Underground modular transformation centre that is resistant to disasters and adverse conditions

Abstract

An underground modular transformation centre that is resistant to disasters and adverse conditions, having a transformer without fins. The tank has electrical connection outlets in the lower lateral zones. This tank is also provided with piping in which holes are drilled, positioned in diametrically opposing points inside the tank, and threading on the external part thereof protruding from the tank. Also provided are threaded casings on the lateral panel of the tank in order to accommodate temperature detectors.

Claims

1. An underground modular transformation centre system that is resistant to disasters and adverse conditions, the transformation system comprising: a transformation centre comprising: a disaster and adverse condition resistant enclosing body having two ends, a coupling system arranged in each of said two ends and closing covers joined to the coupling system; an assembly hatch with an upper watertight access cover of the assembly hatch for inserting a switchgear and a manhole hatch with an upper watertight access cover of the manhole hatch for the access by people; high-voltage protection and operating elements, a power transformer and low-voltage protection and operating elements inside of the transformation centre; tubes passing from the outside to the inside for placing electrical conductors having elements that provide watertightness to said electrical conductors and tubes for circulating a coolant; the transformation centre being modular and configured to be longitudinally connected to other transformation centres through the coupling system arranged in the ends of the enclosing body; and a longitudinal heat exchanger arranged outside the transformation centre with a dimension similar to the length to this transformation centre, formed by horizontal tubes and heat dissipative sheets.

2. The transformation centre system according to claim 1, the power transformer being without fins.

3. The transformation centre system according to claim 2, the power transformer comprising a tank, the tank comprising a lower side area and electrical connection outlets arranged in the lower side area of the tank.

4. The transformation centre system according to claim 3, the tank of the power transformer comprising tubes having bores positioned in diametrically opposing points inside the tank, and having external threads protruding from the tank.

5. The transformation centre system according to claim 4, the tank further comprising threaded casings arranged on a side of the tank in order to attach temperature detectors to the tank.

6. The transformation centre system according to claim 3, the power transformer comprising an upper closing cover having an inner and an outer coupling system; the tank of the power transformer being coupled to the inner coupling system, and the outer coupling system being configured to fasten the power transformer to the enclosing body of the transformation centre.

7. The transformation centre system according to claim 6, the upper closing cover of the power transformer being the assembly hatch.

8. The transformation centre system according to claim 6, the inner and outer coupling system comprising watertight elastic elements.

9. The transformation centre system according to claim 4, further comprising: a closed fluid circuit from the tank of the power transformer to the heat exchanger arranged outside the transformation centre through the tubes of the tank; and a pump configured for circulating a coolant along the closed fluid circuit.

10. The transformation centre system according to claim 1, comprising motorised circuit breakers as high-voltage and low-voltage operating elements by an external surface switchboard, the circuit breakers being configured to be telematically connected to a central unit.

11. The transformation centre system according to claim 10, the circuit breakers comprising devices for disconnecting due to overload and short circuits.

12. The transformation centre system according to claim 10, comprising a surface switchboard installed inside a watertight box with a lock.

13. The transformation centre system according to claim 1, having a fire protection system for complete flooding of the transformation centre with inert gas.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) As a complement to the description provided herein, and for the purpose of helping to make the characteristics of the developments hereof more readily understandable, a set of drawings is attached as an integral part of said description, which, by way of illustration and not limitation represents the following:

(2) FIG. 1 shows the profile of the enclosing body of the transformation centre (10), being able to observe the hatches corresponding to the manholes (3), the tubes for the electrical cables (11) and the lower support of the centre (7).

(3) FIG. 2 shows the elevation view of the enclosing body of the transformation centre (10), being able to observe the assembly hatch (2) as well as the manholes hatches (3).

(4) FIG. 3 shows a plan view of the enclosing body of the transformation centre (10), where the assembly hatch (2) and the manholes hatches (3) can be observed.

(5) FIG. 4 shows a longitudinal cross section of the assembly, where the internal arrangement of the high-voltage equipment (12), the fit of the new transformer (13) and the low-voltage equipment (14), as well as the respective interconnections thereof (18) (19) can be seen.

(6) FIG. 5 shows a plan view of the arrangement of the equipment inside the transformation centre.

(7) FIG. 6 shows a transverse cross section of the transformation centre through the high-voltage area.

(8) FIG. 7 shows a transverse cross section of the transformation centre through the area of the transformer.

(9) FIG. 8 shows a transverse cross section of the transformation centre through the low-voltage area.

(10) FIGS. 9, 10, 11 and 12 show a detailed view of the transfer process from a conventional transformer to the proposed transformer.

(11) FIG. 9 shows an initial standard transformer.

(12) FIG. 10 shows the removal of the ventilation fins (23) and of the transport wheels.

(13) FIG. 11 shows that the transformer is turned over, as well as the incorporation of the upper closing cover of the assembly hatch (2) and rotation of the high and low-voltage terminals.

(14) FIG. 12 shows the incorporation of internal collector tubes (25) and the threaded casings, and a metal box is attached to the tank to accommodate the terminals (26) (27).

(15) FIG. 13 shows the side profile of the underground modular transformation centre system in full operation. Here it shows the arrangement of the different chambers (31) (32) (33) (34) needed, the control and operations switchboard (28), the exchanger embedded in the curb of the sidewalk (30) and the concrete slab needed to ensure the stability of the assembly (29). With this figure, it is easy to get an idea of the dimensions of each element and of the final result thereof once placed in the urban environment.

(16) FIG. 14 shows the option of coupling several transformation centre units to each other in a simple way, thereby being able to easily increase the power provided by the installation, if necessary.

(17) FIGS. 15, 16 and 17 show the heat exchanger of the transformation centre system.

(18) FIG. 15 shows a plan, elevation and profile view of the heat exchanger.

(19) FIG. 16 shows a detailed view of the exchanger, wherein it can be easily seen that it is made up of fins (36) and horizontal tubes (37) (38).

(20) FIG. 17 shows an elevation, plan and profile view of a possible external shape of the housing (35) that accommodates the exchanger on the inside. This figure also shows the arrangement of the possible grilles in the front upper part thereof.

(21) FIG. 18 shows how the evaporator (40) is placed between the tank of the transformer (13) and the cover of the assembly hatch (2). The joints have elastic seals (39) to make them watertight.

(22) FIG. 19 shows an outer appearance of the evaporator (40).

(23) FIG. 20 shows an inner cross section of the evaporator which shows the network of tubes (42) and the heat sinks (41).

DETAILED DESCRIPTION

(24) As mentioned above, the purpose of the described subject matter is to provide greater safety (the operator will not be required to go down to the transformation centre to check the status or to operate the equipment, and furthermore, there is an effective fire protection system), improved operability of the system (due to the fact that any action can be carried out remotely and in a programmed way), improved continuity of the energy supply in the case of disasters (this system is able to withstand floods, tsunamis, earthquakes, etc.), and facilitating the placement of these installations in the urban environment (since it is an underground centre, the problem of occupying urban space does not exist, and furthermore, it does not require ventilation stacks or grilles, thus easily blending in with the environment and being able to be installed both under the sidewalk and under the street).

(25) A particular example of an underground transformation centre system according to the present subject matter and referring to the attached figures is described below.

(26) FIGS. 1, 2 and 3 describe the outer appearance of the transformation centre. The transformation centre has a cylindrical metal enclosing body (10) and two end units that close it at the sides (8) thereof which are screwed by flange joints (9). Thus, if necessary, several modules can be coupled to each other until obtaining the transformer power needed (see FIG. 14). The enclosing body will have lifting hooks (4) for the handling thereof. Furthermore, it will have lower supports (7) that will fasten to the reinforced concrete floor on which the transformation centre will rest.

(27) Three upper hollows will be provided. Two of these hollows are manhole hatches (3), and the third is an assembly hatch (2) that enables the inner switchgear to be inserted or removed. This assembly hatch (2) is hermetically sealed using the upper cover of the transformer by having a screwed perimeter ferrule.

(28) A sufficient number of reinforcement rings (5) are provided to give strength to the enclosing body. To pass the electrical conductors to the outside, tubes (11) for passing electrical cables, threaded on each side, are provided, such that the tubes can be equipped with stuffing boxes that prevent water from passing to the inside.

(29) Distribution of the different equipment is provided according to FIG. 4 and FIG. 5, which enables all high-voltage switchgear (12), the transformer machine (13) and the low-voltage general dashboard (14) to be installed inside the transformation centre. These views show how the interconnection between each of these elements is carried out. These two figures also show the linking conductors between bays and transformer (19) and the connection of the outputs thereof with the general low-voltage busbar by copper plates (18).

(30) These figures also show the arrangement of the coolant pump of the transformer (17), which will push this fluid from the transformer to the outer exchanger through tubes (1) passing from the outside to the inside made in the cover of the transformer.

(31) The inside of the centre is provided with a floor plate (16) as technical flooring, made of Tramex perforated grids of an insulating material. This floor plate is supported on some supports welded to the sides of the wall. Thus, it forms a horizontal plane in such a way that there is a space available (15) under it to accommodate the coolant of the transformer that may be spilled in the case of failure in the tank or in the cooling circuit.

(32) The interconnection lines between the outside and the transformation centre, both lines of high-voltage supply (20) and lines of low-voltage output (22), will run through the inside of the centre, attached to the sides thereof, and fastened to the inner wall by clamps or flanges.

(33) A fire protection system for complete flooding of the site by inert gas will be provided. The gas bottles (21) are attached to one of the ends of the cylinder.

(34) The transformer used in the transformation centre is the standard model (FIG. 9) to which a number of modifications have been made. These modifications do not affect the arrangement of the coils inside of it or the dimensions of the tank. The modifications carried out to obtain the new transformer model are described as follows: a) The entire inner support system and transport wheels are removed. (see FIG. 10). b) All cooling fins (23) are removed. (see FIG. 10). c) The upper cover is replaced by the cover of an assembly hatch (2), and the high and low-voltage vertical outputs are replaced by horizontal outputs (see FIG. 11); to facilitate these outputs, the tank is expanded and high-voltage connection cones (26) and low-voltage output plates (27) are provided on them. (see FIG. 12). d) The entire assembly is rotated 180, such that these outlets are in the lower part thereof. e) Two internal collector tubes are provided for circulating the coolant. These tubes are provided in diametrically opposing points of the tank. Equidistant bores will be provided inside of it to promote perfect internal circulation of the liquid. Each end is extended to the outside of the tank (25) and is equipped with threading (two of the outputs are used for interconnecting the circuit and the other two are equipped with threaded plugs). f) Threaded casings (24) will be provided in the tank to accommodate the temperature detectors. g) The cover of the assembly hatch (2) will be screwed to the transformer by threaded screws and an elastic seal. The dimensions of this cover increases in such a way that it can in turn be used as a cover for the manhole; for this reason, it will have another number of holes for the perfect joining thereof to the ferrule that is provided on the enclosing body of the transformation centre. The assembly ends with the incorporation of welded tubes (1) passing from the outside to the inside, where it will connect the external exchanger and the eyebolts for the assembly (6) thereof.

(35) According to FIG. 15, the external exchanger is formed by two horizontal tubes (37) (38) joined at the end thereof to form a closed circuit. Heat sinks (36) parallel to the generatrix of the tubes are provided, clamping the two tubes and being welded to them. See FIG. 16 to have a better view of the appearance of these dissipative panels. The external exchanger is complemented with an outer housing (35) (see FIG. 17) that will be equipped with ventilation grilles on the front and upper faces thereof; the air enters through the first and exits through the second, heat being transferred by convection from the dissipative grilles to the environment. Emphasis is placed on the fact that in the case of flooding, this system continues to operate since the heat would be transferred from the plates to the surrounding water.

(36) The entire system forms a longitudinal exchanger that can be easily installed in the urban environment, replacing part of the curb of the sidewalk, or in any other similar arrangement that blends in with the environment. (See FIG. 13).

(37) The control panel (28) may include a steel enclosing body equipped with a watertight and submersible cover. The tubes passing from the outside to the inside will have equally watertight and submersible stuffing boxes. The control panel will be provided close to the transformation centre and will blend in with the environment. The cover will have a closure standardised by the supply company. A switchboard with a man-machine touchscreen of a model existing on the market and which will be accepted by the supply company will be provided on the inside.

(38) With regards to the alternative cooling system by subcooling of the machine, we can observe FIG. 16 which shows how the evaporator (40) is placed between the tank of the transformer (13) and the cover of the assembly hatch (2). As can be seen, the transformer used for this system is the modified transformer (13) explained above.

(39) The evaporator systems include a metal ring whose inner dimensions coincide with those of the inside of the tank of the transformer. In the upper and lower perimeter thereof, there is a closure system, in this case, screwed ferrule, whose nominal diameter, placement and spacing coincide with those of the cover of the transformer for the perfect coupling thereof to this transformer and to the cover of the assembly hatch that closes it.

(40) A network of horizontal tubes (42) with heat dissipative panels (41) are placed inside the aforementioned ring. The ends are extended to the outside of the ring, the seals being sealed by soft welding, and they are connected to the external condensing unit, using the tubes passing from the outside to the inside with stuffing boxes (1) existing in the centre, thus forming a closed cycle.

(41) The joints between the elements will be equipped with elastic seals (39) for making the assembly watertight. The inside of the ring and the tank will be filled with the same coolant, such that the evaporator coil is perfectly submerged.

(42) The outer walls of the transformer-evaporator assembly will be equipped with high-density thermal insulation which will stick, by industrial adhesive, to the outer panel of these elements, such that it prevents undesirable gains of heat and condensation outside the tank.