faucet, rinsed with water, reinstalled into the housing, and the clamp is tightened before it can be used again. This cycle repeats.

[0050] The SCR denitration unit used in this embodiment is introduced as follows:

[0051] How it works

[0052] Selective catalytic reduction (SCR) is the current international mainstream method for efficiently removing NO from exhaust gas. X The technical route is mainly aimed at nitrogen oxides (NO X ), at a certain temperature (200℃-400℃), under the action of the catalyst, nitrogen oxides (NO X ) decomposes into harmless nitrogen (N 2 ) and water (H 2 O), the average purification rate is as high as 90%. Compared with the spray tower and SNCR solution, it has the advantages of small footprint, high conversion rate and no by-products.

[0053] The process flow of SCR denitrification unit is as follows:

[0054] The DCU (urea injection control unit) calculates the current urea demand based on the current engine operating status, NOx concentration, exhaust flow (flow sensor), and exhaust temperature. The urea pump extracts the urea solution from the urea tank, mixes it with compressed air after metering, and sends it to the nozzle after preliminary atomization. It is sprayed into the mixing section pipeline under the action of compressed air and further gas-liquid mixing and atomization is performed. The NOx in the exhaust gas and the urea solution react in the catalyst to form harmless nitrogen (N 2 ) and water (H 2 O), and is finally discharged into the atmosphere through the exhaust duct.

[0055] The desulfurization unit used in this embodiment is a sodium alkali desulfurization unit, which is specifically described as follows:

[0056] Working principle of desulfurization unit

[0057] Sodium-alkali method: This method uses an aqueous solution of sodium hydroxide (or sodium carbonate) as the initial absorbent and reacts with SO 2 The Na generated by the reaction 2 SO 3 Continue to absorb SO 2 , the main absorption reaction is:

[0058] NaOH+SO 2 →NaHSO 3

[0059] 2NaOH+SO 2 →Na 2 SO 3 +H 2 O

[0060] Na 2 SO 3 +SO 2 +H 2 O→2NaHSO 3

[0061] The generated absorption liquid is Na 2 SO 3 and NaHSO 3 Different by-products can be obtained by treating the absorption liquid in different ways. 3 Neutralize with NaOH to obtain Na 2 SO 3 Due to Na 2 SO 3 Solubility is higher than NaHSO 3 If the concentration is low, it will crystallize from the solution and the by-product Na 2 SO 3 The mother liquor after crystallization is recycled as absorbent.

[0062] Sodium alkali absorbent has large absorption capacity and is not easy to volatilize. It does not cause scaling and clogging problems in the absorption system. The sodium sulfite method is mature, simple, and has high absorption efficiency. The byproducts obtained are of high purity, but it consumes a lot of alkali and has high costs. Therefore, it is only suitable for the treatment of small and medium-sized flue gases. The absorption liquid circulation method can treat large amounts of flue gas, and the absorption efficiency can reach more than 90%. It is widely used at home and abroad.

[0063] The relevant introduction of the exhaust gas online monitoring equipment in this embodiment is as follows:

[0064] 1. Measurement parameters

[0065] SO 2 , NOx, particulate matter, temperature, pressure, flow, humidity, and oxygen content.

[0066] 2. Measurement method

[0067] Flue gas sampling method: direct extraction (heating) post-processing method

[0068] SO 2 , NOx monitoring method: UV differential absorption spectroscopy

[0069] Particle monitoring method: light scattering method

[0070] Temperature: Thermal resistor Pressure: Metal isolation diaphragm method Flow rate: Pitot tube differential pressure method

[0071] Humidity: resistance-capacitance method Oxygen content: electrochemical method

[0072] 3. System composition

[0073] This embodiment uses a flue gas emission continuous monitoring system model DY-FG200, whose main components are as follows:

[0074] Particulate matter monitoring subsystem: mainly measures the smoke concentration in flue gas emissions.

[0075] Pollutant monitoring subsystem: mainly monitors NOx and SO in flue gas emissions 2 Monitor pollutants such as.

[0076] Flue gas emission parameter monitoring subsystem: mainly monitors the temperature, pressure, flow rate, humidity, oxygen content and other parameters of the flue gas, in order to convert the pollutant concentration into the standard dry flue gas state and the excess air excess coefficient specified in the emission standard.

[0077] Data processing subsystem: mainly completes the collection, display, statistics, storage and transmission functions of measurement data, and transmits data to the maritime department in the format required by relevant requirements.

[0078] The DY-FG200 flue gas emission continuous monitoring system takes samples from the outlet pipe section of the desulfurization tower, and the analyzer host completes the measurement. The measurement data is first transmitted to the industrial computer software platform, and provides real-time and historical data storage, viewing, calculation, output and other functions. 2 , NOx concentration and other real-time measurement signals are synchronously transmitted to the desulfurization unit electric control cabinet PLC and SCR denitrification unit electric control cabinet PLC, and are automatically interlocked with each unit for control. Manual control is also possible. According to the feedback measurement signal, the desulfurization unit adjusts the flow rate / circulating slurry pH value of the slurry circulation pump by frequency conversion, and the denitrification unit adjusts the device operating conditions in real time by adjusting the injection volume of the urea pump, so as to achieve the best treatment effect.

[0079] In summary, the present invention has the following advantages:

[0080] (1) In view of the current situation that most of the domestic diesel engine ship exhaust gas treatment only has desulfurization, and a small number of ships are equipped with desulfurization and denitrification devices, we took the lead in carrying out comprehensive treatment of diesel engine ship exhaust gas dust removal, desulfurization and denitrification. After the exhaust gas is treated, the NOx and PM emission concentrations meet the first stage of the "Emission Limits and Measurement Methods of Exhaust Pollutants from Ship Engines (China Phase I and II)" (GB15097-2016), SO 2 The emission concentration can reach 100mg / m 3 The emission level shall be below 100%, and the phenomenon of “black smoke” from ship exhaust shall be completely eliminated.

[0081] (2) A skid-mounted device that integrates ship exhaust gas dust removal, denitrification and desulfurization is used. The main dust removal, desulfurization and denitrification equipment and their supporting equipment are fixedly installed in a high-cube container. It has a compact structure and occupies a small area. It can be used as a fixed or mobile exhaust gas cleaning system (GCS) for exhaust gas treatment in various diesel engine ships and shipbuilding (repair) yards.

[0082] (3) Integrated visual control is adopted to organically combine the ship exhaust gas dust removal, desulfurization, denitrification control unit, and flue gas emission continuous monitoring system, which can integrate and display SO 2 , NOx, PM real-time emission concentrations, as well as flue gas temperature, pressure, flow, humidity, oxygen content and other parameters. According to the exhaust pollutant emission conditions, the operating parameters of the dust removal, desulfurization and denitrification devices are manually or automatically adjusted to achieve the best pollutant removal effect, and the equipment operation can be remotely controlled.

Claims

1. An integrated device for dust removal, desulfurization and denitrification of ship exhaust gas, characterized in that: The invention comprises a metal DPF dust removal unit (1), a first air-cooled heat exchanger (21), a second air-cooled heat exchanger (22), an SCR denitration unit (3), an induced draft fan (4) and a desulfurization unit, wherein the outlet of the metal DPF dust removal unit (1) is connected to the inlet of the first air-cooled heat exchanger (21), the outlet of the first air-cooled heat exchanger (21) is connected to the inlet of the SCR denitration unit (3), the outlet of the SCR denitration unit (3) is connected to the inlet of the induced draft fan (4), the outlet of the induced draft fan (4) is connected to the inlet of the second air-cooled heat exchanger (22), and the outlet of the second air-cooled heat exchanger (22) is connected to the inlet of the desulfurization unit; The desulfurization unit adopts a wet desulfurization unit, comprising a first desulfurization tower (51) and a second desulfurization tower (52), the outlet of the second air-cooled heat exchanger (22) is connected to the inlet of the first desulfurization tower (51), and the outlet of the first desulfurization tower (51) is connected to the inlet of the second desulfurization tower (52); The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas also includes a flue gas emission continuous monitoring system, which includes a measuring device, an industrial computer, a gas sampling probe, a sampling pipeline and a sample gas pretreatment device. The measuring device is connected to the industrial computer, which is connected to the PLC of the control system of the SCR denitrification unit (3) and the PLC of the control system of the desulfurization unit. The measuring device includes a particle detection probe, a temperature sensor, a pressure sensor, a flow rate measurement device, a humidity sensor and a gas analyzer. The gas analyzer is connected to the sample gas pretreatment device, which is connected to the gas sampling probe through the sampling pipeline. The particle detection probe, the temperature sensor, the pressure sensor, the flow rate measurement device and the gas sampling probe are arranged at the outlet of the desulfurization unit, and the particle detection probe, the temperature sensor, the pressure sensor, the flow rate measurement device and the gas analyzer are all connected to the industrial computer.

2. The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to claim 1 is characterized in that: The metal DPF dust removal unit (1) comprises a filter housing (101), a metal DPF filter element (102) and a back pressure gauge. An air inlet pipe and an air outlet pipe are respectively installed at both ends of the filter housing (101). The air outlet pipe on the filter housing (101) is connected to the inlet of a first air-cooled heat exchanger (21). The back pressure gauge is placed in the air inlet pipe on the filter housing (101). A plurality of mounting holes for mounting the metal DPF filter element (102) are provided on the side wall of the filter housing (101) from one end of the filter housing (101) to the other end. The metal DPF filter element (102) is inserted into the filter housing (101) through the mounting holes. The end of the metal DPF filter element (102) is detachably connected to the filter housing (101).

3. The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to claim 2 is characterized in that: The axis of the metal DPF filter element (102) is perpendicular to the airflow direction in the filter housing (101).

4. The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to claim 2 is characterized in that: The end of the metal DPF filter element (102) is detachably connected to the filter housing (101) via a clamp.

5. An integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to any one of claims 1 to 4, characterized in that: It also includes a container, wherein the metal DPF dust removal unit (1), the first air-cooled heat exchanger (21), the second air-cooled heat exchanger (22), the SCR denitrification unit (3), the induced draft fan (4) and the desulfurization unit are all arranged in the container and fixedly connected to the bottom plate of the container, the inlet of the metal DPF dust removal unit (1) is provided with a flue gas inlet duct, the outlet of the desulfurization unit is provided with a flue gas exhaust duct, and both ends of the container are provided with open double doors.

6. The integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to claim 5, characterized in that: The outside of the container is provided with a base and lifting lugs.

7. A ship, characterized in that: It comprises a smoke exhaust device and an integrated device for dust removal, desulfurization and denitrification of ship exhaust gas according to any one of claims 1 to 6, wherein the smoke outlet of the smoke exhaust device is connected to the inlet of a metal DPF dust removal unit (1).

8. A ship according to claim 7, characterized in that: The smoke exhaust equipment includes a main engine, an auxiliary engine, a fuel oil boiler and a generator.

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