Exhaust gas recirculation system

Abstract

The present invention relates to an exhaust gas recirculation system and, more particularly, to an exhaust gas recirculation system in which a flowmeter and a throttle valve are sequentially installed on the rear side of a water treatment device so that a portion of treated water is returned to a cooling water tank and the rest is discharged overboard, this process can be continuously performed, and the recirculation flow rate of the treated water is precisely controlled according to engine load, seawater temperature change, etc., thereby increasing efficiency.

Description

exhaust gas recirculation system

[0001] The present invention relates to an exhaust gas recirculation system, and more particularly, to an exhaust gas recirculation system in which a flow meter and a throttle valve are sequentially installed at the rear of a water treatment device to return a portion of the treated water to a cooling water tank and discharge the remainder overboard, and this process can occur continuously, and the recirculation flow rate of the treated water is precisely controlled according to changes in engine load, seawater temperature, etc., thereby increasing efficiency.

[0002] Ships are equipped with a main engine that rotates the propeller, a power generation engine that generates electricity, etc., and they burn the supplied fuel to rotate the propeller or generate electricity. In this process, the engine emits exhaust gas generated by the combustion of the fuel.

[0003] The above exhaust gas may contain unburned fuel components or harmful components in the engine. For example, if the engine burns natural gas (LNG) as fuel, the exhaust gas may contain methane that was not burned in the engine, which may cause a methane slip phenomenon. Another example is if the engine burns heavy oil as fuel, the exhaust gas emitted from the engine may contain nitrogen oxides, also known as NOx.

[0004] If exhaust gas containing harmful substances such as methane slip or nitrogen oxides is released into the atmosphere, it can cause serious environmental pollution. Therefore, an exhaust gas recirculation system (EGR) is installed on ships to reduce harmful substances contained in exhaust gas.

[0005] The above exhaust gas recirculation system (EGR) refers to a device that reduces nitrogen oxides (NOx) and the like contained in exhaust gas by cooling a portion of the exhaust gas generated when fuel is combusted in an engine, mixing it with fuel, and reintroducing it into the engine for combustion. The above exhaust gas recirculation system (EGR) includes an exhaust gas cooler (EGC) that cools exhaust gas discharged from the engine with seawater or fresh water, and the exhaust gas cooled by the exhaust gas cooler (EGC) can be supplied to a turbocharger.

[0006] FIG. 1 is a drawing illustrating a conventional exhaust gas recirculation system (90), which is disclosed in Korean Patent Publication No. 10-2023-0082557 (June 8, 2023).

[0007] Referring to FIG. 1, the conventional exhaust gas recirculation system (90) includes an exhaust gas cooler (91), an exhaust gas branch pipe (92), an exhaust gas supply pipe (93), a cooling water tank (94), a cooling water recovery pipe (95), and a cooling water heat exchanger (96).

[0008] The above exhaust gas cooler (91) is configured to cool the exhaust gas by spraying cooling water on the exhaust gas flowing into the inside, and includes a pre-cooling tower (911) formed in front of the main cooling tower (912) to pre-cool the exhaust gas by spraying cooling water on a portion of the exhaust gas discharged from the exhaust gas discharge side of the engine (E), and a main cooling tower (912) to secondarily cool the exhaust gas by re-spraying cooling water on the exhaust gas that has been primarily cooled in the pre-cooling tower (911). The main cooling tower (912) may be equipped with packing that increases the contact area and contact time between the cooling water and the exhaust gas, and a demister that removes moisture contained in the exhaust gas.

[0009] The above exhaust gas branch pipe (92) is configured such that one side is connected to a portion of the exhaust pipe (EP) following the economizer (EM) in the direction of exhaust gas flow, and the other side is connected to the exhaust gas cooler (91). The above economizer (EM) is configured to create steam using waste heat of the exhaust gas and supply it to a steam usage location of the ship, and a portion of the exhaust gas that has passed through the economizer (EM) can flow to the ship cooling tower (911) by the exhaust gas branch pipe (92).

[0010] The above exhaust gas supply pipe (93) is configured such that one side is connected to the exhaust gas cooler (91) and the other side is connected to the air inlet side of the engine (E), thereby supplying exhaust gas cooled by the exhaust gas cooler (91) to the engine (E).

[0011] The above cooling water tank (94) is connected to the exhaust gas cooler (91) and refers to a configuration that stores cooling water discharged from the exhaust gas cooler (91), and the cooling water recovery pipe (95) refers to a configuration that has one side connected to the exhaust gas cooler (91) and the other side connected to the cooling water tank (94) so ​​that the cooling water sprayed to the exhaust gas cooler (91) is recovered to the cooling water tank (94).

[0012] The coolant recovered in the above coolant tank (94) has a relatively high temperature due to heat exchange with the high-temperature exhaust gas, so if the recovered coolant is not cooled, the cooling effect of the exhaust gas by the coolant may be reduced. To prevent this, a coolant heat exchanger (96) is configured on the rear side of the coolant cooler (94) to cool the recovered coolant.

[0013] However, the above conventional exhaust gas recirculation system (90) used random packing as the packing inside the exhaust gas cooler (91), and when such random packing was used, there was a problem that pressure loss occurred and the heat exchange area was small.

[0014] In addition, when cooling the exhaust gas, a problem occurred in which foreign substances contained in the exhaust gas were captured in the cooling water and contaminated the exhaust gas cooler (91).

[0015] In order to solve this problem, a separate water treatment device was constructed to treat the cooling water stored at the rear of the cooling water tank (94), but the three-way valve used to transfer the treated cooling water from the water treatment device to each device had a large fluctuation range in the flow rate, which caused a problem of causing water hammer.

[0016] (Patent Document 1) Korean Patent Publication No. 10-2023-0082557 (June 8, 2023)

[0017] The present invention has been devised to solve the above problems.

[0018] The purpose of the present invention is to provide an exhaust gas recirculation system that cools exhaust gas discharged from an engine with seawater or fresh water and supplies it back to an engine turbocharger, thereby increasing the concentration of carbon dioxide (CO2) in the turbocharged air to delay self-ignition of fuel, increasing the compression ratio in the cylinder to reduce fuel consumption, and suppressing the production of nitrogen oxides (NOx) through re-combustion of methane slip, lowering the combustion temperature, and reducing the oxygen concentration through exhaust gas recirculation.

[0019] Another object of the present invention is to provide an exhaust gas recirculation system capable of treating cooling water discharged after cooling exhaust gas and resupplying it to a cooling water tank.

[0020] Another object of the present invention is to provide an exhaust gas recirculation system that treats cooling water exceeding a standard water quality and reintroduces it into the cooling water tank, thereby allowing the cooling water stored in the cooling water tank to always maintain a constant water quality.

[0021] Another object of the present invention is to provide an exhaust gas recirculation system in which a flow meter and a throttle valve are sequentially installed at the rear of a water treatment device, so that a portion of the treated water is returned to a cooling water tank and the remainder is discharged overboard, and this process can occur continuously.

[0022] Another object of the present invention is to provide an exhaust gas recirculation system that enables precise control of the flow rate of treated water recirculated to a cooling water tank by using a throttle valve instead of using a three-way valve that allows a large range of flow rate fluctuations.

[0023] Another object of the present invention is to provide an exhaust gas recirculation system that increases efficiency by dynamically adjusting the flow rate of treated water recirculated to a cooling water tank according to engine load, changes in seawater temperature, etc.

[0024] Another object of the present invention is to provide an exhaust gas recirculation system that enables efficient operation of the system through precise control of the throttle valve by determining the return water flow rate to be reintroduced into the cooling water tank by subtracting the flow rate discharged overboard from the capacity of the water treatment device by the throttle valve.

[0025] Another object of the present invention is to provide a recirculation system for exhaust gas, which reduces the flow rate of treated water reinjected into the cooling water tank when the amount of condensate is large because moisture in the gas condenses along with the cooling when cooling exhaust gas, thereby increasing the amount of cooling water, and conversely, increases the flow rate of treated water reinjected into the cooling water tank when the amount of condensate is small.

[0026] Another object of the present invention is to provide an exhaust gas recirculation system that prevents frequent on / off operation of a water treatment device by configuring a holding tank that temporarily stores overflowed cooling water exceeding a standard water quality in front of a water treatment device, thereby ensuring a constant supply of cooling water to the water treatment device.

[0027] Another object of the present invention is to provide an exhaust gas recirculation system that discharges treated water overboard in an amount equivalent to the amount of exhaust gas condensate generated, thereby allowing the water level in a holding tank to always be maintained at a constant level.

[0028] Another object of the present invention is to provide an exhaust gas recirculation system that comprises a holding tank return pipe having one end connected to a water treatment device and the other end connected to a holding tank, so that treated water that does not meet the proper requirements can be returned to the holding tank.

[0029] Another object of the present invention is to provide an exhaust gas recirculation system that configures an overflow conveyance pipe to convey overflowed cooling water that does not meet the standard water quality requirements based on the concentration of total suspended solids (TSS) to a water treatment device.

[0030] Another object of the present invention is to provide an exhaust gas recirculation system that prevents coolant from becoming acidic due to sulfur components contained in fuel, acid gases in exhaust gas, etc., by forming a static mixer that is formed on an overflow conveying pipe and receives a pH adjuster from an alkaline supply device and mixes the coolant and the pH adjuster.

[0031] Another object of the present invention is to provide an exhaust gas recirculation system in which a heat exchanger is configured on a cooling water transport pipe through which cooling water satisfying a standard water quality is transported, so that the cooling water, which has a high temperature during the process of cooling exhaust gas, is re-cooled and reused for cooling exhaust gas, and a plate-type heat exchanger is used to increase the heat exchange efficiency during the heat exchange process.

[0032] In order to achieve the above-mentioned purpose, the present invention is implemented by an embodiment having the following configuration.

[0033] According to one embodiment of the present invention, the present invention is characterized by including an exhaust gas cooler that cools exhaust gas, a cooling water tank that stores cooling water discharged from the exhaust gas cooler after cooling the exhaust gas, a cooling water treatment unit that treats the cooling water stored in the cooling water tank, and a treated water transport unit that receives and transports treated cooling water from the cooling water treatment unit.

[0034] According to another embodiment of the present invention, the present invention is characterized in that the treated water transport unit includes a cooling water tank return pipe for returning the treated water to the cooling water tank.

[0035] According to another embodiment of the present invention, the present invention is characterized in that the treated water transport unit includes a treated water transport pipe that is a pipe for transporting the treated water, and the cooling water tank return pipe has one end connected to the treated water transport pipe and the other end connected to the cooling water tank.

[0036] According to another embodiment of the present invention, the treatment water transport unit is characterized in that it includes a flow meter formed at the rear side of a point where the cooling water tank return pipe among the treatment water transport pipes is connected to the treatment water transport pipe to measure the flow rate in the treatment water transport pipe, so that the flow rate of the return water returned to the cooling water tank is precisely controlled, and a throttle valve formed on the treatment water transport pipe at the rear side of the flow meter to control the flow rate.

[0037] According to another embodiment of the present invention, the present invention is characterized in that the throttle valve determines the return flow rate (ab) reintroduced into the cooling water tank as the value obtained by subtracting the flow rate (b) discharged overboard from the capacity (a) of the water treatment device that treats the overflowed cooling water exceeding the standard water quality.

[0038] According to another embodiment of the present invention, the treated water transport unit is characterized in that it includes a holding tank return pipe, one end of which is connected to the water treatment device, and the other end of which is connected to a holding tank that temporarily stores overflowed cooling water exceeding the standard water quality, so that the treated water discharged from the water treatment device is returned to the holding tank.

[0039] According to another embodiment of the present invention, the present invention is characterized in that the cooling water treatment unit includes an overflow transfer pipe, which is a pipe for transferring overflowed cooling water exceeding a standard water quality from the cooling water tank.

[0040] According to another embodiment of the present invention, the present invention is characterized in that the reference water quality is based on the concentration of total suspended solids (TSS).

[0041] According to another embodiment of the present invention, the present invention is characterized in that the cooling water treatment unit includes a holding tank connected to the overflow transfer pipe to temporarily store overflowed cooling water exceeding the standard water quality.

[0042] According to another embodiment of the present invention, the present invention is characterized in that the holding tank maintains a constant water level by discharging the treated water overboard in an amount equivalent to the amount of exhaust gas condensate generated.

[0043] According to another embodiment of the present invention, the cooling water treatment unit is characterized in that it includes a water treatment device that is connected to the holding tank, treats overflowed cooling water exceeding the standard water quality supplied from the holding tank, and discharges the treated water.

[0044] According to another embodiment of the present invention, the present invention is characterized in that the cooling water treatment unit includes a static mixer formed on an overflow transfer pipe on the front side of the holding tank and mixing a pH adjuster into the cooling water.

[0045] According to another embodiment of the present invention, the exhaust gas recirculation system is characterized in that it includes a cooling water recirculation unit that recirculates cooling water that satisfies a standard water quality stored in the cooling water tank.

[0046] According to another embodiment of the present invention, the present invention is characterized in that the cooling water recirculation unit includes a cooling water transport pipe that is connected to the cooling water tank and transports cooling water that satisfies the standard water quality, and a heat exchanger formed on the cooling water transport pipe and cooling the cooling water whose temperature has increased due to cooling of the exhaust gas.

[0047] According to another embodiment of the present invention, the exhaust gas recirculation system is characterized in that it includes an alkali supply device that supplies a pH adjuster to the cooling water.

[0048] The present invention can obtain the following effects through the combination and use of the configuration described below with the previously described embodiment.

[0049] The present invention has the effect of providing an exhaust gas recirculation system that cools exhaust gas discharged from an engine with seawater or fresh water and supplies it back to an engine turbocharger, thereby increasing the concentration of carbon dioxide (CO2) in the turbocharged air to delay self-ignition of fuel, increasing the compression ratio in the cylinder to reduce fuel consumption, and suppressing the production of nitrogen oxides (NOx) through re-combustion of methane slip, lowering the combustion temperature, and reducing the oxygen concentration through exhaust gas recirculation.

[0050] The present invention provides an exhaust gas recirculation system capable of treating cooling water discharged after cooling exhaust gas and resupplying it to a cooling water tank.

[0051] The present invention has the effect of providing an exhaust gas recirculation system that treats cooling water exceeding a standard water quality and reintroduces it into a cooling water tank, thereby allowing cooling water stored in a cooling water tank to always maintain a constant water quality.

[0052] The present invention has the effect of providing an exhaust gas recirculation system in which a flow meter and a throttle valve are sequentially installed at the rear of a water treatment device, so that a portion of the treated water is returned to a cooling water tank and the remainder is discharged overboard, thereby allowing this process to occur continuously.

[0053] The present invention has the effect of providing an exhaust gas recirculation system that enables precise control of the flow rate of treated water recirculated to a cooling water tank by using a throttle valve instead of using a three-way valve that allows a large range of flow rate fluctuations.

[0054] The present invention provides an exhaust gas recirculation system that increases efficiency by dynamically adjusting the flow rate of treated water recirculated to a cooling water tank according to engine load, changes in seawater temperature, etc.

[0055] The present invention has the effect of providing an exhaust gas recirculation system that enables efficient operation of the system through precise control of the throttle valve by determining the return water flow rate reintroduced into the cooling water tank as the value obtained by subtracting the flow rate discharged overboard from the capacity of the water treatment device by the throttle valve.

[0056] The present invention has the effect of providing a recirculation system for exhaust gas, which reduces the flow rate of treated water reinjected into the cooling water tank when the amount of condensate generated is large because moisture in the gas condenses along with the cooling when cooling exhaust gas, thereby increasing the amount of cooling water, and conversely, increases the flow rate of treated water reinjected into the cooling water tank when the amount of condensate generated is small.

[0057] The present invention provides an exhaust gas recirculation system that prevents frequent on / off operation of a water treatment device by configuring a holding tank for temporarily storing overflowed cooling water exceeding a standard water quality in front of a water treatment device, thereby ensuring a constant supply of cooling water to the water treatment device.

[0058] The present invention has the effect of providing an exhaust gas recirculation system that discharges treated water overboard in an amount equivalent to the amount of exhaust gas condensate generated, thereby allowing the water level in a holding tank to always be maintained at a constant level.

[0059] The present invention has the effect of providing an exhaust gas recirculation system that configures a holding tank return pipe, one end of which is connected to a water treatment device and the other end of which is connected to a holding tank, so that treated water that does not meet the appropriate requirements can be returned to the holding tank.

[0060] The present invention provides an exhaust gas recirculation system that configures an overflow transfer pipe to transfer overflowed cooling water that does not meet standard water quality requirements based on the concentration of total suspended solids (TSS) to a water treatment device.

[0061] The present invention has the effect of providing an exhaust gas recirculation system that prevents coolant from becoming acidic due to sulfur components contained in fuel, acid gases in exhaust gas, etc., by forming a static mixer that receives a pH adjuster from an alkaline supply device and mixes the coolant and the pH adjuster on an overflow conveying pipe.

[0062] The present invention has the effect of providing an exhaust gas recirculation system in which a heat exchanger is configured on a cooling water transport pipe through which cooling water satisfying a standard water quality is transported, so that the cooling water, which has a high temperature during the process of cooling exhaust gas, is re-cooled and reused for cooling exhaust gas, and a plate-type heat exchanger is used to increase the heat exchange efficiency during the heat exchange process.

[0063] Figure 1 is a drawing illustrating a conventional exhaust gas recirculation system.

[0064] FIG. 2 is a drawing illustrating an exhaust gas recirculation system according to one embodiment of the present invention.

[0065] Figure 3 is a drawing illustrating an exhaust gas cooler of the present invention.

[0066] Figure 4 is a drawing showing the exhaust gas cooler of Figure 3 from another viewpoint.

[0067] Figure 5 is a drawing showing the exhaust gas cooler of Figure 3 from another viewpoint.

[0068] Figure 6 is a drawing showing the exhaust gas cooler of Figure 3 from another viewpoint.

[0069] Fig. 7 is a drawing showing the exhaust gas cooler of Fig. 3 from another viewpoint.

[0070] Fig. 8 is a drawing showing a partial cut along line A-A' of the exhaust gas cooler of Fig. 3.

[0071] Fig. 9 is a drawing showing a diffuser part of the present invention.

[0072] Fig. 10 is a drawing showing a packing part of the present invention.

[0073] Fig. 11 is a drawing showing the demister part of the present invention.

[0074] FIG. 12 is a drawing showing a cooling water tank, an alkali supply device, a cooling water treatment unit, and a treatment water transport unit integrated into a sump unit of a housing unit according to one embodiment of the present invention.

[0075] FIG. 13 is a drawing showing another embodiment of the present invention in which the coolant tank is separated from the sump portion of the housing portion.

[0076] Figure 14 is a drawing illustrating a cooling water recirculation unit of the present invention.

[0077] Figure 15 is a diagram showing the state of use of the present invention.

[0078] Figure 16 is a diagram showing the state of use of the present invention.

[0079] Hereinafter, preferred embodiments of the exhaust gas recirculation system according to the present invention will be described in detail with reference to the attached drawings. In the following description of the present invention, if a detailed description of a known function or configuration is determined to unnecessarily obscure the gist of the present invention, such detailed description will be omitted. Unless otherwise defined, all terms in this specification have the same general meaning as those skilled in the art to which the present invention pertains. If there is a conflict between the meaning of a term used in this specification and the meaning of the term, the definition used in this specification shall prevail.

[0080] In this specification, cooling water refers to water containing pollutants generated after water is sprayed toward exhaust gas to cool the exhaust gas, and treated water refers to water that has been purified by treating contaminated cooling water.

[0081] In this specification, a location relatively rearward based on the direction in which the fluid flows is expressed as being on the front side, and a location relatively forward based on the direction in which the fluid flows is expressed as being on the rear side.

[0082] The present invention relates to an exhaust gas recirculation system (1), wherein the exhaust gas recirculation system (1) cools exhaust gas discharged from an engine with seawater or fresh water and supplies it back to an engine turbocharger, thereby increasing the concentration of carbon dioxide (CO2) in the turbocharged air to delay self-ignition of fuel, increasing the compression ratio in the cylinder to reduce fuel consumption, and suppressing the production of nitrogen oxides (NOx) through re-combustion of methane slip, lowering the combustion temperature, and reducing the oxygen concentration through exhaust gas recirculation.

[0083] FIG. 2 is a drawing illustrating an exhaust gas recirculation system (1) according to one embodiment of the present invention. Referring to FIG. 2, the exhaust gas recirculation system (1) includes an exhaust gas cooler (10), a cooling water tank (20), an alkali supply device (30), a cooling water treatment unit (40), a treated water transport unit (50), a cooling water recirculation unit (60), and a control unit (70).

[0084] The above exhaust gas cooler (10) refers to a configuration that cools exhaust gas. Referring to FIG. 2, exhaust gas discharged from the engine is received in an exhaust gas receiver, and the exhaust gas discharged from the exhaust gas receiver rotates the turbine at high speed and is discharged through a back pressure valve (BPV, Back Pressure Valve), etc., and some of the exhaust gas may be recovered by a shut-off valve (SOV, Shut-Off Valve), etc., and may enter the exhaust gas cooler (10). The exhaust gas recirculation system (1) cools a portion of the exhaust gas generated when fuel is burned in the engine through the exhaust gas cooler (10), and then mixes it with fuel and reintroduces it into the engine for combustion. According to the exhaust gas recirculation system (1), nitrogen oxides (NOx), etc., contained in the exhaust gas can be reduced.

[0085] FIG. 3 is a drawing showing an exhaust gas cooler (10) of the present invention. Referring to FIG. 3, the exhaust gas cooler (10) includes a line cooling tower (11) and a main cooling tower (12).

[0086] The above-described pre-cooling tower (11) is configured to primarily cool the exhaust gas introduced into the pre-cooling chamber, and rapid cooling of the exhaust gas and removal of foreign substances can be achieved in the pre-cooling tower (11). As described above, after the exhaust gas discharged from the exhaust gas receiver rotates the turbine, a portion of the exhaust gas enters the pre-cooling tower (11). Although not shown in Fig. 2, an economizer may be additionally formed on the front pipe of the pre-cooling tower (11) to generate steam from the waste heat of the exhaust gas and supply the steam to a steam usage location on the ship.

[0087] Referring to FIG. 3, the above-described pre-cooling tower (11) includes a pre-cooling housing section (111), a pre-cooling injection section (112), and a pre-cooling connection section (113).

[0088] The above-described pre-cooling housing part (111) is configured to form a pre-cooling chamber (C1), which is a space capable of receiving exhaust gas therein, and includes an inlet (1111) which is an open upper surface, and the inlet (1111) is communicated with the pre-cooling chamber (C1). The shape of the pre-cooling housing part (111) is not limited to a specific shape, but preferably, as shown in FIG. 3, it may be formed in a cylindrical shape. When a portion of the exhaust gas received in the exhaust gas receiver is recovered after rotating the turbine, the recovered exhaust gas enters the pre-cooling chamber (C1) through the inlet (1111) and is cooled. Referring to FIG. 3, the line cooling housing part (111) may have a cylindrical shape with a constant diameter in a first section from the inlet (1111) to a certain section, but may have a truncated cone shape in which the diameter of the cylinder increases as it goes down in a second section beyond the first section, and may be configured as a cylindrical shape with a maximum diameter in a third section thereafter.

[0089] The above-described pre-cooling spray unit (112) refers to a configuration that sprays water into the chamber to cool the exhaust gas that has entered the pre-cooling chamber (C1) through the inlet (1111). Preferably, the pre-cooling spray unit (112) may be configured in multiple numbers for rapid cooling of the exhaust gas, and as illustrated in FIG. 3, one pre-cooling spray unit (112) may be located in the second section of the pre-cooling housing unit (111), and another pre-cooling spray unit (112) may be located in the third section of the pre-cooling housing unit (111).

[0090] The above-described pre-cooling connection part (113) refers to a configuration that connects the pre-cooling housing part (111) and the main cooling tower (12) to be described later. The pre-cooling connection part (113) forms a connection chamber (C2) therein, and exhaust gas cooled while passing through the pre-cooling housing part (111), water used to cool the exhaust gas, etc. can enter the main cooling chamber (C3) of the main cooling housing part (121) to be described later through the connection chamber (C2). The shape of the pre-cooling connection part (113) is not limited to a specific shape, but preferably, as illustrated in FIG. 3, it can be formed in a shape in which the cross-sectional size becomes smaller as it goes downward.

[0091] Referring to FIGS. 3 and 4, the above-described line cooling connection (113) includes a first connection surface (1131), a second connection surface (1132), and a third connection surface (1133).

[0092] The above first connecting surface (1131) is a portion that forms a substantially vertical surface as illustrated in FIG. 4, and guides exhaust gas, etc., within the line cooling chamber (C1) of the line cooling housing section (111) to move downward.

[0093] The second connecting surface (1132) is a portion formed by extending from the end of the first connecting surface (1131), and the direction of extension is the central axis (A) of the body portion (1211) described later, as shown in FIG. 4. b ) has a feature of being formed to be inclined toward the first connecting surface (1131). The first cooled exhaust gas, etc. guided downward through the first connecting surface (1131) by the second connecting surface (1132) forming the inclined surface can naturally move into the main cooling chamber (C3) of the main cooling housing part (121) to be described later while being guided by the second connecting surface (1132).

[0094] The third connecting surface (1133) refers to a portion that extends approximately horizontally from the end of the second connecting surface (1132). The first-cooled exhaust gas, etc. can be guided by the third connecting surface (1133) and introduced into the cooling chamber (C3) of the cooling housing section (121).

[0095] The above main cooling tower (12) is configured to secondarily cool the exhaust gas that has been primarily cooled by being connected to the line cooling tower (11), so that the exhaust gas can be smoothly cooled to a target temperature in the main cooling tower (12). In addition, water and various pollutants sprayed in the line cooling tower (11) to first cool the exhaust gas can also flow from the line cooling tower (11) to the main cooling tower (12) and be collected in the sump, which is the lowest part of the main cooling tower (12). Preferably, the main cooling tower (12) can be configured to have a larger volume than the line cooling tower (11). The main cooling tower (12) includes a main cooling housing part (121), a diffuser part (122), a packing part (123), a main cooling spray part (124), a demister part (125), a cleaning spray part (126), and an outlet part (127).

[0096] The above cooling housing part (121) is configured to form a cooling chamber (C3) therein, and the shape of the above cooling housing part (121) is not limited to a specific shape, but preferably, the above cooling housing part (121) may be configured to have a shape in which the upper part becomes narrower as it goes up for smooth discharge of exhaust gas, as shown in FIG. 4, and a shape in which the lower part becomes narrower as it goes down for smooth discharge of coolant. Referring to FIG. 4, the above cooling housing part (121) includes a body part (1211), a head part (1212), and a sump part (1213).

[0097] The above body part (1211) is configured to form the body of the above cooling housing part (121), and may be formed in a cylindrical shape with an upper surface and a lower surface open while forming a chamber inside. The cross-sectional shape of the body part (1211) may be configured in various shapes such as circular or non-circular, but in order to increase space efficiency, it may be preferable to be configured to have a rectangular cross-sectional shape, as illustrated in FIGS. 3 and 4.

[0098] The above head portion (1212) is configured to extend upward from the body portion (1211) while communicating with the internal chamber of the body portion (1211), and refers to a portion where exhaust gas that has completed secondary cooling and moisture removal finally gathers. The shape of the head portion (1212) is not limited to a specific shape, but preferably, as shown in FIGS. 4 to 7, it may be configured to have a shape in which the cross-sectional size becomes smaller as it goes upward. The head portion (1212) includes a first surface (12121), a second surface (12122), a third surface (12123), a fourth surface (12124), and a roof surface (12125).

[0099] The first surface (12121) above refers to a surface forming the head portion (1212) on which the outlet portion (127), which will be described later, is formed. Referring to Fig. 4, the first surface (12121) may be configured to have an approximately triangular shape. Preferably, the first surface (12121) is formed along the central axis (A) of the body portion (1211), as illustrated in Fig. 5. b ) can be formed to be inclined in the direction. In the present invention, the outlet (127) formed on the first surface (12121) is formed along the central axis (A) of the body portion. b) so that the treated exhaust gas is discharged in a state where the outlet (127) is inclined upward with respect to the axis perpendicular to the outlet (127), so that even if water is generated due to condensation in an environment with low external temperature such as winter, the condensed water enters the main cooling chamber of the main cooling tower.

[0100] The second surface (12122) is formed on the other side of the first surface (12121). Referring to Fig. 6, the second surface (12122) may also be formed to have a roughly triangular shape, similar to the shape of the first surface (12121). Preferably, the central axis (A) of the body part is formed so that the processed exhaust gas can move while minimizing pressure loss. b ) can be formed to be inclined in the direction of the central axis (A) of the body part. More preferably, b ), the inclined angle (θ1) of the first surface (12121) may be configured to be smaller than the inclined angle (θ2) of the second surface (12122) (θ1<θ2). As a result, as shown in FIG. 5, the second surface (12122) is closer to the central axis (A) of the body than the first surface (12121). b ) direction, the exhaust gas that has undergone secondary cooling and moisture removal in the chamber of the body part (1211) can naturally move toward the outlet part (127) described later without pressure loss.

[0101] The third surface (12123) is formed on the side where the line cooling tower (11) is located, as shown in Fig. 6, and is aligned with the central axis (A) of the body part (1211). b ) refers to a configuration that forms a surface inclined in the direction of the third surface (12123). The shape of the third surface (12123) is not limited to a specific shape, but it can be configured to have a shape that is preferably approximately trapezoidal. Referring to Fig. 6, the central axis (A) of the body portion b) based on the inclined angle of the third surface (12123) may be θ3, and the inclined angle of the third surface (12123) may be configured to be the same as the inclined angle of the fourth surface (12124) described later.

[0102] The above fourth side (12124) is formed on the other side of the third side (12123) and is formed along the central axis (A) of the body part (1211). b ) refers to a configuration that forms a surface inclined in the direction of the central axis (A) of the body portion. b ) based on the inclined angle (θ3) of the third surface (12123) can be configured to be the same as the inclined angle (θ4) of the fourth surface (12124) (θ3=θ4). In the present invention, the third surface (12123) located on the side of the cooling tower (11) among the side surfaces of the head portion (1212) and the fourth surface (12124) on the opposite side thereof have the same inclined angle relative to the central axis (A) of the body portion. b ) so that the head portion (1212) of the cooling housing portion (121) has a shape in which the cross-sectional area gradually narrows as it goes upward, thereby naturally moving the treated exhaust gas toward the outlet portion (127) while minimizing the pressure loss of the treated exhaust gas. The fourth surface (12124) may be configured to have an approximately trapezoidal shape, similar to the third surface (12123).

[0103] The above loop surface (12125) is configured to form the uppermost surface of the head portion (1212), as shown in FIGS. 6 and 7, and the loop surface (12125) may be formed to be rounded along the outer circumference of the outlet portion (127) to be described later. The present invention configures the loop surface (12125) on the head portion (1212) to guide the smooth movement of the treated exhaust gas.

[0104] The above sump part (1213) refers to the part located at the lowest point of the main cooling housing part (121), and as illustrated in FIG. 8, the sump part (1213) may be configured in a hopper shape that becomes narrower toward the bottom while forming a slope for easy discharge of coolant, contaminants, etc. The coolant tank (20) to be described later may be configured within the main cooling housing part (121) using the sump part (1213). That is, the wall of the sump part (1213) may be utilized as the wall of the coolant tank (20), or the wall of the coolant tank (20) may be configured separately within the wall of the sump part (1213). When forming a cooling water tank (20) by utilizing the above sump section (1213), a lot of space can be saved compared to when the cooling water tank (20) is configured separately outside the above cooling housing section (121), so it is useful when installing an exhaust gas recirculation system in a narrow space such as a ship. Referring to Fig. 8, the above sump section (1213) includes a cooling water outlet section (12131).

[0105] The above coolant outlet (12131) is formed on the lower side of the sump (1213) and refers to a configuration that discharges coolant, etc. collected in the sump (1213) to the outside. As illustrated in Fig. 6, the coolant outlet (12131) is formed along the central axis (A) of the body (1211). b ) can be formed in parallel. In the case where the cooling water tank (20) to be described later is formed within the sump section (1213) according to one embodiment of the present invention, the cooling water outlet section (12131) communicates with the internal space of the cooling water tank (20). In the case where the cooling water tank (20) to be described later is formed outside the sump section (1213) according to another embodiment of the present invention, the cooling water outlet section (12131) can be viewed as a configuration that discharges the cooling water collected within the sump section (1213) to the outside and moves it into the cooling water tank (20).

[0106] The above diffuser part (122) refers to a configuration formed within the cooling chamber so that the exhaust gas that has been primarily cooled in the pre-cooling tower (11) is uniformly distributed to the packing part (123), which will be described later and increases the heat exchange area for secondary cooling. The present invention configures the diffuser part (122) below the packing part (123), so that when the exhaust gas that has been primarily cooled in the pre-cooling tower (11) enters the cooling chamber of the pre-cooling tower (12), it is uniformly distributed to the packing part (123) while passing through the diffuser part (122). FIG. 8 is a drawing showing a partial cross-section of the exhaust gas cooler (10) of FIG. 3 along line A-A', and referring to FIG. 8, the diffuser part (122) includes a diffusion plate (1221) and a support part (1222).

[0107] The above diffusion plate (1221) refers to a plate-shaped configuration including a plurality of through holes (12211) penetrating one surface and the other surface. The diffusion plate (1221) allows the primary cooled exhaust gas to pass through the diffusion plate (1221) through the through holes (12211), and through this process, allows the primary cooled exhaust gas to uniformly enter the packing unit (123) to be described later. To this end, as shown in FIGS. 8 and 9, a plurality of diffusion plates (1221) may be arranged at regular intervals, and preferably, the diffusion plates (1221) may be arranged in a stepwise manner so that they are positioned lower on the cooling housing unit (121) as they get farther away from the pre-cooling connection unit (113).

[0108] The above support member (1222) is spaced evenly between the diffuser plates (1221) and the central axis (A) of the body member (1211) b ) refers to a configuration in which a diffuser plate (1221) close to the body is positioned relatively lower than the cooling housing part (121). The diffuser part (122) is positioned along the central axis (A) of the body part (1211) while maintaining a constant distance between adjacent diffuser plates (1221) through the support part (1222).b ) is positioned relatively lower than the main cooling housing section (121), so that the primary cooled exhaust gas is evenly spread within the main cooling chamber, thereby preventing the exhaust gas from being concentrated only in a specific part of the packing section (123) to be described later. Preferably, the support section (1222) may be configured to support the upper and lower sides of the plurality of diffuser plates (1221) in pairs, as illustrated in FIGS. 8 and 9.

[0109] The above packing part (123) refers to a configuration formed in the main cooling chamber of the main cooling housing part (121) to increase the heat exchange area for secondary cooling of the primary cooled exhaust gas. The present invention configures the packing part (123) in the main cooling chamber of the main cooling tower (12) to increase the contact area between the water used for exhaust gas cooling and the exhaust gas in the process of secondary cooling the exhaust gas that was primary cooled in the pre-cooling tower (11), thereby increasing the heat exchange rate and ensuring good cooling of the exhaust gas. Preferably, the packing part (123) is characterized by being a structured packing in which a filler having a certain pattern is structured. The present invention forms a packing section (123) with structured packing, thereby minimizing the tower diameter of the cooling tower by reducing the back pressure compared to when the packing section is formed with random packing, and by using structured packing, pressure loss is reduced and heat exchange area is increased to maximize heat exchange efficiency.

[0110] The above packing part (123) can be formed by stacking a plurality of packing layers, and the filling density of each packing layer can be configured differently. Preferably, the packing part (123) is characterized in that the filling density of the packing layer located relatively upper is higher than the filling density of the packing layer located relatively lower, and the adjacent packing layers can be cross-stacked at a certain angle. That is, the present invention forms a plurality of packing layers having different filling densities for each packing layer, and cross-stacks the adjacent packing layers while making the filling density of the packing layer located relatively upper is higher than the filling density of the packing layer located relatively lower, thereby increasing the removal rate of foreign substances by the lower packing layer having a low density, and achieving high heat exchange by the upper patching layer having a high density.

[0111] Referring to FIG. 8 and FIG. 10, the packing portion (123) includes a first packing layer (1231), a second packing layer (1232), a third packing layer (1233), and a fourth packing layer (1234).

[0112] The first packing layer (1231) is configured to form the lowest layer among the packing sections (123), and the filling density of the first packing layer (1231) can be configured to be the lowest relative to other packing layers.

[0113] The second packing layer (1232) is configured to be formed on the first packing layer (1231), and the second packing layer (1232) is cross-laminated with the first packing layer (1231). As shown in FIG. 10, the second packing layer (1232) is configured to have a higher density than the filling density of the first packing layer (1231).

[0114] The third packing layer (1233) is formed on the second packing layer (1232), and is configured to be cross-laminated with the second packing layer (1232). In addition, the third packing layer (1233) may have a higher density than the filling density of the second packing layer (1232).

[0115] The fourth packing layer (1234) is configured to be formed on the third packing layer (1233), and the fourth packing layer (1234) can be formed to be cross-laminated with the third packing layer (1233). It is preferable that the filling density of the fourth packing layer (1234) be formed higher than the filling density of the third packing layer (1233).

[0116] The above cooling spray unit (124), as illustrated in FIG. 8, is located above the packing unit (123) and is configured to spray water for secondary cooling of the primary cooled exhaust gas onto the packing unit (123). Through this, not only secondary cooling of the primary cooled exhaust gas but also removal of foreign substances can be achieved simultaneously.

[0117] The above demister unit (125) refers to a configuration that is located above the main cooling spray unit (124) and removes mist. Equipment such as an engine turbocharger is connected to the rear side of the main cooling tower (12). If moisture enters this equipment, various problems such as corrosion may occur. Therefore, the present invention configures the demister unit (125) so that moisture accompanying the gas processed at the final stage of the main cooling tower (12) is effectively removed, thereby preventing damage caused by the moisture. Referring to Fig. 11, the demister unit (125) includes a vane unit (1251) and a mesh unit (1252).

[0118] The above-mentioned vane portion (1251) refers to a configuration in which a plurality of blades forming an inclined surface are spaced apart to form a gap. The demister portion (125) of the present invention can be formed by combining the vane portion (1251) and a mesh portion (1252) to be described later, and the vane portion (1251) is configured to be positioned relatively lower than the mesh portion (1252) to be described later, thereby primarily performing the function of removing moisture.

[0119] The above mesh portion (1252) refers to a configuration in which a plurality of thin and long wires are intertwined to form a gap. The gap of the mesh portion (1252) is formed smaller than the gap of the vane portion (1251), and the vane portion (1251) is positioned below the mesh portion (1252). The mesh portion (1252) can be viewed as a configuration in which moisture is removed secondarily after moisture is primarily removed by the vane portion (1251). The present invention configures the demister portion (125) to include both the vane portion (1251) and the mesh portion (1252), thereby increasing the moisture removal rate by the demister portion (125) and minimizing the impact of moisture on subsequent equipment such as a turbocharger.

[0120] The above-described cleaning spray unit (126) is configured to spray water for cleaning onto the demister unit (125) by being positioned above the demister unit (125), as illustrated in FIG. 8. Preferably, the cleaning spray unit (126) may be formed on the head unit (1212). The present invention enables easy cleaning of the device by spraying water for cleaning via the cleaning spray unit (126) when the exhaust gas cooler (10) is not in operation.

[0121] The above outlet (127) is configured to discharge the treated exhaust gas to the outside, and the outlet (127) is characterized in that it is formed at a point that minimizes the connection line with the engine turbocharger that receives the treated exhaust gas. Preferably, the outlet (127) is formed along the central axis (A) of the outlet o ) is the central axis of the body (A b ) may be formed on the side of the head portion (1212) so as not to be parallel to the outlet portion (127). When the outlet portion (127) is formed on the side of the head portion (1212), the central axis (A) of the outlet portion o ) is the central axis of the above body part (A b ) is not parallel to the outlet (127), there is no need to change the flow path using a pipe elbow, etc., and the length of the pipe connecting the outlet (127) and the supercharger can be reduced, thereby solving the problem of back pressure formation that occurs when the length of the pipe is long and preventing the pressure drop phenomenon. Referring to FIG. 5, more preferably, the outlet (127) is oriented along the central axis (A) of the outlet. o ) can be formed parallel to the normal line of the first surface (12121). In addition, the present invention provides a central axis (A) of the outlet (127) o ) so that the central axis (A) of the body part is parallel to the normal line of the first surface (12121) b ) By simply forming a vertically protruding outlet (127) on the first surface (12121) formed to be inclined in the direction of the outlet (127), the outlet (127) can discharge exhaust gas in the upward direction.

[0122] The above cooling water tank (20) refers to a configuration that stores cooling water discharged from the exhaust gas cooler (10) after cooling the exhaust gas. FIG. 12 illustrates an embodiment in which the cooling water tank (20) is integrated into the sump portion (1213) of the cooling housing portion (121), and FIG. 13 illustrates an embodiment in which, unlike FIG. 12, the cooling water tank (20) is configured separately from the cooling housing portion (121). Although the present invention does not exclude an embodiment in which the cooling water tank (20) is separated from the cooling housing portion (121), preferably, the cooling water tank (20) may be formed integrally with the sump portion (1213) of the cooling housing portion (121). The present invention forms the cooling water tank (20) integrally with the sump of the cooling housing section (121), so that the related device for exhaust gas cooling does not take up much space, thereby enabling easy installation of the exhaust gas recirculation system even in ships where securing space is difficult. In addition, the present invention treats cooling water exceeding the standard water quality and reintroduces it into the cooling water tank (20), thereby allowing the cooling water stored in the cooling water tank (20) to always maintain a constant water quality.

[0123] The above alkali supply device (30) is configured to supply a pH adjuster to the cooling water, and by supplying the pH adjuster to adjust the pH of the cooling water, it is possible to prevent the cooling water from becoming acidic due to sulfur components contained in fuel, acid gases in exhaust gas, etc. Preferably, sodium hydroxide (NaOH) can be used as the pH adjuster. Referring to FIG. 12, the alkali supply device (30) can be connected to a static mixer (42) to be described later and supply the sodium hydroxide (NaOH) to the static mixer (42), and referring to FIG. 14, the alkali supply device (30) can be configured to supply the sodium hydroxide (NaOH) to the cooling water, which is discharged from the cooling water tank (20) and has a certain water quality level maintained thereon.

[0124] The above cooling water treatment unit (40) refers to a configuration that treats the cooling water stored in the cooling water tank (20). When water is sprayed to cool exhaust gas, the water that falls after spraying may contain various contaminants. If the concentration of such contaminants satisfies a predetermined water quality measurement standard, the discharged cooling water can be reused. However, if the concentration of contaminants is high and does not satisfy the water quality measurement standard, the cooling water cannot be reused. Therefore, in this case, it is necessary to treat the contaminated cooling water that has exceeded a certain water quality level. Accordingly, the present invention configures the cooling water treatment unit (40) to purify the cooling water that does not satisfy the water quality standard by overflowing it, and then transfer it back to the cooling water tank (20). Referring to FIG. 12, the cooling water treatment unit (40) includes an overflow transfer pipe (41), a static mixer (42), a holding tank (43), and a water treatment device (44).

[0125] The above overflow transfer pipe (41) refers to a pipe that transfers overflowed cooling water exceeding a standard water quality from the cooling water tank (20). Preferably, the standard water quality may be based on the concentration of total suspended solids (TSS). Based on the concentration of the total suspended solids (TSS), the overflowed cooling water that does not meet the standard water quality requirement is transferred to a water treatment device (44) to be described later through the overflow transfer pipe (41). The above overflow transfer pipe (41) includes an overflow valve (411).

[0126] The above overflow valve (411) is formed on the overflow transport pipe (41) to close or open the inside of the pipe. When it is determined that the water quality of the cooling water tank (20) does not meet the standard water quality, the control unit (70) to be described later opens the overflow valve (411) so that the cooling water is transported along the overflow transport pipe (41) toward the water treatment device (44) to be described later. Conversely, when it is determined that the water quality of the cooling water tank (20) meets the standard water quality, the overflow valve (411) is maintained in a closed state, and the cooling water stored in the cooling water tank (20) can be recirculated through the cooling water recirculation unit (60) to be described later.

[0127] The above static mixer (42) is formed on the overflow transfer pipe (41) in front of the holding tank (43) described later, and refers to a configuration that mixes a pH adjuster into the cooling water. For this purpose, the static mixer (42) can be connected to the alkali supply device (30). The present invention prevents the cooling water from becoming acidic due to sulfur components contained in fuel, acid gases in exhaust gas, etc., through the static mixer (42).

[0128] The above holding tank (43) refers to a configuration that functions as a buffer tank that is connected to the overflow transfer pipe (41) and temporarily stores the overflowed cooling water that exceeds the reference water quality. The present invention configures the holding tank (43) that temporarily stores the overflowed cooling water that exceeds the reference water quality in front of the water treatment device (44) described later, thereby preventing frequent operation (On) / stop (Off) of the water treatment device (44) by ensuring that the cooling water is constantly supplied to the water treatment device (44). In addition, the treated water is discharged overboard in an amount equivalent to the amount of exhaust gas condensate generated, so that the water level of the holding tank (43) can be constantly maintained. Since the amount of condensate generated varies depending on the amount of exhaust gas recirculation, the moisture content of the exhaust gas inlet, the cooling temperature of the exhaust gas outlet, the humidity of the installation location, etc. and cannot be accurately determined, three to four conditions can be set according to the amount of circulation and corrected according to the changing water level to maintain an appropriate water level.

[0129] Referring to Fig. 12, the static mixer (42) is configured on the front side of the holding tank (43), and it can be seen that the cooling water in which the pH adjuster is stirred enters the holding tank (43) through the static mixer (42). Referring to Fig. 13, when the end of the transfer pipe that transfers the cooling water discharged from the static mixer (42) is formed so deep that it reaches the bottom surface of the holding tank (43), a gas backflow situation may occur, so the present invention does not configure a deep pipe in which the end of the transfer pipe is formed so deep that it reaches the bottom surface of the holding tank (43), and does not fill the overflow transfer pipe (41) connecting the cooling water tank (20) and the static mixer (42) with water, thereby preventing the gas from being discharged through the vent and causing the gas to backflow.

[0130] The above water treatment device (44), as illustrated in FIG. 12, is connected to the holding tank (43) and is configured to treat overflowed cooling water that exceeds the standard water quality supplied from the holding tank (43) and discharge the treated water. The present invention treats the cooling water discharged after cooling exhaust gas by the water treatment device (44), so that the treated water can be re-supplied to the cooling water tank (20). In order to continuously supply an appropriate amount to the cooling water tank (20), the re-injection flow rate can be determined through a flow meter (52) and a throttle valve (53) described later before discharging the treated water.

[0131] The above-mentioned treated water transport unit (50) refers to a configuration that receives and transports treated water, which is cooling water treated from the above-mentioned cooling water treatment unit (40). Preferably, when cooling the exhaust gas, moisture in the gas condenses along with the cooling, thereby increasing the amount of cooling water. Therefore, if the amount of condensed water generated is large, the flow rate of treated water reinjected into the cooling water tank (20) can be reduced, and conversely, if the amount of condensed water generated is small, the flow rate of treated water reinjected into the cooling water tank (20) can be increased. Referring to FIG. 12, the above-mentioned treated water transport unit (50) includes a treated water transport pipe (51), a flow meter (52), a throttle valve (53), a cooling water tank return pipe (54), and a holding tank return pipe (55).

[0132] The above-mentioned treated water transport pipe (51) refers to a pipe for transporting the treated water, and a portion of the treated water treated in the water treatment device (44) can be reintroduced into the cooling water tank (20), and the remaining treated water can be discharged overboard, or, if the ship passes through an area where discharge of treated water overboard is prohibited, the treated water can be stored in a temporary storage tank. The manager can control, through the control unit (70) described below, whether to discharge the treated water overboard or temporarily store it onboard, depending on whether it is a discharge-regulated area.

[0133] The above flow meter (52) is formed at the rear side of the point where the cooling water tank return pipe (54) among the treated water transfer pipes (51) is connected to the treated water transfer pipe (51) so that the return water flow rate returned to the cooling water tank (20) is precisely controlled, and refers to a configuration that measures the flow rate inside the treated water transfer pipe (51). The present invention configures the flow meter (52) at the rear side of the water treatment device (44), and sequentially installs a throttle valve (53) to be described later at the rear side of the flow meter (52), so that a portion of the treated water is returned to the cooling water tank (20), and the remainder is discharged overboard, so that this process can occur continuously.

[0134] The above throttle valve (53) refers to a configuration formed on the treated water transport pipe (51) at the rear side of the flow meter (52) to control the flow rate. The present invention uses the throttle valve (53) instead of using a three-way valve that allows a large range of flow rate fluctuations, so that the flow rate of the treated water recirculated into the cooling water tank (20) can be precisely controlled. This allows the flow rate of the treated water recirculated into the cooling water tank to be flexibly adjusted according to changes in engine load, seawater temperature, etc., thereby increasing efficiency. Preferably, the throttle valve (53) is characterized in that it determines the return flow rate (ab) that is reintroduced into the cooling water tank (20) as the value obtained by subtracting the flow rate (b) discharged overboard from the capacity (a) of the water treatment device that treats the overflowed cooling water exceeding the standard water quality. By determining the amount of water discharged overboard from the capacity of the water treatment device (44) minus the amount of water discharged overboard by the above throttle valve (53), as the amount of water returned to the cooling water tank (20), efficient operation of the system can be achieved through precise control of the throttle valve (53).

[0135] The above cooling water tank return pipe (54) is configured to return a portion of the treated water to the cooling water tank (20), and is configured such that one side is connected to the treated water transfer pipe (51) and the other side is connected to the cooling water tank (20). The cooling water tank return pipe (54) includes a first return valve (541) and a second return valve (542).

[0136] The above first return valve (541) refers to a valve formed on the side of the treated water transport pipe (51) among the return pipes (54) of the cooling water tank. As described above, if the value obtained by subtracting the flow rate discharged overboard from the capacity of the water treatment device (44) is determined as the reintroduction flow rate, when the first return valve (541) is opened before the discharge of the treated water, the determined reintroduction flow rate is returned to the cooling water tank (20).

[0137] The above second water recovery valve (542) refers to a valve formed on the cooling water tank (20) side of the cooling water tank water recovery pipe (54). Since the treated water to be recovered is treated clean water, by opening the second water recovery valve (542) and supplying the treated water into the cooling water tank (20), the contaminated water can be diluted to adjust the water quality of the cooling water tank (20) to a certain level.

[0138] The above holding tank return pipe (55) is configured such that one side is connected to the water treatment device (44), and the other side is connected to a holding tank (43) that temporarily stores overflowed cooling water exceeding the standard water quality, thereby returning the treated water discharged from the water treatment device (44) to the holding tank (43). Treated water that does not meet the appropriate requirements can be returned to the holding tank (43) through the holding tank return pipe (55).

[0139] The above-described cooling water recirculation unit (60) refers to a configuration that recirculates cooling water that satisfies the standard water quality stored in the cooling water tank (20). As described above, if the water quality of the cooling water tank (20) does not satisfy the standard water quality, the cooling water overflows, and the overflowed cooling water is treated and the purified treated water is returned to the cooling water tank (20), so that the water quality of the cooling water tank (20) can be maintained at a certain level. The present invention configures the cooling water recirculation unit (60) to discharge cooling water that satisfies the standard water quality from the cooling water tank (20), so that the discharged cooling water can be used again as water for cooling exhaust gas. Referring to FIG. 14, the cooling water recirculation unit (60) includes a cooling water transfer pipe (61) and a heat exchanger (62).

[0140] The above cooling water transport pipe (61) refers to a pipe that is connected to the cooling water tank (20) and transports cooling water that satisfies the standard water quality. Preferably, as shown in FIG. 14, a pH adjuster provided from the alkaline supply device (30) can be injected onto the cooling water transport pipe (61), and the pH of the cooling water that satisfies the standard water quality can be adjusted by the pH adjuster.

[0141] The above heat exchanger (62) refers to a configuration formed on the cooling water transport pipe (61) to cool the cooling water whose temperature has increased due to the cooling of the exhaust gas. That is, the present invention configures the heat exchanger (62) on the cooling water transport pipe (61) through which cooling water satisfying the standard water quality is transported, so that the cooling water whose temperature has increased during the process of cooling the exhaust gas can be re-cooled using seawater or the like so that it can be reused for cooling the exhaust gas. Preferably, the heat exchanger (62) may be formed as a plate-type heat exchanger in order to increase the heat exchange efficiency during the heat exchange process.

[0142] The above control unit (70) is configured to control the exhaust gas recirculation system (1), and collects and monitors data while communicating with the components included in the exhaust gas recirculation system (1), and can determine whether to open or close a valve, operate or stop a device, etc. based on the collected data.

[0143] FIG. 15 and FIG. 16 are diagrams showing the state of use of the present invention. As shown in FIG. 15 and FIG. 16, the exhaust gas cooler (10) of the present invention can be directly attached to an engine (E), so that the exhaust gas cooler (10) can be easily installed even in places with many restrictions on installation space, such as ships.

[0144] And the present invention configures a pre-cooling tower (11) in front of the main cooling tower (12), so that primary exhaust gas cooling is achieved by the pre-cooling spray unit (112) that sprays water into the pre-cooling tower (11). The primary cooled exhaust gas enters the main cooling tower (12) through the pre-cooling connection unit (113), and the primary cooled exhaust gas by the water sprayed from the main cooling spray unit (124) is secondarily cooled.

[0145] The exhaust gas cooled within the above body portion (1211) rises and flows into the head portion (1212). By making the head portion (1212) have a unique shape as shown in FIGS. 15 and 16, the exhaust gas that has undergone secondary cooling and moisture removal can naturally move toward the outlet portion (127) without pressure loss.

[0146] The present invention forms the outlet (127) on the side of the head (1212) instead of forming the outlet (127) on the upper surface of the head (1212), so that the use of a pipe elbow or the like for changing the flow path is not necessary, thereby reducing the length of the pipe connecting the outlet (127) and the turbocharger, thereby solving the problem of back pressure formation and preventing the pressure drop phenomenon.

[0147] In particular, since the first surface (12121) of the head portion (1212) is formed to be inclined as illustrated in FIG. 16, the outlet portion (127) coupled to the first surface (12121) discharges the treated exhaust gas in a state inclined upward, and even if water is generated due to condensation in an environment with low external temperature such as winter due to the inclined outlet portion (127), the condensed water can enter the main cooling chamber of the cooling tower.

[0148] The water sprayed for exhaust gas cooling is collected in the sump, which is the lowest point of the above-mentioned cooling housing section (121), and the cooling water tank (20) can be formed integrally with the sump section (1213) to increase space efficiency. If the cooling water stored in the cooling water tank (20) does not satisfy the standard water quality, the overflowed cooling water can be treated and reinjected, and the cooling water satisfying the standard water quality can be discharged and re-cooled to be recycled for exhaust gas cooling.

[0149] The detailed description above is illustrative of the present invention. Furthermore, the above description illustrates and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. In other words, changes or modifications are possible within the scope of the inventive concept disclosed in this specification, the scope equivalent to the written disclosure, and / or the scope of technology or knowledge in the art. The written embodiments illustrate the best possible state for implementing the technical idea of ​​the present invention, and various modifications required for specific application fields and uses of the present invention are also possible. Therefore, the detailed description of the invention above is not intended to limit the present invention to the disclosed embodiments. Furthermore, the appended claims should be construed to include other embodiments.

Claims

1. An exhaust gas cooler that cools the exhaust gas, A cooling water tank for storing cooling water discharged from the exhaust gas cooler after cooling the exhaust gas, A cooling water treatment unit that treats the cooling water stored in the cooling water tank; An exhaust gas recirculation system characterized by including a treated water transport unit that receives and transports treated cooling water, which is cooling water treated from the above cooling water treatment unit.

2. In paragraph 1, An exhaust gas recirculation system, characterized in that the treated water transport unit includes a cooling water tank return pipe for returning the treated water to the cooling water tank.

3. In paragraph 2, The above treatment water transport unit includes a treatment water transport pipe, which is a pipe for transporting the treatment water, An exhaust gas recirculation system, characterized in that the cooling water tank return pipe is connected at one end to the treated water transfer pipe and at the other end to the cooling water tank.

4. In paragraph 3, An exhaust gas recirculation system characterized in that the treated water transport unit includes a flow meter formed at the rear side of a point where the cooling water tank return pipe among the treated water transport pipes is connected to the treated water transport pipe to precisely control the flow rate of the returned water to the cooling water tank, and a throttle valve formed on the treated water transport pipe at the rear side of the flow meter to control the flow rate.

5. In paragraph 4, An exhaust gas recirculation system characterized in that the above throttle valve determines the return flow rate (ab) reintroduced into the cooling water tank as the value obtained by subtracting the flow rate (b) discharged overboard from the capacity (a) of the water treatment device that treats the overflowed cooling water exceeding the standard water quality.

6. In paragraph 5, An exhaust gas recirculation system characterized in that the treated water transport unit includes a holding tank return pipe, one end of which is connected to the water treatment device, and the other end of which is connected to a holding tank that temporarily stores overflowed cooling water exceeding the standard water quality, and returns the treated water discharged from the water treatment device to the holding tank.

7. In paragraph 1, An exhaust gas recirculation system, characterized in that the cooling water treatment unit includes an overflow transfer pipe, which is a pipe for transferring overflowed cooling water exceeding a standard water quality from the cooling water tank.

8. In paragraph 7, An exhaust gas recirculation system, characterized in that the above standard water quality is based on the concentration of total suspended solids (TSS).

9. In paragraph 7, An exhaust gas recirculation system, characterized in that the cooling water treatment unit includes a holding tank connected to the overflow transfer pipe and temporarily storing overflowed cooling water exceeding the standard water quality.

10. In paragraph 9, An exhaust gas recirculation system characterized in that the holding tank maintains a constant water level by discharging the treated water overboard in an amount equivalent to the amount of exhaust gas condensate generated.

11. In paragraph 9, An exhaust gas recirculation system characterized in that the cooling water treatment unit includes a water treatment device that is connected to the holding tank and treats overflowed cooling water that exceeds the standard water quality supplied from the holding tank, and discharges the treated water.

12. In paragraph 9, An exhaust gas recirculation system, characterized in that the cooling water treatment unit includes a static mixer formed on an overflow transfer pipe on the front side of the holding tank and mixing a pH adjuster into the cooling water.

13. In paragraph 1, An exhaust gas recirculation system, characterized in that the exhaust gas recirculation system includes a cooling water recirculation unit that recirculates cooling water that satisfies the standard water quality stored in the cooling water tank.

14. In paragraph 13, An exhaust gas recirculation system characterized in that the cooling water recirculation unit includes a cooling water transport pipe that is connected to the cooling water tank and transports cooling water that satisfies the standard water quality, and a heat exchanger formed on the cooling water transport pipe and cools the cooling water whose temperature has increased due to cooling of the exhaust gas.

15. In any one of paragraphs 1 to 14, An exhaust gas recirculation system, characterized in that the exhaust gas recirculation system includes an alkaline supply device that supplies a pH adjuster to the cooling water.

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