JP7053002B2 - A heat exchange system equipped with heat exchange piping and a method for manufacturing a heat exchange mat. - Google Patents

Description

The present invention is a heat exchange system provided with a heat exchange pipe for flowing a heat exchange medium for heat exchange with a fluid flowing in an existing pipe buried in the ground, and a heat exchange provided with a heat exchange pipe. Regarding the manufacturing method of mats.

In recent years, the fluid flowing through existing pipes buried in the ground (for example, sewage pipes, waterworks pipes, agricultural waterway pipes, industrial waterway pipes, etc.) has little seasonal fluctuation with respect to the outside air temperature. A heat exchange system has been developed that uses heat energy to exchange heat by utilizing the temperature difference with a fluid (for example, water having a temperature close to the outside air temperature).

For example, in Patent Document 1, a heat collection tube extending in the pipe axis direction is arranged on the outer peripheral surface of a sewage pipe buried in the ground, and between the sewage flowing in the sewage pipe and the heat exchange medium flowing through the heat collection pipe. A sewage heat utilization system that utilizes sewage heat by performing heat exchange is described. In this sewage heat utilization system, since the heat sampling tube does not come into direct contact with the sewage, there is an effect that maintenance is not required and the maintenance cost can be reduced.

However, since the heat exchange medium flowing through the heat collection tube exchanges heat with the sewage through the sewage pipe, the heat exchange rate becomes low.

In order to improve the heat exchange rate, a heat exchange system in which a heat sampling tube is arranged inside a sewer pipe has been developed. For example, Patent Document 2 describes a sewage heat utilization system in which a plurality of heat exchange channels are provided inside a rehabilitating material that covers the inner circumference of a sewage pipe. In this sewage heat utilization system, the rehabilitation material and the heat exchange flow path are integrally formed of the resin material.

Japanese Unexamined Patent Publication No. 2008-241226 Japanese Unexamined Patent Publication No. 2013-148314

In the sewage heat utilization system described in Patent Document 2, the heat exchange flow path and the rehabilitation material are formed of a resin material that is more flexible than the metal material, so that the structure has excellent workability and durability. be able to.

However, the resin material has a problem that the thermal conductivity is lower than that of the metal material. Therefore, there has been a demand for a structure capable of increasing the heat exchange rate even when a material having a relatively low thermal conductivity such as a resin material is used for the heat exchange flow path.

The present invention has been made in view of the above problems, and even if the flow path of the heat exchange medium is made of a material having a relatively low thermal conductivity, the heat exchange medium and the fluid flowing through the existing pipe can be used. It is an object of the present invention to provide a heat exchange system provided with a heat exchange pipe capable of improving the heat exchange rate between them, and a method for manufacturing a heat exchange mat provided with the heat exchange pipe .

In order to achieve the above object, the heat exchange system according to claim 1 is used.
Existing pipes buried in the ground and
A heat exchange pipe fixed to the inner wall of the existing pipe is provided.
In a heat exchange system that exchanges heat between the fluid flowing in the existing pipe and the heat exchange medium flowing in the heat exchange pipe.
A heat exchange mat formed by arranging a plurality of heat exchange pipes in parallel in a mat shape,
A fixing member for pressing and fixing the heat exchange mat against the inner wall of the existing pipe is provided.
The heat exchange mat has a concavo-convex surface in which a plurality of the heat exchange pipes having a substantially circular cross section are arranged in parallel so that a flow path is formed in the extension direction of the existing pipe, and arcs are continuous in the width direction. The heat exchange pipe is made of a material that enhances the heat transfer performance between the heat exchange medium and the fluid and is different from the flow path of the heat exchange medium, at least on the surface on the side where the fluid flows. Has a coating layer composed of
The coating layer is made of a material having a higher heat transfer coefficient than the heat exchange pipe, and is formed in a substantially arc shape in cross section along the arcuate surface of the heat exchange pipe.
The fixing member is characterized in that it is attached in a state of being in contact with the top of each heat exchange pipe constituting the heat exchange mat via the coating layer .

According to this configuration, the coating layer formed on the surface of the heat exchange mat can enhance the heat transfer performance between the heat exchange medium flowing through the heat exchange pipe and the fluid flowing through the existing pipe. In addition, since a heat exchange mat formed by arranging multiple heat exchange pipes in parallel in a mat shape is used, the heat exchange rate is high, and the construction is performed compared to the one in which multiple heat exchange pipes are individually arranged. It can be a heat exchange system with excellent properties.

According to this configuration, the heat transferred from the fluid flowing through the existing pipe to the heat exchange pipe via the fixing member and the coating layer is used not only for the top of the heat exchange pipe but also for heat exchange by the coating layer having an arcuate cross section. It can be quickly transmitted over a wide area of the surface of the pipe, and as a result, the heat exchange rate between the fluid and the heat exchange medium can be improved.

Further, the method for manufacturing the heat exchange mat according to claim 2 is as follows.
A heat exchange mat formed by arranging a plurality of heat exchange pipes in parallel in a mat shape, and is fixed to the inner wall of an existing pipe buried in the ground and flows through the heat exchange pipe. A method for manufacturing a heat exchange mat used in a heat exchange system that exchanges heat with a fluid flowing through an existing pipe.
A pipe bundle forming process for forming a pipe bundle made of a resin material in which a plurality of heat exchange pipes connected in parallel are connected.
A primary cooling step of primary cooling the high-temperature pipe bundle after the pipe bundle forming step to a predetermined temperature, and a primary cooling step.
A coating layer forming step of applying a paint having a heat absorption rate and / or a heat transfer coefficient higher than that of the resin material to the surface of the pipe bundle to form a coating layer.
A curing step of secondary cooling and curing of the pipe bundle on which the coating layer is formed, and
Including
The paint is characterized in that it is applied to the surface of the pipe bundle that has been frame-treated or plasma-treated, or the surface of the pipe bundle that has been heated to a predetermined temperature.

According to this configuration, the adhesiveness of the coating layer to the pipe bundle can be improved by applying the paint forming the coating layer on the surface of the pipe bundle made of the resin material in a heated state.

According to this configuration, after the pipe bundle is integrally molded, the pipe bundle is brought into a predetermined heating state by primary cooling, a paint is applied to the pipe bundle to form a coating layer, and then the molded product is cured by secondary cooling. Therefore, it is not necessary to separately provide a heating device for forming the coating layer, and the coating layer can be formed during the process of integrally molding and curing the pipe bundle, so that the manufacturing cost can be suppressed. can.

The invention according to claim 3 is the method for manufacturing a heat exchange mat according to claim 2 .
In the coating layer forming step,
The coating material is a mixture of a powder body containing silicon carbide and / or a carbon nanotube material and a molten material, and is characterized in that the coating material is applied to the surface of the pipe bundle by brushing, spraying, or dipping coating. ..

According to this configuration, the heat absorption performance of the heat exchange mat can be improved, and the heat exchange rate between the fluid flowing through the existing pipe and the heat exchange medium flowing in the heat exchange mat can be improved. ..

INDUSTRIAL APPLICABILITY According to the present invention, a heat exchange pipe having a high heat exchange rate, a heat exchange mat provided with a heat exchange pipe, a heat exchange system provided with a heat exchange pipe, and a method for manufacturing a heat exchange mat are provided. be able to.

The schematic which shows typically the heat exchange system which is 1st Embodiment of this invention. (A) is a sectional view taken along line II-II of FIG. (B) is an enlarged cross-sectional view of a region surrounded by b in FIG. 2 (a). FIG. 2 is a cross-sectional view similar to FIG. 2, which schematically shows a heat exchange system according to a second embodiment of the present invention. Schematic diagram of the heat exchange mat developed in the circumferential direction of the pipe. FIG. 4 is a sectional view taken along line VV of FIG. Explanatory drawing of the manufacturing process of a heat exchange mat. Explanatory drawing of the manufacturing process of a heat exchange mat. FIG. 2A is a cross-sectional view similar to FIG. 2A showing a modification 1 of the heat exchange mat. FIG. 2A is a cross-sectional view similar to FIG. 2A showing a modification 2 of the heat exchange mat.

(First Embodiment)
FIG. 1 is a schematic diagram schematically showing a heat exchange system according to a first embodiment of the present invention. The heat exchange system 10 is applied to a sewer pipe 70, which is an existing pipe buried in the ground. The sewer pipe 70 is arranged between two manholes 72 and 74, and communicates the two manholes 72 and 74. The heat exchange system 10 includes a plurality of heat exchange pipes 20, a rehabilitation pipe 30 as a fixing member for fixing the heat exchange pipe 20 to the sewage pipe 70, and a heat pump unit 40. In FIG. 1, the description of the sewage pipe 70 and the sewage 78 in the manholes 72 and 74 is omitted.

A plurality of heat exchange pipes 20 extend in the pipe axis direction of the sewer pipe 70 and are arranged side by side in the circumferential direction of the sewer pipe 70. As shown in FIG. 2, the heat exchange pipe 20 has a hollow flow path pipe 22 and a coating layer 25 formed on the surface of the flow path pipe 22.

The flow path tube 22 is a cylindrical body through which a heat exchange medium can flow, and its cross-sectional shape can be appropriately set to be circular, elliptical, polygonal, or the like. The thickness and material of the flow path tube 22 are not particularly limited, but are flexible materials having strength and durability that can withstand internal and external pressures, such as PP resin, PBT resin, PET resin, PE resin, and rubber. A resin material such as a material is preferably used.

The coating layer 25 is formed on the outer peripheral surface 22a of the flow path pipe 22 and at least on the surface on the side where the sewage 78 flows. In the present embodiment, the entire outer peripheral surface of the heat exchange pipe 20 is the coating layer 25. It is covered.

The coating layer 25 is made of a material having a higher heat absorption rate (that is, a rate of absorption against heat radiation) and / or a higher thermal conductivity than the flow path tube 22. In the present embodiment, the coating layer 25 contains at least one of silicon carbide and carbon nanotubes so that both the heat absorption rate and the thermal conductivity are higher than those of the resin flow path tube 22. It is composed of materials. Further, in order to enhance the heat absorption performance, the color of the coating layer 25 is preferably a color having low heat reflectivity, particularly black. Further, the coating layer 25 of the present embodiment contains a binder resin (for example, a polyolefin resin or the like) for the flow path tube 22. The thickness of the coating layer 25 is preferably about 0.8 to 45 μm, more preferably about 5 to 15 μm. Generally, the layer thickness of the surface coating is 20 μm or more, but by making the layer thickness thinner than this, high heat absorption performance can be obtained while suppressing a decrease in thermal conductivity. Although not shown, a sealer (undercoat coating) may be provided between the heat exchange pipe 20 and the coating layer 25 to improve the adhesion and adhesion of the coating layer 25.

In the present embodiment, the outward path and the return path of the heat exchange medium are each formed by four heat exchange pipes 20, but the number of heat exchange pipes 20 is not limited to this and can be appropriately selected. Although not shown, each heat exchange pipe 20A serving as an outward route is connected to each heat exchange pipe 20B serving as a return route via a connecting pipe. Specifically, the tip of the heat exchange pipe 20A which is the outward path (that is, the end on the manhole 74 side) is connected to one end of the U-shaped connecting pipe, and the other end of the connecting pipe is the return path. It is connected to the tip of the heat exchange pipe 20B (the end on the manhole 74 side). Instead of using the connecting pipe, the heat exchange pipe may be folded back in a curve so that the outward path and the return path are formed by a series of heat exchange pipes 20.

The heat exchange pipe 20 is pressed and fixed to the inner wall surface side of the sewer pipe 70 by the rehabilitation pipe 30 that covers the inner peripheral surface of the sewer pipe 70. In the example shown in FIG. 2, a plurality of parallel heat exchange pipes 20 are included in a mat material 28 made of a synthetic resin such as a thermoplastic resin to form a heat exchange mat. Each heat exchange pipe 20 is in a state where a part is exposed from the mat material 28, specifically, a state where the surface on the side where the sewage 78 flows is exposed, and the exposed portion 29 comes into contact with the rehabilitation pipe 30. ing. The coating layer 25 is a material having a higher thermal absorption rate and / or thermal conductivity than the matte material 28. Further, in the present invention, the mat material 28 can be omitted.

The heat exchange medium flowing in the heat exchange pipe 20 is not particularly limited, and for example, water or a mixture of water and alcohol or ethylene glycol (antifreeze) can be used.

The rehabilitation pipe 30 is a tubular body provided over the entire inner peripheral surface of the sewer pipe 70, and is formed of a lining material for rehabilitation of the existing pipe. The lining material is a conventionally used lining material, for example, a lining material made of a tubular curable resin body in which a fiber base material (for example, a non-woven fabric such as a glass fiber mat or felt) is impregnated with a curable resin composition. Can be used. This lining material is, for example, drawn into the sewage pipe 70 in an uncured state, pressed against the inner wall of the sewage pipe 70 by compressed air to form a tubular shape, and in this state, the photocurable resin composition is irradiated with light. In the case of a thermosetting resin composition, it can be cured by heating to form a rehabilitation tube 30. As the lining material, a lining material having an inner film and an outer film that protects the inner and outer surfaces of the tubular material can be used, if necessary. As the inner film and the outer film, for example, a polyethylene film, a polypropylene film, a polyethylene terephthalate film and the like can be used. The inner film may be peeled off after the lining material is cured.

The base end portion of each heat exchange pipe 20 is connected to the pipe 45 via a connecting member (not shown). Specifically, the base end portion of the heat exchange pipe 20 that is the outward path is connected to one end of the pipe 45 via a connecting member, and the base end portion of the heat exchange piping 20 that is the return path is connected via the connecting member. Is connected to the other end of the pipe 45. The pipe 45 is arranged so as to pass through the first heat exchanger 41 of the heat pump unit 40.

The heat pump unit 40 includes a compressor that compresses the refrigerant, a first heat exchanger 41, an expansion valve that expands the refrigerant, a second heat exchanger 42, and a refrigerant pipe 43 through which the refrigerant circulating thereof flows. .. Further, the heat pump unit 40 includes a changeover switch that switches the circulation direction of the refrigerant to switch between heating (heating) and cooling (cooling). The refrigerant circulates in the heat pump unit 40 through the refrigerant pipe 43 forming a closed loop, and undergoes a thermal cycle of evaporation, compression, condensation, and expansion. The pipe 45 passes through the first heat exchanger 41, and in the first heat exchanger 41, heat exchange is performed between the heat exchange medium passing through the pipe 45 and the refrigerant. The second heat exchanger 42 constitutes, for example, an indoor unit of an air conditioner, and exchanges heat between the refrigerant and the indoor air.

In the heat exchange system 10 described above, the heat exchange medium is from the pipe 45 passing through the first heat exchanger 41 to the heat exchange pipe 20A for the outward route, the U-shaped connecting pipe, and the heat exchange pipe 20B for the return route. The heat exchange medium collects sewage heat in the heat exchange pipes 20A and 20B while circulating through the circulation pipe that returns to the pipe 45 again.

In particular, in the heat exchange system 10 of the present embodiment, since the coating layer 25 having high heat absorption rate and heat conductivity is provided on the surface of the heat exchange pipe 20, the flow path tube 22 has more heat than the metal. Even if it is made of a resin material with low conductivity, it can absorb a large amount of heat energy from the sewage 78 and quickly transfer it to the surface of the heat exchange pipe 20, and as a result, the sewage 78 and the heat exchange medium It is possible to improve the heat transfer performance between them and improve the heat exchange rate. Further, since the coating layer 25 is made of a material having a higher thermal conductivity than the flow path tube 22, the heat energy transmitted to the heat exchange pipe 20 via the rehabilitation tube 30 is transferred to the surface of the flow path tube 22. It can be quickly transmitted to the whole to further improve the heat exchange rate between the sewage 78 and the heat exchange medium.

Further, since the plurality of heat exchange pipes 20 are integrated by the mat material 28, the workability is excellent as compared with the one in which the plurality of heat exchange pipes 20 are individually arranged in the sewage pipe 70. .. Further, since the heat exchange pipe 20 is fixed to the inner wall of the sewer pipe 70 over the entire area in the extending direction by the rehabilitation pipe 30, the fixed state is stable. Further, since the heat exchange pipe 20 does not come into direct contact with the sewage 78, maintenance can be eliminated and the maintenance cost can be reduced.

(Second embodiment)
The heat exchange system 10 according to the second embodiment of the present invention will be described with reference to FIGS. 3 to 5. FIG. 3 is a cross-sectional view similar to FIG. 2, schematically showing the heat exchange system 10 according to the second embodiment of the present invention. In FIGS. 3 to 5, the parts corresponding to the first embodiment are designated by the same reference numerals. In the second embodiment described below, detailed description of the same configuration as that of the first embodiment will be omitted.

In the present embodiment, the heat exchange mat 50 is laid in the sewer pipe 70. The heat exchange mat 50 is formed by connecting a plurality of heat exchange pipes 52 in parallel in the width direction to form a mat. Specifically, as shown in FIGS. 4 and 5, the heat exchange pipe 52A constituting the outward path of the heat exchange medium and the heat exchange pipe 52B constituting the return path of the heat exchange medium via the joint member 58. These heat exchange pipes 52 are integrally molded from the same material, and are formed into a thick long flat plate having flexibility as a whole. Further, as shown in FIGS. 3 and 5, the heat exchange mat 50 has a coating layer 55 on the surface facing the sewage at least in a state of being installed in the sewage pipe 70.

The heat exchange pipe 52 is formed of, for example, a PP resin, a PBT resin, a PET resin, a PE resin, a rubber material, or the like. In the present embodiment, the outward path and the return path of the heat exchange medium are each formed by nine heat exchange pipes 52, but the number is not limited to this, and each of the outward path and the return path is one or more, that is, the outward path. It suffices to be composed of two or more heat exchange pipes 52 in total for the return path and the return path. Further, in the illustrated example, the cross section of the heat exchange pipe 52 is not limited to a circular one, and may be an elliptical shape, a polygonal shape, or a tubular body capable of circulating the heat exchange medium. In order to increase the surface area of the heat exchange mat 50, it is preferable that the surface on the side facing the sewage is formed in an uneven shape, and in the present embodiment, the surface is formed in a plurality of arcuate shapes in the width direction. ing.

The coating layer 55 is a thin film formed on the surface of the heat exchange mat 50 by a material having a higher thermal conductivity and / or heat absorption rate (that is, absorption rate for heat radiation) than the heat exchange pipe 52. As shown in FIG. 5, the coating layer 55 is formed in a substantially arcuate cross section along the surface of the heat exchange pipe 20 having a substantially circular cross section. The thickness of the coating layer 55 is preferably about 0.8 to 45 μm, more preferably about 5 to 15 μm. The thickness of the coating layer 55 may be uniform, but it is preferable that the coating layer 55 is formed so that the thickness d2 of the arcuate recess is larger than the thickness d1 of the arcuate top.

In the present embodiment, the coating layer 55 is made of a material containing at least one of silicon carbide and carbon nanotubes so that both the heat absorption rate and the thermal conductivity are higher than those of the heat exchange pipe 52. It is configured. Further, in order to enhance the heat absorption performance, the color of the coating layer 55 is preferably a color having low heat reflectivity, particularly black. Further, the coating layer 55 of the present embodiment contains a binder (binder) for the heat exchange pipe 52. As an example of the binder, a binder resin made of a resin material can be used, and as an example, a polyolefin resin of the same type can be used for the heat exchange pipe 52 made of polyethylene resin. If necessary, a sealer (undercoat coating) may be provided between the heat exchange pipe 52 and the coating layer 55. Further, the coating layer 55 may be formed on both surfaces of the plate-shaped heat exchange mat 50.

In the heat exchange mat 50 of the present embodiment, the plurality of heat exchange pipes 52 arranged in parallel are integrally formed of a thermoplastic resin material. The plurality of heat exchange pipes 52 are not limited to those integrally formed, and for example, the heat exchange pipes 52 are connected and fixed to each other by a separate or integrated connecting means from the heat exchange pipes 52, or an adhesive is used. They may be connected so that the parallel state is maintained by adhering them to each other. Further, as shown in FIG. 3A, it is preferable that the plurality of heat exchange pipes 52 are configured to be arranged in a line in the circumferential direction of the pipes in the installed state.

As shown in FIG. 4, the tips of the heat exchange pipes 52A, which are the outward paths, are connected to one end of the U-shaped connecting pipe 59 via the joint material 58, respectively, and the heat exchange pipes, which are the return paths, are connected to each other. The tip of the 52B is connected to the other end of the connecting pipe 59 via the joint member 58, respectively. The shape of the connecting pipe 59 is not limited to that shown in the illustrated example, and may be any pipe shape that connects the heat exchange pipe 52A for the outward route and the heat exchange pipe 52B for the return route. Further, the heat exchange mat 50 is formed by curving each heat exchange tube 52 at the tip of the heat exchange mat 50 so that the outward path and the return path are formed by a series of heat exchange pipes 52. May be.

The heat exchange mat 50 is pressed and fixed to the inner wall of the sewer pipe 70 by the rehabilitation pipe 30. Further, the base end portion of the heat exchange mat 50 is connected to the pipe 45 via a connecting member (not shown). Specifically, the base end portion of the heat exchange pipe 52A for the outward route is connected to one end of the pipe 45 via a connecting member, and the base end portion of the heat exchange pipe 52B for the return route is connected via the connecting member. Is connected to the other end of the pipe 45. As shown in FIG. 1, the pipe 45 is arranged so as to pass through the first heat exchanger 41 of the heat pump unit 40.

In the heat exchange system 10 of the present embodiment, heat exchange is performed with the sewage 78 when the heat exchange medium passes through the heat exchange mat 50. In particular, in the heat exchange mat 50 of the present embodiment, since the coating layer 55 having a high heat absorption rate and heat transfer rate is formed on the surface on the side where the sewage 78 flows, the heat exchange pipe 52 is relatively small. Even if it is made of a material with low heat conductivity or the heat exchange pipe 52 and the sewage 78 are in a non-contact state, a large amount of heat energy from the sewage 78 is absorbed and the heat exchange pipe is used. It can be quickly transferred to the surface of 52, and as a result, the heat transfer performance between the sewage 78 and the heat exchange medium can be enhanced and the heat exchange rate can be improved.

Further, since the coating layer 55 is made of a material having a higher thermal conductivity than the heat exchange pipe 52, as shown in FIG. 3B, the convex portion 55a of the coating layer 55 is passed through the rehabilitation pipe 30. The heat energy transferred to can be quickly transferred to the recesses 55b and 55c of the coating layer 55 in a non-contact state with the rehabilitation tube 30. As a result, the heat energy transmitted to the heat exchange pipe 52 via the rehabilitation pipe 30 and the coating layer 55 is quickly transmitted not only to the top 51 of the heat exchange pipe 52 but also to a wide surface of the heat exchange pipe 52. As a result, the heat exchange rate between the sewage 78 and the heat exchange medium is improved.

Further, in the concave portion of the uneven surface of the heat exchange mat 50, the layer thickness d2 of the coating layer 55 is thicker than the layer thickness d1 of the convex portion, so that the heat exchange has a large separation distance from the sewage 78. Thermal conductivity and heat absorption can be enhanced in the recesses of the mat 50.

Further, since it is not necessary to bundle the heat exchange pipes 52 one by one in the sewer pipe 70, the construction time in the sewer pipe 70 can be shortened. Further, since the heat exchange mat 50 has low rigidity and is easily curved in the recess between the adjacent heat exchange pipes 52, the heat exchange mat 50 is easily curved in an arc shape along the inner wall surface of the sewer pipe 70 and is installed. Is easy.

Next, the method for manufacturing the heat exchange mat 50 described above will be described with reference to FIG.

First, as shown in FIG. 6A, a plurality of liquid resin materials are injected into a molding die 80 forming a parallel bundle-shaped pipe, and the molten resin is cooled by the molding die to form a plurality of pieces in a parallel state. (Piping bundle forming step). After molding, the pipe bundle 90 in a high temperature state is cooled and cured by the cooling device 81 to complete the pipe bundle 90 (curing step).

Next, as shown in FIG. 6B, the completed pipe bundle 90 is conveyed to the painting pretreatment device 83, and a treatment for improving the adhesiveness of the surface of the pipe bundle 90 is performed (pre-painting step). .. The coating pretreatment device 83 can be, for example, a plasma treatment device that performs surface treatment by plasma discharge, or a frame treatment device that performs surface treatment by a frame (flame) using a burner or the like. By performing plasma treatment or frame treatment, the molecular binding structure on the surface of the pipe bundle 90 can be changed to improve the adhesiveness of the paint 92 forming the coating layer 55. Further, instead of these treatment devices, the coating pretreatment device 83 can be a heating device that heats the entire pipe bundle 90. The surface of the pipe bundle 90 heated to a predetermined temperature (for example, about 190 ° C.) by the heating device is in a softened state, and the adhesiveness of the surface is improved.

After the coating pretreatment step, the paint 92 for forming the coating layer 55 is applied to the surface of the pipe bundle 90 (coating layer forming step). When the pipe bundle 90 is surface-treated by plasma or a frame, the coating layer forming step is performed within a certain period after the surface treatment. In this case, the temperature of the pipe bundle 90 can be lower than that for which the pretreatment is performed by the heating device (that is, the temperature at which the pipe bundle 90 does not soften, for example, about 50 ° C., room temperature, etc.). ..

The paint 92 is a powder containing silicon carbide and / or carbon nanotubes as a functional material for improving the heat exchange rate and a binder resin as a binder, and a solvent (for example, an aqueous solvent such as water or an organic solvent). ) And are mixed. In this embodiment, water is used as a solvent. The paint 92 is preferably applied to the surface of the pipe bundle 90 by brushing with a spray or a brush. In the example shown in FIG. 6B, the paint 92 is sprayed from the spray nozzle 84 of the painting device to spray-paint the coating layer 55. Then, if necessary, a cooling device and / or a drying device is used to cure the coating layer 55 and the pipe bundle 90 to complete the heat exchange mat 50.

In this manufacturing method, since the paint 92 forming the coating layer 55 is applied after the coating pretreatment is applied to the pipe bundle 90 made of the resin material, the adhesion of the coating layer 55 to the pipe bundle 90 is improved. Can be done. When the pipe bundle 90 is made of a resin material such as cross-linked polyethylene, the surface after curing is slippery and the paint 92 is difficult to adhere to, but the surface is softened by surface treatment or heating. By adhering the paint 92 in this state, the adhesiveness of the coating layer 55 is enhanced and peeling can be prevented.

Further, by spraying the paint 92 on the surface of the pipe bundle 90, the surface of the coating layer 55 becomes rough, and as a result, the surface area becomes large and the heat absorption rate becomes high.

In the coating layer 55, instead of painting by spraying or brushing, as shown in FIG. 6C, the pipe bundle 90 is immersed in the paint tank 87 containing the paint 92 after passing through the paint pretreatment device 83. It may be formed by dip coating.

FIG. 7 is a diagram illustrating another method of manufacturing the heat exchange mat 50. In FIG. 7, those having the same configuration as the apparatus shown in FIG. 6 are designated by the same reference numerals, and detailed description thereof will be omitted.

In this manufacturing method, first, a liquid resin material is injected into a molding die 80, and the molten resin is cooled by the molding die to integrally form a plurality of pipe bundles 90 in a parallel state (pipe bundle forming step). ..

After that, the formed pipe bundle 90 is primarily cooled to a predetermined temperature by the cooling device 85 (primary cooling step). The pipe bundle 90 after the primary cooling is in a predetermined heating state, and is in a softened state before being completely cured. The cooling temperature can be appropriately set, and as an example, the pipe bundle 90 at about 250 ° C. can be cooled to about 190 ° C. by the first cooling device 81.

Next, the paint 92 for forming the coating layer 55 is applied to the surface of the softened pipe bundle 90 (coating layer forming step). The paint 92 can be applied to the surface of the pipe bundle 90 by spraying or brushing, or can be applied by dipping coating, as in the example shown in FIG.

Next, the pipe bundle 90 on which the coating layer 55 is formed is secondarily cooled by the second cooling device 86 to cure the pipe bundle 90 in the softened state (curing step). As a result, the heat exchange mat 50 is formed.

In this manufacturing method, the coating layer 55 can be formed to complete the heat exchange mat 50 after the resin pipe bundle 90 is integrally molded and then cooled and cured without providing a heating device. Therefore, the manufacturing time can be shortened and the manufacturing cost can be suppressed while ensuring the adhesiveness of the coating layer 55. The heating temperature of the pipe bundle 90 (primary cooling temperature in the example of FIG. 7) may be any temperature as long as the surface of the pipe bundle 90 is in a softened state without being hardened, and is not limited to 190 ° C. and may be appropriately set. Out. Further, in the present manufacturing method, the cooling devices 85 and 86 are not indispensable configurations, and for example, even if one or both of these devices are not used and the cooling devices are naturally cooled to a predetermined temperature or cured. good.

When the coating layer 55 is formed of a metal material having a higher thermal conductivity than that of the pipe bundle 90, for example, an aluminum alloy, the coating layer may be sprayed with metal to form a thermal sprayed film.

(Modification 1)
Next, a modification 1 of the heat exchange mat 50 will be described with reference to FIG. In the heat exchange mat 50 of the first modification, both sides of the flat plate are formed into a smooth surface without unevenness. The plurality of heat exchange pipes 52 have a substantially quadrangular cross section, and the side surfaces of the adjacent heat exchange pipes 52 are integrated, and the cross section of the flow path is formed in a substantially quadrangular shape. Further, on the surface of the heat exchange mat 50 on the rehabilitation pipe 30 side, a coating layer 55 having a higher heat absorption rate and thermal conductivity than the heat exchange pipe 52 is formed.

As in the first modification, the surface of the heat exchange mat 50, more specifically, the surface of the heat exchange pipe 52 in a parallel state may be a smooth surface without unevenness, and the coating layer 55 may be provided. By having it, the heat absorption rate due to radiation is increased. Further, the heat energy absorbed by the coating layer 55 having high thermal conductivity can be quickly transferred to the heat exchange pipe 52.

(Modification 2)
Next, a modification 2 of the heat exchange mat 50 will be described with reference to FIG. The heat exchange mat 50 of the first modification has an uneven shape in which the outer surface 50a facing the inner wall of the sewage pipe 70 is flat and the inner surface 50b facing the rehabilitation pipe 30 has a plurality of arcuate shapes in the width direction. Is formed in. In the illustrated example, the inner surface 50b is crushed by the rehabilitation tube 30, and the arc-shaped top is almost flat. The coating layer 55 has a thicker layer thickness between the adjacent heat exchange pipes 52.

As in the second modification, the heat exchange mat 50 has the other surface 50 while increasing the heat sampling area from the sewage 78 by forming only the surface 50b on the side where the sewage 78 flows in an uneven shape.
It is possible to suppress heat dissipation from.

The heat exchange mats 50 of Modifications 1 and 2 can also be manufactured by the above-mentioned manufacturing method of the heat exchange mat 50.

In each figure showing each embodiment and modification, heat exchange pipes 20 and 52 are provided for the sewage pipe 70 in order to make it easier to understand the configurations of the heat exchange pipes 20 and 52 and the heat exchange mat 50. Although shown largely, the heat exchange pipes 20 and 52 have, for example, an inner diameter of about 7 to 20 mm, an outer diameter of about 10 to 25 mm, and a thickness of about 1.5 to 3 mm, and the sewage pipe 70 has, for example,. The inner diameter is about 1.5 to 3 m, which is sufficiently larger than the heat exchange pipes 20 and 52.

The present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the spirit of the invention. For example, the existing pipe in which the heat exchange system 10 is installed is not limited to the sewage pipe 70, but can be applied to existing pipes such as water pipes, agricultural water pipes, and industrial water pipes. The temperature of water flowing through such a pipeline does not fluctuate significantly throughout the year, and can be used as a high-temperature heat source in winter and as a low-temperature heat source in summer. Further, for example, the circulation pipe through which the heat exchange medium flows is arranged in the heat exchange pipes 20 and 52 and the other manhole 74 after entering the sewer pipe 20 from the heat pump unit 40 via one manhole 72. It may be a circulation pipe that returns to the heat pump unit 40 on the ground through the pipe.

Further, the heat exchange pipe 20 and the heat exchange mat 50 may have a structure of being fixed in the sewer pipe 70 by a fixing member other than the rehabilitation pipe 30. For example, the fixing member can be a ring-shaped or arc-shaped member along the inner wall surface of the sewer pipe 70, which is arranged at intervals in the pipe axis direction of the sewer pipe 70, and is heated by the fixing member. The structure may be such that the replacement pipe 20 and the heat exchange mat 50 are partially pressed from the inside of the sewer pipe 70 against the inner wall of the sewer pipe 70 to be fixed. In such a fixing member, the heat exchange pipe 20 and the heat exchange mat 50 are exposed between the adjacent fixing members and can come into direct contact with the sewage. Therefore, the heat between the sewage and the heat exchange medium is generated. The exchange rate can be further improved.

Further, an acid-resistant paint for improving the durability against sewage 78 may be applied to the surfaces of the coating layers 25 and 55.

10 Heat exchange system 20,52 Heat exchange piping 25,55 Coating layer 30 Rehabilitation pipe (fixing member)
40 Heat pump unit 50 Heat exchange mat 70 Sewage pipe (existing pipe)

Claims (3)

Existing pipes buried in the ground and
A heat exchange pipe fixed to the inner wall of the existing pipe is provided.
In a heat exchange system that exchanges heat between the fluid flowing in the existing pipe and the heat exchange medium flowing in the heat exchange pipe.
A heat exchange mat formed by arranging a plurality of heat exchange pipes in parallel in a mat shape,
A fixing member for pressing and fixing the heat exchange mat against the inner wall of the existing pipe is provided.
The heat exchange mat has a concavo-convex surface in which a plurality of the heat exchange pipes having a substantially circular cross section are arranged in parallel so that a flow path is formed in the extension direction of the existing pipe, and arcs are continuous in the width direction. The heat exchange pipe is made of a material that enhances the heat transfer performance between the heat exchange medium and the fluid and is different from the flow path of the heat exchange medium, at least on the surface on the side where the fluid flows. Has a coating layer composed of
The coating layer is made of a material having a higher heat transfer coefficient than the heat exchange pipe, and is formed in a substantially arc shape in cross section along the arcuate surface of the heat exchange pipe.
The heat exchange system is characterized in that the fixing member is attached in a state of being in contact with the top of each heat exchange pipe constituting the heat exchange mat via the coating layer . A heat exchange mat formed by arranging a plurality of heat exchange pipes in parallel in a mat shape, and is fixed to the inner wall of an existing pipe buried in the ground and flows through the heat exchange pipe. A method for manufacturing a heat exchange mat used in a heat exchange system that exchanges heat with a fluid flowing through an existing pipe.
A pipe bundle forming process for forming a pipe bundle made of a resin material in which a plurality of heat exchange pipes connected in parallel are connected.
A primary cooling step of primary cooling the high-temperature pipe bundle after the pipe bundle forming step to a predetermined temperature, and a primary cooling step.
A coating layer forming step of applying a paint having a heat absorption rate and / or a heat transfer coefficient higher than that of the resin material to the surface of the pipe bundle to form a coating layer.
A curing step of secondary cooling and curing of the pipe bundle on which the coating layer is formed, and
Including
The paint is applied to the surface of the pipe bundle that has been frame-treated or plasma-treated, or the surface of the pipe bundle that has been heated to a predetermined temperature. Production method. In the coating layer forming step,
The coating material is a mixture of a powder body containing silicon carbide and / or carbon nanotubes and a molten material, and the coating material is applied to the surface of the pipe bundle by brushing, spraying, or dipping coating. 2. The method for manufacturing a heat exchange mat according to 2.

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