A waterjet propulsion pump test bench capable of adjusting the pump inlet flow rate

Abstract

The application discloses a water jet propulsion pump test bench capable of adjusting the inlet flow velocity of a pump, which comprises a motor, a pressure stabilizing tank, a ring-shaped circulating water tank and a flow velocity adjusting system, wherein the motor is connected with a water jet propulsion pump to be tested in a power manner and is used for providing power; the pressure stabilizing tank is connected with the outlet of the water jet propulsion pump to be tested; the ring-shaped circulating water tank is communicated with the inlet end of the water jet propulsion pump to be tested; the ring-shaped circulating water tank is connected with the pressure stabilizing tank; a circulating pump is arranged in the ring-shaped circulating water tank; the flow velocity adjusting system is arranged in the ring-shaped circulating water tank and is located at the inlet of the water jet propulsion pump to be tested; and the ring-shaped circulating water tank is further provided with an observation opening for acquiring the inlet flow field information of the water jet propulsion pump by PIV shooting. The water jet propulsion pump test bench with the flow velocity adjusting system and the circulating pump is arranged, the ship sailing working condition is simulated by adjusting the flow velocity of the ring-shaped circulating water tank, the test of the real working state of the water jet propulsion pump in the ship sailing process is carried out, and the inlet flow velocity in the ship sailing process is obtained.

Description

Technical Field

[0001] This invention belongs to the field of water jet propulsion technology, and in particular relates to a water jet propulsion pump test bench with adjustable pump inlet flow velocity. Background Technology

[0002] Waterjet propulsion is a novel marine propulsion technology. Its principle involves drawing water from the bottom of the ship through a high-speed rotating impeller. The impeller performs work, causing the water to be ejected at high speed from a nozzle, thus providing thrust. The main components of a waterjet propulsion pump are the impeller, guide vanes, inlet channel, main shaft, and nozzle. Waterjet propulsion pumps offer high propulsion efficiency, strong cavitation resistance, ease of operation, high maneuverability, low noise, and minimal pump vibration. Compared to propeller-driven ships, waterjet propulsion pumps provide higher propulsion efficiency at high speeds. Due to these advantages, waterjet propulsion pumps are widely used in new high-performance vessels, such as high-speed warships, speedboats, and large transport ships.

[0003] As a core component of the ship's propulsion system, the performance of the waterjet propulsion pump determines the ship's propulsion performance. Currently, waterjet propulsion pumps lag significantly behind foreign counterparts in cavitation and efficiency, making the exploration of the internal flow mechanism and improvement of performance a long and arduous task. To obtain accurate performance parameters, establishing a test rig that conforms to a real flow environment is crucial. Currently, most waterjet propulsion pump test rigs can only perform performance tests on the pump itself, without considering the impact of the external environment on pump performance. In particular, they cannot conduct tests on the actual operating conditions of the waterjet propulsion pump during ship navigation, nor can they obtain the inlet flow velocity during ship navigation. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application proposes a waterjet propulsion pump test bench with adjustable pump inlet velocity. This test bench can not only obtain the actual outlet velocity of the waterjet propulsion pump during ship navigation, but also precisely adjust the inlet water flow velocity of the waterjet propulsion pump, thereby more realistically simulating the operating conditions of the waterjet propulsion pump on flowing rivers with different flow velocities.

[0005] The technical solution adopted in this invention is as follows:

[0006] A test bench for a waterjet propulsion pump with adjustable pump inlet flow velocity, comprising:

[0007] An electric motor, which is connected to the water jet propulsion pump under test to provide power;

[0008] A pressure stabilizing tank, which is connected to the outlet of the water jet propulsion pump under test.

[0009] An annular circulating water tank is connected to the inlet end of the water jet propulsion pump under test; the annular circulating water tank is connected to a pressure stabilizing tank; a circulating pump is installed inside the annular circulating water tank;

[0010] A flow rate regulation system is installed inside an annular circulating water tank and located at the inlet of the water jet propulsion pump to be tested.

[0011] Furthermore, the flow rate regulation system includes a flow guiding mechanism and a flow guiding height adjustment mechanism. The flow guiding mechanism is slidably connected to the inner wall of the annular circulating water tank and is opposite to the inlet of the water jet propulsion pump under test. The flow guiding height adjustment mechanism is disposed between the inner wall of the annular circulating water tank and the flow guiding mechanism to adjust the relative distance between the flow guiding mechanism and the inlet of the water jet propulsion pump under test.

[0012] Furthermore, the flow guiding mechanism includes a platform and a flow guiding plate, with the flow guiding plate hinged to both sides of the platform along the flow channel, and the flow guiding plate being slidably connected to the inner wall of the annular circulating water tank.

[0013] Furthermore, the inner wall of the annular circulating water tank is provided with a slide rail, and the guide plate is provided with a slider. The slider cooperates with the slide rail, so that the guide plate reciprocates along the slide rail.

[0014] Furthermore, the guide height adjustment mechanism is a rotary lifting platform.

[0015] Furthermore, the pressure stabilizing tank is connected to the outlet of the water jet propulsion pump under test through a pipeline system, which includes a pressure measuring pipe section, a flow meter, and a butterfly valve.

[0016] Furthermore, the annular circulating water tank and the pressure stabilizing tank are connected by a pipeline system, which includes a shut-off valve, a reducing tee, and a nozzle. The nozzle extends into one end of the annular circulating water tank, the shut-off valve is installed on the pipeline of the pressure stabilizing tank, and a reducing tee is installed between the nozzle and the shut-off valve. The two ends of the reducing tee are connected to the nozzle and the shut-off valve, respectively, and the third port is connected to the other end of the annular circulating water tank, thus forming a closed system.

[0017] Furthermore, the annular circulating water tank is composed of rectangular pipes and circular pipes. The rectangular pipes are arranged in a U-shape, and both ends of the rectangular pipes are connected to the circular pipes and the reducing tee pipes in sequence to form a loop.

[0018] Furthermore, the circulation pump is installed on a circular pipeline to force the water in the annular circulating water tank to circulate and to regulate the water flow speed in the annular circulating water tank.

[0019] Furthermore, an observation port is provided on the annular circulating water tank for PIV imaging to obtain the inlet flow field information of the water jet propulsion pump.

[0020] The beneficial effects of this invention are:

[0021] This invention discloses a waterjet propulsion pump test bench with adjustable inlet flow velocity. By adjusting the height of the guide plate on the inlet flow velocity adjustment system and the circulating pump, the inlet flow velocity of the waterjet propulsion pump can be changed. The adjustment method is relatively simple, and it can simulate a wide range of inlet flow velocities for the waterjet propulsion pump. Without changing the test bench design, it adds more operating conditions compared to existing waterjet propulsion pump test benches, expanding the inlet flow velocity operating range of the waterjet propulsion pump. Compared to most waterjet propulsion pump test benches, this invention can simulate flow conditions that more closely resemble the actual operating conditions of a waterjet propulsion pump. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a water jet propulsion pump test bench with adjustable pump inlet flow velocity as described in this invention.

[0023] Figure 2 This is an enlarged view of the structure of a partial annular circulating water tank of a water jet propulsion pump test bench with adjustable pump inlet flow velocity as described in this invention.

[0024] Figure 3 This is an enlarged view of the inlet velocity adjustment system of a water jet propulsion pump test bench with adjustable pump inlet velocity as described in this invention.

[0025] Figure 4 This is an enlarged view of the knob lifting platform structure of the water jet propulsion pump test bench with adjustable pump inlet flow rate according to the present invention.

[0026] The annotations in the attached figures are explained as follows:

[0027] In the diagram: 1-Motor, 2-Water jet propulsion pump, 3-Rectangular pipe, 4-Flange, 5-Straight pipe A, 6-Pressure measuring section, 7-Straight pipe B, 8-Reducing pipe section A, 9-Straight pipe C, 10-Flow meter, 11-Straight pipe D, 12-Butterfly valve, 13-Pressure stabilizing tank, 14-Reducing pipe section B, 15-Straight pipe E, 16-Stop valve, 17-Reducing tee, 18-Nozzle, 19-Sealed waterproof rubber ring, 20- - Reducing connector, 21- Circulation pump, 22- Circular pipe, 23- Acrylic glass observation port A, 24- Acrylic glass observation port B, 25- Sealed hatch, 26- Slide rail, 27- Slider, 28- Guide plate A, 29- Guide plate B, 30- Knob lifting platform, 31- Guide plate C, 32- Long strip groove, 33- Guide plate D, 34- Folding frame, 35- Adjusting knob, 36- Buckle, 37- Tabletop. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0029] A test bench for a water jet propulsion pump with adjustable inlet flow velocity includes: a motor 1, an annular circulating water tank, a circulating pump 21, a flow velocity regulation system, a pressure stabilizing tank 13, and corresponding piping systems. The specific structure of the entire test bench is as follows: Figure 1-4 As shown.

[0030] The shaft of the water jet propulsion pump 2 is connected to the motor 1 via a torque meter and is located at the upper end of the annular circulating water tank. The annular circulating water tank is connected to the outlet end of the water jet propulsion pump 2 via a flange 4, and the inlet of the water jet propulsion pump 2 is connected to the upper end of the pressure stabilizing tank 13 via an upper piping system, such as... Figure 1 As shown, the upper piping system consists of a pressure measuring pipe section 6, a reducing pipe section A 8, a flow meter 10, and a butterfly valve 12. The pressure measuring pipe section 6 is connected to the water jet propulsion pump 2 by a straight pipe A 5 via flange 4. The other end of the pressure measuring pipe section 6 is connected to a straight pipe B 7 via flange 4, and then to the reducing pipe section A 8 via flange 4. The reducing pipe diameter helps to reduce the jet velocity and pressure at the outlet of the water jet propulsion pump 2. The reducing pipe section A 8 is connected to the flow meter 10 via a straight pipe C 9. A minimum pipe diameter of five times is required between the reducing pipe section A 8 and the flow meter 10 to ensure a relatively stable water flow through the flow meter and obtain more accurate data. The other end of the flow meter 10 is connected to a straight pipe D 11 via flange 4, and then to the butterfly valve 12 via flange 4. A minimum pipe diameter of three times is required between the butterfly valve 12 and the flow meter 10. The other end of the butterfly valve 12 is connected to the upper end of the pressure stabilizing tank 13 via flange 4.

[0031] The lower end of the pressure stabilizing tank 13 is connected to the lower pipeline system via flange 4. The pressure stabilizing tank 13 can stabilize the system pressure and provide additional water to the test bench pipeline system, preventing the system from overheating due to the work of the water jet propulsion pump 2. Figure 1 As shown, the lower end of the piping system consists of a reducing pipe section B14, a stop valve 16, a reducing tee 17, and a nozzle 18. The lower end of the pressure tank 12 is connected to the reducing pipe section B14 via a flange 4. The other end of the reducing pipe section B14 is connected to a straight pipe section E15 via a flange 4, and then connected to the stop valve 16 via a flange 4. The other end of the stop valve 16 is connected to the reducing tee 17 via a flange 4. The other end of the reducing tee 17 is connected to the nozzle 18 via a flange 4. The nozzle 18 allows water to be sprayed from the pressure tank 13 into the rectangular pipe 3 of the annular circulating water tank through the lower end of the piping system. A sealed waterproof rubber ring 19 is installed between the nozzle 18 and the water tank to prevent leakage from the annular circulating water tank.

[0032] like Figure 1 and Figure 2 As shown, the annular circulating water tank is a closed system consisting of a rectangular pipe 3 and a circular pipe 22. One end of the circular pipe 22 is connected to the rectangular pipe 3 via a reducing joint 20, and the other end is connected to a reducing tee 17. The circulating pump 21 is located at the horizontal straight section of the circular pipe 22 in the annular water tank to force the water to circulate within the annular circulating water tank and to regulate the water flow velocity within the annular circulating water tank. The annular circulating water tank is connected to the inlet of the water jet propulsion pump 2 via an interface at the top of the tank. The lower end of the rectangular pipe 3 in the annular circulating water tank is connected to the lower section of the piping system via a sealed waterproof rubber ring 19.

[0033] An acrylic glass observation port A23 is installed on the upper wall of one side of the annular circulating water tank motor 1 for projecting laser light into the tank. An acrylic glass observation port B24 is installed on one side of the rectangular pipe 3 of the annular circulating water tank below the inlet of the water jet propulsion pump, and a sealed hatch 25 is opened on the other side. A flow rate regulation system is installed on the inner wall of the rectangular pipe 3 of the annular circulating water tank directly below the inlet of the water jet propulsion pump. The flow rate regulation system is adjusted by opening and closing the sealed hatch 25 through a rotating device. The acrylic glass observation port is used for PIV imaging to obtain the flow field information at the inlet of the water jet propulsion pump 2. The flow rate regulation system and the circulating pump 21 are used to adjust the flow rate of the annular circulating water tank to simulate the ship's navigation conditions.

[0034] The flow rate regulation system is installed inside the annular circulating water tank and located at the inlet of the water jet propulsion pump under test. The system includes a flow guiding mechanism and a flow guiding height adjustment mechanism. The flow guiding mechanism is slidably connected to the inner wall of the annular circulating water tank and is positioned opposite the inlet of the water jet propulsion pump under test. The flow guiding height adjustment mechanism is located between the inner wall of the annular circulating water tank and the flow guiding mechanism, adjusting the relative distance between the flow guiding mechanism and the inlet of the water jet propulsion pump under test. Figure 3 and Figure 4As shown, the flow rate adjustment system consists of slider 27, slide rail 26, knob lifting platform 30, guide plate A28, guide plate B29, guide plate C31, and guide plate D33. There are two slide rails 26, tightly welded to the inner surface of the lower end of the water jet propulsion pump inlet in the rectangular pipe 3 of the annular circulating water tank, symmetrically distributed on both sides of the tank's cross-section. Long grooves 32 are provided on both sides of the slide rails 26 to restrict the slider 27 to move left and right. There are four sliders 27 in total, divided into two groups of two, located on both sides of the slide rails 26 and connected perpendicularly to guide plate C31 and guide plate D33 by bolts. One side of guide plate A28 and guide plate B29 is connected to the knob lifting platform surface 37 via a rotating shaft structure, and the other end is connected to guide plate C31 and guide plate D33 via a rotating shaft structure. The knob lifting platform consists of a platform 37, an adjusting rod 35, a buckle 36, and a folding frame 34. The adjusting rod 35 has a threaded structure at its tail. By twisting the rotating rod 35, the distance between the two pillars fixed by the rod is compressed, thereby stretching or compressing the folding frame 34 connected to the pillars. The folding frame 34 has a long groove, which, together with the buckle 36, is used to limit the range of motion of the folding frame 34.

[0035] This invention is implemented through the following steps:

[0036] Step 1: The inlet flow rate adjustment system can be adjusted to a suitable height by adjusting the knob, thereby compressing the cross-sectional area of ​​this flow channel and increasing the flow rate in this section. Before starting the test bench, the height of the guide plate on the knob lifting platform should be adjusted with the annular circulating water tank empty.

[0037] Step 2: Set up the pressure measuring instrument at a suitable location in the pressure measuring pipe section, open all valves, open the valve connecting the pressure stabilizing tank to the external atmosphere, and continuously inject water into the pressure stabilizing tank until the annular circulating water tank, the pipeline system, and the water jet propulsion pump are full of water. Then, inject tracer particles into the water tank from the direction of the motor.

[0038] Step 3: Start the motor to drive the water jet propulsion pump, start the circulation pump to force water to circulate, and analyze the operating condition of the water jet propulsion pump at this time by recording the pressure data and flow meter data of the pressure measuring pipe section and combining the PIV shooting data.

[0039] The above embodiments are only used to illustrate the design concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made based on the principles and design ideas disclosed in the present invention are within the protection scope of the present invention.

Claims

1. A test bench for a waterjet propulsion pump with adjustable pump inlet flow velocity, characterized in that, include: Motor (1), which is connected to the water jet propulsion pump under test to provide power; A pressure stabilizing tank (13) is connected to the outlet of the water jet propulsion pump under test. An annular circulating water tank is connected to the inlet end of the water jet propulsion pump to be tested; the annular circulating water tank is connected to a pressure stabilizing tank (13); a circulating pump (21) is installed inside the annular circulating water tank. A flow rate regulation system is provided, which is located inside an annular circulating water tank and at the inlet of the water jet propulsion pump to be tested. The flow rate regulation system includes a flow guiding mechanism and a flow guiding height adjustment mechanism. The flow guiding mechanism is slidably connected to the inner wall of the annular circulating water tank and is opposite to the inlet of the water jet propulsion pump to be tested. The flow guiding height adjustment mechanism is located between the inner wall of the annular circulating water tank and the flow guiding mechanism to adjust the relative distance between the flow guiding mechanism and the inlet of the water jet propulsion pump to be tested. The flow guiding mechanism includes a platform (37) and a flow guiding plate. The flow guiding plate is hinged to both sides of the flow channel on the platform (37). The flow guiding plate is slidably connected to the inner wall of the annular circulating water tank. The inner wall of the annular circulating water tank is provided with a slide rail. The flow guiding plate is provided with a slider. The slider cooperates with the slide rail to make the flow guiding plate reciprocate along the slide rail. The guide height adjustment mechanism is a rotary lifting platform; The pressure stabilizing tank (13) is connected to the outlet of the water jet propulsion pump under test through a pipeline system, which includes a pressure measuring pipe section, a flow meter, and a butterfly valve; The annular circulating water tank and the pressure stabilizing tank (13) are connected by a pipeline system, which includes a shut-off valve (16), a reducing tee (17), and a nozzle (18). The nozzle (18) extends into one end of the annular circulating water tank. The shut-off valve (16) is installed on the pipeline of the pressure stabilizing tank (13). The reducing tee (17) is installed between the nozzle (18) and the shut-off valve (16). The two ends of the reducing tee (17) are connected to the nozzle (18) and the shut-off valve (16) respectively, and the third port is connected to the other end of the annular circulating water tank. The annular circulating water tank forms a closed system. The annular circulating water tank is composed of a rectangular pipe (3) and a circular pipe (22). The rectangular pipe (3) is arranged in a U-shape. The two ends of the rectangular pipe (3) are connected to the circular pipe (22) and the reducing oblique tee pipe (17) in sequence to form a loop. The circulating pump (21) is installed on the circular pipe (22) to force the water in the annular circulating water tank to circulate and to adjust the water flow speed in the annular circulating water tank. An observation port is provided on the annular circulating water tank for PIV photography to obtain the inlet flow field information of the water jet propulsion pump.

Images