A microseismic monitoring system for hot dry rock mining

Abstract

The present invention relates to a microseismic monitoring system for hot dry rock mining, and relates to the technical field of energy mining. The system comprises a heat exchange device and a central control processing module, wherein the injection pressure range is preset according to the use requirements and the rock mass structure by the central processing unit of the central control processing module, and different initial injection pump speeds are set according to the type of liquid injected into the injection well to inject liquid into the injection well, and the injection pump speed is adjusted in real time based on the initial injection pump speed according to the distribution of cracks, so that the injection pressure is kept within the preset injection pressure range, thereby achieving precise control of the injection process, and the injection pressure is monitored in real time by a pressure sensor, and the return liquid temperature in the mining process according to the use requirements is monitored in real time by a temperature sensor, thereby further improving the precise control of the injection process and improving resource utilization.

Description

Technical Field

[0001] The invention relates to the technical field of energy mining, and in particular to a microseismic monitoring system for hot dry rock mining. Background Art

[0002] Hot dry rock is a high-temperature rock mass buried thousands of meters underground, with a temperature generally above 200°C. my country's existing reserves of hot dry rock are very huge, but the technology for mining hot dry rock needs to be further improved.

[0003] The existing well-dig mining technology is the main mining technology for hot dry rocks. During the mining process, pressurized liquid is injected into the well to heat the rock mass with the liquid to extract heat energy. However, in the existing technology, the control over various data indicators of the overall mining process is insufficient, resulting in low heat extraction rate due to inaccurate control of the injection pressure during the mining process, failure to extract appropriate heat energy according to usage requirements, and high loss rate of heat exchange fluid, thereby resulting in low resource utilization. Summary of the invention

[0004] To this end, the present invention provides a microseismic monitoring system for hot dry rock mining, which is used to overcome the problem of low resource utilization rate caused by inaccurate control of injection pressure during injection in the prior art.

[0005] To achieve the above object, the present invention provides a microseismic monitoring system for hot dry rock mining, comprising:

[0006] A heat exchange device for extracting heat energy from underground hot dry rocks, the heat exchange device comprising a microseismic monitor, a liquid injection controller, a heat exchange well, a heat exchange tube, a temperature sensor and a pressure sensor;

[0007] A central control processing module, including a display and a central processing unit connected to the display, wherein the central processing unit is respectively connected to the liquid injection controller, the microseismic monitor, the temperature sensor and the pressure sensor, and is used to send a corresponding control signal to the liquid injection controller according to the data monitored in real time by the microseismic monitor, the temperature sensor and the pressure sensor;

[0008] When the monitoring system is running, the central processing unit receives in real time the rock crack distribution data monitored by the microseismic monitor, the temperature data monitored by the temperature sensor, and the pressure data monitored by the pressure sensor, and sends a control signal to the injection controller in real time according to the received crack distribution, temperature value, and pressure value to control the injection pump speed, the pumping pump speed, and the control valve opening angle;

[0009] The central processing unit is provided with a preset injection pressure range Py (Pya, Pyb), a preset liquid type matrix Q0 and a preset initial injection pump speed matrix Va0, Pya<Pyb. When the injection pump injects liquid into the rock mass, the central control processing module selects the corresponding initial injection pump speed according to the type of liquid injected into the rock mass so that the injection pump injects liquid into the rock mass. When the injection pressure P belongs to the preset injection pressure range Py, the central control processor does not adjust the injection speed of the injection pump. If the injection pressure P of the injection pump does not fall within the preset injection pressure range Py, the central control processing module selects the corresponding injection pump speed adjustment amount according to the crack distribution monitored by the microseismic monitor to adjust the injection pump speed in real time.

[0010] Further, for the preset injection type matrix Q0, Q0 (Q1, Q2, Q3) is set, wherein Q1 is water, Q2 is brine, and Q3 is high-temperature thermal oil; for the preset initial injection pump speed matrix V0, V0 (V1, V2, V3) is set, wherein V1 is the first preset initial injection pump speed, V2 is the second preset initial injection pump speed, and V3 is the third preset initial injection pump speed, and the preset initial injection pump speeds increase in sequence;

[0011] When the injection pump injects liquid into the injection well, the central control processing module selects different initial injection pump speeds according to the injection type to inject liquid into the injection pipe. When the injection type is Qi, i=1, 2, 3 is set, and the central control processing module adjusts the speed of the injection pump to the corresponding initial injection pump speed Vi so that the injection pump injects liquid into the injection well;

[0012] When the injection pump injects liquid into the injection well and the central control processor adjusts the initial injection pump speed of the injection pump to Vi, the central control processor receives the pressure value P monitored in real time by the pressure sensor, and determines whether the P value is within the Py range.

[0013] If P∈Py, the central control processing module controls the injection pump to inject liquid into the injection well at the initial injection pump speed Vi;

[0014] like The central control processing module adjusts the injection pump speed Vi of the injection pump according to the crack distribution monitored in real time by the microseismic monitor.

[0015] Further, the central processing unit is also provided with a standard crack height Dy, a preset crack height difference matrix D0 and an injection pump speed adjustment matrix ΔV0. For the crack height difference matrix D0, D0 (D1, D2, D3, D4) is set, wherein D1 is a first preset crack height difference, D2 is a second preset crack height difference, D3 is a third preset crack height difference, and D4 is a fourth preset crack height difference, and each preset crack height increases in sequence. For the injection pump speed adjustment matrix ΔV0, ΔV0 (ΔV1, ΔV2, ΔV3, ΔV4) is set, wherein ΔV1 is a first preset injection pump speed adjustment, ΔV2 is a second preset injection pump speed adjustment, ΔV3 is a third preset injection pump speed adjustment, and ΔV4 is a fourth preset injection pump speed adjustment, and each preset injection pump speed adjustment increases in sequence.

[0016] when When P<Pya, the central control processing module calculates the difference D between the actual crack height Db and the standard crack height Dy, and selects the corresponding injection pump speed adjustment amount according to the difference to adjust the injection pump speed;

[0017] When D1≤D<D2 and Db>Dy, the central control processing module selects ΔV1 to adjust and increase the speed of the injection pump; when D1≤D<D2 and Db<Dy, the central control processing module selects ΔV1 to adjust and reduce the speed of the injection pump;

[0018] When D2≥D<D3 and Db>Dy, the central control processing module selects ΔV2 to adjust and increase the speed of the injection pump; when D2≥D<D3 and Db<Dy, the central control processing module selects ΔV2 to adjust and reduce the speed of the injection pump;

[0019] When D3≥D<D4 and Db>Dy, the central control processing module selects ΔV3 to adjust and increase the speed of the injection pump; when D3≥D<D4 and Db<Dy, the central control processing module selects ΔV3 to adjust and reduce the speed of the injection pump;

[0020] When D≥D4 and Db>Dy, the central control processing module selects ΔV4 to adjust and increase the speed of the injection pump; when D≥D4 and Db<Dy, the central control processing module selects ΔV4 to adjust and reduce the speed of the injection pump;

[0021] When the injection pump speed adjustment amount is ΔVi and Db>Dy, set i=1, 2, 3, 4, the adjusted injection pump speed is Vi′, and set Vi′=Vi+ΔVi. When the injection pump speed adjustment amount is ΔVi and Db is less than Dy, set i=1, 2, 3, 4, the adjusted injection pump speed is Vi″, and set Vi″=Vi-ΔVi.

[0022] Further, the central processing unit is also provided with a preset crack effective length matrix H0 and a preset injection pump speed adjustment coefficient matrix Kv0. For the preset crack effective length matrix H0, H0 (H1, H2, H3, H4) is set, wherein H1 is the first preset crack effective length, H2 is the second preset crack effective length, H3 is the third preset crack effective length, and H4 is the fourth preset crack effective length. The preset crack effective lengths increase in sequence and Hb>H4. For the preset injection pump speed adjustment coefficient matrix Kv0, Kv0 (Kv1, Kv2, Kv3, Kv4) is set, wherein Kv1 is the first preset injection pump speed adjustment coefficient, Kv2 is the second preset injection pump speed adjustment coefficient, Kv3 is the third preset injection pump speed adjustment coefficient, and Kv4 is the fourth preset injection pump speed adjustment coefficient, and 1<Kv1<Kv2<Kv3<Kv4<2;

[0023] When the injection pump speed is Vi′ or Vi″ and P<Pya, the central control processing module selects the corresponding injection pump speed adjustment coefficient according to the actual effective length of the crack to perform a second adjustment on the injection pump speed based on the previous adjustment.

[0024] When H

[0025] When H1≤H<H2, the central control processing module selects Kv2 to adjust the speed of the injection pump;

[0026] When H2≤H<H3, the central control processing module selects Kv3 to adjust the speed of the injection pump;

[0027] When H3≤H<H4, the central control processing module selects Kv4 to adjust the speed of the injection pump;

[0028] When the speed of the injection pump is Vi′, the central control processing module selects the injection pump speed adjustment coefficient Kvj to adjust the speed of the injection pump, and sets j=1, 2, 3, 4. The adjusted speed of the injection pump is Vj′, and Vj″=Vi′×Kvj is set.

[0029] When the injection pump speed is Vi″, the central control processing module selects the injection pump speed adjustment coefficient Kvj to adjust the injection pump speed, setting j=1, 2, 3, 4, the adjusted injection pump speed is Vj″, and Vj″=Vi″×Kvj is set.

[0030] ​Further, the central processing unit is also provided with a preset injection valve opening angle matrix Ra0 and a preset fracture inclination matrix Rb0. For the preset injection valve opening angle matrix Ra0, Ra0(Ra1, Ra2, Ra3, Ra4) is set, wherein Ra1 is the first preset injection valve opening angle, Ra2 is the second preset injection valve opening angle, Ra3 is the third preset injection valve opening angle, Ra4 is the fourth injection valve opening angle, and each preset injection valve opening angle increases in sequence. For the fracture inclination matrix Rb0, Rb0(Rb1, Rb2, Rb3, Rb4) is set, wherein Rb1 is the first preset fracture inclination, Rb2 is the second preset fracture inclination, Rb3 is the third preset fracture inclination, Rb4 is the fourth preset fracture inclination, and each preset fracture inclination increases in sequence.

[0031] when When P>Pyb, the central control processing module monitors the crack inclination in real time and sets the opening angle of the injection valve according to the crack inclination Rb.

[0032] When Rb1≤Rb<Rb2, the central control processing module sets the opening angle of the injection valve to Ra1;

[0033] When Rb2≤Rb<Rb3, the central control processing module sets the opening angle of the injection valve to Ra2;

[0034] When Rb3≤Rb<Rb4, the central control processing module sets the opening angle of the injection valve to Ra3;

[0035] When Rb≥Rb4, the central control processing module sets the opening angle of the injection valve to Ra4.

[0036] Furthermore, the central processing unit is also provided with a preset liquid return purpose matrix W0, which is set to (W1, W2), wherein W1 is winter heating and W2 is power generation. The central control processor determines the liquid return temperature range E according to the liquid return purpose and the injection type.

[0037] When the injection purpose is W1 and the liquid type is Q1, the central control processing module sets the return liquid temperature range in the return liquid pipe to E1.

[0038] When the injection purpose is W1 and the liquid type is Q2, the central control processing module sets the return liquid temperature range in the return liquid pipe to E2.

[0039] When the injection purpose is W1 and the liquid type is Q3, the central control processing module sets the return liquid temperature range in the return liquid pipe to E3.

[0040] When the injection purpose is W2 and the liquid type is Q1, the central control processing module sets the return liquid temperature range in the return liquid pipe to E4.

[0041] Further, the central processing unit is also provided with a preset temperature difference matrix ΔT0 and a preset injection valve angle adjustment amount matrix ΔRa0. For the preset temperature difference matrix ΔT0, ΔT0(ΔT1, ΔT2, ΔT3, ΔT4) is set, wherein ΔT1 is the first preset temperature difference, ΔT2 is the second preset temperature difference, ΔT3 is the third preset temperature difference, ΔT4 is the fourth preset temperature difference, and each preset temperature difference increases in sequence. For the preset injection valve angle adjustment amount matrix ΔRa0, ΔRa0(ΔRa1, ΔRa2, ΔRa3, ΔRa4) is set, wherein ΔRa1 is the first preset injection valve angle adjustment amount, ΔRa2 is the second preset injection valve angle adjustment amount, ΔRa3 is the third preset injection valve angle adjustment amount, ΔRa4 is the fourth preset injection valve angle adjustment amount, and each preset injection valve angle adjustment amount increases in sequence.

[0042] When the return liquid temperature range is Ei, i is set to 1, 2, 3, 4, and the central control processing module determines whether the return liquid temperature is within the return liquid temperature range Ei according to the actual temperature T detected by the temperature sensor on the liquid extraction pipe.

[0043] When T∈Ei, the central control processing module determines that the return liquid temperature is suitable for use;

[0044] when The central control processing module calculates the temperature difference between the actual temperature and the highest value of the preset temperature range when the actual temperature value T is higher than the highest value Eimax of the preset temperature range, or calculates the temperature difference between the actual temperature and the lowest value of the preset temperature range when the actual temperature value T is lower than the lowest value Eimin of the preset temperature range. The central control processing module selects the corresponding injection valve angle adjustment amount to adjust the injection valve angle according to the temperature difference ΔT between the actual temperature and the highest value of the temperature range or the lowest value of the temperature range.

[0045] When ΔT<ΔT1, T>Eimax, the central control processing module selects ΔRa1 to adjust to reduce or increase the angle of the injection valve; when ΔT<ΔT1, T<Eimin, the central control processing module selects ΔRa1 to adjust to reduce the angle of the injection valve;

[0046] When ΔT1≤ΔT<ΔT2, T>Eimax, the central control processing module selects ΔRa2 to adjust and increase the angle of the injection valve; when ΔT1≤ΔT<ΔT2, T<Eimin, the central control processing module selects ΔRa2 to adjust and decrease the angle of the injection valve;

[0047] When ΔT2≤ΔT<ΔT3, T>Eimax, the central control processing module selects ΔRa3 to adjust and increase the angle of the injection valve; when ΔT2≤ΔT<ΔT3, T<Eimin, the central control processing module selects ΔRa3 to adjust and decrease the angle of the injection valve;

[0048] When ΔT3≤ΔT<ΔT4, T>Eimax, the central control processing module selects ΔRa4 to adjust and increase the angle of the injection valve; when ΔT3≤ΔT<ΔT4, T<Eimin, the central control processing module selects ΔRa4 to adjust and decrease the angle of the injection valve;

[0049] When the opening angle of the injection valve is Raj, the central control processing module selects ΔRaj to adjust the injection valve angle. When T>Eimax, j=1, 2, 3, 4 is set. The adjusted injection valve angle is Raj′, and Raj′=Raj+ΔRaj is set.

[0050] When the opening angle of the injection valve is Raj, the central control processing module selects ΔRaj to adjust the angle of the injection valve. When T<Eimin, j=1, 2, 3, 4 is set. The adjusted angle of the injection valve is Raj′, and Raj′=Raj-ΔRaj is set.

[0051] Further, the central processing unit is also provided with a preset rock temperature matrix Ty0 and a preset liquid pump speed adjustment coefficient matrix K0. For the preset rock temperature matrix Ty0, Ty0(Ty1, Ty2, Ty3, Ty4) is set, Ty1 is the first preset rock temperature, Ty2 is the second preset rock temperature, Ty3 is the third preset rock temperature, Ty4 is the fourth preset rock temperature, and each preset rock temperature increases in sequence. For the preset liquid pump speed adjustment coefficient matrix K0, K0(K1, K2, K3, K4) is set, wherein K1 is the first preset liquid pump speed adjustment coefficient, K2 is the second preset liquid pump speed adjustment coefficient, K3 is the third preset liquid pump speed adjustment coefficient, K4 is the fourth preset liquid pump speed adjustment coefficient, and 1>K1>K2>K3>K4>0.5;

[0052] When the speed of the injection pump is Vj, the central control processing module sets the initial pumping speed of the pump to Vh, and selects the corresponding pumping speed adjustment coefficient according to the actual temperature of the rock mass to adjust the speed of the pumping pump.

[0053] When Ty<Ty1, the central control processing module selects K1 to adjust the speed of the liquid pump;

[0054] When Ty1≤ΔT<Ty2, the central control processing module selects K2 to adjust the speed of the liquid pump;

[0055] When Ty2≤ΔT<Ty3, the central control processing module selects K3 to adjust the speed of the liquid pump;

[0056] When Ty3≤ΔT<Ty4, the central control processing module selects K4 to adjust the speed of the liquid pump;

[0057] When Ki is selected to adjust the rotation speed of the liquid pump, i=1, 2, 3, 4 is set, and the rotation speed of the liquid pump after adjustment is Vhi′=Vh×Ki.

[0058] Further, the central processing unit is also provided with a preset injection pump speed difference matrix B0 and a preset crack monitoring period matrix t0. For the preset injection pump speed difference matrix B0, B0(B1, B2, B3, B4) is set, wherein B1 is the first preset injection pump speed difference, B2 is the second preset injection pump speed difference, B3 is the third preset injection pump speed difference, B4 is the fourth preset injection pump speed difference, B1<B2<B3<B4, and for the preset crack monitoring period matrix t0, t0(t1, t2, t3) is set, wherein t1 is the first preset crack monitoring period, t2 is the second preset crack monitoring period, t3 is the third preset crack monitoring period, t1<t2<t3;

[0059] When the injection pump speed is Vj, the central control processing module periodically monitors the crack distribution of the rock mass according to the difference B between the initial injection pump speed and the adjusted speed Vj, and adjusts the injection pump speed according to the monitored crack distribution.

[0060] When B1≤B<B2, the central control processing module monitors the crack distribution at t1;

[0061] When B2≤B<B3, the central control processing module monitors the crack distribution at t2;

[0062] When B3≤B<B4, the central control processing module monitors the crack distribution at t3.

[0063] Furthermore, the heat exchange well includes an injection well, a monitoring well and a pumping well, and the microseismic monitor is installed in the monitoring well to monitor the distribution of cracks in the hot dry rock mass in real time;

[0064] The heat exchange pipe comprises an injection pipe and a liquid extraction pipe, which are respectively arranged in the injection well and the liquid extraction well, and the injection pipe and the liquid extraction pipe are both provided with a control valve, and the injection pipe and the liquid return pipe are also provided with a temperature sensor and a pressure sensor, and the injection controller is connected to the injection pipe and the liquid return pipe;

[0065] The rock mass temperature is monitored by a temperature sensor installed at the pipe head of the injection pipe.

[0066] Compared with the prior art, the beneficial effect of the present invention lies in that by presetting the liquid type, the initial speed of the injection pump and the injection pressure in the central control processor, and selecting different initial injection pump speeds according to different liquid types to inject liquids with different boiling points into the injection well, and monitoring the injection pressure at the same time, the injection type and injection speed during the injection process can be adjusted in real time according to the temperature of the rock mass, thereby effectively improving the control of the injection situation during the mining process and further improving the resource utilization rate of the system for hot rock mining.

[0067] Furthermore, the injection pressure is pre-calculated based on the rock structure, type and depth determined during the drilling process, and the injection pressure range Py is preset according to this range. During the injection process with the initial injection pump speed, the injection pressure is monitored in real time by the pressure sensor, and it is determined whether the injection pressure is within the preset injection range. If it is not within the range, the injection speed is adjusted by the central control processing module to make the injection pressure within the preset injection pressure range. By controlling and adjusting the injection pressure to be kept within a certain range, it can be ensured that the extracted heat energy does not meet the demand due to excessive or insufficient injection pressure during the mining process, and that excessive damage to the rock structure due to excessive injection pressure will not cause loss of heat exchange liquid, thereby further improving the resource utilization rate of the system for hot rock mining.

[0068] Furthermore, the fracture height monitored by the microseismic monitor is compared with a preset standard fracture height, and the injection pump speed is adjusted based on the initial injection pump speed according to the comparison result; when the injection pressure is not within the preset injection pressure range, the injection pump speed is adjusted according to the difference between the fracture height and the standard fracture height so that the injection pressure is within the injection pressure range, thereby ensuring that injection is carried out into the injection well at a certain injection pressure, thereby improving the control of injection accuracy during the mining process and further improving the thermal energy extraction efficiency.

[0069] Furthermore, by presetting the fracture length matrix in the central processing unit according to the mining situation, and based on the actual fracture length detected by the microseismic monitor, when the injection pressure is not within the preset injection pressure range, the injection pump speed is adjusted according to the actual fracture length so that the injection pressure reaches the preset injection pressure range, thereby further improving the control of injection accuracy and further improving the heat energy extraction efficiency.

[0070] Furthermore, when the injection pump speed has been adjusted twice as mentioned above, and the injection pressure is still not within the preset injection pressure range, the central control processing module obtains the crack inclination detected by the microseismic monitor, and adjusts the opening angle of the injection control valve according to the crack inclination to adjust the injection pressure, thereby further improving the control of the injection accuracy and further improving the heat energy extraction efficiency.

[0071] Furthermore, by presetting the injection purpose matrix and the return liquid temperature range matrix in the central processing unit, and selecting different liquid types according to the injection purpose, and then setting the return liquid temperature range according to the injection purpose and the liquid type according to the usage requirements, it is achieved to extract thermal energy of different heat according to the usage requirements, further improve the thermal energy extraction efficiency, and thus further improve the resource utilization of the system for hot rock mining.

[0072] Furthermore, when the actual temperature value is lower than the minimum value of the preset temperature range, the central control processing module adjusts the opening angle of the injection valve to decrease according to the difference between the actual temperature and the minimum value of the preset temperature range; when the actual temperature value is higher than the maximum value of the preset temperature range, the central control processing module adjusts the opening angle of the injection valve to increase according to the difference between the actual temperature and the maximum value of the preset temperature range. In this embodiment, the injection valve is initially in a half-open state; the central control processing module adjusts the opening angle of the injection valve in real time according to the return liquid temperature, which effectively improves the control of the injection accuracy, further improves the heat energy extraction efficiency, and thus further improves the resource utilization rate.

[0073] Furthermore, by detecting the temperature of the rock mass through a temperature sensor arranged at the head of the injection pipe, the central control processing module adjusts the rotation speed of the liquid pump in real time according to the temperature of the rock mass, thereby improving the accuracy of liquid temperature control and further improving the efficiency of heat energy extraction, thereby further improving the resource utilization of the system for hot rock mining.

[0074] Furthermore, when injecting liquid into the injection well, the central control processing module compares the initial injection pump speed and the injection pump speed after the final adjustment and calculates the speed difference, and selects different monitoring cycles to monitor the distribution of cracks according to the difference, so as to observe the changes in the crack distribution according to the monitored data to ensure that the injection pressure does not cause serious damage to the rock mass and increase the difficulty of mining, and judge whether excessive loss of liquid will be caused according to the changes in the crack distribution, thereby improving the monitoring of the internal conditions of the rock mass to ensure that the fluid loss rate is not too large, and improving the resource utilization rate of the system for hot rock mining.

[0075] Furthermore, by arranging a temperature sensor at the head of the injection pipe close to the rock mass, the temperature of the rock mass and its temperature change after a certain period of mining can be monitored in real time. By monitoring the temperature change and actual usage needs, the speed of the injection pump is adjusted in real time to adjust the injection pressure, forming a continuous control closed loop, improving the control of injection accuracy, and further improving the resource utilization of the system for hot rock mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 This is a schematic structural diagram of a microseismic monitoring system for hot dry rock mining according to the present invention. DETAILED DESCRIPTION

[0077] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0078] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0079] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0080] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0081] See also Figure 1 As shown, it is a schematic diagram of the structure of the microseismic monitoring system for hot dry rock mining of the present invention. The microseismic monitoring system for hot dry rock mining of the embodiment of the present invention includes a heat exchange device 100 and a central control processing module 200. The heat exchange device 100 is used to extract the heat energy of underground hot dry rock to the ground for use. The heat exchange device includes a microseismic monitor 10, an injection controller 11, a heat exchange well group 12, a heat exchange pipe group 13, a temperature sensor 14 and a pressure sensor 15; the central control processing module 2 is used to send a control signal to the injection controller 11 according to the monitoring data of the microseismic detector 10, the temperature sensor 14 and the pressure sensor 15. The central control processing module 200 includes a display 201 and a central processing unit (not shown in the figure).

[0082] In this embodiment, the heat exchange well group 12 includes an injection well 16, a pumping well group 17 and a monitoring well group 18. The monitoring well group 18 includes three monitoring wells 181, which are distributed in a ring shape with the injection well 16 as the center. The pumping well group 17 includes four pumping wells 171, which are distributed in a ring shape with the injection well 16 as the center. For a single monitoring well 181, it is arranged at the center position of the triangle formed by the two pumping wells 171 and the injection well 16. A microseismic monitor 10 is installed in each monitoring well 181. The microseismic monitor is used to monitor the crack distribution of the hot dry rock mass in real time.

[0083] In this embodiment, the heat exchange tube group 13 includes an injection pipe 19 and a return pipe 142. The injection pipe extends to the rock mass and is provided with at least four adjustable direction pipe heads (not shown in the figure) for injecting high-pressure liquid in different directions. The injection pipe 19 and the return pipe 20 are correspondingly arranged in the injection well and the pumping well. The injection pipe and the return pipe are both provided with control valves, and the injection pipe and the return pipe are both provided with temperature sensors and pressure sensors at a certain interval. The control valves are electrically connected to the injection controller.

[0084] In this embodiment, the central control processing module 2 is electrically connected to the injection controller 11, the microseismic monitor 10, the temperature sensor 14 and the pressure sensor 15, respectively, to receive in real time the data on the crack distribution of the rock mass, the temperature data monitored by the temperature sensor 14 and the pressure data monitored by the pressure sensor 15, and to send a control signal to the injection controller 11 in real time according to the received crack distribution, temperature value and pressure value to control the speed of the injection pump 113, the speed of the liquid extraction pump 112 and the opening angle of the control valve (not shown in the figure).

[0085] In this embodiment, the injection controller 11 is used to pressurize the liquid injected into the injection well and control the extraction of liquid from the extraction well 171 in real time according to the control signal of the central control processing module 200. The injection controller 11 includes an injection hole 114, four extraction holes 110, an injection pump 113 and four extraction pumps 112.

[0086] In this embodiment, the central processing unit is provided with an injection pressure range Py (Pya, Pyb), a preset liquid type matrix Q0, and a preset initial injection pump speed matrix Va0, Pya<Pyb. When injecting liquid into the rock mass, the central control processing module selects different initial injection pump speeds according to the type of liquid injected into the rock mass to inject liquid into the rock mass within the injection pressure range Py, and selects the injection pump speed adjustment amount according to the crack distribution width monitored by the microseismic monitor to adjust the injection pump speed in real time.

[0087] Specifically, by presetting the liquid type Q0, the preset initial injection pump speed matrix Va0 and the preset pressure range Py in the central processing unit, the central control processing module selects the corresponding initial injection pump speed to inject liquid into the injection well according to the different injection types, and monitors the liquid pressure value in the injection pipe in real time through the pressure sensor at the beginning of injection, and compares the pressure value with the preset pressure range. If the liquid pressure value in the injection pipe is within the preset pressure range, the injection well continues to be injected with liquid at the initial injection pump speed. If the pressure value in the injection pipe is not within the preset pressure range, the central control processor controls and adjusts the injection pump speed to make the injection pressure value reach the preset pressure range.

[0088] By presetting the liquid type, the initial speed of the injection pump and the injection pressure in the central control processor, and selecting different initial injection pump speeds according to different liquid types to inject liquids of different densities into the injection well, and monitoring the injection pressure at the same time, the injection type and injection speed can be adjusted in real time according to the temperature of the rock mass during the injection process, effectively improving the control of the injection situation during the mining process and further improving resource utilization.

[0089] Specifically, for the preset injection type matrix Q0, Q0 (Q1, Q2, Q3) is set, where Q1 is water, Q2 is brine, and Q3 is high-temperature thermal oil; for the preset initial injection pump speed matrix V0, V0 (V1, V2, V3) is set, where V1 is the first preset initial injection pump speed, V2 is the second preset initial injection pump speed, and V3 is the third preset initial injection pump speed, and the preset initial injection pump speeds increase in sequence.

[0090] Specifically, when injection begins into the injection well, the central control processing module selects different initial injection pump speeds according to the injection type to inject liquid into the injection pipe. When the injection type is Qi, i=1, 2, 3 is set, and the central control processing selects the corresponding initial injection pump speed Vi to inject liquid into the injection well.

[0091] Specifically, when the injection pump injects liquid into the injection well and the central control processor adjusts the initial injection pump speed of the injection pump to Vi, the central control processor receives the pressure value P monitored in real time by the pressure sensor, and determines whether the P value is within the Py range.

[0092] If P∈Py, the central control processing module controls the injection pump to inject liquid into the injection well at the initial injection pump speed Vi;

[0093] like The central control processing module adjusts the injection pump speed Vi of the injection pump according to the crack distribution monitored in real time by the microseismic monitor.

[0094] The injection pressure range is pre-calculated based on the rock structure, type and depth determined during the drilling process, and the injection pressure range Py is preset according to this range. During the injection process with the initial injection pump speed, the injection pressure is monitored in real time through the pressure sensor to determine whether the injection pressure is within the preset injection range. If it is not within the range, the injection speed is adjusted through the central control processing module to make the injection pressure reach the preset injection pressure range. By controlling and adjusting the injection pressure to maintain it within a certain range, it can be ensured that the extracted heat energy does not meet the demand due to excessive or insufficient injection pressure during the mining process, and that excessive damage to the rock structure due to excessive injection pressure will cause loss of heat exchange liquid, thereby further improving resource utilization.

[0095] Please continue to refer to Figure 1 As shown, the hot dry rock microseismic monitoring system according to the embodiment of the present invention,

[0096] The central processing unit is also provided with a standard crack height Dy, a preset crack height difference matrix D0 and an injection pump speed adjustment matrix ΔV0. For the crack height difference matrix D0, D0 (D1, D2, D3, D4) is set, wherein D1 is a first preset crack height difference, D2 is a second preset crack height difference, D3 is a third preset crack height difference, and D4 is a fourth preset crack height difference. Each preset crack height increases in sequence. For the injection pump speed adjustment matrix ΔV0, ΔV0 (ΔV1, ΔV2, ΔV3, ΔV4) is set, wherein ΔV1 is a first preset injection pump speed adjustment, ΔV2 is a second preset injection pump speed adjustment, ΔV3 is a third preset injection pump speed adjustment, and ΔV4 is a fourth preset injection pump speed adjustment. Each preset injection pump speed adjustment increases in sequence.

[0097] Specifically, when When P<Pya, the central control processing module calculates the difference D between the actual crack height Db and the standard crack height Dy, and selects the corresponding injection pump speed adjustment amount according to the difference to adjust the injection pump speed;

[0098] When D1≤D<D2 and Db>Dy, the central control processing module selects ΔV1 to adjust and increase the speed of the injection pump; when D1≤D<D2 and Db<Dy, the central control processing module selects ΔV1 to adjust and reduce the speed of the injection pump;

[0099] When D2≥D<D3 and Db>Dy, the central control processing module selects ΔV2 to adjust and increase the speed of the injection pump; when D2≥D<D3 and Db<Dy, the central control processing module selects ΔV2 to adjust and reduce the speed of the injection pump;

[0100] When D3≥D<D4 and Db>Dy, the central control processing module selects ΔV3 to adjust and increase the speed of the injection pump; when D3≥D<D4 and Db<Dy, the central control processing module selects ΔV3 to adjust and reduce the speed of the injection pump;

[0101] When D≥D4 and Db>Dy, the central control processing module selects ΔV4 to adjust and increase the speed of the injection pump; when D≥D4 and Db<Dy, the central control processing module selects ΔV4 to adjust and reduce the speed of the injection pump;

[0102] When the injection pump speed adjustment amount is ΔVi and Db>Dy, set i=1, 2, 3, 4, the adjusted injection pump speed is Vi′, and set Vi′=Vi+ΔVi. When the injection pump speed adjustment amount is ΔVi and Db is less than Dy, set i=1, 2, 3, 4, the adjusted injection pump speed is Vi″, and set Vi″=Vi-ΔVi.

[0103] Specifically, a preset standard fracture height Dy is set in advance according to the amount of liquid required to pass through per unit time, the fracture height monitored by the microseismic monitor is compared with the preset standard fracture height, and the injection pump speed is adjusted based on the initial injection pump speed according to the comparison result. When the injection pressure is not within the preset injection pressure range, the injection pump speed is adjusted according to the difference between the fracture height and the standard fracture height so that the injection pressure reaches the injection pressure range, ensuring that the injection well is injected with a certain injection pressure, thereby improving the control of the injection accuracy during the mining process and further improving the thermal energy extraction efficiency.

[0104] Please continue reading Figure 1 As shown, in the microseismic monitoring system for hot dry rock mining described in the embodiment of the present invention, the central processing unit is also provided with a preset crack length matrix H0 and a preset injection pump speed adjustment coefficient matrix Kv0. For the preset crack length matrix H0, H0 (H1, H2, H3, H4) is set, wherein H1 is the first preset crack length, H2 is the second preset crack length, H3 is the third preset crack length, and H4 is the fourth preset crack length. The preset crack lengths increase in sequence and Hb>H4. For the preset injection pump speed adjustment coefficient matrix Kv0, Kv0 (Kv1, Kv2, Kv3, Kv4) is set, wherein Kv1 is the first preset injection pump speed adjustment coefficient, Kv2 is the second preset injection pump speed adjustment coefficient, Kv3 is the third preset injection pump speed adjustment coefficient, and Kv4 is the fourth preset injection pump speed adjustment coefficient, 1<Kv1<Kv2<Kv3<Kv4<2;

[0105] Specifically, when the injection pump speed is Vi′ or Vi″ and P<Pya, the central control processing module selects the corresponding injection pump speed adjustment coefficient according to the actual length of the crack to perform a second adjustment on the injection pump speed based on the previous adjustment.

[0106] Specifically, when H

[0107] When H1≤H<H2, the central control processing module selects Kv2 to adjust the speed of the injection pump;

[0108] When H2≤H<H3, the central control processing module selects Kv3 to adjust the speed of the injection pump;

[0109] When H3≤H<H4, the central control processing module selects Kv4 to adjust the speed of the injection pump;

[0110] Specifically, when the injection pump speed is Vi′, the central control processing module selects the injection pump speed adjustment coefficient Kvj to adjust the injection pump speed, setting j=1, 2, 3, 4, the adjusted injection pump speed is Vj′, and Vj″=Vi′×Kvj is set.

[0111] When the injection pump speed is Vi″, the central control processing module selects the injection pump speed adjustment coefficient Kvj to adjust the injection pump speed, setting j=1, 2, 3, 4, the adjusted injection pump speed is Vj″, and Vj″=Vi″×Kvj is set.

[0112] Specifically, by presetting the fracture length matrix in the central processing unit according to the mining situation, and based on the actual fracture length detected by the microseismic monitor, when the injection pressure is not within the preset injection pressure range, the injection pump speed is adjusted according to the actual fracture length to make the injection pressure reach the preset injection pressure range, thereby further improving the control of injection accuracy and further improving the heat energy extraction efficiency.

[0113] Please continue reading Figure 1 ​As shown, in the hot dry rock mining microseismic monitoring system described in the embodiment of the present invention, the central processing unit is further provided with a preset injection valve opening angle matrix Ra0 and a preset fracture inclination matrix Rb0. For the preset injection valve opening angle matrix Ra0, Ra0 (Ra1, Ra2, Ra3, Ra4) is set, wherein Ra1 is the first preset injection valve opening angle, Ra2 is the second preset injection valve opening angle, Ra3 is the third preset injection valve opening angle, Ra4 is the fourth injection valve opening angle, and each preset injection valve opening angle increases in sequence. For the fracture inclination matrix Rb0, Rb0 (Rb1, Rb2, Rb3, Rb4) is set, wherein Rb1 is the first preset fracture inclination, Rb2 is the second preset fracture inclination, Rb3 is the third preset fracture inclination, Rb4 is the fourth preset fracture inclination, and each preset fracture inclination increases in sequence.

[0114] Specifically, when When P>Pyb, the central control processing module monitors the crack inclination in real time and sets the opening angle of the injection valve according to the crack inclination Rb.

[0115] Specifically, when Rb1≤Rb<Rb2, the central control processing module sets the opening angle of the injection valve to Ra1;

[0116] When Rb2≤Rb<Rb3, the central control processing module sets the opening angle of the injection valve to Ra2;

[0117] When Rb3≤Rb<Rb4, the central control processing module sets the opening angle of the injection valve to Ra3;

[0118] When Rb≥Rb4, the central control processing module sets the opening angle of the injection valve to Ra4.

[0119] Specifically, when the injection pressure is still not within the preset injection pressure range and the injection pressure is relatively high after the injection pump speed is adjusted twice, the central control processing module obtains the fracture inclination detected by the microseismic monitor and adjusts the opening angle of the injection control valve according to the fracture inclination to adjust the injection pressure, thereby further improving the control of the injection accuracy and thus further improving the heat extraction efficiency.

[0120] Please continue reading Figure 1 As shown, in the microseismic monitoring system for hot dry rock mining according to the embodiment of the present invention, the central processing unit is further provided with a preset liquid return purpose matrix W0, which is set to (W1, W2), wherein W1 is winter heating, and W2 is power generation. The central control processor determines the liquid return temperature range E according to the liquid return purpose and the injection type.

[0121] When the injection purpose is W1 and the liquid type is Q1, the central control processing module sets the return liquid temperature range in the return liquid pipe to E1.

[0122] When the injection purpose is W1 and the liquid type is Q2, the central control processing module sets the return liquid temperature range in the return liquid pipe to E2.

[0123] When the injection purpose is W1 and the liquid type is Q3, the central control processing module sets the return liquid temperature range in the return liquid pipe to E3.

[0124] When the injection purpose is W2 and the liquid type is Q1, the central control processing module sets the return liquid temperature range in the return liquid pipe to E4.

[0125] Specifically, by presetting the liquid injection purpose matrix and the liquid return temperature range matrix in the central processing unit, and selecting different liquid types according to the liquid injection purpose, and then setting the liquid return temperature range according to the injection purpose and liquid type according to the usage requirements, it is possible to extract thermal energy of different heat amounts according to usage requirements, further improve the thermal energy extraction efficiency, and thus further improve resource utilization.

[0126] Please continue reading Figure 1 As shown, in the microseismic monitoring system for hot dry rock mining described in the embodiment of the present invention, the central processing unit is further provided with a preset temperature difference matrix ΔT0 and a preset injection valve angle adjustment amount matrix ΔRa0. For the preset temperature difference matrix ΔT0, ΔT0(ΔT1, ΔT2, ΔT3, ΔT4) is set, wherein ΔT1 is the first preset temperature difference, ΔT2 is the second preset temperature difference, ΔT3 is the third preset temperature difference, ΔT4 is the fourth preset temperature difference, and each preset temperature difference increases in sequence. For the preset injection valve angle adjustment amount matrix ΔRa0, ΔRa0(ΔRa1, ΔRa2, ΔRa3, ΔRa4) is set, wherein ΔRa1 is the first preset injection valve angle adjustment amount, ΔRa2 is the second preset injection valve angle adjustment amount, ΔRa3 is the third preset injection valve angle adjustment amount, ΔRa4 is the fourth preset injection valve angle adjustment amount, and each preset injection valve angle adjustment amount increases in sequence;

[0127] Specifically, when the liquid return temperature range is Ei′, i=1, 2, 3, 4 is set, and the central control processing module determines whether the liquid return temperature is within the liquid return temperature range Ei′ according to the actual temperature T detected by the temperature sensor on the liquid extraction pipe.

[0128] When T∈Ei′, the central control processing module determines that the return liquid temperature is suitable for use;

[0129] when The central control processing module calculates the temperature difference between the actual temperature and the highest value of the preset temperature range when the actual temperature value T is higher than the highest value Eimax′ of the preset temperature range, or calculates the temperature difference between the actual temperature and the lowest value of the preset temperature range when the actual temperature value T is lower than the lowest value Eimin′ of the preset temperature range. The central control processing module selects the corresponding injection valve angle adjustment amount to adjust the injection valve angle according to the temperature difference ΔT between the actual temperature and the highest value of the temperature range or the lowest value of the temperature range.

[0130] Specifically, when ΔT<ΔT1, T>Eimax′, the central control processing module selects ΔRa1 to adjust to reduce or increase the injection valve angle; when ΔT<ΔT1, T<Eimin′, the central control processing module selects ΔRa1 to adjust to reduce the injection valve angle;

[0131] When ΔT1≤ΔT<ΔT2, T>Eimax′, the central control processing module selects ΔRa2 to adjust and increase the angle of the injection valve; when ΔT1≤ΔT<ΔT2, T<Eimin′, the central control processing module selects ΔRa2 to adjust and decrease the angle of the injection valve;

[0132] When ΔT2≤ΔT<ΔT3, T>Eimax′, the central control processing module selects ΔRa3 to adjust and increase the angle of the injection valve; when ΔT2≤ΔT<ΔT3, T<Eimin′, the central control processing module selects ΔRa3 to adjust and decrease the angle of the injection valve;

[0133] When ΔT3≤ΔT<ΔT4, T>Eimax′, the central control processing module selects ΔRa4 to adjust and increase the angle of the injection valve; when ΔT3≤ΔT<ΔT4, T<Eimin′, the central control processing module selects ΔRa4 to adjust and decrease the angle of the injection valve;

[0134] When the opening angle of the injection valve is Raj, the central control processing module selects ΔRaj to adjust the injection valve angle. When T>Eimax′, j=1, 2, 3, 4 is set. The adjusted injection valve angle is Raj′, and Raj′=Raj+ΔRaj is set.

[0135] When the opening angle of the injection valve is Raj, the central control processing module selects ΔRaj to adjust the angle of the injection valve. When T<Eimin′, j=1, 2, 3, 4 is set. The adjusted angle of the injection valve is Raj′, and Raj′=Raj-ΔRaj is set.

[0136] Specifically, when the required return liquid temperature range Ei is determined according to the purpose of injection and the type of liquid, the central control processing module compares the real-time temperature monitored by the temperature sensor arranged on the return liquid pipe with the return liquid temperature range. If the real-time temperature is within the preset temperature range, the central control processing module determines that the return liquid temperature is suitable for use. If the real-time temperature is higher than the maximum value of the preset temperature range, the central control processing module determines that the temperature is too high and the return liquid temperature needs to be lowered; if the real-time temperature is lower than the minimum value of the preset temperature range, the central control processor determines that the temperature is too low and the return liquid temperature needs to be increased. The central control processing module selects the injection control valve angle adjustment amount to adjust the injection valve angle according to the temperature difference.

[0137] Specifically, when the actual temperature value is lower than the minimum value of the preset temperature range, the central control processing module adjusts the opening angle of the injection valve to decrease according to the difference between the actual temperature and the minimum value of the preset temperature range. When the actual temperature value is higher than the maximum value of the preset temperature range, the central control processing module adjusts the opening angle of the injection valve to increase according to the difference between the actual temperature and the maximum value of the preset temperature range. In this embodiment, the injection valve is initially in a half-open state. The central control processing module adjusts the opening angle of the injection valve in real time according to the return liquid temperature, which effectively improves the control of the injection accuracy, further improves the heat energy extraction efficiency, and thus further improves the resource utilization rate.

[0138] Please continue reading Figure 1 As shown, in the microseismic monitoring system for hot dry rock mining described in the embodiment of the present invention, the central processing unit is further provided with a preset rock temperature matrix Ty0 and a preset liquid pump speed adjustment coefficient matrix K0. For the preset rock temperature matrix Ty0, Ty0 (Ty1, Ty2, Ty3, Ty4) is set, Ty1 is the first preset rock temperature, Ty2 is the second preset rock temperature, Ty3 is the third preset rock temperature, Ty4 is the fourth preset rock temperature, and each preset rock temperature increases in sequence. For the preset liquid pump speed adjustment coefficient matrix K0, K0 (K1, K2, K3, K4) is set, wherein K1 is the first preset liquid pump speed adjustment coefficient, K2 is the second preset liquid pump speed adjustment coefficient, K3 is the third preset liquid pump speed adjustment coefficient, K4 is the fourth preset liquid pump speed adjustment coefficient, and 1>K1>K2>K3>K4>0.5;

[0139] Specifically, when the injection pump speed is Vj, the central control processing module sets the initial pumping speed of the pump to Vh, and selects the corresponding pumping pump speed adjustment coefficient according to the actual temperature of the rock mass to adjust the speed of the pumping pump.

[0140] When Ty<Ty1, the central control processing module selects K1 to adjust the speed of the liquid pump;

[0141] When Ty1≤ΔT<Ty2, the central control processing module selects K2 to adjust the speed of the liquid pump;

[0142] When Ty2≤ΔT<Ty3, the central control processing module selects K3 to adjust the speed of the liquid pump;

[0143] When Ty3≤ΔT<Ty4, the central control processing module selects K4 to adjust the speed of the liquid pump;

[0144] When Ki is selected to adjust the rotation speed of the liquid pump, i=1, 2, 3, 4 is set, and the rotation speed of the liquid pump after adjustment is Vhi′=Vh×Ki.

[0145] Specifically, the initial rotation speed of the liquid pump in this embodiment is Vh. The temperature of the rock mass is detected by a temperature sensor arranged on the head of the injection pipe. The central control processing module adjusts the rotation speed of the liquid pump in real time according to the temperature of the rock mass, thereby improving the accuracy of liquid temperature control, further improving the heat energy extraction efficiency, and thus further improving resource utilization.

[0146] Please continue reading Figure 1 As shown, in the microseismic monitoring system for hot dry rock mining described in the embodiment of the present invention, the central processing unit is further provided with a preset injection pump speed difference matrix B0 and a preset crack monitoring period matrix t0. For the preset injection pump speed difference matrix B0, B0(B1, B2, B3, B4) is set, wherein B1 is the first preset injection pump speed difference, B2 is the second preset injection pump speed difference, B3 is the third preset injection pump speed difference, B4 is the fourth preset injection pump speed difference, B1<B2<B3<B4, for the preset crack monitoring period matrix t0, t0(t1, t2, t3) is set, wherein t1 is the first preset crack monitoring period, t2 is the second preset crack monitoring period, t3 is the third preset crack monitoring period, t1<t2<t3;

[0147] Specifically, when the injection pump speed is Vj, the central control processing module periodically monitors the crack distribution of the rock mass according to the difference B between the initial injection pump speed and the adjusted speed Vj, and adjusts the injection pump speed according to the monitored crack distribution.

[0148] When B1≤B<B2, the central control processing module monitors the crack distribution at t1;

[0149] When B2≤B<B3, the central control processing module monitors the crack distribution at t2;

[0150] When B3≤B<B4, the central control processing module monitors the crack distribution at t3.

[0151] Specifically, when injecting liquid into the injection well, the central control processing module compares the initial injection pump speed and the injection pump speed after the final adjustment and calculates the speed difference. According to the difference, different monitoring cycles are selected to monitor the distribution of cracks, so as to observe the changes in the crack distribution according to the monitoring data to ensure that the injection pressure does not cause serious damage to the rock mass and increase the difficulty of mining, and judge whether excessive loss of liquid will be caused according to the changes in the crack distribution, thereby improving the monitoring of the internal conditions of the rock mass to ensure that the fluid loss rate is not too large and improve the utilization rate of resources.

[0152] Please continue reading Figure 1 As shown, in the microseismic monitoring system for hot dry rock mining described in an embodiment of the present invention, the temperature sensor for monitoring the temperature of the rock mass is installed at the pipe head of the injection pipe.

[0153] Specifically, by installing a temperature sensor at the head of the injection pipe close to the rock mass, the temperature of the rock mass and its temperature changes after a certain period of mining can be monitored in real time. By monitoring the temperature changes and actual usage needs, the speed of the injection pump can be adjusted in real time to adjust the injection pressure, forming a continuous control closed loop, improving the control of injection accuracy, and thus further improving resource utilization.

[0154] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0155] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A microseismic monitoring system for hot dry rock mining, characterized in that: include: A heat exchange device, including a microseismic monitor, a liquid injection controller, a heat exchange well, a heat exchange tube, a temperature sensor and a pressure sensor, for extracting heat energy from underground hot dry rocks; The heat exchange well includes a liquid injection well, a monitoring well and a liquid extraction well. The microseismic monitor is installed in the monitoring well to monitor the distribution of cracks in the hot dry rock mass in real time. The heat exchange pipe comprises an injection pipe and a liquid extraction pipe, which are respectively arranged in the injection well and the liquid extraction well, and the injection pipe and the liquid extraction pipe are both provided with a control valve, and the injection pipe and the liquid return pipe are also provided with a temperature sensor and a pressure sensor, and the injection controller is connected to the injection pipe and the liquid return pipe; The rock mass temperature is monitored by a temperature sensor installed at the pipe head of the injection pipe; A central control processing module, including a display and a central processing unit connected to the display, wherein the central processing unit is respectively connected to the liquid injection controller, the microseismic monitor, the temperature sensor and the pressure sensor, and is used to send a corresponding control signal to the liquid injection controller according to the data monitored in real time by the microseismic monitor, the temperature sensor and the pressure sensor; When the monitoring system is running, the central processing unit receives in real time the rock crack distribution data monitored by the microseismic monitor, the temperature data monitored by the temperature sensor, and the pressure data monitored by the pressure sensor, and sends a control signal to the injection controller in real time according to the received crack distribution, temperature value, and pressure value to control the injection pump speed, the pumping pump speed, and the control valve opening angle; The central processing unit is provided with a preset injection pressure range Py, a preset liquid type matrix Q0 and a preset initial injection pump speed matrix Va0, wherein Pya<Py<Pyb, Pya<Pyb, when the injection pump injects liquid into the rock mass, the central control processing module selects the corresponding initial injection pump speed according to the type of liquid injected into the rock mass so that the injection pump injects liquid into the rock mass, when the injection pressure P belongs to the preset injection pressure range Py, the central control processing module does not adjust the injection speed of the injection pump, if the injection pressure P of the injection pump does not fall within the preset injection pressure range Py, the central control processing module selects the corresponding injection pump speed adjustment amount according to the crack distribution monitored by the microseismic monitor to adjust the injection pump speed in real time; The central processing unit is also provided with a preset liquid return purpose matrix W0, and W0 (W1, W2) is set, wherein W1 is winter heating and W2 is power generation. The central control processing module determines the liquid return temperature range E according to the liquid return purpose and the injection type. When the injection purpose is W1 and the liquid type is Q1, the central control processing module sets the return liquid temperature range in the return liquid pipe to E1. When the injection purpose is W1 and the liquid type is Q2, the central control processing module sets the return liquid temperature range in the return liquid pipe to E2. When the injection purpose is W1 and the liquid type is Q3, the central control processing module sets the return liquid temperature range in the return liquid pipe to E3. When the injection purpose is W2 and the liquid type is Q1, the central control processing module sets the return liquid temperature range in the return liquid pipe to E4; The central processing unit is also provided with a preset temperature difference matrix △T0 and a preset injection valve angle adjustment amount matrix △Ra0. For the preset temperature difference matrix △T0, △T0 (△T1, △T2, △T3, △T4) is set, wherein △T1 is the first preset temperature difference, △T2 is the second preset temperature difference, △T3 is the third preset temperature difference, △T4 is the fourth preset temperature difference, and each preset temperature difference increases in sequence. For the preset injection valve angle adjustment amount matrix △Ra0, △Ra0 (△Ra1, △Ra2, △Ra3, △Ra4) is set, wherein △Ra1 is the first preset injection valve angle adjustment amount, △Ra2 is the second preset injection valve angle adjustment amount, △Ra3 is the third preset injection valve angle adjustment amount, △Ra4 is the fourth preset injection valve angle adjustment amount, and each preset injection valve angle adjustment amount increases in sequence; When the return liquid temperature range is Ei, set i=1, 2, 3, 4, the central control processing module determines whether the return liquid temperature is within the return liquid temperature range Ei according to the actual temperature T detected by the temperature sensor on the liquid extraction pipe. When T∈Ei, the central control processing module determines that the return liquid temperature is suitable for use; When T Ei, the central control processing module calculates the temperature difference between the actual temperature and the highest value of the preset temperature range when the actual temperature T is higher than the highest value Eimax of the preset temperature range, or calculates the temperature difference between the actual temperature and the lowest value of the preset temperature range when the actual temperature T is lower than the lowest value Eimin of the preset temperature range. The central control processing module selects the corresponding injection valve angle adjustment amount to adjust the injection valve angle according to the temperature difference △T between the actual temperature and the highest value of the preset temperature range or the lowest value of the preset temperature range. When △T<△T1, T>Eimax, the central control processing module selects △Ra1 to adjust to reduce or increase the angle of the injection valve; when △T<△T1, T<Eimin, the central control processing module selects △Ra1 to adjust to reduce the angle of the injection valve; When △T1≤△T<△T2, T>Eimax, the central control processing module selects △Ra2 to adjust and increase the angle of the injection valve; when △T1≤△T<△T2, T<Eimin, the central control processing module selects △Ra2 to adjust and decrease the angle of the injection valve; When △T2≤△T<△T3, T>Eimax, the central control processing module selects △Ra3 to adjust and increase the angle of the injection valve; when △T2≤△T<△T3, T<Eimin, the central control processing module selects △Ra3 to adjust and decrease the angle of the injection valve; When △T3≤△T<△T4, T>Eimax, the central control processing module selects △Ra4 to adjust and increase the angle of the injection valve; when △T3≤△T<△T4, T<Eimin, the central control processing module selects △Ra4 to adjust and decrease the angle of the injection valve; When the opening angle of the injection valve is Raj, the central control processing module selects △Raj to adjust the angle of the injection valve. When T>Eimax, j=1, 2, 3, 4 is set. The adjusted angle of the injection valve is Raj′, and Raj′=Raj+∆Raj is set. When the opening angle of the injection valve is Raj, the central control processing module selects △Raj to adjust the angle of the injection valve. When T<Eimin, j=1, 2, 3, 4 is set. The adjusted angle of the injection valve is Raj′, and Raj′=Raj-△Raj is set.

2. The microseismic monitoring system for hot dry rock mining according to claim 1 is characterized in that: For the preset liquid injection type matrix Q0, set Q0 (Q1, Q2, Q3), where Q1 is water, Q2 is salt water, and Q3 is high-temperature thermal oil. For the preset initial liquid injection pump speed matrix V0, set V0 (V1, V2, V3), where V1 is the first preset initial liquid injection pump speed, V2 is the second preset initial liquid injection pump speed, and V3 is the third preset initial liquid injection pump speed. The speeds of the preset initial liquid injection pumps increase in sequence. When the injection pump injects liquid into the injection well, the central control processing module selects different initial injection pump speeds according to the injection type to inject liquid into the injection pipe. When the injection type is Qm, m=1, 2, 3 is set, and the central control processing module adjusts the speed of the injection pump to the corresponding initial injection pump speed Vi so that the injection pump injects liquid into the injection well; When the injection pump injects liquid into the injection well and the central control processing module adjusts the initial injection pump speed of the injection pump to Vi, the central control processing module receives the pressure value P monitored in real time by the pressure sensor, and determines whether the P value is within the Py range. If P∈Py, the central control processing module controls the injection pump to inject liquid into the injection well at the initial injection pump speed Vi; If P Py, the central control processing module adjusts the injection pump speed Vi of the injection pump according to the crack distribution monitored in real time by the microseismic monitor.

3. The microseismic monitoring system for hot dry rock mining according to claim 2 is characterized in that: The central processing unit is also provided with a standard crack height Dy, a preset crack height difference matrix D0 and an injection pump speed adjustment matrix △V0. For the crack height difference matrix D0, D0 (D1, D2, D3, D4) is set, wherein D1 is a first preset crack height difference, D2 is a second preset crack height difference, D3 is a third preset crack height difference, and D4 is a fourth preset crack height difference. Each preset crack height increases in sequence. For the injection pump speed adjustment matrix △V0, △V0 (△V1, △V2, △V3, △V4) is set, wherein △V1 is a first preset injection pump speed adjustment, △V2 is a second preset injection pump speed adjustment, △V3 is a third preset injection pump speed adjustment, and △V4 is a fourth preset injection pump speed adjustment. Each preset injection pump speed adjustment increases in sequence. When P When Py and P<Pya, the central control processing module calculates the difference D between the actual crack height Db and the standard crack height Dy, and selects the corresponding injection pump speed adjustment amount according to the difference to adjust the injection pump speed; When D1≤D<D2 and Db>Dy, the central control processing module selects △V1 to adjust and increase the speed of the injection pump; when D1≤D<D2 and Db<Dy, the central control processing module selects △V1 to adjust and reduce the speed of the injection pump; When D2≥D<D3 and Db>Dy, the central control processing module selects △V2 to adjust and increase the speed of the injection pump; when D2≥D<D3 and Db<Dy, the central control processing module selects ∆V2 to adjust and reduce the speed of the injection pump; When D3≥D<D4 and Db>Dy, the central control processing module selects △V3 to adjust and increase the speed of the injection pump; when D3≥D<D4 and Db<Dy, the central control processing module selects △V3 to adjust and reduce the speed of the injection pump; When D≥D4 and Db>Dy, the central control processing module selects △V4 to adjust and increase the speed of the injection pump; when D≥D4 and Db<Dy, the central control processing module selects △V4 to adjust and reduce the speed of the injection pump; When the injection pump speed adjustment amount is △Vn and Db>Dy, set n=1, 2, 3, 4, the adjusted injection pump speed is Vi′, and set Vi′=Vi+△Vn. When the injection pump speed adjustment amount is △Vn and Db<Dy, set n=1, 2, 3, 4, the adjusted injection pump speed is Vi′, and set Vi′′=Vi-△Vn.

4. The microseismic monitoring system for hot dry rock mining according to claim 3 is characterized in that: The central processing unit is also provided with a preset crack effective length matrix H0 and a preset injection pump speed adjustment coefficient matrix Kv0. For the preset crack effective length matrix H0, H0 (H1, H2, H3, H4) is set, wherein H1 is the first preset crack effective length, H2 is the second preset crack effective length, H3 is the third preset crack effective length, and H4 is the fourth preset crack effective length. The preset crack effective lengths increase in sequence and Hb>H4. For the preset injection pump speed adjustment coefficient matrix Kv0, Kv0 (Kv1, Kv2, Kv3, Kv4) is set, wherein Kv1 is the first preset injection pump speed adjustment coefficient, Kv2 is the second preset injection pump speed adjustment coefficient, Kv3 is the third preset injection pump speed adjustment coefficient, and Kv4 is the fourth preset injection pump speed adjustment coefficient, and 1<Kv1<Kv2<Kv3<Kv4<2; When the injection pump speed is Vi′ or Vi′′ and P<Pya, the central control processing module selects the corresponding injection pump speed adjustment coefficient according to the actual effective length of the crack to perform a second adjustment on the injection pump speed based on the previous adjustment. When H<H1, the central control processing module selects Kv1 to adjust the speed of the injection pump; When H1≤H<H2, the central control processing module selects Kv2 to adjust the speed of the injection pump; When H2≤H<H3, the central control processing module selects Kv3 to adjust the speed of the injection pump; When H3≤H<H4, the central control processing module selects Kv4 to adjust the speed of the injection pump; When the injection pump speed is Vi', the central control processing module selects the injection pump speed adjustment coefficient Kvj to adjust the injection pump speed, setting j=1, 2, 3, 4, the adjusted injection pump speed is Vj', and Vj''=Vi'×Kvj is set. When the injection pump speed is Vi′′, the central control processing module selects the injection pump speed adjustment coefficient Kvj to adjust the injection pump speed, setting j=1, 2, 3, 4, the adjusted injection pump speed is Vj′′, and Vj′′=Vi′′×Kvj is set.

5. The microseismic monitoring system for hot dry rock mining according to claim 4 is characterized in that: The central processing unit is also provided with a preset injection valve opening angle matrix Ra0 and a preset fracture inclination matrix Rb0. For the preset injection valve opening angle matrix Ra0, Ra0 (Ra1, Ra2, Ra3, Ra4) is set, wherein Ra1 is a first preset injection valve opening angle, Ra2 is a second preset injection valve opening angle, Ra3 is a third preset injection valve opening angle, Ra4 is a fourth injection valve opening angle, and each preset injection valve opening angle increases in sequence. For the fracture inclination matrix Rb0, Rb0 (Rb1, Rb2, Rb3, Rb4) is set, wherein Rb1 is a first preset fracture inclination, Rb2 is a second preset fracture inclination, Rb3 is a third preset fracture inclination, Rb4 is a fourth preset fracture inclination, and each preset fracture inclination increases in sequence; When P When Py and P>Pyb, the central control processing module monitors the crack inclination in real time and sets the opening angle of the injection valve according to the crack inclination Rb. When Rb1≤Rb<Rb2, the central control processing module sets the opening angle of the injection valve to Ra1; When Rb2≤Rb<Rb3, the central control processing module sets the opening angle of the injection valve to Ra2; When Rb3≤Rb<Rb4, the central control processing module sets the opening angle of the injection valve to Ra3; When Rb≥Rb4, the central control processing module sets the opening angle of the injection valve to Ra4.

6. The microseismic monitoring system for hot dry rock mining according to claim 1, characterized in that: The central processing unit is also provided with a preset rock temperature matrix Ty0 and a preset pump speed adjustment coefficient matrix K0. For the preset rock temperature matrix Ty0, Ty0 (Ty1, Ty2, Ty3, Ty4) is set, Ty1 is the first preset rock temperature, Ty2 is the second preset rock temperature, Ty3 is the third preset rock temperature, Ty4 is the fourth preset rock temperature, and each preset rock temperature increases in sequence. For the preset pump speed adjustment coefficient matrix K0, K0 (K1, K2, K3, K4) is set, wherein K1 is the first preset pump speed adjustment coefficient, K2 is the second preset pump speed adjustment coefficient, K3 is the third preset pump speed adjustment coefficient, K4 is the fourth preset pump speed adjustment coefficient, and 1>K1>K2>K3>K4>0.5; When the speed of the injection pump is Vi, the central control processing module sets the initial pumping speed of the pump to Vh, and selects the corresponding pumping speed adjustment coefficient according to the actual temperature of the rock mass to adjust the speed of the pumping pump. When Ty<Ty1, the central control processing module selects K1 to adjust the speed of the liquid pump; When Ty1≤△T<Ty2, the central control processing module selects K2 to adjust the speed of the liquid pump; When Ty2≤△T<Ty3, the central control processing module selects K3 to adjust the speed of the liquid pump; When Ty3≤△T<Ty4, the central control processing module selects K4 to adjust the speed of the liquid pump; When Kr is selected to adjust the speed of the liquid pump, r=1, 2, 3, 4 is set, and the speed of the liquid pump after adjustment is Vhi′=Vh×Kr.

7. The microseismic monitoring system for hot dry rock mining according to claim 6 is characterized in that: The central processing unit is also provided with a preset injection pump speed difference matrix B0 and a preset crack monitoring period matrix t0. For the preset injection pump speed difference matrix B0, B0 (B1, B2, B3, B4) is set, wherein B1 is the first preset injection pump speed difference, B2 is the second preset injection pump speed difference, B3 is the third preset injection pump speed difference, B4 is the fourth preset injection pump speed difference, B1<B2<B3<B4, and for the preset crack monitoring period matrix t0, t0 (t1, t2, t3) is set, wherein t1 is the first preset crack monitoring period, t2 is the second preset crack monitoring period, t3 is the third preset crack monitoring period, t1<t2<t3; When the injection pump speed is Vj, the central control processing module periodically monitors the crack distribution of the rock mass according to the difference B between the initial injection pump speed and the adjusted speed Vj, and adjusts the injection pump speed according to the monitored crack distribution. When B1≤B<B2, the central control processing module monitors the crack distribution at t1; When B2≤B<B3, the central control processing module monitors the crack distribution at t2; When B3≤B<B4, the central control processing module monitors the crack distribution at t3.

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