阅读说明：本技术 一种大流量液控单向阀流场仿真方法 (Flow field simulation method for high-flow hydraulic control one-way valve ) 是由 李优 于 2020-12-14 设计创作，主要内容包括：本发明公开了一种大流量液控单向阀流场仿真方法,本发明通过对液控单向阀小阀芯大阀芯的二维流场和/或三维流场进行仿真,分别对流场内流道受到的压力和速度分布进行分析,实现对液压单向阀进行动态特性分析,发现现有技术中的液压单向阀所所存在的结构上的问题,对提高液控单向阀的性能,延长使用寿命,进而提高液压支架关键零部件及整机的性能具有重大贡献。(The invention discloses a flow field simulation method of a large-flow hydraulic control check valve, which is used for simulating a two-dimensional flow field and/or a three-dimensional flow field of a large valve core of a small valve core of the hydraulic control check valve, respectively analyzing the pressure and speed distribution received by a flow channel in the flow field, realizing dynamic characteristic analysis of the hydraulic check valve, finding the structural problems of the hydraulic check valve in the prior art, and making a great contribution to improving the performance of the hydraulic control check valve, prolonging the service life and further improving the performance of key parts and the whole machine of a hydraulic support.)

1. A flow field simulation method of a high-flow hydraulic control one-way valve is characterized by comprising the following steps:

s1, modeling is carried out according to the structure of the hydraulic control one-way valve, and a hydraulic control one-way valve model is obtained;

s2, respectively establishing a two-dimensional flow channel model and a three-dimensional flow channel model of a single hydraulic control one-way valve when the small valve core is opened according to the hydraulic control one-way valve model, setting the same opening parameters, simulating the process that emulsion flows in the two-dimensional flow channel model and the three-dimensional flow channel model through a hydraulic control one-way valve control port, flows through a hydraulic control port damping hole and flows out from a reverse oil return port through a small valve core valve port, and respectively obtaining a speed distribution cloud picture and a pressure distribution cloud picture in the flow channel of the two-dimensional flow channel model and the three-dimensional flow channel model;

s3, respectively establishing a two-dimensional flow channel model and a three-dimensional flow channel model of the single hydraulic control one-way valve when the large valve element and the small valve element are synchronously opened according to the hydraulic control one-way valve model, setting the same opening parameters, simulating the process that emulsion flows in through a hydraulic control one-way valve control port and a reverse oil inlet, flows through a valve port of the small valve element and a valve port of the large valve element respectively and then flows out from a reverse oil return port, and respectively acquiring a speed distribution cloud picture and a pressure distribution cloud picture in a flow channel of the two-dimensional flow channel model and the three-dimensional flow channel model of the single hydraulic control one-way valve when the large valve;

s4, establishing three-dimensional flow channel models of the parallel hydraulic control one-way valve respectively when the small valve core is opened and when the large valve core and the small valve core are synchronously opened according to the hydraulic control one-way valve model, wherein the three-dimensional flow channel models flow in from a reverse oil inlet of the valve core and flow out from a reverse oil outlet of the valve core under different opening parameters; respectively acquiring a speed distribution cloud picture and a pressure distribution cloud picture in a three-dimensional flow channel model flow channel of a flow field of the parallel small valve core when the small valve core is opened and when the large valve core and the small valve core are synchronously opened;

and S5, analyzing the stress condition in the flow channel respectively aiming at all the speed distribution cloud pictures and the pressure distribution cloud pictures obtained in the S2-S4, and carrying out structure optimization on the hydraulic control one-way valve according to the stress condition.

2. The flow field simulation method for the high-flow pilot-controlled check valve according to claim 1, wherein a cross section of the pilot-controlled check valve in the three-dimensional flow channel model passing through the liquid inlet and return port is taken as an observation surface in S2.

3. The flow field simulation method for the high-flow hydraulic control one-way valve according to claim 1, wherein in S2, under the set starting parameters, a velocity distribution cloud chart and a pressure distribution cloud chart at the position of the small valve element in the two-dimensional flow channel model and a three-dimensional flow channel model are respectively obtained, and further a flow field velocity vector enlarged view and a flow field static pressure enlarged cloud chart at the position of the small valve element, and a flow field velocity vector enlarged view and a flow field static pressure enlarged cloud chart at the position where the valve sleeve is matched with the valve body are obtained.

4. The flow field simulation method of the high-flow hydraulic control one-way valve according to claim 1, wherein the section of S3 with the center of the large and small valve cores and the liquid inlet and return ports taken as an observation surface.

5. The flow field simulation method for the large-flow hydraulic control check valve according to claim 1, wherein in S3, under the set starting parameter, a speed distribution cloud chart and a pressure distribution cloud chart at the positions of the large valve core and the small valve core in the two-dimensional flow channel model and the three-dimensional flow channel model are respectively obtained, and further, a flow field velocity vector enlarged view of the control rod outlet and a pressure distribution cloud chart on the conical surface of the large valve core are obtained.

6. The flow field simulation method of the high-flow hydraulic control one-way valve according to claim 1, wherein two emulsion outflow valve port midplanes in S4 are taken as observation surfaces.

7. The flow field simulation method for the large-flow hydraulic control check valve according to claim 1, wherein in S4, under the set opening parameter, a speed distribution cloud picture and a pressure distribution cloud picture at the position of the small valve element in the three-dimensional flow channel model when the small valve element is opened and a speed vector enlarged view at the position of the valve sleeve of the small valve element are respectively obtained; and further respectively obtaining a flow field velocity vector diagram at the position of the large valve core in the three-dimensional flow channel model, a pressure distribution cloud diagram on the valve sleeve and a pressure distribution cloud diagram on the conical surface of the large valve core when the large valve core and the small valve core are synchronously opened.

8. The flow field simulation method for the large-flow pilot-controlled check valve according to claim 1, wherein in S5, for all the velocity distribution clouds and the pressure distribution clouds corresponding to the two-dimensional flow channel model and the three-dimensional flow channel model of the single pilot-controlled check valve, the pressure and velocity distribution and the reverse opening dynamic characteristics of the pilot-controlled check valve are analyzed, a portion where cavitation and noise are likely to occur and a portion where the opening time of the small valve element is affected are found out, and a structural optimization measure is proposed.

9. The flow field simulation method for the large-flow hydraulic control check valve according to claim 1, wherein in S5, the pressure and velocity distribution are analyzed for all the velocity distribution cloud charts and pressure distribution cloud charts corresponding to the two-dimensional flow channel model and the three-dimensional flow channel model of the single hydraulic control check valve when the large and small valve cores are synchronously opened, the steady-state hydrodynamic force of the valve core is analyzed, whether the pressure distribution on both sides of the valve core is uniform or not and whether the eccentric seizure phenomenon occurs or not are judged, and the structure is optimized according to the judgment result.

10. The flow field simulation method for the large-flow hydraulic control check valve according to claim 1, characterized in that in S5, pressure and velocity distribution are analyzed for all velocity distribution clouds and pressure distribution clouds corresponding to the three-dimensional flow channel model of the parallel hydraulic control check valve when the small valve core is opened and when the large and small valve cores are synchronously opened, the easily damaged part is found out, the internal damage mechanism is researched, and the structural optimization measure is proposed.

Technical Field

The invention relates to the technical field of hydraulic control one-way valves, in particular to a flow field simulation method of a high-flow hydraulic control one-way valve.

Background

The hydraulic control one-way valve on the market at present has the main problem that when a hydraulic support stand column begins to fall, the hydraulic control one-way valve is conducted reversely, so that impact and vibration phenomena occur, the stand column is also subjected to strong pressure impact and vibration, and the hydraulic support cannot stably fall. Severe pressure impact and vibration not only affect the service life and reliability of the hydraulic control one-way valve, but also affect the service life of elements such as pipelines, pipe joints, sealing rings, check rings and the like in a system, so that the safety valve is frequently opened and closed and is difficult to effectively unload, the production efficiency of a fully mechanized mining face is reduced, the workload of workers is increased, and the support stand column elements can be damaged to cause safety accidents in severe cases. Therefore, the dynamic characteristic analysis of the hydraulic control one-way valve is carried out, the internal structure of the valve, the pressure in a valve passage, the flow velocity of the emulsion, the cavitation phenomenon and the like are analyzed, and the method has great significance for improving the performance of the hydraulic control one-way valve, prolonging the service life and further improving the performance of key parts and the whole machine of the hydraulic support.

Therefore, how to provide a flow field simulation method of a high-flow pilot-controlled check valve, which can improve the stability, reliability and service life of the pilot-controlled check valve, is a problem that needs to be solved urgently by those skilled in the art.

Disclosure of Invention

In view of this, the invention provides a flow field simulation method for a high-flow hydraulic control one-way valve.

In order to achieve the purpose, the invention adopts the following technical scheme:

a flow field simulation method of a high-flow hydraulic control one-way valve comprises the following steps:

s1, modeling is carried out according to the structure of the hydraulic control one-way valve, and a hydraulic control one-way valve model is obtained;

s2, respectively establishing a two-dimensional flow channel model and a three-dimensional flow channel model of a single hydraulic control one-way valve when the small valve core is opened according to the hydraulic control one-way valve model, setting the same opening parameters, simulating the process that emulsion flows in the two-dimensional flow channel model and the three-dimensional flow channel model through a hydraulic control one-way valve control port, flows through a hydraulic control port damping hole and flows out from a reverse oil return port through a small valve core valve port, and respectively obtaining a speed distribution cloud picture and a pressure distribution cloud picture in the flow channel of the two-dimensional flow channel model and the three-dimensional flow channel model;

s3, respectively establishing a two-dimensional flow channel model and a three-dimensional flow channel model of the single hydraulic control one-way valve when the large valve element and the small valve element are synchronously opened according to the hydraulic control one-way valve model, setting the same opening parameters, simulating the process that emulsion flows in through a hydraulic control one-way valve control port and a reverse oil inlet, flows through a valve port of the small valve element and a valve port of the large valve element respectively and then flows out from a reverse oil return port, and respectively acquiring a speed distribution cloud picture and a pressure distribution cloud picture in a flow channel of the two-dimensional flow channel model and the three-dimensional flow channel model of the single hydraulic control one-way valve when the large valve;

s4, establishing three-dimensional flow channel models of the parallel hydraulic control one-way valve respectively when the small valve core is opened and when the large valve core and the small valve core are synchronously opened according to the hydraulic control one-way valve model, wherein the three-dimensional flow channel models flow in from a reverse oil inlet of the valve core and flow out from a reverse oil outlet of the valve core under different opening parameters;

respectively acquiring a speed distribution cloud picture and a pressure distribution cloud picture in a three-dimensional flow channel model flow channel of a flow field of the parallel small valve core when the small valve core is opened and when the large valve core and the small valve core are synchronously opened;

and S5, analyzing the stress condition in the flow channel respectively aiming at all the speed distribution cloud pictures and the pressure distribution cloud pictures obtained in the S2-S4, and carrying out structure optimization on the hydraulic control one-way valve according to the stress condition.

Preferably, in S2, the cross section of the pilot-controlled check valve in the three-dimensional flow passage model passing through the liquid inlet and return port is taken as an observation surface.

Preferably, in S2, under the set start parameter, a speed distribution cloud chart and a pressure distribution cloud chart at the small valve core in the two-dimensional flow channel model and the three-dimensional flow channel model are respectively obtained, and further a flow field speed vector enlarged view and a flow field static pressure enlarged cloud chart at the small valve core, and a flow field speed vector enlarged view and a flow field static pressure enlarged cloud chart at the matching position of the valve sleeve and the valve body are obtained.

Preferably, in S3, the cross section of the large and small valve cores and the center of the liquid inlet and return ports is the observation surface.

Preferably, in S3, under the set start parameter, a speed distribution cloud chart and a pressure distribution cloud chart at the positions of the large valve core and the small valve core in the two-dimensional flow channel model and the three-dimensional flow channel model are respectively obtained, and further, a flow field speed vector enlarged view of the control rod outlet and a pressure distribution cloud chart on the conical surface of the large valve core are obtained.

Preferably, the middle plane of two emulsion flows out of the valve port in S4 is taken as a viewing plane.

Preferably, in S4, under the set opening parameter, a velocity distribution cloud chart and a pressure distribution cloud chart at the position of the small valve element in the three-dimensional flow channel model when the small valve element is opened and a velocity vector enlarged view at the position of the valve sleeve of the small valve element are respectively obtained; and further respectively obtaining a flow field velocity vector diagram at the position of the large valve core in the three-dimensional flow channel model, a pressure distribution cloud diagram on the valve sleeve and a pressure distribution cloud diagram on the conical surface of the large valve core when the large valve core and the small valve core are synchronously opened.

Preferably, in S5, for all the speed distribution clouds and the pressure distribution clouds corresponding to the two-dimensional flow channel model and the three-dimensional flow channel model of the single pilot-controlled check valve, the pressure and the speed distribution and the reverse opening dynamic characteristics of the pilot-controlled check valve are analyzed, a portion where cavitation and noise are likely to occur and a portion where the opening time of the small valve element is affected are found, and a structural optimization measure is proposed.

Preferably, in S5, the pressure and velocity distributions are analyzed for all the velocity distribution cloud charts and pressure distribution cloud charts corresponding to the two-dimensional flow channel model and the three-dimensional flow channel model of the single hydraulic control check valve when the large and small valve cores are synchronously opened, the steady-state hydrodynamic force of the valve core is analyzed, whether the pressure distributions on both sides of the valve core are uniform or not and whether the eccentric locking phenomenon occurs or not is judged, and the structure is optimized according to the judgment result.

Preferably, in S5, the pressure and velocity distributions are analyzed for all the velocity distribution cloud charts and pressure distribution cloud charts corresponding to the three-dimensional flow channel models of the parallel pilot-controlled check valves when the small valve element is opened and when the large and small valve elements are synchronously opened, the easily damaged part is found out, the internal failure mechanism is studied, and the structure optimization measures are provided.

According to the technical scheme, compared with the prior art, the invention discloses a flow field simulation method of the large-flow hydraulic control check valve, the invention simulates the two-dimensional flow field and/or the three-dimensional flow field of the large valve core of the small valve core of the hydraulic control check valve, analyzes the pressure and speed distribution received by the flow channel in the flow field respectively, realizes dynamic characteristic analysis of the hydraulic check valve, finds the structural problem of the hydraulic check valve in the prior art, and has great contribution to improving the performance of the hydraulic control check valve, prolonging the service life and further improving the performance of key parts and the whole machine of a hydraulic support.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic diagram of a valve core of a pilot operated check valve provided by the present invention;

FIG. 2 is a schematic view of the emulsion flow when the small valve core provided by the invention is opened;

FIG. 3 is a schematic view of the emulsion flowing when the big and small valve cores are opened according to the present invention;

FIG. 4 is a view showing the small valve element provided by the present invention opening a 0.5mm flow channel;

FIG. 5 is a cloud of velocity distributions at 0.5mm for a small valve element opening provided by the present invention;

FIG. 6 is a static pressure distribution cloud chart of the invention with a small valve core opening of 0.5 mm;

FIG. 7 is a cloud of pressure distribution at 0.5mm for a small valve element according to the present invention;

FIG. 8 is an enlarged cloud of the hydrostatic pressure in the flow field at the small valve element provided by the present invention;

FIG. 9 is a cloud of velocity profiles at 0.5mm for a small cartridge provided by the present invention;

FIG. 10 is an enlarged view of a cloud of flow field velocities at a small valve element according to the present invention;

FIG. 11 is an enlarged view of the flow field velocity vector at the small valve element provided by the present invention;

FIG. 12 is an enlarged view of the pressure at the engagement of the valve sleeve and the valve body in accordance with the present invention;

FIG. 13 is an enlarged view of the velocity vector at the engagement of the valve sleeve and the valve body in accordance with the present invention;

fig. 14 is a schematic view of a valve sleeve according to the present invention;

FIG. 15 is a velocity vector diagram of the valve sleeve provided by the present invention after optimization;

FIG. 16 is a view showing the large and small valve cores opening a 3mm flow channel according to the present invention;

FIG. 17 is a cloud of velocity profiles of 3mm for the openings of the large and small spools provided by the present invention;

FIG. 18 is a cloud view of 3mm pressure distribution of the opening of the large and small valve cores provided by the invention;

FIG. 19 is a velocity distribution cloud chart when the big and small valve cores provided by the invention are opened by 3 mm;

FIG. 20 is a cloud of pressure profiles when the large and small spools provided by the present invention are opened by 3 mm;

FIG. 21 is an enlarged view of the control lever exit velocity vector provided by the present invention;

FIG. 22 is a cloud of pressure distributions on the conical surface of a large valve element according to the present invention;

FIG. 23 is a pressure distribution cloud chart of the invention with a parallel small valve core opened by 0.3 mm;

FIG. 24 is a cloud chart of the velocity distribution of the parallel small valve core opening by 0.3mm provided by the invention;

FIG. 25 is an enlarged view of the velocity vector at the valve pockets of the small parallel spools provided by the present invention;

FIG. 26 is a cloud of velocity profiles for pilot operated check valves according to the present invention;

FIG. 27 is a cloud of pressure profiles for pilot operated check valves according to the present invention;

FIG. 28 is a vector diagram of the flow field velocity at the position of a large valve core provided by the invention;

FIG. 29 is a cloud of pressure profiles on a pilot operated check valve bonnet according to the present invention;

FIG. 30 is a cloud of pressure distributions on the conical surface of a large valve element according to the present invention;

fig. 31 is an overall flowchart of a flow field simulation method of a high-flow pilot-controlled check valve according to the present invention;

wherein, 1-big valve core, 2-small valve core, 3-valve seat, 4-control rod, 5-closed cavity and 6-reverse oil inlet P₁7-damping hole, 8-reverse oil return port P₂9-control rod with rod cavity A₂10-control rod cavity A₁11-control rod emulsion inlet P_K12-fluid inlet, 13-fluid outlet, 14-emulsion outlet, 15-emulsion inlet and 16-vortex.

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 derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention discloses a flow field simulation method for a high-flow hydraulic control one-way valve, which is shown in figure 31.

In this embodiment, a hydraulic control check valve is taken as an example, wherein the hydraulic control check valve is formed by connecting two internal-discharge type valve cores with nominal flow of 1000L/min and nominal pressure of 50MPa in parallel, and the two internal-discharge type valve cores with nominal flow of 500L/min.

As shown in fig. 1, a hydraulic control check valve core with a flow rate of 500L/min in the parallel internal-discharge hydraulic control check valve is modeled by adopting a hydraulic element design library (HCD) and a mechanical library submodel; FIG. 2 is a schematic view of the emulsion flowing when the small valve core 2 is opened; FIG. 3 is a schematic view of the emulsion flowing when the big valve core 2 and the small valve core 2 are opened;

and (3) simulating the flow field when the small valve core 2 of the single hydraulic control one-way valve is opened by 0.5mm, and respectively simulating and contrastively analyzing the two-dimensional flow field and the three-dimensional flow field in order to contrast the difference when simulation software FLUENT simulates the same flow field.

Two-dimensional flow field simulation:

fig. 4 is a two-dimensional flow channel model of a single hydraulic control check valve when the small valve element 2 is opened by 0.5mm, emulsion flows in through a control port of the hydraulic control check valve, flows through a damping hole 7 of the hydraulic control port, flows out from a reverse oil return port through a valve port of the small valve element 2, and is poured into grid processing software GAMBIT after being drawn in CAD. Fig. 5 and 6 are a speed distribution cloud chart and a pressure distribution cloud chart of the flow field when the small valve element 2 of the pilot-controlled check valve is opened by 0.5mm, and it can be known from the speed distribution cloud charts that the average speed of the emulsion in the flow channel is about 53m/s, and the flow speed is increased when the flow channel is suddenly tightened. If the valve path is suddenly tightened at the matching position of the conical surface of the small valve core 2 and the large valve core 1 and the matching position of the front section guide rod of the small valve core 2 and the large valve core 1, the flow speed of the emulsion at the position is about 86m/s at most, the flow area of the small valve core 2 is equal, and the flow of the small valve core 2 is about 25.3L/min at the moment. Correspondingly observing the pressure distribution cloud chart, the speed reduction amplitude of the emulsion is maximum, and the system pressure reduction amplitude is also maximum, wherein the pressure is about 46MPa at the moment. Meanwhile, the pressure at the sharp corner where the large valve core 1 and the small valve core 2 are matched is about 44MPa, the pressure around the large valve core 1 and the small valve core 2 is about 46MPa, negative pressure in a local range occurs, and cavitation is easy to occur in the area. In addition, because only one damping hole 7 of the hydraulic control port is arranged, emulsion mainly passes through one side of the small valve core 2 when passing through the small valve core 2, and the other side of the small valve core 2 has less fluid, so that the radial stress imbalance of the small valve core 2 is easily caused.

Three-dimensional flow field simulation:

and (3) establishing a three-dimensional flow channel model of the single hydraulic control one-way valve when the small valve core 2 is opened by 0.5mm, keeping the flow channel unchanged in the flow direction of the emulsion, storing the flow channel as an stp file after the entity modeling in Pro/E is finished, and importing the stp file into the grid processing software GAMBIT. And performing surface grid division on key parts of the small valve element 2 and the valve seat 3 in the flow passage, then performing body grid division on the flow passage, selecting a body grid type Tet/Hybrid, and selecting a grid integral proportion (Interval size) of 0.4. Then setting flow field boundaries, setting the type of the boundary condition of the fluid inlet 12 as pressure-inlet, setting the type of the boundary condition of the fluid outlet 13 as pressure-outlet, setting the rest of contact surfaces with the emulsion as wall, and finally outputting a mesh file.

And importing the grid file into an ANSYS/FLUENT, checking that the grid file is correct, then performing the next operation, and selecting a Pressure Based solver, a steady-state model and an Explicit format. Setting boundary conditions of inlet and outlet, and selecting the pressure difference of an inlet and an outlet to be 6MPa according to the requirement that the pressure loss of the fluid flowing through the cone valve is not more than 7MPa after the fluid flows through the cone valve in the national standard, wherein the pressure of an emulsion inlet 15 is 50MPa, and the pressure of the outlet is 44 MPa. Setting the solving mode of Pressure-Velocity Coupling in the solving method as simple, setting the mode of differentiation as Second Order, selecting water as a fluid model, setting other settings as same as two-dimensional flow field simulation, and starting simulation after initialization.

As shown in fig. 7, which is a pressure distribution cloud chart when the small valve core 2 is opened by 0.5mm, the cross section of the liquid control one-way valve passing through the liquid inlet and return port is an observation surface. As can be seen from the figure, the pressure of the flow field of the small valve core 2 is reduced in two stages, the first stage is that the pressure is reduced to about 47MPa after passing through the valve sleeve damping hole 7, and the second stage is that the pressure is reduced to about 43MPa when emulsion passes through the valve port of the small valve core 2. As can be seen from the pressure-amplified cloud picture at the valve port of the small valve element 2 in FIG. 8, negative pressure is generated at the sharp corner of the valve seat 3 of the small valve element 2 on the large valve element 1, the sharp corner of the guide rod of the small valve element 2 and the valve hole of the large valve element 1 where emulsion flows out, cavitation and noise are easily generated, and measures such as round corners should be adopted for optimization.

As shown in fig. 9, which is a cloud diagram of the velocity distribution when the small valve element 2 is opened by 0.5mm, it can be known from the cloud diagram that the velocity of most of the area of the emulsion in the flow field of the small valve element 2 is about 25m/s, and the flow velocity of the emulsion in the cavity formed by the cooperation of the valve sleeve and the valve body reaches 160m/s at the fastest, which is not shown in the previous two-dimensional simulation result. It can be seen that the emulsion flow rate in the three-dimensional flow field simulation is faster compared to the two-dimensional flow field simulation of the previous section. FIGS. 10 and 11 are the velocity cloud chart and the velocity vector enlarged view of the small valve core 2 at the valve port, from which the flow velocity of the emulsion at the matching position of the small valve core 2 and the large valve core 1 is about 171m/s, and the valve port flow area of the small valve core 2 is 4.9 x 10^-6m²The valve port flow of the small valve core 2 is 50.3L/min. And the emulsion at the joint of the guide rod and the conical surface on the small valve core 2 generates a vortex 16, the pressure at the corresponding position is reduced, negative pressure is generated, cavitation and noise are easy to generate, and the rounding angle is optimized during design.

As shown in fig. 12 and 13, which are enlarged views of pressure and velocity vectors at the matching position of the valve sleeve and the valve body, it can be seen from the drawings that most of the fluid flows into the cavity formed by the valve sleeve and the valve body after flowing into the reverse oil inlet, only a very small amount of fluid flows into the damping holes 7 on the valve sleeve, and the peak flow velocity of the emulsion reaches about 230 m/s. The pressure of the system acts on the cavity formed by the valve sleeve and the valve body, the emulsion generates pressure drop through the damping hole 7 to open the small valve element 2 after the pressure in the cavity is the same as that of the system, and the cavity has larger volume, so that the sensitivity of the valve element is reduced undoubtedly, and the opening time of the small valve element 2 is prolonged. Therefore, the influence of the cavity on the small valve element 2 is reduced through structural optimization, the original valve sleeve is designed to directly flatten the damping hole 7 to supply liquid to the cavity of the small valve element 2, the area of the damping hole 7 is only removed from the part, and a part is reserved to isolate the cavity formed by the valve sleeve and the valve body from the reverse oil inlet of the hydraulic control one-way valve. Fig. 14 is an optimized schematic diagram, which can not only avoid the influence of the valve sleeve and the valve body forming a cavity on the opening process of the small valve element 2, but also improve the opening time and sensitivity of the small valve element 2 without increasing the complexity of the valve sleeve.

Fig. 15 is an enlarged view of a velocity vector of a valve sleeve part after valve sleeve optimization, the pressure distribution of the cavity of the small valve element 2 after valve sleeve optimization is not changed much compared with that before optimization, but emulsion directly flows into a valve sleeve damping hole 7 after valve sleeve optimization, the peak flow rate of the emulsion is about 208m/s, and is almost the same as that before optimization. Compared with the prior art, the emulsion flow speed at the valve port of the small valve element 2 is not changed greatly, but the vortex 16 phenomenon in the damping hole 7 is weakened, so that the pressure consumption is reduced. The influence of the valve sleeve and the valve body forming the containing cavity on the small valve element 2 is eliminated after optimization, the sensitivity of the small valve element 2 is improved, and the opening time of the small valve element 2 is shortened.

After the two-dimensional and three-dimensional flow field simulation analysis of the small valve core 2 which is opened by 0.5mm is completed, the following conclusion is found through comparison:

(1) the flow rates of the emulsion at the valve port of the small valve core 2 in two-dimensional simulation and three-dimensional simulation are respectively 86m/s and 171m/s, and Table 1 shows the comparison of different simulation modes and theoretical calculation results of the small valve core 2 in the paper. As can be seen from the table, the flow of the small valve core 2 floats at about 40L/min, which shows that the flow of the small valve core 2 at the small flow pressure relief stage is about 40L/min, and the corresponding flow velocity of the emulsion is about 136 m/s.

(2) In the three-dimensional simulation, the cavity formed by the valve sleeve and the valve body is found to reduce the sensitivity and the opening time of the small valve core 2, but the cavity is not found in the two-dimensional simulation.

TABLE 1 Small spool 2 opening flow comparison

(3) In both two-dimensional and three-dimensional simulations, it is found that cavitation and noise are easy to occur at the sharp corner on the conical surface of the small valve core 2, and the optimization is required.

And simulating the flow field of the single hydraulic control one-way valve when the opening degree of the large valve core 2 and the small valve core 2 is 3 mm.

Two-dimensional flow field simulation:

fig. 16 is a two-dimensional model of a flow channel of a single hydraulic control check valve when the opening degree of the large valve element 2 and the small valve element 2 is 3mm, emulsion flows in through a control opening of the hydraulic control check valve and a reverse oil inlet, respectively flows through valve ports of the small valve element 2 and the large valve element 1 and flows out from a reverse oil return opening, the flow channel is divided into grids in software GAMBIT, and then grid files are led into FLUENT. When the big valve core 1 is opened, the pressure of a reverse oil inlet is about 39MPa, the pressure of an emulsion taking inlet 15 is 40MPa, the pressure of an emulsion taking outlet is 34MPa, and the rest settings are the same as the above.

Fig. 17 and 18 are a velocity distribution cloud chart and a pressure distribution cloud chart of a flow field when the large valve core 2 and the small valve core 2 of the hydraulic control one-way valve are synchronously opened for 3mm, and it can be known from the diagrams that emulsion mainly flows out from the valve port of the large valve core 1 in a valve channel, the average flow velocity is about 87m/s, and the flow area of the large valve core 1 is 4.7 multiplied by 10^-5m²The flow rate of the big valve core 1 is 245.3L/min; the flow rate of the emulsion at the valve port of the small valve core 2 is only about 23.2m/s, and the flow area of the small valve core 2 is 4.9 multiplied by 10^-6m²And the flow of the small valve element 2 is about 6.8L/min, and the flow of the hydraulic control one-way valve is 537L/min at the moment, so that the design nominal flow of the hydraulic control one-way valve cannot be reached. The highest speed is generated in the middle of the narrowest part of a valve path formed by the large valve core 1 and the valve seat 3, the speed is close to 116m/s, negative pressure is generated at a sharp corner in a pressure distribution cloud picture correspondingly, air pocket and noise are easy to generate, and the surfaces of the cone valve and the valve seat 3 are greatly damaged. It can also be seen that the location of greatest pressure loss is the location of the fastest increase in emulsion flow rate. Negative pressure is generated at the sharp corner of the valve seat 3, so that cavitation is easy to generate, and the valve seat 3 is made of polyethylene plastic materials, so that the surface of the valve seat 3 is easy to damage and cause leakage. The pressure in the closed cavity 5 formed by the small valve core 2 and the control rod 4 is higher than the pressure outside the closed cavity, which can be seen from the pressure distribution cloud chart, and the side proves the correctness of the conclusion that the pressure impact is caused when the large valve core 2 and the small valve core 2 are synchronously opened because the pressure at the valve ports of the large valve core 2 and the small valve core 2 is unbalanced to cause the phenomenon that the large valve core 2 and the small valve core 2 are stressed unevenly and the valve cores are repeatedly opened and closed.

Three-dimensional flow field simulation:

and constructing a three-dimensional flow channel model of the single hydraulic control one-way valve when the large valve element 2 and the small valve element 2 are synchronously opened for 3mm, enabling the flow direction of the emulsion to be unchanged, outputting a step file after the flow channel completes solid modeling in Pro/E, and guiding the step file into a grid processing software GAMBIT. And carrying out surface grid division on key parts of the large valve core 1 and the small valve core 2 in the flow channel, and matching the small valve core 2 and the valve seat 3, then carrying out body grid division on the flow channel, selecting a body grid type Tet/Hybrid, and selecting a grid integral proportion (Interval size) of 0.4. Then setting flow field boundaries, setting the type of the boundary condition of the fluid inlet 12 as pressure-inlet, setting the type of the boundary condition of the fluid outlet 13 as pressure-outlet, setting the rest of contact surfaces with the emulsion as wall, and finally outputting a mesh file. And (3) introducing the grid file into ANSYS/FLUENT, setting the 15 pressure of an emulsion inlet to be 40MPa and the outlet pressure to be 36MPa, and setting the rest settings to be the same as the previous sections.

As the simulation result is that a three-dimensional model is inconvenient to analyze, the section of the center of the large valve core 2 and the section of the center of the liquid inlet and the liquid outlet are selected as analysis sections, and three-dimensional speed and pressure distribution cloud charts of the large valve core 2 and the small valve core 2 which are taken on the section and are opened by 3mm are shown in figures 19 and 20. As can be seen from the figure, the average flow velocity of the emulsion at the valve port of the big valve core 1 is about 180m/s, and the flow area of the big valve core 1 is 4.7 multiplied by 10^-5m²The flow rate of the big valve core 1 is 507L/min; the flow velocity at the valve port of the small valve core 2 is about 30m/s, and the flow area of the small valve core 2 is 4.9 multiplied by 10^-6m²When the flow rate of the small valve core 2 is 8.82L/min, the flow rate of the hydraulic control one-way valve is 1031.6L/min, and the emulsion mainly flows out of the large valve core 1 at the moment. The flow velocity at the valve port of the large valve core 1 is faster than that in the containing cavity of the small valve core 2, so that the pressure in the containing cavity of the small valve core 2 is increased, and the pressure in the containing cavity of the small valve core 2 is about 38MPa and the pressure at the valve port of the large valve core 1 is about 36.5MPa, and the large pressure difference causes uneven axial stress of the large valve core 2 and the small valve core 2, so that the valve core is opened and closed for a short time, pressure impact is generated, and the simulation result is absent in a two-dimensional simulation result. Meanwhile, it can be seen that negative pressure appearing in the flow field in the three-dimensional simulation is not obvious in the two-dimensional simulation. The too fast flow rate of the emulsion at the reverse return outlet of the pilot operated check valve creates a vortex 16 and the energy loss causes the pressure at the center of the vortex 16 to be lower than the ambient pressure in the pressure cloud.

As shown in fig. 21, which is an enlarged view of the velocity vector at the outlet of the control lever 4, it can be seen that the emulsion mainly flows out of the large spool 1, the flow velocity of the emulsion at the small spool 2 is low at the large spool 1, and a vortex 16 occurs at the outlet. As shown in fig. 22, which is a cloud diagram of pressure distribution on the conical surface of the large valve core 1, it can be seen that the pressure at the small end of the conical surface is higher than that at the large end, which indicates that the end surface of the small end of the large valve core 1 is easily damaged, and corresponding measures should be taken during design to prolong the service life of the large valve core 1.

After the simulation analysis of the two-dimensional and three-dimensional flow fields of the large valve core 2 and the small valve core 2 which are synchronously opened by 3mm is completed, the following conclusions can be found through comparison:

(1) the flow rates of the emulsion at the valve port of the large valve core 1 in the two-dimensional simulation and the three-dimensional simulation are respectively 87m/s and 180m/s, and the table 2 is a comparison of different simulation modes and theoretical calculation results of the small valve core 2 in the embodiment. As can be seen from Table 2, the flow rate of the hydraulically-controlled check valve basically floats around the nominal flow rate after the valve is normally opened, which indicates that the flow rate of the emulsion at the valve port of the large valve core 1 is about 180m/s, and the comparison summary with the above shows that the flow rate of the emulsion in the two-dimensional simulation is generally small. In addition, the flow rates of the emulsion at the valve port of the small valve core 2 in two-dimensional simulation and three-dimensional simulation are respectively 23.2m/s and 30m/s, the corresponding flow rates are respectively 6.8L/min and 8.3L/min, and the difference is not large.

TABLE 2 comparison of pilot operated check valve flow rates

(2) The positions of the valve core, which are easy to generate cavitation and noise, are different in two-dimensional simulation and three-dimensional simulation, so that the two parts are beneficial to analysis of the flow field of the hydraulic control one-way valve.

(3) The three-dimensional flow field simulation can analyze the flow field on the curved surface, for example, the pressure distribution on the conical surface of the large valve core 1 is analyzed to find that the small end of the conical surface is easy to damage.

Numerical simulation and analysis are respectively carried out on the three-dimensional flow field of the hydraulic control one-way valve formed by connecting two valve cores in parallel when the small valve core 2 is opened by 0.5mm and the large valve core 2 and the small valve core 2 are synchronously opened by 3 mm.

And (3) simulating a three-dimensional model of a flow field of the parallel small valve core 2 when the small valve core 2 of the hydraulic control one-way valve is opened by 0.5mm, performing solid modeling in Pro/E, storing the file as a step file, and then pouring the file into mesh processing software GAMBIT to divide the meshes, wherein the dividing steps are the same as the previous steps. And then, importing the grid file into FLUENT for flow field simulation, wherein the parameter setting is the same as that of the three-dimensional flow field simulation of the single small valve element 2.

Fig. 23 and 24 are speed and pressure distribution cloud charts when the parallel small valve cores 2 are opened by 0.3mm, and it can be known from the diagrams that the flow field pressure and speed distribution after the small valve cores 2 are connected in parallel are basically the same as the simulation result of a single valve core. Because the inlet is perpendicular to the reverse oil return opening when the hydraulic control one-way valve is installed on the upright post, the cavity formed by the valve sleeve and the valve body is enlarged.

Fig. 25 is an enlarged view of the velocity vector of the portion, and it can be known from the velocity analysis chart that most of the emulsion flows into the cavity at the initial stage of opening the small valve element 2, and only a small amount of fluid flows into the valve sleeve damping hole 7, so that the opening time of the small valve element 2 is prolonged, and it is important to adopt the valve sleeve optimization measure proposed in section 4.2.2.

And constructing a three-dimensional flow channel model of the parallel hydraulic control one-way valve when the large valve core 2 and the small valve core 2 are synchronously opened for 3mm, wherein the flow direction of the emulsion is as shown in the figure, and outputting a step file after the flow channel finishes solid modeling in Pro/E.

Fig. 26 and 27 are clouds illustrating velocity and pressure distributions of pilot operated check valves taken on a plane midway between two emulsion outlets 14 as an analysis plane, wherein the velocity and pressure distributions at the emulsion inlet 15 are inconsistent with their surroundings due to incomplete cross-sectional views. The speed distribution cloud chart shows that the emulsion mainly flows to two valve ports from the symmetric center of the hydraulic control one-way valve body, the flow rate of the valve port of the big valve core 1 is about 184m/s, and the flow rate of the valve port of the big valve core 1 is 518.8L/min; the flow rate of the emulsion at the valve port of the small valve core 2 is about 45m/s, the flow rate at the valve port of the small valve core 2 is 13.2L/min, and the total flow rate of the hydraulic control one-way valve is about 1064L/min.

The pressure distribution cloud picture shows that the pressure of one side through which the emulsion mainly flows is about 2MPa lower than that of the side through which the emulsion flows, the pressure difference between the two sides of the large valve core 1 and the valve sleeve causes that the two sides of the large valve core 1 and the valve sleeve receive radial pressure with different sizes, the pressure distribution is uneven, the phenomenon of eccentric clamping of the large valve core 1 or the valve sleeve is easily caused, the valve sleeve and the valve body, and the large valve core 1 and the valve sleeve are in clearance fit, and the phenomenon of clamping is difficult to recover, so that the hydraulic control one-way valve cannot be normally closed and breaks down. The hydraulic pressure which causes the valve core to be stuck is different from the hydraulic clamping force and is caused by uneven pressure distribution, so that the necessary protection measures are taken to prevent the valve core from being stuck, and the problem is very important. It is known from the mechanism of the generation of non-uniform radial hydraulic forces that to eliminate or reduce this radial imbalance force, the imbalance pressure on both sides of the large spool 1 and the valve housing must be eliminated, where the problem can be solved by using the emulsion inlet 15 to make the pressure changes on both sides of the spool and the valve housing uniform. In addition, cavitation is easily caused by negative pressure at the sharp corner of the large valve core 1 and the valve sleeve, which is not generated in the previous simulation.

As shown in fig. 28, when the emulsion flows through the large valve port of the valve core 1, the flow channel is narrowed to generate vortex 16, which causes energy loss and reduces the system pressure, and the phenomenon is not desirable, and disappears after the opening degree of the valve core is gradually increased. Therefore, the vibration of the valve core during the opening process of the hydraulic control one-way valve is avoided as much as possible, which not only damages the service life of the valve core, but also causes unnecessary energy loss. As shown in fig. 29, which is a cloud of pressure distribution on the pilot operated check valve sleeve, it can be seen that the emulsion mainly flows from the upper part of the valve sleeve into the port of the large spool 1, and therefore the upper part of the valve sleeve has a lower pressure and tends to push the valve sleeve upward. Furthermore, it can be seen from the figure that the pressure distribution at the emulsion inlet 15 on the valve housing is not uniform, and similar low pressures relative to its surroundings occur at the same positions at the three inlets on the upper part of the valve housing, indicating that these parts on the valve housing are vulnerable parts, which should be taken care of during the design. Fig. 30 is a cloud diagram of pressure distribution on the conical surface of the large valve core 1, and the pressure distribution is similar to the simulation result of the three-dimensional flow channel model of the single hydraulic control check valve when the large valve core 2 and the small valve core are synchronously opened by 3mm, and it can be known from the diagram that the pressure of the small end of the conical surface is large, which indicates that the small end surface of the large valve core 1 is easily damaged and should be strengthened during design.

In the embodiment, the flow fields of the small valve core 2 and the large valve core 1 are analyzed by performing numerical simulation on the internal flow field of the hydraulic control one-way valve. Analysis shows that when the hydraulic control one-way valve is completely opened, radial pressure imbalance exists between the large valve core 1 and the valve sleeve, and the large valve core 1 and the valve sleeve are easily clamped eccentrically; when the small valve element 2 is opened in the early stage, emulsion enters the valve body from the reverse oil inlet and then acts on a cavity formed by the valve sleeve and the valve body, so that the opening time of the small valve element 2 is delayed, and the sensitivity of the hydraulic control one-way valve is reduced; through analyzing the pressure distribution cloud chart on the valve sleeve, the part of the valve sleeve where the emulsion through-flow port is easy to damage is found out. And finally, providing a structure optimization scheme aiming at the problems of the hydraulic control one-way valve in analysis.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.