CN104332240A

CN104332240A - Method for improving carrying capacity of power cable directly buried in soil

Info

Publication number: CN104332240A
Application number: CN201410650947.7A
Authority: CN
Inventors: 唐爱红; 陈志龙; 李进; 杨惠源
Original assignee: Wuhan University of Technology WUT
Current assignee: Wuhan University of Technology WUT
Priority date: 2014-11-17
Filing date: 2014-11-17
Publication date: 2015-02-04

Abstract

The invention relates to a method for improving carrying capacity of a power cable directly buried in soil. The method is characterized in that all power cables are limited within a circle based on the radial sections of the power cables or a power cable group, and the circle is named S; a or a plurality of water supply and draining pipelines are paved below the center of the circle S. According to the method, the temperature of the power cables or the power cable group and the surrounding areas is lowered down through the heat transfer effect between the power cables or the power cable group and the surrounding area and the water supply and draining pipelines; therefore, the carrying capacity is raised, and the conveying capacity of a power supply circuit is improved.

Description

A kind of method improving the ampacity of the power cable of soil directly buried installation

Technical field

the present invention relates to technical field of electric power, be specifically related to a kind of method improving the ampacity of the power cable of soil directly buried installation.

Background technology

Along with the continuous expansion of China's city size, the power consumption of various places and and power load raise year by year, newly-increased power equipment is the way ensureing power demands, but the space in city and subterranean resource are often very limited, cause newly added equipment more difficult; Promote the conveying capacity of existing line, can better realize its economic benefit and social benefit.

Ampacity is a performance parameter of the conveying capacity concerning power cable, and the highest long-term working temperature that conductor allows can affect the size of rated current-carrying capacity.

In the system of laying of power cable, most widely used is at present the mode of soil direct-burried, and in the electric line of cable, power cable group is limited in certain space by the general mode of multiloop cluster laying that adopts.In the power cable group circuit of soil directly buried installation, the heat that power cable produces, not only makes the temperature of self raise, causes the size limiting its current capacity, and also can produce thermal impact to other cables simultaneously, and other cable temperatures are raised.

Urban construction in cities and towns is with in planning, power supply facilities and water supply and sewage facility are all paired appearance usually, this illustrates that power cable line is all consistent with the trend of water supply and sewage circuit usually, and the temperature of the power cable line of the temperature in water supply and sewage spool road under normal circumstances when will be significantly less than work, therefore both are combined and utilize drainage pipeline to lower the temperature to power cable thus the ampacity improving power cable becomes a kind of feasible thinking.

Summary of the invention

the problem that the ampacity that power cable for directly buried installation generates heat and causes declines, the invention provides a kind of method improving the ampacity of the power cable of soil directly buried installation, this method can reduce the temperature of power cable or power cable group and neighboring area thereof, improve ampacity, promote the conveying capacity of supply line.

In order to solve above-mentioned technical problem, the invention provides a kind of method improving the ampacity of the power cable of soil directly buried installation, it is characterized in that: on the radial section of power cable or power cable group, all power cables are limited in a circle, and specify that the name of this circle is called S, state the area of round S at 3m ²below, below the center of circle of described round S, one or several drainage pipeline is laid.

Described drainage pipeline is below the center of circle of circle S within the scope of 5-35cm.

The center of circle of described drainage pipeline and the center of circle lateral separation of described round S are at below 20cm.

The invention has the beneficial effects as follows:

By power cable or power cable group and the heat transfer effect between neighboring area and drainage pipeline thereof, reduce the temperature of power cable or power cable group and neighboring area thereof, improve ampacity, improve the conveying capacity of supply line.

Accompanying drawing explanation

fig. 1 is the longitudinal section view of the relative position of power cable or power cable group and circle S in the present invention.

Fig. 2 is the longitudinal section view of the relative position of circle S and drainage pipeline in the present invention.

The thermo parameters method figure that Fig. 3 a is simulation single loop soil direct-burried power cable when not configuring that under drainage pipeline, aluminium core temperature is 90 DEG C.

Fig. 3 b is thermo parameters method figure when to configure aluminium core temperature under drainage pipeline be 90 DEG C at simulation single loop soil direct-burried power cable 26.9cm place immediately below circle S.

The thermo parameters method figure that Fig. 4 a is simulation three loop soil direct-burried power cable when not configuring that under drainage pipeline, aluminium core temperature is 90 DEG C.

The thermo parameters method figure that Fig. 4 b 48.5cm place that is simulation three loop soil direct-burried power cable immediately below circle S configures aluminium core temperature under drainage pipeline when being 90 DEG C.

The thermo parameters method figure that Fig. 4 c 14cm place that is simulation three loop soil direct-burried power cable immediately below circle S configures aluminium core temperature under drainage pipeline when being 90 DEG C.

In figure: 1-circle S; The center of circle of 2-circle S; 3-drainage pipeline; The center of circle of 4-drainage pipeline.

Embodiment

below in conjunction with drawings and Examples, the present invention is further elaborated.

The invention provides a kind of method improving the ampacity of the power cable of soil directly buried installation, on the radial section of power cable or power cable group, all power cables are limited in a circle, and specify that the name of this circle is called S, below the center of circle of described round S, lay one or several drainage pipeline.

as shown in Figure 1, all power cables can be limited in circle S, and the area of regulation circle S is at 3 below ㎡, if the area of circle S is excessive, can affect the radiating effect of drainage pipeline, the power cable exceeding round S belongs to an other power cable line.

As shown in Figure 2, drainage pipeline is positioned at the below of round S, and in order to there be better cooling-down effect, regulation drainage pipeline is below the center of circle of circle S within the scope of 5-35cm, and the center of circle of drainage pipeline and the center of circle lateral separation of described round S are at below 20cm.In the urban construction in cities and towns, by construction, carry out position adjustment or set up new water pipe making drainage pipeline meet above-mentioned status requirement to the water pipe near the cable line, and simple, cost is low.

Below by the research of temperature simulation simulation software with prove that drainage pipeline is to power cable or the cooling-down effect of power cable group and contacting between different position relationships and cooling-down effect.

In Fig. 3 a, Fig. 3 b, Fig. 4 a, Fig. 4 b and Fig. 4 c, the power cable that simulated experiment adopts adopts general conventional power cable, its concrete structure is followed successively by aluminium core, semi-conductive insulating layer, XLPE insulating barrier, wire armoring and rubber from inside to outside, wherein, aluminium core diameter is 31.3mm, and semiconducting insulation layer thickness is 1.77mm, XLPE thickness of insulating layer is 28.9mm, wire armoring thickness is 3.25mm, and rubber outside diameter is 99.1mm.

in Fig. 3 a, Fig. 3 b, Fig. 4 a, Fig. 4 b and Fig. 4 c, the temperature of the aluminium core of power cable is 90 DEG C.

In Fig. 3 a, Fig. 3 b, Fig. 4 a, Fig. 4 b and Fig. 4 c, inside and outside is all that temperature in the closed area that surrounded by curve is identical everywhere, and temperature reduces step by step from inner ring to outer ring.

In Fig. 3 b, Fig. 4 b and Fig. 4 c, in described drainage pipeline, be filled with water.

in fig. 3 a, single loop soil direct-burried power cable does not configure drainage pipeline, and power cable spacing is 20cm, and setting air temperature is 19 DEG C, the soil moisture is 20 DEG C, soil thermal conductivity linearly changes by temperature.Thermo parameters method when aluminium core temperature that what Fig. 3 a showed is is about 90 DEG C.

In fig 3b, below the center of circle of circle S, 26.9cm place configuration steel matter, internal-and external diameter are followed successively by the drainage pipeline of 14.29cm and 14.79cm, and other condition is identical with the condition in Fig. 3 a.Thermo parameters method when aluminium core temperature that what Fig. 3 b showed is is about 90 DEG C.

Contrasted from Fig. 3 a and Fig. 3 b, drainage pipeline defines the effect of cooling to power cable or power cable group.

in fig .4, three loop soil direct-burried power cables do not configure drainage pipeline, and other condition is identical with the condition in Fig. 3 a.Thermo parameters method when aluminium core temperature that what Fig. 4 a showed is is about 90 DEG C.

In fig. 4b, below the center of circle of circle S, 48.5cm place configuration steel matter, internal-and external diameter are followed successively by the drainage pipeline of 14.29cm and 14.79cm, and other condition is identical with the condition in Fig. 4 a.Thermo parameters method when single aluminium core temperature that what Fig. 4 b showed is is about 90 DEG C.

In Fig. 4 c, below the center of circle of circle S, 14cm place configuration steel matter, internal-and external diameter are followed successively by the drainage pipeline of 14.29cm and 14.79cm, and other condition is identical with the condition in Fig. 4 a.Thermo parameters method when aluminium core temperature that what Fig. 4 c showed is is about 90 DEG C.

Contrasted from Fig. 4 a, Fig. 4 b and Fig. 4 c: drainage pipeline defines the effect of cooling to power cable or power cable group, the nearlyer cooling-down effect in the center of circle of drainage pipeline distance circle S is better, if the center of circle of distance circle S is too far away, cooling-down effect is not obvious.

Claims

1. one kind is improved the method for the ampacity of the power cable of soil directly buried installation, it is characterized in that: on the radial section of power cable or power cable group, all power cables are limited in a circle, and specify that the name of this circle is called S, and the area of described round S is at 3m ²below, below the center of circle of described round S, one or several drainage pipeline is laid.

2. a kind of method improving the ampacity of the power cable of soil directly buried installation as claimed in claim 1, is characterized in that: described drainage pipeline is below the center of circle of circle S within the scope of 5-35cm.

3. a kind of method improving the ampacity of the power cable of soil directly buried installation as claimed in claim 1, is characterized in that: the center of circle of described drainage pipeline and the center of circle lateral separation of described round S are at below 20cm.