Reciprocating compressor fault diagnosis
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Reciprocating compressors are prone to malfunctions; our factory uses a three-stage double-acting compression system. In the first stage of compression, there are four intake valves and four exhaust valves, while the other two stages each have two intake valves and two exhaust valves. I would like to ask how to determine what’s wrong when a failure occurs If a valve leaks, or if there is a leak in the piston rings.
Reply to 1# messi2: The fault of the valve is most evident in changes in the exhaust temperature; it has nothing to do with air leakage from the piston rings. If the exhaust temperature suddenly rises, it is appropriate to check the secondary intake valve
Leakage in the piston rings, along with insufficient pressure, can also cause an increase in temperature.
The exhaust valve leaks, causing high cylinder temperature, as the atmosphere functions as a one-way valve. If there is air leakage in the piston rings, then the rectal temperature will surely be high, as there is pressure near the crosshead.
The simple method for judgment focuses mainly on observing temperature changes; one way is to check the gauge, and another is to feel the temperature of the cylinder. If the temperature gets too high, it might be a problem with the exhaust valve!
My opinion: First, the temperature of the piston cylinder block can be measured； Second, under the condition that the intake air temperature remains relatively stable, observe the temperature variation trend of the exhaust buffer tank ； Secondly, it is important to pay attention to any abnormal vibrations and noises during inspections; this is due to poor exhaust flow, which results in uneven stress on the crankshaft. The vibration patterns vary depending on the cylinder block, and if the engine operates under such conditions for an extended period, it can cause damage to the crosshead, or even destroy it entirely. Our compressors have experienced such a phenomenon.
It is relatively easy to determine when the intake valve is damaged, as the temperature of the valve cover exceeds the intake air temperature by a large margin. To determine if the exhaust valve is damaged, it is necessary to look at the parameters recorded over a long period of time during operation; abnormal exhaust temperatures will indicate the issue at a particular stage. The subsequent stage affects the exhaust temperature of the preceding stage.
In the event of a failure in a reciprocating compressor, an online monitoring system can be used; both domestic and imported versions are available, and they offer good performance. With other methods, only a rough judgment can be made.
In the event of a failure in a reciprocating compressor, an online monitoring system can be used; both domestic and imported versions are available, and they offer good performance. With other methods, only a rough judgment can be made.
Reply to 1# messi2: The valve is leaking, which causes the cylinder temperature to rise. Piston leakage means packing leakage; usually there is a conduit leading from the packing, and if the leakage is severe, it can be detected
Judging valve leakage: 1. Touch: The temperature of a damaged valve gland will rise； 2. Listening: There is a backflow sound inside the valve chamber ； 3. Observation: Pressure at this level decreases, while pressure at the higher level increases. Judgment of piston ring leakage: the pressure at this stage decreases, the pressure at the higher stage increases, and the exhaust temperature at this stage drops.