66results about How to "Guaranteed not to freeze" patented technology

The invention relates to a method for recovery of oilfield associated gas hydrocarbon mixture, which includes steps: firstly, delivering associated gas into a compressor for compression to form compressed gas with a pressure P1; secondly, subjecting the compressed gas to primary condensation at a temperature T1 to form condensed gas and liquid; thirdly, delivering the condensed gas to a molecular sieve for dewatering; fourthly, subjecting the dewatered condensed gas to dew point detection; fifthly, exhausting the dewatered condensed gas as recovered gas if the dew point temperature of the dewatered condensed water is higher than a temperature T2, and performing following steps if the dew point temperature of the dewatered condensed water is lower than the temperature T2; sixthly, subjecting the dewatered condensed gas to secondary precooling at a certain temperature T3; seventhly, subjecting the gas subjected to secondary precooling to secondary condensation at a certain temperature T4; and eighthly, separating and storing a product of secondary condensation to generate recovered hydrocarbon mixture.

The invention provides a control method for turn-on time of a heating pipe of an air conditioner, a controller and an air conditioner. The method comprises the following steps of: judging whether the air conditioner turns on a heating mode or not; after confirming that the air conditioner turns on the heating mode, obtaining an existing outdoor temperature T; when the existing outdoor temperature T meets a preset condition, controlling the air conditioner to enter a first defrosting period, enabling the heating pipe of the air conditioner to turn on and operate for preset time, and obtaining time of the first defrosting period when defrosting is ended; and when the air conditioner enters a next defrosting period, controlling a turn-on moment, within the next defrosting period, of the heating pipe of the air conditioner according to time of the nearest previous defrosting period. According to the control method for the turn-on time of the heating pipe of the air conditioner provided by the invention, turn-on time, within the next defrosting period, of the heating pipe is dynamically regulated according to time of the previous defrosting period, so that a chassis is guaranteed to freeze while energy conservation and emission reduction are realized.

The invention relates to a low-environmental-temperature air source heat pump refrigerating system with a heat pipe loop. The low-environmental-temperature air source heat pump refrigerating system comprises a compressor, an indoor heat exchanger, an outdoor heat exchanger and a liquid storage device. The compressor is connected with a four-way reversing valve, the four-way reversing valve is respectively connected with the indoor heat exchanger and the outdoor heat exchanger, the indoor heat exchanger is connected with the liquid storage device, and the outdoor heat exchanger is connected with a heating power expansion valve. The low-environmental-temperature air source heat pump refrigerating system is characterized in that an air supply loop and the heat pipe loop are arranged between the indoor heat exchanger and the outdoor heat exchanger, an economizer and an electronic expansion valve are arranged on the air supply loop, a first inlet of the economizer is connected with the liquid storage device, a first outlet of the economizer is respectively connected with the electronic expansion valve and the heat pipe loop, the heat pipe loop comprises a first pipe and a second pipe, the first pipe is connected with the economizer and the bottom of the outdoor heat exchanger, and the second pipe is connected with the bottom of the outdoor heat exchanger and the heating power expansion valve. According to the low-environmental-temperature air source heat pump refrigerating system, the heating capacity attenuation rate in a low-temperature environment can be restrained, and the phenomenon that the outdoor heat exchanger is frozen in the low-temperature and high-humidity environment is avoided.

The invention discloses an ice melting device for a gate of a hydropower station. The ice melting device comprises a jetting tube, an air conveying tube and an air compressor, wherein the jetting tube is arranged on an upstream surface of the gate; the jetting tube is connected with the air compressor through the air conveying tube; and air spraying holes are formed in the jetting tube. According to the ice melting device disclosed by the invention, when compressed air is jetted to a water surface underwater, a front water surface of the gate is in a bubble boiling state, so that the front water surface of the gate is guaranteed to be not iced. The ice melting device is simple in structure, is low in cost, and is convenient and practical.

The invention relates to an anti-freezing and anti-theft watering gathering and transportation process flow valve bank for an oil well. The anti-freezing and anti-theft watering gathering and transportation process flow valve bank for the oil well comprises a watering pipe, an incoming water total cut-off valve, a thermal washing cut-off valve, a watering one-way valve, a central watering pipe 1, a central casing pipe, a vertical watering pipe, an oil-gas inlet pipe, a central watering pipe 2, a watering regulating valve, an oil return one-way valve, a vertical oil return pipe, an oil return total cut-off valve and an oil outlet pipe. According to the device, the watering pipe is arranged in a gathering and transportation pipeline, waste heat of watering is utilized to perform cyclic heat preservation on the whole valve bank, if maintenance and well shutdown are needed due to faults of an operation, a wellhead device, a Christmas tree and an oil pumping unit, the overall cyclic heat preservation of the valve bank can be still ensured, and freezing blockage can be avoided.

The invention discloses a multifunctional car washing brush which comprises at least one brush body. The brush bodies are divided into an upper brush body, a middle brush body and a lower brush body which are detachably connected, a dedusting bag is arranged in the upper brush body, the middle brush body is a hollow water inlet and liquid storage cavity, the lower brush body comprises a first partition and multiple soft brush strips, one ends of the soft brush strips are fixedly arranged on the first partition, the soft brush strips are spaced and arranged in parallel, each soft brush strip is of an internally-hollow strip-shaped structure, the other end of each soft brush strip is spherical, and the spherical diameter of the other end of each soft brush strip is larger than the diameter of a cross section of the hollow structure of each soft brush strip. The multifunctional car washing brush is simple in structure, flexible to operate, convenient to use, and multipurpose.

The invention discloses an anti-freezing solar water supply device which comprises a solar heat collection box, a water box and a water mixing valve. A water outlet of the solar heat collection box and a water outlet of the water box are connected to a hot water inlet and a cold water inlet of the water mixing valve through a casing pipe respectively, and the casing pipe is further provided with a heat absorbing and releasing pipe which is filled with phase-change media. The upper end of the solar heat collection box and the upper end of the water box are further connected with a pressure difference adjusting pipe which is provided with a heat insulation adjusting piece sliding in the length direction of the pressure difference adjusting pipe. According to the anti-freezing solar water supply device, the heat absorbing and releasing pipe and the pressure difference adjusting pipe are added, the pressure difference of cold and hot water boxes is balanced by sliding the heat insulation adjusting piece in the pressure difference adjusting pipe, cold water in the cold water box enters the casing pipe, the circulation temperature difference is increased, water flowing in the pipe is promoted, and the purposes of preventing the water pipe from being frozen and preventing water from stopping flowing are achieved.

The invention relates to an anti-freezing method, an anti-freezing control system and a gas water heater. The anti-freezing method comprises the following steps: obtaining a first detection temperature value on a pipeline of a heat exchanger, and obtaining a second detection temperature value of an environment in which the gas water heater is located; determining whether to enter an anti-freezingworking mode or keeping a standby working mode according to the first detection temperature value; and if it is determined to enter the anti-freezing working mode, determining to enter a first anti-freezing working mode, a second anti-freezing working mode or a third anti-freezing working mode according to the second detection temperature value. According to the anti-freezing method, a proper anti-freezing working mode is determined according to the second detection temperature value of the environment in which the gas water heater is located, anti-freezing gradation is distinct, pipeline icing frost cracks of the gas water heater can be effectively prevented, anti-freezing efficiency is relatively high, and energy waste can be avoided.

The invention discloses an anti-freezing method for a cold region water conservancy project road tunnel. The method comprises: 1, building a gate slot on a road tunnel portal, and then mounting a hardrapid lifting gate in the gate slot; 2, arranging induction devices on positions in an out of the road tunnel, the distance between the position and the gate slot being a set distance, when a vehiclepasses through the induction device, the hard rapid lifting gate lifting up; 3, arranging manual buttons used to control the hard rapid lifting gate to lift in and out of the gate slot. The method isdesigned for road tunnels used in cold region water conservancy projects. When no vehicle travels, the tunnel portal is sealed by the hard rapid lifting gate, and temperature in the tunnel is greatlyincreased under the action of ground temperature, and temperature in the tunnel is closed to ground temperature, so as to ensure the back of road tunnel lining and drainage ditches not to freeze, andachieve an objective of road tunnel anti-freezing. Therefore, for road tunnels used in cold region water conservancy projects, according to the method, heat insulation boards and a deeply buried center drainage ditch used in a conventional road tunnel are not needed.

The invention provides an anti-freezing water pump. The anti-freezing water pump comprises a motor and a pump head. The motor is fixedly matched with the pump head and drives the pump head to work. Apower box is fixedly arranged on a shell of the motor and electrically connected with an external power source. A base is arranged at the bottom of a pump case of the pump head, and a heating device is fixedly arranged in the base. The power box provides electricity for the heating device. Due to the fact that the heating device is arranged at the bottom of the pump head, after residual water in the pump head is frozen, and the pump head stops working, the heating device is energized, the purpose that ice blocks in the pump head are melted can be achieved, or the situation that the water in the pump head is not frozen is guaranteed, the anti-freezing water pump can be directly used when the anti-freezing water pump is used again, and the phenomenon that due to the fact that the residual water is frozen, the frost damage to the pump head happens, or startup of the motor is affected can be avoided.

The invention relates to stone-like paint prepared from flexible colored particles and a preparation process of the stone-like paint. The stone-like paint is mainly prepared from the following components in parts by weight: water, attapulgite, cellulose, a pH regulator, a diatomite, a pure acrylic emulsion, a coalescing agent, a water-based wax emulsion, a water-based defoamer, a polyurethane thickener, flexible colored particles, fine sand and an alkali swelling thickener. The invention overcomes the defects that the granulation process of the existing sand-in-water coating and water-in-watercoating is complicated, the effect reproducibility among batches is poor, the granulation process is greatly influenced by the environment temperature, the construction effect is influenced by the air pressure, the construction efficiency is low and the like; through cooperation of the flexible colored particles, the fine sand, the attapulgite, the cellulose, the alkali swelling thickener, the polyurethane thickener and the water-based wax emulsion, the fusion degree of the flexible colored particles and other components in a coating system is high, and the coating has the advantages that theflexible colored particles are not prone to breakage, the production process difficulty is low, atmospheric pressure spraying can be adopted during construction, and the construction efficiency is high.

An air moistener for car is composed of an thermal insulating case and such unit arranged in said thermal insulating case as water tank, the main body of moistener with ultrasonic transducer and communicated via valve to said water tank, fan, air inlet tube, and air outlet tube.

The invention provides an anti-freezing apparatus for an air cooling tower system of an indirect air cooling unit. The anti-freezing apparatus comprises an air cooler, an air cooling tower, a radiator and a draining valve, wherein one end of the air cooler is connected with the air cooling tower, the joint of the end of the air cooler and the air cooling tower is provided with a first valve, the other end of the air cooler is connected with the air cooling tower, the joint of the other end of the air cooler and the air cooling tower is provided with a second valve, the air cooler is connected with a self-circulating pump and a cold water circulating pump, the self-circulating pump and the cold water circulating pump are connected in parallel, the self-circulating pump is arranged between and connected with the air cooler and the second valve, the radiator is connected with the air cooler, the air cooling tower is connected with the draining valve, and the air cooling tower is composed of a fan, a spraying device and a water tank. According to the invention, through arrangement of the self-circulating pump, the cold water circulating pump, a drainage pump and a radiating pump, the air cooler and the air cooling tower are prevented from frost damage according to different indoor and outdoor temperatures and different operation modes, so stable and reliable working is guaranteed all the year round.

The invention discloses a preparation method for hydroxycalcium carbonate for an animal feed. The preparation method comprises the following steps: adding a calcium source to water and warming, addingbicarbonate in a stirring condition, reacting in a constant temperature, after ending a reaction, cooling and crystallizing, filtering and drying, to obtain the hydroxycalcium carbonate. The preparation method is more moderate in reaction rate, controllable in process, more uniform in obtained product particles, less in by-product generation, high in bioavailability of the hydroxycalcium carbonate, and low in processing cost. The invention further discloses an application of the hydroxycalcium carbonate in the animal feed field. While the hydroxycalcium carbonate is used for a pig feed, an additive amount thereof is 1-12 kg / t of a mixed feed; while the hydroxycalcium carbonate is used for a poultry animal feed, the additive amount thereof is 1-23 kg / t of the mixed feed; and while the hydroxycalcium carbonate is used for a ruminant animal feed, the additive amount thereof is 0.1-4 kg / t of a full mixed daily ration feed. The application is capable of neutralizing acidic materials in thefeed, and preventing or delaying metamorphism of the feed.

The invention relates to a water accumulation cup for an oil water separator, in particular to a heating type water accumulation cup for the oil water separator. The heating type water accumulation cup comprises a water accumulation cup body, a temperature controller and a heater. The temperature controller is arranged in the water accumulation cup body, the control end of the temperature controller is connected with the heater, heating pieces of the heater are arranged upwards along the cup wall of the water accumulation cup body, a waterproof through hole is arranged on the bottom face of the water accumulation cup body, and the temperature controller and the power supply input end of the heater penetrate through the waterproof through hole. By means of the structure, the temperature controller is utilized to control the heater to heat water in the water accumulation cup body and ensure that water in the water accumulation cup is not freezing and is in the liquid state, and facilitates discharge of water. Simultaneously, the heater enables temperature of oil on the upper layer to increase while heating water due to the fact that the internal space of the oil water separator is in the communication state to enable the oil water separator to work normally, filter impurities and separate water.

The invention provides a JPEG (Joint Photographic Experts Group) image compression method, system and device and a storage medium, and the method comprises the steps: responding to a condition that a current image frame is in a starting frame, and coding the current image by using a standard quantization coefficient table; in response to the situation that the current image frame is not in the starting frame, calculating a weighted average image data length of adjacent frames with a first preset number, and calculating a coding factor according to the weighted average image data length; predicting the bandwidth factor of the next frame according to the change condition of the bandwidth of the adjacent second predetermined number of frames; and determining a quantization parameter of the current image frame through a quantization table according to the relationship between the coding factor and the bandwidth factor, and updating the quantization parameter to a quantization table corresponding to the next frame. According to the invention, the coding process is optimized frame by frame when the system bandwidth changes and the image characteristics change, so that the coded image is always in the allowed highest image quality.

The invention discloses a passenger car water filling nozzle sealing dustproof device which ensures that a water injection pipe is not frozen and is not polluted by dust, and is clean and sanitary. Hoops are arranged so that later installation of a cover plate is facilitated, disassembly is also facilitated, anti-skid gaskets and protruding strips are arranged on inner walls of a first arc-shapedconnecting plate and a second arc-shaped connecting plate, the anti-skid performance of the hoops is improved, and stability is improved; a hinge reset mechanism facilitates opening and closing of thecover plate and is used for applying an elastic force in an opening and closing direction to the cover plate; limiting plates on connecting flanges on the two sides limit an overturning angle of thecover plate, and a situation that the hinge reset mechanism fails due to excessive deformation caused by excessive overturning of a torsional spring is prevented; a locking block I on the inner wall of a deflector rod is attracted with a locking block II when the cover plate is closed so that the cover plate is prevented from being accidentally and easily opened; and the opening and closing of thebottom of the cover plate and a sealing sheet provided with a cross-shaped water outlet facilitate discharge of internal water vapor, internal and external air pressure is balanced when the internalair pressure is too high, and the cover plate is prevented from being ejected open by the internal high air pressure.

The invention relates to a gate slot anti-icing heating device. The device is embedded in wall bodies on the two sides of a gate and comprises a main box body and sub box bodies which are arranged on the side surface of the main box body in pair and are communicated with the main box body, wherein a liquid medium fills the main box body and the sub box bodies; heating pipes are arranged in the main box body and the sub box bodies; a gate slot for a gate to go through is formed between the pair of sub box bodies; a vertically through gate lateral groove for inserting the side edge of the gate is formed in the side of the main box body; the gate slot is communicated with the gate lateral groove. The device is simple in structure and convenient to use, accumulated ice in the gate slot can be quickly removed, and the gate slot can be guaranteed not to be iced by heating irregularly at intervals; ice breaking can be quickly finished by one worker, so that the safety risk caused during accumulated ice removal by the traditional manual method is reduced, the complexity of accumulated ice removal by the traditional manual method is reduced, and the labor intensity of a worker is relieved.

The invention discloses a methane greenhouse system. According to the methane greenhouse system, methane energy can be fully utilized, and meanwhile it is guaranteed that a greenhouse has an energy-saving and reliable capacity for heating and heat preservation. The methane greenhouse system comprises a methane tank and a greenhouse body. A boiler is arranged in the greenhouse body, methane in the methane tank is fed into the boiler through a methane pipe, water in a circulating water pipe is heated through the boiler, the circulating water pipe is connected with multiple radiators, and the radiators are distributed in the greenhouse body. According to a specific implementation mode, the radiators are buried below the earth surface; the radiators are arranged in the greenhouse body, are radiating coil pipes and are connected in parallel or in series. According to a specific implementation mode, a chimney of the boiler extends to the outside of the greenhouse body; a top beam is arranged on the top of the greenhouse body and provided with methane lamps in a hanging mode.

The present invention discloses plateau type heat preservation and water purification integrated equipment. The equipment comprises a heat preservation room, an energy-saving power supply system, a raw water purification system, a control system and a monitoring system, and the heat preservation room is used for keeping the interior of the room at a constant temperature; the energy-saving power supply system is used for supplying power; the raw water purification system is arranged in the heat preservation room body and is used for purifying raw water; the control system controls the operationof the raw water purification system; and the monitoring system is used for monitoring the purification process and result. The equipment is water filtering equipment for carrying out water quality pretreatment and reverse osmosis treatment by taking municipal tap water, well water and mountain spring water as source water. The plateau type heat preservation and water purification integrated equipment can be widely applied to pure water treatment of pure water, tea beverage blending water, direct drinking water, brackish water desalination, residence communities, hospitals, hotels, chemical engineering, enterprises and public institutions and the like.

An anti-freezing magnetic flip plate liquid level meter comprises a flange, wherein an outer stainless steel sleeve is fixedly arranged on the flange, and a flip plate type height scale is arranged on the outer surface of the outer stainless steel sleeve. The anti-freezing magnetic flip plate liquid lever meter is characterized in that an inner stainless steel sleeve is arranged in the outer stainless steel sleeve, a vacuum layer is formed between the outer stainless steel sleeve and the inner stainless steel sleeve, a stainless steel connecting rod is arranged in the inner stainless steel sleeve, a floating ball is arranged at the bottom of the stainless steel connecting rod, a magnetic sliding block is arranged on the top of the stainless steel connecting rod, and the stainless steel connecting rod is filled with a phase change medium or a heat conducting medium. The anti-freezing magnetic flip plate liquid level meter has the advantages that the inner stainless steel sleeve is arranged in the outer stainless steel sleeve, the vacuum layer is formed between the outer stainless steel sleeve and the inner stainless steel sleeve, and thus the heat preservation effect is achieved; the stainless steel connecting rod is filled with the phase change medium or the heat conducting medium, the heat of liquid in a container can be conducted to the magnetic sliding block through the medium, the temperature of the magnetic sliding block and the temperature of the liquid in a tank can be kept consistent, it can be ensured that the magnetic sliding block is not frozen as long as the liquid in the container is not frozen, and it is ensured that the liquid level meter works normally.

The invention relates to a defrosting method of a high-temperature air source heat supply system, which comprises the following steps: 1) treatment before installation: (1) disassembly of a compressor shell: a welding filler on the outer surface of the compressor shell is polished and removed, the filler can be cleaned by a polishing machine, and after the filler is cleaned up, the compressor shell is defrosted; the compressor shell can be knocked open by a hammer to be divided into an upper part and a lower part; and (2) cleaning the compressor shell and the fins: removing rusty parts on the inner side surface, the outer surface and the surfaces of the fins of the compressor shell, and washing away residual dirt by using clean water. According to the defrosting method of the high-temperature air source heat supply system, the compressor shell and the fins are treated before the capillary tubes are installed, the treatment mode is detailed to removal of rusty parts and dirt on the surfaces of the compressor shell and the fins, and therefore the installation stability of the capillary tubes after welding is avoided; and the capillary tubes are welded after being embedded by forming the grooves, so that the overall stability of welding installation is improved.

The invention discloses a steam pipeline drainage recovery system suitable for severe cold regions, which comprises several drainage recovery units connected with the steam pipeline along the way, and the drainage recovery unit includes a steam trap group connected with the steam pipeline in sequence, a condensed water recovery The device and the condensed water pipeline; wherein, each condensed water pipeline is collectively connected with a condensed water main pipe, and the condensed water main pipe and the steam pipe are laid in the same heat preservation structure. The steam pipeline drainage recovery system connects several drainage recovery units along the way of the steam pipeline, gathers a small amount of condensate recovered in each drainage recovery unit into the condensate main pipe, and lays the condensate water main pipe and the steam pipe outside In the same insulation structure, it solves the phenomenon of difficult condensed water recovery and easy freezing caused by the small amount of condensed water generated per unit time and the low flow rate of condensed water; at the same time, it uses the heat tracing principle of the steam pipe's own heat and adopts low-cost settings to achieve Efficient recovery of condensate.

The invention relates to a gate slot anti-icing heating device. The device is embedded in wall bodies on the two sides of a gate and comprises a main box body and sub box bodies which are arranged on the side surface of the main box body in pair and are communicated with the main box body, wherein a liquid medium fills the main box body and the sub box bodies; heating pipes are arranged in the main box body and the sub box bodies; a gate slot for a gate to go through is formed between the pair of sub box bodies; a vertically through gate lateral groove for inserting the side edge of the gate is formed in the side of the main box body; the gate slot is communicated with the gate lateral groove. The device is simple in structure and convenient to use, accumulated ice in the gate slot can be quickly removed, and the gate slot can be guaranteed not to be iced by heating irregularly at intervals; ice breaking can be quickly finished by one worker, so that the safety risk caused during accumulated ice removal by the traditional manual method is reduced, the complexity of accumulated ice removal by the traditional manual method is reduced, and the labor intensity of a worker is relieved.

The invention provides a freeze-proof type solar flat plate heat collector, relating to the technical field of a flat plate type solar energy heat collector. The heat collector comprises a heat-preserving layer and a heat-collecting board which is arranged in the heat-preserving layer, wherein the heat-collecting board comprises a heat-absorbing piece, an upper heat-collecting pipe, a lower heat-collecting pipe and a plurality of parallel heat-absorbing pipes, the two ends of which are respectively connected with the upper heat-collecting pipe and the lower heat-collecting pipe; the inner diameter of each heat-absorbing pipe is not larger than the inner diameters of the upper heat-collecting pipe and the lower heat-collecting pipe, which are connected with the heat-absorbing pipes; the heat-absorbing pipes are mutually connected with the heat-absorbing piece, one ends of the upper heat-collecting pipe and the lower heat-collecting pipe are larger than the other ends thereof, the middle parts of the upper heat-collecting pipe and the lower heat-collecting pipe are provided with gradually-changed diameters, and the large ends of the upper heat-collecting pipe and the lower heat-collecting pipe are provided with openings which are connected with a water tank; and the direction of the large opening of the upper heat-collecting pipe is opposite to that of the lower heat-collecting pipe. The freeze-proof type solar energy flat plate heat collector has simple and reasonable structure, can effectively overcome the phenomenon that the heat-absorbing pipes, the upper heat-collecting pipe or the lower heat-collecting pipe are cracked caused by the freeze of water therein under the condition of low temperature, can more thoroughly circulate the water, and can be applied to extraordinary-large engineering.

A heating type windshield glass washing device comprises a washing liquid tank, a washing liquid pump, a washing liquid spraying opening, a windshield glass washing device switch, a heating valve, three three-way valves, a one-way valve, a washing liquid heater, a washing liquid heater water inlet pipe, a washing liquid heater water outlet pipe, a temperature sensor and a controller; two gears arearranged on the windshield glass washing device switch so that washing liquids without alcohol components at a low temperature and a high temperature can be sprayed out; when the temperature is lowerthan 0 degree centigrade, the washing liquid without the alcohol components can be heated by using hot water led to an automobile heating system so as to prevent the washing liquid from being frozen;and the washing liquid at the high temperature can be provided to rapidly melt frost or ice on a windshield glass. The heating type windshield glass washing device has the advantages of simple structure and low cost and can adapt to all automobiles with water-heated air conditioner heating systems.

The invention belongs to the field of refrigeration equipment, and particularly relates to an absorption type water chilling unit for preparing low-temperature cold water. The absorption type water chilling unit comprises a condenser, an absorber, an evaporator, a high-temperature regenerator, a low-temperature regenerator, a low-temperature heat exchanger, a high-temperature heat exchanger, a connecting pipeline and a solution pump, wherein a monitoring control system, a solution control pipeline and a coolant water control pipeline are additionally arranged; the monitoring control system comprises a concentration measuring device, a solution control valve and a control device; the concentration measuring device, the solution control valve and a coolant water control valve are electrically connected with the control device respectively; the concentration measuring device is connected with the evaporator; the solution control valve is arranged on the solution control pipeline; and thecoolant water control valve is arranged on the coolant water control pipeline. According to the absorption type water chilling unit for preparing the low-temperature cold water, a low-concentration lithium bromide solution is used as coolant, and the concentration of the lithium bromide solution is accurately controlled through the concentration measuring device, the solution control valve, the coolant water control valve and the control device, so that the coolant is not frozen, and the low-temperature chilled water is prepared.

The invention discloses a preparation method of a snow-melting agent, and relates to the technical field of snow-melting agents, and the preparation method comprises the following steps: (1) preparing an acrylic acid and sodium allylsulfonate copolymer: mixing water, acrylic acid and sodium allylsulfonate in proportion, stirring and dissolving, heating to 70 DEG C, adding an initiator, and reacting at constant temperature for 4 hours to obtain colorless or light yellow transparent viscous liquid; (2) mixing and stirring sodium formate, potassium acetate, potassium phosphate, calcium oxide, propylene glycol and water to obtain a primary mixture; (3) adding the acrylic acid and sodium allylsulfonate copolymer in the step (1) into the primary mixture, and stirring; and (4) performing granulation molding on the mixture in the step (3) to obtain the snow-melting agent. The preparation method has the beneficial effects that the preparation method is simple, the operability is strong, the snow-melting agent can be prepared by stirring and mixing the components, regulating the viscosity and then curing and molding by a granulator, and the snow-melting agent does not contain chlorine elements and is green and environment-friendly.