A ship power system with cooling and noise reduction functions

Abstract

The present application relates to the technical field of ship manufacturing. The ship power system with cooling and noise reduction functions comprises a containing tool and a ship power device. The containing tool comprises an external anti-impact frame and an internal cooling and noise reduction function frame. A non-fully-closed containing cavity is formed in the internal anti-impact frame to accommodate the internal cooling and noise reduction function frame. The internal cooling and noise reduction function frame is enclosed by a top plate, a bottom plate, two side plates and two heat dissipation grids. Air inlet structures are arranged on the top plate, the bottom plate and the side plates. The heat dissipation grids are arranged by a plurality of rectifying and noise reducing elements. In the working state, the peripheral cold air enters through the air inlet structures and directly blows against the ship power device. Then, part of the cold air directly flows out through the rectifying and noise reducing elements, and the remaining part directly blows against the rectifying and noise reducing elements, is rectified, and then is blown against the ship power device again after swirling and mixing. At the same time, part of the working noise directly spreads outward through the rectifying and noise reducing elements, and the remaining part is blocked and returns.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, and in particular to a ship propulsion system that combines cooling and noise reduction functions. Background Technology

[0002] According to current industry design standards, power plants (such as steam engines, steam turbines, diesel engines, gasoline engines, and gas turbines) are directly installed on the deck of the ship's watertight compartments. During ship navigation, the power plant generates a large amount of heat energy, which cannot be dissipated in time. Thus, on the one hand, excessive heat is input into the power plant, causing its own temperature to rise sharply, even to the point of overheating, leading to a serious decrease in its working efficiency and poor fuel economy. On the other hand, if the engine is in an overheated or overheated state for a long time, the end mixture in its combustion chamber receives more heat, and the pre-flame reaction process will inevitably be accelerated and intensified, thereby increasing the probability of detonation and ultimately adversely affecting the ship's navigation safety.

[0003] In previous years, a common solution to address the overheating problem of power units was to install a rapid cooling system (imported from abroad) around the power unit. This system utilized accelerated air convection to lower the operating temperature. While this solution effectively solved the overheating problem, the cost of a single unit was around $8,000. Furthermore, in practical applications, the heat exchange medium needed to be added or replaced periodically, and a corresponding heat exchange medium circulation system was required, resulting in a significant workload for maintenance. More importantly, because the rapid cooling system contained a large number of functional components with considerable length and volume, it was difficult to install protective fixtures around it, making the system highly susceptible to damage from external forces.

[0004] To this end, domestic shipbuilders have conducted in-depth research and development. For example, Chinese invention patent CN112339967B, owned by Wuhan Second Ship Design Institute, discloses a ship's outboard cooling system, including: cooling pipes for inboard power equipment, an external heat exchange device, and a seawater flow regulating device. The external heat exchange device includes a first end cap, a second end cap, a heat exchange pipe, and an outer cover. A cooling chamber is formed between the outer cover and the hull. The heat exchange pipe is located inside the cooling chamber. The cooling chamber and the heat exchange pipe are arranged vertically. The seawater flow regulating device uses medium-pressure air to regulate the seawater flow rate. For example, Chinese utility model patent CN205377569U, owned by Chongqing Yongzhong Heavy Industry Co., Ltd., discloses a cooling system for a marine electric motor, including a base. The lower surface of the base is connected to a shock-absorbing support leg, and a bracket is fixedly installed on the upper surface of the base. An evaporator is fixedly installed at the top of the bracket, and a fan bracket is installed above the evaporator. A fan is fixedly installed at the center of the fan bracket and is located above the evaporator pipe. The inlet end of the evaporator is connected to the outlet end of a liquid storage tank through a water pipe. A throttling valve is installed between the evaporator and the liquid storage tank, and a liquid storage tank support leg is installed at the bottom of the liquid storage tank. The inlet end of the liquid storage tank is connected to the outlet end of a compressor through a water pipe, and the inlet end of the compressor is connected to the outlet end of the evaporator through a water pipe. A motor support is fixedly installed on the right side of the compressor, and the compressor is connected to a power unit through a belt. Both of the aforementioned development schemes can theoretically achieve the design objective of continuous cooling of ship propulsion systems, and the overall manufacturing cost is significantly reduced compared to foreign schemes. However, regarding Scheme 1 (CN112339967B), in actual operation, the forced convection heat exchange between the external heat exchange device and seawater improves heat exchange efficiency, thus laying a good foundation for effectively reducing the operating temperature of the propulsion equipment. However, under the condition of a large amount of heat input in a short period of time, seawater is very likely to reach its boiling point and evaporate. The heat exchange tubes are prone to expansion and cracking due to the high-pressure steam, and there is also a risk of explosion. As for Scheme 2 (CN205377569U), it is an improvement on the foreign design scheme, specifically borrowing the principle of air conditioning cooling. Although the overall manufacturing cost is reduced to a certain extent, it still does not solve the problems mentioned above in the text, such as "high unit purchase cost, need for frequent replacement of heat exchange medium, and difficulty in later maintenance" of the foreign technical scheme. In addition, the aforementioned technical solutions one and two still fail to solve the problem mentioned in the previous paragraph, which is that "the cooling system is so large that there are no effective measures to protect it from external impacts."

[0005] It should also be noted that the power unit is directly installed on the deck of the ship's watertight compartment. During the ship's operation, the power unit generates operating noise due to high-frequency vibration, and the insufficient deck thickness further exacerbates this vibration noise. Thus, on the one hand, the deck area supporting the power unit is prone to fatigue due to long-term exposure to high-frequency vibration forces. This not only affects its own structural strength but also frequently leads to cracking of welds in adjacent areas, adversely impacting the sealing performance of the watertight compartment and ultimately affecting the overall structural safety of the ship. On the other hand, it can damage the hearing of crew members working in this environment for extended periods, thus affecting their health. Although there is extensive research in this area both domestically and internationally, and some applications have been achieved, cooling functionality has not been adequately addressed; some technical solutions have even worsened the heat dissipation conditions of the power unit. Therefore, this provides our research group with a new research direction. Summary of the Invention

[0006] Therefore, in view of the aforementioned existing problems and defects, the research group of this invention collected relevant data, conducted multiple evaluations and considerations, and carried out continuous experiments and modifications by the research group members, which ultimately led to the emergence of this ship propulsion system that combines cooling and noise reduction functions.

[0007] To address the aforementioned technical problems, this invention relates to a marine propulsion system with both cooling and noise reduction functions, comprising a housing fixture and a marine propulsion unit. The housing fixture is used to house and securely install the marine propulsion unit, and is entirely housed within a watertight compartment of the ship. The housing fixture includes an external impact-resistant frame and an internal cooling and noise reduction functional frame assembled as a single unit. The external impact-resistant frame, after being welded together, incidentally forms a partially enclosed cavity. The internal cooling and noise reduction functional frame is housed within this partially enclosed cavity and is used to directly mount the marine propulsion unit. The internal cooling and noise reduction functional frame has a hexahedral structure and is enclosed by a top plate, a bottom plate, two side plates, and two heat dissipation grilles. Air intake structures are provided on the top plate, bottom plate, and side plates. The heat dissipation grilles consist of multiple vertically arranged, linearly arrayed flow-rectifying and noise-reducing components. The upper and lower ends of each flow-rectifying and noise-reducing component respectively contact the top plate and bottom plate. In operation, the cold air located outside the built-in cooling and noise reduction functional frame enters through the air intake structure under the action of excitation compression energy and blows directly onto the ship's power unit to perform a cooling operation. Then, part of the cold air that has completed the first cooling operation bypasses the rectifier and noise reduction component and is directly discharged, while the remaining part blows directly toward the rectifier and noise reduction component. After rectification, it swirls and mixes before blowing onto the ship's power unit again to perform a second cooling operation. At the same time, some of the operating noise bypasses the rectifier and noise reduction component and is directly transmitted outward, while the remaining operating noise is deflected due to obstruction.

[0008] As a further improvement to the technical solution disclosed in this invention, the rectifier noise reduction component presents a C-shaped cavity structure, which is sequentially composed of an external arc-shaped plate, a first transition connecting plate, an internal arc-shaped rectifier noise reduction sheet, and a second transition connecting plate. The internal arc-shaped rectifier noise reduction sheet is directly blown by the cold air that has completed one cooling operation, and it is concentrically fitted with the external arc-shaped plate.

[0009] As a further improvement to the technical solution disclosed in this invention, the built-in arc-shaped rectifier noise reduction sheet is cut from a diaphragm material. A series of pressure-reducing holes are formed on the side wall of the external arc-shaped plate, and the thickness of the built-in arc-shaped rectifier noise reduction sheet is controlled between 0.25-0.28 mm. Incidentally, the external arc-shaped plate, the first transition connecting plate, the built-in arc-shaped rectifier noise reduction sheet, and the second transition connecting plate together form a silencing cavity. In operation, the built-in arc-shaped rectifier noise reduction sheet vibrates at high frequency due to the sound waves emitted by the ship's power unit, causing an adaptive change in the volume of the silencing cavity. Simultaneously, the air remaining in the silencing cavity is discharged through the pressure-reducing holes under positive pressure, or external air enters the silencing cavity through the pressure-reducing holes under negative pressure.

[0010] As a further improvement to the technical solution disclosed in this invention, taking the top plate as an example, the air intake structure is composed of multiple irregularly shaped through holes evenly distributed on it. Along the unidirectional flow direction of cold air, its flow cross-sectional area gradually decreases.

[0011] As a further improvement to the technical solution disclosed in this invention, along the unidirectional flow direction of cold air, the irregularly shaped through-hole is sequentially formed by connecting a flared section and a straight section. The flared section is located on the side away from the ship's power plant.

[0012] Of course, as another modified design of the above technical solution, taking the top plate as an example, the air intake structure is composed of multiple unidirectional Tesla guide chambers evenly distributed on it.

[0013] As a further improvement to the technical solution disclosed in this invention, one side wall of the built-in cooling and noise reduction functional frame directly contacts the external anti-collision frame. Assuming the distance between the top plate and the top wall of the external anti-collision frame is *a*, the distance between the bottom plate and the bottom wall of the external anti-collision frame is *b*, and the distance between the side plate and the side wall of the external anti-collision frame is *c*, then *a* ≥ 25cm; *b* ≥ 25cm; *c* ≥ 25cm.

[0014] As a further improvement to the technical solution disclosed in this invention, the accommodating fixture also includes a cold air initial state rectification section for use in conjunction with the air intake structure.

[0015] As a further improvement to the technical solution disclosed in this invention, the initial state rectification section for cold air is composed of a first rectification waveform plate, a second rectification waveform plate, and a third rectification waveform plate. The first rectification waveform plate, the second rectification waveform plate, and the third rectification waveform plate are all fixed on the inner side wall of the external anti-collision frame, and are respectively aligned with the top plate, the bottom plate, and one of the side plates.

[0016] As a further improvement to the technical solution disclosed in this invention, the distance between the crest of the first rectifier waveform plate and the top plate is set to d, the distance between the crest of the second rectifier waveform plate and the bottom plate is set to e, and the distance between the crest of the third rectifier waveform plate and the side plate is set to f. Then, 10cm≤d≤16cm, 10cm≤e≤16cm, and 10cm≤f≤16cm.

[0017] During ship navigation, the ship's propulsion system, housed within a built-in cooling and noise reduction functional frame, inevitably generates a significant amount of heat. Cool air from the outside enters through the intake structure and blows directly onto the propulsion system to complete the initial cooling operation. It is important to note that, due to the synergistic effect of multiple rectification and noise reduction components, some of the cool air after the initial cooling operation swirls and mixes before being blown back to the other side of the propulsion system for a secondary cooling operation. This ensures that the heat generated by the propulsion system is completely and rapidly dissipated, maintaining its operating temperature within a reasonable range and allowing it to perform at its full potential.

[0018] Furthermore, when the ship's power unit is running, some of the operating noise generated is transmitted directly outward by bypassing the rectifier and noise reduction components, while the remaining operating noise is deflected due to the combined obstruction of the top plate, bottom plate, first side plate, second side plate, and multiple rectifier and noise reduction components, resulting in a significant reduction in operating noise.

[0019] Furthermore, the built-in cooling and noise reduction functional frame, which serves as the main support for the ship's power unit, has a relatively compact design structure, facilitating the addition of protective measures around it, namely the external anti-collision frame mentioned in the text. The external anti-collision frame is a one-piece welded steel plate structure with high design strength. This effectively prevents the built-in cooling and noise reduction functional frame from being damaged by external forces or impacts, ensuring its long-term normal operation.

[0020] It should also be noted that after the ship's power unit is officially started, the built-in cooling and noise reduction functional frame is always in a high-frequency excitation state due to the direct action of reciprocating inertial force. This causes the cold air remaining between the built-in cooling and noise reduction functional frame and the external anti-collision frame to be frequently and regularly compressed, thereby ensuring that the air entering the ship's power unit through the air intake structure has a high initial velocity, which is conducive to the rapid dissipation of heat. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a three-dimensional schematic diagram of the first embodiment of the ship propulsion system with both cooling and noise reduction functions in this invention.

[0023] Figure 2 This is a three-dimensional schematic diagram of the accommodating fixture in the first embodiment of the ship propulsion system of the present invention, which has both cooling and noise reduction functions.

[0024] Figure 3 yes Figure 1 The front view.

[0025] Figure 4 This is a three-dimensional schematic diagram of an external anti-collision frame from one perspective in the first embodiment of the marine power system of the present invention, which has both cooling and noise reduction functions.

[0026] Figure 5 This is a three-dimensional schematic diagram of the external anti-collision frame from another perspective in the first embodiment of the marine power system of the present invention, which has both cooling and noise reduction functions.

[0027] Figure 6 This is a three-dimensional schematic diagram from one perspective of the first embodiment of the ship propulsion system with both cooling and noise reduction functions of the present invention.

[0028] Figure 7 This is a three-dimensional schematic diagram from another perspective of the built-in cooling and noise reduction function frame in the first embodiment of the ship propulsion system of the present invention, which has both cooling and noise reduction functions.

[0029] Figure 8 This is a three-dimensional schematic diagram of the rectifier and noise reduction component from one perspective in the first embodiment of the ship propulsion system of the present invention, which has both cooling and noise reduction functions.

[0030] Figure 9 This is a three-dimensional schematic diagram of the rectifier and noise reduction component from another perspective in the first embodiment of the ship propulsion system of the present invention, which has both cooling and noise reduction functions.

[0031] Figure 10 This is a three-dimensional schematic diagram of the second embodiment of the ship propulsion system with both cooling and noise reduction functions in this invention.

[0032] Figure 11This is a three-dimensional schematic diagram of the built-in cooling and noise reduction function frame in the second embodiment of the ship propulsion system of the present invention, which has both cooling and noise reduction functions.

[0033] Figure 12 This is a schematic diagram of the unidirectional Tesla guide cavity in the second embodiment of the ship propulsion system of the present invention, which has both cooling and noise reduction functions (i.e., a partial cross-sectional view of the air intake structure area on the top plate, bottom plate or side plate).

[0034] Figure 13 This is a schematic diagram of the third embodiment of the ship propulsion system with both cooling and noise reduction functions in this invention.

[0035] 1-Housing fixture; 11-External anti-collision frame; 111-Steel plate; 12-Built-in cooling and noise reduction functional frame; 121-Top plate; 1211-Intake structure; 12111-Irregular through hole; 12112-One-way Tesla guide cavity; 122-Bottom plate; 123-First side plate; 124-Second side plate; 125-First heat bar; 1251-Rectification and noise reduction component; 12511-External arc plate; 125111-Pressure relief hole; 12512-First transition connecting plate; 12513-Built-in arc-shaped rectification and noise reduction sheet; 12514-Second transition connecting plate; 126-Second heat bar; 13-Cold air initial state rectification part; 131-First rectification waveform plate; 132-Second rectification waveform plate; 133-Third rectification waveform plate; 2-Diesel engine. Detailed Implementation

[0036] In the description of this invention, it should be understood that the terms "front", "rear", "up", "down", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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 invention.

[0037] The present invention will be further described in detail below with reference to specific embodiments. Figure 1 This diagram illustrates a first-dimensional representation of a marine propulsion system with both cooling and noise reduction functions, as described in this invention. The system includes a housing 1 and a diesel engine 2. The housing 1 is entirely housed within a watertight compartment of the ship. The diesel engine 2 is housed and carried by the housing 1, and each working cycle consists of four strokes: intake, compression, power, and exhaust, converting fuel energy into mechanical energy to drive the ship's propulsion system.

[0038] Figure 2 , Figure 3The diagrams show a perspective view and a front view of the housing fixture in the first embodiment of the ship propulsion system of the present invention, which combines cooling and noise reduction functions. It can be seen that the housing fixture 1 mainly consists of an external anti-collision frame 11 and an internal cooling and noise reduction functional frame 12, etc. The external anti-collision frame 11 is preferably a cuboid structure, and is welded from multiple steel plates with a thickness of not less than 5mm. After forming, it incidentally forms a non-fully enclosed accommodating cavity (e.g., ...). Figure 4 , 5 (As shown in the diagram). The built-in cooling and noise reduction functional frame 12, which is designed to be directly installed into the diesel engine 2, is built into this non-fully enclosed receiving cavity. Figure 6 , 7 As shown, the built-in cooling and noise reduction functional frame 12 has a hexahedral structure to match the shape of the pre-installed diesel engine 2. The built-in cooling and noise reduction functional frame 12 is formed by a top plate 121, a bottom plate 122, a first side plate 123, a second side plate 124, a first heat dissipation grille 125, and a second heat dissipation grille 126. Among them, the second side plate 124 directly contacts the inner wall of the external anti-collision frame 11. Assuming that the distance between the top plate 121 and the top wall of the external anti-collision frame 11 is a, the distance between the bottom plate 122 and the bottom wall of the external anti-collision frame 11 is b, and the distance between the first side plate 123 and the side wall of the external anti-collision frame 11 is c, then it is advisable that a ≥ 25cm; b ≥ 25cm; c ≥ 25cm. The top plate 121, bottom plate 122, first side plate 123, and second side plate 124 have the same design structure. Taking the top plate 121 as an example, it is provided with an air intake structure 1211. Furthermore, the air intake structure 1211 is preferably composed of a plurality of irregularly shaped through holes 12111 evenly distributed on the top plate 121. Moreover, by Figure 6 , 7 As can be clearly seen from the diagram, the first heat dissipation grille 125 and the second heat dissipation grille 126 also adopt the same design structure. Taking the first heat dissipation grille 125 as an example, it is composed of multiple vertically arranged and linearly arrayed rectifiers and noise reduction components 1251. The upper and lower ends of the rectifiers and noise reduction components 1251 respectively contact the top plate 121 and the bottom plate 122. In operation, the cold air located outside the built-in cooling and noise reduction functional frame 12 enters through the irregular through holes 12111 under the action of excitation compression energy and blows directly into the diesel engine 2 to perform a cooling operation. Then, part of the cold air that has completed the first cooling operation bypasses the rectifier noise reduction component 1251 and is directly discharged, while the remaining part blows directly into the rectifier noise reduction component 1251. After rectification, it swirls and mixes before being blown to the other side of the diesel engine 2 to perform a second cooling operation. At the same time, part of the operating noise bypasses the rectifier noise reduction component 1251 and is directly transmitted to the outside, while the remaining operating noise is deflected due to obstruction, and the operating noise is significantly reduced.

[0039] During ship navigation, the diesel engine 2, housed within the built-in cooling and noise reduction functional frame 12, inevitably generates a large amount of heat. External cold air enters through the various irregularly shaped through-holes 12111 and blows directly onto the diesel engine 2 to complete the first cooling operation. Due to the synergistic effect of multiple rectifiers and noise reduction components 1251, some of the cold air after the first cooling operation swirls and mixes before being blown back to the other side of the diesel engine 2 for a second cooling operation. This ensures that the working heat of the diesel engine 2 is completely and rapidly dissipated, maintaining its operating temperature within a reasonable range and allowing its performance to be fully realized. Furthermore, when the diesel engine 2 is running, some of its operating noise is transmitted directly outwards by bypassing the rectifiers and noise reduction components 1251, while the remaining operating noise is deflected by the combined obstruction of the top plate 121, a bottom plate 122, a first side plate 123, a second side plate 124, and multiple rectifiers and noise reduction components 1251, resulting in a significant reduction in operating noise.

[0040] According to the actual experimental results, the temperature reduction effect of the secondary cooling operation is slightly worse than that of the primary cooling operation. The reason is that during the initial blowing stage of the diesel engine 2, the cold air entering through the various irregular through holes 12111 has a low temperature value and a large temperature gradient compared with the surface temperature of the diesel engine 2. However, during the primary cooling operation, the cold air is heated and its temperature rises. Although it is still much lower than the surface temperature of the diesel engine 2 at this time, the temperature gradient is reduced, and the heat exchange efficiency will inevitably be affected.

[0041] Combined with appendix Figure 6 , 7 As shown, from an overall shape perspective, the built-in cooling and noise reduction functional frame 12 has a relatively compact design structure, which facilitates the addition of protective measures around it, namely the external anti-collision frame 11 mentioned in the text. The external anti-collision frame 11 is a one-piece welded steel plate structure with high design strength, thus effectively preventing the built-in cooling and noise reduction functional frame 12 from being damaged by external forces or impacts, ensuring its performance can be maintained normally for a long time.

[0042] After the diesel engine 2 is officially started, the built-in cooling and noise reduction functional frame 12 is always in a high-frequency excitation state due to the direct action of reciprocating inertial force. As a result, the gap values ​​formed by the built-in cooling and noise reduction functional frame 12 and the external anti-collision frame 11 in all directions undergo regular slight changes. This causes the cold air remaining between the built-in cooling and noise reduction functional frame and the external anti-collision frame to be frequently and regularly compressed, thereby ensuring that the air entering the diesel engine 2 through the intake structure has a high initial velocity, which is conducive to the rapid dissipation of heat.

[0043] Here, it is also important to note that because the diesel engine 2 is directly fixed to the built-in cooling and noise reduction functional frame 12, and the built-in cooling and noise reduction functional frame 12 is indirectly fixed to the ship deck through the external anti-collision frame 11, the excitation energy will not be directly transmitted to the ship deck even when the diesel engine 2 is running, and its energy is also greatly attenuated, thereby effectively avoiding the occurrence of cracking of the adjacent area weld due to long-term fatigue.

[0044] To enable it to also have cooling and noise reduction functions, specific structural limitations need to be defined for the rectifier noise reduction component 1251. For example... Figure 8 , 9 As shown, the rectifier noise reduction component 1251 has a C-shaped cavity structure, and it is sequentially connected by an external arc-shaped plate 12511, a first transition connecting plate 12512, an internal arc-shaped rectifier noise reduction plate 12513, and a second transition connecting plate 12514. The internal arc-shaped rectifier noise reduction plate 12513 is concentrically fitted with the external arc-shaped plate 12511. When the internal arc-shaped rectifier noise reduction plate 12513 is directly blown, due to its arc-shaped design, the cold air that has completed the first cooling operation is swirled and mixed, and then blown back to the diesel engine 2 to perform a second cooling operation. Furthermore, some of the operating noise is deflected due to the obstruction of the external arc-shaped plate 12511, ensuring that the overall operating noise is significantly reduced.

[0045] Furthermore, to further enhance the noise reduction effect of the built-in cooling and noise reduction functional frame 12, as a further optimization of the structure of the rectifier noise reduction component 1251, the built-in arc-shaped rectifier noise reduction sheet 12513 is preferably cut from a diaphragm material (the diaphragm material is preferably a titanium alloy composite film or glass film with a thickness not exceeding 0.3mm). A series of pressure-reducing holes 125111 are provided on the side wall of the external arc-shaped plate 12511, and the thickness of the built-in arc-shaped rectifier noise reduction sheet 12513 is controlled between 0.25-0.28mm. Incidentally, the external arc-shaped plate 12511, the first transition connecting plate 12512, the built-in arc-shaped rectifier noise reduction sheet 12513, and the second transition connecting plate 12514 together form a sound-absorbing cavity. In operation, the built-in arc-shaped rectifier noise reduction plate 12513 is excited at high frequency by the sound waves emitted by the diesel engine 2, causing an adaptive change in the volume of the muffler cavity. Simultaneously, the air remaining in the muffler cavity is discharged through the pressure relief hole 125111 under positive pressure, or external air enters the muffler cavity through the pressure relief hole 125111 under negative pressure. Thus, during the process of some of the sound waves generated by the diesel engine 2 being reflected back by the built-in arc-shaped rectifier noise reduction plate 12513, a portion of the sound waves can be synchronously converted into the mechanical vibration energy of the built-in arc-shaped rectifier noise reduction plate 12513. Due to the precise thickness limitation, it is difficult to generate excitation noise during high-frequency vibration, and its fixed frequency range means it is confined to a specific range, making resonance unlikely. Furthermore, the weakened sound waves can re-enter the muffler cavity for further noise reduction. The sound waves undergo multiple reflections within the muffler cavity, ensuring that the vast majority of sound wave energy is annihilated.

[0046] To further increase the initial velocity of the cold air blowing towards the diesel engine 2, the cross-sectional area of ​​the irregularly shaped through-hole 12111 gradually decreases along the unidirectional flow direction of the cold air. More specifically, along the unidirectional flow direction of the cold air, the irregularly shaped through-hole 12111 is formed by sequentially connecting a flared section and a straight section. The flared section is located on the side away from the diesel engine 2. In this way, when the peripheral cold air passes through the irregularly shaped through-hole 12111, it first flows through the flared section and then enters the straight section. During this process, the cold air is rapidly accelerated under the effect of the "neck-in effect".

[0047] Figure 10 A perspective view of a second embodiment of the marine propulsion system with both cooling and noise reduction functions in this invention is shown. It can be seen that the difference between this embodiment and the first embodiment is that the air intake structure 1211 has a completely different design structure. For example... Figure 11As shown, the top plate 121, bottom plate 122, first side plate 123, and second side plate 124 have the same design structure. Taking the top plate 121 as an example, its upper air intake structure 1211 is composed of multiple unidirectional Tesla guide chambers 12112 evenly distributed on it. Thus, while ensuring that cold air can directly blow onto the diesel engine 2, the cold air maintains a unidirectional irreversible flow state. More importantly, during the forward flow of the cold air, it is expanded and then compressed, and under the action of the pressure difference, the cold air is instantaneously accelerated, thereby significantly enhancing the blowing intensity onto the diesel engine 2 (e.g., Figure 12 (as shown in the image).

[0048] Figure 13 A schematic diagram of a third embodiment of the ship propulsion system with both cooling and noise reduction functions of the present invention is shown. It can be seen that the difference between this embodiment and the first and second embodiments is that the accommodating fixture 1 is further equipped with a cold air initial-state rectification section 13 for use in conjunction with the air intake structure 1211. The cold air initial-state rectification section 13 is composed of a first rectification waveform plate 131, a second rectification waveform plate 132, and a third rectification waveform plate 133. The first rectification waveform plate 131, the second rectification waveform plate 132, and the third rectification waveform plate 133 are all detachably fixed to the inner wall of the external anti-collision frame 11, and are respectively aligned with the top plate 121, the bottom plate 122, and the first side plate 123. Thus, in practical applications, the external cold air first enters the assembly gap formed by the external anti-collision frame 11 and the built-in cooling and noise reduction functional frame 12, and then enters through the irregular through holes 12111 to directly blow onto the diesel engine 2 to perform a cooling operation. Due to the addition of the cold air initial state rectification section 13, the flow speed of the cold air in the assembly gap can be effectively accelerated. The reason for this is that, taking the first rectification waveform plate 131 as an example, when the cold air enters the assembly gap, it flows along the inner sidewall of the first rectification waveform plate 131. Due to the guiding effect of the waveform arc surface, the cold air rises and falls, and depending on its relative position (the peaks and troughs alternate), expansion and compression occur alternately, which causes the cold air to be accelerated under the action of pressure difference, ensuring that the cold air has a higher initial velocity before entering the irregular through holes 12111.

[0049] like Figure 13As shown, the distance between the crest of the first rectifier waveform plate 131 and the top plate 121 is set to d, the distance between the crest of the second rectifier waveform plate 132 and the bottom plate 122 is set to e, and the distance between the crest of the third rectifier waveform plate 133 and the first side plate 123 is set to f. After extensive experimental data verification, when the conditions 10cm≤d≤16cm, 10cm≤e≤16cm, and 10cm≤f≤16cm are met, cold air can achieve the optimal acceleration effect, and it is easy to assemble and operate smoothly and efficiently.

[0050] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A marine propulsion system with both cooling and noise reduction functions, comprising a housing fixture and a marine propulsion unit; the housing fixture is used to house and fix the marine propulsion unit, and is entirely placed within a watertight compartment of the ship, characterized in that, The accommodating fixture includes an external impact-resistant frame and an internal cooling and noise reduction functional frame assembled as a single unit. The external impact-resistant frame, after being welded together, incidentally forms a non-fully enclosed accommodating cavity. The internal cooling and noise reduction functional frame is housed within this non-fully enclosed accommodating cavity and is used to directly mount the ship's propulsion system. The internal cooling and noise reduction functional frame has a hexahedral structure and is enclosed by a top plate, a bottom plate, two side plates, and two heat dissipation grilles. Air intake structures are provided on the top plate, the bottom plate, and the side plates. The heat dissipation grilles are composed of multiple vertically arranged, linearly arrayed rectifier and noise reduction components. The upper and lower ends of each rectifier and noise reduction component are respectively... The air intake is connected to the top plate and the bottom plate in a corresponding manner. In the working state, the cold air located outside the built-in cooling and noise reduction functional frame enters through the air intake structure under the action of excitation compression energy and blows directly onto the ship power unit to perform a cooling operation. Then, part of the cold air after completing the first cooling operation bypasses the rectifier and noise reduction component and is directly discharged, while the remaining part blows directly onto the rectifier and noise reduction component. After rectification, it swirls and mixes before blowing onto the ship power unit again to perform a second cooling operation. At the same time, part of the working noise bypasses the rectifier and noise reduction component and is directly transmitted outward, while the remaining part of the working noise is deflected due to obstruction. The rectification and noise reduction component presents a C-shaped cavity structure, and it is sequentially connected by an external arc plate, a first transition connecting plate, an internal arc-shaped rectification and noise reduction sheet, and a second transition connecting plate; the internal arc-shaped rectification and noise reduction sheet is directly blown by the cold air that has completed one cooling operation, and it is concentrically fitted with the external arc plate. The built-in arc-shaped rectifier noise reduction sheet is cut from a sound diaphragm material; and a series of pressure-reducing holes are opened on the side wall of the external arc-shaped plate, and the thickness of the built-in arc-shaped rectifier noise reduction sheet is controlled at 0.25-0.28mm; incidentally, the external arc-shaped plate, the first transition connecting plate, the built-in arc-shaped rectifier noise reduction sheet and the second transition connecting plate together form a sound-absorbing cavity; in the working state, the built-in arc-shaped rectifier noise reduction sheet is excited at high frequency by the sound waves emitted by the ship's power unit, and the spatial volume of the sound-absorbing cavity changes adaptively. At the same time, the air remaining in the sound-absorbing cavity can be discharged through the pressure-reducing holes under the action of positive pressure, or the external air can enter the sound-absorbing cavity through the pressure-reducing holes under the action of negative pressure.

2. The marine propulsion system with both cooling and noise reduction functions according to claim 1, characterized in that, The air intake structure consists of multiple irregularly shaped through holes evenly distributed on it; along the unidirectional flow direction of cold air, its flow cross-sectional area gradually decreases.

3. The marine propulsion system with both cooling and noise reduction functions according to claim 2, characterized in that, Along the unidirectional flow direction of cold air, the irregularly shaped through hole is formed by connecting a flared section and a straight section in sequence; the flared section is located on the side away from the ship's power unit.

4. The marine propulsion system with both cooling and noise reduction functions according to claim 1, characterized in that, The air intake structure consists of multiple unidirectional Tesla flow chambers evenly distributed thereon.

5. The marine propulsion system with both cooling and noise reduction functions according to claim 1, characterized in that, One side wall of the built-in cooling and noise reduction functional frame directly contacts the external anti-collision frame; assuming the distance between the top plate and the top wall of the external anti-collision frame is a, the distance between the bottom plate and the bottom wall of the external anti-collision frame is b, and the distance between the side plate and the side wall of the external anti-collision frame is c, then a≥25cm; b≥25cm; c≥25cm.

6. The marine propulsion system with both cooling and noise reduction functions according to claim 5, characterized in that, The accommodating fixture also includes a cold air initial state rectification section for use in conjunction with the air intake structure.

7. The marine propulsion system with both cooling and noise reduction functions according to claim 6, characterized in that, The initial rectifier of the cold air is composed of a first rectifier waveform plate, a second rectifier waveform plate, and a third rectifier waveform plate; wherein the first rectifier waveform plate, the second rectifier waveform plate, and the third rectifier waveform plate are all fixed on the inner side wall of the external anti-collision frame, and are respectively aligned with the top plate, the bottom plate, and one of the side plates.

8. The marine propulsion system with both cooling and noise reduction functions according to claim 7, characterized in that, The distance between the peak of the first rectifier waveform board and the top plate is set as d, the distance between the peak of the second rectifier waveform board and the bottom plate is set as e, and the distance between the peak of the third rectifier waveform board and the side plate is set as f. Then 10cm≤d≤16cm, 10cm≤e≤16cm, and 10cm≤f≤16cm.

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