The scroll compressor with internal cooling system – conception and CFD analysis

In the paper the new kind of a scroll compressor is analyzed. To satisfy the working conditions and high operational reliability of that system a geometry of the moving and fixed scrolls was modified. In the central parts of the scroll elements the special chambers were created and used as a space for internal cooling of compressed medium. For analyzing the thermal – flow processes in the working chamber the finite volume method was used and carried out in ANSYS CFX software. This paper describes the system, the applied moving boundaries, the initial conditions and the influence of the modified vanes shape on the output parameters. The results obtained for modified geometry were compared with the “classical” geometry for the same initial conditions

The Scroll Compressor With Internal Cooling System In Cryogenics Applications

In order to decrease the energy cost of a compression process the cooling system has to be applied. Based on the modified vanes geometry the new cooling system for the scroll machines was proposed. The distinctive trait of the new vane is a significant space where the cooling apparatus is possible to install. Applying internal cooling may contribute to decreasing outlet temperature thus increase the efficiency of the process. Based on the initial CFD results a large heat extraction scroll compressor prototype will be build and tested in cryogenics applications. The paper presents the simulation process describing the model assumptions, boundary conditions, taking cooling into account, and the postprocessing

Development and Coil Fabrication Test of the Nb3Sn Dipole Magnet PRESCA2

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LSST: from Science Drivers to Reference Design and Anticipated Data Products

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

M7.3.2: Dipole Nb3_{3}Sn model magnet finished

This report presents the thermal modelling of the Nb$_{3}$Sn magnet called Fresca2 within the EuCARD-HFM project. The goal of this study is to predict the thermal behaviour of the magnet and to calculate the maximum temperature difference in the magnet structure during steady and transient state conditions. Results of the maximum temperature difference are compared with the temperature margin allowed. The steady state thermal calculations of the magnet are performed with AC losses due to ramp rate and homogeneous dissipation of heat as input heat loads. The transient calculations model the cool-down process. The thermal modelling was performed for several scenarios for steady and unsteady processes and for two base temperatures of 1.9 K and 4.2 K

Thermal modeling of Fresca2 magnet

This report presents the thermal modeling of the Nb$_{3}$Sn magnet called Fresca2 within the EuCARD-HFM project. The goal of this study is to predict the thermal behavior of the magnet and to calculate the maximum temperature difference in the magnet structure during steady and transient state conditions. Results of the maximum temperature difference are compared with the temperature margin allowed. The steady state thermal calculations of the magnet are performed with AC losses due to ramp rate and homogeneous dissipation of heat as input heat loads. The transient calculations model the cool-down process. The thermal modeling was performed for several scenarios for steady and unsteady processes and for two base temperatures of 1.9 K and 4.2 K