JPS612998A - Heat-insulating piping material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a heat insulating piping material used in piping construction for conveying a thermal fluid such as hot water.

[L''] As shown in FIGS. 6 and 7, conventional insulating piping materials employ a method in which a thermal fluid transfer pipe 2 such as a copper pipe is coated with a foamed synthetic resin 6. Piping materials made of foamed synthetic resin with low foaming do not have sufficient insulation performance, while those with high foaming have good insulation performance, but the performance depends on the layer thickness, which has the disadvantage of increasing external dimensions. .

Therefore, the present inventors previously proposed in Japanese Patent Application No. 58-182570 that a small-diameter conveying pipe (steel pipe) was inserted into a bellows-shaped inner resin pipe, and the outer surface of this inner resin pipe containing the conveying pipe was We have developed an insulating piping material that is coated with a film with a low heat filtration rate and placed inside a bellows-shaped resin outer tube.

According to this piping material, however, the heat radiation coefficient of the above-mentioned foam resin coating type is K = 0.33 to 0.34, whereas this piping material has a good heat dissipation coefficient of K = 0.16 to 0.18. Results are being obtained. However, since this type has a more complicated structure than the extrusion coating method, it is inevitable that the manufacturing process will be complicated. In particular, when carrying pipes are installed for drought heating, it is preferable to use them as a pair, an outgoing pipe and a returning pipe, whereas it is preferable to use two inner pipes into which the carrying pipes have been inserted and bundle them side by side to place them inside the outer pipe. When inserting it into
Since there are no holes, the insertion work is not necessarily easy, which makes manufacturing complicated.

Objective 1 An object of the present invention is to provide a heat insulating pipe (4) which has a simple IP structure, is easy to manufacture, and has excellent heat insulation performance.

Structure: The present invention provides a structure in which a film having a low thermal emissivity is provided in close contact with a thermofluid transport pipe made of resin and a bellows-shaped resin outer pipe that houses and covers the pipe. This is a characteristically insulating piping material.

For piping materials that have a structure in which the thermal fluid transfer tube is inserted directly into the outer tube, there is a certain amount of space between the outer tube and the transfer tube, and there is no point of contact between the outer tube and the transfer tube. Or, although it is linear, the heat dissipation from the conveying tube to the outer tube is not negligible.

By the way, the possible ways of dissipating heat from the conveyor tube to the outer tube are: 1) conduction through the air, 2) convection through the air, 3) radiation between the outer surface of the conveyor tube and the inner surface of the outer tube. Means to prevent heat radiation +t: -d and its (9
Considering the loss, first, in order to prevent conduction in 1), if a bellows-shaped resin tube is used as the outer tube, contact between the conveying tube and the outer tube can be sufficiently reduced. For convection (2), it is desirable to reduce the space ratio between the outer tube and the conveying tube, but especially when inserting two conveying tubes in a pair,
There is a limit to this, as it becomes difficult.

The present invention is an insulating piping material for thermal fluid transfer pipes made of resin, which reduces radiation in 3) and facilitates insertion of the transfer pipe into the outer pipe.The specific structure thereof will be explained with reference to drawings. do.

As shown in FIGS. 1 to 3, two thermofluid transfer tubes 2 made of resin are inserted into a bellows-shaped outer tube 1 made of resin as a pair. These conveyor pipes, for example, circulate and supply hot water to the radiator, and one pipe is (↑) and the other is a return pipe.

A feature of the present invention is that a film 3 made of a material having a low heat dissipation rate (for example, an aluminum foil laminated film) 3 is provided on the outer surface of the conveying tube 2 made of resin. That is, as shown in FIG. 4, the aluminum foil laminated film 3 is wrapped around the outer surface 111 of the transport tubes so as to bind the pair of transport pipes 2 together, with the aluminum foil facing outward. There is.

The aluminum foil laminated film 3 is, for example, a PE film with a thickness of 2571 mm.
It is a ribbon made by laminating aluminum foil with a thickness of 7μ to 50μ on T or PVC film, as shown in Fig. 4.
A similar ribbon-shaped tape 4 is wrapped around two conveyor tubes 2 so that the edges overlap by 1/3, and glue is applied on top of it.
Attach it to prevent it from rolling back.

FIG. 5 shows another specific example of a film 3 with a low thermal emissivity.
In this example, a film having an aluminum vapor-deposited layer is used instead of the aluminum foil laminated film described above. In this case, the film 3 is placed parallel to the transport tube 2 and wound around the transport tube 2 so that the edges meet at the joint 5. Attached.

Note that the aluminum foil laminated film 3 used in the specific example in Fig. 4 is not glued, and is fixed with adhesive tape 4, but it is glued. If an aluminum foil laminated film is used, the stopper tape 4 can be omitted.

The aluminum foil laminated film and aluminum vapor deposited film are
This effect has the effect of insulating the radiant heat, thereby reducing the amount of heat generated by the IJ of the conveying pipe.

By the way, the amount of radiant heat from a heating body is proportional to the fourth power of the surface temperature of the heating body, so if a heat insulating coating is provided on the outer surface of the conveying pipe 2, an aluminum foil laminated film is provided on the outer surface of the coating. Good too. Then, since this heat-insulating coating reduces the amount of heat transferred from the outer surface of the conveying pipe 2 to the outer surface of the coating layer, the temperature of the outer surface of the coating layer becomes lower. . Furthermore, this heat-insulating coating also has the effect of preventing heat transfer between the outgoing pipe and the returning pipe. When such a heat insulating coating is installed, its thickness may be about 0.25 to 5IIIi, but it is determined by the degree of foaming of the resin and the degree of coating. However, in principle, the thickness should be such that the outer surface temperature of the coating is preferably 10° C. lower than the outer surface temperature of the conveying tube 2.

In addition, as shown in the figure, in the piping material of the present invention, no inner pipe is installed between the transport pipe 2 and the outer pipe 1, so the space between the transport pipe 2 and the outer pipe 1 is compared. Therefore, the conveying tube 2 can be easily inserted into the outer tube 1. In particular, in a simple configuration in which two conveyor tubes 2 are tied together with a film 113 with a low thermal resistance such as an aluminum foil laminated film, the distance between the outer tubes 1 is 21RIl1 more than when an inner tube is provided. Since the amount increased slightly, its insertion can be easily performed.

In addition, when a drought conveyance pipe is composed of an outgoing pipe and a return pipe, heat transfer occurs between the two pipes. In order to reduce this heat transfer, a bridge may be provided between the insulating coatings of the outgoing pipe and the II pipe, if necessary. This bridge is
Both tubes can be integrally formed at the same time as resin coating. In addition, highly foamed (2 to 3 times) aluminum resin should be used as the coating resin, or (substrate 4 such as a hard foamed resin board or a resin board woven with glass fiber between the first pipe and the return pipe).
Heat transfer can also be reduced by intervening.

Furthermore, this spacer allows 'tI4ITEIi! ? 4
You can increase the weight of bamboo.

Next, the heat insulation performance of the piping material according to the present invention will be described.

A test was conducted on the piping material according to the present invention to determine the heat radiation coefficient K using the B1 equation. The test material in this case is two 10φ x 1.5t cross-linked polyethylene pipes, wrapped with an aluminum foil laminated film on the outside without any gaps, and used as an inner tube. This is a piping material with a length of 11+n, with the inner tube inserted into a rugate pipe of 2765φ.

The test equipment places the test material between a constant temperature water tank and a heat exchanger, and passes hot water from the constant temperature water tank through one of the two polyethylene pipes in the test material, which is the outbound pipe.
The hot water was sent to the heat exchanger, and the hot water that was heat exchanged there was passed through the other polyethylene pipe, which is the return pipe inside the test material, and returned to the constant temperature water tank through this pipe, so that the hot water was passed through the two polyethylene pipes. It is designed to circulate.

This test method is carried out using this device at room temperature of 20°C and 1 i 2 J of water! /min, the inlet temperature of the outgoing pipe is 80°C, and the inlet temperature of the returning pipe is 60°C, and the heat dissipation coefficient K is determined using the following formula.

However, W: Water mother (kg/n+in) Cp: Specific heat of water (kcal/k(1'C) = 1
T': Room temperature ('C) < average of 3 points) T1: Outgoing pipe inlet temperature (°C) T2: Same outlet temperature ('C) T3: Return pipe inlet temperature ('C) T4: Same outlet temperature ('C) ) 〒: (T+ +T2 +T3 +Ta)/4 (
'C) 〒I'': (Tr + +Tr? +Tr 3
)/3('C) For comparison, the sample materials include one with the same structure as the above sample except that aluminum foil laminated film was not installed, and one with conventional insulating piping material. was used.

Conventional heat-insulating piping materials have the structure shown in Figs. 6 and 7, in which a steel pipe 2 is coated with an extruded low-foam polyethylene coating 6 of 4n++n thickness, and the two pipes are stably combined as a pair. It is integrally covered with an outer skin 7 made of chemically modified polyethylene.

The test results are shown in the table below.

As can be seen from the above table, by providing the aluminum laminated film, the heat dissipation coefficient K of the present invention is approximately 20% compared to the case without the aluminum laminated film, and approximately 45% compared to the conventional product.
% can be reduced.

ICz In the case of the piping material of the present invention in which a heat insulating coating is provided on the conveyor tube, when curing the end of the conveyor tube during piping construction, the outer side is Slice the tube into rings and pull them out, unwrap and cut out a film with low thermal emissivity such as aluminum foil laminated film, and remove the terminal cap made of vinyl chloride resin or the like to seal the opening between the heat-insulating coating surface and the outer tube. By inserting it into the outer pipe, it is possible to prevent rainwater from entering into the piping material. Furthermore, it is possible to reliably keep the end of the conveying tube warm.

The present invention is not limited to piping materials for a pair of conveyance pipes as described in the specific examples, but can also be applied to piping materials for a single conveyance pipe such as a hot water supply pipe. It is something that

Effects As explained above, the heat insulating piping material according to the present invention has improved heat insulation performance, and in the case of piping with two conveyor pipes, it can be easily inserted into the outer pipe, so piping installation is easy. Improves T properties. Furthermore, the manufacturing process is simple, productivity is improved, and a safe insulating piping material can be provided.

[Brief explanation of the drawing]

Fig. 1 is an axial cross-sectional view showing a specific example of the insulating piping material of the present invention, Fig. 2 is a side sectional view of Fig. 1, Fig. 3 is a perspective view of the above-mentioned specific example, and Fig. 4 is the present invention. FIG. 5 is a side view showing another specific example of the conveying pipe, FIG. 6 is a sectional view of a conventional insulating piping material, and FIG.
It is a perspective view of the piping material shown in the figure. DESCRIPTION OF SYMBOLS 1... Outer tube, 2... Conveying tube, 3... Low thermal emissivity film, 4... Fastening tape, 5... Joint portion of the film, 6... Extrusion coating of resin, 7...Resin outer skin.

Claims (1)

[Claims] A film having a low thermal emissivity is provided in close contact with the thermofluid transport pipe made of resin and a bellows-shaped resin outer pipe that houses the pipe. Characteristic insulation piping material.