Large-scale LNG dual-fuel drag-suction dredger gas supply system arrangement method

Abstract

The application discloses a large LNG dual-fuel drag suction dredger gas supply system arrangement method and relates to the technical field of LNG dual-fuel dredgers. The arrangement method comprises the following steps: arranging and optimizing a three-dimensional digital dual-fuel system; manufacturing a LNG special wall pipe; reserving a subsystem; integrally integrating a storage tank and a fuel cabin joint; conducting a pipeline test; pre-adjusting an LNG gas supply system; adjusting a dual-fuel main engine system; manufacturing a ship body base; and hoisting and loading the integrated whole of the storage tank and the fuel cabin joint to the ship body. The application has the following advantages: the arrangement scheme of the dual-fuel gas supply system is optimized based on three-dimensional design; the pre-fitting rate is high through high integration of the storage tank and the fuel cabin joint; and the whole is hoisted and loaded once. The vaporization heating system, the filling system and the safety control system of the gas supply are arranged inside the fuel cabin joint, are not easy to be damaged in use, can monitor whether gas leakage occurs in the space of the fuel cabin joint, and make the LNG power ship run more safely.

Description

Technical Field

[0001] This invention relates to the field of LNG dual-fuel dredger technology, specifically to a method for arranging the gas supply system of a large LNG dual-fuel trailing suction hopper dredger. Background Technology

[0002] Dredging vessels, used for dredging operations in ports, coastal waterways, and even waterways surrounding cities, have a significant impact on urban atmospheric environment due to their emissions. Developing port and waterway dredging using LNG clean energy, constructing integrated energy-saving and emission-reduction technologies, and building green dredging vessels have become trends in building green, environmentally friendly, and sustainable cities, in line with the needs of green port and waterway construction. In an increasingly competitive market, low vessel operating costs are a crucial advantage for dredging companies. Using LNG clean energy in dredging vessels not only meets the needs of green port and waterway construction but also further reduces vessel operating costs and improves operational efficiency.

[0003] In the existing technology, the gas supply system of large LNG dual-fuel trailing suction hopper dredgers is constructed using the more traditional method of building each component on shore, hoisting them to the hull, and then welding and installing the gas supply system components. This results in low system integration, cumbersome hoisting procedures, low construction efficiency, and the non-integrated gas supply layout is prone to LNG gas leakage during use. If a leak occurs, it cannot be eliminated in time, posing a safety hazard and affecting the normal navigation of LNG-powered vessels. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for arranging the gas supply system of a large LNG dual-fuel trailing suction hopper dredger, which can solve the problems of low integration of the gas supply system, cumbersome hoisting steps, low construction efficiency, and the fact that non-integrated gas supply arrangements are prone to LNG gas leakage, failure to eliminate leakage in time, and safety hazards.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention includes the following steps:

[0006] S1. Optimization of Dual-Fuel System Layout Based on 3D Digital Modeling: Based on the spatial layout requirements of LNG storage tanks, refueling stations, fuel tank locations, fuel tank connection locations, and gas supply equipment rooms, the paths of LNG refueling pipelines, gas supply pipelines, and cooling and heating pipelines are planned. Considering thermal protection and safety protection requirements, the layout scheme of the gas supply system is designed through 3D digital integrated modeling and combined with the ship's compartment division scheme.

[0007] S2. Fabrication of LNG-specific single-wall and double-wall pipes: Based on the protection and welding requirements of LNG-specific single-wall and double-wall pipes, we perform pipe modeling, stress calculation, temperature field calculation, and design drawings, and then fabricate the pipes according to the design drawings.

[0008] S3. Subsystem Reservation: Space is reserved for the installation locations and mounting brackets, cable trays, through-cabin parts, and stuffing boxes of subsystems other than gas supply, including fire alarm system, fire protection system, compressed air system, control and power system equipment, and sensors.

[0009] S4. Integrated Storage Tank and Fuel Tank Connection: This integrates the storage tank, LNG pump, vaporization and heating system, water-glycol supply system, refueling system, and safety and control system. The fuel tank connection is fixedly integrated onto the top of the storage tank. A vaporizer, heater, and gas buffer tank are installed within the fuel tank connection. An LNG pump is installed inside the storage tank, connected to the vaporizer via a liquid phase pipeline. The vaporizer is connected to the gas buffer tank via a connecting pipeline. The gas buffer tank is connected to the external gas supply system via a gas phase pipeline. The components are connected as follows: the top of the storage tank is connected to the heater via a delivery pipeline; the heater is connected to the required components outside the fuel tank joint via an output pipeline; a water-glycol supply system is installed for the heater and the vaporizer; a refueling pipeline is installed on the top of the storage tank and connected to the refueling station outside the fuel tank joint; a venting pipeline and a safety valve are installed on the top of the storage tank and connected to the venting mast outside the fuel tank joint; the venting pipeline, refueling pipeline, and liquid phase pipeline on the top of the storage tank are all located inside the fuel tank joint.

[0010] S5. Pipeline Testing: After the installation and welding of each pipeline are completed, a tightness test and a vacuum test shall be performed.

[0011] S6. Pre-commissioning of LNG supply system: Conducting operational tests of LNG pump and vaporizer system, heating system, and overall operation and functional tests of LNG supply system;

[0012] S7. Dual-fuel main engine system commissioning: Individual and coordinated commissioning of the main engine control system, fuel supply system, cooling water system and gas distribution system of the dual-fuel main engine system;

[0013] S8. Hull base fabrication: The hull base is fabricated based on the integrated laminated wood data of the storage tank and fuel tank joints. The error between the hull base and the storage tank is controlled within a reasonable range through epoxy installation.

[0014] S9. Lifting and mounting: The integrated storage tank and fuel tank joints are directly lifted and mounted onto the hull as a whole, completing the layout of the gas supply system of the large LNG dual-fuel trailing suction hopper dredger on the hull.

[0015] Furthermore, in step S2, when manufacturing the LNG-specific wall pipe, the material is first cut, then the pipe is bent, then straightened, and then welded. After welding, radiographic testing is performed, and then surface treatment is carried out.

[0016] Furthermore, in step S4, during installation, pneumatic valves are installed on the liquid phase pipeline, gas phase pipeline, and refueling pipeline respectively, and the pneumatic valves are connected to the external gas source power at the fuel tank connector. An on-site gas detection system and a fusible system are installed inside the fuel tank connector.

[0017] Furthermore, in step S4, a polyurethane insulation system is wrapped around the outer surface of the bottom of the fuel tank connector, and a polyurethane cold insulation layer is provided on the liquid phase pipeline, gas phase pipeline, and refueling pipeline.

[0018] Furthermore, in step S4, a bilge drainage system is installed at the fuel tank joint, which includes a sludge well, a diaphragm pump, drainage pipes, valves, a level gauge, and sensors. A ventilation system is provided at the fuel tank joint to continuously ventilate the fuel tank joint 30 times per hour. The ventilation system uses both exhaust fans and natural ventilation.

[0019] The advantages of this invention are: based on the three-dimensional design of the ship, the dual-fuel gas supply system layout scheme is optimized; through an integrated construction method, the gas supply system is manufactured, installed and commissioned; through the high integration of the storage tank and fuel tank joints, no hot work is required after installation; the pre-outfitting rate is high; the whole system is lifted in one go, improving construction efficiency and creating a green dredging trailing suction hopper dredger.

[0020] The gas vaporization heating system, water glycol supply system, refueling system, and safety and control system are located inside the fuel tank joint area, making them less prone to damage during use. They are also equipped with an on-site gas detection system, a fusible system, a bilge drainage system, and a ventilation system, which can monitor whether there is a gas leak in the fuel tank joint area and promptly eliminate any leaks, making the operation of LNG-powered ships safer.

[0021] The fabrication and installation of LNG-specific wall pipes can be successfully completed in one go by accurately controlling the fabrication and installation precision, meeting the specifications and usage requirements, and achieving the goal of optimizing the construction process. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the layout of the present invention;

[0023] Figure 2 This is a schematic diagram of the integrated gas supply system of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments will enable those skilled in the art to more fully understand this invention, but do not limit the invention to the scope of the described embodiments.

[0025] like Figure 1 and Figure 2 As shown, this specific implementation method involves constructing a 15000m... 3 Taking a high-grade clean energy trailing suction hopper dredger as an example, the following technical solution is adopted: Arrangement of the gas supply system for a large LNG dual-fuel trailing suction hopper dredger, including the following steps:

[0026] S1. Optimization of Dual-Fuel System Layout Based on 3D Digitalization: Based on the spatial layout requirements of LNG storage tank 1, refueling station 7, fuel tank space, fuel tank connector space 2 and gas supply equipment room, plan the paths of LNG refueling pipeline, gas supply pipeline and cooling and heating pipeline. Considering thermal protection and safety protection requirements, design the layout scheme of the gas supply system through 3D digital integrated modeling and combined with the ship's compartment division scheme.

[0027] S2. Fabrication of LNG-specific single-wall and double-wall pipes: Based on the protection and welding requirements of LNG-specific single-wall and double-wall pipes, we perform pipe modeling, stress calculation, temperature field calculation, and design drawings. The pipes are then fabricated according to the design drawings. During the fabrication of LNG-specific pipes, the material is first cut, then bent, then aligned, and finally welded. After welding, radiographic testing is performed, followed by surface treatment. By accurately controlling the fabrication and installation precision, we can achieve successful construction in one go, meeting specifications and usage requirements, thus optimizing the construction process and ensuring the safe and reliable supply of gas in the future.

[0028] S3. Subsystem Reservation: Space is reserved for the installation locations and mounting brackets, cable trays, through-cabin parts, and stuffing ducts of subsystems other than gas supply, including fire alarm system (fire detectors, cables, etc.), fire protection system (pipelines, sprinklers, etc.), compressed air system (pipelines, valve accessories, etc.), control and power system equipment, and sensors.

[0029] S4. Integrated storage tank and fuel tank connection: Integrate storage tank 1, LNG pump 6, vaporization heating system, water glycol supply system 12, refueling system, and safety and control system: Fix fuel tank connection 2 to the top of storage tank 1. Install vaporizer 3, heater 4 and gas buffer tank 5 in fuel tank connection 2. Install LNG pump 6 in storage tank 1. Connect LNG pump 6 to vaporizer 3 through liquid phase pipeline. Connect vaporizer 3 to gas buffer tank 5 through connecting pipeline. Connect gas buffer tank 5 to the main unit 9, generator 10 and boiler 11 outside fuel tank connection 2 through gas phase pipeline. Absorb heat and vaporize LNG, and then supply it to the demand location.

[0030] The top of the storage tank 1 is connected to the heater 4 via a delivery pipeline. The heater 4 is connected to the generator 10 and boiler 11 outside the fuel tank connector 2 via an output pipeline. A water glycol supply system 12 is installed on the heater 4 and the vaporizer 3. A filling pipeline is installed on the top of the storage tank 1 and connected to the filling station 7 outside the fuel tank connector 2. A venting pipeline 8 and a safety valve are installed on the top of the storage tank 1 and connected to the venting mast outside the fuel tank connector 2. The venting pipeline 8, the filling pipeline, and the liquid phase pipeline on the top of the storage tank 1 are all located inside the fuel tank connector 2.

[0031] During installation, pneumatic valves are installed on the liquid phase pipeline, gas phase pipeline, and refueling pipeline, respectively. The pneumatic valves are connected to the external air source power source of fuel tank connector 2. An on-site gas detection system and a fusible system are installed inside fuel tank connector 2. The outer surface of the bottom of fuel tank connector 2 is wrapped with a polyurethane insulation system. Polyurethane cold insulation layers are provided on the liquid phase pipeline, gas phase pipeline, and refueling pipeline. Fuel tank connector 2 is equipped with a bilge drainage system, which includes a sludge well, diaphragm pump, drainage pipeline, valves, level gauge, and sensors. Fuel tank connector 2 is equipped with a ventilation system that continuously ventilates the fuel tank connector 30 times per hour. The ventilation system uses both exhaust fans and natural ventilation.

[0032] S5. Pipeline Testing: After the installation and welding of each pipeline are completed, a tightness test and a vacuum test are performed.

[0033] S6. Pre-commissioning of LNG supply system: Conducting operational tests of LNG pump 6 and vaporizer 3 system, heating system, and overall operation and function tests of LNG supply system.

[0034] S7. Dual-fuel main engine system commissioning: Individual and coordinated commissioning of the main engine control system, fuel supply system, cooling water system, and gas distribution system of the dual-fuel main engine system. Monitoring of pressure, temperature, and stress conditions of the fuel supply system, cooling water system, and gas distribution system to ensure normal operation of the main engine.

[0035] The commissioning of the ship's LNG supply system includes FGSS pre-commissioning (instrument wiring and range checks, high-voltage cable checks, instrument gas system testing, remote control valve testing, ventilation system operation testing, gas detection system testing, water glycol system operation testing, BOG operation testing and inspection, LNG pump testing and inspection, LNG vaporizer testing and inspection, FGSS overall operational function testing, LNG storage tank preparation and refueling), FGSS terminal commissioning (LNG pump & vaporizer system operation testing, BOG operation testing, LNG pump system and BOG system combined gas supply), and LNG FGSS system sea trials (safety tests, auxiliary engine gas mode independent operation tests, main engine gas mode independent operation tests, hot water boiler gas mode operation tests, power outage tests, gas mode unmanned cabin operation tests, and FGSS purging and inerting post-inspection).

[0036] S8. Hull base fabrication: The hull base is fabricated based on the integrated laminated wood data of the storage tank 1 and fuel tank joint 2. The error between the hull base and the storage tank is controlled within a reasonable range through epoxy installation.

[0037] S9. Lifting and mounting: The integrated storage tank 1 and fuel tank connector 2 are directly lifted and mounted onto the hull as a whole, completing the arrangement of the gas supply system of the large LNG dual-fuel trailing suction hopper dredger on the hull.

[0038] This specific implementation method optimizes the layout of the dual-fuel gas supply system based on the three-dimensional design of the ship. Through an integrated construction approach, the gas supply system is manufactured, installed, and commissioned. The high integration of the storage tank and fuel tank connection points eliminates the need for hot work after installation, resulting in a high pre-outfitting rate and enabling a single-stage hoisting, thus improving construction efficiency and creating a green dredging trailing suction hopper dredger. The fabrication and installation of LNG-specific wall pipes, with precise control over manufacturing and installation accuracy, ensures successful construction in one go, meeting specifications and usage requirements and optimizing the construction process. The gas vaporization heating system, water-glycol supply system, refueling system, and safety and control system are located inside the fuel tank connection points, making them less prone to damage during use. They are also equipped with an on-site gas detection system, a fusible link system, a bilge drainage system, and a ventilation system, which can monitor for gas leaks within the fuel tank connection points and promptly eliminate any leaks, making the operation of LNG-powered ships safer.

[0039] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for arranging the gas supply system of a large LNG dual-fuel trailing suction hopper dredger, characterized in that: Includes the following steps: S1. Optimization of Dual-Fuel System Layout Based on 3D Digital Modeling: Based on the spatial layout requirements of LNG storage tanks, refueling stations, fuel tank locations, fuel tank connection locations, and gas supply equipment rooms, the paths of LNG refueling pipelines, gas supply pipelines, and cooling and heating pipelines are planned. Considering thermal protection and safety protection requirements, the layout scheme of the gas supply system is designed through 3D digital integrated modeling and combined with the ship's compartment division scheme. S2. Fabrication of LNG-specific single-wall and double-wall pipes: Based on the protection and welding requirements of LNG-specific single-wall and double-wall pipes, we perform pipe modeling, stress calculation, temperature field calculation, and design drawings, and then fabricate the pipes according to the design drawings. S3. Subsystem Reservation: Space is reserved for the installation locations and mounting brackets, cable trays, through-cabin parts, and stuffing boxes of subsystems other than gas supply, including fire alarm system, fire protection system, compressed air system, control and power system equipment, and sensors. S4. Integrated Storage Tank and Fuel Tank Connection: This integrates the storage tank, LNG pump, vaporization and heating system, water-glycol supply system, refueling system, and safety and control system. The fuel tank connection is fixedly integrated onto the top of the storage tank. A vaporizer, heater, and gas buffer tank are installed within the fuel tank connection. An LNG pump is installed inside the storage tank, connected to the vaporizer via a liquid phase pipeline. The vaporizer is connected to the gas buffer tank via a connecting pipeline. The gas buffer tank is connected to the external gas supply system via a gas phase pipeline. The components are connected as follows: the top of the storage tank is connected to the heater via a delivery pipeline; the heater is connected to the required components outside the fuel tank joint via an output pipeline; a water-glycol supply system is installed for the heater and the vaporizer; a refueling pipeline is installed on the top of the storage tank and connected to the refueling station outside the fuel tank joint; a venting pipeline and a safety valve are installed on the top of the storage tank and connected to the venting mast outside the fuel tank joint; the venting pipeline, refueling pipeline, and liquid phase pipeline on the top of the storage tank are all located inside the fuel tank joint. S5. Pipeline Testing: After the installation and welding of each pipeline are completed, a tightness test and a vacuum test shall be performed. S6. Pre-commissioning of LNG supply system: Conducting operational tests of LNG pump and vaporizer system, heating system, and overall operation and functional tests of LNG supply system; S7. Dual-fuel main engine system commissioning: Individual and coordinated commissioning of the main engine control system, fuel supply system, cooling water system and gas distribution system of the dual-fuel main engine system; S8. Hull base fabrication: The hull base is fabricated based on the integrated laminated wood data of the storage tank and fuel tank joints. The error between the hull base and the storage tank is controlled within a reasonable range through epoxy installation. S9. Lifting and mounting: The integrated storage tank and fuel tank joints are directly lifted and mounted onto the hull as a whole, completing the layout of the gas supply system of the large LNG dual-fuel trailing suction hopper dredger on the hull.

2. The method for arranging the gas supply system of a large LNG dual-fuel trailing suction hopper dredger according to claim 1, characterized in that: In step S2, when manufacturing the LNG-specific wall pipe, the material is first cut, then the pipe is bent, then straightened, and then welded. After welding, radiographic testing is performed, and then surface treatment is carried out.

3. The method for arranging the gas supply system of a large LNG dual-fuel trailing suction hopper dredger according to claim 1, characterized in that: In step S4, during installation, pneumatic valves are installed on the liquid phase pipeline, gas phase pipeline, and refueling pipeline respectively. The pneumatic valves are connected to the external gas source power at the fuel tank connector. An on-site gas detection system and a fusible system are installed inside the fuel tank connector.

4. The method for arranging the gas supply system of a large LNG dual-fuel trailing suction hopper dredger according to claim 1, characterized in that: In step S4, a polyurethane insulation system is wrapped around the outer surface of the bottom of the fuel tank joint, and a polyurethane cold insulation layer is provided on the liquid phase pipeline, gas phase pipeline, and refueling pipeline.

5. The method for arranging the gas supply system of a large LNG dual-fuel trailing suction hopper dredger according to claim 1, characterized in that: In step S4, a bilge drainage system is installed at the fuel tank joint. The bilge drainage system includes a sludge well, a diaphragm pump, drainage pipes, valves, a level gauge, and sensors. A ventilation system is installed at the fuel tank joint to continuously ventilate the fuel tank joint 30 times per hour. The ventilation system uses both exhaust fans and natural ventilation.

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