Translo-rotating Valve Actuation for Reciprocating Compressor Sealing
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Solution Overview
Problem
Rotary valves have not been used in the oil and gas industry due to unreliable seals and high friction forces when actuating the rotor, which leads to inefficiencies in reciprocating compressors.
Innovation Solution
The implementation of translo-rotating valves that first translate axially away from the stator and then rotate to overlap the rotor opening with the stator opening in the fluid flow direction, utilizing an actuation mechanism with an outer and inner shaft to minimize friction and ensure sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional rotary valve rotates the rotor directly around the shaft, then the valve can switch between open and close states, but high friction forces occur due to system pressure pushing the rotor towards the stator and large friction surface
Solution Approach 1:
The patent introduces an axial translation dimension in addition to the rotational movement. The rotor first translates axially away from the stator before rotating, converting a purely rotational motion into a combined axial-rotational motion. This dimensional change reduces the friction surface area during actuation, thereby lowering friction forces while maintaining valve functionality.
2Productivity
If automatic valves are used in reciprocating compressors, then the valves switch between close and open states due to differential pressure, but clearance volume increases reducing compressor efficiency
Solution Approach 1:
The patent replaces the automatic pressure-driven valve mechanism with an actuated rotary valve system. This substitution allows for more precise control of the valve openings and reduces the clearance volume between the rotor and stator, thereby improving compressor efficiency by enabling more complete evacuation of compressed fluid.
3Productivity
If rotary valves are used to reduce clearance volume, then compressor efficiency improves, but reliable sealing between stator and rotor cannot be achieved
Solution Approach 1:
The patent performs the axial translation of the rotor away from the stator before the rotational movement occurs. This preliminary action creates a gap that prevents friction and wear during rotation, while the sealing function is maintained through the controlled positioning and overlap of the rotor and stator openings during the rotation phase, thus achieving both reduced clearance volume and reliable sealing.
Data Source
Figure 1
Figure 2A~2B
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AI summary
Actuated rotary valves for reciprocating compressors used in oil and gas industry and related methods are provided. A rotary valve 300 has a stator 310 with a stator opening 315, a rotor 320 with a rotor opening 325 and an actuation mechanism. The actuation mechanism 340 is configured to receive a rotation motion and to actuate the rotor to perform first an axial translation moving away from the stator and then a rotation. The actuation mechanism includes an outer shaft configured to receive the rotation motion, and an inner shaft inside the outer shaft and configured to rotate the rotor. The outer shaft is configured to rotate a predetermined angular displacement while pushing the rotor away from the stator before engaging the inner shaft to rotate together with the rotor.