Research on Speed Regulation Technology Reform Strategy of Centrifugal Compressor

Adjustable inlet guide vanes (IGVs) and variable speed drivers are known as providing process compressors with an effective regulation all throughout the operating envelope of the machine. A large number of works exists in literature reporting the successful control of multistage centrifugal compressors by means of IGVs or speed separately, while a few studies document the combined use of both devices and their effect on compressor performance. The present paper details the off-design behavior of a multistage centrifugal compressor equipped with both types of control. It is shown that classical IGVs advantage in extending the operating envelope of a fixed speed multistage compressor tends to reduce when speed regulation is active too. In this sense, the average level of peripheral Mach numbers inside the compressor may be interpreted as a sort of threshold, since it deeply affects the stage mismatching at off-design conditions. This consideration is corroborated by a number of applications in a wide range of design peripheral Mach numbers. Based on those cases, the paper reviews the general effectiveness of the combined regulation, thus outlining some general rules of thumb for the choice of the optimal control device for a multistage centrifugal compressor.

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On the Combined Effect on Operating Range of Adjustable Inlet Guide Vanes and Variable Speed in Process Multistage Centrifugal Compressors

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4026621 ◽

2014 ◽

Vol 136 (8) ◽

Cited By ~ 1

Author(s):

Alberto Scotti Del Greco ◽

Libero Tapinassi

Keyword(s):

Centrifugal Compressor ◽

Control Device ◽

Variable Speed ◽

Centrifugal Compressors ◽

Guide Vanes ◽

Inlet Guide Vanes ◽

Speed Regulation ◽

Wide Range ◽

Mach Numbers ◽

Multistage Centrifugal Compressor

Adjustable inlet guide vanes (IGVs) and variable speed drivers are known as providing process compressors with an effective regulation all throughout the operating envelope of the machine. A large amount of work exists in literature reporting the successful control of multistage centrifugal compressors by means of IGVs or speed separately, while a few studies document the combined use of both devices and their effect on compressor performance. The present paper details the off-design behavior of a multistage centrifugal compressor equipped with both types of control. It is shown that classical IGVs' advantage in extending the operating envelope of a fixed speed multistage compressor tends to reduce when speed regulation is active too. In this sense, the average level of peripheral Mach numbers inside the compressor may be interpreted as a sort of threshold since it deeply affects the stage mismatching at off-design conditions. This consideration is corroborated by a number of applications in a wide range of design peripheral Mach numbers. Based on those cases, the paper reviews the general effectiveness of the combined regulation, thus outlining some general rules of thumb for the choice of the optimal control device for a multistage centrifugal compressor.

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Speed regulation

AccessScience ◽

10.1036/1097-8542.643300 ◽

2015 ◽

Keyword(s):

Speed Regulation

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Banking reform in China: International standards and Chinese specifics

Acta Oeconomica ◽

10.1556/aoecon.58.2008.4.4 ◽

2008 ◽

Vol 58 (4) ◽

pp. 403-426

Author(s):

Z. Kudrna

Keyword(s):

Best Practices ◽

Development Policy ◽

Institutional Reform ◽

International Standards ◽

State Control ◽

Banking Reform ◽

Reform Strategy ◽

Regulatory Frameworks ◽

Bank Governance ◽

Credit Boom

This paper reviews the progress of banking reforms in China. Since 2002, the reform strategy has relied on publicly-financed bailouts, implementation of international best practices in bank governance and regulation, and listing of major banks in Hong Kong. The three largest banks have been stabilised, but we find little reason to expect this to be sustainable. Prudential indicators are comparable to international averages, but this is an outcome of bailouts and ongoing credit boom. Reforms of bank governance and regulatory frameworks that would alter banker’s incentives are implemented in a selective manner; principles that concentrate key powers in the centre are implemented vigorously, whereas those that require independent boards and regulators are ignored. Selectiveness of institutional reform means that the largest banks remain under state control and can be used as means of development policy for the better or the worse.

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