Solid oxide fuel cell and gas turbine hybrid power system

Abstract

The invention provides a solid oxide fuel cell and gas turbine hybrid power system. The solid oxide fuel cell and gas turbine hybrid power system comprises an SOFC module, a gas turbine and an electrolytic tank module, the SOFC module comprises a first SOFC module and a second SOFC module; the gas turbine comprises a compressor unit, combustors and a turbine, the combustors comprise a first combustor and a second combustor which have a combustion mode and a non-combustion mode, and the non-combustion mode is a normal operation mode; the turbines comprise high-pressure, medium-pressure and low-pressure section turbines; external air enters the first SOFC module for power generation after being pressurized and subjected to heat exchange through the compressor unit, then the air enters the second SOFC module for power generation after sequentially passing through the high-pressure section turbine and the low-pressure section turbine to do work through expansion, and then enters the free power turbine to do work through expansion; the electrolytic tank module is connected with an outlet of the free power turbine, and discharged smoke of the free power turbine exchanges heat with water for electrolysis. The combustion loss and emission of the system can be reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of energy conversion and storage technology in renewable energy, and particularly relates to a solid oxide fuel cell and gas turbine hybrid power system. BACKGROUND

[0002] Energy saving and emission reduction technology is to reduce the consumption of energy, improve energy efficiency, reduce harmful gas emissions, and reduce the impact on the environment to achieve the goal of environmental protection and sustainable development. The goal of energy saving and emission reduction can be achieved by renewable energy and high-efficiency energy conversion equipment. These renewable energy sources (such as wind energy, solar energy, hydro energy, etc.) are widely combined with energy conversion equipment to obtain a high-efficiency and environmentally friendly hybrid system.

[0003] Among these systems, SOFC (Solid Oxide Fuel Cell) systems are considered to be one of the most promising energy conversion systems. In fact, they can electrochemically oxidize fuel without combustion, thereby achieving ultra-high electrical efficiency and low emissions. Therefore, various technical integration schemes of SOFC-gas turbine hybrid systems have emerged. However, both atmospheric pressure SOFC-GT systems and pressurized SOFC-GT systems have a large amount of exergy loss, reducing the potential for system efficiency improvement. SUMMARY

[0004] In view of the above problems existing in the prior art, the purpose of the embodiments of the present application is to provide a solid oxide fuel cell and gas turbine hybrid power system that reduces combustion exergy loss and emissions.

[0005] The technical scheme adopted by the embodiments of the present application is a solid oxide fuel cell and gas turbine hybrid power system, comprising: a SOFC module, a gas turbine and an electrolytic cell module; The SOFC module at least includes a first SOFC module and a second SOFC module; The gas turbine includes a compressor unit, a intercooler, a combustor and a turbine, the combustor at least includes a first combustor and a second combustor, the first combustor and the second combustor both have a combustion mode and a non-combustion mode, and the non-combustion mode is the normal operation mode of the first combustor and the second combustor; the turbine at least includes a high-pressure section turbine, a low-pressure section turbine and a free power turbine arranged in sequence; The outside air is pressurized and heated by the compressor set, enters the intercooler, and then enters the first SOFC module through the air inlet of the first SOFC module; the air outlet of the first SOFC module is connected with the air inlet of the first combustor, the air outlet of the first combustor is connected with the inlet of the high-pressure turbine, the air inlet of the second SOFC module is connected with the outlet of the low-pressure turbine, the air outlet of the second SOFC module is connected with the air inlet of the second combustor, and the air outlet of the second combustor is connected with the inlet of the free power turbine, so that the air enters the second SOFC module after being expanded to do work by the high-pressure turbine and the low-pressure turbine in sequence, and then flows through the second combustor and further expands to do work by the free power turbine; The electrolytic cell module is connected with the outlet of the free power turbine, so that the exhaust gas of the free power turbine exchanges heat with the electrolytic water used for the electrolytic cell module, and the temperature of the electrolytic water is increased.

[0006] In an optional embodiment, the gas turbine further comprises a regenerator, which is arranged between the compressor set and the first SOFC module, and the air compressed by the compressor set enters the cold fluid side of the regenerator; the exhaust gas outlet of the free power turbine is connected with the hot fluid side inlet of the regenerator, so that the exhaust gas of the free power turbine flows through the hot fluid side of the regenerator, exchanges heat with the air flowing through the cold fluid side of the regenerator, and then exchanges heat with the electrolytic water in the electrolytic cell module.

[0007] In an optional embodiment, the air outlet of the cold fluid side of the regenerator is divided into two paths, one of which enters the cathode inlet of the first SOFC module, and the other of which enters a first regulating bypass in parallel with the first SOFC module, the first regulating bypass being connected to the air inlet of the first combustor, for sending air into the first combustor through the first regulating bypass when the solid oxide fuel cell and gas turbine hybrid power system is started or stopped; and / or The air outlet of the low-pressure turbine is divided into two paths, one of which enters the cathode inlet of the second SOFC module, and the other of which enters a second regulating bypass in parallel with the second SOFC module, the second regulating bypass being connected to the air inlet of the second combustor, for sending air into the second combustor through the second regulating bypass when the solid oxide fuel cell and gas turbine hybrid power system is started or stopped.

[0008] In an optional embodiment, the compressor set comprises a low-pressure stage compressor, a medium-pressure stage compressor and a high-pressure stage compressor connected in sequence; the intercooler comprises a first intercooler and a second intercooler, the first intercooler is arranged between the low-pressure stage compressor and the medium-pressure stage compressor, and the second intercooler is arranged between the medium-pressure stage compressor and the high-pressure stage compressor, the cold fluid side of the first intercooler and the second intercooler is flowed through with cooling water; the ambient air enters the inlet of the low-pressure stage compressor, is compressed by the low-pressure stage compressor, enters the hot fluid side of the first intercooler and exchanges heat with the cooling water of the cold fluid side of the first intercooler, then enters the medium-pressure stage compressor, is compressed by the medium-pressure stage compressor, enters the hot fluid side of the second intercooler and exchanges heat with the cooling water of the cold fluid side of the second intercooler, and finally enters the high-pressure stage compressor and is compressed, and then enters the cold fluid side of the regenerator.

[0009] In an optional embodiment, the cooling water at the outlet of the cold fluid side of the first intercooler and the second intercooler is used as electrolysis water and / or heat supply water of the electrolysis cell module.

[0010] In an optional embodiment, the electrolysis cell module comprises an electrolysis cell, a waste heat exchanger, a hydrogen storage device and an oxygen storage device, the electrolysis water flows through the cold fluid side of the waste heat exchanger, exchanges heat with the air flowing through the hot fluid side of the waste heat exchanger, and then enters the electrolysis cell, the electrolysis reaction occurs in the electrolysis cell to generate hydrogen and oxygen, the hydrogen enters the hydrogen storage device for storage, and the oxygen enters the oxygen storage device for storage.

[0011] In an optional embodiment, the outlet of the cold fluid side of the intercooler is connected to the inlet of the cold fluid side of the waste heat exchanger, so that the cooling water flowing through the intercooler is used as electrolysis water of the electrolysis cell module, and exchanges heat with the air flowing through the hot fluid side of the waste heat exchanger in the waste heat exchanger of the electrolysis cell module; and / or A first heat exchanger for heating the electrolysis water is arranged between the outlet of the cold fluid side of the waste heat exchanger and the inlet of the electrolysis cell, a second heat exchanger for cooling the hydrogen is arranged between the hydrogen outlet of the electrolysis cell and the hydrogen storage device, and a third heat exchanger for cooling the oxygen is arranged between the oxygen outlet of the electrolysis cell and the oxygen storage device.

[0012] In an optional embodiment, the first combustor and the second combustor are further respectively provided with a fuel inlet for feeding combustion fuel into the first combustor and the second combustor; and a fuel compressor for compressing the fuel is connected to the fuel inlet.

[0013] In an alternative embodiment, the first SOFC module and the second SOFC module are structurally identical, and each comprises a methane hydrogen production device and a plurality of SOFCs. Air and fuel for combustion are compressed by compressors and then enter the methane hydrogen production device for reaction. The fuel gas produced by the reaction enters the anodes of the plurality of SOFCs in parallel. The air enters the cathodes of the plurality of SOFCs in series. The air exhaust from the cathode of the most downstream SOFC enters the first combustor and the second combustor, respectively.

[0014] In an alternative embodiment, the first SOFC module and the second SOFC module further comprise a fourth heat exchanger and a fifth heat exchanger, respectively. The first SOFC module and the second SOFC module each comprise three SOFCs, which are a first SOFC, a second SOFC, and a third SOFC, respectively. The methane hydrogen production device produces three streams of fuel gas, which are a first stream of fuel gas, a second stream of fuel gas, and a third stream of fuel gas. The first stream of fuel gas enters the first SOFC via a first pipeline. The second stream of fuel gas enters the second SOFC via a second pipeline. The third stream of fuel gas enters the third SOFC via a third pipeline. The fourth heat exchanger is arranged on the first pipeline, and the first stream of fuel gas in the first pipeline flows through the cold fluid side of the fourth heat exchanger. After heat exchange in the fourth heat exchanger, the first stream of fuel gas enters the anode of the first SOFC, and after the reaction in the first SOFC, the first stream of fuel gas exits the anode of the first SOFC and flows through the hot fluid side of the fourth heat exchanger. After heat exchange with the first stream of fuel gas flowing through the cold fluid side of the fourth heat exchanger, the first stream of fuel gas returns to the inlet or outlet of the methane hydrogen production device. The fifth heat exchanger is arranged on the third pipeline, and the third stream of fuel gas in the third pipeline flows through the hot fluid side of the fifth heat exchanger. After heat exchange in the fifth heat exchanger, the third stream of fuel gas enters the anode of the third SOFC, and after the reaction in the third SOFC, the third stream of fuel gas exits the anode of the third SOFC and returns to the inlet or outlet of the methane hydrogen production device. External air flows through the cold fluid side of the fifth heat exchanger, and after heat exchange with the third stream of fuel gas flowing through the hot fluid side of the fifth heat exchanger, the external air enters the cathodes of the first SOFC, the second SOFC, and the third SOFC in sequence, and finally exits the air outlet of the third SOFC and enters the first combustor or the second combustor.

[0015] Compared with the prior art, the embodiment of the application has the beneficial effects that the solid carbide fuel cell and gas turbine (SOFC-GT) hybrid power system SOFC module reaction heat release replaces the burner as the turbine inlet air warming heat source, thereby reducing the system combustion loss and emissions, and having higher efficiency and significant carbon emission reduction.

[0016] The SOFC and GT are combined into a hybrid power system, the income is maximized under the condition of reducing the investment cost. Moreover, the generated exhaust gas can be used to drive the bottom thermodynamic cycle, and the overall efficiency of the whole hybrid cycle can be higher than 70% in theory.

[0017] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and are not intended to limit the application.

[0018] The summary of various implementations or examples of the technology described in the application is not a comprehensive disclosure of the entire scope or all features of the disclosed technology. BRIEF DESCRIPTION OF DRAWINGS

[0019] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. The drawings illustrate various embodiments by way of example and not by way of limitation, and together with the description, serve to explain the principles of the claimed embodiments. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts. The drawings are intended to illustrate major functional elements of the application, and in operation, the major functional elements can be implemented in various forms.

[0020] Figure 1 The figure is a schematic diagram of the solid oxide fuel cell and gas turbine hybrid power system of the embodiment of the application.

[0021] Figure 2 The figure is a schematic diagram of the SOFC module of the embodiment of the application.

[0022] Reference signs: 1 - first SOFC module; 2 - hydrogen production plant from methane; 3 - SOFC; 4 - second SOFC module; 5 - first compressor; 6 - second compressor; 7 - fourth heat exchanger; 8 - fifth heat exchanger; 9 - first line; 10 - second line; 11 - third line; 12 - low-pressure stage compressor; 13 - medium-pressure stage compressor; 14 - high-pressure stage compressor; 15 - first intercooler; 16 - second intercooler; 17 - high-pressure stage turbine; 18 - low-pressure stage turbine; 19 - free power turbine; 20 - first combustor; 21 - second combustor; 22 - recuperator; 23 - fuel compressor; 24 - first regulation bypass; 25 - first regulation valve; 26 - second regulation bypass; 27 - second regulation valve; 29 - electrolyser; 30 - waste heat boiler; 31 - hydrogen storage device; 32 - oxygen storage device; 33 - first heat exchanger; 34 - second heat exchanger; 35 - third heat exchanger. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort fall within the scope of the present application.

[0024] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the ordinary meaning commonly understood by one of ordinary skill in the art to which the present application belongs. The terms "first", "second", and similar terms used in the present application do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "include", "contain", and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.

[0025] In order to keep the following description of the embodiments of the present application clear and brief, the detailed description of known functions and known components is omitted in the present application.

[0026] As Figure 1As shown, the embodiment of the present application provides a solid oxide fuel cell and gas turbine hybrid power system, which comprises a SOFC module, a gas turbine (hereinafter referred to as GT) and an electrolytic cell 29 module.

[0027] The SOFC module at least comprises a first SOFC module 1 and a second SOFC module 4.

[0028] The gas turbine comprises a compressor unit, an intercooler, a combustor and a turbine. The combustor at least comprises a first combustor 20 and a second combustor 21. The turbine at least comprises a high-pressure section turbine 17, a low-pressure section turbine 18 and a free power turbine 19 arranged in sequence.

[0029] The ambient air is pressurized and heated by the compressor unit, enters the intercooler for heat exchange, and then enters the first SOFC module 1 through the air inlet of the first SOFC module 1 to generate electricity, and in this process, the heat of the first SOFC module 1 is taken away, and the temperature of the ambient air is raised. The air outlet of the first SOFC module 1 is connected with the air inlet of the first combustor 20, and the air outlet of the first combustor 20 is connected with the inlet of the high-pressure section turbine 17. The air inlet of the second SOFC module 4 is connected with the outlet of the low-pressure section turbine 18, the air outlet of the second SOFC module 4 is connected with the air inlet of the second combustor 21, and the air outlet of the second combustor 21 is connected with the inlet of the free power turbine 19, so that the air is expanded to do work after passing through the high-pressure section turbine 17 and the low-pressure section turbine 18 in sequence, and then enters the second SOFC module 4 to generate electricity, and then flows through the second combustor 21 and enters the free power turbine 19 to further expand and do work.

[0030] The electrolytic cell 29 module is connected with the outlet of the free power turbine 19, so that the exhaust gas of the free power turbine 19 exchanges heat with the electrolytic water used for the electrolytic cell 29 module, and the temperature of the electrolytic water is raised.

[0031] The first combustor 20 and the second combustor 21 both have a combustion mode and a non-combustion mode, and the non-combustion mode is the normal operation mode of the first combustor 20 and the second combustor 21. That is, the first combustor 20 and the second combustor 21 are in the non-combustion mode (closed state) when the hybrid power system of the present application is normally operated, and do not work on the whole system; the first combustor 20 and the second combustor 21 are in the combustion mode when the hybrid power system of the present application is started and stopped, and the combustor only works in the combustion mode to help load regulation.

[0032] The hybrid system of the embodiments of the present application uses SOFC modules to replace the combustor, and uses the SOFC modules as the heater and reheater of the GT, and uses the SOFC modules as the heat source for warming the turbine inlet air, so as to reduce the combustion loss and emission of the system. The GT is responsible for utilizing the heat energy and kinetic energy of the cathode exhaust gas of the SOFC modules, so that the SOFC modules and the GT have better flexibility in collocation and regulation.

[0033] In some embodiments, as shown in Figure 1 The gas turbine further comprises a regenerator 22 arranged between the compressor unit and the first SOFC module 1. The compressed air enters the cold fluid side of the regenerator 22. The exhaust outlet of the free power turbine 19 is connected to the hot fluid side inlet of the regenerator 22, so that the exhaust flow of the free power turbine 19 flows through the hot fluid side of the regenerator 22, and then enters the electrolysis cell 29 module to exchange heat with the water for electrolysis after exchanging heat with the air flowing through the cold fluid side of the regenerator 22. By arranging the regenerator 22, the air with a certain pressure head obtained after compression can absorb the waste heat of the exhaust of the free power turbine 19, increase the temperature of the air before entering the first SOFC module 1, and improve the power generation efficiency of the first SOFC module 1. That is, the regenerative cycle of the GT is utilized to ensure its high efficiency at partial load.

[0034] Continuing to combine Figure 1 The air outlet of the cold fluid side of the regenerator 22 is divided into two paths, one of which enters the cathode inlet of the first SOFC module 1, and the other of which enters the first regulating bypass 24 in parallel with the first SOFC module 1. The first regulating bypass 24 is provided with a first regulating valve 25. The first regulating bypass 24 is connected to the air inlet of the first combustor 20, and the air is sent into the first combustor 20 through the first regulating bypass 24. By arranging the first regulating bypass 24, the air can select two different flow paths of the first regulating bypass 24 or the first SOFC module 1, so that the flow of the air entering the first SOFC module 1, and the temperature and flow of the air entering the first combustor 20 are adjusted to meet the different needs of the hybrid system under different operating loads. For example, when the hybrid system is started or stopped, the high-pressure turbine 17 and the low-pressure turbine 18 may be cooled at any time, and there are other load burst conditions, for example, when a larger power output is required, the system load needs to be increased by a part, and the first combustor 20 can be used for combustion to quickly adjust the turbine and increase the load. At this time, the first regulating valve 25 is opened, and the compressed air enters the first combustor 20 to assist the fuel combustion. When the hybrid system is started and normally operated, the first regulating valve 25 and the first combustor 20 are closed, and the compressed air enters the first SOFC module 1 to generate electricity, and the air heated after electricity generation directly passes through the first combustor 20, and then enters the high-pressure turbine 17 to expand and do work.

[0035] Similarly, the air exiting the low-pressure turbine 18 is also divided into two paths. One path enters the cathode inlet of the second SOFC module 4, and the other path enters the second regulating bypass 26 connected in parallel with the second SOFC module 4. The second regulating bypass 26 is equipped with a second regulating valve 27. The second regulating bypass 26 is connected to the air inlet of the second burner 21, and air is delivered to the second burner 21 through the second regulating bypass 26. By setting the second regulating bypass 26, the air exiting the low-pressure turbine 18 can choose between two different flow paths: the second regulating bypass 26 or the second SOFC module 4. This allows the flow rate of the air entering the second SOFC module 4, as well as the temperature and flow rate of the air entering the second burner 21, to be adjusted to meet the different needs of the hybrid power system under different operating loads. For example, when the hybrid power system is started or stopped, the second regulating valve 27 is opened, allowing compressed air to enter the second burner 21 to assist in fuel combustion. When the hybrid power system is started and running normally, the second regulating valve 27 and the second burner 21 are closed, allowing the compressed air to enter the second SOFC module 4 to generate electricity. The heated air after generating electricity passes directly through the second burner 21 and then enters the free power turbine 19 to expand and do work.

[0036] In some embodiments, such as Figure 1 As shown, the compressor unit includes a low-pressure compressor 12, a medium-pressure compressor 13, and a high-pressure compressor 14 connected in sequence. The intercooler includes a first intercooler 15 and a second intercooler 16 with identical structures. The first intercooler 15 is located between the low-pressure compressor 12 and the medium-pressure compressor 13, and the second intercooler 16 is located between the medium-pressure compressor 13 and the high-pressure compressor 14. Cooling water flows through the cold fluid side of both the first intercooler 15 and the second intercooler 16. Outside air enters through the inlet of the low-pressure compressor 12, is compressed by the low-pressure compressor 12, and then enters the hot fluid side of the first intercooler 15 to exchange heat with the cooling water on its cold fluid side. It then enters the medium-pressure compressor 13, is compressed by the medium-pressure compressor 13, and then enters the hot fluid side of the second intercooler 16 to exchange heat with the cooling water on its cold fluid side. Finally, it enters the high-pressure compressor 14, is compressed, and then enters the cold fluid side of the regenerator 22. This application pressurizes air through a three-stage compressor (low, medium, and high). During the pressurization process, external cooling water cools the air in two-stage intercoolers and gives the air a certain pressure head. The air then enters the regenerator 22 to obtain waste heat from the exhaust gas of the free-powered turbine 19 before entering the SOFC module to generate electricity.

[0037] The hybrid power system of this application adopts an intercooled regenerative gas turbine cycle to ensure its high efficiency under partial load and better flexibility in the combination and regulation of SOFC and GT.

[0038] The cooling water absorbing the air compression heat in the two intercoolers can be used as heat supply for northern heating and as electrolysis water for the electrolysis cell 29 module. Specifically, the cold fluid side outlets of the first intercooler 15 and the second intercooler 16 are connected to a return water pipeline, which can be connected to a heating pipeline or an electrolysis water pipeline of the electrolysis cell 29 module, so that the cooling water with temperature rise after heat exchange in the two intercoolers is used as electrolysis water for the electrolysis cell 29 module and / or heat supply water.

[0039] In some embodiments, the first combustor 20 and the second combustor 21 are further respectively provided with a fuel inlet through which combustion fuel is fed into the first combustor 20 and the second combustor 21 respectively. Figure 1 The electrolysis cell 29 module includes the electrolysis cell 29, the waste heat exchanger 30, the hydrogen storage device 31 and the oxygen storage device 32. The electrolysis water flows through the cold fluid side of the waste heat exchanger 30 and exchanges heat with the air flowing through the hot fluid side of the waste heat exchanger 30, and then enters the electrolysis cell 29 to generate hydrogen and oxygen through electrolysis reaction. The hydrogen enters the hydrogen storage device 31 for storage, and the oxygen enters the oxygen storage device 32 for storage, which can be used as fuel of the SOFC or other purposes. The system coupling the electrolysis cell 29 module with the SOFC and the GT has high power accommodation and peak regulation capacity.

[0040] Further, the cold fluid side outlets of the first intercooler 15 and the second intercooler 16 are connected to the cold fluid side inlet of the waste heat exchanger 30, so that the cooling water absorbing the air compression heat flowing through the intercoolers is used as electrolysis water for the electrolysis cell 29 module and exchanges heat with the air flowing through the hot fluid side of the waste heat exchanger 30. In this way, the temperature of the electrolysis water entering the electrolysis cell 29 can be increased, and the electrolysis efficiency can be improved.

[0041] As shown in FIG. 1, the first combustor 20 and the second combustor 21 are further respectively provided with a fuel inlet through which combustion fuel is fed into the first combustor 20 and the second combustor 21 respectively. Figure 1 As shown in FIG. 1, the cold fluid side outlet of the waste heat exchanger 30 is connected to the inlet of the electrolysis cell 29 through a first heat exchanger 33 for heating the electrolysis water. The hydrogen outlet of the electrolysis cell 29 is connected to the hydrogen storage device 31 through a second heat exchanger 34 for cooling the hydrogen. The oxygen outlet of the electrolysis cell 29 is connected to the oxygen storage device 32 through a third heat exchanger 35 for cooling the oxygen. By providing the first heat exchanger 33, the temperature of the electrolysis water can be increased to meet the temperature requirement of electrolysis. By providing the second heat exchanger 34 and the third heat exchanger 35, the temperature of the hydrogen and the oxygen can be reduced, which is beneficial for storage in the corresponding devices.

[0042] In some embodiments, the first combustor 20 and the second combustor 21 are further respectively provided with a fuel inlet through which combustion fuel is fed into the first combustor 20 and the second combustor 21 respectively. Figure 1 The fuel pipelines connected to the fuel inlets are respectively provided with a fuel compressor 23 for compressing the fuel.

[0043] It can be understood that the first SOFC module 1 and the second SOFC module 4 can be the same or different in structure. The present application takes the first SOFC module 1 and the second SOFC module 4 as the same in structure, and takes the first SOFC module 1 for detailed description of its structure.

[0044] As shown in Figure 2 , the first SOFC module 1 includes a methane hydrogen production device 2 and a plurality of SOFCs 3. The air and fuel for combustion are compressed by the first compressor 5 and the second compressor 6 respectively, and then enter the methane hydrogen production device 2 for reaction. The fuel gas generated by the reaction enters the anodes of the plurality of SOFCs 3 in parallel. The air enters the cathodes of the plurality of SOFCs 3 in series. In the direction of the air flow, the air exhaust of the cathode of the SOFC 3 at the most downstream enters the first combustor 20 and the second combustor 21 respectively. In the first SOFC module 1, the anode gas (fuel) is in parallel, so as to reduce the polarization loss of the SOFC 3. The cathode gas (air) is in series, so that the air entering the turbine can obtain sufficient temperature, and the temperature rise of the cathode air can reach nearly 300 ℃.

[0045] The number of SOFCs 3 included in the first SOFC module 1 is not limited, and can be selected according to actual conditions. The present application embodiment illustrates three SOFCs 3, Figure 2 , in which the three SOFCs 3 are sequentially the first SOFC, the second SOFC and the third SOFC from top to bottom. The SOFC 3 can adopt a bamboo joint pipe structure, for example.

[0046] Continuing to combine Figure 2 , the first SOFC module 1 further includes a fourth heat exchanger 7 and a fifth heat exchanger 8. The fuel gas generated by the methane hydrogen production device 2 is divided into three streams, which are the first fuel gas, the second fuel gas and the third fuel gas. The three streams of fuel gas enter the first SOFC, the second SOFC and the third SOFC respectively, so as to realize parallel inlet of the fuel gas (anode). Among them, the fourth heat exchanger 7 and the fifth heat exchanger 8 can be arranged on the pipeline through which any one of the three streams of fuel gas flows.

[0047] For example, as shown in Figure 2 , the fourth heat exchanger 7 is arranged on the first pipeline 9 through which the first fuel gas flows, and the fifth heat exchanger 8 is arranged on the third pipeline 11 through which the third fuel gas flows. The first pipeline 9 is connected to the cold fluid side of the fourth heat exchanger 7, so that the first fuel gas is heated and enters the anode of the first SOFC after being heated in the fourth heat exchanger 7. After the reaction in the first SOFC, the first fuel gas flows through the hot fluid side of the fourth heat exchanger 7, and exchanges heat with the first fuel gas flowing through the cold fluid side of the fourth heat exchanger 7, and then returns to the inlet or outlet of the methane hydrogen production device 2.

[0048] The second fuel gas generated by the methane hydrogen production device 2 directly enters the anode of the second SOFC through the second pipeline 10, and is discharged from the anode of the second SOFC after the reaction is completed in the second SOFC, and is returned to the inlet or outlet of the methane hydrogen production device 2.

[0049] The third pipeline 11 is connected to the hot fluid side of the fifth heat exchanger 8, so that the third fuel gas enters the anode of the third SOFC after heat exchange and temperature reduction in the fifth heat exchanger 8, is discharged from the anode of the third SOFC after the reaction is completed in the third SOFC, and is returned to the inlet or outlet of the methane hydrogen production device 2 through the fifth heat exchanger 8. The external air flows through the cold fluid side of the fifth heat exchanger 8, is heat-exchanged with the third fuel gas flowing through the hot fluid side of the fifth heat exchanger 8, and then enters the cathode of the first SOFC, the cathode of the second SOFC and the cathode of the third SOFC in sequence, and is finally discharged from the air outlet of the third SOFC and enters the first burner 20 (if it is the second SOFC module 4, it is connected to the second burner 21).

[0050] The anode exhaust of the three SOFCs 3 in the embodiment of the application is connected to the circulating pump, and under the action of the circulating pump, part of the anode exhaust is returned to the anode inlet of the SOFC through the circulating loop, and part of the anode exhaust enters the reforming burner of the methane hydrogen production device 2 to provide a heat source for the reforming reaction. Avoiding all entering the reforming burner, which leads to over-temperature of the reforming burner.

[0051] The working process of the hybrid power system of the embodiment of the application will be described below. Figure 1 The working process of the hybrid power system of the embodiment of the application will be described below. As Figure 1As shown, the air is pressurized by three-stage compressors, i.e., a low-pressure compressor 12 (LPC), an intermediate-pressure compressor 13 (IPC), and a high-pressure compressor 14 (HPC), and cooled by external cooling water in two intercoolers (a first intercooler 15 and a second intercooler 16) during the pressurization. After being compressed, the air obtains a certain pressure head, enters a regenerator 22 to obtain waste heat, and then enters a first SOFC module 1 to generate power, and in this process, the air takes away the heat of the first SOFC module 1 and its temperature is increased. A bypass and a combustor 1 and a fuel compressor 23 (FCOMP) connected in parallel with the first SOFC module 1 form a bypass for fuel proportion adjustment of the first SOFC module 1 (indicated by a dashed line), and the air can be adjusted in temperature and flow rate at the bypass. Thereafter, the air enters a high-pressure turbine 17 (HPT) and a low-pressure turbine 18 (LPT) to expand and do work, and the temperature and pressure are reduced. To improve the efficiency of a free-power turbine 19 (FPT) and the exhaust gas temperature, a second SOFC module 4 is arranged as a reheater of the GT, and the components and flow paths thereof are arranged in the same manner as the first SOFC module 1. After the FPT exhaust gas passes through the regenerator 22 to give heat to the air, the temperature of the air is further reduced, and finally, the air exchanges heat with electrolysis water in a waste heat exchanger 30 and is discharged. The electrolysis water first flows through the first intercooler 15 and the second intercooler 16 before entering the waste heat exchanger 30, obtains air compression heat as cooling water, and then enters the waste heat exchanger 30 to obtain heat, and finally enters an electrolysis cell 29 to perform an electrolysis reaction to generate oxygen and hydrogen. The oxygen and hydrogen are cooled and then sent to an oxygen storage device 32 and a hydrogen storage device 31, respectively, as fuel for the battery or for other purposes. The electrolysis cell 29 consumes redundant power from an external grid in this process, and the system coupled with the SOFC and the GT has high power consumption and peak shaving capacity.

[0052] The SOFC series reaction exothermic method of the embodiments of the present application replaces the combustor as the turbine inlet air warming heat source, thereby reducing the system combustion㶲 loss and emissions. The combustor has two operation modes, i.e., a “combustion” mode and a “non-combustion” mode. In the non-combustion mode, the SOFC replaces the combustor to play the role of a heater and a reheater of the GT. The combustor only helps load regulation in the combustion mode. The connection mode between the SOFC modules is mainly series connection, so that the air obtains sufficient temperature before entering the turbine, and high efficiency in normal operation is ensured, and flexibility in the regulated operating condition is met.

[0053] In the SOFC, the anode gas is parallelly fed to reduce the polarization loss of the SOFC. The cathode gas is multi-stage serially fed to achieve a temperature rise of the cathode air of nearly 300 ℃.

[0054] The power output of the hybrid system of the embodiment of the present application is from the SOFC and the GT, and the thermal output is from the intercooler.

[0055] The solid oxide fuel cell-gas turbine (SOFC-GT) hybrid system of the embodiment of the present application is superior to the conventional SOFC-GT hybrid system in efficiency and carbon emission reduction.

[0056] The above description is intended to be illustrative and not restrictive, and those ordinarily skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present disclosure. Moreover, the above examples (or one or more aspects thereof) can be used in combination with each other, and the embodiments can be combined with each other in various combinations or arrangements.

Claims

1. A solid oxide fuel cell and gas turbine hybrid power system, characterized by, The application relates to a solid oxide fuel cell (SOFC) and gas turbine hybrid power system. The SOFC module comprises at least a first SOFC module and a second SOFC module. The gas turbine comprises a compressor unit, a middle cooler, a combustor and a turbine, the combustor comprises at least a first combustor and a second combustor, the first combustor and the second combustor each have a combustion mode and a non-combustion mode, and the non-combustion mode is the normal operation mode of the first combustor and the second combustor; the turbine comprises at least a high-pressure section turbine, a low-pressure section turbine and a free-power turbine arranged in sequence. External air is pressurized and heated by the compressor unit, enters the middle cooler for heat exchange, and then enters the first SOFC module through the air inlet of the first SOFC module to generate electricity; the air outlet of the first SOFC module is connected with the air inlet of the first combustor, the air outlet of the first combustor is connected with the inlet of the high-pressure section turbine, the air inlet of the second SOFC module is connected with the outlet of the low-pressure section turbine, the air outlet of the second SOFC module is connected with the air inlet of the second combustor, and the air outlet of the second combustor is connected with the inlet of the free-power turbine, so that the air is expanded to do work in the high-pressure section turbine and the low-pressure section turbine in sequence, enters the second SOFC module to generate electricity, and then flows through the second combustor and enters the free-power turbine to be further expanded to do work. The electrolytic cell module is connected with the outlet of the free-power turbine, so that the exhaust gas of the free-power turbine exchanges heat with the electrolytic water used for the electrolytic cell module, and the temperature of the electrolytic water is increased. The gas turbine further comprises a regenerator, the regenerator is arranged between the compressor unit and the first SOFC module, the air compressed by the compressor unit enters the cold fluid side of the regenerator; the exhaust gas outlet of the free-power turbine is connected with the hot fluid side inlet of the regenerator, so that the exhaust gas of the free-power turbine flows through the hot fluid side of the regenerator, exchanges heat with the air flowing through the cold fluid side of the regenerator, and then exchanges heat with the electrolytic water in the electrolytic cell module.

2. The solid oxide fuel cell and gas turbine hybrid power system of claim 1, wherein, The air outlet of the cold fluid side of the regenerator is divided into two paths, one of which enters the cathode inlet of the first SOFC module, and the other of which enters a first regulating bypass parallel to the first SOFC module, the first regulating bypass is connected to the air inlet of the first combustor, and is used for sending air into the first combustor through the first regulating bypass when the solid oxide fuel cell and gas turbine hybrid power system is started or stopped.

3. The solid oxide fuel cell and gas turbine hybrid power system of claim 2, wherein, The air outlet of the low-pressure section turbine is divided into two paths, one of which enters the cathode inlet of the second SOFC module, and the other of which enters a second regulating bypass parallel to the second SOFC module, the second regulating bypass is connected to the air inlet of the second combustor, and is used for sending air into the second combustor through the second regulating bypass when the solid oxide fuel cell and gas turbine hybrid power system is started or stopped. ​ ​ 4. The solid oxide fuel cell and gas turbine hybrid power system of claim 2, wherein, The compressor set comprises a low-pressure stage compressor, a medium-pressure stage compressor and a high-pressure stage compressor connected in sequence; the intercooler comprises a first intercooler and a second intercooler, the first intercooler is arranged between the low-pressure stage compressor and the medium-pressure stage compressor, the second intercooler is arranged between the medium-pressure stage compressor and the high-pressure stage compressor, and the cold fluid sides of the first intercooler and the second intercooler are both flowed through cooling water; external air enters the inlet of the low-pressure stage compressor, is compressed by the low-pressure stage compressor, enters the hot fluid side of the first intercooler and exchanges heat with the cooling water of the cold fluid side of the first intercooler, then enters the medium-pressure stage compressor, is compressed by the medium-pressure stage compressor, enters the hot fluid side of the second intercooler and exchanges heat with the cooling water of the cold fluid side of the second intercooler, and finally enters the high-pressure stage compressor and is compressed to enter the cold fluid side of the regenerator.

5. The solid oxide fuel cell and gas turbine hybrid power system of claim 4, wherein, The cooling water at the cold fluid side outlets of the first intercooler and the second intercooler is used as electrolysis water and / or heat supply water of the electrolysis cell module.

6. The solid oxide fuel cell and gas turbine hybrid power system of claim 1, wherein, The electrolysis cell module comprises an electrolysis cell, a waste heat exchanger, a hydrogen storage device and an oxygen storage device, electrolysis water enters the electrolysis cell after exchanging heat with air flowed through the hot fluid side of the waste heat exchanger, an electrolysis reaction occurs in the electrolysis cell to generate hydrogen and oxygen, the hydrogen enters the hydrogen storage device for storage, and the oxygen enters the oxygen storage device for storage.

7. The solid oxide fuel cell and gas turbine hybrid power system of claim 6, wherein, The cold fluid side outlet of the intercooler is connected with the cold fluid side inlet of the waste heat exchanger, so that the cooling water flowed through the intercooler is used as electrolysis water of the electrolysis cell module, exchanges heat with air flowed through the hot fluid side of the waste heat exchanger in the waste heat exchanger; and / or A first heat exchanger for heating electrolysis water is arranged between the cold fluid side outlet of the waste heat exchanger and the inlet of the electrolysis cell, a second heat exchanger for cooling hydrogen is arranged between the hydrogen outlet of the electrolysis cell and the hydrogen storage device, and a third heat exchanger for cooling oxygen is arranged between the oxygen outlet of the electrolysis cell and the oxygen storage device.

8. The solid oxide fuel cell and gas turbine hybrid power system of claim 1, wherein, The first combustor and the second combustor are also respectively provided with a fuel inlet through which combustion fuel is fed into the first combustor and the second combustor respectively; a fuel compressor for compressing fuel is connected to the fuel inlet.

9. The solid oxide fuel cell and gas turbine hybrid power system of claim 1, wherein, The first SOFC module and the second SOFC module are identical in structure and each comprises a methane hydrogen production device and a plurality of SOFCs, combustion air and fuel are respectively compressed by compressors and then enter the methane hydrogen production device for reaction, fuel gas generated by the reaction enters the anodes of the plurality of SOFCs in parallel, air enters the cathodes of the plurality of SOFCs in series, and air discharged from the cathode of the most downstream SOFC enters the first combustor and the second combustor respectively.

10. The solid oxide fuel cell and gas turbine hybrid power system of claim 9, wherein, The first SOFC module and the second SOFC module further comprise a fourth heat exchanger and a fifth heat exchanger respectively; the first SOFC module and the second SOFC module each comprise three SOFCs, which are a first SOFC, a second SOFC and a third SOFC respectively; The fuel gas produced by the methane hydrogen production device is divided into three streams, which are a first fuel gas stream, a second fuel gas stream and a third fuel gas stream; the first fuel gas stream enters the first SOFC through a first pipeline, the second fuel gas stream enters the second SOFC through a second pipeline, and the third fuel gas stream enters the third SOFC through a third pipeline; The fourth heat exchanger is arranged on the first pipeline, and the first fuel gas stream in the first pipeline flows through the cold fluid side of the fourth heat exchanger, enters the anode of the first SOFC after heat exchange and temperature rise in the fourth heat exchanger, and flows out of the anode of the first SOFC after reaction in the first SOFC, and then flows through the hot fluid side of the fourth heat exchanger, and returns to the inlet or outlet of the methane hydrogen production device after heat exchange with the first fuel gas stream flowing through the cold fluid side of the fourth heat exchanger; The fifth heat exchanger is arranged on the third pipeline, and the third fuel gas stream in the third pipeline flows through the hot fluid side of the fifth heat exchanger, enters the anode of the third SOFC after heat exchange in the fifth heat exchanger, and flows out of the anode of the third SOFC after reaction, and then returns to the inlet or outlet of the methane hydrogen production device; The ambient air flows through the cold fluid side of the fifth heat exchanger, and after heat exchange with the third fuel gas stream flowing through the hot fluid side of the fifth heat exchanger, enters the cathode of the first SOFC, the cathode of the second SOFC and the cathode of the third SOFC in sequence, and finally is discharged from the air outlet of the third SOFC and enters the first combustor or the second combustor.

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