A combined cycle power plant of rankine cycle and brayton gas turbine

Abstract

This application provides a combined cycle power plant of Rankine cycle and Brayton gas turbine, belonging to the field of energy and power technology. Specifically, it includes a working fluid storage tank, a booster pump, an evaporator, a superheater, a steam turbine, and a condenser. The evaporator is located inside the compressor, and the superheater is located on the exhaust side of the turbine. The outlet of the working fluid storage tank is connected to the inlet of the evaporator via the booster pump. The outlet of the evaporator is connected to the internal heating channel of the superheater, which is also connected to the inlet of the steam turbine. The outlet of the steam turbine is connected to the inlet of the internal condensation channel of the condenser, and the outlet of the internal condensation channel of the condenser is connected to the inlet of the working fluid storage tank. A regenerator is also provided on the exhaust side of the turbine. The outlet of the compressor is connected to the inlet of the internal heating channel of the regenerator, and the outlet of the internal heating channel of the regenerator is connected to the inlet of the heating mechanism. This application's solution improves the thermal efficiency of the power plant.

Description

Technical Field

[0001] This application relates to the field of energy and power, and in particular to a combined cycle power plant of Rankine cycle and Brayton gas turbine. Background Technology

[0002] Improving heat-to-work conversion efficiency is a continuous goal pursued in fields such as ground-based power generation and aerospace propulsion. Currently, the growth potential of thermal efficiency in single-cycle models has reached a bottleneck, making significant improvements impossible. Existing combined cycle models are mainly concentrated in fields such as nuclear power generation and industrial waste heat utilization, maximizing heat-to-work conversion efficiency through energy cascade utilization. However, while traditional methods have improved thermal efficiency to some extent, the series superposition of multiple cycles results in excessive weight and volume, leading to an extremely low power-to-weight ratio. Summary of the Invention

[0003] In view of this, this application provides a combined cycle power plant of Rankine cycle and Brayton gas turbine, which solves the problems in the prior art and improves the thermal efficiency of the power plant.

[0004] The technical solution for a combined cycle power plant of Rankine cycle and Brayton gas turbine provided in this application is as follows:

[0005] A Rankine cycle and Brayton gas turbine combined cycle power plant is disclosed. The Brayton gas turbine includes a compressor, a heating mechanism, and a turbine arranged in sequence. The compressor compresses air, the heating mechanism heats the compressed air, and the heated airflow drives the turbine to rotate. The turbine exhausts a hot flow. The Rankine cycle and Brayton gas turbine combined cycle power plant also includes a Rankine cycle mechanism, which includes a working fluid storage tank, a booster pump, an evaporator, a superheater, a steam turbine, and a condenser. The evaporator is located inside the compressor, the superheater is located on the exhaust side of the turbine, the working fluid storage tank stores circulating working fluid, the outlet of the working fluid storage tank is connected to the inlet of the internal heating channel of the evaporator through a booster pump, the outlet of the internal heating channel of the evaporator is connected to the inlet of the internal heating channel of the superheater, the outlet of the internal heating channel of the superheater is connected to the inlet of the internal channel of the steam turbine, the outlet of the internal channel of the steam turbine is connected to the inlet of the internal condensation channel of the condenser, and the outlet of the internal condensation channel of the condenser is connected to the inlet of the working fluid storage tank. The turbine has a load connected to its output end, a regenerator is provided on the exhaust side of the turbine, the compressor outlet is connected to the inlet of the internal heating channel of the regenerator, and the outlet of the internal heating channel of the regenerator is connected to the inlet of the heating mechanism.

[0006] Optionally, the regenerator is located between the turbine and the superheater.

[0007] Optionally, the internal heating channel of the evaporator is a mesh heat exchange structure.

[0008] Optionally, an atomizer is provided at the inlet of the internal heating channel of the evaporator. The inlet of the atomizer is connected to the outlet of the booster pump. The atomizer is used to atomize the circulating working fluid delivered by the booster pump and spray it onto the mesh heat exchange structure.

[0009] Optionally, the circulating working fluid is a haloalkane organic compound or a pure hydrocarbon alkane organic compound.

[0010] Optionally, the Rankine cycle and Brayton gas turbine combined cycle power unit is applied to ground equipment, and the condenser has independent first and second flow channels inside. The first flow channel serves as the internal condensation flow channel, and the second flow channel is used to introduce cooling liquid.

[0011] Optionally, the Rankine cycle and Brayton gas turbine combined cycle power unit is used in an aero engine, wherein the condenser is located in the intake duct of the aero engine, and the duct fan of the aero engine drives airflow to cool the surface of the condenser.

[0012] In summary, this application includes the following beneficial technical effects: This application reduces compressor compression power consumption through a deep nested coupling of Brayton and Rankine cycles and interstage cooling. At the same time, it compensates for compressor outlet temperature loss through a regenerator, which greatly improves turbine thermal efficiency. It also meets the evaporation and superheating requirements in the Rankine cycle through two heat sources, thereby generating effective shaft work, which realizes waste heat utilization and greatly improves the actual thermal efficiency of the power unit.

[0013] The outlet temperature of the Brayton gas turbine compression system is lost due to interstage cooling. By installing a regenerator after the turbine, the temperature loss caused by interstage cooling can be effectively compensated. Under the same turbine inlet temperature requirement, no additional heating power is required, which further improves the thermal energy utilization efficiency. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1This is a schematic block diagram of the combined cycle power unit of Rankine cycle and Brayton gas turbine in this application; Figure 2 This is a schematic diagram of the condenser of the Rankine cycle and Brayton gas turbine combined cycle power plant applied to ground equipment in this application. Figure 3 This is a schematic diagram illustrating the application of the Rankine cycle and Brayton gas turbine combined cycle power plant in an aero engine. Figure 4 This is a schematic diagram of the ducted fan and heat sink fins of this application.

[0016] Explanation of reference numerals in the attached drawings: 1. Compressor; 2. Heating mechanism; 3. Turbine; 4. Regenerator; 5. Working fluid storage tank; 6. Booster pump; 7. Evaporator; 8. Superheater; 9. Steam turbine; 10. Condenser; 11. Generator; 12. Cooling tower; 13. Water pump; 14. Ducted fan; 15. Heat dissipation fins. Detailed Implementation

[0017] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0018] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0020] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0022] This application provides a combined cycle power plant of Rankine cycle and Brayton gas turbine.

[0023] like Figure 1 As shown, a combined cycle power plant of Rankine cycle and Brayton gas turbine is disclosed. The Brayton gas turbine includes a compressor 1, a heating mechanism 2 and a turbine 3 arranged in sequence. The compressor 1 compresses air, the heating mechanism 2 heats the compressed air, the heated airflow drives the turbine 3 to rotate, and the turbine 3 exhausts hot air.

[0024] In this application, the heating mechanism 2 is a combustion chamber. The combustion chamber uses compressed air and fuel to burn and generate a high-temperature airflow that drives the turbine 3 to rotate and is ejected from the exhaust side of the turbine 3. The turbine 3 synchronously drives the compressor 1 to run. In other embodiments, the heating mechanism 2 can be other heating sources. After heating the air, the air expands and drives the turbine 3 to rotate. The expanded high-temperature air is ejected from the exhaust side of the turbine 3.

[0025] The Rankine cycle and Brayton gas turbine combined cycle power plant also includes a Rankine cycle mechanism, which includes a working fluid storage tank 5, a booster pump 6, an evaporator 7, a superheater 8, a turbine 9, and a condenser 10. The evaporator 7 is located inside the compressor 1, and the superheater 8 is located on the exhaust side of the turbine 3. The working fluid storage tank 5 stores circulating working fluid, and its outlet is connected to the inlet of the internal heating channel of the evaporator 7 via the booster pump 6. The outlet of the internal heating channel of the evaporator 7 is connected to the inlet of the internal heating channel of the superheater 8. The outlet of the internal heating channel of the superheater 8 is connected to the inlet of the internal channel of the turbine 9. The outlet of the internal channel of the turbine 9 is connected to the inlet of the internal condensation channel of the condenser 10. The outlet of the internal condensation channel of the condenser 10 is connected to the inlet of the working fluid storage tank 5. A load is connected to the output end of the turbine 9. A regenerator 4 is also provided on the exhaust side of the turbine 3. The outlet of the compressor 1 is connected to the inlet of the internal heating channel of the regenerator 4. The outlet of the internal heating channel of the regenerator 4 is connected to the inlet of the heating mechanism 2. When the Brayton gas turbine starts, the Rankine cycle mechanism is inactive. The evaporator 7, located inside the first stage of the compressor, only allows airflow and does not cool the airflow. When the Brayton gas turbine reaches its preset operating point, the Rankine cycle mechanism begins operation. The booster pump 6 pressurizes the circulating working fluid stored in the working fluid storage tank 5 and delivers it to the evaporator 7. The circulating working fluid evaporates in the evaporator 7, cooling the air passing through the compressor 1. The cooled air is further compressed by the compressor 1 and then delivered to the regenerator 4 for heating. The heated air then enters the heating mechanism 2 for further heating, ultimately driving the turbine 3 to perform work, completing the full Brayton gas turbine cycle. The regenerator 4 utilizes the high-temperature exhaust gas from the turbine 3 to compensate for the temperature loss of the air caused by the evaporator 7, ensuring the thermal power of the heating mechanism 2, and simultaneously achieving waste heat recovery from the Brayton gas turbine exhaust gas.

[0026] After evaporation in evaporator 7, the circulating working fluid enters superheater 8, where it is further heated by the high-temperature airflow from the exhaust side of turbine 3. The superheated working fluid then enters turbine 9, driving it to perform work. Turbine 9 drives a load, which can be generator 11 or other equipment capable of rotational drive. After passing through turbine 9, the circulating working fluid enters condenser 10 for condensation, changing from a gaseous state to a liquid state, and finally returns to working fluid storage tank 5, completing the Rankine cycle.

[0027] This application fully combines the technical characteristics of the Brayton cycle and the Rankine cycle in a nested manner. The heating requirements of the evaporator 7 in the Rankine cycle and the interstage cooling requirements of the compression system of the Brayton gas turbine are met simultaneously. Without the need for additional configuration, the compression power consumption of the compression system is reduced, and the heating and evaporation of the working fluid in the Rankine cycle are also achieved.

[0028] Regarding the flow channel design inside the evaporator 7, superheater 8, and regenerator 4, it should be noted that the medium in the internal heating flow channel is heated. In a specific embodiment, the evaporator 7, superheater 8, and regenerator 4 each have only one flow channel as the internal heating flow channel, placing them in their respective corresponding areas. The ambient temperature is directly used to heat the medium inside the evaporator 7, superheater 8, and regenerator 4, thereby lowering the ambient temperature. For the evaporator 7, this lowers the temperature of the compressed air; for the superheater 8 and regenerator 4, it lowers the final exhaust temperature of the Brayton gas turbine. In other embodiments, the evaporator 7, superheater 8, and regenerator 4 are equipped with two independent flow channels. One channel serves as an internal heating channel, and the other as a cooling channel. For the evaporator 7, the cooling channel connects to the interstage compressed air of the compressor, introducing the higher-temperature compressed air into the cooling channel to exchange heat with the circulating medium in the internal heating channel, heating the circulating working fluid while cooling the compressed air. For the superheater 8, the cooling channel introduces the high-temperature exhaust gas from the turbine 3, allowing it to exchange heat with the circulating medium in the internal heating channel, heating the circulating working fluid, while the high-temperature exhaust gas cools down after passing through the superheater 8. For the regenerator 4, the cooling channel introduces the high-temperature exhaust gas from the turbine 3, allowing it to exchange heat with the compressed air in the internal heating channel, heating the compressed air, while the high-temperature exhaust gas cools down after passing through the regenerator. The specific heat exchange structure of the evaporator 7, superheater 8, and regenerator 4 is designed according to specific circumstances.

[0029] In this application, the regenerator 4 is located between the turbine 3 and the superheater 8. By designing the superheater 8 after the regenerator 4, the residual heat of the exhaust gas after the regenerator 4 is used to further heat the circulating working fluid after passing through the evaporator 7, thereby increasing the superheat of the circulating working fluid and thus increasing the heat-work conversion efficiency of the circulating working fluid driving the turbine 9.

[0030] The internal heating channel of the evaporator 7 is a high-density mesh heat exchange structure. An atomizer is installed at the inlet of the internal heating channel of the evaporator 7, and the inlet of the atomizer is connected to the outlet of the booster pump 6. The atomizer is used to atomize the circulating working fluid delivered by the booster pump 6 and spray it onto the mesh heat exchange structure. After atomization, the circulating working fluid contacts the mesh heat exchange structure inside the evaporator 7 and is heated and vaporized by flash evaporation, which can effectively improve evaporation efficiency and reduce the volume and weight of the evaporator 7.

[0031] The circulating working fluid is a haloalkane organic compound or a pure hydrocarbon alkane organic compound. In one embodiment, the circulating working fluid is R245fa.

[0032] The Rankine cycle and Breton gas turbine combined cycle power plant of this application can be applied to ground equipment and aircraft engines.

[0033] like Figure 2 As shown, when the Rankine cycle and Brayton gas turbine combined cycle power unit is applied to ground equipment, the condenser 10 has independent first and second flow channels inside. The first flow channel serves as the internal condensation flow channel, and the second flow channel is used to introduce cooling liquid, which can be water. Water from the cooling tower 12 is injected into the second flow channel by the water pump 13 and then flows back to the cooling tower 12 for cooling. In one embodiment, the ground is a power generation device, and the turbine 3's shaft drives the generator.

[0034] like Figure 3 and Figure 4 As shown, when the Rankine cycle and Brayton gas turbine combined cycle power unit is applied to an aero engine, the condenser 10 is located inside the intake duct of the aero engine. The ducted fan 14 of the aero engine drives airflow to cool the surface of the condenser 10. The condenser 10 is installed on the exhaust side of the ducted fan 14 and includes multiple hollow and interconnected heat dissipation fins 15. The internal channels of the heat dissipation fins 15 serve as the internal condensation flow channels.

[0035] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A combined cycle power plant of Rankine cycle and Brayton gas turbine, wherein the Brayton gas turbine includes a compressor (1), a heating mechanism (2), and a turbine (3) arranged sequentially, wherein the compressor (1) compresses air, the heating mechanism (2) heats the compressed air, the heated airflow drives the turbine (3) to rotate, and the turbine (3) ejects a hot flow from its exhaust end, characterized in that, The Rankine cycle combined cycle power plant also includes a Rankine cycle mechanism, which includes a working fluid storage tank (5), a booster pump (6), an evaporator (7), a superheater (8), a steam turbine (9), and a condenser (10). The evaporator (7) is located inside the compressor (1), the superheater (8) is located on the exhaust side of the turbine (3), the working fluid storage tank (5) stores circulating working fluid, the outlet of the working fluid storage tank (5) is connected to the inlet of the internal heating channel of the evaporator (7) through the booster pump (6), the outlet of the internal heating channel of the evaporator (7) is connected to the inlet of the internal heating channel of the superheater (8), the outlet of the internal heating channel of the superheater (8) is connected to the inlet of the internal channel of the steam turbine (9), the outlet of the internal channel of the steam turbine (9) is connected to the inlet of the internal condensing channel of the condenser (10), and the outlet of the internal condensing channel of the condenser (10) is connected to the inlet of the working fluid storage tank (5). The turbine (9) is connected to a load at its output end, and a regenerator (4) is provided on the exhaust side of the turbine (3). The outlet of the compressor (1) is connected to the inlet of the internal heating channel of the regenerator (4), and the outlet of the internal heating channel of the regenerator (4) is connected to the inlet of the heating mechanism (2).

2. The Rankine cycle and Brayton gas turbine combined cycle power plant according to claim 1, characterized in that, The regenerator (4) is located between the turbine (3) and the superheater (8).

3. The Rankine cycle and Brayton gas turbine combined cycle power plant according to claim 1, characterized in that, The internal heating channel of the evaporator (7) is a mesh heat exchange structure.

4. The Rankine cycle and Brayton gas turbine combined cycle power plant according to claim 3, characterized in that, An atomizer is provided at the inlet of the internal heating channel of the evaporator (7). The inlet of the atomizer is connected to the outlet of the booster pump (6). The atomizer is used to atomize the circulating working fluid delivered by the booster pump (6) and spray it onto the mesh heat exchange structure.

5. The Rankine cycle and Brayton gas turbine combined cycle power plant according to claim 1, characterized in that, The circulating working fluid is a haloalkane organic compound or a pure hydrocarbon alkane organic compound.

6. The Rankine cycle and Brayton gas turbine combined cycle power plant according to claim 1, characterized in that, The Rankine cycle and Brayton gas turbine combined cycle power unit is applied to ground equipment. The condenser (10) has an independent first flow channel and a second flow channel inside. The first flow channel serves as the internal condensation flow channel, and the second flow channel is used to introduce cooling liquid.

7. The Rankine cycle and Brayton gas turbine combined cycle power plant according to claim 1, characterized in that, The Rankine cycle and Brayton gas turbine combined cycle power unit is used in aero engines. The condenser (10) is located in the intake duct of the aero engine. The duct fan (14) of the aero engine drives the airflow to cool the surface of the condenser (10).

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