High-pressure air concentric shunting multi-stage efficient combustion device

Abstract

The invention discloses a high-pressure air concentric shunting multi-stage efficient combustion device, and relates to the technical field of high-pressure air integrated utilization and energy conversion. Air at an outlet of a gas compressor is divided into three strands through a concentric annular flow dividing structure, wherein the core flow enters the first-stage combustion chamber to be directly combusted; after being mixed with fuel, the laminar air is supplied to the anode of the fuel cell under a fuel-rich condition; and after being mixed with a small amount of fuel, the outer-layer flow air is supplied to the cathode of the fuel cell under a lean-burn condition. High-temperature fuel gas exhausted from the primary combustion chamber and the cathode and the anode of the fuel cell enters the secondary combustion chamber through mixing for blending and afterburning, and finally efficient utilization of high-pressure air is achieved. The device optimizes the high-pressure air flow control, fuel mixing and waste heat recovery process through the concentric annular flow division, multi-stage combustion and heat exchange integrated design, remarkably reduces the flow pressure loss, improves the combustion efficiency and the heat energy utilization rate, and is suitable for high-pressure air energy conversion systems such as a gas turbine and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated utilization of high-pressure air and energy conversion, and particularly relates to a high-pressure air concentric shunt multi-stage efficient combustion device between the compressor outlet and the turbine inlet, and is particularly applicable to a combustion system that requires hierarchical distribution of high-pressure air, multi-stage fuel supply, and efficient utilization of heat energy. Background Art

[0002] In recent years, how to utilize high-pressure gas with high performance and high parameters in gas turbines has become a popular research direction in the field of turbine fuel cells. In the current integrated system of traditional gas turbines and fuel cells, the mainstream technology for the integrated utilization of high-pressure gas (the working medium in the section from the compressor outlet to the turbine inlet) mostly adopts a series architecture. The high-pressure air at the compressor outlet is simply shunted to the cathode of the fuel cell and the combustion chamber through a mechanical shunt valve, resulting in the need for the cathode preheating to rely on an external heat source. Due to the independent configuration of the compressor and the turbine, the system has a large volume and redundant flow channels. Factors such as the heat exchange process between the exhaust gas of the high-temperature fuel cell and the gas at the low-temperature compressor outlet are prone to induce heat stress leakage, etc., which will lead to insufficient utilization of high-pressure gas. At the same time, the pressure energy of the high-pressure gas (accounting for 15–20% of the input energy) will cause great energy waste due to the lack of a cascade release mechanism.

[0003] Although some improvement schemes attempt to introduce multi-stage combustion or shunt regulation, their structures are complex, the adjustability is poor, and the coupling degree between the heat exchange and the combustion process is low, still difficult to meet the requirements of efficient energy conversion of high-pressure air. Therefore, there is an urgent need to develop an efficient combustion device that can achieve refined shunting of high-pressure air, hierarchical preheating injection of fuel, and deep utilization of waste heat, so as to improve the energy conversion efficiency and reduce the flow pressure loss. Summary of the Invention

[0004] In view of this, in order to solve the problems such as the flow distribution of high-pressure air in traditional combustion devices and the generally complex structure, insufficient flexibility of air flow regulation, and low heat exchange efficiency in combustion devices, the present invention proposes a high-pressure air concentric shunt multi-stage efficient combustion device, which optimizes the design of the energy conversion section between the compressor outlet and the turbine inlet, realizes refined air shunting, multi-stage combustion process, and high-efficiency heat energy recovery, and improves the energy conversion efficiency and system compactness. This device optimizes the design of the energy conversion section between the compressor outlet and the turbine inlet. The air passing through the compressor outlet is divided into three streams, and combined with the fuel cascade utilization and waste heat recovery technologies, it realizes the compact and efficient combustion of fuel with high efficiency and low emissions.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a high-pressure air concentric diversion multi-stage high-efficiency combustion device, which belongs to an energy conversion module between the compressor outlet and the turbine inlet, including a compressor outlet interface, a concentric annular diversion structure, a primary combustion chamber, a fuel-air heat exchanger, a fuel cell, an extreme heat exchanger, a premixing pipe, a secondary combustion chamber and a turbine inlet interface; the concentric annular diversion structure is connected to the compressor outlet interface, and the concentric annular diversion structure divides the high-pressure air into three channels for transportation, the first stream of air flows through the primary combustion chamber, the second stream of air flows through the fuel-air heat exchanger and the fuel cell anode, and the third stream of air flows through the cathode extreme heat exchanger and the fuel cell cathode, and then the three streams of air enter the premixing pipe together, and then enter the secondary combustion chamber, and finally are discharged from the turbine inlet interface, and the fuel cell is composed of multiple battery units connected in series in a ring to surround the outside of the high-temperature gas pipeline of the primary combustion chamber.

[0006] Furthermore, the concentric annular diversion structure is a multi-layer coaxial annular cavity, which is divided into a core flow channel, a middle layer flow channel and an outer layer flow channel from the inside to the outside. The cross-sections of the core flow channel, the middle layer flow channel and the outer layer flow channel of the concentric annular diversion structure are tapered, and anti-turbulence ribs are provided on the inner wall surface.

[0007] Furthermore, a fixed guide vane group is installed at the front end of the core flow channel, and the rear end is connected to the first-stage combustion chamber. A fuel injection valve I is welded at the front end of the first-stage combustion chamber, and the fuel inlet of the fuel injection valve I is connected to the fuel pump through a pipeline.

[0008] Furthermore, an adjustable guide vane group I is installed at the front end of the intermediate flow pipe, and a fuel-air heat exchanger and a fuel injection valve II are welded in the channel in sequence. The fuel-air heat exchanger is a serpentine metal pipe that surrounds the outer wall of the first-stage combustion chamber. Its fuel inlet is connected to the fuel pump through a pipeline, and the fuel outlet is welded to the inlet of the fuel injection valve II.

[0009] Furthermore, the anode air inlet of the fuel cell is communicated with the middle layer flow channel through the flange interface of the anode control valve.

[0010] Furthermore, the front end of the outer laminar flow channel is equipped with an adjustable guide vane group II, the end of which is welded with a fuel injection valve III, and is connected to the cathode air inlet of the fuel cell through the flange interface of the cathode control valve.

[0011] Furthermore, the air inlet of the premixing pipe is respectively connected to the outlet of the first-stage combustion chamber, the anode outlet of the fuel cell, and the cathode outlet of the fuel cell, and the outlet end is connected to the secondary combustion chamber; a mixing valve is provided at the front end of the premixing pipe, and a swirl blade group is provided in the pipe. The swirl blade group is a spiral guide structure and is evenly distributed along the axial direction of the pipe.

[0012] Further, an axial swirl nozzle is welded to the front end of the secondary combustion chamber, and the rear end is connected to the turbine inlet interface through a flange.

[0013] Further, the adjustable guide vane group I and the adjustable guide vane group II are each composed of a plurality of sector-shaped vanes, and the vane rotating shafts are fixed to the inner wall of the flow channel through bearings.

[0014] Further, the cathode heat exchanger is a plate heat exchanger, whose hot side inlet is connected to the fuel cell cathode outlet, the cold side inlet is connected to the outer flow channel, and the cold side outlet is connected to the cathode control valve.

[0015] Compared with the prior art, the beneficial effects of a high-pressure air concentric shunt multi-stage high-efficiency combustion device described in the present invention are as follows:

[0016] (1) Through the concentric annular shunt structure and the tapered flow channel design, the present invention realizes the three-stage refined distribution of high-pressure air, and combines the adjustable guide vane group to dynamically regulate the flow rate, significantly reducing the flow pressure loss.

[0017] (2) The present invention adopts a series heat recovery method of a fuel-air heat exchanger and a cathode plate heat exchanger, fully utilizes the combustion waste heat to preheat the fuel and air, and improves the system thermal efficiency.

[0018] (3) By applying the synergistic effect of multi-stage combustion and the spiral guide vanes of the premixing pipeline, the present invention ensures the efficient mixing and staged combustion of fuel and air, reduces the local high-temperature area, and reduces pollutant generation.

[0019] (4) The modular structure design of the present invention simplifies the pipeline layout, enhances the compactness and maintainability of the device, and is applicable to various high-pressure air energy conversion scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0021] Figure 1 is a schematic structural diagram of a high-pressure air concentric shunt multi-stage high-efficiency combustion device described in the present invention;

[0022] In the figure: 1 - Concentric annular flow splitting structure; 2 - Fixed guide vane group; 3 - Adjustable guide vane group I; 4 - Adjustable guide vane group II; 5 - Fuel injection valve I; 6 - Primary combustion chamber; 7 - Fuel-air heat exchanger; 8 - Fuel injection valve II; 9 - Anode control valve; 10 - Fuel injection valve III; 11 - Cathode control valve; 12 - Fuel cell; 121 - Fuel cell anode; 122 - Fuel cell cathode; 13 - Cathode end heat exchanger; 14 - Mixing valve; 15 - Premixing pipeline; 16 - Swirl vane group; 17 - Swirl nozzle; 18 - Secondary combustion chamber; 19 - Fuel pump; T1 - Compressor outlet interface; T2 - Turbine inlet interface; P1 - Core flow channel; P2 - Middle layer flow channel; P3 - Outer layer flow channel. Detailed implementation mode

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0024] See Figure 1 Explaining this implementation mode, a high-pressure air concentric flow splitting multi-stage efficient combustion device includes a compressor outlet interface T1, a concentric annular flow splitting structure 1, a primary combustion chamber 6, a fuel-air heat exchanger 7, a fuel cell 12, an extreme heat exchanger 13, a premixing pipeline 15, a secondary combustion chamber 18, and a turbine inlet interface T2; the concentric annular flow splitting structure 1 is connected to the compressor outlet interface T1, and the concentric annular flow splitting structure 1 divides the high-pressure air into three channels for transportation. The first stream of air flows through the primary combustion chamber 6, the second stream of air flows through the fuel-air heat exchanger 7 and the fuel cell anode 121, and the third stream of air flows through the cathode end heat exchanger 13 and the fuel cell cathode 122. Then the three streams of air enter the premixing pipeline 15 together, then enter the secondary combustion chamber 18, and finally are discharged from the turbine inlet interface T2. The fuel cell 12 is surrounded by multiple battery units in a ring series outside the high-temperature gas pipeline of the primary combustion chamber 6.

[0025] The compressor outlet interface T1 is a flange structure, which is connected to an external compressor to receive high-pressure air and introduce it into the concentric annular flow splitting structure 1.

[0026] The concentric annular flow splitting structure 1 is a multi-layer coaxial annular cavity, which divides the air into three independent paths, and is divided into a core flow channel P1, a middle layer flow channel P2, and an outer layer flow channel P3 from the inside to the outside. The cross-sections of the core flow channel P1, the middle layer flow channel P2, and the outer layer flow channel P3 of the concentric annular flow splitting structure 1 are tapered, and anti-turbulence ribs are provided on the inner wall surface to reduce flow loss.

[0027] A fixed guide vane group 2 is installed at the front end of the core flow channel P1, and the rear end is connected to the primary combustion chamber 6. The first stream of air enters the primary combustion chamber 6 through the core flow pipe. A fuel injection valve Ⅰ5 is welded at the front end of the primary combustion chamber 6 for injecting fuel into the combustion chamber. The fuel and the first stream of air are directly mixed and burned in the primary combustion chamber 6. The fuel inlet of the fuel injection valve Ⅰ5 is connected to the fuel pump 19 through a pipeline.

[0028] An adjustable guide vane set I3 is installed at the front end of the intermediate flow pipe P2, whose angle can be adjusted by an external controller to control the air flow. A fuel-air heat exchanger 7 and a fuel injection valve II8 are welded to the channel in sequence. The second stream of air, passing through the intermediate flow pipe P2, is heated by heat radiation from the outer wall of the primary combustion chamber 6 before exchanging heat with the fuel in the fuel-air heat exchanger 7. The fuel is then injected into the channel by the fuel injection valve II8 and delivered to the anode inlet of the fuel cell 12 via the anode control valve 9, where a reduction reaction occurs. The fuel-air heat exchanger 7 is a serpentine metal pipe that encircles the outer wall of the primary combustion chamber 6. Its fuel inlet is connected to the fuel pump 19 via a pipeline, and its fuel outlet is welded to the inlet of the fuel injection valve II8.

[0029] An adjustable guide blade group II4 is installed at the front end of the outer laminar flow channel P3, and the angle can be reasonably adjusted by an external controller to control the air flow. A fuel injection valve III10 is welded at the end to inject fuel into the channel. The third stream of air is mixed with the fuel and enters the cathode air inlet of the fuel cell 12 through the cathode control valve 11 to participate in the oxidation reaction at the cathode.

[0030] The air inlet of the premixing pipe 15 is connected to the outlet of the primary combustion chamber 6, the outlet of the fuel cell anode 121, and the outlet of the fuel cell cathode 122, respectively. It receives the high-temperature fuel gas from the outlet of the primary combustion chamber 6 and the exhaust from the anode and cathode of the fuel cell 12. The outlet end is connected to the secondary combustion chamber 18. The front end of the premixing pipe 15 is equipped with a mixing valve 14, and a swirl blade group 16 is installed in the pipe to ensure that the three airflows are fully mixed before entering the secondary combustion chamber 18. The swirl blade group 16 has a spiral guide structure and is evenly distributed along the axial direction of the pipe.

[0031] The front end of the secondary combustion chamber 18 is welded with an axial swirl nozzle 17, which is connected to the fuel pump 19 through a fuel delivery channel and injects a small amount of fuel for supplementary combustion to increase the temperature and pressure of the gas. The high-temperature and high-pressure gas after supplementary combustion can drive the turbine to do work; the rear end is connected to the turbine inlet interface T2 through a flange.

[0032] The adjustable guide blade group I3 and the adjustable guide blade group II4 are respectively composed of a plurality of fan-shaped blades, and the blade shafts are fixed to the inner wall of the flow channel through bearings.

[0033] The cathode-side heat exchanger 13 is a plate heat exchanger, whose hot-side inlet is connected to the outlet of the fuel cell cathode 122, the cold-side inlet is connected to the outer laminar flow channel P3, and the cold-side outlet is connected to the cathode control valve 11.

[0034] The driving ends of the adjustable guide vane group I 3, the adjustable guide vane group II 4, the anode control valve 9 and the cathode control valve 11 are connected to an external controller through mechanical linkages.

[0035] The fuel inlets of the fuel injection valve I 5, the fuel injection valve II 8 and the fuel injection valve III 10 are respectively connected to the fuel pump 19 through independent pipelines. The fuel supply at the inlet of the fuel-air heat exchanger 7 and the fuel supply of the swirl nozzle 17 are also regulated by the fuel pump 19 through independent pipelines to ensure that the fuel distribution ratio matches the load demand.

[0036] The fuel cell 12 is arranged in a ring in series by multiple fuel cell units on the outer side of the high-temperature gas pipeline of the primary combustion chamber 6, and uses the radiant heat of the high-temperature gas in the primary combustion chamber 6 to provide heat insulation for the electrochemical reaction, reducing the external heating energy consumption.

[0037] The specific operation process and working principle of a high-pressure air concentric diversion multi-stage high-efficiency combustion device according to the present invention are as follows:

[0038] In the present invention, the high-pressure air at the outlet of the compressor is divided into three streams through the concentric annular diversion structure 1: the core stream air enters the primary combustion chamber 6 and directly burns with the fuel to generate high-temperature gas; the middle laminar air preheats the fuel through the fuel-air heat exchanger 7 and then mixes with the middle laminar air and is supplied to the anode 121 of the fuel cell under fuel-rich conditions; the outer laminar air is preheated by the cathode-side heat exchanger 13 and then mixes with a small amount of fuel and is supplied to the cathode 122 of the fuel cell under fuel-lean conditions. The fuel cell 12 is arranged in a ring in series by multiple cell units to surround the high-temperature gas pipeline of the primary combustion chamber 6 and uses its heat radiation for heat insulation. The fuel undergoes fuel-rich and fuel-lean combustion at the anode and cathode respectively. The high-temperature gas in the primary combustion chamber 6 and the exhaust gases from the anode and cathode of the fuel cell 12 are fully mixed through the premixing pipeline 15 and then enter the secondary combustion chamber 18 for afterburning to increase the temperature and pressure. The adjustable guide vanes independently control the air flow rate in each flow channel, and the fuel injection valve I 5, the fuel injection valve II 8, the fuel injection valve III 10 and the swirl nozzle 17 are connected to the fuel pump 19 to accurately regulate the fuel distribution.

[0039] The present invention significantly improves the energy utilization efficiency and reduces pollutant emissions through multi-stage diversion, fuel preheating and electrochemistry-combustion coordination.

[0040] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. According to the content of this specification, many modifications and variations can be made. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention.

Claims

1. A high-pressure air concentric shunt multi-stage efficient combustion device, characterized in that: It includes a compressor outlet interface (T1), a concentric annular flow splitting structure (1), a primary combustion chamber (6), a fuel-air heat exchanger (7), a fuel cell (12), a cathode heat exchanger (13), a premixing pipe (15), a secondary combustion chamber (18) and a turbine inlet interface (T2); the concentric annular flow splitting structure (1) is connected to the compressor outlet interface (T1), and the concentric annular flow splitting structure (1) divides the high-pressure air into three channels for transportation. The first stream of air flows through the primary combustion chamber (6), the second stream of air flows through the fuel-air heat exchanger (7) and the anode of the fuel cell (121), and the third stream of air flows through the cathode heat exchanger (13) and the cathode of the fuel cell (122). Then the three streams of air enter the premixing pipe (15) together, then enter the secondary combustion chamber (18), and finally discharge from the turbine inlet interface (T2). The fuel cell (12) is surrounded by multiple battery units in a ring in series around the outer side of the high-temperature gas pipeline of the primary combustion chamber (6).

2. The high-pressure air concentric diversion multi-stage efficient combustion device according to claim 1, wherein: The concentric annular flow splitting structure (1) is a multi-layer coaxial annular cavity, which is divided into a core flow channel (P1), a middle flow channel (P2) and an outer flow channel (P3) from the inside to the outside. The cross-sections of the core flow channel (P1), the middle flow channel (P2) and the outer flow channel (P3) of the concentric annular flow splitting structure (1) are tapered, and anti-turbulence rib strips are provided on the inner wall surface.

3. The high-pressure air concentric shunt multi-stage high-efficiency combustion device according to claim 2, wherein: A fixed guide vane group (2) is installed at the front end of the core flow channel (P1), and the rear end is connected to the primary combustion chamber (6). A fuel injection valve I (5) is welded to the front end of the primary combustion chamber (6), and the fuel inlet of the fuel injection valve I (5) is connected to a fuel pump (19) through a pipeline.

4. The high-pressure air concentric diversion multi-stage efficient combustion device according to claim 2, characterized in that: An adjustable guide vane group I (3) is installed at the front end of the intermediate flow pipe (P2). A fuel-air heat exchanger (7) and a fuel injection valve II (8) are welded in the channel in sequence. The fuel-air heat exchanger (7) is a serpentine metal pipe that surrounds the outer wall of the primary combustion chamber (6). Its fuel inlet is connected to a fuel pump (19) through a pipeline, and the fuel outlet is welded to the inlet of the fuel injection valve II (8).

5. The high-pressure air concentric diversion multi-stage high-efficiency combustion device according to claim 4, wherein: [[ID= 6. The high-pressure air concentric shunt multi-stage high-efficiency combustion device according to claim 2, characterized in that: ​ 7. The high-pressure air concentric shunt multi-stage high-efficiency combustion device according to claim 1, characterized in that: ​ 8. The high-pressure air concentric diversion multi-stage high-efficiency combustion device according to claim 6, characterized in that: ​ 9. The high-pressure air concentric shunt multi-stage high-efficiency combustion device according to claim 4 or 6, characterized in that: The adjustable guide vane set Ⅰ (3) and the adjustable guide vane set Ⅱ (4) are each composed of a plurality of sector-shaped vanes, and the vane rotating shafts are fixed to the inner wall of the flow channel through bearings.

10. The high-pressure air concentric diversion multi-stage high-efficiency combustion device according to claim 1, characterized in that: The cathode heat exchanger (13) is a plate heat exchanger, the hot-side inlet of which is connected to the outlet of the fuel cell cathode (122), the cold-side inlet is connected to the outer flow channel (P3), and the cold-side outlet is connected to the cathode control valve (11).

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