Ground heat exchanger system

Abstract

The invention provides a buried pipe heat exchanger system, and relates to the technical field of energy application, the system comprises a water collector, a buried pipe and a rainwater storage station, the water collector is arranged below a building group; the buried pipes are mounted under open spaces on the two sides of the building group; the buried pipe is communicated with the water collector through a pipeline; the rainwater storage station is communicated with the buried pipe through a pipeline; the rainwater storage station is also vertically communicated with a plurality of rainwater pipelines; rainwater of a building group is collected into the rainwater storage station through the rainwater pipeline, the rainwater storage station temporarily stores the collected rainwater and flows into the buried pipe, the rainwater in the buried pipe exchanges heat with underground soil and then flows back to the water collector, and water in the water collector is conveyed into the buried pipe and exchanges heat with air in a building. According to the buried pipe heat exchanger system, heat transfer between the water supply pipe and the water return pipe of the buried pipe can be effectively reduced while rainwater is utilized, the heat production efficiency is improved, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy application, in particular to a buried pipe heat exchanger system. BACKGROUND

[0002] Geothermal energy is a kind of energy generated from nuclear fission in the earth interior, which seeps out of the earth surface to form geothermal resources, and is a renewable clean energy with a very broad development prospect, and has the characteristics of green, low carbon and recyclable.

[0003] Medium-deep geothermal energy is a new type of energy, which is favored by many people due to its own energy properties and other factors. In the application of building heating engineering, the air source heat pump has low efficiency, poor running stability and difficult start-up in low temperature environment, followed by low heat exchange intensity and large land occupation of shallow buried pipe system, and finally, it is difficult for the groundwater source heat pump system to realize 100% same layer recharge. Therefore, in recent years, the medium-deep buried pipe technology has been paid more and more attention in the field of building heating.

[0004] In addition, the heating equipment based on the ground source heat pump has low heat energy conversion rate, in addition to the objective factors such as long distance of heat exchange medium transportation, and it is also one of the important reasons that the heat exchanger is difficult to consider heat exchange and heat preservation effect under the buried state.

[0005] At present, the buried pipe heat exchanger is a key heat transfer device for realizing heat exchange between heat carrying fluid and soil, among which the U-shaped buried pipe heat exchanger is most widely used, and the rainwater collected by the rainwater pipeline also has utilization value, but how to apply it to the field of geothermal energy utilization and develop a buried pipe heat exchanger with higher heat exchange efficiency and how to utilize the rainwater collected by the rainwater pipeline to form a system for cooling and heating in summer and winter have been one of the technical problems to be solved in the field. SUMMARY

[0006] Therefore, the present application provides a buried pipe heat exchanger system to design and develop a buried pipe heat exchanger with higher heat exchange efficiency, and utilize the rainwater collected by the rainwater pipeline to form a system for cooling and heating in summer and winter, so as to consider heat exchange and heat preservation effect. To solve the above problems, the present application provides a buried pipe heat exchanger system for installation on a building group, which comprises: a water collector arranged below the building group; a buried pipe installed below the vacant land on both sides of the building group; the buried pipe is in communication with the water collector through a pipeline; a rainwater storage station in communication with the buried pipe through a pipeline; a plurality of rainwater pipelines are vertically communicated on the rainwater storage station; The rainwater of the building group is collected into the rainwater storage station through the rainwater pipeline, the rainwater storage station temporarily stores the collected rainwater and flows into the buried pipeline, the rainwater in the buried pipeline exchanges heat with the underground soil, and then flows back to the water collector.

[0007] Further, the buried pipeline is a U-shaped structure.

[0008] Further, the buried pipeline comprises: The buried heat exchanger comprises a water supply pipe and a return water pipe which are combined in parallel and symmetrically, and the water supply pipe and the return water pipe are both U-shaped pipe structures, the water supply pipe is sleeved in the inside of the return water pipe, the top of the water supply pipe is flush with the top of the return water pipe, and the height of the water supply pipe is less than the height of the return water pipe.

[0009] Further, the upper section between the water supply pipe and the return water pipe is filled with a first backfill material layer, the lower section between the water supply pipe and the return water pipe is filled with a second backfill material layer, and the thermal conductivity of the first backfill material layer is less than the thermal conductivity of the second backfill material layer.

[0010] Further, the upper section inside of the water supply pipe and the return water pipe is provided with a heat preservation layer.

[0011] Further, the upper section of the water supply pipe and the return water pipe is an optimized structure section.

[0012] Further, the buried pipeline is arranged in parallel in a single column at a fixed interval.

[0013] Further, the top side diameter of the water supply pipe and the return water pipe is less than the bottom side diameter.

[0014] Further, the first backfill material layer and the second backfill material layer are any one of expanded polystyrene board, foamed glass, ceramsite concrete and rock wool.

[0015] Compared with the prior art, the present application has the advantages and beneficial effects, which are embodied in the following aspects: The buried pipe heat exchanger system in the application comprises a water collector, a rainwater storage station and a buried pipe heat exchanger, wherein a first backfill material layer with low thermal conductivity is filled in the upper section between the water supply pipe and the return pipe in the buried pipe heat exchanger, the heat transfer thermal resistance between the water supply pipe and the return pipe is increased, which is beneficial to reduce the heat transfer between the two pipes due to temperature difference, can effectively reduce the heat loss and improve the heat exchanger efficiency; the lower section between the water supply pipe and the return pipe and the periphery adopt a second backfill material layer with high thermal conductivity, which is beneficial to improve the thermal conductivity of the backfill material and enhance the heat exchange performance between the fluid in the buried pipe and the soil; the end wall of the water supply pipe and the return pipe is provided with thermal insulation material, which reduces the heat exchange loss between the outlet fluid and the inlet fluid and improves the heat exchange efficiency of the heat exchanger. The application improves the heat exchange efficiency while reducing the production cost by optimizing the buried pipe in sections considering the relationship between temperature and flow resistance; at the same time, the rainwater collected by the rainwater pipeline is used to improve the efficiency of the system and make the system more sustainable. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 FIG. 1 is a structural schematic diagram of the buried pipe heat exchanger system in the embodiment of the application; Figure 2 FIG. 2 is a structural schematic diagram of the buried pipe in the embodiment of the application; Figure 3 FIG. 3 is a summer cooling schematic diagram in the embodiment of the application; Figure 4 FIG. 4 is a winter heating schematic diagram in the embodiment of the application.

[0017] BRIEF DESCRIPTION OF DRAWINGS 1-buried pipe; 2-water collector; 3-building group; 4-rainwater pipeline; 5-rainwater storage station; 6-buried pipe heat exchanger; 7-water supply pipe; 8-return pipe; 9-first backfill material layer; 10-pipe wall; 11-second backfill material layer; 12-thermal insulation layer; 13-optimized structure section. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the specific embodiments of the application will be described in detail below with reference to the drawings.

[0019] At present, the ground source heat pump system is to first drill a hole in the soil to form a deep well, then bury the prefabricated heat exchange pipeline in the deep well, usually adopt soil backfill, then use the flow of circulating fluid in the heat exchange pipeline to obtain the heat energy in the underground rock mass, realize building winter heating, summer cooling and all-year hot water supply.

[0020] To solve the above technical problems, please refer to Figure 1As shown, the embodiment of the present application provides a ground heat exchanger system for installation on a building group 3, which can provide a ground heat exchanger with higher heat exchange efficiency, and utilize the rainwater collected by the rainwater pipe to form a system for cooling and heating in summer and winter, improve the heating efficiency, and reduce the production cost.

[0021] The system comprises a water collector 2, a ground heat exchanger 1, and a rainwater storage station 5, wherein: The water collector 2 is arranged below the building group 3; The ground heat exchanger 1 is installed below the vacant land on both sides of the building group 3; the ground heat exchanger 1 is in communication with the water collector 2 through a pipe; The rainwater storage station 5 is in communication with the ground heat exchanger 1 through a pipe; the rainwater storage station 5 is also vertically connected with a plurality of rainwater pipes 4; The rainwater of the building group is collected into the rainwater storage station through the rainwater pipes, the rainwater storage station temporarily stores the collected rainwater and flows into the ground heat exchanger, the rainwater in the ground heat exchanger exchanges heat with the underground soil, and then flows back to the water collector; the water in the water collector is transported to the ground heat exchanger to exchange heat with the air in the building.

[0022] Specifically, the rainwater of the building group 3 is collected into the rainwater storage station 5 through the rainwater pipes 4, the rainwater storage station 5 temporarily stores the collected rainwater as an intermediate storage unit, which will participate in the operation of the ground heat exchanger system later; the rainwater in the rainwater storage station 5 is connected with the ground heat exchanger 1 through a pipe, the ground heat exchanger 1 is laid below the vacant land on both sides of the building group 3, and the ground heat exchanger 1 is also in communication with the water collector 2 arranged below the building group 3 through a pipe. The water collector 2 plays a role of collecting and distributing the heat exchange medium (rainwater) in the system, and preliminarily constructs a system architecture including rainwater storage, transportation, and heat exchange medium circulation, laying a foundation for the subsequent heat exchange process.

[0023] As shown, Figure 3 In summer, the outdoor environment temperature is high, and the building group 3 needs to be provided with cool air. When the ground heat exchanger system operates, the rainwater in the rainwater storage station 5 is transported to the ground heat exchanger 1 as the heat exchange medium, and exchanges heat with the underground soil during the flow in the ground heat exchanger 1. Since the underground soil temperature is relatively stable and lower than the outdoor environment temperature in summer, the rainwater is cooled by the soil when flowing in the ground heat exchanger 1, and the rainwater with reduced temperature flows back to the water collector 2, and then is transported from the water collector 2 to the heat exchange equipment (such as fan coil, etc.) of the building group 3 to exchange heat with the air in the building, realizing the effect of providing cooling for the building, completing a heat exchange cycle, and continuously providing cooling for the building group in this way.

[0024] As shown, Figure 4As shown, the outdoor environment temperature is low in winter, and the building group 3 needs heat for heating. At this time, the rainwater in the rainwater storage station 5 is transported into the ground buried pipe 1, the temperature of the underground soil is relatively higher than the outdoor environment temperature in winter, the rainwater exchanges heat with the soil in the ground buried pipe 1, absorbs the heat in the soil and is heated, and the rainwater with the increased temperature returns to the water collector 2 and is transported to the heat exchange equipment in the building group 3 to exchange heat with the air in the building, so as to provide heat for the building, and the circulation is continuously realized to achieve the heating function in winter.

[0025] Therefore, the ground buried pipe 1 is installed in the underground space on both sides of the building group and is in close contact with the underground soil, the heat exchange area is increased, and the heat exchange process is more sufficient. Compared with the traditional ground buried pipe heat exchanger system, the system uses the soil resources on the underground space on both sides through reasonable layout of the ground buried pipe position, so that the heat exchange medium (rainwater) and the soil have a longer distance and more sufficient time for heat exchange, thereby improving the overall heat exchange efficiency and more effectively meeting the load demand of the building group for cooling in summer and heating in winter.

[0026] The rainwater collected by the rainwater pipeline is introduced into the system as the heat exchange medium, which replaces the traditional mode of simply relying on underground water or other purchased heat sources / cold sources. The rainwater itself is a relatively clean and renewable resource, which is recycled in the system, reduces the dependence on traditional energy, and is used for building cooling and heating after being cooled by the soil in summer and heated by the soil in winter, so that the cold and heat energy contained in the rainwater is fully utilized, energy recycling is realized, the efficiency of heat production (heating in winter) and refrigeration (cooling in summer) is improved, and the energy consumption cost in the system operation process is reduced, such as reducing the use of electrically driven refrigeration equipment or fuel-fired heating equipment, so as to reduce the production cost of the whole system.

[0027] More specifically, please refer to Figure 1 , 2 In a preferred embodiment of the present application, the ground buried pipe 1 is in a U-shaped structure, so that the rainwater continuously flows in the middle pipe section of the U-shaped ground buried pipe. Since the ground buried pipe 1 is in a U-shaped structure, the contact area with the soil is increased, so that the heat exchange between the rainwater and the soil is more sufficient. With the flow of the rainwater in the U-shaped pipe, the temperature of the rainwater gradually tends to the temperature of the soil. In summer, the soil temperature is lower than the rainwater temperature, and the rainwater releases heat to the soil; in winter, the soil temperature is higher than the rainwater temperature, and the soil transfers heat to the rainwater.

[0028] More specifically, please refer to Figure 1 , 2As shown, in one preferred embodiment of the present application, the buried pipe 1 comprises a buried pipe heat exchanger 6, which comprises a symmetrically parallel combination of a water supply pipe 7 and a return water pipe 8, and both the water supply pipe 7 and the return water pipe 8 are in a U-shaped pipe structure, the water supply pipe 7 is sleeved inside the return water pipe 8, and the top of the water supply pipe 7 is flush with the top of the return water pipe 8, and the height of the water supply pipe 7 is less than the height of the return water pipe 8.

[0029] When the rainwater enters the water supply pipe 7, it begins to flow upward in the U-shaped pipe and exchanges heat with the surrounding soil. Since the water supply pipe 7 is sleeved inside the return water pipe 8, and the height of the water supply pipe 7 is less than the height of the return water pipe 8, the rainwater in the water supply pipe 7 exchanges heat with the inner wall of the return water pipe 8 during its upward flow, further adjusting the temperature of the rainwater.

[0030] More specifically, please refer to Figure 2 As shown, in another preferred embodiment of the present application, the upper section between the water supply pipe 7 and the return water pipe 8 is filled with a first backfill material layer 11, and the lower section between the water supply pipe 7 and the return water pipe 8 is filled with a second backfill material layer 9, and the thermal conductivity of the first backfill material layer 11 is less than that of the second backfill material layer 9.

[0031] The second backfill material layer 9 is located in the lower section between the water supply pipe 7 and the return water pipe 8, and has a higher thermal conductivity, which can enhance the heat exchange capacity of the lower section. When the contact area between the lower section and the soil is larger, the high-thermal-conductivity backfill material can more effectively transfer the heat between the rainwater and the soil, allowing the rainwater to absorb or release heat more quickly in the lower section of the buried pipe 1, thereby improving the overall heat exchange efficiency.

[0032] The first backfill material layer 11 filled in the upper section has a smaller thermal conductivity, which can appropriately slow down the heat exchange speed of the upper section, making the heat transfer more uniform during the upward and downward flow of the rainwater, and avoiding excessive temperature gradient caused by excessive local heat exchange, thereby improving the heat exchange efficiency of the entire system.

[0033] Therefore, the backfill material layers with different thermal conductivities make the heat exchange process between the water supply pipe 7 and the return water pipe 8 more uniform. In the lower section, the high-thermal-conductivity material is beneficial to rapid heat exchange; in the upper section, the low-thermal-conductivity material makes the heat exchange process relatively stable. This design avoids the problem of insufficient or excessive local heat exchange caused by the same heat exchange characteristics of the entire buried pipe 1 section, improves the uniformity of the heat exchange process, and ensures that the system can operate stably and efficiently under different seasons and operating conditions.

[0034] More specifically, please refer to Figure 2As shown, in another preferred embodiment of the present invention, an insulation layer 12 is provided within the upper sections of both the supply and return pipes 7 and 8, effectively reducing heat loss from the rainwater to the surrounding environment during its rise and fall. In summer, the insulation layer 12 prevents external heat from entering the upper sections of the supply and return pipes 7 and 8, maintaining a low temperature for the rainwater and enhancing heat exchange between the rainwater and the soil in the lower sections. In winter, the insulation layer 12 prevents excessive heat dissipation in the upper sections, maintaining a high temperature for the rainwater and improving heat exchange efficiency between the rainwater and the soil in the lower sections, thereby improving the overall heat exchange efficiency of the buried pipe heat exchanger system.

[0035] More specifically, see Figure 2 As shown, in another preferred embodiment of the present invention, the middle and upper portions of the water supply pipe 7 and the return pipe 8 comprise an optimized structural section 13. This optimized structural section 13 enhances the heat exchange efficiency of the middle and upper portions by increasing the heat exchange area, improving water turbulence, and employing specialized thermally conductive materials. In summer, this optimized structural section 13 more effectively transfers heat from rainwater to the surrounding soil; in winter, it more efficiently absorbs heat from the soil and transfers it to rainwater, improving the overall heat exchange efficiency of the ground heat exchanger system.

[0036] More specifically, see Figure 2 As shown, in another preferred embodiment of the present invention, the underground pipes 1 are arranged in parallel rows at regular intervals, allowing the soil surrounding each pipe 1 to evenly participate in the heat exchange process. This arrangement prevents interference between the underground pipes 1, ensuring more complete and efficient heat exchange between each pipe 1 and the surrounding soil. In summer, rainwater can more effectively transfer heat to the soil during its rise and fall; in winter, it can more effectively absorb heat from the soil, thereby improving the heat exchange efficiency of the entire system.

[0037] More specifically, see Figure 2 As shown, in another preferred embodiment of the present invention, the top diameters of the water supply pipe 7 and the water return pipe 8 are smaller than the bottom diameters.

[0038] In another preferred embodiment of the present invention, the first backfill material layer 11 and the second backfill material layer 9 are any one of expanded polystyrene board, foam glass, ceramsite concrete and rock wool.

[0039] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A buried heat exchanger system for installation on a building complex, characterized in that: The system comprises: a water collector, arranged below the building complex; Buried pipes are installed under the open space on both sides of the building complex; the buried pipes are connected to the water collector through pipes; A rainwater storage station, the rainwater storage station is connected to the buried pipe through a pipeline; the rainwater storage station is also vertically connected to a plurality of rainwater pipes; The rainwater from the building complex is collected into the rainwater storage station through the rainwater pipe. The rainwater storage station temporarily stores the collected rainwater and flows into the buried pipe. The rainwater in the buried pipe exchanges heat with the underground soil and then flows back to the water collector. The water in the water collector is transported to the buried pipe to exchange heat with the air in the building.

2. The underground heat exchanger system according to claim 1, characterized in that: The buried pipe is a U-shaped structure.

3. The underground heat exchanger system according to claim 1, characterized in that: The buried pipe comprises: A buried heat exchanger includes a water supply pipe and a return pipe that are symmetrically combined in parallel, and both the water supply pipe and the return pipe are U-shaped pipe structures. The water supply pipe is sleeved inside the return pipe, and the water supply pipe is flush with the top of the return pipe, and the height of the water supply pipe is less than the height of the return pipe.

4. The underground heat exchanger system according to claim 3, characterized in that: The upper section between the water supply pipe and the return pipe is filled with a first backfill material layer, and the lower section between the water supply pipe and the return pipe is filled with a second backfill material layer, and the thermal conductivity of the first backfill material layer is smaller than the thermal conductivity of the second backfill material layer.

5. The underground heat exchanger system according to claim 4, characterized in that: The upper sections of the water supply pipe and the return pipe are both provided with insulation layers.

6. The underground heat exchanger system according to claim 3, characterized in that: The middle and upper parts of the water supply pipe and the return pipe are optimized structural sections.

7. The underground heat exchanger system according to claim 1, characterized in that: The buried pipes are arranged in parallel in a single row at fixed intervals.

8. The underground heat exchanger system according to claim 3, characterized in that: The top diameters of the water supply pipe and the water return pipe are smaller than the bottom diameters.

9. The underground heat exchanger system according to claim 4, characterized in that: The first backfill material layer and the second backfill material layer are any one of expanded polystyrene board, foam glass, ceramsite concrete and rock wool.

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