How to operate a natural gas compressor

Because natural gas compressors cannot rule out the possibility of long-term operation at full load, the motor capacity can only be determined according to demand during model selection, resulting in a generally large margin in the air compressor system. Traditional compressors all use star-triangle step-down starting, but the current can still reach 2-3 times the rated current when started at power frequency, which has a large impact and will affect the stability of the power grid.

Most of them are running continuously, because the motor of general natural gas compressor cannot reduce speed according to the change of pressure demand, so that the motor output power matches the actual pressure demand on site, resulting in no-load operation when the gas consumption is small, resulting in huge waste of electric energy.

According to statistics, natural gas compressors account for 15% of almost all electricity consumption of large industrial equipment (fans, pumps, boilers, etc.). Problems with the loading and unloading gas supply control method; through energy consumption analysis, it is known that the loading and unloading control method causes the pressure of compressed gas to change back and forth between Pmin-Pmax.

In general, the relationship between Pmin and Pmax can be expressed by the following formula: CPmax=(1 plus δ) Pmin is a percentage, and its value is roughly between 10% and 20%. If variable frequency speed regulation technology is used to continuously adjust the gas supply, the pipeline network pressure can be maintained at a level that can meet the gas supply pressure, that is, near Pmin.

It can be seen that the energy wasted by the natural gas compressor under the loading and unloading gas supply control method is mainly in two parts:

1. Energy consumed by unreasonable regulation during unloading. Normally, when the pressure reaches Pmax, the natural gas compressor uses the following method to reduce the pressure and unload: close the intake valve to make the motor idle, and at the same time, vent the excess compressed natural gas in the separation tank through the vent valve. This regulation method will cause a lot of energy waste.

2. Energy consumed when compressed air pressure exceeds Pmin. After the pressure reaches Pmin, the original control method determines that the pressure will continue to rise (until Pmax). This process is also an energy-consuming process.