NL2003602C2 - PIPELINE NETWORK FOR LARGE DISTANCE TRANSPORTING LIQUIDS, PRESSURE DEVICE, APPLICABLE TO SUCH PIPELINE NETWORK AND METHOD FOR TRANSPORTING LIQUID OVER LARGE DISTANCES THROUGH THE TRANSPORT LIQUID OF THE LID NETWORK PIPE. - Google Patents

Description

Title:

Pipeline network for transporting liquids over a large distance, pressure device applicable for such a pipeline network and method for transporting liquid over large distances through the transport line of such a pipeline network.

The invention relates to a pipeline network for transporting liquids over a large distance, comprising a transport line with line segments and pumping means with a number of pressure devices for pumping the liquid through exerting pressure on the liquid through the transport line.

In order to be able to pump liquids over large distances in known pipeline networks, complicated and expensive installations are required, with expensive pumping stations equipped with large, high-pressure pumps which transport the liquid through the pipeline at a relatively high flow rate.

The invention has for its object to be able to pump liquids in a pipeline network of liquids in a simple yet effective manner over relatively low pressures over large distances without the need for complicated and expensive installations.

To this end, the invention is characterized in that; - the pipeline network also comprises a pneumatic pipe in addition to the transport pipe; and the pressure devices are present at regular distances between the line segments, are connected to the pneumatic line and maintain the pressure on the fluid pneumatically.

A preferred form of a pipeline network according to the invention is characterized in that; 2 the pressure devices each comprise at least one pressure tank which is connected on one side via valves to the respective end parts of two conduit segments of the transport conduit and mutually connects the conduit segments along this way; - the pressure tank on the other side is connected via valves to the pneumatic line for exerting pressure on the liquid present in the pressure tank; and the pressure tank comprises a float control device which alternately opens and closes the connection of the tank to the transport line and the connection to the pneumatic line for filling and subsequently emptying the pressure tank.

The invention also relates to a printing device that can be used with such a pipeline network. According to the invention, this comprises at least one pressure tank with a connection to a pneumatic line and a connection to a liquid line and with a control device with two floats, wherein through a first float the connection of the pressure tank to the pneumatic line and through a second float the connection to the liquid line can be closed.

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The invention further relates to a method for transporting liquid over large distances through the transport pipe of such a pipeline network, wherein liquid is pumped through pipe segments of a transport pipe through pressure devices. The method is characterized by the steps: the pressure devices comprise pressure tanks and at least one pressure tank in each case pumps the liquid through a downstream pipe segment, then at the end of this pipe segment via at least one next pressure tank the liquid is passed through a following downstream pipe segment 3 and the previous step is repeated for each subsequent downstream pipe segment.

The invention will be further elucidated with reference to the drawing, in which Fig. 1 schematically shows a pressure device between two pipe segments of a pipeline network according to the invention, wherein the pressure tank is substantially filled with liquid;

Fig. 2 shows a part of the printing device according to Fig. 1, wherein the printing device has pressed the liquid into the transport line, Fig. 3 schematically shows a printing device as in Fig. 1, but with two pressure tanks.

Figure 1 shows a part of a pipeline network for transporting low-viscous liquids over large distances, for example for water. The network comprises a transport pipe 1 with a large number of pipe segments, of which pipe segments 2 and 3 are shown which are connected by a T-piece 4, to which a printing device consisting of a pressure tank 5 is connected, while in the T-piece before and after the a check valve 6 and 7 is present.

The pressure tanks 5 are present in the pipe 1 at regular distances between the pipe segments and are connected via a connecting pipe 8 to a pneumatic pipe 9, in this embodiment a compressed air pipe, for being able to exert pressure on the liquid and thus through the transport pipe pumping the liquid. In line 8 there is an air valve 10 which is controlled by a control device 11 with floats 12 and 13 and which has an air valve 10a for escaping the air from the tank 5. Through the control device 11 and the air valve 10, the connection of the tank to the transport line 1 and the connection to the pneumatic line 8 is alternately opened and closed for filling with liquid 14 from the upstream line segment 2 and 4, then pressurizing the pressure tank 5 in the downstream line segment 3. FIG. 1 shows the tank 5 in the liquid-filled state, FIG. 2 in the emptied state.

According to the invention, the pipe 1 thus acts as a kind of pulsating artery and virtually all friction losses during liquid transport are overcome without high pressures.

Fig. 3 shows an embodiment with a number of pressure tanks 15 and 16 each between two pipe segments 10, in Fig. 3 two pressure tanks 15 and 16, each provided with an air valve 10 and a control device 11 with floats 12 and 13 and connected via a connecting pipe 8 on the line 9. The control devices 11 of the tanks 15 and 16 are adjusted such that they operate in mutual phase. The use of one tank as in Figs. 1 and 2 gives a pulsating flow, the use of two tanks as in Fig. 3 gives a more continuous flow. An even more continuous flow is achieved by applying three or four tanks.

With a good choice of the diameter of the transport line 1 and of the compressed air line 9, where the pressure in the line is 6 bar, with a pressure drop of 4 bar H = 40 m a liquid in the form of water can be pumped through the line over a pipe segment with a distance of for example 4000 meters. The flow rate is then 2 m / sec and the flow Q = 440 M3 / hour.

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After every 4000 meters a "mini-station" with one or more pressure tanks is placed on a T-piece 4 with a non-return valves 6 and 7 before and after each tank. In the version with a "mini-station" consisting of more pressure tanks as in fig.3 Due to the mutual counter-phase operation of the control devices 11, each tank is pushed full of liquid from the transport line until a certain level is reached and the air valve 10 is activated via the float 12. Now, air is pumped in from the compressed air line 8 at the top of the relevant tank and the water is pushed back into the transport line 1. Through the non-return valves 6 and 7, the water cannot flow back but can be pushed to the next 4000-meter-long pipe segment. In the meantime, the second tank is now full. When the first tank is empty, the second tank is full, the critical level is reached in the second tank and the second tank is put under air pressure, the liquid contained therein is then pushed into the next line segment 10.

Because the tanks are used in turn, only a relatively small tank volume is required. It is not necessary to push a whole pipe segment volume into a tank. The use of a tank with only a limited effective volume means that all valves and valves must be operated more often. With several tanks, a larger volume ensures that the non-return valves 6 and 7 and air valves 10 open and close less often.

In practice, the choice of the effective tank volume is a matter of an economic optimum. It is noted that if only one tank is used, the effective tank volume must be large enough to be compatible with the shortest pipe segment (store away on routes in the pipeline network).

At a pressure in the pipe 9 of 6 bar and a liquid with a viscosity approximately equal to that of water, 4 bar is effectively transferred to the liquid and a flow of 440 m 3 per hour (2 m / sec) per "mini station" can be realized the pipe in this example have an extra length of 4 km. If one now takes a slightly lower flow rate and a "mini-station" every 40 km, the current is still 155 m3 per hour.

6 (v = 0.7 m / sec). If one takes a distance between the "mini stations" of 100 km, then the flow is still 80 m3 per hour. (v = 0.37 m / sec)

The effect of the pipeline network according to the invention is that the transport line 1 no longer has a linear relationship from pumping station to pumping station but a sawtooth offset from T-piece with "ministation" to T-piece with "ministation" with a maximum system pressure of 5 bar.

On route sections which are located downhill there can be done by means of a set of control valves and similar tanks of energy can be recovered in a similar way, which can be reused in the same network by means of a valve fed back into the compressed air line.

In this way it becomes easily possible to pump fairly large quantities of liquid in a pipeline network without expensive or complicated equipment over very large distances under low pressures.

The operation of the "mini-stations" is in fact based on the use of so-called "pneumatic relays compensators" which essentially function as compressed air-driven displacement pumps without membranes.

The advantages of the pipeline network with the "mini stations" include: 25 1 No efficiency losses at pumping stations; 2 No expensive pumping stations, from which energy must be added to the network from a local infrastructure; 3 Small maximum pressures, all pipe segments can be assembled by means of simple techniques from material with 7 low-grade specifications, by local staff, with a price advantage as a result; 4 In view of the low pressures, large parts of the system can be realized outside all kinds of inspection standards, resulting in a short lead time and lower costs; Due to the larger number of valves in the network, it can be closed more quickly in compartments in the event of a leak and also easier to repair; 6 If the venting of the pressure tank ends in a drainage pipe 10, the "mini station" can be carried out underground; 7 The whole of non-return and control valves of the "mini stations" will have to be checked periodically. Compared to the maintenance work at conventional stations, however, there is no question of high tech maintenance, the maintenance can be carried out by a simple trained technician using 15 simple tools.

In an alternative embodiment, the above-described pipeline network is designed for the transport of highly viscous liquids such as, for example, petroleum with a high average chain length and for transport, in particular in cold regions.

The transport pipe 1 is now laid together with a pneumatic pipe 9, the pipe 1 as an oil transport pipe, the pipe 9 as a steam pipe.

At the beginning, steam is blown into the steam line 9 with the aid of a steam boiler or residual steam from a local power plant. Preferably, the steam line 9 lies either within the oil transport line 1, or against the wall of the line, or around the oil transport line (wherein the oil transport line is equipped with a steam outer jacket), or together in an insulation package so that the steam encompasses the oil slightly can heat up or keep liquid.

Where a "mini-station" is present, this works in a similar way as in the water compressed air system, except that this is a pipeline network with oil as a liquid and with steam as a pneumatic pressure medium, which steam is blown in and blown off by means of control valves. . A possible steam condensate that ends up in the oil is not a problem since it can easily be separated from the oil at a later stage in refining processes.

10 If the transport distances are large, a steam boiler can also be installed at a "mini station". Water can be boiled here to keep the network pressure and temperature. Crude oil can already be used as fuel for this in the network. Water can also be made locally from snow or ice.

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An additional advantage of this network is that at the start-up of the flow of the oil it is possible to first blow a quantity of steam through the transport line 1 to give the oil present a less high viscosity. This is particularly effective with a steam line 9 through the oil transport line 1.

The invention is not limited to the details shown and the measures described in the claims.

Claims (9)

A pipeline network for transporting liquids over a large distance, comprising a transport pipe (1) with pipe segments (2,3) and pumping means with a number of pressure devices (5) for pumping through the transport pipe by exerting pressure on the liquid of the liquid, characterized in that; - the pipeline network also comprises a pneumatic pipe (9) in addition to the transport pipe (1); and 10. the pressure devices (5) are present at regular distances between the line segments (2,3), are connected to the pneumatic line (9) and maintain the pressure on the liquid (14) pneumatically. 2. Pipeline network according to claim 1, characterized in that; 15. the pressure devices each comprise at least one pressure tank (5) which is connected on one side via valves (6, 7) to the respective end parts of two conduit segments (2,3) of the transport conduit (1) and mutually along the conduit segments connects; the pressure tank (5) on the other side is connected via valves (10) to the pneumatic line (9) for exerting pressure on the liquid (14) present in the pressure tank; and the pressure tank (5) comprises a control device (11) with floats (12, 13) which alternately opens and closes the connection of the tank to the transport line and the connection to the pneumatic line for filling with liquid and then emptying the pressure tank Pipeline network according to claim 2, characterized in that the pressure devices each comprise at least two pressure tanks (15, 16) and the associated control devices (11) operate in counter-phase. 30 Pipeline network according to claim 2 or 3, characterized in that the effective volume of a pressure tank (5) is smaller than or equal to the volume of the shortest pipe segment of the transport line (1). Pipeline network according to claim 1, characterized in that the network is adapted for transporting low-viscous liquids (14) and the pneumatic pipe (9) is designed as a compressed air pipe. 6. Pipeline network according to claim 1, characterized in that the network is adapted for the transport of highly viscous liquids (14) and the pneumatic pipe (9) is designed as a steam pipe which is positioned along the length such inside or against the outer wall of the transport line (1) is located in that it heats the liquid present in the transport line. 7. Pressure device, applicable to a pipeline network according to one of the preceding claims, characterized in that at least one pressure tank (5: 15,16) is present with a connection to a pneumatic line (9) and a connection (14) to a liquid line and with a control device (11) with two floats (12, 13), wherein through a first float (12) the connection of the pressure tank to the pneumatic line and through a second float (13) the connection to the liquid line can be closed is. 8. Method for transporting liquid over large distances through the transport line (1) of a pipeline network according to one of claims 1-6, wherein liquid is pumped through pressure devices through line segments (2,3) of a transport line (1), characterized by the following steps; - the pressure devices comprise pressure tanks (5) and in each case at least one pressure tank (5) pumps the liquid through a downstream line segment (2,3); - at the end of this line segment via at least one next pressure tank (5) the liquid is pumped through a next line segment downstream; and - the preceding step is repeated for every subsequent downstream pipe segment. Method according to claim 8, characterized in that at least two pressure tanks (15, 16) are arranged in front of each downstream pipe segment (2, 3) with floats (12, 13) controlling the liquid flow, and 10 mutually in opposite phase moving, wherein, when one pressure tank (15) is squeezed into a downstream conduit segment, the other pressure tank (16) simultaneously flows from an upstream conduit segment. 15