CN115402463A

CN115402463A - Ship friction reducing system with gas injection device

Info

Publication number: CN115402463A
Application number: CN202211163496.5A
Authority: CN
Inventors: 孙震; 薛冬梅; 顾时雨; 王星浩
Original assignee: Beijing Fengrunming Science And Trade Co ltd
Current assignee: Beijing Fengrunming Science And Trade Co ltd
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2022-11-29

Abstract

A friction reducing system for a ship having a gas injection device is described, which includes an injection gas control apparatus for performing control using a change in wire speed reflected over time without adversely affecting a main engine. The gas is excessively sent out to prevent the same from occurring due to insufficient supply amount, deterioration of the efficiency of the main machine, deterioration of the exhaust gas, or too much. Also included is a turbocharger driven by exhaust of the main engine, sending pressurized gas to the main engine, and controlling the pressurized gas based on a physical quantity related to a thermal load of the main engine and a characteristic of the turbocharger and a throttle.

Description

Ship friction reducing system with gas injection device

Technical Field

The present invention relates to a frictional resistance reducing device for a ship, and particularly to a frictional resistance reducing device for reducing frictional resistance of a ship.

Background

The current research situation of ship drag reduction obtains many achievements in the aspect of wave resistance, and the general ship sailing frictional resistance accounts for about 80% of the total resistance of a large wire, which is a complex turbulent flow phenomenon. When the ship is underway, a turbulent boundary layer is formed along the surface of the ship body below the waterline, resulting in the formation of frictional resistance on the surface of the ship body and a reduction in the propulsive performance of the ship. As a means of reducing frictional resistance on the surface of a ship hull, microbubble friction reduction, in which bubbles are injected into a boundary layer along the surface to reduce frictional resistance, has received a high degree of attention in the industry as the most promising method of frictional resistance reduction. The micro-bubble has good effect when being applied to energy-saving application and popularization of ships in the future, and can be regarded as an effective means for reducing ship navigation friction resistance because the micro-bubble does not have the problem of environmental pollution to ocean and water space.

However, such microbubble antifriction system requires power because it produces water bubbles from the side of a ship or the bottom of water under water and produces particle bubbles of several hundreds of micrometers or less, so the present research needs to consider the substantial reduction effect of the bubble generation power. In particular, micro-bubbles at grain boundaries of several hundred micrometers or less have a small buoyancy effect on bubbles and are susceptible to wave flow disturbances when they are injected to the bottom of a ship.

Research on ship friction reduction has so far mainly focused on laboratory level and model line research, which has not been applied to sites of substantial research.

Disclosure of Invention

The present invention makes it possible to equip a ship body with a gas injection device capable of injecting bubbles having a particle diameter larger than that of microbubbles by using a state-of-the-art ship for friction reduction research, and attempts to study the relationship between bubble injection and frictional resistance reduction effect in a situation close to reality (e.g., a marine situation) and achieve substantial results. In addition, in order to prevent the gas injected from the gas injection device from diffusing from the bottom without further diffusion in the sea, optimization of the bubble particle diameter, and related studies of the member, the device, and the bottom shape are also underway.

The invention aims to provide a regulator and also provides a device for reducing the frictional resistance of a ship, which can reduce the generation of bubbles and further utilize the bubbles.

The invention also relates to a method and a device for monitoring the state or condition of a ship.

An object of the present invention is to provide a frictional resistance reducing device for a ship, which avoids occurrence of disturbance such as ocean current.

Another object of the present invention is to provide a frictional resistance reducing apparatus for a ship, which is capable of reducing frictional resistance without generating energy for generating bubbles.

Another object of the present invention is to provide a frictional resistance reducing apparatus for a ship, in which more efficient frictional resistance reduction is achieved by bubble injection that accurately reflects the sailing state of the ship.

The present invention also effectively reduces frictional resistance, and effectively prevents air bubbles from being transmitted to the propeller device even when the sailing condition of the ship or the ship condition changes, preventing the efficiency of the propeller device from being reduced.

The present invention also relates to a method for reducing frictional resistance of a ship, which can save energy, prevent noise, etc. by reflecting the condition of the ship.

The invention also relates to a method for controlling bubble generation using residual gas of a turbocharger, wherein the operation of the cycle is not affected while maintaining high efficiency.

Another object of the present invention is to provide a method and apparatus for reducing frictional resistance of a ship, which can control the injection state of gas, such as the injection amount, the injection direction, etc., when gas is injected.

Another object of the present invention is to provide a device element which can be minimized in its overall size, which becomes a resistance element for the vessel to sail or an obstacle when entering the quay, and which provides a method and apparatus for reducing the frictional resistance that limits the diffusion of gas even with respect to the occurring vessel inclination when the vessel is disturbed by sea current fluctuations.

Another object of the present invention is to provide a method and apparatus for reducing frictional resistance, which can stably supply gas from a gas delivery device by preventing water from infiltrating into a gas supply path.

In order to solve the above problem, the frictional resistance reducing apparatus for a ship according to claim 1 of the present application is characterized by comprising: a gas injection port for injecting bubbles having a particle diameter of several millimeters or more at least at the bottom of the vessel; a navigation state detecting device for detecting a navigation state of the ship, which is installed at a position where water is not affected by the injected bubbles so that the bubbles can be efficiently injected, and a means for controlling the injection of the base body so as not to interfere with the propulsion of the ship according to a detection result of the navigation state detecting member.

Further, the apparatus for reducing frictional resistance of a ship according to the present invention is not generally limited to use in the sea, but may be used as a ship for all water systems such as rivers and lakes. In reducing the frictional resistance by applying the marine bubble jet method, a measure for preventing bubbles from entering the propeller device may be used.

Drawings

Fig. 1 is a side view of a ship to which a frictional resistance reduction apparatus of a ship according to an embodiment of the present invention is applied;

fig. 2 is a bottom view of the vessel.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Fig. 1 and 2 show an embodiment in which a frictional resistance reducing apparatus according to an embodiment of the present invention is applied to a ship used in the sea, and

blowers

11, 12,13, 14, 15 are installed side by side as air blowing means on a deck 2 of ship No. 1. These

blowers

11, 12,13, 14 and 15 are installed in the deck 2 of the hangar. The air introduced into the

blowers

11, 12,13, 14, 15 is pressurized and blown through

blow outlets

16, 17, 18, 19, 20 having curved portions (21, 22, 23, 24, 25). In the present embodiment, these

exhaust ports

21, 22, 23, 24 and 25 are arranged substantially on a line symmetrical with respect to the plane center line CL of the bottom 3 of the hull 4. The purpose of providing the

gas ejection openings

21, 22, 23, 24 and 25 on the bottom 3 is to extend the residence time of the ejected gas bubbles in the bottom 3. And alleviate pressure fluctuations caused by the provision of the rear beam 3 in front of the bottom 3. The purpose of providing the rear beam 3 in front of the bottom 3 is to keep the blown out air bubbles as much as possible in the bottom 3.

The substantially in-line arrangement of the

gas ejection openings

21, 22, 23, 24, and 25 can simplify the structure and reduce the number of

blowers

11, 12,13, 14, 17, 18, 19, 20, and the like. In this example, since the five

gas outlets

21, 22, 23, 24 and 25 are arranged in an odd number, one of the gas outlets (gas outlet 23) 1), ejection of bubbles can be achieved at one position.

5. 5', 6', 7' serve to guide the bubbles so as not to leak out the bubbles ejected from the

gas ejection ports

21, 22, 23, 24, which are also arranged symmetrically with respect to the plane center line CL of the hull 4. The shear force sensors 50, 51, 52, 53, and 54 are shear force detectors for detecting shear forces of seawater or bubbles acting on the hull 4.

Claims

1. A ship friction reducing system provided with a gas injection device is characterized in that: including a supercharger that is driven by exhaust gas of the main engine and sends pressurized gas to the main engine; supply means for selecting at least one of pressurized gas and exhaust gas from between the turbocharger and the main engine; a gas injection port for injecting at least one of the injected pressurized gas and the discharged air to a bottom of the waterline below the waterline; and the navigation state detection device is used for detecting the navigation state of the ship.

2. A ship friction reducing system equipped with a gas injection device according to claim 1, said amount of at least one of pressurized gas and exhaust gas being calculated based on physical quantities including pressure related to heat load of a main engine and supercharger characteristics, further comprising a variable nozzle for controlling air supply characteristics of the supercharger and a control device for controlling based on the physical quantities and supercharger characteristics of the supercharger and detection results of the navigation state detecting device.

3. A ship friction reducing system with a gas injection device according to claim 2, wherein the control device is configured to control the supply of at least one of pressurized gas and exhaust gas to the exhaust port according to the pressure of at least one of pressurized gas and exhaust gas and the draught of the port at which the ship is parked.

4. The ship friction reducing system with a gas injection device according to claim 1, further comprising a gas sending device disposed in the exhaust bypass for sending exhaust gas, wherein the amount of gas discharge is controlled by the gas sending device, and the injection diameter is several millimeters or more; a gas jet port provided at the bottom of the vessel for jetting bubbles having a particle diameter of several millimeters or more through a path at the bottom of the vessel; air delivery means for delivering pressurized gas to the gas injection port; a diffusion limiting means for limiting diffusion of the bubbles which is accommodated by the compressive load received from the support when the ship is placed on the support, and a frictional resistance reducing means for reducing frictional resistance of the ship.

5. The ship friction reducing system with a gas injection device according to claim 1, wherein: the device also comprises a bubble inclusion detection device which is used for detecting whether bubbles are entrained by a propulsion device of the ship or not; and control means for controlling the blowing conditions of the gas injection orifice and means for changing at least one operating condition of the propulsion means.

6. The ship friction reducing system with a gas injection device according to claim 1, further comprising an opening/closing device disposed in the path near the gas ejection port for closing the path when the pressurized gas is not injected; and means for closing the exhaust gas when the exhaust gas pressure is applied, and opening the valve after the pressure of the pressurized gas rises to a predetermined value or more when opening.

7. The ship friction reducing system with a gas injection device according to claim 1, wherein the navigation state detecting device is a relative velocity detector for detecting a relative velocity between the ship and water, and increases or decreases at least one key quantitative amount of the number of gas injection openings and the gas injection amount when a frictional resistance of the ship decreases.

8. A ship friction reducing system provided with a gas injection device according to claim 1, wherein the navigation state detecting device is a draft detector for detecting draft of a ship, and at least one of the number of gas injection openings and the amount of gas injected is increased or decreased according to the size of draft, and ship friction resistance is reduced; the navigation state detecting means is provided at a position not affected by the bubbles exposed to the ejection.