Hydrogen storage and reliquefaction coupling fuel exhaust gas low-temperature trapping system for liquid hydrogen-fuel oil dual-fuel ship
Technical Field
The invention relates to new fuel ship low-temperature fuel reliquefaction and storage, dual-fuel ship energy conservation and emission reduction, and low-temperature CO of fuel oil waste gas2The trapping field particularly relates to a hydrogen storage reliquefaction and low-temperature helium compression expansion cooling cycle of a liquid hydrogen-fuel oil dual-fuel ship and a method for trapping tail gas CO by using low-temperature cold energy2The new energy ship multi-fuel composite system.
Background
Natural disasters continue to follow as a result of the accumulation of excessive resource utilization and unregulated emission of pollution from the first few industrial revolution. According to incomplete statistics, landslide, avalanche, drought, forest fire, flood, tsunami and the like which are more than half of the world from the 20 th century to the present are caused by more and more frequent pollutants and the like discharged by mankind in production and life without control. Although China is wide in margins, rich in resources and huge in coastlines, the frequency of natural disasters is more and more severe in recent years. Therefore, how to use new energy, development of sustainable energy, energy conservation and emission reduction are main measures for meeting the challenge of natural disasters caused by global warming and climate change. In recent years, energy conservation and emission reduction and new energy utilization of land traffic in China are rapidly developed, automobile energy sources are from traditional gasoline to liquefied petroleum gas, then new energy sources of ethanol and natural gas, and finally a hydrogen fuel cell is used for pure electric power, and the advantages of energy conservation and emission reduction are particularly remarkable when tail gas emission of the automobile is gradually reduced. At present, shipping almost completely depends on fossil fuel, namely petroleum, and is a transportation mode with high carbon emission. By establishing a greenhouse gas strategy, the international maritime organization sets a strong target, namely the decarbonization operation of shipping is realized at the end of the century. The mid-term goal was to reduce the ship exhaust emissions by 2050 to 50% of 2008. This cannot be achieved unless there is a new clean fuel for the ship and a new way of operating the power system of the ship.
Whether combustion work or fuel cell power generation, hydrogen is considered as the ultimate solution to replace fossil fuels as a clean, abundant, recyclable, and environmentally friendly energy product. The combustion heat value of the fuel cell is about 3 times of that of gasoline, the fuel cell is far higher than natural gas, only water is generated when the fuel cell is used, and if the fuel cell is used for ships, the emission of sulfur oxides and particles can be completely avoided, so that the power pollution emission problem worried by the international maritime organization can be solved once and for all. It is expected that most ships, automobiles and the like will select hydrogen as a main fuel in 30 to 50 years in the future. From an energy perspective, current shipping fuels are not sustainable, creating problems with climate change and local air pollution. This situation cannot be continued in view of the pressure of various countries and international societies in terms of climate change and air pollution. In shipping, the trend toward shipping decarburization has begun to emerge in the future, driven strongly by policies such as the IMO greenhouse gas strategy. Therefore, the application of the zero-emission green energy source of hydrogen and liquid hydrogen to the marine fuel is urgently needed to be rapidly developed. However, the new energy has many differences in ship power configuration, main and auxiliary machinery arrangement, pipeline connection, safe use and the like, unlike the conventional marine diesel fuel in terms of calorific value, use method, condition and environment and the like. The blind and direct use of the new energy can lead to mismatching of ship power equipment, huge energy consumption and incapability of meeting the original purpose of energy conservation and emission reduction, and even more, potential safety hazards such as ship damage and personal death can occur. Therefore, how to safely and efficiently comprehensively use the new energy to match the existing ship power system or specially design a pipeline of the ship power system aiming at the new energy to safely replace the traditional fossil fuel and effectively utilize the new energy, and the method has the advantages of low carbon and environmental protection and is a key scientific and engineering problem for replacing the new energy in the current shipping industry.
At present, the storage of hydrogen mainly comprises high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, metal hydride hydrogen storage and organic liquid hydrogen storage. Although high pressure gaseous hydrogen storage (mass density 4.0 wt% bulk density 39g/L) has been able to meet the daily requirements for small vehicles such as automobiles. However, for large-scale marine power, a low-temperature liquid hydrogen storage method having a mass hydrogen storage density of 5.7 wt% and a volume hydrogen storage density of 70g/L, which is currently known as the largest hydrogen storage method, is necessary. However, liquid hydrogen is a very low temperature fuel at about-252 ℃ like liquefied natural gas, and generally needs to be gasified to room temperature and then enters an engine, a boiler or a fuel cell to work. However, the problem of self-evaporation is inevitable due to heat leakage of the tank body in the storage process of the liquid hydrogen storage tank with large external temperature difference, so how to reliquefy the hydrogen evaporated gas in the liquid hydrogen tank of the ship, and the key for efficiently utilizing the hydrogen fuel is to utilize the cold energy in the gasification of the liquid hydrogen.
There have been some patents mentioning liquid hydrogen storage and utilization process systems. For example, in the invention CN108561749A, a "hybrid filling system applied to a liquid hydrogen filling station" describes that a hybrid filling system applied to a liquid hydrogen filling station has a liquid hydrogen filling unit and a high-pressure hydrogen filling unit, which provides more filling forms for the hydrogen filling station. However, the flow does not analyze in detail how to use liquid hydrogen gasification, or the reliquefaction flow cannot well solve the problem of lossless storage of hydrogen or liquid hydrogen, and cannot meet the requirements of large-scale application and development on ships. As another example, a hydrogen reliquefaction device, in patent CN102155610B, a cryogenic medium liquefaction device is disclosed, which provides a method for integrally liquefying a cryogenic medium by using one or more refrigerators, and provides a cryogenic medium liquefaction device that makes full use of the heat transfer area at the low-temperature end of the cold head of a refrigerator, reduces heat leakage, improves working efficiency, saves energy, is convenient to install and disassemble, and reduces manufacturing and maintenance costs. However, this invention requires a specific refrigerator to perform liquefaction, and has a very low liquefaction temperature of hydrogen and no use of the cold energy of gasification, and thus it is difficult to scale up the ship. The invention CN111174529A discloses a system and a method for removing hydrocarbon and carbon from liquefied natural gas by using cold energy of the liquefied natural gas, the system for removing hydrocarbon and carbon from the liquefied natural gas by using cold energy of the liquefied natural gas provides cold energy required by liquefaction of each component in the process of removing hydrocarbon and carbon from the liquefied natural gas by using cold energy of LNG. However, this technology can only improve the LNG cold energy utilization efficiency by treating the produced natural gas or oil field associated gas using the cold energy released from the LNG gasification process. The energy source device cannot be integrated in a ship power energy system, and the energy in the processes of low-temperature liquid gasification and reliquefaction cannot be completely and comprehensively utilized.
Disclosure of Invention
According to the problems of large energy consumption and tail gas emission caused by the fact that the existing hydrogen evaporation gas reliquefaction storage, liquid hydrogen regasification utilization, ship fuel tail gas treatment and related technologies cannot be used in energy combined application, a liquid hydrogen-fuel double-fuel ship hydrogen storage reliquefaction coupling diesel waste gas low-temperature trapping system is provided. The invention takes the reliquefaction of the low-temperature hydrogen evaporated gas as a starting point, the low-temperature fuel cold energy of the ship is captured at low temperature by using the coupling fuel oil waste gas as a breakthrough, and the single functions of liquefying working media by using low-temperature flow or collecting and processing tail gas of an auxiliary engine boiler of a main engine of the ship and the like in the traditional method are broken through. The invention mainly aims at low-temperature capture of coupling fuel oil waste gas by hydrogen storage and reliquefaction, and a spray-type reliquefaction process is carried out by utilizing helium refrigeration cycle to supercool liquid hydrogen so as to return to a liquid hydrogen storage tank, so that reliquefaction and positive-secondary hydrogen conversion are carried out in a low-temperature hydrogen evaporated gas re-storage tank, the conversion heat is carried away by another needed hydrogen evaporated gas to precool tail gas of a ship main engine and an auxiliary engine boiler for combustion, and the evaporative cold energy of the liquid hydrogen needed by a fuel cell is used for condensing the tail gas of the ship so as to carry out CO (carbon monoxide) recovery2A series of energy conversion systems and methods for trapping and liquefying form a set of energy-saving emission-reduction efficient utilization system for trapping and storing coupled fuel tail gas by liquefying hydrogen vapor of a dual-fuel ship.
The technical means adopted by the invention are as follows:
a hydrogen storage and reliquefaction coupling diesel exhaust gas low-temperature trapping system of a liquid hydrogen-fuel oil dual-fuel ship comprises a low-temperature helium and liquid hydrogen heat exchange network system, a gas helium refrigeration circulating system, a ship host and a boiler tail gas low-temperature trapping system;
the low-temperature helium and liquid hydrogen heat exchange network system comprises a liquid hydrogen storage tank, a liquid hydrogen pump I, a four-stream precooler, a two-stream subcooler, a three-stream heat exchanger and a subcooled liquid hydrogen spraying normal-secondary hydrogen converter which are sequentially communicated with one another through pipelines; liquid hydrogen is firstly pumped into a heat exchange network from the liquid hydrogen storage tank by the liquid hydrogen pump I, and finally enters the supercooled liquid hydrogen spraying n-sec hydrogen converter positioned on the upper layer of the liquid hydrogen storage tank in a supercooled liquid state form after sequentially passing through the four-stream precooler, the two-stream subcooler and the three-stream heat exchanger, and liquid hydrogen evaporated gas generated by environmental heat leakage on the upper layer of the liquid hydrogen storage tank is liquefied into liquid hydrogen again, and a catalyst in the supercooled liquid hydrogen spraying n-sec hydrogen converter converts high-temperature normal hydrogen into low-temperature easily-stored sec hydrogen;
the gas helium refrigeration circulating system comprises a liquid helium storage tank, a liquid helium pump, a heat regenerator, a gas helium compressor and a gas helium expander; the liquid helium is firstly sent into the three-stream heat exchanger and the two-stream subcooler in sequence from the liquid helium storage tank by the liquid helium pump, flows through the heat regenerator, then enters the helium compressor for compression, then sequentially flows through the four-stream precooler and the heat regenerator for heat release, finally enters the expander for expansion and work to be changed into low-temperature helium or liquid helium, and then returns to the liquid helium storage tank;
the low-temperature tail gas trapping system for the marine main engine and the boiler comprises a liquid hydrogen pump II, a control valve, a back pressure valve, a tail gas precooler, a tail gas subcooler, the marine main engine, an auxiliary boiler, a fuel tank, a tail gas filter and CO2An enrichment reservoir; the tail gas is the exhaust gas discharged after the fuel oil in the fuel oil tank in the dual-fuel power ship is supplied to the auxiliary boiler and the ship main engine for combustion; the tail gas firstly passes through the tail gas filter to remove impurities including nitrogen oxide, sulfur oxide and other impurities, and then sequentially enters the tail gas precooler and the tail gas subcooler to exchange heat so as to enable CO to be in a CO state2Liquefaction, liquefied CO2Storing in said CO2In the enrichment reservoir; the tail gas precooler and the tail gas subcooler are respectively connected to the liquid hydrogen storage tank, the control valve is arranged between the tail gas subcooler and the liquid hydrogen storage tank, and the back pressure valve is arranged between the tail gas precooler and the liquid hydrogen storage tank.
Further, working media circulating in the system comprise liquid helium, low-temperature helium gas, liquid hydrogen and supercooled liquid hydrogen; the energy transfer process in the system comprises the following steps: the liquid helium firstly transfers cold energy to the liquid hydrogen and the supercooled liquid hydrogen in the two-stream subcooler and the three-stream heat exchanger, absorbs heat to become low-temperature helium gas, then is compressed by the compressor after the temperature is further raised by the heat regenerator, then sequentially enters the four-stream precooler and the heat regenerator to further reduce heat, and finally enters the expander to be liquefied or cooled.
Further, the energy conversion process in the marine main engine and the boiler tail gas low-temperature capture system comprises the following steps: firstly, controlling the flow of hydrogen evaporation gas introduced into the tail gas precooler from the liquid hydrogen storage tank through the backpressure valve, exchanging heat and precooling tail gas with the hydrogen evaporation gas in the tail gas precooler, then introducing the tail gas into the tail gas subcooler, controlling the flow of liquid hydrogen introduced into the subcooler from the liquid hydrogen storage tank through the control valve, and exchanging heat between the tail gas and the liquid hydrogen in the tail gas subcooler to ensure that CO in the tail gas exchanges heat2Condensing and liquefying.
Further, the four-stream precooler, the two-stream subcooler, the three-stream heat exchanger, the heat regenerator, the tail gas precooler and the tail gas subcooler can be plate-fin, plate, printing plate, wound-tube or shell-and-tube heat exchangers, and the inside can be perforated, corrugated or sawtooth fins.
Further, the liquid hydrogen storage tank and the subcooled liquid hydrogen spraying orthohydrogen converter are integrally or separately arranged.
Further, the CO is2Enriching liquid CO in a reservoir2Can be used as cold storage working medium for ship air conditioning and food freezing and refrigeration, or can be transported to land for further treatment as edible carbon dioxide.
Furthermore, the work of the control valve and the back pressure valve is regulated and controlled according to the internal temperature, pressure and liquid level condition of the system.
Compared with the prior art, the invention has the following advantages:
1. the hydrogen storage and reliquefaction coupling diesel exhaust gas low-temperature trapping system of the liquid hydrogen-fuel oil dual-fuel ship can solve the problems of energy utilization and conversion in the processes of low-temperature fuel storage and reliquefaction of the evaporator of a new energy ship; breaks through the traditional technical mode: the method can be well suitable for ship application, more parameters cannot be considered simultaneously, and the evaluation on the availability of energy, the influence on the environment and the cost is relatively weak; the technical problems of efficient utilization of renewable energy and new energy splitting at present are eliminated, and the problems of re-liquefaction after heat leakage of the tank body in the storage process of the liquid hydrogen storage tank and efficient utilization of liquid hydrogen gasification cold energy caused by large external temperature difference are overcome.
3. According to the hydrogen storage and reliquefaction coupling diesel exhaust gas low-temperature trapping system for the liquid hydrogen-fuel oil dual-fuel ship, the fuel supply process of the liquid hydrogen-fuel oil dual-fuel ship can adopt a fuel oil-based hot start mode to assist the supply of liquid hydrogen fuel when the ship is started, the flexible mode can prevent low-temperature pipeline protection, and can also gasify liquid hydrogen by utilizing the exhaust gas heat of an auxiliary boiler and a ship engine so as to reach the working temperature of the hydrogen fuel required by the engine; in addition, the hydrogen fuel can be used for combustion of a common engine and can also be used as a main fuel of a fuel cell in an electric power ship; the specific sailing working conditions and design forms of the fuel cell and the combustion engine, such as a hybrid power mode, and the like, can be flexibly configured according to the power size and the structural form of the ship, the quantity of the liquid hydrogen storage tank and the like.
4. The hydrogen storage and reliquefaction coupling diesel exhaust gas low-temperature trapping system of the liquid hydrogen-fuel dual-fuel ship provided by the invention is economic, safe, environment-friendly and energy-saving; compared with the traditional method, the ship main engine and the boiler tail gas are low-temperature CO2The trapping system is started only under the condition of adopting fuel oil fuel and hybrid power, so that the exhaust emission is reduced; additional enriched liquid CO2Can be used as cold storage working media such as dry ice and the like to supply to ship air conditioners, food freezing and refrigeration or be transported to land for further processing as edible carbon dioxide.
Based on the reason, the invention can be widely popularized in the fields of ship multi-power systems and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of a hydrogen storage and reliquefaction coupled fuel exhaust gas low-temperature trapping system of a liquid hydrogen-fuel dual-fuel ship.
In the figure: 100. a liquid hydrogen storage tank; 101. a liquid hydrogen pump I; 102. a four-stream precooler; 103. a two-stream subcooler; 104. a three-stream heat exchanger; 105. supercooling liquid hydrogen sprays an orthosteric hydrogen converter; 201. a liquid helium storage tank; 202. a liquid helium pump; 203. a heat regenerator; 204. a gas helium compressor; 205. a gas helium expander; 301. a liquid hydrogen pump II; 302. a control valve; 303. a back pressure valve; 304. a tail gas subcooler; 305. a tail gas precooler; 306. an auxiliary boiler; 307. a marine main engine; 308. a fuel tank; 309. a tail gas filter; 310. CO 22An enrichment reservoir.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
As shown in fig. 1, the invention provides a hydrogen storage and reliquefaction coupling diesel exhaust gas low-temperature trapping system for a liquid hydrogen-fuel double-fuel ship, which comprises a low-temperature helium and liquid hydrogen heat exchange network system, a gas helium refrigeration cycle system, a ship host and a boiler tail gas low-temperature trapping system;
the low-temperature helium and liquid hydrogen heat exchange network system comprises a liquid hydrogen storage tank 100, a liquid hydrogen pump I101, a four-stream precooler 102, a two-stream subcooler 103, a three-stream heat exchanger 104 and a subcooled liquid hydrogen spraying normal-secondary hydrogen converter 105 which are sequentially communicated with one another through pipelines;
liquid hydrogen is firstly pumped into a heat exchange network from the liquid hydrogen storage tank 100 by the liquid hydrogen pump I101, sequentially passes through the four-stream precooler 102, the two-stream subcooler 103 and the three-stream heat exchanger 104, finally enters the subcooled liquid hydrogen spraying normal-secondary hydrogen converter 105 positioned on the upper layer of the liquid hydrogen storage tank 100 in a subcooled liquid state form, and meanwhile, liquid hydrogen evaporated gas generated by environmental heat leakage on the upper layer of the liquid hydrogen storage tank 100 is re-liquefied into liquid hydrogen, and a catalyst in the subcooled liquid hydrogen spraying normal-secondary hydrogen converter 105 converts high-temperature normal hydrogen into low-temperature easy-to-store normal hydrogen;
the low-temperature helium and liquid hydrogen heat exchange network system for reliquefying the hydrogen evaporated gas is a system for reliquefying the hydrogen evaporated gas in a subcooled liquid hydrogen spraying orthodrogen-parahydrogen converter after the low-temperature helium exchanges subcooled liquid hydrogen on the surface in the heat exchange network;
the gas helium refrigeration cycle system comprises a liquid helium storage tank 201, a liquid helium pump 202, a heat regenerator 203, a gas helium compressor 204 and a gas helium expander 205;
liquid helium is firstly sent into the three-stream heat exchanger 104 and the two-stream subcooler 103 in sequence from the liquid helium storage tank 201 by the liquid helium pump 202, flows through the heat regenerator 203, then enters the helium compressor 204 for compression, then flows through the four-stream precooler 102 and the heat regenerator 203 in sequence for heat release, and finally enters the expander 205 for expansion to work and change into low-temperature helium or liquid helium and then returns to the liquid helium storage tank 201;
the gas helium refrigeration cycle system for continuously providing liquid hydrogen storage cold energy is a system for providing cold energy for the low-temperature helium and liquid hydrogen heat exchange network system;
the low-temperature capture system for the tail gas of the marine main engine and the boiler comprises a liquid hydrogen pump II 301, a control valve 302, a back pressure valve 303, a tail gas precooler 305, a tail gas subcooler 304, a marine main engine 307, an auxiliary boiler 306, a fuel tank 308, a tail gas filter 309 and CO2 An enrichment reservoir 310;
the tail gas is exhaust gas discharged after fuel oil in the fuel oil tank 308 in the dual-fuel power ship is supplied to the auxiliary boiler 306 and the ship main engine 307 for combustion; the tail gas first passes through the tail gas filter 309 to remove impurities including nitrogen oxide, sulfur oxide and other impurities, and then enters the tail gas precooler 305 and the tail gas subcooler 304 in sequence to exchange heat so as to enable CO to be cooled2Liquefied, liquefied CO2Storing in said CO2In the enrichment reservoir 310;
the tail gas precooler 305 and the tail gas subcooler 304 are respectively connected to the liquid hydrogen storage tank 100, the control valve 302 is arranged between the tail gas subcooler 304 and the liquid hydrogen storage tank 100, and the back pressure valve 303 is arranged between the tail gas precooler 305 and the liquid hydrogen storage tank 100.
The low-temperature CO capture for purifying and capturing tail gas of ship main engine and boiler of fuel oil2The system is used for purifying tail gas and liquefying CO discharged by fuel oil combustion by using the low temperature2The system of (1).
Further, working media circulating in the system comprise liquid helium, low-temperature helium gas, liquid hydrogen and supercooled liquid hydrogen; the energy transfer process in the system comprises the following steps: the liquid helium firstly transfers cold energy to the liquid hydrogen and the supercooled liquid hydrogen in the two-stream subcooler 103 and the three-stream heat exchanger 104, absorbs heat to become low-temperature helium gas, then is compressed by the compressor 204 after the temperature is further raised by the heat regenerator 203, then sequentially enters the four-stream precooler 102 and the heat regenerator 203 to further reduce heat, and finally enters the expander 205 to be liquefied or cooled.
Further, the energy conversion process in the marine main engine and the boiler tail gas low-temperature capture system comprises the following steps: firstly, the back pressure valve 303 controls the liquid hydrogen to be introduced from the liquid hydrogen storage tank 100The flow rate of the hydrogen evaporation gas in the tail gas precooler 305, the tail gas and the hydrogen evaporation gas in the tail gas precooler 305 are subjected to heat exchange and precooling, then the tail gas is introduced into the tail gas subcooler 304, the flow rate of the liquid hydrogen introduced into the subcooler 304 from the liquid hydrogen storage tank 100 is controlled by the control valve 302, and the heat exchange of the tail gas and the liquid hydrogen in the tail gas subcooler 304 is carried out to ensure that CO in the tail gas is subjected to the heat exchange2Condensing and liquefying.
Furthermore, working media in the ship main engine and the boiler tail gas low-temperature capture system comprise tail gas, liquid hydrogen, gas hydrogen, low-temperature hydrogen steam and the like under different temperature conditions.
Further, the four-stream precooler 102, the two-stream subcooler 103, the three-stream heat exchanger 104, the heat regenerator 203, the tail gas precooler 305 and the tail gas subcooler 304 may be plate-fin, plate, printed plate, wound tube or shell-and-tube heat exchangers, and may be perforated, corrugated or zigzag fins for increasing heat exchange inside, or may increase convection heat exchange coefficient by nano-electroplating surface treatment or other methods.
Further, the liquid hydrogen storage tank 100 and the subcooled liquid hydrogen spraying orthohydrogen converter 105 are integrally or separately disposed.
Due to heat leakage of the environment, the upper part of the liquid hydrogen storage tank can store part of evaporated gas of liquid hydrogen, the pressure of the storage tank can be gradually increased, and the storage tank can roll in severe cases, so that part of hydrogen vapor on the upper part of the storage tank needs to be condensed and liquefied by circularly spraying super-cooled liquid hydrogen, the pressure in the storage tank is reduced, and the storage time and the safety of the storage tank are ensured; the subcooled liquid hydrogen spray ortho-para-hydrogen converter 105 is internally provided with low-temperature catalysts such as iron-based catalysts and nickel-based catalysts necessary for ortho-para-hydrogen conversion, and is used for converting liquefied ortho-hydrogen into para-hydrogen which is easy to store, the conversion heat is given to the residual hydrogen vapor at the upper part of the storage tank, and the hydrogen vapor is conveyed to the tail gas precooler 305 in a mode of controlling the opening degree of the back pressure valve 303.
Further, the low-temperature CO in the tail gas of the marine main engine and the boiler2The trapping system is started only under the conditions of adopting fuel oil and fuel and hybrid power, and is used for reducing the exhaust emission;the CO is2Enriching liquid CO in reservoir 3102Can be used as cold storage working media such as dry ice and the like for supplying to ship air conditioners, freezing and refrigerating foods or transporting to land for further processing as edible carbon dioxide.
Further, the system also includes multiple pipes, valves and control module switches, not limited to the control valve 302 and the back pressure valve 303, which operate according to the temperature, pressure and level conditions inside the system.
Further, the fuel supply process of the liquid hydrogen-oil dual-fuel ship specifically comprises the following steps: firstly, a hot start mode taking fuel as a main mode can be adopted when the ship is started to assist the supply of liquid hydrogen fuel, the flexible mode can prevent low-temperature pipeline protection, and liquid hydrogen can be gasified by utilizing the waste gas heat of an auxiliary engine boiler and a ship engine so as to reach the working temperature of the hydrogen fuel required by the engine; in addition, the hydrogen fuel can be used for combustion of a common engine and can also be used as a main fuel of a fuel cell in an electric power ship; the specific sailing working conditions and design forms of the fuel cell and the combustion engine, such as a hybrid power mode, and the like, can be flexibly configured according to the power size and the structural form of the ship, the quantity of the liquid hydrogen storage tank and the like.
Furthermore, the hydrogen storage and reliquefaction coupling diesel exhaust gas low-temperature trapping system of the liquid hydrogen-fuel oil dual-fuel ship is also suitable for fuel storage and reliquefaction systems of other dual-fuel ships, including liquefied natural gas LNG-fuel oil dual-power, liquid ammonia-fuel oil, combustible ice-fuel oil dual-power and the like.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.