TECHNICAL REPORT

Technical Report



Abstract

This document contains information resulting from a cooperative research effort. The contents hereof are only intended to be guidelines for the subject matter to which the document pertains. Neither Southern Gas Association nor the Gas Machinery Research Council make any warranty or representation, express or implied, with respect to the accuracy, completeness or usefulness of the information contained in this document, including, without limitation, implied warranties of merchantability and fitness for a particular purpose, or that the use of any method, suggestion, technology, information or guidelines disclosed herein may not infringe on rights owned or claimed by others. In no event will Southern Gas Association or the Gas Machinery Research Council be liable for any damages, including, without limitation, liability arising out of contract, negligence, strict liability, environmental or tort, warranty or copyright infringement, or any incidental or consequential damage arising out of the use of this Report.

Table of Content

Introduction4

Background5

Concept Selection5

Design and Installation7

Demonstration Test9

Conclusion10

References12

Appendix13

Technical Report

Introduction

The objectives of research on active surge control are to refine a concept for improved surge control, to develop a practical sensor and a preliminary design, and to assemble and install a prototype system, and conduct a demonstration test that indicates the benefits of active surge control. The overall objectives of this research can be divided into six goals that reflect the accomplishments necessary to realize the benefits available from active surge control. The six parts of the objectives for this research are:

1. To develop a practical surge control concept,

2. To select a sensor and develop implement plans,

3. To design a prototype system,

4. To assemble and install an engineering prototype,

5. To conduct a demonstration test, and

6. To report on results in support of future applications.

A clarifying definition related to active surge control is that active surge control, in the context of this study, means a more fundamental, internal to the compressor, detection of approaching surge that provides a proportional and positive; hence, active control of compressors for the avoidance of surge. Beyond the scope of the current active surge control work, there has been some research and laboratory studies on the introduction of dynamic signals (pressures and flows) into centrifugal compressors to alter the conditions at which surge occurs. This approach can also be called active surge control or more precisely active control of surge.

Background

To obtain and confirm background information on the status of and the benefits of active surge control, a survey of the industry was conducted. The survey responses represent a significant share of centrifugal compressors in natural gas service, and indicated that at least 90 percent of these compressors have surge control systems based on flow and head measurements. Many of these systems measure other variables such as speed, suction pressure, specific gravity, and similar factors that affect the expected surge line, so that adjustments to the surge control limits can be made. None of these systems measure internal or phenomenological indications of surge, and as a result, they all depend on the location of the compressor on ...