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Spray cooling is a promising and effective cooling method, which may be used to solve the heat dissipation problem of high-power electronic components. In this paper, the influences of flow rate, sub-cooling degree, and refrigerant charge on the spray cooling heat transfer performance with R134a as the working fluid were experimentally studied. Results showed that the enhancement effect of the increase of sub-cooling degree on the heat transfer performance is very limited in this experiment. When the sub-cooling degree rises from 5 to 8 K, the heat transfer coefficient increases by 2.6% on average at lower heat flux (45.93–72.55 W/cm2). The increase of refrigerant charge can effectively improve the heat transfer performance, especially at higher heat flux (84.02–105.25 W/cm2). However, the Jacobian number decreases with the increase of the refrigerant charge, which hinders the improvement of heat transfer performance at higher heat flux. Therefore, there is an optimal refrigerant charge of 1.05 kg in this experiment. In addition, based on the experimental data, a Nusselt number dimensionless correlation of R134a solution with higher prediction accuracy was proposed.

In this paper, the outside cabin heat exchanger based on the porous media approach was established. The effects of altitude, viscous resistance coefficient, inertial resistance coefficient, and core thickness on the naturally captured air volume of the heat exchanger were investigated by numerical simulation. Results showed that the naturally captured air volume of the heat exchanger tends to be larger on both sides and smaller in the middle, and there is a quasi-linear increase proportional to the incoming wind velocity. With the increment of altitude, viscous resistance coefficient, and inertial resistance coefficient, the average naturally captured air volume of the heat exchangers shows a downward trend. The trend would be clear with the increment of the incoming wind velocity, nevertheless, the effect of core thickness is weak. In addition, the design values of the viscous resistance coefficient and the inertial resistance coefficient should be restricted in the order of 106 and below 500, respectively. Based on the weak effect of the naturally captured air volume of the heat exchanger, the thickness of the core can be appropriately increased to ensure the heat transfer area of the heat exchanger.

In this study, a closed-loop spray cooling system using R134a as the working fluid was established. The heat transfer characteristics and influencing mechanism of transient spray cooling were studied. The transient spray cooling curve under quenching was built accurately. The results show that the vapor film suppressed time, tsup, is the main period that the spray cooling must pass through. The flow rate and the sub-cooling of R134a have little effect on the cooling rate but the critical heat flux, which are mainly affected by chamber pressure. The transient Jacob number decreases with the increases of chamber pressure. As Jacob number decreases, the growth of vapor film is inhibited, then the tsup reduces in consequence. The surface temperature drop point and critical heat flux increases with the rise of chamber pressure. The maximum critical heat flux is 70.08 W/cm2 in this experiment.

This paper studies the frozen pork transportation in short and long distances, the loss of cooling capacity and the energy consumption in the cold chain transportation are analyzed experimentally and numerically. It finds that the material for freezer insulation plays in important role in energy consumption and energy saving during refrigerated transportation, an optimal freezer can reduce temperature rise by 13.88% and the heat flow by 71.05% compared with the traditional ones. A fractal model is established to reveal the thermal property of the freezer.

The wetting behavior of molten Zn and Zn-Sb alloy and X80 steel in a high vacuum environment was studied by the modified sessile drop method. The wetting morphology and interface structure were analyzed by scanning electron microscope and energy dispersive spectrometer. The results show when the content of Sb in Zn-Sb alloy increases from 0.0 wt. % to 1.0 wt. %, the initial contact angle between the droplet and the substrate decreases from 102.8° to 82.5°, and the equilibrium contact angle also decreases from 57.4° to 41.4°. Sb element in the Zn-Sb alloy can reduce the contact angle and improve the wettability due to its smaller surface tension. The spreading process of Zn-Sb alloys on X80 steel can be divided into rapid adsorption, reaction control, steady-state equilibrium stages, and Zn-Sb alloys with different mass fractions have the same spreading kinetics. The volatilized Zn element in the Zn-Sb alloy will reduce the oxide film on the surface of the substrate, making it easier for the Zn-Sb droplet to wet the steel plate and induce the formation of a precursor film. The formation mechanism of the precursor film is the subcutaneous penetration mechanism.

This paper presents a successful case called “electronic operation ticket” applying Mixed Reality (MR) device HoloLens for intelligent maintenance of high-voltage power grid. Information visualization is proposed with typical AR environment/model settings and the identification/tracking technologies. Experimental results show that the maintenance of power grid using electric operating tickets could improve the accuracy and safety options in dangerous environments, especially for those wrong options must be forbidden, and operator wearing HoloLens can easily follow the options listed in the electronic tickets robustly.

A novel water-based rust conversion agent (abbreviated as “TE-GAE”) was firstly synthesized using gallic acid (3,4,5-Trihydroxybenzoic acid, abbreviated as “GA”) and triethanolamine (abbreviated as “TE”) by esterification reaction. A new type of rust conversion coating (abbreviated as “TE-GAE coating”) containing the TE-GAE and additives was also prepared. The structural feature of rust conversion agent TE-GAE was characterized using Fourier transform infrared spectrum (FT-IR). The effect of the synthetic water-based TE-GAE coating on original rust layer were investigated by X-ray diffractometer (XRD) and Scanning electron microscope (SEM). Compared with traditional rust conversion coatings that apply tannic acid and phosphoric acid as rust converters, the as-synthesized integrated TE-GAE coating firstly revolutionized the application method of the anti-corrosion coatings, combined the traditional “primer” and “topcoat” into one, and improved engineering efficiency while ensuring protective effect. Additionally, the adhesion test indicated that the integrated TE-GAE coating presented remarkably strong film adhesion between the coating and steel substrate. Meanwhile, the neutral salt spray test and weather-resistant test showed significant corrosion resistance. Furthermore, a corrosion resistance mechanism including the combined effect of the rust conversion, barrier and corrosion inhibition for the integrated TE-GAE coating was tentatively proposed, which indicating that the rust converter chelates with Fe2+/Fe3+ to form a dense chelating film, extend the penetration path of corrosive medium and delay the occurrence of corrosion process. Thus, such a “green” and “efficient” integrated rust conversion coating is promising for protecting steel from corrosion, which is critical for the sustainable development of functional coating materials.

As an efficient cooling method for high heat flux, spray cooling has a great application potential on aircraft directed energy weapon cooling. Based on the analysis of previous research results, an experimental system of open loop spray cooling was established. Four different surfaces and two additives were applied and spray cooling performance including surface heat flux, surface temperature and heat transfer coefficient was experimentally investigated with water as the cooling medium. The experimental results indicate that among the four surfaces, drilling surface has the highest heat transfer coefficient and combined surface has the highest cooling efficiency. Meanwhile heat transfer can be enhanced by adding potassium chloride to a certain concentration and then deteriorated with higher concentration; heat transfer is deteriorated with the increase of ethylene glycol concentration. Therefore for aircraft spray cooling system combined surface should be applied for its advantages of low surface temperature and high cooling efficiency while ethylene glycol is preferred to improve the application range of the system in consideration of the corrosion of salt solution.

We evaluate the hydrogen depletion ability of the hydrogen depletion system for Chinese Pressurized Reactor 1000 (CPR1000), which has been applied in nuclear power plants with pressurized water reactors; moreover, we introduce a new device that can continuously monitor hydrogen concentration inside the CPR1000 containment building. Experimental studies show that a moveable hydrogen autocatalytic recombiner alone can sufficiently deplete hydrogen under the condition of a design-basis accident, and 33 passive autocatalytic recombiners placed in the areas of high hydrogen concentration satisfy the hydrogen depletion requirements under the condition of a beyond-design-basis accident. Meanwhile, the hydrogen concentration monitoring system is designed and installed based on the approach of detecting the temperature increase caused by the catalytic reaction of hydrogen. In conclusion, the hydrogen depletion capacity of the CPR1000 meets the requirements, and the system’s safety can be enhanced by the improved hydrogen concentration monitoring system.

Greatly expanded use of wind energy has been proposed to reduce dependence on fossil and nuclear fuels for electricity generation. For wind turbine power generation, as a mature technology in the field of wind power utilization, its large-scale deployment is limited by the cooling technology. Therefore, the temperature distribution of the wind turbine power generation is a key issue for the design of the cooling system. It is because the characteristics of cooling system have a great effect on the performance of the wind turbine power generation. Based on some assumptions and simplifications, a thermal model is developed to describe the heat transfer behavior of wind turbine power system. The numerical calculation method is adopted to solve the governing equation. The heat generation and heat flux are investigated with a given operating boundary. The achieved results can be used to verify whether the cooling system meets the design requirements. Meanwhile, they also can reveal that among the influencing factors, the meteorological conditions, generated output and operation state as well seriously influence its thermal performance. Numerical calculation of the cooling system enables better understanding and results in performance improvement of the system.

The increment of heat load in Wind Turbine's engine room could cause the system shut down. In this paper the heat balance of Wind Turbine's engine room is investigated according to the structure of the engine room, environmental operating requirements as well as heat-dissipating of different components of a 3MW Wind Turbine System. The heat load of the engine room is analyzed and the physical model is developed based on finite volume method. After that, the temperature distribution of the cabin is obtained under different conditions with/without the jet unit. The temperature distribution in engine compartments with different number and the arrangement of jet units is compared in this paper. Based on the analysis, the cabin cooling design is carried out to achieve the purpose of stopping heat gathering and keeping heat balance of the cabin. This work puts forward the heat balance maintenance and completes the corresponding research, which could be helpful for the optimization of large-capacity Wind Turbine cooling system.