Experimental Investigation of a Novel Extracting Water System from Air by Soil Cold Source

The distribution of fresh water resources is extremely uneven at home and abroad, and the air contains a large amount of water vapor that can be used, so air water has been a widespread concern. Air condensation method is simple and efficient and has strong water intake capacity, but it often needs to consume huge energy. Therefore, this work proposes a new simple and innovative method of drawing water from the air, based on extracting water from air process achieved by using the soil as the cold source. The new type of ground cold air water intake system is designed by the new innovative method, which uses the soil with constant temperature as the cold source to reduce energy consumption. By comparing the central composite design experiment with the field experiment and analyzing the condensate water and outlet temperature under different wind speed and humidity conditions, the quadratic equation expression of condensate water and outlet temperature is obtained, and the optimal import wind speed range under a certain humidity range is obtained according to the mathematical model. The experimental results show that the heat transfer effect between air and soil is ideal, the water intake can reach 2.2 kg in 20-hour continuous collection experiment, the air temperature is close to the soil temperature after cooling, and the effect of water intake is good, which confirms the feasibility of soil as a cold source of air condensation.

Experimental Study on the Insulation Layer Thickness of a Novel Ice Coring Device in Loose Sandstone-Type Uranium Deposits

The target strata of sandstone-type uranium deposits are usually located in the fragile and loose strata, which makes it difficult to obtain core samples; consequently, a novel ice coring device for loose sandstone-type uranium deposits is proposed to solve this problem. Experiments proved that the artificial sample can replace the natural sample, and the coring method has high reliability. Ensuring the allegro formation of an ice valve with a given cold source is critical for this coring system, and reducing the loss of cold energy with help of insulation layer is one of the methods to speed up the formation of ice valve. Since the diameter of the drill tool is limited by its working scenario, the thickness of insulation layer is limited to ensure the size of core. Therefore, this paper conducted laboratory experiments of the insulation layer with different thicknesses to study the effect of the insulation layer on the formation of the sand–ice valve. Results show that the insulation layer can reduce the loss of cold energy during the freezing process and significantly affect the formation time of the sand–ice valve. When the thickness of the aerogel insulation layer is 2 mm, the freezing time is 44% shorter than that without insulation layer. According to the tests, the novel ice coring device is expected to solve the coring problem in loose sandstone-type uranium deposits.

Numerical calculation of passenger compartment cooling effect under the action of radiative cooling film based on MATLAB

Radiative cooling uses space cold source to cool the object, and the radiative cooling film made by using this principle can be applied to automobiles effectively to save the refrigeration resources of automobiles. However, due to the limitation of economy, time, space and other factors, it is difficult to carry out comprehensive research on the actual film-forming cooling effect. Based on the principle of passive radiative cooling, a set of simulation models is developed, which is applied to the selection of infrared radiation materials for automotive radiative cooling film and the study of the influence of environmental factors on the radiative cooling effect. SiO2 was finally selected as infrared radiation material. At the same time, the theoretical cooling temperature of the radiative cooling film applied to the passenger compartment of automobiles can reach 6.8°C under the conditions of 35°C ambient temperature, 0.99 atmospheric transmittance and 10 heat transfer coefficient, using SiO2 as infrared radiation material and PE as dispersion substrate. At the same time, the cooling effect of the radiative cooling film is positively correlated with the ambient temperature, atmospheric transmittance to some extent.

Research on Operation Optimization of Central Air Conditioning Cold Source System Based on PSO-SA Algorithm

This paper takes a data center air-conditioning cold source system as the research object. According to the historical operating data of the cold source system in the transition season, a cold source model is built on the EBSILON platform. The total energy consumption of the cold source system is the research goal. This paper establishes an overall optimization strategy based on PSO-SA. A simulation experiment was conducted on a typical day in the transition season, and the results showed that the optimization strategy can achieve 21.68% energy saving based on the original operation mode when the wet bulb temperature in the transition season is low.

Experimental Investigation on Floating Solar-Driven Membrane Distillation Desalination Modules

Membrane distillation (MD) processes need a relatively mild temperature gradient as the driving force for desalination. In the field, it is reasonable to utilize solar energy as the heat source for the feed, and seawater as the infinite cold source for condensation. Solar-driven MD provides a route for the practical application of seawater desalination at a small scale. In this work, we focus on floating MD modules with a solar heating bag as the power source, and perform proof-of-principle experiments on the MD performance under various conditioning parameters, including feed flow rate, feed temperature, salinity, air gap, and sea waves. The results indicate that floating solar-driven MD modules are feasible in terms of permeate flux and salt rejection ratio, and the upward evaporation MD configuration leads to a better performance in terms of permeate flux. The simulation and experiments also show that the natural sea waves disturb the heating bag and the MD module floating on the surface of seawater, and effectively enhance the feed circulation and transport in the system.

Prediction of high thermoelectric performance in the low-dimensional metal halide Cs3Cu2I5

Metal halides have emerged as a new generation of semiconductors with applications ranging from solar cells to chemical sensors. We assess the thermoelectric potential of Cs3Cu2I5, which has a crystal structure formed of zero-dimensional [Cu2I5]3− anionic clusters that are separated by Cs+ counter cations. We find the compound exhibits the characteristics of a phonon-glass electron-crystal with a large imbalance in the conduction of heat and electrons predicted from first-principles transport theory. Strong anharmonic phonon–phonon scattering results in short-lived acoustic vibrations and an ultra-low lattice thermal conductivity (<0.1 W m−1 K−1). The dispersive conduction band leads to a high electron mobility (>10 cm2 V−1 s−1). For an n-type crystal at 600 K, a thermoelectric figure-of-merit ZT of 2.6 is found to be accessible, which for a cold source of 300 K corresponds to a thermodynamic heat-to-electricity conversion efficiency of 15%.