Reciprocating Compressor Valve Wear Reduction via Unloader Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling the flow rate of reciprocating compressors lead to high wear on suction and pressure valves, especially under stepless reverse flow control, resulting in increased maintenance needs and reduced reliability due to excessive stress and temperature increases.
Innovation Solution
A method combining stepless reverse flow control and intermittent control, using an unloader driven by a control device to influence the closing element of the suction valve, ensuring it remains open during certain cycles for smaller delivery quantities and maintaining the pressure valve open for a predetermined angle, reducing wear and allowing precise regulation of flow rates without additional valve stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If stepless reverse flow control is used to control delivery quantity, then flow rate regulation is achieved, but valve wear increases due to high impact stress on closing elements
Solution Approach 1:
The suction valve is closed intermittently rather than continuously, creating periodic open/closed cycles. This periodic action allows the valve to rest during closed periods, reducing cumulative wear while still achieving flow control through the pattern of opening/closing events.
Solution Approach 2:
The unloader is activated before the suction valve would naturally close to gradually build pressure and prepare the closing element for a gentler closure. This preliminary action reduces the impact velocity and force when the closing element strikes the seat, minimizing wear.
2Productivity
If unloader prevents closure during entire cycle (intermittent control), then delivery quantity is reduced, but compression chamber is not flushed and dirt accumulates increasing wear
Solution Approach 1:
The system alternates between periods of intermittent control (for flow regulation) and periods of normal operation (for flushing the compression chamber). This periodic switching ensures that while delivery quantity is controlled during intermittent phases, the compression chamber is periodically flushed to remove dirt and prevent excessive wear.
3Adaptability or versatility
If pressure valve opening time is reduced for smaller flow rates, then delivery control precision is achieved, but opening and closing speeds multiply increasing wear
Solution Approach 1:
The unloader builds pressure gradually before the pressure valve opens, and maintains pressure control during closure. This preliminary and controlled pressure management ensures that the pressure valve opens and closes more gradually, reducing impact speeds and wear even at small flow rates where opening time is naturally shorter.
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 approach allows for wide-range delivery quantity control without additional wear on valves, reducing energy consumption and extending valve lifespan by minimizing stress and maintaining efficient gas delivery across varying flow rates.
Implementation Method 1
the unloader rests against the closing element during a first partial section of the cycle of the crank circuit and prevents its closure
Implementation Method 2
the unloader is moved back during a second partial section of the cycle of the crank circuit and the closing element is closed
Implementation Method 3
a stop control which prevents the unloader from closing the closing element during an entire cycle of the crank circuit
Data Source
AI summary
The invention relates to a method for the delivery quantity control of a reciprocating compressor, wherein the motion of a closing organ (5b) of an automatic suction valve (5) is influenced during at least one part of a cycle of the crankshaft by means of a retraction gripper (6) driven by a control device (2), wherein the method comprises a continuously variable return flow control, wherein the retraction gripper (6) contacts the closing organ (5b) and prevents the same from closing during a first partial segment (K1) of the cycle of the crankshaft, and wherein the retraction gripper (6) is retracted during a second partial segment (K2) of the cycle of the crankshaft and the closing organ (5b) is closed, and wherein the method comprises an interruption control, wherein the retraction gripper (6) prevents the closing organ (5b) from closing during an entire cycle of the crankshaft, wherein the delivery quantity is controlled at least by a combination of continuously variable return flow control and interruption control, and wherein the closing organ (5b) is influenced by the control device (2) and the retraction gripper (6) such that a closing organ (8b) of a pressure valve (8) of the reciprocating compressor is opened at least during a prescribed total opening angle (Kv) of a crankshaft.