CN103225698B - Equal-displacement constant-pressure control method and equal-displacement constant-pressure valve - Google Patents
Equal-displacement constant-pressure control method and equal-displacement constant-pressure valve Download PDFInfo
- Publication number
- CN103225698B CN103225698B CN201310112247.8A CN201310112247A CN103225698B CN 103225698 B CN103225698 B CN 103225698B CN 201310112247 A CN201310112247 A CN 201310112247A CN 103225698 B CN103225698 B CN 103225698B
- Authority
- CN
- China
- Prior art keywords
- valve
- fluid
- inlet
- pressure
- sealing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 65
- 238000006073 displacement reaction Methods 0.000 title claims abstract description 53
- 239000012530 fluid Substances 0.000 claims abstract description 157
- 238000007789 sealing Methods 0.000 claims abstract description 97
- 230000008569 process Effects 0.000 claims abstract description 37
- 210000004907 gland Anatomy 0.000 claims description 12
- 230000000149 penetrating effect Effects 0.000 claims description 3
- 238000002474 experimental method Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 6
- 238000003825 pressing Methods 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 238000011161 development Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000001066 destructive effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000010779 crude oil Substances 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 238000011549 displacement method Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Landscapes
- Lift Valve (AREA)
Abstract
The invention relates to an equal-displacement constant-pressure control method and an equal-displacement constant-pressure valve, wherein the valve is provided with a valve body, a hollow part of the valve body forms a valve rod channel, a valve rod can movably penetrate through the valve rod channel, two sealing devices capable of sealing the valve rod channel are arranged on the valve rod, a sealing area is formed between the two sealing devices, and a fluid outlet can be sealed in the sealing area; two branch inlets are formed in the side wall of the valve body along the length direction of the valve rod, the branch inlets are communicated with the inlet flow channel, and the branch inlets and the fluid inlets are respectively located on two sides of the fluid outlet. In the displacement process of the valve rod of the valve, the fluid on one side to be compressed can be supplemented to the release space on the other side, so that the total volume of the fluid is unchanged in the space of the valve flow channel, the pressure of a closed system is kept constant in the opening and closing process of the valve, and the pressure fluctuation phenomenon of the conventional valve in the opening and closing process is eliminated; the method is suitable for the switch control of a closed system with small fluid volume.
Description
Technical Field
The invention relates to an equal-displacement constant-pressure control method capable of eliminating pressure fluctuation phenomenon of a valve in the opening and closing process and an equal-displacement constant-pressure valve, belonging to the technical field of oil and gas field development experiments.
Background
The valve is widely applied in various industry fields and has various types. In oil and gas field development experiments, 3mm needle valves or ball valves are largely used in low-flow experiment flows, and the device is characterized by simple control and high pressure resistance; the pressure resistance of the ball valve is less than 15MPa, and the pressure resistance of the needle valve can be not less than 100 MPa.
The pore volume of the microscopic physical model is very small and is between 0.01 mu L and 1 mL. In the microscopic physical simulation experiment, the two sides of the microscopic model are required to be provided with the switch valves to control the fluid to enter and exit, and in order to obtain the high-quality experiment effect, the smaller the fluid volume in the valve control range, the better. Typically, the volume of fluid in this range can be controlled to be within 0.2 ml. In the conventional oil and gas field development experiments such as core displacement, the volume of fluid in the model is far more than 1ml, the influence of pressure fluctuation caused by the opening and closing process of a valve on the experiment process can be completely ignored, but the influence on the micro model is not negligible. Taking the ground crude oil as an example, the compression coefficient is 4-7 x 10-4MPa-1When the needle point of the 3mm valve descends for 1mm, the pressure increase of about 3MPa can be caused in 0.2ml of closed fluid, and the micro model made of glass is easy to crack.
There are two methods to avoid this phenomenon: firstly, the valve is very weak in opening degree (namely, the distance for the needle point of the valve to descend when the valve is closed is very small); secondly, the volume of the closed fluid is increased. Clearly, both methods suffer from a number of disadvantages. For example, one method requires that the fluid be single phase, for example, the fluid passing through the foam will change the volume of the gas phase in the foam, which will make the simulation process for this type of fluid much more true; and the weak degree of opening of the valve is difficult to control, so that the too weak degree causes overlarge flow resistance at the needle point inlet, and the misleading of experimental operation is easy. If the second method is applied in the displacement process, the situation that the driving fluid cannot enter the observation range at a later time occurs, and if the driving fluid and the fluid in the model have interaction, the overlong time to be observed already delays the observation, so that the error in recognizing the experimental phenomenon is large.
In view of the defects of the known technology, the inventor develops the constant pressure control method by using equal displacement to eliminate the pressure fluctuation phenomenon of the valve during the opening and closing process and the constant pressure valve with equal displacement according to the production design experience of the field and the related field for many years.
Disclosure of Invention
The invention aims to provide an equal-displacement constant-pressure control method and an equal-displacement constant-pressure valve capable of eliminating pressure fluctuation in the valve opening and closing process.
Therefore, in the constant pressure control method with equal displacement, in the displacement process of the valve rod of the valve, fluid on one side to be compressed can be supplemented to the other side to release the space, so that the total volume of the fluid is unchanged in the space of the valve flow passage, and the pressure of a closed system is kept constant in the opening and closing process of the valve.
The method for controlling constant pressure with equal displacement as described above, wherein a branch inlet communicated with the fluid inlet is provided on the valve stem passage, and the branch inlet and the fluid inlet are respectively located at both sides of the fluid outlet, so that the fluid at one side compressed can be supplemented into the space released at the other side through the branch inlet or the fluid inlet during the movement of the valve stem.
The method for controlling constant pressure with equal displacement as described above, wherein two sealing devices are disposed on the valve rod, a closed space is formed between the two sealing devices, when the valve rod is moved and the two sealing devices move to the fluid outlet, two sides of the fluid outlet can be closed, so that two relatively independent pressure spaces are formed between the fluid outlet, the closed space formed between the two sealing devices and the external flow channels of the two sealing devices, and the pressure in the two pressure spaces is always kept constant during the movement of the valve rod.
The method of the same-displacement constant-pressure control as described above, wherein the two sealing means are located between the fluid inlet and the branch inlet when the two sealing means are located on both sides of the fluid outlet, respectively.
The equal-displacement constant-pressure control method as described above, wherein an angular velocity at which the valve stem moves is 90 °/s or less.
The invention also provides an equal-displacement constant-pressure valve which is provided with a hollow valve body, wherein a valve rod channel is formed in the hollow part of the valve body, a valve rod can be movably arranged in the valve rod channel in a penetrating way, the valve rod channel is respectively communicated with a fluid inlet and a fluid outlet, and the fluid inlet and the fluid outlet are respectively communicated with the outside of the valve body through an inlet flow channel and an outlet flow channel; two ends of the valve body are sealed through an upper gland and a lower gland, wherein two sealing devices capable of sealing a valve rod channel are arranged on the valve rod, a sealing area is formed between the two sealing devices, and the fluid outlet can be sealed in the sealing area; the side wall of the valve body is provided with two branch inlets along the length direction of the valve rod, the branch inlets are communicated with the inlet flow channel, and the branch inlets and the fluid inlet are respectively positioned at two sides of the fluid outlet.
The equal-displacement constant-pressure valve is characterized in that the distance between the branch inlet close to the fluid inlet and the fluid outlet is greater than or equal to the distance between the two sealing devices.
The equal-displacement constant-pressure control valve is characterized in that two grooves are formed in the valve rod, and a sealing ring is embedded in each groove to form the sealing device.
The equal-displacement constant-pressure valve as described above, wherein the distance between the two grooves is equal to or less than the distance between the branch inlet near the fluid inlet and the fluid outlet.
The equal displacement constant pressure valve as described above, wherein the fluid inlet, the fluid outlet, the branch inlet, and the inlet and outlet flow channels have a diameter of about 0.5mm to about 1.0 mm.
The equal displacement constant pressure valve as described above, wherein the width of the sealing means is smaller than the diameter of the inlet and outlet flow passages.
Compared with the prior art, the invention has the following characteristics and advantages:
by utilizing the equal-displacement constant-pressure control method and the constant-pressure valve, the branch inlet communicated with the fluid inlet is arranged, and the fluid on one compressed side can be supplemented to the release space on the other side in the movement process of the valve rod, so that the total volume of the fluid is unchanged in the closed space of the valve, the constant pressure in the closed system in the opening and closing process of the valve is kept, and the pressure fluctuation phenomenon of the conventional valve in the opening and closing process is eliminated; the method is suitable for the switch control of a closed system with small fluid volume.
Drawings
The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein,
FIG. 1 is a schematic diagram of an equal displacement constant pressure valve of the present invention;
FIG. 2 is a schematic view of the valve body structure of the constant pressure valve with equal displacement of the present invention;
FIG. 3 is a schematic view of the valve stem structure of the constant pressure valve with equal displacement of the present invention;
FIG. 4 is a schematic diagram of the closed space state of the valve body when the constant-pressure valve with equal displacement of the invention is opened;
FIG. 5 is a schematic view of the state of the enclosed space of the valve body when the constant-pressure valve with equal displacement according to the present invention is closed;
FIG. 6 is a schematic diagram of a valve test configuration;
FIG. 7 is a graph comparing the test results for an equal displacement constant pressure valve of the present invention with a known valve.
The reference numbers illustrate:
1. handle 2, hollow plug 3, upper gland 400 and valve
4. Valve body 40, stem passages 41, 42, branch inlet 43, flow passage
44. Inlet flow passage 45, fluid inlet 46, fluid outlet 48, outlet flow passage
5. 6, sealing device 560, sealing area 7, valve stem 70, external screw rod
71. 72, groove 8, gasket 9, O-shaped sealing ring 10 and plug
11. Lower gland 12, outer model 13, micro model 14, pressure sensor
15. Pump and method of operating the same
Detailed Description
The invention provides an equal-displacement constant-pressure control method, which is characterized in that in the displacement process of a valve rod of a valve, fluid on one side to be compressed can be supplemented to the other side to release a space, so that the total volume of the fluid is unchanged in the space of a valve flow passage, and the pressure of a closed system (the closed system refers to a micro model connected with the valve or a micro physical model in the background technology) is kept constant in the opening and closing process of the valve.
Furthermore, a branch inlet communicated with the fluid inlet is arranged on the valve rod channel, and the branch inlet and the fluid inlet are respectively positioned at two sides of the fluid outlet, so that the fluid at one side compressed by the valve rod can be supplemented into the space at the other side released by the branch inlet or the fluid inlet during the movement of the valve rod.
One feasible technical scheme is that two sealing devices are arranged on the valve rod, a sealing area is formed between the two sealing devices, when the valve rod and the two sealing devices are moved to the fluid outlet, two sides of the fluid outlet can be sealed, so that the sealing area formed between the fluid outlet and the two sealing devices and an external flow channel of the two sealing devices form two relatively independent pressure spaces, and in the movement process of the valve rod, the pressures in the two pressure spaces are always kept constant.
Wherein, when the two sealing devices are respectively positioned at two sides of the fluid outlet, the two sealing devices are positioned between the fluid inlet and the branch inlet.
The invention also provides an equal-displacement constant-pressure valve, which is provided with a hollow valve body, wherein a hollow part of the valve body forms a valve rod channel, a valve rod can be movably arranged in the valve rod channel in a penetrating way, the valve rod channel is respectively communicated with a fluid inlet and a fluid outlet, and the fluid inlet and the fluid outlet are respectively communicated with the outside of the valve body through an inlet flow channel and an outlet flow channel; the two ends of the valve body are sealed by an upper gland and a lower gland, and the valve is characterized in that two sealing devices capable of sealing a valve rod passage are arranged on the valve rod, a sealing area is formed between the two sealing devices, and the sealing area can seal the fluid outlet; the side wall of the valve body is provided with two branch inlets along the length direction of the valve rod, the branch inlets are communicated with the inlet flow channel, and the branch inlets and the fluid inlet are respectively positioned at two sides of the fluid outlet.
The invention adopts the equal displacement method in the closed space, so that the valve rod can keep the total volume of the fluid in the valve flow passage unchanged in the moving process, thereby eliminating the pressure fluctuation phenomenon of the conventional valve in the opening and closing process, namely, in the process of closing the valve after the injection pressure of the valve is opened to ensure that the pressure in the micro model reaches the design pressure, the pressure difference fluctuation is not generated in the micro model, therefore, the invention is particularly suitable for the on-off control of a closed system with tiny fluid volume.
In order to clearly understand the technical features, objects and effects of the present invention, the following detailed description will be given of specific embodiments, structures, features and effects of the constant pressure control method and the constant pressure valve with equal displacement according to the present invention with reference to the accompanying drawings and preferred embodiments. Furthermore, while the present invention has been described in connection with the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications, alternative constructions, and arrangements included within the scope of the appended claims.
As shown in fig. 1, 2 and 3, the constant pressure valve with equal displacement according to the present invention has a hollow valve body 4, the hollow portion of the valve body 4 forms a valve rod passage 40, a valve rod 7 is movably disposed in the valve rod passage 40, the valve rod passage 40 is respectively communicated with a fluid inlet 45 and a fluid outlet 46, and the fluid inlet 45 and the fluid outlet 46 are respectively communicated with the outside of the valve body through an inlet flow passage 44 and an outlet flow passage 48. The two ends of the valve body 4 are sealed by an upper gland 3 and a lower gland 11, wherein the valve rod 4 is provided with two sealing devices 5 and 6 capable of sealing the valve rod passage 40, a sealing space 560 is formed between the two sealing devices 5 and 6, and the sealing space 560 can seal the fluid outlet 46. The side wall of the valve body 4 is provided with two branch inlets 41, 42 along the length direction of the valve stem, the branch inlets 41, 42 are communicated with an inlet flow passage 44, and the branch inlets 41, 42 and a fluid inlet 45 are respectively positioned at two sides of a fluid outlet 46.
Wherein the distance L2 between the branch inlet 42 and the fluid outlet 46 near the fluid inlet 45 is greater than or equal to the distance between the two sealing devices 5, 6.
In a specific embodiment, two grooves 71, 72 are provided on the valve stem 7, and a sealing ring is embedded in each groove 71, 72 to form the sealing devices 5, 6.
Further, the distance L1 between the two grooves 71, 72 is equal to or less than the distance between the branch inlet 42 near the fluid inlet 45 and the fluid outlet 46. Thereby ensuring that when the two sealing means 5, 6 of the valve stem 7 are respectively located on both sides of said fluid outlet 46 to close the fluid outlet 46 (not in communication with the fluid inlet 45), the sealing means 5, 6 are both located on the lower portion of the branch inlet 42 closest to the fluid outlet 46 and on the upper portion of the fluid inlet 45, see fig. 1 and 5 in combination.
In addition, the diameters of the fluid inlet 45, fluid outlet 46, branch inlets 41, 42, and inlet and outlet flow passages 44, 48 are as small as possible, and may be about 0.5mm to about 1.0 mm.
The specific structure of the constant pressure valve with equal displacement of the invention is described as a specific example with reference to fig. 1 to 3. As shown in the figure, the valve is composed of a valve body 4, a valve rod 7, sealing rings arranged at two ends of the valve body 4 and used for sealing the valve, sealing devices 5 and 6 arranged on the valve rod 7 and used for opening or closing the valve, an upper press cover 3, a lower press cover 11 and the like, and the main components and functions are as follows:
the valve body 4 has an inlet flow passage 44, an outlet flow passage 48 and a stem passage 40 therein, and the ends of the inlet flow passage 44, the outlet flow passage 48 and the stem passage 40 all have standard internal threaded interfaces. The inlet flow passage 44 is a passage after the fluid enters the valve, the inlet flow passage 44 is communicated with the valve rod passage 40 through the fluid inlet 45 and the branch inlets 41 and 42, when the valve is opened or closed, the fluid in the valve rod passage 40 can flow in the inlet flow passage through the branch inlets 41 and 42, and the total volume of the fluid is ensured to be constant in the closed space of the valve body 4. The lower branch inlet 42 of the inlet flow passage 44 is spaced apart from the outlet flow passage 48 by a distance L2. The inlet flow passage 44, the branch inlets 41, 42 and the outlet flow passage 48 communicating with the stem passageway 40 have diameters of about 0.5mm to about 1.0mm under the conditions satisfying the experiments. By reducing the diameters of the fluid inlet 45, the fluid outlet 46, the branch inlets 41 and 42, the inlet flow passage 44 and the outlet flow passage 48 as much as possible, the moving resistance of the valve rod 7 is relatively small, the valve is controlled conveniently, the fluid in the passages is reduced to enter the micro model, and the research accuracy of the micro model is improved. The inner wall of the stem passageway 40 needs to be smooth to reduce resistance to movement of the valve stem 7.
The valve rod 7 is provided with two grooves 71 and 72, the distance between the two grooves 71 and 72 is L1, and in the illustrated embodiment, L1 is L2. The upper portion of the valve stem 7 is externally threaded to form an external screw rod 70, and the valve stem 7 is moved up and down relative to the valve body 4 by the rotation of the external screw rod 70. The valve stem 7 forms the seals 5, 6 by means of sealing rings embedded in the grooves 71, 72, the seals 5, 6 being held in close contact with the stem passageway 40 and ensuring that the fluid in the enclosed space 560 formed between the two seals 5, 6 is isolated from the upper and lower parts of the stem passageway 40.
The two ends of the valve body 4 are provided with pressing covers, namely an upper pressing cover 3 and a lower pressing cover 11 shown in the figure, and the upper pressing cover 3 and the lower pressing cover 11 respectively seal the valve rod 7 through matching with gaskets 8 and O-shaped sealing rings 9 arranged in accommodating spaces 401 and 402 at the two ends of the valve body 4. The inner parts of the upper and lower press covers 3 and 11 are provided with internal threads which are respectively matched with the hollow plug 2 and the plug 10. The hollow plug 2 is engaged with the outer screw 70 of the valve stem 7, and the valve stem 7 is rotated and linearly moved up and down. The plug 10 is at a certain distance from the bottom end of the valve rod 7, so that the bottom of the valve rod can be kept not to contact with the plug 10 all the time in the moving process of the valve rod 7. The above-mentioned upper and lower gland 3, 11 and gland that set up at both ends of the valve block 4 and the seal between valve block 4, valve stem 7, and the valve stem 7 realize moving up and down through the cooperation of external screw 70 and hollow plug 10 belong to the prior art, and will not be described here again.
The method, the operation principle and the operation process of the constant pressure valve with equal displacement according to the present invention will be further described in detail with reference to the accompanying drawings.
From the knowledge of fluid mechanics: in the closed space, under the condition of unchanging fluid volume, objects in the fluid are moved, and the pressure of the closed system cannot be changed.
In the opening process of the conventional valve, the closed space is increased in certain volume due to the lifting of the valve rod, and the pressure in the system is reduced to a certain degree; on the contrary, when the valve is closed, the valve rod moves downwards to reduce the volume of the closed space to reduce the pressure of the system. When the closed volume is larger, the pressure fluctuation is very weak and can be ignored; however, in a space with a small sealed volume such as a micro model, the pressure fluctuation amplitude caused by the operation is large, and the pressure increase is shown in table 1.
TABLE 1 pressure increase during valve closure
The pressure increases in table 1 are destructive to the microscopic glass model due to the slight change in the fluid in the enclosed space as the valve needle is lowered.
In order to overcome the defects of the known valve, particularly destructive influence on microscopic glass model tests, the invention provides an equal-displacement constant-pressure control method, in the displacement process of a valve rod of the valve, fluid on one compressed side can be supplemented to a release space on the other side, so that the total volume of the fluid is unchanged in the space of a valve flow passage, and the pressure of a closed system is kept constant in the opening and closing process of the valve.
One possible solution is to provide branch inlets 41 and 42 communicating with the fluid inlet 45 on the valve stem channel 40, and to locate the branch inlets 41 and 42 and the fluid inlet 45 on two sides of the fluid outlet 46, respectively, as shown in fig. 1 and 2, so that during the movement of the valve stem 7, the fluid on one side which is compressed can be supplemented into the space on the other side which is released through the branch inlets 41 and 42 or the fluid inlet 45. Referring to fig. 4, the fluid-tight space inside the valve body 4 is shown by the shaded portion in fig. 4, and it can be seen that, under the initial condition that the shaded portion has the same fluid pressure, the volume of the shaded portion is not changed in the process of moving the valve rod 7 and the two sealing devices 5 and 6 up and down, and the fluid pressure in the valve-body-tight space in the process of moving the valve rod 7 is constant.
Specifically, two sealing devices 5 and 6 composed of two sealing rings are arranged on the valve rod 7, a sealing area 560 is formed between the two sealing rings, when the valve rod 7 and the two sealing rings move to the fluid outlet 46, two sides of the fluid outlet 46 can be sealed, so that the sealing area formed between the fluid outlet 46 and the two sealing rings and an external flow channel of the two sealing rings form two relatively independent pressure spaces, and in the movement process of the valve rod 7, the pressures in the two pressure spaces are kept constant all the time.
When the two seal rings are located on both sides of the fluid outlet 46, the two seal rings are located between the fluid inlet 45 and the branch inlet 42.
Referring to fig. 4 and 5, in the enclosed space of the valve body, the constant pressure control process when the valve rod 7 moves up and down is expressed as follows, and the valve opening and closing process is expressed as follows:
first, assuming that the valve body 4 is in an initial state as shown in fig. 4, the fluid (hatched portion) is in the closed space of the valve body 4, and the fluid in the closed space of the valve body is in an isobaric state, P being a communication state between the inlet flow passage 44, the annulus formed between the valve stem 7 and the valve body passage 40, and the outlet flow passage 48, etc0；
Secondly, when the valve rod 7 descends to the state shown in the figure 5, the closed space of the valve body is divided into two parts (A and B); the downlink process is as follows:
a. the lower sealing device 6 of the valve rod 7 descends to the fluid outlet 46, and the upper sealing device 5 of the valve body 7 also descends to the lower branch inlet 42 due to L1 being equal to or less than L2, taking L1 being equal to L2 as an example; during the downward movement, the fluid between the two sealing devices 5 and 6 disposed on the valve rod 7 flows out along the lower branch inlet 42 to the flow passage 43 communicated with the inlet flow passage 44, while the fluid at the lower part of the sealing device 6 flows into the inlet flow passage 44 through the fluid inlet 45, and the fluid discharged from the valve body passage 40 enters the top space of the sealing device 5 at the upper part of the valve body through the inlet flow passage 44 and the flow passage 43 and the upper branch inlet 41. That is, since the fluid pushed out of the valve body passage 40 by the seal devices 5 and 6 is supplied to the space increased in the upper part of the valve body passage 40 through the upper branch inlet 41 during the downward movement of the valve stem 7, there is no pressure fluctuation and the pressure is constant at P during the downward movement of the valve stem 70；
b. The stage in which the sealing device 6 of the lower part of the valve stem 7 descends through the fluid outlet 46 (the upper sealing device 5 also passes through the lower branch inlet 42); the sealing rings of the initial sealing devices 5 and 6 are slightly expanded elastically at the fluid inlet 42 and the fluid outlet 46, the sealing ring of the lower sealing device 6 slightly presses the fluid (micro-model) in the outlet flow passage 48, the sealing ring of the upper sealing device 5 slightly presses the fluid in the flow passage 43 communicated with the lower branch inlet 42, and when the width of the sealing ring of the sealing devices 5 and 6 is smaller than the diameter of each passage and flow passage, the fluctuation is reduced to a large extent by moving the valve rod 7 slowly, so that the influence on the fluid is negligible; c. the lower sealing means 6 of the valve stem 7 is in the phase of moving downwards towards the fluid outlet 46 (the upper sealing means 5 moves between the lower branch inlet 42 and the fluid outlet 46); because of the equidistant movement (or L1 ≦ L2), A, B in FIG. 5 has two spaces that are relatively independent, forming a constant pressure system in each space.
Because the constant pressure state is maintained in the steps a, b and c, the pressure in the valve body is kept stable in the closing process of the valve rod.
And similarly, when the valve rod 7 moves upwards, the whole system still keeps the pressure unchanged.
In the opening and closing process of the valve, the outer screw rod 70 of the valve rod 7 is matched with the hollow plug 2 by rotating the valve rod 7, so that the valve rod 7 can linearly move up and down. The angular velocity of the rotary valve stem 7 is usually controlled to 90 deg./s or less, thereby effectively reducing the pressure fluctuation at the time of opening and closing the valve.
The method and the valve are applied to the sand-packed micro model and are tested. The valve 400 is installed outside the outer mold 12 and protected by the ring pressure inside the outer mold 12. The pore volume in micromodel 13 was 0.1mL and the total volume of the tubing connected to the micromodel was 0.3 mL. The ring pressure is 5MPa, the initial pressure in the micro model is 1MPa, the pressure is provided by a quizix micro pump 15, and the pressure change is monitored; the fluid in the quizix micro pump was 9 mL. Test flow the hatched portion is the flow path and the valve 400 position is replaced by the equal displacement constant pressure valve of the present invention and a conventional needle valve, respectively, as shown in fig. 6. Compare the pressure change of the constant pressure valve with the constant displacement of the present invention and the conventional needle valve, see fig. 7. The pressure sensor 14 responds by sensing the pressure on the left side of the valve, which cannot be measured directly and is calculated from the fluid compressibility. The test structure shown in fig. 6 is conventional and will not be described herein.
The test result shows that the pressure fluctuation caused by the conventional needle valve is very large, and the glass model is easily damaged; in the constant pressure valve with the same displacement, the pressure is basically constant in the opening and closing processes.
The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention should be considered within the scope of the invention. It should be noted that the components of the present invention are not limited to the above-mentioned whole application, and various technical features described in the present specification can be selected to be used alone or in combination according to actual needs, so that the present invention naturally covers other combinations and specific applications related to the invention.
Claims (11)
1. In the process of valve rod displacement of the valve, fluid on one side to be compressed can be supplemented to the other side to release space, so that the total volume of the fluid is constant in the space of a valve flow passage, and the pressure of a closed system is kept constant in the process of opening and closing the valve.
2. The method of claim 1, wherein a branch inlet communicating with the fluid inlet is provided in the stem passage, and the branch inlet and the fluid inlet are respectively provided at both sides of the fluid outlet, so that the fluid compressed at one side can be supplemented into the space released at the other side through the branch inlet or the fluid inlet during the movement of the stem.
3. The method of claim 1, wherein the valve stem is provided with two sealing means, a sealing space is formed between the two sealing means, when the valve stem is moved to the fluid outlet, the two sealing means can seal both sides of the fluid outlet, so that the fluid outlet, the sealing space formed between the two sealing means and the flow passage outside the two sealing means form two relatively independent pressure spaces, and the pressure in the two pressure spaces is always kept constant during the movement of the valve stem.
4. The equal-displacement constant-pressure control method as claimed in claim 3, wherein the two sealing means are located between the fluid inlet and the branch inlet when the two sealing means are located on both sides of the fluid outlet, respectively.
5. The equal-displacement constant-pressure control method as claimed in any one of claims 1 to 4, wherein an angular velocity at which the valve stem is moved is 90 °/s or less.
6. An equal displacement constant pressure valve is provided with a hollow valve body, wherein the hollow part of the valve body forms a valve rod channel, a valve rod can be movably arranged in the valve rod channel in a penetrating way, the valve rod channel is respectively communicated with a fluid inlet and a fluid outlet, and the fluid inlet and the fluid outlet are respectively communicated with the outside of the valve body through an inlet flow channel and an outlet flow channel; the two ends of the valve body are sealed by an upper gland and a lower gland, and the valve is characterized in that two sealing devices capable of sealing a valve rod passage are arranged on the valve rod, a sealing area is formed between the two sealing devices, and the sealing area can seal the fluid outlet; the side wall of the valve body is provided with two branch inlets along the length direction of the valve rod, the branch inlets are communicated with the inlet flow channel, and the branch inlets and the fluid inlet are respectively positioned at two sides of the fluid outlet.
7. The constant pressure valve of claim 6, wherein a distance between a branch inlet near the fluid inlet and the fluid outlet is greater than or equal to a distance between two sealing devices.
8. The constant-pressure valve according to claim 6, wherein the valve stem has two grooves, and a sealing ring is embedded in each groove to form the sealing device.
9. An equal displacement constant pressure valve as claimed in claim 8, wherein the distance between two of said grooves is equal to or less than the distance between a branch inlet near said fluid inlet and said fluid outlet.
10. An equal displacement constant pressure valve as claimed in claim 6 wherein the fluid inlet, fluid outlet, branch inlet and outlet flow passages have a diameter of 0.5mm to 1.0 mm.
11. An equal displacement constant pressure valve as claimed in claim 6, wherein the width of the sealing means is less than the diameter of the inlet and outlet flow passages.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310112247.8A CN103225698B (en) | 2013-04-02 | 2013-04-02 | Equal-displacement constant-pressure control method and equal-displacement constant-pressure valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310112247.8A CN103225698B (en) | 2013-04-02 | 2013-04-02 | Equal-displacement constant-pressure control method and equal-displacement constant-pressure valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103225698A CN103225698A (en) | 2013-07-31 |
| CN103225698B true CN103225698B (en) | 2015-07-08 |
Family
ID=48836263
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310112247.8A Active CN103225698B (en) | 2013-04-02 | 2013-04-02 | Equal-displacement constant-pressure control method and equal-displacement constant-pressure valve |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103225698B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110501256A (en) * | 2019-09-09 | 2019-11-26 | 中国矿业大学(北京) | A kind of gas level pressure test device for desorption and method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1605785A (en) * | 2004-10-26 | 2005-04-13 | 大众阀门有限公司 | Two speed hydraulic cylinder for valve |
| CN101625043A (en) * | 2009-08-13 | 2010-01-13 | 凯迈（洛阳）气源有限公司 | High-pressure reducing valve |
| CN102410266A (en) * | 2011-09-27 | 2012-04-11 | 浙江师范大学 | Method for realizing micro-displacement |
| CN203239964U (en) * | 2013-04-02 | 2013-10-16 | 中国石油天然气股份有限公司 | Constant pressure valve with equal displacement |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2803969B2 (en) * | 1993-05-20 | 1998-09-24 | 株式会社クボタ | Variable constant flow valve |
| JPH11230375A (en) * | 1998-02-18 | 1999-08-27 | Hitachi Constr Mach Co Ltd | Directional control valve having restoration circuit |
-
2013
- 2013-04-02 CN CN201310112247.8A patent/CN103225698B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1605785A (en) * | 2004-10-26 | 2005-04-13 | 大众阀门有限公司 | Two speed hydraulic cylinder for valve |
| CN101625043A (en) * | 2009-08-13 | 2010-01-13 | 凯迈（洛阳）气源有限公司 | High-pressure reducing valve |
| CN102410266A (en) * | 2011-09-27 | 2012-04-11 | 浙江师范大学 | Method for realizing micro-displacement |
| CN203239964U (en) * | 2013-04-02 | 2013-10-16 | 中国石油天然气股份有限公司 | Constant pressure valve with equal displacement |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103225698A (en) | 2013-07-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10294763B2 (en) | Bellows valve and an injection valve | |
| US10072682B2 (en) | Multi-chamber diaphragm actuator with synchronized supply system | |
| AU2015324684B2 (en) | Apparatus and method for providing a fluid sample in a well | |
| CN204901013U (en) | Actuator device and valve unit spare | |
| US10161232B2 (en) | Lift valve with bellow hydraulic protection and chatter reduction | |
| AU2014211349B2 (en) | Valve arrangement and method of operating the same | |
| BR102013023549A2 (en) | GAS LIFT VALVE WITH VARIOUS BELLS AND FLOATING CONSTANT FLUID CHAMBER | |
| RU2020104612A (en) | FLUID FLOW REGULATOR FOR APPLICATION WITH PNEUMATIC HYDRAULIC VALVES | |
| US9541104B2 (en) | Inertially stable actuator with telescoping supply port | |
| US10450833B2 (en) | Self-regulating flow control device | |
| CN103225698B (en) | Equal-displacement constant-pressure control method and equal-displacement constant-pressure valve | |
| CN203239964U (en) | Constant pressure valve with equal displacement | |
| IL280735B1 (en) | Fluid control device | |
| CN100480558C (en) | Movable vacuum apparatus | |
| CN202946714U (en) | Pneumatic diaphragm valve | |
| US20160145981A1 (en) | Gas lift valve assemblies and methods of assembling same | |
| CN212479749U (en) | High-temperature-resistant high-pressure-resistant bidirectional hydraulic control ultrahigh-pressure mixed fluid stop valve | |
| US20130276894A1 (en) | Seals | |
| AU2014235126A1 (en) | Deepset wireline retrievable safety valve | |
| RU155716U1 (en) | DEVICE FOR DRIVING PACKING EQUIPMENT | |
| CN201836429U (en) | Sleeve-type regulating valve | |
| JP4982802B2 (en) | Bellows valve for high temperature and pressure | |
| CN203836249U (en) | High-pressure balance-type regulating valve | |
| KR101609063B1 (en) | Valve wiht dynamic seal and stroke measurement method of valve with dynamic seal | |
| RU55417U1 (en) | SAFETY VALVE |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |