Tag Archives: optimization
The most common method of gas purification from acidic impurities is cleaning with amines-natural organic compounds that are derivative of ammonia. Amine purification is a regenerative process. Absorption of acidic pollutants occurs approximately ambient temperature Wednesday, and Amina regeneration occurs at boiling point in stripping column. The disadvantage of the process natural and technological gases from acidic impurities is the large amount of heat required to desorption. The most common and effective method for purification of gas currently cleaning using alkanolaminov. This process differs with the opportunity to achieve a high degree of purification at relatively low cost. Gas purification schemes to reduce heat flow supplied to the bottom of the stripping column, were simulated in the package Unisim Design: standard process flows, Division steam, their combination of recompression. Also offers purification scheme when using a mixture of amines (DEA + MDEA). Method of combining schemes and Division of flow helps reduce the heat load compared with the method of replacing monoethanolamine on 23%, but the method of steam recompression has a lower heat load compared with replacement of monoethanolamine-on 30%.Other options for change process flow diagrams are associated with large capital costs. Thus, the proposed scheme with steam recompression will reduce the heat load with relatively small capital cost.
In article imitating realization of integer model of optimization in a task about distribution of seism prospecting parties of objects is considered. Feature of this model is that imitation of the established statistically probabilistic distributions of the parameters having casual character allows forming with certain accuracy the forecast as loadings of capacities of seism prospecting parties, and estimated time for processing of objects and movements between them.
In work the number of seism prospecting parties and objects of seismic exploration is accepted by fixed values, and elements of transport system of objects are modelled under the set law of distribution of random variables. In other words, the distribution model on the objects distributed in knots of the generated transport network is considered. At the same time, generally the law of distribution has to be determined by results of check of statistical hypotheses on the basis of retrospective data.
In these researches the hypothesis of the uniform (equiprobable) law of distribution as option when any of sizes of a transport network (arch size) can’t be considered as more probable, than other of some fixed range was accepted. Besides, temporary restrictions are also accepted by random variables that imitates limitation of work of seism prospecting parties on objects, proceeding from seasonal restrictions of the region.
In this paper, the problem of taking into account the risks of the preparation and implementation of investment projects is considered. One of the main difficulties of the investment projects efficiency evaluation is taking into consideration the inexact initial data andthe uncertainty caused by the remoteness in time of the investment activity results. The classification of the investments distribution tasks and risk evaluation methods are given. The problem of uncertainty components evaluating is one of the most difficult in the investment analysis. For each type of uncertainty the specific methods of evaluation are being developed. In this paper, a strategy of risk accounting in conditions of uncertainty based on probabilistic evaluation of possible changes, caused by unforeseen circumstances of the project implementation, is suggested. The key elements of the strategy are evaluation of changes of key parameters of the investment project and evaluation of the possible risk, which allows estimating the necessary additional amount of resources to ensure the project implementation with a given probability. These components of the strategy are implemented with the use of the Monte Carlo simulation and the solution of the problem of production plan optimization in terms of stochastic programming. The results analysis of solving the problem for their finery showed that ignoring of the random feature of the investment project’s parameters might lead to unrealistic plans composition. In order to ensure the plan implementation with the given probability, it is better to have an additional amount of each type of resources, which absence may decrease the income immeasurably with costs due to a possible reduction of production output.
MATHEMATICAL OPTIMIZATION MODEL OF GAS FILTERS’ GEOMETRIC PARAMETERS LOCATED IN HEATED ACCOMODATIONS
In acting normative document there absent the recommendations for optimization of gas filters’ geometric parameters located in the heated accommodations, that vastly reduces cost-performance to their usages.
In the analysis result it has been stated, that height of filter body – diameter ratio essentially influence on operation economy and integral costs of gas filter, located in the heated accommodations together with other gas equipment.
When increasing filter body height- diameter ratio, the diameter, metal capacitance, investments to gas filter are decreasing but at the same time investments in accommodations and running expenses for its heating are increasing.
There was offered the mathematical model for defining the optimal height-filter body diameter ratio that includes the estimated schemes, objective function of integral costs, investment and running expenses equations, range of restriction of control parameters. The designed mathematical model allows to take mutual influence geometric parameter filter to his diameter, volume and heat protective characteristics of the accommodation where it is installed, consumption of thermal energy necessary for heating accommodation.
The results of calculations, fulfilled according to the offered mathematical model applicable to the gas filter 0.004 m3 by volume with feed socket and downstream fairing 57mm diameter, show, that optimal height-body diameter ratio of a filter, arranged in a heated technological accommodation with other gas equipment is (H/D)opt =4.5, and minimal integral expenses form Зmin =13200 rubles.
Comparison of the optimal configuration of the offered filter (H/D)opt= 4.5 with mean quantity for existing constructions (H/D)= 2.1 shows substantial difference 2.15 times that is explained by ignoring cost indicators of supporting and heat-protecting constructions of the accommodation, where it is arranged, and also consumption of thermal energy for needs of heating, specific weight of flanged joint value. Using the offered mathematical model for defining optimal height – filters’ body diameter ratio, arranged in a heating accommodation, allows to increase essentially their operation economy.
The main gas pipelines are the body of the gas transmission system. The main share of expenses of energy resources in the pipeline transport of gas belongs to this part of the system. Characteristics of the pipeline network, also as the set technological tasks, are defining factors for an operating mode of other equipment of system which settles down generally at compressor stations.
In this regard, it is very important to provide possibility of calculation of an operating mode of the main gas pipeline with sufficient degree of accuracy. For this purpose you have to consider all significant factors which influence operation of the main gas pipeline. The method of calculation shouldn’t contain insoluble difficulties of mathematical character.
In spite of the simple construction of the gas pipeline at first sight, it contains difficult processes of movement, friction, interaction with gravitation, internal and external heat exchange. These processes, as a rule, change in time therefore they are non-stationary.
The gas transmission system has the difficult scheme where simple gas pipelines are united in a transport network, the operating mode of all elements is interconnected.
The specified complexity of processes has rather difficult mathematical description of all these processes by means of the corresponding models, in this regard; obtaining decisions is accompanied by difficulties of mathematical character. Simplification of models for the avoidance of the specified difficulties can reduce their compliance to the described object.
The author of this work considers existing methods of calculation of simple gas pipelines, does their analysis.
The author classifies models concerning a scope.
The author revealed construction stages for all considered universal models.
By results of the research the author draws a conclusion about the necessity of the solution of the question of mathematical modeling of gas movement in the main gas pipeline and notes the productive directions of further researches of this subject.