Dual working fluid self-suction type ORC compound extended range / hybrid power system

Abstract

The application discloses a dual-working-medium self-suction type ORC composite extended range / mixed motion power system and belongs to the field of internal combustion engine waste heat recovery and vehicle power. The system comprises a dual-working-medium circuit, dual-heat-source heat exchange, self-suction type ORC power generation, pure mechanical control, condensation backflow and power generation modules; the main working medium is water and antifreeze, the secondary working medium is a low-boiling-point refrigerant, the dual circuits share power generation, condensation and power generation units, and are automatically switched by a temperature-sensing rotary air distribution valve in a pure mechanical mode to cover all working conditions. The system adopts a dual-cavity self-suction structure and a flywheel inertia to realize a pump-free self-suction cycle, a water jacket is provided with a membrane cavity for separation and a temperature-sensing bypass valve to balance heat dissipation and heat absorption, and a tail gas heat exchange is provided with a buffer structure and a pressure stabilizing bag to resist cold and hot impact and use ordinary materials. The system is purely mechanically and passively controlled, does not need complex electric control and has no additional energy consumption. The total power generation efficiency of the extended range device reaches 48% to 51%, the comprehensive efficiency of the mixed motion reaches 52% to 58%, the structure is extremely simple, the cost is low, the reliability is high, mass production is easy, and the system is suitable for extended range and mixed motion vehicles.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery from internal combustion engines and vehicle power systems, specifically to a dual-fluid self-aspirated ORC (Organic Rankine Cycle) composite range-extending / hybrid power system, suitable for efficient waste heat recovery from internal combustion engines in range-extended and hybrid vehicles, thereby improving engine thermal efficiency and increasing vehicle range. Background Technology

[0002] With the development of new energy vehicle technology, range-extended and hybrid powertrain architectures have become the core solutions to address range anxiety in pure electric vehicles. However, the internal combustion engines in the existing architecture still have a large amount of waste heat that is not effectively utilized. The engine block water cooling system carries about 20% of the fuel energy, and the exhaust gas carries about 33% of the fuel energy. This waste heat is usually discharged directly through the radiator and exhaust pipe, resulting in a low overall power generation / work efficiency of the internal combustion engine (the power generation efficiency of ordinary range extenders is only 35%-40%, and the thermal efficiency of hybrid engines is about 40%-43%).

[0003] To recover waste heat from internal combustion engines, existing technologies mostly employ the ORC cycle system, but it suffers from the following core drawbacks:

[0004] 1. Poor compatibility with a single working fluid: When water is used as the working fluid, its boiling point is high (100℃), and it cannot boil and produce gas under cold start, idling, and low speed and low load conditions, making the ORC system basically ineffective; when using traditional low-boiling-point organic working fluids, the pressure is too high under high temperature conditions, resulting in poor safety and high cost.

[0005] 2. Requires an additional electric water pump: ORC working fluid circulation relies on an electric water pump, which consumes electrical energy, offsetting the benefits of waste heat recovery, and also increases structural complexity and failure rate;

[0006] 3. Conflict between heat dissipation and heat absorption: The ORC system absorbs heat from the engine, which can easily lead to high engine temperature, especially in summer and under heavy load conditions such as climbing hills. The engine's heat dissipation capacity is insufficient, resulting in heat decay.

[0007] 4. Exhaust gas heat exchangers are prone to damage: The exhaust gas temperature fluctuates drastically (200℃ at idle speed, 800℃ during rapid acceleration). The heat exchanger is susceptible to metal fatigue, cracking, and water leakage due to thermal shock. Existing technology requires the use of high-grade alloy materials, which significantly increases costs.

[0008] 5. Working fluid supply pulsation: Pumpless self-priming structures are mostly single-chamber designs, and the working fluid supply alternates between "suction and stop", resulting in unstable steam output, fluctuating ORC work, and large fluctuations in power generation efficiency;

[0009] 6. The dual-working-fluid system has a complex structure and cannot meet the requirements of vehicle-mounted lightweight and low-cost: The existing dual-working-fluid ORC system requires two independent working modules, which are large in size and costly, cannot be adapted to the limited installation space of the vehicle, and rely on electronic control components to achieve working fluid switching, resulting in low reliability.

[0010] In addition, existing waste heat recovery solutions from automakers mostly focus on electronic stacking or hybrid system optimization, failing to achieve an organic combination of "purely mechanical, minimalist structure, full operating condition coverage, and low-cost mass production," making it difficult to apply waste heat recovery technology on a large scale.

[0011] Therefore, there is an urgent need for an ORC composite power system that can solve all the above defects, achieve efficient cascade recovery of internal combustion engine waste heat, has a minimal structure, is purely mechanically controlled, and is safe and mass-producible. Summary of the Invention

[0012] Purpose of the invention

[0013] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a dual-working-fluid self-aspirated ORC composite range extender / hybrid power system. Through the design of "dual-working-fluid time-sharing operation, dual-heat source cascade heat exchange, pure mechanical self-aspirated cycle, and passive control balance", it achieves efficient recovery of waste heat from the internal combustion engine under all operating conditions, and solves industry problems such as "ineffective low load, contradiction between heat dissipation and heat absorption, thermal shock of heat exchangers, self-aspirated pulsation, and complex structure". Without adding complex electronic control components or significantly modifying the original vehicle structure, it significantly improves the overall efficiency of the engine, reduces vehicle fuel consumption, and increases the range of range-extended vehicles.

[0014] Technical solution

[0015] To achieve the above objectives, this invention provides a dual-working-fluid self-priming ORC composite range extender / hybrid power system, comprising a dual-working-fluid circuit, a dual-heat-source heat exchange module, a self-priming ORC power module, a purely mechanical control module, a condensation reflux module, and a power generation output module. The dual-working-fluid circuit includes a main working-fluid circuit and a secondary working-fluid circuit, sharing the self-priming ORC power module, condensation reflux module, and power generation output module, achieving a minimalist structure. The main working-fluid is a mixture of water and antifreeze, suitable for high-load and high-speed engine operation. The secondary working-fluid is a non-toxic, non-flammable, low-boiling-point refrigerant, suitable for cold-start, idling, and low-speed, low-load engine operation. The self-priming ORC power module has no electric water pump, achieving self-priming circulation of the working-fluid through a purely mechanical structure. The purely mechanical control module achieves automatic switching between the dual working-fluids, balance between engine cooling and ORC heat absorption, pressure safety, and stable working-fluid flow, without any complex electronic control components throughout the process.

[0016] Furthermore, the main working fluid circuit includes a main reservoir, an engine water jacket, an exhaust gas high-temperature superheater, a mechanical valve, a self-priming ORC power module, and a shared condenser connected in sequence. The main reservoir is integrated with the original engine expansion tank, requiring no additional space. The engine water jacket outlet is equipped with a mechanical temperature-sensing bypass valve, the other end of which is connected to the original engine radiator, achieving a passive balance between engine cooling and ORC heat absorption.

[0017] The working logic of the mechanical temperature-sensing bypass valve is as follows: when the engine water jacket temperature is ≤95℃, the valve is completely closed, and the main working fluid enters the exhaust gas high-temperature superheater, and the ORC system fully recovers the waste heat; when the water temperature is >95℃, the valve gradually opens as the water temperature rises, and the diverted part of the main working fluid is directly connected to the original vehicle radiator, giving priority to engine cooling and avoiding engine overheating, thus achieving passive control of "waste heat recovery first, engine safety first".

[0018] Furthermore, the auxiliary working fluid circuit includes, in sequence, an auxiliary liquid storage tank, a perfluoroether rubber low-temperature heat-absorbing membrane cavity, an exhaust gas low-temperature preheater, a mechanical valve, a self-priming ORC power module, and a common condenser. The auxiliary working fluid is a low-boiling-point refrigerant of type R245fa, with a boiling point of 50-60℃. Under cold start, idling, and low-speed, low-load conditions, the auxiliary working fluid can boil and produce gas at an engine water temperature of 60-85℃, filling the gap in operating conditions of a single water working fluid. The main working fluid inlet and outlet are set on the upper bottom surface of the water jacket, and the auxiliary working fluid inlet and outlet are set on the lower bottom surface. The engine water jacket is equipped with a perfluoroether rubber (FFKM) membrane cavity separation structure. The membrane cavity has a temperature resistance range of -50℃ to 290℃, which is much higher than the normal operating temperature of the engine cylinder outer wall (100℃-180℃) and the high-load limit temperature (≤220℃). It does not age, crack, or fail under high-temperature environments. Under low-power conditions, the secondary working fluid fills the membrane chamber, which tightly wraps around the outer wall of the engine cylinder, allowing the secondary working fluid to recover low-temperature waste heat through the membrane chamber. Under high-power conditions, the primary working fluid fills the entire water jacket, compressing the membrane chamber volume. The primary working fluid directly contacts the engine cylinder wall to ensure heat dissipation, with no volume loss or heat exchange area reduction. The structure is simple, the seal is reliable, and the service life meets the vehicle's 10-year / 300,000-kilometer service requirements. This design achieves complete separation of the primary and secondary working fluid vapor circuits while effectively preventing cross-contamination between the primary and secondary working fluids.

[0019] Furthermore, the dual-heat-source heat exchange module includes a high-temperature superheater for exhaust gas, a low-temperature preheater for exhaust gas, and a buffer heat exchange structure. The buffer heat exchange structure is a sandwich design, located at the contact end between the exhaust gas and the heat exchange module. The exhaust gas first enters the buffer heat exchange chamber, smoothing out the drastic temperature fluctuations (±20℃) to ±3℃, before exchanging heat with the working fluid, thus preventing the heat exchanger from being subjected to thermal shock. The outlet of the high-temperature superheater for exhaust gas is equipped with a small steam pressure stabilizing package, further achieving stable temperature and pressure output of the main working fluid steam, extending the service life of the heat exchanger. Moreover, the heat exchanger can be made of ordinary aluminum / carbon steel materials, significantly reducing costs. The low-temperature preheater for exhaust gas is used to further heat and boil the secondary working fluid to form high-pressure steam.

[0020] Furthermore, the self-priming ORC working module includes an ORC piston cylinder, a flywheel, a dual-chamber self-priming structure, and a mechanical pressure relief valve. The dual-chamber self-priming structure is located inside the ORC piston cylinder and includes two cooperating suction chambers and two sets of one-way valves. The two suction chambers alternately complete the "air intake-water replenishment" action. The two chambers are symmetrically arranged and their working phases differ by 180°. When the ORC piston moves upward, one suction chamber opens the one-way valve to draw in the working medium, while the other suction chamber closes the one-way valve and discharges the working medium. When the piston moves downward, the actions of the two chambers switch in opposite directions, alternately and continuously conveying materials to achieve a stable self-priming cycle without a pump. The system transforms pulsating water supply into continuous and stable water supply. A miniature liquid storage tank is installed outside the ORC piston cylinder to further smooth out the pulsation of the working fluid flow, achieving water supply stability comparable to an electric water pump without additional energy consumption. A mechanical pressure relief valve is located at the top of the ORC piston cylinder. When the steam pressure inside the cylinder exceeds a preset safety value, the valve automatically opens, releasing excess steam into a shared condenser, achieving purely mechanical pressure safety control without the need for electronic sensors. The flywheel is coaxially connected to the ORC piston cylinder, using its inertia to provide power for the self-priming return of the working fluid and the alternating operation of the dual chambers, achieving pump-free self-priming circulation.

[0021] Furthermore, the purely mechanical control module is a temperature-sensitive rotary valve, located at the air intake of the self-priming ORC power module. It achieves automatic switching between the two working fluid circuits through water temperature sensing. Its working logic is as follows: when the engine water temperature is <90℃, the secondary working fluid circuit is opened and the primary working fluid circuit is closed, with the secondary working fluid circuit operating independently; when the water temperature is >95℃, the primary working fluid circuit is opened and the secondary working fluid circuit is closed, with the primary working fluid circuit operating independently; the water temperature range of 90℃-95℃ is a transition range, achieving smooth switching between the two working fluid circuits, preventing working fluid mixing and cross-contamination. The entire process is computerless and sensorless, with a simple structure and high reliability. The temperature-sensitive rotary valve is coaxially mounted at the air intake end of the self-priming ORC power module. The valve contains a paraffin heat bulb and a rotary valve core. The paraffin heat bulb expands and contracts according to the engine coolant temperature, driving the valve core to make a gradual angular displacement via a 45° spiral guide groove, achieving smooth switching between the two working fluid circuits. When the engine coolant temperature is below 90°C, the valve core opens the secondary working fluid circuit and blocks the primary working fluid circuit; when the coolant temperature is above 95°C, the valve core opens the primary working fluid circuit and blocks the secondary working fluid circuit; when the coolant temperature is between 90°C and 95°C, the valve core rotates gradually, achieving a smooth transition between the two working fluid circuits and preventing working fluid mixing and cross-contamination.

[0022] Furthermore, the condensation reflux module is a shared condenser. After the main and auxiliary working fluids have done work, the steam enters the condenser and is liquefied. Then, it flows back to the main storage tank and the auxiliary storage tank through one-way valves, respectively. The reflux power is provided by the flywheel inertia and the self-priming suction force of the ORC piston cylinder. There is no additional power input, thus realizing a closed-loop self-circulation.

[0023] Furthermore, the power generation output module includes a main generator and an auxiliary generator; the main generator is connected to the engine main shaft and is directly driven by the engine to generate electricity, providing basic power for the vehicle; the auxiliary generator is coaxially connected to the flywheel of the self-aspirated ORC power module and is driven by the ORC piston cylinder to generate electricity, providing additional power for waste heat recovery; the power output terminals of the main and auxiliary generators are combined to charge the power battery or directly drive the vehicle drive motor, realizing a dual power generation mode of "engine main shaft power generation + ORC waste heat power generation".

[0024] Furthermore, the system is compatible with both range-extended electric vehicles (EREV) and conventional hybrid electric vehicles (HEV / PHEV). When adapted to EREV, the engine only acts as a range extender to generate electricity. The main shaft power generation + ORC waste heat power generation increases the total power generation efficiency to 48%-51%, and 1L of oil can be converted into 4-4.3 kWh of electricity, increasing the vehicle's range on a full tank by 30%-40%. When adapted to conventional hybrid electric vehicles, the engine directly drives the wheels while the ORC system recovers waste heat to generate electricity, increasing the overall hybrid efficiency to 52%-58%, reducing vehicle fuel consumption to 3.0-3.8L / 100km, and the efficiency advantage is more significant under high-speed conditions.

[0025] The dual-working-fluid self-aspirating ORC compound range extender / hybrid power system of the present invention does not conflict with the original vehicle engine structure, does not require major modifications to the original vehicle cooling, exhaust and power systems, and all modules can be modularly designed to fit the limited installation space of the vehicle and meet mass production requirements.

[0026] Beneficial effects

[0027] Compared with the prior art, the present invention has the following significant advantages:

[0028] 1. Full-condition waste heat recovery, significantly improving efficiency: The system adopts a dual-working-fluid system of water and low-boiling-point refrigerant, with the auxiliary working fluid used for cold start / idle / low speed and the primary working fluid used for high load / high speed, achieving cascade recovery of waste heat from the internal combustion engine under all operating conditions without any gaps in operation; the total power generation efficiency of the range-extended engine is increased to 48%-51%, and the comprehensive efficiency of the hybrid system is increased to 52%-58%, approaching the physical efficiency limit of the internal combustion engine;

[0029] 2. Pump-free self-priming circulation with zero additional energy consumption: The working fluid achieves pure mechanical self-priming circulation through a dual-chamber self-priming structure and flywheel inertia, eliminating the need for an electric water pump and consuming no additional electrical energy. Furthermore, the alternating operation of the dual chambers and the micro-accumulation tank ensure a continuous and stable supply of the working fluid, solving the problem of self-priming pulsation.

[0030] 3. Passive heat dissipation balance, engine never overheats: A mechanical temperature-sensing bypass valve is installed at the water jacket outlet, which automatically distributes the working fluid according to the water temperature, realizing a passive balance between engine heat dissipation and ORC heat absorption, prioritizing engine safety, and completely resolving the inherent contradiction between heat dissipation and heat absorption.

[0031] 4. Heat exchanger is shock resistant, low cost and long life: Through the jacketed buffer heat exchange structure + steam pressure stabilizing package, the temperature fluctuation of the exhaust gas is smoothed out. The heat exchanger can be made of ordinary aluminum / carbon steel materials, without the need for high-grade alloys, which greatly reduces the cost and completely solves the cracking and leakage problems caused by thermal shock. Its life is comparable to that of the exhaust pipe.

[0032] 5. Purely mechanical control, high reliability: All control actions (dual working fluid switching, pressure safety, heat dissipation balance, and flow stability) are realized through purely mechanical components. There are no complex electronic control sensors or computer programs. The structure is simple, the failure rate is low, and it meets the reliability requirements of vehicles for 10 years / 300,000 kilometers.

[0033] 6. Extremely simple structure and easy to mass-produce: The dual working fluid circuits share a set of ORC power, condensation and power generation modules. The main liquid tank and the original vehicle expansion tank are integrated into one design, which does not require major modification of the original vehicle structure. It has a high degree of modularity, adapts to vehicle installation space, and eliminates the electric water pump and the generator, so the overall cost is almost not increased.

[0034] 7. Safe and environmentally friendly, compliant with regulations: The main working fluid is the original vehicle antifreeze (water), and the secondary working fluid is a non-toxic, non-flammable, low-boiling-point refrigerant. There is no risk of leakage, no corrosiveness to the engine and heat exchanger, and no safety hazards in the event of a collision or breakage, which meets the safety regulations of the car manufacturer; the exhaust heat exchanger flow channel is optimized, and the back pressure is controlled within 2kPa, which does not affect the engine emission calibration.

[0035] 8. Wide adaptability and multiple application scenarios: It can be directly adapted to existing range-extended electric vehicles (EREV) and ordinary hybrid electric vehicles (HEV / PHEV), without the need to redesign the engine, with low modification costs, and can be quickly industrialized. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The accompanying drawings here are simplified schematic diagrams and are only used to illustrate the core structure of the present invention, and do not constitute a limitation on the present invention.

[0037] Figure 1 : A schematic diagram of the overall structure of the dual-working-fluid self-aspirating ORC composite range extender / hybrid power system of the present invention;

[0038] Figure 2 : Schematic diagram of the dual-cavity self-priming structure of the self-priming ORC power module of the present invention;

[0039] Figure 3 : Schematic diagram of the buffer heat exchange structure of the dual heat source heat exchange module of the present invention;

[0040] The component names represented by the numbers in the attached diagram are as follows:

[0041] 1-Main reservoir, 2-Engine water jacket, 3-Mechanical temperature-sensing bypass valve, 4-Original vehicle radiator, 5-Exhaust gas high-temperature superheater, 6-Steam pressure regulator, 7-Temperature-sensing rotary valve, 8-ORC piston cylinder, 9-Dual-chamber self-priming structure, 91-Left water intake chamber, 92-Right water intake chamber, 93-One-way valve, 10-Miniature reservoir, 11-Mechanical pressure relief valve, 12-Flywheel, 13-Auxiliary generator, 14-Common condenser, 15-Auxiliary reservoir, 16-Perfluoroether rubber low-temperature heat absorption film chamber, 17-Exhaust gas low-temperature preheater, 18-Buffer heat exchange chamber, 19-Engine, 20-Main generator, 21-Power battery, 22-Drive motor, 23-Exhaust pipe. Detailed Implementation

[0042] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1: Dual-fluid self-aspirated ORC hybrid powertrain system adapted for range-extended electric vehicles (EREVs)

[0044] The dual-working-fluid self-aspirated ORC composite range extender / hybrid power system of this embodiment is adapted to range extender vehicles. The engine 19 only serves as a range extender to generate electricity and does not directly drive the wheels. The system includes a main working fluid circuit, a secondary working fluid circuit, a dual heat source heat exchange module, a self-aspirated ORC power module, a temperature-sensing rotary valve 7, a shared condenser 14, and a dual power generation module.

[0045] Main working fluid circuit: The main reservoir 1 is integrated with the original vehicle expansion tank, and the internal fluid is a mixture of water and ethylene glycol antifreeze. When the engine 19 is working, the main working fluid enters the engine water jacket 2 to absorb heat from the cylinder block (the water temperature rises to 95-105℃), and enters the exhaust gas high-temperature superheater 5 through the mechanical temperature-sensing bypass valve 3 (the valve is closed when the water temperature is ≤95℃). After the exhaust gas is discharged from the exhaust pipe 23, it first enters the buffer heat exchange chamber 18 to smooth out temperature fluctuations (from 200℃ at idle speed / 800℃ during rapid acceleration to ±3℃), and then enters the exhaust gas high-temperature superheater 5 to heat the main working fluid. The main working fluid is heated to 120-140℃ to form high-pressure steam. After being stabilized by the steam pressure stabilizer 6, it enters the temperature-sensing rotary valve 7.

[0046] Secondary working fluid circuit: The secondary liquid tank 15 contains R245fa low-boiling-point refrigerant (boiling point 50-60℃); when the engine is cold / idling / low speed, the engine water temperature is 60-85℃. The secondary working fluid enters the perfluoroether rubber heat-absorbing film cavity 16 to absorb low heat, and then enters the exhaust gas low-temperature preheater 17. After being slightly heated by the exhaust gas, it boils and forms high-pressure steam, which enters the temperature-sensing rotary valve 7.

[0047] Dual working fluid switching: Temperature-sensing rotary valve 7 senses the engine water temperature. When the water temperature is <90℃, the secondary working fluid steam circuit is opened, and the secondary working fluid steam enters the ORC piston cylinder 8 to push the piston to do work. When the water temperature is >95℃, the secondary working fluid steam circuit is closed and the primary working fluid steam circuit is opened, and the primary working fluid high-pressure steam enters the ORC piston cylinder 8 to push the piston to do work. When the water temperature is 90-95℃, the steam circuit is smoothly switched.

[0048] Self-priming ORC operation: The ORC piston cylinder 8 has a dual-chamber self-priming structure 9. The left water intake chamber 91 and the right water intake chamber 92 alternately complete the "air intake-water replenishment" action under the inertia of the flywheel 12. The working fluid is continuously and stably supplied through the one-way valve 93, and the micro liquid storage tank 10 further smooths out the flow pulsation. The mechanical pressure relief valve 11 on the top of the ORC piston cylinder 8 automatically opens to release steam to the common condenser 14 when the pressure in the cylinder exceeds 0.62MPa, ensuring pressure safety. The flywheel 12 is coaxially connected to the auxiliary generator 13. The piston's work drives the flywheel 12 to rotate, driving the auxiliary generator 13 to generate electricity.

[0049] Condensation reflux: The steam after the main / auxiliary working fluids have done work enters the common condenser 14 and liquefies. Under the inertia of the flywheel 12 and the self-suction of the ORC piston cylinder 8, it flows back to the main liquid storage tank 1 and the auxiliary liquid storage tank 15 through the one-way valves respectively, realizing a closed self-circulation.

[0050] Dual power output: The main shaft of engine 19 drives the main generator 20 to generate electricity (basic power), and the ORC system drives the auxiliary generator 13 to generate electricity (waste heat power). The two power sources are combined to charge the power battery 21, and the power battery 21 supplies power to the drive motor 22 to drive the vehicle.

[0051] In this embodiment, the total power generation efficiency of the range extender is increased from the traditional 36% to 50%, 1L of oil can be converted into 4.2 kWh of electricity, and the vehicle's range on a full tank of fuel is increased from the traditional 1000km to 1400km, an increase of 40%.

[0052] Example 2: Dual-fluid self-aspirated ORC hybrid powertrain system adapted to conventional hybrid electric vehicles (HEVs)

[0053] The system structure of this embodiment is basically the same as that of embodiment 1, except that: the engine 19 not only drives the main generator 20 to generate electricity, but can also directly drive the vehicle wheels through the clutch; the waste heat power recovered by the ORC system (auxiliary generator 13) can directly drive the drive motor 22, or replenish the power battery 21, realizing a composite power mode of "engine direct drive + motor drive + waste heat power generation".

[0054] In this embodiment, the overall thermal efficiency of the hybrid engine is increased from the traditional 43% to 58%, and the overall fuel consumption of the vehicle is reduced from the traditional 4.5L / 100km to 3.2L / 100km. Moreover, under high-speed constant speed conditions, the ORC system operates at full power, and the fuel consumption can be as low as 3.0L / 100km, solving the problem of high fuel consumption of traditional hybrids at high speeds.

[0055] Example 3: Heat dissipation balance control under heavy load conditions

[0056] When the vehicle is climbing hills or driving under high load for extended periods in summer, the engine water jacket 2 temperature rises to 100℃. The mechanical temperature-sensing bypass valve 3 automatically opens as the water temperature rises, diverting 30% of the main working fluid directly to the original vehicle radiator 4 to prioritize engine cooling. The remaining 70% of the main working fluid enters the exhaust gas high-temperature superheater 5, and the ORC system appropriately reduces power to ensure that the engine water temperature remains stable at 95-105℃, with no heat decay or high-temperature risk. When the vehicle load decreases and the water temperature drops back to 95℃, the mechanical temperature-sensing bypass valve 3 automatically closes, and the ORC system resumes full-power operation to maximize the recovery of waste heat.

[0057] The core of this invention lies in its extremely simple design of "dual working fluid, dual heat source, pure mechanical self-priming, and passive control," which solves all the core defects of existing ORC waste heat recovery systems. It achieves efficient and low-cost recovery of internal combustion engine waste heat under all operating conditions. Moreover, it has a simple structure, high reliability, and is easy to mass-produce. It can be quickly applied to existing range-extended and hybrid vehicles, and has extremely high industrial value and market prospects.

[0058] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-working-fluid self-aspirating ORC (Oriented Range Extender / Hybrid) powertrain system, characterized in that, It includes a dual-working-fluid circuit, a heat exchange structure with multiple heat sources, an ORC power-operating section, a mechanical control section, a condensation reflux section, and a power generation output section. The main working-fluid circuit and the auxiliary working-fluid circuit of the dual-working-fluid circuit are each equipped with an ORC power-operating section, a condensation reflux section, and a power generation output section. The main and auxiliary working fluids operate in a time-sharing manner based on the engine operating conditions. The mechanical control section is a mechanical structure without redundant electronic control and sensors, which includes automatic switching of the dual-working-fluid gas circuit, passive balance between engine heat dissipation and ORC heat absorption, working fluid pressure safety control, and working fluid supply stability control.

2. The dual-working-fluid self-aspirating ORC composite range extender / hybrid power system according to claim 1, characterized in that, The main working fluid circuit includes a main reservoir, an engine water jacket, an exhaust gas high-temperature superheater, a purely mechanical control module, a self-priming ORC power module, and a common condenser, all sequentially and sealed together along the working fluid flow direction. The main reservoir is integrally formed with the original engine expansion tank. The original engine water jacket serves as the preheating chamber for the ORC power module. A mechanical temperature-sensing bypass valve is fixedly installed at the outlet end of the engine water jacket. The other port of the mechanical temperature-sensing bypass valve is sealed and connected to the original engine radiator. The valve opening of the mechanical temperature-sensing bypass valve is linearly related to the engine water jacket temperature.

3. The dual-working-fluid self-aspirating ORC composite range extender / hybrid power system according to claim 2, characterized in that, The passive temperature control logic of the mechanical temperature-sensing bypass valve is as follows: when the engine water jacket temperature is ≤95℃, the valve is completely closed, and the main working fluid enters the exhaust gas high-temperature superheater; when the engine water jacket temperature is >95℃, the valve opens linearly and gradually as the water temperature rises, diverting the main working fluid to the original vehicle radiator, so that the engine heat dissipation and ORC heat absorption are kept in dynamic balance.

4. The dual-working-fluid self-aspirating ORC composite range extender / hybrid power system according to claim 2, characterized in that, The auxiliary working fluid circuit includes an auxiliary liquid storage tank, a perfluoroether rubber low-temperature heat-absorbing membrane cavity, an exhaust gas low-temperature preheater, a pure mechanical control module, a self-priming ORC power module, and a common condenser, which are sequentially sealed and connected along the working fluid flow direction. The main working fluid inlet and outlet are located on the upper bottom surface of the engine water jacket, and the auxiliary working fluid inlet and outlet are located on the lower bottom surface of the engine water jacket. The perfluoroether rubber low-temperature heat-absorbing membrane cavity is fixed to the lower bottom surface of the engine water jacket. Under low load, the auxiliary working fluid pressurizes the membrane cavity to expand and fill the entire engine water jacket. Under high load, the main working fluid pressure compresses the membrane cavity and the main working fluid fills the entire engine water jacket. The primary and secondary working fluids work in separate time periods and do not cross-contaminate each other. The secondary working fluid only absorbs low-temperature heat from the engine block and naturally boils to produce steam when the engine coolant temperature is between 60 and 85°C.

5. The dual-working-fluid self-aspirating ORC composite range extender / hybrid power system according to claim 1, characterized in that, The multi-heat source heat exchange section includes a high-temperature superheater for exhaust gas, a low-temperature preheater for exhaust gas, and a jacketed buffer heat exchange structure. The buffer heat exchange structure is fixedly installed at the connection end between the exhaust pipe and the heat exchange structure. The exhaust gas enters the buffer heat exchange chamber of the buffer heat exchange structure through the exhaust pipe, smoothing the temperature fluctuation from ±20℃ to ±3℃. Then, it is divided into two paths and enters the high-temperature superheater and the low-temperature preheater for exhaust gas respectively to perform stepped heat exchange with the main and auxiliary working fluids. A closed steam pressure stabilizing package is fixedly installed at the outlet end of the high-temperature superheater for exhaust gas to stabilize the temperature and pressure fluctuations of the main working fluid steam.

6. The dual-working-fluid self-aspirating ORC compound range extender / hybrid power system according to claim 1, characterized in that, The self-priming ORC's working part includes an ORC piston cylinder, a flywheel, a dual-chamber self-priming structure, a mechanical pressure relief valve, and a miniature liquid storage tank. The dual-chamber self-priming structure is built into the ORC piston cylinder and includes two symmetrically arranged water intake chambers with a 180° phase difference. Each water intake chamber is equipped with a one-way valve. The two water intake chambers alternately complete the air intake-water replenishment action with the reciprocating motion of the ORC piston cylinder, so as to ensure a continuous and stable supply of working fluid. The miniature liquid storage tank is fixed to the outer wall of the ORC piston cylinder and is used to absorb the flow pulsation of the working fluid. The mechanical pressure relief valve is fixed to the top of the ORC piston cylinder.

7. The dual-working-fluid self-aspirating ORC compound range extender / hybrid power system according to claim 6, characterized in that, The preset spring preload pressure of the mechanical pressure relief valve is 0.62 MPa. When the steam pressure in the ORC piston cylinder exceeds this preset value, the valve disc of the pressure relief valve will automatically open to release the excess steam into the common condenser. The flywheel is rigidly connected to the crankshaft of the ORC piston cylinder on the same axis. The rotational inertia of the flywheel provides pure mechanical power for the alternating operation of the dual-chamber self-priming structure and the self-priming return of the working fluid.

8. The dual-working-fluid self-aspirating ORC compound range extender / hybrid power system according to claim 1, characterized in that, The purely mechanical control part is a temperature-sensitive rotary valve, which is coaxially fixed at the air inlet end of the self-priming ORC power section and has a built-in rotary valve core structure driven by a paraffin thermostat. The dual working fluid circuit switching logic of the temperature-sensitive rotary valve is as follows: when the engine coolant temperature is <90℃, the valve core blocks the main working fluid circuit and opens the secondary working fluid circuit. When the engine coolant temperature is >95℃, the valve core blocks the secondary working fluid steam path and opens the primary working fluid steam path; when the engine coolant temperature is 90-95℃, the valve core gradually moves under the drive of the 45° spiral guide groove to complete the smooth switching of the dual working fluid steam paths and avoid working fluid mixing and cross-contamination.

9. The dual-working-fluid self-aspirating ORC compound range extender / hybrid power system according to claim 1, characterized in that, The condensation reflux section is an integrated shared condenser. After the main and auxiliary working fluids have done work, the steam enters the shared condenser, is liquefied, and then flows back to the main storage tank and auxiliary storage tank through independent one-way reflux valves respectively. The reflux power of the main and auxiliary working fluids is provided solely by the self-suction force generated by the rotational inertia of the flywheel and the reciprocating motion of the ORC piston cylinder, without any additional electrical or mechanical power input.

10. The dual-working-fluid self-aspirating ORC compound range extender / hybrid power system according to claim 1, characterized in that, The power generation output section includes a main generator and an auxiliary generator; the main generator is rigidly connected coaxially to the engine main shaft and is directly driven by the engine to generate electricity; the auxiliary generator is rigidly connected coaxially to the flywheel of the self-aspirated ORC power unit, and the flywheel is driven to rotate by the ORC piston cylinder to drive the auxiliary generator to generate electricity; the power output terminals of the main and auxiliary generators are connected in parallel and connected to charge the vehicle's power battery or directly drive the vehicle's drive motor through the same power distribution circuit.

11. The dual-working-fluid self-aspirating ORC compound range extender / hybrid power system according to any one of claims 1-10, characterized in that, Each part of the system is a standardized modular structure, which does not interfere with the original vehicle engine structure and does not require modification of the core structure of the original vehicle cooling, exhaust and power system; the back pressure of the exhaust gas high temperature superheater and the exhaust gas low temperature preheater is ≤2kPa, and the system is compatible with the power architecture of range-extended electric vehicles (EREV) and ordinary hybrid electric vehicles (HEV / PHEV).

Images