Compressor Discharge Pressure Control for Stable Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing compressed air manufacturing facilities face instability in supply pressure and excessive energy consumption due to the interdependence of discharge pressure and rotating speed control, leading to hunting and inefficiency when air usage changes.
Innovation Solution
A compressed air manufacturing facility with a discharge pressure changing mechanism that computes pressure loss based on rotating speed and adjusts the control range of the compressor's discharge pressure, coupled with a rotating speed control mechanism that varies the electric motor's speed via an inverter to maintain a stable terminal pressure, thereby minimizing power consumption and enhancing convergence characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the control range of discharge pressure is set high to anticipate maximum pressure loss, then the terminal pressure at downstream side can be maintained at desired level, but the compressor is driven more than necessary causing extra power consumption
Solution Approach 1:
The control range of discharge pressure is made dynamically adjustable based on the operating state of the discharge air system. The control device computes pressure loss characteristics and adapts the control range accordingly, transitioning from a fixed high control range to a variable control range that matches actual system needs, thereby reducing unnecessary compressor operation and power consumption while maintaining reliable terminal pressure.
Solution Approach 2:
The discharge pressure control range parameter is changed based on computed pressure loss characteristics of the discharge air system. By adjusting this parameter according to actual system conditions rather than maintaining a fixed conservative value, the system achieves optimal balance between reliability and energy efficiency.
2Adaptability or versatility
If the discharge pressure control and rotating speed control are interdependent, then the system can respond to air usage changes, but hunting occurs and stability is compromised
Solution Approach 1:
The control functions are segmented into distinct modules: a control range computing device that calculates the appropriate discharge pressure control range based on system state, and a control device that executes control within this computed range. This segmentation separates the calculation function from the execution function, preventing mutual interference and hunting while maintaining adaptability to air usage changes.
Solution Approach 2:
The control range computed by the control range computing device acts as an intermediary between the air usage demand and the actual control execution. This intermediate control range parameter mediates the relationship between discharge pressure control and rotating speed control, ensuring stable supply pressure while maintaining system adaptability.
3Device complexity
If pressure loss is computed based on ratio between discharge pressure and specification pressure, then the control can be simplified, but accuracy deteriorates when discharge pressure varies significantly from specification pressure
Solution Approach 1:
The pressure loss computation method is made dynamic and adaptive. Rather than using a fixed ratio-based computation that deteriorates accuracy at extreme pressures, the control range computing device continuously computes pressure loss based on the current operating state and characteristics of the discharge air system, maintaining accuracy across the full range of discharge pressures while keeping the control structure relatively simple.
Data Source
AI summary
In order to provide a compressed air manufacturing facility which can increase a stability of a supply pressure while obtaining an energy saving effect, in a compressed air manufacturing facility provided with a compressor compressing an air, an electric motor driving the compressor, and an inverter variably controlling a rotating speed of the electric motor, the compressed air manufacturing facility is provided with a pressure sensor detecting a discharge pressure of the compressor at an upstream side position of a discharge air system connected to a discharge side of the compressor, and a control apparatus computing a pressure loss of the discharge air system in correspondence to a rotating speed of the electric motor, and changing a control range of the discharge pressure of the compressor at the upstream side position of the discharge air system on the basis of the computation in such a manner that a terminal pressure at a downstream side position of the discharge air system comes to a predetermined range, and variably controlling the rotating speed of the electric motor via the inverter in such a manner that the discharge pressure of the compressor detected by the pressure sensor comes to the changed control range.