Advanced Materials Research Vols. 732-733

Abstract: Mean indicated pressure and indicated thermal efficiency of practical cycle are essential criteria to evaluate the performance and fuel economy of the engine. The HCCI tests fueled with gasoline are conducted on a modified engine. With the change of intake temperature and excessive air coefficient, mean indicated pressure and indicated thermal efficiency are measured. The results show that with the increase of intake temperature, mean indicated pressure and thermal efficiency tend to increase, and with the increase of excessive air coefficient mean indicated pressure increases while the rising rate of indicated thermal efficiency decreases.

Abstract: Thermal power generation in China as the main energy production, the production process consumes a lot of water resources. It is significant and the overall layout of the development of the national economy and the effective utilization of water resources, for the water consumption of the accurate calculation of thermal power generation process. The value through the site have been extracted, The water consumption of power plant cooling tower unit and the emissions per unit of energy was calculated and analyzed.

Abstract: A heat transfer model of external heat exchanger (EHE) in large-scale circulating fluidized bed (CFB) boiler was suggested based on experiment data and theoretical analysis. And the model parameters were also provided. With this model, the heat transfer performance of the EHE in an actual operating 300MW CFB boiler was predicted. The comparison between the model predictive results and the actual results showed that the relative error is less than 7%. This indicated that the model established in this paper is reliable and can provide a significant reference in EHE of large-scale CFB boiler design.

Abstract: Effects of diluents on premixed laminar dimethyl ether (DME)/air flames were studied experimentally and numerically. The results show that measurements and predictions in laminar burning velocities are in reasonably good agreement. Laminar flame speeds of DME mixtures decrease with the increase of dilution ratio. For a specific diluent ratio, suppression effect of diluent decreases in the order of carbon dioxide, nitrogen and argon. Influences of argon and nitrogen are mainly due to the increase of specific heat of the non-fuel gases in the mixture, and that of carbon dioxide is resulted from the combination effect of dilution and direct reaction. CO₂ participating reaction, CO+OHCO₂+H, competes for H radical in the chain branching reaction H+O₂ O+OH. This competition decreases concentration of the radicals like H, O and OH, leading to a significant reduction in laminar burning velocity.

Abstract: Based on comprehensively analyzing the whole structure and its working performance of RT-Flex marine intelligence diesel engine and entirely mastering this kind of engine fuel common rail injection system’s composition, working principle, taking 7RT-Flex60C as simulation object, the mathematical models of this system’s composing part are designed, by using Matlab/Simulink simulation tool, fuel common rail injection system simulation model is set up, then comparing with the simulation data with rack test data, the accuracy and effectiveness of the model are test and verified. The built up model provides a convenient and practical method for design, optimizing and simulation of fuel common rail injection system.

Abstract: A modeling method of the coal-fired utility boiler for a 300MW thermal power plant based on energy balance is presented. Key work sections of the power plant are treated as lumped parameter systems and a first-order model with time delay is used to describe the dynamic characteristic of the entire system. As model validation, comparison between model simulations and the actual process data for the energy of the main steam and hot reheated steam is given. Basically, the model is found to be able to track the output power variations of the boiler under different operation conditions. Rolling parameter identification of the model may further improve the model accuracy.

Abstract: Due to enthalpy-porosity technique, mathematical models of phase change material (PCM) and foam composite phase change material (FCPCM) in two-dimensional rectangular canister were established in the conditions of gravity and natural convection. It solved phase change problems by the enthalpy method coming from computational fluid dynamics. The numerical results show good agreement with reference findings. The numerical comparison between PCM and FCPCM verifies that metal foam can not only enhance the thermal conductivity of the PCMs but also improve the thermal performance of the heat storage system.

Abstract: In the present numerical study, we consider a low-Prandtl liquid metal heated by Joule effect in a rectangular cavity with an aspect ratio of 2. The direct current provides heat to the process medium by a pair of plate electrodes, located at the cavity sidewalls. The simulations have been carried out using finite volume method for fixed values of the Prandtl number, Pr=0.01, and of the Rayleigh number, Ra=1.5×10⁴, while the Hartmann number, Ha=1410, Comparison between the original noise-free data and cleaned data is explored. More precisely, accurate performances predicted using removing noise from numerical simulation data is obtained to define the inherently complicated nature of the competition of buoyancy with electromagnetic body forces.

Abstract: Along with the development of aviation industry, airplane emission pollutants is becoming more and more serious environment problem. All the pollutants of aero engine emission, the airplane and engine manufacture companies ,Airlines and environment protection departments care about most is how to reduce the NOx emission. In order to get the concentration distribution diagraph of NOx emission, a test-bed was constructed, the test-bed is designed of two test sections in emission pipeline, there are 13 sampling point in each section,3 test conditions selected to simulate different flying condition. The emission pollutants is monitored by Testo350,and the monitor results is analyzed by Fluent software to get the NOx concentration field distribution characteristics of a certain type of turbo-jet engine emission.