EXPERIMENTAL AND NUMERICAL RESEARCH ON FLOW IN THE LAST STAGE OF 1090MW STEAM TURBINE

The paper deals with experimental and numerical research in the last stage of real 1090MW steam turbine with the last steel blade length 1220mm placed in nuclear power station. The last stage was equipped with twelve static pressure taps. It was also possible to probe in two planes - before and behind the last stage using pneumatic or optical probes. A number of last stage flow parameters were determined at the root and tip wall for nominal turbine output. Among those parameters are static pressures, Mach and Reynolds numbers, last stage reactions and steam wetness. All the directly measured and evaluated flow parameters are taken from locally measured points and that is why even 3D CFD calculation of the whole system - last stage, diffuser and exhaust hood was implemented. Measured and calculated parameters are compared. Especially static pressures are in very good agreement; the only steam wetness has bigger difference due to different measurement position. Locally measured values are enough to estimate the flow behavior of the last stage. On the other hand, the CFD simulations with well determined boundary conditions, meshes and geometry and is effective tool to simulate even very complicated flow structures in the last stage and exhaust hood

Estimation of fire resistance by means of calculation performed for atypical exterior wall of a woodstructure

The paper describes essential characteristics of a structural system for a wood structure, based on light composite wood stud, designed at Technical University in Zvolen.The system was reviewed by means of calculation method to prove fire resistance, respecting various relevant current standards of Slovak Republic and in accordance to eurocodes series. The methodology considered wider aspects of evaluation (properties, methods, carbonisation, minimal dimensions, cross sections, thermal field).Later, simple wall design alternatives were created by modification of inner part of the assembly, in order to examine the influence of the modifications to the total fire resistance of the wall

EXPERIMENTAL AND NUMERICAL RESEARCH ON FLOW IN THE LAST STAGE OF 1090MW STEAM TURBINE

The paper deals with experimental and numerical research in the last stage of real 1090MW steam turbine with the last steel blade length 1220mm placed in nuclear power station. The last stage was equipped with twelve static pressure taps. It was also possible to probe in two planes - before and behind the last stage using pneumatic or optical probes. A number of last stage flow parameters were determined at the root and tip wall for nominal turbine output. Among those parameters are static pressures, Mach and Reynolds numbers, last stage reactions and steam wetness. All the directly measured and evaluated flow parameters are taken from locally measured points and that is why even 3D CFD calculation of the whole system - last stage, diffuser and exhaust hood was implemented. Measured and calculated parameters are compared. Especially static pressures are in very good agreement; the only steam wetness has bigger difference due to different measurement position. Locally measured values are enough to estimate the flow behavior of the last stage. On the other hand, the CFD simulations with well determined boundary conditions, meshes and geometry and is effective tool to simulate even very complicated flow structures in the last stage and exhaust hood

Summary of the Test Results of ITER Conductors in SULTAN

Abstract. After completing the qualification tests of the ITER cable-in-conduit conductors (CICC), the tests of samples from the series manufacture are running in the SULTAN test facility in Villigen, Switzerland. The key test for the conductor samples is the current sharing temperature, Tcs, at the nominal operating field and current, i.e. the maximum temperature at which the conductors operate before developing an electric field of 10 μV/m. All the TF samples fulfilled the ITER requirement of Tcs ≥ 5.8 K after 1000 load cycles. The Tcs results have a broad scattering among the suppliers, from 5.8 K up to 6.6 K. The assembly of the Nb3Sn based CICC samples (for TF and CS coils) is carried out at CRPP. The NbTi CICC samples (for PF, CC and bus bars) are assembled at the suppliers, with a U-bend replacing the bottom joint. The poor performance of some Main Busbar (MB) conductor samples, caused by poor sample assembly, triggered the effort to assemble a MB sample at CRPP with solder filled terminations and a bottom joint. The superior test results of the MB-CRPP sample, closely matching the performance assessment carried out using 3-D field distribution and n-index behavior was a successful achievement of the last year of operation. According to the Procurement Arrangement for the ITER coils, the winding companies must qualify the joint and termination manufacture by SULTAN samples. The first joint sample tested in SULTAN was a TF joint from EU, followed by a Correction Coil (CC) joint sample from China. Other joint samples are being assembled in USA (Central Solenoid), in Russia (PF1), in EU (PF2 - PF5) and in China (PF6). All the ITER coils use the “twin box” design for joints, except the Central Solenoid. At the first test in SULTAN of a twin-box TF joint sample in 2013, an unexpected resistance increase was observed after an accidental dump of the SULTAN field, causing a large field transient parallel to the joint contact surface, with large eddy currents and electromagnetic loads at the pressure-contact between strand bundle and copper plate of the twin box. The resistance requirement for the TF joint was still fulfilled after the dump. The initial performance of the joint sample for Correction Coil conductor was not satisfactory and a second qualification sample is being prepared

Influence of synthetic jet at the diffuser flow in the openable diffuser

Stěžejním úkolem této práce je získat povědomí o řízení mezní vrstvy vznikající v rovinném difuzoru syntetizovaným paprskem. Zkoumán je vliv řízení mezní vrstvy na vybrané proudové charakteristiky. Především jde o gradient statického tlaku, rozložení výstupní rychlosti reprezentované rychlostním profilem, sledovanou veličinou je též účinnost difuzoru, která je vyjádřena prostřednictvím energetického ztrátového součinitele ?.Katedra energetických strojů a zařízeníObhájenoThe main task of this work is to acquire knowledge regarding the control of the boundary layer that originates in a planar diffuser with a synthetic jet; the influence on the boundary layer control of selected stream characteristics was researched. This primarily concerns the static pressure gradient, the allocation of the output speed represented by the velocity profile and the monitored value, which is also the efficiency of the diffuser expressed through the energy loss coefficient ?