Centrifugal compressor head - Impact of MW and other parametersSudhindra Tiwari
Please read the revised version.
A sequential approach to describe compressor head, pressure, system head and impact of MW and other suction parameters on head.
Centrifugal Compressors
SECTION ONE - ANTI-SURGE PROTECTION AND THROUGHPUT REGULATION
0 INTRODUCTION
1 SCOPE
2 MACHINE CHARACTERISTICS
2.1 Characteristics of a Single Compressor Stage
2.2 Characteristic of a Multiple Stage Having More
Than One Impeller
2.3 Use of Compressor Characteristics in Throughput
Regulation Schemes
3 MECHANISM AND EFFECTS OF SURGE
3.1 Basic Flow Instabilities
3.2 Occurrence of Surge
3.3 Intensity of Surge
3.4 Effects of Surge
3.5 Avoidance of Surge
3.6 Recovery from Surge
4 CONTROL SCHEMES INCLUDING SURGE PROTECTION
4.1 Output Control
4.2 Surge Protection
4.3 Surge Detection and Recovery
5 DYNAMIC CONSIDERATIONS
5.1 Interaction
5.2 Speed of Response of Antisurge Control System
6 SYSTEM EQUIPMENT SPECIFICATIONS
6.1 The Antisurge Control Valve
6.2 Non-return Valve
6.3 Pressure and flow measurement
6.4 Signal transmission
6.5 Controllers
7 TESTING
7.1 Determination of the Surge Line
7.2 Records
8 INLET GUIDE VANE UNITS
8.1 Application
8.2 Effect on Power Consumption of the Compressor
8.3 Effect of Gas Conditions, Properties and Contaminants
8.4 Aerodynamic Considerations
8.5 Control System Linearity
8.6 Actuator Specification
8.7 Avoidance of Surge
8.8 Features of Link Mechanisms
8.9 Limit Stops and Shear Links
APPENDICES
A LIST OF SYMBOLS AND PREFERRED UNITS
B WORKED EXAMPLE 1 COMPRESSOR WITH VARIABLE INLET PRESSURE AND VARIABLE GAS COMPOSITION
C WORKED EXAMPLE 2 A CONSTANT SPEED ~ STAGE COMPRESSOR WITH INTER-COOLING
D WORKED EXAMPLE 3 DYNAMIC RESPONSE OF THE ANTISURGE PROTECTION SYSTEM FOR A SERVICE AIR COMPRESSOR RUNNING AT CONSTANT SPEED
E EXAMPLE OF INLET GUIDE VANE REGULATION
FIGURES
2.1 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT DISCHARGE CONDITIONS
2.2 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT INLET CONDITIONS
2.3 PERFORMANCE CHARACTERISTICS OF A COMPRESSOR STAGE AT VARYING SPEEDS
2.4 SYSTEM WORKING POINT DEFINED BY INTERSECTION OF PROCESS AND COMPRESSOR CHARACTERISTICS
2.5 DISCHARGE THROTTLE REGULATION
2.6 BYPASS REGULATION
2.7 INLET THROTTLE REGULATION
2.8 INLET GUIDE VANE REGULATION
2.9 VARIABLE SPEED REGULATION
3.1 GAS PULSATION LEVELS FOR A CENTRIFUGAL COMPRESSOR
3.2 REPRESENTATION OF CYCLIC FLOW DURING SURGE OF LONG PERIOD
3.3 TYPICAL WAVEFORM OF DISCHARGE PRESSURE DURING SURGE
3.4 MULTIPLE SURGE LINE FOR A MULTISTAGE CENTRIFUGAL COMPRESSOR
3.5 TYPICAL MULTIPLE SURGE LINES FOR SINGLE STAGE AXIAL-FLOW COMPRESSOR
4.1 GENERAL SCHEMATIC FOR COMPRESSORS OPERATING IN PARALLEL TO FEED MULTIPLE USER PLANTS
4.2 ILLUSTRATION OF SAFETY MARGIN BETWEEN SURGE POINT AND SURGE PROTECTION POINT AT WHICH ANTISURGE SYSTEM IS ACTIVATED
4.3 ANTISURGE SYSTEM FOR COMPRESSOR WITH FLAT PERFO ..........
Centrifugal Compressor System Design & SimulationVijay Sarathy
The power point slides focuses on centrifugal compressor design, dynamic simulation including anti surge valve and hot gas bypass requirements. The topics covered are,
Centrifugal Compressor (CC) System Characteristics
Centrifugal Compressor (CC) Drivers
Typical Single Stage System
Start-up Scenario
Shutdown Scenario
Emergency Shutdown (ESD) Scenario
Centrifugal Compressor (CC) System Design Philosophy
Anti-Surge System
Recycle Arrangements
CC Driver Arrangements
General Notes
CENTRIFUGAL COMPRESSOR SETTLE OUT CONDITIONS TUTORIALVijay Sarathy
Centrifugal Compressors are a preferred choice in gas transportation industry, mainly due to their ability to cater to varying loads. In the event of a compressor shutdown as a planned event, i.e., normal shutdown (NSD), the anti-surge valve is opened to recycle gas from the discharge back to the suction (thereby moving the operating point away from the surge line) and the compressor is tripped via the driver (electric motor or Gas turbine / Steam Turbine). In the case of an unplanned event, i.e., emergency shutdown such as power failure, the compressor trips first followed by the anti-surge valve opening. In doing so, the gas content in the suction side & discharge side mix.
Therefore, settle out conditions is explained as the equilibrium pressure and temperature reached in the compressor piping and equipment volume following a compressor shutdown
In the hydrocarbon processing and production industry, gas is compressed for transportation to consuming markets and for use in processing operations. This presentation is about the construction and operation of compressors.
In this presentation you will learn about the construction and operation of centrifugal compressors.
Centrifugal compressor head - Impact of MW and other parametersSudhindra Tiwari
Please read the revised version.
A sequential approach to describe compressor head, pressure, system head and impact of MW and other suction parameters on head.
Centrifugal Compressors
SECTION ONE - ANTI-SURGE PROTECTION AND THROUGHPUT REGULATION
0 INTRODUCTION
1 SCOPE
2 MACHINE CHARACTERISTICS
2.1 Characteristics of a Single Compressor Stage
2.2 Characteristic of a Multiple Stage Having More
Than One Impeller
2.3 Use of Compressor Characteristics in Throughput
Regulation Schemes
3 MECHANISM AND EFFECTS OF SURGE
3.1 Basic Flow Instabilities
3.2 Occurrence of Surge
3.3 Intensity of Surge
3.4 Effects of Surge
3.5 Avoidance of Surge
3.6 Recovery from Surge
4 CONTROL SCHEMES INCLUDING SURGE PROTECTION
4.1 Output Control
4.2 Surge Protection
4.3 Surge Detection and Recovery
5 DYNAMIC CONSIDERATIONS
5.1 Interaction
5.2 Speed of Response of Antisurge Control System
6 SYSTEM EQUIPMENT SPECIFICATIONS
6.1 The Antisurge Control Valve
6.2 Non-return Valve
6.3 Pressure and flow measurement
6.4 Signal transmission
6.5 Controllers
7 TESTING
7.1 Determination of the Surge Line
7.2 Records
8 INLET GUIDE VANE UNITS
8.1 Application
8.2 Effect on Power Consumption of the Compressor
8.3 Effect of Gas Conditions, Properties and Contaminants
8.4 Aerodynamic Considerations
8.5 Control System Linearity
8.6 Actuator Specification
8.7 Avoidance of Surge
8.8 Features of Link Mechanisms
8.9 Limit Stops and Shear Links
APPENDICES
A LIST OF SYMBOLS AND PREFERRED UNITS
B WORKED EXAMPLE 1 COMPRESSOR WITH VARIABLE INLET PRESSURE AND VARIABLE GAS COMPOSITION
C WORKED EXAMPLE 2 A CONSTANT SPEED ~ STAGE COMPRESSOR WITH INTER-COOLING
D WORKED EXAMPLE 3 DYNAMIC RESPONSE OF THE ANTISURGE PROTECTION SYSTEM FOR A SERVICE AIR COMPRESSOR RUNNING AT CONSTANT SPEED
E EXAMPLE OF INLET GUIDE VANE REGULATION
FIGURES
2.1 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT DISCHARGE CONDITIONS
2.2 TYPICAL COMPRESSOR STAGE CHARACTERISTIC PLOTTED WITH FLOW AT INLET CONDITIONS
2.3 PERFORMANCE CHARACTERISTICS OF A COMPRESSOR STAGE AT VARYING SPEEDS
2.4 SYSTEM WORKING POINT DEFINED BY INTERSECTION OF PROCESS AND COMPRESSOR CHARACTERISTICS
2.5 DISCHARGE THROTTLE REGULATION
2.6 BYPASS REGULATION
2.7 INLET THROTTLE REGULATION
2.8 INLET GUIDE VANE REGULATION
2.9 VARIABLE SPEED REGULATION
3.1 GAS PULSATION LEVELS FOR A CENTRIFUGAL COMPRESSOR
3.2 REPRESENTATION OF CYCLIC FLOW DURING SURGE OF LONG PERIOD
3.3 TYPICAL WAVEFORM OF DISCHARGE PRESSURE DURING SURGE
3.4 MULTIPLE SURGE LINE FOR A MULTISTAGE CENTRIFUGAL COMPRESSOR
3.5 TYPICAL MULTIPLE SURGE LINES FOR SINGLE STAGE AXIAL-FLOW COMPRESSOR
4.1 GENERAL SCHEMATIC FOR COMPRESSORS OPERATING IN PARALLEL TO FEED MULTIPLE USER PLANTS
4.2 ILLUSTRATION OF SAFETY MARGIN BETWEEN SURGE POINT AND SURGE PROTECTION POINT AT WHICH ANTISURGE SYSTEM IS ACTIVATED
4.3 ANTISURGE SYSTEM FOR COMPRESSOR WITH FLAT PERFO ..........
Centrifugal Compressor System Design & SimulationVijay Sarathy
The power point slides focuses on centrifugal compressor design, dynamic simulation including anti surge valve and hot gas bypass requirements. The topics covered are,
Centrifugal Compressor (CC) System Characteristics
Centrifugal Compressor (CC) Drivers
Typical Single Stage System
Start-up Scenario
Shutdown Scenario
Emergency Shutdown (ESD) Scenario
Centrifugal Compressor (CC) System Design Philosophy
Anti-Surge System
Recycle Arrangements
CC Driver Arrangements
General Notes
CENTRIFUGAL COMPRESSOR SETTLE OUT CONDITIONS TUTORIALVijay Sarathy
Centrifugal Compressors are a preferred choice in gas transportation industry, mainly due to their ability to cater to varying loads. In the event of a compressor shutdown as a planned event, i.e., normal shutdown (NSD), the anti-surge valve is opened to recycle gas from the discharge back to the suction (thereby moving the operating point away from the surge line) and the compressor is tripped via the driver (electric motor or Gas turbine / Steam Turbine). In the case of an unplanned event, i.e., emergency shutdown such as power failure, the compressor trips first followed by the anti-surge valve opening. In doing so, the gas content in the suction side & discharge side mix.
Therefore, settle out conditions is explained as the equilibrium pressure and temperature reached in the compressor piping and equipment volume following a compressor shutdown
In the hydrocarbon processing and production industry, gas is compressed for transportation to consuming markets and for use in processing operations. This presentation is about the construction and operation of compressors.
In this presentation you will learn about the construction and operation of centrifugal compressors.
Engineers often use softwares to perform gas compressor calculations to estimate compressor duty, temperatures, adiabatic & polytropic efficiencies, driver & cooler duty. In the following exercise, gas compressor calculations for a pipeline composition are shown as an example case study.
Load Sharing for Parallel Operation of Gas CompressorsVijay Sarathy
The art of load sharing between centrifugal compressors consists of maintaining equal throughput through multiple parallel compressors. These compressors consist of a common suction and discharge header. Programmable logic controllers (PLCs) can be incorporated with load sharing functions or can be incorporated as standalone controllers also. Control signals from shared process parameters such as suction header pressure or discharge header pressure can be then fed to individual controllers such as compressor speed controllers (SC) or anti-surge controllers (UIC) to ensure the overall load is distributed efficiently between the compressors.
The following article covers load sharing schemes for parallel centrifugal compressor operation.
This compressor works on the principle of centrifugal action. It finds wide variety of applications in engineering field. It is available in market from low to high capacities.
Surge Control for Parallel Centrifugal Compressor OperationsVijay Sarathy
Parallel Centrifugal Compressor Operations
- Base Load Method
- Suction Side Speed Control Method
- Equal Flow Balance Method
- Equidistant to Surge Line Method
Presentation on Calculation of Polytropic and Isentropic Efficiency of natura...Waqas Manzoor
This presentation demonstrates comparison of calculation of Polytropic and Isentropic Efficiency of Natural Gas Compressor using Aspen HYSYS & using Manual Calculations. Complete derivation of equations of Polytropic and Isentropic efficiency, have also been demonstrated. The slight difference observed in the manually calculated values and Aspen HYSYS simulation, may be attributed to the calculation method of the software which is based on numerical integration.
Pumps are widely used in process plants to transfer fluid from one point to the other and the Process Engineer is often required to specify the correct size of pumps that will optimize system performance. Though pump sizing can easily be performed using software such as Pipe-Flo®, understanding the basic principle will not only aid one to better interpret the results obtained by pump sizing software but also to better design pumps. Centrifugal pump sizing overview is presented in this tutorial.
Engineers often use softwares to perform gas compressor calculations to estimate compressor duty, temperatures, adiabatic & polytropic efficiencies, driver & cooler duty. In the following exercise, gas compressor calculations for a pipeline composition are shown as an example case study.
Load Sharing for Parallel Operation of Gas CompressorsVijay Sarathy
The art of load sharing between centrifugal compressors consists of maintaining equal throughput through multiple parallel compressors. These compressors consist of a common suction and discharge header. Programmable logic controllers (PLCs) can be incorporated with load sharing functions or can be incorporated as standalone controllers also. Control signals from shared process parameters such as suction header pressure or discharge header pressure can be then fed to individual controllers such as compressor speed controllers (SC) or anti-surge controllers (UIC) to ensure the overall load is distributed efficiently between the compressors.
The following article covers load sharing schemes for parallel centrifugal compressor operation.
This compressor works on the principle of centrifugal action. It finds wide variety of applications in engineering field. It is available in market from low to high capacities.
Surge Control for Parallel Centrifugal Compressor OperationsVijay Sarathy
Parallel Centrifugal Compressor Operations
- Base Load Method
- Suction Side Speed Control Method
- Equal Flow Balance Method
- Equidistant to Surge Line Method
Presentation on Calculation of Polytropic and Isentropic Efficiency of natura...Waqas Manzoor
This presentation demonstrates comparison of calculation of Polytropic and Isentropic Efficiency of Natural Gas Compressor using Aspen HYSYS & using Manual Calculations. Complete derivation of equations of Polytropic and Isentropic efficiency, have also been demonstrated. The slight difference observed in the manually calculated values and Aspen HYSYS simulation, may be attributed to the calculation method of the software which is based on numerical integration.
Pumps are widely used in process plants to transfer fluid from one point to the other and the Process Engineer is often required to specify the correct size of pumps that will optimize system performance. Though pump sizing can easily be performed using software such as Pipe-Flo®, understanding the basic principle will not only aid one to better interpret the results obtained by pump sizing software but also to better design pumps. Centrifugal pump sizing overview is presented in this tutorial.
SAIF ALDIN ALI MADIN
سيف الدين علي ماضي
S96aif@gmail.com
Presentation
on
Axial Flow Compressor
Introduction
Construction
Working
Design
Main Parts
Stalling
Surging
Stage Losses
Advantages - Disadvantages & Applications
Research of Turbine Flowmeter Performance under the condition of Low TemperatureIJRES Journal
This paper mainly studied the impeller affecting the performance of turbine flowmeter measurement
under the condition of low temperature -25℃, through the test method, analyzing the impeller affecting the
performance of turbine flowmeter measurement under the conditions of different temperature.
CASE STUDY: Health analysis of reciprocating engines, compressors and gas pip...Abdul Basit Bashir
This paper refers to a detailed study conducted in March 2017 by SUMICO Technologies to evaluate the mechanical performance and condition of critical reciprocating engines, compressors and associated pipelines using state-of-the-art technologies at a natural gas booster station in Mari Gas Field (Sindh, Pakistan).
Results of the study revealed various hidden areas requiring attention to increase efficiency, reduce operational costs and increase reliability of the plant. This paper describes the technologies used, performance parameters analyzed,some interesting findings and the benefits gained through the study.
Prepared by Abdul Basit Bashir (SUMICO Technologies)
https://www.linkedin.com/in/abdulbasitb/
Similar to Fundamentals of Centrifugal Compressor - Head (revised) (20)
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Fundamentals of Centrifugal Compressor - Head (revised)
1. Impact of Molecular Weight and Other
Parameters on
Centrifugal Compressor Head
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
2. What and Why of Presentation
Why this presentation?
◦ These questions arise in many engineers’ minds
◦ Information is not available in structured form
What this presentation is about?
◦ What is compressor head, how different from pressure
◦ Effects of various parameters on compressor head
◦ Presentation is limited to centrifugal machines
◦ Supported by real life examples
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Slide 1
3. Operating Characteristics
Centrifugal compressors rarely work at
single operating point.
They work within an operating envelope
(Fig 1):
◦ Attached envelope is for variable speed
operation.
◦ Operation limited by surge and stonewall
lines and minimum and maximum speeds.
(Centrifugal Compressor Operation – Tony Barletta and Scott W. Golden. www.digitalrefining.com)
Figure 1
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Slide 2
4. Head
Head: Energy required to move unit mass of fluid from one point to another, generally
expressed in feet (or lbf-ft/lbM). For compressor it is the work of compressor performed on
a unit mass of the gas or vapor.
Fig 2: Head, produced by compressor impeller, is proportional to impeller tip velocity (U)
and gas tangential velocity (V) at impeller exit:
Head α U*V
Figure 2
(Forsthopper’s Best Practice Handbook For Rotating Machinery)
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018Slide 3
5. Compressor Characteristics: Head
vs. Capacity
Fig 3 depicts shape of compressor’s characteristic performance curve. Increase in head is
caused at reduced flow rates. Because, in accordance with Fig 2, a lower flow rate reduces
relative gas velocity from Vrel1 to Vrel2, which in turn increases gas tangential velocity from V1
to V2 hence the head.
Figure 3
(www.compressedairducation.com)
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Slide 4
6. Compressor Head – Why Polytropic?
In real life some heat transfer takes place during
compression, resulting in a polytropic process:
Polytropic: falls between the above two processes,
pvn = constant, where (n-1)/n = (k-1)/(k*effpol)
Note: polytropic exponent “n” and polytropic efficiency
“effpol” are provided by compressor manufacturer derived
from actual tests.
Work of compression, being the area under p-v curve, is
minimum for isothermal and maximum for isentropic
compression (Fig 4).
Figure 4
https://en.wikipedia.org/wiki/Compressor
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Two types of theoretical compression processes (two extremes, See Fig 4):
Isothermal: compression at constant temp - all heat generated during
compression is removed, represented by the equation:
pv = constant
Isentropic (reversible adiabatic): no heat transfer during compression,
pvk = constant, where k = cp/cv oor isentropic exponent
Slide 5
7. Head and Pressure
Head and Pressure are inter-related as follows,
For liquids – via specific gravity (density)
For gases/vapors - via pr, temp, MW,
compressibility, sp. heat ratio
Figure 5: the same differential pressure of 100
psi (or the same pressure ratio of 7.8) produced
by a machine (pump or compressor), generates
water head of 231 ft and N2 head of 86,359 ft
(which is equivalent to a N2 column of 86,359 ft
compared to a water column of 231 ft).
Typically the gas / vapor head is much higher
than liquid heads for the same pressure (note
the same 114.7 psia pressure at the bottom of
both columns).
Figure 5
(Forsthopper’s Best Practice Handbook For Rotating Machinery)
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Slide 6
8. Head, Pressure Ratio – Impact of MW
Impact of MW: Equation 1 (isentropic head in
this case) shows, if all other parameters on right
are kept constant, increase in MW will require a
lower head to produce the same discharge
pressure P2.
This is why less number of impellers / stages are
required to compress a heavy gas (Fig 6).
However, in real life the compressibility of gases
and changes in other parameters with change in
MW affect compressor’s characteristics. We will
see this later.
Equation 1
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Compressor head is given by:
Figure 6
Compression Ratio vs. Number of Impellers
(A Practical Guide to Compressor Technology, 2nd Edition – Heinz P Bloch)
Slide 7
9. Compressor Downstream
Requirements and Impact of MW
Constant discharge head: Such as
pipelines where required head
depends on static and friction head,
thus remains more or less constant,
irrespective of change in gas MW
According to equation the
compressor discharge pressure P2
will increase for the same head for a
heavy gas (as shown in next slide).
Constant discharge pressure or
pressure ratio: Such as feed to a
reactor where the process requires
supply of gas at constant pressure,
irrespective of change in gas MW.
Here, the compressor has to speed
down to produce the same
discharge pressure (to reduce the
head per the equation), when
compressing a higher MW gas.
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
There are other compressor applications requiring constant mass flow rates.
Both the cases below (representing compressor’s downstream requirements),
where a constant inlet flow through compressor is assumed, can be explained using
equation 1:
Slide 8
10. Head, Pressure and MW
Figure 7 shows a constant head
requirement of 20,714 ft., where
the compressor discharge pressure
is higher for Oxygen (25.3 psig ,
MW 32) compared to 22.4 psig for
Nitrogen (MW 28).
The next slide presents a real life
case with constant discharge
pressure requirement.
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Figure 7
(Forsthopper’s Best Practice Handbook For Rotating Machinery)
Slide 9
11. Real Life Example – Impact of MW on
Polytropic Head
Compressor performance in Fig 8 is a real life
example depicting the impact of change in
MW from 20.83 to 18.72.
Changes in MW, polytropic head, speed and
power are highlighted in yellow.
Inlet volume (orange highlight) is almost
constant. Compressor suction and discharge
pressures are also constant.
Compressor power, being product of
polytropic head and weight flow rate, does
not change significantly due to decrease in
weight flow rate with MW.
The k value (=Cp/Cv) in fact increases with
reduced MW, which works in the reverse
direction i.e. to reduce the polytropic head
by about 4.8%. Also, the impact of change in
Z value causes only 0.37% increase in the
polytropic head.
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Figure 8
Slide 10
12. Head, Pressure Ratio – Impact of
Other Parameters
Impact of inlet and discharge pr., and inlet temp (constant pressure ratio
application)
The same impact (as that of MW) is produced if compressor suction pressure
(P1) increases while other parameters remain unchanged. Means an increased
compressor suction pressure (P1) requires compressor to produce a lower head
to maintain the same pressure ratio (typically by reducing compressor speed).
An opposite impact is produced if inlet temp (T1) increases, while other
parameters remain unchanged. Means an increased suction temp requires
compressor to produce a higher head to maintain the same pressure ratio
(typically by increasing compressor speed).
The above explains compressor’s behavior, next slide explains system’s behavior.
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Slide 11
13. System Head and Impact of MW
Equation 2 provides pipeline / system
head (generic) required to push a given
gas through a given pipeline of length L:
P2 = pipeline upstream pressure, psia
P3 = pipeline downstream pressure, psia
S = specific gravity of gas,
Q = gas flow rate, MMscf/D
Z = compressibility factor for gas
T = flowing temperature, °R,
f = Moody friction factor
d = pipe ID, in.,
L = pipe length, ft
http://petrowiki.org/Pressure_drop_evaluation_along_pipelines
Figure 9
Equation 2
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Pipeline of length L
Compressor
Note from equation 2 that an increase in specific
gravity ‘S’ (or MW) will require a higher upstream
pipeline pressure (P2) to push the gas to the same
length L of pipeline.
This also jibes with what is explained in Slide 9
already.
Slide 12
14. MW and Performance Curve’s Shape
Gases and vapors being compressible in nature produce the
following impact upon change in MW:
From equation 1, for a constant downstream head, a heavy gas
shall develop higher discharge pressure P2 or shall be compressed
more compared to a light gas. Meaning a heavy gas shall have a
higher volume ratio (or a lower discharge volume) according to the
following relation for volume ratio:
Volume Ratio: V1/V2 = (P2/P1)1/n [Note uppercase V for volume]
In accordance with Slide 3, for a given acfm of gas entering a given
impeller at given speed the magnitude vrel is less for heavy gas than
for a light gas; causing magnitude vt to be greater.
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Since head output is proportional to vt , a given impeller running at a given speed will produce more head
while compressing a heavy gas than when compressing a like acfm of light gas. The magnitude of
difference increases with increased acfm, so the basic slope of a given impeller is less steep for heavy gas
than for a light gas
Slide 13
15. MW and Performance Curve’s Shape
(Real Life Example)
This is an example from constant
pressure ratio application. All curves
are at 8000 rpm compressor speed.
Notice the change in slope and
reduction in surge margin (Fig 11)
Figure 11
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018
Slide 14
16. Thanks for your review and comments
Sudhindra Tiwari
Lead Design Engineer – Rotating Equipment
IMPACT OF MW AND OTHER PARAMETERS ON CENTRIFUGAL COMPRESSOR’S HEAD - SUDHINDRA TIWARI MAR 2018