Dynamic Compressor Recirculation Control for Flow Turndown Stability
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Solution Overview
Problem
Compressors experience performance issues and instability during large flow turndowns, leading to difficulties in maintaining stable operation and target outlet pressures.
Innovation Solution
A dynamic compressor system with variable features such as a variable flow extractor, injector, and choke, along with a controller, adjusts operational parameters to maintain outlet pressures and flow rates within target ranges by recirculating a portion of the flow and mixing it with the inlet stream.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the compressor operates during large flow turndowns, then the inlet flow rate decreases, but the compressor performance deteriorates and stability is compromised
Solution Approach 1:
A recirculation stream is introduced as an intermediary flow path that returns a portion of the outlet stream to the inlet stream. This mediator flow maintains sufficient total flow through the compressor during turndown conditions, preventing stability issues while allowing the system outlet to deliver reduced flow to meet demand.
Solution Approach 2:
The system dynamically adjusts the recirculation flow rate based on operating conditions. The recirculation stream fraction is varied to maintain stable compressor operation across different inlet flow rates, enabling the compressor to adapt to large flow turndowns while preserving stability.
2Quantity of substance
If the compressor operates during large flow turndowns, then the inlet flow rate decreases, but the outlet pressure cannot be maintained in the target range
Solution Approach 1:
The system employs feedback control where the recirculation flow rate is continuously adjusted based on measured outlet pressure and flow conditions. This feedback mechanism ensures that outlet pressure is maintained within the target range even as inlet flow rate varies during turndown operations.
Solution Approach 2:
The system changes operating parameters by varying the recirculation stream fraction and potentially other flow distribution parameters. This parameter adjustment allows the compressor to maintain outlet pressure within the target range while accommodating different inlet flow rates during turndown.
3Reliability
If a recirculation system is added to maintain stable operation, then compressor stability improves, but the device complexity increases
Solution Approach 1:
The recirculation system is designed to serve multiple functions: maintaining stable compressor operation, enabling flow turndown capability, and supporting outlet pressure control. This multi-functionality justifies the added complexity by providing several benefits from a single integrated system.
4Reliability
If the recirculation flow rate is increased to maintain stability, then compressor stability improves, but the energy consumption increases
Solution Approach 1:
The recirculation flow rate is dynamically adjusted rather than maintained at a constant high level. The system uses the minimum necessary recirculation flow to maintain stability, reducing energy consumption while preserving compressor stability during turndown operations.
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
The system effectively maintains compressor operation and prevents stalling or large drops in outlet pressure during high levels of flow turndown, ensuring stable performance across a wide range of inlet flow rates.
Implementation Method 1
a variable flow extractor disposed downstream of the compressor to split the compressor outlet stream into a recirculation stream and a system outlet stream
Implementation Method 2
a variable flow injector disposed upstream of the compressor that receives a system feed stream and mixes the recirculation stream with the system feed stream to form the compressor inlet stream
Data Source
AI summary
Provided herein are dynamic compressor systems and methods of operation. A compressor system comprises a compressor and a variable flow extractor disposed downstream of the compressor to split a compressor outlet stream into a recirculation stream and a system outlet stream. A variable flow injector disposed upstream of the compressor that mixes the recirculation stream with a system feed stream to form a compressor inlet stream. A controller is configured to receive first data indicative of a pressure of the system outlet stream, second data indicative of a pressure of the system feed stream, and third data indicative of flow rates of at least two of the system feed stream, the system outlet stream, and the recirculation stream. The controller adjusts a flow rate of the recirculation stream via the variable flow extractor and the variable flow injector based on the first, second, and third data.