Anti surge control system pdf

Anti surge protection system is a very important part of compressor but it is not presented in anti surge valves only but it contains a several devices that integrate all together to give an output which is the safe protection setpoint for machine. This report on compressor antisurge control closes some of the gaps related to the signi. The anti surge control holds up a stable operation. Knowing how your system is behaving is key to predicting when maintenance or intervention is necessary. This antisurge control system for compressor capacity control usually results in wasting of large amount of compression energy since the pressure of already compressed gas is letdown in a throttling valve called anti surge control valve and recycles back to. Because that function depends on which conditions are fixed and the configuration of your compressor, we provide a flexible method for defining it. Today, more of an emphasis than ever is placed on combining these compressor recycle and compressor anti surge functions into one single valve. Antisurge systemsstate of the art world scientific news. Industrial compressor antisurge computer control citeseerx. The anti surge controller together with the anti surge control valve will do this very important task in a very fast manner.

His first point is that surge control is only needed when the gas flow is low, so most compressors are designed to have their surge valves closed for the majority of the time. Typical studies are not accurate enough to capture the complex interactions leading to catastrophic events, especially for complicated system arrangements. Compressors should be equipped with two independent systems, an anti surge control and a surge protection. Antisurge control ccc compressor controls corporation. Compressor start and stop the inlet valve and blowoff valve are controlled efficiently.

What is an antisurge control system, how it works answer senthil. Thus, the antisurge control program calculates proximityto surge using a multivarible function that is invariant to any process change it might encounter. Pdf gas compression package gcp is a vital system in the distribution of gas. This operation allow reduction of many performance curves to reduce them to one curve by normalizing mass flow and polytropic head with respect to. Antisurge protection is provided by a control valve which will either exhaust the gas or vapor from the compressor into the atmosphere, or recirculate it back to the compressor inlet. During steadystate operation the inlet valve is controlled to regulate the blowoff flow rate of the compressed air. Although control valves are normally sized according to operating conditions and the need for velocity control, anti surge is something that needs specific attention on certain applications. Anti surge control system for centrifugal compressors part 2. Anti surge control is an important issue in operation of e. The anti surge control system is designed to determine the surge condition in the compressor and to operate the anti surge control valve in an efficient and speedy manner to protect the centrifugal compressor from the surge. Centrifugal and axial compressors are susceptible to surge which can cause catastrophic damage to your turbomachinery train. Apr 29, 2015 poor response for anti surge protection system. The antisurge controller is one of the most critical turbomachinery control applications that protect a compressor from surge by continuously calculating the distance between the compressors operating point and its surge limit line.

The potential for damage may be illustrated by the following graph showing the effects of the closure of an esd valve. Centrifugal and axial compressors cannot be allowed to operate in the surge area, see figure 1. If the system upset is severe, a second rate control pid is invoked to more quickly move the valve demand. The paper presents a compressor anti surge control system, that results in maximizing compressor throughput with pressure standard deviation reduction, increased safety margin between design point and surge limit line and avoiding possible machine. Evaluation of antisurge control concepts during esd.

Many facilities employ two or more centrifugal compressors, operated in either series or parallel configurations. These anti surge systems or surge control systems consist of one or two recycle lines around the compressor, which are equipped with fast acting valves that open when the compressor approaches the surge limit. Anti surge controller working principle instrumentation tools. Pertamina ep, in this regard as a stateowned company managing oil and. Surge control considerations in centrifugal compressors. Operating in the surge area will result in unstable compressor. These antisurge systems or surge control systems consist of one or two recycle lines around the compressor, which are equipped with fast acting valves that. Anti surge systems are therefore used to activate and prevent the unit for undergoing surge.

Single stage compressor control rockwell automation. Sep 23, 2016 in order to protect the compressor adequately from surge, the discharged flow must be restored very quickly. Training lectures on industrial control systems and important applications. An accurately designed surge control system that includes multiple compressors with the associated piping systems is a vital element of a facilitys design and ongoing operational integrity. Centrifugal compressor surge control systems fundamentals. Sep 04, 2017 training lectures on industrial control systems and important applications. While approaching the surge line, the flow of the compressor is kept at the lowest possible value by opening a bypass valve. The performance of many antisurge control systems is degraded because they do not adequately compensate for variable gas properties primarily molecular. As an improvement in an anti surge control method for a multistage centrifugal compressor having interstage coolers, this invention comprises, when there is an imbalance of stage flows relative to surge, replacing recycle with warm expanded gas to the maximum extent possible that still achieves an energy saving as compared with not effecting such replacement. Anti surge system layout figure 6 is an illustration of the anti surge system layout. Antisurge control is an important issue in operation of e. The system will also provide smooth control at the surge control line, while also having the additional capacity to step the valve open to prevent compressor surge.

If op is moving leftward toward scl, your algorithm shall open anti surge valve asv. The anti surge controller imaginary operation protection line is surge control line. The valve must be able to control flow and avoid surges. Typical 3stage antisurge system schematic 1 2 3 antisurge controller antisurge system high performance antisurge valve actuation will help you get the most from sophisticated antisurge controllers. Procidia control solutions compressor surge control. Centrifugal compressor surge, modeling and identification for. The process data it self has several cases for several surge possibility. While there are advantages to having a single party responsible for the entire train, it can result in finger pointing and confusion. Conventional anti surge control it is typical antisurge system which is described earlier in this paper. The anti surge system has to control the operating op point on the right of scl.

Matching antisurge control valve performance with integrated. The system will also provide smooth control at the surge control line, while also having the additional capacity to step the valve open to prevent compressor surge due to rapid. An anti surge control system for a centrifugal compressor in a refrigeration system of the type which includes first capacity control means operative to regulate gas flow to the suction side of said compressor, said control system comprising means for generating a first control signal which is a function of the demand for cooling on the load. Outline introduction types of compressor centrifugal compressor surge description anti surge system conclusion 2 3. Anti surge protection is provided by a control valve which will either exhaust the gas or vapor from the compressor into the atmosphere, or recirculate it back to the compressor inlet. Bently nevada 3500 and system 1 vibration monitoring replacing bently nevada 3300 shell casc compressor antisurge control on yokogawa centum dcs replacing basic dcs antisurge control shell casc compressor anti surge control trip in honeywell ips replacing protronic antisurge trip system.

Pdf anti surge control of centrifugal compressor at pt. Us3080712a compressor antisurge control for a gas turbine. A reliable control valve that functions consistently under the most severe conditions. The instability is characterized by large limit cycle oscillations in compressor. Because of the shape of their performance curves, the application of centrifugal compressors frequently is consider ably more complex than that of reciprocating machines. Antisurge controller for axial and centrifugal compressors. Pdf active control of surge compressor system researchgate. On centrifugal discharge, a check valve shall be installed to prevent reverse flow and minimize surge. Mani, cesinsts control philosophy i n c a s e o f a p r o c e s s u n it s t h e e m p h a s is is o n s a f e o p e r a t io n a n d p r e c is e c o n t r o l in c a s e o f r o ta ry m c s th e e m p h a s is is o n s a f e o p e r a tio n a n d m o n it o r in g. Antisurge protection system for compressors turbomachinery. Centrifugal compressor surge, modeling and identification. Pete was recently asked about his thoughts on doing anti surge compressor controls within an automation system, in this case, the deltav system. Further integration of the ccc control applications and the actuators controls and diagnostics will optimally utilize the qualities of the.

In this article torque assisted anti surge control tasc, a compressor anti surge control system based on model predictive control mpc is presented. Surge control design for centrifugal compressor systems three levels of dynamic surge analysis compressor reliability is directly affected by the interaction between the surge controller, piping system, valves, recycle lines and coolers. Our controller combines both closed and open loop control responses to prevent surge without requiring a large control margin while minimizing recycling and unnecessary upsets to the process. Tasc is implemented on an embedded system for the control of compressor stations with electrical variablespeed drives vsd which are used in applications such as natural gas transportation via. The check valve shall be located as close as possible downstream of the compressor to minimize mass inventory.

Antisurge control final of final free download as powerpoint presentation. Surge control design for centrifugal compressor systems. Figure adapted from slidingplug surge relief valve helps meet dot requirements, pipeline industry, january 1992. A reliable control valve that functions consistently under the most severe conditions is absolutely essential to the protection of the compressor. Protecting a centrifugal compressor from surge pipeline. The patented rotary control tball features a nonclogging quarterturn design that provides quick and low impact automation. Procidia control solutions compressor surge control this application data sheet describes implementing compressor surge control in a siemens 353 controller1. With the aid of the kmo surge application software included within the. Before designing the anti surge control valve, the compressor manufacturer usually has some anti surge system study with some set of process data required to design the anti surge control valve.

In order to improve the response of the asc system in emergency situations, implementation of a socalled hot bypass or a cold bypass can be considered. For this reason the anti surge recycle connection and anti surge control valve shall be located upstream of the check valve as close as practical to the compressor discharge connection. The masoneilan 72000 series control valve can be specified with several features that are. Feb 14, 2018 in this video we will describe industrial air axial compressor operation and how surge control system work also we explain the centrifugal critical speed,air compressor maintenance surge is a. Advanced constraint control schemes such as predictive setpoint and feedforward, rateofchange calculations are important in maximizing control system performance. Pdf in this article torque assisted antisurge control tasc, a compressor antisurge control system based on model predictive control mpc is. Pdf industrial compressor antisurge computer control. Even if surge is inevitable due to a severe process upset or other reasons, the emerson antisurge system will instantly detect surge and immediately react to stop it. Flowrotational speed qn technique in this method fan law characteristics are used.

The anti surge control system is designed so that the compressor will not experience the surge by blow off some portion of the discharge flow. Festo servoactuator with ccc control systems increases the operating area while maintaining stable and effective surge protection. Thats why youll find the fisher optimized antisurge valve to be bestinclass for reliability, control, and commissioning. This anti surge control system for compressor capacity control usually results in wasting of large amount of compression energy since the pressure of already compressed gas is letdown in a throttling valve called anti surge control valve and recycles back to. Secondary pid loop overrides, and capacity control are not shown for clarity. Without surge relief the pressure spikes to around.

Anti surge control system for centrifugal compressors part. Pdf model predictive antisurge control of centrifugal. Normal process control during normal operation antisurge system cant. Compressor antisurge control yokogawa electric corporation. The ccc antisurge controller accurately models the surge limit line for all operating conditions of the compressor. This paper introduces three methods of surge control analysis that can be conducted to assess the effectiveness of any surge control system design to prevent the compressor from surge. The surge control algorithm executes in less than 25 ms. For this reason the anti surge recycle connection and antisurge control valve shall be located upstream of the check valve as close as practical to the compressor discharge connection. This report on compressor anti surge control closes some of the gaps related to the signi. Section 3 description of surge 31 surge versus stall surge is a dynamic instability that occurs in dynamic compressors.

In order to protect the compressor adequately from surge, the discharged flow must be restored very quickly. Surge, antisurge system, compressors, flow instabilities. Unfavorable arrangement of piping and process com ponents of the system. Anti surge controller working principle instrumentation. In todays world no piece of machinery can be said to be protected by modern methods without implementing a control system. Antisurge control system design practices encompass the proper sizing, selection, and location of piping of the recycle loops, the recycle valves, volumes of. Using computer simulation software to simulate the system control program has become an integral part of the process of. An effective anti surge control system will generally be able to operate with a surge margin of 10% of the surge line flow. Pic uic ft pt tt pt tt anti surge valve suction valve capacity control compressor cooler.

The following simplified functional block diagram illustrates the features of the algorithm. However, control strategies have not previously been studied thoroughly from a control theoretic viewpoint. Anti surge control of centrifugal compressor at pt. The becker tball anti surge valve is a complete anti surge control solution that delivers high performance and reliable protection even in the most demanding operating environments. Anti surge valves for industrial applications kent introl. Surge control is the use of different techniques and equipment in a hydraulic system to prevent any excessive gain in pressure also known as a pressure surge that would cause the hydraulic process pressure to exceed the maximum working pressure of the mechanical equipment used in the system. An accurately designed surge control system that includes multiple compressors with the associated piping systems is a vital element of.

A new approach to designing centrifugal compressor surge. Health of a rotary machine is best monitored by measuring and monitoring. Rotating equipment validating antisurge control systems. Anti surge control system for centrifugal compressors part 1.