Oxyfuel turbine throughflow design
(2014) ASME Power Conference 2014 In Proceedings of the ASME 2014 Power Conference 2. p.00208 Abstract
 The objective of the paper is to present the throughflow design of a twinshaft oxyfuel turbine. The throughflow design is the subsequent step after the turbine meanline design. The throughflow phase analyses the flow in both axial and radial directions, where the flow is computed from hub to tip and along streamlines. The parameterization of the throughflow is based on the meanline results, so principal features such as blade angles at the meanline into the throughflow phase should be retained. Parameters such as total inlet pressure and temperature, mass flow, rotation speed and turbine geometries are required for the throughflow modelling. The throughflow study was performed using commercial software AxCent(()(TM)()) from... (More)
 The objective of the paper is to present the throughflow design of a twinshaft oxyfuel turbine. The throughflow design is the subsequent step after the turbine meanline design. The throughflow phase analyses the flow in both axial and radial directions, where the flow is computed from hub to tip and along streamlines. The parameterization of the throughflow is based on the meanline results, so principal features such as blade angles at the meanline into the throughflow phase should be retained. Parameters such as total inlet pressure and temperature, mass flow, rotation speed and turbine geometries are required for the throughflow modelling. The throughflow study was performed using commercial software AxCent(()(TM)()) from Concepts NREC. The rotation speed of the twinshaft power turbine was set to 7200 rpm, while the power turbine was set to 4800 rpm. The meanline design determined that the twinshaft turbine should be designed with two compressor turbine stages and three power turbine stages. The throughflow objective was to study the variations in the thermodynamic parameters along the blade. The power turbine laststage design was studied because of the importance of determining exit Mach number distribution of the rotor tip. The last stage was designed with damped forced condition. The term 'damped' is used because the opening from the tip to the hub is limited to a certain value rather than maintaining the full concept of forced vortex. The study showed the parameter distribution of relative Mach number, total pressure and temperature, relative flow angle and tangential velocity. Throughflow results at 50% span and meanline results showed reasonable agreement between static pressure, total pressure, reaction degree and total efficiency. Other parameters such as total temperature and relative Mach number showed some difference which can be attributed to working fluid in AxCent being pure CO2. The relative tip Mach number at rotor exit was 1.03, which is lower than the maximum typically allowed value of 1.2. The total pressure distribution was smooth from hub to tip which minimizes the spanwise gradient of total pressure and thus reduces the strength of secondary vortices. The reaction degree distribution was presented in the paper and no problems were revealed in the reaction degree at the hub. Rotor blades were designed to produce a smooth exit relative flow angle distribution. The relative flow angle varied by approximately 50 from hub to tip. The tangential velocity distribution was proportional to blade radius, which coincided with forced vortex design. Throughflow design showed that the meanline design of a twinshaft oxyfuel turbine was suitable. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/record/8077449
 author
 Sammak, Majed ^{LU} ; Deshpande, Srikanth ^{LU} and Genrup, Magnus ^{LU}
 organization
 publishing date
 2014
 type
 Chapter in Book/Report/Conference proceeding
 publication status
 published
 subject
 keywords
 Throughflow design, meanline design, SCOCCC, oxyfuel turbine, LUAXT, forced vortex
 in
 Proceedings of the ASME 2014 Power Conference
 volume
 2
 pages
 002  08
 publisher
 American Society Of Mechanical Engineers (ASME)
 conference name
 ASME Power Conference 2014
 external identifiers

 WOS:000361161100002
 Scopus:84911954931
 ISBN
 10.1115/POWER201432125
 DOI
 10.1115/POWER201432125
 language
 English
 LU publication?
 yes
 id
 431db62ab2ac4b18940eb05588dbb226 (old id 8077449)
 date added to LUP
 20151026 13:46:13
 date last changed
 20170101 07:57:41
@inproceedings{431db62ab2ac4b18940eb05588dbb226, abstract = {The objective of the paper is to present the throughflow design of a twinshaft oxyfuel turbine. The throughflow design is the subsequent step after the turbine meanline design. The throughflow phase analyses the flow in both axial and radial directions, where the flow is computed from hub to tip and along streamlines. The parameterization of the throughflow is based on the meanline results, so principal features such as blade angles at the meanline into the throughflow phase should be retained. Parameters such as total inlet pressure and temperature, mass flow, rotation speed and turbine geometries are required for the throughflow modelling. The throughflow study was performed using commercial software AxCent(()(TM)()) from Concepts NREC. The rotation speed of the twinshaft power turbine was set to 7200 rpm, while the power turbine was set to 4800 rpm. The meanline design determined that the twinshaft turbine should be designed with two compressor turbine stages and three power turbine stages. The throughflow objective was to study the variations in the thermodynamic parameters along the blade. The power turbine laststage design was studied because of the importance of determining exit Mach number distribution of the rotor tip. The last stage was designed with damped forced condition. The term 'damped' is used because the opening from the tip to the hub is limited to a certain value rather than maintaining the full concept of forced vortex. The study showed the parameter distribution of relative Mach number, total pressure and temperature, relative flow angle and tangential velocity. Throughflow results at 50% span and meanline results showed reasonable agreement between static pressure, total pressure, reaction degree and total efficiency. Other parameters such as total temperature and relative Mach number showed some difference which can be attributed to working fluid in AxCent being pure CO2. The relative tip Mach number at rotor exit was 1.03, which is lower than the maximum typically allowed value of 1.2. The total pressure distribution was smooth from hub to tip which minimizes the spanwise gradient of total pressure and thus reduces the strength of secondary vortices. The reaction degree distribution was presented in the paper and no problems were revealed in the reaction degree at the hub. Rotor blades were designed to produce a smooth exit relative flow angle distribution. The relative flow angle varied by approximately 50 from hub to tip. The tangential velocity distribution was proportional to blade radius, which coincided with forced vortex design. Throughflow design showed that the meanline design of a twinshaft oxyfuel turbine was suitable.}, author = {Sammak, Majed and Deshpande, Srikanth and Genrup, Magnus}, booktitle = {Proceedings of the ASME 2014 Power Conference}, isbn = {10.1115/POWER201432125}, keyword = {Throughflow design,meanline design,SCOCCC,oxyfuel turbine,LUAXT,forced vortex}, language = {eng}, pages = {00208}, publisher = {American Society Of Mechanical Engineers (ASME)}, title = {Oxyfuel turbine throughflow design}, url = {http://dx.doi.org/10.1115/POWER201432125}, volume = {2}, year = {2014}, }