71 results about "Frost crack" patented technology

The invention discloses a tree whitening device and a tree whitening machine, and relates to the technical field of garden greening equipment. The tree whitening device comprises a lifting frame, a main arm is provided on the upper part of the frame, an air knife and a plurality of nozzles are provided on the inner wall of a movable arm below the main arm, the main arm is connected to the movable arm through a lifting mechanism, and a cloth is provided between the main arm and the movable arm; the tree whitening machine is dragged to any work place by a vehicle-mounted mobile device, and the main arm and the movable arm of the split structure can wrap the tree; the air knife connected to the high-pressure gas generator is used to remove dust from the surface of the tree, and the nozzle connected to the pumping mechanism is used to whiten the tree, and the cloth that plays a shielding role can prevent dust and paint from splashing everywhere during dust removal and spraying; the lifting and lowering of the whitening device can be realized by a lifting rod, and it is convenient to store. The invention can prevent trees from being burned, frozen and damaged by pests and diseases, and improve the quality and speed of tree whitening.

The invention provides a method for calculating the integral regulation and control opening degree of a shutter of an indirect air cooling tower, and the method comprises the steps: obtaining a target tower outlet water temperature theoretical value under different working conditions through a three-dimensional numerical simulation method based on parameters such as environmental meteorological parameters, a load ratio, a cooling margin and the like; and calculating according to the heat balance and the draft resistance balance of the cooling tower, and coupling to obtain a suggested value of the opening degree of the shutter. By adjusting the opening degree of the blind window and the air inlet amount, pipe bundle frost crack caused by too low temperature of the cooling triangle is avoided, winter freezing prevention of the indirect cooling tower is achieved, and a theoretical basis is provided for practical engineering implementation.

The invention provides an intelligent digital platform based on cold region highway disaster emergency disposal, and relates to the technical field of cold region highway emergency management. Comprising a cold region highway disaster database and knowledge graph module, an intelligent emergency disposal scheme recommendation module, a dynamic resource allocation module, a data updating and maintenance module, a platform iterative optimization module and a man-machine interaction module. According to the method, by combining the geographical environment and the knowledge graph of the cold region, the recommendation scheme considers the particularity of disasters such as ice and snow, frost heaving and the like, such as snow-melting agent type selection at low temperature, avoiding blind application of a general scheme, improving the disposal accuracy by more than 40%, and by priority ranking and path optimization, the resource arrival time is shortened by 30-50%, resource idling and waste are avoided, and the method is suitable for popularization and application. The emergency cost is reduced by 20%, the efficiency of resource allocation of the platform is improved, and based on user feedback and new technology iteration, the platform can adapt to new disaster types in cold regions, such as road surface frost cracks caused by extreme cold waves, and the practicability is kept for a long time.

The water path structure comprises a first filter element, a raw water path, a pure water path and a waste water path, one end of the raw water path is communicated with a raw water opening, the other end of the raw water path is communicated with a water inlet of the first filter element, a water inlet valve and a booster pump are arranged on the raw water path, and the booster pump is located between the water inlet valve and the first filter element; the pure water path is communicated with a pure water outlet of the first filter element; the wastewater path is communicated with a wastewater outlet of the first filter element, and an air inlet valve is arranged on the pure water path, so that external air can enter the pure water path; the water path structure further comprises an emptying water path, the water inlet end of the emptying water path is connected with the pure water path, the water outlet end of the emptying water path is connected with the raw water path, and an emptying valve is arranged on the emptying water path. The waterway structure and the water purifier can effectively prevent the problem of frost crack of the filter shell caused by freezing of water retained in the waterway and the filter element in a low-temperature environment, are reliable in operation, and do not influence the normal work of the whole machine.

The utility model belongs to the technical field of fire-fighting pipelines, and particularly discloses a frost crack prevention fire-fighting pipeline with protection and heat preservation functions, which comprises a pipeline body, a first protection shell and a second protection block are arranged on the outer surface of the pipeline body, and the first protection shell is rotatably connected with the surface of the second protection block through a shaft. A first mounting block is fixedly connected to the outer surface of the first protective shell, a second mounting block is fixedly connected to the outer surface of the second protective block, two mounting rods are fixedly connected to the side, close to the first mounting block, of the second mounting block, and a mounting groove is formed in the side, close to the second mounting block, of the first mounting block; according to the anti-frost-crack firefighting pipeline with the protection and heat preservation functions, fixing blocks and transmission grooves slide into fixing grooves through resetting of first springs, the positions of a first protection shell and a second protection block are fixed, the pipeline body can be protected more smoothly through the device, and meanwhile a handle can be protected through a protection plate.

An anti-freeze crack device (2), including: a main body (21) and a plugging assembly (22). The main body (21) is provided with a cavity (210) with an open end, and the open end of the cavity (210) is configured to communicate with a water chamber (10) of a water outlet valve (1). The plugging assembly (22) is disposed within the cavity (10) and can be switched between a first state in which the open end is closed and a second state in which the open end is opened.

The invention relates to the technical field of electric appliances, in particular to a defrosting control method and system of a heat pump unit and the heat pump unit, and aims to solve the problem that a plate heat exchanger is frost-cracked during defrosting of an existing heat pump unit. In order to achieve the purpose, the defrosting control method of the heat pump unit comprises the steps that according to the condenser temperature obtained by a defrosting sensor, whether the heat pump unit meets the first defrosting condition or not is judged; according to the waterway state information of the plate heat exchanger, whether the heat pump unit meets a second defrosting condition or not is judged; when the heat pump unit meets the first defrosting condition and the second defrosting condition at the same time, the heat pump unit is controlled to enter a first defrosting mode; and when the heat pump unit meets the first defrosting condition and does not meet the second defrosting condition, the heat pump unit is controlled to enter a second defrosting mode. The defrosting mode can be flexibly adjusted, so that the plate heat exchanger is prevented from being in a low-temperature environment, the plate heat exchanger is prevented from frost cracking, and the service life of the plate heat exchanger is prolonged.

The invention discloses a frost crack prevention overflowing water sterilization device which comprises a mounting sleeve, a sterilization module and a quartz tube and further comprises sealing end caps, and the sealing end caps are mounted at the two ends of the quartz tube; the sealing end cap comprises a base pad, a top seat, a sealing mechanism and an inner supporting mechanism, the top seat is arranged on one side of the base pad and abuts against the inner end of the mounting sleeve, a connecting hole is formed in the top seat, the inner supporting mechanism and the sealing mechanism are arranged on the other side of the base pad, and the end of the quartz tube is inserted between the sealing mechanism and the inner supporting mechanism; according to the anti-frost-crack overflowing water sterilization device, the quartz tube is mounted in the mounting sleeve through the two sealing end caps, a plurality of extrusion cavities are formed in the sealing end caps by optimizing the mechanisms of the sealing end caps, and meanwhile, the sealing end caps are integrally made of elastic sealing materials such as silica gel, so that when fluid in the quartz tube is frozen and expanded, the fluid in the quartz tube is prevented from being frozen and expanded; and the quartz tube has enough buffer space, so that the overall frost crack prevention performance of the device is effectively improved.

The utility model discloses a novel building foundation drainage structure, which relates to the technical field of building foundation drainage, and comprises a wall body, a roof is arranged at the top of the wall body, a drainage pipe is arranged on the roof, a sewer pipe is arranged on the wall body, and a water receiving hopper is inserted into the top of the sewer pipe; a mounting plate is arranged on the left side of the water receiving hopper, an air heater is arranged on the mounting plate, the air heater is communicated with an air supply pipe, the air supply pipe transversely penetrates through the water receiving hopper, accumulated snow on the roof is swept to all the drainage pipes, and then air is blown through the air heater, so that hot air enters a telescopic hose from the air supply pipe; and then the hot air enters the drainage pipe from the vertical pipe, and hot air can be upwards sent out, so that snow melting of the drainage pipe can be accelerated, rapid drainage is facilitated, the accumulated snow on the roof is rapidly discharged, the load of the roof is reduced, and a concrete layer of the roof is prevented from being cracked and damaged by frost.

The utility model discloses a pressing valve core capable of automatically discharging residual water in a pipe, which comprises an outer shell and a bottom shell arranged at the bottom of the outer shell, the bottom of a rotating rod is abutted against a piston capable of moving up and down, the top of the bottom shell is provided with a spring abutted against the piston, the piston is provided with a water passing pipe extending to the bottom shell, and the water passing pipe is connected with the rotating rod. The outer side of the bottom shell is provided with a water drainage hole and a water inlet hole, the inner side of the bottom shell is provided with a water outlet channel communicated with the water inlet hole, and the outer side of the water passing pipe is provided with a water drainage passing hole corresponding to the water drainage hole. The drainage device is simple in structure, when the pressing rod is pressed down and is not rebounded under the action of the rotating rod, the drainage through hole of the piston is communicated with the drainage hole and is in a drainage state, meanwhile, the water outlet channel is closed, and residual water in a water pipe is automatically and rapidly drained and does not drip continuously; the frost crack phenomenon of the water outlet pipe at the extremely low temperature and the scaling problem caused by the fact that residual water is not discharged out of silica gel water outlets of a top shower and a handheld shower head are avoided.

The utility model relates to the technical field of lasers, in particular to a frost crack prevention structure on a laser cooling pipeline, which comprises an inner assembly and a cooling liquid transmission assembly, the inner assembly comprises an inner pipe, the inner pipe is an elastic hose, the cooling liquid transmission assembly comprises a to-be-cooled body, a plug and a support pad, a cavity is arranged in the to-be-cooled body, and the cavity is communicated with the cavity. The inner pipe is located in the body needing to be cooled, the corresponding plugs are used for blocking the ends of the inner pipe respectively, supporting pads are arranged at the two ends in the body needing to be cooled, a plurality of through holes corresponding to the ends of the inner pipe are formed in the supporting pads, and the supporting pads are flexible and tightly attached to the inner wall of the body needing to be cooled. The cooling device has the effect of avoiding the situation that after cooling water encounters extremely low-temperature weather, the volume of the cooling water is expanded due to freezing, pipelines or equipment are damaged, and irreparable losses are caused.

The utility model relates to a cooling water system of a shield pump and the shield pump comprising the cooling water system. The shield pump comprises a cooling water jacket, a cooling water inlet and a water outlet are formed in the bottom of the cooling water jacket, and the cooling water system comprises a first water inlet pipe, a water inlet hose, a second water inlet pipe, a first water outlet pipe, a water outlet hose and a second water outlet pipe. The first water inlet pipe is sequentially connected with the water inlet hose and the other end of the second water inlet pipe to form a water inlet passage; the first water outlet pipe is sequentially connected with the water outlet hose and the other end of the second water outlet pipe to form a water drainage channel; the first water inlet pipe is lower than the second water inlet pipe, and the first water outlet pipe is lower than the second water outlet pipe. Compared with the prior art, the water inlet hose and the water outlet hose have the hose flexibility, when the shield pump is stopped for drainage, drainage is easy, the risk of frost crack of the cooling jacket is avoided after rapid drainage, and normal operation of the shield pump is guaranteed.

The utility model discloses a filter, comprising: a base assembly, which is provided with a water inlet channel, a water outlet channel, an annular inner cavity and an annular outer cavity surrounding the outer side of the annular inner cavity, the water inlet channel is communicated with the annular outer cavity, and the water outlet channel is communicated with the annular inner cavity; a water purification channel is formed in the support, the lower end of the support extends downwards to form a connector part, the connector part is inserted into the annular inner cavity, and the water purification channel is communicated with the water outlet channel; the filter element is sleeved on the bracket; the shell covers the filter element and the bracket and is connected with the base assembly; the hollow hose is placed in the water purification channel, the length of the hollow hose is larger than 1 / 2 of the length of the filter element, and the water passing area of the hollow hose is larger than the water passing area between the outer wall of the hollow hose and the water purification channel. The hollow hose is placed in the water purification channel of the bracket, so that internal stress generated by freezing and swelling of the water body can be effectively resisted, and the filter element and the shell are prevented from being damaged due to frost crack deformation.

The invention discloses a liquid nitrogen quick-freezing process for procambarus clarkii. The liquid nitrogen quick-freezing process comprises the following steps: (1) quick pre-cooling: cooling the procambarus clarkii to 0 DEG C or below; (2) low-temperature protection: uniformly spraying a low-temperature protective agent on the surface of the procambarus clarkii, wherein the low-temperature protective agent is prepared from the following components in percentage by mass: 1-1.5% of trehalose, 3-4% of glycerol, 1.5-2% of sorbitol, 12-15% of glycerol and the balance of water; and (3) performing multi-stage cryogenic quick-freezing: putting the procambarus clarkii in the step (2) into a tunnel type liquid nitrogen quick-freezing machine for cryogenic quick-freezing, taking out the procambarus clarkii after the procambarus clarkii is frozen until the center temperature is-75 DEG C, and performing freezing storage at-18 DEG C. According to the method, a rapid pre-cooling process and a low-temperature protective agent technology are combined with a liquid nitrogen multi-stage ultralow-temperature quick-freezing technology to be jointly applied to the procambarus clarkii deep-cooling quick-freezing inhibition process, the low-temperature frost crack resistance of the procambarus clarkii can be comprehensively improved, the frost crack rate can be reduced and inhibited, the freezing quality of the procambarus clarkii can be improved, and the economic value is increased.

The invention relates to the technical field of anti-freezing testing, in particular to a method and system for testing the anti-freezing performance of an anti-frost-crack water supply pipe, and the method comprises the following steps: S1, selecting an anti-frost-crack water supply pipe sample to be tested, ensuring that the length and diameter parameters of the sample are consistent, and pretreating the sample to ensure the accuracy of a test result; s2, respectively placing the treated samples in a set low-temperature environment, and observing and recording the frost crack resistance of the samples at each temperature; s3, establishing an anti-freezing performance mathematical model by utilizing the characteristic that the anti-freezing crack performance of the water supply pipe sample in each low-temperature state is changed and has a certain regularity; s4, treating a to-be-detected water supply pipe sample according to the same pretreatment steps, placing the sample in a preset low-temperature environment, recording the frost crack resistance performance of the sample, substituting the frost crack resistance performance into the established mathematical model, and calculating the frost resistance performance of the sample at each temperature; s5, setting a qualified standard of the anti-freezing performance according to an industrial standard and a user demand; and the accuracy and the repeatability of the test are improved.

The utility model relates to the technical field of instrument wire harnesses, in particular to a frost crack prevention instrument system wire harness, which comprises a fixed cylinder body, an anti-freezing assembly is connected to the inner wall of the fixed cylinder body in a pluggable manner, a first wire body is connected to the inner wall of the anti-freezing assembly in a pluggable manner, and a second wire body is connected to the outer wall of the anti-freezing assembly in a pluggable manner. A first sealing pipe and a second sealing pipe in the anti-freezing assembly are arranged, a worker inserts the first sealing pipe and the second sealing pipe into a first fixing hole and a second fixing hole in the fixing shell respectively, and then the first sealing pipe and the second sealing pipe are inserted into the first fixing hole and the second fixing hole in the fixing shell respectively. A worker inserts a first wire body and a second wire body into a first sealing pipe and a second sealing pipe respectively, inserts a fixing cylinder into a fixing shell, and inserts a first connecting pipe and a second connecting pipe into the first wire body and the second wire body. And the worker installs the frost crack prevention instrument system wire harness on the instrument.

The utility model relates to the technical field of coil pipe structures, and discloses a frost crack prevention coil pipe structure which comprises a shell, a connecting frame is fixedly connected to one side of the outer wall of the rear end of the shell, a plurality of fan shells are connected to the rear end of the outer wall of the shell in a penetrating mode, and wind wheels are rotationally connected to the inner walls of the fan shells. The middle of the inner wall of one side of the connecting frame is fixedly connected with a servo motor, and the output end of the servo motor is fixedly connected with a rotating rod. According to the coil pipe structure, when the coil pipe structure is used, the temperature in the shell can be conveniently monitored in real time through the temperature monitor, when the temperature reaches a set temperature threshold value, the temperature of the bent position of the copper pipe at the upper end can be increased by starting the heating rod at the moment, and the servo motor is started to drive the rotating rod to rotate and drive the wind wheel to rotate at the same time; and the internal temperature is diffused, so that the local temperature is prevented from being too low, and the risk of freezing cracking of the coil pipe is reduced.

The utility model discloses a frost crack prevention instant heating device. The instant heating device comprises an instant heating device body, a water inlet pipe is arranged at one end of the instant heating device body, a water outlet pipe is arranged at the other end of the instant heating device body, a water flow pipeline allowing water flow to pass through is arranged between the water inlet pipe and the water outlet pipe, and a heating pipe is inserted into the water flow pipeline. The elastic sealing cover covers the opening of the water flow pipeline, and one end of the elastic sealing cover extends towards the heating pipe and is provided with a buffer rod; the buffer rods can absorb internal stress generated by expansion through self deformation when water in the water flow pipeline freezes and expands, and pipeline breakage caused by stress concentration is avoided. When water in the water flow pipeline freezes and expands, pressure generated by volume increase acts on the elastic sealing cover and the buffer rod; after the ice is melted, the buffer rod restores under the action of resilience force of the material, so that the device can be continuously used.

The invention discloses a water mixing system with a frost crack prevention technology, and belongs to the technical field of bathroom hardware. The water mixing system comprises a shell assembly, a water mixing valve is arranged on one side of the shell assembly, and a first water inlet channel, a second water inlet channel and a water mixing channel are formed in the shell assembly; the water outlet side of the first water inlet channel and the water outlet side of the second water inlet channel are communicated with the water mixing valve, the water outlet side of the water mixing valve is communicated with the water inlet side of the water mixing channel, at least one air trapping cavity is formed in the shell assembly, and the volume of the air trapping cavity accounts for 15%-20% of the total volume of the first water inlet channel, the second water inlet channel and the water mixing channel. The air trapping cavity is formed in the shell assembly, sufficient buffer space is provided for frozen and expanded water, the valve body is prevented from being broken from the source, and meanwhile the stability of the water mixing adjusting function is guaranteed.

The low-temperature-resistant metal hose comprises a metal hose body, a protective layer, an air exhaust head, a vacuum layer, a pipeline, a fixing cap and a blocking pad, the outer wall of the metal hose body is sleeved with the protective layer, the vacuum layer is arranged in the protective layer, an outer blocking layer is arranged on the outer ring wall of the vacuum layer, and the outer blocking layer is arranged on the outer ring wall of the pipeline. An outer blocking layer is arranged on the inner ring wall of the vacuum layer, an inner blocking layer is arranged on the inner ring wall of the vacuum layer, reinforcing ribs are arranged between the outer blocking layer and the inner blocking layer, an air exhaust head is installed on the protection layer, a pipeline is installed on the air exhaust head, and the other end of the pipeline is connected with the vacuum layer. The metal hose solves the problem that most metal hoses are poor in cold resistance and low temperature resistance, the low temperature resistance of the metal hose is improved, and the problem that normal transmission of media is affected due to the fact that pipelines are prone to frost crack in low-temperature weather is solved.

A method and apparatus for detecting water flow absence in a unit, and a unit. The method comprises: after a unit is started up to operate, determining whether a shell and tube pressure P and a shell and tube evaporation temperature Tevaporate meet a first preset condition P≤P1 or Tevaporate≤T1; if the first preset condition is met, determining a time interval t from the startup of the unit to when the first preset condition is met, and determining whether t≤tset is met; if so, increasing the degree of opening of a throttle valve, and further identifying a water flow absence fault on the basis of an air intake temperature Tintake, a water input / output temperature of a shell and tube, and Tevaporate, and executing a corresponding protection action; and if not, maintaining the normal operation of the unit, identifying a water flow absence fault on the basis of P and Tintake, and executing a corresponding protection action. When a unit is started up and during the operation of the unit, water flow absence operation is separately identified by means of operation parameters of the unit, and corresponding handling measures are taken, so as to accurately perform early warning and protection on the water flow absence operation of the unit, thereby avoiding the frost crack of the shell and tube.

The frost crack prevention water mixer comprises a water mixing channel shell and a frost crack prevention mechanism, the water mixing channel shell is provided with a cold water inlet, a hot water inlet, a water mixing cavity, a pressure relief opening and a plurality of water outlets, and the cold water inlet, the hot water inlet, the pressure relief opening and the water outlets are all communicated with the water mixing cavity; the frost crack prevention mechanism comprises a fixing block, a diaphragm and an elastic piece, the fixing block and the diaphragm are fixedly connected to the pressure relief opening, the diaphragm seals the pressure relief opening, one end of the elastic piece abuts against the fixing block, the other end of the elastic piece is fixedly connected with a cushion block, and the elastic piece is used for driving the cushion block to move in the direction away from the fixing block so that the cushion block can abut against the diaphragm. According to the frost crack prevention water mixer, the expansion volume of ice can be absorbed, and the possibility that the water mixing channel shell and the valve are cracked and damaged is reduced.

The invention relates to the technical field of cold-drawn section steel, in particular to low-temperature-resistant frost-crack-resistant cold-drawn section steel which comprises a cold-drawn section steel body, an assembling block is arranged at one end of the cold-drawn section steel body, a protective strip is fixed to the surface of the assembling block, a heating wire is arranged in the protective strip, and the heating wire is located between the protective strip and a vertical plate of the cold-drawn section steel body. A sealing block is arranged at the other end of the cold-drawn section steel body, two limiting strips are arranged on the surface of the sealing block, and one end of the protective strip is inserted between the two limiting strips; the low-temperature-resistant anti-frost-crack cold-drawn section steel has the beneficial effects that the heating wires are arranged in the protection strips, the cold-drawn section steel body can be locally heated, heat is transmitted to the whole area of the cold-drawn section steel body through the conduction effect, and low-temperature frost crack is effectively prevented.

A fog-dispersal water-saving modified cooling tower relates to the technical field of cooling towers and comprises a tower body, and a water collecting device, a water distribution system and fog-dispersal water-saving filler are arranged in the tower body from top to bottom. The fog-dispersal water-saving packing is formed by bonding a plurality of dry packing sheets, a plurality of first heat exchange channels and second heat exchange channels which are independent from each other are formed through areas among the packing sheets, and the upper end of each fog-dispersal water-saving packing is vertically and fixedly connected with an upper partition plate which separates the first heat exchange channel from the second heat exchange channel. And the lower end part of each fog-dispersal water-saving filler is vertically and fixedly connected with a lower partition plate, and is divided into a plurality of first inlet channels communicated with the second heat exchange channel and a plurality of second inlet channels communicated with the first heat exchange channel through the lower partition plates. The utility model solves the problems of high energy consumption, scaling, frost crack risk and high reconstruction cost of the fog-dispersal water-saving reconstruction cooling tower in the traditional technology.

The utility model relates to the technical field of intelligent water meters, in particular to a frost crack prevention secondary sealing air bag bowl structure of an intelligent water meter. The intelligent water meter comprises an intelligent water meter body, a through opening is formed in the intelligent water meter body, an air bag bowl is arranged on the intelligent water meter body, the air bag bowl blocks the through opening, a sealing plate is arranged in the air bag bowl, and the sealing plate is installed on the air bag bowl in an ultrasonic welding mode. Original independence and stability of an inner cavity of the intelligent water meter body are kept through the structure of the integrated design of the air bag bowl and the sealing plate, a small part of volume can be expanded by means of elasticity of the sealing plate when water expands or freezes, and sealing of the inner cavity of the intelligent water meter body is guaranteed. The extrusion of the water expansion pressure on the counting gear box structure is buffered, all functions of the intelligent water meter can be recovered in time after the temperature of ice water rises, the risk of frost cracking of the water meter in the cold environment is avoided, and the maintenance cost of the intelligent water meter in the cold region is greatly reduced.

An anti-freeze crack device (2), including: a main body (21) and a plugging assembly (22). The main body (21) is provided with a cavity (210) with an open end, and the open end of the cavity (210) is configured to communicate with a water chamber (10) of a water outlet valve (1). The plugging assembly (22) is disposed within the cavity (10) and can be switched between a first state in which the open end is closed and a second state in which the open end is opened.

The utility model discloses a fresh air heating system capable of preventing a fresh air coil pipe in a low-temperature area from frost cracking. The system comprises a fresh air heating coil, a plate heat exchanger, a hot water circulation loop A and a hot water circulation loop B, the hot water circulation loop A and the fresh air heating coil form a closed loop, the water outlet end of the fresh air heating coil is connected with one end of a water inlet pipe of the hot water circulation loop A, and the other end of the water inlet pipe of the hot water circulation loop A is connected with a water inlet A of the plate heat exchanger through a flexible connector and a pipeline connection reducer. The fresh air heating coil can be arranged at an inlet of the combined air handling unit or at a fresh air taking position of other modes, is in direct contact with outdoor low-temperature fresh air and is used for heating the fresh air and protecting the air handling coil and the like at the rear end from the risk of frost cracking. The plate heat exchanger is placed in a building and used for transferring heat between the two hot water circulation loops, the plate heat exchanger does not make direct contact with outdoor low-temperature fresh air, the plate heat exchanger is placed in a machine room without the frost crack risk, and the frost crack risk is avoided from the source.

The invention discloses a disc type asphalt concrete low-temperature frost crack test method and device, and belongs to the technical field of hydraulic engineering and road engineering material tests. The device comprises a disc clamp system, a leveling cementation layer simulation structure, an angle adjustable structure, a low-temperature constant-temperature test box, a strain monitoring system and a control module. The disc clamp system consists of an upper disc clamp and a lower disc clamp and is used for clamping a circular test piece and simulating actual constraint of a peripheral panel; the leveling cementation layer simulation structure is arranged at the upper part of the lower disc and simulates lower constraint; and the angle adjustable structure can realize adjustment within a certain angle range. During testing, a test piece is installed in the clamp, the temperature is reduced in the low-temperature constant-temperature box according to a set program, the strain of the test piece is collected in real time through the strain monitoring system, and the frost crack temperature is automatically judged by the control module according to strain mutation. According to the invention, the multidirectional constraint state of the asphalt concrete panel in an actual structure can be truly simulated, the test result is accurate, and the engineering applicability is high.

The utility model provides an anti-freezing ball valve which comprises a valve body, the valve body is provided with a valve cavity, an inlet and an outlet are formed in the two sides of the valve cavity respectively, the inlet and the outlet are both provided with connecting flanges, and a ball core controlled to rotate through a valve rod is arranged in the valve cavity. The ball core is provided with a through hole which faces the inlet and the outlet or is staggered with the inlet and the outlet during rotation, the inlet is provided with a first valve seat which is pushed by one connecting flange and abuts against the ball core, and the outlet is provided with a second valve seat which is pushed by the other connecting flange and abuts against the ball core. The first valve seat and the second valve seat are annular, and annular extrusion faces are arranged at the positions, making contact with the ball core, of the first valve seat and the second valve seat. And the inlet is connected with the valve cavity at the outer wall of the ball core through a flow guide channel. The utility model has the advantages of simple structure and capability of avoiding frost crack caused by low temperature.

The invention belongs to the technical field of anti-freezing of cooling water towers, and discloses an electric heating anti-freezing system and method for an outdoor cooling water tower. The system is used for preventing frost crack of the pipeline, and electric heating rods and temperature sensors are additionally arranged at a water inlet and a water outlet of the water tower pipeline; a bypass water pipe is additionally arranged between the water inlet and the water outlet, and a circulating water pump is additionally arranged on the bypass water pipe; the circulating water pump is also connected with an interlocking switch; and the power-on heating rod, the temperature sensor and the interlocking switch are connected with a control system through signal lines. The anti-freezing of the pipeline is ensured, and meanwhile, the use of an ethylene glycol anti-freezing solution is canceled; by means of the anti-freezing mode of electric heating and the circulating water pump, the selection position of the electric heating rod and the control conditions of electric heating and temperature detection, the effect that water in the whole pipeline can not be frozen is achieved.