WO2016043740A1

WO2016043740A1 - Control of boosted air compressors

Info

Publication number: WO2016043740A1
Application number: PCT/US2014/056174
Authority: WO
Inventors: Steven M. Bellinger
Original assignee: Cummins, Inc.
Priority date: 2014-09-17
Filing date: 2014-09-17
Publication date: 2016-03-24

Abstract

A system and method for regulating the pressure of airflow that is delivered to an air compressor based on an operating state of the air compressor. According to certain embodiments in which the air compressor is part of an engine system having an engine, the regulation of the pressure of the airflow that is delivered to the air compressor is independent of an engine load placed on the engine. A pressure control device may be adapted to adjust the pressure of the airflow that is to be compressed by the air compressor to a first pressure when the air compressor is operating in a loaded compressor operating state, and a second pressure when the air compressor is operating in an unloaded compressor operating state. Further, the first pressure may be greater than the second pressure, and the second pressure may be slightly above zero bar.

Description

CONTROL OF BOOSTED AIR COMPRESSORS

BACKGROUND

[0001] The present invention relates generally to internal combustion engine and driven air compressor systems, and more particularly to regulation of the charge pressure of an air compressor independent of engine load and as function of a compressor operating state.

[0002] Some internal combustion engine systems bleed or divert a portion of pressurized air from, or that is being delivered to, an intake manifold and into an inlet of an air compressor. Diverted air that is compressed by the air compressor may then be used in the operation of other components of the engine system and/or stored in compressed air storage tanks of the engine system for later usage. Generally, air compressors may operate in at least a loaded compressor operating state and an unloaded compressor operating state. However, under at least certain conditions, operation of the air compressor in the loaded compressor operating state or the unloaded compressor operating state can adversely impact the operation of the engine system. For example, an air compressor may operate in a loaded compressor operating state when the air compressor is providing compressed air for use by components of the engine and/or vehicle system. Conversely, for example, the air compressor may be in an unloaded compressor operating state when the air storage reservoirs are sufficiently pressurized and/or are within the intended working system pressure range for the engine and/or vehicle system.

[0003] With respect to at least certain engine systems that utilize an upstream turbocharger to pressurize the intake air, the associated charge pressures of the intake air can impact the parasitic load or loss associated with the air compressor. For example, when the air compressor receives intake airflow having elevated boost pressures, such as boost pressures provided by the operation of the turbocharger, the compressed air supplied by the air compressor may exceed the maximum inlet temperature and/or volumetric capacity of components downstream of the air compressor such as, for example, an air dryer.

[0004] Conversely, when the airflow pressure of the outflow outputted from the turbocharger is relatively low, such as, for example, when the air compressor receives intake air at or below 0 bar boost, air being scavenged into the cylinder of the air compressor during the intake stroke can also migrate into the cylinder of the air compressor via the crankcase of the air compressor. When this occurs, greater amounts of oil are carried over into the cylinder of the air compressor. As this air charge is then compressed and heated, the oil within the air compressor cylinder is subject to coking, resulting in carbon formation around critical components such as rings, valves and discharge ports ultimately degrading the performance of the air compressor over time.

[0005] Further, typically, the parasitic load or loss associated with the air compressor increases as boost pressure increases. For example, referencing Figure 1, according to certain systems, when the pressure of the intake airflow is about 0 bar, approximately 0.75 kilowatts (kW) of power may be required to operate, such as turn, an air compressor that is in the unloaded compressor operating state at 2000 revolutions per minute (rpm). However, in this example, as shown in Figure 1 , when the pressure of the intake airflow is raised to about 3 bar, the power consumption of the air compressor increases to around 1 kilowatt (kW).

[0006] Similarly, for example, the power requirements of the air compressor may also increase when the air compressor is in the loaded compressor operating state, as demonstrated, for example, by Figure 2. For example, as illustrated by the example depicted in Figure 2, the horsepower requirements, and thus the associated power consumption, of the air compressor can increase as the pressure of the intake airflow increases. As the example depicted in Figure 2 indicates, an air compressor supplied with 0 bar boost will absorb, or have a power requirement of, approximately 6 horsepower in order to compress air to 8 bar while operating at a speed of 2000 revolutions per minute (rpm). Yet, the power absorbed by the same air compressor may be nearly doubled to approximately 12 horsepower (HP) when the pressure of the delivered intake airflow is elevated to approximately 3 bar.

BRIEF SUMMARY

[0007] An aspect of the present invention is a method for controlling the pressure of airflow delivered to an air compressor that includes determining whether the air compressor is operating in a loaded compressor operating state or an unloaded compressor operating state. The method also includes receiving a first airflow by a pressure control device, the pressure control device being in fluid communication with the air compressor. Based at least in part on the air compressor being in the loaded compressor operating state, a pressure of the first airflow can be adjusted by a pressure control device to provide a regulated airflow having a first pressure. Similarly, based at least in part on the air compressor being in the unloaded compressor operating state, the pressure of the first airflow can be adjusted by the pressure control device to provide a regulated airflow having a second pressure. Additionally, the second pressure is greater than 0 bar, and the first pressure is larger than the second pressure.

[0008] Another aspect of the present invention is a system for controlling the pressure of an airflow supplied to an air compressor of an engine system. The system includes a pressure control device having an inlet and an outlet. The inlet is adapted to receive a first airflow having an airflow pressure. The outlet is in fluid communication with the air compressor. Additionally, the pressure control device is adapted to adjust the airflow pressure based on an operating state of the air compressor and independent of an engine load on an engine of the engine system.

[0009] Another aspect of the present invention is a system having an air compressor that is configured to operate in a loaded compressor operating state and an unloaded compressor operator state. The system further includes a diverter that is configured to divert at least a portion of an airflow to provide a diverted airflow and a pressure control device having an inlet that is in fluid communication with the diverter. The pressure control device also includes an outlet that is in fluid communication with the air compressor. The pressure control device is adapted to adjust a pressure of the diverted airflow to a first pressure based on the air compressor being operated in the loaded compressor operating state, and to a second pressure based on the air compressor being operated in the unloaded compressor operating state, the first pressure being greater than the second pressure and the second pressure being above 0 bar.

[00010] Other aspects of the present invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[00011] Figure 1 illustrates a graphical representation of power consumption of an exemplary air compressor as a function of engine speed for different intake airflow pressures when the air compressor is in the unloaded compressor operating state.

[00012] Figure 2 illustrates a graphical representation of horsepower requirements as a function of speed for an exemplary air compressor that is to compress intake airflow to a pressure of 8 bar.

[00013] Figure 3 illustrates a schematic block diagram of an exemplary internal combustion engine system having an engine driven air compressor. [00014] Figure 4 illustrates a flow chart of a method for controlling the pressure of an airflow that is delivered to an air compressor according to an illustrated embodiment of the invention.

[00015] The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentalities shown in the attached drawings.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[00016] Figure 3 illustrates a schematic block diagram of an exemplary internal combustion engine system 100 having an engine driven air compressor 102. The internal combustion engine system 100 includes an internal combustion engine 104, such as, for example, a diesel engine, a gasoline engine, or a dual fuel engine, among other types of internal combustion engines. The internal combustion engine system 100 further includes an air intake system 106 that delivers fresh air, such as, for example, ambient air, to the engine 104 and the air compressor 102. The air intake system 106 may include a number of features, including, for example, an air filter and noise reduction and flow altering devices, such as, for example, baffles, among other features.

[00017] According to the illustrated embodiment, the air intake system 106 includes an air inlet 108 that draws ambient, intake airflow 109 toward a pressure source 110, such as, for example, a turbocharger, a positive displacement supercharger, or a dynamic compression supercharger, among other pressure increasing devices. Intake airflow 109 received through the inlet 112 of the pressure source 110 may be pressurized or charged by the pressure source 110 so that the pressure source 110 outlets a pressurized airflow 114. During at least certain operating conditions the pressurized airflow 114 may have a pressure greater than ambient pressure, while during other operating conditions, the pressurized airflow 114 outputted from the pressure source 110 may have a pressure that is generally equal to, or lower than, the pressure of the intake airflow 109. Further, according to certain embodiments, the pressurized airflow 114 may be delivered to a charge air cooler or an intercooler that is positioned upstream of the engine 104 and which is configured to reduce a temperature of the pressurized airflow 114. [00018] The air intake system 106 may further include a diverter 116 that is configured to divert at least a portion of the pressurized airflow 114 for use by the air compressor 102 and/or divert at least a portion of the pressurized airflow 114 for use in the combustion chambers 118 of the engine 104. According to certain embodiments, the diverter 116 may be positioned upstream of, within, or be a part of the intake manifold 120. For example, according to certain embodiments, the diverter 116 may be a length of conduit that delivers pressurized airflow 114 from the intake manifold 120 to a pressure control device 122 that may be positioned upstream of, or be part of, the air compressor 102, as discussed below.

[00019] At least a portion of the pressurized airflow 114 delivered to the intake manifold

120 is distributed to one or more of a plurality of combustion chambers or cylinders 118 of the engine 104. The internal combustion engine system 100 may also include an exhaust system 124 having an exhaust gas recirculation system 126. The exhaust gas recirculation system 126 may be configured to recirculate a portion of the exhaust gases outputted from the engine 104 back to the intake manifold 120 and/or into the flow of the pressurized airflow 114 so that recirculated exhaust gases may be delivered to the combustion chambers or cylinders 118 of the engine 104.

[00020] The pressure control device 122 is configured to regulate the pressure of the airflow that is delivered to and/or compressed by the air compressor 102. Further, according to certain embodiments, the pressure control device 122 is configured to regulate the pressure of the intake airflow that is delivered to the air compressor 102 independent of the engine load. Additionally, use of the pressure control device 122 may allow for operation of the air compressor 102 independent of the pressure of the pressurized airflow 114. According to such embodiments, the pressure control device 122 may be configured to regulate the pressure of the airflow that is delivered to the air compressor 102 as a function of the operating state of the air compressor 102, such as, for example, whether the air compressor 102 is operating in the loaded compressor operating state or the unloaded compressor operating state. For example, the pressure control device 122 may be configured to output a regulated airflow 128 at a first pressure when the air compressor 102 is operating in the loaded compressor operating state, and output the regulated airflow 128 at a second pressure when the air compressor 102 is operating in the unloaded compressor operating state.

[00021] The pressure control device 122 may be positioned at a variety of different locations, and may take a variety of different forms. For example, according to certain embodiments, the pressure control device 122 may be a control valve or a pressure regulator that is positioned upstream of the air compressor 102, such as, for example at the diverter 116 or between the diverter 116 and the air compressor 102. Further, according to certain embodiments, the pressure control device 122 may be positioned at, or within, the air compressor 102, such as, for example, at or within an inlet 130 of the air compressor 102. Alternatively, according to other embodiments, the pressure control device 122 may be integrated into a cylinder head of the air compressor 102.

[00022] Operation of the pressure control device 122 may be controlled in a variety of different manners. For example, according to certain embodiments, the air intake system 106 may include one or more pressure sensors 132 that provide information regarding a pressure level of the pressurized airflow 114. The pressure sensors 132 may be located at a variety of different positions, including upstream and/or downstream of the pressure control device 122 and/or within the pressure control device 122. For example, according to certain embodiments, a pressure sensors 132 may be positioned upstream of, or at, an inlet 134 of the pressure control device 122. According to such embodiments, the pressure of the incoming pressurized airflow 114 may provide an indication as to whether the air compressor 102 is, or will be, operating in the loaded compressor operating state or the unloaded compressor operating state. Such an indication of the whether the air compressor 102 is, or will be, operating in the loaded or unloaded compressor operating state may indicate whether the pressure control device 122 is to at least attempt to output the regulated airflow 128 at the first pressure or the second pressure. According to certain embodiments, whether the air compressor 102 is, or should be, operating in the loaded compressor operating state or the unloaded compressor operating state may be determined and/or detected by using an air governor 137 that is positioned downstream of the air compressor 102. For example, the air governor 137 may be positioned in, or about, an air dryer 135 and/or an air storage tank 138 that is in fluid communication with, and downstream of, the air compressor 102. The air governor 137 may be adapted to open an air circuit 139 when the pressure of the pressurized air flow received by the air governor is at, or above, a first level, the air circuit 139 being in communication with the air compressor 102. According to certain embodiments, when the air circuit 139 is in the opened position, a valve of, or operably connected to, the air compressor 102 may be positioned such that the air compressor 102 is in the unloaded operating condition. According to such an embodiment, when the air circuit is in the closed position, such as, for example, when the pressure of the pressurized air flow received by the air governor 137 is at, or below, a second level, the air circuit 139 may be closed such that the valve of, or operably connected to, the air compressor 102 is positioned such that the air compressor 102 is in the loaded operating condition.

[00023] According to certain embodiments, operation of the pressure control device 122 may be controlled by a controller 140, such as, for example, a controller of the pressure control device 122 or a controller of a control module 142 of the engine system 100. For example, the controller 140 may be part of the pressure control device 122 or part of the engine control module of the engine system 100. The controller 140 may provide information or instructions that may be used to adjust at least the output of the pressure control device 122, such as, for example, altering the pressure control device 122 from outputting the regulated airflow 128 at the first pressure to the second pressure, and vice versa. For example, according to certain embodiments in which the pressure control device 122 is a pressure regulator, the controller 140 may issue a command(s) or instruction(s) that is used to adjust the positioning of, or a force exerted against, a restricting element of the pressure control device 122 so as to adjust and/or regulate the pressure of the regulated airflow 128 outputted from the pressure control device 122. For example, according to certain embodiments, the controller 140 may issue a command to a motor or other drive or displacement device that is configured to displace a component, either directly or indirectly, of the pressure control device 122. Such displacement may provide for an adjustment in the degree of force being exerted by a loading element, such as, for example, a spring, diaphragm actuator, or piston actuator, among other loading elements, on a restricting element of the pressure control device 122, and thereby alter the pressure of the regulated airflow 128 that is released from the pressure control device 122.

[00024] For example, when the air compressor 102 is in the unloaded compressor operating state, the pressure control device 122 may output regulated airflow 128 at a second pressure that is at least slightly above 0 bar. By maintaining the regulated airflow 128 at a second pressure that is slightly above 0 bar, the power consumption of the air compressor 102 may be relatively minimal compared to if the regulated airflow 128 had a higher pressure. Thus, the pressure control device 122 and/or the pressure of the regulated airflow 128 that is outputted from the pressure control device 122 may be controlled so as to minimize the power consumption of the air compressor 102 when the air compressor 102 is in the unloaded compressor operating state.

[00025] The second pressure may be high enough above 0 bar to prevent or minimize gases or other fluids, and the particulate matter within those gases and fluids, from being drawn into or toward the regulated airflow 128, while minimizing the power consumption of the air compressor 102 when the air compressor 102 is in the unloaded compressor operating state, as discussed above. For example, by maintaining the second pressure slightly above 0 bar, gases and fluids from within the crank case of the air compressor 102, including oil, may not be drawn through the crank case and/or a ring pack of the air compressor 102 and toward, or into, the regulated airflow 128. Thus, during operation of the air compressor 102 in the unloaded compressor operating state, by controlling the pressure of the regulated airflow 128 that is delivered to the inlet 130 of the air compressor 102, the level of parasitic power consumption by the air compressor 102 may be reduced without incurring oil carry over or undesired oil consumption. According to certain embodiments, the second pressure may be a pressure that greater than 0 bar and less than 1 bar.

[00026] The first pressure of the regulated airflow 128 outputted from the pressure control device 122 may be used to control the power consumption of the air compressor 102 when the air compressor 102 is operating in the loaded compressor operating state. Additionally, by delivering regulated airflow 128 at a first pressure that is independent of the pressure of the pressurized airflow 114, peak delivery rates, as well as the pressure and temperature, of compressed air 136 outputted from the air compressor 102 may also be controlled. Such control the characteristics of the compressed air that is outputted from the air compressor 102 may also at least assist in controlling the level of pumping parasitic losses. Further, controlling level or degree of work at which the air compressor 102 is operating, such as, for example, limiting the horsepower at which the air compressor 102 is working, may allow for optimization of the duty cycle of the air compressor 102 as a function of engine 104 or vehicle operating conditions to further optimize the overall engine efficiency.

[00027] According to certain embodiments, the first pressure may be used to control the maximum power consumption level of the air compressor 102. For example, the pressure control device 122 may be configured to output a first pressure that corresponds to a maximum power consumption level that may be consumed and/or attained by the air compressor 102 during operation of the air compressor 102 in the loaded compressor operating state. The maximum power consumption level may be expressed and/or determined in a number of different manners, such as, for example, in terms of units of energy consumed by the air compressor 102 or the power attained by the air compressor 102 during operation, such as the air compressor 102 working at a particular horsepower. For example, the pressure control device 122 may be configured so that the air compressor 102 cannot exceed 8 horsepower when the air compressor 102 is operating at a maximum speed, such as, for example, a speed of 3000 revolutions per minute (rpm).

[00028] The air compressor 102 receives pressurized airflow 114 at the inlet 130 of the air compressor 102. It is contemplated that the air compressor 102 can be any known compressor, such as a single cylinder positive displacement air compressor, a multiple piston positive displacement compressor, a rotating impeller-type compressor, or any type of compressor which receives and outputs a compressed air 136. Further, it is contemplated that the air compressor 102 is mechanically coupled to the engine 104. According to the illustrated embodiment, compressed air 136 is outputted from the air compressor 102 may be delivered to an air dryer 135 and/or one or more compressed air storage tanks 138. However, according to other embodiments, in addition to, or in lieu of, delivering the compressed air to an air dryer 135 and/or an air storage tank 138, compressed air may be delivered to one or more pneumatic devices, such as, for example, air brakes, suspension equipment, and/or any other pneumatic device or systems of the engine system 100 and/or vehicle.

[00029] Additionally, according to certain embodiments, operation of the pressure control device 122 may at least be based in part on operational limits, specifications, and/or other operating characteristics associated with components downstream of the air compressor 102. For example, according to certain embodiments, the pressure of the regulated airflow 128 exhausted from the pressure control device 122 may be based, at least in part, on inlet compressed gas pressure and/or temperature requirements, specifications, and/or other operating considerations of the air dryer 135 that is in fluid communication with, and downstream of, the air compressor 102. Accordingly, the pressure control device 122 can be operated based, at least in part, on a prediction or estimation of the impact the compression of the delivered regulated airflow 128 by the air compressor 102 in generating inlet compressed gases will have on one or more of those characteristics, such as, for example, on the pressure and/or temperature of the compressed gases that are delivered to those downstream components. For example, the air compressor 102 may be predicted to increase the temperature of the regulated airflow 128 by X° Celsius as the air compressor 102 compresses the delivered regulated airflow 128 when generating an inlet compressed gas for the air dryer 135. If the air dryer 135 is to be provided with an inlet compress gas having a temperature that does not exceed Y° Celsius, the pressure control device 122 may be operated, such as, for example, by the controller 140, so that the regulated airflow 128 is outputted a first pressure that allows for the regulated airflow 128 to have a temperature around, or below Z° Celsius, with Z° Celsius + X° Celsius being below Y° Celsius.

[00030] Thus, according to certain embodiments, the pressure control device 122 may be operated to accommodate for predicted or estimated changes in characteristics of the gases exhausted from the pressure control device 122 by one or more downstream components, such as, the air compressor 102, and the operating characteristics of those or other downstream components, such as the characteristics of the air compressor 102 and/or an air dryer 135. Figure 4 illustrates a flow chart of a method 200 for controlling the pressure of an airflow that is delivered to an air compressor 102 according to an illustrated embodiment of the invention. Steps illustrated are understood to be exemplary only, and steps may be combined or divided, and added or removed, as well as re-ordered in whole or in part. At step 202, an intake airflow 109 is pressurized by the pressure source 1 10 to provide a pressurized airflow 1 14. At step 204, at least a portion of the pressurized airflow 1 14 is diverted by the diverter 1 16 along a flow path to the pressure control device 122, while at least another portion of the pressurized airflow 1 14 may be directed along another flow path to a combustion chamber 1 18 of the engine 104. The diverted pressurized airflow 1 14 may then be delivered to the pressure control device 122 at step 206.

[00031] At step 208, before or while the pressurized airflow 1 14 is delivered to the pressure control device 122, a determination may be made as to whether the air compressor 102 is in the loaded or unloaded compressor operating state. As previously discussed, a determination of whether the air compressor 102 is in the loaded or unloaded compressor operating state may be made in a number of manners, including, for example, the level, if any, to which the pressure source 1 10 is pressurizing the intake airflow 109, and/or the operating conditions of the engine system 100, among other criteria. If the air compressor 102 is in the loaded compressor operating state, then at step 210 a determination may be made as to whether the pressure control device 122 needs to be adjusted to output the pressurized airflow 114 at the first pressure. Again, such adjustment of the pressure control device 122, which may occur at step 212, may occur in a number of different manners, and may include the displacement of a component of the pressure control device 122. At step 214, the pressure control device 122 may output the regulated airflow 128 at the first pressure.

[00032] Similarly, if the air compressor 102 is determined to be in the unloaded compressor operating state, then at step 216 a determination may be made as to whether the pressure control device 122 needs to be adjusted so that regulated airflow 128 is outputted from the pressure control device 122 at the second pressure. Such adjustment of the pressure control device 122, which may occur at step 218, may include displacing a component of the pressure control device 122 so that the regulated airflow 128 is outputted from the pressure control device 122 at the second pressure rather than at the first pressure. At step 220, the pressure control device 122 may output the regulated airflow 128 at the second pressure. The regulated airflow 128 outputted from the pressure control device 122 at either step 214 or step 220 may then be delivered to the air compressor 102 via a flow line or path and be compressed by the air compressor 102 at step 222.

[00033] Various features and advantages of the present invention are set forth in the following claims. Additionally, changes and modifications to the described embodiments described herein will be apparent to those skilled in the art, and such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. While the present invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered illustrative and not restrictive in character, it being understood that only selected embodiments have been shown and described and that all changes, equivalents, and modifications that come within the scope of the inventions described herein or defined by the following claims are desired to be protected.

[00034] While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A method for controlling the pressure of airflow delivered to an air compressor comprising:

determining whether the air compressor is operating in a loaded compressor operating state or an unloaded compressor operating state;

receiving, by a pressure control device, a first airflow, the pressure control device being in fluid communication with the air compressor;

adjusting, by the pressure control device and based at least in part on the air compressor being in the loaded compressor operating state, a pressure of the first airflow to provide a regulated airflow having a first pressure;

adjusting, by the pressure control device and based at least in part on the air compressor being in the unloaded compressor operating state, the pressure of the first airfiow to provide the regulated airfiow at a second pressure, the second pressure being greater than 0 bar, the first pressure being larger than the second pressure; and

delivering the regulated airflow to the air compressor.

2. The method of claim 1, wherein the second pressure is between 0 bar and 1 bar.

3. The method of claim 2, wherein the second pressure is between 0.1 bar and 0.5 bar.

4. The method of claim 3, wherein the steps of adjusting the pressure of the first airfiow are independent of an engine load on the engine.

5. The method of claim 1, wherein the first pressure corresponds to a predetermined power consumption limit of the air compressor.

6. The method of claim 5, wherein the predetermined power consumption limit of the air compressor corresponds to a horsepower limit for the operation of the air compressor.

7. The method of claim 1, wherein the first pressure corresponds to a first temperature of the regulated airfiow, the first temperature being based at least in part on facilitating the delivery of a compressed inlet gas from the air compressor to a downstream component that has a compressed gas temperature that satisfies a temperature criteria of the downstream component.

8. The method of claim 1, wherein the first pressure corresponds is based at least in part on facilitating the delivery of a compressed inlet gas from the air compressor to a downstream component that has a compressed gas pressure that satisfies a pressure criteria of the downstream component.

9. The method of claim 1, wherein the determination of whether the air compressor is in the loaded compressor operating state or the unloaded compressor operating state includes the step of determining a storage level of a compressed air in a compressed air storage tank.

10. The method of claim 1, wherein the determination of whether the air compressor is in the loaded compressor operating state or the unloaded compressor operating state includes the step of determining the pressure of the first airflow.

11. A system for controlling the pressure of an airflow supplied to an air compressor of an engine system, the system comprising:

a pressure control device having an inlet and an outlet, the inlet adapted to receive a first airflow having an airflow pressure, the outlet being in fluid communication with the air compressor, the pressure control device adapted to adjust the airflow pressure based on an operating state of the air compressor and independent of an engine load on an engine of the engine system.

12. The system of claim 11, wherein the pressure control device is adapted to adjust the airflow pressure and output a regulated airflow having a first pressure when the air compressor is in a loaded compressor operating state or having a second pressure when the air compressor is in an unloaded compressor operating state, the second pressure being greater than zero bar and the first pressure being greater than the second pressure.

13. The system of claim 11, further including a controller configured to determine the operating state of the air compressor.

14. The system of claim 11, wherein the second pressure is between 0 bar and 1 bar.

15. The method of claim 14, wherein the second pressure is between 0.1 bar and 0.5 bar.

16. The system of claim 15, wherein the system further includes at least one pressure sensor, the at least one pressure sensor configured to provide information for the controller to determine the operating state of the air compressor.

17. The system of claim 11, wherein the first pressure corresponds to a predetermined power consumption limit of the air compressor.

18. The system of claim 11, wherein the first pressure corresponds to a first temperature of the regulated airflow, the first temperature being based at least in part on facilitating the delivery of a compressed inlet gas from the air compressor to a downstream component that has a compressed gas temperature that satisfies a temperature criteria of the downstream component.

19. The system of claim 11, wherein the first pressure corresponds is based at least in part on facilitating the delivery of a compressed inlet gas from the air compressor to a downstream component that has a compressed gas pressure that satisfies a pressure criteria of the downstream component.

20. A system comprising:

an air compressor configured to operate in a loaded compressor operating state and an unloaded compressor operator state;

a diverter configured to divert at least a portion of an airflow to provide a diverted airflow; and

a pressure control device having an inlet and an outlet, the inlet being in fluid communication with the diverter, the outlet being in fluid communication with the air compressor, the pressure control device adapted to adjust a pressure of the diverted airflow to a first pressure based on the air compressor being operated in the loaded compressor operating state and to a second pressure based on the air compressor being operated in the unloaded compressor operating state, the first pressure being greater than the second pressure and the second pressure being above 0 bar.

21. The system of claim 20, wherein the second pressure is between 0 bar and 1 bar.

22. The method of claim 21, wherein the second pressure is between 0.1 bar and 0.5 bar.

23. The system of claim 20, wherein the first pressure corresponds to a predetermined power consumption limit of the air compressor.

24. The system of claim 23, wherein the predetermined power consumption limit of the air compressor corresponds to a horsepower limit for the operation of the air compressor.

25. The system of claim 20, wherein the first pressure corresponds to a first temperature of the regulated airflow, the first temperature being based at least in part on facilitating the delivery of a compressed inlet gas from the air compressor to a downstream component that has a compressed gas temperature that satisfies a temperature criteria of the downstream component.

26. The system of claim 20, wherein the first pressure corresponds is based at least in part on facilitating the delivery of a compressed inlet gas from the air compressor to a downstream component that has a compressed gas pressure that satisfies a pressure criteria of the downstream component.