CN105627605B - Supply a center return pipe vertical buried pipe heat exchanger more - Google Patents

Abstract

The invention discloses a vertically buried pipe heat exchanger with multiple supply and one return central return pipes for a ground source heat pump system. The heat exchanger includes multiple vertical water supply branch pipes and a vertical return water pipe; the return water pipe is insulated with a coaxial tube in the middle, and is isolated from the outer casing with matching pipe clips every 3 to 5m; multiple water supply branch pipes Evenly distributed around the pipe-in-pipe, the center of the water supply branch pipe is on the concentric circle of the return pipe; the water supply branch pipe, return water pipe and casing are respectively connected with the water supply straight pipe, return water straight pipe and casing straight pipe on the cylindrical joint at the bottom. Casing connection. The invention improves the heat transfer per unit well depth; the structure is stable, convenient for construction, and can be put into the well hole at one time; the cylindrical joint at the bottom has a strong pressure bearing capacity and is not easy to be damaged; During construction, the ordinary insulation layer is wetted and becomes invalid. At the same time, it also avoids the thermal short circuit between the water supply and return pipes and the heat exchange between the return water pipe and the saturated heat exchange layer, improves the heat exchange efficiency and reduces the initial investment.

Description

Multi-supply central return pipe vertical buried pipe heat exchanger

technical field

The invention relates to a ground-buried pipe heat exchanger in a ground-source heat pump system, in particular to a vertical buried-pipe heat exchanger with multiple supply and one return center return pipes.

Background technique

The vertical buried pipe ground source heat pump system has received extensive attention due to its advantages of less land occupation and stable working performance. At present, the single-U and double-U buried tube heat exchangers commonly used in engineering have a small heat transfer per well depth, and there is a thermal short circuit between the water supply and return pipes, which causes heat loss and is not conducive to heat exchange. In order to meet the demand for heat exchange, usually more wells are drilled, which not only increases the floor area, but also greatly increases the initial investment of the ground source heat pump system, hindering the popularization and application of the ground source heat pump system. Therefore, in order to increase heat transfer per unit well depth, improve heat exchanger performance, reduce initial investment, and save floor space, it is necessary to rationally optimize the form and structure of the existing buried tube heat exchanger, so that the ground source heat pump Get better promotion and development.

Contents of the invention

The present invention aims to provide a vertical buried pipe heat exchanger with multiple supply and return central return pipes with simple structure, high heat exchange efficiency, simple construction and low initial investment.

The invention provides a vertically buried pipe heat exchanger with multi-supply and one-return central return pipe, which includes joints, water supply branch pipes, return pipes and sleeves. Water straight pipes, casing straight pipes and ribbed plates, the upper part of the water collector is a cylindrical structure, and the lower part is a conical structure; there are multiple vertical water supply branch pipes and a vertical return water pipe on the upper part of the heat exchanger; the return water pipe It forms a coaxial pipe-in-pipe with the outer casing, and the return pipe and the outer casing are separated by pipe clips every 3 to 5m in the vertical direction; the center of the return pipe coincides with the center of the heat exchanger, and multiple water supply pipes The branch pipes are evenly distributed around the coaxial pipe, and the center of the water supply branch pipe is located on the concentric circle of the return pipe; The return water straight pipe and the casing straight pipe are connected through matching electrofusion casings; multiple water supply branch pipes are positioned with injection molded pipe clamps at intervals of 3 to 5m in the vertical direction to keep a fixed distance in the wellbore.

In the above solution, 2 to 6 vertical water supply branch pipes are provided, and the same number of water supply straight pipes are provided on the bottom cylindrical joint.

In the above scheme, the return pipe adopts pipe-in-pipe heat insulation, and the heat preservation method is pipe-in-pipe vacuum insulation layer, pipe-in-pipe rubber-plastic insulation layer, pipe-in-pipe air insulation layer or pipe-in-pipe vacuum layer low-emissivity film Any type of insulation.

Beneficial effects of the present invention:

(1) The distance between adjacent water supply pipes is appropriate, and they are in full contact with the fill, reducing thermal interference between water supply pipes, increasing heat transfer per unit well depth, improving heat transfer performance of buried pipe heat exchangers, reducing the number of wells drilled and saving Land area - the prerequisite for promotion and application in cities;

(2) The return pipe is insulated by pipe-in-pipe, which effectively avoids the phenomenon that the ordinary insulation layer is wetted and fails during construction, and also avoids the thermal short circuit between the supply and return pipes and the heat loss between the return pipe and the saturated heat exchange layer. exchange, greatly improving the heat exchange efficiency, and using one return pipe instead of multiple return pipes, saving the cost of the heat exchanger;

(3) The water supply pipe and the return pipe are connected as a whole through a cylindrical joint. After the water supply pipe is positioned with injection-molded pipe clamps every 3 to 5m in length, the structure is stable and can be put into the well hole at one time. The operation is simple, the construction is convenient, and the reduction construction workload;

(4) The cylindrical joint at the bottom has a strong pressure bearing capacity and is less prone to damage, which increases the service life of the ground source heat pump, improves the economic benefits of the ground source heat pump, and makes it easier to promote.

Description of drawings

Fig. 1 is a three-dimensional structure diagram of a vertical buried tube heat exchanger with two supply and one return central return pipes.

Figure 2 is a schematic diagram of the front structure of a vertical buried tube heat exchanger with two supply and one return central return pipes.

Fig. 3 is a left side view of Fig. 2 .

FIG. 4 is a sectional view of FIG. 2 .

Fig. 5 is a three-dimensional structure schematic diagram of a vertical buried tube heat exchanger with three supply and one return central return pipes.

Fig. 6 is a schematic diagram of the front structure of a vertical buried tube heat exchanger with three supply and one return central return pipes.

Fig. 7 is a left side view of Fig. 6 .

FIG. 8 is a sectional view of FIG. 6 .

Fig. 9 is a three-dimensional structural schematic diagram of a vertical buried tube heat exchanger with four supply and one return central return pipes.

Fig. 10 is a front structural diagram of a vertical buried tube heat exchanger with four supply and one return central return pipes.

FIG. 11 is a sectional view of FIG. 10 .

In the figure, 1-water collector; 2-water supply straight pipe; 3-water supply pipe electrofusion sleeve; 4-water supply branch pipe; 5-return water straight pipe; 6-return water pipe electrofusion sleeve; 7-return water pipe; 8-Casing straight pipe; 9-Casing electrofusion casing; 10-Casing; 11-Strengthening rib plate; 12-Tube clip.

Detailed ways

The present invention is further illustrated by the following examples, but not limited to the following examples.

Example 1:

This embodiment provides a vertical buried tube heat exchanger with two supply and one return central return pipes.

As shown in Figures 1 to 4, there are two vertical water supply branch pipes, and the same number of water supply straight pipes are provided on the bottom cylindrical joint.

The heat exchanger includes a water collector 1, a water supply straight pipe 2, a return water straight pipe 5, a casing straight pipe 8, a water supply branch pipe 4, a return pipe 7, a casing pipe 10, and a rib plate 11. At the bottom of the water collector, the upper part of the water collector 1 is a cylindrical structure, and the lower part is a conical structure; two vertical water supply branch pipes 4 and a vertical return water pipe 7 are arranged on the upper part of the heat exchanger; the return water pipe 7 and the outer casing 10 Composed of a coaxial pipe-in-pipe, the return pipe 7 and the outer casing 10 are separated by pipe clips 12 every 3m in the vertical direction; the center of the return pipe 7 coincides with the center of the heat exchanger, and the two water supply branch pipes 4 are evenly spaced. Distributed around the pipe in the coaxial pipe, the center of the two water supply branch pipes and the center of the return pipe are connected at 180°, and the center of the water supply branch pipe 4 is located on the concentric circle of the return water pipe 7; the water supply branch pipe 4, return water pipe 7 and sleeve The pipe 10 is respectively connected with the water supply straight pipe 2, the return water straight pipe 5 and the casing straight pipe 8 on the cylindrical joint at the bottom of the heat exchanger through the matching electrofusion casing: the lower end of the water supply branch pipe 4 is connected with the water supply pipe electrofusion casing 3. The lower end of the return pipe 7 is connected to the electrofusion casing 6 of the return pipe, and the lower end of the casing 10 is connected to the electrofusion casing 9; the two water supply branch pipes are positioned with injection molded pipe clips at intervals of 3m in the vertical direction so that they Keep a fixed distance in the well hole, so that the vertical buried tube heat exchanger of the two supply and one return central return pipes becomes a whole. Since the actual length of the vertical buried tube heat exchanger is 10-200m, in order to prevent the deformation of the heat exchanger, the injection molded tube clamp is used for positioning.

The reinforcing rib plate 11 is used for connecting the water supply straight pipe and the sleeve pipe straight pipe, so that the structure between the water supply straight pipe and the sleeve pipe on the joint is stable.

The return pipe adopts pipe-in-pipe heat preservation, and the heat preservation method is a pipe-in-pipe vacuum heat insulation layer.

The radius ratio of the return pipe 7 to the casing 10 is 2:1-3:1. In the project, the water supply branch pipe and the return pipe can choose different pipe diameters according to the needs, and the diameter of the return pipe is the same as that of the water supply pipe or one size larger.

The specific installation and operation methods are:

Before the vertical buried pipe heat exchanger of the two supply and one return central return pipes is put into the wellbore for construction, the return pipes are first provided with pipe clips every 3 to 5m and then put on insulation sleeves to form a pipe-in-pipe air insulation layer; Secondly, connect the vertical water supply branch pipe, a central return water pipe, and the insulation sleeve with the water supply straight pipe, return water straight pipe, and casing straight pipe of the bottom cylindrical joint respectively with matching electrofusion sleeves; Use injection molded pipe clips to position every 3m, so that the whole vertical buried pipe heat exchanger of the central return pipe becomes a whole; then place the whole heat exchanger into the well hole at one time, and fill the well with backfill material Then, after sealing the top of the pipe-in-pipe air insulation layer outside the well, the air heat insulation layer is evacuated to form a pipe-in-pipe vacuum layer for heat preservation; connected to the host of the ground source heat pump system.

Example 2:

This embodiment provides a vertical buried tube heat exchanger with three supply and one return central return pipes.

As shown in Figures 5 to 8, there are three vertical water supply branch pipes, and the same number of water supply straight pipes are provided on the bottom cylindrical joint.

The heat exchanger includes a water collector 1, a water supply straight pipe 2, a return water straight pipe 5, a casing straight pipe 8, a water supply branch pipe 4, a return pipe 7, a casing pipe 10, and a rib plate 11. At the bottom of the water collector, the upper part of the water collector 1 is a cylindrical structure, and the lower part is a conical structure; three vertical water supply branch pipes 4 and one vertical return water pipe 7 are arranged on the upper part of the heat exchanger; the center of the return water pipe 7 and the center of the heat exchanger The center overlaps, and the three water supply branch pipes 4 are evenly distributed around the coaxial pipe, the center of the three water supply branch pipes is 120° to the center of the return water pipe, and the center of the water supply branch pipe 4 is located on the concentric circle of the return water pipe 7; the water supply branch pipe 4. The return water pipe 7 and the casing pipe 10 are respectively connected with the water supply straight pipe 2, the return water straight pipe 5 and the casing straight pipe 8 on the cylindrical joint at the bottom of the heat exchanger through the matching electrofusion casing: the lower end of the water supply branch pipe 4 Connect the water supply pipe electrofusion casing 3, the lower end of the return water pipe 7 to connect the return water pipe electrofusion casing 6, and the lower end of the casing 10 to connect the casing electrofusion casing 9; the three water supply branch pipes are injection molded at intervals of 4m in the vertical direction The pipe clips are positioned to keep a fixed distance in the well hole, so that the vertical buried pipe heat exchanger with three supply and one return center return pipes becomes a whole.

The installation and operation methods of this embodiment are the same as those of Embodiment 1.

Example 3:

This embodiment provides a vertical buried tube heat exchanger with four supply and one return central return pipes.

As shown in Figures 9-11, there are 4 vertical water supply branch pipes, and the same number of water supply straight pipes are provided on the bottom cylindrical joint.

The heat exchanger includes a water collector 1, a water supply straight pipe 2, a return water straight pipe 5, a casing straight pipe 8, a water supply branch pipe 4, a return pipe 7, a casing pipe 10, and a rib plate 11. At the bottom of the water collector, the upper part of the water collector 1 is a cylindrical structure, and the lower part is a conical structure; four vertical water supply branch pipes 4 and a vertical return water pipe 7 are arranged on the upper part of the heat exchanger; the center of the return water pipe 7 and the heat exchanger The centers of the four water supply branch pipes 4 are evenly distributed around the middle pipe of the coaxial pipe, the center of the four water supply branch pipes is connected to the center of the return pipe at 90°, and the center of the water supply branch pipe 4 is located on the concentric circle of the return pipe 7; The water supply branch pipe 4, the return water pipe 7 and the casing pipe 10 are respectively connected with the water supply straight pipe 2, the return water straight pipe 5 and the casing straight pipe 8 on the cylindrical joint at the bottom of the heat exchanger through matching electrofusion casing pipes: water supply The lower end of the branch pipe 4 is connected to the water supply pipe electrofusion casing 3, the lower end of the return pipe 7 is connected to the return water pipe electrofusion casing 6, and the lower end of the casing 10 is connected to the casing electrofusion casing 9; the four water supply branch pipes are vertically separated by 5m The injection molded pipe clips are used for positioning in the range to keep a fixed distance in the well hole, so that the vertical buried pipe heat exchanger with four supply and one return central return pipes becomes a whole.

The installation and operation methods of this embodiment are the same as those of Embodiment 1.

Claims (3)

1. A vertical buried tube heat exchanger with multiple supply and return central return pipes, characterized in that the heat exchanger includes joints, water supply branch pipes, return pipes and sleeves, and the joints are located at the bottom of the heat exchanger, including water collectors, Water supply straight pipes, return water straight pipes, casing straight pipes and ribbed plates, the upper part of the water collector is a cylindrical structure, and the lower part is a conical structure; on the upper part of the heat exchanger, there are multiple vertical water supply branch pipes and a vertical Return pipe; the return pipe and its outer casing form a coaxial pipe-in-pipe insulation casing, and the heat preservation method is tube-in-pipe vacuum insulation layer insulation, and the return pipe and the outer casing are vertically separated every 3 to 5m Use pipe clips to isolate; the center of the return pipe coincides with the center of the heat exchanger, and multiple water supply branch pipes are evenly distributed around the coaxial pipe, and the center of the water supply branch pipe is located on the concentric circle of the return water pipe; the water supply branch pipe, return pipe The water pipe and casing pipe are respectively connected with the water supply straight pipe, return water straight pipe and casing straight pipe on the cylindrical joint at the bottom of the heat exchanger through matching electrofusion casing pipes; multiple water supply branch pipes are connected every 3 In the range of ~5m, use injection molded pipe clamps to keep a fixed distance in the wellbore; stiffeners are connected between the straight water supply pipe and the straight casing pipe to stabilize the connection between the straight water supply pipe and the straight casing pipe structure. 2. According to claim 1, the vertical buried pipe heat exchanger with multiple supply and return center return pipes is characterized in that: the vertical water supply branch pipes are provided with 2 to 6 branch pipes, and the cylindrical joints at the bottom are provided with the same Number of straight water supply pipes. 3. According to claim 1, the vertical buried pipe heat exchanger with multiple supply and one return central return pipe is characterized in that: the return pipe adopts pipe-in-pipe heat preservation, and the heat preservation method also includes a pipe-in-pipe rubber-plastic heat insulation layer , tube-in-pipe air insulation layer or tube-in-pipe vacuum layer low-e film insulation.