Power systems and methods of controlling an engine driven air compressor include an air compressor driven by an engine via a clutch. A first pressure sensor configured to sense a pressure level at an outlet of the air compressor. An inlet valve configured to close in response to the first pressure sensor sensing a pressure level above a first pressure level. In addition, a second pressure sensor to sense a pressure level below a second pressure level at a housing of the air compressor, wherein the clutch is configured to disengage in response to the second pressure level, wherein the first pressure level is higher than the second pressure level.

The invention relates to a method for controlling a rotary screw compressor, having at least a first and a second air-end, wherein both air-ends are driven separately from one another and speed controlled. According to the invention, the following steps are carried out: detection of a volume flow taken at the outlet of the second air-end; adjustment of the rotational speed of both air-ends, when the removed volume flow fluctuates in a range between a maximum value and a minimum value; opening of a pressure-relief valve, if the volume flow falls below the minimum value; and reduction of the rotational speed of at least the first air-end to a predetermined idling speed (V1.sub.L) to reduce the volumetric flow delivered by the first to the second air-end.

A method for regulating the temperature at an outlet channel of a compressor or a vacuum element, comprising providing a pressure regulating valve on a influence channel, said influence channel being in direct fluid communication with the compressor or vacuum element, said valve regulating the pressure within the compressor or vacuum element by adjusting the volume of fluid flowing between a process channel and the compressor or vacuum element relative to the difference between the pressure value within said compressor or vacuum element and a set pressure value, and comprises starting the compressor or vacuum element and starting a pre-purge cycle by connecting the inlet channel to a supply of a purge gas for a preselected time interval; connecting the influence channel to a process channel; and disconnecting the inlet channel from the process channel, for maintaining a set temperature within the vacuum element for a selected time interval.

The present invention discloses an anti-decompression gear fuel pump for broken bubbles, characterized by comprising: a drive motor; and a pump body and a pump cover successively installed on the top end of the drive motor, wherein the pump body is provided with a groove, and a driving gear, a left driven gear and a right driven gear which are installed in the groove and are linked through a motor shaft of the drive motor; meanwhile, the driving gear is respectively internally engaged with the left driven gear and the right driven gear; the pump cover is provided with an A end of a fuel outlet, a D end of a circulating fuel outlet, a B end of a circulating fuel inlet, and a C end of a fuel inlet; and the A end of the fuel outlet, the D end of the circulating fuel outlet, the B end of the circulating fuel inlet, and the C end of the fuel inlet are penetrated into the groove of the pump body. The anti-decompression gear fuel pump for broken bubbles, designed in the present invention, not only solves a decompression problem generated because bubbles appear in a fuel pipeline, but also has scientific and reasonable structure.

A vane pump includes: a rotor configured to rotate under rotational force from a rotary shaft while supporting multiple vanes and including a curved surface portion with an arc shape centered on the rotary shaft and a rotor recess depressed from the curved surface portion toward a rotation center; a cam ring disposed so as to surround the rotor and including an inner peripheral surface facing the curved surface portion of the rotor; and an inner plate disposed on one end of the cam ring in an axial direction of the rotary shaft so as to cover an opening of the cam ring and including a suction inner recess depressed toward the rotation center relative to the curved surface portion of the rotor.

The invention relates to a method for controlling a rotary screw compressor, having at least a first and a second air-end, wherein both air-ends are driven separately from one another and speed controlled. According to the invention, the following steps are carried out: detection of a volume flow taken at the outlet of the second air-end; adjustment of the rotational speed of both air-ends, when the removed volume flow fluctuates in a range between a maximum value and a minimum value; opening of a pressure-relief valve, if the volume flow falls below the minimum value; and reduction of the rotational speed of at least the first air-end to a predetermined idling speed (V1.sub.L) to reduce the volumetric flow delivered by the first to the second air-end.

A power saving vacuuming pump system is based on complete-bearing-sealing and dry-large-pressure-difference root vacuuming root pumps includes an input valve at an input end of a vacuum space for receiving gas mixture of saturation water vapor and non-condensed air from a condenser of a power plant; a first root vacuum pump connected to the input valve for receiving gas mixture from the input valve and then compressing the gas mixture; a second root vacuum pump connected to the first root vacuum pump for receiving gas mixture from the first root vacuum pump and then compressing the gas mixture. Inner connection walls between the vacuum chamber and the two bearing rooms are installed respective bearings which are installed to be around the driving shaft, and thus all the vacuum chamber and the two bearing rooms are tightly sealed. The vacuum chamber is completely dried so as to prevent from internal emulsion.

In order to reduce operation in a rotation-prohibited frequency range and to prevent resonance in a gas compressor wherein inverter control is performed, this gas compressor has: a compressor main body that compresses a gas; a motor that rotationally drives the compressor main body; an inverter that changes the rotational speed of the motor; a check valve arranged downstream from the compressor main body; a pressure detection means that detects load-side pressure downstream from the check valve; and a control device that, in accordance with the pressure detected by the pressure detection means, controls the frequency output by the inverter. The control device performs a control whereby compressed gas having a prescribed pressure is generated/maintained by increasing/decreasing the frequency, and when the frequency that generates the compressed gas having the prescribed pressure includes a specific frequency, the inverter's output frequency is increased or decreased when the pressure detected by the pressure detection means reaches a pressure corresponding to a frequency that has a more constant pressure width than the prescribed pressure and does not include the specific frequency.

The invention relates to a method for controlling a rotary screw compressor, having at least a first and a second air-end, wherein both air-ends are driven separately from one another and speed controlled. According to the invention, the following steps are carried out: detection of a volume flow taken at the outlet of the second air-end; adjustment of the rotational speed of both air-ends, when the removed volume flow fluctuates in a range between a maximum value and a minimum value; opening of a pressure-relief valve, if the volume flow falls below the minimum value; and reduction of the rotational speed of at least the first air-end to a predetermined idling speed (V1.sub.L) to reduce the volumetric flow delivered by the first to the second air-end.

The propagation of a disproportionation reaction of a refrigerant is suppressed. Disclosed is a method that uses a composition as a refrigerant in a compressor, in which the composition includes one or more compounds selected from the group of ethylene-based fluoroolefins, 2,3,3,3-tetrafluoropropene, and 1,3,3,3-tetrafluoropropene, and the flow rate of the refrigerant flowing through a discharge pipe of the compressor under a predetermined high-pressure condition is greater than or equal to 1 m/s.