CN113566027A

CN113566027A - Heat-preservation, resistance-reduction and mute heat supply integrated pipeline, preparation method and application

Info

Publication number: CN113566027A
Application number: CN202110772146.8A
Authority: CN
Inventors: 吕健; 丁良玉; 王百提; 张礼涛; 梁哲楠; 张长伟
Original assignee: Zhejiang Zhongcai Pipes Science and Technology Co Ltd
Current assignee: Zhejiang Zhongcai Pipes Science and Technology Co Ltd
Priority date: 2021-07-08
Filing date: 2021-07-08
Publication date: 2021-10-29
Anticipated expiration: 2041-07-08
Also published as: CN113566027B

Abstract

The invention relates to the technical field of fluid transportation, and discloses a heat-preservation, resistance-reduction and mute heat-supply integrated pipeline, a preparation method and application, wherein the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline comprises an inner-layer working pipe and an outer-layer heat-preservation layer, the inner-layer working pipe comprises polyolefin and polyvinylpyrrolidone, the outer-layer heat-preservation layer comprises polyolefin and modified hollow glass microspheres, and the modified hollow glass microspheres comprise hollow glass microspheres and a silane coupling agent; by adding polyvinylpyrrolidone into the inner working pipe, the inner wall of the pipe can form a hydration layer after contacting with water for a period of time, so that turbulence between the water and the inner wall of the pipe is reduced, the time-average velocity gradient of fluid is increased, and the resistance reduction and the output increase of the pipeline are realized. The heat preservation of the pipeline is realized by adding the hollow glass microspheres in the heat preservation layer, so that the trouble that an outer protective layer is required to be arranged on the surface of the foaming material is avoided, and the integral forming of the pipeline is also realized.

Description

Heat-preservation, resistance-reduction and mute heat supply integrated pipeline, preparation method and application

Technical Field

The invention relates to the technical field of fluid conveying, in particular to a heat-preservation, resistance-reduction and mute heat-supply integrated pipeline, a preparation method and application.

Background

The central heating is a common phenomenon in many families, especially in the north, but one of the disadvantages of the central heating is that the hot water supply distance is too long, the heat loss of the hot water during the transportation process is serious, which not only wastes resources, but also reduces the user experience. To solve this problem, the heat-insulating property of the pipe is improved to reduce the heat transfer efficiency, and the flow rate of the hot water is increased to reduce the retention time of the hot water in the dead zone. The common heat insulation performance in the market is realized by the foaming material, but the heat insulation performance realized by the mode is difficult to realize integral forming. The flow rate of the hot water is increased by increasing the power of the water pump, but the method greatly increases the cost of heat supply and energy consumption, and often causes the noise generated by water flow to be too large, thereby reducing the user experience.

Chinese patent documents with publication number CN108266579A and publication number 2018, 07.10 disclose a high-density polyethylene polyurethane inner anti-drag heat preservation pipe, which comprises a working pipe, wherein the inner wall of the working pipe is coated with an anti-drag material layer, the outer layer of the working pipe is provided with a heat preservation layer, the outer layer of the heat preservation layer is provided with an outer heat preservation protection pipe, and an adhesion agent is arranged between the heat preservation layer and the outer heat preservation pipe. The novel anti-drag coating is used for the heat preservation pipe process, the height of the rough protrusions in the pipe wall is properly reduced, the smoothness of the wall surface is increased, pulsation generated due to the rough protrusions can be effectively reduced, and resistance reduction and increasing of the pipeline are achieved by increasing the time-average speed gradient of fluid. The shearing force of the resistance reducing material layer on the surface of the working pipe and the shearing force of the steel pipe structure are improved, the trinity of the integral structure of the directly-buried pipeline is guaranteed, the integral shearing strength of the directly-buried pipeline is guaranteed, and the oxidation resistance is improved. However, the heat preservation effect of the pipeline is realized by the high-density polyethylene polyurethane material layer, but the heat preservation performance of the material is inferior to that of a foaming material, in addition, the anti-drag effect of the pipeline is realized by coating an anti-drag coating on the inner wall of the pipeline, the coating anti-drag is not only complex in process, but also the uneven coating in the pipeline can cause the increase of resistance.

Disclosure of Invention

In order to solve the technical problem, the invention discloses a heat-preservation, resistance-reduction and mute heat-supply integrated pipeline, wherein an inner-layer working pipe of a pipe is obtained by blending polyolefin and polyvinylpyrrolidone; by adopting a super-infiltration drag reduction method, super-infiltration materials are added into the inner layer working pipe, a hydration layer is formed on the inner wall of the pipe after the inner wall of the inner layer working pipe is contacted with water for a period of time, turbulence between the water and the inner wall of the pipe is reduced, so that the time-average velocity gradient of fluid is increased, and drag reduction and delivery increase of the pipeline are realized. The heat preservation of the pipeline is realized by adding the modified hollow glass microspheres into the heat preservation layer, so that the trouble that an outer protective layer is required to be arranged on the surface of the foaming material is avoided, and the integral molding of the pipeline is realized; the invention also discloses a preparation method and application of the integrated pipeline.

The specific technical scheme of the invention is as follows: a heat preservation, resistance reduction and mute heat supply integrated pipeline comprises an inner layer working pipe and an outer layer heat preservation layer, wherein the inner layer working pipe comprises polyolefin and polyvinylpyrrolidone, the outer layer heat preservation layer comprises polyolefin and modified hollow glass microspheres, and the modified hollow glass microspheres comprise hollow glass microspheres and silane coupling agents; the inner working pipe and the outer heat-insulating layer are integrated into a whole pipeline.

The inner working pipe of the pipe is obtained by blending polyolefin and polyvinylpyrrolidone. After hot water is introduced into the inner layer working pipe, pyrrolidone groups in the pipe can gradually migrate to the water flowing side of the pipe due to the hydrophilic and oleophobic characteristics of the pyrrolidone groups, a polyethylene chain of polyvinylpyrrolidone is better in compatibility with polyolefin, the entanglement among molecular chains is more, the polyvinylpyrrolidone cannot migrate into water, a hydration layer can be formed after the pyrrolidone groups contacted with water are combined with the water, the generation of turbulence on the inner wall of the working pipe is reduced, the loss of water kinetic energy is reduced, the noise generated by the turbulence is reduced, the upper limit of flow rate under quiet use conditions is improved, meanwhile, impurities in water are difficult to attach to the inner wall of the pipe through the self-cleaning effect of the hydration layer, the cleanness of the inner wall of the pipe is maintained, the smoothness of the inner wall is also ensured, and the turbulence caused by the roughness of the inner wall of the pipe is avoided. And the problem that the hydrated layer is easy to form bacterial colony is solved because the pipe is a heat supply pipeline. The heat preservation effect of the pipe heat preservation layer is realized by uniformly dispersing hollow glass microspheres in polyolefin, but because the compatibility between the hollow glass microspheres and the polyolefin is poor, silane coupling agents are required to improve the compatibility between the hollow glass microspheres and the polyolefin, so that an effective heat preservation effect is obtained. The heat-insulating layer and the working pipe are combined together in a co-extrusion mode, and the main bodies of the materials of the heat-insulating layer and the working pipe are consistent, so that the binding force between layers is good through the co-extrusion of the obtained pipe, and an integrated pipe is formed.

Preferably, the inner working pipe is formed by blending polyolefin and polyvinylpyrrolidone, and the mass of the polyvinylpyrrolidone is 30-50% of that of the polyolefin; in the outer-layer heat-insulating layer, the mass of the modified hollow glass microspheres is 10-20% of that of the polyolefin, and the mass of the silane coupling agent is 0.4-0.8% of that of the hollow glass microspheres.

In the invention, the mass of the polyvinylpyrrolidone is 30-50% of that of the polyolefin and is the optimal addition amount of the polyvinylpyrrolidone, the pyrrolidone group of the polyvinylpyrrolidone can migrate to the water-passing side of the pipe due to the hydrophilic and oleophobic characteristics, the polyethylene chain of the polyvinylpyrrolidone has good compatibility with the polyolefin and more entanglement among molecular chains, so that the polyvinylpyrrolidone cannot migrate into water, and when the addition amount of the polyvinylpyrrolidone is less than 30%, the polyethylene chain compatible with the polyolefin as the main material of the pipe is less, so that the polyvinylpyrrolidone migrates into water; when the addition amount of the polyvinylpyrrolidone is more than 50 percent, the ring stiffness and the tensile strength of the pipe are obviously reduced.

Preferably, the polyolefin is one or more of heat-resistant non-crosslinked polyethylene, random copolymer polypropylene and high-density polyethylene; the polyvinylpyrrolidone is one or more of PVP-K15, PVP-K30 and PVP-K90.

Preferably, the preparation method of the modified hollow glass microsphere comprises the following steps:

(1) preparation of a coupling agent: mixing a silane coupling agent with water, adding ethanol until the silane coupling agent and the water are not layered obviously, adding hydrochloric acid, adjusting the pH of the mixed solution to 2-3, and stirring to obtain a coupling agent;

(2) surface treatment of hollow glass microspheres: mixing concentrated sulfuric acid and 30-40% of hydrogen peroxide in a mass ratio of 7-8: 2-3 to obtain a mixed solution, heating the mixed solution until bubbles are generated in the solution, adding hollow glass microspheres, stirring until no bubbles are generated on the surface, taking out the hollow glass microspheres, and cleaning to obtain surface-treated hollow glass microspheres;

(3) modified hollow glass microspheres: and (3) mixing and stirring the hollow glass microsphere subjected to surface treatment obtained in the step (2) and the coupling agent obtained in the step (1), and freeze-drying to obtain the modified hollow glass microsphere.

Preferably, in the step (1), the mass ratio of the silane coupling agent to the water is 0.5-1.5: 100, stirring the mixed solution for 1 to 2 hours.

Preferably, the silane coupling agent in the step (1) is one or more of n-octyltriethoxysilane, isooctyltriethoxysilane, gamma-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane and gamma-methacryloxypropyltrimethoxysilane.

Preferably, in the step (2), the heating temperature of the piranha solution is 70-80 ℃.

Preferably, in the step (3), the mixing and stirring time is 8-12 h.

A preparation method of the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline comprises the following steps:

(1) pipe extrusion: mixing polyolefin and polyvinylpyrrolidone to prepare raw material slurry of the inner working tube; mixing polyolefin and modified hollow glass microspheres to prepare raw material slurry of an outer-layer heat-insulating layer; co-extruding the inner working pipe raw material slurry and the outer heat-insulating layer raw material slurry to form an integrated pipeline;

(2) the tube works: soaking the integrated pipeline prepared in the step (1) in water at the temperature of 80-100 ℃ until the inner wall of the pipe begins to become smooth, and thus obtaining the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline.

An application of the heat-preservation, resistance-reduction and mute heat supply integrated pipeline or the integrated pipeline obtained by preparing the pipeline in a heat supply system.

Compared with the prior art, the invention has the beneficial effects that:

(1) the pipeline has the functions of better heat preservation, resistance reduction, pressure boosting, self-cleaning and the like, reduces the heat energy loss of hot water in the conveying process, improves the flow speed of the hot water under the condition of the same power, and reduces the problems of flow reduction and the like caused by scale accumulation;

(2) the modified hollow glass microspheres are added into the heat insulation layer to realize heat insulation of the pipeline, so that the problem that an outer protective layer is required to be arranged on the surface of the foaming material is solved, the pipeline is integrally formed, and the cost of raw materials is saved;

(3) the raw materials can be blended and added, secondary processing is not needed, and the processing cost is saved.

Drawings

FIG. 1 is a graph showing the change of the contact angle of the inner wall of the pipe after being soaked in water of different temperatures in example 1 of the present invention;

FIG. 2 is a graph of the thermal conductivity of different pipe insulation layers;

FIG. 3 is a graph showing the flow velocity of water flowing through different pipes with a pipe diameter of 25mm by 100m under the same power condition;

FIG. 4 is a water temperature chart after different pipes with the pipe diameter of 25mm flow through 100m under the same power condition;

FIG. 5 is a decibel chart of noise for different pipes with a pipe diameter of 25mm at a flow rate of 1.2 m/s.

Detailed Description

The present invention will be further described with reference to the following examples. The devices, connections, and methods referred to in this disclosure are those known in the art, unless otherwise indicated.

General examples

A heat preservation, resistance reduction and mute heat supply integrated pipeline comprises an inner layer working pipe and an outer layer heat preservation layer, and is characterized in that the inner layer working pipe is formed by blending polyolefin and polyvinylpyrrolidone, and the mass of the polyvinylpyrrolidone is 30-50% of that of the polyolefin; the outer-layer heat-insulating layer comprises polyolefin and modified hollow glass microspheres, and the modified hollow glass microspheres comprise hollow glass microspheres and a silane coupling agent; the modified hollow glass microspheres account for 10-20% of the polyolefin, the silane coupling agent accounts for 0.4-0.8% of the hollow glass microspheres, and the inner working pipe and the outer heat-insulating layer are integrated into a whole pipeline.

The polyolefin is one or more of polyolefin, polypropylene random copolymer and high-density polyethylene; the polyvinylpyrrolidone is one or more of PVP-K15, PVP-K30 and PVP-K90.

The preparation method of the modified hollow glass microsphere comprises the following steps:

(1) preparation of a coupling agent: mixing a silane coupling agent and water according to a mass ratio of 0.5-1.5: 100, adding ethanol until no obvious layering exists between the silane coupling agent and water, adding hydrochloric acid, adjusting the pH value of the mixed solution to 2-3, and stirring for 1-2 hours to obtain the coupling agent;

(2) surface treatment of hollow glass microspheres: mixing concentrated sulfuric acid and 30-40% of hydrogen peroxide in a mass ratio of 7-8: 2-3 to obtain a mixed solution, heating the mixed solution at 70-80 ℃ until bubbles are generated in the solution, adding hollow glass microspheres, stirring until no bubbles are generated on the surface, taking out the hollow glass microspheres, and cleaning to obtain surface-treated hollow glass microspheres;

(3) modified hollow glass microspheres: and (3) mixing and stirring the surface-treated hollow glass microspheres obtained in the step (2) and the coupling agent obtained in the step (1) for 8-12 h, and freeze-drying to obtain the modified hollow glass microspheres.

The silane coupling agent in the step (1) is one or more of n-octyl triethoxysilane, isooctyl triethoxysilane, gamma-aminopropyl triethoxysilane, gamma-glycidyl ether oxypropyl trimethoxysilane and gamma-methacryloxypropyl trimethoxysilane.

Example 1:

the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline comprises an inner-layer working pipe and an outer-layer heat-preservation layer, and is characterized in that the inner-layer working pipe is formed by blending heat-resistant non-crosslinked polyethylene and PVP-K15, and the mass of the PVP-K15 is 30% of that of the heat-resistant non-crosslinked polyethylene; the outer-layer heat-insulating layer comprises heat-resistant non-crosslinked polyethylene and modified hollow glass microspheres, and the modified hollow glass microspheres comprise hollow glass microspheres and n-octyl triethoxysilane; the mass of the modified hollow glass microsphere is 10% of that of the heat-resistant non-crosslinked polyethylene, the mass of the n-octyl triethoxysilane is 0.4% of that of the hollow glass microsphere, and the inner working pipe and the outer heat-insulating layer are integrated into a pipeline.

(1) preparation of a coupling agent: mixing n-octyl triethoxysilane and water according to a mass ratio of 1: 100, adding ethanol until n-octyl triethoxysilane is not obviously layered with water, adding hydrochloric acid, adjusting the pH of the mixed solution to 2, and stirring for 2 hours to obtain a coupling agent;

(2) surface treatment of hollow glass microspheres: mixing concentrated sulfuric acid and 30% hydrogen peroxide in a weight ratio of 7: 3 to obtain a mixed solution, heating the mixed solution at 80 ℃ until bubbles are generated in the solution, adding the hollow glass microspheres, stirring until no bubbles are generated on the surface, taking out the hollow glass microspheres, and cleaning to obtain surface-treated hollow glass microspheres;

(3) modified hollow glass microspheres: and (3) mixing and stirring the hollow glass microsphere subjected to surface treatment obtained in the step (2) and the coupling agent obtained in the step (1) for 10 hours, and freeze-drying to obtain the modified hollow glass microsphere.

(1) pipe extrusion: mixing heat-resistant non-crosslinked polyethylene with PVP-K15 to prepare raw material slurry of the inner-layer working tube; mixing heat-resistant non-crosslinked polyethylene and modified hollow glass microspheres to prepare raw material slurry of an outer-layer heat-insulating layer; co-extruding the inner working pipe raw material slurry and the outer heat-insulating layer raw material slurry to form an integrated pipeline;

(2) the tube works: soaking the integrated pipeline prepared in the step (1) in water at 80 ℃ until the inner wall of the pipe begins to become smooth, thus obtaining the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline.

Example 2:

the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline comprises an inner-layer working pipe and an outer-layer heat-preservation layer, and is characterized in that the inner-layer working pipe is formed by blending high-density polyethylene and PVP-K30, and the mass of the PVP-K30 is 50% of that of the high-density polyethylene; the outer-layer heat-insulating layer comprises polyolefin and modified hollow glass microspheres, and the modified hollow glass microspheres comprise hollow glass microspheres and isooctyl triethoxysilane; the mass of the modified hollow glass microspheres is 20% of that of the high-density polyethylene, the mass of the isooctyl triethoxysilane is 0.8% of that of the modified hollow glass microspheres, and the inner working pipe and the outer heat-insulating layer are integrated into a pipeline.

(1) preparation of a coupling agent: mixing isooctyl triethoxysilane with water at a mass ratio of 0.5: 100, adding ethanol until no obvious layering exists between isooctyltriethoxysilane and water, adding hydrochloric acid, adjusting the pH of the mixed solution to 3, and stirring for 1h to obtain a coupling agent;

(2) surface treatment of hollow glass microspheres: mixing concentrated sulfuric acid and 35% hydrogen peroxide in a weight ratio of 8: 2 to obtain a mixed solution, heating the mixed solution at 70 ℃ until bubbles are generated in the solution, adding the hollow glass microspheres, stirring until no bubbles are generated on the surface, taking out the hollow glass microspheres, and cleaning to obtain surface-treated hollow glass microspheres;

(3) modified hollow glass microspheres: and (3) mixing and stirring the hollow glass microsphere subjected to surface treatment obtained in the step (2) and the coupling agent obtained in the step (1) for 8 hours, and freeze-drying to obtain the modified hollow glass microsphere.

(1) pipe extrusion: mixing high-density polyethylene and PVP-K30 to prepare raw material slurry of the inner-layer working tube; mixing polyolefin and modified hollow glass microspheres to prepare raw material slurry of an outer-layer heat-insulating layer; co-extruding the inner working pipe raw material slurry and the outer heat-insulating layer raw material slurry to form an integrated pipeline;

(2) the tube works: soaking the integrated pipeline prepared in the step (1) in water at 90 ℃ until the inner wall of the pipe begins to become smooth, and obtaining the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline.

Example 3:

the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline comprises an inner-layer working pipe and an outer-layer heat-preservation layer, and is characterized in that the inner-layer working pipe is formed by blending random copolymerization polypropylene and PVP-K90, wherein the mass of the PVP-K90 is 40% of that of the random copolymerization polypropylene; the outer-layer heat-insulating layer comprises random copolymer polypropylene and modified hollow glass microspheres, and the modified hollow glass microspheres comprise hollow glass microspheres and gamma-aminopropyltriethoxysilane; the mass of the modified hollow glass microspheres is 15% of that of the polyolefin, the mass of the gamma-aminopropyl triethoxysilane is 0.5% of that of the modified hollow glass microspheres, and the inner working pipe and the outer heat-insulating layer are integrated into a pipeline.

(1) preparation of a coupling agent: mixing gamma-aminopropyltriethoxysilane with water according to a mass ratio of 1.5: 100, adding ethanol until gamma-aminopropyltriethoxysilane does not obviously layer with water, adding hydrochloric acid, adjusting the pH of the mixed solution to 2, and stirring for 2 hours to obtain a coupling agent;

(2) surface treatment of hollow glass microspheres: mixing concentrated sulfuric acid and 40% hydrogen peroxide in a weight ratio of 7: 3 to obtain a mixed solution, heating the mixed solution at 75 ℃ until bubbles are generated in the solution, adding the hollow glass microspheres, stirring until no bubbles are generated on the surface, taking out the hollow glass microspheres, and cleaning to obtain surface-treated hollow glass microspheres;

(3) modified hollow glass microspheres: and (3) mixing and stirring the hollow glass microsphere subjected to surface treatment obtained in the step (2) and the coupling agent obtained in the step (1) for 12 hours, and freeze-drying to obtain the modified hollow glass microsphere.

(1) pipe extrusion: mixing the random copolymerization polypropylene with PVP-K90 to prepare raw material slurry of the inner layer working tube; mixing the random copolymerization polypropylene and the modified hollow glass microspheres to prepare raw material slurry of an outer-layer heat-insulating layer; co-extruding the inner working pipe raw material slurry and the outer heat-insulating layer raw material slurry to form an integrated pipeline;

(2) the tube works: soaking the integrated pipeline prepared in the step (1) in water at 100 ℃ until the inner wall of the pipe begins to become smooth, thus obtaining the heat-preservation, resistance-reduction and mute heat-supply integrated pipeline.

Comparative example 1:

the comparative example of the invention is a conventional heat-supplying polyolefin pipe.

Comparative example 2:

the invention of comparative example 2 is a commercial insulating pipe with foamed LDPE as the insulating layer and polyolefin as the working pipe.

Comparative example 3:

comparative example 3 is different from example 1 in that polyvinylpyrrolidone is added in an amount of 25% by mass based on the heat-resistant non-crosslinked polyethylene, and other raw materials and processes are the same as those of example 1.

Comparative example 4:

comparative example 4 is different from example 1 in that polyvinylpyrrolidone is added in an amount of 55% by mass based on the heat-resistant non-crosslinked polyethylene, and other raw materials and processes are the same as those of example 1.

Test example

1 contact angle of inner wall of working layer

The pipes obtained in example 1 were soaked in hot water at different temperatures for different periods of time to obtain contact angles, and the results are shown in table 1.

TABLE 1

As can be seen from fig. 1 and table 1, the contact angle of the inner wall of the pipe decreases significantly with the increase of the water temperature, the contact angle of the pipe decreases with the migration of the pyrrolidone groups to the inner wall of the pipe, and the migration rate of the groups becomes more significant with the increase of the temperature and the time.

2 thermal conductivity of the insulating layer

The pipe insulating layers obtained in example 1 and comparative examples 1 to 2 were subjected to a thermal conductivity test, and the results are shown in table 2.

TABLE 2

	Thermal conductivity (W/(m.K))
		Example 1	0.056
Comparative example 1	0.420
		Comparative example 2	0.044

As can be seen from fig. 2 and table 2: the heat conductivity coefficient of the heat-insulating layer added with the modified hollow glass microspheres is obviously reduced, the difference of the heat conductivity coefficient is not large compared with that of a foaming material, the hollow glass microspheres replace bubbles in the foaming material with the hollow characteristic, the heat conductivity of the heat-insulating material is reduced, and more hollow glass microspheres can be added for improving the heat-insulating property.

3 flow rate of insulating pipe

The pipe insulation layers obtained in example 1 and comparative examples 1-2 were subjected to a thermal conductivity test, and the results are shown in table 3.

TABLE 3

	Flow velocity (m/s)
		Example 1	1.18
Comparative example 1	0.96
		Comparative example 2	0.92
Comparative example 3	0.98
		Comparative example 4	1.02

As can be seen from fig. 3 and table 3: under the same power condition, namely the same water pump is used, after 100m, the water flow velocity can be seen, and the flow velocity of the common heat supply pipeline and the heat preservation pipe is obviously lower than that of the heat preservation, resistance reduction and mute heat supply integrated pipeline. After hot water is introduced into the working pipe, the pyrrolidone group in the pipe can gradually migrate to the water-passing side of the pipe due to the hydrophilic and oleophobic characteristics, the polyethylene chain of the polyvinylpyrrolidone has good compatibility with polyolefin, the entanglement among molecular chains is more, the polyethylene chain cannot migrate into water, the pyrrolidone group contacted with water can form a hydration layer after being combined with the water, the generation of turbulence on the inner wall of the working pipe is reduced, the loss of water kinetic energy is reduced, and the upper limit of the flow rate under quiet use conditions is improved.

Comparison between comparative example 3 and comparative example 4 and example 1 shows that the addition amount of polyvinylpyrrolidone is 30-50% of the heat-resistant non-crosslinked polyethylene as the optimum addition amount, this is because the pyrrolidone group of polyvinylpyrrolidone migrates to the water-passing side of the pipe due to its hydrophilic and oleophobic properties, the compatibility of the polyvinyl chain of the polyvinylpyrrolidone and the polyolefin is better, the entanglement among molecular chains is more, so that the polyvinylpyrrolidone can not migrate into water, when the addition amount of the polyvinylpyrrolidone is less than 30%, the polyethylene chains compatible with the polyolefin of the main material of the pipe are less, the entanglement among the molecular chains is less, the polyvinylpyrrolidone migrates into water, and in addition, the pyrrolidone group migrating into the water is less, so that the formation of a hydration layer is not facilitated, the formation of the hydration layer is the key to reducing the water flow energy loss and increasing the upper flow rate limit under quiet conditions.

4 temperature change of insulating pipe

The water temperatures after passing 100m for different pipes having a pipe diameter of 25mm obtained in example 1 and comparative examples 1-2 under the same power are shown in Table 4.

TABLE 4

	Initial temperature (. degree. C.)	Temperature after 100m (. degree. C.)
			Example 1	91	81
Comparative example 1	91	86
			Comparative example 2	91	87

As can be seen from fig. 4 and table 4: the change rate of the water temperature change heat preservation, drag reduction and mute heat supply integrated pipeline after different pipes with the pipe diameter of 25mm flow through 100m is that the water temperature loss is less under the same length due to the excellent heat preservation performance and the reduction of the water flow resistance.

Noise decibel of 5 insulating tube

The decibels of noise of the different pipes with a pipe diameter of 25mm at a flow rate of 1.2m/s obtained for example 1 and comparative examples 1-2 are given in Table 5.

TABLE 5

	Noise decibel (dB)
		Example 1	59.6
Comparative example 1	23.5
		Comparative example 2	16.5
Comparative example 3	25.6
		Comparative example 4	24.3

As can be seen from fig. 5 and table 5: under the condition of the flow velocity of 1.2m/s, the noise of the heat-preservation, drag-reduction and mute heat-supply integrated pipeline in noise decibels of different pipes with the pipe diameter of 25mm is obviously lower, because the hydration layer enables the turbulence phenomenon of the pipeline to be less, and the conversion of kinetic energy to vibration is reduced.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A heat preservation, resistance reduction and mute heat supply integrated pipeline comprises an inner layer working pipe and an outer layer heat preservation layer, and is characterized in that the inner layer working pipe comprises polyolefin and polyvinylpyrrolidone, the outer layer heat preservation layer comprises polyolefin and modified hollow glass microspheres, and the modified hollow glass microspheres comprise hollow glass microspheres and silane coupling agent; the inner working pipe and the outer heat-insulating layer are integrated into a whole pipeline.

2. The heat-insulating, drag-reducing and mute heat supply integrated pipeline as claimed in claim 1, wherein the inner layer working pipe is formed by blending polyolefin and polyvinylpyrrolidone, and the mass of the polyvinylpyrrolidone is 30-50% of that of the polyolefin; in the outer-layer heat-insulating layer, the mass of the modified hollow glass microspheres is 10-20% of that of the polyolefin, and the mass of the silane coupling agent is 0.4-0.8% of that of the hollow glass microspheres.

3. The heat-insulating, drag-reducing and noise-reducing heat-supplying integrated pipeline as claimed in claim 1, wherein the polyolefin is one or more of heat-resistant non-crosslinked polyethylene, random copolymer polypropylene and high-density polyethylene; the polyvinylpyrrolidone is one or more of PVP-K15, PVP-K30 and PVP-K90.

4. The heat-insulating, drag-reducing and silencing heat-supplying integrated pipeline as claimed in claim 1, wherein the preparation method of the modified hollow glass microsphere comprises the following steps:

5. The heat-preservation, drag-reduction and mute heat-supply integrated pipeline as claimed in claim 4, wherein the mass ratio of the silane coupling agent to water in the step (1) is 0.5-1.5: 100, stirring the mixed solution for 1 to 2 hours.

6. The heat-preserving, drag-reducing, and noise-reducing heat-supplying integrated pipeline as claimed in claim 4, wherein the silane coupling agent in step (1) is one or more of n-octyltriethoxysilane, isooctyltriethoxysilane, γ -aminopropyltriethoxysilane, γ -glycidoxypropyltrimethoxysilane, and γ -methacryloxypropyltrimethoxysilane.

7. The heat-preserving, drag-reducing and noise-reducing heat-supplying integrated pipeline as claimed in claim 4, wherein in the step (2), the heating temperature of the piranha solution is 70-80 ℃.

8. The heat-insulating, drag-reducing and noise-reducing heat supply integrated pipeline as claimed in claim 4, wherein in the step (3), the mixing and stirring time is 8-12 h.

9. The preparation method of the heat-preservation, drag-reduction and mute heat-supply integrated pipeline as claimed in any one of claims 1 to 8, characterized by comprising the following steps:

10. Use of the heat-insulating, drag-reducing, silent heat-supplying integrated pipe according to any one of claims 1 to 8 or the integrated pipe obtained by manufacturing the pipe according to claim 9 in a heat-supplying system.