Equipment of technological acceptance line, storage and fuel delivery

2. Equipment for fuel receiving

fuel delivery is the cheapest way of transporting. delivery by water transport the reception points are built directly near moorings and piers, equipped by tie devices. Fuel pumping can be realized by floating or stationary pumping stations.for fuel discharge from self-propelled tanks can be inside or outside the depot. In this case the fuel discharge is performed by gravity.calculation of technological equipment is made on example of the Irkutsk petroleum storage depot situated on the Lena River, Russia.

General structure of a river petroleum storage depotloading terminals

For river petroleum products transportation realization is necessary to construct special mooring structures for mooring and fuel running into oil carries’ (oil tankers, barges) tanks. Complexes of such facilities are called oil-loading terminals.

The oil-loading terminal consists of: tank farm, technological pipelines, technological pump stations, account units, hydroshock protection units, mooring structures (riverside moorings, piers, remote receiving devices etc.), hosing stands (standpipes, flexible reinforced rubber hoses), treatment facilities, auxiliary buildings and structures (chemical laboratory, central dispatch unit etc.), dispatch control system and communications.oil-loading terminals perform a number of accompanying functions on watercraft service: acceptance of ballast water, acceptance and treatment of steam-gas mixtures from oil tanks, watercraft fuelling and so on. Number of services depends on accepted in the port watercraft servicing modes.

The oil-loading terminal equipment is to provide oil-carrier loading with maximally feasible efficiency for minimization of watercraft demurrage and emergency risk appearance.

Mooring structuresharbors and mooring constructions serve for oil shipping operations performing at water transportations. At constructing of oil harbors the following requirements are to be kept:

·        Minimal water level in harbors near moorings (m)

Н_o - the lowest vessel draught, m;_в -the biggest wave height, m.

·        The oil harbor is to have a sufficient water area to place the necessary moorings quantity and for free vessels maneuvering.

·        The oil harbor has to be safely screened from prevailing winds.

·        To protect water from oil pollution special measures have to be foreseen in view of emergency spill.river harbors the moorings are placed parallel to the riverside at distance no less than 300m from dry cargo moorings. River tank farms moorings are usually placed downstream at distance no less than 1000m from settlements, major roads and places of island water transport permanent mooring. At impossibility of this requirement maintenance the tank farms river moorings can be constructed upstream but the mentioned distance should be no less than 5000m.tank farms moorings can be stationary and temporal representing floating pontoons or demountable wooden piers placed for navigation period. Floating moorings are quite expensive and are reasonable to be applied if construction of stationary mooring is complicated.most widespread type of stationary moorings is ferroconcrete pier moorings with a pump unit inside the pier. On fig. there is a scheme of stationary pier mooring. It consists of mooring piers for vessels mooring, central pier for pumps and vessels hose coupling units installing, feed piers for technological pipelines laying which communicate the tank farm with a mooring, antiicing devices, which protect a pier form possible destruction while ice drift.

.1 River pier mooring on a pile base: 1 - metallic mooring-fendering dolphins; 2- passing gangway; 3 - superstructure for remote control equipment placing and service rooms; 4 - ferroconcrete pier with a pump station; 5 - ferroconcrete piles-piers; 6 - pump rooms; 7 - feed pier.

Means of petroleum products water transportations

There are the following types of oil carriers:

·        Tankers

·        Bargesof oil carriers is characterized by next factors:

·        Displacement - water weight displaced by a loaded vessel. The displacement ton at complete draught equals the vessel’s own weight and full cargo in it;

·        Deadweight - the full weight of carried cargo (transported and for own use);

·        Burden - transport ship weight;

·        Draught at full loading;

·        Speed at full loading.essential distinction of oil tankers design from other transport ships is caused by special properties of a liquid load:

·        A liquid load, having spare surface, flows at list taking on one side, which decreases the vessel stability;

·        Impacts of a liquid load at roll create additional stress on sides and bulkheads;

·        Increasing of liquid volume at its temperature increase requires a spare volume in tanks availability;

·        The increased fire safety requires taking of some fire preventing measures;

·        Necessity of special technological pipelines and pumps application for loading/unloading operations.all types of oil carriers the most applicable is an oil tanker. The oil tanker is a self-propelled vessel, which body is divided on sections by a system of longitudinal and transversal bulkheads. There distinguish forepeak, achter-peak and cargo sections. To prevent oil vapours passing to service and engine rooms the tanks are separated from forepeak and achterpeak sections by special blind sections. To collect oil vapors and regulate pressure in tanks on the tanker deck there is a special gas eliminating system with breathers.tanks are connected between each other by pipes, passing from the pump room along the tanks bottom. Besides, tanks are equipped by heaters, irrigation, cleaning, ventilating and steam devices, firefighting equipment etc.

.2 Transverse section of oil tanker body

and unloading of oil tanker is performed with following requirements maintenance:

·        For unloading of tanker body from dangerous stress concentrations the oil product (at empty passage - ballast) is to be placed in sections considering possible uniform load distribution along the vessel. Loading and unloading are to be performed in strictly predetermined turn. For example, forepeak and achter-peak tank groups are to be loaded uniformly.

·        To prevent a vessel normal list the side tanks are to be loaded uniformly.

of oil level in tanks at the end of unloading can cause air suction which leads to sharp efficiency decrease up to pumping stop in result of disruption of pump work. To eliminate air passing to pumps on tankers there is widely used pumping with vacuum tanks application. The essence of this method is in that pumps pump fuel not separately from each tank but from one hermetically closed in which vacuum is kept; from the rest of tanks the product passes into the vacuum tank due to pressure difference. The tank 1 adjacent to the pump room is used as vacuum one (fig.4). The tank is equipped with additional receiver 3, connecting it with the pump 4, and also sluices valves on gas eliminating and other pipelines, supplied to the tank from the deck.pumping start the vacuum tank is disconnected from all pipelines and checked for sealing reliability. Then through the additional receiver 3 the petroleum product is pumped out the tank approximately on 2/3 of filling height, at this in the tank is created vacuum equaling 0,035 MPa. Thereafter pumping continues, the vacuum tank is connected to another cargo tank for what the corresponding sluice valve 2 is opened on the cargo pipeline. Transfer to a next tank, as pumping goes, is executed by a usual switching of receiving sluice valves.vacuum value in the vacuum tank is to be set considering the petroleum product saturated vapors pressure at pumping temperature. If P_y>P_vac1 the petroleum product starts boiling. Vacuum tanks application allows reducing pumping time by 20%.of sand spits and small depths in rivers, especially in summer period, requires application of tankers with a minimal draught. The minimal draught value, basing on conditions of engines regular operation, can be brought to 1,25m (the carrying capacity makes up nearly 600 ton in this case).

barges (fig.5) are also widespread in river transportations. Barges carry huge loads but have to be propelled with some motor vessel.

Means of fuel discharge to oil carriers

In case if an oil carrier doesn’t have own pumps the movable pump station can be used for fuel discharge to reservoirs.pump stations are also widespread in places, where construction of stationary pump station is not economically reasonable.pump stations are applied on riverside tank farms with considerable water level fluctuation (around 5 m). In such conditions riverside pump stations can pump fuels from oil tankers at low water. Application of floating stations mounted on barges or pontoons, moored to an oil tanker side, allows realizing pumping independently from water level.

. 6 floating pump station

pump stations are usually equipped by cargo pumps for oil products pumping, stripping pumps for oil tanker reservoirs cleaning, ballast pumps for filling and emptying of ballast sections and fire pumps. Floating pump stations connect to riverside pipelines by flexible hoses or globe joint pipes.of floating pump station:

·        Rises and lowers together with the water level;

·        Operates in a totally automated mode;

·        Is equipped with fish protective devices.the navigation period on the Lena River makes up around 1/3 of year I suppose it’s better to have an easy demountable movable pump station. Withal, the floating pump station is the most productive variant of those.

Means of fuel shipment to oil carriersrealizing of liquid products loading operations between farm tanks and tankers standpipes are used.standpipe is the basic loading equipment, which is mounted on the loading bay and provides cargo, ballast and bunker pipelines connection to tanker.

.7 A standpipe

consists of a supporting pipe, a hinged arm, current collecting systems with auxiliary counterweights for keeping balanced the whole sleeve and standpipe non-operating position fixation lock.standpipe is balanced in all positions by two counterweights and a current collector. Shipboard and riverside pipe sections as well as whole unit rotation in a vertical plane is managed due to hydraulic cylinders, operated in loco or remotely.the standpipe is connected to a tanker the hydraulic cylinders automatically switch to a fail-safe operation, which allows the standpipe to follow the tanker, considering tossing, wind, stream and tides.the top of the standpipe vertical pipe there are mounted two cargo arms for rotation in horizontal and vertical planes and a vacuum breaker to prevent the liquid spill on the tanker deck (fig.7).

Standpipes are mounted on the oil mooring loading bay in group of 3-6 pieces.standpipe connecting to the tanker suction manifolds, loading, unloading and disconnection control is performed by radio, as well as from the control center, located on the shore, and portable console operator. If the load exceeds the available value the standpipe is provided with a loading-unloading operations abort system which stops pumps and cuts the coupling off.

3.      Calculation of reservoirs capacity for fuel storage, selecting of reservoirs type, its equipment

At fuel delivery by water transportation is possible only in navigation period.

Reservoir capacity:

(m3);

V_res - tank farm capacity, m3;ⁿ_mean - average fuel consumption, kg/day;- internavigation period, days (the navigation period on river Lena is from June, 1 to October, 15);

К_d - additional term of 15 days for possible internavigate period deviation, days;

К_res - utilization of capacity, Крез =0,9…0,95;- density of the fuel, кг/м3.

Selection of reservoirs

Reservoirs are one of the main structures of tank farms, they serve for petroleum products storage and implementation of some technological operations.arrangement reservoirs can be:

·        Underground - when the highest oil product level is no less than 0,2 m lower than the lowest mark of the surrounding area;

·        Ground - when the reservoir bottom is on the same level or higher than the surrounding area., there are following subdivisions:

·        By material: metallic, ferroconcrete, stone, ground, ice-ground etc.;

·        By excess pressure value: low-pressure reservoirs (the internal pressure slightly differs from the atmospheric one, p≤0,02MPa) and high pressure reservoirs (p>0,02MPa);

·        By technological operations supplied: reservoirs for low-viscous oil products, reservoirs for high-viscous oil products, sedimentation-drainages, mixing tanks, special design reservoirs for oil products with high saturated vapor pressure storage;

·        By design: steel reservoirs (vertical cylindrical with conic and spherical top, horizontal cylindrical with flat and spatial bottom, drop-shaped, globular), ferroconcrete reservoirs (vertical and horizontal cylindrical, square and trench). depot petroleum fuel equipmentdiesel fuel storage, which is consumed at the rate of 110 m³ per day I’ve chosen steel vertical cylinder reservoirs. As there happen quite sharp weather fluctuations, the reservoirs top will be floating to minimize fuel evaporation.

Reservoir with floating top

The body of a reservoir with floating top (fig.) represents an ordinary cylindrical casing. Nowadays the most popular are floating tops with a central disk on which circumference is placed an annular pontoon, divided with radial partitions by hermetic sections, which prevent the top from leaking.

.8 Scheme of a reservoir with a floating top: 1 - swing pipe for storm water escape from the floating top; 2 - manifold for fuel intake; 3 - manifold for fuel supply; 4 - reservoir body; 5 - floating top; 6 - gate, tightening the gap between the floating top and body; 7 - stairs for top inspection; 8 - stairway.

1. Main characteristics of the reservoir

Equipment of the reservoir with floating top

.9 Scheme of equipment placing on a vertical steel reservoir

- toplight; 2 - vent manifold; 3 - fire safety device; 4 - main breather; 5 - dip hatch; 6 - level meter; 7 - access door; 8 - water discharge; 9 - tank-cap valve; 10 - cargo manifold; 11 - bypass device; 12 - tank-cap valve lifter; 13 - hydraulic safety breather.

The distinctive point of reservoirs with floating top is that the toplight, level meter and breathers are mounted directly on the floating roof. The need to install vent manifolds arises from the fact that at reservoir emptying below supporting poles there is a gas space forming underneath the floating roof. At further reservoir filling this gas "cushion", being forced out through the gap between the top and body, may create warp of the floating roof and cause its self-locking. To avoid this, the gas phase release from under the floating roof is made in an organized way - through the breathers.

Toplight

The toplight LS- 500 is intended for oil reservoir internal inspection and airing before repair. The toplight is mounted on a reservoir top into a preliminary prepared orifice, and then the reinforcing flange is welded.

Vent manifold

. 10 Vent manifold

manifolds are designed to provide two-way dispensing operations, ventilation and avoidance of foreign objects entry inside the reservoir.

Fire safety device

Fire safety devices prevent reservoir from flames and sparks penetration inside it. Therefore, breathing devices - hydraulic and mechanical valves - are set on fire arresters.arrester (Fig.11) consists of a box filled with densely goffered plates of copper, brass, aluminum and other materials with high heat capacity. At flame passage through the flame arrester the plates take heat away from the burning gas and reduce its temperature below the flash point - the flame dies out.

.11 Flame arrester 1 - body; 2 - flanges; 3 - box with plates; 4 - body cap; 5-nuts; 6 - box handle.

Non-freezing breathing valves are mounted on reservoirs with low viscosity products for pressure supporting and vacuum holding in determined limits.serve for losses shortening from evaporation. Upon increasing the pressure in the tank valve produces steam mixture, lifting the pressure plate, and in low-pressure - lets in air tank through the vacuum plate.

. 12 Nonfreezing breathing valve: 1-case; 2-ring; 3-saddle; 4-covering; 5-plate; 6-membrane; 7- clamping nut; 8-directing tube; 9-rod; 10-membrane; 11-core; 12-grid; 13-loads.

eceiving and distributing unit consists of the receiving-distributing manifold, tank-cap valve, tank-cap valve control mechanism that includes a winch and wire rope, the bypass device and the supply pipe.

Dip hatch

A dip hatch serves for sampling and measuring the level of fuel in reservoirs of tank farms.dip hatch consists of a body 1, cover 2, pedal 3, rubber gasket 4 and relieving unit with nut 5.dip hatch housing has a flange in its lower part by which it is attached to a reservoir through a gasket. In the eye of the body is the lever on which the cover 2 with a rubber seal which seals the dip hatch is mounted. Fixing of the covering in the closed position is carried by the relieving unit nut.

. 13 General view of the dip hatch: 1 - body; 2 - covering; 3 - pedal; 4 - rubber gasket; 5 - relieving unit with a nut.

Access door

The access door is designed for internal inspection, repair or cleaning of a vertical steel tank. It is always mounted opposetly disposed to the toplight.

.14 General view of the access LL-600: 1 - flange; 2 - body; 3 - reinforcement plate; 4 - bolt; 5 - nut; 6 - gasket.

on a floating roof are mounted drainage system water intake, side rolling ladder, manifolds for supporting poles fixing and grounding device.

Tank-cap valve

The tank-cap valve is a metal gate installed on the receiving-distributing manifold. The flap is mounted on the hinge and closes the manifold under the action of its own weight. The valve opening is going either under the pressure of pumped in fluid or due to control mechanism.

.15 Tank-cap valve: 1 - valve open; 2 - valve closed.

.16 Tank-cap valve lifter: 1 - wheel; 2 - lifter shaft; 3 - cylinder; 4 - seal case; 5 - seal hub; 6 - stuffing box; 7 - lifter rope; 8 - tank-cap valve stop; 9 - tank-cap valve.

with floating roof are protected by stationary and mobile units:

• with a simultaneous foam of low expansion feed from both above the annular gap between tank wall and the edge of the floating roof and into the layer of fuel;

• with feed of refrigerant (gas) located in containers on a floating roof in the annular gap and low expanding film-forming foam in the fuel layer.whole I have 15 vertical steel reservoirs with floating roof with capacity of 2000 m³ in my tank farm.

4.      Calculation of reservoir foundation

Foundation under a reservoir is the most critical part of the total structure because it takes the hydrostatic fuel pressure in the reservoir. That allows decreasing the reservoir bottom wall thickness. An error in foundation calculus can lead to uneven reservoir settling resulting in cracks in a reservoir body.pressure of full reservoir on the ground:

 (kg/m²);

 P - pressure on the ground, kg/m²;

G - reservoir mass, kg;

S - reservoir bottom area, m²;

p - fuel density, kg/m³;

H - height of reservoir filling, m., foundations are constructed of coarse-grained materials (sand, shingly, crushed stone and others), which transfer pressure to a larger area and give a slight uniform settlement.

Such foundations are irreplaceable when the tank farm is located on filled-up ground, saturated with water (as near river). In this case the pressure is fully transferred first to the ground water. The water force increases and its filtration from under the reservoir bottom starts towards free ground surface. Thus, under the reservoir appears hydrodynamic pressure on the soil skeleton, tending to press the soil up. Since the ground has low resistance to shear, at large stresses the destruction of foundation can happen due to soil man-induced.such cases the coarse grained material cushion presence under the reservoir changer the direction of filtration flows and prevents progradation.

The foundation produces following functions:

- distributes the pressure from the tank to the base metal;

carries out drainage bottoms;

provides corrosion protection of the bottom.

For foundation we use the following materials:

·        compacted coarse sand;

·        crushed stone;

·        gravel;

·        gravel-sand mixture.provide corrosion protection for the bottom of the top embankment hydrophobic layer is laid with the addition of petroleum-based binders.used mound height of 0.2 - 2.5 m. This value depends on the results of engineering-geological survey of the construction site.surface of the mound usually has the slope from the center to the periphery. This compensates for non-uniform sediment tank, and facilitates the flow of the stored product to the recovery unit. In practice, the tank bottom sludge can reach up to 2 m, that is why the rise of the central part of the bottom may be the key to long-term performance design., at the construction site at a shallow depth (up to 3 m) lie low or heaving soils (in areas with deep seasonal freezing of soils), practiced their replacement with local seal sandy or clay soil, often imported. A more extensive layer of bedding soft ground, this method is often economically inefficient due to high operating costs for leveling tanks installed in such a way.width of the horizontal surface of the pad beyond the selvages must be:

·        0.7 m - for tanks with a capacity of 1000 m3;

·        1.0 m - for tanks with a capacity of more than 1000 m3;

·        1.0 m - regardless of the amount, for construction sites with an estimated seismic 7 points or more., parameters of foundation for considered tank farm: height of earth addition - 1m, height of foundation - 2 m (with preliminary local soil compaction), width and length - 19,7 m.

5.      Pumps selection for fuel pumping in the reservoirs and for delivery to consumer

fuel receiving from takers for the considered tank farm are needed simple and reliable pumps, which can be easily demounted for long non-navigation period. As fuel is delivered by water, the risk to contaminate it with mechanical particles is minimal, so I can use ЦСП-57 - self-priming centrifugal pump (it can’t endure any dirt as it clogs the hydraulic part). It’s efficient, durable and cheap.

ЦСП-57 pump unit is intended for pumping gasoline, kerosene, diesel fuel, water at temperatures from -40 to +50^oC.centrifugal pump ЦСП-57 is designed to supply light products, not contaminated by foreign impurities. Pump ЦСП-57 is a horizontal centrifugal pump with two impellers which provides two modes of operation: parallel and serial.of operating modes is manual by turning the valve. When the valve is located in the socket housing of the spool, rotating the lever opens or closes the respective passages in the pressure and suction channels of the spool housing. The twist handle is fixed in a parallel pump operation mode.operation start the pump body and the suction line have to be filled by pumping liquid.principle of operation is the following: the impeller sends fuel into rotary motion, whereby the fuel is ejected in a spiral channel around the impeller from whence it is directed to the discharge conduit. The greater the speed, the greater the rate of fuel ejecting from the impeller. The pump work is illustrated on the scheme (Fig.18).the fuel acceptance line there are two pumps ЦСП-57 mounted parallel to provide the necessary feed, which has to correspond the average daily fuel consumption.the distribution line one pump can be mounted.

6.      Selection of fuel purification means

purity of the fuel is an indicator which determines the efficiency and reliability of the engine operation, especially fuel equipment. Fuel pumps plungers and liners clearance is 1.5-4.0 microns. Dirt particles which size is greater than 4.0 microns cause increased wear of the fuel equipment that determines the relevant requirements to fuel purification.fuel purity is estimated by filtration coefficient in accordance to GOST 19006-73, which represents the ratio of the filtration time through a paper filter at atmospheric pressure of the tenth portion of filtered fuel to the first one. Filterability is affected by water presence, mechanical impurities, resinous substances, soaps of naphthenic acids. In commercial diesel fuels there is contained mostly dissolved water from 0.002 to 0.008 % which does not affect the filterability coefficient. The undissolved water quantity of 0.01 % and more leads to filterability coefficient increase. The allowed content of mechanical impurities in commercial diesel fuels produced by refineries is 0.002-0.004%. Sulphur content has not to exceed 0,2%.

СТ-500-2М is going to serve as a fine filter-separator.

As filters capacities are less then one of pump, it’s necessary to install them parallel. Quantity of СТ-500-2М filters:

ФГН-120 filter only one is needed.

7.      Equipment for fuel distributing, characteristics of equipment and the distributing process itself

Equipment delivery areas fuel must meet for enterprises and operations to be performed in this area. The points of aviation kerosene fuel- expected to perform the following operations:

·        lower fill fuel tanks ;

·        cleaning of fuel impurities and water ;

·        registration number issued by the fuel;

·        protecting equipment from the effects of hydraulic shock ;

·        neutralization of static charges ;

·        automatic stop the flow of fuel when filling the tank to a predetermined level.performance of such operations needs next equipment:

·        fine filters and water separators;

·        device for pressure control and fuel consumption;

·        liquid level alarm device;

·        counter and measuring apparatus of AWC-liquid;

·        devices of system of automatic supply stop of fuel to refueller;

·        neutralizer of static electricity.equipment must meet next requirements:

·        fast connection and disconnection at AC fuelling;

·        provide and support necessary pressure at AC connecting pipe;

·        provide and support necessary fuelling efficiency.

·        Development of the technological receiving, storage, prepare and distribution linesof production line in our work means creation of technological scheme which represents processes of receiving, storage, preparation and delivery of fuel to aircraft. Also such production lines provide internal storage of fuel, its transfer from tank to tank and carry out maintenance according to purpose of fuel.

Conclusion

I’ve got some skills in solution of problems of necessary equipment for a tank farm selection. I’ve familiarized to the tank farm equipment complex for fuel delivery, determined the total volume of tank farm reservoirs and selected the most suitable types.selected equipment was taken from the real data and can provide normal operation of an enterprise.

Fig.19. Technological scheme of fuel depot

1 - reservoirs; 2 - valve; 3 - grid filter; 4 - manometer; 5 - pump; 6 - safety valve; 7 - fine filters; 8 - counter; 9 - shock absorber; 10 - distributing hoses

Sources

C.Г. Едигаров, С.А. Бобровский Проектирование и эксплуатация нефтебаз и газохранилищ

http://manceethat.at.ua/news/neftenalivnye_terminaly

http://www.ngm-group.ru/rezervoir/spravochnik/one_swim_roof/

http://pas.zp.ua

В.Я. Карелин, А.В. Минаев Насосы и насосные станции