Operation method of middle-deep layer interference-free geothermal system

Abstract

The invention relates to an operation method of a medium-deep layer interference-free geothermal system, which comprises the following steps of: arranging a first foaming part which is formed by a first foaming material formed by foaming and curing a first fluid raw material which is firstly injected into a geothermal well; a second foaming part is arranged, and the second foaming part is formed by a second foaming material formed by foaming and curing a second fluid raw material which is subsequently injected into the geothermal well and attached to the upper portion of the first foaming material; a third foaming part is arranged, and the third foaming part is formed by a third foaming material formed by foaming and curing a third fluid raw material which is finally injected into the geothermal well and attached to the upper portion of the second foaming material; when used, the first foaming part and the third foaming part are in contact with existing geothermal water in a geothermal well and inlet water input from an inlet of the geothermal well respectively and play a role in waterproof sealing, and the second foaming part is connected between the first foaming part and the third foaming part and plays a role in flexible and deformable connection. And better geothermal well channel adaptability and sealing effect are realized.

Description

Technical Field

[0001] The invention relates to an operation method of a mid-deep interference-free geothermal system. Background Art

[0002] The medium-deep non-interference geothermal system drills into the medium-deep underground layer (usually at a depth of 1 km to 5 km) and injects water into the ground using closed circulation pipes without affecting the geological structure. The water is heated underground and then pumped back to the surface for power generation or heating. Compared with traditional geothermal development methods, the medium-deep non-interference geothermal system has little impact on the environment, strong sustainability, and a wide range of applications. It is considered to be a clean, safe, and renewable new energy utilization method. At present, during the operation of the medium-deep non-interference geothermal system, geothermal water is completely dependent on pumps to be lifted from underground to the surface, resulting in high mechanical energy consumption.

[0003] The applicant has developed a geothermal water treatment method and geothermal water treatment equipment for a medium-deep non-interference geothermal system, which can reduce the mechanical energy consumption of lifting geothermal water from underground to the ground through a pump during the operation of the medium-deep non-interference geothermal system. The method includes the following steps performed in a geothermal water repetitive cycle: 1) inputting the first inlet water into the inlet of the geothermal well of the mid-deep non-interference geothermal system, the first inlet water adopts raw water, and the raw water becomes the first round of geothermal water after being input into the geothermal well from the inlet of the geothermal well; 2) inputting the second inlet water into the inlet of the geothermal well and simultaneously driving the first round of geothermal water in the geothermal well to be output from the outlet through the first driving mode to form the first outlet water, the second inlet water contains dispersed substances dispersed in the water, the concentration of dispersed substances in the second inlet water is greater than the concentration of dispersed substances in the first round of geothermal water, and the geothermal water remaining in the geothermal well after the first outlet water is output from the outlet becomes the second round of geothermal water; 3) adding dispersed substances to the first outlet water to form the third inlet water, the concentration of dispersed substances in the third inlet water is greater than the concentration of dispersed substances in the second round of geothermal water; 4) inputting the third inlet water into the inlet of the geothermal well and simultaneously driving the second round of geothermal water in the geothermal well to be output from the outlet through the first driving mode to form the second Outlet water, the geothermal water remaining in the geothermal well after the second outlet water is discharged from the outlet becomes the third round of geothermal water; 5) repeat the above steps 3)-step 4), the number of repetitions is an integer ≥0 and each time the above steps 3)-step 4) are repeated, the corresponding batch of inlet water, the round of geothermal water and the batch of outlet water are respectively accumulated by 1 on the original basis, until the geothermal water remaining in the geothermal well becomes the Nth round of geothermal water, N is an integer ≥3; 6) the Nth round of geothermal water is driven to be discharged from the outlet through the second driving mode to form the Nth outlet water, the dispersed matter in the Nth outlet water is filtered to obtain raw water with the dispersed matter concentration reduced to the set range, and the raw water is used as the first inlet water of the next geothermal water repetition cycle; wherein the density of the dispersed matter used is greater than the density of the raw water, and the first driving mode uses the gravity sinking of each batch of inlet water in all the i-th inlet water to lift the corresponding i-1th round of geothermal water, i is each integer from 2 to N. Since the dispersed matter concentration in the i-th water inflow (i=2 to N) is greater than the dispersed matter concentration in the i-1th round of geothermal water, and the higher the dispersed matter concentration in the water body, the greater the density of the water body, therefore, the density of the i-th water inflow must also be greater than the density of the i-1th round of geothermal water. In this way, all batches of water in the i-th water inflow will sink by gravity in the geothermal well and lift the i-1th round of geothermal water, thereby reducing the mechanical energy required for the first driving method.

[0004] In addition, in order to avoid mixing between each batch of water in the entire i-th inflow and the corresponding i-1 round of geothermal water, before the i-th inflow is input into the inlet of the geothermal well, a section of isolation material can be injected into the inlet of the geothermal well. The isolation material can maintain an isolation layer between the i-th inflow and the i-1 round of geothermal water. The isolation layer can effectively prevent the i-th inflow from directly mixing with the i-1 round of geothermal water, ensure the relative independence of the dispersion systems with different dispersoid concentrations, and maintain the concentration gradient of the dispersion systems with different dispersoid concentrations. Foaming materials have many advantages as isolation materials, the most prominent of which is the convenience of injection and removal. This material can usually be injected into the geothermal well in liquid form, and then foam itself in the well to form an effective isolation barrier. This feature makes the operation process simple and efficient, without the need for complex equipment or procedures. After flowing out of the geothermal well, the foaming material can be separated from the effluent through a simple physical filtration procedure, so that it can be easily removed without causing long-term impact on the mid-deep non-interference geothermal system. In addition, foam materials also have the advantages of low density, strong compressibility, good thermal stability, high chemical stability, and no clogging of geothermal wells. They can maintain good isolation effects in geothermal environments with high temperature and pressure. At the same time, they have strong adaptability and can effectively fill irregular spaces to ensure the integrity of isolation. These characteristics make foam materials an ideal choice for isolation materials.

[0005] Before the filing date of the present invention, the applicant has not disclosed the specific configuration of the above-mentioned isolation material. Summary of the invention

[0006] The purpose of the present invention is to provide a method for operating a mid-deep interference-free geothermal system, and to solve the technical problem of optimizing the setting of the isolation materials mentioned in the above background technology.

[0007] To this end, the operating method of the medium-deep non-interference geothermal system of the present invention includes the operation of setting the isolation material, wherein the isolation material is a foaming material that is injected into the geothermal well in the form of a fluid and then foamed and solidified in the geothermal well by itself, and the isolation material is used in the medium-deep non-interference geothermal system to isolate the incoming water input from the entrance of the geothermal well from the existing geothermal water in the geothermal well; the setting operation specifically includes: setting a first foaming part, that is, the first foaming part is formed by the first foaming material formed by the foaming and solidification of the first fluid raw material first injected into the geothermal well; setting a second foaming part, that is, the first foaming part is formed by the subsequent injection of the geothermal well into the geothermal well and attached to the top of the first foaming material The second foaming part is formed by the second foaming material formed by the foaming and solidification of the second fluid raw material; and a third foaming part is provided, that is, the third foaming part is formed by the third foaming material formed by the foaming and solidification of the third fluid raw material finally injected into the geothermal well and attached to the second foaming material; when the first foaming part and the third foaming part are in use, they are respectively in contact with the existing geothermal water in the geothermal well and the incoming water input from the entrance of the geothermal well and play a role of water-proof sealing, and the second foaming part is connected between the first foaming part and the third foaming part and plays a role of flexible and deformable connection, so that the isolation material can adaptively follow the movement of water flow in the geothermal well.

[0008] The above-mentioned insulating material of the present invention achieves better adaptability and sealing effect in the geothermal well channel through the design of three-layer foaming parts. The first foaming part and the third foaming part provide reliable sealing, and the second foaming part in the middle plays a flexible connection role, so that the entire insulating material can flexibly turn in the geothermal well, thereby maintaining the sealing performance while enabling the insulating material to adaptively follow the water flow in the geothermal well, better avoiding the blockage of the geothermal well.

[0009] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be learned through practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The drawings constituting a part of this specification are used to assist the understanding of the present invention. The contents provided in the drawings and the related descriptions in this specification can be used to explain the present invention, but do not constitute improper limitations on the present invention.

[0011] Figure 1 It is a schematic diagram of the principle of the geothermal water treatment method for the mid-deep non-interference geothermal system mentioned in the background technology.

[0012] Figure 2 It is a schematic structural diagram of the isolation material involved in the operation method of a mid-deep interference-free geothermal system according to an embodiment of the present invention.

[0013] Figure 3 for Figure 2 Schematic diagram of the movement of isolation material in a geothermal well.

[0014] Figure 4 for Figure 2 Schematic diagram of the external structure of the tee pipe used in the setting operation of the isolation material in the mid-depth non-interference geothermal system.

[0015] Figure 5 for Figure 4 Schematic diagram of the structure of the spraying device installed in.

[0016] Marked in the figure: geothermal well 1, the first water inlet 21, the second water inlet 22, the third water inlet 23, the first round of geothermal water 31, the second round of geothermal water 32, the third round of geothermal water 33, the first water outlet 41, the second water outlet 42, the third water outlet 43, the first water storage device 51, the second water storage device 52, the filtering device 53, the isolation material 6, the first foaming part 61, the second foaming part 62, the third foaming part 63, the three-way pipe 7, the spraying device 8, the first spraying unit 81, the nozzle 811 of the first spraying unit, the shell 812, the flange 813, the inner sleeve 814, the first mixing chamber 815, the annular gap 816, the first feeding channel 817, the second spraying unit 82, the nozzle 821 of the second spraying unit, the inner tube 822, the nozzle 823, the second mixing chamber 824, and the second feeding channel 825. DETAILED DESCRIPTION

[0017] The present invention is described clearly and completely below in conjunction with the accompanying drawings. A person skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that: The technical solutions and technical features provided in each section, including the following description, can be combined with each other without conflict. In addition, where possible, these technical solutions, technical features and related combinations can be assigned specific technical themes and protected by relevant patents.

[0018] The embodiments of the present invention involved in the following description are generally only a part of the embodiments rather than all the embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of patent protection.

[0019] Regarding the terms and units in this specification: The terms "include", "comprises" and any variations thereof in this specification and the corresponding claims and related parts are intended to cover non-exclusive inclusions. Other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0020] 1. Mid-deep undisturbed geothermal system.

[0021] Figure 1 This is a schematic diagram of the principle of a method for treating geothermal water in a medium-deep non-interference geothermal system mentioned in the background technology. Figure 1 , the method for treating geothermal water in a medium-deep non-interference geothermal system according to an embodiment of the present invention is described. Figure 1 As shown, the method for treating geothermal water in a medium-deep non-interference geothermal system comprises the following steps performed in a geothermal water repetitive circulation cycle: 1) The first water inlet 21 is input into the inlet of the geothermal well 1 of the mid-deep undisturbed geothermal system. The first water inlet 21 uses raw water. The raw water becomes the first round of geothermal water 31 after being input into the geothermal well from the inlet of the geothermal well.

[0022] 2) The second inlet water 22 is input into the inlet of the geothermal well 1 and the first round of geothermal water 31 in the geothermal well 1 is driven to be discharged from the outlet through the first driving method to form the first outlet water 41. The second inlet water 22 contains dispersed substances dispersed in the water. The concentration of dispersed substances in the second inlet water 22 is greater than the concentration of dispersed substances in the first round of geothermal water 31. The geothermal water remaining in the geothermal well after the first outlet water 41 is discharged from the outlet becomes the second round of geothermal water 32.

[0023] 3) Adding dispersed matter to the first effluent 41 to form the third influent 23 , wherein the dispersed matter concentration in the third influent 23 is greater than the dispersed matter concentration in the second round of geothermal water 32 .

[0024] 4) The third water inlet 23 is input into the inlet of the geothermal well 1 and the second round of geothermal water 32 in the geothermal well 1 is driven to be output from the outlet through the first driving method to form the second output water 42. The geothermal water remaining in the geothermal well 1 after the second output water 42 is output from the outlet becomes the third round of geothermal water 33.

[0025] 5) Repeat the above steps 3 to 4), the number of repetitions is an integer ≥ 0 and each time the above operation is repeated, the corresponding batch of incoming water, the round of geothermal water and the batch of output water are respectively accumulated by 1 on the original basis, until the geothermal water retained in the geothermal well becomes the Nth round of geothermal water, N is an integer ≥ 3.

[0026] 6) The Nth round of geothermal water is driven to be output from the outlet through the second driving mode to form the Nth effluent water, and the dispersed matter in the Nth effluent water is filtered to obtain raw water with the dispersed matter concentration reduced to the set range, and the raw water is used as the first inlet water 21 of the next geothermal water repetition cycle.

[0027] Among them, the density of the dispersed medium used is greater than the density of the raw water, and the first driving method completely or partially relies on the gravity sinking of all batches of water in the i-th water inflow to lift the corresponding i-1th round of geothermal water, where i is an integer from 2 to N.

[0028] To simplify, Figure 1 In the example, N is set to 3. That is, the actual number of repetitions in the above step 5) is 0, which is equivalent to the fact that step 5) does not exist. However, it should be pointed out in advance that the value of N can usually be set to be greater than 3.

[0029] like Figure 1 As shown, a geothermal water repetitive cycle is represented as six states AF, namely state A, state B, state C, state D, state E, and state F.

[0030] In state A, the first water storage device 51 is inputting the second water inflow 22 to the inlet of the geothermal well 1. At the same time, the mid-deep non-interference geothermal system drives the first round of geothermal water 31 in the geothermal well 1 through the first driving mode to be output from the outlet of the geothermal well 1 to form the first water outflow 41. The above state A actually continues the state F of the previous geothermal water repetitive cycle.

[0031] Since the concentration of dispersed matter in the second inflow water 22 is greater than that in the first round of geothermal water 31, and the density of dispersed matter used in the geothermal water treatment method of the mid-deep non-interference geothermal system is greater than that of raw water, the density of the second inflow water 22 must also be greater than that of the first round of geothermal water 31. Thus, in state A, the first driving mode can completely or partially utilize the gravity sinking of the second inflow water 22 to lift the first round of geothermal water 31.

[0032] After the first output water 41 is output from the outlet of the geothermal well 1, it is first subjected to energy recovery (power generation or heat exchange, etc.) and then enters the second water storage device 52 for temporary storage.

[0033] In state B, the second incoming water 22 has replaced the first round of geothermal water 31 and becomes the second round of geothermal water 32; at the same time, the first outflow water 41 in the second water storage device 52 begins to enter the first water storage device 51. The third incoming water 23 is formed by adding dispersed substances to the first outflow water 41. At this time, the first water storage device 51 is used to store the third incoming water 23.

[0034] In state C, the first water storage device 51 is inputting the third water inlet 23 into the inlet of the geothermal well 1. At the same time, the mid-deep interference-free geothermal system drives the second round of geothermal water 32 in the geothermal well 1 through the first driving mode to be output from the outlet of the geothermal well 1 to form the second water outlet 42.

[0035] Since the concentration of dispersed matter in the third inflow water 23 is greater than that in the second round of geothermal water 32, and the density of dispersed matter used in the geothermal water treatment method of the mid-deep non-interference geothermal system is greater than that of raw water, the density of the third inflow water 23 must also be greater than that of the second round of geothermal water 32. Thus, in state C, the first driving mode can completely or partially utilize the gravity sinking of the third inflow water 23 to lift the second round of geothermal water 32.

[0036] After the second water 42 is output from the outlet of the geothermal well 1, it first undergoes energy recovery (power generation or heat exchange, etc.) and then enters the second water storage device 52 for temporary storage.

[0037] In state D, the third incoming water 23 has basically replaced the second round of geothermal water 32 and becomes the third round of geothermal water 33; at the same time, the second outgoing water 42 in the second water storage device 52 is ready to enter the first water storage device 51 for storage.

[0038] In state E, the third round of geothermal water 33 is driven by the second driving mode to be output from the outlet to form the third water outlet 43. At the same time, the third water outlet 43 is input into the filtering device 53. The filtering device 53 filters the dispersed substances in the third water outlet 43 to obtain raw water with the dispersed substance concentration reduced to a set range. The raw water is then input from the inlet of the geothermal well 1 as the first water inlet 21 of the next geothermal water repetition cycle.

[0039] In state F, the first incoming water 21 has replaced the third round of geothermal water 33 of the previous geothermal water recirculation cycle and becomes the first round of geothermal water 31 ; meanwhile, the second incoming water 22 has been stored in the second water storage device 52 .

[0040] In the above geothermal water recirculation cycle, the geothermal water is lifted three times. The following is an explanation of the relevant energy consumption in the above geothermal water recirculation cycle.

[0041] First assume that: geothermal well 1 is a U-shaped geothermal well with a depth of 2000m and a parallel section length of 500m. The inner diameter of geothermal well 1 is 200mm. The total length of the geothermal well = 2*2000m+500m=4500m. The volume of the geothermal well = π*(0.1 m)²*4500m≈141.37m³. The density of raw water is 1000kg / m³. The density of the second water inlet 22 is increased by 10% based on the density of raw water. The density of the third water inlet 23 is increased by 10% based on the density of the second round of geothermal water.

[0042] If the first round of geothermal water 31 (raw water) is extracted from the geothermal well 1 entirely by pumping, the required mechanical energy consumption is calculated as follows: I. Calculate the mass of the first round of geothermal water 31: Mass = density * volume = 1000kg / m³ * 141.37m³ = 141,370kg.

[0043] II. Calculate gravitational potential energy: Potential energy = m*g*h.

[0044] Among them, m=mass, g=gravitational acceleration (9.81m / s²), h is the average lifting height, h=depth / 2+parallel section length / 2=2000m / 2+500m / 2=1000m+250m=1250m.

[0045] Potential energy = 141370kg*9.81m / s²*1250m=1733308875J≈1.73GJ.

[0046] III. Estimation of Friction Losses: Friction losses depend on several factors including flow rate, pipe roughness, etc. As a rough estimate, assume that friction losses are 20-30% of the gravitational potential energy.

[0047] Take 25%: friction loss ≈ 0.43GJ.

[0048] IV. Total energy requirements: Total energy = potential energy + friction loss = 1.73GJ + 0.43GJ = 2.16GJ.

[0049] V. Consider the efficiency of the pump: Assume the pump efficiency is 80% The actual energy required = total energy / efficiency = 2.16GJ / 0.8 = 2.7GJ.

[0050] VI. Results: In theory, about 2.7 GJ of energy is required to extract all the first round of geothermal water 31 (raw water) from the U-shaped geothermal well, which is equivalent to about 750 kWh of electricity.

[0051] Assuming that the density of the second water inflow 22 increases by 5% on the basis of the original water density, that is, the density of the second water inflow 22 is 1050kg / m³, it can be calculated that: I. Pressure difference caused by density difference: Pressure difference = density difference * gravitational acceleration * depth = (1050-1000) kg / m³ * 9.81 m / s² * 2000 m = 981000 Pa ≈ 0.981 MPa.

[0052] II. Friction loss: Assuming that friction loss is 25% of the total energy, friction pressure loss ≈ pressure difference*25%=0.981MPa*0.25≈0.245Mpa.

[0053] III. Effective pressure difference: Effective pressure difference = pressure difference caused by density difference - friction pressure loss = 0.981MPa-0.245MPa=0.736MPa.

[0054] IV. According to the Darcy–Weisbach equation, the velocity during the second water inflow 22 replacing the first round of geothermal water 31 (raw water) is estimated to be 0.5 m / s-3 m / s, which meets the requirements of a mid-deep undisturbed geothermal system.

[0055] V. Results: The second water inflow 22 with an input density of 1050kg / m³ can theoretically allow the first round of geothermal water 31 (raw water) to flow out of the U-shaped geothermal well naturally and achieve complete replacement. This process is self-driven and does not require additional pump support. In other words, the first round of geothermal water 31 can be lifted without relying on pumps, thereby saving 750kWh of electricity.

[0056] Similarly, the second round of geothermal water 32 can be raised without relying on a pump, thereby saving at least an additional 750 kWh of electricity.

[0057] Assuming that the density of the third round of geothermal water 33 is 1102.5kg / m³ (i.e., the density is increased by 5% on the basis of 1050kg / m³), it can be calculated that the mechanical energy consumption required to completely rely on the pump to lift the third round of geothermal water 33 from the geothermal well 1 is 830kWh of electrical energy. The specific calculation process is: I. Calculate the mass of the first round of geothermal water 31: Mass = density * volume = 1102.5kg / m³ * 141.37m³ = 155860.125kg.

[0058] II. Calculate gravitational potential energy: Potential energy = m*g*h.

[0059] Where m = mass, g = acceleration due to gravity (9.81 m / s²), and h = average lift height = 1250 m.

[0060] Potential energy = 155,860.125kg*9.81m / s²*1250m=1,911,011,484.375J≈1.91GJ.

[0061] III. Estimation of Friction Losses: Assume that friction losses are 25% of the gravitational potential energy.

[0062] Friction loss≈1.91GJ*0.25=0.48GJ.

[0063] IV. Total energy requirements: Total energy = potential energy + friction loss = 1.91GJ + 0.48GJ = 2.39GJ.

[0064] V. Consider the efficiency of the pump: Assume the pump is 80% efficient.

[0065] The actual energy required = total energy / efficiency = 2.39GJ / 0.8 = 2.99GJ.

[0066] VI. Results: To extract all the geothermal water with a density of 1102.5kg / m³ from the U-shaped geothermal well, theoretically, about 2.99GJ of energy is required, which is equivalent to about 830kWh of electricity (2.99GJ*277.778kWh / GJ≈830kWh).

[0067] visible, Figure 1 The mechanical energy consumed by the three-time lifting pump for geothermal water in one geothermal water recirculation cycle is 830kWh. However, if the existing solution is adopted, the mechanical energy consumed by the three-time lifting pump is 3*750kWh=2250kWh. In one geothermal water recirculation cycle, the mechanical energy consumption of lifting geothermal water from underground to the ground by pumping is 2250kWh-830kWh=1420kWh.

[0068] Therefore, the method for treating geothermal water in a medium-deep layer non-interference geothermal system according to the embodiment of the present invention is Figure 1 In a geothermal water repetitive circulation cycle shown, the mechanical energy consumption of lifting geothermal water from underground to the surface through a pump during the operation of a mid-deep undisturbed geothermal system can be significantly reduced.

[0069] Furthermore, if the N value is set to be greater than 3, for example, a reasonable range is to set the N value to any integer between 5 and 8 (based on 1000 kg / m³, the density increases by 5% each time, and the fifth water inlet density is 1276.2815625 kg / m³), the mechanical energy consumption of the pump can be further reduced.

[0070] The energy consumption of common water filtration systems is usually in the range of 0.1kWh / m³-1kWh / m³. Taking the middle value of 0.5kWh / m³, filtering 141.37m³ of water once consumes about 70kWh. In other words, the energy consumption increased by filtering dispersed substances in the Nth effluent water using the above-mentioned medium-deep non-interference geothermal system geothermal water treatment method is basically negligible compared to the energy saved.

[0071] Generally speaking, the dispersion system formed by the dispersed substance and water in the i-th inflow is a colloid or a suspension. Here, the dispersion system formed by the dispersed substance and water in the i-th inflow is set as a colloid or a suspension, which can ensure the density adjustment ability of the i-th inflow (the density adjustment range of the solution is relatively limited), and the dispersed substance in the colloid or suspension can be separated by physical means, which is easier to recycle.

[0072] Preferably, the particle size of the dispersant in the dispersion is 0.1 micron-50 micron. Selecting a dispersant with a particle size range of 0.1 micron-50 micron can provide many advantages for the mid-deep non-interference geothermal system: it can form a stable dispersion with geothermal water, maintain good fluidity and heat transfer efficiency; it is suitable for filling formation pores of various sizes (although the desired situation is that the pipe body of the geothermal well 1 is completely isolated from the formation, but, limited by the current construction technology for U-shaped geothermal wells, the intersection of the parallel section and the vertical section of the U-shaped geothermal well may still be exposed to a certain extent); the sedimentation rate is controllable, which is convenient for subsequent filtration treatment; it will not significantly increase the system pressure loss or equipment wear; it allows the use of a variety of materials as dispersants (for example, the dispersant can be selected from one or more of iron oxide, silicon dioxide, aluminum oxide, silicon carbide, glass microspheres, and montmorillonite), providing design flexibility; and this range is wide enough to achieve a particle size gradient design between batches (described later in this manual), thereby optimizing system performance and long-term stability.

[0073] As an improvement, the particle size range of the dispersed substances in each batch of water in the entire i-th water inflow can also be set to show a gradient upward trend with the increase of i value. For example, if N is set to 5, the particle size range of the dispersed substances in each batch of water in the entire i-th water inflow can be set as follows: the second water inflow: 0.1 micron-5 micron; the third water inflow: 10 micron-20 micron; the fourth water inflow: 25 micron-35 micron; the fifth water inflow: 40 micron-50 micron. It is best that the particle size ranges do not overlap to facilitate the separation of dispersed substances in different particle size ranges.

[0074] The main advantages of this setting are: first, the use of smaller-sized dispersed matter in the early batches of all the i-th water inflow can reduce the initial aggregation effect. As time goes by, the dispersed matter particle size gradually increases, but since the dispersed matter with smaller particle size has been distributed, the aggregation tendency of the dispersed matter with larger particle size will be reduced. Second, the dispersed matter with smaller particle size at the beginning provides a large surface area, which is conducive to the heat recovery of geothermal water; the dispersed matter with larger particle size later further increases the overall heat capacity of geothermal water. At the same time, the dispersed matter with larger particle size uses the heat transfer mode established by the dispersed matter with smaller particle size to achieve heat output, and the heat transfer efficiency is higher. Third, the dispersed matter with smaller particle size at the beginning will fill the tiny pores in the rock or formation (mainly at the junction of the parallel section and the vertical section of the U-shaped geothermal well), which helps to reduce the flow resistance of geothermal water. Fourth, the dispersed matter with smaller particle size at the beginning will have a slower sedimentation rate, which helps them to be more evenly distributed in the system; the dispersed matter with larger particle size later, although the sedimentation rate is faster, will be "supported" by the dispersed matter with smaller particle size, slowing down its sedimentation.

[0075] As a preferred embodiment, silicon carbide is particularly used as the dispersant. Silicon carbide particles have many advantages as dispersants in geothermal water: they have extremely high thermal conductivity, which can significantly improve the heat transfer efficiency; excellent wear resistance and chemical stability enable them to maintain performance for a long time in harsh environments; high temperature stability and low thermal expansion coefficient ensure reliability in temperature changes; good fluidity is conducive to system operation; at the same time, its environmental friendliness, controllable particle size distribution and long-term cost-effectiveness make silicon carbide an ideal dispersant material in the present invention, which can effectively improve system efficiency.

[0076] In addition, optionally, a dispersant for increasing the separation of dispersed particles and preventing aggregation may be added to the dispersion system, for example, sodium polyacrylate (PAAS).

[0077] Based on the above, the second water inlet 22 can be prepared from the following raw materials (% is weight ratio): Water: 94.2%-94.7%; Silicon carbide powder: 5%-5.5%; Sodium polyacrylate: 0.3%-0.5%.

[0078] The contents of each raw material in the second influent water 22 are converted into volume percentages and the thermal conductivity of each raw material is weighted averaged according to the volume percentage. The thermal conductivity of the second influent water 22 is calculated to be 3.89 W / (m·K), which is much higher than the thermal conductivity of water 0.6 W / (m·K).

[0079] Furthermore, in order to prevent the mixing of each batch of water in the entire i-th water inflow with the corresponding i-1th round of geothermal water, before the i-th water inflow is input into the inlet of the geothermal well 1, a section of isolation material 6 can be injected into the inlet of the geothermal well 1, and the isolation material 6 can maintain an isolation layer between the i-th water inflow and the i-1th round of geothermal water. The isolation layer can effectively prevent the i-th water inflow from directly mixing with the i-1th round of geothermal water, ensuring that the dispersed systems with different dispersed substance concentrations are relatively independent and maintaining the concentration gradient of the dispersed systems with different dispersed substance concentrations.

[0080] It is possible to use chemical gel as the isolation material 6. Chemical gel sealing technology has been widely used in oil exploration and development, mainly for the isolation of formations and wellbores under high-strength pressure and acidic gas corrosion conditions (which is similar to the use environment of the isolation material 6). However, the chemical gel is formed by adding curing agents, retarder agents, weighting agents and other materials to the gel base liquid, so it is inconvenient to use at the entrance of the geothermal well.

[0081] Optionally, the isolation material uses a foaming material. Foaming materials have many advantages as isolation materials, the most prominent of which is the convenience of injection and removal. This material can usually be injected into the geothermal well in liquid form (this can maintain the closedness of the medium-deep non-interference geothermal system, and the thickness of the isolation layer is not easy to control), and then foam itself in the geothermal well to form an effective isolation barrier. This feature makes the operation process simple and efficient, without the need for complex equipment or procedures. After flowing out of the geothermal well, the foaming material can be separated from the effluent through a simple physical filtration procedure, so that it can be easily removed without causing long-term effects on the medium-deep non-interference geothermal system. In addition, the foaming material also has the advantages of low density, strong compressibility, good thermal stability, high chemical stability, and no clogging of geothermal wells. It can maintain a good isolation effect in a high-temperature and high-pressure geothermal environment. At the same time, it has strong adaptability and can effectively fill irregular spaces to ensure the integrity of the isolation. These characteristics make the foaming material an ideal choice of isolation material in the present invention.

[0082] The foam material can be selected from foam materials having at least the following characteristics: a) being water-proof; b) being able to withstand the temperature at a depth of several thousand meters underground; and c) being light in weight and being able to float on the surface of water without being deformed.

[0083] The geothermal water treatment equipment for a medium-deep non-interference geothermal system for implementing the above-mentioned geothermal water treatment method for a medium-deep non-interference geothermal system is arranged in a ground plant and is used for the above-mentioned geothermal water treatment method for a medium-deep non-interference geothermal system, comprising: a first water storage device 51, used to store all batches of water in the i-th inflow and input all batches of water in the i-th inflow into the inlet of a geothermal well 1 (the geothermal well 1 is opened in the formation and adopts a U-shaped geothermal well, which is a common form of geothermal well); a second water storage device 52, used to store all batches of water in the j-th outflow, where j is an integer from 1 to N; a dispersed matter adding device, used to add dispersed matter to the water body of the first water storage device 51 and / or the second water storage device 52; a filtering device 53, used to filter the dispersed matter in the N-th outflow to obtain raw water with the dispersed matter concentration reduced to a set range.

[0084] The above-mentioned mid-deep non-interference geothermal system geothermal water treatment equipment is usually also equipped with energy recovery devices in the ground plant, such as geothermal generators or heat exchangers.

[0085] 2. Isolation materials and their installation and operation in mid-deep non-interference geothermal systems.

[0086] Figure 2 It is a schematic structural diagram of the isolation material involved in the operation method of a mid-deep interference-free geothermal system according to an embodiment of the present invention. Figure 3 for Figure 2 Schematic diagram of the movement of isolation materials in a geothermal well. Figure 2-Figure 3 As shown, the above-mentioned isolation material may include a first foaming portion 61, a second foaming portion 62 and a third foaming portion 63, wherein the first foaming portion 61 is formed by a first foaming material formed by foaming and solidifying the first fluid raw material first injected into the geothermal well 1, the second foaming portion 62 is formed by a second foaming material formed by foaming and solidifying the second fluid raw material subsequently injected into the geothermal well 1 and attached to the first foaming material, and the third foaming portion 63 is formed by a third foaming material formed by foaming and solidifying the third fluid raw material finally injected into the geothermal well 1 and attached to the second foaming material; when in use, the first foaming portion 61 and the third foaming portion 63 are respectively in contact with the existing geothermal water in the geothermal well and the incoming water input from the entrance of the geothermal well and play a role of water-proof sealing, and the second foaming portion 62 is connected between the first foaming portion 61 and the third foaming portion 63 and plays a role of flexible and deformable connection, so that the isolation material can adaptively follow the movement of water flow in the geothermal well.

[0087] The above-mentioned isolation material adopts a three-layer foaming part design to achieve better adaptability and sealing effect to the geothermal well channel, wherein the first foaming part 61 and the third foaming part 63 provide reliable sealing effect, and the middle second foaming part 62 acts as a flexible connection, so that the entire isolation material can flexibly turn in the geothermal well 1, thereby maintaining the sealing performance while enabling the isolation material to adaptively follow the water flow in the geothermal well, thereby better avoiding blockage of the geothermal well.

[0088] Preferably, the diameter of the first foaming portion 61 and the diameter of the third foaming portion 63 are larger than the diameter of the second foaming portion 62, so that the second foaming portion 62 forms a connecting neck connected between the first foaming portion 61 and the third foaming portion 63. This design with larger ends and a connecting neck in the middle can ensure that the first foaming portion 61 and the third foaming portion 63 are in contact with the well wall respectively, thereby providing a better sealing effect, and at the same time provide the isolation material with better flexible deformation ability.

[0089] Optionally, the thickness of the first foaming portion 61 and the thickness of the third foaming portion 63 are less than or equal to the length of the second foaming portion 62. The longer second foaming portion 62 provides sufficient deformation space to ensure that the isolation material has sufficient bending margin when the water flows.

[0090] In a specific implementation manner, the first foaming material and / or the third foaming material is / are modified polyurethane foaming material, and the second foaming material is modified phenolic resin foaming material.

[0091] The modified polyurethane foam material can achieve excellent sealing and waterproof properties, and can achieve good chemical resistance, especially stable performance in acid, alkali and salt water environments. The modified phenolic resin foam material can have excellent flexibility, good stress relaxation performance and fatigue resistance, can adapt to dynamic deformation environments, has good structural stability and is not easy to become brittle, and is suitable as the second foaming part 62.

[0092] Specifically, the formula of the modified polyurethane foam material is as follows: Component A: accounting for 43%-45% of the total weight of the raw materials and containing 85%-88% of the total weight of the modified MDI (i.e., modified diphenylmethane diisocyanate) of the A component, 8%-10% of the total weight of the A component of the high temperature resistant modifier, 2%-3% of the total weight of the A component of the reinforcing filler and 2%-3% of the total weight of the A component of the antioxidant; Component B: accounting for 55%-57% of the total weight of the raw materials and containing 63%-66% of the total weight of the B component of the polyether polyol (it is recommended to use a commercially available special polyether polyol developed specifically for high temperature applications), 20%-22% of the total weight of the B component of the crosslinking agent, 8%-10% of the total weight of the B component of the foaming agent, 2%-3% of the total weight of the B component of the catalyst and 2%-3% of the total weight of the B component of the stabilizer.

[0093] Among them, the high temperature resistant modifier is tri(1-chloro-2-propyl) phosphate; the reinforcing filler is nano-silicon dioxide; the antioxidant is butylated hydroxytoluene; the cross-linking agent is pentaerythritol; the foaming agent is cyclopentane; the catalyst is triethylenediamine; and the stabilizer is polyether modified silicone oil.

[0094] The foaming principle of the above-mentioned modified polyurethane foam material is: the modified MDI (diphenylmethane diisocyanate) in component A and the polyether polyol in component B undergo addition polymerization reaction, and cyclopentane (foaming agent) is vaporized to form bubbles during the exothermic reaction. Under the action of triethylenediamine (catalyst) and polyether modified silicone oil (stabilizer), the bubbles grow stably and solidify into shape, and finally form a foam material with a closed pore structure; pentaerythritol as a cross-linking agent increases the cross-linking degree of the material and improves the mechanical properties.

[0095] The modified polyurethane foam material is a two-component modified polyurethane foam material. The main component modified MDI reacts with polyether polyol to form a basic network structure, wherein tri(1-chloro-2-propyl) phosphate is used as a high temperature modifier to improve the heat resistance, nano-silicon dioxide is used as a reinforcing filler to enhance the mechanical properties, and dibutyl hydroxytoluene prevents oxidative degradation. Pentaerythritol is used as a cross-linking agent to increase the cross-linking density and enhance the structural stability, cyclopentane is used as a foaming agent to control the pore size distribution, triethylenediamine is used to catalyze the reaction rate, and polyether modified silicone oil stabilizes the foaming process. This formula design makes the foam material have excellent high temperature resistance (up to 18°C ​​or above), good sealing (density 0.45-0.55g / cm³), high mechanical strength (designed compressive strength ≥1.2MPa) and excellent dimensional stability.

[0096] Specifically, the formula of the modified phenolic resin foaming material is as follows: Component A: accounting for 45%-47% of the total weight of the raw materials and containing 70%-75% of the modified phenolic resin of the total weight of Component A, 15%-18% of the elastic toughening agent of the total weight of Component A, 8%-10% of the modifier of the total weight of Component A and 5%-7% of the filler of the total weight of Component A; Component B: accounting for 53%-55% of the total weight of the raw materials and containing 70%-75% of the curing agent of the total weight of Component B, 12%-15% of the foaming agent of the total weight of Component B, 8%-10% of the catalyst of the total weight of Component B and 3%-5% of the surfactant of the total weight of Component B.

[0097] The elastic toughening agent is nitrile rubber; the modifier is melamine; the filler is glass fiber; the curing agent is p-toluenesulfonic acid; the foaming agent is cyclopentane; the catalyst is dimethylethanolamine; and the surfactant is polyether modified silicone oil.

[0098] The foaming principle of the above-mentioned modified phenolic resin foam material is as follows: the modified phenolic resin in component A undergoes a condensation reaction under the action of p-toluenesulfonic acid (curing agent) in component B, and at the same time, cyclopentane (foaming agent) is vaporized to produce bubbles during the exothermic reaction, and under the action of dimethylethanolamine (catalyst) and polyether modified silicone oil (surfactant), the bubbles grow stably and solidify to form a foam material with a closed pore structure; melamine as a modifier improves the heat resistance of the material, and nitrile rubber as an elastic toughening agent improves the toughness of the material.

[0099] The modified phenolic resin foaming material is a two-component modified phenolic resin foaming material, in which the modified phenolic resin and the p-toluenesulfonic acid curing agent form a basic skeleton, nitrile rubber is used as an elastic toughening agent to improve toughness, melamine modification improves heat resistance, and glass fiber filler enhances overall strength. Cyclopentane is used as a foaming agent to control the pore structure, dimethylethanolamine adjusts the curing rate, and polyether modified silicone oil ensures foaming uniformity. This formula combination gives the material excellent flexibility (designed elongation at break ≥150%), good elastic modulus (0.3-0.5MPa), moderate density (0.35-0.45g / cm³) and excellent fatigue resistance (designed compression permanent deformation rate ≤5%), and is particularly suitable for use as the second foaming part 62.

[0100] Figure 4 for Figure 2 Schematic diagram of the external structure of the tee pipe used in the setting operation of the isolation material in the mid-depth non-interference geothermal system. Figure 5 for Figure 4 Schematic diagram of the structure of the spraying device installed in the Figure 4-Figure 5As shown, the method for setting the above-mentioned isolation material in the mid-deep non-interference geothermal system comprises: first, installing a three-way pipe 7 at the entrance of the geothermal well 1, the three-way pipe 7 having a lower water outlet, a side water inlet and an upper spray device installation port, the lower water outlet is connected to the entrance of the geothermal well, the side water inlet is connected to the water inlet pipe, and the upper spray device installation port is used to install a spray device 8, the spray device 8 comprises a first spray unit 81 and a second spray unit 82, the nozzle 811 of the first spray unit and the nozzle 821 of the second spray unit are both facing downward, the nozzle 811 of the first spray unit is arranged around the outside of the nozzle 821 of the second spray unit, the first spray unit 81 is used for injection spraying of the first fluid raw material and the third fluid raw material, and the second spray unit 82 Used for injection spraying of the second fluid raw material; then, when the liquid level of the existing geothermal water in the geothermal well 1 drops to the preset position below the spraying device 8 (a liquid level meter can be set at the lower water outlet of the three-way pipe 7 to detect the liquid level), the first fluid raw material is injected into the liquid level of the existing geothermal water in the geothermal well through the first spraying unit 81 and foamed and solidified to form the first foaming material, and then the second fluid raw material is injected into the first foaming material through the second spraying unit 82 and foamed and solidified to form the second foaming material, and then the third fluid raw material is injected into the second foaming material through the first spraying unit 81 and foamed and solidified to form the third foaming material, thereby completing the setting of the isolation material; finally, the water is supplied to the geothermal well through the water inlet pipe. The working principles of the above-mentioned first spraying unit 81 and the second spraying unit 82 refer to the subsequent description.

[0101] The above setting method adopts the design of a three-way pipe 7 and a spray device 8 with double spray units (a first spray unit and a second spray unit), so that the first fluid raw material, the second fluid raw material and the third fluid raw material can be accurately injected in a specific order and position, ensuring the shape and position of the isolation material.

[0102] like Figure 5As shown, the specific structure of the spraying device 8 is as follows: the first spraying unit 81 has a cylindrical shell 812, the upper end of the shell 812 is provided with a flange 813, the flange 813 is used to fix the shell 812 to the corresponding flange on the upper spraying device installation port, the shell 812 is internally sleeved with an inner sleeve 814, the gap between the upper section of the inner sleeve 814 and the inner wall of the shell 812 is large and forms a first mixing chamber 815, the first mixing chamber 815 is used to achieve the mixing of the A component and the B component of the modified polyurethane foam material A spiral mixing component is provided in the first mixing chamber 815 to promote the mixing of component A and component B of the modified polyurethane foam material. A small gap between the lower section of the inner sleeve 814 and the inner wall of the shell 812 forms an annular gap 816 connected to the nozzle 811 of the first spraying unit. In addition, different feed channels (i.e., first feed channels 817) are respectively provided in the shell 812, so that component A and component B of the modified polyurethane foam material and compressed air (compressed air is not necessary) can enter the first mixing chamber 815 respectively.

[0103] In addition, the second spray unit 82 has an inner tube 822 which is sleeved in the inner sleeve 814, and a nozzle 823 is provided at the lower end of the inner tube 822. The upper end of the inner tube 822 is fixed to the bottom of the flange 813 by bolts, and a second mixing chamber 824 is provided in the inner tube 822. The second mixing chamber 824 is used to achieve mixing of component A and component B of the modified phenolic resin foaming material. A spiral mixing component is provided in the second mixing chamber 824 to promote mixing of component A and component B of the modified phenolic resin foaming material. The lower end of the second mixing chamber 824 is connected to the nozzle 821 of the second spray unit on the nozzle 823, and different feed channels (i.e., second feed channels 825) are respectively opened in the inner tube 822, so that component A and component B of the modified phenolic resin foaming material and compressed air (compressed air is not necessary) can enter the second mixing chamber 824.

[0104] During the spraying process of the first spraying unit 81, the components A and B of the modified polyurethane foam material are respectively transported to the first mixing chamber 815 through different first feed channels 817 under high pressure (for example, 15-20 MPa). In the first mixing chamber 815, under the action of the spiral mixing component, the components A and B are mixed by high-speed vortex to form a uniform liquid mixture (first fluid raw material). Subsequently, the first fluid raw material passes through the annular gap 816 formed between the inner sleeve 814 and the shell 812, and is finally sprayed out from the nozzle 811 at a high speed. After the first fluid raw material is sprayed out, due to the sudden drop in pressure and the start of the exothermic reaction, the cyclopentane in the component B is rapidly vaporized, and uniform bubbles are formed under the stabilizing effect of the polyether-modified silicone oil. Finally, the first fluid raw material forms a modified polyurethane foam material (the foaming and curing time is about 5 minutes).

[0105] During the spraying process of the second spraying unit 82, component A and component B of the modified phenolic resin foaming material are transported to the second mixing chamber 824 in the inner tube 822 through different second feed channels 825. In this second mixing chamber 824, under the action of the spiral mixing component, component A and component B are vortex mixed to form a uniform liquid mixture (second fluid raw material). Subsequently, the second fluid raw material passes through the lower end of the second mixing chamber 824, enters the nozzle 823, and is sprayed out from the nozzle 821 of the second spraying unit 82 at a high speed; after the mixture is sprayed out, due to the sudden drop in pressure and the heat release of the condensation reaction, the cyclopentane in the B component is rapidly vaporized, and uniform bubbles are formed under the surface activity of the polyether-modified silicone oil, and finally the second fluid raw material forms a modified phenolic resin foaming material (the foaming and curing time is about 8 minutes).

[0106] It should be pointed out that: when the first fluid raw material is injected into the liquid surface of the existing geothermal water in the geothermal well through the first spraying unit 81 and is foamed and solidified to form the first foaming material, the isocyanate group (-NCO) from diphenylmethane diisocyanate will react with water, but this reaction is local, and the first foaming material can still be formed by rapid foaming.

[0107] According to the formula of the modified polyurethane foam material, the foaming process of the first fluid raw material does not require high temperature conditions (the addition polymerization reaction can be carried out at room temperature, and the presence of the catalyst triethylenediamine can significantly accelerate the reaction speed. In addition, the foaming process of the first fluid raw material itself is exothermic), and the foaming of the first fluid raw material can be sprayed at room temperature. The density of the first fluid raw material is about 1.16g / cm³, which is slightly higher than water. As long as the spraying flow rate of the first fluid raw material is ensured to be sufficient, the part of the first fluid raw material that reaches the liquid surface will start to foam before it has time to react with water and sink. After foaming, the density is reduced and thus it remains above the liquid surface to form a "bridge", and the first foaming material is further thickened at the "bridge" later. It should be noted here that compressed air can be introduced into the first mixing chamber 815, so that the first fluid raw material sprayed from the nozzle 811 is atomized, and the atomized droplets are easily supported by the liquid surface, and the foaming speed is faster, thereby further ensuring the success rate of liquid surface foaming. In addition, in this embodiment, the nozzle 811 also uses a sintered fluidizing disk, which can be purchased from the market and has the characteristics of small pore size and large pore density (the pore size and pore density can be selected according to needs). It can make the fine droplets formed by the first fluid raw material evenly distributed on the cross-section of the lower water outlet of the tee pipe 7, thereby improving the initial bridging effect.

[0108] When the first foaming material is not completely cured, the second fluid raw material is injected through the second spraying unit 82. The foaming process of the second fluid raw material also does not require high temperature conditions, and can be sprayed at room temperature. When the first foaming material (modified polyurethane foaming material) is not completely cured, there are active isocyanate groups (-NCO) and polyether modified silicone oil on the surface, and polyurethane has adhesiveness. At this time, the second fluid raw material is sprayed on the modified polyurethane foaming material. When the A component and the B component of the modified phenolic resin foaming material are mixed and contacted, the hydroxyl group in the modified phenolic resin will react with the active isocyanate group remaining on the surface of the modified polyurethane foaming material. At the same time, the phenolic resin is polycondensed and released heat under the action of p-toluenesulfonic acid, so that cyclopentane is gasified to generate foaming pressure. In this process, the foaming pressure promotes interface contact and material interpenetration, forming a composite interface structure of chemical bonding and mechanical bite, and the nitrile rubber and glass fiber in the second fluid raw material further enhance the flexibility and mechanical strength of the interface. Thus, the second foaming material is attached to the first foaming material.

[0109] When the second foaming material is not completely solidified, the third fluid raw material is injected through the first spraying unit 81. For the combination process of the third foaming material and the second foaming material, reference can be made to the above content. It should be pointed out here that the third fluid raw material attached to the upper end of the second foaming material will expand to the surroundings, having a similar "bridging" effect as described above, thereby gradually forming the third foaming part.

[0110] The above is a description of the relevant contents of the present invention. A person skilled in the art will be able to implement the present invention based on these descriptions. Based on the above contents of this specification, all other embodiments obtained by a person skilled in the art without making any creative work shall fall within the scope of patent protection.

Claims

1. A method for operating a medium-deep, non-interference geothermal system, characterized in that: The process includes setting up an isolation material, which is a foamed material injected into a geothermal well in fluid form and subsequently foamed and cured within the well. This isolation material is used in a medium-deep, non-interfering geothermal system to isolate the incoming water from the geothermal water already present in the well. The setting up operation specifically includes: setting up a first foaming section, which is formed by foaming and curing a first foamed material from a first fluid raw material initially injected into the geothermal well; and setting up a second foaming section, which is formed by foaming and curing a second fluid raw material subsequently injected into the geothermal well and adhering to the first foamed material. The formed second foamed material forms a second foamed section; and a third foamed section is provided, that is, a third foamed material formed by the foaming and solidification of a third fluid raw material that is finally injected into the geothermal well and attached to the second foamed material; when in use, the first foamed section and the third foamed section respectively contact the existing geothermal water in the geothermal well and the incoming water input from the geothermal well inlet and play a water-proof sealing role; the second foamed section is connected between the first foamed section and the third foamed section and plays a flexible and deformable connection role, so that the isolation material can adaptively follow the water flow in the geothermal well.

2. The operation method of the medium-deep undisturbed geothermal system as described in claim 1, characterized in that: During the setting operation, the diameters of the first foaming part and the third foaming part are made larger than the diameter of the second foaming part, and the second foaming part forms a connecting neck between the first foaming part and the third foaming part.

3. The operation method of the medium-deep undisturbed geothermal system as described in claim 2, characterized in that: During the setting operation, the thickness of the first foaming part and the thickness of the third foaming part are made less than or equal to the length of the second foaming part.

4. The operation method of the medium-deep undisturbed geothermal system as described in claim 1, characterized in that: During the setting operation, the first foaming material and / or the third foaming material are modified polyurethane foaming materials, and the second foaming material is modified phenolic resin foaming material.

5. The operation method of the medium-deep non-interference geothermal system as described in claim 4, characterized in that: The formulation of the modified polyurethane foam material is as follows: Component A: accounts for 43%-45% of the total weight of raw materials and contains 85%-88% of modified MDI, 8%-10% of high-temperature resistant modifier, 2%-3% of reinforcing filler and 2%-3% of antioxidant. Component B: Comprising 55%-57% of the total weight of raw materials, and containing 63%-66% of polyether polyol, 20%-22% of crosslinking agent, 8%-10% of foaming agent, 2%-3% of catalyst, and 2%-3% of stabilizer. During the preparation of the modified polyurethane foam material, modified MDI undergoes an addition polymerization reaction with polyether polyol. Simultaneously, the foaming agent vaporizes to form bubbles during the exothermic reaction. Under the action of catalyst and stabilizer, the bubbles grow stably and solidify, ultimately forming a foam material with a closed-cell structure.

6. The operation method of the medium-deep undisturbed geothermal system as described in claim 5, characterized in that: The high-temperature resistant modifier is tris(1-chloro-2-propyl) phosphate; the reinforcing filler is nano-silica; the antioxidant is butylated hydroxytoluene; the crosslinking agent is pentaerythritol; the foaming agent is cyclopentane; the catalyst is triethylenediamine; and the stabilizer is polyether-modified silicone oil.

7. The operation method of the medium-deep non-interference geothermal system as described in claim 4, characterized in that: The formulation of the modified phenolic resin foaming material is as follows: Component A: accounts for 45%-47% of the total weight of raw materials and contains 70%-75% of modified phenolic resin, 15%-18% of elastic toughening agent, 8%-10% of modifier and 5%-7% of filler. Component B: comprises 53%-55% of the total weight of raw materials and contains 70%-75% of curing agent, 12%-15% of foaming agent, 8%-10% of catalyst, and 3%-5% of surfactant. During the preparation of the modified phenolic resin foam material, the modified phenolic resin undergoes a condensation reaction under the action of the curing agent. At the same time, the foaming agent vaporizes and generates bubbles during the exothermic reaction. Under the action of the catalyst and surfactant, the bubbles grow stably and solidify to form a foam material with a closed-cell structure.

8. The operation method of the medium-deep non-interference geothermal system as described in claim 7, characterized in that: The elastic toughening agent is nitrile rubber; the modifier is melamine; the filler is glass fiber; the curing agent is p-toluenesulfonic acid; the foaming agent is cyclopentane; the catalyst is dimethylethanolamine; and the surfactant is polyether-modified silicone oil.

9. The operation method of the medium-deep undisturbed geothermal system as described in any one of claims 1-8, characterized in that: A tee pipe is installed at the inlet of the geothermal well. The tee pipe has a lower outlet, a side inlet, and an upper spraying device mounting port. The lower outlet is connected to the inlet of the geothermal well, the side inlet is connected to the inlet pipe, and the upper spraying device mounting port is used to install a spraying device. The spraying device includes a first spraying unit and a second spraying unit. The nozzles of the first spraying unit and the second spraying unit both face downwards. The nozzle of the first spraying unit is arranged around the outside of the nozzle of the second spraying unit. The first spraying unit is used for injection spraying of the first fluid material and the third fluid material, and the second spraying unit is used for injection spraying of the second fluid material. During the setup operation, after the level of the existing geothermal water in the geothermal well drops to a preset position below the spraying device, the first fluid raw material is injected onto the surface of the existing geothermal water in the geothermal well through the first spraying unit and foamed and cured to form the first foamed material. Then, the second fluid raw material is injected onto the first foamed material through the second spraying unit and foamed and cured to form the second foamed material. After that, the third fluid raw material is injected onto the second foamed material through the first spraying unit and foamed and cured to form the third foamed material, thereby completing the setup operation. After the setup operation is completed, water is supplied to the geothermal well through the water inlet pipe.

10. The operation method of the medium-deep non-interference geothermal system as described in claim 9, characterized in that: The operation of the medium-deep non-interference geothermal system includes the following steps performed within a geothermal water repetition cycle: 1) Inputting the first water intake into the inlet of the geothermal well of the medium-deep non-interference geothermal system. The first water intake uses raw water, which becomes the first round of geothermal water after being input into the geothermal well from the inlet. 2) A second influent is introduced into the geothermal well inlet, and simultaneously, the first round of geothermal water in the geothermal well is driven out of the outlet through the first driving method to form the first outfluent. The second influent contains dispersed substances, and the concentration of dispersed substances in the second influent is greater than that in the first round of geothermal water. The geothermal water remaining in the geothermal well after the first outfluent is discharged from the outlet becomes the second round of geothermal water; 3) Dispersed substances are added to the first outfluent to form a third influent. The concentration of dispersed substances in the third influent is greater than that in the second round of geothermal water; 4) A third influent is introduced into the geothermal well inlet, and simultaneously, the second round of geothermal water in the geothermal well is driven out of the outlet through the first driving method to form the second outfluent. The geothermal water remaining in the geothermal well after the second outfluent is discharged from the outlet becomes the third round of geothermal water; 5) Steps 3)-4) above are repeated a number of times greater than or equal to 0, and each repetition is repeated as follows. In steps 3)-4), the batches of incoming water, the cycles of geothermal water, and the batches of outgoing water are all incremented by 1 from the original values ​​until the geothermal water remaining in the geothermal well becomes the Nth cycle of geothermal water, where N is an integer ≥ 3; 6) The Nth cycle of geothermal water is driven out of the outlet by the second driving method to form the Nth outgoing water. The dispersed matter in the Nth outgoing water is filtered to obtain raw water with the dispersed matter concentration reduced to a set range. The raw water is used as the first incoming water in the next geothermal water recirculation cycle; wherein, the density of the dispersed matter used is greater than the density of the raw water, and the first driving method uses the gravity sinking of each batch of incoming water in the ith cycle to lift the corresponding (i-1)th cycle of geothermal water, where i takes integers from 2 to N; the isolation material is set at the inlet of the geothermal well by the setting operation before the ith incoming water is input into the inlet of the geothermal well.

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