Integral add heat and surge control valve for compressor

Abstract

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.

Description

[0001] 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 INVENTION [0002] This invention relates to a compressor that is used, for example, in an aircraft for supplying compressed air to a cabin air conditioning system. [0003] 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. [0004] 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...

AI Technical Summary

Benefits of technology

[0007] 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.

[0008] Accordingly, the present invention provides a deicing and surge control device that deices the compressor and prevents surge.

Problems solved by technology

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.

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