A transcritical wind power direct compression carbon dioxide cycle power generation method and device

Abstract

The present invention belongs to the technical field of wind power generation, and discloses a transcritical wind power direct compression carbon dioxide cycle power generation method and device. The wind turbine directly drives the compressor to adiabatically compress carbon dioxide to supercritical pressure. After entering the peak-shaving station of the wind farm, the carbon dioxide is liquefied and stored in an insulated tank after passing through the first heat exchanger and the throttle valve. The gas at the top of the tank can be re-inhaled into the compressor through a pipeline. When the tank solenoid valve is opened during power generation, the liquid carbon dioxide is quickly gasified after absorbing heat through the second heat exchanger, driving the expander to work and generate electricity, and the exhaust gas is re-inhaled into the compressor for recirculation and compression. The first heat exchanger and the second heat exchanger rely on the water in the heat balance pool to complete the heat absorption and heat release respectively to achieve balance. The present invention utilizes the characteristics of carbon dioxide being easy to liquefy, high expansion pressure, not geographically restricted and highly safe, and overcomes the disadvantages of large compressed air volume. It solves the intermittent problem of wind power generation and takes into account both energy density and efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind power generation, and in particular relates to a transcritical wind power direct compression carbon dioxide cycle power generation method and device. Background Art

[0002] At present, wind power generation actually converts wind energy into mechanical energy, and then converts mechanical energy into electrical energy. Since wind power is unstable, sometimes strong and sometimes weak, the electricity it generates is also volatile. These energies cannot be dispatched. During low seasons, thermal power is used for peak regulation, and during peak seasons, wind power can only be abandoned.

[0003] Of course, the best way to solve this problem is to use energy storage to convert it into stable electricity and then connect it to the grid. Common energy storage technologies include electrochemical energy storage technology (high cost), pumped storage technology (geographical restrictions), hydrogen energy storage technology (requires a complete industrial chain), and compressed air energy storage. Taking into account the geographical conditions and economic feasibility of wind power, compressed air energy storage is currently the best solution for wind power energy storage.

[0004] Existing compressed air energy storage mainly uses photovoltaic, wind energy, etc. to generate unstable electricity, and then uses electric motors to connect air compressors to achieve air compression energy storage.

[0005] Compressed air energy storage is achieved by separating the compression process and expansion process of gas turbine power generation in the time dimension, storing and releasing electrical energy separately. When there is an excess supply of electricity, the compressor converts the electrical energy into high-pressure air internal energy for storage; when there is an insufficient supply of electricity, the high-pressure air is released into the expander to perform work, driving the generator to generate electricity, thereby converting the compressed air internal energy back into electrical energy.

[0006] The initial compressed air energy storage scheme directly dissipates the heat generated in the compression energy storage stage in the form of cooling heat exchange, and in the energy release stage, the high-pressure air at the expander inlet needs to be heated by fuel combustion, so it is defined as a non-adiabatic compressed air energy storage system, also known as the first generation of compressed air energy storage system. The energy storage efficiency of the first generation of compressed air energy storage system is only about 50%.

[0007] Later, based on the first generation of compressed air energy storage system, the combustion chamber was removed, and the compression heat of the energy storage stage was recovered and stored by cooling and heat exchanging the compressor outlet airflow, and then the heat exchanger was used to heat the expander inlet airflow during the energy release stage. This is the second generation of compressed air energy storage system, and the cycle efficiency of the second generation system can reach 60% to 70%.

[0008] Compressed air energy storage requires large high-pressure storage equipment or areas. Air is not easy to liquefy and often requires the use of caves or underground mines, so it is dependent on geographical conditions.

[0009] Through the above analysis, the problems and defects of the prior art are as follows:

[0010] (1) Existing solutions to wind power fluctuations all rely on thermal power peak regulation and energy storage.

[0011] (2) Existing energy storage technologies lack economic feasibility or have strict requirements on geographical conditions.

[0012] (3) Currently all wind farms are unable to supply electricity as scheduled.

[0013] (4) Installing an energy storage device converts electrical energy into other energies and then converts it into electrical quantity. This causes the problem of multiple conversions, thus reducing efficiency. Summary of the invention

[0014] In order to solve the problems existing in the prior art, the present invention provides a transcritical wind power direct compression carbon dioxide cycle power generation method and device, utilizing the fact that carbon dioxide is easy to liquefy and has a high expansion pressure, and can take into account both energy density and efficiency.

[0015] The present invention is implemented as follows: a transcritical wind power direct compression carbon dioxide cycle power generation method, comprising:

[0016] Step 1: The wind turbine directly drives the compressor to adiabatically compress the carbon dioxide to supercritical pressure; the high-pressure carbon dioxide transmission pipeline from the wind turbine to the peak-shaving station is adiabatically transmitted;

[0017] Step 2: After the carbon dioxide enters the peak-shaving station of the wind farm, it passes through the first heat exchanger and the throttle valve and is liquefied and stored in an insulated tank. The gas at the top of the tank is re-inhaled into the compressor through a pipeline.

[0018] Step three, after opening the tank solenoid valve for power generation, the liquid carbon dioxide absorbs heat through the second heat exchanger and quickly vaporizes, driving the expander to generate electricity, and the exhaust gas is re-inhaled into the compressor for recirculation and compression.

[0019] Furthermore, the first heat exchanger and the second heat exchanger achieve balance by absorbing and releasing heat respectively through water in the heat balance water pool.

[0020] Another object of the present invention is to provide a transcritical wind-driven direct compression carbon dioxide cycle power generation device provided with a wind turbine;

[0021] The wind turbine directly drives the compressor, reducing the number of energy conversions and improving work efficiency;

[0022] The output pipeline of the compressor is connected to the first heat exchanger through an insulated pipeline, and the high-temperature and high-pressure carbon dioxide generated by the compressor is cooled down to low-temperature and high-pressure, and the replaced heat is stored in a heat balance water pool; the first heat exchanger is connected through a pipeline and a throttle valve and then liquefied and stored in an insulated carbon dioxide tank, which solves the problem of energy density, greatly reduces the volume, and is no longer dependent on special geographical conditions;

[0023] The insulated carbon dioxide tank is connected to the second heat exchanger via a tank solenoid valve at the lower end;

[0024] The second heat exchanger is connected to the expander through a pipeline; the expander is connected to the return pipeline of the compressor through a pipeline.

[0025] Furthermore, the wind turbine is connected to the compressor via a gear box.

[0026] Furthermore, there are multiple wind turbines.

[0027] Furthermore, there are multiple insulated carbon dioxide tanks, which are connected to the loop pipeline of the compressor through a gas recovery compression pipeline.

[0028] Furthermore, the first heat exchanger and the second heat exchanger are both connected to a heat balance water tank through pipelines.

[0029] Furthermore, the heat balance water pool is connected to the first heat exchanger and the second heat exchanger via a circulation pump.

[0030] Furthermore, the expander is connected to the loop pipeline of the compressor via a low-pressure buffer tank, so that the pressure of carbon dioxide is reduced after expansion, and the volume is naturally increased, so that the carbon dioxide is re-absorbed into the compressor.

[0031] Another object of the present invention is to provide a control method for a transcritical wind-driven direct compression carbon dioxide cycle power generation device, including: changing the power generation mechanism of an ordinary fan into an air compressor; the concentric shaft transmits the kinetic energy of the fan blades to the input shaft of the steering gearbox, the two shafts are connected by a coupling, the input end of the coupling structure is a clamping hoop structure, and the output end is an expansion structure, so that the support rod and the input shaft of the steering gearbox are connected as a whole; the steering gearbox is used to change the transmission direction, the torque of the acceleration gearbox is used to increase the speed, and the electromagnetic brake is used to brake the fan when the wind force is too strong; the output of compressed carbon dioxide is controlled by an output electromagnetic valve in the pipeline, and when the wind force is too strong, the electromagnetic brake is remotely controlled to control the fan to stop and close the electromagnetic valve, and then connected to the main pipe. The input end of the steering gearbox is connected to the lower end of the concentric shaft of the vertical axis fan, the output end of the steering gearbox is connected to the input end of the acceleration gearbox, and the output end of the acceleration gearbox is connected to the screw compressor; the outer end of the screw compressor is connected with an air inlet and an air outlet, and the air outlet is connected to the output pipeline of the compressor through the output electromagnetic valve.

[0032] Combining all the above technical solutions, the advantages and positive effects of the present invention are as follows:

[0033] The present invention uses wind power to directly compress carbon dioxide, which changes the current status of wind turbines outputting electricity. It directly outputs high-temperature and high-pressure carbon dioxide gas, which reduces the number of energy conversions compared to other energy storage methods. The efficiency of a general generator is about 90%, so the efficiency can be increased by 10%. Carbon dioxide reaches a supercritical state at 31.2°C and 7.38MPa, and is easier to liquefy than air, which increases the energy density, overcomes the disadvantage of the large volume of compressed air, and solves the problem of dependence on special geographical conditions. The present invention converts wind energy into liquid carbon dioxide and then expands it to generate electricity, so the power generation process can be controlled, solving the intermittent problem of wind power generation. Electricity production can be carried out as planned and the output is stable. Therefore, this power generation device is a dispatchable stable energy source like thermal power and hydropower, and it is a renewable clean energy source. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 It is a flow chart of the transcritical wind direct compression carbon dioxide cycle power generation method provided by an embodiment of the present invention.

[0036] Figure 2 It is a schematic diagram of a transcritical wind direct compression carbon dioxide cycle power generation device provided in an embodiment of the present invention.

[0037] Figure 3 It is a schematic diagram of a control method for a transcritical wind direct compression carbon dioxide cycle power generation device provided in an embodiment of the present invention.

[0038] In the figure: 1. wind turbine; 2. compressor; 3. first heat exchanger; 4. throttle valve; 5. high-pressure solenoid valve; 6. insulated carbon dioxide tank; 7. tank solenoid valve; 8. second heat exchanger; 9. expander; 10. gear box; 11. gas recovery compression pipeline; 12. compressor loop pipeline; 13. compressor output pipeline; 14. heat balance water tank; 15. circulation pump; 16. low-pressure buffer tank; 201. electromagnetic brake; 202. fan blades; 203. support rod; 204. concentric shaft; 205. steering gear box; 206. acceleration gear box; 207. screw compressor; 208. air outlet; 209. air inlet; 210. output solenoid valve. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the 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.

[0040] In view of the problems existing in the prior art, the present invention provides a transcritical wind power direct compression carbon dioxide cycle power generation method and device, and the present invention is described in detail below with reference to the accompanying drawings.

[0041] like Figure 1 As shown, the present invention provides a transcritical wind direct compression carbon dioxide cycle power generation method, comprising:

[0042] S101, the wind turbine directly drives the compressor to adiabatically compress the carbon dioxide to supercritical pressure; the high-pressure carbon dioxide transmission pipeline from the wind turbine to the peak-shaving station is adiabatically transmitted;

[0043] S102, after the carbon dioxide enters the peak-shaving station of the wind farm, it passes through the first heat exchanger and the throttle valve and is liquefied and stored in an insulated tank. The gas at the top of the tank is re-inhaled into the compressor through a pipeline;

[0044] S103, when the tank solenoid valve is opened for power generation, the liquid carbon dioxide is rapidly vaporized after absorbing heat through the second heat exchanger, driving the expander to generate electricity, and the exhaust gas is re-inhaled into the compressor for recirculation and compression.

[0045] The first heat exchanger and the second heat exchanger achieve balance by absorbing and releasing heat respectively through the water in the heat balance water pool.

[0046] like Figure 2 As shown, the present invention provides a transcritical wind-driven direct compression carbon dioxide cycle power generation device provided with a wind turbine 1;

[0047] The wind turbine 1 is directly connected to the compressor 2;

[0048] The compressor output pipeline 13 is connected to the first heat exchanger 3 through a pipeline; the first heat exchanger is connected to the insulated carbon dioxide tank 6 through a pipeline, a throttle valve 4, and a high-pressure solenoid valve 5;

[0049] The insulated carbon dioxide tank is connected to the second heat exchanger 8 via the tank solenoid valve 7 at the lower end;

[0050] The second heat exchanger is connected to the expander 9 via a pipeline; the expander is connected to the return pipeline of the compressor via a pipeline.

[0051] The wind turbine is connected to the compressor via a gear box 10 .

[0052] There are multiple wind turbines.

[0053] There are multiple insulated carbon dioxide tanks, which are connected to the return line 12 of the compressor via a gas recovery compression line 11.

[0054] The first heat exchanger and the second heat exchanger are both connected to the heat balance water tank 14 through pipelines.

[0055] The heat balance water pool is connected to the first heat exchanger and the second heat exchanger via a circulation pump 15 .

[0056] In a preferred embodiment of the present invention, the expander is connected to the loop pipeline 12 of the compressor via a low-pressure buffer tank 16, so that the pressure of carbon dioxide decreases after expansion, the volume naturally increases, and the carbon dioxide is re-absorbed into the compressor.

[0057] like Figure 3 As shown, in a preferred embodiment of the present invention, a control method for a transcritical wind power direct compression carbon dioxide cycle power generation device includes: the vertical axis fan in the embodiment of the present invention is based on the ordinary fan and the power generation mechanism is removed and replaced with an air compressor. Its core is the concentric shaft 204 that transmits the kinetic energy of the fan blade 202 to the input shaft of the steering gear box 205. The two shafts are connected by a coupling. The input end of the coupling structure is a clamping hoop structure, and the output end (i.e., the input shaft of the steering gear box) is an expansion structure, so that the support rod 203 and the input shaft of the steering gear box 205 are connected as a whole. The steering gear box 205 is used to change the transmission direction; the acceleration gear box 206 is used to change the speed with torque to increase the speed. The electromagnetic brake 201 is used to brake the fan to achieve protection when the wind force is too strong. The output solenoid valve 210 is placed in the pipeline to control the output of compressed carbon dioxide. When the wind force is too strong, the electromagnetic brake is remotely controlled to stop the fan and close the solenoid valve, and then connected to the main pipe.

[0058] In the present invention, the gearbox is provided with a steering gearbox 205 and an acceleration gearbox 206, the input end of the steering gearbox 205 is connected to the lower end of the concentric shaft 204 of the vertical axis fan, the output end of the steering gearbox 205 is connected to the input end of the acceleration gearbox 206, and the output end of the acceleration gearbox 206 is connected to the screw compressor 207. The outer end of the screw compressor 207 is connected to an air inlet 209 and an air outlet 208, and the air outlet 208 is connected to the output pipeline 13 of the compressor through an output solenoid valve 210.

[0059] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0060] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A transcritical wind power direct compression carbon dioxide cycle power generation method, characterized in that: The transcritical wind power direct compression carbon dioxide cycle power generation method comprises: Step 1: The wind turbine directly drives the compressor to adiabatically compress the carbon dioxide to supercritical pressure; the high-pressure carbon dioxide transmission pipeline from the wind turbine to the peak-shaving station is adiabatically transmitted; Step 2: After the carbon dioxide enters the peak-shaving station of the wind farm, it passes through the first heat exchanger and the throttle valve and is liquefied and stored in an insulated tank. The gas at the top of the tank is re-inhaled into the compressor through a pipeline. Step 3: When the tank solenoid valve is opened for power generation, the liquid carbon dioxide is rapidly gasified after absorbing heat in the second heat exchanger, driving the expander to generate electricity, and the exhaust gas is re-inhaled into the compressor for recirculation and compression; The first heat exchanger and the second heat exchanger respectively absorb and release heat to achieve equilibrium by relying on the water in the heat balance water pool; A transcritical wind-powered direct compression of carbon dioxide cycle power generation device for implementing a transcritical wind-powered direct compression of carbon dioxide cycle power generation method, wherein the transcritical wind-powered direct compression of carbon dioxide cycle power generation device is provided with a wind turbine; The wind turbine directly drives the compressor; The output pipeline of the compressor is connected to the first heat exchanger through an insulated pipeline, and the high-temperature and high-pressure carbon dioxide generated by the compressor is cooled down to low-temperature and high-pressure, and the replaced heat is stored in a heat balance water pool; the first heat exchanger is connected through a pipeline and a throttle valve and then liquefied and stored in an insulated carbon dioxide tank; The insulated carbon dioxide tank is connected to the second heat exchanger via a tank solenoid valve at the lower end; The second heat exchanger is connected to the expander through a pipeline; the expander is connected to the return pipeline of the compressor through a pipeline; The wind turbine is connected to the compressor via a gear box; The insulated carbon dioxide tanks are multiple and connected to the return line of the compressor via a gas recovery compression pipeline; The expander is connected to the loop pipeline of the compressor through a low-pressure buffer tank, so that the pressure of carbon dioxide is reduced after expansion, the volume is naturally increased, and the carbon dioxide is sucked back into the compressor; The power generation mechanism of the ordinary fan is changed into an air compressor; the concentric shaft transmits the kinetic energy of the fan blades to the input shaft of the steering gearbox, and the two shafts are connected by a coupling. The input end of the coupling structure is a clamping hoop structure, and the output end is an expansion structure, so that the support rod and the input shaft of the steering gearbox are connected as a whole; the steering gearbox is used to change the transmission direction, the torque of the acceleration gearbox is used to increase the speed, and the electromagnetic brake is used to brake the fan when the wind force is too strong; the output of compressed carbon dioxide is controlled by an output electromagnetic valve in the pipeline. When the wind force is too strong, the electromagnetic brake is remotely controlled to stop the fan and close the electromagnetic valve, and then connected to the main pipe; the input end of the steering gearbox is connected to the lower end of the concentric shaft of the vertical axis fan, the output end of the steering gearbox is connected to the input end of the acceleration gearbox, and the output end of the acceleration gearbox is connected to the screw compressor; the outer end of the screw compressor is connected with an air inlet and an air outlet, and the air outlet is connected to the output pipeline of the compressor through the output electromagnetic valve.

2. The transcritical wind direct compression carbon dioxide cycle power generation method according to claim 1, characterized in that: There are multiple wind turbines.

3. The transcritical wind power direct compression carbon dioxide cycle power generation method according to claim 1, characterized in that: The first heat exchanger and the second heat exchanger are both connected to the heat balance water tank through pipelines.

4. The transcritical wind direct compression carbon dioxide cycle power generation method according to claim 1, characterized in that: The heat balance water pool is connected to the first heat exchanger and the second heat exchanger through a circulation pump.

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