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A heat pipe coal pile experiment platform was established to test the performance of the heat pipe in the heat transfer of the coal pile. Experiments were carried out to measure and analyze the continuous cooling characteristics and cooling rate of the internal heat dissipation of coal piles of different heights under different temperature heat sources. The results show that when the heat source temperature is higher, there is a greater cooling rate inside the coal pile. The closer it is to the heat source, the more obvious the heat dissipation inside the coal pile will be affected by the heat pipe and heat source. This experiment verifies the feasibility of the heat pipe to automatically and continuously transfers the internal heat of the coal pile under the action of the difference between the outside temperature and the internal temperature of the coal pile, to achieve the purpose of preventing spontaneous combustion of the coal pile.

Dry-hot rock is a kind of new geothermal energy with abundant energy storage. At present, the extraction of dry-hot rock geothermal energy is mainly through artificial fracturing of the rock mass by injecting water as a working fluid. The heat energy is extracted with water as a heat-carrying medium.This paper combines super-long gravity heat pipe with dry-hot rock, and buries carbon dioxide in dry-hot rock as artificial heat storage. Then, the feasibility of extracting geothermal energy from dry-hot rock by 2500m super-long gravity heat pipe is studied by numerical simulation.The artificial heat storage of carbon dioxide dry-hot rock is equivalent to porous continuous medium model. The temperature field distribution, pressure field distribution and velocity field distribution were simulated by Fluent software to analyze the evaporation and condensation process of liquid refrigerants in heat pipes at different times.Through numerical simulation, it is concluded that water vapor at 80°C can be obtained at the outlet of overlength gravity heat pipe, and the flow rate of water vapor is about 2m/s. The scheme of extracting dry-hot rock heat energy by overlength gravity heat pipe is feasible.

In order to solve the icing phenomenon of mine wind gap, a physical model of L-type gravity heat pipe was designed in combination with calculation of shaft operating condition, which based on the new idea that geothermal energy of thermostatic formation is used as driving heat source of heat pipe for shaft antifreeze. The numerical simulation showed that the condensation end temperature of the heat pipe could reach 275K. The heat pipe optimization simulation was carried out for the length of the condensation and insulation section of the heat pipe. When the condensing section is 5 m, the effect is the best. The results showed that the temperature at the condenser end of the heat pipe was increased by 275.6K after optimization. The optimized scheme for extracting heat energy from thermostat by heat pipe has a good effect.

When a solid sphere exits water at a given velocity, the liquid column is pulled out of a liquid reservoir. The present study focuses on the dynamic deformation of the liquid column and on the identification of the liquid column regime on the Weber number and dimensionless time (We-t*) map. The three-dimensional model of water exit has been established on the basis of the lattice Boltzmann method. A mass tracking algorithm was incorporated to capture the free surface, where the liquid–gas​ two-phase flow is simplified to a single-phase free surface flow. The surface tension is included by adding a perturbation term and the gravity as a body force is introduced in form of calculating the equilibrium distribution with an altered velocity. The contact angle condition in numerical simulation is not considered. The accuracy of the numerical results is demonstrated through the comparisons with the prior numerical and the experimental results in the literature. A parametric study has been conducted numerically on the radius and volume and of liquid column. Besides, the relationship between the pinch-off time of a liquid column and the Froude number has been obtained. Moreover, the evolution of the liquid column shape with a wide range of the Weber number and time scales are discussed based on the number of ligaments and droplets. The liquid column exhibits different characteristics and has been divided into three regimes. The transition between different regimes has been analyzed and the critical Weber number is given.

Surface wax of mature Satsuma mandarin (Citrus unshiu) and 'Newhall' navel orange (Citrus sinensis) was analysed by crystal morphology, chemical composition, and gene expression levels. The epicuticular and total waxes of both citrus cultivars were mostly composed of aldehydes, alkanes, fatty acids and primary alcohols. The epicuticular wax accounted for 80% of the total wax in the Newhall fruits and was higher than that in the Satsuma fruits. Scanning electron microscopy showed that larger and more wax platelets were deposited on the surface of Newhall fruits than on the Satsuma fruits. Moreover, the expression levels of genes involved in the wax formation were consistent with the biochemical and crystal morphological analyses. These diversities of fruit wax between the two cultivars may contribute to the differences of fruit postharvest storage properties, which can provide important information for the production of synthetic wax for citrus fruits.