JP2014194193A - Exhaust emission control system in ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently achieve both of treatment of NOx in exhaust gas to be harmless and recovery of waste heat of an engine 25 for power generation as electric energy with a simple structure in a ship.SOLUTION: An exhaust filter device 62 for collecting particulate matter in exhaust gas, a reducing agent supply device 60 for supplying a reducing agent into the exhaust gas, a selective catalytic reduction device 61 for prompting reduction of NOx in the exhaust gas, and a thermoelectric power generating device 30 for generating power by temperature difference using heat of the exhaust gas are arranged in order from an exhaust gas movement direction upstream side in an exhaust passage 27 of an internal combustion engine 25 mounted on a ship 1.

Description

  The present invention relates to an exhaust gas purification system for removing harmful components in exhaust gas in an internal combustion engine such as a diesel engine mounted on a ship.

  Conventionally, in a ship such as a tanker or a transport ship, the amount of power consumed by various auxiliary machines, cargo handling devices, lighting, air conditioning, and other equipment is enormous. There are provided a plurality of diesel generators (hereinafter referred to as Patent Document 1, etc.) that combine a power generation engine (hereinafter referred to as a power generation engine) and a power generator that generates power by driving the power generation engine. In addition, waste heat released from the ship's main diesel engine (hereinafter referred to as the main engine) is recovered to generate high-temperature and high-pressure steam that can be used as a power source for power generation or as a heat source for hot water supply. Such waste heat recovery systems are well known (see, for example, Patent Document 2).

JP 2006-341742 A JP 2007-1339 A

  A diesel engine is one of the most energy efficient types of internal combustion engines, and the amount of carbon dioxide contained in exhaust gas per unit output is small. In addition, since a low-quality fuel such as heavy oil can be used, there is an advantage that it is economically excellent.

  However, exhaust gas from a diesel engine contains a large amount of nitrogen oxide, sulfur oxide, particulate matter, and the like in addition to carbon dioxide. These are harmful substances that hinder environmental conservation. In particular, nitrogen oxides (hereinafter referred to as NOx) are harmful to human bodies and exhibit strong acidity, and are considered to be the cause of acid rain.

  Therefore, it is understood that a ship that drives a diesel engine has a large amount of NOx emission and a large burden on the global environment. Considering the global environment, it is necessary to remove NOx in the exhaust gas as much as possible. For this purpose, it is required to treat NOx and make it harmless with a simple structure and efficiency.

  On the other hand, efficient recovery of waste heat from various engines as electrical energy is important not only in terms of reducing energy costs, but also in terms of reducing environmental impact. However, the techniques described in Patent Documents 1 and 2 do not consider recovering waste heat from the power generation engine as electric energy. Even if the waste heat recovery system for the main engine is applied to each power generation engine, not only will the structure of the waste heat recovery system increase as a whole, but the structure will also become complicated and the number of manufacturing steps and parts will increase. It is considered that the manufacturing cost will increase.

  As a measure for solving the above-mentioned problems, it is possible to apply a thermoelectric power generation technology, which is one of energy conversion technologies with a low environmental load, to a waste heat recovery system for a power generation engine. Thermoelectric power generation technology uses the Seebeck effect that generates an electromotive force by giving a temperature difference to both ends of a thermoelectric module made of metal, semiconductor, or the like, and can directly convert thermal energy into electrical energy.

  The present invention seeks to provide an exhaust gas purification system in a ship that has been improved by examining the current situation as described above.

  An exhaust gas purification system for a ship according to the invention of claim 1 is an exhaust filter device for collecting particulate matter in the exhaust gas in an exhaust path of an internal combustion engine mounted on the ship in order from the upstream side in the exhaust gas movement direction. A reducing agent supply device that supplies a reducing agent to the exhaust gas, a selective catalyst reduction device that promotes reduction of NOx in the exhaust gas, and a thermoelectric power generation device that generates electric power based on a temperature difference using the heat of the exhaust gas. It is that.

  According to a second aspect of the present invention, in the exhaust gas purification system for a ship according to the first aspect, with respect to the exhaust filter device, the supply port portion of the reducing agent supply device is directed in a vertical direction along the exhaust gas movement direction. It is configured to supply a reducing agent.

  According to a third aspect of the present invention, in the exhaust gas purification system for a ship according to the first or second aspect, an engine room and a funnel provided in a ship body of the ship are partitioned vertically by a plurality of decks, and the internal combustion engine is disposed. The exhaust filter device, the reducing agent supply device, the selective catalyst reduction device, and the thermoelectric power generation device are arranged above the deck.

  In general, in order to diffuse the reducing agent in the exhaust gas, it is necessary to take a sufficient exhaust path distance from the reducing agent supply device to the selective catalytic reduction device. The exhaust path distance can be easily secured after following the internal combustion engine mounting structure. The temperature of the exhaust gas used for the thermoelectric power generation device should not be too high depending on the type of the thermoelectric power generation device, but by placing the thermoelectric power generation device on the most downstream side and separating it from the internal combustion engine to some extent, Exhaust gas can be used, and the structure of the thermoelectric generator can be simplified. Since the exhaust filter device is positioned upstream of the selective catalyst reduction device in the exhaust gas movement direction, the roughness of the selective catalyst reduction device can be reduced, and the selective catalyst reduction device can be made compact.

  According to the second aspect of the invention, the exhaust filter device is configured to supply the reducing agent from the supply port of the reducing agent supply device in the vertical direction along the exhaust gas movement direction. For example, as compared with the case where the reducing agent is supplied into the pipe connecting the exhaust filter device and the selective catalytic reduction device, the exhaust path only allows the reducing agent to diffuse, evaporate, and thermally decompose without extending the pipe. A sufficient distance can be ensured.

  According to the invention of claim 3, the engine room and the funnel provided in the ship's hull are vertically partitioned by a plurality of decks, and the exhaust filter device and the reducing agent are disposed above the deck on which the internal combustion engine is disposed. Since the supply device, the selective catalyst reduction device, and the thermoelectric power generation device are disposed, the exhaust path distance from the reducing agent supply device to the selective catalyst reduction device is sufficiently secured, and then the internal combustion engine to the funnel. In the meantime, the exhaust filter device, the reducing agent supply device, the selective catalyst reduction device, and the thermoelectric generator can be arranged efficiently.

It is the whole ship side view in an embodiment. It is II-II front sectional drawing of FIG. It is a schematic front view which shows the thermoelectric generator provided in the exhaust path. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. FIG. 5 is a vertical sectional view taken along line VV in FIG. 3. It is side surface sectional drawing which shows the relationship between an exhaust filter apparatus and a reducing agent supply apparatus.

  Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings (FIGS. 1 to 5) when applied to a thermoelectric generator mounted on a ship.

  As shown in FIG. 1, a ship 1 according to an embodiment includes a hull 2, a cabin 3 (bridge) provided on the stern side of the hull 2, a funnel 4 (chimney) disposed behind the cabin 3, and a hull 2. A propeller 5 and a rudder 6 provided at the rear lower part are provided. In this case, the skeg 8 is integrally formed on the bottom 7 of the stern side. A propeller shaft 9 that rotationally drives the propeller 5 is supported on the skeg 8. A hold 10 is provided on the bow side and the center in the hull 2. An engine room 11 is provided on the stern side in the hull 2.

  In the engine room 11, a main engine 21 (diesel engine in the embodiment) and a speed reducer 22 that are driving sources of the propeller 5, and a power generation device 23 for supplying electric power to the electrical system in the hull 2 are arranged. Yes. The propeller 5 is rotationally driven by the rotational power from the main engine 21 via the speed reducer 22. The interior of the engine room 11 is partitioned vertically by an upper deck 13, a second deck 14, a third deck 15, and an inner bottom plate 16. In the embodiment, the main engine 21 and the speed reducer 22 are installed on the inner bottom plate 16 at the lowermost stage of the engine room 11, and the power generator 23 is installed on the third deck 15 at the middle stage of the engine room 11. Although detailed illustration is omitted, the hold 10 is divided into a plurality of sections.

  As shown in FIG. 2, the power generation apparatus 23 includes a plurality of diesel generators 24 (implemented with a combination of a power generation engine 25 (diesel engine in the embodiment) and a power generator 26 that generates power by driving the power generation engine 25). 3 in the form). The diesel generator 24 is basically configured to operate efficiently in accordance with the required power amount in the hull 2. For example, all the diesel generators 24 are operated at the time of entry / exit that consumes a large amount of power, and an arbitrary number of diesel generators 24 are operated at the time of berthing where the power consumption is relatively low.

  The generated power generated by the operation of each generator 26 is supplied to the electrical system in the hull 2. Although not shown in detail, a power transducer is electrically connected to each generator 26. The power transducer detects power generated by each generator 26.

  Each power generation engine 25 is connected to an intake path (not shown) for air intake and an exhaust path 27 for exhaust gas discharge. The air taken in through the intake path is sent into each cylinder of the power generation engine 25 (inside the cylinder in the intake stroke). When the compression stroke of each cylinder is completed, the fuel sucked up from the fuel tank is pumped into the combustion chamber of each cylinder by the fuel injection device, and the expansion stroke accompanying the self-ignition combustion of the air-fuel mixture is performed by each combustion chamber.

  The exhaust passage 27 of each power generation engine 25 extends to the funnel 4 and directly communicates with the outside. As described above, since there are three power generation engines 25, there are three exhaust paths 27. In each exhaust path 27, in order from the upstream side in the exhaust gas movement direction, an exhaust filter device 62 that collects particulate matter in the exhaust gas, a reducing agent supply device 60 that supplies a reducing agent for NOx reduction to the exhaust gas, A selective catalytic reduction device 61 that promotes reduction of NOx in the exhaust gas, and a thermoelectric generator 30 that converts waste heat from the power generation engine 25 (heat of exhaust gas that is a heat medium) into electric energy are arranged. . Exhaust gas discharged from each power generation engine 25 is discharged outside the ship 1 through the exhaust filter device 62, the reducing agent supply device 60, the selective catalyst reduction device 61, and the thermoelectric power generation device 30. An exhaust filter device 62, a selective catalyst reduction device 61, a reducing agent supply device 60, and a thermoelectric power generation device 30 are arranged above the third deck 15 on which the respective power generation engines 25 are arranged. In this case, the exhaust filter device 62 and the reducing agent supply device 60 are arranged on the upper side of the engine room 11 (on the second deck 14 at the upper stage of the engine room 11). The selective catalyst reduction device 61 and the thermoelectric power generation device 30 are disposed in the funnel 4 above the upper deck 13.

  The exhaust filter device 62 includes a plurality of soot filters 68 having a honeycomb structure and made of a heat-resistant metal material and incorporated in a substantially cylindrical filter casing 70. As shown in detail in FIG. 6, the inside of the filter casing 70 is partitioned into three chambers 73, 74, 75 by a pair of left and right partition walls 71, 72. A space between the inner surface of the filter casing 70 and the upstream partition wall 71 is an inflow chamber 73 into which exhaust gas of the power generation engine 25 flows. A space between the upstream partition wall 71 and the downstream partition wall 72 is a purification chamber 74 in which the soot filter 68 is disposed. A space between the downstream partition wall 72 and the inner surface of the filter casing 70 is an outflow chamber 75 through which the exhaust gas that has passed through the purification chamber 74 passes.

  A purification inlet pipe 76 extending from the power generation engine 25 in the exhaust path 27 is connected to the most upstream side in the exhaust gas movement direction of the inflow chamber 73, while the most downstream side (upper end side) of the outflow chamber 75 in the exhaust gas movement direction. ) Is connected to a purification outlet pipe 77 extending toward the selective catalyst reduction device 61 in the exhaust path 27. A plurality of communication pipes 78 connecting the inflow chamber 73 and the outflow chamber 75 are provided between the left and right partition walls 71 and 72. The upstream side of each communication pipe 78 in the exhaust gas movement direction passes through the upstream partition wall 71, and the downstream side of each communication pipe 78 in the exhaust gas movement direction passes through the downstream partition wall 72. The soot filter 68 is accommodated in each communication pipe 78.

  A dust box 87 for collecting particulate matter is connected to the lower end side of the inflow chamber 73 of the filter casing 70 via a soot discharge pipe 86. A backwash nozzle 89 is attached to the outflow chamber 75 side of the filter casing 70 so as to face the end surface of each soot filter 68 on the downstream side in the exhaust gas movement direction. Each backwash nozzle 89 is connected to an air chamber 88. A blower (not shown) is connected to the air chamber 88. High pressure air from the blower is supplied to each backwash nozzle 89 via the air chamber 88 and blown to the downstream side of each soot filter 68 in the exhaust gas movement direction. Particulate matter contained in the exhaust gas of the power generation engine 25 is collected by the soot filter 68 and intermittently collected by the high pressure air backwash from each backwash nozzle 89.

  The reducing agent supply device 60 includes a urea water tank 80 that stores a urea aqueous solution (hereinafter referred to as urea water) as a reducing agent, a feed pump 81 that sucks urea water from the urea water tank 80, and an electric motor that drives the feed pump 81. A motor 82 and a urea water injection nozzle 64 as a supply port connected to the feed pump 81 via a urea water injection pipe 83 are provided (see FIG. 6). The urea water injection nozzle 64 is attached to the most upstream side (lower end side) of the outflow chamber 75 in the filter casing 70 in the exhaust gas movement direction via the injection base 84. By driving the feed pump 81, urea water is sent from the urea water tank 80 to the urea water injection nozzle 64, and urea water is injected from the urea water injection nozzle 64 into the outflow chamber 75 of the filter casing 70. In this case, as is apparent from the mounting position of the urea water injection nozzle 64, the urea water is injected from the urea water injection nozzle 64 in a vertical direction (from bottom to top) along the exhaust gas movement direction. That is, the length L of the outflow chamber 75 in the filter casing 70 in the exhaust gas movement direction is used as an exhaust path distance for diffusing, evaporating, and thermally decomposing at least urea water.

  The selective catalyst reduction device 61 includes a NOx catalyst 65 that promotes reduction of NOx in the exhaust gas and an extra supplied reducing agent (in this case, after hydrolysis) in a substantially cylindrical catalyst casing made of a refractory metal material. And a slip treatment catalyst 66 for promoting the oxidation treatment of ammonia) are accommodated in series in the exhaust gas movement direction. The NOx catalyst 65 and the slip treatment catalyst 66 have a honeycomb structure composed of a large number of cells partitioned by porous (filterable) partition walls. For example, a catalyst such as alumina, zirconia, vanadia / titania or zeolite is used. Has metal. The NOx catalyst 65 is an exhaust gas sent into the selective catalyst reduction device 61 by selectively reducing NOx in the exhaust gas using ammonia generated by hydrolysis of urea water from the urea water injection nozzle 64 as a reducing agent. To purify. The slip treatment catalyst 66 oxidizes unreacted (surplus) ammonia flowing out from the NOx catalyst 65 to harmless nitrogen. Therefore, the exhaust gas discharged from each power generation engine 25 is purified through the exhaust filter device 62 and then purified through the reducing agent supply device 60 and the selective catalyst reduction device 61. Then, it is discharged out of the ship 1 via the thermoelectric generator 30.

  As shown in FIGS. 3 to 5, the thermoelectric power generator 30 provided in the middle of each exhaust path 27 includes a substantially cylindrical pipe 31 through which exhaust gas as a heat medium flows, a low temperature side and a high temperature side. And a plurality of thermoelectric units 32 having a plate-like thermoelectric module 33 that generates electric power according to the temperature difference, and the high temperature side of each thermoelectric module 33 is configured to be heated with exhaust gas. The upstream side exhaust pipe 34 and the downstream side exhaust pipe 35 that constitute the exhaust path 27 are located on both sides of the pipe 31 of the thermoelectric generator 30 so as to be distributed. An upstream flange 36 protruding in the outer peripheral direction is attached to the opening end of the upstream exhaust pipe 34 on the exhaust downstream side. A downstream flange 37 protruding in the outer peripheral direction is attached to the opening end of the downstream exhaust pipe on the exhaust upstream side. A connecting flange 38 that protrudes in the outer peripheral direction is attached to the opening ends of both ends of the pipe 31 in the exhaust direction.

  A pipe 31 is interposed between the upstream side exhaust pipe 34 and the downstream side exhaust pipe 35. The upstream flange 36 and the connecting flange 38 on the upstream side of the exhaust are brought into contact with each other via a gasket (not shown), and both the flanges 36 and 38 are fastened with a plurality of sets of bolts 39 and nuts 40. Further, the downstream flange 37 and the connecting flange 38 on the exhaust downstream side are abutted with each other via a gasket (not shown), and both flanges 37 and 38 are fastened with a plurality of sets of bolts 39 and nuts 40. As a result, the upstream side exhaust pipe 34, the pipe 31, and the downstream side exhaust pipe 35 are detachably connected. Exhaust gas as a heat medium discharged from each power generation engine 25 flows from the upstream exhaust pipe 34 to the downstream exhaust pipe 35 through the pipe 31 of the thermoelectric generator 30 in the exhaust path 27.

  As shown in FIG. 4, the pipe 31 of each thermoelectric generator 30 is formed in a polygonal cross section. The pipe 31 according to the embodiment has an octagonal cross-sectional shape in which a corner portion of a cylindrical body having a quadrangular cross-section is chamfered. In other words, the pipe 31 of the embodiment has a cylindrical shape with an octagonal cross section in which the wide flat surface portions 41 and the chamfered portions 42 are alternately connected. A thermoelectric unit 32 group is attached to each flat surface portion 41 of the pipe 31.

  In this case, rectangular opening holes 43 penetrating in the plate thickness direction are formed in each flat portion 41 in a matrix form of two rows parallel in the exhaust direction. A mounting frame 44 surrounding the outer peripheral side of each opening hole 43 is provided on the outer surface side of each flat portion 41 by welding or the like. The mounting frame 44 of the embodiment is formed in an 8-character shape so as to surround the outer peripheral side of two opening holes 43 adjacent in the circumferential direction. And the thermoelectric unit 32 is attached to each attachment frame 44 so that each opening hole 43 of the plane part 41 may be plugged up.

  In the embodiment, two rows of parallel opening holes 43 are formed in each plane portion 41, and a plurality of attachment frames 44 are fixed to one plane portion 41. The thermoelectric unit 32 is mounted on the mounting frame 44. Therefore, the thermoelectric generator 30 is constituted by the thermoelectric units 32 arranged on the four planes. Each thermoelectric unit 32 includes a thermoelectric module 33 that generates electricity by a temperature difference between a low temperature side and a high temperature side, a cooling case 45 as a low temperature side member, and a heat collecting fin 46 as a high temperature side member. The cooling case 45 has a passage through which a coolant such as cooling water is circulated. The cooling case 45 of each thermoelectric unit is connected to, for example, a heat exchanger of each power generation engine 25 via a cooling pipe (not shown). The cooling case 45 is cooled by causing the refrigerant from the heat exchanger to flow through the passage in the cooling case 45.

The thermoelectric module 33 is formed by electrically connecting two types of semiconductors of p-type and n-type made of, for example, Bi ₂ Te ₃ or the like alternately with electrodes, and insulating between adjacent electrodes. Each thermoelectric module 33 is connected in parallel or in series, and is connected to an electrical load via electrical wiring. An electromotive force is generated in the thermoelectric module 33 by cooling one wide side surface of the thermoelectric module 33 with the refrigerant in the cooling case 45 and heating the other wide side surface of the thermoelectric module 33 with heat from the heat collecting fins 46 in contact with the exhaust gas. Is generated and the generated power is taken out.

  The heat collecting fins 46 are formed by projecting a large number of fin portions 48 on a base 47 having a wide rectangular flat plate covering a portion corresponding to the opening hole 43 in the mounting frame 44. The heat collection fins 46 of the embodiment are formed of a highly heat conductive ceramic such as AlN or SiC in addition to a metal having a good heat conductivity such as an aluminum alloy, a copper alloy, or stainless steel. Between the thermoelectric module 33 and the heat collection fins 46, a rectangular flat plate-like heat insulating member 49 is interposed as necessary. The heat insulating member 49 according to the embodiment is formed by stacking a plurality of metal plates or ceramic plates. For example, the heat insulating member 49 is transmitted to the thermoelectric module 33 from the heat collecting fins 46 on which an exhaust gas of about 350 to 400 ° C. hits on average. It is comprised so that heat may be suppressed to 200 degrees C or less.

  When attaching each thermoelectric unit 32 to the pipe 31, the fin portion 48 of the heat collection fin 46 of each thermoelectric unit 32 is inserted into the opening hole 43 through the attachment frame 44, and the heat collection fin 46 is inserted into the pipe 31. The fin part 48 is protruded. Then, the base 47 of the heat collecting fin 46 is overlapped with the mounting frame 44 and fastened with bolts. When the exhaust gas flows into the pipe 31, the exhaust gas comes into contact with the fin portions 48 in the pipe 31 of each heat collection fin 46, and waste heat (heat of the exhaust gas) is collected by the heat collection fins 46. By the heat transfer from each heat collection fin 46, the other wide side surface (high temperature side) of each thermoelectric module 33 is heated. A refrigerant flows into each cooling case 45 to cool one wide side surface (low temperature side) of each thermoelectric module 33. As a result, a temperature difference occurs between the low temperature side and the high temperature side of each thermoelectric module 33, and an electromotive force is generated in each thermoelectric module 33 to generate power.

  As shown in FIGS. 4 and 5, in the pipe 31, a shield 50 as a heat medium guide member that sends exhaust gas, which is a heat medium, to each heat collection fin 46 side is appropriately separated from the inner peripheral surface of the pipe 31. Arranged. The shield 50 according to the embodiment plays a role of narrowing the cross-sectional area inside the pipe 31 and forms the base of the shield 50 in a square cross section. The outer peripheral surfaces of the four flat portions 51 at the base of the shield 50 are opposed to the inner peripheral surfaces of the four flat portions 41 of the pipe 31. The piping 31 and the shielding body 50 are integrally connected via a plurality of bridge bodies 53 that are appropriately separated from each other in a narrow passage 52 between the pipes 31 and 50. That is, the pipe 31 and the shield 50 have a double cylinder structure. The inner peripheral surface of each flat surface portion 41 of the pipe 31 and the outer peripheral surface of the flat portion 51 of the shield 50 base that faces this are aligned in parallel along the exhaust direction. The fin portions 48 of the respective heat collecting fins 46 are positioned between the inner peripheral surface of each flat surface portion 41 of the pipe 31 and the outer peripheral surface of the flat portion 51 of the shield 50 base that faces the flat surface portion 41.

  In this case, since the inner peripheral surface of each flat surface portion 41 of the pipe 31 and the outer peripheral surface of the flat portion 51 of the shield 50 base opposite thereto are arranged in parallel along the exhaust direction, the collection of each thermoelectric unit 32 is arranged. When making the projection length of the heat fin 46 constant, each heat collecting fin 46 is arranged between the inner peripheral surface of each flat surface portion 41 of the pipe 31 and the outer peripheral surface of the flat portion 51 of the shield 50 base portion opposed thereto. It is easy to arrange the fin portions 48 as long as possible. In other words, the structure of each heat collection fin 46 and thus each thermoelectric unit 32 can be easily shared. Note that the cross-sectional shape of the shield 50 preferably corresponds to the cross-sectional shape of the pipe 31. This is because it is easy to set the inner peripheral surface of each flat surface portion 41 of the pipe 31 and the outer peripheral surface of the flat portion 51 of the shield 50 base opposite thereto in parallel along the exhaust direction.

  The exhaust upstream side of the shield 50 is a tapered cone portion 54 as it approaches the upstream tip. The cone part 54 of the shield 50 according to the embodiment has a quadrangular pyramid shape because the base part has a quadrangular cross section. If the shield 50 is simply disposed in the pipe 31, the flow resistance of the exhaust gas increases. However, since the cone part 54 is formed on the exhaust upstream side of the shield 50, the pipe 31 is formed by the cone part 54. The exhaust gas can be smoothly guided to the narrow passage 52 between the shield 50 and the increase in flow resistance of the exhaust gas by the shield 50 is suppressed. It is sufficient that the shape of the cone portion 54 corresponds to the cross-sectional shape of the shield 50. That is, the cone portion 54 is not limited to a quadrangular pyramid shape, and may be a polygonal pyramid shape. Note that the exhaust upstream side of the shield 50 is not limited to the cone portion 54, and may be provided with a stationary blade or a movable blade as long as the exhaust gas can be smoothly guided to the narrow passage 52, or a spiral A shaped screw body may be provided.

  As is clear from the above description, the embodiment includes a pipe 31 through which exhaust gas flows, and a plurality of thermoelectric units 32 having a plate-like thermoelectric module 33 that generates power by a temperature difference between the low temperature side and the high temperature side, In the thermoelectric generator 30 that heats the high temperature side of each thermoelectric module 33 with the exhaust gas, the pipe 31 is formed in a polygonal cross section, and the thermoelectric unit 32 group is attached to each flat surface portion 41 of the pipe 31. Therefore, the plurality of thermoelectric units 32 can be densely arranged on the outer peripheral surface of the pipe 31 having a polygonal cross section. For this reason, the heat collection efficiency from the said exhaust gas can be improved, and the power generation efficiency in the said thermoelectric power generation apparatus 30 whole can be improved by extension.

  Further, the heat collecting fins 46 provided on the high temperature side of the thermoelectric modules 33 are protruded into the pipes 31 and shields as heat medium guide members for sending the exhaust gas to the heat collecting fins 46 side. 50, the exhaust gas can be actively supplied to the heat collecting fins 46 due to the presence of the shield 50, and the heat (waste heat) of the exhaust gas can be efficiently supplied. It can be transmitted to the fin 46. The heat collection efficiency from the exhaust gas to the heat collection fins 46 is high, and the power generation efficiency can be improved.

  A heat shield fin 46 provided on the high temperature side of each thermoelectric module 33 protrudes into the pipe 31 and a shield 50 that narrows the cross-sectional area inside the pipe 31 is provided from the inner peripheral surface of the pipe 31. Since the heat collection fins 46 are positioned between the inner peripheral surface of the pipe 31 and the outer peripheral surface of the shield 50, the heat collecting fins 46 are positioned between the inner peripheral surface of the pipe 31 and the outer periphery of the shield 50. The exhaust gas is actively sent to and from the surface, and the cost can be reduced with a simple configuration, but the heat collection efficiency from the exhaust gas to each of the heat collection fins 46 can be further improved. Contributes to improved efficiency.

  In addition, since the inner peripheral surface of each of the flat portions 41 of the pipe 31 and the outer peripheral surface of the shield 50 facing the same are set in parallel, the heat collecting fins 46 of the thermoelectric units 32 are set in parallel. When the projecting length of each of the pipes 31 is made constant, the heat collecting fins 46 are extended as much as possible between the inner peripheral surface of each flat surface portion 41 of the pipe 31 and the outer peripheral surface of the shield 50 facing it. And densely arranged. That is, the structure of each heat collecting fin 46 and thus each thermoelectric unit 32 can be made common, which contributes to improving the versatility of each thermoelectric unit 32.

  In addition, since the upstream side of the shield 50 is formed into a tapered cone portion 54 as it approaches the upstream tip portion, the pipe 31 and the shield 50 are separated by the cone portion 54. The exhaust gas can be smoothly guided to the narrow passage 52 therebetween, and an increase in the flow resistance of the exhaust gas by the shield 50 can be suppressed.

  By the way, generally, in order to diffuse the reducing agent (ammonia generated by hydrolysis of urea water) in the exhaust gas, it is necessary to take a sufficient exhaust path distance from the reducing agent supply device 60 to the selective catalyst reduction device 61. In this regard, as in the embodiment, the exhaust filter device 62 that collects particulate matter in the exhaust gas in the exhaust path 27 of the internal combustion engine 25 mounted on the ship 1 in order from the upstream side in the exhaust gas movement direction, A reducing agent supply device 60 that supplies a reducing agent to the exhaust gas, a selective catalyst reduction device 61 that promotes reduction of NOx in the exhaust gas, and a thermoelectric power generation device 30 that generates power by a temperature difference using the heat of the exhaust gas are arranged. When the configuration is adopted, the exhaust path distance (the outflow chamber 75 of the filter casing 70) can be easily secured after following the structure of the general ship 1 where the internal combustion engine 25 is mounted. The temperature of the exhaust gas used for the thermoelectric generator 30 may not be too high depending on the type of the thermoelectric generator 30, but the thermoelectric generator 30 is arranged on the most downstream side to be separated from the internal combustion engine 25 to some extent. Therefore, the exhaust gas having an appropriate temperature can be used and the structure of the thermoelectric generator 30 can be simplified. Since the exhaust filter device 62 is positioned upstream of the selective catalyst reduction device 61 in the exhaust gas movement direction, the roughness of the selective catalyst reduction device 61 can be reduced, and the selective catalyst reduction device 61 can be made compact. I can plan.

  Further, the exhaust filter device 62 is configured to supply the reducing agent from the supply port portion 64 of the reducing agent supply device 60 toward the vertical direction along the exhaust gas movement direction. Compared with the case where the reducing agent is supplied into the pipe 77 connecting the filter device 62 and the selective catalyst reduction device 61, the exhaust gas is only diffused, evaporated, and thermally decomposed without extending the pipe 77. The path distance (outflow chamber 75 of the filter casing 70) can be secured sufficiently and reliably.

  In particular, according to the embodiment, the engine room 11 and the funnel 4 provided in the hull 2 of the ship 1 are divided up and down by a plurality of decks 13 to 16, and above the deck 15 on which the internal combustion engine 25 is disposed, Since the exhaust filter device 62, the reducing agent supply device 60, the selective catalyst reduction device 61, and the thermoelectric generator 30 are arranged, the exhaust path distance from the reducing agent supply device 60 to the selective catalyst reduction device 61 ( After sufficiently securing the outflow chamber 75) of the filter casing 70, the exhaust filter device 62, the reducing agent supply device 60, the selective catalyst reduction device 61, and the like are provided between the internal combustion engine 25 and the funnel 4. The thermoelectric generator 30 can be arranged efficiently.

  In addition, the structure of each part is not limited to embodiment of illustration, A various change is possible in the range which does not deviate from the meaning of this invention. For example, the thermoelectric generator 30 of the present application may be disposed in the exhaust path of the main engine 21.

DESCRIPTION OF SYMBOLS 1 Ship 2 Hull 4 Funnel 11 Engine room 21 Main engine 23 Electric power generation device 24 Diesel generator 25 Electric power generation engine 27 Exhaust path 30 Thermoelectric power generation device 60 Reducing agent supply device 61 Selective catalyst reduction device 62 Exhaust filter device 64 Urea water injection nozzle 65 NOx catalyst 66 Slip treatment catalyst 68 Soot filter 70 Filter casing 73 Inflow chamber 74 Purification chamber 75 Outflow chamber 80 Urea water tank 81 Feed pump

Claims (3)

An exhaust filter device that collects particulate matter in the exhaust gas in order from the upstream side in the exhaust gas movement direction to the exhaust path of the internal combustion engine mounted on the ship, a reducing agent supply device that supplies the reducing agent to the exhaust gas, A selective catalytic reduction device that promotes the reduction of NOx in the exhaust gas, and a thermoelectric power generation device that generates electric power by a temperature difference using the heat of the exhaust gas,
Exhaust gas purification system for ships. The exhaust filter device is configured to supply a reducing agent from a supply port of the reducing agent supply device in a vertical direction along the exhaust gas movement direction.
The exhaust gas purification system for a ship according to claim 1. The engine room and funnel provided in the hull of the ship are vertically divided by a plurality of decks, and the exhaust filter device, the reducing agent supply device, and the selective catalyst reduction device are disposed above the deck on which the internal combustion engine is disposed. And arranging the thermoelectric generator,
The exhaust gas purification system for a ship according to claim 1 or 2.

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