Double-circulation combined power system of split-flow heat storage type X-type rotor engine

Abstract

The invention provides a double-circulation combined power system of a split-flow heat storage type X-type rotor engine, which comprises the X-type rotor engine, the X-type rotor engine takes pure hydrogen as fuel, high-temperature tail gas of the X-type rotor engine is split into two parts through a split-flow valve II and then is introduced into an EGR (Exhaust Gas Recirculation) system, and the EGR system is connected with an external motor. The X-type rotor engine is adopted to solve the problems that a Wankel rotor engine is high in oil consumption, prone to abrasion and leakage and the like, and meanwhile pure hydrogen serves as fuel, so that oxycarbide emission and SOOT emission generated by combustion of traditional fossil fuel can be directly eliminated. And with the assistance of an EGR tail gas circulating system, NOx pollutant emission can be further reduced while the indicating heat efficiency of the engine is improved, tail gas waste heat of the rotor engine can be stored, power generation is conducted through the tail gas waste heat, and therefore the heat efficiency of a power system is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of internal combustion engine power, and in particular to a dual-cycle combined power system of a split-flow heat storage X-type rotor engine. Background Art

[0002] The development of small UAVs cannot be separated from the support of power systems. In view of the use characteristics, combat requirements, flight performance, etc. of distributed coordinated attack weapon systems, the basic capabilities and characteristics of the power unit of small UAVs should include: high-altitude rapid start capability, low fuel consumption and power extraction capability under long flight time, efficient propulsion capability, and safety and reliability of the use of power units. In the selection of power units for small UAVs, a variety of power systems such as electric motors, piston engines, turbojet engines, and rotary engines can be used. Among them, electric motors are only suitable for small, low-speed, and short-range flight platforms; piston engines are suitable for low-speed, medium- and low-altitude long-flight patrol weapon platforms, but are limited by low power-to-weight ratio and insufficient load; turbojet engines are suitable for medium- and high-altitude, high-speed patrol weapon platforms, but have high fuel consumption and short flight time. The rotary engine has outstanding advantages such as few components, compact structure, low vibration and noise, and high power-to-weight ratio. It has excellent performance in the power unit of small and low-cost UAVs and is very suitable for use in the power system of distributed coordinated attack small UAVs.

[0003] However, rotary engines mostly burn traditional fuel, and the special high-altitude, low-pressure environment of aviation rotary engines, as well as their narrow and long combustion chambers, lead to incomplete combustion, resulting in high fuel consumption, serious pollution emissions, difficult sealing, low thermodynamic efficiency and other problems. They even faded out of the history of internal combustion engines. Therefore, it is very important to improve the rotary engine to achieve higher exhaust gas utilization and thermal efficiency.

[0004] The triangular rotor engine is a triangular rotor engine designed by German scientist Wankel, also known as the Wankel rotor engine. As a branch of the internal combustion engine, it is significantly different from the reciprocating piston engine. It does not rely on the crank-connecting rod mechanism of the reciprocating piston engine, but directly drives the eccentric crankshaft to rotate to perform work through its internal rotor. It has the advantages of compact structure, small size, uniform torque, low noise, and high power-to-weight ratio. It has obvious advantages in the fields of hybrid electric vehicles, range extenders, and small drones, but it also has structural defects such as narrow combustion chambers and mutual leakage between combustion chambers. It has problems such as high fuel consumption, difficult sealing, and low thermodynamic efficiency. The X-type rotor engine has high fuel consumption and low thermodynamic efficiency. At the same time, it will bring about incomplete combustion, resulting in increased emissions of hydrocarbons (HC), carbon monoxide (CO), and carbon dioxide (CO2) that are not completely burned in the X-type rotor engine. However, improving the combustion performance of the X-type rotor engine will cause NOx emissions, and the X-type rotor engine will also produce carbon smoke emissions during the combustion process. For the X-type rotor engine, the high-temperature exhaust gas generated by its combustion process is directly discharged into the atmosphere, which will also cause an increase in the greenhouse effect and low thermal efficiency of the engine. However, the existing X-type rotor engine exhaust gas recovery technology has received little attention. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention proposes a dual-cycle combined power system of a split-flow heat storage X-type rotor engine, which uses an X-type rotor engine to solve many problems of the Wankel rotor engine, such as high fuel consumption, easy wear and leakage, while pure hydrogen as a fuel can directly eliminate carbon oxide emissions and SOOT emissions generated by the combustion of traditional fossil fuels. The EGR exhaust gas circulation system can further reduce NOx pollution emissions while improving the indicated thermal efficiency of the engine, and can store the exhaust waste heat of the rotor engine and use the exhaust waste heat to generate electricity, thereby further improving the thermal efficiency of the power system.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a dual-cycle combined power system of a split-flow heat storage X-type rotor engine, comprising an X-type rotor engine, wherein the X-type rotor engine uses pure hydrogen as fuel, and the high-temperature exhaust gas of the X-type rotor engine is split into two parts by a splitter valve 1, one part is mixed with the fuel of the X-type rotor engine and sent into the X-type rotor engine, and the other part is split into two parts by a splitter valve 2 and then introduced into an EGR circulation system, and the EGR circulation system is connected to an external motor.

[0007] Furthermore, the equivalence ratio of the X-rotor engine is 0.6~1.0.

[0008] Furthermore, it also includes a mixing valve 1 and a mixing valve 2. The mixing valve 1 is used to mix hydrogen and air to obtain a mixed gas, and the mixing valve 2 is used to mix the mixed gas and a part of the high-temperature exhaust gas diverted by the diverter valve 1, and send the mixed gas into the X-type rotor engine.

[0009] Furthermore, the high temperature exhaust gas is diverted through the diverter valve 1 at an EGR rate of 5% to 20%.

[0010] Furthermore, the EGR circulation system includes a first-stage heat storage reheater, a second-stage heat storage reheater and an evaporator, wherein the high-temperature exhaust gas of the X-type rotor engine is split into two parts by a second diverter valve, one part of which is used as a heating medium and passes through the first-stage heat storage reheater, the second-stage heat storage reheater and the evaporator in sequence, and the other part of the exhaust gas is used as a heating medium and passes through the evaporator.

[0011] Furthermore, it also includes a high-pressure stage turbine, a medium-pressure stage turbine, a low-pressure stage turbine, a condenser and a working fluid pump, the outlet of the working fluid pump is connected to the organic working fluid inlet of the evaporator, the organic working fluid outlet of the evaporator is connected to the inlet of the high-pressure stage turbine, the first outlet of the high-pressure stage turbine is connected to the inlet of the medium-pressure stage turbine, the first outlet of the medium-pressure stage turbine is connected to the inlet of the low-pressure stage turbine, the outlet of the low-pressure stage turbine is connected to the inlet of the condenser, and the outlet of the condenser is connected to the inlet of the working fluid pump.

[0012] Furthermore, under low power load conditions, the first outlet of the high-pressure stage turbine is connected to the inlet of the medium-pressure stage turbine through valve one, and the first outlet of the medium-pressure stage turbine is connected to the inlet of the low-pressure stage turbine through valve two.

[0013] Furthermore, the second outlet of the high-pressure stage turbine is connected to the organic working fluid inlet of the first-stage heat storage reheater, and the organic working fluid outlet of the first-stage heat storage reheater is connected to the inlet of the medium-pressure stage turbine; the second outlet of the medium-pressure stage turbine is connected to the organic working fluid inlet of the second-stage heat storage reheater, and the organic working fluid outlet of the second-stage heat storage reheater is connected to the inlet of the low-pressure stage turbine.

[0014] Furthermore, under high power load conditions, the second outlet of the high-pressure stage turbine is connected to the organic working fluid inlet of the first-stage heat storage reheater through valve three; the second outlet of the medium-pressure stage turbine is connected to the organic working fluid inlet of the second-stage heat storage reheater through valve four.

[0015] Furthermore, the high-pressure stage turbine, the medium-pressure stage turbine and the low-pressure stage turbine are all connected to an external motor.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: The present invention provides a dual-cycle combined power system of a split-flow heat storage X-type rotor engine. The X-type rotor engine has the characteristics of high power-to-weight ratio, high compression ratio and high reliability, can solve many problems of the Wankel rotor engine such as high fuel consumption, easy wear and leakage, and is more suitable for use in small low-cost cluster drones.

[0017] The X-type rotor engine has the characteristics of higher theoretical compression ratio, higher high-efficiency hybrid cycle (HEHC) thermal efficiency, higher thermal efficiency and higher power-to-weight ratio. Hydrogen is used as the fuel of the X-type rotor engine to achieve higher theoretical compression ratio, higher cycle thermal efficiency, higher thermal efficiency and higher power-to-weight ratio. As a secondary clean energy, hydrogen has the advantages of high flame propagation speed and high calorific value, and is expected to become a savior for the depletion of fossil fuels. Unlike traditional fossil fuels, hydrogen fuel itself does not contain carbon elements, so hydrogen will not produce carbon emissions during combustion. In addition, hydrogen has many advantages that other fuels do not have, such as extremely low ignition energy, fast laminar combustion speed, high flame propagation speed, high calorific value, and high combustion efficiency. However, hydrogen itself is highly flammable, and the production cost is high and difficult to store, which has led to the difficulty of developing pure hydrogen fuel engines for a long time. Now, with the development of science and technology, pure hydrogen fuel engines have gradually become possible. Compared with reciprocating piston engines, rotary engines are more suitable for burning pure hydrogen as fuel. The combustion chamber of the rotary engine is narrower and the surface-to-volume ratio is larger. When burning fossil fuels such as gasoline, more unburned hydrocarbon emissions will be generated. The low ignition energy, short quenching distance and fast flame propagation of hydrogen make up for the above shortcomings of the rotor to a certain extent.

[0018] The present invention uses EGR technology to reduce NOx emissions, mainly including the following aspects: (1) Since the inert gases in the recirculated exhaust gas are mostly triatomic molecules, such as carbon dioxide, water vapor, etc., this will increase the specific heat capacity of the working fluid in the engine cylinder. When the total heat release in the engine cylinder remains unchanged, the temperature will decrease, thereby reducing NOx emissions.

[0019] (2) The addition of recirculated exhaust gas will further reduce the concentration of oxygen in the mixed gas in the cylinder. In addition, since the recirculated exhaust gas will also occupy a part of the volume of fresh air, it will hinder the contact between N2 and O2 to a certain extent, thereby achieving the purpose of reducing emissions.

[0020] (3) Compared with the traditional water vapor Rankine cycle, the size and weight of the required steam turbine and related equipment can be reduced due to the high density and small specific volume of the working fluid such as pentane in the organic Rankine cycle. The organic Rankine cycle operates in a dry state, avoiding the corrosion problem that may be caused by water vapor, and is more stable under partial load and large power fluctuations. Importantly, the low freezing point of the organic Rankine cycle working fluid enables it to operate efficiently in cold weather, and the entire system operates at near atmospheric pressure, reducing the leakage of the working fluid, which is extremely important for the high-altitude drone environment used by the X-rotor engine. The cycle design of the organic Rankine cycle is flexible, and the performance can be optimized by changing the type and proportion of components to adapt to different heat source characteristics and improve energy conversion efficiency. These characteristics give the organic Rankine cycle a great advantage in the waste heat power generation of the X-rotor engine. In addition, the circulating working fluid has no ability to damage the ozone layer and is environmentally friendly.

[0021] In summary, the present invention effectively utilizes the exhaust gas with a large amount of high-temperature heat that could only be discharged to the outside of the X-type rotary engine through the EGR cycle and organic Rankine cycle system, thereby reducing the heat of the exhaust gas discharged into the atmosphere, reducing the greenhouse effect and achieving a higher thermal energy utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 , Figure 2 It is a structural comparison between the triangular rotor engine and the X-rotor engine; Figure 3 It is the working principle of the X-rotor engine; Figure 4 It is a schematic diagram of the charging stage of the present invention.

[0024] Figure 5 It is a schematic diagram of the discharge stage of the present invention.

[0025] Figure 6 , Figure 7 This is the result diagram of the variable equivalence ratio of the X-type rotor engine using pure hydrogen fuel. Figure 8 , Fig. 9 This is the result diagram of the variable EGR rate of the X-rotor engine using pure hydrogen fuel.

[0026] In the attached figure: 1. Mixing valve one; 2. Mixing valve two; 3. Diverter valve one; 4. Diverter valve two; 5. First-stage heat storage reheater; 6. Second-stage heat storage reheater; 7. Evaporator; 8. Valve one; 9. Valve two; 10. Valve three; 11. Valve four; 12. X-type rotor engine; 13. High-pressure stage turbine; 14. Medium-pressure stage turbine; 15. Low-pressure stage turbine; 16. Condenser; 17. Working fluid pump; 18. Motor. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] like Figure 1 , Figure 2 As shown in the figure, the X-type rotor engine is very different from the traditional Wankel rotor engine in structure. The internal rotor shape of the Wankel rotor engine is similar to a triangle, and the cylinder body profile is similar to an ellipse; while the X-type rotor engine is exactly the opposite, its internal rotor shape is the same as the cylinder body profile of the Wankel rotor engine, and the outer cylinder body is similar to a triangle. That is, the cylinder body profile and rotor profile of the two are just "inverted", so that the X-type rotor engine combines the characteristics of constant volume combustion and overexpansion, greatly improving the combustion efficiency. At the same time, the X-type rotor engine is also a four-stroke cycle internal combustion engine. In terms of sealing devices, compared with the Wankel rotor engine, the X-type rotor engine overcomes the gas leakage problem by using two axially loaded end face seals; the direct contact between the apex seal and the end face seal eliminates the need for corner seals, significantly reducing the blowby between combustion chambers.

[0029] like Figure 3 As shown, when the rotor rotates in the cylinder body, since the rotor is installed on the eccentric shaft and its outer contour always maintains a tangent point with the inner edge of the cylinder body, three closed chambers are formed with the three corners of the cylinder body. Taking the purple combustion chamber as an example, 0~180°CA is the intake stage of the combustion chamber. It is connected to the fixed intake port through the intake channel on the rotor, and the premixed fuel and air are sucked in. The volume of the chamber gradually increases with the rotation of the eccentric shaft, thus completing the intake process; 180~360°CA is the compression process. As the eccentric shaft rotates, the volume of the combustion chamber formed with the cylinder body gradually decreases, the mixed gas is compressed, and the pressure and temperature increase until it reaches the top dead center at 360°CA, and the volume in the cylinder is the smallest; according to the physical and chemical properties of the mixed gas, the appropriate ignition time is selected to perform work. During the crankshaft angle of 360~540°CA, the mixed gas burns, the pressure and temperature increase sharply, and the fuel gas expands to drive the rotor to rotate, completing the expansion work process; finally, at 540~720°CA, it enters the exhaust stage, and the exhaust gas in the chamber is connected to the fixed exhaust port through the exhaust channel on the rotor and discharged to the outside, completing a working cycle. The rotor rotates one circle, completing three four-stroke thermodynamic cycles.

[0030] In the present invention, the high-temperature exhaust gas of the X-type rotor engine is first diverted through the first diverter valve, a part of which is connected back to the engine intake mixture through a pipeline, and then enters the engine combustion chamber for combustion after mixing. The other part of the high-temperature exhaust gas that does not participate in EGR is diverted through the second diverter valve, a part of which passes through the first-stage heat storage reheater and the heat storage reheater, and is discharged into the atmosphere through the evaporator, and the other part does not pass through the first-stage heat storage reheater and the second-stage heat storage reheater, and is directly discharged after passing through the evaporator. Provide a high-temperature heat source for the first-stage heat storage reheater, the second-stage heat storage reheater and the evaporator. After the organic working fluid in the working fluid pump is heated by the evaporator, it passes through the high-pressure turbine, the medium-pressure turbine and the low-pressure turbine respectively to generate power. Finally, it flows back to the working fluid pump through the condenser to complete a cycle.

[0031] Specific as Figure 1~2 As shown in , 4-5, the present invention is a dual-cycle combined power system of a split-flow heat storage X-type rotor engine, including a normally operating X-type rotor engine, a first-stage heat storage reheater, a second-stage heat storage reheater, an evaporator, a condenser, a working fluid pump, an output motor, two splitter valves and mixing valves, three turbines, and four switch valves.

[0032] The method of the present invention mainly includes four steps: engine working stage, EGR cycle exhaust stage, exhaust stage, heat storage stage and power generation stage.

[0033] Engine working stage: The X-type rotary engine 12 uses pure hydrogen as fuel. First, hydrogen and air pass through a mixing valve 1 and then pass through a mixing valve 2 to become a premixed gas with the high-temperature exhaust gas circulated back from the EGR before entering the new rotary engine for combustion.

[0034] Hydrogen is a green dye. Compared with common hydrocarbon fuels, it has excellent physical and chemical parameters such as wider flammable limits, faster diffusion rate, higher adiabatic flame temperature and lower ignition energy. However, hydrogen itself is highly flammable, has high production costs and is difficult to store, which has made it difficult to develop pure hydrogen fuel engines for a long time. Compared with reciprocating piston engines, rotary engines are more suitable for burning pure hydrogen as fuel. The rotary engine has a narrower combustion chamber and a larger surface-to-volume ratio, which will produce more unburned hydrocarbon emissions when burning fossil fuels such as gasoline. The low ignition energy of hydrogen, short quenching distance and fast flame propagation make up for the above shortcomings of the rotary to a certain extent.

[0035] EGR cycle exhaust stage: the high-temperature exhaust gas generated by the full combustion of the pure hydrogen fuel X-rotor engine 12 is diverted through the diverter valve 3 at an EGR rate of 5% to 20%. A part of the exhaust gas is connected to the mixing valve 2 through a pipeline to mix with hydrogen and air to obtain a premixed gas, and then the premixed gas enters the X-rotor engine 12 for combustion and work, and the other part of the high-temperature exhaust gas is connected to the diverter valve 2 4 through the exhaust pipe.

[0036] Heat storage stage: The high-temperature exhaust gas discharged by the engine is divided into two parts through the diverter valve 2 4. One part first passes through the first-stage heat storage reheater 5 and the second-stage heat storage reheater 6 as the heating medium of the first-stage heat storage reheater 5 and the second-stage heat storage reheater 6, providing high-temperature heat energy for the two heat storage reheaters, and then the high-temperature exhaust gas enters the evaporator 7 and is discharged into the atmosphere. Since the high-temperature exhaust gas passing through the first-stage heat storage reheater 5 and the second-stage heat storage reheater 6 transfers heat as a high-temperature medium in the heat storage reheater, the temperature entering the reheater will be reduced to a certain extent, so the other part of the high-temperature exhaust gas separated by the diverter valve 2 4 is required to be discharged into the atmosphere together with the exhaust gas after passing through the first-stage heat storage reheater 5 and the second-stage heat storage reheater 6 as the high-temperature medium of the evaporator 7, providing high-temperature heat for the evaporator 7.

[0037] Power generation stage: The power generation stage can be mainly divided into two operating conditions: low power load conditions and high power load conditions.

[0038] like Figure 4 As shown, under low power load conditions, the external machinery is in low load operation and does not require much power supply. At this time, the working fluid pump 17 transports the organic working fluid to the evaporator 7, and the high-temperature exhaust gas discharged by the engine in the evaporator 7 heats the organic working fluid to form high-temperature organic steam. At this time, valve 1 8 and valve 2 9 are opened, and valve 3 10 and valve 4 11 are closed. After the high-pressure turbine 13 performs work, the high-temperature organic steam is connected from the tail of the turbine to enter the medium-pressure turbine 14. After the medium-pressure turbine 14 performs work, it is connected from the tail to enter the low-pressure turbine 15. Finally, the organic steam discharged after the work is cooled by the condenser 16 with cooling water as the working fluid to obtain the organic working fluid, and the organic working fluid enters the evaporator 7 through the working fluid pump 17.

[0039] like Figure 5As shown, under high power load conditions, the external machinery is in high load operation and requires more electricity. At this time, the turbine is required to do more work for the external motor. This means that the organic steam that needs to pass through the turbine needs to carry more heat. Therefore, when the organic steam is discharged from the evaporator 7, valves 1 8 and 2 9 are closed, and valves 3 10 and 4 11 are opened. After the organic steam passes through the high-pressure turbine 13 to do work, it is connected to the end of the high-pressure turbine 13 and enters the first-stage heat storage reheater 5. In the first-stage heat storage reheater 5, the high-temperature exhaust gas discharged by the X-rotor engine 12 is used as heat transfer for the organic steam. The heated organic steam enters the medium-pressure turbine 14 to do work. The organic steam discharged from the end of the medium-pressure turbine 14 enters the second-stage heat storage reheater 6. After the high-temperature exhaust gas discharged by the engine in the second-stage heat storage reheater 6 is heat-transferred, the high-temperature steam enters the low-pressure turbine 15. The organic steam after doing work passes through the condenser 16 with cooling water as the working fluid to cool it into an organic working fluid. The organic working fluid enters the evaporator 7 through the working fluid pump 17.

[0040] The high-pressure stage turbine 13, the medium-pressure stage turbine 14 and the low-pressure stage turbine 15 are all connected to an external motor 18, and drive the motor to generate electricity as the turbine works, thereby providing electrical energy for external machinery.

[0041] like Figure 6 , Figure 7 The performance diagram of the X-rotor engine using pure hydrogen fuel is shown. Figure 6 It can be seen that when the X-type rotary engine 12 using pure hydrogen fuel has an equivalence ratio within the range of 0.6~1.0, as the equivalence ratio increases, the amount of hydrogen entering the engine increases. Therefore, the larger the equivalence ratio, the more intense the engine combustion and the greater the engine indicated power. When the equivalence ratio increases from 0.6 to 1.0, the engine indicated power increases from 62.9384J to 84.8046J, an increase of 34.74%. However, as the equivalence ratio increases, the indicated thermal efficiency of the engine gradually decreases, from 35.17% at an equivalence ratio of 0.6 to 31.89% at an equivalence ratio of 1.0, a relative decrease of 9.32%. Good combustion conditions will inevitably lead to an increase in pollutant emissions. No carbon oxides are generated during the combustion of pure hydrogen fuel, so the main pollution is NOx emissions, such as Figure 7 As shown, as the equivalence ratio increases, the NOx pollutant emissions increase. When the equivalence ratio is 0.6, the NOx emissions are only 0.06451, while at an equivalence ratio of 1.0, the NOx emissions mass reaches 0.8129 mg, an increase of nearly 11.6 times.

[0042] like Figure 8 , Fig. 9 The figure shows the engine performance analysis under different EGR rates. Figure 8It can be seen that as the engine EGR rate increases, the indicated work done by the engine gradually decreases. This is because as the EGR rate increases, the intake mass fraction of the fuel in the intake stage decreases, resulting in a decrease in the total mass of hydrogen combustion. When the EGR rate reaches 20%, the engine indicated work is 72.2193, which is 16.04% and 12.98% lower than the EGR cycle and EGR rate of 5%, respectively. It can be seen that after the introduction of the EGR cycle, the indicated thermal efficiency of the engine is higher than that of the strategy without the EGR cycle. Although the indicated thermal efficiency of the engine reaches the highest at the 20% EGR rate, the decrease in engine power caused by the relatively low indicated work and the small difference in the indicated thermal efficiency of the engine indicate that the high EGR rate is not suitable for conditions with high requirements for engine performance.

[0043] Fig. 9 The figure shows the NOx emission mass of the engine with different EGR rates. As the EGR rate increases, the NOx emission mass of the engine decreases, which shows that although increasing the EGR rate has a certain negative impact on the engine combustion performance, it is a relatively effective means from the perspective of energy conservation and emission reduction. The NOx emission mass is 0.596mg when the EGR cycle is not used, while the NOx emission mass is 0.357mg and 0.044mg when the EGR rate is 5% and 20%, respectively, which is 40.1% and 92.6% lower than that of the non-EGR cycle. It can be seen that even when the EGR rate is not very high, that is, when the engine performance decline is small, the NOx emission mass is greatly reduced.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art can still modify or make equivalent substitutions to the specific implementations of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the scope of protection of the claims of the present invention to be approved.

Claims

1. A dual-cycle combined power system of a split-flow heat storage X-rotor engine, characterized in that: The invention comprises an X-shaped rotor engine (12), wherein the X-shaped rotor engine (12) uses pure hydrogen as fuel, and high-temperature exhaust gas of the X-shaped rotor engine (12) is split into two parts through a first splitter valve (3), one part is mixed with the fuel of the X-shaped rotor engine (12) and sent into the X-shaped rotor engine (12), and the other part is split into two parts through a second splitter valve (4) and then introduced into an EGR circulation system, wherein the EGR circulation system is connected to an external motor (18).

2. A dual-cycle combined power system of a split-flow heat storage X-type rotor engine according to claim 1, characterized in that: The equivalence ratio of the X-rotor engine (12) is 0.6 to 1.

0.

3. A dual-cycle combined power system of a split-flow heat storage X-type rotor engine according to claim 1, characterized in that: The invention also comprises a mixing valve 1 (1) and a mixing valve 2 (2). The mixing valve 1 (1) is used to mix hydrogen and air to obtain a mixed gas. The mixing valve 2 (2) is used to mix the mixed gas with a part of the high-temperature exhaust gas diverted by the diverter valve 1 (3) and send the mixed gas into the X-shaped rotor engine (12).

4. A dual-cycle combined power system of a split-flow heat storage X-rotor engine according to claim 1, characterized in that: The high-temperature exhaust gas is diverted through the diverter valve 1 (3) at an EGR rate of 5% to 20%.

5. The dual-cycle combined power system of a split-flow heat storage X-type rotor engine according to claim 1, characterized in that: The EGR circulation system comprises a first-stage heat storage reheater (5), a second-stage heat storage reheater (6) and an evaporator (7), wherein high-temperature exhaust gas of an X-type rotor engine (12) is split into two parts by a second splitter valve (4), one part of which is used as a heating medium and passes through the first-stage heat storage reheater (5), the second-stage heat storage reheater (6) and the evaporator (7) in sequence, and the other part of which is used as a heating medium and passes through the evaporator (7).

6. A dual-cycle combined power system of a split-flow heat storage X-rotor engine according to claim 5, characterized in that: The evaporator further comprises a high-pressure turbine (13), a medium-pressure turbine (14), a low-pressure turbine (15), a condenser (16) and a working fluid pump (17). The outlet of the working fluid pump (17) is connected to the organic working fluid inlet of the evaporator (7), the organic working fluid outlet of the evaporator (7) is connected to the inlet of the high-pressure turbine (13), the first outlet of the high-pressure turbine (13) is connected to the inlet of the medium-pressure turbine (14), the first outlet of the medium-pressure turbine (14) is connected to the inlet of the low-pressure turbine (15), the outlet of the low-pressure turbine (15) is connected to the inlet of the condenser (16), and the outlet of the condenser (16) is connected to the inlet of the working fluid pump (17).

7. A dual-cycle combined power system of a split-flow heat storage X-type rotor engine according to claim 6, characterized in that: Under low power load conditions, the first outlet of the high pressure stage turbine (13) is connected to the inlet of the medium pressure stage turbine (14) through valve one (8), and the first outlet of the medium pressure stage turbine (14) is connected to the inlet of the low pressure stage turbine (15) through valve two (9).

8. A dual-cycle combined power system of a split-flow heat storage X-type rotor engine according to claim 6, characterized in that: The second outlet of the high-pressure stage turbine (13) is connected to the organic working fluid inlet of the first-stage heat storage reheater (5), and the organic working fluid outlet of the first-stage heat storage reheater (5) is connected to the inlet of the medium-pressure stage turbine (14); the second outlet of the medium-pressure stage turbine (14) is connected to the organic working fluid inlet of the second-stage heat storage reheater (6), and the organic working fluid outlet of the second-stage heat storage reheater (6) is connected to the inlet of the low-pressure stage turbine (15).

9. A dual-cycle combined power system of a split-flow heat storage X-rotor engine according to claim 8, characterized in that: Under high power load conditions, the second outlet of the high-pressure stage turbine (13) is connected to the organic working fluid inlet of the first-stage heat storage reheater (5) through valve three (10); the second outlet of the medium-pressure stage turbine (14) is connected to the organic working fluid inlet of the second-stage heat storage reheater (6) through valve four (11).

10. A dual-cycle combined power system of a split-flow heat storage X-rotor engine according to claim 6, characterized in that: The high-pressure stage turbine (13), the medium-pressure stage turbine (14) and the low-pressure stage turbine (15) are all connected to an external motor (18).

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