IT202100006401A1 - SYSTEM AND METHOD OF LAYING PIPE - Google Patents

Description

DESCRIPTION of the invention entitled:

?PIPES LAYING SYSTEM AND METHOD?

The present invention relates to a system for laying at least one pipe, and to a pipe laying method which can be implemented through said laying system.

From the previous document DE 20 2006 006 307 U1 ? a device is known for the preparation of electrically and thermally insulated pipes during the process of laying them.

Such a device includes a heating equipment, an electrical power supply, temperature sensors, an output for a heating electric current, and a unit? control. The unit control ? configured to regulate the heating current with reference to a temperature detected in correspondence of the pipes and to a desired temperature.

As described in the earlier document DE 20 2006 006 307 U1, the heating current can pass through a metallic central duct of electrically and thermally insulated pipes, or heating cables integrated in said pipe.

A problem encountered in the system known from DE 20 2006 006 307 U1 ? the impossibility to proceed with heating the pipes in the presence of non-linear or special pieces (for example: branches, valves, curvilinear sections, or the like), or in the presence of variations in the diameter of the pipes. In fact, when a pipe has a variable diameter, also the resistance of the material of which this pipe is? constituted ? variable, resulting in a difference in the induced current.

Furthermore, in the system proposed by the earlier document DE 20 2006 006 307 U1 ? Is it possible that the insulated pipes can be damaged in virtue? of the high localized temperatures (especially when generated inside the thermal insulation) which must be reached to cause a longitudinal extension of the pipe.

The Applicant, after a long and intense activity? of research and development, has perfected a system and a generator capable of providing an adequate response to the existing limits, drawbacks and problems.

In particular, the Applicant has designed a system comprising a generator capable of simulating, during the laying process, the operating conditions of the pipes during their use: through an entry of a saturated steam under pressure into the conduit for the heated fluid, the this generator allows you to introduce a pre-tension in the pipes that ? after installation and during operation at temperature ? allow? to reduce the stresses compared to pipes laid in the traditional way for which this pre-tensioning is not ? present. This operative expedient, feasible through the system object of the present invention, will allow to avoid ? on the contrary with respect to the modalities? of traditional laying - geometric type compensations on the route created, compensations made by means of geometric deviations of the route which, in addition to generating extra laying costs, are sometimes not feasible due to ? for example - interference with other subservices, traffic problems, overlapping with unavailable areas.

Therefore, the object of the present invention is a system for laying at least one pipe, having the characteristics as defined in the accompanying claims.

Furthermore, the object of the present invention is a pipe laying method which can be implemented through said laying system, having the characteristics as defined in the accompanying claims.

Preferred embodiments of the present invention will be described hereinafter by way of example, and therefore not in a limiting way, with the aid of figure 1, which illustrates a schematic view of a system, object of the present invention, according to a possible embodiment of the present invention.

With reference to the attached table, with the reference number 1 yes ? characterized, in its entirety, by a system for laying at least one pipe 100 comprising at least one pipe 100 which develops along a mainly development direction X, and at least one portable steam generator 10.

Within the present description the expressions ?axial?, ?coaxial? or ?radial? will always be used with reference to the prevailing development direction X, unless there? not otherwise specified.

Furthermore, in this description the expression ?portable? does it mean that said steam generator 10 can? be moved and transported from one place to? Another, and therefore not ? a fixed installation.

Said pipe 100, or each pipe 100, comprises at least one conduit for heated fluid 101 (preferably corrugated, i.e. provided with an alternation of peaks and valleys in the axial direction), a layer of thermal insulation 102 which mainly houses or substantially complete said conduit for heated fluid 101, and an outer tubular casing 103 which at least partially surrounds the thermal insulation layer 102.

The heated fluid conduit 101, the thermal insulation layer 102 and the outer tubular casing 103 are preferably arranged coaxially with respect to each other.

In one embodiment, said pipe 100 (or each pipe 100) comprises a pair of pipes for heated fluid 101 side by side, a layer of thermal insulation 102 which mainly or substantially completely houses said pair of pipes for heated fluid 101, and an outer tubular casing 103 which at least partially surrounds the thermal insulation layer 102.

Preferably, the tube 100 ? a pre-insulated pipe from a district heating system.

Pi? preferably, the pipe 100 comprises or, alternatively, consists of at least one conduit for heated fluid 101 of the metal type (for example a conduit 101 or a pair of said conduits 101 side by side with each other), a thermal insulation layer 102 in expanded polyurethane, and an outer tubular polyethylene casing 103.

even more preferably, the tube 100 ? built according to the DIN EN 253 standard. This standard ? to be understood in the version of validity? on the priority date? of this application.

The thermal insulation layer 102 has a maximum operating temperature.

Within this description ?maximum operating temperature? ? intended as the maximum temperature that the thermal insulation layer 102 ? able to reach without undergoing substantial deterioration, for example due to carbonization phenomena. Preferably, the maximum operating temperature? equal to or lower than 140?C, preferably between 110?C and 140?C, plus? preferably ranging from 125?C to 140?C.

The embodiment of figure 1 shows a laying system 1 comprising two portable steam generators 10: the generator on the left ? shown in detail of its construction parts. The generator on the right ? only schematized but, preferably, ? constructively compliant with what is described below. However, this embodiment must not be considered as a limitation of the present invention since the installation system 1 could comprise a single portable steam generator 10, or two, or more? of two portable steam generators 10 mutually arranged in parallel.

In fact, preferably, the installation system 1 comprises a plurality of of portable steam generators 10 mutually arranged in parallel and connected to the heated fluid duct 101 via a manifold 22 connected to a steam outlet opening 14 of the boiler 11 of each of said portable steam generators 10.

The portable steam generator 10, or each portable steam generator 10, comprises:

(i) a boiler 11 delimiting a boiler room 12, a water inlet opening 13 connectable to water supply means 50 (e.g. a municipal water system), and a steam outlet opening 14 connected in releasable to the conduit(s) for heated fluid 101;

(ii) electric heating means 15 in thermal contact with said boiler compartment 12;

(iii) pressure detection means 16 in the boiler compartment 12; And

(iv) means of management and control 17.

For the releasable connection between the steam outlet opening 14 and the heated fluid conduit 101, the portable steam generator 10 preferably comprises (v) at least one saturated steam transport conduit 23 (preferably a flexible type conduit), equipped with a connection joint 24 of the reversible type (i.e., which can be connected to, and disconnected from, the heated fluid conduit 101, preferably in a repeated manner).

Preferably, the electric heating means 15 comprise at least one electric resistance.

Pi? preferably, the electric heating means 15 are housed at least in part (for example: substantially completely) in the boiler compartment 12.

The electric heating means 15 can preferably be powered by electric power supply means 51. The electric power supply means 51 are preferably selected from a generator set, an electric battery or an electric network. According to another embodiment, the electric power supply means 51 are of the renewable type, preferably wind and/or solar.

The pressure detection means 16 preferably comprise at least one pressure gauge, plus a pressure gauge. preferably an electronic pressure gauge.

Preferably, the boiler 11 could comprise at least one safety or over-pressure valve 27, configured to create a passage between the boiler compartment 12 and an environment external to said compartment 12, so as to reduce the pressure in the latter when the pressure value measured in the boiler room 12 exceeds a predefined value.

The boiler 11 also preferably comprises a condensate drain system 28.

The management and control means 17 are functionally connected to the electric heating means 15 and to the pressure detection means 16 so that a saturated steam leaving the steam outlet opening 14 has a temperature equal to or lower than the maximum operating temperature .

In other words, the management and control means 17 are configured to receive first measurement signals from the pressure detection means 16, and to generate control signals for the electric heating means 15. precisely, when the first measurement signals correspond to a measured pressure value lower than a first predefined value (for example equal to or lower than 140 kPa), the management and control means 17 generate command signals such as to increase the generation of steam . Conversely, when the first measurement signals correspond to a measured pressure value equal to or greater than a second predefined value (for example equal to or greater than 450 kPa), the management and control means 17 generate command signals such as to reduce the power of the electric heating means 15, or stop the generation of steam by the latter.

The system object of the present invention ? was designed to induce ? during laying - a condition that allows a reduction of the mechanical stresses induced in the operating conditions of the pipes.

Choosing steam heating? considered advantageous under a plurality? of points of view. In particular:

- ? extremely safe from an environmental and worker safety point of view even in the event of steam leaks from the circuit;

- the use of saturated steam allows, through the reduction of volume which occurs during the condensation, to introduce new saturated steam into the conduit for heated fluid 101, thus allowing to reach a steady state;

- it allows to optimize transport and diffusion phenomena inside pipes even of considerable longitudinal length;

- allows you to exploit the? huge amount? of latent heat involved in the vapor-liquid phase change;

- ? independent of the geometry, thickness and/or section variations of the pipes;

- ? capable of heating even non-linear or special components or circuit sections, such as: derivations, valves, curvilinear sections, or similar.

The pressure detected by the pressure detection means 16 at the maximum operating temperature? preferably higher than 140 kPa and ? equal to or less than 450 kPa.

The management and control means 17 preferably comprise a programmable logic controller or PLC (from the English "programmable logic controller"). In the presence of a plurality of portable steam generators 10, these generators could have management and control means 17 in common, or separate management and control means 17 operatively connected to each other.

The installation system 1 preferably also comprises means 106 for detecting the temperature (preferably one or more thermocouples) placed in correspondence with one or more thermocouples. pipes 1 and, more? preferably, at the heated fluid conduit 101 of this(s).

The temperature detection means 106 are preferably functionally connected to the management and control means 17. In this way, the management and control means 17 are configured to receive second measurement signals from the temperature detection means 106. Consequently, the means management and control devices 17 are configured to generate the command signals for the electric heating means 15 following receipt of both the first measurement signals from the pressure detection means 16 and the second measurement signals from the temperature detection means 106. In other words, in this embodiment the command signals generated by the management and control means 17 for the electric heating means 15 also take into account the actual temperature measured at the pipe 100 or the plurality of of them. Preferably, the portable steam generator 10 also comprises, arranged fluidically upstream of the boiler compartment 12:

(vi) an accumulation tank 18 of a predefined volume (or reserve volume) of the water fed by the water supply means 50; and/or

(vii) means 19 for softening the water fed by the water supply means 50 or by the storage vessel 18 to the boiler compartment 12.

Preferably, the portable steam generator 10 comprises, fluidly interposed between the accumulation vessel 18 and the softening means 19 or between the accumulation vessel 18 and the boiler 11, at least one pump 26 for moving the water from the accumulation vessel 18 to the softening means 19 or from the storage tank 18 to the boiler 11.

Preferably, the sweetening means 19 are of the ion exchange or reverse osmosis type, more preferably ion exchange.

The steam outlet opening 14 from the boiler compartment 12 is preferably connected releasably at only one end? inlet 20 of the conduit for heated fluid 101, one? outlet 21 of the conduit for heated fluid 101, or one? outlet 21 of a heated fluid conduit 101 arranged last in a series of pipes, being sealed, for example by a sealing element 25 .

The steam outlet opening 14 from the boiler compartment 12 is preferably connected in a releasable way to an?extremity? inlet 20 of a first conduit for heated fluid 101, a? outlet 21 of the first heated fluid conduit 101 being connected at one end inlet 20 of at least a second conduit for heated fluid 101 of a further pipe 100 placed downstream fluidically.

The mechanical and fluidic connection between the first heated fluid line 101 and the second heated fluid line 101? preferably accomplished via a flexible joint or conduit 105 and/or via a compressible or variable length joint 104.

The end? outlet 21 of the first conduit for heated fluid 101 and the end? inlet ports 20 of the second heated fluid conduit 101 are mutually spaced apart and connected by a compressible or variable length joint 104. In this specification, the terms ?compressible joint? and ?variable length joint? they are used interchangeably. That joint 104 ? configured to allow an approach of said extremity? of exit 21 and of said extremity? inlet 20 as a function of a linear thermal expansion of said pipes 100.

In other words, before the heating induced by the saturated steam generated by the steam generator 10, the tubes 100 have ends 20, 21 spaced apart and connected by the variable length joint 104. However, as the temperature increases, each tube 100 will expand. axially approaching the? end? of exit 21 and the? extremity? inlet 20 of each pair of tubes placed in series. In this approach, the joint 104 must not impede the reciprocal motion, and indeed must support the reduction of the distance. Finally, after the pipes are sufficiently approached (for example mutually in contact), the ends? 20, 21 can be paid.

Furthermore, the object of the present invention is a method for laying pipes 100 which can be implemented in part by means of the laying system 1 according to any of the embodiments illustrated above.

This method includes the following stages:

(A) heating at least one pair of heated fluid lines 101 by saturated steam to a temperature at or below a maximum operating temperature;

(B) maintaining said temperature at or below the maximum operating temperature for a predefined time;

in which said default time ? a time necessary for? the pair of heated fluid conduits 101 experiences a desired linear thermal expansion, e.g., maximum linear thermal expansion;

(C) welding said pair of heated fluid conduits 101 into the desired linear thermal expansion;

(D) capping the heated fluid conduits (101) in the desired linear thermal expansion;

(E) cooling the heated fluid lines (101) to ambient temperature.

Preferably, after step (C) and before step (D), said method comprises a step of making a thermal insulation (or muffle) around the weld obtained from step (C).

Phases (C) and (D), and the optional muffle phase, are not implemented through laying system 1.

Advantageously, the system object of the present invention ? It has been designed to operate in a long-lasting manner, without undergoing deterioration phenomena such as the formation of encrustations.

Advantageously, the system object of the present invention ? built in a modular way in order to face different contingencies. For example, to be able to provide a quantity? of heat sufficient to produce linear thermal expansion of pipes or pipe systems of different lengths.

Advantageously, the steam generator object of the present invention ? able to tolerate any fluctuations in the water and/or electricity supply of the boiler, thus ensuring continuity? operational.

Advantageously, the steam generator object of the present invention can be implemented with simple operations, and does not require a large number of workers to ensure its effectiveness. Advantageously, the system object of the present invention ? able to adapt a quantity? of steam generated based on actual heating of the pipes. Advantageously, the system ? based on a saturated steam production pressure value which intrinsically guarantees compliance with the maximum permissible temperatures for the materials of the pipes or circuit.

To the embodiments of the aforementioned system and method, a person skilled in the art could make substitutions or modifications to the characteristics described according to the contingencies. Also these embodiments are to be considered included in the scope of protection formalized in the following claims. Furthermore, it is specified that any embodiment may be implemented independently of the other disclosed embodiments.

LIST OF REFERENCE NUMBERS

1 laying system

10 portable steam generator

11 boiler

12 boiler room

13 inlet-water opening

14 steam outlet opening

15 electric means of heating

16 pressure detection means 17 management and control means

18 storage tank

19 sweetening means

20 ends? input

21 ends? of output

22 collector

23 flexible transport conduit

24 connecting joint

25 closing element

26 displacement pump

27 safety or overpressure valve 28 condensate drain system

50 means of water supply

51 Means of Electrical Supply

100 tube

101 conduit for heated fluid

102 layer of thermal insulation

103 outer tubular casing

104 compressible joint

105 joint or flexible conduit

106 temperature detection means X prevailing development direction

Claims (10)

1. A laying system (1) of at least one pipe (100) comprising: - at least one pipe (100) comprising at least one conduit for heated fluid (101), a thermal insulation layer (102) which substantially completely houses said conduit for heated fluid (101) and which has a maximum operating temperature, and an outer tubular casing (103) which at least partially surrounds the thermal insulation layer (102); - at least one portable steam generator (10) comprising: (i) a boiler (11) delimiting a boiler room (12), a water inlet opening (13) connectable to water supply means (50) , and a steam outlet port (14) releasably connected to the heated fluid conduit (101), (ii) electric heating means (15) in thermal contact with said boiler room (12); (iii) means for detecting the pressure (16) in the boiler compartment (12); and (iv) management and control means (17); wherein the management and control means (17) are functionally connected to the electric heating means (15) and to the pressure detection means (16) so that a saturated steam leaving from said steam outlet opening (14) has a temperature equal to or lower than the maximum operating temperature. 2. The system according to the preceding claim, wherein the pressure sensed by the pressure sensing means (16) at the maximum operating temperature is? higher than 140 kPa and ? equal to or less than 450 kPa. 3. The system according to any one of the preceding claims, wherein said portable steam generator (10) comprises: (v) at least one flexible saturated steam transport line (23), equipped with a connection joint (24) for the releasable connection between the steam outlet opening (14) and the heated medium line (101). The system according to any one of the preceding claims, wherein said tube (100) comprises a metal-type heated fluid conduit (101), a thermal insulation layer (102) of polyurethane foam, and an outer tubular casing (103 ) in polyethylene, said pipe (100) being constructed according to the DIN EN 253 standard. 5. The system according to any one of the preceding claims, wherein the portable steam generator (10) further comprises, arranged fluidically upstream of the boiler room (12): (vi) an accumulation tank (18) of a predefined volume of the water fed by the water supply means (50); And (vii) means (19) for softening the water fed from the storage vessel (18) to the boiler compartment (12). 6. The system according to the preceding claim, wherein said sweetening means (19) are of the ion exchange or reverse osmosis type. 7. The system according to any one of the preceding claims, wherein the steam outlet opening (14) from the boiler room (12) is? releasably connected at one end? inlet (20) of the conduit for heated fluid (101), one end? outlet (21) of the heated fluid conduit (101) being sealed. 8. The system according to any one of claims 1-6, wherein the steam outlet opening (14) from the boiler room (12) is? connected in a releasable way to a? extremity? inlet (20) of a first conduit for heated fluid (101), a? outlet (21) of the first heated fluid conduit (101) being connected to one end inlet (20) of a second conduit for heated fluid (101) of a further pipe (100) placed downstream fluidically; in which the? extremity? outlet (21) of the first conduit for heated fluid (101) and the? inlet (20) of the second conduit for heated fluid (101) are mutually spaced and connected by a compressible joint (104) configured to allow an approach of said end? output (21) and said end? inlet (20) as a function of a linear thermal expansion of said pipes (100). 9. The system according to any one of the preceding claims, comprising a plurality? of portable steam generators (10) mutually arranged in parallel and connected to the conduit for heated fluid (101) via a manifold (22) connected to the steam outlet opening (14) of the boiler (11) of each of said generators portable steamer (10). A pipe laying method (100) implementable in part by the laying system (1) according to any one of the preceding claims; wherein said method comprises the following steps: (A) heating at least one pair of heated fluid lines (101) by saturated steam to a temperature at or below a maximum operating temperature; (B) maintaining said temperature at or below the maximum operating temperature for a predefined time; in which said default time ? a time necessary for? the pair of heated fluid conduits (101) experiences a desired linear thermal expansion, e.g., maximum linear thermal expansion; (C) welding said pair of heated fluid conduits (101) into the desired linear thermal expansion; (D) capping the heated fluid conduits (101) in the desired linear thermal expansion; (E) cooling the heated fluid lines (101) to ambient temperature.