A method of three-pump series internal combustion engine continuous detonation constant volume combustion cycle

Abstract

This invention discloses a continuous detonation isochoric combustion cycle method for a three-pump series internal combustion engine. A turbocharger pump, a compressor pump, and a power pump are arranged in series according to the gas flow direction. The three pumps are rigidly coaxially connected by the same main shaft or linked by a transmission mechanism. A constant-volume combustion chamber is located between the compressor pump and the power pump, limiting the volume change rate ratio of each pump. The entire engine eliminates the valve timing mechanism, and the gas passage remains open throughout the entire process. There is no need for timing and phase coordination control of the three pumps, and different structural types can be flexibly selected for the three pumps. During operation, the power pump expands and performs work under the impetus of high-pressure combustion gas, and drives the compressor pump and turbocharger pump to operate synchronously through the coaxial main shaft, forming a self-driven closed-loop cycle for the entire engine. This invention achieves continuous detonation and equivalent isochoric combustion within the combustion chamber, while simultaneously possessing the dual advantages of small size and high power density of aero-turbine engines and low-speed, stable operation of traditional piston and rotary engines. The thermal efficiency, energy utilization, and output torque of the thermodynamic cycle are significantly improved. The coaxial rigid linkage simplifies the transmission structure, eliminating the need for complex timing valve train mechanisms. The overall structure is simple, the operation is stable, and the adaptability to various operating conditions is wide. This invention overcomes the inherent defects of existing thermodynamic cycle technologies and fills the technological gap in this type of coaxial self-driven continuous detonation isochoric combustion cycle.

Description

Technical Field

[0001] This invention relates to the fields of internal combustion engine thermodynamic cycle, aerospace power derivative technology, and high-efficiency detonation combustion technology. Specifically, it relates to an internal combustion engine cycle method that combines the high power density of an aerospace turbine engine with the low-speed operation characteristics of a traditional internal combustion engine by arranging three variable volume pumps in series and coaxial rigid linkage transmission, thereby achieving continuous detonation and equivalent isochoric combustion. Background Technology

[0002] Currently, the mature engine thermodynamic cycles in the industry are mainly divided into the following types. Each type of cycle has technical defects that are difficult to overcome, and cannot simultaneously meet the requirements of high power density, high thermal efficiency, stable low-speed load carrying, and simple and reliable structure.

[0003] Traditional reciprocating internal combustion engines include Otto cycle, Diesel cycle, Atkinson cycle, and Miller cycle engines. These piston-type internal combustion engines can achieve stable operation at low speeds; however, they are all intermittent reciprocating working cycles, relying on the reciprocating motion of the piston in conjunction with a controllable valve train and a complex timing transmission system. They can only achieve intermittent, approximately isochoric combustion, resulting in high scavenging losses, large valve mechanical losses, discontinuous combustion, large overall engine size, low power density, and limited thermal efficiency due to low compression ratio. Furthermore, they have many moving parts, a complicated timing matching structure, and generally poor overall reliability and maintainability.

[0004] Conventional rotary engines possess the ability to operate smoothly at low speeds; however, they still operate in an intermittent combustion mode, lacking an independent, constant-volume dedicated combustion chamber, thus failing to achieve controllable continuous detonation and stable equivalent isochoric combustion. Furthermore, they suffer from high sealing difficulty, high wear, insufficient combustion completeness, limited energy utilization, and a limited range of operating conditions. They also have shortcomings such as limited power density improvement due to low compression ratios and an inability to balance high thermal efficiency and high torque output.

[0005] Turbine jet and turbofan engines for aircraft employ a coaxial structure of bladed compressor and turbine to achieve isobaric continuous combustion, possessing outstanding advantages such as small size and high power density. However, these types of engines inherently lack the ability to operate effectively at low speeds and can only work stably in the rated high-speed range. It is difficult to establish an effective compression ratio and output torque at low speeds, making it impossible to operate at low speeds and limiting its applicable scenarios. At the same time, the working process is isobaric combustion, and the theoretical thermal efficiency is far lower than that of the ideal isochoric combustion cycle. Furthermore, the blade structure is prone to stall at low speeds, resulting in poor adaptability to operating conditions.

[0006] While existing pulse detonation and rotary detonation engines employ detonation combustion to improve energy efficiency, they lack a staged positive displacement pump to handle the gas expansion pressure. Consequently, they cannot output shaft power to form a self-driven cycle that synchronously drives the compressor end. Their operation relies on complex ignition timing and control systems, resulting in insufficient operational stability and significant challenges in engineering implementation and practical adaptation.

[0007] In summary, while existing piston internal combustion engines and rotary engines can achieve stable low-speed operation, they generally suffer from low power density, limited thermal efficiency improvement, and the inability to achieve constant-volume continuous detonation isochoric combustion. Aero-turbine engines have high power density but cannot effectively operate under load at low speeds, and their isobaric combustion results in low thermal efficiency. Existing detonation engines have a shaftless power-driven self-driving architecture, complex control, and poor practicality. Currently, no thermodynamic cycle scheme can simultaneously combine the advantages of small turbine stage size and high power density, stable low-speed load operation of pistons and rotors, continuous detonation equivalent isochoric high thermal efficiency, valveless simplified valve distribution, three-pump coaxial rigid linkage self-driving, and no need for complex timing phase matching. Therefore, it is necessary to propose a novel technical solution in this invention to fill the gap in existing technology. Summary of the Invention

[0008] Purpose of the invention The purpose of this invention is to overcome the inherent defects of existing engine thermodynamic cycles and provide a method for continuous detonation isochoric combustion cycle of a three-pump series internal combustion engine. This invention retains the core advantages of aero-turbine engines, such as small size and high power density, while also possessing the characteristics of traditional piston internal combustion engines and rotary engines, such as stable low-speed operation and low-speed load-bearing power delivery. Three variable volume pumps are set up to share the same main shaft and are rigidly coaxially connected. The power pump expands and does work under the drive of high-pressure gas, and drives the compressor pump and booster pump to follow the operation synchronously through the main shaft, forming a self-driven working cycle of the whole machine, eliminating the need for a complex timing and distribution mechanism and an additional independent drive device. By limiting the precise volume change rate ratio of the three pumps and setting a constant volume combustion chamber between the compressor and the power machine, controllable and continuous detonation and equivalent ideal isochoric combustion are achieved in the combustion chamber, which greatly improves the thermal efficiency of the thermodynamic cycle and the output torque of the whole machine. At the same time, it simplifies the overall gas distribution and transmission structure, reduces the difficulty of pump design, processing and control, and achieves stable, efficient and self-driven continuous operation under all working conditions.

[0009] Technical solution: A method for continuous detonation isochoric combustion cycle of a three-pump tandem internal combustion engine, characterized in that: Three independent variable volume pumps—a booster pump, a compressor pump, and a power pump—are connected in series according to the gas flow sequence. The three variable volume pumps are rigidly coaxially connected by the same main shaft or by a gear transmission mechanism. The three pumps are set with different speed ratios according to the actual working conditions to match the different volume change rates of the three pumps. The combustion chamber is fixedly located between the compressor pump and the power pump, and the working volume of the combustion chamber remains constant. The entire machine eliminates the traditional valve train mechanism, and all intake passages, pump-to-pump communication passages, and exhaust passages are set to be permanently open structures. There is no need to individually adjust the rotation timing of the three variable volume pumps, nor is there a need to set up angle phase matching and timing coordination control between the three pumps. Mechanical synchronous linkage is achieved by relying on the coaxial main shaft. The volume change rate of the three pumps strictly follows the ratio: the volume change rate of the booster pump is greater than that of the power pump, and the volume change rate of the power pump is much greater than that of the compressor pump, with a difference of more than 20 times, reaching a compression ratio that exceeds the detonation and knocking conditions, so as to reach the limit value of energy utilization. The booster pump, compressor pump, and power pump can be selected independently from any one of the rotary, piston, gear, and vane variable displacement pumps according to different application conditions. There is no need to keep the three pump types structurally consistent. Only the air port series layout, volume change rate ratio and combustion chamber installation position need to be kept unchanged. The functions of each pump are as follows: The booster pump operates at high speed and has a large volumetric change rate, responsible for achieving an ultra-high air compression ratio. The compressor pump operates at low speed, has a good seal, and a very low volumetric change rate, responsible for transferring the compressed air and forcing it into the combustion chamber for combustion. Simultaneously, the small volumetric change rate of the compressor pump, combined with the large volumetric change rate of the power pump, achieves an extremely high unidirectional pressure gradient, causing the high-pressure detonation gases to advance into the power pump. The power pump, resistant to high temperatures and with a good seal, is primarily responsible for generating shaft power.

[0010] The combustion chamber adopts a ring-shaped direct current structure similar to that of an aircraft engine, which realizes continuous detonation combustion in a constant volume cavity and forms an equivalent ideal isochoric combustion. During operation, the power pump is pushed by the high-pressure gas in the combustion chamber to expand and do work. At the same time, it drives the compressor pump and booster pump to follow the operation through the coaxial main shaft or through the speed change mechanism, forming a self-driven closed-loop working cycle of the whole machine. The engine combines the advantages of small size and high power density of aero turbine engines with the ability of traditional piston and rotary engines to operate smoothly at low speeds and perform stable load-bearing work at low speeds.

[0011] The specific loop steps are as follows: 1. Continuous booster air intake: The booster pump rotates synchronously with the coaxial main shaft or rotates at high speed after speed change. With its own large volume and high volume change rate structure, it continuously draws in outside air to complete the booster. After compressing the air to the critical pressure of detonation combustion, the normally open gas passage continuously delivers sufficient booster air to the compressor pump. There is no valve throttling or additional timing control action throughout the process. 2. High-pressure air transfer: The compressor pump operates synchronously with the coaxial main shaft, receives the pre-pressurized air delivered by the booster pump, and completes the transfer of high-pressure air through its own small volume pump chamber, continuously and quantitatively pressurizing it into the constant volume combustion chamber; 3. Continuous detonation isochoric combustion: High-pressure air is fully mixed with fuel in a constant-volume combustion chamber, triggering and maintaining continuous and stable detonation combustion; relying on the constant-volume structure of the combustion chamber, and relying on the fact that the volume change rate of the power pump is much greater than that of the compressor pump to form an extremely high pressure gradient before and after, the backflow of the combustion gas is effectively blocked, and the combustion process is completed within a constant volume, achieving equivalent ideal isochoric combustion. The fuel releases high-density heat energy instantaneously and in a concentrated manner, greatly improving the energy utilization rate of the thermodynamic cycle; 4. Continuous high-torque power generation and coaxial self-drive: The high-temperature and high-pressure gas generated by detonation isochoric combustion directly enters the power pump, whose volume change rate is much greater than that of the compressor pump, driving the pump body to expand and achieve continuous expansion to generate power and output high torque; at the same time, the power pump, relying on the coaxial main shaft, rigidly drives the compressor pump and booster pump to rotate continuously in linkage, and with the help of the gear transmission mechanism, increases the volume change rate of the booster pump, providing mechanical power for intake and compression conditions. The whole machine can maintain self-drive circulation without additional external drive; the exhaust gas after power generation is continuously discharged through the open exhaust channel; 5. Self-sustaining closed-loop cycle: The three variable displacement pumps operate synchronously in conjunction with the coaxial main shaft or speed change mechanism, without the need to set the speed sequence and angle phase coordination separately; relying on the preset volume ratio to form a stable unidirectional pressure gradient, combined with the self-driving effect of the power pump, to achieve valveless, uninterrupted, self-driving continuous detonation isovolumetric combustion closed-loop cycle, which can still stably complete the entire working process under low-speed conditions. Beneficial effects

[0012] 1. This invention integrates the core advantages of three types of power devices. It has the characteristics of small size and high power density of aero-turbine engines, as well as the ability of traditional piston internal combustion engines and rotary engines to operate smoothly at low speeds and carry loads at low speeds. It avoids the dual shortcomings of low power density of traditional internal combustion engines and the inability of aero-turbine engines to carry loads effectively at low speeds, and greatly expands the range of working conditions that can be adapted.

[0013] 2. This invention employs a constant-volume combustion chamber in conjunction with continuous detonation combustion to achieve equivalent ideal isochoric combustion under constant-volume conditions. Unlike the isobaric combustion mode of aero-turbine engines and the intermittent approximate isochoric combustion mode of traditional reciprocating internal combustion engines, it has higher thermodynamic cycle theoretical efficiency, is closer to the ideal thermodynamic cycle limit, and significantly improves energy utilization and fuel economy.

[0014] 3. A limited, exclusive three-pump volume ratio is used. The large-capacity booster pump ensures sufficient air intake for the entire unit, meeting the pressure and flow requirements of detonation combustion. The volume change rate of the power pump is much greater than that of the compressor pump, effectively amplifying the gas expansion ratio and significantly improving the output torque and power performance of the entire unit.

[0015] 4. A unique three-pump coaxial linkage and self-driven power-operating architecture: while the power pump is driven by high-pressure gas to perform work, it drives the compressor pump and booster pump to operate synchronously through a shared main shaft. This eliminates the complex timing and valve train mechanism and independent drive device of traditional engines, greatly simplifies the overall transmission and valve train structure, reduces the difficulty of designing, processing and controlling the variable displacement pump, reduces mechanical transmission losses, and improves the reliability of the overall machine operation.

[0016] 5. The entire unit eliminates the traditional valve train mechanism, and all gas passages are always open. There is no need to set up the three-pump operation sequence and phase coordination control, resulting in a simple structure, fewer parts, and a low failure rate.

[0017] 6. The three variable displacement pumps can be flexibly selected with different structural types, and can be adapted to a variety of application scenarios such as automotive power, light aviation, construction machinery, and heavy-duty equipment. They have extremely strong versatility and engineering adaptability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure and gas flow layout of the three pumps of the present invention; Figure 2 This is a schematic diagram of the layout of the three pumps with shafts and different speed ratios of the present invention; Figure 3 Schematic diagram of Example 1; Figure 4 Schematic diagram of Example 2.

[0019] Explanation of reference numerals in the attached figures 1—Booster pump 2—Compressor Pump 3—Combustion Chamber 4—Power Pump 5—Normal open intake passage 6—Normal open pump room connecting passage 7—Normal open exhaust channel 8—Coaxial drive spindle 9—Transmission Mechanism Detailed Implementation

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, so as to fully understand the structural layout, speed transmission principle, self-drive working process and technical effects of the present invention. Example

[0021] Combination Figure 1 , Figure 2 , Figure 3As shown, a three-pump series internal combustion engine continuous detonation isochoric combustion cycle method is provided. The complete engine structure includes: a turbocharger pump (1), a compressor pump (2), and a power pump (4) arranged in series; a combustion chamber (3) is fixedly installed between the compressor pump (2) and the power pump (4); the intake passage (5), the inter-pump communication passage (6), and the exhaust passage (7) all adopt a straight normally open structure, without any controllable valve opening and closing or timing valve distribution mechanism; the turbocharger pump (1), the compressor pump (2), and the power pump (4) are fixedly assembled together and mechanically linked through a gear transmission mechanism (9).

[0022] In this embodiment, the booster pump (1) is a high-flow sliding vane rotor pump with high-speed rotation, the compressor pump (2) is an internal gear pump with good sealing at low speed, and the power pump (4) is a cam rotor pump with good sealing and resistance to high temperature and high pressure detonation gas. When connecting, the inlet and outlet of these pumps are connected in sequence. A speed change mechanism (9) is set for each pump to match the volume change rate of each pump. The three pumps are designed in strict accordance with the volume change rate of booster pump > volume change rate of power pump > volume change rate of compressor pump. The compression ratio of booster (1) and compressor (2) is set to 50:1 to reach the critical value of detonation combustion, so that the gas can still reach the compression ratio of detonation combustion after diffusion and pressure reduction in the combustion chamber. The combustion chamber (3) adopts a ring-shaped DC constant volume combustion chamber similar to that of an aircraft engine.

[0023] Specific implementation steps: 1. After the machine is initially started, the power pump (4) increases the speed through the speed change mechanism (9) to drive the booster pump (1) to rotate. The pump chamber volume expands and contracts periodically, and continuously draws in outside air through the normally open intake channel (5) to complete the boosting and form a high-pressure airflow, raising the air pressure to the critical pressure range of detonation combustion. The normally open inter-pump connection channel (6) delivers the air to the compressor pump (2) without obstruction, and no valve opening and closing adjustment is required throughout the process.

[0024] 2. The compressor pump (2) rotates with the speed change mechanism (9) and uses its own small volume pump chamber to transfer the high pressure air flowing in, and continuously and quantitatively deliver it into the combustion chamber (3).

[0025] 3. After high-pressure air enters the combustion chamber (3), it is uniformly mixed with the fuel injected by the fuel injection mechanism inside the combustion chamber. Under the guiding effect of the annular flow channel inside the combustion chamber, it triggers and maintains continuous and stable detonation combustion. Since the volume of the combustion chamber (3) is fixed, the high pressure gradient formed by the high volume change rate difference between the front and rear pump bodies can effectively block the reverse flow of the gas. The combustion process is stably completed in the constant volume chamber, realizing equivalent ideal isochoric combustion, and the fuel releases high-density heat energy instantaneously.

[0026] 4. The high-temperature and high-pressure gas generated by the detonation isochoric combustion is directly introduced into the power pump (4), which drives the power pump (4) to expand its volume and continuously convert the gas thermal energy into rotational mechanical energy, continuously outputting large torque; at the same time, the power pump (4) is driven by the high-pressure gas to actively do work, and drives the transmission mechanism (9) to rotate stably in the opposite direction, thereby synchronously linking the compressor pump (2) and the booster pump (1) to continue to operate. After the whole machine is separated from the external initial drive, it can maintain its self-driving working cycle autonomously; the exhaust gas after the work is completed is directly and continuously discharged through the normally open exhaust channel (7).

[0027] 5. The three pumps rely on the speed change mechanism (9) to always maintain mechanical synchronous linkage operation without additional angle phase matching; relying on the volume change rate ratio generated by the different speed ratios of the three pumps, a stable unidirectional pressure gradient is formed, which spontaneously maintains a complete closed loop cycle from intake, boosting, compression, combustion, power to exhaust; the whole machine has the same low-speed stable operation and load-bearing power as traditional piston and rotary engines, and relies on the coaxial self-drive architecture to achieve long-term stable continuous operation. Example

[0028] Combination Figure 4 As shown, this embodiment is basically the same as embodiment 1 in terms of structure, principle and working logic. The difference is that the three pumps, namely the booster pump (1), the compressor pump (2) and the power pump (4), are all cam rotor volumetric pumps and are mounted on the same coaxial drive shaft (8) and rotate synchronously. The three pumps are designed in strict accordance with the principle that the booster pump volume > the power pump volume > the compressor pump volume. The compression ratio of the booster and the compressor is set to 50:1 to adapt to miniaturized and high power density application scenarios. The combustion chamber matches the fuel supply parameters according to the intake air flow to stably maintain continuous detonation and equivalent isochoric combustion conditions. The coaxial and same speed layout, relying on the inherent volume ratio of each pump, and the working process are consistent with embodiment 1. It also has the technical effects of high power density, low-speed stable operation, high thermal efficiency, large torque output, and stable coaxial self-drive operation.

[0029] This invention is not limited to the preferred embodiments described above. Any equivalent substitutions, structural fine-tuning, or working condition adaptation improvements made based on the structural layout, coaxial transmission principle, thermodynamic cycle logic, and working method of this invention are within the scope of protection of this invention.

Claims

1. A method for continuous detonation isochoric combustion cycle of a three-pump tandem internal combustion engine, characterized in that, Three independent variable volume pumps—a booster pump (1), a compressor pump (2), and a power pump (4)—are connected in series according to the gas flow sequence. The three variable volume pumps are rigidly coaxially connected via the same main shaft (8) or synchronously linked by a gear transmission mechanism (9). The combustion chamber (3) is fixedly arranged between the compressor pump (2) and the power pump (4), and the working volume of the combustion chamber remains constant. The traditional valve distribution mechanism is eliminated throughout the process, and all gas flow channels (5), (6), and (7) are permanently open. No phase coordination or collaborative control of the three pumps is required; mechanical synchronous linkage is achieved by relying on the main shaft in conjunction with the transmission mechanism of each pump. The volume change rate of the three pumps is strictly controlled. Satisfy the following: The volume change rate of the booster pump (1) is greater than that of the power pump (4), and the volume change rate of the power pump (4) is much greater than that of the compressor pump (2), with a difference of more than 20 times; continuous detonation combustion and equivalent isochoric combustion are achieved in the combustion chamber (3); the whole machine has the advantages of small size and high power density of aviation turbine engine, as well as the ability of traditional piston and rotor engine to run smoothly at low speed; during operation, the power pump (4) is pushed by the high pressure gas in the combustion chamber to expand and do work, and the compressor pump (2) and booster pump (1) are linked through the coaxial (8) or speed change mechanism (9) to follow the operation, forming a self-driven closed loop cycle of the whole machine; The specific loop steps are as follows: (1) Continuous pressurization intake: The booster pump (1) rotates at high speed in conjunction with the main shaft, continuously draws in outside air through the intake channel (5) and completes air pressurization. The pressurized air is compressed to the critical pressure of detonation combustion, and the normally open channel (6) continuously delivers pressurized air to the compressor pump (2). (2) High-pressure air transfer: The compressor pump (2) operates in conjunction with the main shaft to continuously transfer high-pressure air into the constant volume combustion chamber (3). (3) Continuous detonation isochoric combustion: High-pressure air and fuel are mixed in a constant volume combustion chamber (3) to achieve continuous detonation combustion and form equivalent isochoric combustion, which efficiently releases heat energy; (4) Continuous high torque power and coaxial self-drive: High temperature and high pressure gas enters the power pump (4), which drives the pump body to continuously expand and do work and output high torque. At the same time, the power pump (4) is linked with the compressor pump and booster pump through the main shaft (8) or through the speed change mechanism (9) to achieve the self-drive of the whole machine; the power exhaust gas is continuously discharged through the open exhaust channel (7); (5) Self-sustaining closed-loop cycle: Three variable volume pumps rely on the coaxial main shaft (8) or gear transmission mechanism (9) to operate in linkage. The volume change rate of the power pump (4) is much greater than that of the compressor pump (2), and the ratio of the difference of more than 20 times forms an extremely high unidirectional pressure gradient, realizing a self-driven continuous detonation isochoric combustion cycle without interruption or valve control.

2. The method for continuous detonation isochoric combustion cycle of a three-pump tandem internal combustion engine according to claim 1, characterized in that, The equivalent isochoric combustion is detonation combustion under constant volume conditions in the combustion chamber, which is different from isobaric combustion in aero-turbine engines. This invention takes into account the high power density of the turbine stage and also achieves the dual advantages of low-speed operation and isochoric combustion, resulting in higher thermodynamic cycle efficiency.

3. The method for continuous detonation isochoric combustion cycle of a three-pump tandem internal combustion engine according to claim 1, characterized in that, The equivalent isochoric combustion is detonation combustion under constant volume conditions in the combustion chamber, which is different from the intermittent combustion of traditional reciprocating internal combustion engines and rotary engines. This invention takes into account the low-speed operation capability of traditional internal combustion engines, while also realizing continuous detonation combustion in an aircraft engine-like combustion chamber. By exceeding the detonation conditions in the combustion chamber through an ultra-high compression ratio, it achieves extremely high power density and reaches the limit of energy utilization.

4. The method for continuous detonation isochoric combustion cycle of a three-variable-volume pump series internal combustion engine according to claim 1, characterized in that, The booster pump, compressor pump, and power pump can be independently selected from any type of variable volume pump, such as rotor, piston, gear, or vane pump. There is no need to maintain a consistent pump structure or coordinate the timing and phase of the three pumps. Stable operation can be achieved by maintaining the air port series normally open layout and limiting the ratio of volume change rate by the volume of each pump and the speed change mechanism.

5. The method for continuous detonation isochoric combustion cycle of a three-pump tandem internal combustion engine according to claim 1, characterized in that, By using a ratio where the volume change rate of the power pump is much greater than that of the compressor pump, the gas expansion and work capacity and the overall output torque are improved; by using a ratio where the volume change rate of the booster pump is greater than that of the power pump, the intake air volume and working pressure required for detonation combustion are kept stable.

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