Energy-saving equipment and method for additive and subtractive composite machining based on phase change heat storage

Abstract

The application provides a kind of energy-saving equipment and method based on phase change heat storage of additive-subtractive composite machining, belongs to additive-subtractive composite machining technical field, including heat exchange module being arranged in the heat-sensitive area of processing cabin, the heat exchange module includes the shell that can conduct heat, shell inside is filled with the energy storage medium that can absorb and store heat energy, the shell inside is also provided with microchannel for the flow of protective gas, the energy storage medium is filled in the outside space of microchannel, the microchannel realizes the heat exchange between protective gas and energy storage medium, and the protective gas after heat exchange is introduced into powder feeding unit and temperature control jet interface.The application can realize the absorption and storage of heat in additive manufacturing stage, and preheat the processing equipment and processing environment using the stored heat, and maintain a constant temperature environment in subtractive manufacturing stage, avoid the geometric size deviation of workpiece due to thermal effect, and ensure the processing quality.

Description

Technical Field

[0001] This invention belongs to the field of additive and subtractive composite processing technology, and particularly relates to an energy-saving device and method for additive and subtractive composite processing based on phase change thermal storage. Background Technology

[0002] With the increasing demands for precision and production efficiency in the manufacturing of complex and irregularly shaped components in fields such as aerospace, precision molds, and high-end medical devices, additive and subtractive composite manufacturing technology has become an important evolutionary direction in modern advanced manufacturing due to its ability to combine the near-net-shape forming capability of additive manufacturing with the high-precision surface quality of subtractive machining. In current mainstream composite machining systems, high-energy beam additive manufacturing units, such as laser cladding heads or electron beam melting devices, are typically integrated with CNC subtractive manufacturing units, such as high-speed milling cutters, within a unified vacuum or inert gas-protected machining chamber. Through the coordinated movement of a multi-axis linkage worktable or industrial robotic arm, the system can achieve a cyclical process of layer-by-layer deposition and in-situ precision subtraction within a single clamping station. This integrated approach not only effectively avoids secondary clamping and positioning errors caused by multiple transfers of workpieces between different devices but also significantly shortens the process chain, making it possible to achieve precision forming of complex internal cavity structures and difficult-to-machine materials.

[0003] Currently, significant contradictions in thermal requirements and spatiotemporal energy mismatch exist in additive and subtractive manufacturing processes. From a technological perspective, additive manufacturing often requires intensive initial preheating of the substrate, powder feeding gas, or processing environment to reduce the temperature gradient during forming, thereby suppressing residual stress and cracking tendency. Subtractive manufacturing, on the other hand, has stringent requirements for temperature field stability; even slight thermal expansion and contraction can lead to failure in the processing dimensional chain. Existing passive cooling systems are prone to causing severe nonlinear fluctuations in the temperature field inside the processing chamber during process transitions. More critically, the low-grade residual heat dissipated during the additive manufacturing stage exhibits highly discrete spatial distribution, while the energy required for preheating is highly instantaneous in time. Due to the lack of effective high-density energy buffering and secondary regulation mechanisms, existing systems must continuously consume large amounts of external electrical energy to drive auxiliary heaters for preheating, while simultaneously consuming additional power for heat dissipation. This energy efficiency paradox of simultaneously forcing heat dissipation and high-power heating not only results in significant waste of resources and energy, but also, due to the lack of effective regulation of thermal inertia, makes it impossible to maintain a quasi-constant temperature environment in the processing chamber. This makes the workpiece prone to micro-instability and macro-precision inaccuracies during frequent thermal cycles, thus affecting the processing quality. Summary of the Invention

[0004] To address the deficiencies or shortcomings in existing technologies, this invention provides an energy-saving device and method for additive and subtractive composite processing based on phase change thermal storage. This method can absorb and store heat during the additive processing stage, use the stored heat to preheat the processing equipment and environment, and maintain a quasi-constant temperature environment during the subtractive processing stage. This avoids geometric dimensional deviations in the workpiece caused by thermal effects and ensures processing quality.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, embodiments of the present invention provide an energy-saving device for additive and subtractive composite processing based on phase change thermal storage, including a heat exchange module disposed in a heat-sensitive area inside the processing chamber. The heat exchange module includes a shell capable of conducting heat, and the shell is filled with an energy storage medium capable of absorbing and storing thermal energy. The shell is also provided with a microchannel for the flow of protective gas. The energy storage medium fills the outer space of the microchannel. The microchannel realizes convective heat exchange between the protective gas and the energy storage medium. The heat-exchanged protective gas is introduced into a powder feeding unit and a temperature-controlled jet interface.

[0006] Furthermore, the outer surface of the housing is coated with a composite coating, which is composed of multiple alternating layers of metal-ceramic materials.

[0007] Furthermore, the microchannel is integrally formed on the inner wall of the shell using a laser selective melting process. Molten energy storage medium is injected into the shell to fill the outer space of the microchannel, and after cooling, a solid-liquid composite structure is formed.

[0008] Furthermore, the microchannel is provided with a gas inlet and a gas outlet at both ends, wherein the gas inlet is connected to a protective gas supply source, and the gas outlet is connected to a powder feeding unit and a temperature control jet interface, respectively.

[0009] Furthermore, the protective gas supply source is connected to the gas inlet of the microchannel via a pipeline, and a flow regulating device is installed on the pipeline between the protective gas supply source and the gas inlet of the microchannel.

[0010] Furthermore, it also includes a host computer control unit, which is electrically connected to the flow regulation device, the high-energy beam generator integrated in the processing chamber, and the heat flow sensor installed inside the energy storage medium.

[0011] Secondly, embodiments of the present invention provide an energy-saving method for additive-subtractive composite processing based on phase change thermal storage, utilizing an energy-saving device for additive-subtractive composite processing based on phase change thermal storage as described above, comprising the following steps: During the additive manufacturing process, the composite coating on the outer surface of the shell passively receives the infrared energy radiated into space from the molten pool area and the convective heat transfer energy in the processing chamber. When the real-time temperature collected by the heat exchange module reaches the preset phase change temperature point of the energy storage medium, the energy storage medium absorbs and stores heat energy using the latent heat of phase change, and suppresses the surge in ambient temperature in the processing chamber through the heat sink effect. During the interlayer pauses in additive manufacturing and / or the transition phase from additive manufacturing to subtractive manufacturing, the host computer control unit activates the flow regulation device according to process requirements, controls the protective gas to flow through the microchannel, so that the protective gas and the energy storage medium in the liquid phase can carry out convective heat exchange, raising the internal energy of the gas to the preset process target range. The preheated gas is then injected into the powder feeding unit and / or guided to the workpiece surface through the temperature-controlled jet interface. During the subtractive machining process, the solid-liquid two-way phase change characteristics of the energy storage medium are used to compensate for the temperature gradient caused by the heat generated during cutting in the machining chamber, thereby limiting the temperature field fluctuation range in the machining chamber to a preset range.

[0012] Furthermore, the additive manufacturing execution stage also includes: using the host computer control unit to retrieve the heat flow sensor data deployed on the heat exchange module in real time, and combining the phase change interface movement and heat flow field coupling mathematical model to calculate the real-time total heat load of the heat exchange module during the heat absorption stage.

[0013] Furthermore, the additive manufacturing execution stage also includes: the host computer control unit, based on the calculated real-time total heat load, further predicts the evolution of the liquid phase ratio of the energy storage medium to ensure that the amount of thermal energy stored is within the preset safety threshold range.

[0014] Furthermore, the subtractive processing stage specifically involves the following steps: when the local ambient temperature exceeds the preset thermal equilibrium point due to the heat from the cutting machinery, the energy storage medium absorbs the excess heat through further liquefaction. When the local ambient temperature falls below the preset range due to the intervention of the external cooling medium, the energy storage medium begins to transform from the liquid phase to the solid phase and releases latent heat, thereby compensating for the temperature drop.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a heat exchange module installed in the heat-sensitive area inside the machining chamber to absorb and store the heat energy generated during the additive manufacturing process. The heat sink effect suppresses sudden temperature spikes within the machining chamber. Simultaneously, microchannels facilitate convective heat transfer between the protective gas and the energy storage medium, preheating the protective gas and replacing traditional electric heating with recovered waste heat, thus achieving secondary recycling of thermal energy. During the subtractive manufacturing stage, the solid-liquid bidirectional phase change characteristics of the energy storage medium compensate for the temperature gradient caused by cutting heat within the machining chamber, limiting temperature fluctuations within the chamber to a preset range. This maintains a quasi-constant temperature environment within the machining chamber, eliminating workpiece dimensional deviations caused by thermal effects and ensuring machining quality. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the energy-saving equipment for additive and subtractive material composite processing in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the heat exchange module structure in Embodiment 1 of the present invention; Figure 3 This is a flowchart of the energy-saving method for additive and subtractive composite processing in Embodiment 2 of the present invention; The components include: 1. Shell; 2. Energy storage medium; 3. Microchannel; 4. Composite coating; 5. Molten pool; 6. Powder feeding unit; 7. Temperature-controlled jet interface; 8. Heat flow sensor; 9. Host computer control unit; 10. Processing chamber; 11. High-energy beam generator; 12. Worktable; 13. Flow regulating device; and 14. Protective gas supply source. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Example 1 A typical embodiment of the present invention provides an energy-saving device for additive and subtractive composite processing based on phase change thermal storage, such as... Figure 1 As shown, the process includes a processing chamber 10, which integrates a high-energy beam generator 11. The high-energy beam generator 11 can emit high-energy beams, such as high-power lasers or electron beams, to selectively melt the metal powder on the worktable 12 to form a molten pool 5. During the additive manufacturing process, due to the continuous input of the high-energy beam, the molten pool 5 region will generate extremely high instantaneous heat. Part of this heat is used for material melting and microstructure evolution, while the other part is dissipated into the ambient space of the processing chamber 10 through thermal radiation and thermal convection.

[0019] Multiple heat exchange modules are arranged on the walls of the processing chamber 10 and around the workbench 12. The multiple heat exchange modules are evenly distributed around the workbench 12 and located in the heat-sensitive area inside the processing chamber 10. Each heat exchange module is encapsulated by a shell 1 and filled with an energy storage medium 2 with specific performance parameters.

[0020] Furthermore, the shell 1 is a closed metal shell, made of a material with extremely high thermal conductivity and thermophysical stability, such as 6061-T6 aluminum alloy with surface passivation treatment or TC4 titanium alloy with high structural strength. The thickness of the shell 1 needs to fully consider the balance of internal phase change pressure and the minimization of thermal resistance. In this embodiment, the thickness of the shell 1 is 1.5mm~3.0mm.

[0021] To maximize the capture of high-frequency short-wave radiation generated during additive manufacturing, such as Figure 2 As shown, the outer surface of the shell 1 is coated with a composite coating 4. The composite coating 4 is a nanostructured composite coating, which is prepared by plasma spraying or chemical vapor deposition. It has high light trapping properties. The composite coating 4 has a predetermined absorption ratio within a preset spectral range. It can convert the scattered light energy that would otherwise be reflected to other precision components in the cabin into heat energy, and then conduct it to the internal energy storage medium 2. This not only improves the energy recovery rate, but also protects the optical components and mechanical transmission system inside the processing cabin 10.

[0022] In this embodiment, the composite coating 4 is composed of multiple alternating layers of metal-ceramic materials. In other embodiments, the composite coating 4 may also be composed of a carbon nanotube composite film with a hierarchical pore structure, so that the composite coating 4 has an infrared absorption rate of more than 0.95 in the spectral range of 0.8μm to 2.5μm, ensuring that the radiation emitted by the molten pool 5 can be efficiently converted into the internal energy of the shell 1 and conducted to the internal energy storage medium 2.

[0023] The energy storage medium 2 is a phase change energy storage medium, which adopts modified paraffin-based composite materials or medium- and low-temperature eutectic salts and other phase change materials. In order to overcome the defect of low thermal conductivity of traditional phase change materials, a high thermal conductivity enhancement phase, such as graphene microplates or aluminum nitride nanoparticles, is uniformly doped into the energy storage medium 2 with a volume fraction of 5% to 12%, which increases the equivalent thermal conductivity of the energy storage medium 2 to more than 5.0 W / (m·K), ensuring that heat absorption and storage are completed in an extremely short thermal response time.

[0024] During the additive manufacturing process, the system selectively melts metal powder using a high-energy beam to construct the component. In this process, the molten pool 5 radiates high-density infrared energy into space, and the high-temperature gas forms a complex convective heat transfer field within the processing chamber 10. Heat exchange modules arranged on the walls of the processing chamber 10 and around the worktable 12 passively receive and capture radiant and convective energy through their high infrared absorption coatings. When the real-time temperature collected by the heat exchange modules reaches the preset phase change temperature of the energy storage medium 2, the energy storage medium 2 begins to undergo a physical phase change from solid to liquid. During this process, the heat exchange modules utilize the latent heat of phase change of the material to absorb and store a large amount of heat energy lost from the outside while maintaining a relatively constant module temperature. This heat absorption not only serves as temporary energy storage but also, through its powerful heat sink effect, suppresses the temperature surge of the gas and precision mechanical components within the processing chamber 10, thereby reducing the system's power requirements for traditional auxiliary cooling systems at the physical level.

[0025] The housing 1 is also provided with a microchannel 3. In this embodiment, the microchannel 3 is integrally formed on the inner wall of the housing 1 by laser selective melting process. The molten energy storage medium 2 is injected into the housing 1 and fills the outer space of the microchannel 3. After cooling, a solid-liquid composite structure is formed.

[0026] Microchannel 3 is used to circulate the protective gas to be preheated. Microchannel 3 adopts a nonlinear three-dimensional interwoven layout generated based on topology optimization algorithm. In this embodiment, microchannel 3 is a spiral or biomimetic skeleton structure. The inner wall of microchannel 3 has controlled roughness, which can induce the generation of microscale vortices to destroy the boundary layer thermal resistance.

[0027] The microchannel 3 is provided with a gas inlet and a gas outlet at both ends. The gas inlet is connected to the protective gas supply source 14, and the gas outlet is connected to the powder feeding unit 6 and the temperature-controlled jet interface 7, respectively. The protective gas supply source 14 injects protective gas into the microchannel 3. In this embodiment, the protective gas is argon. The protective gas undergoes convective heat exchange with the energy storage medium 2 in the liquid phase to raise the internal energy of the protective gas to the preset process target range. The preheated gas is then injected into the powder feeding unit 6 or guided to the workpiece surface through the temperature-controlled jet interface 7.

[0028] The outlet of the protective gas supply source 14 is connected to the gas inlet of the microchannel 3 through a pipe. A flow regulating device 13 is installed on the pipe between the outlet of the protective gas supply source 14 and the gas inlet of the microchannel 3. In this embodiment, the flow regulating device 13 adopts a commonly available flow regulating valve.

[0029] During interlayer pauses in additive manufacturing and / or the transition phase from additive to subtractive manufacturing, the system dynamically determines the priority of heat release requirements based on real-time monitored process parameters. If the system determines that subsequent process steps require gas preheating or substrate insulation, it activates the flow regulation device 13 connected to the microchannel 3. At this time, the protective gas, which is in a low-temperature state, flows through the microchannel 3 inside the heat exchange module. Since the energy storage medium 2 contains a large amount of latent heat in the liquid phase, the protective gas undergoes efficient convective heat exchange with the energy storage medium 2 within the microchannel 3, increasing the gas's internal energy and raising its temperature to the preset process target range. The preheated gas is then injected into the powder feeding unit 6 or blown onto the workpiece surface. This process achieves secondary recycling of heat energy by directly utilizing recovered waste heat instead of the traditional electric heating preheating mode.

[0030] The entire system is intelligently controlled by the host computer control unit 9. In this embodiment, the host computer control unit 9 adopts a PLC controller. The host computer control unit 9 is electrically connected to the flow regulating device 13, the high-energy beam generator 11, and the heat flow sensor 8 installed inside the energy storage medium 2.

[0031] To address the requirements for environmental temperature stability during the subtractive machining stage, the host computer control unit 9 is pre-programmed with active temperature control logic based on phase change thermal resistance. During subtractive machining, the temperature gradient within the machining chamber 10 changes due to the mechanical heat generated during the cutting process. At this time, the heat exchange module acts as a thermal buffer unit. When the local temperature exceeds the preset thermal equilibrium point, the module continues to absorb residual heat; conversely, when the local temperature falls below the preset range due to the intervention of the cooling medium, the phase change material begins to transform from the liquid phase to the solid phase, releasing latent heat to compensate for the temperature drop. This bidirectional energy regulation mechanism based on physical phase change limits the temperature field fluctuations within the machining chamber 10 to a preset range, effectively preventing geometric dimensional deviations in the workpiece caused by thermal effects.

[0032] Furthermore, the host computer control unit 9 integrates an intelligent energy scheduling algorithm, which predicts the heat generation and heat demand of each processing stage in advance based on the pre-input part geometry model and process path. The algorithm pre-adjusts the initial thermal state of the heat exchange module by integrating the heat load within a specific time window. Specifically, the outer wall of the housing 1 is provided with a jacketed cooling chamber, which forms a closed cooling loop with an external circulating pump and heat exchanger through pipelines. Before high-power additive scanning, the host computer control unit 9 starts the circulating pump to allow the coolant to flow through the jacketed cooling chamber to forcibly cool the energy storage medium 2. Before entering the stage requiring high-precision subtractive processing, it ensures that the phase change material is in a predetermined phase state to exert its temperature regulation effect.

[0033] Example 2 This embodiment provides an energy-saving method for additive-subtractive composite processing based on phase change thermal energy storage, utilizing an energy-saving device for additive-subtractive composite processing based on phase change thermal energy storage as described in Embodiment 1. Figure 3 As shown, it includes the following steps: Before performing additive and subtractive composite processing, the host computer control unit 9 initializes the system, which mainly includes starting the processing chamber 10, calibrating the sensors, and detecting the status of the heat exchange module. Subsequently, the host computer control unit 9 makes a judgment on the process stage.

[0034] During the additive manufacturing process, the composite coating 4 on the outer surface of the shell 1 passively receives the infrared energy radiated from the molten pool 5 region into space and the convective heat transfer energy in the processing chamber 10. When the real-time temperature collected by the heat exchange module reaches the preset phase change temperature point of the energy storage medium 2, the energy storage medium 2 absorbs and stores heat energy using the latent heat characteristics of phase change, and suppresses the surge in ambient temperature in the processing chamber 10 through the heat sink effect.

[0035] To accurately quantify and control energy transfer during the phase change process, the host computer control unit 9 retrieves data from the heat flow sensors 8 deployed on the heat exchange module in real time, and calculates the real-time total heat load Q of the heat exchange module during the heat absorption phase using a mathematical model that couples phase change interface movement with heat flow field. total It follows the following energy conservation principle: ; In the formula, Q total This represents the total heat captured by the heat exchange module per unit time, expressed in W. The effective infrared emissivity coefficient of composite coating 4 within a preset spectral range is represented by σ; σ is the Stefan-Boltzmann constant; T s The equivalent radiation temperature of the molten pool 5 and the high-temperature forming zone is expressed in K; T. pcm The temperature of the shell 1 surface is measured in Kelvin (K); A represents the effective heat exchange area of ​​the heat exchange module facing the heat source, measured in m². 2 h represents the convective heat transfer coefficient of the inert gas in processing chamber 10, with units of W / (m²·K); T g This represents the real-time temperature of the ambient gas inside the processing chamber 10, in Kelvin (K).

[0036] The host computer control unit 9 is based on the calculated real-time total heat load Q total Furthermore, the evolution prediction of the liquid phase ratio beta of energy storage medium 2 is performed to ensure that the thermal energy storage capacity is within the preset safety threshold range. The evolution law of liquid phase ratio beta follows the following relationship: ; In the formula, beta is the liquid volume fraction of energy storage medium 2, and its value fluctuates between the first preset value 0 and the second preset value 1; L represents the latent heat of phase change per unit mass of energy storage medium 2, in J / kg; ρ represents the average density of energy storage medium 2, in kg / m³. 3 V represents the total volume of energy storage medium 2 within the casing 1, in m³. 3 ; k is the equivalent thermal conductivity of energy storage medium 2 in the current state of matter, in W / (m·K); T is the temperature field distribution inside energy storage medium 2 as time changes; t is the time for continuous heat capture, in s.

[0037] After the additive manufacturing process is completed, the host computer control unit 9 determines whether to switch processes. When it is determined that subtractive manufacturing is required, the system enters the subtractive manufacturing process.

[0038] During the interlayer pauses in additive manufacturing and / or the transition phase from additive manufacturing to subtractive manufacturing, the host computer control unit 9 activates the flow regulating device 13 according to process requirements, controls the protective gas to flow through the microchannel 3, so that the protective gas and the energy storage medium 2 in the liquid phase can carry out convective heat exchange, raising the internal energy of the gas to the preset process target range. The preheated gas is then injected into the powder feeding unit 6 and / or guided to the workpiece surface through the temperature-controlled jet interface 7. When the protective gas flows through microchannel 3, its temperature rise process follows the following convective heat transfer control equation: ; In the formula, ρ g The density of the protective gas flowing through microchannel 3 is expressed in kg / m³. 3 c pg The isobaric specific heat capacity of the gas is used to protect it; the unit is W / (m·K); v g T represents the controlled flow velocity of the gas in the flow channel after being regulated by the flow regulating device 13, expressed in m / s. g,out The preheated protective gas outlet temperature is expressed in Kelvin (K); α is the enhanced heat transfer coefficient, the value of which is adjusted by the turbulence structure on the inner wall of the flow channel; P is the wetted perimeter length of microchannel 3 on the cross section perpendicular to the flow direction, expressed in meters (m); the host computer control unit 9 regulates the flow rate v through a closed loop. g This enables precise control of the output gas temperature, matching it to the process target values ​​required by the powder feeding unit 6.

[0039] In this way, the recovered heat energy is given secondary utilization value. The preheated gas enters the processing area through the powder feeding unit 6, effectively reducing the temperature gradient of the metal powder before melting and reducing the energy barrier of the molten pool 5 in the early stage of melting. Experiments have shown that this can reduce the effective power requirement of the high-energy beam by more than 8%. At the same time, part of the preheated gas is guided to the sensitive temperature control zone of the processing chamber 10 through the temperature-controlled jet interface 7. By adjusting the gas flow rate and distribution ratio, precise compensation of the ambient temperature of the processing chamber 10 is achieved, and the amplitude is limited to within ±2°C.

[0040] Furthermore, during the switching between additive and subtractive machining processes, the workpiece is extremely sensitive to thermal deformation due to the precision milling or drilling operations involved in subtractive machining. At this time, the thermal resistance effect of the energy storage medium 2 acts as a temperature stabilizer. When milling generates heat, causing a local temperature increase, the medium that has not fully undergone phase change continues to absorb heat; if the workpiece becomes too cold due to the introduction of a large amount of coolant, the phase change material undergoes a reverse phase change, releasing latent heat to compensate for the temperature drop. This automatic regulation based on physical phase change requires no external power input, fundamentally reducing the energy efficiency ratio of the air conditioning system needed to maintain the constant temperature chamber environment.

[0041] During the subtractive processing stage, the solid-liquid two-way phase change characteristics of the energy storage medium 2 are used to compensate for the temperature gradient caused by the heat generated during cutting in the processing chamber 10, thereby limiting the temperature field fluctuation amplitude in the processing chamber 10 to a preset range.

[0042] Specifically, when the local ambient temperature exceeds the preset thermal equilibrium point due to the heat from cutting machinery, the energy storage medium 2 absorbs the excess heat through further liquefaction; when the local ambient temperature falls below the preset range due to the intervention of the external cooling medium, the energy storage medium 2 begins to transform from liquid to solid phase and release latent heat, thereby compensating for the temperature drop; the host computer control unit 9 uses this bidirectional energy regulation mechanism based on physical phase change to help maintain a quasi-constant temperature environment in the processing chamber 10 and eliminate workpiece geometric deviations caused by thermal effects.

[0043] After the subtractive processing stage is completed, the host computer control unit 9 determines whether the processing is complete. If the processing is complete, the system enters standby mode. If the processing is not complete, the host computer control unit 9 re-determines the process stage.

[0044] By setting up a heat exchange module in the heat-sensitive area inside the processing chamber 10, the heat energy of the additive manufacturing stage is absorbed and stored by the heat exchange module. The heat sink effect suppresses the temperature surge inside the processing chamber 10. At the same time, the protective gas and the energy storage medium 2 are preheated through the microchannel 3. The recovered waste heat replaces the traditional electric heating preheating mode, realizing the secondary recycling of heat energy. In the subtractive manufacturing stage, the solid-liquid bidirectional phase change characteristics of the energy storage medium 2 are used to compensate for the temperature gradient caused by the heat generated by cutting in the processing chamber 10. The temperature field fluctuation amplitude in the processing chamber 10 is limited to a preset range, thereby maintaining a quasi-constant temperature environment in the processing chamber 10, eliminating the workpiece geometric dimension deviation caused by the thermal effect, and ensuring the processing quality.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An energy-saving equipment for additive and subtractive manufacturing composite processing based on phase change thermal storage, characterized in that, The system includes a heat exchange module located in a heat-sensitive area inside the processing chamber. The heat exchange module includes a shell capable of conducting heat, and the shell is filled with an energy storage medium capable of absorbing and storing thermal energy. The shell also has microchannels for the flow of protective gas. The energy storage medium fills the outer space of the microchannels. The microchannels enable convective heat exchange between the protective gas and the energy storage medium. The heat-exchanged protective gas is then introduced into the powder feeding unit and the temperature-controlled jet interface.

2. The energy-saving equipment for additive and subtractive manufacturing composite processing based on phase change thermal storage as described in claim 1, characterized in that, The outer surface of the housing is coated with a composite coating, which is composed of multiple alternating layers of metal-ceramic materials.

3. The energy-saving equipment for additive and subtractive manufacturing composite processing based on phase change thermal storage as described in claim 1, characterized in that, The microchannel is integrally formed on the inner wall of the shell using a laser selective melting process. Molten energy storage medium is injected into the shell and fills the outer space of the microchannel. After cooling, a solid-liquid composite structure is formed.

4. The energy-saving equipment for additive and subtractive manufacturing composite processing based on phase change thermal storage as described in claim 1, characterized in that, The microchannel is provided with a gas inlet and a gas outlet at both ends, with the gas inlet connected to a protective gas supply source and the gas outlet connected to a powder feeding unit and a temperature control jet interface, respectively.

5. The energy-saving equipment for additive and subtractive manufacturing composite processing based on phase change thermal storage as described in claim 4, characterized in that, The protective gas supply source is connected to the gas inlet of the microchannel via a pipeline, and a flow regulating device is installed on the pipeline between the protective gas supply source and the gas inlet of the microchannel.

6. The energy-saving equipment for additive and subtractive manufacturing composite processing based on phase change thermal storage as described in claim 5, characterized in that, It also includes a host computer control unit, which is electrically connected to the flow regulation device, the high-energy beam generator integrated in the processing chamber, and the heat flow sensor installed inside the energy storage medium.

7. An energy-saving method for additive-subtractive composite processing based on phase change thermal energy storage, utilizing an energy-saving device for additive-subtractive composite processing based on phase change thermal energy storage as described in any one of claims 1-6, characterized in that, Includes the following steps: During the additive manufacturing process, the composite coating on the outer surface of the shell passively receives the infrared energy radiated into space from the molten pool area and the convective heat transfer energy in the processing chamber. When the real-time temperature collected by the heat exchange module reaches the preset phase change temperature point of the energy storage medium, the energy storage medium absorbs and stores heat energy using the latent heat of phase change, and suppresses the surge in ambient temperature in the processing chamber through the heat sink effect. During the interlayer pauses in additive manufacturing and / or the transition phase from additive manufacturing to subtractive manufacturing, the host computer control unit activates the flow regulation device according to process requirements, controls the protective gas to flow through the microchannel, so that the protective gas and the energy storage medium in the liquid phase can carry out convective heat exchange, raising the internal energy of the gas to the preset process target range. The preheated gas is then injected into the powder feeding unit and / or guided to the workpiece surface through the temperature-controlled jet interface. During the subtractive machining process, the solid-liquid two-way phase change characteristics of the energy storage medium are used to compensate for the temperature gradient caused by the heat generated during cutting in the machining chamber, thereby limiting the temperature field fluctuation range in the machining chamber to a preset range.

8. The energy-saving method for additive and subtractive composite processing based on phase change thermal storage as described in claim 7, characterized in that, The additive manufacturing execution phase also includes: using the host computer control unit to retrieve the heat flow sensor data deployed on the surface of the heat exchange module in real time, and combining the phase change interface movement and heat flow field coupling mathematical model to calculate the real-time total heat load of the heat exchange module during the heat absorption phase.

9. The energy-saving method for additive and subtractive composite processing based on phase change thermal storage as described in claim 8, characterized in that, The additive manufacturing execution phase also includes: the host computer control unit, based on the calculated real-time total heat load, further predicts the evolution of the liquid phase ratio of the energy storage medium to ensure that the amount of thermal energy stored is within the preset safety threshold range.

10. The energy-saving method for additive and subtractive composite processing based on phase change thermal storage as described in claim 7, characterized in that, The specific execution stage of subtractive processing is as follows: when the local ambient temperature exceeds the preset thermal equilibrium point due to the heat of the cutting machinery, the energy storage medium absorbs the excess heat through further liquefaction. When the local ambient temperature falls below the preset range due to the intervention of the external cooling medium, the energy storage medium begins to transform from the liquid phase to the solid phase and releases latent heat, thereby compensating for the temperature drop.

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