Ventilation connecting structure and system for large pipeline of ship ammonia fuel engine

Abstract

The invention discloses a ventilation connecting structure and system for a large pipeline of a ship ammonia fuel engine, and belongs to the technical field of ships, the ventilation connecting structure comprises a first ventilation flange and a second ventilation flange which are connected in a paired mode, and an inner ring sealing structure is arranged at the contact position of the first ventilation flange and the second ventilation flange; an outer ring sealing structure is arranged outside the inner ring sealing structure, an annular discharging groove is formed between the inner ring sealing structure and the outer ring sealing structure, and a ventilation outlet and a cleaning opening are formed in the outer portion of the first ventilation flange and communicate with the annular discharging groove. The ventilation structure of paired installation flanges is simplified, the layout of a ventilation system is optimized, the manufacturing cost is low, and installation is convenient; the required negative pressure ventilation air quantity is small, the type selection capacity and size of each related device and accessory are small, and the initial investment cost, the later maintenance cost and the operation cost are low; ventilation air is distributed in a centralized mode, and through switching of on-off states of the ventilation stop valves, which group of flange connection in the system leaks can be distinguished and confirmed conveniently.

Description

Technical Field

[0001] The present invention relates to the technical field of ships, and in particular to a ventilation connection structure and system for large pipelines of ammonia fuel engines of ships. Background Art

[0002] In ship ammonia fuel engine systems, low-flashpoint fuels (such as ammonia and methanol) are flammable, explosive, or toxic, so leak-proof designs are usually adopted in their supply and exhaust systems and other locations prone to leakage. The most common leak-proof design on ships is double-wall piping combined with negative pressure ventilation.

[0003] Double-wall piping is to add another layer of piping outside the single-layer piping, forming an annular space between the inner and outer pipes. To ensure the connectivity of the annular space, it is necessary to add several corresponding connecting holes between the two matching flanges. The size and number of the connecting holes are calculated based on the connection strength and ventilation flow requirements. Dry negative pressure air is introduced into the annular space. The pressure of the negative pressure air is jointly adjusted by the ventilation air supply, induced draft fan, pressure regulating valve and throttling orifice plate. The required ventilation volume is generally 30 to 40 times the volume of the annular space per hour. Leakage from the inner pipe will not continue to leak outside the outer wall pipe under the action of negative pressure ventilation. A leak detector is installed at the end of the negative pressure ventilation pipeline to detect leaks. However, this technology has the following significant defects: First, the application of large pipelines is limited. Large pipelines (DN500 and above), such as ammonia-fueled engine exhaust pipes, face significant challenges with double-wall pipe designs due to their large size, high temperatures (550°C), and high pressures (PN10). Double-wall pipe designs face significant material cost increases, complex manufacturing processes, and installation difficulties. The large annular space required for a double-wall structure requires high-flow ventilation equipment (such as high-power induced draft fans and air storage tanks), resulting in extremely high initial investment and operational costs. Second, ventilation efficiency is low and energy consumption is high. Existing technology requires that the annular space of double-walled pipes be ventilated at a rate of 30-40 times its volume per hour. Large pipes require ultra-large capacity ventilation systems, which consume a significant proportion of the ship's power system. Furthermore, the equipment takes up a large space, making it difficult to adapt to the compact layout of ships. Third, leak location is unclear. The annular spaces of all flanges in double-wall pipes are interconnected. When a leak occurs, the end detector can only alarm but cannot identify the specific leaking flange location. This requires checking each flange one by one or adding multiple sets of detectors, increasing system complexity and maintenance costs. Fourth, maintenance operations are cumbersome. The double-wall pipe structure is closed, and the flange needs to be disassembled to clean the annular space. The operation is time-consuming and can easily damage the sealing. After long-term use, problems such as salt spray corrosion and carbon deposition increase the difficulty of maintenance. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a ventilation connection structure and system for large pipelines of marine ammonia fuel engines, which simplifies the ventilation structure of the paired mounting flanges, optimizes the layout of the ventilation system, does not require a double-wall piping design, and has a compact and flexible ventilation structure design, low manufacturing cost, and easy installation; the required amount of negative pressure ventilation air is small, so the capacity and size of the selected related equipment and accessories are small, and the initial investment cost and subsequent maintenance and operating costs are low; the ventilation air is centrally arranged, and by switching the on / off state of the ventilation shut-off valve, it is convenient to identify and confirm which group of flange connections in the system is leaking.

[0005] The technical solutions of the present invention are as follows: In a first aspect of the present invention, a ventilation connection structure for a large pipeline of a ship ammonia fuel engine is provided, comprising a first ventilation flange and a second ventilation flange arranged in a matching connection, an inner ring sealing structure is provided at the position where the first ventilation flange contacts the second ventilation flange, an outer ring sealing structure is provided on the outside of the inner ring sealing structure, an annular discharge groove is provided between the inner ring sealing structure and the outer ring sealing structure, a ventilation outlet and a cleaning port are provided on the outside of the first ventilation flange, both of which are connected to the annular discharge groove. In some embodiments of the present invention, the first ventilation flange and the second ventilation flange are connected in pairs by a plurality of bolts. In some embodiments of the present invention, the inner ring sealing structure includes an inner ring sealing groove provided on the first ventilation flange, and an inner ring sealing ring is provided in the inner ring sealing groove; The outer ring sealing structure comprises an outer ring sealing groove which is arranged at a certain distance outside the inner ring sealing groove, and an outer ring sealing ring is arranged in the outer ring sealing groove. In some embodiments of the present invention, the ventilation outlet is provided on the outer arc-shaped side wall of the first ventilation flange and is connected to the annular discharge groove at the annular end surface of the first ventilation flange.

[0006] In some embodiments of the present invention, the ventilation outlet is provided on the outer arcuate side wall of the first ventilation flange and communicates with the annular discharge groove, or is provided at the annular end surface of the first ventilation flange and communicates with the annular discharge groove.

[0007] In some embodiments of the present invention, the cleaning port is provided on the outer arc-shaped side wall of the first ventilation flange and is connected to the annular discharge groove at the annular end surface of the first ventilation flange.

[0008] In some embodiments of the present invention, the cleaning port is provided on the outer arcuate side wall of the first ventilation flange and communicates with the annular discharge groove, or is provided at the annular end surface of the first ventilation flange and communicates with the annular discharge groove.

[0009] In a second aspect of the present invention, a large-scale pipeline ventilation system for a ship ammonia fuel engine is provided, comprising any one of the above-mentioned large-scale pipeline ventilation connection structures for a ship ammonia fuel engine.

[0010] In some embodiments of the present invention, several ventilation ducts are included, one end of the several ventilation ducts are respectively connected to a plurality of ventilation outlets, the other ends of the several ventilation ducts are respectively connected to a plurality of ventilation shut-off valves, the plurality of ventilation shut-off valves are connected to an air collecting mechanism, the air collecting mechanism is also connected to a ventilation air supply unit and an air induced draft unit, and a leakage detector is provided on the pipeline connecting the air collecting mechanism and the air induced draft unit. In some embodiments of the present invention, the ventilation air supply unit is used to provide dry air with appropriate pressure flow to the ventilation system; the air induction unit is used to adjust the ventilation pressure of the ventilation system; and the leakage detector is used to detect leakage of target gas components in the ventilation air.

[0011] One or more technical solutions of the present invention have the following beneficial effects: The ventilation connection structure and system for large pipelines of marine ammonia fuel engines provided by the present invention simplify the pipeline structure and reduce costs. It abandons the double-wall pipe structure and adopts a single-layer pipe combined with a flange double sealing ring structure, that is, the inner ring seal cooperates with the outer ring seal to ensure the sealing effect, thereby improving installation efficiency.

[0012] The present invention utilizes the discharge trough for centralized ventilation and directly extracts leaked fuel through the flanged annular discharge trough, eliminating the need to maintain a large annular space. This greatly reduces ventilation volume compared to traditional solutions, miniaturizes the selection of supporting equipment (blowers, storage tanks), and further saves costs.

[0013] The present invention can achieve precise leak positioning and rapid response. Through segmented control of the ventilation shut-off valve, each flange connection is independently equipped with a ventilation shut-off valve. When a leak occurs, the specific leaking flange can be located in a short time by switching the valve on and off, without the need for additional detectors. A centralized gas collection mechanism is adopted, and the leaked fuel is collected to the gas collection mechanism through the discharge trough, and combined with a high-sensitivity detector (such as an ammonia sensor), the detection response time is effectively shortened.

[0014] The present invention facilitates efficient maintenance by operators and extends service life. It has a disassembly-free cleaning function. The discharge groove supports the injection of compressed air or cleaning agent. Carbon deposits and salt spray deposition can be removed without disassembling the flange, effectively extending the maintenance cycle. The flange sealing ring is made of suitable materials such as composite fiber, graphite packing, etc., which has the characteristics of high temperature and high pressure resistance and is suitable for the extreme working conditions of ship ammonia fuel engines.

[0015] The present invention effectively reduces ventilation energy consumption, improves the overall energy efficiency of ships, and achieves energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of a large-scale pipeline ventilation system for a marine ammonia fuel engine provided in Example 1 of the present invention; Figure 2 Provided in Example 1 of the present invention Figure 1 A partially enlarged schematic diagram of a ventilation connection structure for large pipelines of a ship's ammonia fuel engine at points A and B.

[0017] In the figure: 1. Ventilation connection structure; 101. First ventilation flange; 102. Second ventilation flange; 103. Outer ring sealing ring; 104. Inner ring sealing ring; 105. Annular discharge groove; 106. Ventilation outlet; 107. Cleaning port; 2. Ventilation pipeline; 3. Ventilation shut-off valve; 4. Air collecting mechanism; 5. Ventilation air supply unit; 6. Leakage detector; 7. Air induced draft unit. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Example 1 In a typical embodiment of the present invention, a ventilation connection structure 1 for a large pipeline of a ship ammonia fuel engine is proposed, comprising a first ventilation flange 101 and a second ventilation flange 102 that are arranged in a matching connection, an inner ring sealing structure is provided at the contact position between the first ventilation flange 101 and the second ventilation flange 102, an outer ring sealing structure is provided on the outside of the inner ring sealing structure, an annular discharge groove is provided between the inner ring sealing structure and the outer ring sealing structure, a ventilation outlet 106 and a cleaning port 107 are provided on the outside of the first ventilation flange 101, both of which are connected to the annular discharge groove. Such an arrangement realizes double sealing safety protection and integrated leakage management in large pipelines, greatly improving the practicality of the ventilation connection structure 1, wherein the inner ring sealing structure serves as the main sealing barrier, directly blocking the leakage of ammonia fuel from the inside of the pipeline, and the outer ring sealing structure serves as a secondary sealing line of defense, intercepting trace leakage that breaks through the inner ring, forming a double insurance mechanism, and the annular discharge groove is located between the double sealing rings, becoming a temporary collection chamber for the leaked fuel, preventing the leakage from spreading to the external environment, and the ventilation outlet 106 is directly connected to the discharge groove, and the leaked gas is actively extracted by negative pressure suction to avoid accumulation in the sealed chamber.

[0020] The above-mentioned arrangement simplifies the ventilation structure of the paired mounting flanges, abandons the double-wall pipe design, and greatly reduces the manufacturing cost and space occupancy by using a single-layer pipe plus flange double-seal structure. Among them, the ventilation volume is reduced from 30-40 times the annular space volume per hour to only needing to deal with trace leakage, which greatly reduces the fan power and tank volume, and reduces the space occupied by the ship's engine room.

[0021] The ventilation structure is compact and flexible in design, with low manufacturing cost and easy installation. While ensuring the effect of preventing gas leakage, the required negative pressure ventilation air volume is small. Therefore, the capacity and size of the relevant equipment and accessories are small, and the initial investment cost and subsequent maintenance and operation costs are low.

[0022] In addition, the cleaning port 107 supports the injection of compressed air or cleaning agent, realizing disassembly-free maintenance and solving the problems of salt spray corrosion and carbon deposition.

[0023] In some embodiments of the present invention, the first ventilation flange 101 and the second ventilation flange 102 are connected by a plurality of bolts. This arrangement, through standardized bolt connections, ensures the tightness and uniformity of the flange installation, adapting to the high temperature (550°C) and high pressure (PN10) operating conditions of large pipelines (DN500 and above), and preventing seal failure due to thermal deformation. In some embodiments of the present invention, the inner ring sealing structure includes an inner ring sealing groove provided on the first ventilation flange 101 , and an inner ring sealing ring 104 is provided in the inner ring sealing groove; The outer ring sealing structure includes an outer ring sealing groove arranged at a certain distance outside the inner ring sealing groove, and an outer ring sealing ring 103 is arranged in the outer ring sealing groove.

[0024] With this arrangement, through modular sealing design, the inner and outer ring sealing rings 103 are respectively embedded in independent sealing grooves, which facilitates the replacement of damaged parts and reduces maintenance costs; and improves the safety redundancy of the pipeline. The double sealing rings are arranged at intervals. Even if the inner ring fails, the outer ring can still maintain a short-term seal, buying time for system shutdown. The two have synergistic advantages, forming a double insurance mechanism to prevent gas leakage while becoming a temporary collection chamber for leaked fuel with the annular discharge groove 105, preventing the leakage from spreading to the external environment. In addition, the processing accuracy of the sealing groove ensures that the sealing ring is evenly stressed and adapts to the vibration environment of the ship engine. In some embodiments of the present invention, the ventilation outlet 106 is provided on the outer arc-shaped side wall of the first ventilation flange 101 and is connected to the annular discharge groove at the annular end surface of the first ventilation flange 101 .

[0025] In some embodiments of the present invention, the ventilation outlet 106 is provided on the outer arcuate side wall of the first ventilation flange 101 and communicates with the annular discharge groove, or is provided at the annular end surface of the first ventilation flange 101 and communicates with the annular discharge groove.

[0026] In this embodiment, the ventilation outlet 106 provided on the outer curved sidewall of the first ventilation flange 101 is vertically connected to the side of the annular discharge groove 105. The ventilation outlet 106 provided on the annular end surface of the first ventilation flange 101 is parallelly connected to one end of the annular discharge groove. It is understood that the connection between the ventilation outlet 106 and the annular discharge groove 105 can be reasonably arranged according to actual conditions, namely, based on the flange size, flange thickness, and space available, to improve the practicality of the device.

[0027] Through the above-mentioned arrangement, the ventilation outlet 106 is vertically connected to the side wall of the annular discharge groove 105, which is suitable for scenarios with limited space on board and shortens the fluid path. The ventilation outlet 106 is parallelly connected to the end face of the annular discharge groove 105, which facilitates integration into the pipe end face and simplifies the external pipeline layout. The directional design of the ventilation outlet 106 can improve the negative pressure suction efficiency.

[0028] In some embodiments of the present invention, the cleaning port 107 is provided on the outer arc-shaped side wall of the first ventilation flange 101 and is connected to the annular discharge groove at the annular end surface of the first ventilation flange 101 .

[0029] In some embodiments of the present invention, the cleaning port 107 is provided on the outer arcuate side wall of the first ventilation flange 101 and communicates with the annular discharge groove, or is provided at the annular end surface of the first ventilation flange 101 and communicates with the annular discharge groove. In this embodiment, a cleaning port 107 provided on the outer curved sidewall of the first ventilation flange 101 is vertically connected to the side of the annular discharge groove 105. A cleaning port 107 provided on the annular end surface of the first ventilation flange 101 is parallelly connected to one end of the annular discharge groove. It will be appreciated that the connection between the cleaning port 107 and the annular discharge groove 105 can be appropriately arranged based on actual conditions, namely, flange size, flange thickness, and space availability, to improve the practicality of the device.

[0030] Through the above-mentioned arrangement, the vertical connection between the cleaning port 107 and the side wall of the annular discharge groove 105 is suitable for scenarios with limited space on board, shortening the fluid path, and the parallel connection between the cleaning port 107 and the end face of the annular discharge groove 105 facilitates integration into the pipe end face, simplifying the external pipeline layout, and the flexible position setting of the cleaning port 107 supports the injection of cleaning agents at different angles to remove sediments in the discharge groove, thereby solving the technical pain point of difficult cleaning of the annular space of the double-wall pipe and extending the service life of the ventilation structure.

[0031] In a second aspect, the present invention provides a large-scale pipeline ventilation system for marine ammonia-fueled engines, comprising any of the aforementioned large-scale pipeline ventilation connection structures 1 for marine ammonia-fueled engines. By utilizing the ventilation connection structure 1 as the core unit of the ventilation system, each pipeline connection point is ensured to have independent leakage control capabilities, laying the foundation for system-level segmented management.

[0032] In some embodiments of the present invention, several ventilation pipes 2 are included, one end of the several ventilation pipes 2 is respectively connected to multiple ventilation outlets 106, the other end of the several ventilation pipes 2 is respectively connected to multiple ventilation shut-off valves 3, the multiple ventilation shut-off valves 3 are connected to an air collecting mechanism 4, and the air collecting mechanism 4 is also connected to a ventilation air supply unit 5 and an air induced draft unit 7, and a leakage detector 6 is provided on the pipeline connecting the air collecting mechanism 4 and the air induced draft unit 7. The ventilation system is set up in this way to achieve segmented leakage positioning. Each ventilation outlet 106 is connected to an independent ventilation shut-off valve 3. When a leak occurs, closing some valves can lock the leakage flange. If the detector still alarms after closing valve A, it can be inferred that the leakage point is downstream of valve A, and the leakage point can be continued to be detected and locked; the ventilation air supply unit 5 provides dry air to prevent moisture corrosion; the draft unit 7 maintains the system negative pressure to ensure the directional flow of the leaked gas; the leakage detector 6 monitors the ammonia concentration in the gas collection mechanism 4 in real time, and links the alarm system. The three-in-one system realizes the regulation and detection of ventilation pressure, replacing the existing fully connected annular space of the double-walled pipe, eliminating the problem of ambiguity in leakage positioning.

[0033] In some embodiments of the present invention, the ventilation air supply unit 5 is used to provide dry air with appropriate pressure flow to the ventilation system; the air induction unit 7 is used to adjust the ventilation pressure of the ventilation system; and the leakage detector 6 is used to detect leakage of target gas components in the ventilation air.

[0034] The ventilation air supply unit 5 is used to provide dry air with appropriate pressure and flow rate to the ventilation system to prevent aging or ice blockage of the sealing ring caused by condensation of water vapor in the pipeline under low-temperature conditions of ammonia fuel; The negative pressure is precisely adjusted by the draft unit 7, and a high-sensitivity detector such as a laser ammonia sensor is provided on the pipeline connecting the gas collecting mechanism 4 and the draft unit 7 to achieve rapid leakage response.

[0035] The present invention provides a ventilation connection structure 1 and system for large pipelines of marine ammonia fuel engines, which simplifies the pipeline structure and reduces costs. It abandons the double-wall pipe structure and adopts a single-layer pipeline combined with a flange double sealing ring structure, that is, the inner ring seal cooperates with the outer ring seal to ensure the sealing effect, thereby improving the installation efficiency.

[0036] The present invention utilizes the discharge trough for centralized ventilation and directly extracts the leaked fuel through the flange annular discharge trough 105 without the need to maintain a large annular space. This greatly reduces the ventilation volume compared to traditional solutions, and the selection of supporting equipment (blower, storage tank) is miniaturized, further saving costs.

[0037] The present invention can achieve precise leak positioning and rapid response. Through the segmented control of the ventilation shut-off valve 3, each flange connection is independently equipped with a ventilation shut-off valve 3. When a leak occurs, the specific leaking flange can be located in a short time by switching the valve on and off, without the need for additional detectors. A centralized gas collection mechanism 4 is adopted, and the leaked fuel is collected to the gas collection mechanism 4 through the discharge trough. In combination with a high-sensitivity detector (such as an ammonia sensor), the detection response time is effectively shortened.

[0038] The present invention facilitates efficient maintenance by operators and extends service life. It has a disassembly-free cleaning function. The discharge groove supports the injection of compressed air or cleaning agent. Carbon deposits and salt spray deposition can be removed without disassembling the flange, effectively extending the maintenance cycle. The flange sealing ring adopts a ceramic composite material with the characteristics of high temperature and high pressure resistance, which is suitable for the extreme working conditions of ship ammonia fuel engines.

[0039] The present invention effectively reduces ventilation energy consumption, improves the overall energy efficiency of ships, and achieves energy conservation and emission reduction.

[0040] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A ventilation connection structure for large pipelines of marine ammonia fuel engines, characterized in that: It includes a first ventilation flange and a second ventilation flange arranged in a matching connection. An inner ring sealing structure is provided at the contact position between the first ventilation flange and the second ventilation flange. An outer ring sealing structure is provided on the outside of the inner ring sealing structure. An annular discharge groove is provided between the inner ring sealing structure and the outer ring sealing structure. A ventilation outlet and a cleaning port are provided on the outside of the first ventilation flange, both of which are connected to the annular discharge groove.

2. A ventilation connection structure for large pipelines of a marine ammonia fuel engine according to claim 1, characterized in that: The first ventilation flange and the second ventilation flange are connected in pairs by a plurality of bolts.

3. A ventilation connection structure for large pipelines of a marine ammonia fuel engine according to claim 1, characterized in that: The inner ring sealing structure comprises an inner ring sealing groove provided on the first ventilation flange, wherein an inner ring sealing ring is provided in the inner ring sealing groove; The outer ring sealing structure comprises an outer ring sealing groove which is arranged at a certain distance outside the inner ring sealing groove, and an outer ring sealing ring is arranged in the outer ring sealing groove.

4. A ventilation connection structure for large pipelines of a marine ammonia fuel engine according to claim 1, characterized in that: The ventilation outlet is arranged on the outer arc-shaped side wall of the first ventilation flange and is communicated with the annular discharge groove at the annular end surface of the first ventilation flange.

5. A ventilation connection structure for large pipelines of a marine ammonia fuel engine according to claim 1, characterized in that: The ventilation outlet is arranged on the outer arc-shaped side wall of the first ventilation flange and communicates with the annular discharge groove, or is arranged at the annular end surface of the first ventilation flange and communicates with the annular discharge groove.

6. A ventilation connection structure for large pipelines of a marine ammonia fuel engine according to claim 1, characterized in that: The cleaning port is arranged on the outer arc-shaped side wall of the first ventilation flange and is communicated with the annular discharge groove at the annular end surface of the first ventilation flange.

7. A ventilation connection structure for large pipelines of a marine ammonia fuel engine according to claim 1, characterized in that: The cleaning port is arranged on the outer arc-shaped side wall of the first ventilation flange and communicates with the annular discharge groove, or is arranged at the annular end surface of the first ventilation flange and communicates with the annular discharge groove.

8. A large-scale pipeline ventilation system for ammonia fueled marine engines, characterized in that: The invention comprises a large-scale pipeline ventilation connection structure for a marine ammonia fuel engine as described in any one of claims 1 to 9.

9. A large-scale pipe ventilation system for a marine ammonia fuel engine according to claim 8, characterized in that: It includes several ventilation pipes, one end of which is connected to multiple ventilation outlets respectively, and the other end of which is connected to multiple ventilation shut-off valves respectively. The multiple ventilation shut-off valves are connected to an air collecting mechanism, and the air collecting mechanism is also connected to a ventilation air supply unit and an air induced draft unit. A leakage detector is provided on the pipeline connecting the air collecting mechanism and the air induced draft unit.

10. A large-scale pipe ventilation system for a marine ammonia fuel engine according to claim 9, characterized in that: The ventilation air supply unit is used to provide dry air with appropriate pressure and flow rate for the ventilation system; the air induction unit is used to adjust the ventilation pressure of the ventilation system; and the leakage detector is used to detect leakage of target gas components in the ventilation air.

Images