133 results about "Liquid nitrogen cooling" patented technology

The invention discloses a liquid nitrogen cooling and laser heating collaborative auxiliary cutting device and a cutting method thereof. The device comprises a laser heating system, a liquid nitrogen cooling system, a cutting system, a tool temperature monitoring system and a control system. Laser emitted by the laser heating system is focused on a to-be-machined area of a workpiece in front of a cutting edge after transmitting through the cutter body; the liquid nitrogen cooling system accurately sprays liquid nitrogen to the cutting edge area of the tool through a heat insulation liquid supply pipeline and a nozzle which are integrated in the tool rest. The control system dynamically and synergistically adjusts the laser output power and the liquid nitrogen injection flow based on a temperature signal sent by a thermocouple embedded in the cutter. According to the device, parallelism of the two processes of laser heating of a workpiece and liquid nitrogen cooling of a tool is achieved in space, dynamic matching and accurate balance of laser heating and liquid nitrogen cooling are achieved in time, and the problems that in laser-assisted cutting, the tool is prone to thermal damage, the cooling efficiency is low, and a thermal field is out of control are effectively solved.

The invention relates to the technical field of medical materials, and particularly discloses a preparation process of a nickel-titanium-based shape memory alloy micro flat filament, which comprises the following steps: S1, pickling and polishing a nickel-titanium-based composite material, heating under the protection of inert gas, and repeatedly annealing and cold-drawing until the filament diameter is 0.1 mm; the annealing temperature is 650-750 DEG C, and the deformation of each heating number of cold drawing is 30-40%; s2, a wire with the wire diameter of 0.1 mm is polished, then the temperature is increased under inert gas protection, and annealing and cold drawing are repeatedly conducted till the wire diameter ranges from 0.03 mm to 0.08 mm; the annealing temperature is 600-700 DEG C, and the deformation of each heating number of cold drawing is 35-48%; and S3, the blank obtained in the S2 is rolled under liquid nitrogen cooling, and the micro flat filaments are obtained. According to the preparation technology of the nickel-titanium-based shape memory alloy micro flat wire, the micro flat wire which is high in size precision and excellent in mechanical property and fatigue property and has the developing function can be prepared.

The utility model relates to the technical field of color paste cooling, and particularly discloses a color paste cooling constant temperature device which comprises a box body, a feeding port is formed in the upper end of the box body and fixedly connected with the box body, and a material guide pipe is arranged below the feeding port and located in the box body; the bracket is positioned below the box body and is fixedly connected with the box body; the controller is located on the right side of the box body; the cold water circulation mechanism is located on the left side of the box body, and the cold water circulation mechanism can reduce the temperature of the color paste in the box body; the liquid nitrogen cooling mechanism is located on the right side of the box body, the liquid nitrogen cooling mechanism can achieve a remarkable compensation cooling effect, efficient cooling of color paste is achieved under the combined action of the cold water circulation mechanism and the liquid nitrogen cooling mechanism, the color paste can be evenly acted, and the cooling efficiency is improved by combining the two modes of cold water circulation and liquid nitrogen cooling. The cooling intensity can be flexibly adjusted according to production requirements, and the cooling requirements of different color pastes are met.

The application discloses a method for eliminating water stain defects of micro-channel aluminum flat tubes, and the continuously extruded micro-channel aluminum flat tube is cooled through a liquid nitrogen cooling box after being treated by zinc spraying, and then is wound on a winding drum. The method adopts the liquid nitrogen cooling mode to replace the traditional water cooling, so that the water stain defects caused by water cooling can be completely avoided, and the product yield and the product qualification rate are improved.

According to the present invention fragmented material 2, e.g. made from a material having Polyamides, is passing through a liquid bath 6 filled with liquid nitrogen 7 to cool the fragmented material 2 before entering a mill 10 for grinding the fragmented material 2. The fragmented material 2 is moved through the liquid bath 6 by exciting mechanical vibrations in the liquid bath 6 e.g. by a vibrational motor 28 coupled to the liquid bath 6 and / or an ultrasonic resonator 26 attached to the liquid bath 6. The invention allows to grind even materials being difficult to grind by reaching a temperature of −150° C. and less before entering the mill 10 while avoiding a direct cooling e.g, by introducing liquid nitrogen directly into the mill 10.

The invention provides a double-refrigeration device applied to high-temperature superconducting magnetic fluid propulsion, and relates to the technical field of high-temperature superconducting magnet cooling, the device comprises a magnet Dewar, a magnet liquid nitrogen cylinder, a fixing assembly and a conduction refrigeration system; the magnet liquid nitrogen cylinder is located in the magnet Dewar, one end of the fixing assembly is fixed to the side portion of the magnet liquid nitrogen cylinder, and the other end of the fixing assembly is fixed to the magnet Dewar; dewar protrusions are arranged on the circumferential side wall of the magnet Dewar, and the conduction refrigeration system is installed on the Dewar protrusions and exchanges heat with the superconducting magnet coil in the magnet liquid nitrogen cylinder. The superconducting magnet coil is also provided with a wiring port. The dual-refrigeration device provided by the invention breaks through the dilemma that the critical current cannot be tested after packaging, the liquid nitrogen cooling unit can independently, quickly and uniformly cool the packaged magnet, and the detachable sealing wiring port is arranged, so that the performance verification after packaging is realized, and the quality blind area is eliminated.

The utility model discloses a granulating device for waste pipe fitting processing, which relates to the technical field of waste pipe fitting processing, and comprises an L-shaped base, one end of the top of the L-shaped base is fixedly connected with a supporting clamping seat, the supporting clamping seat is connected with an extruder device in a clamping manner, the top of the L-shaped base is fixedly connected with a cutting bin, and the cutting bin is fixedly connected with a conveying device. The side wall of one end of the L-shaped base is fixedly connected with a cooling bin, the cooling bin corresponds to the extruder device and the cutting bin in position, and the side wall of the cooling bin is fixedly connected with a liquid nitrogen cooling jacket device. The L-shaped base provided by the utility model is convenient to cut and granulate on the basis of quickly cooling a solution produced by smelting a waste pipe fitting after bracing, so that the problem that the existing granulating device for processing the waste pipe fitting cannot quickly cool and shape a plastic bracing produced by an extrusion mechanism when in use is solved; and a worker needs to pull into cooling water for shaping to carry out pelletizing in the next step, so that the pelletizing working efficiency is influenced.

The utility model relates to the technical field of pipeline maintenance, in particular to a liquid nitrogen intercepting system which comprises a fluid pipeline, a liquid nitrogen bottle, a liquid nitrogen pipeline connected with the liquid nitrogen bottle and a control device. The middle section of the liquid nitrogen pipeline is a bent pipeline arranged around the fluid pipeline in an embracing mode, the bent pipeline comprises a plurality of C-shaped pipelines which are sequentially arranged from top to bottom, arc-shaped connectors used for connection are arranged between the head ends and the tail ends of every two adjacent C-shaped pipelines, and gaps are reserved between the arc-shaped connectors at the head ends and the tail ends of the C-shaped pipelines; a first temperature sensor is fixedly arranged at the installation position, corresponding to the bent pipeline in the liquid nitrogen pipeline, of the fluid pipeline, and a second temperature sensor is fixedly arranged at the outlet position of the liquid nitrogen pipeline; according to the scheme, the technical problem that the fluid freezing efficiency of an existing liquid nitrogen cooling system is not high can be solved.

The invention discloses an ABS plastic part low-temperature metallization vacuum coating process and equipment. The equipment comprises a machine body, a coating tank is embedded in the machine body, a side plate is fixedly installed at the upper end of the machine body, a storage rack is movably installed in the coating tank, an operation ring is movably installed in the coating tank, and the side face of the operation ring is movably connected with a threaded rod through threads. The stable coating equipment is arranged, a plastic part is placed in a storage rack in the vacuum coating equipment, a plasma cleaning opening in the upper end of an operation ring is used for cleaning the surface of the plastic part and removing grease and impurities on the surface, and a temperature controller is installed in the equipment and used for controlling the internal temperature; when the temperature is too high, the liquid nitrogen cooling system is used for cooling, the high-power pulse magnetron sputtering device mounted at the upper end of the operation ring is used for coating a plastic part and depositing a metal layer, finally, ultraviolet curing treatment is performed, and meanwhile, the high-power pulse magnetron sputtering technology is adopted, so that the pollution to the environment is reduced, and the coating precision is improved.

The invention provides a liquid nitrogen cooling system for maintaining continuous infiltration of the upper surface of a cold cavity. The liquid nitrogen cooling system comprises a liquid nitrogen Dewar, a gas-liquid separator and a cooling temperature control cavity, wherein the liquid nitrogen Dewar is used for providing low-temperature liquid nitrogen; one end of the gas-liquid separator is connected with the liquid nitrogen Dewar through a liquid-phase pipeline, the bottom of the other end of the gas-liquid separator is connected with the cooling temperature control cavity through a liquid-phase pipeline, and the top of the gas-liquid separator is connected with a gas-phase pipeline for exhausting gas; a temperature sensor and an acoustic emission probe are mounted in the cooling temperature control cavity, the temperature sensor is used for monitoring the wall surface temperature change of the cooling temperature control cavity in real time, and the acoustic emission probe is used for monitoring a high-frequency elastic wave signal in the cooling temperature control cavity; the wetting state of the upper surface of the cooling temperature control cavity can be judged, so that liquid nitrogen on the surface of the cooling temperature control cavity is conveniently controlled, the cooling temperature control cavity is prevented from entering a dry condition, and the liquid nitrogen heat exchange efficiency is improved.

The application discloses a high-temperature superconducting conductor and a preparation method thereof, and relates to the technical field of high-temperature superconductivity, wherein the conductor comprises an inner pipe body and an outer pipe body arranged coaxially, a liquid nitrogen convection cooling zone is formed in the inner pipe body, and a vacuum heat insulation cavity is formed between the inner pipe body and the outer pipe body. By forming the liquid nitrogen convection cooling zone in the inner pipe body and the vacuum heat insulation cavity between the inner pipe body and the outer pipe body, the liquid nitrogen can directly soak the superconducting cable for efficient heat exchange, the vacuum heat insulation cavity effectively blocks the radial conduction of environmental heat to the inner pipe body, and the heat load of the refrigeration system is greatly reduced; by electrically connecting the low-temperature end electrode and the superconducting cable and connecting the room-temperature end electrode and the low-temperature end electrode in series to form a loop, the room-temperature end electrode is avoided from directly contacting the superconducting cable, the axial heat leakage along the electrode is reduced, and one end of the liquid nitrogen cooling pipe is communicated with the inner pipe body and the other end of the liquid nitrogen cooling pipe extends to the outside through the outer pipe body, so that the stable supply and the sealing reliability of the liquid nitrogen are ensured.

The application discloses a neon cryogenic separation and purification device, which comprises a vacuumizing device, a hollow box body and a gas collecting ball, and further comprises an inner pressure-resistant cover, a middle pressure-resistant cover and an outer pressure-resistant cover; the inner pressure-resistant cover is arranged in the middle pressure-resistant cover, the middle pressure-resistant cover is arranged in the outer pressure-resistant cover, a spiral flow guide mechanism is arranged between the outer side surface of the inner pressure-resistant cover and the inner side surface of the middle pressure-resistant cover, a liquid nitrogen cooling cabin is arranged between the outer side surface of the middle pressure-resistant cover and the inner side surface of the outer pressure-resistant cover, the outer side surface of the inner pressure-resistant cover and the inner side surface of the middle pressure-resistant cover form a purification cabin, and the upper end surface of the purification cabin is connected with a gas conveying pipe; the neon cryogenic separation and purification device can continuously liquefy impurity gas in neon through the liquid nitrogen cooling mode, the liquefied impurity gas can be easily separated by an adsorption device, and the purity and yield of the neon are effectively improved.

The invention provides a cable trench liquid nitrogen fire extinguishing scheme generation method, system and device and a medium, and belongs to the field of intelligent fire prevention and control, and the method comprises the steps: obtaining structure data of a cable trench and real-time monitoring data of a sensor, and obtaining prediction results of corresponding fire behavior expansion trend data, liquid nitrogen cooling temperature field change data and oxygen concentration replacement data. Performing parameter combination search by using a target optimization algorithm based on the prediction result to obtain an optimal parameter combination; and acquiring actual measurement data of the environment of the fire scene, dynamically comparing the actual measurement data with the prediction result, and performing correction feedback. And recalculating by using a target optimization algorithm based on the corrected prediction result to obtain a real-time adjusted fire extinguishing scheme. Accurate fire recognition, self-adaptive fire extinguishing control and resource optimization configuration are achieved, the fire extinguishing efficiency is remarkably improved, and the equipment damage risk is reduced.

The invention discloses a low-temperature cutting machining method based on material removal mechanism control and an intelligent machine tool, and relates to the field of machine tool machining.The low-temperature cutting machining method comprises the steps that a cutting force signal and a vibration signal in the cutting process are collected; preprocessing the cutting force signal and the vibration signal to obtain a key characteristic value; a preset plasticity-brittleness transformation critical model is obtained, and a critical characteristic threshold value of a corresponding material is extracted; the key characteristic values are compared with a critical characteristic threshold value, the plastic membership degree of each key characteristic value is calculated, the comprehensive plastic membership degree is calculated in a weighted mode, and the material removal mechanism is judged; and based on a state index output by a material removal mechanism, a cutting processing strategy is regulated and controlled in a self-adaptive manner. According to the method, the material removal mechanism in the cutting process can be recognized on line, the cutting parameters and the liquid nitrogen cooling parameters are adjusted in a self-adaptive mode, it is guaranteed that the machining process is always stabilized in the dominant range of material plasticity removal, and therefore high-efficiency and high-quality machining of materials difficult to machine is achieved.

The invention provides an adiabatic heat testing method for a room-temperature violent reaction system. The room-temperature violent reaction system comprises at least two components which are in contact with each other to react under the room-temperature condition. Comprising the following steps: S1, performing adiabatic scanning from a first temperature to a room temperature on an empty test pool by adopting an adiabatic acceleration calorimeter so as to provide test reference data; the empty test pool is cooled to a first temperature through liquid nitrogen in advance, and the first temperature is-196 DEG C to-50 DEG C; s2, in a liquid nitrogen bath temperature environment, cooling the room-temperature severe reaction system, so that the room-temperature severe reaction system is kept in a solid ultralow-temperature state, and components which are in contact with one another to react are isolated from one another in the test pool before cooling; and S3, keeping the test pool at a first temperature for at least 2 minutes, and then operating a temperature rising program of the adiabatic acceleration calorimeter to carry out an adiabatic heat test. According to the invention, accurate and reliable initial reaction temperature can be obtained, and an accurate and comprehensive adiabatic heat test result of a room-temperature violent reaction system can be obtained.

The invention discloses a nano-cellulose reinforced biomass-based high-strength furniture board and a preparation method thereof, and belongs to the technical field of furniture board preparation, and the method comprises the following steps: preparing ZnO nanowire functionalized CNF by using a sol-gel method and a hydrothermal method and inducing by using an orienting agent, then preparing ferulic acid and lignin-based microcapsules by using an emulsion solvent evaporation method, and finally preparing the nano-cellulose reinforced biomass-based high-strength furniture board. Then, mixing the ZnO nanowire functionalized CNF, ferulic acid and lignin-based microcapsules, hydroxypropyl methyl cellulose and the like at a high speed to obtain a compound, and finally, carrying out gradient temperature melt extrusion, and carrying out liquid nitrogen cooling molding at-40 DEG C; through the synergistic effect of vertical growth of the ZnO nanowires to enhance interface bonding, stable ultraviolet resistance of the microcapsules and optimized dispersion of the dispersing agent, the problems of mechanical attenuation / color fading caused by weak mechanical property and ultraviolet aging of a biomass-based plate and failure of a traditional anti-ultraviolet agent are solved, synergistic improvement of mechanical property and ultraviolet resistance is realized, and the mechanical property and the anti-ultraviolet property of the biomass-based plate are improved. And the requirements of stable load bearing and ultraviolet fading resistance of medium-and-high-end furniture are met.

The application discloses a laser coaxial fuse additive equipment and method for simulating a microgravity environment, which comprises a laser coaxial fuse additive equipment body, a negative pressure suction method device is installed on a laser coaxial fuse wire feeding nozzle part, a plurality of liquid nitrogen flow pipes are arranged on the top outer side of the negative pressure suction method device and are externally connected with cooling substances through the liquid nitrogen flow pipes, airflow pipes are installed on both sides of the negative pressure suction method device, and cooling housings are fixedly connected with the top of the airflow pipes through the airflow pipes, the whole process creates an annular negative pressure suction field in the vertical direction according to the Bernoulli principle, and the gravity is balanced in real time, so that the laser fuse additive under the microgravity environment can be simulated for a long time, continuously, at low cost and truly, the liquid nitrogen cooling and protective airflow device are integrated, the influence of thermal expansion caused by high temperature generated by laser heating on airflow disturbance and deformation of the negative pressure suction method device can be offset, and meanwhile, the side-blowing protective gas device can be replaced, so that oxidation in the additive printing process is prevented.

The invention provides a liquid nitrogen cooling auxiliary disassembling device for a composite insulator. The liquid nitrogen cooling auxiliary disassembling device comprises an intelligent control unit, a gradient cooling embrittlement unit and a composite vibration separation unit, the intelligent control unit collects real-time material data of the composite insulator in real time, inputs the real-time material data into an internal preset material brittleness prediction model to calculate a brittleness index, and sends out a valve opening signal according to the brittleness index; capturing the material fracture characteristic frequency in real time, and calculating the vibration parameters of the composite vibration separation unit by adopting a PID (Proportion Integration Differentiation) algorithm; the gradient cooling embrittlement unit cools the composite insulator step by step according to a valve opening signal to embrittle the composite insulator; and the composite vibration separation unit is arranged at the output end of the gradient cooling embrittlement unit and is used for applying composite vibration to the catalyzed composite insulator according to the vibration parameters so as to separate metal and rubber materials. Through cooperative operation of multiple systems, efficient separation of silicone rubber and metal parts is achieved.

The application discloses a crosshead bushing inlay processing method, system, equipment and medium, and belongs to the field of processing technology.The method comprises the following steps: acquiring the design size and the interference range of the crosshead and the bushing; determining the bushing shrinkage under the condition of liquid nitrogen cooling based on a cooperative calculation rule formed by a preset shrinkage standard calculation mode and a machine learning calculation mode; determining the outer diameter processing size range and the inner diameter processing size range of the bushing according to the bushing shrinkage and the interference range; generating a processing control instruction based on the outer diameter processing size range and the inner diameter processing size range of the bushing, and sending the processing control instruction to a processing unit; the processing unit performs grinding processing on the bushing in response to the processing control instruction; and after the grinding processing, an assembly instruction is generated and sent to an assembly unit.The application has the advantages of reducing cost, enhancing adaptability and improving processing precision.

The invention provides an environment simulation device for an aircraft tire dynamic simulation test, and relates to the field of aircraft tire test equipment, the environment simulation device comprises an environment box, a heating circulation system, a liquid nitrogen cooling system and a connecting pipeline; a box body of the environment box is defined by side plates, a top plate and a bottom plate, the side plates comprise the first set of side plates and the second set of side plates which are oppositely arranged, the first set of side plates are each provided with an installation groove used for allowing a tire shaft to penetrate through in the hoisting process, and the environment box further comprises translation sliding doors arranged on the first set of side plates correspondingly; the bottom plate is a split type bottom plate; a pipeline connecting opening is formed in the top plate, and the heating circulating system and the liquid nitrogen cooling system communicate with the pipeline connecting opening through a connecting pipeline and are used for adjusting and controlling the temperature in the environment box. According to the invention, high and low temperature environment simulation can be rapidly carried out without dismounting the tire, and rapid evacuation is carried out, so that the tire is subjected to a dynamic test at a simulated temperature, the test accuracy and safety are improved, and the equipment cost and the operation difficulty are reduced.

The application relates to the field of low-temperature engineering and heat transfer technology and discloses an ultralow-temperature heat pipe system based on nitrogen phase change circulation, which comprises a cold head with a first cold end, a heat pipe body with a second cold end at one end and surrounding the first cold end, the first cold end liquefying nitrogen in the space surrounded by the second cold end into liquid nitrogen, the other end of the heat pipe body being a hot end, the heat pipe body internally having a liquid nitrogen conveying channel communicating the second cold end and the hot end and a nitrogen backflow channel communicating the hot end and the second cold end, and a vacuum interlayer arranged outside the heat pipe body and used for heat preservation of the heat pipe body. The application takes nitrogen as a working medium, completes the phase change circulation of liquefaction and vaporization in the system and does not discharge to the outside, thereby avoiding the safety hazard of the increase of nitrogen concentration caused by the discharge of nitrogen vaporized after liquid nitrogen cooling into the room in the traditional flowing liquid nitrogen cooling mode; the system does not need to frequently supplement liquid nitrogen, can be long-term and stable in operation, improves the use efficiency of the equipment to be cooled, and the setting of the vacuum interlayer improves the refrigeration efficiency.

The utility model provides a multifunctional electron beam heating sample table, which comprises a base, an electron beam emitting device, an electron beam receiving device, a sample receiving device, a sample receiving device and a sample receiving device, and is characterized in that an accommodating space is arranged in the middle of the base; ceramic chips are arranged on the side wall and the bottom of the accommodating space, so that electron beams emitted by the electron beam emitting device are led out from the opening; the electric brush is electrically connected to the sample bearing device, and the electric brush is used for electrifying and heating the sample; and the low-temperature connecting piece is used for connecting a low-temperature device and the base, and the low-temperature device is used for cooling the base. According to the multifunctional electron beam heating sample table, the base is cooled to about 120 K through liquid nitrogen, then the sample support is cooled to about 130 K, and continuous temperature change of the temperature of the sample support between 130 K and 1300 K is achieved by combining the three modes of radiation heating, electron beam heating and liquid nitrogen cooling.

The application discloses a vacuum low-temperature surface source blackbody, a plurality of pyramid structures of polygonal pyramids are processed on the surface of a blackbody radiation panel, and a high-emissivity coating is matched, so that the surface source blackbody with micro-cavity structures is formed, and the effective emissivity of the vacuum low-temperature surface source blackbody is improved. In addition, the application adopts a reasonable liquid nitrogen pipeline and an I-shaped heat-conducting bridge to form a low-temperature module, and connects a uniform temperature plate to uniformly distribute cold energy, so that the radiation performance of the vacuum low-temperature surface source blackbody is ensured. The vacuum low-temperature surface source blackbody has the characteristics of high emissivity and uniform temperature field distribution. The application adopts a liquid nitrogen cooling mode, reduces the requirement on the use environment, can realize real-time calibration of a laboratory full aperture and full temperature range of an infrared detector, effectively improves calibration precision, and further improves the detection precision of the infrared detector.

The invention provides a thick-layer PCB drilling method based on a liquid nitrogen cooling drilling processing system. The method comprises the steps that a pressed PCB is acquired; drilling operation is carried out on the pressed PCB, so that a drilled PCB can be formed; the drilling instantaneous temperature of the drill point is obtained; detecting whether the borehole instantaneous temperature is greater than or equal to the critical borehole heat temperature; and if the drilling instantaneous temperature is larger than or equal to the critical drilling heat temperature, liquid nitrogen cooling operation is conducted on the drill point. When drilling is carried out for a long time, heat is generated by friction between a drill pin and a PCB, the drill pin has a high temperature, the temperature is transmitted to resin in the PCB, the resin is melted, and the overall quality problem is caused, a liquid nitrogen cooling mode is adopted in the scheme, and when drilling is carried out on the PCB through the drill pin, if the instantaneous temperature, collected by a system, of the drill pin is higher than a preset value, the drill pin is cooled; and liquid nitrogen cooling operation is carried out, accelerated abrasion caused by continuous heating of the drill point is prevented, and rapid melting of resin in a drill hole and rapid oxidation of a copper layer are prevented.

The utility model provides a cooling circulation system for a magnet in a liquid nitrogen temperature zone, and relates to the technical field of magnet cooling, the cooling circulation system comprises a helium storage tank, the gas outlet end of the helium storage tank is communicated with the cooling input end of the magnet, and the gas return end of the helium storage tank is communicated with the cooling output end of the magnet; the liquid nitrogen cooler takes liquid nitrogen as a cooling medium and is arranged on a pipeline through which the gas outlet end of the helium storage tank is communicated with the cooling input end of the magnet; helium in the helium storage tank flows out from the gas outlet end of the helium storage tank, is cooled by the liquid nitrogen cooler, flows into the magnet from the cooling input end of the magnet so as to cool the magnet, and flows out to the gas return end of the helium storage tank from the cooling output end of the magnet. Liquid nitrogen temperature-level efficient circulating cooling can be carried out on the magnet, and the risk caused by gasification impact on a cooling part due to liquid nitrogen gasification expansion caused by liquid nitrogen circulating cooling can be avoided.

The invention discloses a combined supply device and method for cold and heat comprehensive gradient utilization, and belongs to the technical field of cold and heat comprehensive utilization and refrigeration of a synthetic ammonia device.The combined supply device comprises a refrigeration system and a cold water circulation system, and the refrigeration system comprises a heating medium supply mechanism, a refrigeration mechanism and a cooling mechanism; the cold water circulation system comprises an ammonia washing tower cooling mechanism, a compressor cooling mechanism and a low methyl liquid nitrogen cooling mechanism, the heating medium supply mechanism is connected with the refrigeration mechanism, and the refrigeration mechanism is connected with the cooling mechanism, the ammonia washing tower cooling mechanism, the compressor cooling mechanism and the low methyl liquid nitrogen cooling mechanism. The ammonia washing tower cooling mechanism is connected with the low methyl liquid nitrogen cooling mechanism, and the low methyl liquid nitrogen cooling mechanism is connected with the compressor cooling mechanism. According to the combined supply device and method for cold and heat comprehensive gradient utilization, the compression efficiency of the synthesis gas compressor is improved, the absorption effect of the low-methyl-liquid nitrogen washing unit and the ammonia washing tower is improved, and the influence of the high temperature of circulating water in summer on the system load is avoided.

The application relates to the technical field of power maintenance equipment, in particular to a device for dismounting bearing shaft pins of power transformation equipment by using liquid nitrogen cooling technology, which comprises a liquid nitrogen gun power device, a control bin, a lithium battery, a whole-dismountable nitrogen storage module, a buffer pipe and a telescopic fixing support. The control bin and the lithium battery are installed on the liquid nitrogen gun power device. The lithium battery is used for supplying power to the liquid nitrogen gun power device. The control bin is used for adjusting the power outputted by the liquid nitrogen gun power device. The whole-dismountable nitrogen storage module is connected with the control bin. The whole-dismountable nitrogen storage module is installed with a nitrogen storage tank. The nitrogen storage tank is used for storing liquid nitrogen. The whole-dismountable nitrogen storage module is installed with the buffer pipe at the other end. The buffer pipe is connected with the telescopic fixing support at the other end. The extremely low temperature characteristics of the liquid nitrogen are utilized to rapidly cool the bearing to a shrinkage state, so that the safe dismounting of the bearing is easily realized.

This application relates to the field of aluminum profile extrusion technology, specifically disclosing a method and system for controlling liquid nitrogen cooling of aluminum profile extrusion dies. The method includes the following steps: continuously collecting multi-source temperature data and operating status data of the extrusion production line within a preset historical period; establishing a mapping relationship between operating status and temperature response, and predicting the operating status change sequence; generating die temperature prediction curves and profile temperature prediction curves based on the operating status change sequence and the mapping relationship; calculating the deviations from the corresponding preset temperature control targets, generating die cooling demand curves and profile cooling demand curves, and adjusting the injection strategy of the liquid nitrogen injection device to perform cooling intervention in advance. The technical solution of this application can calculate the cooling demand curve matching future heat load changes in advance and drive the liquid nitrogen injection device to perform forward-looking flow and mode adjustments, overcoming the response lag problem caused by thermal inertia in traditional control.

The application relates to the technical field of catalysts, in particular to a modified graphene nanocoil as well as a preparation method and application thereof. The preparation method of the modified graphene nanocoil comprises the following steps: sequentially performing liquid nitrogen cooling and microwave treatment on a mixed solution containing a reducing organic solvent, a noble metal source and a graphite-based carbon material to obtain a graphene nanocoil loaded with noble metal nanoparticles; wherein the graphite-based carbon material is selected from one or more of graphite oxide and doped graphite oxide. The above preparation method can effectively avoid the formation of an agglomerated structure of the graphene carrier and improve the catalytic activity of the catalyst.

A multi-material low-temperature constant-pressure anti-blocking food 3D printer comprises a frame, a three-way adjusting mechanism, a workbench, a printing head, a material storage mechanism, a cooling mechanism, a blocked material disposal mechanism, a waste recovery mechanism and a cleaning mechanism. The three-way adjusting mechanism is arranged on the frame; the printing head is arranged on the three-way adjusting mechanism; the workbench is arranged at the bottom of the frame. The storage mechanism is arranged at the top of the frame and is connected with the printing head through a feeding pipe; the cooling mechanism is connected with the printing head; the material blocking treatment mechanism is connected with the printing head; the waste recovery mechanism is connected with the workbench; and the cleaning mechanism is connected with the storage mechanism. According to the multi-material low-temperature constant-pressure anti-blocking food 3D printer, liquid nitrogen cooling is adopted in the cooling mechanism, the cooling rate can be increased, the food material forming precision can be improved, the food material printing quality can be improved, when a material blocking fault occurs, ultrasonic vibration automatic dredging and waste recycling can be achieved, the food material pollution risk is reduced, and the production efficiency is improved. And industrial application of the food 3D printer is promoted.