High-pressure fuel gas system of dual-fuel container ship

Abstract

The utility model relates to the field of container ships, and provides a high-pressure fuel gas system of a dual-fuel container ship. Comprising a fuel cabin, a fuel pump is installed in the fuel cabin, and the fuel pump pumps LNG from the fuel cabin and outputs the LNG from a fuel output pipeline and is connected with a main engine gas supply pipeline and a generator gas supply pipeline. A high-pressure air supply unit is installed on the main engine air supply pipeline, and a low-pressure air supply unit is installed on the generator air supply pipeline. The fuel cabin achieves primary pressurization when outputting liquefied natural gas through a fuel pump, fuel sent to a generator is supplied with gas through a low-pressure gas storage tank after being subjected to low-pressure gasification and heating to a proper temperature, and fuel sent to a main engine is subjected to secondary pressurization through a high-pressure pump, heat exchange after pressurization is conducted and finally adjusted through a valve set, so that the fuel is supplied to the generator through a low-pressure gas storage tank. The gas pressure is adjusted to proper high pressure, and then the gas is fed into the main engine for combustion, so that the combustion efficiency can be improved, the energy consumption is reduced, and environmental pollution caused by insufficient combustion is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to container ship field, concretely relates to dual-fuel container ship high pressure gas system. BACKGROUND

[0002] Dual-fuel container ship is the ship that heavy oil and liquefied natural gas (LNG) are fuelled. Liquefied natural gas is injected into the fuel cabin of the ship through the filling device, and the liquefied natural gas is evaporated into natural gas gas through the configuration of low-pressure pump and low-pressure heat exchanger and then sent into the main engine and generator of the ship for combustion to provide power and generate electricity. The low-pressure natural gas gas enters the main engine and cannot be fully combusted, and a large amount of methane escapes into the air, causing fuel waste. At the same time, the liquid natural gas in the fuel cabin inevitably evaporates to produce flash gas, which accumulates at the top of the fuel cabin. When the pressure reaches a certain value, the flash gas will be discharged through the venting device under the action of the pressure valve. In addition to polluting the environment, the discharged gas also wastes energy and increases the operating cost of the ship. SUMMARY

[0003] In order to improve the combustion efficiency of LNG, reduce fuel loss and reduce operating costs, the utility model provides a dual-fuel container ship high pressure gas system.

[0004] To achieve the above purpose, the utility model takes the technical scheme that:

[0005] The dual-fuel container ship high pressure gas system comprises a fuel cabin, the fuel cabin is filled with liquid LNG fuel, an injection pipeline, a flash gas exhaust pipeline and a fuel output pipeline are installed at the top of the fuel cabin, a fuel pump is installed in the fuel cabin, the fuel pump pumps the LNG out of the fuel cabin and outputs it through the fuel output pipeline, a filter device is installed on the fuel output pipeline, the filter device is connected to a main engine gas supply pipeline and a generator gas supply pipeline through branch pipelines; a high-pressure gas supply unit is installed on the main engine gas supply pipeline, the high-pressure gas supply unit comprises a high-pressure pump, a high-pressure heat exchanger and a high-pressure gas storage tank, the filter device is connected to the high-pressure pump, the output end of the high-pressure pump is connected to the high-pressure heat exchanger, the high-pressure heat exchanger is connected to the high-pressure gas storage tank, and the high-pressure gas storage tank supplies gas to the main engine through a main engine gas valve group; a low-pressure gas supply unit is installed on the generator gas supply pipeline, the low-pressure gas supply unit comprises a low-pressure vaporizer, a low-pressure heater and a low-pressure gas buffer tank, the filter device is connected to the low-pressure vaporizer, the heat exchange cavities of the low-pressure vaporizer and the low-pressure heater are communicated, the heat exchange cavity of the low-pressure heater is connected to the low-pressure gas storage tank through a valve, and the low-pressure gas storage tank supplies gas to multiple generators.

[0006] Further, the flash gas exhaust pipeline is connected with the compressor unit and the heater unit by branch pipelines respectively, the compressor unit comprises a compressor and a cooler, the flash gas exhaust pipeline is connected with the suction port of the compressor, the exhaust port of the compressor is connected with the cooler, the cooler is connected with the low-pressure gas storage tank, and the heater unit comprises a heater which supplies gas to the boiler through a pipeline.

[0007] Further, the fuel tank is provided with a top injection pipeline, a bottom injection pipeline, a top spray pipeline and an inertization purge pipeline, the top injection pipeline and the bottom injection pipeline are connected with the side filling pipeline of the ship respectively, the top spray pipeline is connected with the side filling pipeline through a pipeline and a valve, and the inertization purge pipeline is connected with an external nitrogen input.

[0008] Further, the fuel tank is provided with a gas output pipeline which is connected with the gas phase pipeline of the ship through a pipeline and a valve.

[0009] Further, the gas output port of the low-pressure vaporizer is connected with the gas input port of the low-pressure heater, and the liquid output port of the low-pressure heater is connected with the liquid input port of the low-pressure vaporizer.

[0010] Further, the high-pressure gas storage tank, the low-pressure gas storage tank and the fuel tank are connected with the air breather mast through pipelines and pressure valves respectively.

[0011] Further, the heat exchange medium of the high-pressure heat exchanger, the low-pressure vaporizer, the low-pressure heater and the cooler is ethylene glycol.

[0012] After the above technical scheme is adopted, the utility model has the beneficial effects that:

[0013] When the fuel tank outputs liquid natural gas through the fuel pump, primary pressurization is realized, for the fuel sent to the generator, the fuel is supplied to the low-pressure gas storage tank after low-pressure gasification and heating to a proper temperature, for the fuel sent to the main engine, the fuel is sent to the main engine after being pressurized by the high-pressure pump, heat exchanged after pressurization and regulated by the valve group, the fuel pressure is adjusted to a proper high pressure, the combustion efficiency is improved, the energy consumption is reduced, and environmental pollution caused by insufficient combustion is avoided.

[0014] For the flash gas generated in the fuel tank, the flash gas is sent to the low-pressure gas storage tank after being pressurized by compression and cooled and adjusted in temperature, is used by the generator, or is directly sent to the heater after being heated to a proper temperature and is sent to the boiler for combustion, the flash gas in the fuel tank is utilized, and waste and environmental pollution caused by direct discharge are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The figure is a gas supply principle diagram of the utility model.

[0016] In the figure: fuel tank 1, filling pipe 11, flash gas exhaust pipe 12, fuel output pipe 13, gas output pipe 14, top injection pipe 15, bottom injection pipe 16, top spray pipe 17, inertization purge pipe 18, fuel pump 19, filling unit 2, low-pressure gas supply unit 3, low-pressure vaporizer 31, low-pressure heater 32, low-pressure gas buffer tank 33, high-pressure gas supply unit 4, high-pressure pump 41, high-pressure heat exchanger 42, high-pressure gas storage tank 43, main engine gas valve group 44, compressor unit 5, compressor 51, cooler 52, heater unit 53, main engine 6, generator 7, gas phase pipe 8, filter device 9, boiler 10. DETAILED DESCRIPTION

[0017] The specific embodiments of the utility model will be further described in detail below in combination with the drawings:

[0018] As shown in the figure, the high-pressure gas system of the dual-fuel container ship is composed of a fuel tank 1, a filling unit 2, a low-pressure gas supply unit 3, a high-pressure gas supply unit 4, and a compressor unit 5, and is used for supplying gas to the main engine 6 and the generator 7 of the container ship. Figure 1 The fuel tank 1 is filled with low-temperature (-163℃) liquid LNG fuel, and the top of the fuel tank 1 is provided with a filling pipe 11, a flash gas exhaust pipe 12, a fuel output pipe 13, and a gas output pipe 14. The fuel tank is provided with a top injection pipe 15, a bottom injection pipe 16, a top spray pipe 17, and an inertization purge pipe 18, and the inertization purge pipe 18 is connected with a nitrogen input. Before filling, the fuel tank 1 is purged by replacing the air inside with nitrogen, and the air is discharged through the gas output pipe and the gas phase pipe 8 of the ship. After the nitrogen replacement is completed, the fuel tank is inertized, liquid LNG is injected into the fuel tank through the top spray pipe 17, and the fuel tank is cooled by the low-temperature LNG, which is convenient for subsequent filling. The filling pipe 11 is connected with the filling unit 2, and the filling unit is installed on the side of the container ship. The left and right sides are respectively provided with filling units 2, and the filling unit 2 includes joints, pipes, and various valve groups connected with filling devices. The fuel of the filling vehicle or the shore filling station is injected into the fuel tank 1 through the filling unit 2.

[0019] The fuel tank 1 is provided with a fuel pump 19, which pumps LNG out of the fuel tank and out of the fuel output pipe 13. The fuel output pipe 13 is provided with a filter device 9, which filters the impurities in the liquid LNG. The filtered LNG is transported to the main engine gas supply pipe and the generator gas supply pipe through branch pipes and control valves.

[0020]

[0021] ​The high-pressure gas supply unit 4 is installed on the main engine gas supply pipeline. The high-pressure gas supply unit 4 is mainly used to convert the liquid natural gas into high-pressure gaseous natural gas for the main engine to improve the combustion efficiency. The high-pressure gas supply unit is composed of a plurality of high-pressure pumps 41 connected in series, a high-pressure heat exchanger 42, a high-pressure gas storage tank 43 and a main engine gas valve group 44. The LNG output by the fuel pump 19 reaches 8 bar. After entering the high-pressure pump 41, the LNG is gradually pressurized, and the final pressure reaches 325 bar. Then the LNG enters the high-pressure heat exchanger 42 to exchange heat with the ethylene glycol medium. The temperature of the high-pressure natural gas is increased and then sent to the high-pressure gas storage tank 43 for storage. The LNG gas output from the high-pressure gas storage tank 43 enters the main engine 6 after being regulated by the main engine gas valve group 44 and is burned in the main engine.

[0022] The low-pressure gas supply unit 3 is installed on the generator gas supply pipeline. The low-pressure gas supply unit 3 includes a low-pressure vaporizer 31, a low-pressure heater 32 and a low-pressure gas buffer tank 33. The filtered LNG from the filter device 9 enters the low-pressure vaporizer 31. The low-pressure vaporizer 31 uses ethylene glycol as the heat exchange medium to vaporize the liquid LNG into steam at about -50°C. The vaporized steam from the low-pressure vaporizer 31 enters the low-pressure heater 32 through a pipeline. The low-pressure heater 32 also uses ethylene glycol as the heat exchange medium to heat the low-temperature steam to normal temperature steam at about 40°C. The heated normal temperature steam enters the low-pressure gas storage tank 33 for collection. The low-pressure gas storage tank 33 supplies gas to a plurality of generators 7.

[0023] Since LNG is extremely easy to vaporize at room temperature, evaporation and vaporization of methane steam will inevitably occur in the fuel tank 1 under good insulation conditions. In order to maintain the stability of the gas supply system, the generated steam and the steam generated during the cooling stage of the fuel tank are recycled in two ways. The first way is to send the steam into the compressor unit 5 through valves and pipelines. The compressor unit 5 includes a plurality of parallel compressors 51. The steam enters the compressors 51 and is compressed. The pressure of the steam is increased. The compressed steam needs to be heat exchanged with ethylene glycol in the cooler 52 due to its high temperature. The temperature is stably reduced to about 40°C, and then enters the low-pressure gas buffer tank 33 through a pipeline for use by the generator. The second way is to send the steam into the heater unit 53 through the control of pipelines and valves. The steam is heat exchanged with ethylene glycol in the heater unit 53 to increase the temperature to about 40°C, and then directly sent to the boiler 10 for combustion.

[0024] In the technical solution, pressure control elements such as pressure relief valves are installed on each pipeline of the system. The high-pressure gas storage tank 43, the low-pressure gas storage tank 33, the fuel tank 1 and each pipeline are connected to the vent mast through pipelines and pressure control elements. When the pressure is too high, the pressure in the system is kept stable by releasing to ensure safety.

Claims

1. A high-pressure gas system for a dual-fuel container ship, comprising a fuel tank in which liquid LNG fuel is stored, a filling pipe, a flash gas exhaust pipe and a fuel output pipe being arranged on the top of the fuel tank, a fuel pump being arranged in the fuel tank, the fuel pump pumping the LNG from the fuel tank out of the fuel output pipe, a filter device being arranged on the fuel output pipe, characterized in that The filtering device is connected with the main engine gas supply pipeline and the generator gas supply pipeline through branch pipelines respectively; a high-pressure gas supply unit is installed on the main engine gas supply pipeline, which comprises a high-pressure pump, a high-pressure heat exchanger and a high-pressure gas storage tank, the filtering device is connected with the high-pressure pump, the output end of the high-pressure pump is connected with the high-pressure heat exchanger, the high-pressure heat exchanger is connected with the high-pressure gas storage tank, and the high-pressure gas storage tank supplies gas to the main engine through a main engine gas valve group; a low-pressure gas supply unit is installed on the generator gas supply pipeline, which comprises a low-pressure vaporizer, a low-pressure heater and a low-pressure gas buffer tank, the filtering device is connected with the low-pressure vaporizer, the heat exchange cavity of the low-pressure vaporizer is communicated with the low-pressure heater, the heat exchange cavity of the low-pressure heater is connected with the low-pressure gas storage tank through a valve, and the low-pressure gas storage tank supplies gas to multiple generators.

2. The dual-fuel container ship high-pressure gas system of claim 1, wherein, The flash gas exhaust pipeline is connected with a compressor unit and a heater unit through branch pipelines respectively, the compressor unit comprises a compressor and a cooler, the flash gas exhaust pipeline is connected with the suction port of the compressor, the exhaust port of the compressor is connected with the cooler, and the cooler is connected with the low-pressure gas storage tank; the heater unit comprises a heater, and the heater supplies gas to the boiler through a pipeline.

3. The dual-fuel container ship high-pressure gas system of claim 1, wherein, The fuel tank is provided with a top injection pipeline, a bottom injection pipeline, a top spray pipeline and an inertization purge pipeline, the top injection pipeline and the bottom injection pipeline are connected with a ship side filling pipeline respectively, the top spray pipeline is connected with the ship side filling pipeline through a pipeline and a valve, and the inertization purge pipeline is connected with an external nitrogen input.

4. The dual-fuel container ship high-pressure gas system of claim 3, wherein, A gas output pipeline is installed on the top of the fuel tank, and the gas output pipeline is connected with a gas phase pipeline of a ship through a pipeline and a valve.

5. The dual-fuel container ship high-pressure gas system of claim 1, wherein, The gas output port of the low-pressure vaporizer is connected with the gas input port of the low-pressure heater, and the liquid output port of the low-pressure heater is connected with the liquid input port of the low-pressure vaporizer.

6. The dual-fuel container ship high-pressure gas system of claim 1, wherein, The high-pressure gas storage tank, the low-pressure gas storage tank and the fuel tank are connected with a vent mast through pipelines and pressure valves respectively.

7. The dual-fuel container ship high-pressure gas system of claim 1, wherein, The heat exchange medium of the high-pressure heat exchanger, the low-pressure vaporizer, the low-pressure heater and the cooler is ethylene glycol.

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