scholarly journals Building envelope integrated green plants for energy saving

2019 ◽  
Vol 38 (1) ◽  
pp. 222-234 ◽  
Author(s):  
Hang Tan ◽  
Xiaoli Hao ◽  
Pinhan Long ◽  
Qingwei Xing ◽  
Yaolin Lin ◽  
...  

In China, rapid urbanization brought about the problems of increased building energy consumption and decreased area of green space as well as poor air quality and heat island effect. Building envelope integrated green plants (BIGP), which is also called as vertical greening, is regarded as the potential solution to the energy and environmental issues. This article verifies and analyzes the energy saving potential of BIGP in China's hot summer and cold winter regions through comparative experiments between a vertical greening room and a reference room. The winter time experiment was carried out from December 2017 to January 2018, and the summer time experiment was from July to August 2018. During winter, the heat flux density of the exterior wall is reduced by 3.11 W/m2 with BIGP, and the hourly power consumption of the reference room is 1.22 times that of the room with BIGP. The energy saving rate of BIGP is approximately 18%. During summer, the heat flux density of the exterior wall of the reference room is 4.15 W/m2 larger than that of the vertical green room and the hourly power consumption is 1.33 times that of the vertical greening room. The energy saving rate of BIGP is about 25%.

Author(s):  
A. G. Korotkikh ◽  
◽  
V. A. Arkhipov ◽  
I. V. Sorokin ◽  
E. A. Selikhova ◽  
...  

The paper presents the results of ignition and thermal behavior for samples of high-energy materials (HEM) based on ammonium perchlorate (AP) and ammonium nitrate (AN), active binder and powders of Al, B, AlB2, and TiB2. A CO2 laser with a heat flux density range of 90-200 W/cm2 was used for studies of ignition. The activation energy and characteristics of ignition for the HEM samples were determined. Also, the ignition delay time and the surface temperature of the reaction layer during the heating and ignition for the HEM samples were determined. It was found that the complete replacement of micron-sized aluminum powder by amorphous boron in a HEM sample leads to a considerable decrease in the ignition delay time by a factor of 2.2-2.8 at the same heat flux density due to high chemical activity and the difference in the oxidation mechanisms of boron particles. The use of aluminum diboride in a HEM sample allows one to reduce the ignition delay time of a HEM sample by a factor of 1.7-2.2. The quasi-stationary ignition temperature is the same for the AlB2-based and AlB12-based HEM samples.


2019 ◽  
Vol 80 (3) ◽  
pp. 45-51
Author(s):  
L. Anatychuk ◽  
N. Pasyechnikova ◽  
V. Naumenko ◽  
O. Zadorozhnyy ◽  
R. Kobylianskyi ◽  
...  

2018 ◽  
pp. 27-32
Author(s):  
S. Kovtun

The article presents the results of investigations of factors that influence the accuracy of reproduction of the unit of measurement of the surface density of the heat flow by conductivity. Components of the uncertainty of the surface heat flux density measurement were analyzed using the Ishikawa cause-and-effect diagram, as shown in Fig. 1 The mathematical model of the method of reproduction of the unit of measurement was obtained, which takes into account the influence of the sources of uncertainty by making the corresponding corrections. The possibility of extending the lower boundary of the dynamic range by the correction of the factors having the greatest influence is substantiated. The rationale is based on the estimation of the uncertainty of the individual components, which, in the course of the correction of their impact, should not exceed the values (achieved to date). As an example, the calculation of the total uncertainty in the reproduction of the heat flux density of 20 W·m-2 is given. Table 1 contains all data important for the uncertainty analysis such as input quantities, their estimated values as well as the associated sensitivity coefficients and the variances determined.


Vestnik MEI ◽  
2021 ◽  
pp. 19-26
Author(s):  
Valentin S. Shteling ◽  
◽  
Vladimir V. Ilyin ◽  
Aleksandr T. Komov ◽  
Petr P. Shcherbakov ◽  
...  

The effectiveness of stabilizing the surface temperature by a dispersed coolant flow is experimentally studied on a bench simulating energy intensive elements of thermonuclear installations A test section in which the maximum heat flux density can be obtained when being subjected to high-frequency heating was developed, manufactured, and assembled. The test section was heated using a VCh-60AV HF generator with a frequency of not lower than 30 kHz. A hydraulic nozzle with a conical insert was used as the dispersing device. Techniques for carrying out an experiment on studying a stationary heat transfer regime and for calculating thermophysical quantities were developed. The experimental data were obtained in the stationary heat transfer regime with the following range of coolant operating parameters: water pressure equal to 0.38 MPa, water mass flow rate equal to 5.35 ml/s, and induction heating power equal to 6--19 kW. Based on the data obtained, the removed heat flux density and the heat transfer coefficients were calculated for each stationary heat transfer regime. The dependences of the heat transfer coefficient on the removed heat flux density and of the removed heat flux density on the temperature difference have been obtained. High values of heat transfer coefficients and heat flux density at a relatively low coolant flow rate were achieved in the experiments.


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