Influence of air inlet/outlet arrangement of displacement ventilation on local environment control for unearthed relics within site museum

2021 ◽  
pp. 111116
Author(s):  
Xilian Luo ◽  
Xingyu Huang ◽  
Zhuangbo Feng ◽  
Juan Li ◽  
Zhaolin Gu
2001 ◽  
Author(s):  
Ruth Mossad

Abstract Pigs are subjected to intensive environment control and management for higher productivity due to their sensitivity to climatic variation, which affects their growth. The aim of the current work is to numerically model the air speed and temperature in forced and free ventilation piggeries to achieve optimum environmental control. A steady two-dimensional numerical model including the effect of buoyancy, turbulence and heat generated by the pigs was solved using the computational fluid dynamics software Fluent, which is based on the integral volume method. In the forced ventilation case, air speed and temperature inside the piggery and at the pigs’ level were predicted for three different locations of ventilation opening, variable air inlet velocities (in the range 0.3 m/s – 7 m/s), and insulated or non insulated external walls, for ambient temperatures of 5 °C and 32 °C. In the free ventilation case, temperature and air speed at the pig’s level were predicted for a particular wind speed and direction, and some variations in the design. These variations were adding louvers in the air opening, lowering the outer wall of the piggery and changing the type of pen fence used. These results helped to identify problems in the design and offer suggestions for improvements.


2013 ◽  
Vol 46 (4) ◽  
pp. 58-61
Author(s):  
Yuta MIYOSHI ◽  
Kota HIDAKA ◽  
Takashi OKAYASU ◽  
Osamu HIRANO ◽  
Daisuke YASUTAKE ◽  
...  

2012 ◽  
Vol 468-471 ◽  
pp. 1099-1103
Author(s):  
Hong Cai Li ◽  
Fei Fan Chen ◽  
Yong Gui Dong

A sealed air cooling local environment control apparatus that can provide constant working environment for precision instruments has been developed. Based on electrical analogy, the thermal network model has been derived, and the parameters of thermal conductance and capacitance in the model were measured in different test conditions. The obtained maximum relative errors between the measured values and the theoretical values are in the range of 0.6% to 6%, which indicates that the proposed theoretical model and the test method are feasible. The obtained parametes can help to understand the heat transfer properties of the apparatus, and the methods can be also as the reference for the test and rapid commissioning of other local environment control apparatus.


2011 ◽  
Vol 120 ◽  
pp. 258-262
Author(s):  
Hong Cai Li ◽  
Fei Fan Chen ◽  
Yong Gui Dong

Local environment control system (LECS) has been widely used in many areas as the necessary guarantee for most precision instruments. A sealed air cooling constant temperature box with dual-chamber structure that can provide constant working condition for precision instruments in-vehicle was developed. According to the heat transfer analysis of the double plate-fins heatsink, the heat radiation area and dimensions were determined based on electrical analogy. The air flow rate and temperature distribution of the system in heat steady-state was simulated by CFD software, and the results are consistent with that of experimental test. In different conditions, the thermal test results indicate that when the heat flow rate in the inner chamber is about 170 W, the temperature difference between inner chamber and environment is no more than 6.5 °C. The thermal design and test methods can be as the reference for the design of other precision instruments in-vehicle.


2021 ◽  
pp. 1420326X2098562
Author(s):  
Xilian Luo ◽  
Yuexi Dang ◽  
Chuck Wah Yu ◽  
Zhaolin Gu

Author(s):  
Chester J. Calbick ◽  
Richard E. Hartman

Quantitative studies of the phenomenon associated with reactions induced by the electron beam between specimens and gases present in the electron microscope require precise knowledge and control of the local environment experienced by the portion of the specimen in the electron beam. Because of outgassing phenomena, the environment at the irradiated portion of the specimen is very different from that in any place where gas pressures and compositions can be measured. We have found that differential pumping of the specimen chamber by a 4" Orb-Ion pump, following roughing by a zeolite sorption pump, can produce a specimen-chamber pressure 100- to 1000-fold less than that in the region below the objective lens.


Sign in / Sign up

Export Citation Format

Share Document