Aiming at the diagnosis technology of the horizontal well fracturing effect, a numerical fracture diagnosis method based on the water hammer effect is proposed. Because of the energy dissipation caused by the fracture to the pump shutdown pressure, the traditional water hammer mathematical model is difficultly to apply to the fracture diagnosis of horizontal Wells. In this paper, considering the influence of fracture on the water hammer effect, a mathematical model of water hammer in a horizontal well is established based on the equivalent circuit method, and the model is solved by the characteristics method line. The fracture parameters are deduced based on the characteristics of the water hammer pressure curve, and the variation characteristics of the water hammer pressure curve with different influencing factors are analyzed. The results show that the characteristics of water hammer pressure wave are affected by fracture morphology and construction parameters. and the amplitude and period of hydraulic pressure are changed by fracture volume, displacement and fracturing stage length. The water percussion model is used to carry out historical fitting to the field data, and the coincidence rate of the obtained fracture half-length and height with the microseismic monitoring data is more than 80%, which verifies the accuracy of the model and provideds on idea and method for the fracture parameter evaluation of horizontal wells.
As RWCE algorithm is used to optimize heat exchanger networks, the existence of fixed investment cost makes it difficult to produce and retain heat exchanger units with small loads. It makes structures that have not yet fully evolved be eliminated too early. We established a relaxation method of fixed investment cost. The fixed investment cost and the heat exchange of heat exchange unit are processed according to their variation. With heat exchange of heat exchange unit, relaxation strength in optimization process is adjusted in real time to guide and promote the smooth generation and evolution of small load heat exchange unit, so as to enhance structural evolution ability of heat exchange network. The relaxation strategy is applied to 9SP and 15SP examples to verify that the relaxation strategy promotes structural evolution effectively and improves optimization quality. The optimal results (2 903 528 ＄ ·a-1, 5 115 061 ＄ ·a-1) are better than those in literatures.
Development of superintense laser technology has brought historic opportunities and space to expand for the study of interaction between light and matter. The process of nuclear reaction assisted by superintense laser field, especially the influence on cross sections of deuteron-triton fusion reaction, has attracted more and more attention. In this paper, we introduce the rapid development of laser technology and the wide application of superintense laser technology. Then we introduce the cross sections of nuclear fusion reaction and its influencing factors, and review recent progress in the study of light nuclear fusion cross sections in superintense laser field with emphasis on deuteron-triton fusion reaction. At last, we make some prospects for future development in this direction.
An evolutionary algorithm of multi-directional compulsive search strategy for dominant individuals is proposed to evaluate the health of global search of current population by examining individual difference index.When the optimization results stagnate for a long time, the health index becomes worse and the multi-direction forced search strategy of the dominant individual is started to expand the search direction of the dominant individual near the local optimal solution region, so as to ensure the global search ability of the algorithm.The strategy was applied to 15SP and 20SP calculation examples and results were compared with optimal results in the literature.They are decreased by 1.09% and 0.83%, respectively.It in dicates that the dominant individual multi-directional compulsive search strategy exerts fully the evolutionary potential of the dominant individual and improves the optimization efficiency of the algorithm.
