WO2010054534A1

WO2010054534A1 - Mixing apparatus for ship flow-guiding propulsion system

Info

Publication number: WO2010054534A1
Application number: PCT/CN2009/001245
Authority: WO
Inventors: 孙志伟
Original assignee: Sun Zhiwei
Priority date: 2008-11-12
Filing date: 2009-11-11
Publication date: 2010-05-20
Also published as: CN101734361A

Abstract

A mixing apparatus for a ship flow-guiding propulsion system is provided to solve the jet flow problem of the ship flow-guiding propulsion system. It is composed of three parts a jet pipe (1), a wake pipe (2), and a mixing pipe (3), wherein a nozzle (11) of the jet pipe and an outlet of the wake pipe both are communicated with the mixing pipe. The inlet (21) of the wake pipe is disposed at the side of the jet pipe. The cross section of the jet pipe is smaller than that of mixing pipe. The jet flow and the wake flow are mixed in the mixing chamber. Compared with the flow through the jet nozzle, the flow speed of the flow through the outlet of the mixing pipe is lower and the flow quantity is increased. Thus the stern flow field of the ship is improved and the wave resistance is reduced. Alternatively, the flow field ahead of the screw or impeller is improved, the propulsive efficiency is increased and the damage caused by the cavitation and the water hammer is decreased. The induced velocity and the induced pressure produced by the outside flow of the wake pipe inlet can be used to further improve the stern flow field of the ship and reduce the stern wave resistance.

Description

Mixed flow device for ship diversion propulsion system

The invention belongs to the technical field of ship propulsion, in particular to solving the jet problem in the ship propulsion technology, especially the diversion propulsion technology, for improving the flow field of the ship and its propulsion system, thereby reducing the wave resistance of the ship. And a flow mixing device that improves the propulsion efficiency of the ship. Background technique

Ships are used in a wide variety of applications, such as transportation, fisheries, engineering, marine development, and military. This requires a wide variety of high performance vessels. The main performance of the ship, such as rapidity, maneuverability, seakeeping and economy, is mainly influenced and restricted by the ship type and propulsion system. Under the current state of the art, the high performance of a ship is mainly referred to as rapidity, and often at the expense of economy.

The existing ship propulsion technology is mainly two series of propeller propulsion and water jet propulsion. The working process of the water jet propulsion system is mainly that the water is sucked in by the water inlet, pressurized by the propulsion pump, and finally ejected from the water spout. Thus, this can be said to be a diversion propulsion system. The velocity of these injected waters relative to the ship is much greater than the speed of the ship's wake, especially the ankle flow. This creates a jet phenomenon. The energy of the jet eventually dissipates in the wake of the ship. Not only that, but the jet will also worsen the flow field of the ship's crotch and increase the wave resistance.

In addition, when the ship is moving forward, the crotch is boosted and the crotch is decompressed. If it is backward, the situation is reversed. The existing technology is that the ship's concrete pressure surface is communicated by pipes to reduce the pressure difference and reduce the wave-making resistance. It is also possible to install a water pump in the pipe to actively reduce the pressure difference and further reduce the wave resistance. . Broadly speaking, this is also a diversion propulsion system, which can be called a diversion propulsion system. Due to the difference in pressure and the effect of pump pressurization, the flow of water through this pipe creates a jet phenomenon. These jets with higher energy, if directly entering the crotch of the ship, have the same problem as the jet of the water jet propulsion system; if it is a propeller or pump wheel that enters the rear, then this part of the energy is not only not obtained. Recycling or utilization, and will result in a decrease in propulsion load and a decrease in propulsion efficiency.

A concept of a ship's diversion propulsion system was introduced here. Specifically, the water jet propulsion system is a conventional ship diversion propulsion system, and is a relatively mature prior art widely used; and the 艏艉 diversion propulsion system is an ideal ship diversion propulsion system. It is also a ship propulsion technology that is mainly in the theoretical and experimental stages and needs further improvement. If the 艏艉 pilot propulsion system is independent, or there is no propeller or pump wheel behind it, then when it is equipped with a water pump, this is a diversion main propulsion system; if it does not have a pump, then it is A flow guiding auxiliary propulsion system. If there is a propeller behind the 艏艉 guide propulsion system, it is a kind of guide propulsion system, which together with the propeller and the like constitutes the ship's diversion hybrid propulsion system; if there is a pump wheel behind, it is also a guide The flow propulsion system, together with the water jet propulsion system, constitutes a diversion composite propulsion system. Summary of the invention

The technical problem to be solved by the present invention is that the existing marine propulsion technology, especially the diversion propulsion technology, has a jet problem. If the energy of the jet cannot be recovered or utilized, or the speed of the jet is reduced, the propulsion efficiency of the vessel or the efficiency of the diversion propulsion system is encountered as a bottleneck that is difficult to break through.

In order to solve the above-described jet problem existing in the prior art, the present invention is achieved by the following technical solutions: The mixed flow device of the ship's diversion propulsion system mainly consists of a jet pipe, a companion pipe and a mixed flow pipe. The spout of the jet pipe and the outlet of the companion pipe are connected with the mixed flow pipe, and the inlet of the flow pipe is in the jet pipe. On the side, the cross section of the jet tube is smaller than the cross section of the mixing tube.

The invention also has the following technical features:

The nozzle of the jet tube may be a conventional straight flat end surface, and a vacuum is generated in the vicinity of the straight flat end surface due to the entrainment action of the jet flow, so that the accompanying flow generates an induced velocity of the impinging jet, and at the same time, a vortex is generated, and the mixed flow effect is compared. Or; the spout of the jet tube is from the outside to the end of the streamline, that is, the outer tube of the spout faces the inner tube surface in a streamlined transition, which also causes the induced flow of the impinging jet to induce the velocity, and the mixed flow effect is slightly worse; The end face of the spout may have a groove connecting the inner and outer tube faces to increase the turbulence intensity and thereby improve the mixed flow effect.

The inlet of the wake-up pipe is open at the bottom or side of the ship, below the surface of the water. In this way, the ship's companion flow can be fully utilized.

The inlet of the wake tube is or is approximately rectangular or elliptical, and its long axis is in the direction of the ship's accompanying flow. This makes it possible to take full advantage of the relative speed of the ship's wake and reduce the local resistance of the inlet of the wake.

The inlet of the wake pipe has a grille to filter to prevent blockage or damage of the pipe by foreign matter.

The inlet portion of the wake tube is a bell mouth, which is streamlined, and is offset and extended toward the flow direction of the ship accompanying flow. This makes it possible to make full use of the relative speed of the ship's wake, and to reduce the local resistance of the wake, so that the wake has better hydrodynamic performance.

The wake tube has an elbow, and the outlet of the elbow is in communication with the inlet of the mixed flow tube. The jet tube passes through the wall of the elbow of the companion tube, and the companion tube and the mixed flow tube are bounded by the spout of the jet tube. The elbow of the accompanying flow tube has guiding and rectifying action. After the ship's wake-up enters the inlet of the wake-up pipe, it becomes the wake of the jet. After the flow of the accompanying flow through the outlet of the curved pipe of the accompanying flow pipe, the flow can be sufficiently contacted with the jet around the nozzle of the flow pipe, thereby improving the effect of the mixed flow.

The outlet of the wake-up pipe is open to the pipe wall of the mixed flow pipe, and the jet pipe passes through the closed end face of the mixed flow pipe or the pipe wall of the mixed flow pipe in the vicinity thereof. In this case, the contact between the jet and the accompanying flow is uneven and insufficient, but the accompanying flow has an impact on the jet, and the mixed flow effect is slightly worse. Its disadvantage is that energy loss or pressure difference loss is large, and the flow rate of the mixed flow tube is small.

The outlet portion of the mixed flow pipe is a bell mouth, which is streamlined, so that the mixed water flow generates a radial induction speed, which can be used to improve the crotch flow field of the ship, and the propulsion efficiency is better.

The bellows of the mixed flow tube has a fluid distribution and is streamlined, and is fixed on the wall of the mixed flow tube by a bracket. The cross section of its bracket is also streamlined to reduce drag. The fluid separation itself can be asymmetrical, and its position can also be asymmetrical, to match the bell mouth. Its function is to make the speed of the mixed water flow more uniform, to distribute the flow of the mixed water flow in its circumferential direction, to make the mixed water flow to have a radial guiding speed, and to function as a grid when the water flows backward. Therefore, the fluid separation in the bell mouth of the mixed flow tube can make the effect of the mixed flow better, and further improve the flow field of the ship's ankle.

The mixed flow tube is deflected in a contralateral direction with respect to the center line of the flow tube in the opposite side of the inlet of the flow tube, and its deflection angle is smaller than the angle of the flow direction of the accompanying flow entering the mixed flow tube with respect to the center line of the flow tube. This not only makes better use of the speed and energy of the companion flow, but also reduces the loss of energy and improves the flow field of the ankle, and facilitates the arrangement of the propeller or the drive shaft of the pump impeller.

The end of the spout of the jet tube is deflected toward the deflecting direction of the mixing tube. In this way, the mixed flow is started and strengthened on this side, and the jet is deflected to the side to reduce the impact of the jet on the pipe wall, so that a better mixed flow effect can be achieved.

The outlet of the mixed flow tube, when there is a propeller or pump wheel behind, the structure and arrangement of the entire flow mixing device is more complicated. Miscellaneous. In general, the propeller or pump wheel requires a drive shaft to drive, so the direction and arrangement of the drive shaft will affect the structure and arrangement of the flow mixing device. If the drive shaft passes through the jet tube or the companion tube, the structure of the flow mixing device will be complicated, the required power equipment and the like are also difficult to arrange, and the local resistance of the jet tube or the accompanying flow tube is increased, and the hydrodynamic performance is deteriorated. If the drive shaft only passes through the mixed flow tube, not only the structure and arrangement of the flow mixing device are relatively simplified, but also the effect of mixing and deceleration is better. The drive shaft of the propeller or pump impeller and its shaft tube pass through the pipe wall of the mixed flow pipe, the shaft tube is fixed and sealed on the pipe wall of the mixed flow pipe, and the drive shaft protrudes from the outlet of the mixed flow pipe at the end of the drive shaft A propeller or pump wheel is installed. The centerline of the drive shaft intersects the centerline of the mixing tube at an angle that intersects the front of the propeller or pump impeller. The centerline of the drive shaft is often parallel to the centerline of the jet tube, so they have to be separated by a certain distance; of course, the two lines can also have a certain angle of intersection, but the greater the angle of intersection, the less efficient.

The flow tube may have multiple sets distributed around the jet tube. These flow tubes can have a common rectification portion, and the outlet of the rectification portion is connected to the inlet of the mixed flow tube, and the mixed flow effect is good. Alternatively, the flow tubes are directly connected to the mixed flow tube around the spout of the jet tube, and the mixed flow effect is slightly worse.

In the above technical solution, the jet entering the mixed flow chamber through the jet tube and the spout thereof is water having higher energy; and the companion flow entering the companion through the inlet of the companion tube is no energy or has lower energy. Water, this part of the water also enters the mixed flow chamber through the guiding and rectifying action of the accompanying flow tube. In the mixed flow chamber, through the complex interaction processes such as entrainment, impact, shearing, viscous, vortexing and rectification, the two different energy waters are thoroughly mixed, and the original jet passes through the energy transfer and consumption. The speed is greatly reduced, and the original wake is increased in speed due to the energy obtained. The speed of the mixed water flow is relatively uniform, and the speed of the original jet is relatively low.

The beneficial effect of the above technical solution is that the flow rate of the water flowing through the mixing device is lower than that of the water flowing through the nozzle, and the flow rate is increased, thereby improving the flow field of the crotch of the ship and reducing the wave-making resistance of the crotch; or improving The flow field in front of the propeller or pump impeller improves the propulsion efficiency and also reduces the hazards of cavitation and water hammer. As the companion pipe draws in the water flow, the water flow outside the inlet of the companion pipe produces an induction velocity, which in turn Inducing pressure, this induction speed or induced pressure can be used to further improve the crotch flow field of the ship and reduce the wave-making resistance of the crotch. Therefore, the improvement of propulsion efficiency by the mixed flow device of the ship's diversion propulsion system is not only reflected in the increase of thrust, but also in the improvement of the flow field. In this way, by adding the above-mentioned mixed flow device to the ship's diversion propulsion system, the problem that the propulsion efficiency is difficult to be greatly improved due to the jet phenomenon is solved. It makes the phenomenon of jets generated during the propulsion process of the ship profitable, while reducing the hazards of the wave and the wake and noise of the ship. DRAWINGS

Figure 1 is a longitudinal sectional view of the mixing device at the rear of the water jet propulsion system.

Figure 2 is a longitudinal cross-sectional view of the mixing device in front of the propeller or pump impeller.

The meaning of the symbol in the figure: 1. The jet tube, 1. 1. The spout of the jet tube, 2. The companion tube, 2. The inlet of the companion tube, 2. The bell mouth of the companion tube, 2 3. Elbow of the accompanying flow tube, 3. Mixed flow tube, 3. 1 mixed flow part of the mixed flow tube, 3. 2 bell mouth of the mixed flow tube, 3. 3 outlet of the mixed flow tube, 3. 4, mixed flow chamber, 3. 5, divided fluid, 4, propeller or pump wheel, 5, drive shaft, 6, shaft tube. Specific implementation

The present invention will be further described below in conjunction with the accompanying drawings and embodiments. Embodiment 1

As shown in Fig. 1, the mixing device at the rear of the water jet propulsion system is mainly composed of a jet pipe 1, a companion pipe 2 and a mixed flow pipe 3. This is equivalent to upgrading the sprinkler pipe of the water jet propulsion system to a flow mixing device. Wherein, the flow tube 1 of the flow mixing device is equivalent to the original water spray pipe; the flow tube 2 includes a bell mouth of the flow tube 2. 2 and the curved tube of the accompanying flow tube 2. 3; the mixed flow tube 3 includes a mixed flow tube 5之间之间。 The mixing portion 3. 1 and the bellows of the mixing tube 3. 2, in the bell mouth of the mixing tube 3.2 has a fluid separation 3.5 and its support.

At the moment when the propulsion pump of the water jet propulsion system is started, the positive pressure difference is transmitted from the propulsion pump through the jet tube 1 to the mixing chamber 3. 4, the water in the mixing chamber 3.4 is generated by the positive pressure difference. The induction rate of the outlet of the tube of 3.3, also the rate of induction of the inlet 2.1 to the inlet tube. At the same time, the water flows from the spout 1.1 of the jet tube to form a jet. The jet increases the water flow rate from the mixing chamber 3. 4 to the outlet of the mixing tube. Under the action of the entrainment of the jet, a negative pressure difference is generated in the mixing chamber 3.4 around the nozzle 1 of the jet tube. This negative pressure difference decelerates the jet, or the jet consumes a portion of the energy to create a negative pressure differential. This negative pressure difference replaces the positive pressure difference, resulting in an induction rate from the inlet of the wake tube 2. 1 to the mixing chamber 3. 4 . This creates a wake of the jet. The jet and the companion flow together in the mixed flow chamber 3. 4, achieving a better mixed flow effect. Therefore, the mixing device at the rear of the water jet propulsion system not only reduces the speed of the original jet, but also increases the flow rate of the propulsion system, which is beneficial to improve the crotch flow field of the ship and reduce the wave-making resistance of the crotch; The induction velocity and induced pressure generated by the outer side of the inlet 2.1 can also be used to further improve the ankle flow field and improve the propulsion efficiency.

5的水流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流流The induction velocity of the flow mixing chamber 3.4 is also induced by the water in the vicinity of the inlet of the flow tube. The water in the vicinity of the outlet of the mixing tube 3. 3 smoothly flows to the mixing chamber 3. 4; and the inlet of the accompanying flow tube 2. The water in the vicinity of the outlet of the mixing tube is smoothly flowing to the mixing chamber 3. 4; When the water near the flow is at the orifice of the incident flow tube 1.1, the flow rate and flow rate are much smaller because of the blockage of the local resistance. The speed of the ship retreating is getting faster and faster, and the difference is so large that the flow in the companion tube 2 is reversed and there is a speed from the mixing chamber 3.4 to the inlet of the companion tube 2.1. . Therefore, when the ship is reversing, the flow mixing device at the rear of the water jet propulsion system basically does not deteriorate the flow field of the crotch, and there is even improvement.

Embodiment 2

As shown in Fig. 2, the mixing device in front of the propeller or the pump impeller is mainly composed of the jet pipe 1, the companion pipe 2 and the mixed flow pipe 3. Wherein, the jet tube 1 is equivalent to the original sprinkler pipe; the companion tube 2 includes the bell mouth of the companion tube 2. 2 and the elbow of the companion tube 2. 3; the mixed flow tube 3 is mainly the mixed flow part of the mixed flow tube 3 . 1. The mixing tube 3 is deflected with respect to the center line of the jet tube 1 in the opposite direction of the inlet 2.1 of the companion tube, and its deflection angle is smaller than the angle of the flow direction of the companion flowing into the mixing tube 3 with respect to the center line of the jet tube 1. . The nozzle of the jet tube 1. The end of 1 is deflected toward the deflection direction of the mixing tube 3.

The outlet of the mixing tube 3. 3 has a propeller or pump wheel 4 behind it. The drive shaft 5 of the propeller or pump impeller 4 passes through the mixed flow tube 3, which not only simplifies the structure and arrangement of the flow mixing device, but also makes the effect of mixing and deceleration better. The drive shaft 5 is fixedly connected to the propeller or pump impeller 4 after passing through the wall of the mixing tube 3, the mixing chamber 3. 4 and the outlet of the mixing tube 3. 3. The centerline of the drive shaft 5 is parallel to the centerline of the jet tube 1, so they are separated by a certain distance. The center line of the drive shaft 5 intersects the center line of the mixing tube 3 at an angle, intersecting the front of the propeller or pump wheel 4.

The sealing problem of a mixed flow chamber 3.4 is present when the drive shaft 5 passes through the wall of the mixing tube 3. The solution is to first pass the shaft tube 6 from the wall of the mixed flow tube 3, fix and seal the two, and then pass the drive shaft 5 through the shaft tube 6, and the shaft 5 of the drive shaft 5 The bearings at both ends are positioned relative to the shaft tube 6, and the outer side of the bearing has an oil seal, close to the spiral There is a water seal on the outer side of the oil seal on the side of the paddle or the pump wheel 4, and a drain pipe is arranged between the oil seal and the water seal. The shaft tube 6 can be long or short, and the length means that the shaft tube 6 extends to the outside of the outlet of the mixed flow tube 3. 3. The shaft tube 6 requires a shaft tube bracket for reinforcement; short means that there is only one near the tube wall of the mixed flow tube 3. In the small section, the drive shaft 5 also needs a shaft bracket for positioning; not long or short means that the shaft tube 6 has not yet extended out of the outlet of the mixed flow tube 3. 3, the shaft tube 6 requires a shaft tube bracket to be reinforced and the drive shaft 5 requires a shaft bracket to Positioning. When the shaft tube 6 is long outside the mixing tube, the shaft tube bracket is also required to be reinforced.

When the propeller or pump impeller 4 is started positively, a negative pressure difference is generated in front of the propeller or pump impeller 4. The differential pressure difference is transmitted to the mixing chamber 3.4, so that the water in the jet tube 1 generates a velocity of the induction flow to the mixing chamber 3.4, and also causes the water near the inlet of the companion tube to flow to the mixing chamber 3. 4 induction speed. When the jet nozzle of the jet tube has a jet, a negative pressure difference is added to the outer mixing chamber 3. These negative pressure differentials further increase the induction velocity from the inlet of the wakepipe 2. 1 to the mixing chamber 3. 4, resulting in a larger wake. The jet and the companion flow work together in the mixing chamber 3. 4 to achieve a better mixed flow effect. The mixing device of the ship's diversion propulsion system in front of the propeller or pump impeller 4 not only reduces the speed of the original jet, but also increases the flow rate of the propulsion system, which is beneficial to improve the flow field before the propeller or pump impeller 4, and improves the propulsion efficiency. . The induced velocity or induced pressure generated by the water flow outside the inlet of the companion tube can be used to further improve the turbulent flow field of the vessel and reduce the wave-making resistance of the ankle.

When the propeller or pump impeller 4 is reversely activated, a positive pressure difference is created in front of the propeller or pump impeller 4. The positive pressure difference is transmitted to the mixing chamber 3. 4, the water in the mixing chamber 3. 4 is generated to flow to the inlet of the companion tube 2. The induction speed of 1 also produces an induction velocity to the jet tube 1. The water in the mixing chamber 3.4, some of the water flowing down the inlet of the accompanying flow tube 2 from the mains 2.1, and the thrust on the oblique direction; some enter the jet tube 1, if it is from the crotch Outflow, then not only the thrust is generated, but also the flow field of the ankle is improved, and the wave resistance is reduced.

Since the inlet of the companion pipe is relatively close to the propeller or the pump impeller 4, and the hydrodynamic performance of the companion flow tube 2 is relatively good, when the propeller or the pump impeller 4 is positively started or accelerated, the accompanying flow The presence of the tube 2 and its accompanying flow can effectively reduce the magnitude and velocity of the pressure drop before the propeller or pump wheel 4. This reduces the occurrence of cavitation and reduces the risk of cavitation. When the propeller or pump impeller 4 is decelerating, stopping or reversing, a water hammer will occur, but the intensity of the water hammer will increase in turn. Since the companion tube 2 and the mixed flow tube 3 are relatively short, the water hammer effect itself is weak, and the water hammer effect caused by the jet tube 1 and the pipe in front thereof can be greatly alleviated. Therefore, the improvement of the flow field before the propeller or pump impeller 4 by the mixed flow device of the ship diversion propulsion system is not only reflected in the improvement of propulsion efficiency, but also reduces the hazards of cavitation and water hammer.

Claims

Claim

1. The mixed flow device of the ship diversion propulsion system is characterized in that: the jet pipe, the companion pipe and the mixed flow pipe are composed of three parts, wherein the spout of the jet pipe and the outlet of the companion pipe are connected with the mixed flow pipe, and the flow pipe is connected The inlet is on the side of the jet tube, and the cross section of the jet tube is smaller than the cross section of the mixing tube.

2. The flow mixing device of a ship diversion propulsion system according to claim 1, wherein: the wake pipe has an elbow, the outlet of the elbow communicates with the inlet of the mixed pipe, and the jet pipe passes through the pipe wall of the elbow. The flow tube and the mixed flow tube are bounded by the spout of the jet tube.

3. The flow mixing device of a ship diversion propulsion system according to claim 1, wherein: the outlet of the flow pipe is open to the pipe wall of the mixed flow pipe, and the jet pipe passes through the closed end face of the mixed flow pipe or a mixed flow pipe near the mixed flow pipe. The wall of the pipe.

4. A flow mixing device for a ship diversion propulsion system according to claim 1, 2 or 3, wherein: the end surface of the spout of the jet tube has a groove communicating with the inner and outer tube faces thereof.

5. The flow mixing device of a ship diversion propulsion system according to claim 1, 2 or 3, wherein: the inlet portion of the flow pipe is a bell mouth and is streamlined, and the ship is accompanied by a ship when advancing toward the ship. The flow direction is offset and extended.

6. The flow mixing device of a ship diversion propulsion system according to claim 1, 2 or 3, wherein: the outlet portion of the mixed flow pipe is a bell mouth and is streamlined.

7. The flow mixing device of a ship diversion propulsion system according to claim 1, 2 or 3, characterized in that: opposite to the center line of the jet pipe, the mixed flow pipe is deflected to the opposite side of the inlet of the flow pipe, and its deflection The angle is less than the angle of the flow of the accompanying flow as it enters the mixing tube relative to the centerline of the jet.

A flow mixing device for a ship diversion propulsion system according to claim 7, wherein: the end face of the spout of the jet pipe is deflected toward the deflecting direction of the mixed flow pipe.

9. The mixing device of the ship diversion propulsion system according to claim 7, wherein: the propeller or the pump shaft of the pump shaft and the shaft tube thereof pass through the wall of the mixed flow tube, and the shaft tube is in the wall of the mixed flow tube. It is fixed and sealed, the drive shaft passes through the shaft tube, and the drive shaft is positioned relative to the shaft tube. The outer side of the bearing has oil seals and water seals. The drive shaft extends from the outlet of the mixed flow tube. The end is fitted with a propeller or pump wheel.

10. The flow mixing device of the ship diversion propulsion system according to claim 6, wherein: the fluid flow in the bell mouth of the mixed flow pipe is in a streamline shape, and is fixed on the pipe wall of the mixed flow pipe by a bracket.