Integral add heat and surge control valve for compressor
A compressed air system includes a compressor having an inlet and an outlet. A duct fluidly connects the outlet to the inlet and has a valve arranged in the duct. A controller communicates with the valve and commands the valve to move between first and second positions in response to a surge condition and/or an add-heat condition to regulate an amount of fluid flowing through the duct. The valve opens to provide hot air from the compressor outlet to deice the inlet or to provide the higher pressure compressor outlet air to the lower pressure compressor inlet air to obtain a pressure ratio in a desired range. The inventive compressed air unit is designed to provide a compact arrangement so that the valve providing the heated, pressurized air to the inlet is located in close proximity to the inlet for a rapid response time. The duct comprises a relatively short length of tubing interconnecting an add-heat supply outlet and an add-heat plenum inlet, which are provided by a housing of the compressor. The housing also includes an add-heat plenum having an annular wall arranged at the inlet to provide an annular cavity. Hot air from the compressor outlet is provided to the plenum to heat the annular wall quickly at the inlet to prevent deicing.
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The present application is a continuation-in-part application of U.S. application Ser. No. 10/978,641 filed on Nov. 1, 2004 that claims priority to U.S. Provisional Patent Application Ser. No. 60/611,992, filed Sep. 22, 2004.
BACKGROUND OF THE INVENTIONThis invention relates to a compressor that is used, for example, in an aircraft for supplying compressed air to a cabin air conditioning system.
In some compressor applications in aircraft, air entering a compressor inlet contains water and operates at temperatures below freezing. Ice forming at the inlet reduces the thermodynamic performance of the compressor, can cause damage to the compressor as the ice sheds and can damage the bearing and support structure of the compressor.
Compressors may occasionally operate in an undesirable surge condition in which the ratio between compressor outlet and compressor inlet pressures is undesirable. To avoid surge it is desirable to either lower the compressor outlet pressure or raise the compressor inlet pressure to obtain a pressure ratio within a desired range.
What is needed is a deicing and surge control device that is capable of deicing the compressor inlet and controlling surge in efficient, rapid manner.
SUMMARY OF THE INVENTIONThe invention provides a compressed air system that includes a compressor having an inlet and an outlet. A duct fluidly connects the outlet to the inlet and has a valve arranged in the duct. A controller communicates with the valve and commands the valve to move between first and second positions in response to a surge condition and/or for an add-heat condition to regulate an amount of fluid flowing through the duct. The valve opens to provide hot air from the compressor outlet to deice the inlet or to provide the higher pressure compressor outlet air to the lower pressure compressor inlet air to obtain a pressure ratio in a desired range.
The inventive compressed air unit is designed to provide a compact arrangement so that the valve providing the heated, pressurized air to the inlet is located in close proximity to the inlet for a rapid response time. The duct comprises a relatively short length of tubing interconnecting an add-heat supply outlet and an add-heat plenum inlet, which are provided by a housing of the compressor. The housing also includes an add-heat plenum having an annular wall arranged at the inlet to provide an annular cavity. Hot air from the compressor outlet is provided to the plenum to heat the annular wall quickly at the inlet to prevent deicing.
Accordingly, the present invention provides a deicing and surge control device that deices the compressor and prevents surge.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
A compressed air system is shown schematically at 10 in
The present invention utilizes a duct 30 to fluidly connect the inlet 20 and outlet 22. A valve 32 is arranged between the inlet 20 and outlet 22 within the duct 30. The controller 34 is in communication with the valve 32 to move it between first and second positions F and S in response to the surge and add-heat conditions. According to this invention, only one valve is used for these conditions. In one example, the valve 32 is a butterfly valve.
Referring to
An impeller 66 is secured to the rotor 64. The impeller 66 has an inlet side 65 and outlet side 67. The diffuser 18 is arranged on the outlet side 67 between the impeller 66 and the outlet 22. The housing 40 includes a diffuser shroud 68 in close proximity to the impeller 66. The diffuser shroud 68 extends beyond an end 69 of the impeller 66.
The housing 40 provides an add-heat plenum 72 formed by the diffuser shroud 68 and the add-heat housing 46. The diffuser shroud 68 provides a curved annular wall 70 that tapers radially outwardly as it extends axially away from the end 69 of the impeller 66.
The outlet housing 44 provides an add-heat supply outlet 74 (best shown in
Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
Claims
1. A compressed air system comprising:
- a compressor having an inlet and an outlet;
- a duct fluidly connecting the outlet to the inlet with a valve arranged in the duct; and
- a controller communicating with the valve and commanding the valve to move between first and second positions in response to a surge condition and an add-heat condition to regulate an amount of fluid flowing through the duct.
2. The system according to claim 1, comprising inlet and outlet pressure sensors respectively associated with the inlet and outlet, the controller monitoring a ratio of inlet and outlet pressures respectively from the inlet and outlet pressure sensors to determine the surge condition.
3. The system according to claim 1, comprising an inlet temperature sensor associated with the inlet, the controller monitoring an inlet temperature from the inlet temperature sensor to determine the add-heat condition.
4. The system according to claim 1, wherein the compressor includes a housing providing an add-heat plenum having a generally annular wall, the add-heat duct fluidly connecting the add-heat plenum to the outlet.
5. The system according to claim 4, wherein the housing includes a shroud at least partially surrounding an impeller of the compressor, the shroud providing the generally annular wall.
6. The system according to claim 4, wherein the valve is moved from the first position to the second position in response to the add-heat condition providing fluid from the outlet to the add-heat plenum to heat the annular wall.
7. A compressed air unit comprising:
- a housing including first and second housing portions respectively providing an inlet and an outlet, and the first and second housing portions respectively providing an add-heat plenum inlet and an add-heat supply outlet respectively in fluid communication with the inlet and outlet;
- an impeller arranged in the housing between the inlet and the outlet for compressing fluid; and
- a duct fluidly connecting the add-heat supply outlet and the add-heat plenum inlet with a valve arranged in the duct for regulating the flow of fluid from the outlet to the inlet.
8. The unit according to claim 7, wherein the first housing is an outlet housing and the second housing is an add-heat housing secured to the outlet housing, the housing including an inlet housing secured to the add-heat housing opposite the outlet housing, the add-heat and inlet housings arranged upstream of the impeller.
9. The unit according to claim 8, wherein a shroud is arranged between the impeller and the add-heat housing forming an add-heat plenum in fluid communication with the add-heat plenum inlet, the shroud providing an annular wall.
10. The unit according to claim 8, wherein the housing includes a motor housing secured to the outlet housing opposite the add-heat housing, an electric motor arranged in the motor housing and including a rotor coupled to the impeller.
11. The unit according to claim 7, wherein the housing has a length that is greater than a length of the duct.
12. The unit according to claim 7, wherein a variable diffuser is arranged between the impeller and the outlet.
13. A compressed air unit comprising:
- a housing including an inlet and an outlet;
- an impeller arranged between the inlet and outlet; and
- a portion of the housing providing a plenum including an annular wall defining an annular cavity, the annular cavity in fluid communication with the inlet and the outlet, and the annular wall near the impeller.
14. The unit according to claim 13, wherein a duct fluidly connects the outlet and the plenum, and a valve arranged in the duct.
15. The unit according to claim 13, wherein the impeller includes an end and the annular wall extends across the end and away from the impeller.
16. The unit according to claim 13, wherein the annular wall tapers radially outwardly in a direction axially away from the impeller.
Type: Application
Filed: Nov 8, 2005
Publication Date: Mar 30, 2006
Applicant:
Inventors: Christopher McAuliffe (Windsor, CT), Craig Beers (Wethersfield, CT)
Application Number: 11/269,082
International Classification: F04B 49/10 (20060101); F04B 49/00 (20060101);