The boiler consumes a lot of energy in the process of operation. Therefore, how to reduce the energy consumption of the boiler is the key to energy saving and emission reduction. The gas-steam ratio ...of the boiler is an important index to measure the boiler operation efficiency. Thus, in view of the present situation of the gas-steam ratio, the main influencing factors of the boiler steam-gas ratio are determined through comprehensive analysis and on-site argumentation. Then, the boiler operation parameters are optimized by using the experimental design method (DOE), and the optimization effect is verified. The results show that after taking corresponding measures, the gas-steam ratio is reduced by 7.7% compared with the same period last year. Its stability is also improved.
The global economy is at a turning point when the raw material is less and less about demand and harder to obtain. Moreover, the reduction of dioxide emissions carbon is mandatory in the context of ...climate change. At the same time, the waste in construction and other economic areas is increasingly difficult to manage because its sorting and recycling are not yet in line with the rules imposed by the European community and assumed by each state. In the current context of the need to reduce carbon dioxide emissions more and more, materials used for thermal protection of buildings must be obtained if possible from recyclable materials with low thermal conductivity and minimum energy consumption. In this paper, we propose a comparative analysis of the thermal conductivity obtained experimentally of some synthetic wood boards with variable content of recyclable waste (polystyrene, fly ash, sunflower husks, cement, polymer, etc ) using a double-climate chamber, with those obtained by numerical modeling using the finite element method. Experimental planning of synthetic wood boards was carried out with the help of the design of the experiment method which allowed a decrease in the number of experiments necessary for such investigations but with maximum efficiency on the results of the physicomechanical characteristics obtained. The results obtained by the two methods were very conclusive surrounding this material in the category of insulating ones with thermal conductivity between 0.071 and 0.107. We can say that synthetic wood obtained with variable addition of different compatible waste can contribute to more efficient use of this and implicitly to the decrease of the effect on the environment.
Micro semi-pyramidal pattern arrays were directly created on the commercially available polymer substrate (polycarbonate, PC) by pressing a glassy carbon (GC) mold in the hot-embossing process with ...self-made hot-embossing machine. The micro feature of negative cavity on the GC mold was fabricated by Focus Ion Beam technique (FIB). The cavities were approximately 65times70 um at width and 42 um at depth. The space periodicity between the micro cavities is about 120times120 um. By adopting an orthogonal design of experiment method with four parameters of the micro hot-embossing process, each one at three levels was studied. The key parameters which have important influence to the forming result, such as embossing force, embossing temperature, heating time and force holding time were studied. Good forming result was obtained by using a set of optimal parameters according to analysis of experiment data.
Mass-produced electrical machines are subjected to manufacturing uncertainties in terms of geometry. A robust design is inevitable to ensure the consistent performance of the electric motor. Some ...parts of the rotor geometry are often simplified, like the flux barrier at the end of the magnets. This paper presents a design optimisation regarding the torque ripple and the average torque. The aim is to assess the effects of the flux barrier on the main properties of a permanent magnet synchronous motor. Also, robust design analysis is presented on the flux barrier. The computational burden of the robust design analysis is immense, even if uniform uncertainties are assumed. In this case, different Design of Experiment (DoE) methods reduce the number of simulations. The efficiency of the DoE methods is compared in terms of simulation number and extreme value approximation. We found that the Central Composite method is the most accurate, while the Plackett–Burman is the most efficient in this particular case.
