Gas cooler for NOX emission reduction of two-stroke marine diesel engine

Abstract

The utility model provides a gas cooler for NOX emission reduction of a two-stroke marine diesel engine, and relates to the technical field of coolers, the gas cooler comprises a shell, an end cover and a rear tube plate, the end cover and the rear tube plate are connected at two ends of the shell, one end of the end cover is sequentially provided with a liquid inlet cavity, a transfer cavity and a liquid discharge cavity from top to bottom, and the other end of the end cover is connected with the liquid discharge cavity. A transfer cavity is formed in the shell, an upper half cavity and a lower half cavity are formed in the transfer cavity, U-shaped pipes are arranged in the shell, the number of the U-shaped pipes is three, and an inlet and an outlet of the U-shaped pipe at the upper end are connected with the liquid inlet cavity and the upper half cavity correspondingly; according to the utility model, the U-shaped pipe is adopted as the cooling pipe, no fin is contained, no backflow water end cover is arranged, cooling water is fed through the liquid inlet cavity and flows back to the transfer cavity and the liquid discharge cavity on the end cover through the U-shaped pipe, the U-shaped pipe is only connected to the cavity of the end cover in an expanded manner, the rear end of the U-shaped pipe is not connected in an expanded manner, and the U-shaped pipe can transversely and freely move along with the end cover, so that different heating expansion amounts are avoided; and the pipeline is damaged.

Description

Technical Field

[0001] The utility model relates to the technical field of coolers, in particular to a gas cooler for NOx emission reduction of a two-stroke marine diesel engine. Background Art

[0002] EGR is a method for reducing NOx (nitrogen oxides) emissions of MAN B&W two-stroke marine diesel engines according to Annex VI of MARPOL to comply with the IMO International Maritime Organization's TIER III NOx emission standard regulations. The EGR cooler is one of the EGR components required for this EGR process, where the exhaust gas is recycled to the engine inlet to reduce thermal NOx (nitrogen oxides) by lowering the stoichiometric combustion temperature;

[0003] For existing air coolers of the type with cooling tubes and fins, since the cooling tubes and the floating end tube sheet are connected by an expansion joint, the parts expand by different amounts when heated in a high-temperature environment, which may cause relative movement between the parts and easily lead to tube damage. Moreover, finned coolers are very sensitive to particles that may clog the cooler in the exhaust system, affecting normal use. Therefore, the utility model proposes a gas cooler for NOx emission reduction of a two-stroke marine diesel engine to solve the problems existing in the prior art. Summary of the Invention

[0004] In view of the above problems, the utility model proposes a gas cooler for NOx emission reduction of a two-stroke marine diesel engine. The U-shaped tubes of this gas cooler for NOx emission reduction of a two-stroke marine diesel engine are only expanded and connected to the cavities of the end covers, and are not expanded at the rear end. The U-shaped tubes can freely move horizontally with the end covers, avoiding the situation of different thermal expansion amounts and pipe damage.

[0005] To achieve the purpose of the utility model, the utility model is realized through the following technical solutions: A gas cooler for NOx emission reduction of a two-stroke marine diesel engine, including a housing, end covers, and a rear tube sheet. The end covers and the rear tube sheet are connected to both ends of the housing. One end of the end cover is provided with a liquid inlet cavity, a transfer cavity, and a liquid discharge cavity from top to bottom in sequence. The transfer cavity internally has an upper half cavity and a lower half cavity. The housing internally is provided with U-shaped tubes, and there are three groups of U-shaped tubes. The inlets and outlets of the upper U-shaped tubes are respectively connected to the liquid inlet cavity and the upper half cavity. The inlets and outlets of the middle U-shaped tubes are respectively connected to the upper half cavity and the lower half cavity. The inlets and outlets of the lower U-shaped tubes are respectively connected to the lower half cavity and the liquid discharge cavity;

[0006] A liquid inlet pipe and a liquid outlet pipe are respectively provided on the liquid inlet cavity and the liquid discharge cavity. An air inlet nozzle and an exhaust nozzle communicating with the interior of the housing are respectively provided above and below one end of the end cover.

[0007] A further improvement lies in that: an extension tube sheet is provided between the end cover and the outer shell, and one end of each of the three U-shaped tubes passes through the extension tube sheet, and the end cover, the extension tube sheet and the outer shell are fixed by bolts at the edges.

[0008] A further improvement lies in that: connecting plates are provided on both sides of one end of the end cover, and connecting holes are provided above and below the inside of the connecting plates.

[0009] A further improvement lies in that: the rear ends of the three U-shaped tubes all movably penetrate through the rear tube sheet, and the edge of the rear tube sheet is fixed to the outer shell by bolts, a rear protective cover is provided at the outer end of the rear tube sheet, and lifting lugs are provided on the outside of the rear protective cover.

[0010] A further improvement lies in that: a support tube sheet is provided inside the outer shell, and multiple groups of support tube sheets are equidistantly arranged, and the three U-shaped tubes all penetrate through multiple groups of the support tube sheets, and the support tube sheet is a hollow and breathable plate.

[0011] A further improvement lies in that: each group of the U-shaped tubes is composed of multiple U-shaped fine tubes combined.

[0012] A further improvement lies in that: the lower end inside the air inlet nozzle is closed, and the upper end inside the air inlet nozzle communicates with the inside of the outer shell, the upper end inside the exhaust nozzle is closed, and the lower end inside the exhaust nozzle communicates with the inside of the outer shell.

[0013] The beneficial effects of the present utility model are as follows:

[0014] 1. The present utility model uses U-shaped tubes as cooling tubes, without fins and without a return water end cover. Cooling water enters through the liquid inlet cavity, flows back through the U-shaped tubes to the transfer cavity and the liquid discharge cavity on the end cover. The U-shaped tubes are only expanded and connected to the cavity of the end cover, and are not expanded and connected at the rear end. The U-shaped tubes can move freely horizontally along with the end cover, avoiding the situation of different thermal expansion amounts and pipeline damage.

[0015] 2. The U-shaped tubes of the present utility model are composed of multiple groups of U-shaped fine tubes combined, are insensitive to particles that may block the cooler in the exhaust system, can effectively exchange heat to adjust the engine combustion process, reduce the combustion temperature, thereby ensuring the engine performance and reducing the emission of Nox nitrogen oxides.

[0016] 3. The front end of the U-shaped tube of the present utility model passes through the extension tube sheet for reinforcement, and the inside of the outer shell supports the U-shaped tubes through multiple groups of support tube sheets, which is very firm and does not interfere with the pipeline, ensuring the reliability of the device. Description of the Drawings

[0017] Figure 1 [[ID=3ģ]]is the front view of the present utility model;

[0018] Figure 2 is the sectional schematic view of the present utility model;

[0019] Figure 3 is the top view sectional view of the present utility model;

[0020] Figure 4 is the schematic diagram of the air inlet nozzle and the exhaust nozzle of the present utility model.

[0021] Wherein: 1. Outer shell; 2. End cover; 3. Rear tube plate; 4. Liquid inlet chamber; 5. Transfer chamber; 6. Liquid discharge chamber; 7. U-shaped tube; 8. Liquid inlet pipe; 9. Liquid outlet pipe; 10. Air inlet nozzle; 11. Exhaust nozzle; 12. Extension tube plate; 13. Connecting plate; 14. Rear protective cover; 15. Support tube plate; 16. Lifting lug. Specific embodiments

[0022] In order to deepen the understanding of the present utility model, the following will further elaborate on the present utility model in combination with embodiments. These embodiments are only used to explain the present utility model and do not constitute a limitation to the protection scope of the present utility model. Embodiment 1

[0023] According to Figure 1 , 2 , 3, and 4, this embodiment proposes a gas cooler for reducing NOX emissions of a two-stroke marine diesel engine, which includes an outer shell 1, an end cover 2, and a rear tube plate 3. The end cover 2 and the rear tube plate 3 are connected to both ends of the outer shell 1. One end of the end cover 2 is successively provided with a liquid inlet chamber 4, a transfer chamber 5, and a liquid discharge chamber 6 from top to bottom. The transfer chamber 5 internally has an upper half chamber and a lower half chamber. The inner part of the outer shell 1 is provided with U-shaped tubes 7, and there are three groups of U-shaped tubes 7. The inlet and outlet of the upper U-shaped tube 7 are respectively connected to the liquid inlet chamber 4 and the upper half chamber. The inlet and outlet of the middle U-shaped tube 7 are respectively connected to the upper half chamber and the lower half chamber. The inlet and outlet of the lower U-shaped tube 7 are respectively connected to the lower half chamber and the liquid discharge chamber 6;

[0024] The liquid inlet chamber 4 and the liquid discharge chamber 6 are respectively provided with a liquid inlet pipe 8 and a liquid outlet pipe 9. The upper and lower sides of one end of the end cover 2 are respectively provided with an air inlet nozzle 10 and an exhaust nozzle 11 communicating with the inside of the outer shell 1. The U-shaped tube 7 is a pure stainless steel U-shaped cooling tube. During use, the U-shaped tube 7 is used as the cooling tube, without fins and without a return water end cover. Cooling water enters the liquid inlet chamber 4 through the liquid inlet pipe 8, returns to the transfer chamber 5 and the liquid discharge chamber 6 on the end cover 2 through the U-shaped tube 7, and then is discharged from the liquid outlet pipe 9. When not in use, plugs can be installed on the liquid inlet pipe 8 and the liquid outlet pipe 9. The air inlet nozzle 10 is used for air intake, and after heat exchange with the U-shaped tube 7, the air is exhausted through the exhaust nozzle 11. The U-shaped tube 7 is only expanded and connected to the cavity of the end cover 2, and is not expanded and connected at the rear end. The U-shaped tube 7 can freely move horizontally along with the end cover 2, avoiding the situation of different thermal expansion amounts and pipeline damage.

[0025] An extension tube sheet 12 is provided between the end cover 2 and the outer shell 1. One end of each of the three U-shaped tubes 7 passes through the extension tube sheet 12, and the end cover 2, the extension tube sheet 12 and the outer shell 1 are fixed by bolts at the edges. The front end of the U-shaped tube 7 passes through the extension tube sheet 12 for reinforcement. The inside of the outer shell 1 supports the U-shaped tube 7 through multiple support tube sheets 15, which is very strong and does not interfere with the pipeline, ensuring the reliability of the device.

[0026] On both sides of one end of the end cover 2, connecting plates 13 are provided, and connecting holes are provided above and below the inside of the connecting plates 13. The connecting plates 13 cooperate with the connecting holes to connect other devices.

[0027] The rear ends of the three U-shaped tubes 7 all movably penetrate through the rear tube sheet 3. The U-shaped tubes 7 are only expanded and connected to the cavity of the end cover 2, and are not expanded and connected at the rear end. The U-shaped tubes 7 can move horizontally freely with the end cover 2 to avoid the situation of different thermal expansion amounts and pipeline damage. The edge of the rear tube sheet 3 is fixed to the outer shell 1 by bolts. A rear protective cover 14 is provided at the outer end of the rear tube sheet 3 to protect the rear of the U-shaped tube 7. A lifting lug 16 is provided on the outside of the rear protective cover 14 for easy lifting.

[0028] The inside of the outer shell 1 is provided with support tube sheets 15, and multiple groups of support tube sheets 15 are equidistantly arranged. The three U-shaped tubes 7 all penetrate through multiple groups of support tube sheets 15. The support tube sheets 15 are hollow and breathable plates. The front end of the U-shaped tube 7 passes through the extension tube sheet 12 for reinforcement. The inside of the outer shell 1 supports the U-shaped tube 7 through multiple support tube sheets 15, which is very strong and does not interfere with the pipeline, ensuring the reliability of the device. The support tube sheets 15 are hollow and breathable plates and do not block the flow of gas.

[0029] Each group of the U-shaped tubes 7 is composed of multiple U-shaped fine tubes. The U-shaped tubes 7 are composed of multiple U-shaped fine tubes, are insensitive to the particles that may block the cooler in the exhaust system, can effectively exchange heat to regulate the engine combustion process, reduce the combustion temperature, thereby ensuring the engine performance and reducing the emission of Nox nitrogen oxides. Embodiment 2

[0030] According to Figure 1 、 2As shown in Figures 3 and 4, this embodiment proposes a gas cooler for reducing NOX emissions of a two-stroke marine diesel engine, which includes a housing 1, end caps 2, and a rear tube sheet 3. The end caps 2 and the rear tube sheet 3 are connected to both ends of the housing 1. One end of the end cap 2 is sequentially provided with a liquid inlet chamber 4, a transfer chamber 5, and a liquid discharge chamber 6 from top to bottom. The inside of the transfer chamber 5 is provided with an upper half chamber and a lower half chamber. Inside the housing 1, there are three groups of U-shaped tubes 7. The inlets and outlets of the upper U-shaped tubes 7 are respectively connected to the liquid inlet chamber 4 and the upper half chamber. The inlets and outlets of the middle U-shaped tubes 7 are respectively connected to the upper half chamber and the lower half chamber. The inlets and outlets of the lower U-shaped tubes 7 are respectively connected to the lower half chamber and the liquid discharge chamber 6;

[0031] An inlet pipe 8 and an outlet pipe 9 are respectively provided on the liquid inlet chamber 4 and the liquid discharge chamber 6. An air inlet nozzle 10 and an exhaust nozzle 11 communicating with the inside of the housing 1 are respectively provided above and below one end of the end cap 2. The U-shaped tube 7 is a pure stainless steel U-shaped cooling tube. When in use, the U-shaped tube 7 is used as a cooling tube, without fins and without a return water end cap. Cooling water enters the liquid inlet chamber 4 through the inlet pipe 8, flows back through the U-shaped tube 7 to the transfer chamber 5 and the liquid discharge chamber 6 on the end cap 2, and then is discharged from the outlet pipe 9. When not in use, plugs can be installed on the inlet pipe 8 and the outlet pipe 9. The air inlet nozzle 10 is used for air intake, and after heat exchange with the U-shaped tube 7, the air is exhausted through the exhaust nozzle 11. The U-shaped tube 7 is only expanded and connected to the cavity of the end cap 2, and is not expanded and connected at the rear end. The U-shaped tube 7 can freely move horizontally along with the end cap 2, avoiding the situation of different thermal expansion amounts and pipeline damage.

[0032] Each group of the U-shaped tubes 7 is composed of multiple groups of U-shaped thin tubes. The U-shaped tube 7 composed of multiple groups of U-shaped thin tubes is not sensitive to the particles that may block the cooler in the exhaust system, can effectively exchange heat to regulate the engine combustion process, reduce the combustion temperature, thereby ensuring the engine performance and reducing the emission of Nox nitrogen oxides.

[0033] The lower end inside the air inlet nozzle 10 is closed, and the upper end inside the air inlet nozzle 10 communicates with the inside of the housing 1 to ensure that the gas reaches the upper part inside the housing 1 when entering. The upper end inside the exhaust nozzle 11 is closed, and the lower end inside the exhaust nozzle 11 communicates with the inside of the housing 1. Ensure that the flue gas passes through the lower part inside the housing 1 and then is discharged, with high heat exchange efficiency.

[0034] The gas cooler for reducing NOX emissions of this two-stroke marine diesel engine uses U-shaped tubes 7 as cooling tubes, without fins and without a return water end cover. Cooling water enters through the liquid inlet cavity 4, flows back through the U-shaped tubes 7 to the transfer cavity 5 and the liquid discharge cavity 6 on the end cover 2. The U-shaped tubes 7 are only expanded and connected to the cavity of the end cover 2, and are not expanded at the rear end. The U-shaped tubes 7 can move freely horizontally with the end cover 2 to avoid situations where the heat expansion amounts are different and the pipes are damaged. Moreover, the U-shaped tubes 7 are composed of multiple groups of U-shaped thin tubes, are insensitive to particles that may block the cooler in the exhaust system, can effectively exchange heat to regulate the engine combustion process, reduce the combustion temperature, thereby ensuring the engine performance and reducing NOx nitrogen oxide emissions. At the same time, the front end of the U-shaped tubes 7 passes through the extension tube plate 12 for reinforcement, and the inside of the outer shell 1 supports the U-shaped tubes 7 through multiple groups of support tube plates 15, which is very strong and does not interfere with the pipes, ensuring the reliability of the device.

[0035] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A gas cooler for reducing NOX emissions of a two-stroke marine diesel engine, comprising a housing (1), end covers (2) and a rear tube sheet (3), characterized in that: The end cover (2) and the rear tube sheet (3) are connected to both ends of the outer shell (1). One end of the end cover (2) is sequentially provided with a liquid inlet cavity (4), a transfer cavity (5), and a liquid discharge cavity (6) from top to bottom. The inside of the transfer cavity (5) is provided with an upper half cavity and a lower half cavity. The inside of the outer shell (1) is provided with U-shaped tubes (7), and there are three groups of U-shaped tubes (7). The inlets and outlets of the upper U-shaped tube (7) are respectively connected to the liquid inlet cavity (4) and the upper half cavity. The inlets and outlets of the middle U-shaped tube (7) are respectively connected to the upper half cavity and the lower half cavity. The inlets and outlets of the lower U-shaped tube (7) are respectively connected to the lower half cavity and the liquid discharge cavity (6); A liquid inlet pipe (8) and a liquid outlet pipe (9) are respectively provided on the liquid inlet cavity (4) and the liquid discharge cavity (6). An air inlet nozzle (10) and an air outlet nozzle (11) communicating with the inside of the outer shell (1) are respectively provided above and below one end of the end cover (2).

2. The gas cooler for reducing NOX emissions of a two-stroke marine diesel engine according to claim 1, characterized in that: An extension tube sheet (12) is provided between the end cover (2) and the outer shell (1). One end of each of the three groups of U-shaped tubes (7) passes through the extension tube sheet (12). The end cover (2), the extension tube sheet (12), and the outer shell (1) are fixed by bolts at the edges.

3. A gas cooler for NOx emission reduction of a two-stroke marine diesel engine according to claim 2, characterized in that: Connecting plates (13) are provided on both sides of one end of the end cover (2), and connection holes are provided above and below the inside of the connecting plates (13).

4. The gas cooler for reducing NOX emissions of a two-stroke marine diesel engine according to claim 1, characterized in that: The rear ends of the three groups of U-shaped tubes (7) all movably penetrate through the rear tube sheet (3), and the edge of the rear tube sheet (3) is fixed to the outer shell (1) by bolts. A rear protective cover (14) is provided at the outer end of the rear tube sheet (3), and a lifting lug (16) is provided on the outer side of the rear protective cover (14).

5. A gas cooler for reducing NOX emissions of a two-stroke marine diesel engine according to claim 1, characterized in that: A support tube sheet (15) is provided inside the outer shell (1), and multiple groups of the support tube sheets (15) are equidistantly arranged. The three groups of U-shaped tubes (7) all penetrate through the multiple groups of support tube sheets (15), and the support tube sheets (15) are hollow and breathable plates.

6. A gas cooler for reducing NOX emissions of a two-stroke marine diesel engine according to claim 5, characterized in that: Each group of U-shaped tubes (7) is composed of multiple groups of U-shaped fine tubes combined together.

7. A gas cooler for reducing NOX emissions of a two-stroke marine diesel engine according to claim 1, characterized in that: The lower end inside the air inlet nozzle (10) is closed, and the upper end inside the air inlet nozzle (10) communicates with the inside of the outer shell (1). The upper end inside the air outlet nozzle (11) is closed, and the lower end inside the air outlet nozzle (11) communicates with the inside of the outer shell (1).

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