Computerized system for calculating an optimal route of the pipeline in conditions of the settlement

Abstract: The article presents a new method of choosing the optimal route of the pipeline on the basis of genetic algorithm theory. The use of this method makes it possible to carry out an alternative design and ground the minimum cost of the gas pipeline route.

Keyword: pipeline transport, route planning, minimal spanning tree, ant colony algorithm, fuzzy logic apparatus.

Gas pipelines affect more infrastructure objects than other engineering complexes and structures. Until recently, the route laying of gas pipelines has been chosen by hand on topographic maps. The choice of the route is the first significant step in a gas pipeline design and construction, this step can have a significant impact on the construction and operation of the gas pipeline as a whole, therefore the optimization of this process can significantly affect the financial and material resources necessary for constructing the gas pipeline.

To make gas supply operate safely and fault-free it is to be designed and calculated. It is essential that the pipes for all types of pressure lines should be properly selected to ensure stable gas supply to the devices. In order to select pipes, fittings and equipment as accurately as possible the gas pipeline hydraulic calculation is to be done.

Any hydraulic calculation to be done means determining the parameters of a future gas pipeline. This procedure is mandatory, as well as one of the most important preparatory stages for construction. Optimal gas pipeline operation will depend on proper calculation.

When each hydraulic calculation is being carried out the following is determined:

• the required diameter of pipes that will ensure efficient and stable transportation of the required amount of gas;
• whether pressure losses will be acceptable when transporting the required amount of blue fuel in pipes of the diameter which is set.

Pressure losses occur because of the hydraulic resistance in any gas pipeline. If it is calculated incorrectly, it can cause gas shortage for consumers' normal operation in all modes or at the moments of its maximum consumption.

Thus, an efficient way of route laying selection is important to minimize economic losses.

The purpose of the thesis is to determine the optimal route of the gas pipeline. Information about the gas pipeline. Before starting the construction of the gas pipeline, the process of the future route designing is carried out. The selection of the latter affects profitability and reliability of the future transport line, as it is important to solve a number of problems dealt with the minimization of financial costs, construction conditions, limitations of construction terms, reliability of the pipeline and environmental protection.

Information about the future pipeline means an amount of information that enables designers to quantify the conditions of construction and operation of the future pipeline. The lack of such information can lead to loss of the best route, an excessive amount of it – to unjustified complication of the design process. Therefore, designers are to select the most significant factors from the huge number of them that affect the position of the future route in order to take them into account when determining the so-called General direction of the route [2].

All information can be divided into two main groups: independent of climatic, topographic and hydrogeological conditions in which the future pipeline will be laid, and the information determined by these conditions.

The first group of information includes: the initial, final and intermediate points of the gas pipeline, its diameter, the type and quantity of the pumped product, the shortest distance between the initial and final points. The second group of information includes the data that to some extent depend on the position of the future gas pipeline and the natural conditions under which it may be laid:

• hydrogeological and climatic data of the route;
• the number of large and medium-sized rivers, marshes, lakes, railways and roads, which could be intersected constructing the pipeline;
• density of settlements and the presence of parallel roads and railways, river and sea routes;
• location of operating pipelines and other extended facilities (power lines, main cable communication, etc.) passing along the proposed route;
• the quantity and quality of cultivated agricultural land (arable land, gardens, meadows), the intersection of which, taking into account reclamation and alienation, increases the cost of the pipeline [3].

These are the factors that in most cases determine both the General direction and the detailed laying of the route on the area. Before finding an optimal route, the scope of its search has to be limited in order to reduce the amount of the source information. Though within it the best track should pass by all means, but outside it any track should obviously be the worst.

The construction of pipelines undoubtedly requires long-term planning, including management decisions to determine the route, as well as effective protection of soil, water and people. A well-planned, well-constructed, properly operated pipeline with proper maintenance and repair is a reliable and environmentally friendly means of transporting liquid and gaseous hazardous substances. Route planning and environmental studies are among the most expensi0ve stages, therefore the success of the investment project depends on effectiveness of their implementation as a whole. The task of planning the route laying of pipeline transport networks includes the need to find the optimal cost-minimization criterion (or, for example, profit maximization) sequence of combining the territories of cities and other settlements, taking into account the restrictive conditions determined by the demand indicator in each of them and the characteristics of the pipes.

When determining the search area, a fuzzy ant algorithm for planning the optimal route of gas pipeline transport can be used [5].

Ant algorithm. The problem is solved by searching on the graph G (V, E) (where V is the set of settlements, and E is the distance between them) the minimum spanning tree (MOD)–a tree connecting all vertices of V with the minimum length of edges. There is also a marked MODE, which differs in that for any edge of the graph, according to the marking function l: E, the marking label of the set of labels is set. It is necessary to note that the formulation of the problem does not prohibit the use of parallel edges, which allows to assign several labels to one edge at the same time. To solve the problem, it is advisable to use an approach based on the search for optimal routes (marked MODES) using a modified algorithm of ant colonies. The essence of this method is to analyze and simulate the behavior of the colony of ants that are looking for a way to a source of food [4]. Communication between ants is carried out at the expense of pheromone, pheromone trails being collective memory of ants. The pheromone evaporates after a certain time, making it possible for ants to find new, more optimal routes. Unlike other types of heuristic search, such as simulated annealing or evolutionary algorithms, the ant colony method make it possible to integrate the knowledge about the problem into the construction of a new solution. In case of a new combinatorial optimization problem, there is often some knowledge of the problem that can be used for heuristic search. Thus, the main application of the ant colony algorithm is in the field of combinatorial optimization. The first problem to which this version of heuristics was applied was the traveling salesman problem [4].

The analysis of the problem solved allowed us to conclude that in order to improve the efficiency and validity of decisions it is advisable to take into account the vagueness and insufficiency of existing information about the problem. For example, the indicator of the amount of consumption in different settlements (tops of the graph) can be calculated only approximately, without taking possible deviations into account. The estimation of the total cost of the pipeline laying between the vertices, which sets the weight of the graph edge, is also an interval one. Processing of such data can be carried out with the use of fuzzy-logical apparatus, which makes it possible to move to formal rules and descriptions on the basis of fuzzy expert assessments [1].

On finishing to apply the developed fuzzy ant colonies algorithm to search the labeled MODES on the graph, which makes it possible to take the uncertainty and fuzziness of demand for products in settlements into account, the efficiency of the enterprise operation goes up due to improvement of the quality of pipelines route planning.

References

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