Full-range control type rotary cup exhaust valve for reciprocating compressor

Abstract

A kind of reciprocating compressor full-range control type rotary cup exhaust valve, including valve seat, valve core, valve rod and the like components, valve core and valve seat all adopt V cup type structure, valve core and valve rod adopt integrated structure, are controlled by rotary motion driving device full range, set the motion law of valve core, valve rod, execute acceleration, deceleration, waiting and brake and the like motion instruction, realize rotary valve opening and closing, rotary friction is small, sealing performance is good, long-term use wear can be automatically compensated, flow coefficient is big, resistance coefficient is small, the effective flow area of valve core and valve seat is more than 2 times of conventional plane-shaped meshed intake valve;The present application also has the characteristics of no impact, long stay time when fully open, overcome the essential defects of the prior art meshed exhaust valve, such as large resistance loss, valve piece impact is serious;The present application can be used for the modification of existing meshed exhaust valve, and can also be used as a complete set of exhaust valve for new reciprocating compressor.

Description

Technical Field

[0001] This invention belongs to the technical field of reciprocating piston compressors, and in particular relates to a structure for an exhaust valve of a reciprocating piston compressor. Background Technology

[0002] The compressor exhaust valve is one of the key components of a reciprocating compressor. Currently, the exhaust valve structure of existing compressors is a traditional automatic valve structure. The opening and closing of the exhaust valve relies entirely on the thrust of the discharged gas and its own elastic force. When the gas flows out of the valve during exhaust, when the thrust exceeds the elastic force, the valve plate is pushed open. When the piston approaches the exhaust dead point, the spring force forces the valve to close.

[0003] However, this automatic valve structure and self-driven method result in defects such as delayed opening, premature closing, and short full-opening time during actual operation. Moreover, the strong impact between the valve plate and the valve seat, the lift limiter, and the valve plate spring leads to a high failure rate and short service life of the exhaust valve.

[0004] In recent years, in order to solve the problem of the inability to adjust the air volume of compressors, stepless air volume regulation technology has emerged, among which the partial stroke top-opening intake valve technology is widely used.

[0005] However, the above technology only takes a delayed closing measure for the compressor intake valve and does not involve the exhaust valve. If the technology of partially opening the exhaust valve is adopted, it will lead to a significant reduction in the exhaust volume, causing the existing mesh exhaust valve to deviate seriously from the design conditions, making the exhaust valve plate unable to fully open and increasing the exhaust resistance loss. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a rotary cup-type exhaust valve for reciprocating compressors with full-process control, which features a large flow area, a large flow coefficient, low pressure loss, no impact on the valve core during switching, low rotational friction, fully controllable opening and closing times, and exhaust valve operation unaffected by changes in compressed gas volume.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a rotary cup-type exhaust valve for a reciprocating compressor with full-process control, comprising a valve seat, a valve core, a valve stem, and a rotary motion drive device, characterized in that: both the valve core and the valve seat adopt a V-cup structure, the valve core and the valve stem adopt an integral structure, the rotary motion drive device is connected to the valve stem, and the rotary motion drive device drives the valve stem and valve core to rotate outside the valve, controlling the valve core and valve seat to perform periodic opening and closing movements according to a preset program.

[0008] The valve seat and valve core are nested together, with the valve core located inside the valve seat. The valve stem passes through the center of the bottom of the valve seat. Multiple trapezoidal airflow channels are opened on the peripheral walls of both the valve seat and the valve core. When the valve is closed, the annular walls of the valve seat and the valve core are tightly pressed together, and a seal is achieved through the staggered airflow channels. When the valve is opened, there is a micro-gap between the annular walls of the valve seat and the valve core, and the airflow channels of the valve core and the valve seat are directly connected to each other.

[0009] The valve stem and valve core are driven by a rotary motion drive device outside the air valve to execute acceleration, deceleration, waiting and braking commands. The motion cycle and frequency of the rotary motion drive device, as well as the rotation angle, opening time, closing time and dwell time of the valve core, can be manually set by an external controller as needed.

[0010] The valve core and valve seat have the same cone angle, and the angle between the generatrix of the cone surface and the bottom surface is no greater than 80°. The valve core and valve seat are made of wear-resistant metal or non-metal.

[0011] The number of valve core airflow channels and valve seat airflow channels corresponds to the valve core rotation step. Each time the valve core rotates, the valve core airflow channel and the valve seat airflow channel achieve one connection or one staggered seal. As the valve core rotates gradually, the valve core airflow channel and the valve seat airflow channel alternately switch between connection and staggered seal.

[0012] The width between adjacent valve core airflow channels is 2-3 mm greater than the width of the valve core airflow channel; the width between adjacent valve seat airflow channels is 2-3 mm greater than the width of the valve seat airflow channel; the width and length of the outer end orifice of the valve core airflow channel are exactly the same as the width and length of the inner end orifice of the valve seat airflow channel.

[0013] The valve seat is fixedly pressed onto the valve mounting hole seat by a support seat. A support seat sealing gasket is installed between the pressing surfaces of the support seat and the valve mounting hole seat. The support seat adopts a cylindrical structure and the cylindrical wall is airtight. The bottom of the support seat is provided with multiple vent holes. When the valve is closed, the valve core and the valve seat together with the support seat isolate the air intake space from the cylinder space.

[0014] An upper reinforcing plate is provided on the upper surface of the bottom wall plate of the valve core, and a lower reinforcing plate is provided on the lower surface of the bottom wall plate of the valve core. The bottom wall plate of the valve core is sandwiched between the upper reinforcing plate and the lower reinforcing plate, and the upper reinforcing plate and the lower reinforcing plate are connected and fixed by fastening screws.

[0015] The external controller is a PLC, DCS, or other control device.

[0016] The rotary motion drive device adopts a rotary servo motor, a stepper motor, or an actuator with high acceleration, high deceleration, and position loop control functions.

[0017] The beneficial effects of this invention are:

[0018] The valve core and valve seat of this invention adopt an innovative V-cup structure. Compared with conventional planar mesh intake valves, the surface area and flow area are more than twice that of conventional planar mesh exhaust valves, and it has the characteristics of large flow coefficient and small resistance coefficient.

[0019] After the valve is opened, the airflow channel of the valve core and the airflow channel of the valve seat are directly connected, the effective flow area is further increased, and the gas flow rate is low. Since the pressure loss of the exhaust valve is proportional to the square of the gas flow rate in the valve gap, the pressure loss of the rotary cup exhaust valve of the present invention will be greatly reduced.

[0020] The valve core opening and closing actions of the present invention are directly driven by an external rotary motion drive device, which can realize acceleration, deceleration, waiting, braking and other movements. The valve core can achieve "zero speed landing" relative to the valve seat, ensuring that there is no impact when opening and closing the valve core and improving the service life of the air valve.

[0021] Since the valve core opening and closing actions of the present invention are directly driven by an external rotary motion drive device, the valve can be opened and closed according to an ideal motion law, overcoming the insurmountable drawbacks of existing mesh intake valves such as delayed opening and untimely closing, making the PV indicator diagram more ideal and having a good energy-saving effect.

[0022] The valve core movement of this invention is not driven or constrained by gas force and elastic force, which increases the residence time at the maximum opening position, reduces the average gas flow velocity, and further reduces pressure loss.

[0023] The rotary cup-shaped intake valve of the present invention has low friction loss during opening and closing. Since the contact surface between the valve core and the valve seat is coaxially conical, the sealing surface is automatically ground during rotation, and long-term wear can also achieve automatic repair and compensation.

[0024] This invention can be directly used to modify the mesh valve of an existing reciprocating compressor without changing the original installation conditions of the valve, and can also be used as a matching valve for a newly manufactured reciprocating compressor.

[0025] When the rotary cup-type intake valve of the present invention is continuously adjusted from 0 to 100% compression load, it always operates under the design conditions. Compared with the existing technology of continuously adjusting the air volume of the intake valve by partially opening the process, the energy loss of the exhaust valve can be greatly reduced. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the reciprocating compressor fully controlled rotary cup-type exhaust valve of the present invention (open valve state);

[0027] Figure 2 This is a schematic diagram of the reciprocating compressor fully controlled rotary cup-type exhaust valve of the present invention (valve closed state);

[0028] Figure 3 This is a schematic diagram of the reciprocating compressor fully controlled rotary cup-type exhaust valve of the present invention (valve mounting hole seat, valve cover, pressure valve cover, support seat and plug are not shown).

[0029] Figure 4 This is a side view of the valve core of the rotary cup-type exhaust valve for full-range control of the reciprocating compressor of the present invention;

[0030] Figure 5 This is a side view of the valve seat of the rotary cup-type exhaust valve for full-range control of the reciprocating compressor of the present invention;

[0031] Figure 6 This is a top view of the pressure valve cover of the rotary cup-type exhaust valve for the reciprocating compressor with full-process control according to the present invention;

[0032] Figure 7 This is a top view of the support base for the rotary cup-shaped exhaust valve with full-range control of the reciprocating compressor according to the present invention;

[0033] In the diagram, 1—valve mounting hole seat, 2—valve cover, 3—valve core, 4—valve seat, 5—valve stem, 6—pressure valve cover, 7—plug, 8—rotary motion drive device, 9—sliding sleeve, 10—support bracket sealing gasket, 11—bolt, 12—valve cover sealing gasket, 13—sealing ring, 14—sealing ring, 15—support seat, 16—valve seat sealing gasket, 17—pressure claw, 18—upper reinforcing plate, 19—lower reinforcing plate, 20—fastening screw, 21—vent hole, 22—valve core airflow channel, 23—valve seat airflow channel. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] like Figures 1-7As shown, a rotary cup-type exhaust valve for a reciprocating compressor with full-process control includes a valve cover 2, a valve core 3, a valve seat 4, a valve stem 5, a pressure valve cover 6, a plug 7, and a rotary motion drive device 8. Both the valve core 3 and the valve seat 4 adopt a V-cup structure. The valve core 3 is located on the upper part of the valve seat 4. The middle part of the valve stem 5 is fixedly connected to the center of the valve core 3, and the top end of the valve stem 5 extends to the outside of the valve cover 2. The power output end of the rotary motion drive device 8 is fixedly connected to the top end of the valve stem 5, and a sliding sleeve 9 is fitted onto the bottom end of the valve stem 5. The valve seat 4 is located below the valve core 3, and the valve seat 4 is fixedly pressed against the valve mounting hole seat 1 by a support seat 15. A support is installed between the support seat 15 and the pressing surface of the valve mounting hole seat 1. A valve seat sealing gasket 10 is installed between the pressing surfaces of the valve seat 4 and the support seat 15; the sliding sleeve 9 is fixedly installed at the center of the bottom of the support seat 15; the pressure valve cover 6 is fitted onto the valve stem 5, the pressure valve cover 6 is located above the valve seat 4, and the pressure valve cover 6 is fixedly pressed onto the valve seat 4; the threaded plug 7 is threadedly screwed onto the valve stem 5, the threaded plug 7 is located above the pressure valve cover 6, the threaded plug 7 is fixedly installed at the center of the valve cover 2, the valve cover 2 is fixedly installed on the air valve mounting hole seat 1 by bolts 11, a valve cover sealing gasket 12 is installed between the valve cover 2 and the air valve mounting hole seat 1; a sealing ring 13 is installed between the threaded plug 7 and the valve cover 2, and a sealing ring 14 is installed between the threaded plug 7 and the valve stem 5.

[0036] The valve core 3 and valve seat 4 have the same cone angle, and the angle between the generatrix of the cone surface and the bottom surface is generally no greater than 80° to prevent self-locking. The taper of the contact surface between the valve core 3 and valve seat 4 must be exactly the same. The wall thickness of the valve core 3 and valve seat 4 is designed according to the required strength and rigidity.

[0037] In the specific implementation process, the valve stem 5 and the valve core 3 can be manufactured separately and then combined to form an assembly. The connection method between the two can be welding or bonding. Alternatively, the valve stem 5 and the valve core 3 can be manufactured as an integral assembly. The top wall plates of the valve stem 5 and the valve core 3 are precisely perpendicular, and the axial center lines of the valve core 3 and the valve seat 4 are precisely coincident.

[0038] An upper reinforcing plate 18 is provided on the upper surface of the top wall plate of the valve core 3, and a lower reinforcing plate 19 is provided on the lower surface of the top wall plate of the valve core 3. The top wall plate of the valve core 3 is sandwiched between the upper reinforcing plate 18 and the lower reinforcing plate 19, and the upper reinforcing plate 18 and the lower reinforcing plate 19 are connected and fixed by fastening screws 20.

[0039] In the specific implementation process, the sliding sleeve 9 can be selected from graphite copper sleeve bearings, wear-resistant metal sleeves or non-metallic sleeves.

[0040] In the specific implementation process, the pressure valve cover 6 adopts a disc structure, and multiple pressure claws 17 are provided on the outer periphery of the pressure valve cover 6. The pressure claws 17 of the pressure valve cover 6 are directly pressed onto the valve seat 4.

[0041] In the specific implementation process, the support base 15 adopts a cylindrical structure, the cylindrical wall of the support base 15 is airtight, and the bottom of the support base 15 is provided with multiple ventilation holes 21.

[0042] A plurality of valve core airflow channels 22 are provided on the core body of the valve core 3. The plurality of valve core airflow channels 22 are all isosceles trapezoids and are distributed along the circumferential direction of the core body of the valve core 3.

[0043] In specific implementation, the number of valve core airflow channels 22 is 10, 12, 15 or 18.

[0044] In specific implementation, the technical formula for the width of the upper and lower edges of the isosceles trapezoidal valve core airflow channel 22 is as follows:

[0045]

[0046]

[0047] In the formula, a—width of the upper edge, b—width of the lower edge, D2—diameter of the bottom of the valve core, H—height of the valve core, h1—height of the upper edge from the top of the valve core, h2—height of the lower edge from the bottom of the valve core, α1—angle between the generatrix of the outer wall cone of the valve core and the bottom surface, N—number of airflow channels in the valve core, λ—slot-to-blind ratio (the ratio of the central angle of the upper edge to the central angle of the valve wall between adjacent airflow channels of the valve core, and the sum of the two central angles is 360° / N).

[0048] In the specific implementation process, the formula for calculating the total flow area of ​​the valve core airflow channel 22 on the valve core 3 is as follows:

[0049]

[0050] In the formula, Q is the total flow area, a is the width of the upper edge, b is the width of the lower edge, H is the valve core height, h1 is the height of the upper edge from the top of the valve core, h2 is the height of the lower edge from the bottom of the valve core, α1 is the angle between the generatrix of the outer wall cone surface and the bottom surface, and N is the number of airflow channels in the valve core.

[0051] A plurality of valve seat airflow channels 23 are provided on the seat body of the valve seat 4, and the number is the same as that of the valve core airflow channels 22. The plurality of valve seat airflow channels 23 are all isosceles trapezoids and are distributed along the circumferential direction of the seat body of the valve seat 4. The valve seat airflow channels 23 are directly opposite to all the valve core airflow channels 22 on the valve core 3.

[0052] In specific implementation, the width of the blind surface of the valve core 3 between adjacent valve core airflow channels 22 should be at least 2 mm greater than the width of the valve core airflow channel 22 to ensure that each valve core airflow channel 22 has a sealing edge of at least 1 mm on both sides. Similarly, the width of the blind surface of the valve seat 4 between adjacent valve seat airflow channels 23 should also be at least 2 mm greater than the width of the valve seat airflow channel 23 to ensure that each valve seat airflow channel 23 has a sealing edge of at least 1 mm on both sides. The fewer the number of valve core airflow channels 22 and valve seat airflow channels 23 designed, the larger the switching angle and flow area, but the higher the requirements for the dynamic characteristics of the rotary motion drive device 8 will be.

[0053] The number of valve core airflow channels 22 and valve seat airflow channels 23 corresponds to the rotation step of valve core 3. Each time valve core 3 rotates, valve core airflow channels 22 and valve seat airflow channels 23 achieve one connection or one staggered seal. As valve core 3 rotates gradually, valve core airflow channels 22 and valve seat airflow channels 23 alternately switch between connection and staggered seal.

[0054] The rotary motion drive device 8 adopts a rotary servo motor, stepper motor, or other rotary actuators with high acceleration, high deceleration, and position control functions.

[0055] In the specific implementation process, parameters such as motion cycle, frequency, rotation angle, opening time, closing time, and dwell time of rotary actuators such as rotary servo motors and stepper motors are set. When the rotary motion drive device 8 is used to control the action of the valve stem 5, the valve core 3 can be driven to perform actions such as acceleration, deceleration, waiting, and braking.

[0056] When the valve core airflow channel 22 of valve core 3 is completely misaligned with the valve seat airflow channel 23 of valve seat 4, the air valve is in the closed state; when the valve core airflow channel 22 of valve core 3 is completely connected with the valve seat airflow channel 23 of valve seat 4, the air valve is in the open state.

[0057] When the compressor reaches the required load, the rotary motion drive device 8 will receive the valve opening command and drive the valve stem 5 to move. The valve core airflow channel 22 of the valve core 3 and the valve seat airflow channel 23 of the valve seat 4 are fully connected. The exhaust valve is in the open state, and the compressor enters the exhaust process, realizing stepless adjustment of the compressor air volume.

[0058] In the specific implementation process, since the contact surfaces of valve core 3 and valve seat 4 have the same taper, when the valve is closed, valve core 3 is pressed tightly against valve seat 4, and the valve core airflow channel 22 of valve core 3 and the valve seat airflow channel 23 of valve seat 4 are completely offset and sealed to each other, so the exhaust valve is in a closed state. When the compression section in the cylinder just ends, the pressure difference between the gas inside and outside valve core 3 transitions from a negative value to a positive value. This is exactly the time for the exhaust valve to open. The rotary motion drive device 8 drives valve core 3 to start rotating. The starting friction is close to zero, and with the movement of the piston, the pressure difference between the gas inside and outside valve core 3 quickly becomes a positive value. Valve core 3 disengages from valve seat 4 and then rotates to the fully open position in a frictionless state.

[0059] As the piston approaches its outer dead center, the valve core 3, under the control of the rotary motion drive device 8, closes rapidly in a frictionless state, and the compressor enters the expansion stage, followed by the intake stage, compression stage, and the next exhaust stage.

[0060] The solutions described in the embodiments are not intended to limit the scope of patent protection of this invention. All equivalent implementations or modifications that do not depart from the scope of this invention are included in the patent scope of this case.

Claims

1. A rotary cup-type exhaust valve for a reciprocating compressor with full-process control, comprising a valve seat, a valve core, a valve stem, and a rotary motion drive device, characterized in that: Both the valve core and valve seat adopt a V-cup structure, and the valve core and valve stem adopt an integral structure. The rotary motion drive device is connected to the valve stem. The rotary motion drive device drives the valve stem and valve core to rotate outside the air valve, and controls the valve core and valve seat to perform periodic opening and closing movements according to a preset program. The valve seat and valve core are nested together, with the valve core located inside the valve seat. The valve stem passes through the center of the bottom of the valve seat. Multiple trapezoidal airflow channels are opened on the peripheral walls of both the valve seat and the valve core. When the valve is closed, the annular walls of the valve seat and the valve core are tightly pressed together, and a seal is achieved through the staggered airflow channels. When the valve is opened, there is a micro gap between the annular walls of the valve seat and the valve core, and the airflow channels of the valve core and the airflow channels of the valve seat are directly connected to each other. The valve core airflow channels are all isosceles trapezoids and are distributed along the circumference of the valve core body; the number of valve seat airflow channels is the same as that of the valve core airflow channels; the valve seat airflow channels are all isosceles trapezoids and are distributed along the circumference of the valve seat body, and the valve seat airflow channels are directly opposite the valve core airflow channels. The width 'a' of the upper edge of the valve core airflow channel satisfies: ； The width b of the lower edge of the valve core airflow channel satisfies: ； In the formula, D 2 The diameter of the valve core bottom is H Valve core height h 1 The height of the upper edge of the valve core channel from the top of the valve core. h 2 This refers to the height of the lower edge of the valve core channel from the bottom of the valve core. α 1 The angle between the generatrix of the conical surface of the valve core's outer wall and the bottom surface. N This refers to the number of airflow channels in the valve core. λ The slot blind ratio is specifically the ratio of the central angle corresponding to the upper edge to the central angle corresponding to the valve wall between the adjacent valve core airflow channels. The contact surfaces between the valve core and the valve seat have the same taper. When the compression section in the cylinder just ends, the pressure difference between the gas inside and outside the valve core transitions from negative to positive. This is the time for the exhaust valve to open. The valve core is driven by the rotary motion drive device to start rotating. The starting friction is close to zero. As the piston moves, the pressure difference between the inside and outside of the valve core quickly becomes positive. The valve core disengages from the valve seat and then rotates to the fully open position in a frictionless state. As the piston approaches outer dead center, the valve core, under the control of the rotary motion drive, closes rapidly in a frictionless state, and the compressor enters the expansion stage, followed by the intake stage, compression stage, and the next exhaust stage.

2. The rotary cup-shaped exhaust valve for full-process control of a reciprocating compressor according to claim 1, characterized in that: The valve stem and valve core are driven by a rotary motion drive device outside the air valve to execute acceleration, deceleration, waiting and braking commands. The motion cycle and frequency of the rotary motion drive device, as well as the rotation angle, opening time, closing time and dwell time of the valve core, can be manually set by an external controller as needed.

3. The rotary cup-shaped exhaust valve for full-process control of a reciprocating compressor according to claim 1, characterized in that: The valve core and valve seat have the same cone angle, and the angle between the generatrix of the cone surface and the bottom surface is no greater than 80°. The valve core and valve seat are made of wear-resistant metal or non-metal.

4. The rotary cup-shaped exhaust valve for full-process control of a reciprocating compressor according to claim 1, characterized in that: The number of valve core airflow channels and valve seat airflow channels corresponds to the valve core rotation step. Each time the valve core rotates, the valve core airflow channel and the valve seat airflow channel achieve one connection or one staggered seal. As the valve core rotates gradually, the valve core airflow channel and the valve seat airflow channel alternately switch between connection and staggered seal.

5. A rotary cup-shaped exhaust valve for full-process control of a reciprocating compressor according to claim 1, characterized in that: The width between adjacent valve core airflow channels is 2-3 mm greater than the width of the valve core airflow channel; the width between adjacent valve seat airflow channels is 2-3 mm greater than the width of the valve seat airflow channel; the width and length of the outer end orifice of the valve core airflow channel are exactly the same as the width and length of the inner end orifice of the valve seat airflow channel.

6. The rotary cup-shaped exhaust valve for full-process control of a reciprocating compressor according to claim 1, characterized in that: The valve seat is fixedly pressed onto the valve mounting hole seat by a support seat. A support seat sealing gasket is installed between the pressing surfaces of the support seat and the valve mounting hole seat. The support seat adopts a cylindrical structure and the cylindrical wall is airtight. The bottom of the support seat is provided with multiple vent holes. When the valve is closed, the valve core and the valve seat together with the support seat isolate the air intake space from the cylinder space.

7. A rotary cup-shaped exhaust valve for full-process control of a reciprocating compressor according to claim 1, characterized in that: An upper reinforcing plate is provided on the upper surface of the bottom wall plate of the valve core, and a lower reinforcing plate is provided on the lower surface of the bottom wall plate of the valve core. The bottom wall plate of the valve core is sandwiched between the upper reinforcing plate and the lower reinforcing plate, and the upper reinforcing plate and the lower reinforcing plate are connected and fixed by fastening screws.

8. A rotary cup-shaped exhaust valve for full-process control of a reciprocating compressor according to claim 2, characterized in that: The external controller is a PLC, DCS, or other control device.

9. A rotary cup-shaped exhaust valve for full-process control of a reciprocating compressor according to claim 1, characterized in that: The rotary motion drive device adopts a rotary servo motor, a stepper motor, or an actuator with high acceleration, high deceleration, and position loop control functions.

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