Compressor flow rate issues
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I have a question for everyone: my system is equipped with two piston compressors used to compress ammonia. Due to the low volume of ammonia produced, an ammonia vapor line comes from the liquid ammonia tank to supply enough ammonia at the compressor inlet. If the amount of ammonia at the compressor inlet is low, what harm can that cause to the compressor? Is it necessary to install a pressure relief line? Please share your thoughts, thank you
General experience shows that when the inlet volume is small, the compressor will continuously pressurize the gas inside the cylinder, causing the temperature of the piston cylinder to rise; in severe cases, this can damage the equipment.
A circulation control system should be established, involving pipes and circulation valves from the outlet to the inlet; this can be a single-stage circulation or a circulation from the final stage back to the inlet, in order to maintain the suction pressure. However, attention must be paid to temperature control.
1. Generally, the pressure compensation line you mentioned is installed; typically, the compressed gas is cooled first and then sent back to the inlet via a control valve. 2. Hazards: ① The direct hazard is negative pressure in the pipelines – poor system sealing can lead to air being drawn in, or damage to the equipment at the beginning of the pipeline. ② It affects the compression ratio; an increased compression ratio results in greater work for the compressor and higher heating. 3. If there are significant fluctuations in flow rate, variable-frequency motors can be used from an energy-saving perspective
Once the reciprocating machine is completed, the inlet air volume remains essentially unchanged. . . If the volume of air entering the compressor decreases, while the amount of air drawn in by the compressor remains roughly constant, this will cause the system pressure before the inlet to drop further. The pressure at the exhaust valve side is determined by the exhaust system; if the pressure at the exhaust end remains unchanged, the compression ratio of the compressor will gradually increase, resulting in a higher and higher exhaust temperature. . . Suggestion: The method of adjusting air volume using such small reciprocating machines is usually quite fixed; check whether there is a unloader, and try operating at 50% air volume. . . Some people say that replacing it with an inverter-driven motor is necessary; reciprocating machines already have a low speed, and special attention must be paid when using inverters. It is essential to calculate the system’s moment of inertia, as frequency conversion cannot be done casually. . .
The compressor creates negative pressure; over time, the compression ratio increases and the outlet temperature rises, which can easily damage the equipment. A pressure compensation line needs to be installed; it is recommended to add a pressure gauge for easy monitoring~~
Flow regulation in reciprocating compressors is generally achieved through backflow regulation, that is, by returning the flow to the inlet, provided that cooling equipment is available to maintain the inlet temperature. If energy savings are a concern, it is recommended to install a variable air volume control system.
Filler seals are all unidirectional seals; if the amount of filler used is insufficient, negative pressure will be generated, the compression ratio will increase, which can lead to the entry of protective gas or air as well as overload
As the compression ratio increases, the outlet temperature rises, which can easily damage equipment and spare parts