Three-Stage Reciprocating Compressor Shared Piston Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional three-stage compressors are unable to achieve a high enough compression ratio, as the first and second stages have almost equal suction and compression chamber volumes, limiting the pressure buildup and requiring multiple cylinders to achieve high pressures.
Innovation Solution
A three-stage reciprocating compressor design where the first and second stages share a piston and cylinder wall, with a third stage piston extending through the first stage cylinder head, separated by one-way valves, allowing for sequential compression and increased pressure through a common acting piston with separate cylinder heads and a smaller diameter third stage cylinder tube.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional three-stage compressors use equal volume suction and compression chambers for first and second stages, then the structure is simple, but the compression ratio is insufficient and high pressure cannot be achieved
Solution Approach 1:
The patent applies local quality by creating different chamber volumes at different locations within the same cylinder. The first stage suction chamber (27) has a larger volume than the second stage suction chamber (28), achieved by positioning the first stage inlet (24) and outlet (24b) to create an asymmetric chamber configuration. This local volume differentiation enables each stage to have optimized compression ratios while maintaining a single cylinder structure.
2Stress or pressure
If multiple cylinders are used to achieve high pressure, then the compression ratio is sufficient, but the device complexity and number of components increase
Solution Approach 1:
The patent merges three compression stages into a single cylinder by using a common piston (1) that simultaneously forms part of the first stage piston assembly and the second stage piston assembly. The first and second stage suction and compression chambers (27, 28) share the same cylinder wall and piston structure, eliminating the need for separate cylinders while achieving the required compression ratios for high pressure output.
Solution Approach 2:
The patent implements a nested configuration where the second stage compression chamber (28) is effectively nested within the first stage cylinder assembly. The common piston (1) creates overlapping chamber configurations, with the third stage piston (7) extending through the first stage cylinder head (3) into a third stage cylinder tube (8). This nested arrangement allows three compression stages to occupy a compact single-cylinder space.
3Device complexity
If a common piston is used for first and second stages, then the device complexity is reduced, but the suction volume control for pressure buildup becomes limited
Solution Approach 1:
The patent applies local quality by creating different chamber volumes at different locations within the same cylinder. The first stage suction chamber (27) has a larger volume than the second stage suction chamber (28), achieved by positioning the first stage inlet (24) and outlet (24b) to create an asymmetric chamber configuration. This local volume differentiation enables each stage to have optimized compression ratios while maintaining a single cylinder structure.
Solution Approach 2:
The patent employs dynamic volume control through the movement of the common piston (1) and the third stage piston (7). The third stage piston (7) extends through the first stage cylinder head (3) and can independently adjust the volume of the third stage compression chamber (29). This dynamic adjustment capability allows optimization of pressure buildup efficiency at each stage during the compression cycle, overcoming the limitations of fixed-volume common piston designs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enables a compression ratio of 1:3 or more, allowing for efficient high-pressure gas compression in a single unit, reducing the need for multiple cylinders and enabling effective CO2 regeneration in applications like breweries without using CFC or ammonia refrigeration systems.
Implementation Method 1
each stage fluidly separated by one or more one way valves
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The disclosure relates to a three-stage reciprocating compressor (30) comprising pistons (1, 7) and suction and compression chambers (27, 28, 29) in which a medium is compressed for each separate stage, which stages are connected in series and where a first stage is fluidly connected to an inlet (24) for inlet of uncompressed or pre-compressed gas where the three-stage pistons (1, 7) move synchronously along a common axis in one connected unit such that the first and second stage suction and compression chambers (27, 28) share piston (1) as well as cylinder wall (2), and having separate cylinder heads (3, 4), a top headpiece (3) and a bottom headpiece (4) on each side of the piston (1), the third stage piston (7) extending from a center of the first and second stage common piston (1) and is passed through an opening in the cylinder head (3) of the first stage suction and compression chamber, in extension of which is placed a third stage cylinder tube (8) with a smaller diameter than a diameter of the cylinder (2) for stage one and two, each stage fluidly separated by one or more one way valves (20a - 20f), where the second stage suction and compression chamber (28) is formed between the cylinder wall (2) and a piston skirt (5) as well as between an underside of the piston (1) and the headpiece (4) placed in a bottom of the cylinder (2). The disclosure further relates to a system for a CO2 regeneration plant (31) comprising a foam trap (32), a low pressure water scrubber (33), a stepless three-stage compressor (30) comprising one or more intercoolers (22) and water separators (23), a regenerable dehydrator (35) or an adsorber and a condensing unit comprising a condenser (36), a reboiler (38) and a stripper (37), where the compressor (30) is a three-stage reciprocating compressor.