What are the characteristics of the performance curves of centrifugal compressors?
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What are the characteristics of the performance curves of centrifugal compressors? 1. Each speed corresponds to a performance curve; at a constant speed, an increase in flow rate leads to a decrease in pressure ratio, while at the same flow rate, a higher speed results in a higher exhaust pressure. 2. As the speed increases, the performance curve becomes steeper. 3. There is a maximum flow rate limit – at a constant speed, an increase in flow rate causes the exhaust pressure to decrease; if the flow rate rises to a certain level, the exhaust pressure will drop sharply. 4. There is also a minimum flow rate limit, and a surge line is indicated on the performance curve; if the compressor’s flow rate falls below the value specified by this surge line, the compressor will experience surging.
The original poster answered their own question, and what they said is correct.
May I ask the original poster: In point 3, it states that at a constant rotational speed, an increase in flow rate leads to a decrease in exhaust pressure at the minimum flow rate. Does this sentence not make sense when read in Chinese? ! At a constant speed, as the flow rate increases, then how should the sentence be broken after \"then\"? The exhaust pressure decreases with minimum flow rate
Additional notes: 1. The axial flow compressor is also a type of centrifugal compressor. 2. The characteristics of the performance curve for axial flow compressors differ from what was described by the original poster; for example, rather than having one performance curve for each rotation speed, due to the presence of adjustable stator vanes, the operating range of the compressor is a region rather than a single curve.
What will happen to the compressor if it exceeds the maximum flow limit?
Normal operating conditions will not exceed it. Some compressors also have a “stone wall” line. The operating point has passed the stone wall line; the stone wall valve needs to be opened.
When the flow rate exceeds the maximum limit, the compressor becomes clogged and enters a blocked operating condition, which represents a dangerous abnormal state for the unit.
What is the definition of blocked operating condition, and how to solve it?~~
Blocking flow is a condition corresponding to the maximum flow rate, while surge corresponds to the minimum flow rate; between these two lies the operating flow range of the compressor. In the flow channel of a compressor stage, the airflow reaches a critical state at a certain throat; at this point, the volumetric flow rate of the gas is at its maximum value. No matter how much the back pressure of the compressor decreases, the flow rate cannot increase any further. This condition is known as a \"choking\" condition.
“\"Stone Wall\" refers to STONEWALL, that is, the blocked condition. So what should be done when this blocked condition occurs? “What kind of valve is a “stone wall valve”?
As the speed decreases, the curve moves toward lower flow rates