Methods and systems to provide compressed air via exhaust gases of an internal combustion engine are presented. In one example, a pump comprising two pistons is driven via engine exhaust gases. On piston within the pump moves in response to the exhaust gases while the other piston acts to compress air.

A system for compressing gas from a wellbore that uses a single reciprocating compressor unit to boost pressure of the gas to an intermediate stage, and from the intermediate stage to a final stage. The final stage is at a destination pressure for distribution. Between the intermediate and final stages the gas is treated to remove water and higher molecular weight hydrocarbons so that the gas pressurized to the final stage is compressed natural gas. The reciprocating compressor is made up of a series of throw assemblies that are all driven by a single shaft. Each throw assembly includes a cylinder with a piston that reciprocates within the cylinder to compress and pressurize the fluid therein. The reciprocating compressor can be a non-lube design thereby eliminating lube oil contamination of downstream compressed natural gas or higher molecular weight hydrocarbons.

A mobile compressed natural gas (CNG) vessel and unloader are used to supply CNG to a compressor during regulatory emissions testing of the compressor (e.g., U.S. EPA's Quad J testing). CNG output by the compressor is recirculated to an inlet of the unloader so that it is reused during the emissions testing. Lean CNG from the vessel may be used to power the compressor during the testing. The unloader ensures that the compressor is run at at least a predetermined load factor during the emissions testing.

A drive train (1) includes an internal combustion engine (2) and working hydraulics (4) having at least one hydraulic pump (7). When operated as a pump, the hydraulic pump (7) sucks hydraulic fluid from a tank (9) and delivers into a delivery line (10) that leads to the working hydraulics (4). When operated as a motor, the hydraulic pump (7) is supplied with hydraulic fluid from a hydraulic accumulator (25). The drive train (1) has a charge pump (20) to supply a charging circuit (23). The charge pump (20), when operated as a pump, sucks hydraulic fluid out of the tank (9) and delivers into a charge pressure line (22) that leads to a charging circuit (23), and the charge pump (20) when operated as a motor is supplied with hydraulic fluid from the hydraulic accumulator (25).

Provided is a forced-regeneration treatment method for an exhaust-gas aftertreatment device (DPF) and an associated engine-driven compressor. When the amount of particulate matter (PM) deposited in a filter element of a DPF reaches a predetermined amount and a forced-regeneration start command is input, a capacity controlling means of the engine-driven compressor is disabled to close an intake valve and to open the discharge side of a compressor main unit to atmosphere, thereby causing the compressor main unit to achieve a low-load state. The operation mode of the engine is switched to a predetermined forced-regeneration mode to operate the engine at a predetermined speed and to increase the temperature of the gas. The temperature inside the DPF is increased to reach a temperature at which an oxidative catalyst is activated and to a temperature lower than the self-combustion temperature of the PM, thereby forcibly burning the PM.

A method of mounting a bearing to an air compressor including a shaft element having a first end defining a central cylindrical recess and a second is disclosed, which includes the steps of: fixing the second end of the shaft element to a center of a gear; inserting the first end of the shaft element through a central hole of a bearing to have an annular step of the shaft element abutted an inner ring of the bearing; and hitting the first end of the shaft element by a striking tool with a central pin to form an outwardly extending rim on the first end of the shaft element. With the method, the bearing can be firmly fixed between the outwardly extending rim and the annular step of the shaft element.

A system that can eliminate engine combustion emissions in addition to raw and fugitive methane emissions associated with a gas compressor package. The system may comprise an air system for starting and instrumentation air supply; electrically operated engine pre/post-lube pump, compressor pre-lube pump, and cooler louver actuators; compressor distance piece and pressure packing recovery system; blow-down recovery system; engine crankcase vent recovery system; a methane leak detection system; and an overall remote monitoring system.

An engine compressor unit including at least one rotary engine; and at least one rotary compressor for compressing at least one gaseous fluid; the rotary engine including an engine housing including at least one engine ring that is rotatably supported in the engine housing about an engine axis, at least one engine cylinder that is arranged in the engine ring, wherein an engine piston is arranged in the at least one engine cylinder so that the engine piston defines a combustion chamber of the at least one engine cylinder together with a wall of the at least one engine cylinder, wherein the engine piston is supported in the at least one engine cylinder by an engine connecting rod so that the engine piston is movable in the at least one engine cylinder in a linear manner.

An air system and method includes an air compressor, a temperature sensors, a valve, and a controller. The air compressor is configured to receive filtered air. The temperature sensor is positioned at or near an outlet of the air compressor and configured to sense a temperature at or near the outlet of the air compressor. The valve is operatively connected to an outlet of the air compressor and external to the air compressor. The controller is configured to monitor the sensed temperature at the outlet of the air compressor and control the valve to permit air to flow from the outlet of the air compressor through the valve to unload the air compressor if the sensed temperature exceeds a threshold temperature.

A multi-stage gas compression system useful at the production site and at central collection points, having an energy efficient and effective intercooler system. The system includes a reciprocating compressor having a plurality of compressor valves and cylinders configured in series to provide staged compression to the natural gas. Coupled with the compressor are an inlet port for receiving natural gas to be compressed, and an outlet port for delivering compressed fluid from the compressor to a discharge line, to the transmission pipeline or storage. Facilitating transmission and intercooling of the natural gas between cylinders are a plurality of pipes, each pipe in close proximity with an intercooler. The rate of cooling of the intercooler is determined by a control system coupled therewith, including a temperature sensor positioned within pipe proximal to the intercooler, and means to compare the temperature measured by the temperature sensor and an optimal temperature or temperature range, and determine appropriate levels of cooling provided by the intercooler.