Permeable energy pile and ground source heat pump system

Abstract

The invention discloses a permeable energy pile and a ground source heat pump system, and relates to the field of geothermal energy application, the permeable energy pile comprises a pipe pile cavity, a cold water pipe and a hot water pipe, the pipe pile cavity is used for being arranged in a saturated soil body, and a separation part is arranged in the pipe pile cavity to divide the pipe pile cavity into an upper permeable cavity and a lower permeable cavity in the vertical direction; the lower water-permeable cavity is located below the diving surface of the saturated soil body, and a plurality of water-permeable holes are formed in the peripheral side wall of the upper water-permeable cavity and the peripheral side wall of the lower water-permeable cavity; the cold water pipe is inserted into the tubular pile cavity, the water inlet end of the cold water pipe is connected with a cold water source, and the water outlet end of the cold water pipe is located in the upper permeable cavity and used for conveying cold water to the upper permeable cavity; the hot water pipe is inserted into the pipe pile cavity, the water inlet end of the hot water pipe is located in the lower permeable cavity and used for collecting geothermal water flowing into the lower permeable cavity from the saturated soil body, and the water outlet end of the hot water pipe is used for being connected with an indoor heating terminal; therefore, heat exchange between the cold water and the saturated soil body is achieved, the heat exchange efficiency is greatly improved, and the heat exchange time is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of geothermal energy application, and particularly relates to a permeable energy pile and a ground source heat pump system. Background Art

[0002] With the growth of energy demand and the enhancement of environmental protection awareness, shallow geothermal energy, as a renewable energy source, has attracted much attention. The soil temperature below 15m of the ground surface is stable, and the temperature difference with the atmosphere forms available geothermal energy. Shallow geothermal energy resources in China are rich, and effectively utilizing it is of great significance for alleviating energy pressure and reducing pollution.

[0003] The ground source heat pump system is an effective way to utilize shallow geothermal energy and can achieve building heating and cooling. Compared with the air source heat pump, it is not affected by the unstable atmospheric temperature; compared with the groundwater source heat pump, it has the advantages of large reserves, simple operation, no water waste, and the energy efficiency ratio can reach more than 5, with remarkable energy-saving effects.

[0004] The buried form of the heat exchanger in the traditional ground source heat pump system has limitations. The horizontal buried pipe occupies a large area and is easily affected by the surface temperature; the vertical buried pipe has high heat exchange efficiency, but the initial investment cost is high. For this reason, the geothermal energy pile technology appears, placing the heat exchange pipeline in the building pile foundation to achieve the integration of load-bearing and heat exchange. However, the heat exchange efficiency of the existing geothermal energy piles is relatively low, restricting their wide application. Summary of the Invention

[0005] The main object of the present invention is to propose a permeable energy pile and a ground source heat pump system, aiming to solve the above problems.

[0006] To achieve the above object, a permeable energy pile proposed by the present invention includes:

[0007] A pipe pile cavity for being arranged in saturated soil. A partition part is arranged in the pipe pile cavity to divide the pipe pile cavity into an upper permeable cavity and a lower permeable cavity along the up and down direction. The lower permeable cavity is located below the phreatic surface of the saturated soil. A plurality of permeable holes are opened on the peripheral side wall of the upper permeable cavity and the peripheral side wall of the lower permeable cavity;

[0008] A cold water pipe inserted into the pipe pile cavity, and its water inlet end is used to connect with a cold water source, and its water outlet end is located in the upper permeable cavity for delivering cold water to the upper permeable cavity; and,

[0009] A hot water pipe inserted into the pipe pile cavity, and its water inlet end is located in the lower permeable cavity for collecting geothermal water flowing into the lower permeable cavity from the saturated soil, and its water outlet end is used to connect with an indoor heating terminal.

[0010] Optionally, at least one sealing structure is arranged between the hot water pipe and the partition part.

[0011] Optionally, two of the sealing structures are provided between the hot water pipe and the partition portion.

[0012] Optionally, one of the two sealing structures is a sealing ring and the other is a sealant layer. The sealing ring is sleeved on the outer periphery of the hot water pipe, and the sealant layer is coated on the outer periphery of the sealing ring.

[0013] Optionally, the sealing ring is a rubber washer.

[0014] The present invention further provides a ground source heat pump system, which includes:

[0015] A permeable energy pile;

[0016] A heat pump unit, including an evaporator and a compressor. The inlet of the evaporator is connected to the water outlet end of the hot water pipe of the permeable energy pile, and the outlet of the evaporator is connected to the inlet of the compressor; and,

[0017] An indoor heating terminal, whose inlet is connected to the outlet of the compressor;

[0018] Wherein, the permeable energy pile includes:

[0019] A pipe pile cavity for being arranged in a saturated soil body. A partition portion is arranged in the pipe pile cavity to divide the pipe pile cavity into an upper permeable cavity and a lower permeable cavity in the up-down direction. The lower permeable cavity is located below the phreatic surface of the saturated soil body. A plurality of permeable holes are formed in the peripheral side wall of the upper permeable cavity and the peripheral side wall of the lower permeable cavity;

[0020] A cold water pipe inserted into the pipe pile cavity, and its water inlet end is used for being connected to a cold water source, and its water outlet end is located in the upper permeable cavity for delivering cold water to the upper permeable cavity; and,

[0021] A hot water pipe inserted into the pipe pile cavity, and its water inlet end is located in the lower permeable cavity for collecting geothermal water flowing into the lower permeable cavity from the saturated soil body, and its water outlet end is used for being connected to the indoor heating terminal.

[0022] Optionally, the evaporator is connected to the water inlet end of the cold water pipe;

[0023] A first transmission pipe is arranged in the evaporator. The first transmission pipe is used for containing a heat exchange working medium and / or a heat source steam, and the outlet of the first transmission pipe is connected to the compressor;

[0024] The heat pump unit further includes a condenser, whose inlet is connected to the outlet of the indoor heating terminal, and whose outlet is connected to the inlet of the first transmission pipe.

[0025] Optionally, a water pump is provided between the evaporator and the cold water pipe.

[0026] Optionally, the heat pump unit further includes a throttle valve disposed between the condenser and the evaporator.

[0027] Optionally, the throttle valve is a thermostatic expansion valve or an electronic expansion valve.

[0028] In the technical solution of the present invention, cold water is transported to the upper water-permeable cavity through the cold water pipe, and under the action of pressure, it is evenly distributed to the saturated soil around the upper water-permeable cavity through the water-permeable holes of the upper water-permeable cavity. Since the density of cold water is relatively large, it sinks to the saturated soil on the lower side, that is, the saturated soil around the lower water-permeable cavity under the action of gravity, and squeezes out the geothermal water in the saturated soil at this position and guides it to enter the lower water-permeable cavity through the water-permeable holes of the lower water-permeable cavity, realizing the heat exchange between the cold water and the saturated soil, effectively extracting the soil heat energy. Then, the geothermal water in the lower water-permeable cavity flows out through the hot water pipe for heating the indoor heating terminal; thus, the heat exchange efficiency can be greatly improved and the heat exchange time can be reduced; at the same time, by setting the partition part to separate the upper water-permeable cavity and the lower water-permeable cavity, the contact between cold water and geothermal water is avoided, thereby ensuring the heat exchange efficiency. The water-permeable energy pile provided by the present invention can not only meet the building bearing requirements, but also serve as a heat exchange carrier of the ground source heat pump, reduce the additional space requirements, reduce the project cost, and utilize geothermal energy to reduce carbon emissions and protect the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of an embodiment of the water-permeable energy pile provided by the present invention;

[0031] Figure 2 For Figure 1 Partial structural schematic diagram of the middle water-permeable energy pile;

[0032] Figure 3 For Figure 1 Schematic structural diagram of an embodiment of the ground source heat pump system of

[0033] Figure 4 For Figure 3 Partial structural schematic diagram of the middle ground source heat pump system.

[0034] Explanation of the reference numerals in the drawings:

[0035] Label Name Label Name 1000 Ground source heat pump system 4 Sealing ring 100 Permeable energy pile 5 Sealant layer 1 Pipe pile cavity 200 Heat pump unit 11 Partition part 201 Evaporator 12 Upper permeable cavity 202 Compressor 13 Lower permeable cavity 203 Condenser 14 Permeable hole 204 Water pump 2 Cold water pipe 205 Throttle valve 3 Hot water pipe

[0036] The realization, functional features and advantages of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

[0038] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0039] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0040] The ground source heat pump system is an effective way to utilize shallow geothermal energy and can achieve building heating and cooling. Compared with the air source heat pump, it is not affected by the unstable atmospheric temperature; compared with the groundwater source heat pump, it has the advantages of large reserves, simple operation, and no waste of water source, and the energy efficiency ratio can reach more than 5, with remarkable energy-saving effects.

[0041] The burial form of the heat exchanger in the traditional ground source heat pump system has limitations. The horizontal buried pipes occupy a large area and are easily affected by the surface temperature; the vertical buried pipes have high heat exchange efficiency, but the initial investment cost is high. For this reason, the geothermal energy pile technology appears, placing the heat exchange pipeline in the building pile foundation to achieve the integration of load bearing and heat exchange. However, the heat exchange efficiency of the existing geothermal energy piles is relatively low, which restricts their wide application.

[0042] In view of this, the present invention provides a permeable energy pile 100, Figure 1 and Figure 2 which is an embodiment of the permeable energy pile 100 provided by the present invention.

[0043] Please refer to Figure 1 , the permeable energy pile 100 includes a pipe pile cavity 1, a cold water pipe 2 and a hot water pipe 3. The pipe pile cavity 1 is used to be arranged in saturated soil. A partition part 11 is arranged in the pipe pile cavity 1 to divide the pipe pile cavity 1 into an upper permeable cavity 12 and a lower permeable cavity 13 in the up-down direction. The lower permeable cavity 13 is located below the phreatic surface of the saturated soil. A plurality of permeable holes 14 are formed in the peripheral side walls of the upper permeable cavity 12 and the lower permeable cavity 13. The cold water pipe 2 is inserted into the pipe pile cavity 1, and its water inlet end is used to be connected with a cold water source, and its water outlet end is located in the upper permeable cavity 12 for delivering cold water to the upper permeable cavity 12. The hot water pipe 3 is inserted into the pipe pile cavity 1, and its water inlet end is located in the lower permeable cavity 13 for collecting geothermal water flowing into the lower permeable cavity 13 from the saturated soil, and its water outlet end is used to be connected with an indoor heating terminal.

[0044] In the technical solution of the present invention, cold water is delivered to the upper permeable cavity 12 through the cold water pipe 2, and uniformly diffuses into the saturated soil around the upper permeable cavity 12 through the permeable holes 14 of the upper permeable cavity 12 under the action of pressure. Since the density of cold water is relatively large, it sinks to the saturated soil on the lower side, that is, the saturated soil around the lower permeable cavity 13 under the action of gravity, and extrudes the geothermal water in the saturated soil at this position and guides it to enter the lower permeable cavity 13 through the permeable holes 14 of the lower permeable cavity 13, realizing the heat exchange between cold water and the saturated soil, effectively extracting soil heat energy. Then, the geothermal water in the lower permeable cavity 13 flows out through the hot water pipe 3 for heating the indoor heating terminal. In this way, the heat exchange efficiency can be greatly improved and the heat exchange time can be reduced. At the same time, by arranging the partition part 11 to separate the upper permeable cavity 12 and the lower permeable cavity 13, the contact between cold water and geothermal water is avoided, so as to ensure the heat exchange efficiency. The permeable energy pile 100 provided by the present invention can not only meet the building bearing requirements, but also be used as a heat exchange carrier of a ground source heat pump, reducing the additional space requirement, reducing the project cost, and using geothermal energy to reduce carbon emissions and protect the environment.

[0045] It should be noted that the saturated soil is composed of solid particles and pore water, and its water content reaches saturation.

[0046] It should also be noted that in the present invention, the pore diameter of the water permeable holes 14 is 1 - 3 cm, and the pore diameter of the water permeable holes 14 is selected according to the actual situation to achieve the maximum heat exchange efficiency and stable exchange.

[0047] Further, please refer to Figure 2 , at least one sealing structure is provided between the hot water pipe 3 and the partition portion 11. In this way, by providing the sealing structure to seal the partition portion, the upper water permeable cavity 12 and the lower water permeable cavity 13 are completely separated to prevent the hot water entering the lower water permeable cavity 13 from contacting the cold water in the upper water permeable cavity 12.

[0048] It should be noted that in the present invention, the number of the sealing structures provided between the hot water pipe 3 and the partition portion 11 is not limited, and one, two, three, etc. can be provided.

[0049] Further, in an embodiment of the present invention, two sealing structures are provided between the hot water pipe 3 and the partition portion 11 to improve the sealing reliability. Even if one sealing structure has a problem, the other sealing structure can still play a sealing role to form double protection, thereby ensuring the heat exchange efficiency of the water permeable energy pile 100.

[0050] Further, please refer to Figure 2 , in an embodiment of the present invention, one of the two sealing structures is a sealing ring 4, and the other is a sealing glue layer 5. The sealing ring 4 is sleeved on the outer periphery of the hot water pipe 3, and the sealing glue layer 5 is covered on the outer periphery of the sealing ring 4.

[0051] Further, the sealing ring 4 is a rubber washer, which has a long service life, low cost, and high practicability.

[0052] Specifically, a filter screen is provided at one end of the water permeable hole 14 of the lower water permeable cavity 13 away from the lower water permeable cavity 13 to prevent solid particles in the saturated soil from entering the lower water permeable cavity 13 to deposit or block the hot water pipe 3 and / or the water permeable hole 14, affecting the heat exchange efficiency.

[0053] It should be noted that if the solid particles in the saturated soil block the filter screen, the reverse water injection method can be adopted to flush out the blocked solid particles. Specifically, clean water is pumped into the lower water permeable cavity 13 to flush out the blocked solid particles to achieve the purpose of clearing the holes.

[0054] The present invention also provides a ground source heat pump system 1000, Figure 3 and Figure 4 is an embodiment of the ground source heat pump system 1000 provided by the present invention. Please refer to Figure 3 and Figure 4, the ground source heat pump system 1000 includes a permeable energy pile 100, a heat pump unit 200, and an indoor heating terminal. The heat pump unit 200 includes an evaporator 201 and a compressor 202. The inlet of the evaporator 201 is connected to the water outlet end of the hot water pipe 3 of the permeable energy pile 100, and the outlet of the evaporator 201 is connected to the inlet of the compressor 202; the inlet of the indoor heating terminal is connected to the outlet of the compressor 202.

[0055] In the technical solution of the present invention, the geothermal water collected by the permeable energy pile 100 is transported to the evaporator 201 through the hot water pipe 3 of the permeable energy pile 100, and heat exchange is carried out with the heat exchange working medium in the evaporator 201, so that the heat exchange working medium absorbs heat and evaporates to form a heat source steam. The heat source steam is then introduced into the compressor 202, and the compressor 202 does work on the heat source steam to increase the temperature and pressure, obtaining a high-grade working medium heat source and transporting it to the indoor heating terminal to meet the heat demand.

[0056] It should be noted that the above permeable energy pile 100 adopts the permeable energy pile 100 as described above. That is, the ground source heat pump system 1000 has all the technical features of all the embodiments of the above permeable energy pile 100, and thus has all the technical effects brought by the above all technical features. Details are not repeated here one by one.

[0057] Further, please refer to Figure 3 and Figure 4 , the inlet of the evaporator 201 is connected to the inlet of the cold water pipe 2; a first transmission pipe is provided in the evaporator 201, and the first transmission pipe is used to contain the heat exchange working medium and / or the heat source steam. The outlet of the first transmission pipe is connected to the compressor 202; the heat pump unit 200 further includes a condenser 203, whose inlet is connected to the outlet of the indoor heating terminal, and whose outlet is connected to the inlet of the first transmission pipe.

[0058] In this way, after the high-grade working medium heat source completes energy release at the indoor heating terminal, it will become a working medium fluid with a lower temperature and enter the condenser 203, where it exchanges heat with an external cooling medium (such as a cooler, etc.) to release the remaining heat, and re-condenses into a liquid working medium cold source and flows back into the first transmission pipe of the evaporator 201 as the heat exchange working medium in the evaporator 201 as described above. It exchanges heat with the geothermal water flowing into the evaporator 201 through the hot water pipe 3 to form a heat source steam, and then is introduced into the compressor 202 to act to form a high-grade working medium heat source and is transported to the indoor heating terminal for use, realizing energy recovery and working medium recycling, so as to continuously extract heat energy from the underground soil, realizing efficient geothermal exchange and continuous heat supply.

[0059] Further, please refer toFigure 3 and Figure 4 A water pump 204 is provided between the evaporator 201 and the cold water pipe 2.

[0060] More specifically, a second transfer pipe is provided in the evaporator 201. The inlet of the second transfer pipe is connected to the hot water pipe 3, and the outlet of the second transfer pipe is connected to the cold water pipe 2 through the water pump 204. In this way, the geothermal water flowing into the second transfer pipe through the hot water pipe 3 exchanges heat with the heat transfer working fluid in the evaporator 201 and then becomes cold water, which is then pumped into the cold water pipe 2 through the water pump 204 for recycling, saving energy.

[0061] Specifically, please refer to Figure 3 and Figure 4 The heat pump unit 200 further includes a throttle valve 205, and the throttle valve 205 is provided between the condenser 203 and the evaporator 201. In this way, the liquid working fluid cold source formed by the action of the condenser 203 is throttled and depressurized by the throttle valve 205 to meet the working requirements of the evaporator 201, and then enters the evaporator 201 again to exchange heat with the geothermal water transmitted by the cold water pipe 2 and becomes a steam state, realizing cyclic heating.

[0062] Further, the throttle valve 205 is a thermal expansion valve or an electronic expansion valve.

[0063] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the description and drawings of the present invention under the inventive concept of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A water-permeable energy pile, characterized in that: The permeable energy pile comprises: A pipe pile cavity is used to be arranged in a saturated soil body, wherein a partition is arranged in the pipe pile cavity to divide the pipe pile cavity into an upper water-permeable cavity and a lower water-permeable cavity in the up-down direction, wherein the lower water-permeable cavity is located below the water table of the saturated soil body, and a plurality of water-permeable holes are provided on the peripheral side walls of the upper water-permeable cavity and the peripheral side walls of the lower water-permeable cavity; A cold water pipe is inserted into the pile cavity, and its water inlet end is used to connect to a cold water source, and its water outlet end is located in the upper permeable cavity, and is used to transport cold water to the upper permeable cavity; and A hot water pipe is inserted into the pipe pile cavity, and its water inlet end is located in the lower permeable cavity, for collecting geothermal water flowing from the saturated soil into the lower permeable cavity, and its water outlet end is used to connect with the indoor heating terminal.

2. The permeable energy pile according to claim 1, characterized in that: At least one sealing structure is provided between the hot water pipe and the partition.

3. The permeable energy pile according to claim 2, characterized in that: Two sealing structures are provided between the hot water pipe and the partition.

4. The permeable energy pile according to claim 3, characterized in that: One of the two sealing structures is a sealing ring, and the other is a sealing rubber layer. The sealing ring is sleeved on the outer periphery of the hot water pipe, and the sealing rubber layer is covered on the outer periphery of the sealing ring.

5. The permeable energy pile according to claim 4, characterized in that: The sealing ring is a rubber gasket.

6. A ground source heat pump system, characterized in that: The ground source heat pump system comprises: The permeable energy pile according to any one of claims 1 to 5; A heat pump unit, comprising an evaporator and a compressor, wherein the inlet of the evaporator is connected to the water outlet of the hot water pipe of the water-permeable energy pile, and the outlet of the evaporator is connected to the inlet of the compressor; and, The inlet of the indoor heating terminal is connected to the outlet of the compressor.

7. The ground source heat pump system according to claim 6, characterized in that: The evaporator is connected to the water inlet end of the cold water pipe; The evaporator is provided with a first transmission pipe, the first transmission pipe is used to contain the heat replacement medium and / or heat source steam, and the outlet of the first transmission pipe is connected to the compressor; The heat pump unit further comprises a condenser, an inlet of which is connected to the outlet of the indoor heating terminal, and an outlet of which is connected to the inlet of the first transmission pipe.

8. The ground source heat pump system according to claim 7, characterized in that: A water pump is provided between the evaporator and the cold water pipe.

9. The ground source heat pump system according to claim 7, characterized in that: The heat pump unit further comprises a throttle valve, and the throttle valve is arranged between the condenser and the evaporator.

10. The ground source heat pump system according to claim 9, characterized in that: The throttle valve is a thermal expansion valve or an electronic expansion valve.

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