Optimization of a sequential irrigation system on differential irrigation plots

Summary

The optimization of a sequential irrigation system used on differential irrigation areas is considered. The sequential regime of differential plot irrigation is analyzed in detail. Target functionals have been generated for the synthesis of two extreme modes of sequential irrigation of differential plots based on the Kostiakov–Lewis equation and its derivation. As a result of the analysis using the variational optimization method, it was found that the first synthesized extreme mode provided for minimizing the corresponding target functional with an inverse relationship between the irrigation time and plot area, which is estimated as a negative extreme mode; the second synthesized extreme mode, with a limited total irrigation time, allows for a direct dependence of the irrigation time on the irrigated area, ensuring the maximum of the assumed optimization criterion.

Key words

optimization criterion , purification of mine water , irrigated area , Kostiakov equation , water use efficiency

The time factor in a technical and economic calculation task

Summary

Developing quantitative estimates of technical solutions assumes the calculation of economic indicators of the considered solutions. The properties of engineering and economic comparison models with account of the time factor are considered. The key aspects and properties of engineering and economic comparison models of the options are presented; the analysis of the content of the discounted cost indicator was carried out; its main properties were highlighted. The conditions for bringing options to a comparable form, identical material result and targeted economic efficiency are considered. The graphical material interpreting the discounted cost indicator is given. A simple interpretation of the discount rate is proposed. Its effect on the result of solving the problem of engineering and economic comparison of the options is shown. The ratio of the discounted cost indicator to the indicator of the duration of the life cycle of objects is considered. A method for interpreting the discounted cost indicator in practical calculations is proposed. It is shown that the knowledge of the general principles compensates for the ignorance of certain facts.

Ключевые слова

reduced expenditures , efficiency of investments , discounted costs , discount rate , the task of optimizing the parameters and structure of pipeline systems , optimization criterion