Process Control for Compression Systems

Author(s):  
Rainer Kurz ◽  
Klaus Brun

This paper discusses the interaction between a centrifugal compressor and the process, and as a result, the control requirements for centrifugal compressor packages. The focus is on variable speed, upstream, and midstream applications. The impact of the interaction between system characteristics and compressor characteristics both under steady-state and transient conditions is explained. Also considered are the concepts to optimize and control the units. Special attention is given to the issue of surge avoidance. Additionally, the impact of the process and how the process dynamics interact with the compressor is analyzed, categorized, and explained.

Author(s):  
Rainer Kurz ◽  
Klaus Brun

The paper discusses the interaction between a centrifugal compressor and the process, and as a result, the control requirements for centrifugal compressor packages. The focus is on variable speed, upstream and midstream applications. The impact of the interaction between system characteristics and compressor characteristics, both under steady state and transient conditions is explained. Also considered are concepts to optimize and control the units. Special attention is given to the issue of surge avoidance. Additionally, the impact of the process and how the process dynamics interact with the compressor is analyzed, categorized, and explained.


1971 ◽  
Vol 4 (5) ◽  
pp. T80-T83
Author(s):  
S. A. E. Barrow

The accent on centralised control has led to a considerable reduction in panel length by the use of high density instrumentation. Condensing the panel length introduces the problem of mounting back of panel equipment in a much reduced area. Several designs of control panels have been developed within the process industry and the paper reviews the various answers to this problem. One particularly successful integrated design is described and includes development, layout, fabrication, shop testing, transport, installation, maintenance and control house layout. The paper concludes with various improvements and innovations for the future and the impact of integrated panel design on manufacturers and users.


Author(s):  
Rainer Kurz ◽  
Robert C. White ◽  
Klaus Brun

Different upstream and midstream applications lead to different compression system characteristics and control requirements that are the result of compressor requirements (eg high pressure ratio, wide operating range) and the process requirements. Multiple unit installations, or installations with multiple compressors per train require specific process control considerations to match the compressors with the process system behavior and the objectives of the station or system operator. This paper explains the impact of the interaction between system characteristics and compressor characteristics, both under steady state and transient conditions. Also considered are concepts to optimize and control the units.


2021 ◽  
Author(s):  
Costas Kravaris ◽  
Ioannis K. Kookos

Presenting a fresh look at process control, this new text demonstrates state-space approach shown in parallel with the traditional approach to explain the strategies used in industry today. Modern time-domain and traditional transform-domain methods are integrated throughout and explain the advantages and limitations of each approach; the fundamental theoretical concepts and methods of process control are applied to practical problems. To ensure understanding of the mathematical calculations involved, MATLAB® is included for numeric calculations and MAPLE for symbolic calculations, with the math behind every method carefully explained so that students develop a clear understanding of how and why the software tools work. Written for a one-semester course with optional advanced-level material, features include solved examples, cases that include a number of chemical reactor examples, chapter summaries, key terms, and concepts, as well as over 240 end-of-chapter problems, focused computational exercises and solutions for instructors.


2002 ◽  
Vol 26 (6) ◽  
pp. 371-381 ◽  
Author(s):  
A. Haniotis ◽  
S. Papathanassiou ◽  
A. Kladas ◽  
M. Papadopoulos

A prototype of the electrical part of a variable speed wind turbine is considered, equipped with a permanent-magnet synchronous generator. The modelling of the generator and power electronics interface is checked with measurements realized in the prototype, under both steady-state and dynamic conditions. Measurements and control functions are performed by using a microprocessor. The outcome of the simulation and experimental work are actually utilized in the development of a 25 kW wind turbine, in the frame of a research project.


Author(s):  
Jose´ L. Gilarranz R. ◽  
Louis M. Lombardi ◽  
Jarrod E. Keesler ◽  
William C. Maier ◽  
Jay M. Koch ◽  
...  

In recent years, several papers have been written regarding the use of moveable geometry systems to enable the rotation of otherwise stationary vanes used in centrifugal compressor research test vehicles. These systems typically are installed in single stage rigs or are placed at the inlet of the first stage of multi-stage centrifugal compressor test vehicles. This paper describes the capabilities of a state-of-the-art test vehicle that was developed by the Original Equipment Manufacturer (OEM) as a result of the OEM’s ongoing Research and Development Program aimed towards the implementation of novel and advanced technologies during the development of high-performance centrifugal compressors. The test vehicle is equipped with a variety of internal instrumentation that allow the collection of detailed aero/thermodynamic inter-stage performance data that is used to evaluate the behavior of the machine. The design of the unit also incorporates moveable vanes at the inlet guides upstream of each impeller, at each diffuser inlet and at the inlet of each return channel. The moveable geometry components allow infinite tuning of these components in a multistage environment, which allows the optimization of the aerodynamic performance of the stages based on design and/or off-design operating requirements of the process. The variable geometry system also allows the vanes to be positioned in such a way as to maximize the operating range of the compressor. The incorporation of adjustable vanes into the test vehicle allowed the OEM to significantly reduce the test cycle time, while maximizing the test data that was obtained from a single build. The positioning of the moveable vanes is controlled by a PC-based system that has been integrated into the OEM’s data acquisition system. This paper presents the work executed during the specification, design and implementation of the moveable geometry control system that was developed for the test vehicle. It covers topics such as the selection of the actuators and control hardware, as well as the integration of the actuators with the moveable vanes and other test unit components. Also discussed are the specification and development of the control software and the techniques, hardware and procedures used for the calibration of the moveable geometry system. The calibration was required to accurately determine the transfer function between the actuator movement and the actual rotation of the vanes. The paper also discusses the use of 5-hole pressure probes during the actual test to measure the flow direction upstream of the moveable vanes and how this information was used to achieve the test objectives. Finally, sample test data is presented to illustrate the impact that the moveable geometry system had over the performance of the compressor stages.


2011 ◽  
Vol 70 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Beat Meier ◽  
Anja König ◽  
Samuel Parak ◽  
Katharina Henke

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.


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