Hybrid propulsion vessel equipped with fuel cell and hybrid propulsion system

Abstract

The present invention provides an environmentally friendly hybrid propulsion vessel that utilizes both electric power and heat, two forms of energy generated by a fuel cell, and has a steam turbine power source driven by heat as the main power source and an electric motor power source driven by electric power as the auxiliary power source, and obtains propulsion force by rotating a propeller by one or both of them. In order to solve the above problem, the present invention provides a hybrid propulsion device for a vessel that obtains propulsion force by the rotation of a propeller, comprising a fuel cell unit, a power storage device, a steam turbine power source that generates rotational force for rotating the propeller, an electric motor power source that generates rotational force for rotating the propeller, and a power source coupling shaft that transmits the rotational force of the steam turbine power source and the rotational force of the electric motor power source to the propeller.

Description

[Technical field]

[0001] The present invention relates to a hybrid propulsion ship that uses a steam turbine power source driven by heat produced by a fuel cell unit as its main power source, and an electric motor power source driven by electricity produced by the fuel cell unit as its auxiliary power source, with propellers rotated by either one or both of these power sources to obtain thrust. [Background technology]

[0002] Generally, most ships used for commercial purposes to transport cargo or passengers are propulsed by the rotation of a propeller, and large ships usually use an internal combustion engine to generate the power to rotate the propeller.

[0003] In recent years, as IMO's environmental regulations have become stronger, there has been an increasing demand for environmentally friendly ships that reduce emissions of greenhouse gases, including pollutants such as sulfur oxides (SOx) and nitrogen oxides (NOx).

[0004] As one area of ​​environmentally friendly ships, active research is being conducted on ships that use electric motors to generate power to rotate propellers and fuel cells to generate the electricity required by the electric motors.

[0005] Fuel cells are electrochemical devices that directly convert the chemical energy of hydrogen and oxygen into electrical energy, and are a new power generation technology that uses the reverse chemical reaction of water being decomposed into hydrogen and oxygen by applying an electric current to combine hydrogen and oxygen to produce water and generate an electric current. The hydrogen required for this chemical reaction can be supplied in a variety of ways.

[0006] Although in a different technology field, fuel cells are already widely used in land vehicles.

[0007] In the case of fuel cell vehicles, a polymer electrolyte fuel cell (PEMFC) is used as the fuel cell.

[0008] Polymer electrolyte fuel cells have a small size, which makes them highly mobile, and they operate at low temperatures of 100° C. or less, which makes them advantageous in terms of cooling properties.

[0009] On the other hand, ships, unlike land vehicles, require high power output for propulsion and have relatively little space, so it is advantageous to use large-scale molten carbonate fuel cells (MCFCs) or solid oxide fuel cells (SOFCs).

[0010] During the electrochemical reaction in a fuel cell, the energy contained in hydrogen is converted into electrical energy and thermal energy. The power conversion efficiency of currently developed fuel cells is difficult to exceed 55% in practical use, so while fuel cells produce electrical energy, they simultaneously generate an equal amount of thermal energy.

[0011] Conventional onshore fuel cell power plants in operation use a cogeneration system in which thermal energy generated by fuel cells is supplied to nearby areas in the form of hot water.

[0012] However, since ships are isolated at sea and cannot supply thermal energy to the outside, conventional patented technologies for ships using fuel cells are used only passively, limited to heating and vaporizing liquefied fuel stored at low temperatures, or reforming fuel to extract hydrogen, making their usability extremely low. In fact, accumulated heat reduces the efficiency of the fuel cell, so a cooling device may be required to dissipate the generated heat in order to maintain the fuel cell at an appropriate temperature.

[0013] Another patented technology recovers waste heat and uses it to generate secondary electricity using a gas or steam turbine, but the process of converting thermal energy into kinetic energy to produce electricity again inevitably results in energy losses.

[0014] Taking all of these conventional technologies into consideration, ships equipped with fuel cells have been unable to break away from the fixed idea that fuel cells only produce electricity and that electric motors are used exclusively to propel the ship, which is the drive system used for land vehicles. No ship has ever been presented that directly uses the heat generated by the fuel cell to obtain propulsion power. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Korean Patent No. 10-1258941 [Patent Document 2] Korean Patent Publication No. 10-2017-0073793 [Patent Document 3] Korean Registration No. 10-1806254 [Patent Document 4] Korean Registration No. 10-2115103 Summary of the Invention [Problem to be solved by the invention]

[0016] The present invention has been devised to solve the problems of the conventional technology as described above, and aims to provide an environmentally friendly hybrid propulsion vessel that utilizes both electricity and heat, two forms of energy generated in fuel cells, with a steam turbine power source driven by heat as the main power source and an electric motor power source driven by electricity as the auxiliary power source, and with one or both of these power sources rotating a propeller to generate thrust. [Means for solving the problem]

[0017] In order to solve the above problems, the present invention provides a ship that obtains propulsion force by the rotation of a propeller, and is characterized by including: a fuel cell unit including a fuel cell that receives a supply of fuel and produces electricity and heat; a power storage device that receives a supply of electricity produced by the fuel cell unit and can store it; a steam turbine power source that generates rotational force for rotating the propeller using steam generated using the heat produced by the fuel cell unit, an electric motor power source that generates rotational force for rotating the propeller using electricity supplied from the fuel cell unit or the power storage device, and a power source connecting shaft that is connected to the steam turbine power source, the electric motor power source, and the propeller and transmits the rotational force of the steam turbine power source and the rotational force of the electric motor power source to the propeller.

[0018] In the above: the steam turbine power source is composed of a power steam turbine that generates rotational force using steam, and a reduction gear unit that decelerates and outputs the rotational force of the power steam turbine; and it is preferable that a clutch unit is provided for transmitting the rotational force between the power source connecting shaft and the propeller or for cutting off the transmission of the rotational force.

[0019] In the above, it is preferable that the system further includes a heat exchanger that converts fresh water into steam using heat produced in the fuel cell section and supplies the steam to the power steam turbine, a condenser that receives steam that has passed through the power steam turbine and condenses it into fresh water, and a pump that supplies the fresh water from the condenser to the heat exchanger.

[0020] In the above, it is preferable that there be further provided a power generation steam turbine disposed between the power steam turbine and the condenser, which generates rotational force using steam that has passed through the power generation steam turbine, and a turbine generator which produces electricity using the rotational force of the power generation steam turbine.

[0021] In the above, it is preferable that a power distribution control unit is further provided, electrically connected to the fuel cell unit, the power storage device, the electric motor power source, and the turbine generator, and configured to change and control the power distribution path in accordance with the power load.

[0022] In the above, it is preferable that the electric motor power source is capable of receiving an input of a rotational force of the steam turbine power source via the power source connecting shaft and being usable as a regenerative generator capable of producing electric power.

[0023] In the above, the fuel cell may be a phosphoric acid fuel cell, a molten carbonate fuel cell, or a solid oxide fuel cell that produces electricity and heat through an electrochemical reaction between hydrogen contained in fuel and oxygen in the air; the fuel cell may use hydrogen gas, liquefied petroleum gas, natural gas, ethylene, methane, methanol, or ammonia as fuel; and the fuel cell section may be a single fuel cell or multiple fuel cells connected in series or parallel to produce electricity and heat. Effect of the Invention

[0024] As described above, the present invention can provide an environmentally friendly hybrid propulsion vessel capable of highly efficient propulsion by utilizing both electric power and heat, two forms of energy generated by a fuel cell.

[0025] In addition, since the present invention is propelled using electricity and heat produced by the fuel cell, it is possible to reduce emissions of environmental pollutants such as sulfur oxides and nitrogen oxides compared to internal combustion engine ships that are propelled by burning fuel. It also achieves higher efficiency and fuel efficiency compared to electric propulsion ships that use only electricity produced by the fuel cell, so the size of the fuel cell installed in the ship can be reduced.

[0026] In addition, considering that the power conversion efficiency of conventional fuel cells is a maximum of 55% or less, while the heat conversion efficiency generated by fuel cells operating at high temperatures approaches 50%, it is expected that by combining power conversion and heat conversion as in the present invention, an energy conversion efficiency of nearly 90% can be achieved. [Brief description of the drawings]

[0027] [Figure 1] 1 is a conceptual diagram of a hybrid propulsion vessel according to one embodiment of the present invention. [Diagram 2] 2A-2C are diagrams showing various operational configurations of FIG. 1; [Diagram 3] 2A-2C are diagrams showing various operational configurations of FIG. 1; [Figure 4] 2A-2C are diagrams showing various operational configurations of FIG. 1; [Diagram 5] 2A-2C are diagrams showing various operational configurations of FIG. 1; [Figure 6] 2A-2C are diagrams showing various operational configurations of FIG. 1;

[0028] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings so that a person having ordinary skill in the art to which the present invention belongs can easily carry out the embodiments. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In the drawings, in order to clearly explain the present invention, parts that are not related to the description are omitted, and similar parts are designated by similar reference numerals throughout the specification.

[0029] Throughout the specification, when a part "comprises" certain elements, this means that it may further include other elements, rather than excluding other elements, unless specifically stated to the contrary.

[0030] FIG. 1 is a schematic diagram of a hybrid propulsion vessel according to an embodiment of the present invention, and FIGS. 2 to 6 are diagrams showing various operational modes of FIG.

[0031] The hybrid propulsion vessel according to one embodiment of the present invention relates to a vessel that obtains propulsive force by the rotation of a propeller 10.

[0032] The ship is equipped with a fuel cell section 110 as an energy source production section.

[0033] The fuel cell section 110 includes a fuel cell 111 that receives a supply of fuel and produces electricity and heat.

[0034] The fuel cell portion 110 can produce power and heat as a single fuel cell 111 or as a collection of multiple fuel cells 111 connected in series or parallel, or in series and parallel.

[0035] The fuel cell 111 may use hydrogen gas, or liquefied petroleum gas, or natural gas, or ethylene, or methane, or methanol, or ammonia as a fuel.

[0036] The fuel cell 111 is preferably a phosphoric acid fuel cell, a molten carbonate fuel cell, or a solid oxide fuel cell that produces electricity and high-temperature heat through an electrochemical reaction between hydrogen contained in the fuel and oxygen in the air.

[0037] Phosphoric Acid Fuel Cells (PAFCs) operate at high temperatures of around 200°C, Molten Carbonate Fuel Cells (MCFCs) operate at high temperatures of around 700°C, and Solid Oxide Fuel Cells (SOFCs) operate at high temperatures of around 700°C to 1000°C.

[0038] As described above, phosphoric acid fuel cells, molten carbonate fuel cells, and solid oxide fuel cells require a large space, but can achieve high power conversion efficiency. Furthermore, they require high operating temperatures and generate high-temperature thermal energy, making them suitable fuel cells for implementing the present invention.

[0039] The power storage device 120 is for storing power, and in particular, can store power generated by the fuel cell unit 110 or the like.

[0040] This embodiment includes a hybrid propulsion device 200 as a drive source for rotating the propeller 10.

[0041] The hybrid propulsion device 200 is configured to include a steam turbine power source 210 as a main power source, an electric motor power source 220 as an auxiliary power source, and a power source connection shaft 230 that transmits the rotational forces of these to the propeller 10.

[0042] The steam turbine power source 210 is a driving source that generates a rotational force by using steam generated by using the heat produced in the fuel cell unit 110 .

[0043] In this embodiment, the steam turbine power source 210 includes a power steam turbine 211 that generates rotational force by steam, and a reduction gear unit 212 that reduces the rotational force of the power steam turbine 211 and outputs it.

[0044] The reduction gear section 212 converts the high-speed rotational force of the power steam turbine 211 into a low-speed rotational force having high torque and outputs it.

[0045] The electric motor power source 220 is a driving source that generates a rotational force by using electric power supplied from the fuel cell unit 110, the power storage device 120, and the like.

[0046] Meanwhile, the electric motor power source 220 may, in some cases, be used as a regenerative generator capable of receiving the rotational force of the steam turbine power source 210 via the power source coupling shaft 230 and producing electric power.

[0047] In general, an electric motor is a device that converts electrical energy into mechanical energy by utilizing the force that a current-carrying conductor receives in a magnetic field, while a generator is a device that obtains electrical energy from mechanical energy, etc.

[0048] Therefore, when an electric motor receives mechanical energy from an external source, it can be used as a regenerative generator that produces electrical energy. This technology is a common technology, so a detailed description will be omitted.

[0049] The power source connection shaft 230 is connected to the steam turbine power source 210, the electric motor power source 220, and the propeller 10, and transmits either one or both of the rotational force of the steam turbine power source 210 and the rotational force of the electric motor power source 220 to the propeller 10.

[0050] Depending on the embodiment, the power source connection shaft 230 is provided independently of the steam turbine power source 210 and the electric motor power source 220, and the steam turbine power source 210 and the electric motor power source 220 can be detachably connected to each other, and the power source connection shaft 230 can be connected to either one of the steam turbine power source 210 and the electric motor power source 220, or to both.

[0051] Depending on the embodiment, the power source connecting shaft 230 may be the output shaft of the reduction gear section 212 (i.e., the power source connecting shaft 230 is part of the reduction gear section 212), in which case the output shaft of the electric motor power source 220 may be directly connected to the power source connecting shaft 230 (the output shaft of the reduction gear section 212).

[0052] The clutch unit 240 is provided between the power source connecting shaft 230 and the propeller 10 and can transmit rotational force to the propeller 10 or cut off transmission of rotational force to the propeller 10 .

[0053] The configuration for utilizing the heat generated in the fuel cell unit 110 will now be described in more detail.

[0054] The power steam turbine 211 utilizes the heat produced in the fuel cell unit 110 through a steam power cycle that uses steam to generate power.

[0055] In this embodiment, the steam power cycle is formed by sequentially connecting a power steam turbine 211, a power generation steam turbine 134, a condenser 132, a pump 133, a heat exchanger (131, which corresponds to a type of boiler), and the power steam turbine 211.

[0056] In the heat exchanger 131, the heat (waste heat) produced in the fuel cell section 110 is used (by exchanging heat with the heat discharged from the fuel cell section 110) to convert the fresh water into high-temperature, high-pressure steam, which is then supplied to the power steam turbine 211.

[0057] The power steam turbine 211 generates rotational force using high-temperature, high-pressure steam, and the high-temperature, high-pressure steam is discharged as high-temperature, low-pressure steam.

[0058] The high-temperature, low-pressure steam is supplied to a power-generating steam turbine 134 to generate rotational force, and a turbine generator 135 connected to the power-generating steam turbine 134 uses the rotational force of the power-generating steam turbine 134 to produce electricity.

[0059] The steam passing through the power-generating steam turbine 134 is supplied to the condenser 132 and condensed into fresh water, and the fresh water in the condenser 132 is supplied to the heat exchanger 131 by the pump 133 .

[0060] In this embodiment, electricity is produced by the fuel cell unit 110 and the turbine generator 135, the electric motor power source 220 is either a power load or produces electricity (if used as a regenerative generator), and the power storage device 120 can store electricity and can also supply the stored electricity to the outside.

[0061] Further, the ship's electrical system 20, which is made up of various electrical devices on the ship, is an electric power load.

[0062] A power distribution control unit 140 is provided for changing and controlling the power distribution path so that power can be appropriately produced in accordance with various power loads and appropriately supplied to the necessary power loads.

[0063] The power distribution control unit 140 is electrically connected to the fuel cell unit 110, the power storage device 120, the electric motor power source 220, and the turbine generator 135 in order to change the power distribution path, and is further electrically connected to the ship's electrical system 20, which is the various electrical devices of the ship.

[0064] Electricity produced by the fuel cell unit 110, or the turbine generator 135, or the electric motor power source 220 (if used as a regenerative generator) may be supplied to the ship electrical system 20, or the power storage device 120, or the electric motor power source 220 via the power distribution control unit 140.

[0065] That is, the power distribution control unit 140 controls the power production of the fuel cell unit 110 and changes the power distribution path according to the power load of the ship's electrical system 20, the power storage device 120, or the electric motor power source 220.

[0066] In particular, the power distribution control unit 140 controls the operation of the fuel cell unit 110 according to the power required for the ship's electrical system 20 and the driving force required to propel the ship, and optimally combines the driving forces of the power steam turbine 211 and the electric motor power source 220 to maximize efficiency.

[0067] Various operational modes of the vessel will now be described with reference to Figures 2 to 6.

[0068] First mode of operation: With reference to FIG. 2, an operation mode in which both the steam turbine power source 210 and the electric motor power source 220 are driven by the heat and electricity generated in the fuel cell section 110 will be described.

[0069] High temperature heat generated in the fuel cell section 110 is discharged through the heat exchanger 131, and fresh water is converted into steam from the heat exchanger 131, passes through the power steam turbine 211 and the power generation steam turbine 134, and is condensed in the condenser 132 and supplied to the heat exchanger 131 by the pump 133 to form a steam power cycle. As a result, the steam turbine power source 210 operates as the main power source, and the rotational force of the steam turbine power source 210 is transmitted to the power source connecting shaft 230 through the reduction gear section 212.

[0070] The electricity generated in the fuel cell unit 110 and the electricity generated in the turbine generator 135 drive the electric motor power source 220 via the power distribution control unit 140. The electric motor power source 220 operates as an auxiliary power source. The rotational force generated in the electric motor power source 220 is transmitted to the power source connecting shaft 230 and superimposed on the rotational force of the steam turbine power source 210, and then output to the propeller 10 via the clutch unit 240, thereby propelling the ship.

[0071] The electricity generated by the fuel cell unit 110 and the turbine generator 135 is supplied not only to the electric motor power source 220 via the power distribution control unit 140, but also to the ship's electrical system 20, which is the various electrical devices of the ship. If surplus electricity is generated even with this power supply, it is supplied to the power storage device 120 and stored.

[0072] Second mode of operation: With reference to FIG. 3, an operation mode in which both the steam turbine power source 210 and the electric motor power source 220 are driven by the heat and power generated in the fuel cell unit 110 and the power supplied from the power storage device 120 will be described.

[0073] FIG. 3 is almost identical to FIG. 2, except that in FIG. 3, the heat and electricity generated in the fuel cell unit 110 alone is insufficient to propel the ship. Unlike FIG. 2, electricity stored in the power storage device 120 is additionally supplied to the electric motor power source 220 via the power distribution control unit 140 to generate propulsive force for the hull.

[0074] Third mode of operation: With reference to FIG. 4, an operation mode in which only the steam turbine power source 210 is driven by heat generated in the fuel cell unit 110 will be described.

[0075] FIG. 4 shows a situation in which sufficient driving force required for propulsion of the ship can be obtained by the steam turbine power source 210 alone, and the electric motor power source 220 is not driven.

[0076] The electric power generated by the fuel cell unit 110 and the turbine generator 135 is supplied to the ship's electrical system 20 via the power distribution control unit 140, while most of the surplus electric power is supplied to the power storage device 120 and stored therein.

[0077] Fourth mode of operation: With reference to FIG. 5, an operating mode in which the fuel cell unit 110 is not in operation will be described.

[0078] That is, the fuel cell unit 110 does not generate electricity or heat, and therefore the power steam turbine 211 is not driven.

[0079] In FIG. 5 , the electricity stored in the power storage device 120 is supplied to the electric motor power source 220 and the ship's electrical system 20 via the power distribution control unit 140, and only the electric motor power source 220 operates as a power source. The electric motor power source 220 rotates the propeller 10 via the power source connecting shaft 230 and the clutch unit 240, thereby propelling the ship.

[0080] Fifth mode of operation: A situation where the fuel cell unit 110 operates but the hull maintains a non-accelerating state (a situation where no propulsive force is required) will be described with reference to FIG.

[0081] In FIG. 6, the rotational force of a steam turbine power source 210 is used to generate electricity in an electric motor power source 220 .

[0082] The high temperature heat generated in the fuel cell section 110 is discharged through the heat exchanger 131, thereby driving the steam turbine power source 210, while the clutch section 240 blocks the transmission of rotational force to the propeller 10, and the rotational force of the steam turbine power source 210 is transmitted to the electric motor power source 220 via the reduction gear section 212 and the power source connecting shaft 230, at which time the electric motor power source 220 functions as a regenerative generator that produces electricity.

[0083] The electricity generated by the fuel cell section 110, the turbine generator 135, and the electric motor power source 220 is partially supplied to the ship's electrical system 20, and most of it is supplied to the power storage device 120 as surplus electricity and stored there.

[0084] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. Therefore, the above-described embodiments should be understood to be merely illustrative and not restrictive in all respects. For example, each component described as a single component may be implemented in a distributed manner, and similarly, each component described as a distributed component may be implemented in a combined manner.

[0085] The scope of the present invention is indicated by the claims set forth below rather than by the above detailed description, and all modifications and variations that fall within the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. [Industrial Applicability]

[0086] The present invention can be used as a ship that obtains propulsion force by the rotation of a propeller, and in particular, can be used as a hybrid propulsion ship in which a steam turbine power source driven by heat produced by a fuel cell unit is used as a main power source, and an electric motor power source driven by electricity produced by the fuel cell unit is used as an auxiliary power source, with the propeller rotating by either one or both of these power sources to obtain propulsion force.

Claims

1. In vessels that derive their propulsion from the rotation of a propeller: A fuel cell unit including a fuel cell that receives a supply of fuel and produces electricity and heat; a power storage device capable of receiving and storing the power produced by the fuel cell unit; a hybrid propulsion device including: a steam turbine power source that generates a rotational force for rotating the propeller by steam generated by using heat produced in the fuel cell unit; an electric motor power source that generates a rotational force for rotating the propeller by power supplied from the fuel cell unit or the power storage device; and a power source connection shaft that is connected to the steam turbine power source, the electric motor power source, and the propeller and transmits the rotational force of the steam turbine power source and the rotational force of the electric motor power source to the propeller; Hybrid propulsion vessels, including:

2. The steam turbine power source includes a power steam turbine that generates a rotational force by steam, and a reduction gear unit that reduces the rotational force of the power steam turbine and outputs the reduced speed; 2. The hybrid propulsion vessel according to claim 1, further comprising a clutch unit for transmitting or blocking a rotational force between the power source connecting shaft and the propeller.

3. 3. The hybrid propulsion vessel according to claim 2, further comprising: a heat exchanger that converts fresh water into steam using heat produced in the fuel cell section and supplies the steam to the power steam turbine; a condenser that receives a supply of steam that has passed through the power steam turbine and condenses it into fresh water; and a pump that supplies the fresh water of the condenser to the heat exchanger.

4. 4. The hybrid propulsion vessel according to claim 3, further comprising: a power generating steam turbine provided between the power steam turbine and the condenser, the power generating steam turbine generating rotational force by the steam that has passed through the power generating steam turbine; and a turbine generator that produces electric power using the rotational force of the power generating steam turbine.

5. 5. The hybrid propulsion vessel according to claim 4, further comprising a power distribution control unit electrically connected to the fuel cell unit, the power storage device, the electric motor power source, and the turbine generator, and configured to change and control a power distribution path in accordance with a power load.

6. 3. The hybrid propulsion vessel according to claim 2, wherein the electric motor power source receives an input of rotational force of the steam turbine power source via the power source coupling shaft and is usable as a regenerative generator capable of producing electric power.

7. 2. The hybrid propulsion vessel of claim 1, wherein the fuel cell is a phosphoric acid fuel cell, a molten carbonate fuel cell, or a solid oxide fuel cell that produces electricity and heat through an electrochemical reaction between hydrogen contained in fuel and oxygen in the atmosphere; the fuel cell uses hydrogen gas, liquefied petroleum gas, natural gas, ethylene, methane, methanol, or ammonia as fuel; and the fuel cell section is a single fuel cell or multiple fuel cells connected in series or parallel that produce electricity and heat.

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