The structure and spatial distribution of electrochemical inert phase (EIP) in electrodes are highly heterogeneous, which deteriorates the performance of electrodes under harsh operating conditions such as high-rate o...
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To fully utilize solar energy as a driving heat source, an experimental study was carried out of the thermodynamic performance of a standing-wave type thermoacoustic engine installed at various inclination angles. The...
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To fully utilize solar energy as a driving heat source, an experimental study was carried out of the thermodynamic performance of a standing-wave type thermoacoustic engine installed at various inclination angles. The test results show that the installation inclination angle of the thermoacoustic engine can exercise a remarkable influence on such parameters as the vibration-initiation temperature, vibration-fading temperature of the thermoacoustic system and temperature gradient in a plate stack during the initiation of vibration etc. When the nitrogen pressure in the system has reached 1.3 MPa, at the seven angles used during the experiment, the highest vibration initiation temperature is 484°C and the lowest, 428°C. These characteristics can provide an experimental basis for choosing an appropriate angle to lower the vibration-initiation temperature of the system. When the system is in a stable oscillation state, any change of the installation inclination angle has a relatively small influence on such thermodynamic characteristics of the system as pressure ratio and pressure vibration amplitude. These characteristics create favorable conditions for driving at different angles thermoacoustic engines operating in a stable oscillation state by utilizing an auto-tracking solar energy collector. The test results can well provide an experimental basis for the design of solar-energy-driven thermoacoustic engines.
Over the past few decades, plate-type fuel elements have been widely used in advanced research reactors, small modular pressurized water reactors, production reactors, etc., with the advantages of compact structure ar...
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Aerosol pH is not only a diagnostic indicator of secondary aerosol formation, but also a key factor in the specific chemical reaction routes that produce sulfate and nitrate. To understand the characteristics of aeros...
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A system has been established to conduct the experimental study of dynamic characteristics of shell-and-tube heat exchangers. Through experimental methods, an experimental study has been performed of the dynamic chara...
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A system has been established to conduct the experimental study of dynamic characteristics of shell-and-tube heat exchangers. Through experimental methods, an experimental study has been performed of the dynamic characteristics of heat exchangers with continuous spiral baffle plates, which have water and oil to serve as heat exchange working media. With the inlet flow disturbance representing equal percentage flow rate characteristics, studied were the dynamic responses to water and oil temperature at the outlet in four modes of flow rate disturbance. In the meantime, the effect of fluid disturbing quantity on the temperature rise at heat exchanger inlet and outlet at a certain Re number was also studied with a correlation equation between the temperature rise at the inlet and outlet of the heat exchanger and fluid disturbing quantity being obtained. The tests show that the dynamic response to the temperature of a liquid-liquid heat exchange system needs a comparatively long time. It has been found through the study that under a disturbance with a positive or negative flow rate, the change of temperature at the inlet and outlet of spiral-baffle plate heat exchangers assumes a linear relationship and the variation curve featuring temperature rise at the inlet and outlet has a symmetric feature at a positive or negative flow rate disturbance. A finite-difference numerical forecast model and artificial neural network one have been established respectively to dynamically forecast the outlet temperature at the heat exchanger oil side. The forecast results are in good agreement with the test values. The forecast results obtained from the neural network is better than those from the numerical simulation with the absolute value of the deviation being less than 1.3%, indicating that artificial neural network has a definite merit for engineering reference and applications when performing the discrimination of complicated systems.
Dioxins, emanating from the waste incineration, constitutes an organic pollutant that poses considerable risks to human health and environment. In this study, the corn straw char (CSC) and oak char (OC) derived from t...
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An investigation was conducted of the flow distribution characteristics of distribution header water-wall tubes under a supercritical pressure for a home-made 600 MW once-through boiler. The test parameters can be lis...
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An investigation was conducted of the flow distribution characteristics of distribution header water-wall tubes under a supercritical pressure for a home-made 600 MW once-through boiler. The test parameters can be listed as follows: pressure p=23-25 MPa, mass flow rate G=400-1200 kg/(m2·s), working medium temperature t=10-400°C. An experimental study has been conducted of the impact of working medium pressure, mass flow rate and working medium temperature on the vertical water-wall tube flow distribution characteristics of the distribution header. The test results show that with an increase in mass flow rate, the uniformity of flow distribution among the vertical water-wall tubes could be enhanced. The non-uniformity of flow distribution will undergo a step increase near the quasi-critical points. Moreover, with an increasing pressure, the above-mentioned step increase will become weaker. By employing a discrete model of the parallel-connected branch tubes of the distribution header, the flow distribution among the distribution header vertical water-wall tubes was calculated and the calculation results are in good agreement with the test ones.
Biomass energy is renewable and rich in the world, providing a solution for the shortage in fossil fuel and serious environmental pollution. Proposing efficient utilization method of biomass waste demands urgent atten...
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In this paper, a new numerical procedure is proposed for the steady flow of a viscous, incompressible fluid based on SIMPLER algorithm on a non-orthogonal non-staggered grid, together with Cartesian velocity component...
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In this paper, a new numerical procedure is proposed for the steady flow of a viscous, incompressible fluid based on SIMPLER algorithm on a non-orthogonal non-staggered grid, together with Cartesian velocity components as dependent variables in the momentum equations. The main feature of the algorithm is that the pressure and pressure correction equations are obtained by explicitly treating pressure cross-derivatives terms in interface contravariant velocities. A collocated arrangement of variables is introduced on numerical grids, and the cell face velocities are calculated by the momentum interpolation. It is proved that this algorithm can be effectively used to simulate fluid flow and heat transfer in complex geometry, by the validation calculation of flow inside branching channel.
The clean and efficient utilization of biomass waste for hydrogen production conforms to social development in the future. In this work, hydrogen production from supercritical water gasification (SCWG) of fir bark (FB...
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