Gravity energy storage old fan and reconstruction method thereof

Abstract

The gravity energy storage old draught fan comprises a draught fan tower drum and a cabin at the top of the draught fan tower drum, a motor generator is arranged in the cabin, and the working end of the motor generator is connected with a winch-cable-speed control system; a weight is arranged in the fan tower drum, the weight is hung at the tail end of the cable, and the weight is controlled to move up and down through the winch-cable-speed control system to achieve gravity energy storage. An old fan is adopted to reconstruct a gravity energy storage facility, the height and the bearing capacity of a fan tower are utilized, a cabin of the fan and the transformation and utilization of a generator are explored, the advantages that the old fan is close to a wind power plant and the cost of reconstruction is low compared with that of new construction are brought into full play, and meanwhile the decommissioning problem of the old fan and the wind power energy storage requirement gap are solved.

Description

Technical Field

[0001] The present invention belongs to the field of energy storage, and in particular relates to an old gravity energy storage fan and a reconstruction method thereof. Background Art

[0002] Existing gravity energy storage technologies are mainly divided into three types of structures: based on structure height difference, based on mountain drop, and based on underground shafts. Mountain drop and underground shafts mostly use existing hillsides and shafts, but existing hillsides and shafts are generally far away from wind and solar power stations. Gravity energy storage with structure height difference is mostly newly built and can be built near wind and solar power stations, but the construction cost is high and does not make full use of existing facilities.

[0003] There is currently no relevant technology for converting old wind turbines into gravity energy storage. The existing plans do not, first, modify and utilize the old wind turbines; second, they do not fully utilize the height advantage and load-bearing capacity of the wind turbine tower; third, they do not utilize the nacelles and generators of the old wind turbines to transform them into electric generators and nacelles for gravity energy storage; fourth, they do not calculate the power and capacity range of the wind turbine converted into gravity energy storage, nor do they explore its characteristics and uses. Summary of the invention

[0004] In view of the above problems, the present invention proposes an old wind turbine with gravity energy storage, comprising a wind turbine tower and a nacelle at the top of the wind turbine tower, wherein an electric generator is arranged in the nacelle, and a working end of the electric generator is connected to a winch-cable-speed transmission system;

[0005] A heavy object is set inside the wind turbine tower and hung at the tail end of the cable. The winch-cable-speed transmission system controls the up and down movement of the heavy object to achieve gravity energy storage.

[0006] Furthermore, it also includes an operation control system, which is electrically connected to the winch-cable-speed transmission system to control the up and down movement of the heavy object to achieve gravity energy storage.

[0007] Furthermore, multiple rebuilt old wind turbines are provided, and the multiple rebuilt old wind turbines are connected in parallel or in series to realize gravity energy storage.

[0008] Furthermore, the heavy objects include sand, gravel, metal, and cement.

[0009] The present invention also provides a method for rebuilding an old wind turbine using gravity energy storage, the method comprising:

[0010] The hub and blades were removed, the generator inside the nacelle was converted into an electric generator, and the gearbox inside the nacelle was converted into a winch-cable-speed transmission system;

[0011] The cable is suspended inside the wind turbine tower and a weight is hung at the end of the cable. Gravity energy storage is achieved through the effective conversion of the gravitational potential energy of the weight moving up and down and the electrical energy.

[0012] Furthermore, the energy storage power is determined by the energy storage duration, which is 10s-10min.

[0013] Furthermore, the method also includes connecting multiple rebuilt old wind turbines in parallel or series to form an array to achieve gravity energy storage.

[0014] Furthermore, the mass of the heavy object is determined by the weight borne by the tower and the mass of the removed hub and blades.

[0015] Furthermore, the energy storage power is determined by the energy storage capacity, energy storage duration, response time, weight speed and weight acceleration.

[0016] Furthermore, the energy storage efficiency is not less than 90%.

[0017] The gravity energy storage old wind turbine and its reconstruction method of the present invention adopt the old wind turbine to rebuild the gravity energy storage facility, utilize the height and load-bearing capacity of the wind turbine tower, and explore the transformation and utilization of the wind turbine cabin and generator, give full play to the advantages of the old wind turbine being close to the wind farm and the lower cost of reconstruction than new construction, and at the same time solve the problem of decommissioning old wind turbines and the gap in wind power energy storage demand.

[0018] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of remodeling an old wind turbine tower into gravity energy storage is shown in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the embodiment of the present invention, the use of old wind turbines to rebuild gravity energy storage facilities can simultaneously solve the retirement problem of old wind turbines and the gap in wind power energy storage demand. The wind turbine is rebuilt into gravity energy storage, and the height and load-bearing capacity of the wind turbine tower can be utilized, and the transformation and utilization of the wind turbine generator can be explored. Taking advantage of the hollow structural characteristics of the wind turbine tower, combined with the advantages of height and load-bearing capacity, heavy objects can be placed in the tower, and the combination of cables, pulleys, and electric generators (the original generators can be transformed) can be used to effectively convert the gravitational potential energy and electrical energy of the heavy objects moving up and down, thereby achieving the effect of gravity energy storage.

[0023] Figure 1 A schematic diagram of remodeling an old wind turbine tower into a gravity energy storage device in an embodiment of the present invention is shown. Figure 1 In the old wind turbine with gravity energy storage, there is a wind turbine tower and a cabin on the top of the wind turbine tower. An electric generator is arranged in the cabin, and the working end of the electric generator is connected to the winch-cable-speed transmission system. A heavy object is arranged inside the wind turbine tower, and the heavy object is suspended at the tail end of the cable. The gravity energy storage is realized by controlling the up and down movement of the heavy object through the winch-cable-speed transmission system.

[0024] Specifically, it also includes an operation control system, which is electrically connected to the winch-cable-speed change system to control the up and down movement of the heavy object to achieve gravity energy storage.

[0025] Specifically, in order to increase the power and duration of gravity energy storage, old wind turbines can be converted into gravity energy storage facilities, and they can also be operated in an array mode of multiple parallel or series connections.

[0026] Specifically, the heavy objects include sand, gravel, metal, and cement.

[0027] The embodiment of the present invention also provides a method for rebuilding an old wind turbine using gravity energy storage, the method comprising:

[0028] The hub and blades were removed, the generator inside the nacelle was converted into an electric generator, and the gearbox inside the nacelle was converted into a winch-cable-speed transmission system;

[0029] The cable is suspended inside the wind turbine tower and a weight is hung at the end of the cable. Gravity energy storage is achieved through the effective conversion of the gravitational potential energy of the weight moving up and down and the electrical energy.

[0030] Specifically, the energy storage power is determined by the energy storage duration, which is 10s-10min.

[0031] Specifically, the method also includes connecting multiple rebuilt old wind turbines in parallel or series to form an array to achieve gravity energy storage.

[0032] Specifically, the mass of the heavy object is determined by the weight borne by the tower and the mass of the removed hub and blades.

[0033] Specifically, the energy storage power is determined by the energy storage capacity, energy storage duration, response time, weight speed and weight acceleration.

[0034] In the embodiment of the present invention, a 1.5MW old wind turbine is converted into a gravity energy storage facility as an example for specific description, focusing on the height, load-bearing performance and other performance of the wind turbine tower, and analyzing the potential of the conversion into gravity energy storage.

[0035] Wind turbine tower parameters:

[0036] The tower of a 1.5MW wind turbine usually adopts a tapered variable cross-section design, with a typical total height of 75 meters. The tower is divided into three sections, and each section is bolted together through a butt flange. The diameter of the top of the tower is 2.5m, and the diameter of the bottom is 4.5m.

[0037] The nacelle, hub and blades are installed above the 1.5MW wind turbine tower, and the total mass is typically 100 tons. The mass of the nacelle (including the generator, gearbox, etc.) is 60 tons, and the mass of the hub and blades is 40 tons. The typical size of the nacelle is 8m×4m×4m

[0038] Gravity energy storage parameters:

[0039] The power and capacity calculation method during the stable energy storage / release process is as follows:

[0040] The power of the energy storage system P = mgv, where m is the mass of the weight, g is the acceleration of gravity, and v is the speed of the weight moving; the capacity of the energy storage system E = mgh, where m is the mass of the weight, g is the acceleration of gravity, and h is the distance the weight moves.

[0041] In the embodiment of the present invention, the power and capacity of gravity energy storage are mainly related to the mass of the weight, the moving height and the set speed, wherein the set speed depends on the selection of the energy storage duration. The energy storage duration l = h / v. In the embodiment of the present invention, the range of the energy storage duration l and the set speed can be flexibly selected, which is also one of the advantages of gravity energy storage. Considering that there are certain requirements for the response time during the startup of the energy storage, the heavy object has a certain acceleration. The maximum instantaneous power P of the uniformly accelerated startup of the energy storage is P = (mg + ma) v, where a is the acceleration, and the calculation method is a = v / t, and t is the response time.

[0042] In the embodiment of the present invention, the method for reconstructing a gravity energy storage system for a 1.5MW wind turbine is to remove the hub and blades, retain the nacelle and tower, and transform the generator and gearbox in the nacelle into an electric generator and a winch-cable-speed transmission system. It is expected that after the reconstruction, the size of the nacelle will remain unchanged, and the mass will increase from the original 60 tons to about 65 tons.

[0043] When a 1.5MW wind turbine is stationary, the tower can bear the total mass of the nacelle, hub and blades, which is 100 tons. After the gravity energy storage is converted, there is still a surplus of 35 tons of load-bearing capacity, which can be used to configure solid weights. The 35 tons of solid weight can be placed in a cylinder with a diameter of 2.5m, which is convenient for placement in the tower.

[0044] In the embodiment of the present invention, the heavy objects include sand, metal, and cement. When iron blocks are used, the length of the cylinder is about 2.3 m, and when stones are used, the length of the cylinder is about 5 m.

[0045] In the design and construction of the 1.5MW wind turbine, various extreme working conditions were taken into consideration, and the tower bearing capacity was significantly higher than 100 tons in a static state. However, considering that there are no engineering applications for wind turbines converted to gravity energy storage, from a safety perspective, the solid weight configuration is still calculated at 35 tons.

[0046] The tower height is 75m. Considering the size of the heavy object and the margin for up and down movement, the moving distance of the modified gravity energy storage system is set to 70m. From this calculation, the energy storage capacity of the gravity energy storage system is E=mgh=35000kg×9.8m / s2×70m=24MJ=6.67kWh. Considering the energy storage efficiency of about 90%, the system can store about 6 kWh of electricity.

[0047] When the energy storage duration is 70s and the speed is set to 1m / s, the power of the energy storage system P = mgv = 35000kg × 9.8m / s 2 ×1m / s=343kW. When the energy storage duration is 700s and the speed is set to 0.1m / s, the power P of the energy storage system is 34.3kW. The power and cost of the electric generator can be greatly reduced, but the control difficulty increases significantly when heavy objects are running at low speeds, making it difficult to achieve a stable power output. Therefore, it is generally more appropriate to choose an energy storage duration of 10 seconds to 10 minutes. The power of the electric generator can also be comprehensively considered in combination with the transformation potential of the original 1.5MW wind turbine generator.

[0048] In summary, an old 1.5MW wind turbine can be converted into a 6.67kWh gravity energy storage system. The system power can be selected in the range of 20kW to 2MW, and the energy storage duration is correspondingly in the range of 20 minutes to 10 seconds. However, considering factors such as transformation, control, safety, and cost, a moderate power and duration within the range should be selected.

[0049] In addition, in the embodiment of the present invention, the determination of gravity energy storage also takes into account the response time and instantaneous power during the energy storage startup process. For a storage time of 70s and a set speed of 1m / s, the response time of the energy storage is set to 1s, then the maximum power of the energy storage startup process P = (mg + ma) v = (35000kg × 9.8m / s 2 +35000kg×1m / s2 )×1m / s=378kW. It can be seen that the electric generator is in motor mode during the energy storage startup process, and the power needs to reach more than 378kW to better meet the response time requirements and energy storage power requirements.

[0050] In the embodiment of the present invention, the 35-ton solid weight adopts a cylinder with a diameter of 2.5m, which is convenient to place in the tower. The tower height is 75m. Considering the size of the weight itself and the margin for up and down movement, the moving distance of the rebuilt gravity energy storage system is set to 70m. The solution calculation shows that the energy storage capacity of the gravity energy storage system is 24MJ (6.67kWh), the energy storage efficiency is about 90%, and it can store and release about 6 kWh of electricity.

[0051] Under the condition of constant energy storage capacity, the energy storage power, energy storage duration, response time, weight speed, weight acceleration and other parameters of the modified gravity energy storage system are interrelated. Selecting a moderate weight speed of 3.5m / s and acceleration of 3.5m / s2, the energy storage duration is 20s and the response time is 1s. The calculated energy storage power is about 1.2MW and the startup instantaneous power is about 1.6MW, which can maximize the transformation and utilization of the original wind turbine 1.5MW generator.

[0052] In the embodiment of the present invention, the parameter characteristics of the old wind turbine converted into gravity energy storage are suitable for application scenarios such as short-term peak regulation or frequency regulation auxiliary services.

[0053] Taking 10 old 1.5MW wind turbines as an example, each wind turbine selects a storage time of 20s and a response time of 1s, then the energy storage power is 1.2MW, and the instantaneous startup power is about 1.6MW, which can maximize the transformation and utilization of the original wind turbine generators.

[0054] If 10 energy storage systems are used in parallel and synchronously, a storage effect of 12MW and 20s can be achieved, supporting the frequency regulation needs of a 120MW wind farm; if 10 energy storage systems are used in series and relayed, a storage effect of 1.2MW and 200s can be achieved, supporting the short-term peak regulation and frequency regulation needs of a 12MW wind farm.

[0055] In the embodiment of the present invention, taking a 1.5MW old wind turbine as an example, by analyzing relevant parameters, it has the potential to be rebuilt into a 6.67kWh gravity energy storage system. The system power can be selected in the range of 20kW to 2MW, and the energy storage duration is correspondingly in the range of 20 minutes to 10 seconds. Generally, it is necessary to comprehensively consider factors such as transformation, control, safety, and cost to select an appropriate power and duration. Multiple old wind turbines can also be converted into multiple gravity energy storage subsystem arrays, which can be operated in parallel or in series to achieve energy storage power amplification or time extension to support frequency regulation needs or short-term peak regulation needs.

[0056] The gravity energy storage old wind turbine and its reconstruction method of the present invention effectively utilize the height advantage and load-bearing capacity of the old wind turbine tower, give play to the advantages of rebuilding the gravity energy storage facility close to the wind farm and saving costs, and meet the energy storage needs of the wind farm; clarify the route of rebuilding the gravity energy storage facility of the old wind turbine, remove the blades and retain the nacelle and generator for transformation, and save costs and recycle to the greatest extent; clarify the performance parameters of the gravity energy storage facility rebuilt from the old wind turbine, which is suitable for application scenarios of short-term peak-shaving and frequency regulation services, and also clarify that the comparison object is a technical form such as flywheel energy storage, and proposes an expansion application path in the form of an array.

[0057] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An old wind turbine with gravity energy storage, It is characterized in that It includes a wind turbine tower and a nacelle on the top of the wind turbine tower, wherein an electric generator is arranged in the nacelle, and a working end of the electric generator is connected to a winch-cable-speed transmission system; A heavy object is set inside the wind turbine tower and hung at the tail end of the cable. The winch-cable-speed transmission system controls the up and down movement of the heavy object to achieve gravity energy storage.

2. The gravity energy storage old wind turbine according to claim 1, It is characterized in that It also includes an operation control system, which is electrically connected to the winch-cable-speed change system to control the up and down movement of the heavy object to achieve gravity energy storage.

3. The gravity energy storage old wind turbine according to claim 1, It is characterized in that A plurality of rebuilt old wind turbines are arranged, and the plurality of rebuilt old wind turbines are connected in parallel or in series to realize gravity energy storage.

4. The gravity energy storage old wind turbine according to claim 1 or 2, It is characterized in that The heavy objects include sand, gravel, metal and cement.

5. A method for rebuilding old wind turbines with gravity energy storage. It is characterized in that The method comprises: The hub and blades were removed, the generator inside the nacelle was converted into an electric generator, and the gearbox inside the nacelle was converted into a winch-cable-speed transmission system; The cable is suspended inside the wind turbine tower and a weight is hung at the end of the cable. Gravity energy storage is achieved through the effective conversion of the gravitational potential energy of the weight moving up and down and the electrical energy.

6. The method for rebuilding an old wind turbine using gravity energy storage according to claim 5, It is characterized in that The energy storage power is determined by the energy storage duration, which is 10s-10min.

7. The method for rebuilding an old wind turbine using gravity energy storage according to claim 5, It is characterized in that The method also includes connecting a plurality of rebuilt old wind turbines in parallel or in series to form an array to realize gravity energy storage.

8. The method for rebuilding an old wind turbine using gravity energy storage according to claim 5, It is characterized in that The mass of the heavy object is determined by the weight borne by the tower and the mass of the removed hub and blades.

9. The method for rebuilding an old wind turbine using gravity energy storage according to claim 6, It is characterized in that The energy storage power is determined by the energy storage capacity, energy storage duration, response time, weight speed and weight acceleration.

10. The method for rebuilding an old wind turbine using gravity energy storage according to any one of claims 5 to 9, It is characterized in that The energy storage efficiency is not less than 90%.

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