WO2002068809A1

WO2002068809A1 - Exhaust gas recirculating engine with scrubber and exhaust gas recirculating system

Info

Publication number: WO2002068809A1
Application number: PCT/JP2002/001663
Authority: WO
Inventors: Tatsuo Takaishi; Tadashi Hirai; Tomohiro TATEISHI; Katsuhiko Sakaguchi; Hirokazu Akagawa; Noriyasu Inenaga; Satoru Goto; Noboru Ohta; Shinichi Ohtani; Satoshi Morikawa; Takeshi Kumagai; Jiro Fukushima; Kou Sasaki; Eiji Nagasawa; Kouji Ikegami; Tetsuya OMATSU; Nozomu HABATA; Junichi Hayashi
Original assignee: Mitsubishi Heavy Industries, Ltd.; Niigata Engineering Co., Ltd.; Akasaka Diesels Limited; Kawasaki Jukogyo Kabushiki Kaisha; Hitachi Zosen Corporation; Mitsui Engineering & Shipbuilding Co., Ltd.; Nkk Corporation; Ishikawajima-Harima Heavy Industries Co., Ltd.; Diesel United, Ltd.; The Shipbuilding Research Association Of Japan
Priority date: 2001-02-26
Filing date: 2002-02-25
Publication date: 2002-09-06
Also published as: JP2002332919A

Abstract

An exhaust gas recirculating system forming an exhaust gas recirculating engine capable of stably, properly, and safely reducing harmful substances by controlling the EGR rate or the content of NOx in exhaust gas of an EGR engine, comprising circulating lines (11-1) to (11-5) for recirculating the exhaust gas therein, a scrubber (21) for cleaning the exhaust gas, a recirculating exhaust gas flow sensor (114) for measuring the flow of the recirculating exhaust gas, a mixed gas flowmeter (125) for metering the flow of the mixed gas formed of the recirculating exhaust gas and the external air fed to the engine, an engine speed sensor (124) for measuring the speed of the engine, and a control part (110) for controlling the flow of the recirculating exhaust gas based on the flow of the recirculating exhaust gas metered by the recirculating exhaust gas flow sensor (114), the flow of the mixed gas metered by the mixed gas flowmeter (125), and the engine speed measured by the engine speed sensor (124).

Description

Description Exhaust gas recirculation engine and exhaust gas recirculation, equipped with gas scrubber: Technical field

The present invention particularly relates to an exhaust gas recirculation engine provided with a gas cleaning device adapted for use in a diesel engine or the like using low-quality fuel, and an exhaust gas recirculation system. Background technology.

In general, the exhaust gas of diesel engines contains harmful substances such as NOx, CO, S〇x, and dust, and substances that add to the environment. Particularly, marine diesel engines that use low-quality fuels In some cases, the content of harmful substances is high, and these harmful substances are being reduced.

The system for reducing them containing materials, by burning a portion of the exhaust gas discharged from the combustion chamber is mixed with fresh air back into the combustion chamber, lowering the 0 ₂ concentration in the working gas, the generation of NOx Exhaust gas recirculation (EGR), which suppresses air pollution, is known. In this method, part of the exhaust gas generated by combustion is mixed into combustion air and burned, and NOx is reduced by lowering the combustion temperature. Air diluted with exhaust gas has a lower oxygen concentration than ordinary air. Therefore, the speed of combustion, which is the reaction between fuel and oxygen, can be reduced. As a result, the maximum temperature of the flame decreases, so that NO x generation (Therma 1 NO x) can be suppressed.

The EGR system has the characteristic that the NOx reduction effect is great, despite the small penalty for deterioration of fuel efficiency.

However, in large marine diesel engines used for large vessels such as tongue power, even if EGR is used, the dust ring contained in the returned exhaust gas S Ox causes the piston ring and cylinder liner One wears out, or The scavenging chamber and air cooler connected to the combustion chamber could become dirty, reducing the reliability and durability of the engine.

In the EGR method, the oxygen concentration of the combustion air supplied to the engine is reduced. For this reason, when the ratio of exhaust gas recirculation (the ratio of exhaust gas contained in the mixed gas of exhaust gas and air (%), hereafter referred to as the EGR ratio) is high, there is a disadvantage that CO and dust will increase. Also, when the exhaust gas is recirculated, the exhaust gas may leak to the outside of the engine near the turbocharger, so it is necessary to take measures from the safety measures in the engine room of the ship. The present invention has been made in view of the above circumstances, and has as its object to provide an exhaust gas recirculation engine equipped with a gas cleaning device that does not cause a problem due to returned exhaust gas even when using low-quality fuel. And

It is another object of the present invention to provide an exhaust gas recirculation system which does not cause problems due to recirculated exhaust gas even when using low-quality fuel.

Another object of the present invention is to provide an exhaust gas recirculation system capable of reducing the amount of harmful substances contained in exhaust gas.

Another object of the present invention is to automatically control the ratio of exhaust gas recirculation (the ratio of exhaust gas contained in a mixed gas of exhaust gas and air, ./.,..., EGR rate) within a certain range. It is to provide an exhaust gas recirculation system which can be used.

Still another object of the present invention is to provide an exhaust gas recirculation system that stably reduces NOx emissions irrespective of the engine speed.

Still another object of the present invention is to provide an exhaust gas recirculation system that stably reduces NOx emissions regardless of the load on the engine.

Another object of the present invention is to provide an exhaust gas recirculation system in which exhaust gas in exhaust gas recirculation does not leak to the outside. DISCLOSURE OF THE INVENTION Means for solving the problems will be described below using the numbers and symbols used in [Best Mode for Carrying Out the Invention]. These numbers and symbols are in [Claims] It is added to clarify the correspondence between the description and [Best Mode for Carrying Out the Invention]. However, those numbers and signs shall not be used for interpreting the technical scope of the invention described in [Claims].

In order to achieve the above object, an exhaust gas recirculation engine 1 equipped with a gas scrubbing device according to a first aspect of the present invention is configured to transfer a part of exhaust gas from a combustion chamber to a circulation pipe 11. (1) Mixing with fresh air through (5) and sending it again to the combustion chamber for combustion to reduce the O ₂ concentration in the working gas and to suppress the generation of harmful substances and other contained substances. A gas cleaning device 21 having a gas cleaning unit 21 A for cleaning exhaust gas is provided in the circulation line 1 1 1 1 to 1 1 1 5 for circulating exhaust gas of the recirculation method. It is characterized by having.

In this way, the gas cleaning provided in the circulation line 1 1 1 1 to 1 1 1 5 that constitutes the exhaust gas recirculation system that mixes part of the exhaust gas with fresh air and sends it back to the combustion chamber for combustion Since the exhaust gas that is returned to the engine 1 and burned by the gas cleaning unit 21A of the device 21 is cleaned again, the dust ring and the SOx contained in the exhaust gas allow for the use of biston rings and cylinder liners. It is possible to eliminate such a problem that the exhaust gas is worn or the scavenging chamber 2 and the air cooler 4 connected to the combustion chamber are contaminated, whereby the reliability and durability of the engine can be improved.

The exhaust gas recirculation engine 1 including the gas cleaning device 21 according to the second embodiment of the present invention is the exhaust gas recirculation engine 1 including the gas cleaning device 21 according to the first embodiment. However, an element 36, which is a packing in which a plurality of wall bodies 37 bent in a wave form are arranged at an interval from each other, and washing water is sprayed on the element 36 to surface of the wall body 37 And a washing water supply means 24 for wetting the exhaust gas through the flow path between the wall bodies 37 so as to absorb the soot and soot contained therein into the washing water and wash the filling. It is characterized by a layer scrubber 21.

In other words, by passing the exhaust gas through the flow path between the walls 37 of the element 36, which is the packing wetted by the washing water of the packed bed scrubber 21, the dust in the exhaust gas As a result, S Ox is absorbed into the surface cleaning water, so that dust and S Ox in the exhaust gas can be easily removed and washed.

The exhaust gas recirculation engine 1 provided with the gas cleaning device 21 of the third embodiment of the present invention is the exhaust gas recirculation engine 1 provided with the gas cleaning device 21 of the second embodiment. An exhaust gas intake pipe 33 having a cooling water ejection nozzle 35 for cooling and simply desulfurizing the exhaust gas by spraying water into the exhaust gas sent to the exhaust gas is provided.

That is, by jetting water from the cooling water jet nozzle 35 provided on the exhaust gas intake pipe 33, it is possible to cool and easily desulfurize the exhaust gas supplied to the gas cleaning unit 21A.

The exhaust gas recirculation engine 1 including the gas cleaning device 21 according to the fourth embodiment of the present invention is the exhaust gas recirculation engine 1 including the gas cleaning device 21 according to the first embodiment. However, a plurality of washing water nozzles 35 A are installed in an exhaust gas intake pipe 33 into which exhaust gas is taken in, and the washing water nozzle 35 A is connected to a washing water supply section 24 capable of increasing pressure, The cleaning water nozzle 35 A is a jet that reduces the size of the cleaning water and accelerates the atomization of the cleaning water to make the cleaning water droplets impinge on the exhaust gas dust to enlarge and remove the dust particles and desulfurize. It is characterized by being composed of 21 A of toscrubbers.

In other words, the cleaning water from the multiple cleaning water nozzles 35 A has been miniaturized and accelerated, and this collides with the dust particles in the exhaust gas. For example, it is taken into the washing water storage tank 34 provided on the side, so that most of the soot and dust can be removed. In addition, since fine cleaning water droplets enter the entire exhaust gas at this portion, sufficient desulfurization is possible, and a scrubber 21 with greatly improved cleaning efficiency can be provided.

The exhaust gas recirculation engine 1 including the gas cleaning device 21 of the fifth aspect of the present invention is an exhaust gas recirculation engine 1 including the gas cleaning device 21 of any one of the first to fourth aspects. Waveforms arranged at intervals downstream of the gas cleaning section 21A A demister 32 is provided for removing the water contained in the exhaust gas by passing the exhaust gas between a plurality of bent plate members 41.

In this way, by passing the exhaust gas that has exited the gas washing unit 21A between the plurality of plates 41 that constitute the demister 32, water in the exhaust gas can be easily removed.

The exhaust gas recirculation engine 1 provided with the gas cleaning device 21 of the sixth aspect of the present invention is an exhaust gas recycle engine provided with the gas cleaning device 21 of any one of the first to fifth aspects of the present invention. In the recirculation engine 1, a gas cleaning device 21 provided in an inert gas system for cleaning a combustion gas and extracting it as an inert gas can be used as the gas cleaning device 21.

In this way, the combustion gas is washed and taken out as an inert gas, and the taken out inert gas is filled into, for example, a tank for storing crude oil to reduce the amount of oxygen in the tank, thereby reducing ignition safety. "In addition to increasing the raw material, we are working to reduce the corrosion of tank doors, etc. Furthermore, the exhaust gas returned to the combustion chamber using the gas cleaning device 21 installed in the inert gas system (IGS: Inert Gas System) is Since the cleaning is performed, the configuration can be simplified by also using the gas cleaning device 21.This can reduce the space for disposing the equipment on the ship and effectively use the space of the ship. can do.

Seventh exhaust gas recirculation system aspect of the invention, the exhaust gas is a circulation line 1 1 one 1-1 1 one ₅ the recirculating comprises a gas washing unit 2 1 for cleaning the exhaust gas. The gas cleaning device 21 is provided in the middle of the circulation pipes 11-11 to 11-15.

Further, in the exhaust gas recirculation system according to the eighth aspect of the present invention, the gas cleaning device 21 includes a gas cleaning unit 31. The gas cleaning section 31 includes: an element 36 in which a plurality of wall bodies 37 bent in a waveform are arranged at intervals from each other; and a spray of cleaning water onto the element 36 to spray the cleaning water onto the element 36. Cleaning liquid supply means 38, 39 for wetting the surface of the body 37; Here, the exhaust gas flows between the wetted wall 37 on the surface. Pass through.

Further, in the exhaust gas recirculation system according to the ninth aspect of the present invention, the gas cleaning section 31 is attached to the exhaust gas intake pipe 33 for taking in the exhaust gas, and the exhaust gas intake pipe 33, and the exhaust gas is provided with cleaning water. further comprising a cooling water jetting nozzles ³ 5 for spraying. Further, in the exhaust gas recirculation system according to the tenth aspect of the present invention, the gas cleaning device 21A includes a gas cleaning unit 31A. The gas cleaning section 31A includes a cleaning water nozzle 35A that is attached to an exhaust gas intake pipe 33 that takes in the exhaust gas and sprays the exhaust gas by atomizing cleaning water at a high speed. I do.

Further, in the exhaust gas recirculation system according to the first aspect of the present invention, the gas cleaning device 21 includes a demister 132 in which a plurality of plate bodies 41 bent in a waveform are arranged at intervals. It also has Then, the exhaust gas removes moisture contained in the exhaust gas while passing between the plate bodies 41.

Further, in the exhaust gas recirculation system according to the twelfth aspect of the present invention, the gas cleaning section 31 may further include a combustion gas pipe 52 of an inert gas system that cleans the combustion gas and removes the gas as an inert gas. Also connected to 53, it is used for cleaning the combustion gas. Furthermore, an exhaust gas recirculation system according to a thirteenth aspect of the present invention includes an engine 1, a recirculated exhaust gas flow sensor 114 for measuring a flow rate of the recirculated exhaust gas, and an external A mixed gas flow rate sensor 125 that measures the flow rate of the mixed gas supplied to the engine mixed with air, an engine rotation sensor 124 that measures the number of revolutions of the engine, and the recirculated exhaust gas flow rate sensor 1 Based on the recirculated exhaust gas flow rate, which is the measurement result of 14, the mixed gas flow rate, which is the measurement result of the mixed gas flow rate sensor 125, and the engine speed, which is the measurement result of the engine rotation sensor 124, A control unit 110 for controlling the flow rate of the recirculated exhaust gas.

Further, the exhaust gas recirculation system according to a fourteenth aspect of the present invention is characterized in that the recirculating exhaust gas recirculating the recirculated exhaust gas is recirculated in the middle of a recirculation line 11-11 to 11-15. It is equipped with a blower 22 that can control the flow rate of the ring exhaust gas by its own rotation speed. Then, the control unit 110 controls the recirculated exhaust gas flow rate based on the number of revolutions of the probe 22.

The exhaust gas recirculation system according to a fifteenth aspect of the present invention includes: A flow control valve 9 for distributing the exhaust gas to the recirculated exhaust gas and the exhaust gas discharged to the outside is provided in the middle of a pipe 7-1 to 7-4 for discharging the gas. Then, the control unit 110 controls the flow rate of the recirculated exhaust gas by the flow rate control valve 9.

Further, in the exhaust gas recirculation system according to a sixteenth aspect of the present invention, there are provided a supercharger 5 for sucking and compressing the recirculated exhaust gas and the outside air and sending the compressed air to the engine 1; A pressure sensor 109 for measuring a supercharger inlet pressure of the recirculated exhaust gas. Further, in the middle of the circulation line 11-1 to 11-15, an inlet of the blower 22 is provided. A pressure regulating valve for regulating the pressure. Then, the control unit 110 further controls the regulating valve 130 so that the pre-supercharger inlet pressure, which is the measurement result of the pressure sensor 109, becomes a preset negative pressure.

Hereinafter, the outline of the present invention will be specifically described with reference to FIGS. 7, 8, 9 and 11. In the exhaust gas recirculation system of the present invention, exhaust gas discharged from the engine 1 flows into the turbocharger turbine section 106 of the supercharger 5 via the exhaust chamber 3. The high-temperature and high-pressure exhaust gas expands in the turbine section to drive the supercharger compressor section 107 of the supercharger 5 connected coaxially. This expansion work pressurizes the exhaust gas that recirculates with the outside air to the required pressure. Exhaust gas that has exited the turbocharger turbine section 106 is recovered by the economizer 18 and split by the EGR flow control valve 9 into a chimney side and a recirculation side.

The recirculated exhaust gas flows into the packed bed scrubber 21 as a gas scrubber via the circulation line 111 and is purified there. Then, the air is sucked out to the control blower 22 as a blower through the circulation line 1 1 and 2. After that, it flows into the turbocharger compressor section 107 via the circulation line 113. The recirculated exhaust gas is pressurized to the required pressure here, passes through the circulation line 111 through the air cooler 4, and returns to the scavenging chamber 2 through the circulation line 111.

In the exhaust gas recirculation system shown in Fig. 9, in addition to the above, a recirculated exhaust gas flow sensor is installed between the packed bed scrubber 21 and the control blower 22 installed in the circulation line 111-1-1115. 1 1 4 is installed. By cooperating with the control blower rotation sensor 115 mounted on the control blower 22, it is possible to control the recirculated exhaust gas to the required recirculated exhaust gas flow rate. A recirculation exhaust gas inlet pressure sensor 109 as a pressure sensor is mounted near the inlet of the supercharger compressor section 107 of the circulation line 113. During EGR operation of the engine 1, the opening of the pressure regulating throttle valve 1 30 as the pressure regulating valve at the control blower 2 2 inlet is adjusted so that the recirculated exhaust gas inlet pressure is always lower than the atmospheric pressure, indicating a negative pressure. It is supposed to. Further, since the turbocharger compressor section 107 sucks in both the outside air and the recirculated exhaust gas through the compressor guide section 108, the total flow rate of both the air cooler 4 and the scavenging chamber 2 is measured. The mixed gas flow sensor 1 25 is installed.

With this, the EGR rate [= recirculated exhaust gas flow rate / mixed flow rate] can be calculated and controllable at every moment of engine operation. That is, the required amount of recirculated gas is controlled by controlling the number of revolutions of the control blower 22 itself capable of sending the recirculated exhaust gas to the supercharger compressor 107. As a result, it is possible to keep the amount of N O X exhausted sufficiently low irrespective of the operating load rate of the engine 1.

On the other hand, the first gas cleaning device installed in the exhaust gas circulation system in FIG. 3 has an element 36 in which a plurality of bent walls 37 are arranged at regular intervals in a gas cleaning section 31. Then, there is provided cleaning water supply means 38, 39 for spraying cleaning water to the element 36 to wet the surface of the wall 37, and including the exhaust gas passing through the wall 37. It is characterized by a packed-bed scrubber 21 that collides with soot and further absorbs SOx and the like into the cleaning water to purify the soot.

The second gas scrubber installed in the exhaust gas circulation system shown in Fig. 5 is a gas scrubber 31 that has a plurality of washing water jet nozzles 3 in an exhaust gas intake pipe 3 that takes in exhaust gas into the gas scrubber. 5 Attach A. Then, a washing water jet nozzle 35A is connected to the washing water supply unit 24, which is a high-pressure pump, and the washing water is atomized and sprayed at a high speed to collide the washing water spray with the exhaust gas soot. The dust particles are enlarged and removed. At the same time, it is characterized by a jet scrubber 21 A capable of desulfurization.

Further, near the outlets of the scrubbers 21 and 21A, water droplets contained in the purified exhaust gas can be removed by an element having a plurality of bent plates 41 arranged at regular intervals. A possible demister 32 is provided. The gas scrubbers 21 and 21 A can be used as gas scrubbers in an inert gas system that cleans combustion gas used in oil tankers and uses it as inert gas. Similarly, a gas cleaning device provided in an exhaust gas system that cleans combustion gas used in an oil tanker and the like and uses it as an inert gas is provided by the gas recirculation engine of the present invention. It can be diverted as the cleaning devices 21 and 21 A. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the configuration of an exhaust gas recirculation engine provided with a gas cleaning device according to a first embodiment of the present invention. FIG.

FIG. 2 is a front view illustrating the configuration and structure of an exhaust gas recirculation engine provided with the gas cleaning device according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a packed bed scrubber for explaining the configuration and structure of an exhaust gas recirculation engine provided with the gas cleaning device of the first embodiment of the present invention and a scrubber of the exhaust gas recirculation system.

FIG. 4 is a schematic piping diagram illustrating a configuration of an exhaust gas recirculation engine including a gas cleaning device according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a jet scrubber illustrating the configuration and structure of an exhaust gas recirculation engine provided with a gas cleaning device and a scrubber constituting an exhaust gas recirculation system according to a second embodiment of the present invention. .

FIG. 6 is a schematic piping diagram for explaining another example of an exhaust gas recirculation engine including the gas cleaning device according to the embodiment of the present invention and a scrubber constituting the exhaust gas recirculation system.

FIG. 7 is a diagram showing the configuration of the first embodiment of the exhaust gas recirculation system according to the present invention.

FIG. 8 is a diagram showing a configuration of an exhaust gas recirculation system according to a second embodiment of the present invention.

FIG. 9 shows a configuration of a third embodiment of the exhaust gas recirculation system according to the present invention. FIG.

FIG. 10 is a configuration diagram showing a supercharger according to a third embodiment of the exhaust gas recirculation system of the present invention.

FIG. 11 is a diagram showing a configuration of a fourth embodiment of the exhaust gas recirculation system according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

(First embodiment)

Hereinafter, an embodiment of an exhaust gas recirculation engine and an exhaust gas recirculation system including the gas cleaning device of the present invention will be described with reference to the drawings.

First, an exhaust gas recirculation engine provided with the gas cleaning device of the first embodiment will be described.

1 and 2 both show an exhaust gas recirculation engine equipped with the gas cleaning device of the present embodiment. FIGS. 1 and 3 are schematic piping diagrams, and FIG. 2 is a front view. In the figure, reference numeral 1 denotes an engine, and this engine 1 is provided with a scavenging chamber 2 and an exhaust chamber 3. In the engine 1, the air sent from the scavenging chamber 2 to a cylinder (not shown) is burned together with the fuel, and the exhaust gas is sent to the exhaust chamber 3. A supercharger 5 is connected to the scavenging chamber 2 via an air cooler 4. The supercharger 5 allows fresh air, which is outside air, to be sent from the intake pipe 6 to the scavenging chamber 2. I have. The supercharger 5 is connected to an exhaust pipe 7 connected to the exhaust chamber 3, and the supercharger 5 is driven by exhaust gas sent from the exhaust chamber 3, and fresh air is collected in the scavenging chamber 2. It is to be sent to. The exhaust gas sent out via the supercharger 5 passes through the economizer 18 so that its heat is extracted and used. A part of the exhaust gas heat-exchanged by the economizer 18 is sent to the circulation line 11 by the EGR flow control valve 9, and the rest is sent to the exhaust line 7 and discharged from the chimney. Yo I'm swelling. The circulation pipe 11 is provided with a packed bed scrubber 21 which is a gas cleaning device for cleaning exhaust gas passing therethrough. In other words, the exhaust gas sent to the circulation line 11 is washed by the packed bed scrubber 21 and sent out. The exhaust gas washed by the packed bed scrubber 21 is drawn by the blower 22. Then, the exhaust gas is sent to the intake pipe 6 to which the circulation pipe 11 is connected, mixed with fresh air, and supplied to the scavenging chamber 2.

A washing water circulation path 23 is connected to the packed bed scraper 21, and seawater is supplied to the packed bed scrubber 21 as washing water by a pump 24 provided in the washing water circulation path 23. It is supposed to be. Then, the exhaust gas is washed by the washing water supplied to the packed bed scrubber 21. In addition, a drain pipe 25 is connected to the packed bed scrubber 21, and the washing water supplied to the packed bed scrubber 21 is drained through the drain pipe 25.

Next, a specific structure of the above-described packed bed scrubber 21 will be described. Figure 3 shows the packed bed scrubber 21. The packed bed scrubber 21 has a packed bed section 31 serving as a gas cleaning section, and a demister 32 provided above the packed bed section 31. The packed bed portion 31 is formed in a cylindrical shape with a bottom, and an exhaust gas intake pipe 33 is provided on a lower side of a peripheral surface thereof. A circulation pipe is provided at an end of the exhaust gas intake pipe 33. Road 1 1 is connected. A wash water storage tank 34 is provided on the bottom surface of the packed bed section 31, and the wash water is stored in the wash water storage tank 34. Further, an end of the exhaust gas intake pipe 33 is opened in the cleaning water stored in the cleaning water storage tank 34. That is, the exhaust gas sent to the exhaust gas intake pipe 33 passes through the washing water stored in the washing water storage tank 34 and is sent out into the packed bed portion 31.

Further, a cooling water jet nozzle 35 connected to the washing water circulation path 23 is provided in the exhaust gas intake pipe 33, and cooling water flows from the cooling water jet nozzle 35 into the exhaust gas intake pipe 33. Sprayed, SOX in the exhaust gas dissolves in the cooling water, Simple desulfurization is being performed.

A drain pipe 25 is connected to the bottom surface 31a of the packed bed portion 31 so that the washing water collected on the bottom surface 31a is drained. An element 36 is provided in the packed layer portion 31 at an intermediate portion in the vertical direction. The element ^3-6 have a plurality of walls 3 7 which is bent in the waveform, these walls 3 7, are disposed along the vertical direction at intervals in the horizontal direction.

A washing water supply pipe (washing water supply means) 38 is provided above the packed bed section 31. The washing water supply pipe 38 has a plurality of washing water supply sprays (washing water supply means). Supply means) 39 is provided downward. The end of the washing water supply pipe 38 is led to the side of the packed bed section 31 as a washing water inlet 38a, and the washing water inlet 38a is connected to the washing water circulation path described above. 2 3 are connected. In other words, the washing water supplied from the washing water circuit 23 to the washing water supply pipe 38 is blown downward from the washing water supply spray 39 provided in the washing water supply pipe 38. Has become. Then, the exhaust gas that has passed through the washing water stored in the washing water storage tank 34 and sent out into the packed bed portion 31 flows upward and downward between the walls 37 of the element 36. Pass through.

The demister 32 provided above the packed bed portion 31 having the above configuration has a plurality of plate members 41 bent in a wave shape, and these plate members 41 force S are spaced apart in the horizontal direction. Are arranged along the vertical direction. The upper part of the demister 32 is connected to the circulation line 11 or 11-2 on its side.

As a result, the exhaust gas passing through the element 36 passes between the plates 41 of the demister 32 and is sent out to the circulation line 11 or 112.

In FIG. 3, reference numeral 42 denotes an outlet for discharging water stored in the storage tank 34, and reference numeral 43 denotes an inspection for visually inspecting and monitoring the inside of the packed bed portion 31 from outside. It is a window.

Next, the operation of the engine 1 including the packed bed scraper 21 having the above configuration will be described. When the engine 1 is driven, the exhaust gas is mixed with fresh air by the supercharger 5 via the air cooler 4, sent to the scavenging chamber 2, and burned by the engine 1.

Exhaust gas generated during combustion in the engine 1 is sent from the exhaust chamber 3 to the exhaust line 7 or 7-1 to drive the supercharger 5, and then heat-exchanged by the economizer 18 to perform EGR. Part of the flow is sent to the circulation line 11 or 11 1 by the flow control valve 9, and the rest is sent to the exhaust line 7 or 7-3 and discharged from the chimney. The exhaust gas sent to the circulation line 11 or 11 is sent to a packed bed scrubber 21, which is a gas cleaning device, and is washed by the packed bed scrubber 21.

Here, the cleaning of the exhaust gas by the packed bed scraper 21 will be described. The exhaust gas sent to the circulation pipe 11 is sent to the exhaust gas intake pipe 33 of the packed bed scrubber 21. Here, the exhaust gas is cooled and easily desulfurized in the exhaust gas intake pipe 33 by the cooling water sprayed from the cooling water jet nozzle 35. The exhaust gas cooled in the exhaust gas intake pipe 33 flows from the end of the exhaust gas intake pipe 33 through the washing water stored in the washing water storage tank 34 serving as a water seal. It is sent out into the packed bed 3 1. -And the exhaust gas sent out into the packed bed portion 31 passes from the bottom to the top between the walls 37 of the element 36, which is the packing material provided in the middle part of the packed bed portion 31. Passing in the direction removes the soot and SOx contained. Here, soot contained in the exhaust gas is removed from the exhaust gas by colliding and adhering to a plurality of bent (waveform) walls 37 of the element 36 as a filler. In addition, S Ox contained in the exhaust gas is separated from the liquid layer and the gas by the wetted wall of the wall 37 wet by the washing water supplied from the washing water supply spray 39 provided above the element 36. Due to the mass transfer caused by the partial pressure difference with the bed, it is diffused and absorbed by the washing water and removed from the exhaust gas.

The exhaust gas from which dust and S Ox have been removed by the element 36 of the packed bed 31 passes between the plates 41 constituting the demister 32 provided above the packed bed 31. As a result, the contained water adheres to the plate body 41 and is removed, and is sent to the circulation pipeline 11 or 11-2 connected to the demister 32.

As described above, the exhaust gas washed by the packed bed scrubber 21 is then drawn by the blower 22 and sent to the intake pipe 6, where it is mixed with fresh air passing through the intake pipe 6. As described above, the gas is sent into the scavenging chamber 2 via the air cooler 4 by the supercharger 5, whereby the generation of NOx during combustion of the engine 1 is suppressed.

Here, the exhaust gas mixed with the fresh air and sent to the scavenging chamber 2 and burned in the combustion chamber of the engine 1 is washed by the packed bed scrubber 21 provided in the middle of the circulation pipe 11. Since dust and S Ox are removed, the dust and S Ox do not wear the piston ring / cylinder liner, or keep the scavenging chamber 2 and air cooler 4 that lead to the combustion chamber, etc., dirty.

As described above, according to the engine 1 including the packed bed scrubber 21 described above, a part of the exhaust gas is mixed with fresh air, sent to the combustion chamber again, and burns. The exhaust gas that is returned to the regenerator 1 and combusted by the packed bed scrubber 21 installed in the exhaust gas is cleaned. It is possible to eliminate such a problem that the engine 1 is worn or the scavenging chamber 2 and the air cooler 4 connected to the combustion chamber are contaminated, whereby the reliability and durability of the engine 1 can be improved.

(Second embodiment)

Next, an exhaust gas recirculation engine and an exhaust gas recirculation system provided with the gas cleaning device of the second embodiment will be described with reference to FIGS.

As shown in FIG. 4, in the exhaust gas recirculation engine, the exhaust gas sent out from the engine 1 through the exhaust chamber 3 is driven by the supercharger 5 similarly to the first embodiment described above. The heat is exchanged through the economizer 18, and a part of the heat is sent to the circulation line 11 by the EGR flow control valve 9. The circulation pipe 11 into which a part of the exhaust gas is fed is provided with a jet scrubber 21 A as a gas cleaning device for cleaning the passing exhaust gas in the middle thereof. In other words, the exhaust gas sent into the circulation pipe 11 is washed by the jet scrubber 21A and sent out.

The exhaust gas washed by the jet scrubber 21 A is drawn into the intake pipe 6 by the blower 22, mixed with fresh air, supplied to the scavenging chamber 2, and supplied with fuel by the engine 1. It is designed to be burned.

Further, a washing water circulation path 23 is connected to the jet scraper 21 A, and seawater is supplied as washing water to the jet scrubber 21 A by a pump 24 provided in the middle of the cleaning water circulation path 23. It is supplied and used for cleaning, and then drained from the distribution pipe 25. Here, a high-pressure pump 24 is used as the pump 24 provided in the washing water circulation path 23.

Figure 5 shows a jet scrubber 21A. The jet scrubber 21 A has a jet nozzle part (gas cleaning part) 33 A with a plurality of cleaning water nozzles 35 A attached to the exhaust gas intake pipe 33 and a main body part having a cleaning water storage tank 34. It has a demister 32 provided on the upper part of 31 A and the main body part 31A.

A circulation line 11 is connected to the jet scrubber 21A. Further, the plurality of washing water nozzles 35 A are connected to a pump 24 capable of relatively high injection pressure. A jet water scraper 2;! A main body 31 A A wash water storage tank 34 is installed on the bottom of A, and the wash water storage tank 34 stores the wash water. The end of the exhaust gas intake pipe 33 opens into the washing water stored in the washing water storage tank 34. In other words, the exhaust gas sent to the exhaust gas intake pipe 33 via the circulation line 11 is sent to the jet nozzle section 33 connected to the high-pressure pump 24. Since the washing water from A has been miniaturized. The speed has been increased, and this collides with the soot particles in the exhaust gas, so that the soot particles become as large as water droplets. The enlarged dust particles are taken into the washing water in the washing water storage tank 34 installed on the bottom of the main body 31A. In addition, a plurality of washing water nozzles in the jet nozzle 33A Desulfurization is almost complete because fine cleaning water droplets from the chisel 35 A penetrate into the entire exhaust gas.

A drain pipe 25 is connected to the bottom of the body 31 A of the jet scraper 21 A, and the washing water leaking from the washing water storage tank 34 is drained.

The demister 32 on the upper part of the main body 31A has a plurality of plate members 41 bent in a waveform, and these plate members 41 are spaced apart in the horizontal direction and along the vertical direction. , Each is arranged. The water droplets flowing into the demister 32 are completely collected. Furthermore, a circulation line 11 or 11 is connected to the upper side of the demister 32, and the exhaust gas flowing into the jet scraper 21A is purified and sent out to the circulation line 11. It is.

Reference numeral 42 in FIG. 5 denotes a discharge outlet for discharging water stored in the washing water storage tank 34.

Next, the exhaust gas cleaning by the jet scrubber 21 A will be described.

Exhaust gas flows into the exhaust gas intake pipe 33 from the circulation pipe 11. In the exhaust gas intake pipe 33 having a jet nozzle 33 A with a plurality of washing water nozzles 35 A, finer washing water spray than the plurality of washing water nozzles 35 A is always performed at high speed. Exhaust gas intake pipe 3 The pump 24, which can set the injection pressure higher so that the washing water spray is faster than the exhaust gas speed, is connected and operated, so that the washing water droplets collide with very fine soot particles, and The soot and dust grows to the size of the water droplets, and is taken into the washing water in the washing water storage tank 34 installed on the bottom of the main body 31A. In addition, since the washing water drops are filled and flow in the exhaust gas intake pipe 33, SOX in the exhaust gas is absorbed by surrounding water droplets, and desulfurization is performed.

As described above, both dust removal and desulfurization are performed in the jet nozzle 33A.

The exhaust gas flowing inside the main body 31 A is the exhaust gas mixed with water droplets because the washing water stored in the washing water storage tank 34 is wound up. When this passes between the bent plate members 41 constituting the demister 32, only water droplets are completely collected due to inertial collision. Only the purified exhaust gas is sent out to the circulation line 11 or 11 connected to the demister 32.

Other operations are the same as those in the first embodiment, and a description thereof will not be repeated.

In the case of the second embodiment as well, since the recirculated gas is removed and desulfurized, there is no abrasion of the bistone ring / cylinder liner and no contamination of the combustion chamber, which are problems during EGR. Further, in this case, it is not necessary to use an element having a bent wall, and a space for accommodating the element is not required. This can reduce the cost of the entire system.

(Third embodiment)

Next, an engine equipped with a system combining an exhaust gas recirculation system (EGR) and an inert gas system (IGS) will be described.

Here, this IGS is generally used for large tankers, and supplies inert gas to the tank provided in the hull to reduce the amount of oxygen in the tank where crude oil is stored. In addition to improving the safety of ignition, it is intended to reduce corrosion of tank doors and the like.

The one shown in FIG. 6 is a combination of the above EGR and IGS. As shown in the figure, an exhaust pipe 52 connected to the boiler 51 is connected to the packed bed scrubber 21, and the exhaust gas is discharged from the boiler 51 via this exhaust pipe 52. The combustion gas, which is the exhaust gas, is sent to the packed bed scraper 21, where it is cooled, washed, and desulfurized to produce an appropriate inert gas.

Then, the exhaust gas converted into an appropriate inert gas by the packed bed scrubber 21 is sent to an inert gas supply pipe 53, and is blown by a blower 54 provided in the middle of the inert gas supply pipe 53. After being drawn in, the water is supplied through a water seal device 55 into a tank 56 provided on the hull. In other words, according to the engine 1, the exhaust gas cleaning on the EGR side and the exhaust gas cleaning on the IGS side are performed by one packed bed scrubber 21. As a result, by adopting it for large tankers, it is possible to purify exhaust gas and enable safe navigation.

Moreover, the configuration can be simplified by also using the packed bed scrubber 21, whereby the space for disposing the equipment on the ship can be reduced, and the space of the i¾ ship can be used effectively.

In the above example, the exhaust gas from the boiler 51 is used as the exhaust gas used on the IGS side, but the exhaust gas from the engine 1 may be used on the IGS side.

Although the packed bed scraper 21 is used in the example of FIG. 6, a jet scrubber 21 A may be used as a scrubber for the inert gas system.

Ships other than tankers that transport oil, LPG, LNG, etc. do not require an inert gas system. Figure 1 shows an implementation system that uses an exhaust gas recirculation engine on a ship other than a tanker. The recirculated gas can also be extracted from the front of the economizer 18 to reduce the pressure loss of the economizer 18 and guided to the packed bed scrubber 21 and the jet scrubber 21 A via the EGR flow control valve 9. .

(Fourth embodiment)

Fourth Embodiment An exhaust gas recirculation system according to a fourth embodiment of the present invention will be described with reference to FIG. 9 and FIG. The difference between the first and second embodiments and the present embodiment is that the exhaust gas recirculation rate (EGR rate) of the exhaust gas recirculation engine always has a constant value (range) regardless of the engine load. The point is to control positively. In order to implement it, the control unit controls the related devices based on the data of various sensors. Hereinafter, the EGR rate control method in the exhaust gas recirculation system will be described. The exhaust gas recirculation (EGR) system is a system in which part of the exhaust gas after combustion is mixed with outside air (fresh air) and used as combustion air. Combustion of fuel using this method has the effect of lowering the combustion temperature and reducing NOX significantly because the amount of oxygen in the combustion air is small, and is considered to be the deciding factor in NOX reduction measures for future large diesel engines. .

The NOX reduction rate is calculated as EGR rate [EGR rate = recirculated exhaust gas flow rate Z (recirculated exhaust gas flow rate) Volume + outside air inflow)]. Here, the recirculated exhaust gas flow rate is the amount of recirculated exhaust gas contained in the combustion air, and the outside air inflow amount is the amount of outside air (fresh air) contained in the combustion air. NOX decreases as the EGR rate increases. However, if the EGR rate is set too high, carbon monoxide and dust will increase. Therefore, it is preferable to control the EGR rate within an appropriate range.

The amount of air for combustion and the amount of exhaust gas vary depending on the load condition of the engine. In order to make this NOx emission constant regardless of operating conditions, it is necessary to perform necessary EGR rate control corresponding to different operating conditions.

During the EGR operation, recirculated exhaust gas may leak from near the turbocharger 5. If it leaks, it is extremely dangerous because it contains low oxygen and contains harmful gases such as carbon monoxide. Therefore, an exhaust gas recirculation system is a necessary condition for EGR rate control and measures for leakage of recirculated exhaust gas. For example, by setting the pressure of the supercharger compressor unit 107 (described later) of the supercharger 5 to a negative pressure, leakage to the outside (normal pressure, atmospheric pressure) can be prevented.

Hereinafter, the configuration shown in FIG. 9 will be described. FIG. 9 is a diagram showing a configuration of an engine having an exhaust gas recirculation system provided with a gas cleaning device in a recirculation gas line in an embodiment of the exhaust gas recirculation system according to the present invention. In FIG. 9, the paths to a plurality of sensors that the control unit 110 senses and outputs and the paths to the devices that the control unit 110 adjusts are connected by dotted lines.

First, an engine rotation sensor 124 that measures the engine speed is mounted on the engine 1 around the engine 1 and the turbocharger 5. At the outlet of the air cooler 4, a mixed gas flow sensor 125 that measures the mixed gas flow (recirculated exhaust gas flow + outside air inflow) is installed. Further, a recirculation gas inlet pressure sensor 109 for measuring the pressure of the recirculated exhaust gas flowing into the compressor 107 of the supercharger 5 is attached to the circulation path 113 near the supercharger 5. Then, those sensors are measured via the control unit 110.

Around the packed bed scraper 2 1, the recirculated exhaust gas flow rate that measures the recirculated exhaust gas flow rate flowing through the circulation pipes 1 1 1 1 to 1 1 1 1 3 near the control blower 2 2 inlet of the circulation pipes 1 1 and 2 Attach sensor 1 1 4 Also, the control blower 22 itself has a blower Attach the blower rotation sensor 1 15 that measures the rotation speed. The control unit 110 measures them.

The devices that the control unit 110 adjusts and controls based on the measurement results from the various sensors include the opening of the EGR flow control valve 9, the rotation speed of the control blower 22, and the pressure adjustment throttle at the control blower 22 inlet. The opening of the valve 130. The opening degree of each of the valves branched to the discharge pipe 7-4 and the circulation pipeline 11-11 can be adjusted by the opening degree of the EGR flow control valve 9. Also, the amount of exhaust gas drawn into the circulation line 11 can be adjusted by the number of rotations of the control blower 22. The amount of exhaust gas drawn into the circulation line 111 can be adjusted by the opening of the pressure adjustment throttle valve 130.

Next, the supercharger 5 will be described with reference to FIG. FIG. 10 shows a sectional view of the turbocharger 5. In the figure, the left part is the turbocharger turbine part 106 of the supercharger 5 which works by expanding the exhaust gas. On the other hand, the right part is the turbocharger compressor unit 107. The compressor blade 107 A is driven by a drive shaft 140 that communicates with the turbine blade 106 A. The compressor cap 1 28 is provided with an outer inlet 1 2 1-1 corresponding to the outside air inlet with a filter attached to the outer periphery. The outside air (partially recirculated exhaust gas) is mainly guided to the compressor blade 107A along the wall of the compressor guide 108.

On the other hand, a port for exclusive use of recirculated gas is provided in the center of the cap. The tip of the dedicated port for the recirculated gas, 1 2 1–2 A, is introduced to the vicinity of the compressor guide 1 108, and the resistance increases in order for the recirculated exhaust gas to flow to the outer inlet 1 2 1–1. It has a structure. The recirculated exhaust gas travels mainly from the center of the compressor guide section 108 from the tip of the dedicated port for recirculated gas 1 2 1–2 A, and is guided to the compressor blade 107 A. The port 1 2 1-2 for exclusive use of the recirculated gas is connected to the circulation line 1 1 1 3 via a telescopic tube 1 2 9. A recirculation gas inlet pressure sensor 109 is mounted on the circulation line 113 near the telescopic tube 127. Then, the control unit 110 monitors and controls the recirculation gas inlet pressure so as to always maintain a negative pressure.

Other configurations shown in FIG. 9 are as described in the first and second embodiments. Therefore, the description is omitted. Next, the operation of the fourth embodiment of the exhaust gas recirculation system according to the present invention will be described.

The control of the EGR rate by the control unit 110 will be described below. The control unit 110 receives the measurement results of the various sensors described above. Then, based on the measured value (engine speed) of the engine speed sensor 124 and the data indicating the correspondence between the set value of the load factor and the engine speed (stored in the storage unit of the control unit 110 not shown), the engine Determine the load factor.

Next, the control unit 110 calculates an EGR rate for the engine load rate. The EGR rate is measured by the mixed gas flow rate sensor 125 (mixed gas flow rate Q t == recirculated exhaust gas flow rate Q1 + outside air inflow rate Qa) and the measured value of the recirculated exhaust gas flow rate sensor 114 (recirculated exhaust gas flow rate). From Q 1), EGR rate = recirculated exhaust gas flow rate Q 1 mixed gas flow rate Qt. Then, the validity for the current EGR rate is determined from a comparison between the obtained actual EGR rate and a preset value of the EGR rate (stored in a storage unit of the control unit 110, not shown).

As a result of the calculation, if the EGR rate deviates from the set value, the EGR rate is adjusted to the set value by finely adjusting the rotation speed of the control blower 22. By finely adjusting the number of revolutions of the control blower 22, the recirculated exhaust gas flow rate Q 1 is controlled to the desired EGR rate. The EGR rate can be finely adjusted by the opening of the EGR flow control valve 9 and the opening of the pressure regulating throttle valve 130 at the inlet of the control blower 22. Generally, once an engine is determined, the value of Qt for the load factor of the engine is constant. Therefore, if the recirculated exhaust gas flow rate Q 1 is set to a value corresponding to the EGR rate to be set, it can be set correctly.

Next, measures taken by the control unit 110 to prevent leakage of recirculated exhaust gas from the vicinity of the supercharger 5 will be described below. The control unit 110 receives the measurement value (recirculation gas supercharger inlet pressure) of the recirculation gas inlet pressure sensor 109 at the same time as the control of the EGR rate. Then, based on the measured values, the recirculation gas inlet pressure flowing into the compressor guide section 108 and the set value of the recirculation gas supercharger inlet pressure set in advance (stored in the storage section of the control section, not shown) and To determine if the current recirculating gas turbocharger inlet pressure is appropriate. If the recirculated gas turbocharger inlet pressure is deviated (high) from the set value (negative pressure), the recirculated exhaust gas may leak to the outside, which is dangerous. Therefore, the control unit 110 can monitor and control the pressure to a constant value (negative pressure) by finely adjusting the opening of the pressure regulating throttle valve 130 as a pressure regulating valve in front of the control blower 22. I have to.

As for each set value (EGR rate and recirculation gas supercharger inlet pressure) set in advance, a value at a specific point may be specified or may be specified with a certain allowable range.

The operation of each of the other components is the same as in the first and second embodiments, and thus the description thereof is omitted.

The exhaust gas recirculation system of the present invention makes it possible to control the EGR rate regardless of the rotational speed of the EGR type engine or the load on the engine, and to automatically keep the EGR rate within a certain range. Become. Along with this, it is possible to control the NOx content in the exhaust gas and keep the NOx content below a certain value, regardless of the engine speed or the load on the engine.

Further, the exhaust gas recirculation system according to the present invention makes it possible to control the engine of the EGR system so that the exhaust gas in the exhaust gas recirculation leaks to the outside and workers do not adapt to the disaster. .

(Fifth embodiment).

A fifth embodiment of the exhaust gas recirculation engine according to the present invention will be described with reference to FIGS. FIG. 11 is a diagram showing a configuration in a case where the exhaust gas recirculation engine according to the present invention of Embodiments 1 and 2 is combined with an inert gas system (IGS).

The difference between Embodiments 1 and 2 and this embodiment is that an exhaust gas recirculation engine is combined with an inert gas system (IGS). The IGS has been introduced to increase the safety of ignition by reducing the oxygen concentration by constantly filling the tanker fuel tank with an inert gas, and to reduce tank corrosion. V. In FIG. 11, a packed bed scrubber 21 or a jet scrubber 21 A is connected to a boiler 51, and a combustion gas as an exhaust gas discharged from the boiler 51 via an exhaust pipe 52 is provided. It is sent to the filling tank scrubber 21 and 21 A, where it is cooled, dedusted, and desulfurized to generate a suitable inert gas. This proper inert gas enters the inert gas supply pipe 53 from the packed bed scrubber 21. Then, the air is sucked from the probe 54, passes through the water hole 55, and is introduced into the tank 56 provided in the hull.

Other configurations and operations are the same as those in the first and second embodiments, and thus description thereof is omitted.

According to the exhaust gas recirculation system of the present invention, both EGR and IGS can be performed by a single filling tank scrubber 21. Therefore, safe navigation is possible along with purification of exhaust gas. It is possible to reduce the space required to arrange equipment on a ship.

In the present embodiment, the gas from the boiler 51 is used as the exhaust gas used on the IGS side, but the exhaust gas from the engine 1 can also be used. Further, it is also possible to use the exhaust gas recirculation system of Embodiment 4 in combination with the inert gas system.

Ships other than tankers that transport oil, LPG, LNG, etc. do not require an inert gas system. For ships that do not require such an inert gas system, the exhaust gas recirculation system will have the configuration shown in Figure 1 or Figure 3. Also, the recirculated gas can be extracted from the front of the economizer 18 to reduce the pressure loss of the economizer 18 and guided to the packed bed scrubber 21 and the jet scrubber 21 A via the EGR flow control valve 9. .

In a ship equipped with the exhaust gas recirculation system of the present invention, an EGR engine is controlled by a ship control unit including a control unit 10 for controlling the engine of the ship. That is, such a ship can appropriately control the EGR rate of the EGR method or the NOX content rate in the exhaust gas to be within a predetermined range or a predetermined value. As a result, harmful substances emitted from ships are significantly reduced. In other words, it is a ship with significantly reduced adverse effects on the environment. Although the present invention describes an engine in a ship, the present invention can be widely applied to a system using the engine on land such as a stationary facility. In that case, industrial water can be used instead of seawater.

Industrial applicability

As described above, according to the exhaust gas recirculation system provided with the gas cleaning device of the present invention, the following effects can be obtained.

According to the exhaust gas recirculation engine equipped with the gas cleaning device of the first aspect of the present invention, a circulation constituting an exhaust gas recirculation system in which a part of the exhaust gas is mixed with fresh air, sent again to the combustion chamber, and burned The gas scrubber of the gas scrubber installed in the pipeline cleans the flue gas that is returned to the engine and burns again. It is possible to eliminate such a problem that the scavenging chamber and the air cooler connected to the combustion chamber are worn or become dirty, thereby improving the reliability and durability of the engine.

According to the exhaust gas recirculation engine provided with the gas scrubber of the second aspect of the present invention, the exhaust gas is passed through the flow path between the walls of the element wetted by the washing water of the packed bed scrubber. In addition, soot and dust in the exhaust gas can be made to collide and adhere, and S Ox can be absorbed into the cleaning water on the surface, so that the soot and soot in the exhaust gas can be easily removed and washed.

According to the exhaust gas recirculation engine provided with the gas cleaning device of the third aspect of the present invention, the water is supplied from the cooling water jet nozzle provided in the exhaust gas intake pipe to the gas cleaning unit by discharging water. Exhaust gas cooling and simple desulfurization can be performed.

According to the exhaust gas recirculation engine equipped with the gas cleaning device of the fourth aspect of the present invention, since the exhaust gas is subjected to advanced dust removal and desulfurization by a jet scrubber having a washing water drip which is a jet nosfle part, Piston ring, cylinder liner One type of wear reduction is realized. Furthermore, since the combustion chamber, the scavenging chamber, and the pipes communicating therewith can be prevented from being stained, the reliability and durability of the entire engine can be improved.

According to the exhaust gas recirculation engine provided with the gas cleaning device of the fifth aspect of the present invention, the exhaust gas is cleaned by the gas cleaning unit by passing the exhaust gas between a plurality of plates constituting the demister. Water can be easily removed.

According to the exhaust gas recirculation engine provided with the gas cleaning device of the sixth aspect of the present invention, the combustion gas is cleaned and taken out as an inert gas, and the taken out inert gas is stored in, for example, a tank for storing crude oil. To reduce the amount of oxygen in the tank to increase the safety of ignition and to reduce corrosion of tank doors. Further, since the exhaust gas returned to the combustion chamber is cleaned using the gas cleaning device provided in the inert gas system, the configuration can be simplified by also using the gas cleaning device. The space for disposing the equipment can be reduced, and the space of the ship can be used effectively.

The exhaust gas recirculation systems according to the seventh to sixteenth aspects of the present invention can be operated with the EGR rate controlled to be constant regardless of the load factor of the engine. Not only can N〇x be reduced to the required value, but also because the packed bed and the jet scrubber are installed in the exhaust gas circulation system, the wear of the engine's biston ring and the cylinder liner is reduced. A highly reliable ship or the like that can be greatly reduced can be provided.

Claims

The scope of the claims

1. A part of the exhaust gas from the combustion chamber is mixed with fresh air through the circulation pipe and sent back to the combustion chamber for combustion, thereby lowering the o concentration in the working gas and containing harmful substances.

Two

An exhaust gas recirculation system for suppressing the generation of substances is provided, and a gas cleaning device having a gas cleaning unit for cleaning exhaust gas is provided in the circulation line for circulating exhaust gas of the exhaust gas recirculation system. An exhaust gas recirculation engine equipped with a gas scrubbing device.

2. The gas cleaning section comprises: an element in which a plurality of corrugated wall bodies are arranged at intervals from each other; and a cleaning water supply means for spraying cleaning water onto the elements to wet the surface of the wall bodies. The gas cleaning apparatus according to claim 1, further comprising a packed bed scrubber that removes soot and soot contained therein by passing the exhaust gas through a flow path between the wall bodies. Exhaust gas recirculation engine equipped with.

3. The gas cleaning section is provided with an exhaust gas intake pipe having a cooling water jet nozzle capable of performing cooling of the exhaust gas and simple desulfurization by spraying water on the exhaust gas to be sent. An exhaust gas recirculation engine provided with the gas cleaning device according to claim 2.

4. The gas cleaning section is provided with a plurality of cleaning water nozzles in an exhaust gas intake pipe into which exhaust gas is introduced, and the cleaning water nozzle is connected to a high-pressure cleaning water supply section. Claims: A jet scrubber, which makes cleaning water finer and accelerates and sprays water so that the spray of cleaning water droplets collides with exhaust gas soot to enlarge and remove soot particles and desulfurize. An exhaust gas recirculation engine equipped with the gas cleaning device described in 1.

5. On the downstream side of the gas cleaning unit, the water contained in the exhaust gas is removed by passing the exhaust gas between a plurality of plate bodies bent in a waveform arranged at intervals. An exhaust gas recirculation system equipped with the gas cleaning device according to any one of claims 1 to 4, wherein a demister is provided.

6. The gas cleaning device according to any one of claims 1 to 5, wherein a gas cleaning device provided in an inert gas system for cleaning a combustion gas and extracting the gas as an inert gas is used as the gas cleaning device. An exhaust gas recirculation engine equipped with a gas cleaning device.

7. An exhaust gas recirculation type engine, comprising: a circulation line for recirculating exhaust gas; and a gas cleaning device for cleaning the exhaust gas, wherein the gas cleaning device is provided in the middle of the circulation line. The exhaust gas recirculation has been:

8. The gas cleaning device includes a gas cleaning unit, wherein the gas cleaning unit includes: an element in which a plurality of corrugated wall bodies are disposed at intervals from each other; The exhaust gas recirculation system according to claim 7, further comprising: a cleaning liquid supply unit that wets a surface of the wall body, and wherein the exhaust gas passes between the wall bodies wetted on the surface.

9. The gas cleaning unit according to claim 8, wherein the gas cleaning unit further includes: an exhaust gas intake pipe that takes in the exhaust gas; and a cooling water jet nozzle that is attached to the exhaust gas intake pipe and sprays cleaning water onto the exhaust gas. Exhaust gas recirculation system.

10. The gas cleaning device includes a gas cleaning unit, the gas cleaning unit is attached to the exhaust gas intake pipe for taking in the exhaust gas, and is attached to the exhaust gas intake pipe, and the cleaning water is refined into the exhaust gas. The exhaust gas recirculation system according to claim 7, further comprising: a cleaning water nozzle that sprays at an increased speed.

11. The gas cleaning apparatus further includes a demister in which a plurality of plate bodies bent in a waveform are arranged at intervals from each other, and the exhaust gas is passed through the space between the plate members. The exhaust gas recirculation system according to any one of claims 7 to 10, which removes moisture contained in the exhaust gas.

12. The gas cleaning section is also connected to the combustion gas pipe of an inert gas system that cleans the combustion gas and removes it as four inert gases, and is also used for the cleaning of the combustion gas. Exhaust gas recirculation according to any one of Items 7 to 11:

13 3. In the exhaust gas recirculation engine, a recirculation exhaust gas flow sensor that measures the flow rate of the recirculated exhaust gas, and measures the flow rate of the mixed gas supplied to the engine by mixing the recirculated exhaust gas and the outside air. A mixed gas flow meter for measuring, an engine rotation sensor for measuring the engine speed, a recirculated exhaust gas flow rate that is a measurement result of the recirculated exhaust gas flow sensor, a mixed gas flow rate that is a measurement result of the mixed gas flow meter, The exhaust gas recirculation, comprising a control unit for controlling the flow rate of the exhaust gas to be recirculated, based on the engine speed, which is a measurement result of the engine rotation sensor,

14. In the middle of the circulation line for recirculating the recirculated exhaust gas, there is provided a processor capable of controlling the flow rate of the recirculated exhaust gas flowing through the circulation line by its own rotation speed. The exhaust gas recirculation system according to claim 13, wherein the exhaust gas recirculation flow rate is controlled by a number.

15. A flow control valve connected to the middle of a pipe for discharging the exhaust gas of the engine and distributing the recirculated exhaust gas and the exhaust gas discharged to the outside, wherein the control unit recirculates by the flow control valve 14. The exhaust gas recirculation system according to claim 13, which controls a flow rate of the exhaust gas.

16. A supercharger that suction-compresses the recirculated exhaust gas and outside air and sends the compressed air to the engine includes a pressure sensor that measures the pressure of the recirculated exhaust gas sucked into the supercharger, In the middle of the circulation line, a pressure regulating valve for regulating the pressure at the inlet of the blower is provided, and the control unit further comprises a supercharger inlet pressure which is a measurement result of the pressure, 15. The exhaust gas recirculation system according to claim 14, wherein the pressure control valve is controlled such that the supercharger pressure becomes a preset negative pressure.