heat load
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2022 ◽  
Vol 175 ◽  
pp. 113009
T. Kobayashi ◽  
H. Yamazaki ◽  
S. Hiranai ◽  
M. Sawahata ◽  
M. Terakado ◽  

2022 ◽  
Yu-Qiang Tao ◽  
Guo-Sheng Xu ◽  
Ling-Yi Meng ◽  
Rui-Rong Liang ◽  
Lin Yu ◽  

Abstract A series of L-mode discharges have been conducted in the new ‘corner slot’ divertor on the Experimental Advanced Superconducting Tokamak (EAST) to study the divertor plasma behavior through sweeping strike point. The plasma control system controls the strike point sweeping from the horizontal target to the vertical target through poloidal field coils, with keeping the main plasma stability. The surface temperature of the divertor target cools down as the strike point moves away, indicating that sweeping strike point mitigates the heat load. To avoid the negative effect of probe tip damage, a method based on sweeping strike point is used to get the normalized profile and study the decay length of particle and heat flux on the divertor target λ js , λ q .In the discharges with high radio-frequency (RF) heating power, electron temperature T e is lower and λ js is larger when the strike point locates on the horizontal target compared to the vertical target, probably due to the corner effect. In the Ohmic discharges, λ js , λ q are much larger compared to the discharges with high RF heating power, which may be attributed to lower edge T e .

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 99
Olga Shevchenko ◽  
Sergiy Snizhko ◽  
Sergii Zapototskyi ◽  
Andreas Matzarakis

The human-biometeorological conditions in Ukraine during two mega-heat waves were analyzed. The evaluation is based on physiologically equivalent temperature (PET). The calculation of PET is performed utilizing the RayMan model. The results revealed these two mega-heat waves produced strenuous human-biometeorological conditions on the territory of Ukraine. During the summer 2010 mega-heat wave, strong and extreme heat stress prevailed at about midday at the stations where this atmospheric phenomenon was observed. The mega-heat wave of August 2015 was characterized by a lower heat load. The diurnal variation of PET values during the researched mega-HW was similar to that of the diurnal variation of air temperature with minimum values in the early morning and maximum values in the afternoon. On the territory where mega-heat waves were observed, the number of days during which heat stress occurred for 9 h amounted to 97.6% for the period from 31 July to 12 August 2010 and 77.1% for the mega-heat wave of August 2015.

2022 ◽  
Giuseppe Francesco Nallo ◽  
Giuseppe Mazzitelli ◽  
Matteo Moscheni ◽  
Fabio Subba ◽  
Roberto Zanino

Abstract In this work, we study the effect of installing a liquid metal divertor (LMD) using a capillary-porous structure in the EU DEMO tokamak within the same envelope of the baseline solid divertor. We used the SOLPS-ITER code to model the Scrape-Off Layer (SOL) plasma and neutrals, coupled to a target thermal model to enable the self-consistent calculation of the LM target erosion rate, and adopting a fluid neutral model for the sake of simplicity. First calculations considering only D and Li (or Sn) showed a significant reduction of the steady state target heat load with respect to simulations considering only D, thanks to vapor shielding. Nevertheless, the computed peak target heat flux (~31 MW/m2 and ~44 MW/m2 for Li and Sn, respectively) was still larger than/borderline to the power handling limit of the LMD concepts considered. Moreover, the impurity concentration in the pedestal - a proxy for the core plasma dilution/contamination - was computed to be above/close to tolerability limits suggested by previous COREDIV calculations. These results indicate that the operational window of an LMD for the EU DEMO, without any additional impurity seeding, might be too narrow, if it exists, and that Sn looks more promising than Li. A second set of calculations was then performed simulating Ar seeding in the SOL, to further reduce the target heat load, and consequently the metal erosion rate. It was found that the mitigation of the plasma heat load due to Ar radiation in the SOL effectively replaces the radiation associated to vapor shielding in front of the target, thus allowing to operate the LMD in a regime of low target erosion. The resulting operational window was found to be significantly wider, both in terms of tolerable peak target heat flux and of acceptable core plasma contamination.

2022 ◽  
Shuyu Dai ◽  
Defeng Kong ◽  
Vincent Chan ◽  
Liang Wang ◽  
Yuhe Feng ◽  

Abstract The numerical modelling of the heat flux distribution with neon impurity seeding on CFETR has been performed by the three-dimensional (3D) edge transport code EMC3-EIRENE. The maximum heat flux on divertor targets is about 18 MW m-2 without impurity seeding under the input power of 200 MW entering into the scrape-off layer. In order to mitigate the heat loads below 10 MW m-2, neon impurity seeded at different poloidal positions has been investigated to understand the properties of impurity concentration and heat load distributions for a single toroidal injection location. The majority of the studied neon injections gives rise to a toroidally asymmetric profile of heat load deposition on the in- or out-board divertor targets. The heat loads cannot be reduced below 10 MW m-2 along the whole torus for a single toroidal injection location. In order to achieve the heat load mitigation (<10 MW m-2) along the entire torus, modelling of sole and simultaneous multi-toroidal neon injections near the in- and out-board strike points has been stimulated, which indicates that the simultaneous multi-toroidal neon injections show a better heat flux mitigation on both in- and out-board divertor targets. The maximum heat flux can be reduced below 7 MWm-2 on divertor targets for the studied scenarios of the simultaneous multi-toroidal neon injections.

2022 ◽  
Vol 52 (1) ◽  
pp. 21-26
Serap Akdemir

Objective of this research was to design, construction and test of a cold store with chiller unit. Dimensions of the cold store were 5x4x3m. Heat load was calculated and capacity of cooling system was determined. Ambient temperature was set 2oC and relative humidity 90% for cold store testing. Ambient temperature, relative humidity and air velocity were measured for 3 different levels and 12 points for each level in the cold store. Total heat load and capacity of cooling system were calculated 5222 kcal/h. and 6.07 kW respectively.  The descriptive statistics  were calculated for the ambient temperature;  mean, 2.82oC, standard deviation 0.02oC and CV(%) 0.56, and  for the relative humidity; mean 88.01%, standard deviation 0.61 (%) and CV(%)  0.70 and for the air velocity mean 0.37m/s, standard deviation 0.22 m/s, CV 33.45 %. Even the air velocity CV was high, the ambient temperature and relative humidity variations were evaluated very good.

Samer Mohamed Saleh Trissi, Mohamed Najib Kayali, Ahmed Haj Samer Mohamed Saleh Trissi, Mohamed Najib Kayali, Ahmed Haj

This research aims to find innovative design solution to create sustainable compound residential towers in Aleppo city, for the reconstruction phase, by using the concept of sustainability and benefiting from natural energy sources. International organizations and many countries are interested in applying sustainable architecture standards, reducing emissions, mitigating pollution, and reducing long- term operating costs for buildings by making the most of natural resources. Tower buildings are among the most important design models that have been subject to the concepts of sustainability and their applications, due to their consumption of large amounts of energy. This research presents a study of a sustainable design for a residential compound tower, for the reconstruction phase in Aleppo city, using the genetic algorithm within the Grasshopper program. The tower design Idea depends on developing and linking the basic design idea of ​​the project with main design determinants such as dimensions, heights and other variables, including location and climatic characteristics, and then creating a barometric chart for these connections within the Grasshopper program. This chart links to the Galapagos tool, which is responsible for running the genetic algorithm. The random structure is generated when the algorithm started, and as a result of the cross- breeding, more advanced generations are created. The process continues to reach the most appropriate environmentally sustainable form to reduce the heat load acquired in summer. The model is evaluated environmentally using Ladybug simulation software, to provide solutions for modular residential towers that fit the local environment of Aleppo city. The results of the research showed that the solar heat load was reduced by adopting the genetic algorithm to find the most suitable configuration for the tower. The amount of reduction is 35% between the initial solutions and the final approved solution. The research also revealed that the use of green roofs reduces the heat load by 20%. The research also showed the effect of using shading facades. On the southern, western and eastern directions, the heat gain was reduced by 5%.

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