New method of transportation of viscous petroleum products is proposed, ensuring their high average temperature and fluidity without the use of thermal insulation of the railway tank boiler and ground heating. A simulation model for the transportation of viscous petroleum products was constructed using a new method of modeling the physical process, allowing to estimate the amount of resources consumed
CURRENT CONDITION OF TRANSPORT OF geographical capabilities of the country, is not anticipated [Car]. 2. The ability to provide bulk cargo delivery by rail, unlike road transport, which has a maximum volume of one tank-vehicle cargo of 25 tons. At the same time, the specialized rolling stock in 45 wagons is able to carry cargo weighing up to 3000 tons [Zhe17]. 3. The unisonality of transport in contrast to water transport.
Let us consider in detail the scheme of transportation of viscous oil products (Figure 1).
The most energy-intensive and expensive processes are heating petroleum products before unloading and draining, as well as cleaning the boiler of the railway tank from the remains of petroleum products with preliminary evaporation, disposal and disposal of a large amount of waste [Gon89]. A significant role here is played by: • Long distances and low branching of railways, which lead to long-term transport duration. • During transportation, transported oil products are cooled, and in dark petroleum products (masuts, oils, paraffin oil products, etc.) viscosity increases so much that their discharge without long and intensive heating necessary for the restoration of fluidity becomes impossible [Moi12, Bak04].
These problems lead to the fact that transportation of dark petroleum products is a labor-intensive, long-term and expensive operation, which causes low turnover of tank wagons, requiring expensive equipment and high costs of heat energy and water (steam). 2 STRATIFICATION OF VISCOUS OIL PRODUCTS (NEW TRANSPORTATION MODEL) The most rapid cooling of viscous petroleum products in the first 20-25 hours after pouring into the railway tank, when the temperature of the petroleum product is high, and the viscosity is small [Zhe17].
Cooling of cargo occurs due to mixed free-forced convection through the walls of the boiler of the railway tank. As a result, cooled during transportation, the load during unloading needs to be heated to restore fluidity. This problem is particularly acute in winter, which in some regions of the country can last up to 8 months [Mik77,Mon65] Now, specialized railway tanks are used to slow down the freezing of viscous petroleum products: With a steamheater cover, with stationary steam coils, with thermal insulation of the boiler walls, etc. Their disadvantage is that these railway tanks have a large mass of containers, which, creating excessive loads on the axle of wheel pairs, causes the need to reduce the weight of the load. The consequence of the use of specialized trains is the nonproductivity of transportation and a very large, empty run, usually reaching 50% [Mor06].
One possible way to reduce the cost of railway transportation is to slow down the rate of cooling of viscous petroleum products during transportation by transferring them to stratified state at the time of loading. This non-equilibrium condition can be achieved by increasing the density of the cargo carried at the bottom of the railway tank even during loading. Directly in the places of interaction between the transported cargo and the walls of the boiler, the viscous oil product solidifies, forming a high-viscosity layer, which has a small thermal conductivity, which itself becomes thermal insulation. As a result, the bulk of the product remains in a fluid state throughout the transport. In this case, when unloading into the warming-up, a small share of the transported cargo (not more than 10%) is required. The unloading and cleaning process is approaching summer time standards. The advantage of this type of transport is the use of the existing fleet of general-purpose railway tanks.
To assess the cost effectiveness of the proposed mode of transportation, a number of simulation models of various processes of transportation of petroleum products were developed, allowing to conduct functional and cost analysis. As an instrumental environment was used the domestic platform Business Studio [Bis,Kse19]. The modeling used BPMN notation, which allows a very thin and precise description of the simulated business process.
With Business Studio, you can see how many times each process has been started, what processes are waiting to run, and why (lack of material resources), the average number of launches per day. The consumption of material resources (pair) is visible.
Let's consider one of the most expensive processes of transportation of oil products - cleaning of the railway tank from the remains of cargo, including preparatory operations, draining of residues and cleaning of the tank directly. The duration of the cleaning of the railway tank depends on the nature of the cargo, the period of delivery (winter or summer) and can amount to 5-6 hours in winter, unlike the summer time, when the cleaning of the tank takes only 1,5-2 hours.
We will carry out simulation of the process of cleaning the boiler of the tank-car in winter period at work of one drain device and average temperature of air -25̊С. The result of the simulation is visible in Fig.2.
The diagram shows that during the past day, a composition consisting of 22 railway tanks arrived at the wash-and-row station. Of this number, 6 railway tanks were completely cleaned, another 17 are waiting for their turn.
In Table 1, it is shown that process "Steaming" was launched 21 times, in 18 cases it is completed, and in 3 it is being carried out at the moment. The queue was formed during the "Solvent washing" process, which was launched 18 times, of which in 8 cases the process was Three climatic zones are allocated for clarity of calculation. 0 0 0 0 0 0 0 0 1. 2.
a itsn eeu iaw uq A e th l ed ira tc t
e epx am E eg fo ady rea re re av b p ehT unm ttrssa raeeaevhgT rfebunom ltiecponom reapdy - - 22 6 0 0 22 22 0 0 22 22 0 0 22 21 14 0 21 7 0 0 7 7 0 0 7 6 0 0 6 6 14 0 The 1st climatic zone, to which the south the country belongs with a duration of winter period up to 3 months and an average temperature of -9,5̊С and a summer period with an average temperature of + 30̊С.
The 2nd Primorsky climatic zone, to which the region belongs, the central, With the new loading system, petroleum products come to the end user in a hot state and practically does not need heating during draining. Therefore, the cleaning process will be similar to the summer time of the year. Let us carry out simulation at work of one drain device and average temperature of air 18̊С. The result of the simulation is visible in Fig.3.
The wash-and-row station received a composition consisting of 20 tank wagons. Of these, when one is working with one drain device, completely cleaned 16. The Table 3 show the average number of launches per day and the material consumption.
The process "Washing water", for example, was launched 17 times, of which 16 are completed, and 1 are waiting in the queue.
It is clear from Table 4 that during the cleaning of 16 tank wagons in summer less steam was spent than the winter period for cleaning 6 railway tanks.
The final Table 5 shows the amount of steam used to clean the tank during summer and winter periods, depending on the climate zone, calculated using the Business Studio platform. 4173,0749 810,3542 4983,4291 western and northwestern parts of the battle with a duration of the winter period up to 5 months and an average winter temperature of -10̊С and summer temperature of +25̊С n o i t its ta a en s w m A le p m i 0 0 0 0 0 0 0 0 a in e s eu t i aw uq A 0 0 0 1 0 0 0 1 e th l ed ira tc t
e e a p m x E 0 0 0 0 0 0 0 0
y eg fo ad rea re re av b p ehT unm ttrsa
s 3. The 3rd climatic zone, which includes the regions of Siberia and the far East, with a winter period of up to 8 months and an average temperature of -22̊С in winter, and in summer +18̊С. The data obtained using the simulation model correspond to the data obtained from the calculation [Tkt16]. The Figure 4 shows the change in the vapor mass (G) from the ambient temperature (t) at the thickness of the oil deposits on the walls of the tank 0,02m.
A new way of transportation of viscous petroleum products is proposed. A simulation model for the transportation of petroleum products was constructed, allowing to estimate the amount of resources necessary for heating the oil product before unloading and during the cleaning of the railway tank.
Advantages of the built model: 1. For the first time a new method for modeling physical processes was used. 2. To build the simulation model, a new tool was used, which was previously used exclusively for modeling economic business processes. 3. The domestic Business Studio platform was used as a tool environment. 4. The data obtained from simulation are consistent with the data obtained from the calculation. 5. In the future, for more complete calculations, it is planned to integrate a process that takes into account external factors into the existing model.