Micro-scale pulse detonation thurstor and cell stack power system

Abstract

The application discloses a micro-scale pulse detonation Tesla turbine shaft engine and a unit stack type power system, and relates to the field of engine technology.The micro-scale pulse detonation Tesla turbine shaft engine comprises a micro-scale pulse detonation combustion chamber and a Tesla turbine.The micro-scale pulse detonation combustion chamber is used for generating airflow pulses and comprises a spiral channel.The spiral channel outlet end of the Tesla turbine and the micro-scale pulse detonation combustion chamber is connected in communication, used for converting kinetic energy of the airflow pulses into shaft work for output, and providing an initial explosion pressure for the micro-scale pulse detonation combustion chamber.The micro-scale pulse detonation Tesla turbine shaft engine uses a micro-scale pulse detonation tube to replace a nozzle which limits the efficiency of the Tesla turbine, and uses a Tesla turbine to replace a conventional blade turbine to convert the energy of the strong pulsation characteristic detonation gas, so that the efficiency of the detonation turbine engine is improved.

Description

Technical Field

[0001] This invention relates to the field of detonation turbine engine technology, specifically to a microscale pulse detonation Tesla turboshaft engine and a unitary reactor power system. Background Technology

[0002] With the development of the hydrogen energy industry, the requirements for methods to convert hydrogen energy into electrical and mechanical energy are increasing. Existing hydrogen fuel cells have become the core of development due to their high efficiency and cleanliness, but their high cost and short lifespan significantly limit their widespread adoption. Currently, Japan's high-power-density third-generation metal stack PEM fuel cells have a power output of approximately 4 kW / L, which is still significantly lower than that of ordinary internal combustion engines with power outputs of hundreds of kilowatts per liter. Therefore, fuel cells are still unable to handle high-load, high-performance operating conditions. However, traditional internal combustion engines are not suitable for direct hydrogen combustion: for reciprocating hydrogen internal combustion engines, in-cylinder knocking is difficult to resolve, and the low volume density of hydrogen results in a significant reduction in power output for the same displacement; for gas turbines, the extremely high flame propagation speed of hydrogen makes backfire prone to occur during premixed combustion, therefore, gas turbines based on strong swirl premixed combustors cannot currently adapt to pure hydrogen fuel. Furthermore, the long residence time of high-temperature gas in traditional internal combustion engines leads to high NOx emissions when using hydrogen as fuel, requiring exhaust gas treatment.

[0003] Hydrogen is a zero-carbon fuel that readily produces detonation combustion. In the field of internal combustion engine research, almost all existing hydrogen combustion studies focus on suppressing detonation, and utilizing hydrogen detonation may be a future research direction for internal combustion engines. Engines based on pulse detonation combustion are favored by researchers due to their high theoretical thermal cycle efficiency (approximately isochoric cycle), high power density, low NOx emissions, simple structure, and ease of miniaturization, making them an ideal method for high-performance hydrogen energy applications.

[0004] Among existing pulse detonation engine technologies, besides pure pulse detonation engines that directly use the products of detonation combustion for propulsion, there are many concepts that combine pulse detonation combustors with traditional turbine engines. These engines have a wider range of applications. Pulse detonation combustors can replace the isobaric combustion chambers or afterburners in traditional turbine engines, or they can be added separately to the bypass duct of turbofan engines; these concepts all belong to the category of detonation turbine engines. The main purpose of this type of engine design is to utilize the self-pressurizing characteristics of detonation combustion to increase the combustion pressure in the combustion chamber, thereby improving engine thermal efficiency and reducing fuel consumption. However, many studies have shown that although detonation combustion has advantages over isobaric combustion, traditional bladed turbines have low energy conversion efficiency for detonation gases and are prone to damage. Therefore, the matching problem between the detonation combustor and the turbine urgently needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a microscale pulse detonation Tesla turboshaft engine to improve the efficiency of detonation turbine engines.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a microscale pulse detonation Tesla turboshaft engine, comprising a microscale pulse detonation combustion chamber and a Tesla turbine;

[0008] The microscale pulse detonation combustion chamber is used to generate airflow pulses, including a spiral channel;

[0009] The Tesla turbine and the spiral channel outlet of the microscale pulse detonation combustion chamber are connected to each other, which is used to convert the kinetic energy of the airflow pulse into shaft work for output, and to provide the initial detonation pressure for the microscale pulse detonation combustion chamber.

[0010] Furthermore, an enthalpy adjustment groove is provided at the top of the spiral channel wall, and a flexible material is embedded inside the enthalpy adjustment groove.

[0011] Furthermore, the perimeter of the cross-section of the spiral channel ranges from 1 mm to 300 mm.

[0012] Furthermore, the microscale pulse detonation combustion chamber also includes a spark plug and an air intake port, which are located in the space at the center of the spiral channel.

[0013] Furthermore, the Tesla turbine includes a turbine rotor and a volute; the turbine rotor is installed in the volute, and the turbine rotor includes a main shaft, a bottom plate, an upper plate, and a through support. The bottom plate is thicker than the upper plate. The main shaft is fixed in the center hole of the bottom plate. The through support is fixed on the bottom plate in a ring array. At least two upper plates are provided, arranged coaxially and parallel to each other without contact, and fixed on the through support.

[0014] Furthermore, the main shaft is equipped with a guide cone, and the through support between the upper discs is equipped with a spacing adjustment shim.

[0015] Furthermore, the spacing between two adjacent upper disks shall not exceed 3 mm.

[0016] Furthermore, the initial detonation pressure within the helical channel is higher than atmospheric pressure, and the pulse detonation frequency within a single helical channel does not exceed 300Hz; the operating speed of the Tesla turbine does not exceed 200,000rpm.

[0017] Furthermore, the microscale pulse detonation Tesla turboshaft engine also includes auxiliary equipment, which includes an auxiliary motor, a fuel source, a compressed air source, a premixing device, and an electronic control system.

[0018] The auxiliary motor and the main shaft of the Tesla turbine are driven by each other;

[0019] The premixing device is connected to the fuel source and the compressed air source respectively. The output port of the premixing device is connected to the air inlet of the spiral channel. A gas intake control valve is installed on the connected pipeline.

[0020] The compressed air source is also connected to the air inlet of the spiral channel, and an isolation air inlet control valve is installed on the connected pipeline.

[0021] The electronic control system is used to control the opening and closing of the gas intake control valve and the isolation gas intake control valve.

[0022] Secondly, the present invention provides a unit-type power system, including any of the microscale pulse detonation Tesla turboshaft engines described above. A single microscale pulse detonation Tesla turboshaft engine is used as the smallest power unit, namely a microscale pulse detonation Tesla turboshaft power unit (PDTTU). By constructing a "unit-type" system and using unit parallel, frequency conversion, and start-stop control methods, the system power is amplified and regulated.

[0023] Compared with the prior art, the advantages of this invention are as follows:

[0024] 1. In the field of Tesla turbines, this invention uses a microscale pulse detonation tube to replace the nozzle that limits the efficiency of Tesla turbines, thereby making Tesla turbines more efficient.

[0025] 2. In the field of detonation turbine engines, this invention uses a Tesla turbine instead of a traditional blade turbine, which makes the initial detonation pressure in the channel higher than atmospheric pressure, and transfers most of the kinetic energy of the detonation gas during the pulsation cycle to the disk through viscous force under microscale conditions, making the energy conversion efficiency of the detonation gas higher, while improving the life of the detonation combustion chamber and the turbine.

[0026] 3. In the field of hydrogen energy applications, this invention provides a power device based on hydrogen detonation combustion, which improves the power density of hydrogen energy power devices and reduces NOx emissions from hydrogen-fired heat engines.

[0027] 4. In the field of internal combustion engines, this invention provides a micro heat engine solution based on microscale pulse detonation combustion, which has higher power density and efficiency than traditional micro heat engines. By building a "unit stack" type system, it can achieve extremely strong variable load performance and better emission characteristics without changing the combustion conditions.

[0028] In summary, this invention features high thermal efficiency, high power density, strong variable load performance, low NOx emissions, and wide applicability, which can help realize low-cost, high-performance applications of new energy sources such as hydrogen energy. Attached Figure Description

[0029] Figure 1 A schematic diagram of the matching structure between a microscale pulse detonation combustion chamber and a micro Tesla turbine;

[0030] Figure 2 This is a schematic diagram of the three-dimensional structure and airflow path of the combustion chamber and turbine cross-section;

[0031] Figure 3 A schematic diagram of the auxiliary equipment required for a microscale pulse detonation Tesla turboshaft engine;

[0032] Figure 4 A schematic diagram of the startup process and working cycle of a microscale pulse detonation Tesla turboshaft engine;

[0033] Figure 5 A schematic diagram of a microscale pulse detonation Tesla turboshaft engine "unit stack" type system;

[0034] Explanation of reference numerals in the attached diagram: 1. Microscale pulse detonation combustion chamber; 2. Spark plug; 3. Intake port; 4. Helical channel; 5. Extra enthalpy regulating groove; 6. Volute; 7. Through-support; 8. Main shaft; 9. Upper plate; 10. Bottom plate; 11. Tesla turbine; 12. Engine cover; 13. Spark plug screw hole; 14. Turbine exhaust port; 15. Auxiliary motor; 16. Microscale pulse detonation Tesla turboshaft engine (six combustion chambers); 17. Fuel source; 18. Compressed air source; 19. Premixing device; 20. Gas intake control valve; 21. Electronic control system; 22. Matching structure of six combustion chambers and turbine; 23. Isolation gas intake control valve. Detailed Implementation

[0035] Example:

[0036] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] See Figure 1-3 As shown, the microscale pulse detonation Tesla turboshaft engine 16 provided in this embodiment mainly includes a microscale pulse detonation combustion chamber 1 and a micro Tesla turbine 11. The microscale pulse detonation combustion chamber 1 is used to generate high-speed airflow pulses and includes a helical channel 4. The micro Tesla turbine 11 and the outlet end of the helical channel 4 of the microscale pulse detonation combustion chamber 1 are connected to convert the kinetic energy of the high-speed airflow pulse into shaft work for output, and to provide initial detonation pressure for the microscale pulse detonation combustion chamber. Specifically, the gas flow paths in the microscale pulse detonation combustion chamber 1 and the Tesla turbine 11 are as follows: Figure 2 As indicated by the middle arrow,

[0038] Therefore, the microscale pulse detonation Tesla turboshaft engine provided in this embodiment adopts the DDT (Deflagration to Detonation Transition) and fluid viscosity force work principle, sets up a microscale pulse detonation combustion chamber and a micro Tesla turbine, uses a microscale pulse detonation tube to replace the nozzle that limits the efficiency of the Tesla turbine, and uses a Tesla turbine to replace the traditional blade turbine to convert the energy of the highly pulsating detonation gas, thereby improving the efficiency of the detonation turbine engine.

[0039] In one specific embodiment, the initial detonation pressure (static pressure) in the helical channel 4 is higher than atmospheric pressure, the pulse detonation frequency in a single helical channel 4 does not exceed 300Hz, and the operating speed range of the Tesla turbine 11 does not exceed 200,000rpm.

[0040] In one specific embodiment, the microscale pulse detonation combustion chamber 1 includes a spark plug 2, an air inlet 3, and an enthalpy adjustment groove 5 in addition to the helical channel 4. The spark plug 2 and the air inlet 3 are located in the space at the center point of the helix of the helix channel 4. The cross-section of the helix channel 4 can be rectangular, elliptical, or other closed shapes. The perimeter of the cross-section ranges from 1 mm to 300 mm. The size and shape of the cross-section can gradually change at different positions of the helix. The enthalpy adjustment groove 5 is located at the top of the wall of the helix channel 4, and flexible material can be embedded inside to suppress air leakage between adjacent channels.

[0041] In one specific embodiment, the Tesla turbine 11 includes a turbine rotor and a volute 6. The turbine rotor is installed in the volute 6 and includes a main shaft 7, a bottom disk 8, an upper disk 9, and a through-support 10. The bottom disk 8 is thicker than the upper disk 9. The main shaft 7 is fixed in the center hole of the bottom disk 8. The through-support 10 is fixed on the bottom disk in a circular array. Two or more upper disks 9 are arranged coaxially and parallel to each other without contact and are fixed on the through-support 10. The distance between adjacent upper disks 9 does not exceed 3 mm, and the outer diameter of the bottom disk 8 and the upper disks 9 does not exceed 300 mm. In addition, the main shaft 7 may be equipped with a guide cone to guide the exhaust gas out of the Tesla turbine and improve exhaust performance. The through-support 10 between the upper disks 9 may be equipped with a spacing adjustment shim to adjust the distance between two adjacent upper disks 9. The Tesla turbine rotor may also be a spoke structure.

[0042] In one specific embodiment, the microscale pulse detonation combustion chamber 1 and the Tesla turbine 11 are sealed by a cover 12, which may have spark plug holes, air intake holes, turbine exhaust holes, heat dissipation fins, etc. The spark plug 2 and air intake hole 3 may be arranged on the bottom material of the space at the center point of the microscale pulse detonation combustion chamber spiral, or they may be arranged on the sealed cover of the microscale pulse detonation combustion chamber and the micro Tesla turbine.

[0043] In one specific embodiment, such as Figure 3 As shown, the microscale pulse detonation Tesla turboshaft engine 16 includes auxiliary equipment in addition to the main body. The auxiliary equipment consists of an auxiliary motor 15, a fuel source 17, a compressed air source 18, a premixing device 19, a gas intake control valve 20, an isolation gas intake control valve 23, and an electronic control system 21. The fuel source can be hydrogen, liquid hydrogen, ethylene, acetylene, propane, ethane, methane, gasoline, or other detonable fuels. In this embodiment, the fuel source 17 is high-pressure hydrogen. The main body of the microscale pulse detonation Tesla turboshaft engine 16 consists of six microscale pulse detonation combustion chambers 1 and one micro Tesla turbine 11. Its structure is a six-combustion-chamber and turbine matching structure 22.

[0044] The startup process and working cycle of a single combustion chamber in a microscale pulse detonation Tesla turboshaft engine are as follows: Figure 4 As shown, before starting the engine, the auxiliary equipment should be started in advance. After the compressed air source 18 reaches a stable storage pressure, the first air flows to the premixing device 19, the second air flows to the isolation gas intake control valve 23 as isolation gas, and the third air supplies air bearings and other components. The fuel source 17 flows to the premixing device 19 through storage pressure or pumping to mix with the first air to form a combustible premixed gas with a set equivalent ratio. The combustible premixed gas flows to the fuel gas intake control valve 20. The total pressure of the combustible premixed gas is not less than the total pressure of the isolation gas. The electronic control system 21 is energized. At this time, the auxiliary equipment has started. Subsequently, the electronic control system 21 opens the isolation gas intake control valve 23 to allow isolation gas to enter the spiral channel 4. The gas flow in the spiral channel 4 is as follows: Figure 2As indicated by the arrow, the electronic control system 21 drives the auxiliary motor 15 to increase its speed to the starting speed. At this time, the airflow in the flow channel between the upper disks 9 of the Tesla turbine generates a radial pressure gradient due to centrifugal motion, causing the pressure at the outer diameter of the Tesla turbine rotor to increase. At this time, the isolation airflow velocity in the helical channel 4 slows down and the static pressure rises. When the static pressure reaches the set detonation pressure, the microscale pulse detonation Tesla turboshaft engine 16 starts. Then, the electronic control system 21 instantly opens the gas intake control valve 20 and closes the isolation gas intake control valve 23. After a suitable amount of combustible premixed gas enters the helical channel 4, the electronic control system 21 immediately closes the gas intake control valve 20. When the high-pressure combustible premixed gas expands and fills the helical channel 4 and the static pressure drops to the set detonation pressure, the electronic control system 21 sends an ignition signal to the spark plug 2. Figure 2 As shown, after the combustible premixed gas is ignited from the center, the deflagration flame propagates along the spiral channel 4. Through stretching and shock wave convergence, the deflagration flame rapidly transforms into detonation combustion, forming a high-speed airflow pulse. This high-speed airflow pulse further expands and accelerates at the variable cross-section of the spiral channel 4 before entering the upper disks 9 of the Tesla turbine. The high-speed airflow pulse applies a force to the upper disks 9 using fluid viscosity. This force passes sequentially through the upper disks 9, the through-support 7, the bottom disk 10, and the main shaft 8 before being output to the outside. This force can drive the auxiliary motor 15 to generate electricity or be output as shaft power. After the kinetic energy of the airflow pulse decreases to a lower level, it exits from the upper disks 9. The gas flows out from the center and is discharged into the atmosphere. At this time, the first working cycle of the microscale pulse detonation Tesla turboshaft engine 16 after starting is completed. The second working cycle begins when the electronic control system 21 opens the isolation gas intake control valve 23 to allow the isolation gas to re-enter the channel. Since the Tesla turbine rotor is already running at the starting speed, the isolation gas will directly reach the set detonation pressure after entering and purging the spiral channel 4. Then, the combustible premixed gas is filled and ignited to complete the second working cycle. The second working cycle is then repeated. At this time, the microscale pulse detonation Tesla turboshaft engine 16 enters the working cycle.

[0045] The six combustion chambers of the microscale pulse detonation Tesla turboshaft engine 16 are all started in the manner described above and operate with a certain phase difference. By adjusting the pressure of the premixing device 19, the pressure of the isolation gas, the speed of the Tesla turbine main shaft 8, the opening time of the gas intake control valve 20 and the isolation gas intake control valve 23, and the ignition phase and cycle of the spark plug 2, the operating frequency and detonation pressure of the pulse detonation combustion chamber can be controlled, thereby realizing the variable frequency and variable load operation of a single unit.

[0046] A microscale pulse detonation Tesla turboshaft engine 16, an auxiliary motor 15, a gas intake control valve 20, an isolation gas intake control valve 23, and an electronic control system 21 can form a power generation type microscale pulse detonation Tesla turboshaft power unit (PDTTU), such as... Figure 5As shown, multiple microscale pulse detonation Tesla turboshaft power units are assembled into a "unit stack" type system. By using the engine parallel operation, frequency conversion, and start-stop method, the system power output is amplified and regulated. This can achieve extremely strong variable load performance and better emission characteristics without changing the combustion conditions.

[0047] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A microscale pulse detonation Tesla turboshaft engine, characterized in that, Including microscale pulse detonation combustion chambers and Tesla turbines; The microscale pulse detonation combustion chamber is used to generate airflow pulses and includes a helical channel with a gradually expanding outlet; the perimeter of the cross-section of the helical channel ranges from 1 mm to 300 mm. The Tesla turbine and the spiral channel outlet of the microscale pulse detonation combustion chamber are connected to each other, which is used to convert the kinetic energy of the airflow pulse into shaft work for output, and to provide the initial detonation pressure for the microscale pulse detonation combustion chamber. An extra-enthalpy regulating groove is provided at the top of the spiral channel wall, and a flexible material is embedded inside the extra-enthalpy regulating groove; The Tesla turbine includes a turbine rotor and a volute; the turbine rotor is installed in the volute, and the turbine rotor includes a main shaft, a bottom plate, an upper plate, and a through support. The bottom plate is thicker than the upper plate. The main shaft is fixed in the center hole of the bottom plate. The through support is fixed on the bottom plate in a ring array. At least two upper plates are provided, arranged coaxially and parallel to each other without contact and fixed on the through support. The distance between two adjacent upper disks shall not exceed 3mm.

2. The microscale pulse detonation Tesla turboshaft engine as described in claim 1, characterized in that, The microscale pulse detonation combustion chamber also includes a spark plug and an air intake port, which are located in the space at the center of the spiral channel.

3. The microscale pulse detonation Tesla turboshaft engine as described in claim 1, characterized in that, The main shaft is equipped with a flow guide cone, and the through support between the upper disks is equipped with a spacing adjustment shim.

4. The microscale pulse detonation Tesla turboshaft engine as described in claim 1, characterized in that, The initial detonation pressure in the spiral channel is higher than atmospheric pressure, and the pulse detonation frequency in a single spiral channel does not exceed 300Hz; the operating speed of the Tesla turbine does not exceed 200,000rpm.

5. The microscale pulse detonation Tesla turboshaft engine as described in claim 1, characterized in that, It also includes auxiliary equipment, which includes an auxiliary motor, a fuel source, a compressed air source, a premixing device, and an electronic control system; The auxiliary motor and the main shaft of the Tesla turbine are driven by each other; The premixing device is connected to the fuel source and the compressed air source respectively. The output port of the premixing device is connected to the air inlet of the spiral channel. A gas intake control valve is installed on the connected pipeline. The compressed air source is also connected to the air inlet of the spiral channel, and an isolation air inlet control valve is installed on the connected pipeline. The electronic control system is used to control the opening and closing of the gas intake control valve and the isolation gas intake control valve.

6. A unitary reactor power system, characterized in that, Including the microscale pulse detonation Tesla turboshaft engine as described in any one of claims 1-4, a single microscale pulse detonation Tesla turboshaft engine is used as the smallest power unit, and the system power is amplified and regulated by constructing a unit stack system and using unit parallel, frequency conversion, start-stop control methods.

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