19 results about "Dry spot" patented technology

The invention discloses a forming method of a composite material special-shaped yacht cab in the technical field of composite material manufacturing, which comprises the following steps of: performing resin flow simulation based on a three-dimensional model, and identifying a high-resistance area; a flow guide system and a layering scheme are optimally designed; arranging a diversion net by adopting a layered laying strategy; the flow effect is optimized through experimental verification; a vacuum system is constructed, and multi-inlet synchronous glue injection is carried out; and gradient curing molding and post-treatment are carried out, so that the production of products is realized. According to the method, through CFD flow simulation and dynamic diversion system optimization, flow lag of high-resistance areas such as curved surfaces and sharp corners is accurately predicted and compensated, the infiltration effect of resin in a complex structure is remarkably improved by combining layered diversion net design and a stress-oriented layering strategy, common defects such as dry spots and pores in a traditional process are fundamentally eliminated, and the method is suitable for large-scale production. And the forming quality of complex components such as the special-shaped yacht cab is greatly improved.

The invention relates to a combined strengthening method of critical heat flux density and a visual experiment device, after a water glass nano solution is uniformly sprayed on a boiling wall surface, the water glass nano solution is further heated until the water glass nano solution on the boiling wall surface is bubbled and solidified on the boiling wall surface, a nano-particle coating is obtained after polishing, a specific dropper device is adopted in the boiling process, and the water glass nano solution on the boiling wall surface is solidified on the boiling wall surface. The supercooled liquid is dropwise added on the boiling wall surface, the critical heat flux is accurately measured by adopting a visual experimental device, and the critical heat flux strengthening mechanism is verified by shooting images. The prepared nano-particle coating is high in porosity, the hydrophilicity of the boiling wall surface can be remarkably improved, the dropper device is simple in structure and low in cost, formation of irreversible dry spots can be inhibited, and the critical heat flux density is improved through the superposition effect of the two methods. The device is low in cost, easy and convenient to operate, high in expansibility and capable of being rapidly applied to boiling wall surfaces made of different materials. A pool boiling experiment device is adopted as the visual experiment device, and the mechanism and the effect of critical heat flux density strengthening are verified.

The invention discloses a product manufacturing process monitoring method and device based on a resin transfer molding process. The method comprises the following steps: monitoring a resin flowing front edge according to a first regression model and a second regression model when resin flows; inputting the monitored optical fiber signal into a pre-trained curing stage identification model to obtain a current curing stage when the resin is cured, and determining a current curing degree according to a fusion image obtained by the optical fiber signal and the ultrasonic guided wave signal; and determining a dry spot area according to the monitored optical fiber signal when the resin is cured, and determining the quantitative information of the dry spot according to the monitored ultrasonic guided wave signal in the dry spot area. In the resin injection process, the obtained ultrasonic guided wave signals and optical fiber signals are analyzed to monitor the flowing front edge, the curing degree and the dry spots of the resin, and through mutual verification of optical fiber monitoring results and ultrasonic monitoring results, the product manufacturing precision and the finished product quality are improved, and intelligent manufacturing of composite materials is achieved.

An RTM molding die and a method for preparing resin composite materials from the RTM molding die belong to the field of composite material molding. It includes a lower die and an upper die. The lower die has a cavity and an O-ring groove on its upward-facing side, in which an O-ring is embedded. The upper die has inlet and outlet interfaces and an O-ring insertion groove on its downward-facing side. The key feature is that an inflation sealing ring groove is provided on the upward-facing side of the lower die, surrounding the outer side of the O-ring groove. An inflation sealing ring is placed within the inflation sealing ring groove, and the inflation sealing ring has an inflation / deflation nozzle corresponding to an inflation / deflation nozzle receiving cavity recessed on the upward-facing side of the lower die. An inflation sealing ring mating groove is provided on the downward-facing side of the upper die. The steps are: preliminary preparation; fiber laying; liquid epoxy resin injection; mold closing; and curing. Advantages: avoids dry spots on the resin composite material, ensures excellent stiffness and strength, and improves preparation efficiency.

The invention relates to the technical field of composite material manufacturing, and discloses a light-weight carbon fiber plate vacuum infusion forming method which comprises matrix resin, a curing agent, a controllable phase change self-expanding pressing agent and a pressure response type gel triggering agent. The intelligent resin system is pre-arranged on a fiber pre-forming body and is sealed and vacuumized to form a sealed cavity, and then the controllable phase change self-expanding pressing agent is subjected to phase change gas production at a preset triggering temperature through programmed temperature rise, so that internal micro-positive pressure is formed in the cavity. The internal micro-positive pressure drives the resin to infiltrate the fibers, and activates the pressure response type gel triggering agent to initiate gel curing, and then high-temperature curing is completed. According to the method, through internal micro-positive pressure generated in situ, self-expanding, complete and uniform infiltration of the resin on fibers is achieved, the compaction effect can be continuously applied in the curing stage, the internal porosity and dry spot defects of a workpiece are remarkably reduced, and the mechanical property and the internal quality of a composite material plate are improved.

A falling film apparatus has tube inserts located at the top end of heat exchange tubes. The tube inserts have internal circumferential ribs. The ribs distribute a process flow into a uniform, annual film within the tube inserts and the tubes, and eliminate dry spots, even at low operating rates. This provides greater operating latitude, can improve operating efficiency and can reduce fouling.

The invention relates to an immersed liquid cooling device and method, and relates to the technical field of thermal management and electronic cooling. Comprising a closed cavity, an electronic element, a phase change material layer and a condensation piece, the closed cavity is filled with dielectric cooling liquid, the phase change material layer is loaded on the surface of the electronic element, and the superheat degree needed by bubble nucleation is remarkably reduced through the combined action of heat absorption and phase change of the phase change layer; a large number of effective nucleation sites are formed on the heating surface, so that bubbles are generated more easily, bubble merging is reduced, and bubble separation and updating are promoted; the phase change material layer maintains more stable nucleate boiling under medium-high heat flow, the porous structure not only can improve the average heat transfer coefficient, but also can absorb cold fluid through the capillary force effect to form heat convection to delay local dry spot formation, higher boiling heat exchange intensity is achieved, and boiling enhancement and heat flux density improvement are achieved.

The application discloses an energy-saving industrial mobile air conditioner. It comprises a machine body and a condenser inside, and water curtains are arranged on the two sides of the condenser. In view of the pain point that the dry spots of the water curtain are prone to spread downward, the application provides a gravity-guided self-adaptive dry spot prevention and self-repairing mechanism. The core of the mechanism is a "gravity wheel disc multi-position lock" structure. The structure utilizes the water absorption and weight increase characteristics to realize the follow-up anchoring of "who is below, who is locked", so that the mechanism can not only be immune to the disturbance deflection caused by water flow scouring, but also can be automatically unlocked when the dry spots spread downward and cause local water loss. At this time, the external high-speed airflow drives the inner curtain to overturn, and the water-rich area above is forced to be matched with the dry spot area below, so that the spread of the dry spots is blocked. In addition, the rotating blades can passively consume the kinetic energy of the airflow, thereby playing the roles of wind speed attenuation and water film protection. The pure mechanical structure is maintenance-free and has high reliability.

The present invention discloses a resin infiltration control system and its control method for the liquid molding VARI process. The control system includes: a mold, a preform, a fixture group, a vacuum bag group, a glue injection pipeline, a vacuum pumping device, and a semi-permeable membrane. The method includes: First, laying the preform above the mold; Second, laying an auxiliary material layer above the preform; Third, dividing the exhaust channels according to the thickness of the preform perpendicular to the resin infiltration direction, and drilling holes in the glue injection pipeline and the exhaust channels; Fourth, covering the holes of the exhaust channels with a semi-permeable membrane, and placing the glue injection pipeline and the exhaust channels above the auxiliary material; Fifth, performing steps such as sealing. The present invention establishes a "zero glue leakage" system for the composite material VARI process, which can accurately control the resin amount and reduce the resin waste phenomenon. Moreover, it controls the flow front of the resin infiltration process of the variable-thickness reinforcement preform, avoids the problem of air entrainment caused by the convergence of the flow front, and reduces the risk of quality problems such as dry spots and pores in the parts.

The invention discloses a purging device and a rolling mill thereof.The purging device comprises a telescopic assembly capable of stretching out and drawing back in the axial direction and a blowing pipe assembly, the blowing pipe assembly is arranged at one end of the telescopic assembly, and the other end of the telescopic assembly is rotatably arranged in the rolling mill; according to the blowing device, the pipe blowing assembly can be close to or far away from the pipe fitting through stretching and retracting of the telescopic assembly and running fit between the telescopic assembly and the rolling mill, then the pipe blowing assembly penetrates into the fin machining initial position of the rolling mill, and the problem that fin segments cannot be completely covered and blown in the prior art is solved; the rolling machine can be flexibly adjusted to be retracted and released, production adjustment is not affected, and in production, the rolling machine rolls the blowing device while conducting surface blowing on the rolled part of the pipe fitting and removing residual cutting fluid, so that residual stains on the surface are reduced, the residual cutting fluid is removed from the whole section of the pipe fitting, dry spots and accumulated dirt on the outer surface of the pipe fitting are eliminated, and the service life of the pipe fitting is prolonged. And the surface quality of the pipe fitting is ensured.

A numerical prediction method for heat transfer fire (CHF) based on dry spot-dry spot dynamics and conjugate heat conduction includes the following steps: S1: Establishing a functional relationship model between wall superheat and bubble dynamic parameters through regression analysis of experimental data, i.e., the bubble dynamic parameter model; S2: Establishing a dry spot-dry spot dynamic model based on the bubble dynamic parameter model; S3: Establishing a heat transfer boundary condition model based on the distribution characteristics of dry spots-dry spots on the wall and their corresponding thermal resistance characteristics; S4: Simulating the dry spot-dry spot dynamic model established in step 2 using particle dynamics; S5: Constructing a three-dimensional conjugate heat conduction equation, coupling it with the dynamically updated heat transfer boundary condition model established in S3, obtaining the wall temperature and heat flux distribution through numerical solution, and feeding the results back to the bubble dynamic parameter model established in S3; S6: Visualizing the wall temperature and heat flux distribution in S5. This application improves the physical interpretability and reliability of the simulation results.

The invention discloses an RTM forming mold and a method for preparing a resin composite material through the RTM forming mold, and belongs to the field of composite material forming. Comprising a lower die and an upper die, the lower die is provided with a die cavity, an O-shaped sealing ring groove is formed in the upward side of the lower die, an O-shaped sealing ring is embedded in the groove, a leading-in interface and a leading-out interface are formed in the upper die, and an O-shaped sealing ring probing groove is formed in the downward side of the upper die. The die is characterized in that an inflation sealing ring groove is formed in the upward side of the lower die and surrounds the outer side of the O-shaped sealing ring groove, an inflation sealing ring is arranged in the inflation sealing ring groove and provided with an inflation and deflation nozzle, and the inflation and deflation nozzle corresponds to an inflation and deflation nozzle containing cavity formed in the upward side of the lower die in a concave mode. An inflatable sealing ring matching groove is formed in the downward side of the upper die; the method comprises the steps of early-stage preparation; laying fibers; injecting liquid epoxy resin; closing the mold; and curing and molding. The method has the advantages that dry spots of the resin composite material are avoided, excellent rigidity and strength are ensured, and the preparation efficiency is improved.

The invention belongs to the technical field of composite material product manufacturing, and discloses a composite material cylindrical part RTM forming die which comprises a core die, an upper die, a lower die, a sealing ring and a connector. The invention further discloses a forming method using the composite material cylindrical part RTM forming mold. According to the invention, the heavy and difficult problems of mold closing, air tightness and the like of the composite material cylindrical part mold are solved, and the reasonable cylindrical part RTM molding process is designed to solve the problems of dry spots and air holes after the product is cured. The RTM forming mold and the RTM forming process provided by the invention are a near-net forming technical scheme which is low in cost, good in product internal quality and surface quality, high in dimensional precision and relatively high in automation degree.

The application discloses a composite material special-shaped speedboat cabin forming method in the technical field of composite material manufacturing, and comprises the following steps: resin flow simulation is carried out based on a three-dimensional model, and a high-resistance area is identified; a flow guide system and a layering scheme are optimized and designed; a layered laying strategy is adopted to arrange a flow guide net; the flow effect is verified through experiments; a vacuum system is constructed, and multiple inlets are used for synchronous glue injection; gradient curing forming and post-processing are carried out, and the production of the product is realized. Through CFD flow simulation and dynamic flow guide system optimization, the application precisely predicts and compensates the flow lag of high-resistance areas such as curved surfaces and sharp corners, and combines layered flow guide net design and stress-oriented layering strategy, so that the resin infiltration effect in the complex structure is significantly improved, the defects such as dry spots and pores commonly seen in traditional processes are fundamentally eliminated, and the forming quality of complex components such as special-shaped speedboat cabins is greatly improved.

The invention discloses a slow lifting device which comprises a rack, lifting equipment is arranged on the rack, a slow lifting groove is formed in the bottom end of the rack, the slow lifting groove is connected with a water inlet device, the water inlet device comprises a distributed water inlet pipe arranged at the bottom of the slow lifting groove, a plurality of water inlet holes are formed in the distributed water inlet pipe, and the water inlet holes are communicated with the slow lifting groove. The distributed water inlet pipe is connected with a filter through a pipeline, an exhaust valve is arranged at the top of the filter, an air draft device is arranged at the bottom of the slow lifting groove, and an air supply filtering device is arranged at the top of the rack. According to the slow lifting device and the method for cleaning the photomask substrates without the dry spots, the slow lifting device is simple in structure and has the capability of cleaning the multiple photomask substrates at a time, the working efficiency of the photomask substrates is greatly improved, and meanwhile, the method for cleaning the photomask substrates without the dry spots has the advantages that the cost is low, and the working efficiency is high. The watermark problem of the photomask substrate can be effectively avoided.

The invention provides a resin pouring process control method and system, and relates to the technical field of liquid molding. By introducing the double-region parallel permeability model, the parallel flow characteristics of the resin in the gully runner and the fiber preform are accurately described, and the prediction deviation caused by neglecting the region difference in the traditional single model is broken through; and based on self-adaptive closed-loop control of model prediction and visual feedback, blindness and hysteresis of traditional control depending on experience or a fixed program are fundamentally overcome, fine and active coordination of the resin flowing process is realized, internal defects such as dry spots or air bags caused by flow incoordination are effectively prevented, and the service life of the resin is prolonged. And the process success rate and the quality uniformity and reliability of a composite material product are greatly improved.

This invention discloses a method and apparatus for monitoring the product manufacturing process based on resin transfer molding, comprising: monitoring the resin flow front according to a first regression model and a second regression model during resin flow; inputting the monitored fiber optic signal into a pre-trained curing stage recognition model to obtain the current curing stage during resin curing, and determining the current degree of curing based on the fused image obtained from the fiber optic signal and the ultrasonic guided wave signal; determining the dry spot region based on the monitored fiber optic signal when resin curing is complete, and determining the quantitative information of the dry spot based on the ultrasonic guided wave signal monitored in the dry spot region. During resin injection, the acquired ultrasonic guided wave signal and fiber optic signal are analyzed to monitor the resin flow front, degree of curing, and dry spot. The fiber optic monitoring results are cross-validated with the ultrasonic monitoring results to improve the precision of product manufacturing and the quality of finished products, thereby realizing intelligent manufacturing of composite materials.

The present application belongs to the technical field of composite material forming, and particularly relates to a resin transfer molding-mold pressing combined forming method based on resin reaction state, which determines a preliminary transfer window according to the reaction state of a thermosetting resin system in a curing cross-linking reaction process; places a fiber preform in a resin transfer molding tool, injects the thermosetting resin system into the fiber preform and makes the fiber preform impregnated; pre-cures and heats under the preliminary transfer window, has a first pre-curing cross-linking reaction, and obtains a transfer window; within the transfer window, transfers the impregnated fiber preform to a mold pressing station or an integrated mold switched to a mold pressing working condition, makes the fiber preform contact, compact, solidify, cross-link and pressure-keeping cool, and obtains a product after demolding. The present application can consider full impregnation and efficient compaction, reduce defects such as dry spots, resin enrichment, interlayer separation, porosity and fiber disturbance, improve product thickness consistency and interface bonding state, and improve comprehensive performance.