The photocatalytic production of solar hydrogen through water splitting by graphitic carbon nitride (g-C3N4) has gained substantial interest due to its advantageous characteristics, such as eco-friendliness, wealth on...
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A new absorption refrigeration system, which is driven by solar energy, biomass energy and geothermal energy simultaneously, was designed with capillaries as its radiation surface. Likewise, variations of water temper...
A new absorption refrigeration system, which is driven by solar energy, biomass energy and geothermal energy simultaneously, was designed with capillaries as its radiation surface. Likewise, variations of water temperature in the capillaries with the change in both time and its flow rate were experimentally researched as well as how COP of the system varies with the surrounding temperature. The following conclusions have been obtained: Common refrigeration demand can be met by the system after its operation in 1 hour; with the increase in water flow rate in the capillaries, its temperature, which drops down after an increase, gets its peak value at the flow rate of 4.5-5.5 L/min; COP of the system decreases with the rise of surrounding temperature, thus it’s better to keep it from direct sunlight. With the utilization of natural energy and the structure of capillaries, the system’s advantages in simple structure, low cost, environment-friendly working process and nice performance lead to promising application prospects, especially in residence refrigeration in countryside.
Photocatalytic H2 prodcution from lignocellulosic biomass photoreforming is deemed to be a promising alternative to overall water splitting owing to its more sustainable and value-added oxidation half-reaction. Howeve...
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The condensing heat exchanger is commonly applied in various heat exchange systems. It can efficiently recover moisture and heat from the flue gas that contains water vapor. However, the convective-condensation heat t...
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The interaction between the particle migration and vortex evolution aggravates the complexity of erosion on the flow components. In this work, the liquid-solid two-phase flow of semi-open centrifugal pump under differ...
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With the rapid development of technology and the accelerated degradation of the global environment, there is an urgent need to find a clean and efficient energy solution to replace traditional fossil fuels for energy ...
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With the rapid development of technology and the accelerated degradation of the global environment, there is an urgent need to find a clean and efficient energy solution to replace traditional fossil fuels for energy production. Additionally, this solution should also meet the growing demand for various energy products for energy user. In particular for remote areas such as islands, coastal regions and deserts which are far from the power grid, regular resources such as power, freshwater, and cooling are all scarce. Therefore, integrating freshwater and cooling subsystems into the power generation system to create a multi-generation system can facilitate achieving energy self-sufficiency in remote regions. This paper proposes an integrated multi-generation system powered by a solar power tower (SPT) according to the principle of cascading energy utilization, which includes a supercritical CO2 (SCO2) Brayton cycle, an Organic Rankine cycle (ORC), an ejector refrigeration cycle (ERC), and a reverse osmosis (RO) unit. A mathematical model is established to analyze the system performance from the perspectives of energy, exergy and economics. Different machine learning algorithms including back propagation neural network (BPNN), support vector regression (SVR), random forest (RF) are used to develop prediction models of the system performance. By comparing and analyzing the predictive performance of different machine learning models, the optimal machine learning model is obtained as a surrogate model for the thermodynamic model of the proposed system to accelerate the optimization process. The results show that the BPNN model demonstrates the highest predictive accuracy and the lowest relative error fluctuation, maintaining a relative error of less than 1% for over 97.5% of the data in the testing set. When comparing the multi-objective optimization results of the BPNN model with those of the thermodynamic model from multiple perspectives, it can be observed that the res
In China, coal quality fluctuates and deviates greatly from the original design in many large-scale coal-fired power plants. To maintain a secure level and combustion efficiency, a "coal combustion life cycle onl...
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Cryogen spray cooling (CSC) in conjunction with laser therapy has been the clinical standard for hypervascular lesions. In order to optimize nozzle and enhance the cooling efficiency to improve the treatment of laser ...
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Cryogen spray cooling (CSC) in conjunction with laser therapy has been the clinical standard for hypervascular lesions. In order to optimize nozzle and enhance the cooling efficiency to improve the treatment of laser surgery, an experimental system of transient cryogen spray cooling is built and eight straight-tube nozzles with different diameter and length are designed. A thin film thermocouple is directly deposited on the cooling surface to measure the surface temperature during the cryogen spray cooling. An analytical expression based on Fourier's law and Duhamel's theorem is used to calculate surface heat flux from the temperature measurements. Based on the measurements and calculations, the effect of the eight straight-tube nozzles on the heat transfer dynamics of the cooling surface and the atomization characterics are comparatively studied. Additionally, the criterion to evaluate the cooling efficiency of different nozzles is proposed, and the variation of heat extraction from the cooling surface with different spray distances by different nozzles is given.
In this paper, we study a mixed discontinuous Galerkin (MDG) method to solve linear elasticity problem with arbitrary order discontinuous finite element spaces in d-dimension (d = 2, 3). This method uses polynomials o...
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