KR20220034713A - Fuel supply system of eco-friendly ship and ship including the same - Google Patents

Abstract

The present invention relates to a fuel supply system for an eco-friendly ship that mixes ammonia gas and engine fuel and supplies the same to an engine, comprising: a solid ammonium storage tank in which solid ammonium is stored; a first heater for heating the solid ammonium to generate an ammonia gas and a carbon dioxide gas; a heat exchanger converting the ammonia gas and the carbon dioxide gas into an ammonia liquid by exchanging heat with the engine fuel; and a separator for separating the ammonia liquid and the carbon dioxide gas, thereby capable of improving cost-effectiveness and safety of facilities.

Description

Fuel supply system for eco-friendly ships and ships including them

The present invention relates to a fuel supply system for an eco-friendly ship and a ship including the same.

Air pollution is getting serious all over the world, and climate change is taking place due to air pollution. Since pollutants emitted from ships have a large impact on air pollution, the International Maritime Organization (IMO), the European Union, and the United States are strengthening regulations on pollutants emitted from ships to reduce air pollution, and there is.

As the greenhouse gas emission regulations of ships will be strengthened step by step by 2050 at each major point, it is expected that it will be difficult to comply with the regulations on pollutants only with the existing engines and fuels.

Therefore, as the strengthened ship greenhouse gas emission regulations are applied, it is expected that the use of the existing fossil fuels currently used will be difficult, and it is very urgent to discover alternative fuels that can satisfy the regulations to be strengthened in the future. As an alternative fuel, non-fossil fuels such as ammonia (NH ₃ ), biofuel, solar energy, and wind energy are being considered.

Among them, ammonia is a chemical that can be produced, stored, transported and supplied, and ammonia ships using ammonia as fuel are being developed.

Existing ammonia ships store ammonia fuel as a liquid. Since ammonia has a lower boiling point (at atmospheric pressure, -33°C) than room temperature, in order to store ammonia as a liquid, the ammonia storage tank must also have certain specifications. In addition, since the inside of the tank must be maintained at a low temperature to maintain ammonia in a liquid state, the storage tank must be cooled and a lot of energy is consumed in the cooling process.

In addition, the storage tank of liquid ammonia may generate vaporized gas in the tank, and the pressure inside the storage tank rises due to the vaporization gas, and there is a risk of the tank exploding. There is a risk of personal injury due to ammonia toxicity.

As such, the existing ammonia vessel stores liquid ammonia fuel and supplies ammonia fuel to the engine, in terms of facility cost and operating cost, the efficiency is lowered, and the safety of the facility is also lowered.

The present invention was created to solve the problems of the prior art as described above, and an object of the present invention is to supply ammonia fuel using solid ammonium to provide fuel for eco-friendly ships that can improve cost efficiency and safety of facilities to provide a system.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

The fuel supply system for an eco-friendly ship according to the present invention is a fuel supply system for an eco-friendly ship for supplying an engine by mixing ammonia gas and engine fuel, comprising: a solid ammonium storage tank in which solid ammonium is stored; a first heater for heating the solid ammonium to generate the ammonia gas and carbon dioxide gas; a heat exchanger converting the ammonia gas and carbon dioxide gas into an ammonia liquid by exchanging heat with the engine fuel; and a separator for separating the ammonia liquid from the carbon dioxide gas.

Specifically, it may further include a second heater provided downstream of the separator to convert the ammonia liquid into a gas.

Specifically, it may include a fuel supply line for supplying the engine fuel to the engine, and a fuel branch line branched from the fuel supply line to supply the engine fuel to the heat exchanger.

Specifically, the solid ammonium may be ammonium carbonate or ammonium bicarbonate.

The ship according to the present invention may include a fuel supply system for the eco-friendly ship.

The fuel supply system for an eco-friendly ship of the present invention has the following effects.

The fuel supply system for eco-friendly ships according to the present invention can improve cost efficiency and safety of facilities by supplying ammonia to the engine using solid ammonium.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the art from the description of the claims.

1 is a view showing a conventional liquid ammonia fuel supply system.
2 is a view showing a fuel supply system according to the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In the present specification, in adding reference numbers to the components of each drawing, it should be noted that only the same components are given the same number as possible even though they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a view showing a conventional liquid ammonia fuel supply system (1).

Referring to Figure 1, the conventional liquid ammonia fuel supply system (1), a liquid ammonia storage tank (10), a heater (20), a heat exchanger (30), a fuel storage tank (40), a vaporizer (50), a mixer 60 and an engine 70 .

Ammonia is stored in the liquid ammonia storage tank (10). Ammonia can be stored in a liquid state in the form of aqueous ammonia.

The fuel storage tank 40 may store engine fuel.

The conventional liquid ammonia fuel supply system 1 may use engine fuel stored in the fuel storage tank 40 and ammonia stored in the liquid ammonia storage tank 10 as fuel of the engine 70 . At this time, the engine fuel and ammonia may be selectively supplied to the engine 70 or may be supplied together.

Liquid ammonia is vaporized through the heater 20 and supplied to the engine 70 . The engine fuel supplied from the fuel storage tank 40 is also vaporized in the carburetor 50 and supplied to the engine 70 . The ammonia and the engine fuel may be mixed before being supplied to the engine 70 or after being supplied to the engine 70 before being combusted to be uniformly mixed.

The heat exchanger 30 heats the vaporized gas generated in the liquid ammonia storage tank 10 with the engine fuel in the fuel storage tank 40 to liquefy the vaporized gas and increase the temperature of the engine fuel before vaporization.

2 is a view showing a fuel supply system 2 according to the present invention.

Referring to FIG. 2 , the fuel supply system 2 of the present invention includes a solid ammonium storage tank 100 , a first heater 200 , a heat exchanger 300 , a fuel storage tank 400 , a separator 500 , It includes a carburetor 600 , a second heater 700 , a mixer 800 , and an engine 900 .

Solid ammonium is stored in the solid ammonium storage tank 100 . Solid ammonium refers to solid ammonia compounds, such as ammonium carbonate and ammonium bicarbonate, which can generate ammonia gas.

The solid ammonium storage tank 100 is a storage tower having an internal pressure of 2 to 3 bar, and the storage tower may be in the form of a silo. A means (not shown) for controlling the amount of solid ammonium delivered to the first heater 200 may be provided in the solid ammonium storage tank 100 .

Engine fuel may be stored in the fuel storage tank 400 . Engine fuel stored in the fuel storage tank 40 is HFO (High sulfur Feul Oil), LSFO (Low Sulfur Fuel Oil), ULSFO (Ultra-Low Sulfur Fuel Oil), MGO (Marine Gas Oil), LNG (Liquefied Natural Gas) ), LPG (Liquefied Petroleum Gas), LEG (Liquefied Ethylene Gas), MeOH (methanol), DME (dimethyl ether), etc. may be a conventionally used fuel, and the engine fuel is preferably LNG.

Solid ammonium stored in the solid ammonium storage tank 100 is heated in the first heater 200 and separated into ammonia gas and carbon dioxide gas.

As an example, the reaction formula in which ammonium carbonate in solid ammonium is thermally decomposed to produce ammonia is as follows.

(NH ₄ ) ₂ CO ₃ ↔ 2NH ₃ +CO ₂ +H ₂ O

Water may be generated during the thermal decomposition of solid ammonium, and the generated water may be stored or discharged after being separated from the first heater 200 .

The first heater 200 is preferably heated to 60 ℃ or more in order to convert solid ammonium into ammonia gas.

The ammonia gas converted by the first heater 200 is supplied to the separator 500 through the heat exchanger 300 through the first ammonia gas supply line L5. Low-temperature ammonia (liquid and gaseous phase mixed state) is discharged from the separator 500, and the ammonia is supplied to the mixer 800 through a second ammonia gas supply line L6 through a second heater 700. . The engine fuel stored in the fuel storage tank 400 passes through the carburetor 600 through the fuel supply line L2 and is supplied to the mixer 800 in a gaseous state. In the mixer 800, engine fuel and ammonia gas are mixed. The mixed gas may be used as a fuel of the engine 900 .

The control valve V1 controls the amount of engine fuel that exchanges heat with solid ammonium in the heat exchanger 300, and the opening degree of the control valve V1 is adjusted according to the temperature of the rear end of the mixer 800 and the fuel required according to the engine load. can

Engine fuel and ammonia gas may be selectively supplied to the engine 900 . A valve (not shown) may be provided in the first ammonia gas supply line L5 or the second ammonia gas supply line L6 to control the supply of ammonia gas, and solid ammonium storage to control the amount of solid ammonium Means (not shown) for regulating the supply of solid ammonium to the tank may be provided.

The engine fuel may be partially branched from the fuel supply line L2 to the heat exchanger 300 . The heat exchanger 300 exchanges heat with ammonia gas and carbon dioxide gas from the first heater 200 and engine fuel in the fuel branch line L4 branched from the fuel supply line L2.

The engine fuel stored in the fuel storage tank 400 is a cryogenic liquid, and has a lower temperature than the ammonia gas and the carbon dioxide gas. The engine fuel is preferably LNG fuel, and since the boiling point of the LNG fuel is -163° C., it is maintained at a lower temperature than the boiling point, so that the ammonia gas can be cooled using the cooling heat of the LNG fuel.

Since the boiling point of ammonia gas is -33°C and the boiling point of carbon dioxide gas is -78°C, only ammonia gas can be selectively liquefied in the heat exchange process using the difference in boiling point between ammonia gas and carbon dioxide gas.

The separator 500 separates the ammonia liquid and the carbon dioxide gas from the heat exchanger 300 . Downstream of the separator 500, the ammonia liquid is discharged. The ammonia liquid downstream of the separator is supplied to the second heater 700 through the second ammonia gas supply line L6. The second heater 700 heats the ammonia liquid to re-convert the ammonia liquid into ammonia gas.

Carbon dioxide gas may be discharged from the upstream of the separator 500 , and the carbon dioxide gas may be discharged to the outside or stored in a separate facility (not shown) provided in the ship to reduce greenhouse gas.

The mixer 800 may mix ammonia gas and vaporized engine fuel before being supplied to the engine 900 or before combustion after being supplied to the engine 900 .

The engine 900 may be a DF engine (dual fuel engine) capable of using both engine fuels such as ammonia and LNG as fuel, and the engine 900 may be a propulsion engine or a power generation engine of a ship.

Since ammonia is a carbon-free fuel, only nitrogen and water are produced during the combustion reaction and there is no carbon dioxide (reaction formula: 4NH ₃ + 3O ₂ → 2N ₂ + 6H ₂ O), so it is possible to cope with the greenhouse gas emission regulations of ships.

In the engine 900, when a mixture of engine fuel and ammonia stored in the fuel storage tank 400 is burned, C _x H _y + 4NH ₃ + (3+z)O ₂ → xCO ₂ + 2N ₂ + (6+y) /2) H ₂ O has a reaction formula. Engine fuel mixed with ammonia can reduce the generation of carbon dioxide as much as it is replaced with ammonia.

In addition to the embodiments described above, the present invention encompasses all combinations of the above embodiments and embodiments generated by a combination of at least one of the above embodiments and known techniques.

As described above, the fuel supply system 2 according to the present invention can supply ammonia fuel by decomposing solid ammonium, so that storage safety of the fuel supply system can be improved when compared to supplying ammonia fuel by storing unstable liquid ammonia. can

In addition, in the fuel supply system 2 according to the present invention, solid ammonium, which is the source of ammonia, has a low vaporization rate to ammonia, and exists in a solid state even if it leaks from the storage tank, so the risk of human accidents due to leakage of solid ammonium is low. .

In addition, since the fuel supply system 2 according to the present invention stores solid ammonium, there is no need to have a storage tank having pressure resistance necessary to store liquid ammonia, and since there is no need to maintain the inside of the storage tank at a low temperature, liquid When compared to supplying ammonia fuel by storing ammonia, it is possible to reduce facility costs and operating costs.

Although the present invention has been described in detail through specific examples, this is for the purpose of describing the present invention in detail, and the present invention is not limited thereto. It will be clear that the transformation or improvement is possible.

All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be made clear by the appended claims.

1: Conventional liquid ammonia fuel supply system
2: Fuel supply system according to the present invention
10: liquid ammonia storage tank 20: heater
30, 300: heat exchanger 40, 400: fuel storage tank
50, 600: carburetor 60, 800: mixer
70, 900: engine
100: solid ammonium storage tank 200: first heater
500: separator 700: second heater
L1: Liquid ammonia supply line L2: Fuel supply line
L3: Evaporative gas circulation line L4: Fuel branch line
L5: first ammonia gas supply line L6: second ammonia gas supply line
L7: CO2 emission line
V1: control valve

Claims (5)

In the fuel supply system of an eco-friendly ship that mixes ammonia gas and engine fuel and supplies it to the engine,
Solid ammonium storage tank in which solid ammonium is stored;
a first heater for heating the solid ammonium to generate the ammonia gas and the carbon dioxide gas;
a heat exchanger converting the ammonia gas and the carbon dioxide gas into an ammonia liquid by exchanging heat with the engine fuel; and
and a separator for separating the ammonia liquid from the carbon dioxide gas. The method of claim 1,
The fuel supply system for eco-friendly ships, characterized in that it further comprises a second heater provided downstream of the separator to convert the ammonia liquid into a gas. The method of claim 1,
and a fuel supply line for supplying the engine fuel to the engine;
and a fuel branch line branching from the fuel supply line and supplying the engine fuel to the heat exchanger. The method of claim 1,
The solid ammonium is ammonium carbonate or ammonium bicarbonate fuel supply system for eco-friendly ships, characterized in that. A ship equipped with a fuel supply system for the eco-friendly ship according to any one of claims 1 to 4.

Images