JP2024064907A - Injection type propulsion generation method, propulsion method for navigation body, injection type propulsion generation system, and navigation body - Google Patents

Abstract

To obtain a propulsion generation system obtaining propulsion used for a navigation body in a structure without a rotational mechanism, with easy manufacture, and maintenance.SOLUTION: Propulsion T is obtained by injecting condensation water Ws2 of steam S2, Sw1 and suctioned water W2 as well as increasing suction force for suctioning water W2 by suctioning water W2 by venturi effect due to injection of driving fluid Fd2 by using gas S2 composed by steam or gas G2 containing steam Sw1 as driving fluid Fd2, and condensing steam S2, Sw1 contained in the driving fluid Fd2 by cooling the driving fluid Fd2 by the suctioned water W2.SELECTED DRAWING: Figure 1

Description

The present invention relates to the generation of thrust for use in a watercraft that has a surface in contact with water, and more specifically to a jet thrust generation method, a method for propelling a watercraft, a jet thrust generation system, and a watercraft that can generate thrust without a rotating mechanism and with a structure that is easy to manufacture and maintain.

For vessels such as ships that navigate on the surface of the water or submarines that navigate underwater, the surfaces that come into contact with the water experience fluid resistance from the water when the vessel moves, so it is necessary to exert a propulsive force to resist this. For this reason, in many cases, a thruster is installed at the stern of the vessel to generate the propulsive force required for navigation.

Generally, screw propeller thrusters and water jet thrusters are used as thrusters. Such thrusters require rotational force to drive the propeller or pump, and therefore often use diesel engines, turbine engines, or combinations of generators and electric motors. This makes the propulsion system complex, requiring advanced technology during manufacturing and maintenance, and is expensive. In response to this, several methods have been proposed to obtain thrust by injecting gas or water without using rotational force.

For example, a distributed injection type engine for ships has been proposed in which the exhaust gas from a turbojet, which has a turbine that runs from a compressor through a combustor, is injected into the seawater inside a cylinder from a number of small diameter pipes arranged inside the cylinder, the exhaust gas is mixed with the seawater to create an injection fluid, and this is injected rearward to generate thrust (see, for example, Patent Document 1).

In this marine engine, exhaust gas is dispersed and injected from a small diameter pipe, mixed with the seawater inside the cylinder, and injected from the rear of the cylinder while sucking in seawater from the front of the cylinder. Then, by injecting exhaust gas rearward into the middle part of the cylinder, which is open at the front and rear, the velocity energy converted from the pressure energy of the exhaust gas is used to suck in and eject seawater. As a result, the seawater is accelerated by the ejection of exhaust gas, which has become room temperature (about 50 degrees) and low pressure (2 Pascal) upon contact with seawater, and thrust is obtained by ejecting the exhaust gas and seawater rearward. Note that the exhaust gas that has passed through the turbine is lowered in temperature from 1000°C during combustion to 50°C when injected, and is injected in a state where there is almost no thermal expansion due to temperature.

In addition, a marine propulsion device has been proposed that generates thrust by utilizing the expansion of combustible gas when it is burned. In this device, a combustion chamber is equipped with a check valve at the front end and an injection port at the rear end. In this combustion chamber, combustible gas is injected through the check valve onto the water filling the chamber, and the gas is ignited to cause it to burn rapidly and expand, causing all of the water filling the chamber to be ejected from the injection port, thereby generating thrust (see, for example, Patent Document 2).

In this ship propulsion device, the combustion gas expands and expands as it cools down to room temperature and contracts, drawing in the filled water. This eliminates the need for a rotary drive prime mover, a propeller shaft for power transmission, and a screw, resulting in a simple structure with fewer friction points in the main drive mechanism, which is said to result in a ship propulsion device that generates less water pollution and noise, and is easy to handle.

An underwater jet device has also been proposed in which compressed air and ions (such as hydrogen ions) are mixed in a combustion chamber, and the resulting combustion gas obtained by burning and exploding is supplied to an injection nozzle as a jet stream, and water pumped from a water pumping device is added to this jet stream and injected into the water (see, for example, Patent Document 3). Regarding the effect of adding water, it is described that "by spraying the jet stream together with water pumped from a seawater pumping device, even greater propulsion power for the ship can be obtained," but there is no specific description of the method or configuration for adding water to the jet stream.

A water-injection propulsion system vessel has also been proposed, in which seawater is directly pressurized with high-pressure combustion gas and sprayed overboard at high speed to obtain propulsive force (see, for example, Patent Document 4). In this vessel, the combustion pressure is directly pressurized by seawater in a high-pressure accumulator pipe via an insulated free piston arranged in a vertical pipe below the combustion chamber. The combustion pressure is adjusted by increasing or decreasing the amount of combustion, and the spray speed and amount of seawater, which is affected by seawater pressure, are adjusted to adjust the propulsive force.

A cylindrical device has also been proposed that uses the change in water pressure caused by the injection of steam and superheated high-pressure steam to generate a jet water stream to obtain propulsion, rather than mechanical operation such as a screw (see, for example, Patent Document 5). In this cylindrical device, the jet stream draws in water from the surrounding area and expels it to the rear to obtain propulsion, but there is no specific description of the reason for using steam and superheated high-pressure steam, other than the following: "The jet water stream is generated by utilizing the change in water pressure caused by the injection of steam," "To generate the jet water stream," and "Superheated high-pressure steam is used as the steam injected to generate the reduced pressure zone to generate the jet water stream."

A thrust enhancing device has also been proposed that draws low-pressure gas or high-pressure gas such as exhaust gas from gas outlets on the walls of a gas outlet tube and an injection nozzle into the inside of a high-speed axial water flow generated by a screw, mixes the gas with water, and releases it from an injection nozzle (see, for example, Patent Document 6). In this thrust enhancing device, after the gas mixes with the water, a large amount of bubbles are generated, which are compressed by the gas compression function in the reduced diameter section of the injection nozzle. When the bubbles are released from the injection nozzle, they expand instantly due to the pressure difference between the inside and outside, increasing the reaction force and enhancing the thrust of the water jet propulsion device.

Furthermore, a marine propulsion system has been proposed that obtains propulsion by injecting high-temperature gas generated in a combustion chamber from the exhaust nozzle of the combustion chamber into external water, and another marine propulsion system that obtains propulsion by injecting this high-temperature gas into the nozzle, sucking in water in front and injecting it rearward (see, for example, Patent Document 7). In these marine propulsion systems, propulsion is said to be obtained by the thrust of the high-temperature gas (similar to an aircraft jet engine) and the back pressure of air bubbles formed in the water near the exhaust nozzle.

None of the configurations described in Patent Documents 1 to 7 mentions any change in volume due to exhaust gas temperature, any change in volume due to water vapor temperature, any change in volume due to water vapor condensing and changing from gas phase to liquid phase, or any change in pressure (generation of negative pressure) based on these volume changes, and are not devices that make use of these characteristics. In particular, there is no mention of the negative pressure that occurs with the decrease in volume due to water vapor condensation (liquefaction), or the increase in the suction force of external water using this negative pressure.

On the other hand, as shown in FIG. 16, there is a device 200 that uses the Venturi effect to reduce the pressure around the first nozzle 220 by using the first fluid S that is sprayed at high speed from the first nozzle 220 arranged in the throat of a diffuser (divergent nozzle), and then uses this low pressure to suck in the second fluid W1, decelerates and pressurizes it in the divergent section 214, mixes the sucked second fluid W1 with the first fluid S, pressurizes it, and sprays it. Note that when the first fluid S is a liquid discharge device, it may be called an "ejector," and when the first fluid S is a gas discharge device, it may be called an "eductor," but here both are called "ejectors" (water ejectors, steam ejectors, air ejectors). These devices have a simple structure and no moving parts, so they are durable and reliable.

There is also a device called an "injector" that is used in boilers, etc. In this "injector," steam is injected into the tube, creating low pressure inside it using the principle of a spray bottle, and water is sucked in. The sucked in water is accelerated by the ejected steam. In this process, the steam mixes with the room temperature water and condenses, resulting in a liquid with a relatively high temperature and large amount of kinetic energy.

Another example of a "simple thrust generating engine" that serves as a reference for the present invention is an aircraft pulse jet engine (an intermittent combustion jet propulsion engine). This pulse jet engine includes pulse jet engine A, which has a combustion chamber 110 and a long exhaust pipe 120, as shown in Figure 14, and U-shaped bubbleless pulse jet engine 100B, as shown in Figure 15.

In the pulse jet engine 100A shown in FIG. 14, the air intake 111 of the combustion chamber 110 is provided with an inlet check valve 112, and the outlet of the combustion gas G is provided with a nozzle with a throttle section 113 for compressing the intake air by reflecting the shock waves generated by combustion. Then, the process of fuel F being blown into the air A taken into the combustion chamber 110 from the air intake 111 with the inlet check valve 112 (ignited by the ignition device 132 only at the beginning) and burning (low-volume combustion), the process of the inlet check valve 112 closing as the pressure rises due to combustion (adiabatic expansion) and the combustion gas G flowing out of the exhaust pipe 120, and the process of the inlet check valve 112 opening and fresh air A being introduced when the combustion gas G flows out due to inertia and the pressure of the combustion chamber 110 drops below atmospheric pressure (low-pressure cooling) are repeated as a cycle. Then, the exhaust of the combustion gas G generates thrust.

In addition, in the bubbleless pulse jet engine 100B shown in FIG. 15, instead of providing an inlet check valve 112, a thin tube 114 is used to draw in air A from the opposite direction to the injection direction of the combustion gas G. The exhaust pipe 120 is enlarged in diameter to increase the exhaust pressure.

These pulse jet engines are more efficient than normal combustion because the air-fuel mixture is compressed and exploded, and they also have good thermal efficiency. In addition, they have no rotating drive parts and a very simple structure, making them suitable for low-cost mass production. On the other hand, compared to turbojet engines, they have a lower compression ratio, so they have low thrust for their fuel efficiency and low performance, and they also produce a lot of noise and vibration. For this reason, they are currently often used in "pulse combustors" that provide heat for water heaters, rather than as aircraft engines.

JP 2013-117230 A JP 2016-107665 A JP 2000-168683 A JP 2009-126509 A JP 2008-302912 A JP 2013-52719 A JP 2011-520691 A

Considering the similarity in structure between the simple pulse jet engine and the steam ejector as described above, and the fluid suction action of the steam ejector due to the Venturi effect, it was concluded that by condensing the water vapor of the driving fluid to generate negative pressure, it would be possible to maximize the suction effect of the steam ejector while using the sucked in second fluid for thrust.

They thought that simply sucking water into the high-pressure steam that is the driving fluid of the steam ejector and turning it into steam would make it difficult to generate a large thrust, as the mass is small compared to the volume ejected. Also, when seawater is introduced into the steam ejector from the surrounding seawater, salt in the seawater will precipitate, so to avoid this, it is possible to use the negative pressure generated by the Venturi effect of the steam ejector to suck water into a water tank placed at a high position, and then use the potential energy of this water to eject it and generate thrust. However, there is a need for a water tank and there is the issue of cooling the steam, which is the driving fluid, and this would make the thrust generation system complicated and would also be energy inefficient.

The present invention has been made in consideration of the above, and its object is to provide an ejection type thrust generating method, a method for propelling a vehicle, an ejection type thrust generating system, and a vehicle that generate thrust by utilizing the change in volume due to a decrease in temperature of high enthalpy gas and water vapor, particularly the decrease in volume due to condensation of water vapor, while incorporating the Venturi effect of sucking in surrounding water by ejecting the driving fluid in the ejector, and the effect of the increase in pressure due to the deceleration of the fluid by the diffuser, thereby eliminating the need for a rotating mechanism, being simple in structure, and easy to manufacture and maintain.

The jet thrust generating method of the present invention, which is intended to achieve the above-mentioned objectives, uses a gas composed of water vapor or a gas containing water vapor as a driving fluid, sucks in water by the Venturi effect caused by the injection of the driving fluid, cools the driving fluid with the sucked-in water, condenses the water vapor, and increases the suction force for sucking in the water, while jetting the condensed water of the water vapor and the sucked-in water to generate thrust.

According to this method, water vapor in a large gas phase is used as all or part of the driving fluid, and by cooling this driving fluid, it condenses into water in a small liquid phase, creating a low pressure state (negative pressure state) and sucking in a large amount of surrounding water. Then, by ejecting this large amount of water, thrust can be generated efficiently.

And because this jet thrust generation method utilizes the Venturi effect of the ejector, all that is required is to inject water vapor or gas containing water vapor with high enthalpy (the sum of internal energy and pressure energy), so there is no need to use a rotating mechanism such as a "high-pressure pump (axial water pump)" or a "propeller called an impeller" as used in water jet propulsion. Therefore, the devices and systems for implementing this jet thrust generation method have a simple configuration with no rotating mechanism, and because there is no rotating mechanism, the design, manufacturing, testing, maintenance, inspection, etc. are simplified and can be provided at low cost.

In the above-mentioned jet thrust generating method, the driving fluid is mixed with the sucked water, and the driving fluid is cooled by direct contact, causing the water vapor contained in the driving fluid to condense. This allows the driving fluid to be cooled efficiently with a simple configuration.

In addition, in the above-mentioned jet-type thrust generating method, the driving fluid is generated by contacting or mixing water vapor, a gas containing water vapor, or a gas and water. This makes it possible to generate a driving fluid containing water vapor efficiently with a simple configuration.

The method for propelling a naval vessel of the present invention to achieve the above-mentioned objectives is characterized in that the thrust generated using the above-mentioned jet thrust generating method is used as part or all of the propulsion force for propelling the naval vessel. This method makes it possible to propel the naval vessel using a jet thrust generating device that does not have a rotation mechanism, has a simple structure, and is easy to manufacture and maintain.

To achieve the above-mentioned object, the jet thrust generating system of the present invention is an jet thrust generating system characterized by comprising: a vaporizing and expanding section that generates a driving fluid composed of water vapor or a gas containing water vapor; a cooling and condensing section that sucks in water by the Venturi effect accompanying the ejection of the driving fluid from a driving nozzle provided at the outlet of the vaporizing and expanding section, cools the driving fluid with the sucked water, and condenses the water vapor contained in the driving fluid; a pressure recovery section that has a diverging member provided continuously with the cooling and condensing section and recovers the pressure of the jet fluid composed of the driving fluid and the sucked water; and an ejection section that ejects the jet fluid whose pressure has been restored by the pressure recovery section. With this jet thrust generating system, the above-mentioned jet thrust generating method can be implemented, and the same effect can be achieved.

The above-mentioned jet-type thrust generating system is configured with a vaporization expansion section that generates the driving fluid by contacting or mixing water vapor, a gas containing water vapor, or a gas and water. This allows the driving fluid containing water vapor to be generated efficiently with a simple configuration.

The navigation vehicle of the present invention, which is intended to achieve the above-mentioned objective, is characterized by being equipped with the above-mentioned jet thrust generating system. This allows the same effects to be achieved as the above-mentioned jet thrust generating method and the above-mentioned jet thrust generating system.

The jet thrust generating method, the propulsion method for a navigation body, the jet thrust generating system, and the navigation body of the present invention can generate thrust by utilizing the volume change caused by the decrease in temperature of high enthalpy gas and water vapor, in particular the decrease in volume caused by the condensation of water vapor, while incorporating the effect of the suction of water (second fluid) by the injection of the driving fluid in the ejector and the effect of the increase in pressure caused by the deceleration of the fluid by the diffuser. Therefore, it is possible to provide a jet thrust generating method, the propulsion method for a navigation body, the jet thrust generating system, and the navigation body that can obtain thrust with a structure that does not require a rotating mechanism and is easy to manufacture and maintain.

1 is a block diagram showing functions of an ejection type thrust generation system according to a first embodiment of the present invention; 1 is a side cross-sectional view illustrating a specific configuration of an ejection type thrust generating system according to a first embodiment of the present invention. 11A and 11B are diagrams relating to a second method of introducing primary water, in which (a) is a block diagram showing the functions, and (b) is a diagram showing an example of the configuration. 11A and 11B are diagrams relating to a third method of introducing primary water, in which (a) is a block diagram showing the functions, and (b) is a diagram showing an example of the configuration. FIG. 5 is a block diagram showing the functions of an ejection type thrust generation system according to a second embodiment of the present invention. FIG. 11 is a side cross-sectional view illustrating a specific configuration of an ejection type thrust generating system according to a second embodiment of the present invention. 11 is a side cross-sectional view partially illustrating an example of a configuration in which a gas generating unit and a gas supply unit are integrated in an ejection type thrust generating system according to a second embodiment of the present invention. FIG. 1A, 1B, 1C, and 1D are diagrams illustrating an ejection type thrust generating unit in an ejection type thrust generating system, in which (a) is a side cross-sectional view, (b) is a plan view, (c) is a front view, and (d) is a rear view. FIG. 11 shows an example of an ejection type thrust generating unit being arranged on board a vessel, where (a) is a side view of the ejection type thrust generating unit arranged above the water surface for above-water ejection, (b) is a bottom view of the vessel in (a), (c) is a side view of the ejection type thrust generating unit arranged below the water surface for underwater ejection, and (d) is a bottom view of the vessel in (c). FIG. 11 shows an example of an ejector thrust generating unit in a watercraft arranged on the water surface beside the ship, where (a) is a side view of the ejector thrust generating unit utilizing an onboard waterway, (b) is a bottom view of the ship in (a), (c) is a side view of the ejector thrust generating unit utilizing an outboard waterway, and (d) is a bottom view of the ship in (c). These figures show an example of an ejector thrust generating unit being placed on the water surface on the stern side of a watercraft and ejecting power onto the water, where (a) is a side view of the ejector thrust generating unit placed in an onboard waterway that draws in power from the bottom of the ship, (b) is a bottom view of the ship in (a), (c) is a side view of the ejector thrust generating unit placed in an onboard waterway that draws in power from the side of the ship, and (d) is a bottom view of the ship in (c). These figures show an example of an ejector thrust generating unit being placed under the water surface on the stern side of a navigation body and ejecting it into the water, where (a) is a side view of the ejector thrust generating unit placed in an onboard waterway that draws in water from the bottom of the ship, (b) is a bottom view of the ship in (a), (c) is a side view of the ejector thrust generating unit placed in an onboard waterway that draws in water from the side of the ship, and (d) is a bottom view of the ship in (c). These figures show an example of an ejection type thrust generating unit in a watercraft being arranged on the side of the ship and ejecting into the water, where (a) is a side view in which the ejection type thrust generating unit is arranged on the bow side, (b) is a bottom view of the ship in (a), (c) is a side view in which the ejection type thrust generating unit is arranged on the stern side, and (d) is a bottom view of the ship in (c). 1 is a side cross-sectional view illustrating the configuration of a pulse jet engine that serves as a reference for the present invention. FIG. 1A and 1B are side cross-sectional views illustrating the configuration of a U-shaped valveless pulse jet engine that is a reference for the present invention, in which (a) shows a configuration for sucking in air and supplying fuel, and (b) shows a configuration for supplying fuel and air. FIG. 1 is a side cross-sectional view illustrating a configuration of a steam ejector according to the present invention.

[Introduction and Overview of Figures] Below, with reference to the drawings, an embodiment of the jet thrust generating method, the propulsion method for a watercraft, the jet thrust generating system, and the watercraft according to the present invention will be explained. Note that the drawings shown here are schematic diagrams for explaining the present invention, and are not necessarily drawn to exact dimensional proportions, and do not necessarily show exact positions.

The first embodiment of the injector thrust generating method and the injector thrust generating system of the present invention uses high enthalpy water vapor as the driving source, and the second embodiment of the injector thrust generating method and the injector thrust generating system of the present invention uses high enthalpy gas (not including water vapor) as the driving source. And the third embodiment of the injector thrust generating method and the injector thrust generating system of the present invention uses high enthalpy gas (including water vapor) as the driving source.

Figures 1 to 7 are diagrams showing the configuration of an ejector thrust generating system. Figure 8 is a diagram showing the configuration of an ejector thrust generating unit, and Figures 9 to 13 are diagrams showing the configuration of a naval vehicle. Figures 14 and 15 are explanatory side cross-sectional views of a pulse jet engine that serves as a reference for the present invention, and Figure 16 is a side cross-sectional view of a steam ejector that serves as a reference for the present invention.

More specifically, Figs. 1 to 4 show an injection type thrust generating system that uses high enthalpy steam as the driving fluid, and Figs. 5 and 6 show an injection type thrust generating system that uses high enthalpy gas as the driving fluid. Fig. 7 shows an injection type thrust generating system that integrates a combustion gas generator and a gas expansion section. Figs. 1, 3(a), 4(a), and 5 are block diagrams showing the basic components of an injection type thrust generating system and their functions, and Figs. 2, 3(b), 4(b), and 6 are side cross-sectional views that typically show the specific configuration of an injection type thrust generating system.

Figures 9 to 13 are diagrams illustrating the placement of the jet thrust generating unit in a watercraft equipped with the jet thrust generating system of the present invention. More specifically, Figure 9 shows an example where the suction port is placed at the bow, Figure 10 shows an example where the suction port is placed at the side of the ship, and Figures 11 and 12 show examples where the suction port is placed at the stern. Figure 13 shows an example where the jet thrust generating unit is placed at the side of the ship.

[Embodiment] First, an embodiment of an ejection type thrust generating system will be described, followed by an embodiment of an ejection type thrust generating method. Next, an embodiment of a watercraft equipped with an ejection type thrust generating system will be described, followed by an embodiment of a method of propelling the watercraft.

[First embodiment of the injector thrust generating system] As shown in Figures 1 to 4, the injector thrust generating system 1A of the first embodiment of the present invention uses water vapor (hereinafter referred to as "primary steam") S1 with high enthalpy (sum of internal energy and pressure energy) such as saturated steam, generates water vapor Sw1 in addition to this water vapor S1, and uses this water vapor (hereinafter referred to as "secondary steam") S2 (= S1 + Sw1) as the driving fluid Fd2 of the steam ejector, and uses the negative pressure generated by the condensation of the water vapor S2 together with the Venturi effect to suck in surrounding water (secondary water) W2, which is then passed through an expanding member such as a diffuser and then injected to obtain thrust T.

As shown in FIG. 1, this jet thrust generating system 1A is configured with a steam generating section 2A and an jet thrust generating device 10A. The jet thrust generating device 10A is configured with a steam supply section 20A, a vapor expansion section 30A, a cooling and condensing section 40A, a pressure recovery section 50A, an injection section 60A, etc.

[Steam generating section] This steam generating section 2A is the section that generates high enthalpy steam (gas: gas phase state: hereafter referred to as "primary steam") S1 to be supplied to the steam supply section 20A. This steam generating section 2A can be a commonly used steam boiler.

However, when using this jet-type thrust generating device 10A at sea, it is necessary to store fresh water in a tank in advance for the boiler water, or to have equipment or devices to desalinate seawater, so it is not currently practical.

Therefore, the jet thrust generating system 1A of the first embodiment is suitable for cases where some water steam can be utilized, such as a portion of the water steam used in the vehicle 5 equipped with this jet thrust generating system 1A, excess water steam, or water steam discarded after use, or where water steam can be easily generated in some way. If a practical, low-cost method for desalinating seawater is developed, a steam boiler can be used.

[Injection type thrust generating device: steam supply unit] The steam supply unit 20A of the injection type thrust generating device 10A is a part for temporarily storing the high enthalpy primary steam S1 supplied from the steam generating unit 2A and adjusting the pressure and discharge amount of the primary steam S1 discharged from the steam outlet 23A. This steam supply unit 20A is configured with a tank 21A for temporarily storing the primary steam S1, a steam inlet 22A, a steam outlet 23A, and a pressure adjustment mechanism 24A such as a pressure adjustment valve. The steam inlet 22A is an inlet through which the primary steam S1 from the steam generating unit 2A enters, and is connected to the steam supply flow path 2Aa. The steam outlet 23A is an outlet through which the primary steam S1 is sent to the vaporization expansion unit 30A. In addition, it is desirable to cover the steam supply unit 20A with a heat insulating material or the like to prevent the enthalpy of the primary steam S1 from decreasing due to heat radiation from the tank 21A.

The amount of primary steam S1 supplied from the steam generating section 2A to the steam supply section 20A is adjusted by a steam supply adjustment valve 2Ab arranged in the steam supply flow path 2Aa. The amount of primary steam S1 discharged from the steam supply section 20A to the vaporization expansion section 30A is controlled by controlling the steam supply adjustment valve 2Ab arranged in the steam supply flow path 2Aa and by controlling the steam pressure by the pressure adjustment mechanism 24A.

[Evaporation expansion section] The evaporation expansion section 30A is a section that generates the water vapor S2 that constitutes the driving fluid Fd2, and is a section that evaporates water (hereinafter referred to as "primary water") W1 with a part of the enthalpy of the primary steam S1 supplied from the steam supply section 20A to increase the amount of steam. It is composed of a tank (or flow path) 31A for evaporating the primary water W1, a steam introduction mechanism 32A that introduces the primary steam S1 supplied from the steam outlet 23A of the steam supply section 20A, a water introduction mechanism 33A that introduces the primary water W1, and a driving nozzle 34A that sprays the secondary steam S2 into the cooling and condensing section 40A. It is preferable that the tank (or flow path) 31A has a heat-retaining structure so that the enthalpy of the primary steam S1 does not decrease due to heat radiation from the tank (or flow path) 31A.

In this vaporization and expansion section 30A, primary water W1 is added to the primary steam S1, and heat is exchanged between the primary water W1 and the primary steam S1 to vaporize the primary water W1. In other words, by imparting a portion of the enthalpy of the primary steam S1 to the primary water W1 through heat exchange, the primary water W1 is heated to above its boiling point to generate water vapor Sw1. This increases the overall amount of water vapor S2 (= S1 + Sw1). Since the primary water W1 is to be evaporated, it is preferable to use a structure in which the water channel of the water introduction mechanism 33A runs around the tank 21A of the steam supply section 20A and heat is released from the tank 21A to preheat it.

In this heat exchange, the volume of the primary steam S1 decreases due to a decrease in the temperature of the primary steam S1, but on the other hand, the primary water W1 evaporates, turning the primary water W1 into steam Sw1 and increasing its volume. Therefore, although it depends on the temperature and pressure of the vaporization expansion section 30A, the increase in volume due to the evaporation (vaporization) of the primary water W1 is usually greater than the decrease in volume due to the decrease in temperature of the primary steam S1, so the overall volume (S2 = S1 + Sw1) increases.

The following three methods are considered as a method for evaporating the primary water W1 with this primary steam S1. The first method is to suck the primary water W1 using a steam ejector 32AA as shown in FIG. 2. The second method is to inject the primary water W1 into the steam S1 as shown in FIG. 3(a). The third method is to mix the accumulated water W0 with the primary steam S1 and boil the water W0 as shown in FIG. 3(b).

In the first method, as shown in FIG. 2, a steam ejector 32AA using steam S1 as a driving fluid is used to draw in primary water W1 by the Venturi effect, thereby mixing the primary water W1 with the steam S1. In this case, the steam ejector 32AA has both the steam introduction mechanism 32A and a part of the water introduction mechanism 33A, and the water introduction mechanism 33A is configured to have a suction section for the second fluid of the steam ejector 32AA. Then, the steam ejector 32AA ejects primary steam S1 and draws in primary water W1.

When there is a water inlet passage 33Aa connected to the suction section as shown in Figures 1 and 2, the amount of primary water W1 supplied is adjusted by opening/closing or adjusting the water inlet amount adjustment valve 33Ab provided in the water inlet passage 33Aa. Alternatively, the amount of primary water W1 is adjusted by an opening area adjustment mechanism (not shown), such as a shutter, provided in the suction section of the water inlet passage 33Aa.

In the second method, as shown in FIG. 3, primary water W1 is injected from a water supply nozzle 33Ac or the like into the primary steam S1 filled in the vaporization expansion section 30A. In this case, the steam introduction mechanism 32A is configured with a steam introduction passage 32Aa and a steam injection nozzle 32Ac for avoiding the influence of pressure from the vaporization expansion section 30A side. Then, primary water W1 is mixed into the primary steam S1 filled in the vaporization expansion section 30A from the water introduction passage 33Aa.

The amount of primary water W1 introduced is adjusted by opening/closing or adjusting the water introduction amount adjustment valve 33Ab provided in the water introduction flow path 33Aa. Alternatively, the amount of water introduced is adjusted by an opening area adjustment mechanism (not shown), such as a shutter, provided in the suction section of the water introduction flow path 33Aa.

The third method is a method for avoiding residual salt when the water surrounding the jet thrust generating device 10A is seawater or the like and may leave behind salt after evaporation. In this third method, as shown in FIG. 4, the steam introduction mechanism 32A is configured with a water introduction flow path 33Aa and an underwater injection nozzle 32Ad, and the water introduction mechanism 33A is configured with a water introduction flow path 33Aa for supplying water W0 for boiling by overcoming the pressure of the water vapor S1 inside the vaporization expansion section 30A. In addition, it is configured with a water discharge flow path 33Ad for discharging the water W0 for boiling before it is concentrated.

Then, the primary steam S1 is released into the boiling water W0 that has accumulated at the bottom of the vaporization and expansion section 30A, and the enthalpy of the primary steam S1 boils the boiling water W0, evaporating the primary water W1, which is part of the boiling water W0.

As shown in FIG. 4(b), when a navigable body 5 equipped with an injection type thrust generating device 10A is navigating, the water W1 flowing into the inlet of the water introduction passage 33Aa provided below the water surface can be introduced into the vaporization expansion section 30A using the force of the water flow and used as the boiling water W0 or primary water W1. Alternatively, the water pressure of water stored in a separate water tank can be used to introduce this water into the vaporization expansion section 30A.

When seawater is used as the primary water W1, salts and other substances in the seawater may precipitate as the primary water W1 evaporates. In the first and second methods, these precipitates are converted into small particles and transported to the cooling and condensing section 40A together with the secondary steam S2. However, since there is a possibility that the precipitates may accumulate inside the tank (or flow path) 31A during start-up and shutdown, it is necessary to configure the tank (or flow path) 31A so that the inside can be cleaned and the precipitates can be discharged.

In the third method, the boiling water W0 can be replaced before it is concentrated, allowing the precipitate to be discharged. This replacement can be performed intermittently or continuously. As shown in FIG. 4, this replacement is performed by opening/closing or adjusting the water introduction amount adjustment valve 33Ab provided in the water introduction flow path 33Aa and opening/closing or adjusting the water discharge amount adjustment valve 33Ae provided in the water discharge flow path 33Ad. If this water discharge flow path 33Ad is connected to the water suction flow path 43Aa of the secondary water W2 of the cooling and condensing section 40A, the boiling water W0 can be replaced more smoothly.

[Cooling and condensation section] Thermodynamically, the cooling and condensation section 40A has the important function of converting part of the enthalpy of the secondary steam S2 into the kinetic energy of the injected fluid (moisture) W3. As shown in Figures 1 to 4, it is composed of a flow path (or tank) 41A for mixing the secondary steam S2 with the secondary water W2 and generating negative pressure to suck in the secondary water W2. This flow path (or tank) 41A does not need to have an insulating structure because it is necessary to cool the secondary steam S2, but in relation to the position where the negative pressure is generated, it may be better to have an insulating structure on the upstream side.

In this cooling and condensing section 40A, secondary water W2 is sucked in by the Venturi effect caused by the injection of driving fluid Fd2 from the driving nozzle 34A provided at the outlet of the vaporizing and expanding section 30A, and the sucked in secondary water W2 cools the driving fluid Fd2, condensing the water vapor S2 contained in the driving fluid Fd2. In this cooling and condensing section 40A, the secondary water W2 is sucked in and heat exchanged until the secondary vapor S2 condenses and negative pressure is generated.

In this cooling and condensing section 40A, secondary steam S2 ejected from the driving nozzle 34A is used as the driving fluid Fd2 of the ejector, and water (hereinafter referred to as "secondary water") W2 surrounding the jet type thrust generating device 10A is sucked in from the outside, and this secondary water W2 is mixed with the secondary steam S2. This causes heat exchange between the secondary water W and the secondary steam S2, causing the secondary steam S2 to condense (liquefy). By condensing the secondary steam S2, the volume of the secondary steam S2 is reduced, and the reduction in pressure (generation of negative pressure) caused by this reduction in volume is utilized to increase the effect of sucking in the secondary water W2.

In this cooling and condensing section 40A, secondary steam S2 and secondary water W2 mix together, causing the secondary steam S2 to condense and generate negative pressure. Some of this secondary water W2 is sucked in by the suction force of the external fluid in the drive nozzle 34A, but also by the suction force caused by the generated negative pressure, so a suction port 42A is provided in front of the negative pressure generating section to suck in the remaining secondary water W2. The location where this negative pressure is generated and the position of the suction port 42A for the secondary water W2 are important, but the position and size of this suction port 42A can be easily set by analyzing the results of water tank experiments using a model or the actual jet thrust generating device 10A, simulation calculations using computational fluid dynamics (CFD), etc.

In other words, in this cooling and condensing section 40A, in addition to the Venturi effect caused by the jet flow of the driving fluid Fd2, a further negative pressure is generated due to the reduction in volume caused by the condensation of the secondary steam S2, which increases the suction force on the secondary water W2 and promotes the suction of the secondary water W2. Note that the water (hereinafter referred to as the "jet fluid") W3 at the outlet of this cooling and condensing section 40A is the secondary water W2 plus water Ws2, which is liquefied secondary steam S2.

In the cooling and condensing section 40A, there is a possibility that the injected fluid W3 may backflow, so this backflow is prevented by the kinetic energy of the secondary water W2. In other words, the flow of the injected fluid W3 is directed toward the pressure recovery section 50A by the inflow direction and inflow speed of the secondary water W2, preventing the injected fluid W3 from backflowing. Note that backflow may occur, particularly during start-up and shutdown. If this backflow does occur, a backflow prevention mechanism or a flow path area adjustment mechanism is provided on the outlet side of the cooling and condensing section 40A to prevent the backflow.

Increasing the kinetic energy of the jet fluid W3 in the cooling and condensing section 40A increases the energy efficiency of this jet thrust generating system 1A. Therefore, the inflow direction of the secondary steam S2, the suction direction of the secondary water W2, and the outflow direction of the jet fluid W3 are configured to be as similar as possible, so that the inflow energy of the secondary water W2 can be efficiently utilized.

[Pressure recovery section] The pressure recovery section 50A is a section that recovers the pressure of the injection fluid W3, which is composed of the driving fluid Fd2 and the sucked secondary water W2. In other words, the pressure of the injection fluid W3, which has been reduced in the cooling and condensing section 40A, is increased by reducing the flow rate of the injection fluid W3, thereby obtaining a pressure at which injection is possible in the injection section 60A. The pressure recovery section 50A is configured with a diffuser (divergent member) 51A that is connected to the outlet of the cooling and condensing section 40A. The cooling and condensing section 40A does not need to have an insulating structure.

[Injection section] The injection section 60A is a section that obtains thrust T by injecting the injection fluid W3 whose pressure has been restored from the thrust generating nozzle 62A, and is composed of a tank (or flow path) 61A for maintaining pressure and the thrust generating nozzle 62A. The injection fluid W3 whose pressure has been restored is injected from this thrust generating nozzle 62A, thereby generating thrust T. This injection section 60A also does not need to have a heat-retaining structure.

[Summary 1] As described above, in the jet thrust generating device 10A, the primary water W1 and secondary water W2 around the jet thrust generating device 10A are sucked in from the outside by injecting the primary steam S1 and secondary steam S2, and the jet fluid W3 is jetted from the thrust generating nozzle 62A to generate thrust T. Here, the primary steam S1 and the primary water W1 exchange heat to generate secondary steam S2, and then the secondary steam S2 is cooled by the secondary water W2 to condense the secondary steam S2, thereby reducing the volume of the secondary steam S2 and reducing the pressure (generating negative pressure). This reduction in pressure increases the suction force on the secondary water W2, and increases the amount and speed of the jet fluid W3 jetted from the thrust generating nozzle 62A, thereby increasing the thrust T.

Thermodynamically, the enthalpy of the primary steam S1 is used to generate secondary steam S2, which is then condensed, generating negative pressure, converting the enthalpy of the secondary steam S2 into kinetic energy of the ejected fluid W3, and converting this kinetic energy into thrust T.

[Calculation Example 1] For reference, the results of a calculation example are shown below for the case where steam S1 and S2 are used as driving fluids Fd1 and Fd2. Regarding the specific amounts of primary steam S1, secondary steam S2, primary water W1, secondary water W2, and jet fluid W3, it is assumed that 1 kg (0.51 ^m3 : 1.244 ^Nm3 /kg) of saturated steam at 3.7 Pa (about 3.8 atm) at 140°C is used as primary steam S1, and further, jet fluid W3 is cooled to 50°C using water at 15°C. In order to turn primary steam S1 at 140°C into secondary steam S2 at 100°C and 1.0 Pa (about 1.0 atm), about 0.022 kg of primary suction water W1 at 15°C is required, resulting in 1.022 kg (1.71 ^m3 ) of secondary steam S2.

To turn this secondary steam S2 into 1.0 Pa (approximately 1.0 atm) water at 100°C, 6.48 kg of water at 15°C is required, and 7.50 kg of water at 100°C is generated. To turn this into water at 50°C, 10.71 kg of water at 15°C is required, so the required secondary suction water W2 is 18.21 kg. Meanwhile, the total amount of jetted water W3 is 18.21 kg.

Therefore, in order to convert 1 kg (0.51 ^m3 ) of primary steam S1, which is saturated water vapor at 3.7 Pa (approximately 3.8 atm) at 140° C., into a jet fluid W3 at 50° C., it is necessary to aspirate 17.21 kg of water at 15° C. To obtain jet fluid W3 at 25° C., it is necessary to aspirate an additional 28.7 kg of water at 15° C., so that the jet fluid W3 becomes 49.5 kg (0.050 ^m3 ).

[Second embodiment of the injection type thrust generating system] The second embodiment of the injection type thrust generating system 1B of the present invention uses a gas (hereinafter referred to as "primary gas") G1 with a large enthalpy (the sum of internal energy and pressure energy) such as combustion gas as the driving fluid Fd1 to generate water vapor Sg1, and uses this gas (hereinafter referred to as "secondary gas") G2 (= G1 + Sg1) as the driving fluid Fd2 of the ejector. Using the Venturi effect, along with the reduction in volume due to the change in enthalpy of the primary gas G1 and the negative pressure generated by the condensation of the water vapor Sg1, the system obtains thrust T by sucking in surrounding water (secondary water) W2 and injecting it after passing it through an expanding member such as a diffuser.

As shown in Figures 5 and 6, the jet thrust generating system 1B is configured with a gas generating unit 3B and an jet thrust generating device 10B. The jet thrust generating device 10B is configured with a gas supply unit 20B, a vaporizing and expanding unit 30B, a cooling and condensing unit 40B, a pressure recovery unit 50B, an injection unit 60B, etc. Also, as shown in Figure 7, the gas generating unit 3B and the gas supply unit 20B may be configured as one unit.

[Gas generating section] The gas generating section 3B is a section that generates a high enthalpy primary gas (gas: gas phase state) G1 to be supplied to the gas supply section 20B. A combustor may be used as this gas generating section 3B. Since the gas generating section 3B only needs to generate a high enthalpy primary gas G1, it may be configured with a combustor (burner) 3Bb provided in the combustion chamber 3Ba, as shown in Figures 6 and 7. In this case, the gas generating section 3B is configured to have a combustor 3Bb suitable for the fuel F used, an air supply device (not shown) that supplies air A for combustion, and a combustion chamber 3Ba, depending on the fuel F used.

In the configuration shown in FIG. 6, the amount of primary gas G1 generated in the gas generating unit 3B is controlled by the operation of the fuel supply regulating valve 3Bfv arranged in the fuel supply flow path 3Bf and the operation of the air supply regulating valve 3Bcv arranged in the air supply flow path 3Bc. Also, the amount of primary gas G1 supplied from the gas generating unit 3B to the gas supply unit 20B is controlled by the adjustment of the gas supply regulating valve 3Be arranged in the gas supply flow path 3Bd. On the other hand, in the configuration shown in FIG. 7, the amount of primary gas G1 generated in the gas generating unit 3B (gas supply unit 20B) is controlled by the operation of the fuel supply regulating valve 3Bfv arranged in the fuel supply flow path 3Bf, the operation of the air supply regulating valve 3Bcv arranged in the air supply flow path 3Bc, and the adjustment of the gas pressure by the pressure adjustment mechanism 24B.

If the enthalpy of the primary gas G1 is reduced by passing it through a gas treatment device that removes NOx, SOx, etc., energy efficiency will deteriorate, so it is preferable to use clean fuels such as hydrogen gas or natural gas that do not require a gas treatment device. Furthermore, the high-enthalpy primary gas G1 is not limited to combustion gas, and may be high-pressure air or high-temperature air. Therefore, in the case of the second embodiment of the injector thrust generating system 1B, any high-enthalpy gas will suffice, and engine exhaust gas, cooling air, excess compressed air, etc. used in the naval vehicle 5 equipped with the injector thrust generating system 1B may also be used.

[Injection type thrust generator: Gas supply unit] The gas supply unit 20B of the injection type thrust generator 10B is a part that temporarily stores high enthalpy primary gas G1 such as combustion gas and adjusts the pressure of the primary gas G1 discharged from the gas outlet 23B.

In the configuration shown in FIG. 6, the gas supply unit 20B includes a tank 21B for temporarily storing the primary gas G1, a gas inlet 22B, a gas outlet 23B, and a pressure adjustment mechanism 24B such as a pressure adjustment valve. The gas inlet 22B is an inlet through which the primary gas G1 from the gas generation unit 3B enters, and is connected to the gas supply flow path 3Bd. The gas outlet 23B is an outlet through which the primary gas G1 is sent to the vaporization expansion unit 30B. The amount of primary gas G1 supplied from the gas supply unit 20B to the vaporization expansion unit 30B is controlled by operating the gas supply adjustment valve 3Be disposed in the gas supply flow path 3Bd and by adjusting the gas pressure by the pressure adjustment mechanism 24B.

On the other hand, in the configuration shown in FIG. 7, the gas supply unit 20B is integrated with the gas generation unit 3B, so the combustion chamber 3Ba also serves as the tank 21B, and the gas inlet 22B is omitted. The amount of primary gas G1 supplied from the gas generation unit 3B (also serves as the gas supply unit 20B) to the vaporization and expansion unit 30B is the amount of primary gas G1 generated in the gas generation unit 3B, and this amount is controlled by operating the fuel supply adjustment valve 3Bfv, the air supply adjustment valve 3Bcv, and adjusting the gas pressure by the pressure adjustment mechanism 24B.

[Evaporation and expansion section] The evaporation and expansion section 30B is a section for evaporating water (hereinafter referred to as "primary water") W1 from a portion of the primary gas G1 supplied from the gas supply section 20B to generate water vapor and increase the amount of water vapor. It is equipped with a tank (or flow path) 31B for evaporating the primary water W1, a gas introduction mechanism 32B for introducing the primary gas G1 supplied from the gas outlet 23B of the gas supply section 20B, a water introduction mechanism 33B for introducing the primary water W1, and a drive nozzle 34B for spraying the secondary gas G2 into the cooling and condensing section 40B.

In this vaporization expansion section 30B, primary water W1 is added, and heat is exchanged between this primary water W1 and the primary gas G1 to vaporize the primary water W1. In other words, by imparting a portion of the enthalpy of the primary gas G1 to the primary water W1 through heat exchange, the primary water W1 is heated to above its boiling point to generate water vapor Sw1. This increases the overall amount of gas G2 (= G1 + Sw1).

In other words, a decrease in the temperature of the primary gas G1 reduces the volume of the primary gas G1, but on the other hand, the evaporation of the primary water W1 causes the primary water W1 to become steam Sw1 and its volume increases. Therefore, although it depends on the temperature and pressure of the vaporization expansion section 30B, the increase in volume due to the evaporation (vaporization) of the primary water W1 is usually greater than the decrease in volume due to a decrease in the temperature of the primary gas G1, so the volume of the entire gas (G2 = G1 + Sw1) increases. Note that for the supply of this primary water W1, a method and configuration similar to those of the jet thrust generating device 10B of the first embodiment can be adopted.

[Cooling and condensing section] The cooling and condensing section 40B uses the secondary gas G2 ejected from the driving nozzle 34B of the vaporizing and expanding section 30B as the driving fluid of the ejector, sucks in water (hereinafter referred to as "secondary water") W2 around the jet type thrust generating device 10B from the outside, mixes this secondary water W2 with the secondary gas G2, exchanges heat between the secondary gas G2 and the secondary water W2, cools the secondary gas G2, and condenses (liquefies) the water vapor Sw1 contained in the secondary gas G2. As shown in FIG. 5, the cooling and condensing section 40B is composed of a tank (or flow path) 41B for mixing the secondary gas G2 and the secondary water W2. In this cooling and condensing section 40B, the secondary water W2 is sucked in and heat exchanged until the water vapor Sw1 contained in the secondary gas G2 condenses and negative pressure is generated.

In this cooling and condensing section 40B, the secondary gas G2 supplied from the vaporizing and expanding section 30B is cooled with the secondary water W2, thereby reducing the volume of the primary gas G1 and reducing the volume due to the condensation of the water vapor Sw1, and the effect of sucking in the secondary water W2 is increased by utilizing the reduction in pressure (generation of negative pressure) due to this reduction in volume. In other words, in addition to the Venturi effect due to the injection flow of the secondary gas G2 as the driving fluid Fd2, the reduction in volume due to the condensation of the water vapor Sw1 contained in the secondary gas G2 generates negative pressure, increasing the suction force on the secondary water W2 and promoting the suction of the secondary water W2. In addition to the combustion gas G1 and secondary water W2, the water Ws1, which is liquefied water vapor Sw1 contained in the secondary gas G2, is added to the water containing gas (hereinafter referred to as the "injected fluid") F3 at the outlet of the cooling and condensing section 40B.

[Pressure recovery section] The pressure recovery section 50B is a section that increases the pressure of the injection fluid F3, which has been reduced in the cooling and condensing section 40B, by decreasing the flow rate, to obtain a pressure that allows injection from the injection section 60B, and is composed of a diffuser (a diverging member) 51B.

[Injection section] The injection section 60B is a section that obtains thrust T by injecting the injection fluid F3 whose pressure has been restored from the thrust generating nozzle 62B, and is composed of a tank (or flow path) 61B for maintaining pressure and a thrust generating nozzle 62B. Thrust T is generated by injecting the injection fluid F3 whose pressure has been restored from this thrust generating nozzle 62B.

[Summary 2] As described above, in the jet thrust generating device 10B, primary gas G1 and secondary gas G2 are injected to suck in primary water W1 and secondary water W2 from the outside around the jet thrust generating device 10B, and then injected from the thrust generating nozzle 62B to generate thrust T. Here, secondary gas G2 is generated by exchanging heat with the primary gas G1, and then the volume of the secondary gas G2 is reduced, thereby decreasing the pressure (generating negative pressure) due to the decrease in the volume of the secondary gas G2. This decrease in pressure increases the suction force on the secondary water W2, increasing the amount and speed of the injection fluid F3 injected from the thrust generating nozzle 62B, and increasing the thrust T.

[Calculation Example 2] For reference, the following is a provisional calculation result regarding the specific amounts of primary gas G1, secondary gas G2, primary water (primary suction water) W1, secondary water (secondary suction water) W2, and injection fluid F3 in the case where water vapor Sw1 is generated by combustion gas G1 and combustion gas G2 containing this water vapor Sw1 is used as driving fluid Fd2.

Suppose that the primary gas G1 is 0.80 ^m3 ( ¹ Nm3: specific heat is assumed to be 1.37 kJ/ ^Nm3 ·K: 0.33 kcal/ ^Nm3 ) of combustion gas at 600°C and 4.0 Pa (approximately 4.0 atm), and furthermore, that the injected fluid F3 is cooled to 50°C using water at 15°C. To turn the 600°C primary gas G1 into a 100°C secondary gas G2 of 1.0 Pa (approximately 1.0 atm), approximately 1.9 kg of 15°C primary suction water W1 is required, which amounts to 2.4 ^Nm3 in steam, and the secondary gas G2 is 4.65 ^m3 (3.4 ^Nm3 ).

To turn this secondary gas G2 into 1.0 Pa (approximately 1.0 atm) 100°C water, even if there is no water for the combustion gas, 12.1 kg of water at 15°C is required for the steam, and 14.0 kg of water at 100°C is generated. To turn this into water at 50°C, 0.47 kg of water at 15°C is required for the gas, and another 20.0 kg is required for the water, so the required secondary water W2 is 20.5 kg. Meanwhile, the total amount of injected fluid F3 is 34.5 kg, and the amount of injected gas is 1.05 ^m3 ( ^1.0 Nm3).

Therefore, to convert ^0.80 m3 ( ¹ Nm3) of primary gas G1, which is combustion gas at 600°C and 4.0 Pa (approximately 4.0 atm), into injected fluid F3 (water Wa and gas G2) at 50°C, it is necessary to aspirate 34.5 kg of water at 15°C. To convert this to the moisture content W3a of the injected fluid at 25°C, it is necessary to aspirate an additional 86.5 kg of water at 15°C, so that the moisture content W3a of the injected fluid is 121.0 kg (0.12 ^m3 ), which, when combined with 1.05 ^m3 of combustion gas, amounts to 1.12 ^m3 .

[Third embodiment of the injector thrust generating system] The third embodiment of the injector thrust generating system according to the present invention is a system that uses initial gas that contains a large amount of primary steam, generated in the gas generating section by burning hydrogen gas or mixing water vapor into the combustion gas.

In the jet thrust generating system of the third embodiment, the initial gas G0 is treated as a mixture of the primary steam S1 of the first embodiment and the primary gas G1 of the second embodiment, and the respective states of the water vapor S1 and gas G1 can be treated. The components of the jet thrust generating system of the third embodiment are the same as those of the jet thrust generating system 1B of the second embodiment, and therefore are not specifically illustrated. In addition, the explanation of the jet thrust generating system of the third embodiment will be omitted, as it is merely a physical quantity of the primary steam S1 of the first embodiment and the primary gas G1 of the second embodiment combined.

[Unitization] Next, we will explain the unitization of the jet thrust generating systems 1A and 1B. Since the steam generating section 2A is often an existing device, in the jet thrust generating system 1A of the first embodiment, the steam generating section 2A is disconnected, and the primary steam S1 is supplied from outside, and the jet thrust generating device 10A is unitized.

In the second embodiment of the jet thrust generating system 1B, on the other hand, it is relatively easy to integrate the gas generating unit 3B as well, so the gas generating unit 3B and the jet thrust generating device 10B are integrated into a unit that receives fuel. Note that the gas generating unit 3B may be separated from the gas generating unit 3B and the jet thrust generating device 10B, and only the jet thrust generating device 10B may be integrated into a unit that receives primary gas G1 from the outside. Note that when this unitization is performed, it is preferable that the gas generating unit 3B has a heat-retaining structure so that the enthalpy of the primary steam S1 and primary gas G1 does not decrease.

The primary water W1 required to generate the secondary steam S2 is preferably preheated before being introduced into the vaporization expansion sections 30A and 30B. A possible configuration for heating the primary water W1 is to use a portion of the heat dissipated from the steam generating section 2A or the gas generating section 3B to heat and raise the temperature of the primary water W1. In this case, a suction channel for sucking in the primary water W1 is arranged around the steam generating section 2A or the gas generating section 3B. Specifically, a pipe serving as a suction channel is provided in contact with the periphery of the steam generating section 2A or the gas generating section 3B, or a double structure is formed around the steam generating section 2A or the gas generating section 3B, and the space between them is used as a suction channel. In this case, the outside of the steam generating section 2A or the gas generating section 3B, including the suction channel, is kept warm.

Also, as shown in FIG. 8, for example, it is preferable that the outer shape of unit 10U, including support members 11A and 11B, has a shape with low underwater resistance, considering that it may be placed underwater or in a waterway. For example, it is formed into a cylindrical shape used in torpedoes, and is provided with a primary suction port 12B and a secondary suction port 13B for taking in primary water W1 and secondary water W2. In this case, it is preferable that the parts that supply primary steam S1, primary gas G1, fuel F, combustion air A, etc. are housed within support members 11A and 11B of unit 10U.

The design elements of this unit 10U include the volume of the vaporization and expansion sections 30A and 30B, the volume of the cooling and condensation sections 40A and 40B, the volume of the pressure recovery sections 50A and 50B, and the volume of the injection sections 60A and 60B. For example, the volume of the vaporization and expansion sections 30A and 30B is determined by the amount of water vapor Sw1 evaporated from the primary water W1 and the primary steam S1 (or primary gas G1), but the amount of water vapor Sw1 evaporated from the primary water W1 depends on the pressure and temperature during operation of the system and changes according to the enthalpy of the primary steam S1 (or primary gas G1). The volume of the cooling and condensation sections 40A and 40B is determined by the volume of the secondary steam S2 and secondary gas G2 and the amount of secondary water W2. The volume of the pressure recovery sections 50A and 50B is determined by the amount of water W3a in the injection fluid and the operating pressure (inlet pressure and outlet pressure).

When the cross-sectional area (cross-sectional shape) of the cylindrical shape is fixed, the length of the cylinder is an issue with regard to each of these volumes, but by setting in advance the reference pressure and reference temperature during operation, these lengths can be set. Note that different operating conditions can be accommodated by preparing several standard parts with different volumes, or by preparing additional parts to increase volume. Therefore, by selecting and combining these parts for each functional part, a unit 10U that corresponds to each operating condition can be assembled.

[Effects of unitization] By unitizing in this way, it becomes easy to adopt the jet type thrust generating systems 1A, 1B by arranging these units 10U in an existing vessel 5. Furthermore, these units 10U can provide auxiliary thrust T when there is excess high enthalpy gas (primary steam S1, primary gas G1) such as excess steam, exhaust gas, or compressed air.

In addition, in a newly constructed vessel 5, the necessary propulsive force can be obtained by adjusting the number of these units 10U. Therefore, unlike conventional propulsion systems that are relatively often made to order using engines and propellers, the units 10U can be mass-produced, reducing manufacturing costs. In addition, because the structure of the units 10U themselves is simple and has no rotating parts, breakdowns are unlikely to occur and maintenance and inspection are easy. Furthermore, by standardizing the units 10U and making them replaceable, maintenance is made even easier.

[Injection type thrust generating method] Next, an embodiment of the injection type thrust generating method of the present invention will be described. This injection type thrust generating method can be implemented using the injection type thrust generating systems 1A and 1B of the above-mentioned embodiments, and is the following method. Note that the injection type thrust generating system 1A of the first embodiment can be implemented in the case of "gas S2 composed of water vapor," while the injection type thrust generating systems 1B of the second and third embodiments can be implemented in the case of "gas G2 containing water vapor Sw1."

The first embodiment of the jet thrust generating method according to the present invention is a method that uses the jet thrust generating system 1A, and in this jet thrust generating method, secondary steam (gas) S2 composed of water vapor is used as the driving fluid Fd2, secondary water (water) W2 is sucked in by the Venturi effect caused by the injection of the driving fluid Fd2, and the sucked secondary water (water) W2 is cooled by this sucked secondary water (water) W2 to condense the water vapor (secondary steam S2), increasing the suction force sucking in the secondary water (water) W2, and the water vapor S2, the condensed water Ws2 of the water vapor Sw2, and the sucked secondary water (water) W2 are injected to obtain thrust T.

The second embodiment of the jet thrust generating method according to the present invention uses the jet thrust generating system 1B, and this jet thrust generating method uses a high enthalpy gas such as combustion gas as the driving source, a secondary gas (gas) G2 containing water vapor Sw2 as the driving fluid Fd2, and sucks in secondary water (water) W2 due to the Venturi effect caused by the injection of the driving fluid Fd2. The sucked in secondary water (water) W2 cools the driving fluid Fd2, condensing the water vapor (water vapor Sw2 or secondary steam S2 contained in the secondary gas G2), increasing the suction force sucking in the secondary water (water) W2, and injecting the condensed water Ws2 of the water vapor S2 and the condensed water Ws2 of the water vapor Sw2 and the sucked in secondary water (water) W2 to obtain thrust T.

The third embodiment of the jet thrust generating method according to the present invention uses an jet thrust generating system, and uses a high enthalpy gas (G1+S1) containing water vapor S1 as a driving source, secondary steam S1, S2, and secondary gas (gas) G2 containing water vapor Sw2 as a driving fluid Fd2, sucks in secondary water (water) W2 by the Venturi effect caused by the injection of the driving fluid Fd2, cools the driving fluid Fd2 with the sucked secondary water (water) W2, condenses the water vapor (secondary steam S1, S2, and water vapor Sw2 contained in the secondary gas G2), and increases the suction force for sucking in the secondary water (water) W2. At the same time, thrust T is obtained by injecting the condensed water Ws1 of the water vapor S1, the condensed water Ws2 of the secondary steam S2, and the condensed water Wsw2 of the water vapor Sw2 and the sucked secondary water (water) W2.

In summary, the jet thrust generating method according to the embodiment of the present invention uses secondary steam (gas) S2 composed of water vapor or gas G2 containing steam Sw1 as the driving fluid Fd2, sucks in secondary water (water) W2 due to the Venturi effect caused by the injection of the driving fluid Fd2, cools the driving fluid Fd2 with this sucked in secondary water (water) W2 to condense the water vapor S2 and Sw1, and increases the suction force sucking in the secondary water (water) W2, while injecting the condensed water Ws2 of the water vapor S2 and Sw1 and the sucked in secondary water (water) W2 to obtain thrust T. This jet thrust generating method can be implemented using the jet thrust generating systems 1A and 1B described above.

[Effects of the jet thrust generating system and the jet thrust generating method] According to the above-mentioned jet thrust generating systems 1A and 1B and the jet thrust generating method, the large volume of gas-phase water vapor S1, S2, Sw2 is used as all or part of the driving fluid Fd2, and by cooling this driving fluid Fd2, it is condensed into small volume of liquid-phase water Ws1, Ws2, creating a low pressure state (negative pressure state). By utilizing this negative pressure state (low pressure state) in addition to the Venturi effect, a large amount of surrounding secondary water W2 can be sucked in. Then, by injecting the jet fluids W3, F3 containing this large amount of secondary water W2, thrust T can be generated efficiently.

These jet thrust generating methods utilize the Venturi effect of the ejector by injecting a gas G2 containing water vapor S2 or water vapor Sw1 and with high enthalpy (the sum of internal energy and pressure energy) as the driving fluid Fd2, eliminating the need for a rotating mechanism used in high-pressure pumps (axial water pumps) and propellers called impellers, as used in water jet propulsion. Therefore, the jet thrust generating systems 1A and 1B for implementing these jet thrust generating methods have a simple configuration without a rotating mechanism, and because there is no rotating mechanism, the design, manufacturing, testing, maintenance, inspection, etc. are simplified, and they can be provided at low cost.

In the above-mentioned jet thrust generating systems 1A, 1B and jet thrust generating methods, the driving fluid Fd2 is mixed with the aspirated secondary water W2, the driving fluid Fd2 is cooled by direct contact, and the water vapor S2, Sw2 contained in the driving fluid Fd2 is condensed. This allows the driving fluid Fd2 to be cooled efficiently with a simple configuration.

In addition, in the above-mentioned jet thrust generating system 1B and jet thrust generating method, if the driving fluid Fd2 is generated by directly contacting or mixing primary water (water) W1 with the combustion gas G1, as in the jet thrust generating system 1B of the second embodiment, the driving fluid Fd2 containing water vapor Sw2 can be generated efficiently with a simple configuration.

[Navigation vehicle] Next, a navigation vehicle according to an embodiment of the present invention will be described. As shown in Figures 9 to 11, the navigation vehicle 5 according to an embodiment of the present invention is configured with the above-mentioned jet thrust generating systems 1A and 1B.

[Layout of main parts] First, the layout of the main parts of the jet thrust generating devices 10A, 10B or the unit 10U will be described. These main parts are arranged in connection with the suction channel 7 and the discharge channel 8, or in a channel consisting of the suction channel 7 and the discharge channel 8, or in the water outside the navigable body 5.

Regarding the vertical position of this main part, if this main part is placed above the water surface, the suction waterway 7 that guides the water W1, W2 from the suction port 6 to the jet thrust generating device 10A, 10B or unit 10U, and the discharge waterway 8 that guides the jet fluid W3, F3 from this main part to the discharge port 9 will be longer. As a result, a bend in the water flow is required, and the flow resistance in these waterways will increase. However, in this case, since the main part is above the water surface, there is a major advantage in that maintenance and inspection are easier.

On the other hand, when the main part is placed under the water surface, it can be provided in the water channels (suction water channel 7 and discharge water channel 8) that connect the suction port 6 and the discharge port 9 in a substantially straight line, and the length of the water channels 7 and 8 can be shortened and the number of bends in the water flow can be reduced. As a result, the flow resistance in these water channels 7 and 8 can be reduced. In this case, since the main part is under the water surface, maintenance and inspection are more troublesome than when it is placed above the water surface, but the structure of the main part is originally simple, and inspection, repair, and part replacement are easy. There are few disadvantages to placing it underwater. In addition, by making the main part or the water channel part in which the main part is placed removable or replaceable, maintenance and inspection work can be simplified.

The position of this main part in the fore-aft direction of the navigation body 5 can be determined in various positions, but considering the need to reduce flow resistance in the waterways 7 and 8, it is roughly determined by the positions of the suction port 6 and the discharge port 9.

[Arrangement of suction ports] As for the arrangement of the suction ports 6 for the primary water W1 and the secondary water W2, the first arrangement shown in FIG. 9 is arranged at the bow 5a of the navigable body 5, the second arrangement shown in FIG. 10 and FIG. 11 is arranged at the hull side 5c of the navigable body 5, and the third arrangement shown in FIG. 12 is arranged at the stern 5d of the navigable body 5. These suction ports 6 correspond to "point sinks," so depending on the arrangement of the suction ports 6, they can be effective in reducing wave-making resistance. In addition, by bundling multiple units 10U together or providing multiple suction ports 6 of a single unit 10U, it is also possible to form a "suction area" in which "point sinks" are arranged in a strip or plane.

In the first arrangement, as shown in Figs. 9(a) and (b), the suction port 6 is provided in a high pressure area such as near the stagnation point of the bow 5a of the navigable body 5, thereby reducing the pressure resistance generated at the bow 5a. Also, by providing the suction port 6 in the area where waves are generated at the bow 5a, the wave-making resistance can be reduced. Furthermore, as shown in Figs. 9(c) and (d), a "suction area" can be provided at the bottom 5b of the bow 5a, etc., so that the waves generated by this "suction area" can be made to interfere with the bow-based waves generated at the bow 5a, thereby reducing the wave-making resistance of the navigable body 5. In this case, the suction port 6 is located at the center of the bow 5a or on both sides of the center, and the suction channel 7 is located inside the hull of the bow 5a.

In the second arrangement, the suction port 6 is arranged on the hull side 5c of the navigable body 5, thereby providing a "suction area" on the hull side 5c of the navigable body 5. This allows the waves generated in this "suction area" to interfere with the bow waves generated at the bow 5a and the bow shoulder, etc., thereby reducing the wave-making resistance of the navigable body 5. In these cases, the suction channel 7 is arranged inside the hull at the bow 5a, as shown in Figures 10(a) and (b), or outside the hull at the bow 5a, as shown in Figures 10(c) and (d).

On the other hand, the units 10U can be arranged on the hull side 5c as shown in FIG. 13 without providing the waterways 7 and 8. In this case, as shown in FIG. 13(a) and (b), the units 10U can be arranged individually, or several units 10U can be bundled together and arranged in a strip or plane.

In the third arrangement, as shown in Figures 11 and 12, the thrusters are arranged in the stern section 5d, similar to where many thrusters (propeller thrusters, water jet thrusters, etc.) are currently arranged. Possible locations for the suction port 6 in the stern section 5d include on the side section 5c of the hull, on the bottom section 5b, or behind the stern end. Since it is difficult to keep a large distance between the units 10U when arranging the suction port 6 in the stern section 5d, the suction channel 7 will be a short channel or will be integrated with the unit 10U.

In this third arrangement, there is no need to significantly change the internal arrangement of the navigable body 5 from the current internal arrangement. Furthermore, by providing the suction port 6 in the stern section 5d, a "suction area" can be provided in the stern section 5d of the navigable body 5, and the waves generated in this "suction area" can be made to interfere with the stern waves generated in the stern section 5d, thereby reducing the wave-making resistance of the navigable body 5.

[Discharge outlet placement] Regarding the placement of the discharge outlet 9 of the unit 10U, if the discharge outlet 9 is placed above the water surface WL, the pressure outside the discharge outlet 9 is small, so the injection fluid W3 can be injected efficiently. On the other hand, if the discharge outlet 9 is placed below the water surface WL, water pressure according to the water depth is applied to the discharge outlet 9, so the pressure of the injection fluid W3 required for injection increases.

However, this outlet 9 can be made a "point source," so the waves generated by this "point source" can be made to interfere with bow and stern waves, reducing wave resistance. By bundling multiple units 10U together or providing multiple outlets 9 on a single unit 10U, it is also possible to form a "blowout area" in which "point suctions" are arranged in a band or a surface.

In addition, regarding the arrangement of the discharge outlet 9 in the longitudinal direction of the vessel, a first arrangement is possible in which the discharge outlet 9 is arranged at the bow 5a of the vessel 5, a second arrangement is possible in which the discharge outlet 9 is arranged at the hull side 5c of the vessel 5, and a third arrangement is possible in which the discharge outlet 9 is arranged at the stern 5d of the vessel 5.

In this first arrangement, although not shown, by arranging the exhaust port 9 in the bow section 5a, a "blowing area" can be provided in the bow section 5a. Therefore, the waves generated in this "blowing area" can be made to interfere with the bow-based waves generated in the bow section 5a, reducing the wave-making resistance of the navigable body 5. However, in this case, if the direction of the jet fluids W3 and F3 is not toward the stern, the thrust T due to the jet cannot be used as the propulsion force of the navigable body 5. Therefore, if the jet fluids W3 and F3 are jetted in the forward direction of the navigable body 5, it is necessary to consider the balance between the effect of reducing the wave-making resistance and the increase in resistance of the thrust T due to the jet. On the other hand, if the jet fluids W3 and F3 are jetted in the rearward direction of the navigable body 5, the thrust T due to the jet can be used as the propulsion force Tt.

In the second arrangement, as shown in Figures 9(a), (b), 10 and 13, by arranging the exhaust port 9 on the hull side 5c of the navigable body 5, a "blowing area" can be provided on the hull side 5c of the navigable body 5, and the waves generated in this "blowing area" can be made to interfere with the bow waves generated at the bow 5a and the bow shoulder, etc., thereby reducing the wave-making resistance of the navigable body 5. In this case, thrust T can be obtained by the ejected fluids W3 and F3 ejected from the exhaust port 9. And because exhaust ports 9 capable of generating thrust T are provided on both sides, the turning force of the navigable body 5 can be obtained by adjusting these thrust forces T, respectively.

As shown in Figure 12, the third arrangement is similar to the current arrangement of many propulsors, in the stern section 5d, or in the side section 5c of the hull, in the bottom section 5b, or behind the stern end. With this arrangement of the discharge port 9 in the stern section 5d, it is difficult to keep a large distance between the units 10U, so the discharge waterway 8 will be a short waterway or will be integrated with the unit 10U.

With this third arrangement, there is no need to significantly change the current arrangement of the equipment, tanks, holds, etc. of the navigable body 5. In addition, by providing the exhaust port 9 at the stern 5d, a "blowing area" can be provided at the stern 5d of the navigable body 5, and the waves generated in this "blowing area" can be made to interfere with the stern waves generated at the stern 5d, reducing the wave-making resistance of the navigable body 5.

[Method of propelling a naval vessel] Next, a method of propelling a naval vessel according to an embodiment of the present invention will be described. The method of propelling a naval vessel according to an embodiment of the present invention is characterized in that the thrust T generated using the above-mentioned jet thrust generating method is used as all or part of the thrust Tt that propels the naval vessel 5. This method of propelling a naval vessel can be implemented using the above-mentioned naval vessel 5. This method makes it possible to propel the naval vessel 5 using the jet thrust generating devices 10A, 10B or unit 10U, which have no rotating mechanism, are simple in structure, and are easy to manufacture and maintain.

[Effects of the present invention] According to the above-mentioned jet thrust generating method, method for propelling a naval body, jet thrust generating systems 1A, 1B, and naval body 5, thrust T can be generated by utilizing the change in volume due to a decrease in temperature of high enthalpy gas G1 and water vapor S1, in particular the decrease in volume due to condensation of water vapor S1, S2, and Sw1, while incorporating the effect of sucking in water (second fluid) W2 by the ejection of driving fluid Fd2 in the ejector and the effect of increasing pressure due to the deceleration of the fluid by the diffuser. Therefore, it is possible to provide a jet thrust generating method, method for propelling a naval body, jet thrust generating systems 1A, 1B, and naval body 5 that have no rotating mechanism, are simple in structure, and are easy to manufacture and maintain.

Reference Signs List 1A, 1B Injection type thrust generating system 2A Steam generating section 2Aa Steam supply flow passage 2Ab Steam supply regulating valve 3B Gas generating section 3Ba Combustion chamber 3Bb Combustor 5 Vessel 5a Bow section 5b Ship bottom section 5c Ship side section 5d Stern section 6 Suction port 7 Suction waterway (waterway)
8. Discharge channel (channel)
9 Exhaust port 10A Injection type thrust generating device (first embodiment: water vapor)
10B Injection type thrust generating device (second embodiment: combustion gas)
11A, 11B Support member 12B Primary suction port 13B Secondary suction port 20A Steam supply section 20B Gas supply section 21A, 21B Tank 22A Steam inlet 22B Gas inlet 23A Steam outlet 23B Gas outlet 24A, 24B Pressure adjustment mechanism 30A, 30B Vaporization expansion section 31A, 31B Tank (or flow path)
32A Steam introduction mechanism 32AA Steam ejector 32Aa Steam introduction passage 32Ac Steam injection nozzle 32Ad Underwater injection nozzle 32B Gas introduction mechanism 33A, 33B Water introduction mechanism 33Aa, 33Ba Water introduction passage 33Ab Water introduction amount adjustment valve 33Ac Water supply nozzle 33Ad Water discharge passage 33Ae Water discharge amount adjustment valve 34A, 34B Drive nozzle 40A, 40B Cooling and condensing section 41A, 41B Tank (or passage)
43Aa, 43Ba: Water suction flow passages 50A, 50B: Pressure recovery sections 51A, 51B: Diameter expansion members (diffusers)
60A, 60B: Injection section 61A, 61B: Tank (or flow path)
62A, 62B Thrust generating nozzle 100 Pulse jet engine 100A Intermittent combustion type jet propulsion engine 100B U-shaped bubble-less pulse jet engine 110 Combustion chamber 111 Air intake 112 Inlet check valve 114 Thin tube 120 Exhaust pipe 132 Ignition device A Air (fresh air)
F: fuel; G: combustion gas; G1: primary gas; G2: secondary gas; S1: primary steam; S2: secondary steam; Sw1: steam produced by evaporation of primary water (steam generated by primary gas)
Sw2: Water vapor T formed by evaporation of secondary water Thrust Tt: Thrust force W0: Accumulated water W1: Primary water W2: Secondary water W3: Injected fluid Ws1: Water liquefied from water vapor contained in secondary gas Ws2: Water liquefied from secondary steam

Claims (7)

A method for generating thrust using an injection type thrust, characterized in that a gas (S2) composed of water vapor or a gas (G2) containing water vapor (Sw1) is used as a driving fluid (Fd2), water (W2) is sucked in by the Venturi effect caused by the injection of the driving fluid (Fd2), the sucked water (W2) is cooled by the sucked water (W2) to condense the water vapor (S2, Sw1), and thrust (T) is obtained by injecting the condensed water (Ws2) of the water vapor (S2, Sw1) and the sucked water (W2). The method for generating thrust using an ejection type thruster as described in claim 1, characterized in that the driving fluid (Fd2) is mixed with the aspirated water (W2), the driving fluid (Fd2) is cooled by direct contact, and the water vapor (S2, Sw1) contained in the driving fluid (Fd2) is condensed. The method for generating thrust using an ejection type thruster according to claim 1, characterized in that the driving fluid (Fd2) is generated by contacting or mixing water vapor (S1), or a gas (G1) containing water vapor (Sw1), or the gas (G1) with water (W1). A method for propelling a watercraft, characterized in that the thrust generated using the jet thrust generating method according to any one of claims 1 to 3 is used as part or all of the propulsive force for propelling the watercraft. A vaporization expansion section (30A, 30B) that generates a driving fluid (Fd2) composed of water vapor (S2) or a gas (G2) containing water vapor (Sw1);
a cooling and condensing section (40A, 40B) which draws in water (W2) by a Venturi effect caused by the ejection of the driving fluid (Fd2) ejected from a driving nozzle (34A) provided at the outlet of the vaporization and expansion section (30A, 30B), cools the driving fluid (Fd2) with the drawn water (W2), and condenses water vapor (S2, Sw1) contained in the driving fluid (Fd2);
a pressure recovery section (50A, 50B) having a divergent member (51A, 51B) provided continuously to the cooling and condensing section (40A, 40B) for recovering the pressure of a jet fluid (W3, F3) composed of the driving fluid (Fd2) and the sucked water (W2);
An injection type thrust generating system, characterized in that it is configured to have an injection unit (60A, 60B) that injects the injection fluid (W3, F3) whose pressure has been restored in the pressure recovery unit (50A, 50B). The jet-type thrust generating system according to claim 5, characterized in that it is configured with a vaporization expansion section (30A, 30B) that generates the driving fluid (Fd2) by contacting or mixing water vapor (S1), or a gas (G1) containing water vapor (Sw1), or the gas (G1) and water (W1). A watercraft comprising the jet thrust generating system according to claim 5 or 6.

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