Marine main engine exhaust smoke sampling device

Abstract

The utility model belongs to the technical field of marine main engine exhaust smoke sampling, and particularly relates to a marine main engine exhaust smoke sampling device. The double cavities formed by the left and right butt welding partition plates separate the sampling function from the discharging function, the front half cavity notch and the inclined bottom plate cooperate to guide high-temperature flue gas to enter and promote cooling backflow, and the combination of the top companion flange and the preassembled support and the inclined structure of the inclined bottom plate and the discharging cavity ensure that the dryness of the measured flue gas reaches the standard. A sensor control panel and a probe are intensively installed in a top flange area, sensor layout is integrated, direct exposure to high-temperature airflow is avoided, thermal radiation damage is reduced in combination with a protective shell, and data acquisition stability is improved. According to the invention, interference of moisture condensation on measurement is effectively reduced; and carbon deposition and pressure fluctuation are avoided. The air tightness under the high-temperature working condition is ensured, and the service life of the device is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of marine main engine exhaust sampling technology, specifically relating to a marine main engine exhaust sampling device. Background Technology

[0002] Accurate measurement of the exhaust gas performance parameters of marine low-speed diesel engines is crucial for optimizing main engine performance and meeting the requirements of the International Maritime Organization (IMO) regulations.

[0003] Existing marine main engine exhaust sampling devices mostly use zirconia sensors for flue gas composition analysis, but they have significant drawbacks: direct contact between high-temperature flue gas and the sensor can easily damage the probe; the approximately 5.2% moisture content in the flue gas condenses and affects measurement accuracy; simultaneously, traditional sampling devices have a simple structure and lack effective protection and cooling designs, resulting in short sensor lifespan and severe data drift. Furthermore, existing equipment installation relies on on-site welding or complex positioning, and maintenance requires disassembling the entire system, which is inefficient and poses safety hazards. Although some improvement solutions attempt to alleviate these problems by adding insulation layers or using compartmentalized designs, they do not fundamentally resolve the contradictions between flue gas flow control, condensate drainage, and equipment integration. Therefore, there is an urgent need for an exhaust sampling device that combines high-efficiency sampling, active cooling, anti-condensation interference, and easy pre-installation and maintenance to meet the long-term stable operation requirements under harsh marine conditions. Summary of the Invention

[0004] To address the problems of low sampling efficiency, lack of active cooling, inability to prevent condensation interference, and complex pre-installation and maintenance of existing marine main engine exhaust sampling devices, this invention proposes a marine main engine exhaust sampling device, characterized by comprising a dual-chamber shell sampling return pipe body, a sensor control board mounting component, an exhaust main pipe pre-installation support base, and an exhaust main pipe.

[0005] The main body (1) of the dual-cavity housing sampling return pipe is composed of a flange-welded dual-cavity housing. Its interior is divided into a front half-cavity and a measuring flue gas venting cavity by left and right butt-welded partitions. The top of the front half-cavity is provided with a rectangular notch for sampling flue gas. Below the notch is a sloping bottom plate with an inclination angle of 15°-30°. The lower end of the sloping bottom plate extends to the inlet of the venting cavity. The rear side of the measuring flue gas venting cavity is provided with a venting port. The venting port has a trapezoidal cross-section, and its width gradually increases from the inside to the outside. The top of the dual-cavity housing is provided with a pairing flange. The pairing flange integrates a sensor measuring port. The sensor measuring port is connected to the sensor control board mounting component (2) through a sealing gasket. The pre-installation support base (3) of the exhaust main pipe is an annular sleeve structure. Its inner wall is provided with a high-temperature resistant ceramic coating and is fixed to the bottom of the dual-cavity housing by flange bolts. The outer wall of the pre-installation support base (3) is welded to the side opening of the exhaust main pipe (4).

[0006] According to the above-described marine main engine exhaust sampling device, the thickness of the left and right butt-welded partitions is 8-12mm, and the welding joint between the front end of the left and right butt-welded partitions and the inclined bottom plate is provided with a chamfered transition structure.

[0007] According to the above-described marine main engine exhaust sampling device, the inclined angle of the inclined bottom plate is 22°, and its surface is covered with a silicon nitride wear-resistant coating.

[0008] According to the above-described marine main engine exhaust sampling device, the inner wall of the exhaust port of the measuring exhaust cavity is provided with a spiral guide groove, and the ratio of the spiral guide groove pitch to the diameter of the exhaust pipe is 1:5.

[0009] According to the above-described marine main engine exhaust sampling device, a graphite spiral wound gasket is provided between the mating flange and the sensor control board mounting component (2), and the temperature resistance rating of the graphite spiral wound gasket is not lower than 800℃.

[0010] According to the above-described marine main engine exhaust smoke sampling device, the inner diameter of the sleeve of the pre-installed support base (3) of the exhaust main pipe is 1-2 mm larger than the outer diameter of the double-cavity pipe shell, and the gap is filled with ceramic fiber sealing rings.

[0011] According to the above-described marine main engine exhaust sampling device, a zirconia sensor probe is embedded in the sensor measurement port, and the front end of the probe extends to the central axis of the venting cavity.

[0012] According to the above-described marine main engine exhaust sampling device, the outer wall of the double-cavity shell is covered with a double-layer heat insulation cover, the inner layer being aluminum silicate fiber felt and the outer layer being 304 stainless steel corrugated plate.

[0013] According to the above-described marine main engine exhaust sampling device, the spiral guide groove has a depth of 3mm and a bottom fillet radius of 1.5mm.

[0014] According to the above-described marine main engine exhaust sampling device, the ceramic fiber sealing ring has a compression rate of 30%-40% and is pre-coated with high-temperature sealant.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. The dual-cavity structure formed by the left and right butt-welded partitions of the present invention separates the sampling and venting functions. The notch in the front half of the cavity works in conjunction with the inclined bottom plate to guide the high-temperature flue gas in while promoting cooling reflux, effectively reducing the interference of moisture condensation on the measurement. The vent in the rear half of the cavity optimizes the flue gas flow and avoids carbon buildup and pressure fluctuations.

[0017] 2. The combination of the top mating flange and the pre-installed support of the present invention enables modular installation, reduces on-site welding work, improves assembly accuracy and maintenance convenience; the flange sealing design ensures airtightness under high temperature conditions and extends the sensor life.

[0018] 3. The inclined structure of the inclined bottom plate and the venting cavity of the present invention utilizes fluid dynamics characteristics to actively cool and control moisture, thereby achieving the natural separation and discharge of 5.2% moisture in the flue gas, ensuring that the measured flue gas dryness meets the standard.

[0019] 4. The sensor control board and probe of the present invention are centrally installed in the top flange area, which integrates the sensor layout, avoids direct exposure to high temperature airflow, and reduces heat radiation damage by combining with the protective shell, thereby improving the stability of data acquisition by more than 30%. Attached Figure Description

[0020] Figure 1 This is a front view of a structural schematic diagram of a marine main engine exhaust smoke sampling device according to the present invention.

[0021] Figure 2 This is a partial sectional view of the left view of a structural schematic diagram of a marine main engine exhaust smoke sampling device according to the present invention.

[0022] Figure 3 This is a right view of a structural schematic diagram of a marine main engine exhaust smoke sampling device according to the present invention.

[0023] In the diagram: 1-Dual-cavity housing sampling return pipe body, 2-Sensor control board mounting component, 3-Air supply section module, 4-Total exhaust pipe, 5-Sensor control board, 6-Sensor probe, 11-Left and right butt-welded partitions, 12-Dual-cavity pipe housing, 13-Front half cavity, 14-Measured flue gas venting cavity, 15-Notch, 16-Sloping bottom plate, 17-Vent port, 18-Matching flange, 19-Sensor measurement port. Detailed Implementation

[0024] Preferred Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0026] like Figures 1 to 3 As shown: In this embodiment,

[0027] A marine main engine exhaust smoke sampling device, characterized in that: it includes a dual-chamber shell sampling return pipe body 1, a sensor control board mounting component 2, an exhaust main pipe pre-installation support 3, and an exhaust main pipe 4;

[0028] The dual-cavity sampling return pipe body 1 is composed of a flange-welded dual-cavity pipe shell 12, which is internally divided into a front half-cavity 13 and a flue gas venting cavity 14 by left and right butt-welded partitions 11. The top of the front half-cavity 13 is provided with a rectangular notch 15 for sampling flue gas, and a sloping bottom plate 16 with an inclination angle of 15°-30° is welded below the notch 15. The lower end of the sloping bottom plate 16 extends to the inlet of the flue gas venting cavity 14. A vent 17 is provided on the rear side of the flue gas venting cavity 14. The cross-section is trapezoidal, and its width gradually increases from the inside to the outside. The top of the double-lumen tube housing 12 is provided with a mating flange, and the mating flange 18 integrates a sensor measuring port 19. The sensor measuring port 19 is connected to the sensor control board mounting component 2 through a sealing gasket. The pre-installation support of the main exhaust pipe 4 is an annular sleeve structure with a high-temperature resistant ceramic coating on its inner wall. It is fixed to the bottom of the double-lumen tube housing 12 by flange bolts. The outer wall of the pre-installation support 3 is welded to the side opening of the main exhaust pipe 4.

[0029] The thickness of the left and right butt-welded partitions 11 is 8-12mm, and the welding joint between the front end of the left and right butt-welded partitions 11 and the inclined bottom plate 16 is provided with a chamfered transition structure.

[0030] The inclined angle of the inclined base plate 16 is 22°, and its surface is covered with a silicon nitride wear-resistant coating.

[0031] The inner wall of the vent 17 of the flue gas venting chamber 14 is provided with a spiral guide groove, and the ratio of the spiral guide groove pitch to the diameter of the main exhaust pipe is 1:5.

[0032] A graphite spiral wound gasket is provided between the mating flange 18 and the sensor control board mounting component 2. The temperature resistance rating of the graphite spiral wound gasket is not lower than 800℃.

[0033] The inner diameter of the sleeve of the pre-installed support base of the main exhaust pipe 4 is 1-2 mm larger than the outer diameter of the double-lumen pipe shell 12, and the gap is filled with ceramic fiber sealing rings.

[0034] The sensor measurement port 19 is embedded with a zirconium oxide sensor probe, and the front end of the probe extends to the central axis of the flue gas venting chamber 14.

[0035] The outer wall of the double-lumen tube shell 12 is covered with a double-layer heat insulation cover, with the inner layer being aluminum silicate fiber felt and the outer layer being 304 stainless steel corrugated plate.

[0036] The spiral guide groove has a depth of 3mm and a bottom fillet radius of 1.5mm.

[0037] The ceramic fiber sealing ring has a compression rate of 30%-40% and is pre-coated with high-temperature sealant.

[0038] Combined with appendix Figure 1-2The following is a detailed description of the marine main engine exhaust smoke sampling device of the present invention:

[0039] The dual-lumen tube housing 12 of this invention is constructed as follows: A dual-lumen tube housing 12 with an outer diameter of 200mm is welded from Q345R steel plate. Left and right butt-welded partition plates 11, 10mm thick, made of 316L stainless steel, are welded along the axial direction, dividing the inner cavity of the dual-lumen tube housing 12 into a front half-cavity 13 (80mm wide) and a flue gas venting cavity 14 (120mm wide). A 60mm × 40mm rectangular notch 15 is formed at the top of the front half-cavity 13. Below the notch, a sloping bottom plate 16 with an inclination angle of 22° and a thickness of 6mm is welded. The surface of the sloping bottom plate 16 is coated with a silicon nitride coating to resist flue gas erosion.

[0040] A trapezoidal vent 17 is opened at the end of the flue gas venting chamber 14, with an upper bottom width of 50mm, a lower bottom width of 80mm, and a height of 100mm. A spiral guide groove with a depth of 3mm and a pitch of 40mm is machined on the inner wall of the vent 17 to guide the flue gas swirling to accelerate the settling of particulate matter.

[0041] The top mating flange 18, conforming to the DN150 PN16 standard, is bolted to the sensor control board mounting component 2. A zirconia sensor probe, model ZS-02, is fixed to the sensor control board mounting component. The probe tip extends 20mm below the centerline of the flue gas venting chamber 14 to ensure representative sampling. A 3mm thick graphite spiral wound gasket is sandwiched between the mating flanges 18, with the preload controlled at 50-60 N·m.

[0042] The pre-installed support for the main exhaust pipe 4 is an annular sleeve with an outer diameter of 210mm and an inner wall coated with a 0.5mm thick alumina ceramic layer. During installation, the support is first welded to the opening on the side wall of the main exhaust pipe 4, then the double-lumen pipe shell 12 is inserted into the sleeve, the gap is filled with ceramic fiber sealing rings with a compression rate of 35%, and finally fixed with flange bolts.

[0043] The double-lumen tube shell 12 is covered with a double-layer heat insulation cover. The inner layer is aluminum silicate fiber felt with a thickness of 20mm, which is fixed with stainless steel wire mesh. The outer layer is 304 stainless steel corrugated plate with a thickness of 1.5mm, which is locked with clamps. The surface temperature can be reduced to below 80℃.

[0044] Workflow: High-temperature flue gas enters the front chamber from the main exhaust pipe 4 through the notch 15. Guided by the inclined bottom plate 16, part of the flue gas flows upward to the measuring flue gas venting chamber 14, while the other part, carrying condensate, flows back to the main exhaust pipe 4 along the inclined bottom plate 16. The dry flue gas entering the measuring flue gas venting chamber 14 forms a swirling flow through the spiral guide groove. Particulate matter is deposited at the bottom of the flue gas venting chamber 14 under the action of centrifugal force. The purified flue gas is then discharged after being measured by the sensor probe 6.

[0045] Through structural optimization and modular design, this device integrates efficient flue gas sampling, moisture separation, and sensor protection. Installation time is reduced by 60% compared to traditional solutions, and the maintenance cycle is extended to more than 2 years.

[0046] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A marine main engine exhaust smoke sampling device, characterized by: Includes the main body of the dual-chamber housing sampling return pipe, the sensor control board mounting components, the pre-installation support base for the main exhaust pipe, and the main exhaust pipe; The dual-cavity tube housing sampling return pipe is composed of a flange-welded dual-cavity tube housing, which is internally divided into a front half-cavity and a measurement flue gas venting cavity by left and right butt-welded partitions. The top of the front half-cavity has a rectangular notch for sampling flue gas, and below the notch is a sloping bottom plate with an inclination angle of 15°-30°, the lower end of which extends to the inlet of the measurement flue gas venting cavity. The rear side of the measurement flue gas venting cavity has a vent, the cross-section of which is trapezoidal, and its width gradually increases from the inside to the outside. The top of the dual-cavity tube housing has a mating flange, on which a sensor measurement port is integrated. The sensor measurement port is connected to the sensor control board mounting component through a sealing gasket. The pre-installation support base of the main exhaust pipe is an annular sleeve structure with a high-temperature resistant ceramic coating on its inner wall, and is fixed to the bottom of the dual-cavity tube housing by flange bolts. The outer wall of the pre-installation support base is welded to the side opening of the main exhaust pipe.

2. The marine engine exhaust sampling device of claim 1, wherein: The thickness of the left and right butt-welded partitions is 8-12mm, and the welding joint between the front end of the left and right butt-welded partitions and the inclined bottom plate is provided with a chamfered transition structure.

3. The marine engine exhaust sampling device of claim 2, wherein: The inclined bottom plate has an inclination angle of 22° and its surface is covered with a silicon nitride wear-resistant coating.

4. The marine engine exhaust sampling device of claim 3, wherein: The inner wall of the vent of the flue gas venting chamber is provided with a spiral guide groove, and the ratio of the spiral guide groove pitch to the diameter of the main exhaust pipe is 1:

5.

5. The marine engine exhaust sampling device of claim 4, wherein: A graphite spiral wound gasket is provided between the mating flange and the sensor control board mounting component, and the temperature resistance rating of the graphite spiral wound gasket is not lower than 800℃.

6. The marine engine exhaust sampling device of claim 5, wherein: The inner diameter of the sleeve of the pre-installed support for the main exhaust pipe is 1-2 mm larger than the outer diameter of the double-lumen pipe shell, and the gap is filled with a ceramic fiber sealing ring.

7. The marine engine exhaust smoke sampling device of claim 6, wherein: The sensor measuring port is embedded with a zirconium oxide sensor probe, and the front end of the probe extends to the central axis of the flue gas venting chamber.

8. The marine engine exhaust smoke sampling device of claim 7, wherein: The outer wall of the dual-cavity tube shell is covered with a double-layer heat insulation cover, with the inner layer being aluminum silicate fiber felt and the outer layer being 304 stainless steel corrugated plate.

9. The marine engine exhaust smoke sampling device of claim 8, wherein: The spiral guide groove has a depth of 3mm and a bottom fillet radius of 1.5mm.

10. The marine engine exhaust sampling device according to claim 6 or 9, characterized in that: The ceramic fiber sealing ring has a compression rate of 30%-40% and is pre-coated with high-temperature sealant.

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