A turbine cooling system and method for driving a lithium bromide refrigeration system by waste heat of a combustion engine power plant

Abstract

The application provides a turbine cooling system and method for driving lithium bromide refrigeration by waste heat of a gas turbine power plant, and relates to the technical fields of waste heat utilization of a gas turbine power plant and turbine cooling. The turbine cooling system comprises a flue gas waste heat recovery module, a lithium bromide refrigeration module, a turbine cooling module and a control module. The flue gas waste heat recovery module comprises a flue gas heat exchanger arranged in a flue of a flue gas outlet of a waste heat boiler, and the flue gas heat exchanger is used for recovering flue gas waste heat. The lithium bromide refrigeration module comprises a lithium bromide absorption refrigerating unit, and a driving heat source inlet of the lithium bromide absorption refrigerating unit is connected with the flue gas heat exchanger. The application combines the turbine cooling system with the lithium bromide absorption refrigeration technology, realizes efficient recovery and utilization of waste heat resources, effectively utilizes the originally abandoned low-grade heat energy, reduces heat pollution, solves the situation that the turbine cooling device is difficult to adjust during the cooling process, and improves the stability of power plant operation.

Description

Technical Field

[0001] This invention relates to the field of waste heat utilization and turbine cooling technology in gas turbine power plants, and more specifically, to a turbine cooling system and method for driving lithium bromide refrigeration with waste heat from gas turbine power plants. Background Technology

[0002] As a crucial component of high-efficiency power generation equipment, gas turbine power plants rely on their core component, the gas turbine, which operates under high temperature and high pressure conditions. The temperature of components such as turbine blades and rotors directly affects the operating efficiency, service life, and safety of the gas turbine. To ensure stable turbine operation, continuous cooling with a cooling medium is necessary. Currently, the mainstream cooling method in the industry is water cooling, which involves pumping cooling water into the turbine cooling channels to absorb heat from the components before discharging it into the steam drum.

[0003] In existing gas turbine cooling systems, the cooling medium is mostly supplied by high-pressure feedwater pumps. During the adjustment process, large fluctuations in the steam drum water level can occur, making it difficult to adjust and leading to protective shutdowns, which affects the continuous and stable operation of the power plant.

[0004] On the other hand, waste heat boilers in gas turbine power plants generate a large amount of high-temperature flue gas during operation. Even after heat exchange in these boilers, the flue gas still retains a certain temperature. Currently, most power plants simply release this portion of low-temperature flue gas directly into the atmosphere, resulting in a significant waste of waste heat resources. Furthermore, the direct emission of low-temperature flue gas may also cause thermal pollution to the environment, which is inconsistent with the current development trend of energy conservation, emission reduction, and environmental protection in the power industry.

[0005] Therefore, there is an urgent need to propose a turbine cooling system and method for using waste heat from gas turbine power plants to drive lithium bromide refrigeration. Summary of the Invention In order to overcome the above-mentioned technical problems, the purpose of this invention is to provide a turbine cooling system and method for lithium bromide refrigeration driven by waste heat from gas turbine power plants.

[0006] The objective of this invention can be achieved through the following technical solutions: A turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant includes: a flue gas waste heat recovery module, a lithium bromide refrigeration module, a turbine cooling module, and a control module. The flue gas waste heat recovery module includes a flue gas heat exchanger installed in the flue gas outlet flue of the waste heat boiler, and the flue gas heat exchanger is used to recover the waste heat of the flue gas. The lithium bromide refrigeration module includes a lithium bromide absorption chiller unit, the driving heat source inlet of which is connected to the flue gas heat exchanger to receive the waste heat of the flue gas recovered by the flue gas heat exchanger as the driving heat source. The turbine cooling module includes a turbine cooling channel disposed inside the gas turbine. The inlet of the turbine cooling channel is connected to the cooling water outlet of the lithium bromide absorption chiller unit through a cooling water delivery pipeline, and the outlet of the turbine cooling channel is connected to the cooling water inlet of the lithium bromide absorption chiller unit through a cooling water return pipeline, forming a cooling water circulation loop. The control module includes a control unit and a temperature detection unit. The temperature detection unit is located at the outlet of the turbine cooling channel. The control unit is electrically connected to the temperature detection unit, the flue gas waste heat recovery module, and the lithium bromide absorption chiller.

[0007] As a further aspect of the present invention: the flue gas waste heat recovery module further includes a heat transfer medium storage tank and a heat transfer medium circulation pump. The heat transfer medium storage tank, the heat transfer medium circulation pump, and the flue gas heat exchanger are connected in sequence through pipelines to form a heat transfer medium circulation loop. The outlet of the flue gas heat exchanger is connected to the inlet of the driving heat source of the lithium bromide absorption chiller, and the outlet of the driving heat source of the lithium bromide absorption chiller is connected to the inlet of the heat transfer medium storage tank.

[0008] As a further aspect of the present invention: the lithium bromide refrigeration module further includes a cooling water storage tank and a cooling water circulation pump disposed on the cooling water delivery pipeline, the cooling water outlet of the lithium bromide absorption chiller is connected to the inlet of the cooling water storage tank, and the outlet of the cooling water storage tank is connected to the inlet of the turbine cooling channel via the cooling water circulation pump.

[0009] As a further aspect of the present invention: the temperature detection unit is a temperature sensor, the control module is a PLC control system, and the control module is electrically connected to the heat transfer medium circulation pump, the cooling water circulation pump, and the lithium bromide absorption chiller unit.

[0010] As a further aspect of the present invention: the flue gas heat exchanger is suitable for recovering waste heat from waste heat boiler flue gas at a temperature of 80℃~150℃.

[0011] A turbine cooling method for lithium bromide refrigeration driven by waste heat from a gas turbine power plant, employing a turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant as described in any of the preceding claims, includes the following steps: S1: Introduce the flue gas discharged from the waste heat boiler into the flue gas heat exchanger to recover the waste heat of the flue gas; S2: The recovered waste heat from the flue gas is sent to the lithium bromide absorption chiller unit as a driving heat source. S3: Use a driving heat source to drive a lithium bromide absorption chiller to produce low-temperature cooling water; S4: Low-temperature cooling water is sent into the turbine cooling channel inside the gas turbine through the cooling water delivery pipeline. The low-temperature cooling water absorbs the heat of the turbine and forms cooling return water. S5: The cooling return water is sent back to the lithium bromide absorption chiller unit for recooling through the cooling water return pipeline; S6: The temperature sensor installed at the turbine cooling channel outlet detects the cooling return water temperature in real time. Based on the deviation between the detected cooling return water temperature and the set value, the control module adjusts the operating parameters of the flue gas waste heat recovery module and / or the lithium bromide absorption chiller to maintain the cooling return water temperature within the set range required for turbine cooling.

[0012] As a further aspect of the present invention: In step S2, the high-temperature heat transfer medium, driven by the heat transfer medium circulation pump, enters the flue gas heat exchanger from the heat transfer medium storage tank to absorb heat, and is then sent to the lithium bromide absorption chiller unit. After releasing heat and cooling down, it returns to the heat transfer medium storage tank, forming a closed-loop circulation of the heat transfer medium.

[0013] As a further aspect of the present invention: in step S1, the temperature of the waste heat boiler flue gas entering the flue gas heat exchanger is 80℃~150℃; in step S3, the temperature of the low-temperature cooling water produced by the lithium bromide absorption chiller is 7℃~25℃.

[0014] As a further aspect of the present invention: in step S4, low-temperature cooling water is sent from the cooling water storage tank to the turbine cooling channel after being pressurized by the cooling water circulation pump.

[0015] As a further aspect of the present invention: In step S6, the control module adjusts the speed of the heat transfer medium circulation pump, the speed of the cooling water circulation pump, and the operating load of the lithium bromide absorption chiller unit based on the deviation between the cooling return water temperature detected by the temperature detection module and the set value.

[0016] The beneficial effects of this invention include, but are not limited to: by combining waste heat from the waste heat boiler flue gas with lithium bromide absorption refrigeration, efficient recovery and utilization of waste heat resources are achieved. This changes the existing treatment method of directly emitting low-temperature flue gas into the atmosphere, effectively utilizing previously discarded low-grade heat energy and reducing thermal pollution. At the same time, the use of an independent closed-loop cooling water circulation loop to cool the turbine avoids water level fluctuations and adjustment difficulties caused by drawing water from a high-pressure feedwater pump, improving the stability and reliability of the cooling system. Furthermore, the closed-loop control system composed of a temperature detection unit and a control unit automatically adjusts operating parameters according to the actual cooling needs of the turbine, further enhancing the intelligence level and operational stability of the system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant, as described in this invention. Figure 2 Another schematic diagram of the turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to the present invention; Figure 3 This is a schematic diagram showing the connection between the lithium bromide refrigeration module and the turbine cooling module in the turbine cooling system of the waste heat-driven lithium bromide refrigeration system of the gas turbine power plant of the present invention. Figure 4 This is a schematic diagram illustrating the steps of the turbine cooling method for using waste heat from a gas turbine power plant to drive lithium bromide refrigeration, as described in this invention.

[0018] Explanation of reference numerals in the attached diagram: 1. Flue gas waste heat recovery module; 2. Lithium bromide refrigeration module; 3. Turbine cooling module; 4. Control module; 11. Flue gas heat exchanger; 21. Lithium bromide absorption chiller unit; 22. Cooling water delivery pipeline; 25. Cooling water return pipeline; 31. Turbine cooling channel; 41. Control unit; 42. Temperature detection unit; 12. Heat transfer medium storage tank; 13. Heat transfer medium circulation pump; 23. Cooling water storage tank; 24. Cooling water circulation pump. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described clearly and completely below with reference to the accompanying drawings. It should be understood that the described embodiments are only one module of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," "comprise," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms, indicating that a method comprises one or more steps, or an apparatus comprises one or more elements, but do not exclude the inclusion of other steps or elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or primary / secondary relationship. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] See Figures 1-3 An embodiment of the present invention discloses a turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant, comprising: a flue gas waste heat recovery module 1, a lithium bromide refrigeration module 2, a turbine cooling module 3, and a control module 4; the gas turbine is a gas turbine; the flue gas waste heat recovery module 1 includes a flue gas heat exchanger 11 disposed in the flue gas outlet duct of the waste heat boiler, the flue gas heat exchanger 11 being used to recover waste heat from the flue gas; the lithium bromide refrigeration module 2 includes a lithium bromide absorption chiller 21, the driving heat source inlet of the lithium bromide absorption chiller 21 being connected to the flue gas heat exchanger 11 to receive the waste heat from the flue gas recovered by the flue gas heat exchanger 11 as a driving heat source; the turbine cooling module 3 includes... The turbine cooling channel 31 is located inside the gas turbine. The inlet of the turbine cooling channel 31 is connected to the cooling water outlet of the lithium bromide absorption chiller unit 21 through the cooling water delivery pipeline 22. The outlet of the turbine cooling channel 31 is connected to the cooling water inlet of the lithium bromide absorption chiller unit 21 through the cooling water return pipeline 25, forming a cooling water circulation loop. The control module 4 includes a control unit 41 and a temperature detection unit 42. The temperature detection unit 42 is located at the outlet of the turbine cooling channel 31. The control unit 41 is electrically connected to the temperature detection unit 42, the flue gas waste heat recovery module 1, and the lithium bromide absorption chiller unit 21.

[0024] Specifically, during the gas turbine power generation process, the flue gas discharged from the waste heat boiler flows directly through the flue gas outlet duct of the waste heat boiler. A flue gas heat exchanger 11, installed within the duct, exchanges heat with the flue gas, recovering the waste heat and transferring it to a lithium bromide absorption chiller unit 21. The lithium bromide absorption chiller unit 21 uses the recovered waste heat from the flue gas as a driving heat source to complete the refrigeration cycle through thermal energy, producing low-temperature cooling water. This low-temperature cooling water enters the turbine cooling channel 31 inside the gas turbine through the cooling water delivery pipeline 22, exchanging heat with high-temperature components such as turbine blades and rotors. After absorbing heat, its temperature rises, forming cooling return water. This cooling return water returns to the lithium bromide absorption chiller unit 21 through the cooling water return pipeline 25 for recooling, forming a closed-loop cycle. During this process, the temperature detection unit 42, located at the outlet of the turbine cooling channel 31, monitors the cooling return water temperature in real time. After receiving the temperature signal, the control unit 41 compares it with the preset turbine cooling temperature range based on its built-in algorithm and calculates the temperature deviation. Based on this, it sends a signal to the flue gas waste heat recovery module 1 and the lithium bromide absorption chiller unit 21 to adjust the operating parameters of the flue gas waste heat recovery module 1 and the lithium bromide absorption chiller unit 21, so that the cooling water temperature is maintained within the set range required for turbine cooling.

[0025] In this embodiment, by combining the waste heat from the waste heat boiler flue gas with lithium bromide absorption refrigeration technology, the efficient recovery and utilization of waste heat resources is achieved. This changes the existing treatment method of directly emitting low-temperature flue gas into the atmosphere, effectively utilizing the originally discarded low-grade heat energy and reducing thermal pollution. At the same time, an independent closed-loop cooling water circulation loop is used to cool the turbine, avoiding the water level fluctuations and adjustment difficulties caused by drawing water from a high-pressure feedwater pump, thus improving the stability and reliability of the cooling system. In addition, the closed-loop control system composed of the temperature detection unit 42 and the control unit 41 automatically adjusts the operating parameters according to the actual cooling needs of the turbine, further enhancing the intelligence level and operational stability of the system.

[0026] See Figures 1-3 Optionally, the flue gas waste heat recovery module 1 also includes a heat transfer medium storage tank 12 and a heat transfer medium circulation pump 13. The heat transfer medium storage tank 12, the heat transfer medium circulation pump 13 and the flue gas heat exchanger 11 are connected in sequence through pipelines to form a heat transfer medium circulation loop. The outlet of the flue gas heat exchanger 11 is connected to the inlet of the driving heat source of the lithium bromide absorption chiller 21, and the outlet of the driving heat source of the lithium bromide absorption chiller 21 is connected to the inlet of the heat transfer medium storage tank 12.

[0027] In this embodiment, the heat transfer medium in the heat transfer medium storage tank 12 enters the flue gas heat exchanger 11 under the drive of the heat transfer medium circulation pump 13. After absorbing the heat from the waste heat boiler flue gas, it becomes a high-temperature heat transfer medium. The high-temperature heat transfer medium is output from the flue gas heat exchanger 11 and sent to the lithium bromide absorption chiller unit 21 as a driving heat source through the pipeline. After releasing heat in the unit, the temperature decreases and then returns to the heat transfer medium storage tank 12 through the pipeline to complete the cycle. The heat transfer medium storage tank 12, the heat transfer medium circulation pump 13 and the flue gas heat exchanger 11 are connected in sequence through pipelines to form a closed loop, which ensures that the heat transfer medium can continuously and stably circulate between the flue gas heat exchanger 11 and the lithium bromide absorption chiller unit 21, providing a stable heat source for lithium bromide refrigeration.

[0028] See Figures 1-3 Optionally, the lithium bromide refrigeration module 2 also includes a cooling water storage tank 23 and a cooling water circulation pump 24 disposed on the cooling water delivery pipeline 22. The cooling water outlet of the lithium bromide absorption chiller unit 21 is connected to the inlet of the cooling water storage tank 23, and the outlet of the cooling water storage tank 23 is connected to the inlet of the turbine cooling channel 31 via the cooling water circulation pump 24.

[0029] In this embodiment, the low-temperature cooling water produced by the lithium bromide absorption chiller 21 flows out from the cooling water outlet and enters the cooling water storage tank 23 for temporary storage. Under the pressure of the cooling water circulation pump 24, the low-temperature cooling water in the cooling water storage tank 23 enters the turbine cooling channel 31 through the cooling water delivery pipeline 22. After absorbing heat inside the turbine, it forms cooling return water, which flows out from the outlet of the turbine cooling channel 31 and returns to the cooling water inlet of the lithium bromide absorption chiller 21 through the cooling water return pipeline 25. After being cooled again, it re-enters the cooling water storage tank 23, forming a closed-loop circulation of cooling water.

[0030] Specifically, the cooling water storage tank 23 plays a role in stabilizing pressure and buffering water volume, effectively absorbing water volume fluctuations caused by fluctuations in the output of the refrigeration unit or changes in the turbine heat load. The cooling water circulation pump 24 independently provides power for the cooling water circulation, overcomes the resistance of the turbine cooling channel 31 and the pipeline system, and delivers low-temperature cooling water into the turbine cooling channel 31 with sufficient pressure and flow to achieve effective cooling.

[0031] See Figures 1-3 Optionally, the temperature detection unit 42 is a temperature sensor, and the control module 4 is a PLC control system. The control module 4 is electrically connected to the heat transfer medium circulation pump 13, the cooling water circulation pump 24, and the lithium bromide absorption chiller unit 21.

[0032] In this embodiment, the temperature sensor serves as the temperature detection unit 42, and its detection position is set at the outlet of the turbine cooling channel 31. It can directly reflect the actual temperature of the cooling water after absorbing heat from the turbine. When the turbine heat load changes, causing the cooling return water temperature to deviate from the set value, the PLC control system, based on its built-in algorithm, coordinates the speed of the heat transfer medium circulation pump 13, the speed of the cooling water circulation pump 24, and the operating load of the lithium bromide absorption chiller unit 21 according to the temperature deviation. When the cooling return water temperature is detected to be higher than the set upper limit, the PLC control system can increase the speed of the heat transfer medium circulation pump 13 to increase the amount of waste heat recovery, or increase the operating load of the lithium bromide absorption chiller unit to enhance the cooling capacity, or correspondingly increase the speed of the cooling water circulation pump 24 to match the heat exchange demand, or simultaneously adopt a combination of multiple measures. Conversely, when the temperature is lower than the set lower limit, the operating parameters of the above-mentioned equipment are reduced. Through multi-parameter linkage adjustment, the system can quickly respond to changes in turbine cooling demand, achieve precise control of cooling return water temperature, and significantly improve the automation level of the system.

[0033] See Figures 1-4 Optionally, the flue gas heat exchanger 11 is suitable for recovering waste heat from waste heat boiler flue gas with a temperature of 80℃~150℃. Flue gas in this temperature range is a common low-grade waste heat resource in gas turbine power plants. Its heat is sufficient to drive the generation process of lithium bromide absorption chiller 21, while avoiding thermal stress damage to the heat exchange equipment and chiller due to excessive temperature.

[0034] Another embodiment of the present invention provides a turbine cooling method for lithium bromide refrigeration driven by waste heat from a gas turbine power plant, employing a turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant as described above, including the following steps: S1: Introduce the flue gas discharged from the waste heat boiler into the flue gas heat exchanger 11 to recover the waste heat of the flue gas. S2: The recovered waste heat from the flue gas is sent to the lithium bromide absorption chiller unit 21 as a driving heat source. S3: Use a driving heat source to drive a lithium bromide absorption chiller 21 to produce low-temperature cooling water; S4: Low-temperature cooling water is sent into the turbine cooling channel 31 inside the gas turbine through the cooling water delivery pipeline 22. The low-temperature cooling water absorbs the heat of the turbine and forms cooling return water. S5: The cooling return water is sent back to the lithium bromide absorption chiller unit 21 for recooling through the cooling water return pipe 25; S6: The temperature of the cooling return water is detected in real time by a temperature sensor installed at the outlet of the turbine cooling channel 31. The control module 4 adjusts the operating parameters of the flue gas waste heat recovery module 1 and / or the lithium bromide absorption chiller unit 21 according to the deviation between the detected cooling return water temperature and the set value, so that the cooling return water temperature is maintained within the set range required for turbine cooling.

[0035] In this embodiment, a complete closed-loop process of waste heat recovery, refrigeration, cooling, and control is formed through six steps, realizing the cascade utilization of energy and closed-loop control of turbine cooling. The operation process is coherent and orderly, and the steps are closely connected through pipelines and control systems to ensure the efficient and stable operation of the entire cooling cycle. Steps S1, S2, and S3 realize the recovery and utilization of waste heat resources, solving the problems of waste heat waste and thermal pollution in the prior art. Steps S4 and S5 establish an independent closed-loop cooling water circulation, eliminating dependence on the high-pressure feedwater system and eliminating the risk of water level fluctuations and uncontrolled regulation. The closed-loop automatic control in step S6 realizes the intelligentization of the cooling process, enabling the cooling water temperature and flow rate to accurately match the real-time cooling needs of the turbine, ensuring the continuous and stable operation of the power plant.

[0036] See Figures 1-4 Optionally, in step S2, the high-temperature heat transfer medium, driven by the heat transfer medium circulation pump 13, enters the flue gas heat exchanger 11 from the heat transfer medium storage tank 12 to absorb heat, and then is sent to the lithium bromide absorption chiller unit 21. After releasing heat and cooling down, it returns to the heat transfer medium storage tank 12, forming a closed-loop circulation of the heat transfer medium. This makes the recovery and transfer process of waste heat from the flue gas more stable and controllable, and also avoids the corrosion and blockage problems that may be caused by the flue gas directly entering the lithium bromide unit.

[0037] See Figures 1-3 Optionally, in step S1, the temperature of the waste heat boiler flue gas entering the flue gas heat exchanger 11 is 80℃~150℃; in step S3, the temperature of the low-temperature cooling water produced by the lithium bromide absorption chiller unit 21 is 7℃~25℃.

[0038] In this embodiment, the flue gas temperature of 80℃~150℃ is the typical temperature range of the exhaust gas from the waste heat boiler of the gas turbine power plant. The waste heat of the flue gas in this range is low-grade heat energy. The lithium bromide absorption chiller unit 21 can operate stably and efficiently within this heat source temperature range to produce low-temperature cooling water of 7℃~25℃. The cooling water in this temperature range can meet the conventional cooling requirements of the gas turbine.

[0039] See Figures 1-4 Optionally, in step S4, the low-temperature cooling water is pressurized from the cooling water storage tank 23 and sent into the turbine cooling channel 31 by the cooling water circulation pump 24. The low-temperature cooling water produced by the lithium bromide absorption chiller unit 21 first enters the cooling water storage tank 23 for temporary storage. Under the pressurization of the cooling water circulation pump 24, the low-temperature cooling water in the cooling water storage tank 23 can overcome the resistance of the cooling water delivery pipeline 22 and the turbine cooling channel 31 and be distributed to each cooling part of the turbine.

[0040] See Figures 1-4Optionally, in step S6, the control module 4 adjusts the speed of the heat transfer medium circulation pump 13, the speed of the cooling water circulation pump 24, and the operating load of the lithium bromide absorption chiller unit 21 based on the deviation between the cooling return water temperature detected by the temperature detection module and the set value.

[0041] In this embodiment, the control module 4 calculates the temperature deviation in real time based on the cooling return water temperature fed back by the temperature sensor. When the cooling return water temperature is higher than the set upper limit, the control module 4 increases the speed of the heat transfer medium circulation pump 13 to increase the heat source supply, or increases the speed of the cooling water circulation pump 24 to increase the cooling water flow, or increases the operating load of the lithium bromide absorption chiller unit 21 to increase the cooling capacity, or takes a combination of the above measures. When the cooling return water temperature is lower than the set lower limit, the opposite action is taken. The control module 4 reduces the speed of the heat transfer medium circulation pump 13 or the speed of the cooling water circulation pump 24 or the operating load of the lithium bromide absorption chiller unit 21, or takes a combination of the above measures to reduce the cooling capacity output.

[0042] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant, characterized in that, include: The flue gas waste heat recovery module (1), the lithium bromide refrigeration module (2), the turbine cooling module (3), and the control module (4) are included. The flue gas waste heat recovery module (1) includes a flue gas heat exchanger (11) installed in the flue gas outlet flue of the waste heat boiler, and the flue gas heat exchanger (11) is used to recover the waste heat of the flue gas. The lithium bromide refrigeration module (2) includes a lithium bromide absorption chiller (21), the driving heat source inlet of the lithium bromide absorption chiller (21) is connected to the flue gas heat exchanger (11) to receive the waste heat of the flue gas recovered by the flue gas heat exchanger (11) as the driving heat source. The turbine cooling module (3) includes a turbine cooling channel (31) located inside the gas turbine. The inlet of the turbine cooling channel (31) is connected to the cooling water outlet of the lithium bromide absorption chiller (21) through a cooling water conveying pipeline (22), and the outlet of the turbine cooling channel (31) is connected to the cooling water inlet of the lithium bromide absorption chiller (21) through a cooling water return pipeline (25), forming a cooling water circulation loop. The control module (4) includes a control unit (41) and a temperature detection unit (42). The temperature detection unit (42) is located at the outlet of the turbine cooling channel (31). The control unit (41) is electrically connected to the temperature detection unit (42), the flue gas waste heat recovery module (1), and the lithium bromide absorption chiller (21).

2. The turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to claim 1, characterized in that, The flue gas waste heat recovery module (1) also includes a heat transfer medium storage tank (12) and a heat transfer medium circulation pump (13). The heat transfer medium storage tank (12), the heat transfer medium circulation pump (13) and the flue gas heat exchanger (11) are connected in sequence through pipelines to form a heat transfer medium circulation loop. The outlet of the flue gas heat exchanger (11) is connected to the driving heat source inlet of the lithium bromide absorption chiller (21), and the driving heat source outlet of the lithium bromide absorption chiller (21) is connected to the inlet of the heat transfer medium storage tank (12).

3. The turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to claim 2, characterized in that, The lithium bromide refrigeration module (2) also includes a cooling water storage tank (23) and a cooling water circulation pump (24) installed on the cooling water delivery pipeline (22). The cooling water outlet of the lithium bromide absorption chiller (21) is connected to the inlet of the cooling water storage tank (23), and the outlet of the cooling water storage tank (23) is connected to the inlet of the turbine cooling channel (31) via the cooling water circulation pump (24).

4. The turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to claim 3, characterized in that, The temperature detection unit (42) is a temperature sensor, and the control module (4) is a PLC control system. The control module (4) is electrically connected to the heat transfer medium circulation pump (13), the cooling water circulation pump (24), and the lithium bromide absorption chiller (21).

5. The turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to claim 1, characterized in that, The flue gas heat exchanger (11) is suitable for recovering waste heat from waste heat boiler flue gas at a temperature of 80℃~150℃.

6. A turbine cooling method for lithium bromide refrigeration driven by waste heat from a gas turbine power plant, employing the turbine cooling system for lithium bromide refrigeration driven by waste heat from a gas turbine power plant as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Introduce the flue gas discharged from the waste heat boiler into the flue gas heat exchanger (11) to recover the waste heat of the flue gas; S2: The recovered waste heat from the flue gas is sent to the lithium bromide absorption chiller (21) as a driving heat source; S3: Use a driving heat source to drive a lithium bromide absorption chiller (21) to produce low-temperature cooling water; S4: Low-temperature cooling water is sent into the turbine cooling channel (31) inside the gas turbine through the cooling water delivery pipeline (22). The low-temperature cooling water absorbs the heat of the turbine and forms cooling return water. S5: The cooling return water is sent back to the lithium bromide absorption chiller (21) through the cooling water return pipe (25) for recooling; S6: The temperature of the cooling return water is detected in real time by a temperature sensor set at the outlet of the turbine cooling channel (31). The control module (4) adjusts the operating parameters of the flue gas waste heat recovery module (1) and / or the lithium bromide absorption chiller (21) according to the deviation between the detected cooling return water temperature and the set value, so that the cooling return water temperature is maintained within the set range required for turbine cooling.

7. The turbine cooling method for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to claim 6, characterized in that, In step S2, the high-temperature heat transfer medium, driven by the heat transfer medium circulation pump (13), enters the flue gas heat exchanger (11) from the heat transfer medium storage tank (12) to absorb heat, and is then sent to the lithium bromide absorption chiller (21) to release heat and cool down before returning to the heat transfer medium storage tank (12), forming a closed-loop circulation of the heat transfer medium.

8. The turbine cooling method for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to claim 6, characterized in that, In step S1, the temperature of the waste heat boiler flue gas entering the flue gas heat exchanger (11) is 80℃~150℃; in step S3, the temperature of the low-temperature cooling water produced by the lithium bromide absorption chiller (21) is 7℃~25℃.

9. The turbine cooling method for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to claim 7, characterized in that, In step S4, the low-temperature cooling water is pressurized from the cooling water storage tank (23) and sent into the turbine cooling channel (31) by the cooling water circulation pump (24).

10. The turbine cooling method for lithium bromide refrigeration driven by waste heat from a gas turbine power plant according to claim 9, characterized in that, In step S6, the control module (4) adjusts the speed of the heat transfer medium circulation pump (13), the speed of the cooling water circulation pump (24), and the operating load of the lithium bromide absorption chiller (21) according to the deviation between the cooling return water temperature detected by the temperature detection module and the set value.

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