Propulsion device

Abstract

A propulsion device (10A) is provided with a main combustor (11) and a supply system (12A) for supplying a fuel and an oxidant to the main combustor (11). The supply system (12A) is provided with: a first pump (13) that suctions a fuel and pressure-feeds the fuel to the supply system (12A); a second pump (14) that suctions an oxidant and pressure-feeds the oxidant to the supply system (12A); a generator (16) that includes a turbine (16a) driven by the supply of a working fluid; a power storage device (17) that stores power generated by the generator (16); a first electric motor (18) that drives the first pump (13) by the power from the power storage device (17); and a second electric motor (19) that drives the second pump (14) by the power from the power storage device (17).

Description

propulsion device

[0001] The present disclosure relates to propulsion devices aboard spacecraft or rockets.

[0002] Bipropellant propulsion systems for spacecraft or rockets generate thrust by burning fuel and oxidizer. Within the propulsion system, these propellants are supplied to a combustor by a turbine pump and burned. The turbine of the turbine pump is driven by hot gas, which serves as the turbine's working fluid. Hot gas can be either the combustion gas of fuel and oxidizer or fuel vaporized during regenerative cooling. Which gas is generated depends on the operating cycle of the propulsion system. For example, in a gas generator (GG) cycle, hot gas is obtained by burning fuel and oxidizer using a gas generator (see Patent Document 1). In an expander cycle, hot gas is obtained by vaporizing liquid fuel during regenerative cooling of the nozzle and combustor.

[0003] Japanese Patent Application Laid-Open No. 2007-218899

[0004] In either operating cycle, the two propellant pumps are driven by the same or separate turbines, which are connected to each other via a rotating shaft (drive shaft) and rotate together at the same speed.

[0005] However, in general, the optimal rotational speeds of the fuel pump and the oxidizer pump are different. Furthermore, the optimal rotational speeds of the pump and the turbine that drives the pump are also different. Therefore, conventional configurations cannot simultaneously optimize the efficiency of the pump and the turbine. For example, if thrust is to be reduced, the amount of propellant supplied must be reduced. However, the turbine rotational speed must be maintained above a predetermined value so that the turbine's efficiency and output do not decrease excessively. Therefore, as thrust is reduced, the pump rotational speed (output) increases excessively, reducing the efficiency of the entire propulsion system.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a propulsion device that can operate efficiently in response to various thrust forces.

[0007] A propulsion device according to one aspect of the present disclosure comprises a main combustor and a supply system that supplies fuel and oxidizer to the main combustor, the supply system including a first pump that draws in the fuel and pumps it into the supply system, a second pump that draws in the oxidizer and pumps it into the supply system, a first generator including a turbine driven by a supply of a first working fluid, a power storage device that stores electricity generated by the first generator, a first electric motor that drives the first pump using electricity from the power storage device, and a second electric motor that drives the second pump using electricity from the power storage device.

[0008] The first generator may be a motor-generator that also serves as the second electric motor. In this case, the first pump is drivingly connected to the first turbine of the first generator. The propulsion device may include an auxiliary combustor that produces the first working fluid from the fuel and the oxidizer. The first working fluid may be the fuel that has undergone regenerative cooling of the main combustor. The propulsion device may include a supply amount adjustment unit that adjusts the amount of the first working fluid supplied to the first turbine in accordance with an amount of power generation set for the first generator. Control of ignition of the first auxiliary combustor may be performed independently of the timing of ignition of the main combustor. The supply system may include a second auxiliary combustor that produces a second working fluid from the fuel and the oxidizer, and a second generator including a second turbine driven by the supply of the second working fluid, and the power storage device may further store electric power from the second generator.

[0009] According to the present disclosure, it is possible to provide a propulsion device that can operate efficiently in response to various thrust forces.

[0010] FIG. 1 is a schematic configuration diagram of a propulsion device according to a first embodiment of the present disclosure. FIG. 2 is a diagram showing an example of an operation sequence of the propulsion device. FIG. 3 is a diagram showing changes in efficiency with thrust. FIG. 4 is a schematic configuration diagram of a propulsion device according to a second embodiment of the present disclosure. FIG. 5 is a schematic configuration diagram of a propulsion device according to a third embodiment of the present disclosure. FIG. 6 is a schematic configuration diagram of a propulsion device according to a fourth embodiment of the present disclosure. FIG. 7 is a schematic configuration diagram of a propulsion device according to a fifth embodiment of the present disclosure. FIG. 8 is a schematic configuration diagram of a propulsion device according to a sixth embodiment of the present disclosure. FIG. 9 is a schematic configuration diagram of a propulsion device according to a seventh embodiment of the present disclosure. FIG. 10 is a schematic configuration diagram of a propulsion device according to an eighth embodiment of the present disclosure.

[0011] A propulsion device according to an embodiment of the present disclosure will be described below with reference to the drawings. Common parts in the drawings will be assigned the same reference numerals, and duplicated descriptions will be omitted. The propulsion device according to the embodiment is a bipropellant propulsion device that burns a mixed gas of an oxidizer such as liquid oxygen and a fuel such as liquid hydrogen or a liquefied hydrocarbon (e.g., liquefied methane), and is mounted on a spacecraft (e.g., an artificial satellite) or a rocket. Hereinafter, for convenience of explanation, the oxidizer and fuel may be collectively referred to as a propellant.

[0012] [First Embodiment] Fig. 1 is a schematic diagram of a propulsion device 10A according to a first embodiment. As shown in Fig. 1, the propulsion device 10A includes a main combustor 11 and a supply system (power pack) 12A that supplies fuel and oxidizer to the main combustor 11. The supply system 12A includes a first pump 13, a second pump 14, a secondary combustor (first secondary combustor) 15, a generator 16, an electrical storage device 17, a first electric motor 18, and a second electric motor 19. The propulsion device 10A employs a gas generator (GG) cycle as an example of an operating cycle. Therefore, the secondary combustor 15 of this embodiment is a so-called gas generator.

[0013] The first pump 13 and the second pump 14 are, for example, centrifugal pumps having impellers (wheels). The first pump 13 and the second pump 14 are provided separately and driven by corresponding electric motors (first electric motor 18 or second electric motor 19, described below). The first pump 13 and the second pump 14 can operate independently, and their respective rotation speeds are set independently. The first pump 13 and the second pump 14 are physically (mechanically) isolated from each other. Therefore, there is no need to supply an inert gas (so-called purge gas), which is required in single-shaft turbine pumps. Therefore, an inert gas supply facility can be omitted.

[0014] The first pump 13 sucks the fuel stored in the fuel tank 1 and pressurizes and discharges (i.e., pumps) the fuel. Most of the fuel discharged from the first pump 13 passes through a passage 20a for regenerative cooling of the nozzle 11b and the main combustor 11, and is then supplied to the main combustor 11. The remainder is supplied to the auxiliary combustor 15 via a passage 20b branching from the passage 20a.

[0015] The second pump 14 sucks the oxidizer stored in the oxidizer tank 2 and pressurizes and discharges (i.e., pumps) the oxidizer. Most of the oxidizer discharged from the second pump 14 is supplied to the main combustor 11 via a path 21a, and the remainder is supplied to the auxiliary combustor 15 via a path 21b branching from the path 21a.

[0016] The main combustor 11 of this embodiment burns a mixed gas of fuel discharged from the first pump 13 and oxidizer discharged from the second pump 14. The combustion gas in the main combustor 11 expands and accelerates, and is discharged from the nozzle 11b via the throat 11a. The thrust of the propulsion device 10A is generated by a reaction caused by the injection of this combustion gas, as in conventional propulsion devices.

[0017] The auxiliary combustor 15 also combusts a mixed gas of fuel and oxidizer. The combustion gas from the auxiliary combustor 15 is supplied to a turbine (first turbine) 16a of a generator 16. This supply of combustion gas rotates the turbine 16a. In other words, the auxiliary combustor 15 generates a working fluid (first working fluid) for the turbine 16a from the fuel and oxidizer. The combustion gas that passes through the turbine 16a is discharged to the outside of the spacecraft or rocket on which the propulsion device 10A is mounted.

[0018] The amount of combustion gas supplied by the auxiliary combustor 15 depends on the amounts of fuel and oxidizer supplied to the auxiliary combustor 15. The amounts of fuel and oxidizer supplied are adjusted by a supply amount adjustment unit 24 according to the amount of power generation set in the generator 16. The supply amount adjustment unit 24 is composed of, for example, valves V1 and V2, which are flow rate adjustment valves. Valve V1 is provided in a fuel path 20b leading to the auxiliary combustor 15, and valve V2 is provided in an oxidizer path 21b leading to the auxiliary combustor 15. The opening degrees of these valves are controlled by a control unit (not shown) that performs overall control of the propulsion device 10A.

[0019] The generator 16 includes the turbine 16a and a power generating unit 16b having a rotor and a stator. The turbine 16a is drivenly connected to the rotor of the power generating unit 16b. That is, the rotating shaft of the turbine 16a is directly or indirectly connected to the rotating shaft of the rotor so that the rotational force of the turbine 16a is transmitted to the rotor.

[0020] When the turbine 16a rotates due to the supply of combustion gas, the rotor of the power generation unit 16b rotates. As a result, the power generation unit 16b generates AC power corresponding to the rotation speed of the turbine 16a. The generated AC power is converted into DC power by a converter (not shown). This DC power is stored in the power storage device 17. Alternatively, the DC power is supplied to the first electric motor 18 and the second electric motor 19 via an inverter (not shown).

[0021] The power storage device 17 includes a battery (not shown) and a control circuit (not shown) for the battery, and stores the electric power generated by the generator 16. In other words, the power storage device 17 is configured to be able to store electric power generated by the generator 16. As described above, the electric power stored in the power storage device 17 is supplied to the first electric motor 18 and the second electric motor 19.

[0022] The first electric motor 18 is drivingly connected to the first pump 13. That is, the rotary shaft of the first electric motor 18 is directly or indirectly connected to the rotary shaft of the first pump 13 so that the rotational force of the first electric motor 18 is transmitted to the first pump 13. In other words, the first pump 13 is an electric pump. The power and waveform supplied to the first electric motor 18 are controlled by an inverter (not shown).

[0023] The second electric motor 19 is drivingly connected to the second pump 14. That is, the rotary shaft of the second electric motor 19 is directly or indirectly connected to the rotary shaft of the second pump 14 so that the rotational force of the second electric motor 19 is transmitted to the second pump 14. That is, like the first pump 13, the second pump 14 is also an electric pump. The power and waveform supplied to the second electric motor 19 are also controlled by an inverter (not shown).

[0024] Next, an example of thrust change by the propulsion device 10A will be described. In this example, the thrust increases from 0% to 100%. 100% thrust is maintained for a certain period of time, after which the thrust is gradually reduced to a value less than 10%. Finally, the thrust is set to 0%, and the series of operations related to thrust generation ends.

[0025] Fig. 2 is a diagram showing an example of the operating sequence of the propulsion device 10A in the above-mentioned example. Specifically, Fig. 2 shows, in chronological order, changes in the propellant supply capacity of the first pump 13 and the second pump 14 to the main combustor 11 and the auxiliary combustor 15, the power generation capacity of the generator 16, the remaining battery charge in the power storage device 17, and the thrust of the propulsion device 10A. The upper part of the diagram shows the operating states of the first electric motor 18 and the second electric motor 19 (referred to as EM), the first pump 13 and the second pump 14 (referred to as P), the auxiliary combustor 15 (referred to as GG), and the generator 16 (referred to as EG).

[0026] The propulsion device 10A is ０ Therefore, the propellant supply capacity, power generation capacity, and thrust are 0% at this time. Meanwhile, the remaining battery charge is 100%. Then, at time t ０ The propulsion device 10A starts operation related to thrust. Specifically, the first electric motor 18 starts operating using the power of the power storage device 17, and the first electric motor 18 drives the first pump 13. The second electric motor 19 also starts operating using the power of the power storage device 17, and the second electric motor 19 drives the second pump 14. Therefore, the supply of propellant to the main combustor 11 and the auxiliary combustor 15 begins. At this time, the substantial drive energy of the first pump 13 and the second pump 14 is only the power to drive the first electric motor 18 and the second electric motor 19.

[0027] Thereafter, the rotation speeds of the first pump 13 and the second pump 14 increase, and at time t １ At time t ２ The main combustor 11 and the auxiliary combustor 15 are ignited. The thrust increases to 100% due to combustion in the main combustor 11. Furthermore, the auxiliary combustor 15 starts operating, and combustion gas from the auxiliary combustor 15 is supplied to the turbine 16a of the generator 16.

[0028] In the initial stage of operation of the propulsion device 10A, the first electric motor 18 and the second electric motor 19 operate solely on the power from the power storage device 17 to drive the first pump 13 and the second pump 14. As a result, propellant is supplied to the main combustor 11 and the auxiliary combustor 15, and each is ignited. The order of ignition at this time is arbitrary. In other words, the ignition control of the auxiliary combustor 15 is executed independently of the ignition timing of the main combustor 11.

[0029] In conventional propulsion devices, propellant is supplied to the main combustor by driving a turbine pump using combustion gas from the auxiliary combustor. Therefore, the main combustor must be ignited after the auxiliary combustor is ignited. However, in this embodiment, each pump is driven by an electric motor, which is powered by battery power. In other words, combustion gas from the auxiliary combustor is not required to drive each pump. Therefore, the order of ignition of the main combustor 11 and the auxiliary combustor 15 can be set arbitrarily. Furthermore, electric motors have better responsiveness than turbopump turbines. Therefore, rotational speed overshoot (i.e., a short-term rotational speed overshoot or undershoot) is less likely to occur, reducing the burden on the pump.

[0030] By increasing the amount of propellant supplied to the auxiliary combustor 15, the amount of combustion gas generated by the auxiliary combustor 15 also increases. Therefore, the rotation speed of the turbine 16a also increases, and the amount of electricity generated by the power generation unit 16b also increases. The generated electricity is charged into the power storage device 17 (battery), and at time t ２ The amount of power consumed up to that point is replenished.

[0031] Charging continues thereafter, and at time t ３ At time t, the remaining battery charge reaches 100%. After that, the amount of propellant supplied to the auxiliary combustor 15 is slightly reduced (for example, by about 2%) while maintaining 100% thrust. ４ Thereafter, the amount of power generated by the generator 16 is reduced to, for example, 80%, thereby maintaining the charge in the power storage device 17 (battery) and preventing excessive consumption of propellant.

[0032] When the thrust is to be reduced, the rotation speeds of the first electric motor 18 and the second electric motor 19 are reduced. As a result, the rotation speeds of the first pump 13 and the second pump 14 are reduced, and the amount of propellant supplied to the main combustor 11 is reduced. In the example shown in FIG. 2 , at time t ５ The thrust is set to 60% at time t ６ Set the thrust to 40%.

[0033] Generally, electric motors are more efficient than turbo pumps and their efficiency varies less with rotation speed. For example, the rotation speed of a turbo pump must be set above a certain value to prevent excessive reduction in turbine efficiency and output. However, this is not a concern when using an electric motor.

[0034] Therefore, even after the thrust is reduced, the first electric motor 18 and the second electric motor 19 can efficiently consume the electric power stored in the power storage device 17. For example, while the generator 16 is operating (in the example of FIG. 2, from time t ３ From time t ７ The generated electric power can be used to drive the first electric motor 18 and the second electric motor 19 and to charge the power storage device 17. Furthermore, electric motors have better responsiveness than turbo pumps. Therefore, the optimal supply amount of propellant to the main combustor 11 can be set in various amounts and in a short time.

[0035] In addition, with conventional propulsion devices, it is difficult to supply a small amount of propellant to the main combustor, making it relatively difficult to throttle the thrust. On the other hand, this embodiment uses electric motors as the power source for each pump. Therefore, compared to conventional propulsion devices that use turbopumps, it is possible to obtain a small thrust more efficiently.

[0036] For example, as an example of setting a small thrust, at time t ７ It is assumed that the thrust is set to 7% thereafter. In this case, the valves V1 and V2, which are the supply amount adjusting unit 24, are ７ Therefore, the supply of propellant to the auxiliary combustor 15 is stopped. Therefore, the supply of combustion gas to the turbine 16a is stopped, and the power generation by the generator 16 is also stopped. In other words, the first electric motor 18 and the second electric motor 19 are operated only by the electric power from the power storage device 17.

[0037] Time t ７ Thereafter, the first electric motor 18 and the second electric motor 19 drive the first pump 13 and the second pump 14 to obtain 7% thrust. At this time, the propellant supply capacity is, for example, 10%. The first pump 13 and the second pump 14 then supply the amount of propellant to the main combustor 11 according to the set thrust.

[0038] Regardless of the thrust setting value, if it is determined that charging of the power storage device 17 is necessary, the supply of propellant to the auxiliary combustor 15 may be continued or resumed regardless of the combustion in the main combustor 11. For example, as shown in FIG. ８ Assume that the thrust is changed from 7% to 2% in the battery 100. If the remaining battery charge falls below a predetermined threshold (e.g., 80% shown in FIG. 2) at which charging is required, the valves V1 and V2 of the supply amount adjuster 24 are opened.

[0039] Then, propellant is supplied to the auxiliary combustor 15, and combustion by the auxiliary combustor 15 is restarted. As a result, combustion gas from the auxiliary combustor 15 is supplied to the turbine 16a, the generator 16 restarts power generation, and charging of the power storage device 17 is restarted. Meanwhile, the amount of propellant supplied to the main combustor 11 does not increase. In other words, charging is performed independently of thrust control.

[0040] When the remaining battery capacity reaches 100% due to charging of the power storage device 17, the supply of propellant to the main combustor 11 and the auxiliary combustor 15 is stopped, and at time t ９ 2, the supply of propellant to the main combustor 11 and the auxiliary combustor 15 is stopped simultaneously. However, the supply of propellant to the auxiliary combustor 15 may be stopped before or after the supply of propellant to the main combustor 11 is stopped.

[0041] FIG. 3 is a diagram showing the change in efficiency with thrust. The black circles and solid line indicate the efficiency of the propulsion device 10A according to this embodiment (example), while the white circles and dashed line indicate the efficiency of a comparative example propulsion device using a turbo pump. In calculating the efficiency of the propulsion device 10A, the efficiencies of the first electric motor 18 and the second electric motor 19 were calculated based on the efficiency of a typical high-efficiency motor, and values ​​ranging from 90% to 95% were used. Furthermore, it was assumed that the generator 16 would operate in the most efficient state at each thrust, and an efficiency of 75% was used.

[0042] As shown in Figure 3, when the thrust is close to 100%, there is not much difference in efficiency between this embodiment and the comparative example. However, as the thrust decreases, the characteristics of the electric motor that maintain high efficiency are exerted, and it can be seen that the efficiency is improved compared to the comparative example. In other words, according to this embodiment, it is possible to provide a propulsion device 10A that can operate efficiently in response to various thrusts.

[0043] [Second Embodiment] Fig. 4 is a schematic configuration diagram of a propulsion device 10B according to a second embodiment. As shown in Fig. 4, the propulsion device 10B includes a main combustor 11 and a supply system 12B that supplies fuel and oxidizer to the main combustor 11. The supply system 12B includes a first pump 13, a second pump 14, a generator 16, a power storage device 17, a first electric motor 18, and a second electric motor 19.

[0044] The propulsion device 10B according to this embodiment employs an expander cycle (full expander cycle) as an example of an operating cycle. Therefore, the propulsion device 10B does not include the auxiliary combustor 15 employed in the first embodiment. Instead, the fuel path 20a thermally contacts the outer walls of the main combustor 11, throat 11a, and nozzle 11b, and then passes through the turbine 16a of the generator 16. After passing through the turbine 16a, the path 20a finally connects to the main combustor 11.

[0045] The fuel is discharged from the second pump 14 and cools the main combustor 11, the throat 11a, and the nozzle 11b (i.e., performs regenerative cooling). The regeneratively cooled fuel (so-called hot gas) is supplied to the turbine 16a and rotates the turbine 16a. In other words, the regeneratively cooled fuel is the working fluid of the turbine 16a. The fuel that has passed through the turbine 16a is supplied to the main combustor 11 and combusted together with an oxidizer in the main combustor 11.

[0046] In the second embodiment, the operational sequence shown in Fig. 2 can also be executed. However, when thrust is being generated (i.e., when the main combustor 11 is burning), fuel always passes through the turbine 16a. Therefore, while thrust is being generated, the generator 16 continues to generate electricity. Furthermore, the amount of fuel flowing through the turbine 16a varies depending on the set thrust.

[0047] Therefore, the amount of power generated by the generator 16 varies depending on the set thrust. However, despite such variations, by ensuring sufficient battery capacity in the power storage device 17, for example, it is possible to drive the first electric motor 18 and the second electric motor 19 at a desired rotation speed (for example, an optimized rotation speed) over the entire range of thrust. Furthermore, as in the first embodiment, the improvement in efficiency shown in FIG. 3 can also be achieved. Therefore, it is possible to provide a propulsion device 10B that can operate efficiently in response to various thrusts.

[0048] [Third Embodiment] Fig. 5 is a schematic configuration diagram of a propulsion device 10C according to a third embodiment. As shown in Fig. 5, the propulsion device 10C includes a main combustor 11 and a supply system 12C that supplies fuel and oxidizer to the main combustor 11. The supply system 12C includes a first pump 13, a second pump 14, a generator 16, a power storage device 17, a first electric motor 18, and a second electric motor 19.

[0049] The propulsion device 10C according to this embodiment employs an expander-bleed cycle as an example of an operating cycle. Therefore, the supply system 12C includes a path 20b branching off from a path 20a for fuel that has undergone regenerative cooling. The fuel (i.e., hot gas) flowing through the path 20b is supplied to the turbine 16a via a valve V1, which serves as a supply amount adjustment unit 24. The fuel discharged from the turbine 16a is discharged to the outside of the spacecraft or rocket carrying the propulsion device 10C.

[0050] As in the second embodiment, the operation sequence shown in Fig. 2 can also be executed in the third embodiment. However, it is possible to reduce the back pressure of the turbine 16a more than in the second embodiment. Therefore, compared to the second embodiment, it is easier to increase the rotation speed of the turbine 16a, improving the power generation performance of the generator 16 or reducing the size of the generator 16. Furthermore, as in the first and second embodiments, the improvement in efficiency shown in Fig. 3 can also be achieved.

[0051] [Fourth Embodiment] Fig. 6 is a schematic configuration diagram of a propulsion device 10D according to a fourth embodiment. As shown in Fig. 6, the propulsion device 10D includes a main combustor 11 and a supply system 12D that supplies fuel and oxidizer to the main combustor 11. The supply system 12D includes a first pump 13, a second pump 14, an auxiliary combustor (gas generator) 15, a generator 16, an electricity storage device 17, a first electric motor 18, and a second electric motor 19.

[0052] As with the first embodiment, the propulsion device 10D according to the fourth embodiment also employs a gas generator (GG) cycle as an example of an operating cycle. Accordingly, combustion gas from the main combustor 11 is ejected from a nozzle 11b. Meanwhile, combustion gas from the auxiliary combustor 15 is supplied to a turbine 16a of a generator 16 and then exhausted to the outside of the spacecraft or rocket.

[0053] 2 can also be executed in the fourth embodiment. However, the generator 16 in the fourth embodiment is a motor-generator that also serves as the first electric motor 18 that drives the first pump 13. Therefore, the turbine 16a is drivingly connected to the power generation section 16b and the first pump 13.

[0054] When the combustion gas from the auxiliary combustor 15 is supplied to the turbine 16a, the turbine 16a rotates and drives the rotor of the power generation unit 16b and the first pump 13. This causes the power generation unit 16b to generate electric power, which is then stored in the power storage device 17.

[0055] When power from the power storage device 17 is supplied to the power generation unit 16b, the rotor of the power generation unit 16b rotates, driving the first pump 13. As a result, the first pump 13 supplies fuel to the main combustor 11 and the auxiliary combustor 15. At this time, the auxiliary combustor 15 does not generate combustion gas. In other words, the valves V1 and V2 of the supply amount adjustment unit 24 are closed, and the supply of propellant to the auxiliary combustor 15 is stopped.

[0056] However, the first pump 13 may be driven by both the turbine 16 a and the power generation unit 16 b. In this case, the valves V1 and V2 of the supply amount adjustment unit 24 are opened, and the propellant is supplied to the auxiliary combustor 15, which then supplies the combustion gas to the turbine 16 a.

[0057] In this embodiment, the turbine 16a and the power generating unit 16b are used together as a drive source for the first pump 13 depending on the situation. For example, when the thrust is set to a value equal to or greater than a predetermined value, the auxiliary combustor 15 is ignited, and the turbine 16a is driven by the combustion gas of the auxiliary combustor 15. For example, in the operation sequence of FIG. 2, this operation is performed at time t １ From t ５ This applies to the period.

[0058] The driving of the first pump 13 by the turbine 16a assists the driving of the first pump 13 by the power generation unit 16b. In other words, the turbine 16a provides part of the energy required to drive the first pump 13. Generally, a fuel pump has a larger output (pump) than an oxidizer pump, and therefore the drive source for the pump tends to be large. In this embodiment, the drive source is shared by two drive sources (i.e., the turbine 16a and the power generation unit 16b). As a result, the power generation unit 16b can be made smaller.

[0059] Fifth Embodiment Fig. 7 is a schematic configuration diagram of a propulsion device 10E according to a fifth embodiment. As shown in Fig. 7, the propulsion device 10E includes a main combustor 11 and a supply system 12E that supplies fuel and oxidizer to the main combustor 11. The supply system 12E includes a first pump 13, a second pump 14, a generator 16, a power storage device 17, a first electric motor 18, and a second electric motor 19. This configuration is the same as the configuration of the propulsion device 10B according to the second embodiment.

[0060] However, the generator 16 of the fourth embodiment is applied to the generator 16 of this embodiment. That is, the generator 16 of the fifth embodiment is a motor-generator that also serves as the first electric motor 18 that drives the first pump 13.

[0061] As in the second embodiment, the propulsion device 10E according to this embodiment also employs an expander cycle (full expander cycle) as an example of an operating cycle. Therefore, the fuel discharged from the second pump 14 cools the main combustor 11, the throat 11a, and the nozzle 11b. Furthermore, the fuel passes through the turbine 16a in a gaseous state and is then supplied to the main combustor 11.

[0062] In the fifth embodiment, the operation sequence shown in Fig. 2 can also be executed. Although the amount of power generated by the generator 16 varies depending on the set thrust, by ensuring sufficient battery capacity in the power storage device 17, the first electric motor 18 (generator 16) and the second electric motor 19 can be driven at the desired rotation speed over the entire range of thrust. Furthermore, as in the first embodiment, the improvement in efficiency shown in Fig. 3 can also be achieved. Furthermore, as in the fourth embodiment, the power generation unit 16b can be made smaller.

[0063] [Sixth Embodiment] Figure 8 is a schematic configuration diagram of a propulsion device 10F according to a sixth embodiment. As shown in Figure 8, the propulsion device 10F includes a main combustor 11 and a supply system 12F that supplies fuel and oxidizer to the main combustor 11. The supply system 12F includes a first pump 13, a second pump 14, a generator 16, an electricity storage device 17, a first electric motor 18, and a second electric motor 19. This configuration is the same as the configuration of the propulsion device 10C according to the third embodiment.

[0064] However, the generator 16 of the fourth embodiment is applied to the generator 16 of the sixth embodiment. That is, the generator 16 of the sixth embodiment is a motor-generator that also serves as the first electric motor 18 that drives the first pump 13.

[0065] As with the third embodiment, the propulsion device 10E according to this embodiment also employs an expander-bleed cycle as an example of an operating cycle. Therefore, the supply system 12F includes a path 20b branching off from a path 20a for fuel that has undergone regenerative cooling. The fuel flowing through path 20b is supplied to the turbine 16a via a valve V3, which serves as a supply amount adjustment unit 24. The fuel discharged from the turbine 16a is discharged to the outside of the spacecraft or rocket on which the propulsion device 10E is mounted.

[0066] In the sixth embodiment, the operational sequence shown in FIG. 2 can also be executed. However, the back pressure of the turbine 16a can be reduced more than in the fifth embodiment. Therefore, compared to the fifth embodiment, it is easier to increase the rotation speed of the turbine 16a, improving the power generation performance of the generator 16 or reducing the size of the generator 16. Furthermore, since the turbine 16a can be driven by fuel that has undergone regenerative cooling, the generator 16 can be further reduced in size. Furthermore, as in the first embodiment, the improved efficiency shown in FIG. 3 can also be achieved.

[0067] Seventh Embodiment Fig. 9 is a schematic configuration diagram of a propulsion device 10G according to a seventh embodiment. As shown in Fig. 9, the propulsion device 10G includes a main combustor 11 and a supply system 12G that supplies fuel and oxidizer to the main combustor 11. The supply system 12G includes a first pump 13, a second pump 14, an auxiliary combustor (first auxiliary combustor) 15, a generator 16, an electricity storage device 17, a first electric motor 18, and a second electric motor 19.

[0068] The propulsion device 10G employs a two-stage combustion cycle as an example of an operating cycle. Therefore, the auxiliary combustor 15 of this embodiment is a so-called preburner that generates fuel-rich combustion gas (pre-combustion gas). The generated combustion gas is supplied to a turbine (first turbine) 16a of a generator 16, rotating the turbine 16a. The combustion gas that passes through the turbine 16a is supplied to the main combustor 11 and combusted therein together with the oxidizer discharged from the second pump. The amount of combustion gas supplied (generated) by the auxiliary combustor 15 is adjusted, for example, by a valve V4 serving as a supply amount adjustment unit 24 installed in the oxidizer path 21b.

[0069] As in the above-described embodiments, the seventh embodiment can also execute the operation sequence shown in Fig. 2 and achieve the improved efficiency shown in Fig. 3. As in the fourth to sixth embodiments, the generator 16 may be a motor-generator that also serves as the first electric motor 18 that drives the first pump 13. In other words, the turbine 16a may be drivingly connected to the power generation unit 16b and the second pump 14.

[0070] Eighth Embodiment Fig. 10 is a schematic configuration diagram of a propulsion device 10H according to an eighth embodiment. As shown in Fig. 10, the propulsion device 10H includes a main combustor 11 and a supply system 12H that supplies fuel and oxidizer to the main combustor 11. The supply system 12H includes a first pump 13, a second pump 14, an auxiliary combustor (first auxiliary combustor) 15, an auxiliary combustor (second auxiliary combustor) 25, a generator (first generator) 16, a generator (second generator) 26, an electric storage device 17, a first electric motor 18, and a second electric motor 19.

[0071] The propulsion device 10H employs a full-flow staged combustion cycle as an example of an operating cycle. Therefore, the auxiliary combustors 15 and 25 of this embodiment are both so-called preburners. The auxiliary combustor 15 generates fuel-rich combustion gas, while the auxiliary combustor 25 generates oxidizer-rich combustion gas.

[0072] The combustion gas generated by the auxiliary combustor 15 is supplied to a turbine (first turbine) 16a of a generator 16, causing the turbine 16a to rotate. That is, the auxiliary combustor 15 generates a first working fluid from fuel and oxidizer to drive the turbine 16a. The rotation of the turbine 16a causes the power generation unit 16b to generate electric power. The generated electric power is stored in the power storage device 17.

[0073] The combustion gas generated by the auxiliary combustor 25 is supplied to a turbine (second turbine) 26a of the generator 26, causing the turbine 26a to rotate. That is, the auxiliary combustor 25 generates a second working fluid from fuel and oxidizer to drive the turbine 26a. The rotation of the turbine 26a causes the power generation unit 26b to generate electric power. The generated electric power is stored in the power storage device 17.

[0074] The combustion gas that has passed through the turbine 16a is supplied to the main combustor 11. The combustion gas that has passed through the turbine 26a is also supplied to the main combustor 11. These combustion gases are mixed in the main combustor 11 and combusted.

[0075] In the supply system 12H, the fuel path 20a branches into a path 20b and a path 20c. The path 20b connects to the auxiliary combustor 15 via a valve V5. The path 20c connects to the auxiliary combustor 25 via a valve V6. Similarly, the oxidizer path 21a branches into a path 21b and a path 21c. The path 21b connects to the auxiliary combustor 15 via a valve V7. The path 20c connects to the auxiliary combustor 25 via a valve V8.

[0076] Similar to the valves V1 to V4 described above, the valves V5 to V8 may also function as the supply amount adjuster 24. In this case, the valves V5 and V7 adjust the amount of the first working fluid supplied to the turbine 16a in accordance with the amount of power generation set for the generator 16. Furthermore, the valves V6 and V8 adjust the amount of the second working fluid supplied to the turbine 26a in accordance with the amount of power generation set for the generator 26.

[0077] As in the above-described embodiments, the eighth embodiment can also execute the operation sequence shown in Fig. 2 and achieve the improved efficiency shown in Fig. 3. As in the fourth to sixth embodiments, the generator 16 may be a motor-generator that also serves as the first electric motor 18 that drives the first pump 13. In other words, the turbine 16a may be drivingly connected to the power generation unit 16b and the first pump 13.

[0078] In the eighth embodiment, two generators can be operated. This increases the amount of power generated. Alternatively, each generator can be made smaller and lighter in weight relative to the required amount of power.

[0079] The present disclosure is not limited to the above-described embodiments, but is defined by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

Claims

1. A propulsion device comprising: a main combustor; and a supply system that supplies fuel and oxidizer to the main combustor, wherein the supply system includes: a first pump that sucks in the fuel and pumps it into the supply system; a second pump that sucks in the oxidizer and pumps it into the supply system; a first generator including a first turbine driven by a supply of a first working fluid; a power storage device that stores electricity generated by the first generator; a first electric motor that drives the first pump with electricity from the power storage device; and a second electric motor that drives the second pump with electricity from the power storage device.

2. A propulsion device according to claim 1, wherein the first generator is a motor-generator that also serves as the first electric motor, and the first pump is drivingly connected to the first turbine of the first generator.

3. A propulsion device according to claim 1 or 2, comprising a first auxiliary combustor that produces the first working fluid from the fuel and the oxidizer.

4. A propulsion device according to claim 1 or 2, wherein the first working fluid is the fuel that has undergone regenerative cooling of the main combustor.

5. A propulsion device as described in claim 1 or 2, comprising a supply amount adjusting unit that adjusts the amount of the first working fluid supplied to the first turbine in accordance with the amount of power generation set in the first generator.

6. A propulsion device according to claim 3, wherein the ignition control of the first auxiliary combustor is performed independently of the ignition timing of the main combustor.

7. A propulsion device according to claim 5, wherein the supply system comprises: a second auxiliary combustor that produces a second working fluid from the fuel and the oxidizer; and a second generator including a second turbine that is driven by the supply of the second working fluid; and the power storage device further stores electric power generated by the second generator.

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