9results about How to "Reduce temperature stress" patented technology

The utility model relates to a tube plate structure for a heat exchanger and a winding tube type heat exchanger, and the tube plate structure comprises a heat-conducting tube plate main body which is provided with a first plate surface facing a tube pass medium in the heat exchanger and a second plate surface facing a shell pass medium in the heat exchanger, a plurality of tube holes penetrating through the first plate surface and the second plate surface are formed in the tube plate main body at intervals; an annular groove extending in the circumferential direction is formed in the second plate surface of the tube plate main body, and the annular groove is formed in the periphery of each tube hole; the tube plate structure further comprises an annular check ring which is arranged in the annular groove in the circumferential direction so as to shield a groove opening of the annular groove. A through hole for a shell pass medium to enter the annular groove is formed in the check ring, or / and a gap for the shell pass medium to enter the annular groove is formed between the periphery of the check ring and the corresponding inner wall of the notch in a spaced mode. The tube plate structure disclosed by the utility model can bear a larger temperature difference between a tube pass medium and a shell pass medium.

This invention discloses a seed crystal oxidation structure to prevent oxidation of single-crystal superalloys during directional solidification, aiming to effectively suppress surface oxidation of the seed crystal during directional solidification. To this end, the seed crystal oxidation structure provided by this invention includes a ceramic mold shell, in which a seed crystal is fitted into the seed crystal cavity of the ceramic mold shell. The top of the seed crystal is covered by an alloy spacer, the melting point of which is lower than that of the seed crystal.

The application discloses a kind of high temperature pressure vessel nozzle temperature self-regulating heat insulation device, including heat bridge and heat insulation layer.Heat bridge is arranged on the outer surface of the nozzle of high temperature pressure vessel and the outer surface of the pipeline connected with nozzle;Heat insulation layer is coated on the outer surface of heat bridge.The application can automatically adjust the outer surface temperature of high temperature pressure vessel nozzle according to fluid temperature by taking heat or releasing heat to the pipeline surface close to fluid temperature in steady-state operating condition and transient operating condition, reduce the temperature difference and thermal stress between inner surface and outer surface of nozzle, and does not need power supply, does not need working medium, is resistant to high temperature, has long service life, works stably, has simple structure and is easy to manufacture.

This invention belongs to the field of fixed-point punching technology for couplings, and in particular, it is a surface fixed-point punching device for high-precision coupling processing. A hydraulic rod is fixedly connected to the top of the base. An upper plate is fixedly connected to the upper movable end of the hydraulic rod. A connecting plate is provided on the lower side of the upper plate. A third motor is fixedly connected to the inner side of the connecting plate. A drill bit is fixedly connected to the end of the spindle of the third motor. A rotating rod is rotatably mounted on the outer side of the drill bit. A ball bearing for reducing frictional resistance is rotatably mounted at the bottom end of the rotating rod. A paddle is fixedly connected to the lower side of the rotating rod. A cylindrical enclosure is provided on the outer side of the rotating rod. A cavity for placing cooling water is opened on the inner side of the enclosure. An arc-shaped inner groove exists on the upper side of the cavity. One end of the inner groove extends towards the lower side of the rotating rod. An outlet channel is opened on the inner side of the upper and lower middle positions of the enclosure. A baffle is slidably connected to the inner side of the outlet channel.

The invention provides a brazing method of a heat exchanger assembly, the heat exchanger assembly comprises a heat exchanger body and a heat exchange tube, and the outer surface of the heat exchanger body is provided with a heat exchange groove. The brazing method comprises the steps that S1, the heat exchange pipe is coiled into the shape matched with the heat exchange groove in advance through a profiling mold; s2, the surfaces of the heat exchange tube and the heat exchanger body are plated with nickel; s3, the heat exchange tubes are embedded into the heat exchange grooves, and the heat exchange tubes are pressed and fixed through pressing blocks with chamfers; s4, the brazing filler metal is applied to the edge of the contact face of the heat exchange pipe and the heat exchange groove in a differentiated mode, and the surface, where the brazing filler metal possibly flows through, of the heat exchanger body is coated with a solder resist; and S5, the heat exchanger assembly is brazed in a stepped heating mode. According to the method, through cooperative implementation of multiple steps such as heat exchange tube preforming, composite nickel plating, precise fixing, differential brazing filler metal applying and stepped temperature rising, tight attachment of the thin-walled tube and the complex curved surface heat exchanger is achieved, the bonding strength and stability of a brazed joint are improved, brazing defects are effectively eliminated, and the product percent of pass is increased.

The invention discloses a multipurpose converter transformer valve hall firewall structure, which comprises a flat plate wall body, a deformation joint and a fire fighting equipment platform, and is characterized in that the flat plate wall body comprises a transverse wall body for replacing a valve hall outer wall and a longitudinal wall body for separating a plurality of converter transformers; the deformation joint is arranged at the junction of the transverse wall body and the longitudinal wall body and is arranged to be in a T shape. The deformation joint is filled with a refractory material; the fire-fighting equipment platform is arranged at the top end of the counter-fire side of the transverse wall body; the fire-fighting equipment platform is provided with a fire-fighting nozzle, and a pipeline is arranged in the fire-fighting equipment platform. Compared with the prior art, the T-shaped deformation joint is arranged on the back-to-fire surface of the joint of the longitudinal wall body and the transverse wall body of the firewall, and the deformation joint is filled with the refractory material, so that on one hand, the wall body has certain expansion and contraction capacity to weaken temperature stress; on the other hand, the wall surface is divided, and the problems that the wall surface cracks and the durability of the wall is affected due to the fact that the cast-in-place firewall is too long, and internal stress of the wall is generated when concrete is solidified, heated and cooled are solved.

The invention relates to a preparation method of a functional concrete admixture with high impermeability and crack resistance. According to the technical scheme, a proper amount of deionized water and a prepared GO-PCs solution are sequentially added into a reaction container, stirring is started, then a certain amount of organic silicon modified acrylic emulsion, vinyl acetate-acrylic emulsion, polyvinyl alcohol, sodium gluconate, glycerol, xanthan gum and a defoaming agent are sequentially added, and the time interval of adding each raw material is 2 minutes; after all the materials are added, continuously stirring for 30 minutes, and then adding the air entraining agent; and continuously stirring for 5 minutes to finish the preparation of the product. The anti-permeability concrete has the beneficial effects that the anti-permeability performance of the concrete is greatly improved from traditional P6-P12 to P20 or above, and the limit anti-permeability performance can exceed P40; product application is simple, material putting is simpler and more convenient, and production and construction are more facilitated; compared with a traditional product, the construction performance, the mechanical performance and the durability of the concrete are all improved to different degrees, and the anti-cracking capacity is obviously improved.

The application provides a peanut drying machine and drying method based on microwave and hot air cooperation, wherein the drying machine comprises a drying main cabin, a multifunctional treatment cabin is connected to one side of the drying main cabin, and a driving device drives a material bucket to revolve around a hot air duct and revolve around a central axis of the material bucket. The material bucket is exchanged between the drying main cabin and the multifunctional treatment cabin through a transfer track, a plurality of microwave devices are arranged in the circumference of the shell of the drying main cabin, the microwave devices are used for emitting microwaves to dry the peanuts in the material bucket, and the outer part of the multifunctional treatment cabin is respectively connected with a feeding device and a discharging device. The application seamlessly integrates three key processes of preheating, drying and tempering in one equipment, realizes automatic switching through physical rotation, forms a complete closed-loop processing chain, greatly simplifies the production line and reduces the material turnover loss. Through the uniform temperature in the preheating stage and the slow recovery in the tempering stage, the color, flavor and nutritional ingredients of the peanuts can be better maintained.

This invention discloses a method for forming ultra-thin stainless steel pipe fittings, relating to the field of stainless steel pipe production and processing technology. It aims to solve the problems of branch pipe rupture and inner wrinkling during the current hydroforming process of ultra-thin stainless steel pipe fittings. The method includes: S1: billet preparation and pretreatment; S2: mold and sealing assembly; S3: staged collaborative forming; S301: pre-expansion and mold-fitting stage, where the internal pressure is increased to 0.8 MPa at a rate of 0.1 MPa / s and maintained stably; S302: main forming precise material replenishment stage, employing a gradient pressure increase strategy; S303: forming stress release stage, maintaining a stable internal pressure of 6-7 MPa for 10 seconds to ensure the billet completely fits the mold cavity, followed by a staged pressure relief method. This invention, through the application of a nano-lubricating film coating on the inner wall of the billet, low-temperature preheating treatment, stress-dispersing mold design, and the collaborative control of gradient pressure increase and real-time monitoring and material replenishment during the main forming stage, achieves effective dispersion of tensile stress concentration at the top of the branch pipe of the ultra-thin stainless steel pipe fitting and precise material replenishment, significantly reducing the risk of rupture.