Parallel-Train Refrigeration Control for Compressor Shutdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for maximizing Natural Gas Liquids (NGL) production in gas plants are inefficient due to high energy costs, as they rely heavily on refrigeration systems, which are no longer economical with increasing energy costs, and previous approaches do not provide the most cost-effective means to optimize NGL recovery while minimizing energy usage.
Innovation Solution
A method that optimizes NGL production by establishing a baseline recovery, modeling scenarios for selective deactivation of refrigeration compressors, and classifying scenarios to deactivate compressors without reducing NGL recovery, while optimizing feed flow distribution across multiple processing trains, using statistical modeling and controllers to manage refrigeration systems effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If refrigeration systems are used to maximize NGL production, then NGL recovery is improved, but energy consumption increases
Solution Approach 1:
The patent implements dynamic optimization of refrigeration system operation by continuously adjusting compressor states based on real-time process conditions. The system transitions from static full-operation mode to dynamic selective deactivation, where compressors are turned on or off based on current NGL recovery requirements and energy cost conditions, resolving the contradiction between maintaining high productivity and reducing energy consumption.
Solution Approach 2:
The system changes operational parameters by modeling different compressor deactivation scenarios and selecting optimal configurations. It dynamically adjusts the number of active compressors, refrigeration load distribution, and feed flow rates based on process conditions, allowing the system to achieve high NGL recovery with minimized energy consumption by operating at optimal parameter sets rather than fixed high-capacity settings.
2Use of energy by moving object
If refrigeration compressors are deactivated to reduce energy usage, then energy consumption is reduced, but NGL recovery may be compromised
Solution Approach 1:
The system performs preliminary scenario modeling and simulation before actual compressor deactivation. It pre-calculates the impact of potential compressor shutdowns on NGL recovery under various process conditions, allowing operators to make informed decisions about which compressors can be safely deactivated without compromising productivity. This preliminary analysis ensures that energy reduction actions do not adversely affect NGL recovery.
Solution Approach 2:
The system implements feedback control by continuously monitoring actual NGL recovery performance against model predictions and adjusting compressor operation accordingly. When NGL recovery approaches specification limits, the system provides feedback to prevent further compressor deactivation or to activate additional compressors, ensuring that energy consumption is minimized while maintaining required productivity levels.
Data Source
AI summary
An optimization method based on statistical modeling relating NGL plant process variables. The modeling may rely on input data from process history and modeled data. The method identifies process scenarios when a compressor from an associated propane/propylene refrigeration system may be deactivated and still allow the NGL plant to achieve product specification.