Gas Compressor Control Using Pressure Rate-of-Change Prediction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas compressor control methods fail to account for delay time and pressure fluctuations when adjusting the number of operating compressor bodies, leading to control delays and pressure undershoots during changes in air supply.
Innovation Solution
A control device that determines whether to increase the number of operating compressor bodies based on the pressure value and temporal changing amount, allowing for dynamic adjustment of motor driving frequencies to maintain stable discharge pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of operating compressor bodies is unconditionally increased when discharge pressure drops below a predetermined lower limit, then the discharge pressure can be restored, but control delay and pressure undershoot occur due to not accounting for delay time
Solution Approach 1:
The control device predicts future discharge pressure by calculating the temporal changing amount (rate of change) of discharge pressure. When the discharge pressure is higher than the lower limit but the temporal changing amount indicates a sharp decrease, the control device preemptively increases the number of operating compressor bodies before the pressure actually drops below the limit, avoiding control delay and pressure undershoot.
Solution Approach 2:
The control device continuously monitors both the discharge pressure value and its temporal changing amount, using this feedback information to dynamically adjust the number of operating compressor bodies. This feedback mechanism allows the system to respond to pressure trends rather than just static pressure values, reducing control delay.
2Reliability
If the number of operating compressor bodies is increased to maintain discharge pressure, then sufficient compressed air supply is ensured, but unnecessary compressor body operation increases energy consumption
Solution Approach 1:
The control device dynamically adjusts the number of operating compressor bodies based on real-time discharge pressure and its temporal changing amount, rather than using a fixed control strategy. This dynamic adjustment ensures compressor bodies are operated only when necessary, reducing energy consumption while maintaining sufficient compressed air supply.
Solution Approach 2:
The control device uses the temporal changing amount of discharge pressure as an additional control parameter alongside the discharge pressure value itself. By monitoring both parameters, the system can make more precise decisions about when to increase or decrease the number of operating compressor bodies, avoiding unnecessary operation and energy waste.
3Reliability
If inverter-based rotational speed control is used to maintain constant discharge pressure, then pressure control is achieved, but sharp increases in used air amount cause pressure undershoot
Solution Approach 1:
By monitoring the temporal changing amount of discharge pressure, the control device can detect sharp decreases in pressure trends before they result in actual pressure undershoot. This allows preemptive action to increase compressor body operation, improving the system's response speed to sudden increases in air demand.
Solution Approach 2:
The dual-parameter feedback system (discharge pressure value + temporal changing amount) provides more comprehensive information about system state and trends, enabling faster and more accurate control decisions in response to sudden changes in air demand, thereby preventing pressure undershoot.
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 reduces discharge pressure fluctuations and prevents unnecessary decreases, ensuring stable operation by dynamically adjusting the number of compressor bodies and their driving frequencies in response to changing air demand.
Implementation Method 1
an inverter for controlling a rotational speed of the motor
Implementation Method 2
a plurality of compressor units each having a compressor body
Data Source
AI summary
A gas compressor includes inverters, a plurality of compressor units and a control device for controlling each of the inverters. The control device increases the number of compressor bodies to be operated after confirming that the rotational speed of the operational motors will reach a steady value immediately after causing the number of the compressor bodies to be operated to increase.