MEDSI2016 - List of Authors (Escaler, X.)

Paper	Title	Page
TUPE05	Numerical Simulation of the ALBA Synchrotron Light Source Cooling System Response for Failure Prevention	162
	X. Escaler UPC, Barcelona, Spain J.J. Casas, C. Colldelram, M. Prieto, M. Quispe ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA Synchrotron Light Source cooling system is designed with a common return pipe that interconnects the four consumption rings. Such configuration is believed to compromise its optimal operation. To understand its thermo-fluid dynamic behaviour, a detailed 1D model has been built comprising all the components such as the pipes, fittings, bends, valves, pumping stations, heat exchangers and so on, and the various regulation mechanisms. Preliminarily, the model results in steady state operating conditions have been compared with experimental measurements and the maximum deviations have been found below 13%. Then, a series of transient numerical simulations have been carried out to determine the system response. Specifically, effects of the blockage and leakage of a consumption line as well as the increase and decrease of heat duty for the tunnel rings have been investigated. As a result, the stability of the system has been evaluated and the operational limits have been estimated in front of hydraulic and thermal load variations. Moreover, particular behaviors have been identified which can be used to design monitoring and control strategies to prevent unexpected failures.
	Poster TUPE05 [0.615 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE05
About •	paper received ※ 07 September 2016 paper accepted ※ 21 September 2016 issue date ※ 22 June 2017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPE06	Thermo-Fluid Numerical Simulation of the Crotch Absorbers’ Cooling Pinholes for ALBA Storage Ring	165
	X. Escaler, V. Arbo Sangüesa UPC, Barcelona, Spain J.J. Casas, C. Colldelram, M. Prieto, M. Quispe ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA Synchrotron Light Facility crotch absorbers, that remove the unused storage ring radiation, incorporate an internal cooling system composed by a number of parallel pinholes and by the corresponding stainless steel inner tubes inserted into each of them. Water flows in the resulting annular sections to evacuate the total heat power. Around each inner tube, a spiral wire is fixed along the whole length with a given pitch height in order to enhance the convection heat transfer. The influence of several design parameters on the absorber thermo-fluid behavior has been evaluated by means of the CFD software ANSYS CFX. In particular, the wall heat transfer coefficients and the pressure losses through a single pinhole have been evaluated for a range of different flow rates and pitch heights. Moreover, some modifications of the end wall geometry have been simulated as well as the effect of reversing the flow direction inside the channels. Finally, the critical crotch absorber type 3 has also been simulated and the limiting pitch height-flow rate combinations have been found based on the available driving pressure of the cooling system.
	Poster TUPE06 [1.546 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE06
About •	paper received ※ 07 September 2016 paper accepted ※ 21 September 2016 issue date ※ 22 June 2017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPE09	Thermo-Fluid Study of the UPC Race-Track Microtron Cooling System	173
	X. Escaler, V. Blasco, Yu.A. Kubyshin, J.A. Romero, A. Sanchez UPC, Barcelona, Spain M. Prieto ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain V.I. Shvedunov SINP MSU, Moscow, Russia
	The cooling system of the race-track microtron (RTM), which is under construction at the Universitat Politècnica de Catalunya (UPC), has been simulated by means of a computational fluid dynamics (CFD) software. The hydraulic and thermal performance of the system has been studied for various operation conditions. Firstly, the hydraulic model has been validated by comparison with experimental measurements at different flow rates. Then, the cooling fluid temperatures and the pressure losses of the system have been determined and the capacity of the current design to remove the generated heat at nominal power has been confirmed. Finally, the wall maximum and average temperatures and heat transfer coefficients inside the magnets and the accelerating structure have been calculated. These results have allowed us to localize sections of the cooling system with a low convection due to detached flows where, therefore, a risk of zones of high temperatures exists. An optimization of the cooling circuit with the aim to reduce such high temperature zones has been proposed.
	Poster TUPE09 [0.552 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE09
About •	paper received ※ 02 September 2016 paper accepted ※ 21 September 2016 issue date ※ 22 June 2017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPE13	Numerical Simulation of the ALBA Synchrotron Light Source Cooling System Response to Pump Start-Up and Shut-Down	187
	X. Escaler, D. Juan Garcia UPC, Barcelona, Spain J.J. Casas, C. Colldelram, M. Prieto, M. Quispe ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA Synchrotron Light Source cooling system is submitted to regular pump start-ups and shut-downs. Moreover, pumps can trip due to motor power failures. As a result, the piping system can be subjected to surges and pressure oscillations. The 1D thermo-fluid simulation software Flowmaster has been used to predict these transient conditions taking into account the fluid compressibility, the pipe elasticity, the characteristic time response of the check valves and the pump/motors moments of inertia. During pump start-ups, significant pressure rises are detected that can be reduced by readjusting the PID controller parameters. Unexpected pump shut-downs do not appear to provoke significant water hammer conditions. However, pressure fluctuations are generated mainly in the same pumping line but also in the rest of the system due to the particular common return configuration. In all the cases the pressure regulation mechanisms acting on the pump rotating speeds serve to attenuate the consequences of these transients. Finally, the feasibility of the model to simulate the effect on the system response of trapped air inside the pipes has also been evaluated.
	Poster TUPE13 [0.743 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE13
About •	paper received ※ 07 September 2016 paper accepted ※ 22 September 2016 issue date ※ 22 June 2017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Numerical Simulation of the ALBA Synchrotron Light Source Cooling System Response for Failure Prevention

162

X. Escaler
UPC, Barcelona, Spain
J.J. Casas, C. Colldelram, M. Prieto, M. Quispe
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The ALBA Synchrotron Light Source cooling system is designed with a common return pipe that interconnects the four consumption rings. Such configuration is believed to compromise its optimal operation. To understand its thermo-fluid dynamic behaviour, a detailed 1D model has been built comprising all the components such as the pipes, fittings, bends, valves, pumping stations, heat exchangers and so on, and the various regulation mechanisms. Preliminarily, the model results in steady state operating conditions have been compared with experimental measurements and the maximum deviations have been found below 13%. Then, a series of transient numerical simulations have been carried out to determine the system response. Specifically, effects of the blockage and leakage of a consumption line as well as the increase and decrease of heat duty for the tunnel rings have been investigated. As a result, the stability of the system has been evaluated and the operational limits have been estimated in front of hydraulic and thermal load variations. Moreover, particular behaviors have been identified which can be used to design monitoring and control strategies to prevent unexpected failures.

Poster TUPE05 [0.615 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE05

About •

paper received ※ 07 September 2016 paper accepted ※ 21 September 2016 issue date ※ 22 June 2017

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPE06

Thermo-Fluid Numerical Simulation of the Crotch Absorbers’ Cooling Pinholes for ALBA Storage Ring

165

X. Escaler, V. Arbo Sangüesa
UPC, Barcelona, Spain
J.J. Casas, C. Colldelram, M. Prieto, M. Quispe
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The ALBA Synchrotron Light Facility crotch absorbers, that remove the unused storage ring radiation, incorporate an internal cooling system composed by a number of parallel pinholes and by the corresponding stainless steel inner tubes inserted into each of them. Water flows in the resulting annular sections to evacuate the total heat power. Around each inner tube, a spiral wire is fixed along the whole length with a given pitch height in order to enhance the convection heat transfer. The influence of several design parameters on the absorber thermo-fluid behavior has been evaluated by means of the CFD software ANSYS CFX. In particular, the wall heat transfer coefficients and the pressure losses through a single pinhole have been evaluated for a range of different flow rates and pitch heights. Moreover, some modifications of the end wall geometry have been simulated as well as the effect of reversing the flow direction inside the channels. Finally, the critical crotch absorber type 3 has also been simulated and the limiting pitch height-flow rate combinations have been found based on the available driving pressure of the cooling system.

Poster TUPE06 [1.546 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE06

About •

paper received ※ 07 September 2016 paper accepted ※ 21 September 2016 issue date ※ 22 June 2017

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPE09

Thermo-Fluid Study of the UPC Race-Track Microtron Cooling System

173

X. Escaler, V. Blasco, Yu.A. Kubyshin, J.A. Romero, A. Sanchez
UPC, Barcelona, Spain
M. Prieto
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
V.I. Shvedunov
SINP MSU, Moscow, Russia

The cooling system of the race-track microtron (RTM), which is under construction at the Universitat Politècnica de Catalunya (UPC), has been simulated by means of a computational fluid dynamics (CFD) software. The hydraulic and thermal performance of the system has been studied for various operation conditions. Firstly, the hydraulic model has been validated by comparison with experimental measurements at different flow rates. Then, the cooling fluid temperatures and the pressure losses of the system have been determined and the capacity of the current design to remove the generated heat at nominal power has been confirmed. Finally, the wall maximum and average temperatures and heat transfer coefficients inside the magnets and the accelerating structure have been calculated. These results have allowed us to localize sections of the cooling system with a low convection due to detached flows where, therefore, a risk of zones of high temperatures exists. An optimization of the cooling circuit with the aim to reduce such high temperature zones has been proposed.

Poster TUPE09 [0.552 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE09

About •

paper received ※ 02 September 2016 paper accepted ※ 21 September 2016 issue date ※ 22 June 2017

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPE13

Numerical Simulation of the ALBA Synchrotron Light Source Cooling System Response to Pump Start-Up and Shut-Down

187

X. Escaler, D. Juan Garcia
UPC, Barcelona, Spain
J.J. Casas, C. Colldelram, M. Prieto, M. Quispe
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The ALBA Synchrotron Light Source cooling system is submitted to regular pump start-ups and shut-downs. Moreover, pumps can trip due to motor power failures. As a result, the piping system can be subjected to surges and pressure oscillations. The 1D thermo-fluid simulation software Flowmaster has been used to predict these transient conditions taking into account the fluid compressibility, the pipe elasticity, the characteristic time response of the check valves and the pump/motors moments of inertia. During pump start-ups, significant pressure rises are detected that can be reduced by readjusting the PID controller parameters. Unexpected pump shut-downs do not appear to provoke significant water hammer conditions. However, pressure fluctuations are generated mainly in the same pumping line but also in the rest of the system due to the particular common return configuration. In all the cases the pressure regulation mechanisms acting on the pump rotating speeds serve to attenuate the consequences of these transients. Finally, the feasibility of the model to simulate the effect on the system response of trapped air inside the pipes has also been evaluated.

Poster TUPE13 [0.743 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE13

About •

paper received ※ 07 September 2016 paper accepted ※ 22 September 2016 issue date ※ 22 June 2017

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)