Development and application of a multi-domain dynamic model for direct steam generation solar power plant

International audienceDirect Steam Generation (DSG) concentrated solar plants are promising but complex power systems. This latter feature originates both from the variety of physical phenomena and the dynamic nature of the boundary conditions at play during plant operation. A representative yet computationally efficient numerical simulator is a valuable tool to assist engineers in the proper design, control and operation of such specific water-steam cycle. The present communication reports on the development of a multi-domain dynamic model representing a DSG plant. To do so, we followed a code-coupling approach and relied on the domain-decomposition paradigm. More specifically, we built three sub-models respectively in the thermal-hydraulic, the optical and the control-command domains and coupled them through an in-house co-simulation platform called PEGASE. We used the CATHARE system code to solve the thermal-hydraulic problem and the more generalist DYMOLA software to model the convective and radiative heat exchanges within the solar receiver. As an example, we then applicate the simulator to elaborate an efficient controller for the steam separator level

Overview of the system alone and system/CFD coupled calculations of the PHENIX Natural Circulation Test within the THINS project

International audienceThe PHENIX sodium cooled fast reactor started operation in 1973 and was shut down in 2009. Before decommissioning, an ultimate test program was designed and performed to provide valuable data for the development of future sodium cooled fast reactors, as the so-called Astrid prototype in France. Among these ultimate tests, a thermal-hydraulic Natural Convection Test (NCT) was set-up in June 2009. Starting from a reduced power state of 120 MWt, the NCT consists of a loss of the heat sink combined with a reactor scram and a primary pumps trip leading to stabilized natural circulation in the primary sodium system. The thermal-hydraulics innovative system project (THINS project), sponsored by the European Community in the frame of the 7th FP has selected this transient for validation of both stand-alone system code simulations and coupled simulations using system and CFD codes. Participants from three organizations (CEA, IRSN and KIT) have addressed this transient using different system codes (CATHARE, DYN2B and ATHLET) and CFD codes (TRIO-U and OPEN FOAM). The present paper depicts the different modeling approaches, methodologies and compares the numerical results with the available experimental data. Finally, the main lessons learned from the work performed within the THINS project on the PHENIX NCT with respect to code development and validation are summarized. © 2014 Elsevier B.V. All rights reserved

Additional file 2: of Single and multiple resistance QTL delay symptom appearance and slow down root colonization by Aphanomyces euteiches in pea near isogenic lines

Effects of NILs carrying single or combined resistance on variables of the Aphanomyces root rot development cycle. A-C/ Single QTL NIL experiment #1; D/ Combined and single QTL NIL experiment #4; E/ Single QTL NIL experiment #2. The first graph represents the evolution of the probability of symptom appearance for seven days after inoculation, for each line. It corresponds to the percentage of plants with symptoms per block for each scoring day. The second graph shows for each line the root colonization speed, corresponding to the slope of the curve of pathogen DNA amounts per block, until 10 days after inoculation, from 104 DNA copies detected. Pathogen DNA data was used from one biological replicate at the fourth day in experiments #1 and #2 and the seventh day in experiment #4. In the third graph, the AUDPC was calculated from the pathogen DNA quantification data over the ten days after inoculation. Bars represent standard errors. Attribution of each line to LSMeans group(s) is indicated by letter(s), according to the Tukey test (P < 0.05). Blue and red lines indicate the NIL without QTL and the donor or resistant control lines, respectively. (PDF 380 kb