PSI - Issue 59

Mariia Serediuk et al. / Procedia Structural Integrity 59 (2024) 763–770 Mariia Serediuk et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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Using the formula (2) and performing simple calculations, it was established that the environmental impact factor for pipeline 1 is KE = 1.2, and for pipeline 2 – KE = 1.53. Then, the value of the defective score will be, respectively, for pipeline 1 – DB = 0.52, and for pipeline 2 – 0.26. Thus, according to the calculation, pipeline 1 will be more reliable in operation. However, as mentioned above, pipeline 2 can be chosen for transporting such a product as vegetable oil. The next stage, after choosing a pipeline for transferring to another type of transported product, it is necessary to carry out its reconstruction or repair. Repair of pipelines is mainly carried out using arc welding, with the aim of restoring the pipeline wall. In order to reconstruct the pipeline, intra-pipe repair methods are often used: the method of pulling the pipe in the pipe, coating the inner surface of the pipeline, etc. Such methods of repair and reconstruction of pipelines are given in works by Boreman et al. (2000), Amend and Bruce (2013), Doroshenko et al. (2019), Serediuk (2021), Zapukhlyak et al. (2022b), so there is no need to dwell on them in detail. 3. Features of the design hydrodynamic calculation of the pipeline for the transportation of vegetable oils The next stage in the process of converting a long-used pipeline to the transportation of vegetable oils is the design calculation of the hydraulic processes of pumping this type of product. The task of designing a pipeline for pumping vegetable oils was put before scientists and designers of Ukraine for the first time. Solving this task is complicated by the lack of regulatory documents that regulate the design, construction and operation of such non-traditional technical facilities. Vegetable oils are characterized by significant viscosity at low temperatures. According to this indicator, they are closest to high-viscosity oils or technical oils. Since there is no regulatory framework for the design of pipelines transporting vegetable oils, it is advisable to use the normative document in force in Ukraine, according to which the design of pipelines for pumping oil and oil products, including technical oils - VNTP 2-86 (1987). It is known that the solidification temperature of sunflower oil is minus (16- 19) °C, the Deborah number is 0.5. This gives grounds for asserting that at temperatures higher than 0 °C, the abnormal rheological properties of the oil are weakly manifested and this factor can be neglected. Therefore, further studies were performed for the case of the absence or weak manifestation of abnormal rheological properties of vegetable oils. Using the recommendations of the regulatory document VNTP 2-86 (1987), depending on the annual volume of pumping of the transported product Mrych, choose the value of the external diameter of the pipeline Dz and the value of the working pressure Pr. Next, the mechanical calculation of the pipeline is carried out: the wall thickness δ is determined and the internal diameter D is calculated. The projected daily volume of transportation of sunflower oil through the pipeline Qd is found. At the same time, the calculated density of the transported produ ct ρp must correspond to the value of the density at the minimum operating temperature in the pipeline. Calculate the hourly Qh and second Q design productivity of the pipeline, find the average speed of oil movement in the pipeline w. To determine the mode of movement of oil in the pipeline, the Reynolds number Re is found for the calculated value of the kinematic viscosity of the oil νр. Accordi ng to VNTP 2-86 (1987), the estimated viscosity of the transported product must correspond to the value of viscosity at the minimum operating temperature. VNTP 2-86 (1987) offers the following method for determining the coefficient of hydraulic resistance of the pipeline: Re < Re cr =2000

Re 64

,

 

(3)

if Re cr < Re < Re T1 =2800 4 (0.16 Re 13) 10      ,

(4)

if Re T1 < Re < Re T2