DK170383B1

DK170383B1 - District heating pipe stretching and method of establishing it

Info

Publication number: DK170383B1
Application number: DK70793A
Authority: DK
Inventors: Hans Noerregaard Pedersen
Original assignee: Abb District Heating
Priority date: 1993-06-15
Filing date: 1993-06-15
Publication date: 1995-08-14
Also published as: SE504171C2; DK70793A; DK70793D0; FI955951A0; SE9504445L; GB2294742A; FI955951A; SE9504445D0; WO1994029635A1; AU6994994A; DE4493874T1; PL312037A1; CN1125475A; GB9524789D0

Description

i DK 170383 B1in DK 170383 B1

Den foreliggende opfindelse angår en underjordisk fjernvarmerørstrækning. Fjernvarmerør er oftest monteret ved lægning i opgravede render, men indenfor kabel- og rørlægningsteknikken benytter man i stigende grad en 5 såkaldt 'styret underboring', hvor man i et borespor i jorden indskyder eller -trækker et rør, som vidtgående udfylder boresporet, således at der f.eks. ved trafikbelastning ikke vil opstå forsænkninger i overfladen over borestrækningen.The present invention relates to an underground district heating pipe stretch. District heating pipes are most often mounted by laying in excavated trenches, but within the cable and pipe laying technique, a 5 so-called 'controlled underbore' is increasingly used, where in a drilling track in the ground a pipe is inserted or pulled, which fills the drilling track extensively, so that that e.g. at traffic congestion, no recesses will occur in the surface over the drill line.

10 Det er ønskeligt at forlægge også fjernvarmerør på denne måde, men konventionelt udførte rør egner sig dårligt til det, fordi de er sammensat af præfabrikerede rørlængder, der er samlet og ved samlingsstederne er forsynet med omgivende tætningsmuffer, der primært skal 15 virke totalt tætnende mod vandindtrængning i det isolationsmateriale, som er anbragt imellem det eller de indre ledningsrør og et omgivende kapperør af formstof. Mufferne anbringes uden om de mod hinanden vendende ender af kapperørene ved hvert samlingssted, og de udgø-20 res normalt af krympemuffer eller svejste muffesvøb af formstof, henholdsvis af sammenspændte metalpladeskaller. I gængs udførelse er mufferne ikke egnede til at modstå de mekaniske længdeforskydningskræfter, som de vil udsættes for ved forlægning i snævre borespor, hvor 25 det endda er ønskeligt, at røret monteres ved en forholdsvis høj indføringshastighed, hvorved der kan opstå aksiale slagpåvirkninger på mufferne.It is desirable to place district heating pipes in this way as well, but conventionally made pipes are poorly suited for this because they are composed of prefabricated pipe lengths which are assembled and provided at the assembly points with surrounding sealing sleeves, which should primarily act totally sealing against water penetration into the insulating material disposed between the inner pipe (s) and a surrounding plastic casing. The sleeves are disposed around the opposite ends of the casing tubes at each assembly site, and are usually constituted by shrink sleeves or welded sleeve sleeves of resin or compressed metal plate shells, respectively. In conventional designs, the sleeves are not suitable to withstand the mechanical longitudinal shear forces to which they will be subjected to placement in narrow drill grooves, where it is even desirable for the tube to be mounted at a relatively high insertion speed, thereby producing axial impact on the sleeves.

Det har dog ved nærværende opfindelse vist sig, at man på ønskværdig måde kan bibeholde de gængse samlings-30 teknikker, herunder også mufferne, når der anvendes kapperør med indsnævrede endepartier, idet mufferne så kan anvendes med således formindsket tykkelse, at de alligevel ikke er radialt udstående fra den ydre røroverflade. Ydermere kan der så også opnås en kraftig 35 mekanisk låsning af mufferne i rørets længderetning, hvis forholdene er således afpassede, at muffeenderne DK 170383 B1 2 støder op til de radiale indsnævringsområder på kapperørene.However, it has been found by the present invention that desirable conventional techniques can be retained, including the sleeves, when using sheath pipes with narrowed end portions, the sleeves then being used at such a reduced thickness that they are nevertheless not radially protruding from the outer tube surface. In addition, a strong mechanical locking of the sleeves in the longitudinal direction of the pipe can also be achieved if the conditions are so adapted that the sleeve ends DK 170383 B1 2 abut the radial narrowing areas of the casing pipes.

Opfindelsen forklares i det følgende nærmere under henvisning til tegningen, på hvilken 5 fig. 1 er et længdesnitbillede af en rørsamling i henhold til opfindelsen, medens 4 fig. 2 er et tilsvarende billede af en alternativ udførelsesform.The invention will now be explained in more detail with reference to the drawing, in which 1 is a longitudinal sectional view of a pipe assembly according to the invention, while FIG. 2 is a similar view of an alternative embodiment.

I fig. 1 er vist to fjernvarmerørelementer 2 og 4, 10 der på sædvanlig måde er opbygget med et indre ledningsrør 6, en omgivende isolation 8 og et ydre kapperør 10.In FIG. 1, two district heating pipe elements 2 and 4, 10 are shown in the usual manner with an inner conduit 6, a surrounding insulation 8 and an outer casing pipe 10.

Enderne af ledningsrørene 6 er udstående fra enderne af de omgivende dele 8 og 10, og de er sammenføjet på egnet måde, f.eks. ved svejsning, omend gerne på anden og 15 hurtigere udført måde.The ends of the conduits 6 are protruding from the ends of the surrounding portions 8 and 10, and are joined together in a suitable manner, e.g. by welding, albeit in a different and 15 faster way.

Forud for samlingen af rørene 6 og fortrinsvis i selve produktionsfasen af rørene er kapperørenderne tildannet med indsnævrede frie ender 12, f.eks. ved at være påsvejset et reduktionsstykke 14. Efter samlingen 20 af rørene 6 vil det så være muligt at afslutte samlear-bejdet på principielt konventionel måde, nemlig ved at montere en rørmuffe 16 imellem og udenpå rørenderne 12 og ved en efterfølgende skumudfyldning af det frie rum inde under muffen, henholdsvis ved anbringelse af isola-25 tionsmateriale omkring de frie ender af rørene 6 og efterfølgende montering af muffen. Ved brug af en krym-pemuffe bør denne fra starten være så stor, at den kan anbringes i en 'paratstilling' udenpå den tykkere hoveddel af det ene af rørene 2 eller 4 således som det er 30 antydet ved oversiden i fig. 1. Principielt kan endedelen 12 på reduktionsstykket 14 være tildannet med så stor længde, at den kan optage muffen i paratstillingen uden at muffen fra starten behøver at have overtykkelse .Prior to the assembly of the pipes 6 and preferably in the actual production phase of the pipes, the casing ducts are formed with narrowed free ends 12, e.g. by welding a reduction piece 14. After the joint 20 of the pipes 6, it will then be possible to finish the joint work in a generally conventional manner, namely by mounting a pipe sleeve 16 between and outside the pipe ends 12 and by a subsequent foam filling of the free space. inside the sleeve, respectively, by placing insulating material around the free ends of the tubes 6 and subsequently mounting the sleeve. When using a shrink sleeve, this should initially be so large that it can be placed in a "ready position" outside the thicker body of one of the tubes 2 or 4, as indicated at the upper side of FIG. 1. In principle, the end portion 12 of the reducer 14 may be formed so long that it can accommodate the sleeve in the ready position without the sleeve having to have a thickness from the start.

i forhold til kapperøret 10, men herved forlænges det 35 indsnævrede rørstykke, hvor isolationen er nedsat som følge af indsnævringen.in relation to the casing pipe 10, but thereby the 35 narrowed pipe piece is extended, where the insulation is reduced as a result of the narrowing.

DK 170383 B1 3DK 170383 B1 3

Det vil forstås, at den således tilvejebragte rør-samling vil udmærke sig ved, at ydersiden af muffen 16, trods dennes konventionelle udførelse og anbringelse, ikke vil rage uden for ydersiden af kapperørene 10, og 5 at de samlede rør dermed kan deltage i en fremføring gennem et snævert borespor uden nogen væsentlig aksial-rettet påvirkning på muffen.It will be appreciated that the pipe assembly thus provided will be distinguished by the fact that the outer surface of the sleeve 16, despite its conventional design and arrangement, will not protrude outside the outer surface of the casing pipes 10, and 5 that the total pipes can thus participate in a advancement through a narrow drill groove without any significant axial-directed impact on the sleeve.

Der kan dog alligevel optræde en vis påvirkning i aksialretnigen, og det kan derfor være en fordel, at de 10 indsnævrede endedele 12 på kapperørene 10 ikke er længere end at de lige netop kan modtage muffen 16, da dette vil betyde, at muffen i sin endelige tilstand vil være aksialstabiliseret imellem de rørudvidelser, som forekommer ved grunddelen af indsnævringerne 12. Muffen kan 15 eventuelt være en plademuffe med halvcylindriske skaller, der samles ved udstående kantflanger. Det kan i så fald eventuelt tolereres, at selve kantflangerne rager uden for omkredsen af kapperørene.However, there may still be some influence in the axial direction, and it can therefore be advantageous that the 10 narrowed end portions 12 of the sheath pipes 10 are no longer than that they can just receive the sleeve 16, since this will mean that the sleeve in its the final state will be axially stabilized between the tube expansions that occur at the base of the constrictions 12. The sleeve 15 may optionally be a plate sleeve with semi-cylindrical shells assembled by protruding edge flanges. In this case, it can possibly be tolerated that the edge flanges themselves extend beyond the circumference of the sheath pipes.

Det er konstateret, at der under visse uheldige 20 forhold dog kan optræde problemer ved rørindføringen, hvis muffen 16 er udført på helt konventionel måde.However, it has been found that under certain unfortunate conditions, problems can occur with the pipe insertion if the sleeve 16 is designed in a completely conventional manner.

Disse problemer kan imidlertid imødegås ganske effektivt uden nogen ændring i selve dette forhold, nemlig ved at der som vist i fig. 2 tilføjes en ydre dækmuffe 18, der 25 kan være en krympemuffe, som er udragende forbi enderne af tætningsmuffen 16, og som selv kan være stabiliseret i aksialretningen ved at fæstnes ved limning til kapperørenderne eller ved selv at støde op til rørudvidelserne ved grunddelene af de indsnævrede rørender 12. Herved 30 opnås en meget effektiv mekanisk afskærmning af tætningsmuffen 16, men skulle den end forskydes en smule vil dette være uden afgørende betydning for effektiviteten af den indre muffe 16. Det kan endda tolereres, at selve dækmuffen 18 har sin yderside beliggende en smule 35 udenfor omkredsen af kapperørene.However, these problems can be dealt with quite effectively without any change in this condition itself, namely that, as shown in FIG. 2, an outer cover sleeve 18 is added, which may be a shrink sleeve protruding past the ends of the sealing sleeve 16, and which itself may be stabilized in the axial direction by being secured by bonding to the casing ends or by supporting the tube extensions at the base portions of the narrowed pipe ends 12. Hereby a very effective mechanical shielding of the sealing sleeve 16 is obtained, but even if it is slightly displaced, this will be of no decisive importance to the efficiency of the inner sleeve 16. It can even be tolerated that the cover sleeve 18 itself has its outer surface. slightly 35 outside the circumference of the sheath pipes.

Claims

A district heating pipe which is composed of assembled prefabricated pipe elements and preferably is mounted in the ground by insertion into a drill groove therein, which pipe elements at the joints are enclosed by sealing joints for sealing bridging between the ends of outer casing pipes on the pipe elements, characterized in that they enclosing joint sleeves are mounted on narrowed casing ends in such a way that they at their outside align with or lie within the outer circumference of the casing pipes.

Pipe stretch according to claim 1, wherein an outer tire sleeve is arranged on the outside of the connecting sleeves, characterized in that the tire sleeves are also at least partially recessed in relation to the circumference of the jacket pipes. 20

Pipe stretch according to claim 1, characterized in that the sockets at the ends adjoin the narrowing areas of the casing pipes.

A pipe element for a stretch according to claim 1, 25, characterized in that it is formed with narrowed end portions of the casing pipe.

Method for establishing a pipe line according to claim 1, characterized in that after 30 assembly of the line it is mounted in the ground by insertion according to the principle of drilling. Ψ 35