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31.
Optimal control (OC) methodology is used to develop a control policy for a batch-operated solar sludge dryer with ventilation as the dominant control. Batch performance criteria and instantaneous optimization criteria are developed for two economic environments: quota limited and capital limited. The general formulation, as well as simplifications resulting from the multiplicative form of the evaporation (drying) rate model, are presented. The multiplicative form results in a single constant number, called here “control intensity,” which is used to guide the on-line control decisions. These decisions turn out to be independent of the dry solids content (DSC) of the sludge. Further simplification, by assuming a strictly constant weather, is used to demonstrate the general effects of the economic and physical (weather) environment on the solution.
The OC approach is used to address, via simulation under realistic weather conditions, several design, operation, and pricing problems. In particular, the following have been considered: sizing of the ventilation fans, determination of a fair fee for sludge disposal, finding the best final DSC, and evaluating the effect of the price of electricity. Regarding the particular location represented by the data, it has been shown that the installed capacity of the ventilation fans should be increased and that there seems to be sufficient economic incentive for solar drying. 相似文献
The OC approach is used to address, via simulation under realistic weather conditions, several design, operation, and pricing problems. In particular, the following have been considered: sizing of the ventilation fans, determination of a fair fee for sludge disposal, finding the best final DSC, and evaluating the effect of the price of electricity. Regarding the particular location represented by the data, it has been shown that the installed capacity of the ventilation fans should be increased and that there seems to be sufficient economic incentive for solar drying. 相似文献
32.
R K Mandal Ch. Durga Prasad O M Parkash Devendra Kumar 《Bulletin of Materials Science》1987,9(4):255-262
Glasses with varying molar ratios of PbO/BaO in the system BaO-PbO-TiO2-B2O3-SiO2 were prepared keeping (BaO + PbO)/TiO2 ratio equal to one. The glasses were ceramized by two-stage heat treatment. X-ray diffraction indicates that PbTiO3 crystallizes in lead-rich glasses while BaTiO3 precipitates in barium-rich compositions. Solid solution (Ba, Pb)TiO3 does not seem to crystallize over the entire range of compositions. Simultaneous presence of PbO and BaO in the initial glass
composition reduces the yield of ferroelectric phase. Dielectric properties have been interpreted in terms of microstructural
features. 相似文献
33.
34.
针对2011年和2012年全国中职院校竞赛项目使用的《建筑设备给排水控制调试装置》设备,对其电气控制部分的安装调试过程进行分解。 相似文献
35.
介绍了用电导法测定乙酸解离常数的实验原理和步骤,给出了用计算机对电导法测定乙酸解离常数的实验数据进行处理的软件设计方法,同时给出了用Visual FoxPro 6.0编写电导法测定乙酸解离常数的处理软件的基本结构和部分程序代码。 相似文献
36.
目前反倾岩质边坡弯曲倾倒破坏分析方法仍以基于极限平衡理论的悬臂梁模型为主,但大多未考虑坡脚岩层的剪切破坏。为准确评价该类边坡的稳定性,建立考虑坡脚岩层剪切破坏的分析计算方法。首先,根据岩层变形破坏特征,将边坡分为后缘稳定区、中部弯曲倾倒区和前缘剪切区3个区域;其次,建立弯曲倾倒-剪切滑移破坏模式的稳定性分析方法;最后,通过工程实例验证,并进行参数分析。研究结果表明:提出的分析方法与工程实际符合性较好;边坡在倾角较陡、坡角较大时稳定性最差,坡角对边坡稳定性影响大于岩层倾角的影响;岩层厚度及层面内摩擦角增加有利于边坡稳定性,且会扩大坡脚剪切区范围。研究成果对反倾岩质边坡破坏的防治具有实践指导意义。 相似文献
37.
38.
Solid-liquid phase equilibria of the benzene + 2-methyl-2-propanol system have been investigated at temperatures from 278 to 323 K and pressures up to 300 MPa using a high-pressure optical vessel. The uncertainties of the measurements of temperature, pressure and composition are within ±0.1 K, ±0.5 MPa, and ±0.001 mole fraction, respectively. The freezing pressure at a constant composition increases monotonously with pressure. The eutectic point shifts to a higher temperature and benzene-rich composition with increasing pressure. In order to describe the pressure-temperature-composition relation of high-pressure solid-liquid phase equilibria, a new simple equation has been proposed as follows:
相似文献
39.
Experimental vapor pressures andP--T data of an important alternative refrigerant, 1, 1-difluoroethane (HFC-152a), have been measured by means of a constant-volume method coupled with expansion procedures. SixtyP--T data were measured along eight isochores in a range of temperaturesT from 330 to 440 K, at pressuresP from 1.6 to 9.3 MPa, and at densities from 51 to 811 kg·m–3. Forty-six vapor pressures were also measured at temperatures from 320 K to the critical temperature. The uncertainties of the temperature and pressure measurements are within ±7mK and ±2kPa, respectively, while the uncertainty of the density values is within ±0.1%. The purity of the sample used is 99.9 wt%. On the basis of the measurements along each isochore, five saturation points were determined and the critical pressure was determined by correlating the vapor-pressure measurements. The second and third virial coefficients for temperatures from 360 to 440 K have also been determined. 相似文献
40.
The flexible BJH- and flexible or semiflexible MCY-type water-water potentials (4 potential modifications in each nonrigid family, i.e., altogether 12 potentials) are used for evaluation of the gas-phase water-dimerization equilibrium constants. The potential-energy term is adjusted for best reproduction of the available experimental equilibrium constants. An independent test using the experimental steam second-virial coefficient isotopic difference shows that the adjustment also improves the computational evaluation of the difference. A set of dimerization equilibrium constants is suggested over a wide temperature interval (based on the BJH/G, MCY-B, or MCYB potential modifications). The best reproduction of the experimental equilibrium constants (in conjunction with good performance for the second-virial isotopic difference) is produced by the BJH/G potential. The results are applicable to various problems such as the formation of water clusters in large-scale natural and artificial water jets (e.g., hydrogen-oxygen rocket motors, orbital capsule water dumps, water ejection from a comet nucleus) or in atmospheric chemistry. 相似文献
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