Ship engine and exhaust back pressure control device thereof

Abstract

The utility model relates to the technical field and discloses a ship engine and an exhaust back pressure control device thereof. The exhaust back pressure control device of the ship engine comprises a first connecting pipeline and a second connecting pipeline, the energy recovery device is connected to the end, back on to the engine, of the first connecting pipeline; the cleaning device is connected to an outlet of the energy recovery device; and the negative pressure device is arranged at the outlet of the desulfurization device, and the negative pressure device reduces the pressure of the space facing one side of the desulfurization device so as to promote the exhaust gas to be discharged. The arrangement of the negative pressure device can make up the local resistance loss of waste gas in the exhaust pipeline, so that the exhaust back pressure value at the outlet of the engine is within the range specified by an equipment manufacturer, and when a plurality of waste gas cleaning devices and energy recovery devices are additionally arranged on the exhaust pipeline, the working performance of the engine can still be ensured not to be influenced; the requirements of users are met to the maximum extent, the economical efficiency, applicability and environmental protection performance of the ship are guaranteed, and the comprehensive performance of the ship is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of marine engine exhaust, particularly to a marine engine and exhaust back pressure control device thereof. BACKGROUND

[0002] Under the trend of pursuing energy saving, environmental protection and improving applicability, more and more ship owners not only require new ships, but also hope to retrofit existing ships by adding exhaust gas boilers, denitration devices, desulfurization devices and other energy recovery system devices on the engine exhaust pipe.

[0003] When the exhaust gas discharged by the engine flows through these devices and pipelines, it inevitably causes a certain degree of pressure loss. In addition, the arrangement of the exhaust pipeline usually includes corrugated expansion joints, elbows, transition pipes, control valves, branch pipe joints and other pipeline accessories. The resistance coefficients of these accessories are large, which will further increase the local resistance loss. The specific situation is shown in Figure 1 The above factors superimpose each other, resulting in a significant increase in the total resistance of the exhaust pipeline system, which eventually leads to the exhaust back pressure value at the engine outlet exceeding the range specified by the equipment manufacturer.

[0004] Once the engine exhaust back pressure is too high, a series of problems will follow: the combustion efficiency of the fuel is reduced, the economic efficiency of the ship operation is reduced; the power output of the engine is limited, and it cannot fully exert its performance; the content of harmful gases in the exhaust gas increases, causing more serious pollution to the environment, and it is difficult to meet the requirements of relevant regulations of the flag state and the International Maritime Organization.

[0005] Due to these factors, it is often difficult to install multiple intended devices on the exhaust pipe of the marine engine at the same time. For example, it is not possible to simultaneously set up desulfurization, denitration and energy recovery devices and other facilities on the exhaust pipe. This undoubtedly has a negative impact on the economy, applicability and environmental protection of the ship, and limits the improvement of the comprehensive performance of the ship. INVENTION CONTENTS

[0006] The utility model aims at providing a marine engine and exhaust back pressure control device, so that the exhaust back pressure value at the engine outlet is within the range specified by the equipment manufacturer, ensuring the economy, applicability and environmental protection of the ship, and improving the comprehensive performance of the ship.

[0007] In order to achieve the above purpose, the utility model provides an exhaust back pressure control device of a marine engine, comprising:

[0008] A first connecting pipeline, one end of the first connecting pipeline is connected to the engine;

[0009] An energy recovery device, the energy recovery device is connected to one end of the first connecting pipeline away from the engine;

[0010] a cleaning device connected to the outlet of the energy recovery device;

[0011] a negative pressure device provided at the outlet of the cleaning device, which reduces the pressure of the space on the side of the cleaning device to facilitate the exhaust gas discharge.

[0012] Compared with the prior art, the exhaust back pressure control device of the ship engine has the beneficial effects that: the negative pressure device is arranged at the end of the exhaust pipe of the ship engine, the exhaust gas discharged by the engine is forced to discharge after being pressurized, low pressure is generated at the suction inlet end, a certain vacuum degree is formed, the arrangement of the negative pressure device can compensate for the local resistance loss of the exhaust gas in the exhaust pipe, the exhaust back pressure value at the outlet of the engine is within the range specified by the equipment manufacturer, so that when multiple required devices, such as exhaust cleaning devices and energy recovery devices, are installed in the exhaust pipe, the working performance of the engine can still be guaranteed, the user's demand is met to the greatest extent, the economy, applicability and environmental protection of the ship are guaranteed, and the comprehensive performance of the ship is improved.

[0013] The exhaust back pressure control device of the ship engine of the embodiment of the utility model, the negative pressure device includes a vacuum fan, and the outlet of the vacuum fan is arranged towards the air outlet direction.

[0014] The exhaust back pressure control device of the ship engine of the embodiment of the utility model, the outlet of the vacuum fan is connected with a horn air outlet, and the diameter of the horn air outlet gradually increases along the air outlet direction.

[0015] The exhaust back pressure control device of the ship engine of the embodiment of the utility model, a pressure sensor is arranged in the first connecting pipeline, the pressure sensor is electrically connected with a frequency conversion control box, and the frequency conversion control box is electrically connected with the vacuum fan.

[0016] The exhaust back pressure control device of the ship engine of the embodiment of the utility model, the cleaning device includes a first denitration device and a second desulfurization device, and a second connecting pipeline is arranged between the first denitration device and the second desulfurization device.

[0017] The exhaust back pressure control device of the ship engine of the embodiment of the utility model, a corrugated expansion joint is arranged in the second connecting pipeline.

[0018] The exhaust back pressure control device of the ship engine of the embodiment of the utility model, a control valve is further arranged in the second connecting pipeline.

[0019] The exhaust back pressure control device of the ship engine of the embodiment of the utility model, the energy recovery device includes an exhaust gas boiler.

[0020] The utility model provides a kind of marine engine, including the exhaust back pressure control device of the marine engine of any one of above embodiment.

[0021] Compared with prior art, the marine engine of the utility model embodiment has the beneficial effects that: a negative pressure device is arranged at the end of the exhaust pipe of the marine engine, so that the exhaust gas discharged by the engine is forced to be discharged after being pressurized, and low pressure is generated at the suction inlet end thereof, forming a certain vacuum degree; the arrangement of the negative pressure device can compensate for the local resistance loss of the exhaust gas in the exhaust pipeline, so that the exhaust back pressure value at the outlet of the engine is within the range specified by the equipment manufacturer, so that when multiple required devices, such as exhaust cleaning devices and energy recovery devices, are installed in the exhaust pipeline, the working performance of the engine can still be guaranteed, the user's demand is maximally met, the economy, applicability and environmental protection of the ship are guaranteed, and the comprehensive performance of the ship is improved.

[0022] The additional aspects and advantages of the utility model will be partially given in the following description, partially will become obvious from the following description, or be understood through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is the structure schematic diagram of the exhaust back pressure control device of the marine engine of the utility model embodiment;

[0024] Figure 2 is the exhaust pipeline local resistance distribution schematic diagram of the exhaust back pressure control device of the marine engine of the utility model embodiment;

[0025] Figure 3 is the vacuum fan working characteristic curve requirement typical schematic diagram of the exhaust back pressure control device of the marine engine of the utility model embodiment;

[0026] In the figure, 1, first connecting pipeline;11, pressure sensor;2, engine;3, energy recovery device;4, cleaning device;41, first denitration device;42, second desulfurization device;43, second connecting pipeline;44, corrugated expansion joint;45, control valve;5, negative pressure device;6, horn exhaust port;7, frequency conversion control box. DETAILED DESCRIPTION

[0027] The embodiments of the utility model are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the utility model, and cannot be understood as limiting the utility model.

[0028] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0030] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0031] like Figure 1 As shown, a preferred embodiment of the present invention provides an exhaust back pressure control device for a marine engine, comprising a first connecting pipe 1, one end of which is connected to an engine 2 for collecting and discharging exhaust gas after the engine 2 has been running; the first connecting pipe 1 is sequentially connected to an energy recovery device 3 and a cleaning device 4, the energy recovery device 3 being connected to the end of the first connecting pipe 1 facing away from the engine 2, thereby recovering the waste heat and kinetic energy of the exhaust gas from the engine 2, improving the thermal efficiency of the engine 2, and also improving the economy of the engine 2; the cleaning device 4 is connected to the outlet of the energy recovery device 3, thereby cleaning the exhaust gas before discharge to meet environmental standards and ensuring the environmental friendliness of the engine 2; a negative pressure device 5 is provided at the end of the exhaust device, the negative pressure device 5 being located at the outlet of the cleaning device 4, the negative pressure device 5 reducing the pressure in the space facing the cleaning device 4 to promote the discharge of exhaust gas.

[0032] The negative pressure device 5 is arranged at the end of the exhaust pipe of the ship engine 2, so that the exhaust gas discharged by the engine 2 is forced to be discharged after being pressurized in the pipeline, and low pressure is generated at the suction inlet end, and a certain vacuum degree is formed. The arrangement of the negative pressure device 5 can make up for the local resistance loss of the exhaust gas in the exhaust pipeline, so that the exhaust back pressure value at the outlet of the engine 2 is within the range specified by the equipment manufacturer, so that a plurality of required devices, such as the exhaust gas cleaning device 4 and the energy recovery device 3, can be installed in the exhaust pipeline, and the working performance of the engine 2 is not affected, the user's demand is met to the greatest extent, and the economy, applicability and environmental protection of the ship are ensured, so that the comprehensive performance of the ship is improved. Without the need for pipeline modification, the manufacturing and use cost of the engine 2 exhaust system is low, and the practicability of the ship can be greatly improved; by using the negative pressure device 5, the exhaust back pressure of the engine 2 can also be reduced, the fuel combustion efficiency of the engine 2 is improved, the fuel consumption rate is reduced, and the power capacity of the engine 2 is improved.

[0033] In some embodiments of the utility model, the negative pressure device 5 includes a vacuum fan, the outlet of the vacuum fan is arranged towards the air outlet direction, the vacuum fan forces the exhaust gas in the pipeline to be discharged after being pressurized by high-speed operation, and low pressure is generated at the suction inlet end, and a certain vacuum degree is formed. The vacuum fan is arranged at the outlet end of the exhaust pipeline, and the temperature of the outlet end of the exhaust pipeline is the lowest, so that the temperature of the vacuum fan can be prevented from being too high, and the service life and working reliability of the vacuum fan are improved.

[0034] The flue gas discharged by the engine 2 reaches the inlet of the vacuum fan after passing through the first connecting pipeline 1, the energy recovery device 3 and the cleaning device 4, and is discharged to the atmosphere from the exhaust outlet under the power action of the rotating impeller. During the flue gas discharge process, the flue gas is subjected to the damping of the pipeline and the above-mentioned devices and pipeline accessories, respectively, and generates a certain total back pressure Pb=P1+P2+P3+…+Pi along the pipeline, as shown in the formula. Figure 2 As can be seen from the formula, if the pressure of any point is changed, the total back pressure Pb will change accordingly. By adding a vacuum fan at a certain position of the exhaust pipeline, the pressure in the pipeline at the certain position can be changed.

[0035] When the vacuum fan is running, the impeller accelerates the gas at the inlet of the vacuum fan, thereby forming a certain vacuum negative pressure Pv at the inlet of the vacuum fan, and the Pv changes with the change of the rotating speed n of the fan impeller, as shown in the formula. Figure 3 After the vacuum fan is installed, Pb=P1+P2+P3+…+Pi-Pv at this time, thereby reducing the value of Pb. As can be seen from the calculation formula, if the flue gas flow is constant, P1+P2+P3+…+Pi will be a constant value, and if the value of Pv is changed, the value of Pb will change accordingly. By changing the rotating speed of the vacuum fan, the value of Pv can be changed, the adjustment of Pb is realized, and the back pressure required by the engine 2 for exhaust is achieved.

[0036] In some embodiments of the utility model, the outlet of vacuum fan is connected with horn exhaust 6, the diameter of horn exhaust 6 gradually increases along the air outlet direction. The outlet gas flow rate of horn exhaust 6 reduces, and its outlet resistance reduces, so that the working efficiency of vacuum fan can be improved. The characteristic of vacuum fan is that: under certain working condition, assuming that its flow rate is a fixed value, the pressure difference ΔP=P 出口 -P 进口 of its inlet and outlet is also a constant value, if the outlet pressure P 出口 of vacuum fan is reduced, the pressure P 进口 of its inlet also reduces, that is, the vacuum degree of its inlet further improves, so that the working efficiency of vacuum fan is ensured.

[0037] In some embodiments of the utility model, pressure sensor 11 is arranged in first connecting pipeline 1, pressure sensor 11 is electrically connected with frequency conversion control box 7, and frequency conversion control box 7 is electrically connected with vacuum fan. The total back pressure Pb of flue gas pipeline is measured by pressure sensor 11 installed at the outlet of engine 2 and is converted into an electric signal and sent to frequency conversion control box 7, frequency conversion control box 7 converts the received back pressure electric signal into control data through software and transmits to the motor of vacuum fan, so that the rotating speed of the motor is controlled in frequency conversion, so that the vacuum degree at the inlet of vacuum fan is changed, the exhaust back pressure value Pb at the outlet of engine 2 is always stabilized within the range value specified by the equipment manufacturer, and the excessive vacuum degree generated on the exhaust pipe can be prevented to affect the normal operation of the inlet and exhaust valves of engine 2.

[0038] In some embodiments of the utility model, cleaning device 4 includes first denitration device 41 and second desulfurization device 42, the denitration device is used to reduce the emission of nitrogen oxides (NOx) and improve the environmental protection of engine 2, second connecting pipeline 43 is arranged between first denitration device 41 and second desulfurization device 42, and multiple groups of cleaning devices are arranged in stages to purify exhaust gas and further reduce the emission of nitrogen oxides.

[0039] In some embodiments of the utility model, corrugated expansion joint 44 is arranged in second connecting pipeline 43. During the operation of the exhaust device, the temperature of the discharged gas is usually high, according to the principle of thermal expansion and cold contraction, the pipeline will elongate due to heating. Corrugated expansion joint 44, as a flexible element, can deform axially, transversely or angularly, and absorb the elongation through its elastic deformation, so as to avoid damage of the pipeline due to excessive thermal stress. The corrugated pipe structure inside corrugated expansion joint 44 has a certain elasticity and can effectively buffer and absorb the vibration. It can convert the mechanical vibration in the pipeline system into the elastic deformation energy of the corrugated pipe, so as to reduce the transmission of vibration. At the same time, by changing the propagation medium and propagation path of sound wave, the propagation of noise can also be reduced.

[0040] In some embodiments of the utility model, still be provided with control valve 45 in second connecting pipe, control valve 45 can control the opening and closing of second connecting pipe 43 between first denitration device 41 and second desulfurization device 42 in emergency (such as when vacuum fan fails), make the gas after first denitration device 41 can not pass through second desulfurization device 42, by other path exhaust.

[0041] In some embodiments of the utility model, energy recovery device 3 includes exhaust gas boiler, and exhaust gas usually contains high heat energy.The working principle of exhaust gas boiler is that high-temperature exhaust gas passes through the heating surface of the boiler, and heat is transferred to the water in the boiler, so that the water is converted into steam.The recovered steam can be used to heat fuel oil, domestic water, etc., reducing the demand for additional energy of the ship and reducing operating costs.

[0042] The utility model provides a kind of ship engine 2, including the exhaust back pressure control device of any one of above embodiment of ship engine 2.In the exhaust pipe end of ship engine 2, negative pressure device 5 is arranged, so that the exhaust gas discharged by engine 2 is forcedly discharged after being pressurized, and low pressure is generated at the suction inlet end thereof, forming a certain vacuum degree.The arrangement of negative pressure device 5 can compensate for the local resistance loss of exhaust gas in the exhaust pipeline, so that the exhaust back pressure value at the outlet of engine 2 is within the range specified by the equipment manufacturer, so that multiple required devices, such as exhaust gas cleaning device 4 and energy recovery device 3, can be installed in the exhaust pipeline without affecting the operating performance of engine 2, thereby maximizing user demand, ensuring the economy, applicability and environmental friendliness of the ship, and improving the overall performance of the ship.

[0043] The working process of the utility model is as follows: negative pressure device 5 is arranged at the end of the exhaust pipe of ship engine 2, so that the exhaust gas discharged by engine 2 is forcedly discharged after being pressurized in the pipeline, and low pressure is generated at the suction inlet end thereof, forming a certain vacuum degree.The arrangement of negative pressure device 5 can compensate for the local resistance loss of exhaust gas in the exhaust pipeline, so that the exhaust back pressure value at the outlet of engine 2 is within the range specified by the equipment manufacturer, so that multiple required devices, such as exhaust gas cleaning device 4 and energy recovery device 3, can be installed in the exhaust pipeline without affecting the operating performance of engine 2.

[0044] In summary, the exhaust back pressure control device for ship engine 2 provided by the embodiments of the utility model maximizes user demand, ensures the economy, applicability and environmental friendliness of the ship, and improves the overall performance of the ship.No modification is needed for the pipeline, which reduces the manufacturing and use costs of the exhaust system of engine 2 and greatly improves the practicality of the ship.By using negative pressure device 5, the exhaust back pressure of engine 2 can also be reduced, the fuel combustion efficiency can be improved, the fuel consumption rate can be reduced, and the power capacity can be improved.

[0045] The above are only preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and substitutions can be made, and these improvements and substitutions should also be considered as the protection scope of the present application.

Claims

1. An exhaust back pressure control device for a marine engine, characterized by comprising: The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine.

2. The exhaust back pressure control device of a marine engine according to claim 1, characterized by: The application relates to a back pressure control device for an exhaust of a marine engine.

3. The exhaust back pressure control device of a marine engine according to claim 2, characterized by: The application relates to a back pressure control device for an exhaust of a marine engine.

4. The exhaust back pressure control device of a marine engine according to claim 3, characterized by: The application relates to a back pressure control device for an exhaust of a marine engine.

5. The exhaust back pressure control device of a marine engine according to claim 1, characterized by: The application relates to a back pressure control device for an exhaust of a marine engine.

6. The exhaust back pressure control device of a marine engine according to claim 5, characterized by: The application relates to a back pressure control device for an exhaust of a marine engine.

7. The exhaust back pressure control device of a marine engine according to claim 5, characterized by: The application relates to a back pressure control device for an exhaust of a marine engine.

8. The exhaust back pressure control device of a marine engine according to claim 1, characterized by: The application relates to a back pressure control device for an exhaust of a marine engine.

9. A marine engine, characterized by: The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to a back pressure control device for an exhaust of a marine engine. The application relates to

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