Purely passive temperature difference driven self-generating heat engine and its working method

Abstract

This invention discloses a purely passive temperature difference-driven self-generating circulating heat engine and its operating method, belonging to the field of thermal power engineering technology. The heat engine consists of a high-temperature heat collection unit, a circulating power unit, a low-temperature heat dissipation unit, and a dual-heat conduction path interlocking on / off structure connected sequentially. The method passively controls the opening and closing of the two heat conduction paths through the temperature change or deformation state of the circulating power unit itself, maintaining a constant interlocked state of one on and one off. It can spontaneously circulate and perform work solely based on the external temperature difference, requiring no external intervention throughout the process. This invention transforms the gradual, slight temperature difference of natural heat flow into an effective working temperature difference through interlocking on / off, efficiently utilizing low-grade heat energy such as industrial waste heat and medium-low temperature geothermal energy. It is suitable for solid, liquid, and gaseous working fluids, especially piezoelectric power generation. The addition of a heat recovery structure allows for the recovery of waste heat and active heat interception, achieving integrated heat dissipation and power generation. The overall structure is simple, modularly deployable, possesses adaptive dynamic balancing capabilities, and is adaptable to extreme environments, filling the technological gap in purely passive temperature difference power devices.

Description

Technical Field

[0001] This invention belongs to the field of thermal power engineering technology, specifically relating to a purely passive temperature difference driven self-generating cycle heat engine and its working method. Background Technology

[0002] A heat engine is a core piece of equipment that converts thermal energy into mechanical energy. Existing technologies are mainly divided into two categories: one is the mainstream heat engine represented by internal combustion engines and steam turbines, which rely on forced valve trains and crankshaft connecting rods to achieve the working cycle. These engines have complex structures, many failure points, and require continuous operation and maintenance. The other is the temperature difference driven heat engine represented by Stirling heat engines, thermoacoustic heat engines, semiconductor thermoelectric generators, and shape memory alloy (SMA) heat engines. Although these engines can operate using external temperature differences, each has its own core bottlenecks.

[0003] Stirling engines and thermoacoustic engines still require forced linkage components such as gas distribution pistons and resonant tubes to maintain circulation, making it impossible to achieve completely passive operation without intervention; semiconductor thermoelectric generators have no moving parts, but their conversion efficiency is extremely low, and they are only suitable for low-power scenarios.

[0004] Although shape memory alloy (SMA) heat engines appear to be driven solely by the thermal deformation of the material, they are not essentially purely passive. Their operating cycle depth is bound to the martensitic-austenitic phase transformation temperature range of the SMA material itself. Their "start-up," "cycle frequency," and "stroke range" are entirely determined and limited by the material's inherent, non-adjustable phase transformation temperature, making them extremely sensitive to external temperature differences. Once the temperature difference deviates from its phase transformation range, the cycle terminates.

[0005] In contrast, the solution of this invention completely eliminates the dependence on the physical properties of specific materials. This invention constructs an independent temperature difference potential energy accumulation mechanism through a universal structural design. Its cycle state is determined by designable structural parameters (such as the switch trigger threshold), rather than by the inherent phase change properties of the working fluid material, thus truly realizing active adaptation to the external temperature difference range and configurable "purely passive" operation.

[0006] The aforementioned solutions fall into two path dependencies: forced cyclic dependence leads to structural redundancy and reliability bottlenecks, while dependence on special material properties (such as the SMA phase transition point) limits application scenarios to the fixed physical parameters of the materials, making it impossible to flexibly adapt to diverse low-grade thermal energy scenarios. Furthermore, existing technologies generally lack mechanisms for accumulating potential energy due to temperature differences—natural heat flow can only maintain a very small temperature difference along the conduction path, insufficient to drive continuous work, resulting in the ineffective utilization of low-grade thermal energy such as industrial waste heat and medium-to-low temperature geothermal energy, which account for a significant portion of total energy consumption.

[0007] In summary, there is an urgent need in this field for a heat engine that fully complies with the second law of thermodynamics, achieves the accumulation and release of thermal potential energy through pure structural design rather than relying on special materials, does not require a forced linkage structure, and can spontaneously start and continuously cycle to do work based solely on the external natural temperature difference, in order to fill the technological gaps in clean energy, extreme unmanned environments and other scenarios. Summary of the Invention

[0008] Terminology Definition To clearly define the scope of protection of this invention and avoid ambiguity, the core terms used in this application are hereby uniformly defined as follows. Unless otherwise specified, the following terms appearing in this application shall be understood in accordance with these definitions: Purely passive means that the entire working cycle of the system, method, or apparatus of this invention is spontaneously driven and controlled by changes in the internal thermodynamic state of the apparatus caused by external temperature changes (i.e., temperature rises and falls and the resulting deformation or associated signals), without the need for any external commands, external electrical energy, external mechanical intervention, or manual timing control. This differs from existing systems that rely on external controllers, solenoid valves, forced gas distribution mechanisms, or require manual timing settings, and also from systems that simply rely on specific absolute temperature thresholds for triggering. A heat conduction path refers to the macroscopic heat transfer path from one physical port (such as a high-temperature end) to another physical port (such as a circulating work unit). A heat conduction path includes at least a heat-conducting medium and may include a switching element. The core heat conduction paths in this invention include a "first heat conduction path" and a "second heat conduction path," and when a heat recovery structure is provided, a "heat recovery path" is also included. Furthermore, the terms "high-temperature end / low-temperature end" and "high-temperature heat collection unit / low-temperature heat dissipation unit" used in the claims of this application are functional generalizations and structural examples of the same technical feature under different protection subjects. They are completely equivalent in thermodynamic function and both refer to the input and output sides of heat energy. The structural expressions of "high-temperature heat collection unit" or "low-temperature heat dissipation unit" should not be interpreted as limiting the scope of protection. An interlocking on / off structure (or interlocking logic) refers to a specific heat conduction state switching mechanism. Its core feature is that at any instant during the cycle, of all available heat conduction paths thermally connected to the cyclic work unit (including but not limited to the first heat conduction path, the second heat conduction path, and if a regenerating path exists, this path is also included), only one is in an effective thermal connection (conductivity) state, while all other paths are in an effective thermal blocking (off) state. The conduction and off states of each path are mutually causal and interlocked, preventing intermediate states where two or more paths are simultaneously conducting, or all paths are simultaneously off. This structure is the core of realizing the "temperature difference potential energy accumulation" of this invention. In the simplest configuration, the interlocking logic manifests as a one-to-one conduction and one-to-off relationship between the first and second heat conduction paths; in a configuration with a regenerating structure, this logic manifests as interlocking conduction between multiple paths, both essentially belonging to the "interlocking on / off structure" described in this invention. A controllable thermally conductive switch refers to a functional switching element installed in the thermally conductive path to control the "on" and "off" states of heat transfer in that path. It includes, but is not limited to, mechanical travel switches, temperature change threshold-triggered switches, heat flow reversing valves, or equivalents. Its core feature is that its switching action is passively triggered by temperature changes or deformation of the cyclic work unit. When multiple thermally conductive paths exist, the controllable thermally conductive switch for each path can be an integrated multi-position switch (such as a rotary step thermal switch or a reversing valve), or it can be multiple independent switches working in coordination. A temperature difference-related signal refers to a measurable physical quantity that has a monotonic functional relationship with the temperature difference, and whose numerical change can uniquely and definitively indicate the direction and magnitude of the temperature difference change. Temperature difference-related signals include, but are not limited to: voltage differences directly generated by the thermoelectric effect of temperature difference, changes in material resistance or capacitance caused by temperature difference, changes in working fluid pressure caused by temperature difference, and electrical signals converted from deformation driven by temperature difference. When the numerical change of the temperature difference-related signal indicates that the temperature difference has changed to a preset threshold, a corresponding control action is triggered. In this application, the expression "temperature difference or temperature difference-related signal" means that the same control objective can be achieved either by directly measuring the temperature difference itself or by measuring any of the aforementioned related signals that characterize the temperature difference. The cyclic work unit refers to the core work-generating component of this invention, which includes a working medium (working fluid) and is capable of generating physical state changes that can output mechanical energy as its temperature changes. Here, "working fluid" can encompass working fluids in solid, liquid, or gaseous form; Deformation (in a broad sense) refers to any change in physical state of the cyclic work unit caused by temperature changes that can be used to generate mechanical work. This includes, but is not limited to: a) free thermal expansion or contraction without external constraints, resulting in macroscopic displacement; b) under external constraints, the tendency of thermal expansion / contraction is suppressed, thereby converting into high-intensity mechanical stress output (i.e., "constrained work"). The term "deformation" in the claims and specification of this application covers both of the above-mentioned work modes. In the claims, the expressions "expansion" and "contraction" are used to refer to the most common deformation directions, but under external constraints, the internal stress generated by temperature changes also constitutes the deformation output described in this invention.

[0009] The purpose of this invention is to address the core deficiencies and application gaps of existing heat engines. The core objective is to provide a purely passive, temperature-difference-driven, self-circulating heat engine that fully conforms to the natural law of heat spontaneously flowing from high to low temperatures, as described by the second law of thermodynamics. The core relies on an interlocking on / off structure formed by two heat conduction pathways to construct a dedicated temperature difference potential energy accumulation structure. This structure spontaneously accumulates temperature difference, and once the temperature difference reaches a critical threshold, it releases the potential energy to drive the cyclic work unit to complete the reciprocating mechanical energy output. The entire process requires no active electronic control or external control commands, and no initial external force triggering. It can spontaneously start and continuously cycle and perform work solely based on a continuous external temperature difference, realizing the core design logic of accumulating potential energy and concentrating work along the natural flow of energy. A secondary objective of this invention is to provide a technical solution adaptable to all types of working fluids and all triggering methods, covering the full power range from micro-actuators to ultra-high-power power plants, based on the aforementioned core cycle principle. It also provides implementation schemes for this heat engine in all scenarios, including clean energy, extreme environments, and unmanned platforms, enabling the invention to achieve commercial application across all scenarios.

[0010] To achieve the aforementioned objectives, this invention employs the following technical solution: the core loop logic is independent of the working fluid state, on / off triggering method, and specific component implementation method, relying solely on the natural laws of thermodynamics to achieve operation: This invention first provides a purely passive temperature difference-driven spontaneous circulation method, the core steps of which are as follows: 1. Set up a cyclic work unit that can deform with temperature changes and output mechanical energy; 2. Establish a first heat conduction path between the cyclic power unit and the high-temperature end, and establish a second heat conduction path between the cyclic power unit and the low-temperature end; 3. By passively controlling the opening and closing of the two heat conduction paths through the temperature change or deformation state of the cyclic work unit itself, the two paths are kept in an interlocked state of one conducting and one closing at any time during the cycle. 4. When the first heat conduction path is open, heat flows unidirectionally from the high-temperature end into the circulating work unit, causing it to heat up and expand to do work. This process also widens the temperature difference between the circulating work unit and the low-temperature end, thereby accumulating the potential energy of the temperature difference at the cold source end. When the second heat conduction path is open, heat is discharged unidirectionally from the circulating work unit to the low-temperature end, causing it to cool down, contract, and reset or do work. This process also widens the temperature difference between the circulating work unit and the high-temperature end, thereby accumulating the potential energy of the temperature difference at the heat source end. 5. It can be spontaneously started and continuously cycled according to the above interlocking mechanism simply by relying on the continuous temperature difference between the high temperature end and the low temperature end; The core of the above method lies in constructing an interlocked heat conduction path, so that the cyclic work unit can unidirectionally absorb heat from the high-temperature end and store energy during the heat absorption phase, and unidirectionally discharge heat to the low-temperature end and reset during the heat release phase, repeating the cycle continuously, operating purely passively throughout the entire process.

[0011] The core design of this heat engine is a purely passive temperature difference-driven self-generating cycle heat engine, comprising a high-temperature heat collection unit, a first heat conduction path, a circulating power unit, a second heat conduction path, and a low-temperature heat dissipation unit. The components are sequentially thermally connected along the heat conduction paths, with the specific configuration as follows: 1. High-temperature heat collection unit: This is the heat input interface of the heat engine, used to collect heat energy from external high-temperature heat sources. It can be directly attached to the surface of the heat source or thermally coupled to the external heat source through a heat-conducting medium. It is compatible with natural and artificial heat sources, covering the entire temperature range of heat sources from low-grade waste heat to ultra-high-temperature concentrated heat. All high-temperature heat sources must first be raised in temperature by the heat collection / concentration structure before supplying stable heat energy to the heat engine to ensure cycle efficiency. 2. First heat conduction path: Located between the high-temperature heat collection unit and the circulating power unit, its opening and closing are passively triggered by state changes during the heat engine's own cycle, without any external intervention. A controllable heat conduction switch can be installed in this path; 3. Cyclic work unit: This is the core work component of the heat engine. It is configured to change volume or pressure with temperature. It expands by absorbing heat and outputs mechanical energy, and contracts by releasing heat to restore the structure. It continuously converts thermal energy into usable mechanical energy. Its physical state changes due to absorbing heat and heating up or releasing heat and cooling down, which in turn triggers the switching of the on and off states of the first heat conduction path and the second heat conduction path. 4. Second heat conduction path: Located between the circulating power unit and the low-temperature heat dissipation unit, its on / off triggering logic is completely matched with that of the first heat conduction path, requiring no external intervention and being naturally controlled by the heat engine's own circulation state. A controllable heat conduction switch can be installed in this path; 5. Low-temperature heat dissipation unit: This is the heat dissipation interface of this heat engine, used to connect to an external low-temperature cold source, continuously releasing the heat discharged by the cycle work unit to the low-temperature environment, maintaining the temperature difference potential energy required for the heat engine cycle, and is compatible with natural and artificial cold sources. The first heat conduction path and the second heat conduction path form an interlocked on / off structure. The initial assembly state of the two is one conduction and one off. After the on / off state is switched, the interlocked logic of one conduction and one off is always maintained, forming an alternating unidirectional heat conduction path at both ends of the cyclic work unit. This heat engine can start spontaneously and continuously cyclically perform work by relying solely on the continuous temperature difference between the external high-temperature heat source and the low-temperature cold source.

[0012] Based on the aforementioned core solution, this invention provides the following optional preferred configurations to further improve the performance and adaptability of the heat engine: 1. Preferred Regenerative Efficiency Scheme: The heat engine further includes a regenerative structure for temporarily storing and releasing heat flowing into and / or out of the circulating work unit during the heat conduction state switching process. With the addition of the regenerative structure, the system expands to three interlocked heat conduction paths: a first heat conduction path, a second heat conduction path, and a regenerative path. This three-way on / off mechanism also follows the interlocking logic described in this invention, meaning that only one path is active at any given time. The regenerative structure can be implemented in various forms, such as: a) Independent Regenerator: An independently installed heat storage component thermally coupled to the circulating work unit, absorbing and temporarily storing heat during a specific stage of the cycle, and releasing the heat back to the circulating work unit in subsequent stages; b) Mutually Regenerative Structure: The circulating work unit includes at least two working bodies that can controllably come into thermal contact or separate from each other, so that during thermal contact, the high-temperature working body directly transfers heat to the low-temperature working body, thereby achieving mutually regenerative heating. In the heat recovery scheme, the controllable heat conduction switch of each heat conduction path can be an integrated multi-position switch (such as a rotary step heat switch or a reversing valve), or it can be multiple independent switches that work together, as long as the interlocking logic can be implemented between multiple paths. 2. Preferred Interlocking Trigger Scheme: The interlocking on / off function formed by the first and second heat conduction paths can be achieved through a double-throw thermal switch. This is passively triggered by temperature changes or deformation of the cyclic work unit, synchronously switching between the heat absorption and release paths, always maintaining a one-on-one interlocking state. Alternatively, independent stroke-triggered mechanical thermal switches can be used, with the on / off trigger thresholds and switching strokes of the two switches perfectly matched. The initial assembly is set to one on and one off. A linkage triggering mechanism is fixed on the cyclic work unit. When the deformation state of the cyclic work unit changes due to temperature variations, the linkage triggering mechanism simultaneously acts on the trigger ends of both switches, synchronously completing the bidirectional on / off switching. 3. Optimal Solution for Stable Temperature and Enhanced Efficiency: A stable temperature heat storage unit is installed, employing a phase change box structure with built-in phase change material, positioned between the high-temperature heat collection unit and the first heat conduction path. Its core function is to stabilize the heat source output temperature, eliminate temperature fluctuations, maintain the effective maximum operating temperature of the circulating work unit, and prevent the effective temperature difference from decreasing and the cycle efficiency from dropping due to heat source temperature fluctuations. Simultaneously, during the heat release phase of the circulating work unit, it absorbs and stores heat from the heat source, preventing the heat source from being idle and maximizing the utilization rate of thermal energy. This simultaneously improves the overall cycle efficiency of the heat engine in terms of both temperature stability and thermal energy utilization. 4. Modular Configuration Optimal Solution: This heat engine features an integrated, pluggable, independent modular structure. A single module can operate independently to output mechanical energy; multiple independent modules can be connected in parallel to form a network, sharing the same heat collection and dissipation terminals, enabling flexible expansion of torque output and power; multiple independent modules can be connected in series with thermal coupling, with the low-temperature heat dissipation unit of one module thermally connected to the high-temperature heat collection unit of the next module, achieving cascaded utilization of thermal energy and improving overall thermal energy utilization efficiency. In particular, when modules have built-in regenerative structures, especially when they are mutually regenerative structures, the series-parallel combination of multiple modules can significantly improve the efficiency of a single unit, and further achieve a synergistic multiplication of overall efficiency and output power through system-level cascaded utilization of thermal energy and power aggregation. 5. Optimal Solution for All Working Fluids: The core loop logic of this invention is independent of the working fluid form and can be adapted to all types of working fluids, including: Solid working fluid solution: The circulating work unit uses a thermally expanding reciprocating component made of a solid material with a high linear coefficient of thermal expansion. Through the linear expansion of the solid when heated and the linear contraction when cooled, it outputs linear reciprocating mechanical energy and naturally has the characteristics of high torque output. Liquid working fluid scheme: The circulating work unit is a closed liquid cylinder structure, which is filled with a liquid working fluid with a high expansion coefficient. The liquid expands when heated and contracts when cooled, which drives the work components to output linear reciprocating mechanical energy. Gas working fluid scheme: The circulating working unit is a closed cylinder structure, filled with inert gas working fluid. The gas pressure increases when heated and decreases when cooled, driving the working parts to output linear reciprocating mechanical energy. 6. Optimal Power Generation Adaptation Scheme: The linear reciprocating mechanical energy output by the cyclic work unit can be directly connected to a piezoelectric power generation component, directly converting mechanical energy into electrical energy. Alternatively, it can be directly connected to an electromagnetic induction power generation component, where the reciprocating motion drives the stator and rotor to generate relative displacement, cutting magnetic field lines to generate electricity. This eliminates the need for complex transmission mechanisms, and multiple arrays can be arranged to achieve large-scale power output. More universally, this invention can directly use the power generation output signal (such as voltage, current, and power) of the cyclic work unit itself as a sensing signal to perceive its thermodynamic state (temperature change, degree of deformation), and use this signal as the basis for triggering the switching of the heat conduction path. This scheme combines the "power generation" and "sensing" functions into one, eliminating the need for independent temperature difference or displacement sensors, achieving a high degree of system integration and purely passive self-adaptation. Furthermore, under external constraints, the work unit of this invention can also operate in a "constrained work" mode, where the thermal deformation trend is suppressed and converted into high-intensity mechanical stress output. This stress can be directly coupled to piezoelectric power generation components, making it particularly suitable for applications requiring extremely high power density.

[0013] The core working principle of this heat engine is that it operates without any active control commands or external intervention. Its core operation completely follows the second law of thermodynamics, which states that heat spontaneously flows from a high-temperature heat source to a low-temperature cold source. In conventional heat conduction under natural conditions, when heat flows along the conduction path, the two ends of the path maintain a very small temperature difference. Even with a continuous heat flow, it is impossible to generate sufficient power to drive the mechanical structure to do work. This is the core reason why a large amount of low-grade heat energy is difficult to utilize.

[0014] The core innovation of this invention lies in constructing an interlocking on / off structure to form a unique temperature difference potential energy accumulation mechanism. Relying on the interlocking characteristics of this structure, it breaks the inherent state of a gradual temperature difference in natural heat flow. During the heat absorption phase, unidirectional conduction causes the work-generating unit to continuously heat up and expand, simultaneously widening the temperature difference between it and the low-temperature end, thus accumulating potential energy at the cold source end. During the heat release phase, unidirectional conduction causes the work-generating unit to continuously cool down and contract, simultaneously widening the temperature difference between it and the high-temperature end, thus accumulating potential energy at the heat source end. Both heat absorption expansion and heat release contraction can perform work individually or simultaneously depending on the type of working fluid and structural configuration, without any external forced intervention, driven purely by natural thermodynamic laws.

[0015] It must be specifically stated that the "interlocking on / off structure" in this invention is not an optional preferred feature, but a necessary technical means to achieve the core technical effect of "temperature difference potential energy accumulation". It is precisely through the interlocking logic of "one and only one conductive path" that this heat engine is able to break the inherent state of a gentle temperature difference in natural heat flow: during the heat absorption phase, heat dissipation to the low-temperature end and other non-target pathways is blocked, causing the working unit to continuously heat up and widen the temperature difference with the low-temperature end, accumulating potential energy at the cold source end; during the heat release phase, heat intake to the high-temperature end and other non-target pathways is blocked, causing the working unit to continuously cool down and widen the temperature difference with the high-temperature end, accumulating potential energy at the heat source end. A heat engine lacking the interlocking structure cannot achieve the temperature difference potential energy accumulation and efficient pure passive cycle described in this invention; the two are technically inseparable.

[0016] The "purely passive" control logic disclosed in this invention can be further embodied in a more advanced form: the electrical signal (such as piezoelectric voltage) directly output by the cyclic work unit when it generates deformation is used as a sensing signal to perceive its own thermodynamic state, and this electrical signal triggers the switching of the heat conduction path. This "power control integration" design combines power generation and sensing functions into one, eliminating the need for separate temperature difference or displacement sensors, achieving a high degree of system integration and purely passive self-adaptation, and is one of the preferred control methods of this invention.

[0017] The complete spontaneous cycle of this heat engine, as described in the general thermodynamic cycle process, consists of four continuous and seamlessly connected stages. The entire cycle is naturally triggered without external intervention and is independent of the working fluid state, triggering method, or specific component implementation: 1. Heat Absorption and Energy Storage Stage: In the initial state, the temperature of the circulating work unit and the low-temperature heat dissipation unit are close to the same, and the whole is in a low-temperature state. During this stage, the first heat conduction path remains open, while the second heat conduction path remains closed. Heat from the high-temperature heat collection unit continuously flows into the circulating work unit. During this process, the temperature difference between the circulating work unit and the high-temperature heat source end continues to decrease, and the potential energy of the temperature difference at the heat source end is gradually released, driving positive work. Simultaneously, the temperature difference with the low-temperature cold source end continues to increase, and the cold source end simultaneously accumulates a new round of potential energy of the temperature difference. The circulating work unit is heated and expands, outputting positive mechanical energy to the outside through the mechanical energy output end. Throughout the process, it releases potential energy and performs work while storing energy for the subsequent heat release stage, without any waste, and without a state of simply storing or releasing potential energy. 2. Thermal equilibrium switching stage: The cyclic work unit continuously absorbs heat and heats up. When its temperature change and / or deformation reach the preset state, the interlocking on / off structure is triggered simultaneously to complete the state switching. The first heat conduction path is then completely shut off, completely blocking the heat inlet channel. At this time, the second heat conduction path is simultaneously fully open, and the system switches to the heat release path. There is no external trigger throughout the process. The switching of the energy storage and release ports is completed naturally by the heat engine's own circulation state. 3. Heat Release and Reset Phase: After the second heat conduction path is activated, the heat inside the circulating work unit continues to be discharged to the low-temperature heat dissipation unit according to natural laws. During this process, the temperature difference between the circulating work unit and the low-temperature cold source end continues to decrease, and the temperature difference potential energy accumulated at the cold source end is gradually released, driving reverse work (when the working fluid type and structural configuration support it). Simultaneously, the temperature difference with the high-temperature heat source end gradually widens again, and the heat source end simultaneously accumulates the temperature difference potential energy for the next cycle. The circulating work unit cools down and contracts upon encountering cold, outputting reverse mechanical energy to the outside through the mechanical energy output end (when the working fluid type and structural configuration support it), forming a symmetrical closed loop with the heat absorption phase. 4. Cycle restart phase: The cycle work unit continues to release heat and cool down. When its temperature change and / or deformation reach another preset state, the interlocking on / off structure is triggered again to complete the state switch. The second heat conduction path is completely shut off, blocking the reverse flow of heat. At this time, the first heat conduction path is simultaneously fully open, and the system seamlessly switches back to the heat absorption and energy storage state, starting the next complete cycle. The above four stages continue to repeat. As long as there is a continuous total temperature difference between the high-temperature heat source and the low-temperature cold source, this heat engine can achieve uninterrupted self-circulation operation, with continuous power output without gaps, and can stably output reciprocating mechanical energy to the outside for a long time.

[0018] The following description of a general thermodynamic cycle process with a regenerative structure applies to both the method and the heat engine of this invention. When the heat engine is equipped with a regenerative structure, the system expands from a basic two-way interlock to a three-way interlock. The original two interlocked heat conduction paths, together with the newly added regenerative path (from the cycle work unit to the regenerative structure), constitute three interlocked heat conduction paths. All three paths always follow the interlock logic, meaning that only one path is active at any given time, and its on / off state is passively triggered by temperature changes or deformation of the cycle work unit. The control logic for the on / off of the regenerative path is as follows: The on signal reuses the cold or hot switching signal of the main path. That is, when the circulating work unit triggers the switching of the heat absorption and heat release main circuits due to temperature changes, the regenerative path is simultaneously turned on. The off signal can use a temperature difference or temperature difference-related signal. That is, when the temperature difference or temperature difference-related signal between the regenerative structure and the circulating work unit changes to below a preset threshold, the regenerative path is automatically turned off, ensuring that heat is only directionally transferred when there is an effective temperature difference, and automatically shuts off when the temperature difference is insufficient. After the regenerative path is turned off, this off action also serves as an enable signal to trigger the next stage of the main path (the first heat conduction path or the second heat conduction path), triggering the corresponding heat release or heat absorption path to turn on, ensuring seamless cycle connection. This linkage triggering mechanism can be achieved through mechanical linkage, electrical logic circuits, or changes in the thermodynamic state of the system itself, and is consistent with the main path switching logic, requiring no external active intervention. The complete process of the upgrade cycle is as follows: 1. Heat absorption and energy storage stage: The first heat conduction path is open, while the second heat conduction path and the regeneration path are closed. Heat from the high-temperature heat collection unit continuously flows into the circulating work unit, causing the work unit to heat up, expand, and perform work. 2. First Switching Stage (Heat Absorption → Heat Regeneration): The cyclic power unit heats up due to heat absorption. When its temperature change and / or deformation reach a preset state, the first heat conduction path is shut off, and the heat regeneration path is simultaneously activated (using the heat switching signal). The second heat conduction path remains off. At this time, the power unit is still at a high temperature, and some heat is temporarily stored in the heat regeneration structure via the heat regeneration path. As heat is transferred, the temperature difference between the power unit and the heat regeneration structure gradually decreases. When the temperature difference or temperature difference-related signal changes below a preset threshold, the heat regeneration path automatically shuts off (triggered by the temperature difference or temperature difference-related signal). 3. Second switching phase (regenerative → exothermic): After the regenerative path is shut down, its shutdown action acts as an enable signal, triggering the second heat conduction path to open, while the first heat conduction path remains shut down. The system then enters the exothermic path. 4. Heat release and contraction stage: The second heat conduction path is open, and the heat from the circulating work unit is discharged to the low-temperature heat dissipation unit through the second heat conduction path. The work unit cools down and contracts, completing its reset or performing work externally. 5. Third Switching Stage (Heat Release → Heat Recovery): When the cyclic power unit cools down due to heat release, and its temperature change and / or deformation reaches another preset state, the second heat conduction path is triggered to shut down, and the heat recovery path is triggered to open (using the cold switching signal), while the first heat conduction path remains closed. At this time, the power unit is still in a low-temperature state, and the heat temporarily stored in the heat recovery structure is released back to the power unit through the heat recovery path to preheat the power unit. As heat is transferred, the temperature difference between the heat recovery structure and the power unit gradually decreases. When the temperature difference or temperature difference-related signal changes below a preset threshold, the heat recovery path automatically shuts down. 6. Fourth switching phase (regenerative → endothermic): After the regenerative path is shut down, its shutdown action acts as an enable signal, triggering the first heat conduction path to open, while the second heat conduction path remains shut down. The system then re-enters the endothermic path, initiating the next complete cycle. In the upgrade cycle, the regenerative pathway inserts a brief conduction between the switching of the two main pathways: capturing temporarily stored heat when switching from heat absorption to heat release, and releasing replenished heat when switching from heat release to heat absorption. The conduction timing is synchronously triggered by the main pathway switching signal, and the shutdown timing is adaptively controlled by the temperature difference or temperature difference-related signal. The three pathways maintain strict interlocking at all times, completing a full cycle through four switching steps. This mechanism reduces the net heat taken from external heat sources and the net heat discharged from external cold sources, thereby improving the overall thermal efficiency of the heat engine.

[0019] Adaptive Dynamic Balance Reconfiguration Characteristics: This heat engine possesses a unique thermodynamic adaptive balance reconfiguration capability. Without any active intervention such as electrical control or mechanical adjustment, it can automatically adjust its operating parameters according to temperature fluctuations of external heat and cold sources, reconstructing a stable dynamic operating balance and maintaining a purely passive self-sustaining cycle. The core of this heat engine's adaptive capability relies on the inherent thermal expansion and contraction characteristics of the circulating work unit and the triggering logic of the interlocking on / off structure: the switching of the on / off structure depends only on the temperature change and / or deformation state of the circulating work unit driven by the temperature difference, and is not bound to the absolute temperature values ​​of the hot and cold ends; as long as the total temperature difference between the external high-temperature heat source and low-temperature cold source can drive the circulating work unit to produce a state change that meets the on / off switching requirements, the heat engine can automatically adapt to the new hot and cold end temperature conditions and reconstruct a stable cycle.

[0020] Thermodynamic compliance demonstrates that the working cycle of this invention fully complies with the first and second laws of thermodynamics, fundamentally different from perpetual motion machines that violate these basic laws. All the energy for the entire machine's operation comes from the spontaneous flow of heat energy from the high-temperature heat source to the low-temperature cold source; there is no design that generates energy out of thin air. Heat is always transferred unidirectionally from the high-temperature end to the low-temperature end, without any design that goes against the natural laws of thermodynamics. The heat engine can only circulate when there is a continuous temperature difference between the high and low-temperature heat sources externally; the cycle stops immediately when the temperature difference disappears, and there is no situation where work is continuously performed without external energy input.

[0021] Core beneficial effects 1. This invention transforms low-grade, gradual temperature differences into effective driving force, achieving completely passive, self-sustaining cyclic work. Through an interlocking on / off structure, it blocks heat dissipation to the low-temperature end and other non-target pathways during the heat absorption phase, and blocks heat intake to the high-temperature end and other non-target pathways during the heat release phase, thereby increasing the temperature difference between the cyclic work unit and the cold or heat source. This mechanism transforms the inherent, unusable, gradual temperature differences in natural heat flow into an effective temperature difference sufficient to continuously drive the deformation of the work unit and output mechanical energy. This allows low-grade heat energy, such as industrial waste heat and medium-low temperature geothermal energy, to be used for work without high-temperature and high-pressure conditions. The entire unit can spontaneously start and continuously cycle based solely on the external temperature difference, without any active control or forced linkage, truly achieving unattended, purely passive operation after deployment. 2. Significantly Improved Cycle Thermal Efficiency Through Regenerative Structure: This invention, by adding a regenerative structure, temporarily stores and re-releases heat flowing into and / or out of the cycle work unit during the heat conduction state switching process, reducing the heat demand on external heat and cold sources and improving the overall utilization rate of thermal energy. In particular, when using a regenerative structure, the irreversible heat loss during the cycle can be significantly reduced by at least two work units alternately absorbing and releasing heat and transferring heat to each other, enabling the heat engine to achieve higher output power and efficiency under the same temperature difference. 3. Imparting efficient heat dissipation capabilities to the heat engine, converting heat dissipation into electrical energy generation: When this heat engine is equipped with a regenerative structure, its operation exhibits characteristics drastically different from traditional heat dissipation. In traditional heat dissipation modes, heat is simply conducted unidirectionally and dissipated into the environment, with heat dissipation itself generating no added value. However, in the regenerative cycle of this heat engine, heat is actively intercepted and temporarily stored by the regenerative structure before being discharged, significantly reducing the heat discharged to the cold source. The system demonstrates the ability to actively retain heat. This characteristic makes the heat engine itself a highly efficient heat dissipation device, especially suitable for high-temperature heat dissipation scenarios: facing stringent heat dissipation requirements ranging from thousands of degrees to below 100 degrees Celsius, the regenerative structure can progressively retain heat and simultaneously generate electricity, transforming the purely energy dissipation process of heat dissipation into an electrical energy generation process, achieving the integration of heat dissipation and power generation. 4. Adaptable to all working fluids and scenarios, especially suitable for piezoelectric power generation. The core cycle logic of this invention is independent of the working fluid form and triggering method, and can be adapted to all types of working fluids, including solid, liquid, and gas. When using liquid or solid working fluids, it can output linear thrust in the hundreds of tons range. High thrust output can also be achieved when using gaseous working fluids, with strong single-stroke work capacity. In particular, when using solid working fluids, the thermal expansion and contraction process directly generates high stress output, which is naturally matched with the stress-charge conversion mechanism of piezoelectric power generation components. Efficient thermoelectric conversion can be achieved without intermediate transmission mechanisms, making it suitable for thermal power scenarios ranging from micro-actuators, distributed power generation, and industrial high-voltage drives to unmanned mobile platforms and deep space exploration, with outstanding technical extensibility. 5. Modular and pluggable design, flexible and adjustable performance: Single modules can operate independently to achieve micro-power output, while multiple modules can be connected in parallel to achieve unlimited power expansion, or connected in series to achieve cascaded utilization of thermal energy. Low marginal expansion cost perfectly adapts to the full power range requirements, from small civilian equipment to ultra-large power plants. In particular, when modules have built-in regenerative structures, especially when they are mutually regenerative, the series-parallel combination of multiple modules can significantly improve the efficiency of a single unit, and further achieve a synergistic multiplication of overall efficiency and output power through system-level cascaded utilization of thermal energy and power aggregation. 6. The structure is simple and highly reliable, adaptable to extreme environments. It has few core components, no complex motion transmission parts, no easily damaged parts, and no high-pressure or explosive components, making manufacturing costs controllable and enabling long-term maintenance-free operation. The initial investment and long-term operating costs are significantly lower than existing heat engines. Furthermore, it requires no oxygen, no fuel combustion, and no precision electrical control components, making it suitable for various extreme environments such as vacuum, alternating high and low temperatures, high radiation, deserts, and deep underground wells, filling the application gap of existing power units in extreme scenarios. 7. Possesses Adaptive Dynamic Balance Reconfiguration Capability: This heat engine requires no active intervention such as electrical control or mechanical adjustment. It automatically adjusts its cycle frequency and operating parameters according to temperature fluctuations in external heat and cold sources, reconfiguring a stable dynamic operating balance. The switching of the on / off structure depends solely on the temperature change and / or deformation state of the cycle work unit driven by the temperature difference, and is not tied to the absolute temperature values ​​of the hot and cold ends. As long as the total external temperature difference can drive the work unit to produce a state change that meets the switching requirements, the heat engine can automatically adapt to the new hot and cold end temperature conditions and maintain a stable cycle. This characteristic allows the heat engine to operate continuously without manual adjustment when facing non-steady-state conditions such as diurnal temperature variations in the natural environment and temperature fluctuations in industrial waste heat. Furthermore, the introduction of a stable-temperature heat storage unit can further smooth heat source temperature fluctuations, enhancing the system's cycle stability and thermal energy utilization rate under unstable heat source conditions. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the core main structure of the pure passive temperature difference driven self-generating cycle heat engine of the present invention, showing the overall structural composition and connection relationship; Figure 2 is a schematic diagram of the core main structure of the present invention with the heat recovery structure ⑧. The current cycle work unit ③ is in the heat absorption stage. When the switching signal is triggered, rotating the step switch ⑨ clockwise by one step (90°) will switch to the heat recovery stage. Figure 3 is a schematic diagram of the thermal path state during the heat absorption and energy storage stage of the present invention, used to show the heat flow path when the first heat conduction path is open and the second heat conduction path is closed; Figure 4 is a schematic diagram of the thermal path state during the heat release and reset stage of the present invention, used to show the thermal path when the first heat conduction path is turned off and the second heat conduction path is turned on.

[0023] Explanation of reference numerals in the attached diagram: ① High-temperature heat source / high-temperature heat collection unit; ② First heat conduction path / first controllable heat conduction switch; ③ Circulating work unit; ④ Second heat conduction path / second controllable heat conduction switch; ⑤ Low-temperature cold source / low-temperature heat dissipation unit; ⑥ Linkage triggering mechanism; ⑦ Interlocking on / off function module; ⑧ Heat recovery structure; ⑨ Rotary stepping thermal switch.

[0024] Note: Figures 3 and 4 are simplified thermal circuit diagrams. To clearly show the on / off state, the preferred configuration (⑧) and some functional module details have been omitted. For the complete structure, please refer to Figures 1 and 2. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. The described embodiments are only preferred exemplary solutions 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. All values ​​in the following embodiments are exemplary selection reference values, and those skilled in the art can flexibly adjust them according to actual working conditions, which do not constitute a mandatory limitation of the present invention.

[0026] Example 1: A basic embodiment for verifying the core principle of a bidirectional linkage triggering mechanism. This embodiment is the core preferred implementation of the present invention. All unnecessary auxiliary structures are removed, and only the core necessary components of the present invention are retained. The core principle of the bidirectional displacement synchronous triggering interlocking on and off of the cyclic work unit and the spontaneous cycle of pure temperature difference is fully reproduced. The focus is on verifying the feasibility of the present invention in normal room temperature environment and low-grade temperature difference scenario, as well as the core characteristic of non-intervention adaptive construction of steady-state cycle. All components are existing commercial mature products, and those skilled in the art can reproduce them without creative effort in a normal 20°C room temperature environment. 1. Core Structure and Component Selection

[0027] The reference ambient temperature in this embodiment is 20℃. The heat engine structure, along the heat conduction path, includes, in sequence: a high-temperature heat source, a high-temperature heat collection unit 1, a first heat conduction path 2, a circulating power unit 3, a second heat conduction path 4, a low-temperature heat dissipation unit 5, and a low-temperature cold source. The specific selection is as follows: * High-temperature heat source: A constant-temperature circulating water bath device is adopted, and the built-in circulating water pump can maintain the continuous flow of hot water and stably control the outlet water temperature to 90°C. It simulates a stable low-grade waste heat source as the heat energy input of this embodiment. The flowing hot water can avoid local temperature fluctuations of the heat source and continuously maintain a stable heating temperature. * Low-temperature cold source: A constant temperature circulating water bath device is adopted, and the built-in circulating water pump can maintain the continuous flow of cold water and stably control the inlet water temperature to 40°C, which serves as the heat energy discharge end in this embodiment; the flowing cold water can continuously remove the heat discharged by the circulating work unit 3, avoid the local temperature of the cold source from rising, and stably maintain the heat dissipation temperature difference. * High-temperature heat collection unit 1 and low-temperature heat dissipation unit 5: Both use high-purity copper heat exchange blocks, with the heat exchange surface in close contact with the corresponding heat source and cold source, and the contact surface is coated with high thermal conductivity silicone grease to reduce contact thermal resistance. * First heat conduction path 2 and second heat conduction path 4: Two stroke-triggered mechanical heat conduction switches of identical model and parameters are used as controllable heat conduction switches, which are common and mature standard components in the field of thermal management; the rated heat conduction power of each switch is 100W, the thermal resistance in the on state is ≤0.05℃ / W, the thermal resistance in the off state is ≥10℃ / W, the trigger stroke is 0.3mm, the trigger thrust is ≥3N, the switch body has high thermal conductivity, and can realize directional and efficient heat transfer when on, and can completely block the heat conduction path when off. The two switches are initially assembled in an interlocked state: the first heat conduction path 2 is initially in a normally closed on state, and the second heat conduction path 4 is initially in a normally closed off state; the trigger ends of the two switches are arranged vertically relative to each other along the axis of the cyclic work unit 3, and the trigger action direction is completely matched with the thermal expansion and contraction displacement direction of the cyclic work unit 3; * Cyclic work unit 3: Utilizes a 12mm diameter, 200mm length 6061 aluminum alloy rod, combining high thermal conductivity with a high linear thermal expansion coefficient (23.6×10⁻⁻). 6 / ℃), and also serves as the heat conduction medium and working component in this embodiment; a steel trigger block 7 is radially fixed on its outer wall, and the upper and lower ends of the trigger block 7 are tightly attached to the trigger ends of the first heat conduction path 2 and the second heat conduction path 4 respectively. The contact surface is coated with high thermal conductivity silicone grease to reduce contact thermal resistance; the working temperature difference in this embodiment is 50℃, and the axial thermal expansion of the aluminum alloy rod is 0.236mm, which is perfectly matched with the 0.3mm trigger stroke of the two thermal switches, which can ensure that when the deformation caused by temperature change reaches the preset state, the two switches are accurately triggered to complete the on / off state switching; * Thermally conductive connection and insulation structure: The components are thermally connected by high-purity copper busbars. The copper busbars are fully wrapped with a heat-resistant rubber insulation layer and an aerogel insulation layer to minimize heat loss to the ambient air during the heat conduction process, reduce the interference of ambient temperature on the circulation process, and ensure directional and efficient heat transfer. 2. Assembly method

[0028] The heat exchange end of the high-temperature heat collection unit 1 is in close contact with the high-temperature heat source, and its heat output end is thermally connected to the heat input end of the first heat conduction path 2 through a copper busbar with a heat insulation layer; the heat output end of the first heat conduction path 2 is thermally connected to the upper end of the circulating work unit 3; the lower end of the circulating work unit 3 is thermally connected to the heat input end of the second heat conduction path 4; the heat output end of the second heat conduction path 4 is thermally connected to the heat input end of the low-temperature heat dissipation unit 5 through a copper busbar with a heat insulation layer; the heat exchange end of the low-temperature heat dissipation unit 5 is in close contact with the low-temperature cold source; the whole is fixed by an insulating bracket, only retaining the axial thermal expansion and contraction freedom of the circulating work unit 3, and all thermally conductive connection surfaces are coated with high thermal conductivity silicone grease to reduce contact thermal resistance; the axial thermal expansion and contraction displacement of the circulating work unit 3 caused by temperature changes can be synchronously applied to the trigger ends of the two thermally conductive switches by the trigger block 7 to realize synchronous bidirectional switching of the on and off states. 3. Core Operation and Loop Verification Logic

[0029] The operating premise of this embodiment is that the total temperature difference between the high-temperature heat source (90℃) and the low-temperature cold source (40℃) is 50℃, which is sufficient to drive the cyclic work unit 3 to generate an effective thermal expansion and contraction displacement that meets the switching trigger stroke, thus satisfying the spontaneous cycle operation conditions of this invention. After assembly according to the above scheme by those skilled in the art, the heat engine will automatically build a steady-state dynamic equilibrium without intervention in a normal room temperature environment of 20℃, relying on its own thermodynamic characteristics and the inherent triggering characteristics of the stroke-triggered thermal conductive switch, and enter a continuous spontaneous cycle, completely replicating the core working logic of this invention: 1. Heat absorption and potential storage stage: In the initial state, the temperature of the circulating work unit 3 and the low-temperature cold source are close to the same (around 40℃). The first heat conduction path 2 remains normally closed and the second heat conduction path 4 remains normally open. The heat from the high-temperature heat source continues to flow into the circulating work unit 3 in one direction. The temperature of the circulating work unit 3 steadily increases from 40℃ to 90℃, generating axial thermal expansion and outputting positive linear displacement (i.e., positive mechanical energy). This process also causes the temperature difference between the circulating work unit 3 and the low-temperature cold source to be widened, thereby accumulating the potential energy of the temperature difference at the cold source end. 2. Thermal equilibrium switching stage: The cyclic work unit 3 continuously absorbs heat and heats up. When the temperature rises to about 90°C, its deformation reaches the preset state. The axial expansion displacement pushes the trigger ends of the two thermal conductive switches simultaneously through the trigger block 7, so that the first thermal conductive path 2 switches from the conductive state to the off state, completely blocking the heat inlet path; at the same time, the second thermal conductive path 4 switches from the off state to the conductive state. The entire system is without external triggering or manual intervention. It relies solely on the displacement driven by the temperature difference of the cyclic work unit 3 to naturally complete the reversal of the potential storage end and the potential release end. After the switch, it still maintains the interlocked state of one conducting and one disconnecting. 3. Heat release and reset stage: After the second heat conduction path 4 is turned on, the heat of the circulating work unit 3 is continuously discharged unidirectionally into the low-temperature cold source through the second heat conduction path 4 and the heat-conducting copper busbar with insulation layer. The low-temperature cold source is stably maintained at 40°C by the continuous flow of constant-temperature cold water. The temperature of the circulating work unit 3 steadily decreases from 90°C to 40°C, generating axial contraction and outputting reverse linear displacement (i.e., reverse mechanical energy). This process also causes the temperature difference between the circulating work unit 3 and the high-temperature heat source end to be widened, thereby accumulating the potential energy of the heat source end temperature difference for the next cycle. 4. Cycle restart phase: Cycle work unit 3 continuously releases heat and cools down. When the temperature drops to about 40℃, its deformation reaches another preset state. The axial contraction displacement pulls the trigger ends of the two heat conduction switches in opposite directions through the trigger block 7, so that the second heat conduction path 4 switches from the on state to the off state, and the first heat conduction path 2 switches from the off state back to the on state, seamlessly switching back to the heat absorption and storage state, and starting the next complete cycle. During the above-mentioned cycle, the heat-conducting structure with insulation layer can minimize environmental heat loss and ensure directional heat flow. Even if there is a small amount of unavoidable environmental heat interference, the heat engine can automatically adapt to the working conditions, adjust the cycle period, reconstruct and maintain a stable dynamic balance by relying on the inherent interlocking on / off characteristics of the two sets of heat conduction paths. Without manual intervention or electronic control adjustment, it can achieve uninterrupted spontaneous cycle operation by relying solely on the continuous temperature difference that is easily achieved in a normal natural environment. It continuously converts low-grade heat energy into linear reciprocating mechanical energy of the cycle work unit 3, thus fully realizing all the technical effects claimed in this invention.

[0030] Example 2: Temperature change triggering alternative embodiment based on dual-standard temperature control switch series hysteresis structure This embodiment is an alternative implementation of the present invention. It uses two standard temperature control switches connected in series to achieve adjustable hysteresis characteristics. No custom-designed hysteresis switches are required; only commercially available, mature components can achieve interlocking on / off switching and stable self-circulation. It is suitable for miniaturized, low-cost, and explosion-proof applications, and can be reproduced by those skilled in the art without creative effort. The reference ambient temperature for this embodiment is 20℃. The core structure is basically the same as in Embodiment 1, with the only difference being the implementation method of the first heat conduction path 2 and the second heat conduction path 4, as detailed below: 1. Core Structure and Selection of Switching Part

[0031] * First heat conduction path 2 (heat inlet: high-temperature heat collection unit 1 → circulating power unit 3): Implemented using two commercially available standard temperature control switches connected in series, satisfying the hysteresis working logic of conducting in the low-temperature range and turning off in the high-temperature range. Both switches are common and mature standard components in the thermal management field. The temperature sensing ends are tightly thermally coupled to the circulating power unit 3, accurately responding to its temperature changes: Low-temperature normally open closed type temperature control switch: The trigger threshold is 50℃. It remains open when the ambient temperature is below 50℃, and turns off when the temperature reaches 50℃ or above (i.e., from low temperature to this threshold). ) Maintain closed conduction; High-temperature normally closed open type temperature control switch: The trigger threshold is 90℃. When the ambient temperature is below 90℃, it remains closed and conduction. When the temperature reaches 90℃ or above (i.e., when the temperature rises further to this threshold), it remains open; Series combination logic: Only when the cyclic work unit 3 heats up to the range of 50℃≤T≤90℃ due to heat absorption, both switches close simultaneously, and the heat conduction path of the first heat conduction path 2 is open; When the temperature is below 50℃ or above 90℃, at least one switch is open, and the heat conduction path is completely shut off, naturally forming a fixed hysteresis range; * Second heat conduction path 4 (heat outlet: circulating work unit 3 → low temperature heat dissipation unit 5): Implemented by two commercial standard temperature control switches of the same model and specifications connected in series. The overall system meets the hysteresis working logic of being turned on in the high temperature range and turned off in the low temperature range. The triggering characteristics are completely matched with the first heat conduction path 2. The temperature sensing ends are tightly thermally coupled to the circulating work unit 3: High temperature normally open closed type temperature control switch: The trigger threshold is 90℃. It remains open when the ambient temperature is below 90℃ and remains closed when the temperature reaches 90℃ or above (heating to this threshold); Low temperature normally closed open type temperature control switch: The trigger threshold is 50℃. It remains closed when the ambient temperature is above 50℃ and remains open when the temperature drops to 50℃ or below (cooling to this threshold); Series combination logic: Only when the circulating work unit 3 heats up to the T≥90℃ range due to heat absorption, both switches close simultaneously, and the heat conduction path of the second heat conduction path 4 is turned on; When the temperature is below 90℃, at least one switch is turned off, and the heat conduction path is completely turned off, forming a strict interlock with the first heat conduction path 2; * Cyclic work unit 3: It adopts 6061 aluminum alloy rod with a diameter of 10mm and a length of 50mm, which has both high thermal conductivity and high linear thermal expansion coefficient. Its outer wall is closely attached to the temperature sensing end of the four temperature control switches. The contact surface is coated with high thermal conductivity silicone grease to reduce contact thermal resistance and ensure the accuracy of temperature response. * The high-temperature heat source uses a 92℃ constant temperature circulating water bath device, and the low-temperature cold source uses a 48℃ constant temperature circulating water bath device, with a total temperature difference of 44℃, which completely covers the 50℃~90℃ trigger range of the two heat conduction paths and meets the conditions for spontaneous circulation operation. 2. Core Operation and Interlocking Loop Logic

[0032] This embodiment requires no external triggering or manual intervention throughout the entire process. It automatically achieves interlocking switching and continuous spontaneous cycling solely based on the temperature changes of the cyclic work unit 3, thus fully replicating the core working logic of this invention. 1. Heat absorption and potential storage stage: In the initial state, the temperature of the circulating work unit 3 is close to that of the low-temperature cold source (around 48°C), and both the first heat conduction path 2 and the second heat conduction path 4 are in the off state. The circulating work unit 3 gradually heats up due to heat absorption. When its temperature rises to 50°C, the two switches of the first heat conduction path 2 close simultaneously and automatically switch to the conducting state. The second heat conduction path 4 remains off, and the heat from the high-temperature heat source continues to flow unidirectionally into the circulating work unit 3. The temperature of the circulating work unit 3 steadily rises from 50°C to 90°C. This process also causes the temperature difference between the circulating work unit 3 and the low-temperature cold source to increase, thereby accumulating the potential energy of the temperature difference at the cold source end. At the same time, it expands due to the temperature increase and outputs positive mechanical energy to the outside. 2. Thermal equilibrium switching stage: The cyclic power unit 3 continuously absorbs heat and heats up. When its temperature reaches 90℃, its temperature change reaches the preset state. The high-temperature normally closed open type switch of the first heat conduction path 2 is triggered to open, and the first heat conduction path 2 is automatically shut off, completely blocking the heat inlet path. At the same time, the high-temperature normally open closed type switch of the second heat conduction path 4 is triggered to close, and the second heat conduction path 4 is automatically switched to the conducting state. The switching of the potential storage end and the potential release end is completed naturally by the temperature change of the cyclic power unit itself. After the switching, the interlocking state of one conducting and one closed is still maintained, without intermediate transition state. 3. Heat release and reset stage: After the second heat conduction path 4 is turned on, the heat of the circulating work unit 3 is continuously discharged into the low temperature cold source in one direction. The temperature of the circulating work unit 3 steadily decreases from 90℃ to 50℃. This process also causes the temperature difference between the circulating work unit 3 and the high temperature heat source end to be widened, thereby accumulating the potential energy of the temperature difference at the heat source end for the next cycle. At the same time, it contracts due to the temperature drop, outputs reverse mechanical energy to the outside and completes the structural reset. 4. Cycle restart phase: Cyclic work unit 3 continuously releases heat and cools down. When its temperature drops to 50℃, its temperature change reaches another preset state. The low-temperature normally closed open-type switch of the second heat conduction path 4 is triggered to open, and the second heat conduction path 4 is automatically turned off. At the same time, the first heat conduction path 2 meets the conduction conditions again, automatically switches back to the conduction state, and seamlessly switches back to the heat absorption and energy storage state to start the next complete cycle. 3. Core Advantages of the Solution

[0033] This embodiment does not require custom-made dedicated hysteresis temperature control switches. All components are commercially available and standardized, resulting in low procurement costs and strong adaptability. The hysteresis range can be flexibly adjusted by replacing temperature control switches with different trigger thresholds, making it suitable for application scenarios with different temperature differences. Within the transition range of 50℃ to 90℃, the two heat conduction paths always maintain the previous stable state, completely avoiding the jitter problem of frequent switching on and off near the critical temperature, and can maintain long-term stable self-circulation operation.

[0034] Example 3: Preferred embodiment of a purely passive thermoelectric engine with a regenerative structure This embodiment is a preferred implementation of the present invention. Based on Embodiment 1 or Embodiment 2, a heat recovery structure is added, expanding the original two interlocked heat conduction paths into three interlocked heat conduction paths, forming a three-way interlocking logic, further improving thermal energy utilization efficiency. In this embodiment, the heat recovery structure can be implemented using any one or more of the following combinations:

[0035] An independent regenerator is installed in the regenerative path, and the regenerator is filled with a high specific heat capacity heat storage medium (such as metal wire mesh, ceramic honeycomb, or phase change material). When heat absorption turns to heat release, the regenerator is briefly open, and some heat is temporarily stored in the regenerator; when heat release turns to heat absorption, the regenerator is briefly open again, and the temporarily stored heat is released back to the circulation work unit, reducing dependence on external heat and cold sources and improving circulation efficiency. The switching between the regenerator path and the main path can be achieved by rotating a stepping thermal switch. Each rotation of the switch by a fixed angle sequentially connects the first heat conduction path, the regenerator path, the second heat conduction path, and the regenerator path, consistent with the three-way interlocking switching logic.

[0036] The cyclic work unit includes at least two working elements (e.g., a first working element and a second working element). Each of the two working elements is independently connected between a first heat conduction path and a second heat conduction path. A controllable heat conduction switch is provided between the two working elements, forming a third interlocked heat conduction path—a regenerative path. Only one of the three paths is active at any given time, forming a three-way interlock. The on / off state is passively triggered by the temperature change or deformation of the working element itself. The operating phases of the two working elements differ by 0.5 cycles; that is, when the first working element is in the heat absorption and heating phase, the second working element is in the heat release and cooling phase, and vice versa. They alternately absorb and release heat, mutually regenerating heat.

[0037] The control logic for the on / off of the regenerative path is as follows: The on signal reuses either the cold switching or hot switching signal, meaning that when any working element triggers a switch between the cold and hot main paths due to a temperature change, the regenerative path is simultaneously turned on; the off signal can use a temperature difference or temperature difference-related signal, meaning that when the temperature difference or temperature difference-related signal between the two working elements changes to below a preset threshold, the regenerative path automatically turns off, ensuring that heat is transferred only directionally when an effective temperature difference exists, and automatically shuts off when the temperature difference is insufficient. Its working process is described below using the first working element as an example: 1. Heat absorption and energy storage stage (first working body): The first heat conduction path is open, while the second heat conduction path and the regeneration path are closed. The first working body absorbs heat from the high-temperature heat collection unit, heats up, expands, and performs work; at this time, the second working body is in the heat release and cooling stage. 2. First Switching Phase (Heat Absorption → Heat Regeneration): When the first working body heats up due to heat absorption, and its temperature change and / or deformation reaches a preset state, the first heat conduction path is triggered to shut down, and the heat regeneration path is simultaneously triggered to open (reusing the heat switching signal), while the second heat conduction path remains closed. The first working body is in a high-temperature state, and some heat is temporarily stored in the second working body, which is in a low-temperature state, through the heat regeneration path. As heat is transferred, the temperature difference between the two working bodies gradually decreases. When the temperature difference or temperature difference-related signal changes to below a preset threshold, the heat regeneration path automatically shuts down (triggered by the temperature difference or temperature difference-related signal). 3. Second switching stage (regeneration → exothermic): After the regeneration path is shut down, its shutdown action acts as an enable signal, triggering the second heat conduction path to open, while the first heat conduction path remains shut down. The first working body enters the exothermic cooling stage, where heat is discharged to the low-temperature heat dissipation unit through the second heat conduction path, cooling down, contracting, and completing reset or performing external work; at this time, the second working body enters its own heat absorption and heating stage. 4. Third switching stage (heat release → heat recovery): When the first working body cools down due to heat release, and its temperature change and / or deformation reaches another preset state, the second heat conduction path is triggered to shut down, and the heat recovery path is triggered to open (reusing the cold switching signal), while the first heat conduction path remains closed. At this time, the second working body is in a high-temperature state (just completed heat absorption and temperature rise), and some of the heat from the second working body is released back to the first working body, which is in a low-temperature state, through the heat recovery path to preheat the first working body. As heat is transferred, the temperature difference between the two working bodies gradually decreases. When the temperature difference or temperature difference-related signal changes to below a preset threshold, the heat recovery path automatically shuts down. 5. Fourth switching stage (regenerative → endothermic): After the regenerative path is shut down, its shutdown action acts as an enable signal, triggering the first heat conduction path to open, while the second heat conduction path remains shut down. The first working body re-enters the endothermic heating stage, starting the next complete cycle; The cycle of the second working element is exactly the same as that of the first, only lagging behind by 0.5 cycles in phase. Both elements are briefly connected during their respective switching phases via a regenerative pathway, with the shut-off timing controlled by temperature difference or a temperature-related signal. This allows for the cross-storage and release of heat, significantly reducing the heat demand on external heat and cold sources and substantially improving the overall thermal efficiency of the heat engine. This scheme is particularly suitable for high-energy-density heat engines using solid working fluids.

[0038] Example 4: Universal Working Fluid Adaptation Example This example demonstrates the universal adaptability of the core loop logic of this invention to different types of working fluids. Those skilled in the art can flexibly select the working fluid type according to the actual working conditions: Solid working fluid solution: The cyclic work unit is a thermally expanding reciprocating component made of a metal material with a high linear thermal expansion coefficient. It naturally has the characteristics of high torque and short stroke. The linear reciprocating motion can directly drive the electromagnetic induction power generation module without the need for an additional transmission mechanism. It is suitable for industrial and civil scenarios such as ultra-high pressure static pressing, high pressure valve opening and closing, large component locking, and micro distributed electromagnetic induction power generation. The structure is extremely simple and can achieve long-term maintenance-free operation. Liquid working fluid solution: The circulating power unit is a closed liquid cylinder structure, filled with commercial liquid working fluid with a high expansion coefficient, and equipped with a metal bellows sealing structure, eliminating the risk of dynamic seal leakage; it has the advantages of high torque output and larger expansion stroke, and is suitable for medium and low temperature geothermal power generation and industrial waste heat recovery power generation scenarios. Multi-module parallel networking can achieve stable power output, and the initial investment is much lower than that of traditional steam turbine systems. Gas working fluid solution: The circulating power unit is a closed cylinder structure, filled with high-pressure inert gas working fluid, and equipped with a metal bellows sealing structure, eliminating the risk of dynamic seal leakage; it can achieve faster circulation speed and higher power density, and can be directly converted into rotational power through the crank-connecting rod mechanism, making it suitable for scenarios such as mobile platform power and waste heat auxiliary drive of ships. With the matching electromagnetic induction power generation module, it can achieve stable vehicle / ship power supply.

[0039] Example 5: Application of a Solar-Powered Mobility Vehicle Based on Road Surface Temperature Difference This example demonstrates a purely passive solar-powered mobility vehicle based on the present invention. It utilizes the stable temperature difference created by the natural high temperature of the asphalt road surface during the day and the low temperature of the air at high altitudes to achieve continuous heat engine circulation and vehicle propulsion. During the day, under direct sunlight, the black asphalt road surface can be heated to a high temperature, while the air temperature at a certain height above the ground is significantly lower than that of the road surface, forming a continuous and stable temperature difference. In this example, the underside of the vehicle, close to the road surface, serves as the high-temperature heat collection end, employing a high-absorption-rate heat collection plate to collect heat radiation from the road surface; the roof serves as the low-temperature heat dissipation end, using a high-mirror reflector to reflect sunlight, preventing the roof from being heated, while simultaneously forming a stable cold source through heat dissipation fins and convection with high-altitude air. The vehicle is equipped with multiple parallel gaseous working fluid heat engine modules, which rely on the natural temperature difference between the road surface and the high altitude to achieve continuous self-circulation. The output mechanical energy directly drives the wheels through a pure mechanical transmission mechanism. An electromagnetic induction power generation module powers the on-board auxiliary equipment. The entire process requires no electronic control, no battery, and no fuel supply. The vehicle can drive continuously and stably by relying solely on the natural temperature difference of the asphalt road during the day. It is suitable for short-distance commuting, park patrol, and other scenarios.

[0040] Example 6: Application Example of a Stratospheric Airship This example describes a stratospheric airship based on the present invention. A lightweight solar concentrator film is laid on the sun-facing side of the airship to collect heat and raise its temperature, forming a stable high-temperature heat source. A radiant heat dissipation plate is installed on the shaded side to connect with the low-temperature environment, creating a continuous ultra-large temperature difference. Multiple gaseous working fluid heat engine modules directly drive the airship propellers. An electromagnetic induction power generation module meets the power needs of the onboard equipment, eliminating the need for photovoltaic panels, lithium batteries, motors, and electronic control systems. A phase-change heat storage unit stabilizes the heat source temperature and improves circulation efficiency, enabling continuous cyclic operation under no-light conditions at night. It requires no landing or resupply and can remain in the stratosphere for extended periods, making it suitable for scenarios such as meteorological monitoring, forest patrols, and communication relay.

[0041] Example 7: Integrated Power System Based on Mutual Regeneration and Piezoelectric Power Generation This example is the culmination of the present invention, integrating a mutual regeneration structure, piezoelectric power generation components, and a modular series-parallel architecture to form a complete, scalable pure passive thermoelectric power generation system. 1. Core Structure

[0042] This embodiment adopts the regenerative heat recovery structure described in Scheme 2 of Embodiment 3. The cyclic work unit includes at least two work bodies (a first work body and a second work body). Both work bodies are made of solid materials with a high linear coefficient of thermal expansion and are independently connected between the first and second heat conduction paths. A controllable heat conduction switch is provided between the two work bodies, forming a third interlocked heat conduction path—a regenerative path, thus creating a three-way interlock. The operating phases of the two work bodies differ by 0.5 cycles, alternating between heat absorption and release, and mutually regenerating heat. The thermal expansion and contraction displacement of each work body directly acts on the piezoelectric ceramic stack coupled to it, directly converting mechanical energy into electrical energy output through stress-charge conversion. In the above process, the voltage across the piezoelectric ceramic stack rises and falls with the temperature and displacement changes of the work bodies—the higher the temperature and the more complete the expansion, the higher the voltage; the lower the temperature and the more complete the contraction, the lower the voltage. This voltage signal serves both as the external output electrical energy and as a system status sensing signal, used to trigger the switching of each heat conduction path. 2. Control logic for three-way interlock switching

[0043] The interlocking switching of the three heat conduction paths is triggered by the piezoelectric voltage difference signal between the two working elements, requiring no external control unit or timing circuit. The control logic is based on the following principle: the operating phases of the two working elements differ by 0.5 cycles. At any given moment, one working element is in a high-temperature, high-pressure state, while the other is in a low-temperature, low-pressure state, resulting in a significant voltage difference between them. The control logic only needs to set a high voltage difference threshold. When the voltage difference between any two working elements reaches this threshold, the main path is switched to the regenerative path. After the switch, the voltage change directions of the two working elements reverse, and the voltage difference naturally decreases and then increases in the opposite direction until the voltage difference between the other working element and the first working element reaches the same threshold again, triggering the next switch. The specific process is as follows: Thermal switching (endothermic → regenerative): The first working body absorbs heat, heats up, and expands, causing its piezoelectric ceramic voltage to continuously increase; the second working body is in the heat release, cooling, and contraction phase, causing its piezoelectric ceramic voltage to continuously decrease. When the voltage difference between the first and second working bodies reaches a preset high voltage difference threshold, the first heat conduction path is turned off, and the regenerative path is turned on. Heat flows from the high-temperature first working body to the low-temperature second working body through the regenerative path. Regenerative → Exothermic: After the regenerative pathway is activated, the first working body transfers heat to the second working body. The former's temperature decreases and its voltage begins to drop, while the latter's temperature increases and its voltage begins to rise, naturally reducing the voltage difference between the two. As heat transfer continues, the temperature difference between the two further decreases. The regenerative pathway automatically shuts off when the temperature difference or temperature difference-related signal changes below a preset threshold (triggered by the temperature difference or temperature difference-related signal). After the regenerative pathway shuts off, its shutdown action acts as an enable signal, triggering the activation of the second heat conduction pathway. The first working body enters the exothermic cooling and contraction phase, with heat being discharged to the low-temperature heat dissipation unit, and its piezoelectric ceramic voltage continuously decreases. Simultaneously, the second working body, having undergone regenerative preheating, enters its own heat absorption, heating, and expansion phase, and its piezoelectric ceramic voltage continuously increases. Cold switching (heat release → heat recovery): The first working body releases heat, cools down, and contracts, causing its piezoelectric ceramic voltage to continuously decrease; the second working body absorbs heat, heats up, and expands, causing its piezoelectric ceramic voltage to continuously increase. When the voltage difference between the second and first working bodies reaches the same preset high voltage difference threshold again, the second heat conduction path is triggered to shut off, and the heat recovery path is activated. Heat flows from the high-temperature second working body to the low-temperature first working body through the heat recovery path. Regeneration → Heat Absorption: After the regeneration path is activated, the second working body transfers heat to the first working body, and the voltage difference between them naturally decreases. The regeneration path automatically shuts off when the temperature difference or temperature difference-related signal changes below a preset threshold. After the regeneration path shuts off, its shutdown action acts as an enable signal, triggering the activation of the first heat conduction path, and the first working body re-enters the heat absorption and heating stage, starting the next complete cycle. In the above four-step cycle, only a high voltage difference threshold needs to be set, and the voltage difference between the two working bodies is detected alternately. When the voltage of the first working body is higher than that of the second working body and the difference reaches the threshold, hot switching is triggered; when the voltage of the second working body is higher than that of the first working body and the difference reaches the same threshold, cold switching is triggered. The shutdown of the regenerative path is controlled by the temperature difference or a temperature difference-related signal, without the need for voltage detection. This mechanism makes the switching timing naturally adaptive: when the heat source temperature is high, heat absorption is fast, the voltage difference increases rapidly, the threshold is reached earlier, and the cycle frequency automatically increases; when the heat source temperature is low, heat absorption is slow, and the cycle frequency automatically decreases. The specific threshold setting can be achieved through a voltage comparison circuit or an adjustable switching element, which will not be elaborated here. 3. Modular serial and parallel deployment

[0044] Each regenerative + piezoelectric power generation unit is an independent module, allowing for flexible deployment: Parallel mode: Multiple modules share the same high-temperature heat collection terminal and low-temperature heat dissipation terminal, with the outputs of each module connected in parallel to achieve power expansion. A single module failure does not affect the operation of other modules, and hot-swappable replacement is supported. Series mode: Multiple modules are connected in series along the heat flow direction, with the low-temperature heat dissipation unit of the preceding module thermally connected to the high-temperature heat collection unit of the following module, achieving cascaded utilization of thermal energy and improving overall thermal efficiency. The outputs of series modules can be powered independently or connected in series for voltage boosting and unified output. Parallel and series configurations can be mixed, flexibly configured according to actual heat source conditions and power demand, adapting to the full power range from watt-level micro-collection to megawatt-level industrial waste heat power generation. 4. System Advantages

[0045] Purely passive operation: It can automatically cycle based solely on the external temperature difference. All control signals originate from the system's own piezoelectric voltage and temperature difference, without external electrical control or forced linkage structure; High-efficiency thermoelectric conversion: The stress output of the solid working fluid is directly coupled with the charge response of the piezoelectric ceramic, without intermediate transmission losses; Three-in-one sensing and control: The piezoelectric ceramic simultaneously performs three functions: power generation, displacement sensing, and switching triggering, resulting in a streamlined and highly reliable system; Adaptive switching: Only one high voltage differential threshold is needed to drive all switching, without the need for preset timing, and the cycle frequency automatically adjusts according to the operating conditions; Scalable: The modular design supports parallel expansion and series cascade utilization, allowing for flexible deployment and convenient maintenance. Technological Evolution Direction

[0046] Based on the purely passive temperature difference-driven spontaneous cycle principle disclosed in this invention, higher-performance power generation units and system architectures can be further developed. For example, the cycle-driven power unit can adopt a "multi-dimensional constrained thermo-stress power generation unit," which converts minute thermo-deformation materials into enormous mechanical stress by constraining them in a specific direction, and couples them with a piezoelectric ceramic array to achieve extremely high thermoelectric conversion power density. Furthermore, multiple such power units can be integrated with a distributed switch array to form a "thermal core," and through multi-level series and parallel connections of the thermal core, full coverage of extreme temperature differences and tiered full utilization of heat can be achieved. These variations are all natural extensions of the core principle of this invention and should be understood as falling within the protection scope of this invention.

Claims

1. A purely passive temperature difference-driven spontaneous circulation method, characterized in that, Includes the following steps: A cyclic work unit is provided, which can deform and output mechanical energy according to its own temperature changes; It provides a high-temperature end and a low-temperature end, which serve as the input and exhaust sides of heat energy, respectively; A first heat conduction path is established between the circulating power unit and the high-temperature end, and a second heat conduction path is established between the circulating power unit and the low-temperature end. By passively controlling the opening and closing of the first and second heat conduction paths through the temperature change or deformation state of the cyclic work unit itself, the two paths are kept in an interlocked state of one conducting and one closing at any time during the cycle. When the first heat conduction path is open, heat flows unidirectionally from the high-temperature end into the circulating work unit, causing it to heat up and expand to do work. This process also causes the temperature difference between the circulating work unit and the low-temperature end to be widened, thereby accumulating the potential energy of the temperature difference at the cold source end. When the second heat conduction path is open, heat is discharged unidirectionally from the circulating work unit to the low-temperature end, causing it to cool down, contract, reset, or perform work. This process also causes the temperature difference between the circulating work unit and the high-temperature end to increase, thereby accumulating the potential energy of the temperature difference at the heat source end. The method can be automatically started and continuously cycled according to the above-mentioned interlocking mechanism simply by relying on the continuous temperature difference between the high-temperature end and the low-temperature end.

2. A purely passive temperature difference driven self-generating circulating heat engine, comprising a high-temperature heat collection unit, a circulating power unit, and a low-temperature heat dissipation unit, characterized in that: A first heat conduction path connects the high-temperature heat collection unit and the circulating power unit, and a second heat conduction path connects the circulating power unit and the low-temperature heat dissipation unit. The first heat conduction path and the second heat conduction path are configured to maintain an interlocked state of one conduction and one disconnection at any time during the cycle process. The switching of the interlocked state is passively triggered by the temperature change or deformation state of the cycle work unit itself. When the first heat conduction path is open, heat flows unidirectionally from the high-temperature heat collection unit into the circulating work unit, causing it to heat up and expand to do work. This process also causes the temperature difference between the circulating work unit and the low-temperature heat dissipation unit to be widened, thereby accumulating the potential energy of the temperature difference at the cold source end. When the second heat conduction path is open, heat is discharged unidirectionally from the circulating work unit to the low-temperature heat dissipation unit, causing it to cool down, contract, reset, or perform work. This process also causes the temperature difference between the circulating work unit and the high-temperature heat collection unit to be widened, thereby accumulating the potential energy of the temperature difference at the heat source end. This heat engine can start spontaneously and continuously cycle according to the above-mentioned interlocking mechanism, relying solely on the continuous temperature difference between the external heat source and the cold source.

3. The method according to claim 1 or the heat engine according to claim 2, characterized in that, The first heat conduction path and the second heat conduction path are respectively provided with controllable heat conduction switches, and the interlocking state is achieved by the linkage of the on and off of each of the controllable heat conduction switches.

4. The method according to claim 1 or the heat engine according to claim 2, characterized in that, It also includes a regeneration step or regeneration structure, with a switchable regeneration path provided between the cyclic work unit and the regeneration structure; the opening of the regeneration path is triggered by the temperature change or deformation state of the cyclic work unit when the first heat conduction path or the second heat conduction path is switched; the closing of the regeneration path is passively triggered when the temperature difference or temperature difference-related signal between the regeneration structure and the cyclic work unit changes to a preset threshold, and the closing action of the regeneration path is configured to trigger the opening of the corresponding first heat conduction path or the second heat conduction path.

5. The method or heat engine according to claim 4, characterized in that, The cyclic work unit includes at least two work bodies, and the regeneration structure is formed by a controllable thermal connection between the work bodies. The two work bodies alternately absorb and release heat during operation, and transfer heat to each other when the regeneration path is open to achieve mutual regeneration. The shutdown of the regeneration path is configured to trigger the opening of the first or second heat conduction path corresponding to the next opening stage.

6. The method according to claim 1 or the heat engine according to claim 2, characterized in that, Multiple cyclic work units are modularly deployed, and they are connected in parallel to share heat collection and heat dissipation terminals, or connected in series for thermal coupling to achieve cascade utilization of thermal energy.

7. The method or heat engine according to claim 4 or 5, characterized in that, Multiple cyclic power units containing the aforementioned regenerative structure are modularly deployed, and they are connected in parallel to share heat collection and heat dissipation terminals, or connected in series for thermal coupling to achieve cascade utilization of thermal energy.

8. The method or heat engine according to claim 4 or 5, characterized in that, The deformation generated by the cyclic work unit is configured to be output as mechanical stress to perform work externally.

9. The method or heat engine according to claim 4 or 5, characterized in that, The cyclic power unit is coupled with a power generation component. The electrical signal output by the power generation component during the power generation process is directly used as a sensing signal to sense the temperature change or deformation state of the cyclic power unit. This electrical signal is used as the basis for triggering the opening and closing of each heat conduction path. When the signal reaches a preset threshold, the switching of the thermal connection is triggered.

10. The method or heat engine according to claim 9, characterized in that, The cyclic work unit includes at least two work elements, and the electrical signal is the voltage difference or current difference between the two work elements.

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