Single-cycle gas turbine coupling Carnot cell power generation system and working method

Abstract

The invention belongs to the field of single-cycle gas turbine coupled Carnot battery power generation, and discloses a single-cycle gas turbine coupled Carnot battery power generation system and a working method, fused salt is used as a heat energy storage medium, heat can be stored and released in different time periods, and load fluctuation is balanced. Therefore, the system is more stable when the load changes, and possible efficiency fluctuation of a single-cycle gas turbine system is avoided. Through the design of the fused salt-water heat exchanger and the fused salt cold tank, the temperature change can be effectively adjusted, the optimal temperature difference between the heat source and the cold source is ensured, and the overall efficiency of the Carnot cell power generation system is further improved. Molten salt heat storage and circulation are combined, so that heat energy utilization is more efficient, fuel consumption and operation cost can be reduced, and the economical efficiency of the system is improved.

Description

Technical Field

[0001] The invention belongs to the field of single - cycle gas turbine coupled with Carnot battery power generation, and particularly relates to a single - cycle gas turbine coupled with Carnot battery power generation system and a working method thereof. Background Technique

[0002] With the promotion of the spot market and the development of renewable energy, extreme high prices and extreme low prices will frequently appear in the electricity price market, and it is expected that the country will introduce a price - limit policy with a lower limit below zero and a continuously increasing upper limit. Therefore, if the unit can start and stop quickly, it can avoid low - price losses and strive for high - efficiency power generation. A single - cycle gas turbine can complete startup and reach full load within 15 minutes, quickly participate in peak power supply guarantee, and is 2 - 3 times the ramping rate of combined - cycle gas turbines and conventional coal - fired units. Similarly, the output of a single - cycle gas turbine can also drop rapidly, improving the peak - shaving ability. In the future, when building a unified capacity market, both gas turbines and coal - fired power will be charged capacity fees. Since the cost of a single - cycle gas turbine (not exceeding 2000 yuan per kilowatt) is much lower than that of coal - fired power units, with the increase of coal - fired power capacity fees, under the condition of obtaining the same capacity fees, a single - cycle gas turbine can basically make up for the fixed investment. Therefore, compared with combined - cycle gas turbines, the economy of single - cycle gas turbines is gradually rising, and the system value is getting higher and higher.

[0003] A Carnot battery refers to a large - scale power energy storage system based on energy storage. In the charging stage, electrical energy is converted into heat energy and stored in a certain form; in the discharging stage, heat energy is converted back into electrical energy for reuse. It is a new type of electrical energy storage technology that can achieve medium - to - large - scale electrical energy storage at low cost and without geographical restrictions. The energy storage scale of the system can be as high as 100MW / 1000MWh, which is expected to solve the global problem of renewable electrical energy storage and can provide a more economical and environmentally friendly energy storage solution compared with traditional battery energy storage.

[0004] Because the high - temperature exhaust gas in the combustion section of a single - cycle gas turbine is directly discharged into the atmosphere without any waste - heat utilization, its cycle efficiency is relatively low. Summary of the Invention

[0005] The purpose of the invention is to overcome the above - mentioned deficiency of relatively low cycle efficiency and provide a single - cycle gas turbine coupled with Carnot battery power generation system and a working method thereof.

[0006] To achieve the above purpose, the invention adopts the following technical solutions: In a first aspect, the present invention provides a single-cycle gas turbine coupled with a Carnot battery power generation system, including a single-cycle gas turbine system. The single-cycle gas turbine system is connected to the heat source side of a flue gas-salt heat exchanger. The outlet of the cold source side of the flue gas-salt heat exchanger is connected to the inlet of a molten salt hot tank. The outlet of the molten salt hot tank is connected to the inlet of the heat source side of a molten salt-water heat exchanger. The outlet of the heat source side of the molten salt-water heat exchanger is connected to the inlet of a molten salt cold tank. The outlet of the molten salt cold tank is connected to the inlet of the cold source side of the flue gas-salt heat exchanger. The cold source side of the molten salt-water heat exchanger is connected to the Carnot battery power generation system.

[0007] A further improvement of the present invention is that the Carnot battery power generation system includes a steam turbine. The inlet of the steam turbine is connected to the outlet of the cold source side of the molten salt-water heat exchanger. The outlet of the steam turbine is connected to the inlet of the cold source side of the molten salt-water heat exchanger. The steam turbine is connected to a first generator.

[0008] A further improvement of the present invention is that a condenser is provided between the outlet of the steam turbine and the inlet of the cold source side of the molten salt-water heat exchanger.

[0009] A further improvement of the present invention is that a first feed water pump is provided between the condenser and the inlet of the cold source side of the molten salt-water heat exchanger.

[0010] A further improvement of the present invention is that the single-cycle gas turbine system includes a compressor and a turbine. A combustion chamber is provided between the compressor and the turbine. Both the compressor and the turbine are connected to a second generator.

[0011] A further improvement of the present invention is that a first pressure pump is provided between the outlet of the molten salt hot tank and the inlet of the heat source side of the molten salt-water heat exchanger.

[0012] A further improvement of the present invention is that a second pressure pump is provided between the outlet of the molten salt cold tank and the inlet of the cold source side of the flue gas-salt heat exchanger.

[0013] In a second aspect, the present invention provides a working method for a single-cycle gas turbine coupled with a Carnot battery power generation system, including the following steps: The exhaust gas of the circulating gas turbine system is sent to the heat source side of the flue gas-salt heat exchanger, and the molten salt on the heat source side and the cold source side of the flue gas-salt heat exchanger exchanges heat. The molten salt heated by heat exchange is sent to the molten salt hot tank for storage. The molten salt in the molten salt hot tank is sent to the heat source side of the molten salt-water heat exchanger, and the heat source side and the cold source side of the molten salt-water heat exchanger exchange heat with the working medium. The heated working medium generates electricity in the Carnot battery power generation system. The molten salt cooled by heat exchange is sent to the molten salt cold tank for storage. The molten salt in the molten salt cold tank is sent to the cold source side of the flue gas-salt heat exchanger to re-perform heat exchange.

[0014] A further improvement of the present invention lies in that the specific method for the working medium after temperature rise to generate electricity in the Carnot battery power generation system is as follows: The water on the cold source side of the salt-water heat exchanger is heated to superheated steam by the heat source side and sent into the steam turbine to do work; The steam turbine drives the first generator to generate electricity; The exhaust steam of the steam turbine after doing work is condensed into condensate by the condenser and then sent back to the cold source side of the molten salt-water heat exchanger.

[0015] A further improvement of the present invention lies in that the specific method for the exhaust gas of the circulating gas turbine system to be sent to the heat source side of the flue gas-molten salt heat exchanger is as follows: The compressor inhales air for compression and incorporates the compressed air into the combustion chamber; The combustion chamber mixes the compressed air with fuel and then burns it; The burned gas drives the turbine, and the turbine drives the compressor to work, as well as the second generator to generate electricity; The exhaust gas of the turbine is sent to the heat source side of the flue gas-molten salt heat exchanger.

[0016] Compared with the prior art, the present invention has the following beneficial effects: Through the coupled design of the flue gas-molten salt heat exchanger and the molten salt heat storage tank, the present invention can efficiently recover and store the heat in the waste gas. This reuse of heat greatly improves the overall thermal efficiency and reduces energy waste. The molten salt of the present invention serves as a heat storage medium and can store and release heat at different time periods to balance the load fluctuations. This makes the system more stable during load changes and avoids the efficiency fluctuations that may occur in a single-cycle gas turbine system. Through the design of the molten salt-water heat exchanger and the molten salt cold storage tank, the present invention can effectively regulate the temperature change, ensure the optimal temperature difference between the heat source and the cold source, and thus improve the overall efficiency of the Carnot battery power generation system. The present invention combines molten salt heat storage with circulation, making the utilization of thermal energy more efficient, helping to reduce fuel consumption and operating costs, and improving the economy of the system. The present invention can promote more environmentally friendly and sustainable energy utilization and reduce greenhouse gas emissions by efficiently using waste heat and reducing energy consumption. In summary, the present invention optimizes the heat flow and conversion path, makes up for the problem of low efficiency of the traditional single-cycle gas turbine system, and provides an efficient, economical and environmentally friendly solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the system diagram of the present invention; Among them, 1. Flue gas-molten salt heat exchanger; 2. Molten salt heat storage tank; 3. Molten salt-water heat exchanger; 4. Molten salt cold storage tank; 5. Steam turbine; 6. Condenser; 7. First feed water pump; 8. Compressor; 9. Turbine; 10. First generator; 11. Second generator; 12. Combustion chamber; 13. First pressurizing pump; 14. Second pressurizing pump. Detailed implementation manners

[0018] To further understand the content of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention rather than limiting it.

[0019] See Figure 1 , a single-cycle gas turbine coupled with a Carnot battery power generation system, including a single-cycle gas turbine system. The single-cycle gas turbine system is connected to the heat source side of the flue gas-molten salt heat exchanger 1. The outlet of the cold source side of the flue gas-molten salt heat exchanger 1 is connected to the inlet of the molten salt hot tank 2. The outlet of the molten salt hot tank 2 is connected to the inlet of the heat source side of the molten salt-water heat exchanger 3. The outlet of the heat source side of the molten salt-water heat exchanger 3 is connected to the inlet of the molten salt cold tank 4. The outlet of the molten salt cold tank 4 is connected to the inlet of the cold source side of the flue gas-molten salt heat exchanger 1. The cold source side of the molten salt-water heat exchanger 3 is connected to the Carnot battery power generation system.

[0020] Preferably, a first pressure pump 13 is provided between the outlet of the molten salt hot tank 2 and the inlet of the heat source side of the molten salt-water heat exchanger 3.

[0021] Preferably, a second pressure pump 14 is provided between the outlet of the molten salt cold tank 4 and the inlet of the cold source side of the flue gas-molten salt heat exchanger 1.

[0022] A working method of a single-cycle gas turbine coupled with a Carnot battery power generation system includes the following steps: Step 1, the exhaust gas of the circulating gas turbine system is sent to the heat source side of the flue gas-molten salt heat exchanger 1, and the molten salt on the heat source side and the cold source side of the flue gas-molten salt heat exchanger 1 exchanges heat.

[0023] Step 2, the molten salt after heat exchange and temperature rise is sent into the molten salt hot tank 2 for storage; Step 3, the molten salt in the molten salt hot tank 2 is sent to the heat source side of the molten salt-water heat exchanger 3, and the heat source side and the cold source side of the molten salt-water heat exchanger 3 exchange heat with the working medium.

[0024] Step 4, the working medium after temperature rise generates electricity in the Carnot battery power generation system.

[0025] Step 5, the molten salt after heat exchange and temperature drop is sent into the molten salt cold tank 4 for storage.

[0026] Step 6, the molten salt in the molten salt cold tank 4 is sent to the cold source side of the flue gas-molten salt heat exchanger 1 to re-exchange heat.

[0027] Example 1: In this embodiment, the Carnot battery power generation system includes a steam turbine 5. The inlet of the steam turbine 5 is connected to the outlet of the cold source side of the molten salt-water heat exchanger 3, and the outlet of the steam turbine 5 is connected to the inlet of the cold source side of the molten salt-water heat exchanger 3. The steam turbine 5 is connected to a first generator 10. A condenser 6 is provided between the outlet of the steam turbine 5 and the inlet of the cold source side of the molten salt-water heat exchanger 3, and a first feed water pump 7 is provided between the condenser 6 and the inlet of the cold source side of the molten salt-water heat exchanger 3. The water on the cold source side of the salt-water heat exchanger 3 is heated to superheated steam by the heat source side and sent into the steam turbine 5 to do work; the steam turbine 5 drives the first generator 10 to generate electricity; the exhaust steam of the steam turbine after doing work is condensed into condensate by the condenser 6 and then sent back to the cold source side of the molten salt-water heat exchanger 3 again.

[0028] In this embodiment, by introducing the steam turbine 5 and the condenser 6, the system can better convert the superheated steam heated on the cold source side of the molten salt-water heat exchanger 3 into mechanical work, and then drive the generator 10 to generate electricity. This method effectively improves the conversion efficiency of thermal energy, especially during the transfer of thermal energy from molten salt to water. In a traditional Carnot battery system, the condenser 6 condenses the exhaust steam of the steam turbine into condensate and reintroduces it into the cold source side of the molten salt-water heat exchanger 3. In this way, the condensate can continue to be heated and sent into the steam turbine to do work, forming a closed steam cycle system, further improving the thermodynamic cycle efficiency. The steam turbine 5 in this embodiment drives the first generator 10 to generate electricity, enabling the system to provide a stable power output under different load conditions. By recycling the condensate, not only the stability of the system is improved, but also excessive energy losses are avoided, which helps to maintain the power generation efficiency. This embodiment uses the first feed water pump 7 to send the condensate back to the cold source side of the molten salt-water heat exchanger 3, optimizing the water circulation and eliminating the need for an external water supply system, reducing additional energy consumption. Through such water circulation utilization, the overall operating cost of the system is reduced, and the economic benefits are improved. By maximizing the recovery of thermal energy and the closed-loop utilization of water resources, this system not only improves the energy utilization rate, but also reduces the environmental burden, decreases the dependence on external energy, and has significant environmental protection advantages. The configuration of the steam turbine and the condenser in this embodiment enables the system to flexibly respond to different operating conditions and maintain high stability and efficiency during load changes and environmental fluctuations. In addition, the system can further optimize the operating state of the generator by adjusting the temperature and flow rate of the condensate. In this embodiment, by using the condenser 6 to condense the exhaust gas, the steam turbine system is prevented from suffering thermal shock caused by overheating or excessive temperature difference, thereby extending the service life of key equipment such as the steam turbine, the generator, and the heat exchanger.

[0029] In summary, after adding the steam turbine 5, the condenser 6, and the feed water pump 7 in this embodiment, the system further optimizes the conversion of thermal energy, improves the thermal cycle efficiency, enhances the power generation capacity and economy, and at the same time improves the system stability and environmental protection.

[0030] Embodiment 2: In this embodiment, the single-cycle gas turbine system includes a compressor 8 and a turbine 9. A combustion chamber 12 is provided between the compressor 8 and the turbine 9. Both the compressor 8 and the turbine 9 are connected to a second generator 11. The compressor 8 sucks in air for compression and incorporates the compressed air into the combustion chamber 12; the combustion chamber 12 mixes the compressed air with fuel and then burns it; the burned gas drives the turbine 9, the turbine 9 drives the compressor 8 to work, and the second generator 11 generates electricity; the exhaust gas of the turbine 9 is sent to the heat source side of the flue gas-salt heat exchanger 1.

[0031] In this embodiment, the compressor 8 compresses the air and sends it into the combustion chamber 12, where it is mixed with fuel and burned. This efficient air compression and combustion process can improve the combustion efficiency. And through the design of the salt-water heat exchanger, the heat in the flue gas is effectively recovered and supplied to the salt-water heat exchanger 3, further enhancing the thermal energy utilization rate. The turbine 9 in this embodiment not only drives the compressor 8 to work but also drives the second generator 11 to generate electricity. This direct coupling design enables the system to more effectively distribute mechanical energy between the compressor and the turbine. By adding the second generator 11, more power output can be provided, further improving the overall power and power generation capacity of the system. In this embodiment, the exhaust gas of the turbine 9 is sent to the heat source side of the flue gas-salt heat exchanger 1. Through this efficient heat exchange, the system realizes the continuous circulation of thermal energy. Since the hot gas flow is directly used to heat the molten salt system, the emission of waste heat is reduced, while maintaining the energy tightness and stability of the system and avoiding excessive dependence on external energy. The design of the compressor and the turbine in this embodiment enhances the system's adaptability to load fluctuations. Especially when the load changes, the gas turbine can quickly adjust the gas flow rate and combustion efficiency, thereby improving the system's response speed and overall operation flexibility. The gas turbine system in this embodiment has a shorter start-up time and a higher response speed compared with the traditional steam turbine system. The combination of the compressor and the turbine can start and operate stably in a short time, adapt to rapid load changes, and improve the operation efficiency of the system under variable working conditions. Since the compressor and the turbine work together in the processes of air compression and gas expansion, the overall thermodynamic efficiency of the system is improved. By increasing the precise control of the combustion process, the exhaust gas after combustion can directly drive the turbine to generate electricity, and then the heat recovery of the exhaust gas is realized through the flue gas-salt heat exchanger, thereby greatly improving the thermal efficiency of the overall system. By introducing the configuration of the turbine and the compressor, this system can not only generate electricity using a gas turbine but also be effectively coupled with a molten salt thermal energy storage system, a Carnot battery system, etc., to achieve co-generation of multiple energy forms, thus improving the flexibility and economy of energy use. Due to the linkage mechanism between the turbine and the compressor, the system can operate stably within a wide load range, thereby enhancing the reliability of the system and avoiding problems such as low efficiency or instability of the gas turbine caused by load fluctuations.

[0032] In summary, after adding a compressor, a turbine, a combustion chamber, and a second generator in this embodiment, the overall energy efficiency, stability, and power generation capacity of the single-cycle gas turbine system have been greatly improved. Through these optimized designs, the system can not only convert thermal energy more efficiently, but also provide more power output, and reduce energy consumption and environmental impact.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific embodiments of the present invention, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A single-cycle gas turbine coupled Carnot battery power generation system, characterized in that: The invention comprises a single-cycle gas turbine system, wherein the single-cycle gas turbine system is connected to the heat source side of the flue gas-molten salt heat exchanger (1), the cold source side outlet of the flue gas-molten salt heat exchanger (1) is connected to the inlet of the molten salt hot tank (2), the outlet of the molten salt hot tank (2) is connected to the heat source side inlet of the molten salt-water heat exchanger (3), the heat source side outlet of the molten salt-water heat exchanger (3) is connected to the inlet of the molten salt cold tank (4), the outlet of the molten salt cold tank (4) is connected to the cold source side inlet of the flue gas-molten salt heat exchanger (1), and the cold source side of the molten salt-water heat exchanger (3) is connected to the Carnot battery power generation system.

2. A single-cycle combustion engine coupled Carnot battery power generation system according to claim 1, characterized in that: The Carnot battery power generation system comprises a steam turbine (5), wherein the inlet of the steam turbine (5) is connected to the outlet of the cold source side of the molten salt-water heat exchanger (3), the outlet of the steam turbine (5) is connected to the inlet of the cold source side of the molten salt-water heat exchanger (3), and the steam turbine (5) is connected to a first generator (10).

3. A single-cycle combustion engine coupled Carnot battery power generation system according to claim 2, characterized in that: A condenser (6) is provided between the outlet of the steam turbine (5) and the inlet of the cold source side of the molten salt-water heat exchanger (3).

4. A single-cycle combustion engine coupled Carnot battery power generation system according to claim 3, characterized in that: A first water supply pump (7) is provided between the condenser (6) and the inlet of the cold source side of the molten salt-water heat exchanger (3).

5. The single-cycle combustion engine coupled Carnot battery power generation system according to claim 1, characterized in that: The single-cycle combustion engine system comprises a compressor (8) and a turbine (9), a combustion chamber (12) is arranged between the compressor (8) and the turbine (9), and the compressor (8) and the turbine (9) are both connected to a second generator (11).

6. The single-cycle combustion engine coupled Carnot battery power generation system according to claim 1, characterized in that: A first booster pump (13) is provided between the outlet of the molten salt heat tank (2) and the heat source side inlet of the molten salt-water heat exchanger (3).

7. The single-cycle combustion engine coupled Carnot battery power generation system according to claim 1, characterized in that: A second booster pump (14) is provided between the outlet of the molten salt cold tank (4) and the cold source side inlet of the flue gas-molten salt heat exchanger (1).

8. A working method based on the single-cycle combustion engine coupled Carnot battery power generation system according to claim 1, characterized in that: The following steps are involved: The exhaust gas of the circulating combustion engine system is sent to the heat source side of the flue gas-molten salt heat exchanger (1), and the heat source side of the flue gas-molten salt heat exchanger (1) exchanges heat with the molten salt on the cold source side; The molten salt after heat exchange and temperature increase is sent to the molten salt hot tank (2) for storage; The molten salt in the molten salt hot tank (2) is fed into the heat source side of the molten salt-water heat exchanger (3), and the heat source side of the molten salt-water heat exchanger (3) exchanges heat with the working fluid on the cold source side; The heated working fluid generates electricity in the Carnot battery power generation system; The molten salt after heat exchange and temperature reduction is sent to the molten salt cold tank (4) for storage; The molten salt in the molten salt cold tank (4) is sent to the cold source side of the flue gas-molten salt heat exchanger (1) for re-heat exchange.

9. The working method of a single-cycle combustion engine coupled Carnot battery power generation system according to claim 8, characterized in that: The specific method of generating electricity in the Carnot battery power generation system using the heated working fluid is as follows: The water on the cold source side of the salt-water heat exchanger (3) is heated to superheated steam by the heat source side and is sent to the steam turbine (5) to perform work; The steam turbine (5) drives the first generator (10) to generate electricity; The exhaust steam of the steam turbine after work is condensed into condensed water through the condenser (6) and then sent back to the cold source side of the molten salt-water heat exchanger (3).

10. The working method of a single-cycle combustion engine coupled Carnot battery power generation system according to claim 8, characterized in that: The specific method of feeding the exhaust gas of the circulating gas turbine system into the heat source side of the flue gas-molten salt heat exchanger (1) is as follows: The compressor (8) sucks in air for compression and then introduces the compressed air into the combustion chamber (12); The combustion chamber (12) mixes the compressed air with fuel and burns them; The combusted gas drives the turbine (9), the turbine (9) drives the compressor (8) to work, and the second generator (11) to generate electricity; The exhaust gas from the turbine (9) is fed into the heat source side of the flue gas-molten salt heat exchanger (1).

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