A power generation system combining solar thermal and compressed gas energy storage

Abstract

This invention relates to the field of energy storage, specifically disclosing a power generation system combining solar thermal and compressed gas energy storage. The system includes a solar thermal energy storage system, a compressed gas energy storage system, a steam turbine power generation system, and a turbine power generation system. The compressed gas energy storage system is connected to the solar thermal energy storage system, collecting solar thermal energy through it. The turbine power generation system is also connected to the compressed gas energy storage system, storing energy for turbine power generation. The steam turbine power generation system is connected to the compressed gas energy storage system, storing energy for steam power generation. A coolant circulation system is also included, connected to each of the steam turbine power generation system, the turbine power generation system, and the compressed gas energy storage system. This invention improves the utilization rate of compressed gas energy storage and cooling water resources, resulting in more efficient power generation.

Description

Technical Field

[0001] This invention relates to the field of energy storage, specifically a power generation system that combines solar thermal and compressed gas energy storage. Background Technology

[0002] To reduce carbon emissions and build a clean, low-carbon, safe, and efficient energy system, the power industry has proposed specific measures for the development of multi-energy complementarity, including fully leveraging the flexible regulation role of the power supply side or rationally allocating energy storage. Compressed air energy storage power stations offer numerous advantages, such as large scale, high efficiency, low cost, long lifespan, short construction period, and clean operation. They can also replace thermal power units to provide rotational inertia for the power system, making them a suitable emerging energy storage technology for large-scale applications. However, traditional compressed air systems require fossil fuels for supplementary combustion. Traditional fossil fuel supplementary heating consumes a lot of energy and causes heavy pollution. Furthermore, the heat released from the last stage of the compressor is of low quality and cannot participate in the discharge process, resulting in waste.

[0003] Concentrated solar power (CSP) relies on sunlight, leading to unstable power output (e.g., affected by weather). By connecting to a compressed air energy storage system, excess solar energy can be directly used for compressed air storage, releasing energy to generate electricity during periods without sunlight, achieving a continuous and stable power supply and reducing reliance on traditional backup power sources. Existing systems that alternate between compressed air and CSP storage for power generation suffer from insufficient energy and resource utilization, particularly CSP systems, which, due to limitations in solar energy utilization, cannot consistently maintain a high enough temperature for power generation. Summary of the Invention

[0004] The purpose of this invention is to provide a power generation system that combines solar thermal energy storage with compressed gas energy storage, which can improve the utilization rate of compressed gas energy storage and cooling water resources, making power generation more efficient.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A power generation system combining solar thermal and compressed gas energy storage includes:

[0007] Solar thermal energy storage system;

[0008] A compressed gas energy storage system, wherein the compressed gas energy storage system is connected to a solar thermal energy storage system, and the solar thermal energy storage system collects solar thermal energy through the compressed gas energy storage system;

[0009] A turbine power generation system, wherein the turbine power generation system is connected to a compressed gas energy storage system, and the turbine power generation system generates electricity by storing energy through the compressed gas energy storage system;

[0010] A steam turbine power generation system, wherein the steam turbine power generation system is connected to a compressed gas energy storage system, and the steam turbine power generation system generates electricity by storing steam through the compressed gas energy storage system;

[0011] Coolant circulation system; the coolant circulation system is connected to the steam turbine power generation system, the turbine power generation system and the compressed gas energy storage system respectively. The steam generated by the steam turbine power generation system is cooled by cooling water after passing through the coolant circulation system to cool the turbine power generation system and the compressed gas energy storage system.

[0012] The solar thermal energy storage system is a trough-type concentrating solar collector.

[0013] In a further embodiment, the compressed gas energy storage system includes a multi-stage compressor, a multi-stage first oil-gas heat exchanger, a multi-stage first gas-water heat exchanger, a cold water tank, a hot water tank, a cold oil tank, a hot oil tank, and a gas storage tank. The multi-stage compressor, the multi-stage first oil-gas heat exchanger, and the multi-stage first gas-water heat exchanger correspond one-to-one according to their respective stages.

[0014] The oil outlet of each stage's first oil-gas heat exchanger is connected to the oil inlet of the solar thermal energy storage system. The oil outlet of the solar thermal energy storage system is connected to the hot oil tank. The oil outlet of each stage's first oil-gas heat exchanger is connected to the oil outlet of the cold oil tank. The air inlet of each stage's first oil-gas heat exchanger is connected to the air outlet of the corresponding stage's compressor. The air outlet of each stage's first oil-gas heat exchanger is connected to the air inlet of the corresponding stage's first gas-water heat exchanger. The air outlet of the corresponding stage's first gas-water heat exchanger is connected to the air inlet of the next stage's compressor. The air outlet of the final stage's first gas-water heat exchanger is connected to the air inlet of the gas storage tank. The compressed gas outlet of each stage's compressor is connected to the air inlet of a first oil-gas heat exchanger. The water inlet of each stage's first gas-water heat exchanger is connected to the water outlet of the cold water tank. The water outlet of each stage's first gas-water heat exchanger is connected to the water inlet of the hot water tank.

[0015] In a further embodiment, the turbine power generation system includes a multi-stage turbine, a multi-stage second oil-gas heat exchanger, and a second gas-water heat exchanger. The inlet of the second gas-water heat exchanger is connected to the outlet of the hot water tank, and the outlet of the second gas-water heat exchanger is connected to the inlet of the cold water tank. The stages of the multi-stage turbine and the multi-stage second oil-gas heat exchanger correspond one-to-one. The inlet of the second gas-water heat exchanger is connected to the gas storage tank, and the outlet of the second gas-water heat exchanger is connected to the multi-stage turbine. The primary stage of the turbine is connected to the inlet of the second oil-gas heat exchanger. The inlet of each stage turbine is connected to the outlet of the corresponding stage's second oil-gas heat exchanger. The outlet of each stage turbine is connected to the inlet of the next stage's second oil-gas heat exchanger. The outlet of the final stage turbine may not be connected to the inlet of the next stage's second oil-gas heat exchanger. The oil inlet of each stage's second oil-gas heat exchanger is connected to the outlet of the hot oil tank, and the oil outlet of each stage's second oil-gas heat exchanger is connected to the inlet of the cold oil tank.

[0016] In a further embodiment, the steam turbine power generation system includes a steam turbine generator and a steam thermal oil heat exchanger. The oil inlet of the steam thermal oil heat exchanger is connected to a hot oil tank, the oil outlet of the steam thermal oil heat exchanger is connected to a cold oil tank, the steam inlet of the steam thermal oil heat exchanger is connected to the coolant outlet of the coolant circulation system, the steam outlet of the steam thermal oil heat exchanger is connected to the steam inlet of the steam turbine generator, and the steam outlet of the steam turbine generator is connected to the coolant inlet of the coolant circulation system.

[0017] In a further embodiment, the coolant circulation system includes an air-cooling device. The coolant inlet of the air-cooling device is connected to the steam outlet of the steam turbine generator. The coolant outlet of the air-cooling device is connected to the coolant inlet of each stage compressor and turbine. The coolant outlet of each stage compressor and turbine is connected to the coolant inlet of the air-cooling device.

[0018] In a further embodiment, the aforementioned solar thermal combined compressed gas energy storage power generation system also includes a pump connected to the inlet and outlet ends of a cold oil tank, a hot oil tank, a cold water tank, and / or a hot water tank.

[0019] In a further embodiment, the pump is connected to the coolant delivery pipeline of the coolant circulation system.

[0020] In a further embodiment, the steam turbine generator has multiple parallel power generation chambers, the steam inlet of each power generation chamber is connected to the steam outlet of the steam heat transfer oil heat exchanger, and the steam inlet of each power generation chamber is connected to the coolant inlet of the coolant circulation system.

[0021] In a further embodiment, the steam heat exchanger has multiple heat exchange chambers connected in series. The oil inlet of the multiple heat exchange chambers is connected to a hot oil tank, the oil outlet of the multiple heat exchange chambers is connected to a cold oil tank, the steam inlet of the multiple heat exchange chambers is connected to the coolant outlet of the coolant circulation system, and the steam outlet of the multiple heat exchange chambers is connected to the steam inlet of the steam turbine generator.

[0022] In a further embodiment, the trough-type concentrating solar collector may be a tower-type concentrating solar collector.

[0023] The beneficial effects of this invention are:

[0024] This invention's solar thermal energy storage system collects solar thermal energy through a compressed gas energy storage system, which can further enhance the energy collected by the compressed gas energy storage system. More stored energy is then used to generate electricity through a turbine power generation system and a steam turbine power generation system. Two power generation systems are employed: the steam turbine power generation system is used for normal power generation of the solar thermal system, while the turbine power generation system is used for the expansion side of the compressed air energy storage. During the day when sunlight is abundant, the steam turbine power generation system operates normally, with part of its power used to maintain grid supply and part used for compressed air energy storage. At night, due to the lack of sunlight, compressed air is released from the gas storage to maintain system power, activating the turbine power generation system on the expansion side. On cloudy days with poor sunlight, compressed air is also released from the gas storage to maintain system power, activating the turbine power generation system on the expansion side. The steam generated by the steam turbine power generation system is circulated through a cooling liquid system to form cooling water, which then cools both the turbine power generation system and the compressed gas energy storage system. By recycling the cooling water, resource utilization is improved.

[0025] Compared to traditional compressed air energy storage systems, this invention utilizes a heat exchange medium within the compressed air energy storage system. This allows the temperature of the heat exchange medium entering the solar thermal energy storage system to be raised to over 250 degrees Celsius. The solar thermal energy storage system can further heat the medium, raising its temperature from 250°C to over 550°C. This preheats the steam entering the turbine power generation system and / or the gas entering the turbine power generation system. The electricity generated by the power generation system then supplies power to the compressed air energy storage system. This allows the high-temperature heat from solar thermal energy to directly drive the air compression process, reducing intermediate conversion steps and improving overall system efficiency (estimated to be 10-20%). It also reduces energy waste. The turbine power generation system and the turbine power generation system share a closed-loop cooling water system. This system not only cools the compressor and turbine but also cools the steam and supplies return water, improving cooling water utilization.

[0026] This invention employs two power generation systems: a steam turbine power generation system for normal power generation of the solar thermal system, and a turbine power generation system for compressed air energy storage on the expansion side. During the day when sunlight conditions are good, the steam turbine power generation system operates normally, with part of its power used to maintain the grid supply and part used for compressed air energy storage. At night, due to the lack of sunlight, compressed air is released from the gas storage tank to maintain system power, driving the turbine power generation system on the expansion side to generate electricity. On cloudy days when sunlight conditions are poor, compressed air is also released from the gas storage tank to maintain system power, driving the turbine power generation system on the expansion side to generate electricity. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a power generation system based on a combination of solar thermal and compressed gas energy storage in an embodiment of the present invention;

[0029] Figure 2 This is a connection diagram of the coolant circulation system in an embodiment of the present invention;

[0030] In the diagram: 1. Compressed gas energy storage system; 11. Compressor; 12. First oil-gas heat exchanger; 13. First gas-water heat exchanger; 14. Cold water tank; 15. Hot water tank; 16. Cold oil tank; 17. Hot oil tank; 18. Gas storage tank; 2. Solar thermal energy storage system; 3. Coolant circulation system; 31. Air cooling device; 4. Steam turbine power generation system; 41. Steam turbine generator; 42. Steam heat transfer oil heat exchanger; 5. Turbine power generation system; 51. Turbine; 52. Second oil-gas heat exchanger; 53. Second gas-water heat exchanger; 6. Pump. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figure 1 As shown, a power generation system combining solar thermal and compressed gas energy storage includes: a solar thermal energy storage system 2;

[0033] Compressed gas energy storage system 1, which is connected to a solar thermal energy storage system 2, and the solar thermal energy storage system 2 collects solar thermal energy through the compressed gas energy storage system 1;

[0034] Turbine power generation system 5, which is connected to compressed gas energy storage system 1, and the turbine power generation system 5 generates electricity by storing energy in the compressed gas energy storage system 1.

[0035] Steam turbine power generation system 4, which is connected to compressed gas energy storage system 1, and the steam turbine power generation system 4 generates electricity by storing steam through compressed gas energy storage system 1;

[0036] Coolant circulation system 3; the coolant circulation system 3 is connected to the steam turbine power generation system 4, the turbine power generation system 5 and the compressed gas energy storage system 1 respectively. The steam generated by the steam turbine power generation system 4 is cooled by the cooling water formed by the coolant circulation system 3, which then cools the turbine power generation system 5 and the compressed gas energy storage system 1.

[0037] Its working principle or implementation method is as follows: the compressed gas energy storage system 1 heats the heat exchange medium by exchanging heat between the compressed gas and the heat exchange medium. The compressed gas energy storage system 1 is connected to the solar thermal energy storage system 2, and is used to input the heated heat exchange medium into the solar thermal energy storage system 2 to continue absorbing solar thermal energy. The heat exchange medium absorbing solar thermal energy is controlled to be divided into two paths. The turbine power generation system 5 is connected to the compressed gas energy storage system 1, and is used to send one path into the turbine power generation system 5 to exchange heat with the compressed gas after heat exchange to raise the temperature of the compressed gas for power generation by the turbine power generation system 5. The turbine power generation system 4 is connected to the compressed gas energy storage system 1, and is used to supply another path to the turbine power generation system 4 for heat exchange with steam to increase the steam temperature for power generation. The coolant circulation system 3 is connected to the turbine power generation system 4, the turbine power generation system 5, and the compressed gas energy storage system 1 respectively, and is used to condense the steam after heat exchange in the turbine power generation system 4 into cooling water, and then supply the cooling water to the turbine power generation system 5 and the compressed gas energy storage system 1 for cooling. The arrows in the diagram indicate the direction of light or the direction of gas-liquid flow.

[0038] By absorbing the heat of the compressed gas during the compression process in the compressed gas energy storage system 1 through a heat exchange medium, the heat of the compressed gas is reduced, thus obtaining low-temperature, high-pressure compressed gas for stable storage. The heat exchange medium that absorbs heat can be reheated through the solar thermal energy storage system 2. Since the temperature of the heat transfer medium entering the solar thermal energy storage system 2 is increased after heat exchange, the temperature can be further raised to reach the steam heat exchange temperature of the steam turbine power generation system 4, such as 550 degrees Celsius in this invention. This temperature is used for heat exchange and power generation in the steam turbine power generation system 4. If the generated electricity meets the preset power requirements, such as meeting a certain power supply requirement, then... Excess electricity can be stored in the compressed gas energy storage system 1. When sunlight conditions are insufficient to heat the heat exchange medium to reach the temperature required for steam heat exchange in the turbine power generation system 4, the previously stored compressed gas can be used to generate electricity through the turbine power generation system 5, supplementing the insufficient power generation of the turbine power generation system 4. This ensures stable power generation and improves energy utilization. The steam generated after heat exchange in the turbine power generation system 4 is condensed into cooling water and fed into the turbine power generation system 5 and the compressed gas energy storage system 1 for cooling, saving resources and improving cooling water utilization. This system integrates the compressed gas energy storage system 1, the solar thermal energy storage system 2, the coolant circulation system 3, the turbine power generation system 4, and the turbine power generation system 5 into a unified system. Through heat exchange between these systems, the system stably obtains and controls the temperature and pressure of the medium required for power generation, improving resource and energy utilization.

[0039] In some embodiments, the compressed gas energy storage system 1 includes a multi-stage compressor 11, a multi-stage first oil-gas heat exchanger 12, a multi-stage first gas-water heat exchanger 13, a cold water tank 14, a hot water tank 15, a cold oil tank 16, a hot oil tank 17, and a gas storage tank 18. The multi-stage compressor 11, the multi-stage first oil-gas heat exchanger 12, and the multi-stage first gas-water heat exchanger 13 correspond one-to-one according to their stages. The oil outlet of each stage's first oil-gas heat exchanger 12 is connected to the oil inlet of the solar thermal energy storage system 2. The oil outlet of the solar thermal energy storage system 2 is connected to the hot oil tank 17. The oil outlet of each stage's first oil-gas heat exchanger 12 is connected to the oil outlet of the cold oil tank 16. The air inlet of each stage is connected to the air outlet of the corresponding stage compressor 11. The air outlet of each stage first oil-gas heat exchanger 12 is connected to the air inlet of the corresponding stage first gas-water heat exchanger 13. The air outlet of the corresponding stage first gas-water heat exchanger 13 is connected to the air inlet of the next stage compressor 11. The air outlet of the last stage first gas-water heat exchanger 13 is connected to the air inlet of the gas storage tank 18. The compressed gas outlet of each stage compressor 11 is connected to the air inlet of a first oil-gas heat exchanger 12. The water inlet of each stage first gas-water heat exchanger 13 is connected to the water outlet of the cold water tank 14. The water outlet of each stage first gas-water heat exchanger 13 is connected to the water inlet of the hot water tank 15.

[0040] Each stage of the compressed gas in compressor 11 undergoes heat exchange through an oil-gas heat exchanger. The compressed gas, after each heat exchange, then passes through a water-gas heat exchanger for further heat exchange before entering the next stage compressor 11. This multi-stage heat exchange before compression ensures a stable temperature for the compressed gas and maintains the temperature of the heat exchange medium at a stable required value. This improves the stability of the compressed gas energy storage system 1 and ensures that the heat exchange medium input into the solar thermal energy storage system 2 reaches the preset temperature requirement. Heat exchange reduces the heat of the compressed gas, facilitating its storage, and also utilizes the heat of the compressed gas, improving energy efficiency.

[0041] If a 4-stage compressor 11 configuration is used, the rated displacement of the first-stage compressor 11 is 120m³. 3 / min, compression ratio 1.5, inlet pressure 0.1MPa, outlet pressure 0.15MPa, equipped with 4m 3 Buffer tank; two-stage compressor, compression ratio 2.0, outlet pressure 0.3MPa, buffer tank volume 6m³. 3 The three-stage compressor has a compression ratio of 3.0, an outlet pressure of 0.9 MPa, and a buffer tank volume of 8 m³. 3 The final stage compressor has a compression ratio of 4.0, an outlet pressure of 3.6 MPa, and a buffer tank volume of 10 m³. 3 All compressors 11 at each stage adopt a screw-type structure, with motor power of 500kW, 800kW, 1200kW, and 1800kW respectively. The first oil-gas heat exchanger 12 has a single-unit heat exchange area of ​​200m². 2 The shell has a diameter of 1.2m and a length of 6m, and contains 300 heat exchange tubes with a diameter of φ25×2mm. The tube-side flow velocity is 1.5m / s, and the shell-side flow velocity is 8m / s. Under design conditions, the inlet compressed gas temperature is 180℃, the outlet temperature is 80℃, the inlet heat transfer oil temperature is 50℃, the outlet temperature is 150℃, the heat exchange capacity is 2.5MW, and the fouling factor is taken as 0.0002m. 2 •℃ / W. Gas storage cell 18 adopts a salt cavern gas storage cell 18, with an effective volume of 500,000 m³ per cavern. 3 The well has a depth of 1200m, a casing diameter of 244.5mm, and the production casing material is P110 steel grade. The working pressure range is 8-12MPa, the maximum working temperature is 50℃, and an integrated injection and production tubing string is used. The wellhead equipment has a pressure resistance rating of 20MPa and is equipped with a Rosemount 3051 pressure transmitter and a Pt100 temperature sensor, with a data sampling frequency of 1 time / minute.

[0042] Thermally conductive mineral oil is selected as the heat exchange medium, and air is chosen as the gas in the compressed gas energy storage system 1. The heat generated by the compressor 11 when compressing the air provides primary heating to the thermally conductive oil in the oil-gas heat exchanger, raising the oil temperature to above 250°C, such as 260°C. The heat provided by the solar thermal energy storage system 2 provides secondary heating to the thermally conductive oil, raising it to 550°C. This assists the primary heating of the compressor 11 and effectively reduces the area of ​​the solar thermal mirror field. Through the two-stage heating structure of the thermally conductive oil, the compressed air energy storage system and the solar thermal energy storage system 2 can share a single thermally conductive oil circulation loop, further reducing the number of devices required.

[0043] In some embodiments, the turbine power generation system 5 includes a multi-stage turbine 51, a multi-stage second oil-gas heat exchanger 52, and a second gas-water heat exchanger 53. The inlet of the second gas-water heat exchanger 53 is connected to the outlet of the hot water tank 15, and the outlet of the second gas-water heat exchanger 53 is connected to the inlet of the cold water tank 14. The stages of the multi-stage turbine 51 and the multi-stage second oil-gas heat exchanger 52 correspond one-to-one. The inlet of the second gas-water heat exchanger 53 is connected to the gas storage tank 18, and the outlet of the second gas-water heat exchanger 53 is connected to... The inlet end of the second oil-gas heat exchanger 52 in the primary stage of the multi-stage turbine 51 is connected to the inlet end of the second oil-gas heat exchanger 52 of the corresponding stage. The outlet end of the turbine 51 of each stage is connected to the inlet end of the second oil-gas heat exchanger 52 of the next stage. The outlet end of the turbine 51 of the final stage may not be connected to the inlet end of the second oil-gas heat exchanger 52 of the next stage. The oil inlet end of the second oil-gas heat exchanger 52 of each stage is connected to the oil outlet end of the hot oil tank 17, and the oil outlet end of the second oil-gas heat exchanger 52 of each stage is connected to the oil inlet end of the cold oil tank 16.

[0044] In some embodiments, the steam turbine power generation system 4 includes a steam turbine generator 41 and a steam thermal oil heat exchanger 42. The oil inlet of the steam thermal oil heat exchanger 42 is connected to a hot oil tank 17, the oil outlet of the steam thermal oil heat exchanger 42 is connected to a cold oil tank 16, the steam inlet of the steam thermal oil heat exchanger 42 is connected to the coolant outlet of the coolant circulation system 3, the steam outlet of the steam thermal oil heat exchanger 42 is connected to the steam inlet of the steam turbine generator 41, and the steam outlet of the steam turbine generator 41 is connected to the coolant inlet of the coolant circulation system 3. Two power generation systems are provided: the steam turbine power generation system 4 uses a steam turbine for normal power generation of the solar thermal system, and the turbine power generation system 5 uses a compressed air turbine for compressed air energy storage and expansion. During the day when sunlight conditions are good, the steam turbine power generation system 4 operates normally, with part of the system power used to maintain the grid supply and part used for compressed air energy storage. At night, due to the lack of sunlight supply, compressed air is released from the gas storage tank 18 to maintain system power, driving the turbine power generation system 5 on the expansion side to generate electricity. On cloudy days when sunlight conditions are poor, compressed air is also released from the gas storage tank 18 to maintain system power, driving the turbine power generation system 5 on the expansion side to generate electricity.

[0045] In some embodiments, the steam turbine generator 41 has multiple parallel generator chambers, the steam inlet of each generator chamber is connected to the steam outlet of the steam heat exchanger, and the steam inlet of each generator chamber is connected to the coolant inlet of the coolant circulation system 3. This can improve power generation efficiency.

[0046] In some embodiments, the steam thermal oil heat exchanger 42 has multiple heat exchange chambers connected in series. The oil inlet of the multiple heat exchange chambers is connected to a hot oil tank, the oil outlet of the multiple heat exchange chambers is connected to a cold oil tank, the steam inlet of the multiple heat exchange chambers is connected to the coolant outlet of the coolant circulation system, and the steam outlet of the multiple heat exchange chambers is connected to the steam inlet of the steam turbine generator. This can increase the heat exchange area and the heat absorption of steam, thereby obtaining high-temperature steam at the required temperature. Compared with large-flow heat exchange in a single heat exchange chamber, the heat exchange efficiency during steam flow is better.

[0047] like Figure 2As shown, in some embodiments, the coolant circulation system 3 includes an air-cooling device 31. The coolant inlet of the air-cooling device 31 is connected to the steam outlet of the steam turbine generator 41, and the coolant outlet of the air-cooling device 31 is connected to the coolant inlet of each stage compressor 11 and turbine 51. The coolant outlet of each stage compressor 11 and turbine 51 is connected to the coolant inlet of the air-cooling device 31. The steam turbine generator system 4 and the turbine generator system 5 share a closed-loop cooling water system. The cooling water system not only cools the compressor 11 and turbine 51, but also cools the steam and supplies return water, improving the utilization rate of cooling water.

[0048] like Figure 1 As shown, in some embodiments, a pump 6 is also included, which drives the heat transfer oil and / or coolant, such as pumping the heat transfer oil into or out of the cold oil tank 16, hot oil tank 17, hot water tank 15, and / or cold water tank 14. This facilitates the flow of these heat exchange media, and the electrical energy used by the pump 6 can be supplied by the aforementioned power generation system.

[0049] In some embodiments, the solar thermal energy storage system 2 is a trough-type concentrating solar collector or a tower-type concentrating solar collector. Figure 1 shows a trough-type concentrating solar collector with an inclination angle of 25° to facilitate solar concentration.

[0050] This invention also proposes an embodiment of a power generation method that combines solar thermal and compressed gas energy storage, comprising the following steps:

[0051] S1. The gas is compressed in multiple stages through the compressed gas energy storage system 1, and the heat exchange medium is controlled to exchange heat with the compressed gas during the gas compression process, thereby raising the temperature of the heat exchange medium.

[0052] S2. The heated heat exchange medium is introduced into the solar thermal energy storage system 2, and the solar thermal energy storage system 2 absorbs and stores solar thermal energy.

[0053] S3. Control the heat exchange medium that absorbs solar thermal energy storage to be divided into two paths. Control one path to be introduced into the turbine power generation system 5 to exchange heat with the compressed gas after heat exchange, and raise the temperature of the compressed gas for power generation in the turbine power generation system 5. Control the other path to be introduced into the steam turbine power generation system 4 to exchange heat with steam and raise the temperature of the steam for power generation in the steam turbine power generation system 4.

[0054] S4. The steam generated by the turbine power generation system 4 after heat exchange is condensed into cooling water through the coolant circulation system 3 and then fed into the turbine power generation system 5 and the compressed gas energy storage system 1 for cooling.

[0055] In some embodiments, the heat exchange medium includes heat transfer oil and water. After gas compression, it first exchanges heat with the heat transfer oil and then with the water to recover heat before being introduced into the gas storage tank 18 for storage and backup. When the electricity generated by the heat exchange medium absorbing solar thermal energy storage through the steam turbine power generation system 4 exceeds the preset power generation requirement, the excess electricity can be used for energy storage in the compressed gas energy storage system 1. When the electricity generated by the heat exchange medium absorbing solar thermal energy storage through the steam turbine power generation system 4 is lower than the preset power generation requirement, the compressed gas stored in the gas storage tank 18 can be used for power generation in the turbine power generation system 5 to increase the power generation to the preset requirement. For example, when the light intensity fluctuates between 400-700 W / m²... 2 At that time, the hybrid power generation mode is activated: the solar thermal system provides 15MW of thermal power, and 50% of the heat transfer oil is used in a 40m³ process. 3 / h of heat transfer oil is fed into the turbine system, generating 12MW of electrical power; the remaining 50% of the heat transfer oil is fed into the turbine 51 system, while the gas storage tank 18 is supplied with 800m³ of oil. 3 The gas released at a flow rate of / h is heated and then drives turbine 51 to generate 8MW of electric power, with the total output stabilizing at 20MW. Hot water tank 15 maintains a water temperature of 90℃, and the gas is preheated for turbine intake through the second gas-water heat exchanger 53, saving 15% of heat transfer oil consumption.

[0056] In some embodiments, the steps further include exchanging the heat transfer oil to a temperature above 250°C via an oil-gas heat exchanger before introducing it into the solar thermal energy storage system 2, and storing the heat transfer oil in the hot oil tank 17 when the temperature of the heat transfer oil is raised to greater than or equal to 500°C by the solar thermal energy storage system 2. The 250°C temperature of the heat transfer oil ensures that the temperature rise after passing through the solar thermal energy storage system 2 is greater than or equal to 500°C. This not only maximizes the utilization of the heat of the compressed gas through the heat transfer oil, but also allows for rapid temperature reduction of the compressed gas by connecting each stage compressor 11 in series with the cold oil tank 16. The number of stages of compressor 11 required can be determined based on the compressor 11 model, with four stages being preferred. Existing four-stage compressor 11 can achieve better pressure and volume for the compressed gas after compression.

[0057] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein.

[0058] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A combined photothermal compression gas energy storage power generation system, characterized in that, Including solar thermal energy storage systems (2); A compressed gas energy storage system (1) is connected to a photothermal energy storage system (2), and the photothermal energy storage system (2) collects photothermal energy through the compressed gas energy storage system (1). Turbine power generation system (5), the turbine power generation system (5) is connected to compressed gas energy storage system (1), the turbine power generation system (5) stores energy through compressed gas energy storage system (1) to generate electricity from the turbine; A steam turbine power generation system (4) is connected to a compressed gas energy storage system (1), and the steam turbine power generation system (4) generates electricity by storing steam through the compressed gas energy storage system (1); Cooling fluid circulation system (3); the cooling fluid circulation system (3) is connected to the steam turbine power generation system (4), the turbine power generation system (5) and the compressed gas energy storage system (1) respectively. The steam generated by the steam turbine power generation system (4) is cooled by the cooling fluid circulation system (3) to form cooling water. The solar thermal energy storage system (2) is a trough-type concentrating solar collector.

2. The combined photovoltaic and gas storage power generation system of claim 1, wherein, The compressed gas energy storage system (1) includes a multi-stage compressor (11), a multi-stage first oil-gas heat exchanger (12), a multi-stage first gas-water heat exchanger (13), a cold water tank (14), a hot water tank (15), a cold oil tank (16), a hot oil tank (17), and a gas storage tank (18). The multi-stage compressor (11), the multi-stage first oil-gas heat exchanger (12), and the multi-stage first gas-water heat exchanger (13) correspond one-to-one according to their stages. The oil outlet of each stage's first oil-gas heat exchanger (12) is connected to the oil inlet of the solar thermal energy storage system (2). The oil outlet of the solar thermal energy storage system (2) is connected to the hot oil tank (17). The oil outlet of each stage's first oil-gas heat exchanger (12) is connected to the oil outlet of the cold oil tank (16). The air inlet of each stage's first oil-gas heat exchanger (12) is connected to the air outlet of the corresponding stage's compressor (11). The air outlet of each stage's first oil-gas heat exchanger (12) is connected to the air inlet of the corresponding stage's first gas-water heat exchanger (13). The outlet of the first gas-water heat exchanger (13) of the corresponding stage is connected to the inlet of the next stage compressor (11), the outlet of the first gas-water heat exchanger (13) of the last stage is connected to the inlet of the gas storage tank (18), the outlet of the compressed gas of each stage compressor (11) is connected to the inlet of a first oil-gas heat exchanger (12), the inlet of the first gas-water heat exchanger (13) of each stage is connected to the outlet of the cold water tank (14), and the outlet of the first gas-water heat exchanger (13) of each stage is connected to the inlet of the hot water tank (15).

3. The combined photovoltaic and gas storage power generation system of claim 2, wherein, The turbine power generation system (5) includes a multi-stage turbine (51), a multi-stage second oil-gas heat exchanger (52), and a second gas-water heat exchanger (53). The inlet of the second gas-water heat exchanger (53) is connected to the outlet of the hot water tank (15), and the outlet of the second gas-water heat exchanger (53) is connected to the inlet of the cold water tank (14). The stages of the multi-stage turbine (51) and the multi-stage second oil-gas heat exchanger (52) are one-to-one. The inlet of the second gas-water heat exchanger (53) is connected to the gas storage tank (18), and the outlet of the second gas-water heat exchanger (53) is connected to the multi-stage turbine (51). The primary second oil-gas heat exchanger (52) in the flatbed turbine (51) is connected to the air inlet end. The air inlet end of each stage turbine (51) is connected to the air outlet end of the corresponding stage second oil-gas heat exchanger (52). The air outlet end of each stage turbine (51) is connected to the air inlet end of the next stage second oil-gas heat exchanger (52). The air outlet end of the final stage turbine (51) may not be connected to the air inlet end of the next stage second oil-gas heat exchanger (52). The oil inlet end of each stage second oil-gas heat exchanger (52) is connected to the oil outlet end of the hot oil tank (17). The oil outlet end of each stage second oil-gas heat exchanger (52) is connected to the oil inlet end of the cold oil tank (16).

4. The combined photovoltaic and gas storage power generation system of claim 2, wherein, The steam turbine power generation system (4) includes a steam turbine generator (41) and a steam heat transfer oil heat exchanger (42). The oil inlet of the steam heat transfer oil heat exchanger (42) is connected to the hot oil tank (17), the oil outlet of the steam heat transfer oil heat exchanger (42) is connected to the cold oil tank (16), the steam inlet of the steam heat transfer oil heat exchanger (42) is connected to the coolant outlet of the coolant circulation system (3), the steam outlet of the steam heat transfer oil heat exchanger (42) is connected to the steam inlet of the steam turbine generator (41), and the steam outlet of the steam turbine generator (41) is connected to the coolant inlet of the coolant circulation system (3).

5. A power generation system combining solar thermal and compressed gas energy storage according to claim 4, characterized in that, The coolant circulation system (3) includes an air-cooling device (31). The coolant inlet of the air-cooling device (31) is connected to the steam outlet of the steam turbine generator (41). The coolant outlet of the air-cooling device (31) is connected to the coolant inlet of each stage compressor (11) and turbine (51). The coolant outlet of each stage compressor (11) and turbine (51) is connected to the coolant inlet of the air-cooling device (31).

6. The combined photovoltaic and gas storage power generation system of claim 4, wherein, It also includes a pump (6) connected to the inlet and outlet of the cold oil tank (16), the hot oil tank (17), the cold water tank (14) and / or the hot water tank (15).

7. The combined photovoltaic and gas storage power generation system of claim 6, wherein, The pump (6) is connected to the coolant delivery pipeline of the coolant circulation system (3).

8. The combined photovoltaic and gas storage power generation system of claim 4, wherein, The steam turbine generator (41) has multiple parallel generator chambers. The steam inlet of each generator chamber is connected to the steam outlet of the steam heat exchanger (42), and the steam inlet of each generator chamber is connected to the coolant inlet of the coolant circulation system (3).

9. The combined photovoltaic and gas storage power generation system of claim 4, wherein, The steam heat exchanger (42) has multiple heat exchange chambers connected in series. The oil inlet of the multiple heat exchange chambers is connected to the hot oil tank (17), the oil outlet of the multiple heat exchange chambers is connected to the cold oil tank (16), the steam inlet of the multiple heat exchange chambers is connected to the coolant outlet of the coolant circulation system (3), and the steam outlet of the multiple heat exchange chambers is connected to the steam inlet of the steam turbine generator (41).

10. The combined photovoltaic and gas storage power generation system of claim 1, wherein, The trough-type concentrating solar collector may be a tower-type concentrating solar collector.

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