A generator set test system based on abandoned mine pumped storage

Abstract

The utility model provides a kind of generator set test system based on abandoned mine pumped storage, including energy storage unit and test unit;Energy storage unit includes low reservoir by utilizing the transformation of abandoned mine and high reservoir by utilizing the transformation of subsidence area lake, and there is water level difference between high reservoir and low reservoir;Test unit includes load control cabinet, generator set to be measured, switch cabinet and water pump, load control cabinet is connected with generator set to be measured, for adjusting load;Generator set to be measured is connected with water pump by switch cabinet, and water pump can pump water in low reservoir to high reservoir.The utility model realizes the accurate control of test load by load control cabinet, and completes the conversion of electric energy to mechanical energy by water pump motor, and water pump pumps mine water from low abandoned mine to high subsidence area lake to store energy, and finally regenerates stored gravitational potential energy as electric energy by hydroelectric generator, greatly improves the energy efficiency and economy of test process.

Description

Technical Field

[0001] This utility model belongs to the field of generator set testing technology, specifically relating to a generator set testing system based on pumped storage in abandoned mines. Background Technology

[0002] Generator sets (such as coal-fired generator sets, steam turbines, diesel generator sets, and gas generator sets) must undergo load testing to verify their performance indicators after leaving the factory, after major overhauls, or during regular maintenance. Traditional testing methods generally employ resistive load cabinets (dummy loads) to directly dissipate the electrical energy generated by the generator set as heat energy through resistance. For example, the technologies disclosed in Chinese patents CN201210021700.X and CN201310513979.8 belong to this type of method. While this method achieves the testing objective, it suffers from problems such as enormous energy consumption, serious resource waste, and the generation of large amounts of waste heat, which does not meet the requirements of green development.

[0003] Pumped storage technology is a mature large-scale energy storage technology that can effectively regulate power grid peak loads. However, building conventional pumped storage power stations requires the construction of upper and lower reservoirs and a massive underground cavern system, which presents challenges such as difficult site selection, long construction periods, and huge investments (unit costs typically reach 7,000-10,500 yuan / kW).

[0004] On the other hand, my country has a large number of abandoned mines. Due to geological subsidence, these mines often form natural and considerable water level differences with the surrounding areas, possessing the potential for pumped-storage energy development. Currently, research on energy storage utilization in abandoned mines mainly focuses on achieving grid peak-shaving functions, but their system architecture and operation modes do not consider the testing needs of generator units, making it impossible to effectively store and reuse the electricity generated during testing. In reality, some areas combine subsidence lakes (such as the Shiliying subsidence area in Jining City), abandoned mines (such as Xuchang Coal Mine and Tianzhuang Coal Mine in Jining City), and generator unit testing centers (such as the 20MW testing center of Shandong Huali Electromechanical Co., Ltd. in Jining City). However, these resources are currently in an isolated state, failing to undergo systematic integrated development and comprehensive utilization, resulting in resource idleness and waste.

[0005] Therefore, it is necessary to provide an innovative technical solution that can solve the problem of high energy consumption in generator set testing, while also utilizing abandoned mine resources at low cost and achieving synergy of multiple energy sources. Utility Model Content

[0006] To address the technical problems existing in the prior art, this utility model provides a generator set testing system based on pumped storage in abandoned mines.

[0007] In this embodiment of the invention, a generator set testing system based on pumped-storage power generation in an abandoned mine includes an energy storage unit and a testing unit. The energy storage unit includes a low-level reservoir converted from an abandoned mine and a high-level reservoir converted from a lake / artificial slope in a subsidence area, with a water level difference between the high-level and low-level reservoirs. The testing unit includes a variable-frequency adjustable power load control cabinet, a generator set under test, a switch cabinet, and a water pump. The load control cabinet is connected to the generator set under test and is used to adjust the load. The generator set under test is connected to the water pump through the switch cabinet, and the water pump can pump water from the low-level reservoir to the high-level reservoir.

[0008] Compared with the prior art, the beneficial effects of the superior technical solution of this utility model include:

[0009] 1. This utility model constructs a series topology of "load control cabinet → water pump motor → water turbine generator". The load control cabinet realizes precise control of the test load, the water pump motor completes the conversion of electrical energy to mechanical energy, the water pump pumps mine water from the low-level abandoned mine to the high-level subsidence area lake, converts mechanical energy into gravitational potential energy for storage, and finally the water turbine generator regenerates the stored gravitational potential energy into electrical energy and feeds it back to the power grid, turning energy consumption into energy storage, thereby realizing a closed loop of three-level energy conversion, which greatly improves the energy efficiency and economy of the testing process.

[0010] 2. By adding photovoltaic panels and wind turbines, this utility model constructs a collaborative system of "new energy power generation - pumped storage - grid peak shaving", which effectively solves the problem of new energy consumption and improves the green energy ratio and operating economy of the entire system.

[0011] 3. This utility model enhances the structural integrity and stability of abandoned mines by adopting a dome support system that includes reinforced concrete lining, radial anchor bolts, and prestressed steel cables, effectively reducing the risk of collapse.

[0012] 4. This utility model constructs an integrated protection system of "seepage prevention-monitoring-location-early warning" by using a composite geomembrane seepage prevention layer, a distributed fiber optic acoustic sensor, a water level sensor and a flow meter. It can not only actively reduce the risk of leakage, but also monitor structural and water level anomalies in real time, and accurately locate and provide immediate early warning of leakage points, thereby comprehensively improving the safety and reliability of the system. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a generator set test system based on pumped storage in an abandoned mine, as described in an embodiment.

[0014] Figure 2 This is a schematic diagram of the reinforcement structure and dome support system of the waste gas mine.

[0015] Figure 3This is a schematic diagram of a distributed fiber optic acoustic sensor installed on the inner wall and sidewall of a waste gas mine.

[0016] Figure 4 This is a schematic diagram of a purification buffer zone arranged around a waste gas mine.

[0017] The reference numerals in the accompanying drawings include: 1. Low-level reservoir (abandoned mine), 2. High-level reservoir (subsidence area lake), 3. Load control cabinet, 4. Generator set under test, 5. Switch cabinet, 6. Water pump, 7. Energy storage generator (hydro turbine generator), 8. Power grid, 9. Control system, 10. Water pump frequency converter cabinet, 11. Generator control cabinet, 12. Photovoltaic panel, 13. Wind turbine, 14. Inverter, 15. Reinforced concrete lining, 16. Anchor bolt, 17. Prestressed steel cable, 18. Composite geomembrane seepage prevention layer, 19. Hot melt welding, 20. Gravel filter layer, 21. Activated carbon adsorption layer, 22. Distributed fiber optic acoustic sensor, 23. Water level sensor, 24. Flow meter. Detailed Implementation

[0018] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0019] This embodiment provides a generator set testing system based on pumped-storage power generation in abandoned mines, such as... Figure 1 As shown, in a preferred embodiment, the generator set testing system includes an energy storage unit and a testing unit. The energy storage unit includes a low-level reservoir 1 converted from an abandoned mine and a high-level reservoir 2 converted from a subsidence area lake / artificial slope. Preferably, the subsidence area lake is used as the high-level reservoir to reduce costs. There is a water level difference between the high-level reservoir 2 and the low-level reservoir 1, preferably ≥50m. Since the abandoned mine 1 has the risk of subsidence and leakage, and the subsidence area lake 2 has the risk of leakage, safe water storage is achieved through conversion. Details of the conversion of the abandoned mine 1 and the subsidence area lake / artificial slope are described later.

[0020] The test unit includes a variable frequency adjustable power load control cabinet 3, a generator set under test 4, a switch cabinet 5, and a water pump 6. The load control cabinet 3 is connected to the generator set under test 4 for load adjustment. The generator set under test 4 is connected to the water pump 6 via the switch cabinet 5 (specifically, connected to the motor of the water pump 6 to provide power to the water pump 6). The water pump 6 can pump water from the low-level reservoir 1 to the high-level reservoir 2. The load control cabinet 3 uses IGBT power modules (rated voltage ≥ 690V, response time ≤ 5ms), and achieves continuous adjustment of the load power (range 10%-100% rated power) through PWM modulation, with a test accuracy of ±1%. The water pump 6 is a multi-stage centrifugal pump (head ≥ 50m, efficiency ≥ 85%), and its flow rate is steplessly adjustable (200-1000m³ / h) through the variable frequency cabinet, adaptable to different power generator sets under test 4 (1MW-20MW).

[0021] During testing, the electrical energy output from the generator set under test 4 drives the motor of the water pump 6, causing the pump to run. The load control cabinet 3 precisely controls the speed and torque of the water pump 6 motor to adjust the load (±1% accuracy). Variable frequency speed regulation is used during steady-state testing, and circuit breaker switching simulates sudden load changes during transient testing. The water pump 6 pumps mine water from the low-level abandoned mine shaft 1 to the high-level subsidence area lake 2, forming a gravitational potential energy storage. The potential energy storage density is determined by the water level difference (≥50m) between the high-level reservoir 2 and the low-level reservoir 1, and a single energy storage cycle can reach 8 hours. Compared to traditional resistive loads, this testing system uses the water pump 6 motor as an adjustable load, converting the test electrical energy of the generator set under test 4 into mechanical energy instead of waste heat, thus recovering 90% of the test electrical energy.

[0022] In another preferred embodiment, the generator set testing system further includes a power generation unit, which includes at least one energy storage generator 7 capable of storing and generating electricity from the hydraulic potential energy of water released from a high-level reservoir. The power output terminal of the energy storage generator 7 is connected to the power grid 8, and the power supply terminal of the power grid 8 is also connected to the water pump 6 to supply power to it. The energy storage generator 7 is a hydro-generator or flywheel energy storage unit installed in the abandoned mine shaft 1, preferably a hydro-generator. The hydro-generator 7 adopts a mixed-flow design (single unit power 200-500kW), and multiple hydro-generators 7 are connected in parallel to form a hydro-generator set to adapt to flow fluctuations. The hydro-generator set is dynamically started and stopped according to the needs of the power grid 8 to ensure that the total output power fluctuation rate is <2%.

[0023] When there are no testing tasks, the test system executes the peak-shaving strategy of power grid 8. It utilizes off-peak electricity to drive the motor of water pump 6, which draws mine water from abandoned mine 1 to subsidence area lake 2 for energy storage. During peak hours, lake 2 releases water to drive turbine generator 7, generating electricity that is then fed into power grid 8. This process not only adapts to fluctuations in power grid 8 but also provides stable power support to power grid 8 through the inertial output of turbine generator 7.

[0024] Preferably, the test system employs a dual-pump configuration: one pump serves as the test load, connected to the generator set under test 4, for energy conversion during testing; the other pump serves as the power supply pump 6 for the power grid 8, directly driven by the power grid 8, and is dedicated to pumping water for energy storage. This design decouples the testing function from the conventional energy storage function in terms of physical structure, allowing them to operate independently and in parallel, thus improving the system's scheduling flexibility and overall utilization.

[0025] This invention replaces the energy-consuming load (resistor cabinet) in traditional power generation testing with a reversible energy conversion chain, realizing a cycle of "electrical energy → mechanical energy → potential energy → electrical energy" through a three-stage structure: First stage (electrical energy → mechanical energy): The electrical energy output by the generator set under test 4 drives the motor of the water pump 6 to operate, and this stage converts the test electrical energy into mechanical energy; Second stage (mechanical energy → potential energy): The water pump 6 pumps mine water from the low-level abandoned mine 1 to the high-level subsidence area lake 2, forming a gravitational potential energy storage; Third stage (potential energy → electrical energy): During the water release process of the subsidence area lake 2, the water flow drives the water turbine generator 7 to generate electricity and connect it to the power grid 8, and the water turbine generator 7 serves as a regenerative power generation unit.

[0026] In another preferred embodiment, the test system further includes a control system 9. The power supply end of the power grid 8 is connected to the water pump 6 via the water pump frequency converter cabinet 10 (specifically connected to the motor of the water pump 6). The energy storage generator 7 is connected to the generator control cabinet 11. Both the water pump frequency converter cabinet 10 and the generator control cabinet 11 are connected to the control system 9 via communication modules (such as Ethernet modules or 4G / 5G wireless modules) for data acquisition and dispatch command issuance. The control system 9 has preset dispatch commands, which are sent to the generator control cabinet 11. These commands can be used to dynamically adjust the guide vane opening (range 10°-90°) and generator excitation current of the hydro-generator 7. When the frequency of the power grid 8 fluctuates by ±0.5Hz, the hydro-generator unit can respond to power changes within 200ms.

[0027] This technical solution uses the pump frequency converter cabinet 10 and the generator control cabinet 11 as the underlying execution units to control the operation of the pump motor 6 and the turbine generator, respectively. The control system 9 serves as the upper-level monitoring terminal, establishing a communication connection with the pump frequency converter cabinet 10 and the generator control cabinet 11 to collect their operating parameters in real time and issue scheduling commands. This architecture achieves integrated management and control of the entire system from a single terminal, replacing the traditional decentralized mode of operating each control cabinet separately, and improving the convenience and coordination of operation.

[0028] like Figure 1As shown, in another preferred embodiment of this utility model, the power generation unit further includes a photovoltaic panel 12 and a wind turbine 13. The photovoltaic panel 12 and the wind turbine 13 are installed on the surface of the lake 2 in the subsidence area to maximize space utilization. The photovoltaic panel 12 and the wind turbine 13 are connected to the power grid 8 through an inverter 14. The inverter 14, which has communication function, is connected to the control system 9 for data acquisition and dispatch command issuance. When there is excess electricity generated by photovoltaic and wind power generation, the control system 9 prioritizes dispatching this portion of electricity to drive the water pump 6 to pump water from the abandoned mine 1 to the lake 2 in the subsidence area for energy storage, thereby realizing the on-site consumption and efficient storage of new energy.

[0029] like Figure 2 As shown, in another preferred embodiment of this utility model, the internal sidewall of the abandoned mine shaft 1 is provided with a reinforcement structure, which includes a reinforced concrete lining 15 and a reinforcing mesh embedded in the reinforced concrete lining 15. The reinforced concrete lining 15 has a thickness ≥300mm and a strength grade of C40; the reinforcing mesh is made of GFRP (with a tensile strength ≥800MPa) to enhance the crack resistance of the structure.

[0030] More preferably, a number of radially arranged anchor bolts 16 are provided on the roof of the abandoned mine shaft 1, with a spacing of ≤1.5m between anchor bolts 16, a length of ≥6m and a diameter of 28mm; the ends of the anchor bolts 16 are connected to each other by prestressed steel cables 17 with a tension of ≥100kN to form a spatial mesh support.

[0031] like Figure 4 As shown, in another preferred embodiment, to protect the groundwater system, a purification buffer zone is set up around the abandoned mine shaft 1. The purification buffer zone includes a gravel filter layer 20 on the surface and an activated carbon adsorption layer 21 on the inner surface. The gravel filter layer 20 has a thickness ≥1m and a filter media particle size of 5-20mm, used to block and filter suspended solids in the water; the activated carbon adsorption layer 21 has a thickness ≥0.5m, used to adsorb and remove heavy metal ions from the water, thereby achieving graded purification.

[0032] like Figure 3 As shown, in another preferred embodiment, a composite geomembrane impermeable layer 18 is laid on the outer side of the reinforced concrete lining 15. The composite geomembrane impermeable layer 18 is made of HDPE material, with a thickness ≥2mm and a permeability coefficient ≤10-12 cm / s to ensure reliable seepage prevention performance. The composite geomembrane impermeable layer 18 is composed of several composite geomembrane sub-units spliced ​​together. The overlaps of the composite geomembrane sub-units are fixed by hot-melt welding 19, and the peel strength of the welded joint is ≥15N / mm.

[0033] like Figure 3As shown, in another preferred embodiment, the testing system further includes a leakage monitoring system. This system comprises distributed fiber optic acoustic wave sensors 22 installed in the sidewall of the abandoned mine shaft 1 for real-time monitoring of leakage and deformation. The signal output of the distributed fiber optic acoustic wave sensors 22 is connected to the deformation signal input of the control system 9. The data collected by the distributed fiber optic acoustic wave sensors 22 is transmitted to the control system 9, achieving a leakage location accuracy of ±0.5m. The distributed fiber optic acoustic wave sensors 22 are installed along the reinforced concrete lining 15 at intervals ≤5m, for real-time monitoring of leakage and deformation of the sidewall of the abandoned mine shaft 1, such as the KSDA3000 system from Keguang Communication.

[0034] like Figure 1 As shown, in another preferred embodiment, the leakage monitoring system further includes a water level sensor 23 installed at the bottom of the abandoned mine shaft 1, and a flow meter 24 installed on the pipeline connected to the water pump 6 and the turbine generator. The signal output terminals of the water level sensor 23 and the flow meter 24 are respectively connected to the water level signal and flow signal input terminals of the control system 9. The alarm output terminal of the control system 9 is connected to at least two alarm units. The data collected by the water level sensor 23 and the flow meter 24 are transmitted to the control system 9. When the water level sensor 23 and the flow meter 24 detect that the abnormal rise or fall rate of the water level exceeds a set threshold, such as when the rise or fall rate of the water level is greater than 5 cm / 24h, the alarm is triggered to issue an alarm, so as to realize the immediate warning of leakage risk. The control system 9 may include a first comparator and a second comparator. The first input of the first comparator is connected to the output of the water level sensor 23, and the second input is connected to the water level threshold memory. The first input of the second comparator is connected to the output of the flow meter 24, and the second input is connected to the flow threshold memory. The output of the first comparator is connected to a first alarm unit, and the output of the second comparator is connected to a second alarm unit (specifically, this connection can be achieved through a drive circuit). When the water level or flow rate exceeds the threshold, the alarm unit will sound an alarm.

[0035] Specifically, the water level sensor 23 and the flow meter 24 work together through the principle of water balance. The control system 9 acts as the processing core, comparing the expected water level calculated from the flow data of the flow meter 24 with the actual water level read by the water level sensor 23 in real time. When the deviation between the two exceeds the set threshold (e.g., >5cm / 24h), it indicates that an unknown leakage or water surge has occurred. At this time, not only can the alarm be triggered to issue an alarm, but the distributed fiber optic acoustic sensor 22 can also be linked to perform precise positioning and provide a decision basis for executing control commands such as production restriction or shutdown.

[0036] The above describes the reinforcement and seepage prevention modifications made to abandoned mine shaft 1. The modifications to the lake / artificial slope in the subsidence area are as follows:

[0037] 1) Topographic assessment and reinforcement: First, assess the geological stability of the subsidence area or slope. Reinforce unstable areas, such as by using stepped blasting excavation technology (similar to the Jurong pumped storage power station case), to ensure a reasonable slope ratio (e.g., 1:1.7) and prevent landslide risks.

[0038] 2) Seepage prevention: Use concrete lining or lay a seepage-proof membrane to cover the reservoir basin to reduce leakage (refer to the seepage prevention practices of pumped storage in mines); at the same time, clean up debris in the reservoir area to ensure that the water storage capacity meets the standards.

[0039] 3) Structural integration: Construct connecting channels (such as water diversion tunnels) to smoothly connect the high-level reservoir 2 with the low-level reservoir 1. The water level difference should be achieved through natural terrain or artificial elevation (such as by using a combined system of subsidence area and underground space).

[0040] After the renovation, the high-level reservoir 2 needs to have sufficient volume (e.g., several thousand cubic meters) and structural strength to support water pumping and power generation testing. The entire project needs to monitor quality and safety, optimize costs, and reduce earthwork by utilizing the existing terrain.

[0041] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A test system for generator sets based on pumped-storage power generation in abandoned mines, characterized in that, Includes energy storage units and testing units; The energy storage unit includes a low-level reservoir converted from an abandoned mine and a high-level reservoir converted from a lake in a subsidence area / artificial slope, with a water level difference between the high-level reservoir and the low-level reservoir; The test unit includes a variable frequency adjustable power load control cabinet, a generator set under test, a switch cabinet, and a water pump. The load control cabinet is connected to the generator set under test and is used to adjust the load. The generator set under test is connected to the water pump through the switch cabinet. The water pump can pump water from a low-level reservoir to a high-level reservoir.

2. The generator set testing system based on pumped-storage power generation in abandoned mines according to claim 1, characterized in that, It also includes a power generation unit, which includes at least one energy storage generator capable of storing the hydraulic potential energy of water released from the high-level reservoir to generate electricity. The power output terminal of the energy storage generator is connected to the power grid, and the power supply terminal of the power grid is also connected to the water pump to supply power to it.

3. A generator set testing system based on pumped-storage power generation in abandoned mines according to claim 2, characterized in that, The energy storage generator is a hydro generator or flywheel energy storage unit installed in an abandoned mine.

4. The generator set testing system based on pumped-storage power generation in abandoned mines according to claim 1, characterized in that, It also includes a control system. The power supply end of the power grid is connected to the water pump through the water pump frequency converter cabinet, and the energy storage generator is connected to the generator control cabinet. Both the water pump frequency converter cabinet and the generator control cabinet are communicatively connected to the control system for data acquisition and dispatch command issuance.

5. A generator set testing system based on pumped-storage power generation in abandoned mines according to claim 1, characterized in that, The abandoned mine shaft has a reinforced structure on its internal sidewalls, which includes a reinforced concrete lining and a reinforcing mesh embedded therein.

6. A generator set testing system based on pumped-storage power generation in abandoned mines according to claim 1, characterized in that, The roof of the abandoned mine is provided with several radially arranged anchor bolts, the ends of which are connected to each other by prestressed steel cables to form a spatial mesh support.

7. A generator set testing system based on pumped-storage power generation in abandoned mines according to claim 1, characterized in that, The abandoned mine shaft is surrounded by a purification buffer zone, which includes a gravel filter layer on the surface and an activated carbon adsorption layer on the inner surface.

8. A generator set testing system based on pumped-storage power generation in abandoned mines according to claim 5, characterized in that, The outer side of the reinforced concrete lining is covered with a composite geomembrane anti-seepage layer, which is composed of several composite geomembrane sub-units spliced ​​together, and the overlapping parts of the composite geomembrane sub-units are fixed by hot-melt welding.

9. A generator set testing system based on pumped-storage power generation in abandoned mines according to claim 4, characterized in that, It also includes a leakage monitoring system, which includes distributed fiber optic acoustic wave sensors installed in the sidewall of the abandoned mine for real-time monitoring of leakage and deformation. The signal output end of the distributed fiber optic acoustic wave sensor is connected to the deformation signal input end of the control system, and the data collected by the distributed fiber optic acoustic wave sensor is transmitted to the control system.

10. A generator set testing system based on pumped-storage power generation in abandoned mines according to claim 9, characterized in that, The leakage monitoring system also includes a water level sensor installed at the bottom of the abandoned mine shaft and a flow meter installed on the pipeline connected to the water pump and the turbine generator. The signal output terminals of the water level sensor and the flow meter are respectively connected to the water level signal and flow signal input terminals of the control system. An alarm is connected to the alarm output terminal of the control system. The data collected by the water level sensor and flow meter are transmitted to the control system. When the water level sensor and flow meter detect that the water level rises or falls abnormally at a rate exceeding a set threshold, an alarm is triggered to sound an alarm.

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