31 results about "Dichloroprop" patented technology

The invention relates to a preparation method of propargyl alcohol, and belongs to the technical field of organic chemistry. The reaction formula is as follows: # imgabs0 #; comprising the following steps: (1) taking Z-1, 3-dichloropropene as a raw material, adding dimethyl sulfoxide and solid alkali into an organic solvent, heating, carrying out heat preservation reaction until the content of the Z-1, 3-dichloropropene is less than or equal to 1%, and cooling to room temperature; (2) adding a phase transfer catalyst and water into the reaction liquid obtained in the step (1), heating, and carrying out a heat preservation reaction until an intermediate 3-chloropropyl-2-ene-1-ol is less than or equal to 0.5%; cooling to room temperature; (3) filtering, separating liquid, and adding an extracting agent into a water phase for extraction; and rectifying the extracted organic phase to obtain propargyl alcohol. By controlling the alkaline strength and reaction parameters in the reaction, the production of organic impurity ether compounds can be effectively controlled, the purity and yield of the product are improved, and meanwhile, the reaction time is shortened.

The invention relates to a method for resource utilization of 1, 1, 2-trichloropropane, and the method comprises the following steps: (1) carrying out high-temperature cracking on a material flow containing 1, 1, 2-trichloropropane to obtain a material flow containing 3, 3-dichloropropene; and (2) carrying out chlorination on the material flow containing 3, 3-dichloropropene to obtain a material flow containing 1, 1, 2, 3-tetrachloropropane. According to the method disclosed by the invention, the propylene chlorination by-product 1, 1, 2-trichloropropane can be subjected to high-temperature cracking to obtain 3, 3-dichloropropene, and 1, 1, 2, 3-tetrachloropropane is obtained after the 3, 3-dichloropropene is chlorinated. The byproduct 1, 1, 2-trichloropropane is fundamentally solved, the process route is simple, the flow is short, the reaction conversion rate is high, the selectivity is good, and industrial implementation is facilitated.

The invention belongs to the technical field of organic synthesis, and particularly relates to a chloroamine synthesis method which comprises the following steps: S1, mixing a hydroxylamine sulfate aqueous solution and methyl acetate, and then dropwise adding a NaOH aqueous solution to react for 1-2 hours; s2, adding trans-1, 3-dichloropropene and the sulfonated niobium-doped TS-1 molecular sieve, uniformly mixing, heating to 60-70 DEG C, and carrying out etherification reaction for 5-6 hours to generate an intermediate product; s3, adding hydrochloric acid into the intermediate product, fully stirring, and carrying out reflux reaction at 60-70 DEG C for 2-3 hours; s4, organic matter is separated through reduced pressure distillation, then a NaOH aqueous solution is added to adjust the pH to be larger than 9, extraction is conducted, the extraction agent is removed through reduced pressure distillation, and chloramine is obtained. According to the synthesis method provided by the invention, the selectivity of the chloro-amine is 99% or above, the yield of the chloro-amine is 98% or above, the production efficiency of the chloro-amine can be effectively improved, and the synthesis method is suitable for industrial application.

The invention relates to a device and a method for refining 1, 2-dichloropropane as a byproduct of a 3-chloropropene device by combining rectification, polymerization and adsorption. The invention discloses a refining device and a refining method for a byproduct 1, 2-dichloropropane of a 3-chloropropene device. According to the device, the light component removal tower, the polymerization reactor, the heavy component removal tower and the adsorption tower are combined, dichloropropene impurities which are difficult to separate are subjected to polymerization reaction to generate a polydichloropropene polymer, and due to the fact that the boiling point difference between the polymer and dichloropropane is large, the polymer is easy to separate and purify, refining and purification of 1, 2-dichloropropane are successfully achieved. The purity of final 1, 2-dichloropropane is greater than or equal to 99.9%, and the content of residual dichloropropene is 1t; and the total weight is 100 ppm. Meanwhile, the dichloropropene polymerization process is mild in condition, low in equipment requirement, simple in flow and beneficial to expanded production.

This utility model relates to the field of chemical product refining technology, and provides a refining apparatus for trans-1,3-dichloropropylene. The apparatus includes a distillation column body with an anti-clogging mechanism inside, and a pretreatment mechanism at the bottom. The distillation column body includes a jacketed heater, with a reboiler fixedly connected to its bottom. The jacketed heater is fitted onto the upper end of the reboiler, with an oil inlet pipe fixedly connected to its input end and a return oil pipe fixedly connected to its output end. The anti-clogging mechanism includes an insulation pipe, a ring pipe, and a sieve. This technical solution solves the problems in the prior art where high-boiling-point substances adhere to the inner wall of the reboiler and the surface of the guide plates, leading to decreased heat transfer efficiency and increased heating energy consumption to maintain the reboiler temperature; and also causes clogging of the reboiler discharge port and reboiler heat exchange tubes.

The invention relates to a high-yield synthesis method of 1, 1, 2, 3-tetrachloropropene, which comprises the following steps: by taking 1, 3-dichloropropene as a raw material, carrying out four-step reaction of chlorination addition, catalytic removal of HCl, re-chlorination addition and catalytic removal of HCl to obtain a 1, 1, 2, 3-tetrachloropropene product. The technology has the advantages of short process flow, low production cost, low requirements on production equipment, high selectivity, high conversion rate and the like, and industrialization is easy to realize. And the reaction device can obviously improve the chlorination reaction efficiency and the chlorine utilization rate.

This invention belongs to the field of organic synthesis technology and discloses a method for preparing trans-3-chloro-2-propenylhydroxylamine hydrochloride. The method involves adding trans-1,3-dichloropropene to a ketoxime, a base, a phase transfer catalyst, and a first solvent for etherification. After the reaction, the mixture is first extracted with an extractant, and the resulting oil phase is then distilled to obtain the oxime ether. The oxime ether, an aqueous hydrochloric acid solution, and a second solvent are mixed and subjected to vacuum distillation in a distillation column to obtain trans-3-chloro-2-propenylhydroxylamine hydrochloride. This invention avoids the use of an aqueous base in the etherification stage, effectively preventing the hydrolysis of the ketoxime. The purified oxime ether obtained in the etherification step is purified by distillation, significantly reducing side reactions during the subsequent hydrolysis. Adding a solvent during the hydrolysis stage allows for better mixing of the aqueous hydrochloric acid solution and the oxime ether, resulting in more uniform acidification, a more complete reaction, and improved conversion and selectivity.

The invention relates to the technical field of synthesis, and provides a method for efficiently and continuously synthesizing 1-isothiocyanate-2-chloro-2-propylene, which comprises the following steps: S1, reacting 2, 3-dichloropropene and a thiocyanate compound in a first-stage reaction kettle to obtain a reaction solution; s2, upwards discharging a water phase of the reaction liquid out of the first-stage reaction kettle, enabling an oil phase of the reaction liquid and undissolved sodium chloride solid to run downwards until the oil phase separated by an oil-solid separator enters a second-stage reaction kettle, and discharging the sodium chloride solid out of the system; s3, carrying out rearrangement reaction on the oil phase in a secondary reaction kettle to obtain a mixed solution; and S4, cooling the mixed solution, adding water, mixing, standing for layering to form a first oil phase and a first water phase, and carrying out reduced pressure rectification on the first oil phase to obtain the 1-isothiocyanate-2-chloro-2-propylene. According to the technical scheme, the problems of tedious reaction steps and low production efficiency of the 1-isothiocyanate-2-chloro-2-propylene in the prior art are solved.

This invention relates to the preparation and application of a dichloropropenyl phenyl ether (I) containing a trifluoromethylphenylbioxadiazole structure. It is obtained by reacting a trifluoromethylphenylbioxadiazole thiol intermediate (II) with a dichloropropenyloxyphenoxy bromide (III). The dichloropropenyl phenyl ether containing the trifluoromethylphenylbioxadiazole structure exhibits excellent control effects against harmful insects.

The present application relates to the field of organic synthesis technology, and specifically discloses a method for preparing propargyl alcohol. A method for preparing propargyl alcohol, comprising the following steps: 1,3-dichloropropylene and sodium carbonate aqueous solution are mixed and heated to 70-80 DEG C of reflux reaction for 4-6h, first put into dimethyl sulfoxide and mix evenly, then put into sodium hydroxide, react under the conditions of 100-150 DEG C, remove sodium chloride after the reaction ends, obtain propargyl alcohol crude product, distillation, obtain propargyl alcohol. The yield and purity of propargyl alcohol using the preparation method of propargyl alcohol of the present application can reach 73.8% and 99.9% respectively, improve the yield and purity of propargyl alcohol, and the preparation method is simple, production safety is high, sodium hydroxide is directly put into the reactor during the reaction, the time of preliminary reaction stratification is reduced, production steps are saved, heat loss and material loss are reduced when reflux and upper organic phase are taken, and production efficiency is improved.

The utility model discloses a liquid sorting detection control device in dichloroacrylonitrile production. The liquid sorting detection control device comprises a reaction kettle, a main discharge pipe is arranged at a discharge port at the bottom of the reaction kettle, a main valve is arranged on a pipe section of the main discharge pipe, an observation sight glass is arranged at the lower end of the main discharge pipe, and a detection sensor is mounted on the main discharge pipe and on the opposite side of the observation sight glass; the detection sensor comprises a light supplementing light source and a color and brightness detection device, the detection sensor is connected with the control part through a signal line, and the control part comprises a PLC and a touch screen. According to the utility model, dichloro acrylonitrile and liquid impurities can be effectively layered in the reaction kettle, and dichloro acrylonitrile and impurities can be automatically detected.

The present application relates to a method for preparing tetrachloropropane and 1, 2-dichloropropane from a D-D mixture, the method comprising the steps of: a) feeding a first feed into a first reaction device via an inlet of the first reaction device, the first feed comprising a D-D mixture and chlorine gas, the first reaction device being a microchannel reactor, the first reaction device being a reactor having a plurality of microchannels; and the D-D mixture comprises 1, 2-dichloropropane, 1, 3-dichloropropene and 2, 3-dichloropropene, and the component A comprises 1, 2-dichloropropane, 1, 3-dichloropropene and 2, 3-dichloropropene. B) reacting the first feed in the first reaction device to form a first reaction mixture, the first reaction mixture comprising 1, 2-dichloropropane, 1, 1, 2, 3-tetrachloropropane, and 1, 2, 2, 3-tetrachloropropane, and b) reacting the first feed in the first reaction device to form a second reaction mixture comprising 1, 2-dichloropropane, 1, 1, 2, 3-tetrachloropropane and 1, 2, 2, 3-tetrachloropropane. The invention also relates to a method for preparing tetrachloropropene from the DD mixture, a system for implementing the method for preparing tetrachloropropane and 1, 2-dichloropropane from the DD mixture, and a system for implementing the method for preparing tetrachloropropene from the DD mixture.

A device and method for refining 1,2-dichloropropane, a by-product of a 3-chloropropene unit, by combining distillation, polymerization, and adsorption. The present invention discloses a device and method for refining 1,2-dichloropropane, a by-product of a 3-chloropropene unit. The device utilizes a combination of a light removal tower, a polymerization reactor, a heavy removal tower, and an adsorption tower to convert difficult-to-separate dichloropropene impurities into a polydichloropropene polymer through a polymerization reaction. Since the polymer has a large boiling point difference from dichloropropane, it is easy to separate and purify, thereby successfully achieving the refining and purification of 1,2-dichloropropane. The final 1,2-dichloropropane purity is ≥99.9%, and the residual dichloropropene content is <100 ppm. At the same time, the dichloropropene polymerization process conditions are mild, the equipment requirements are low, the process is simple, and it is conducive to expanding production.

The application discloses a refining device and method for 1,2-dichloropropane by-produced in a 3-chloropropylene device. The device combines a light-removing tower, a chlorination reaction kettle, a heavy-removing tower and an adsorption tower, so that dichloropropylene compounds which are difficult to separate from 1,2-dichloropropane react with chlorine to form saturated chloro-compounds heavy components which are easy to separate from 1,2-dichloropropane, thereby purifying 1,2-dichloropropane, and the purity of 1,2-dichloropropane by-produced in the 3-chloropropylene device is greater than or equal to 99.9%, and the residual dichloropropylene is less than 100 ppm, the economic value of the product is improved, the energy-saving and consumption-reducing effect of the extractive distillation technology is achieved, and the device has a wide industrial application prospect.

The invention discloses a preparation method of 3, 3, 3-trifluoro-1-propyne, and the preparation method comprises the following steps: S1, in the presence of a solvent, reacting 3, 3, 3-trifluoro-1, 1-dichloro-1-propylene or 3, 3, 3-trifluoro-1, 1-dibromo-1-propylene with a strong base to prepare a 3, 3, 3-trifluoro-1-propyne strong base salt; s2, enabling the 3, 3, 3-trifluoro-1-propyne strong alkali salt to react with water, so as to prepare the 3, 3, 3-trifluoro-1-propyne. The preparation method of the 3, 3, 3-trifluoro-1-propyne, disclosed by the invention, has the advantages of easily available raw materials, simple process, no need of using a catalyst, recyclable solvent, small amount of three wastes, high product yield and suitability for industrial application.

The present application relates to a kind of preparation method of pentanediamine. Including the following steps: a) 1,3-dichloropropene is prepared by cyanation reaction 4-chloro-3-butenenitrile;B) the product of step a) is prepared by double bond isomerization 4-chloro-2-butenenitrile;C) the product of step b) is prepared by cyanation reaction again 2-vinyl-pentanedinitrile;D) the product of step c) is prepared by hydrogenation reaction pentanediamine. Compared with the traditional lysine as raw material, biological synthesis pentanediamine, the present application is cheap propylene thermal chlorination by-product 1,3-dichloropropene as raw material, by cyanation-isomerization-cyanation-hydrogenation 4 steps important chemical raw material pentanediamine, for pentanediamine preparation provides a new way, and the route condition is mild, process is simple, process cost is low, with environmental protection and economic advantage, suitable for pentanediamine large-scale production.

The invention discloses a herbicide stabilizer and a preparation process thereof. The invention relates to a water-retaining agent, which is prepared from the following raw materials in percentage by mass: 20 to 25 percent of dichloropropene amine, 10 to 15 percent of beta-cyclodextrin-chitosan graft, 12 to 18 percent of sodium lignin sulfonate modified bentonite, 3 to 6 percent of alpha-tocopherol succinate, 4 to 8 percent of nano titanium dioxide coated UV-P, 1 to 3 percent of ethylene diamine tetraacetic acid, 2 to 5 percent of polyaspartic acid, 1 to 4 percent of sodium glycerophosphate and 8 to 11 percent of polyoxyethylene polyoxypropylene ether block copolymer. And the balance of modified white carbon black. The invention relates to the technical field of pesticides. According to the present invention, the dichloropropene amine is subjected to double anchoring, and the ultrasonic microwave synergistic inclusion process is combined to enhance the binding force of the dichloropropene amine and the carrier, such that the oxidation, the photolysis and the metal ion catalytic decomposition path of the dichloropropene amine are inhibited so as to further reduce the dichloropropene amine degradation rate, and the adaptation range of the dichloropropene amine can be improved; the function attenuation rate is also reduced, and the problem of insufficient dosage form compatibility caused by strong hydrophobicity of dichloropropene amine is effectively solved.

The utility model belongs to the technical field of chemical equipment, and discloses a trans-3-chloro-2-allyl hydroxylamine continuous production device which comprises a mixer, a tubular reactor, a receiving tank, an extraction kettle and a distillation kettle which are sequentially communicated through pipelines, valves and pumps, a feeding hole of the mixer is respectively communicated with an acetohydroxamic acid storage tank and a 1, 3-dichloropropene storage tank through a pipeline and a metering pump; the feeding hole of the tubular reactor is also communicated with a liquid caustic soda storage tank through a pipeline and a metering pump; the feed port of the extraction kettle is also communicated with a dichloromethane head tank through a pipeline and a metering pump, and the discharge port of the extraction kettle is respectively communicated with a water receiving tank and a distillation kettle through pipelines and valves; and a steam outlet of the distillation kettle is communicated with a dichloromethane receiving tank through a pipeline and a condenser. The device disclosed by the utility model can realize continuous production, is high in production efficiency and yield and good in product quality, and can meet the requirements of large-scale production.

The present invention discloses a production method of propylene glycol ether. The method uses 3-chloro-1-propanol derived from 1,3-dichloropropene in the DD mixture by-produced from epichlorohydrin as a raw material, and continuously produces propylene glycol ether through gas-phase etherification reaction under the catalysis of a perovskite composite material, providing a new route for the production of propylene glycol ether. Moreover, this route has mild conditions, low cost, and advantages such as environmental protection and economy.

The utility model relates to the technical field of chemical engineering, and provides a novel dichloropropene purifying device which comprises a stepped tank, a feeding hole is formed in the top of the stepped tank, a flow dividing block is arranged on a rotating shaft, a spiral processing sheet is fixedly connected onto the flow dividing block, an output motor is arranged at the bottom of the stepped tank, and the output motor is fixedly screwed and connected with the stepped tank. The output end of the output motor is inserted into the stepped tank and fixedly connected with the rotating shaft. According to the technical scheme, the problem that in the prior art, temperature loss is fast in the dichloropropene purification process is solved, when solid caustic soda sodium hydroxide is put into crude dichloropropene, the solid caustic soda sodium hydroxide can rapidly settle to the bottom of the tank body, at the moment, the crude dichloropropene is stirred, and the temperature of the dichloropropene is reduced. However, coarse dichloropropene at the bottom of the tank body cannot flow quickly in a common stirring mode, so that solid caustic soda sodium hydroxide is difficult to dissolve in the coarse dichloropropene quickly.

The invention provides a method for synthesizing dichloroallylamine, comprising: putting diallylamine, a solvent and pyridine into a reaction bottle, adding dichloroacetyl chloride into a constant pressure dropping funnel, and dropping dichloroacetyl chloride into the reaction bottle under normal pressure to form a reaction system; after the dropping of dichloroacetyl chloride is completed, the reaction system in the reaction bottle is fully reacted; after the reaction is completed, the mixture in the reaction bottle is filtered to obtain a filtrate containing dichloroallylamine and a filtered precipitate, the precipitate is washed with an organic solvent to obtain an organic solution containing dichloroallylamine, the filtrate containing dichloroallylamine and the organic solution containing dichloroallylamine are combined into an organic phase and washed to neutrality, and the organic phase is desolvated to obtain the product dichloroallylamine. The synthesis method uses pyridine as an acid binding agent, which can reduce the occurrence of side reactions, and pyridine can generate a hydrochloride precipitate with the byproduct hydrogen chloride, which is easy to separate from the product dichloroallylamine, so that high-purity and high-yield dichloroallylamine can be obtained.

The invention discloses a refining device and a refining method for a byproduct 1, 2-dichloropropane of a 3-chloropropene device. According to the device, a light component removal tower, a chlorination reaction kettle, a heavy component removal tower and an adsorption tower are combined, so that a dichloropropene compound which is difficult to separate from 1, 2-dichloropropane is reacted with chlorine, and a saturated chlorinated compound heavy component which is easy to separate from the 1, 2-dichloropropane is formed, so that the 1, 2-dichloropropane is purified, and the byproduct 1, 2-dichloropropane of a 3-chloropropene device is obtained. The purity of 1, 2-dichloropropane is greater than or equal to 99.9%, and dichloropropene 1t is remained; and the economic value of the product is improved, the extractive distillation technology has the effects of saving energy and reducing consumption, and the method has a wide industrial application prospect.

The present invention provides a method for treating a trans-dichloropropylene deteriorated product, the method comprising the following steps: (1) mixing the trans-dichloropropylene deteriorated product with a solid inorganic base to react, and obtaining a filtrate after solid-liquid separation; (2) mixing the filtrate with a Tulsimer ARR‑1 anion exchange resin to perform an aldehyde removal reaction to obtain a mixed dichloropropylene crude product; (3) the mixed dichloropropylene crude product is subjected to a molecular sieve to remove water and then subjected to a rectification treatment to obtain high-purity trans-1,3‑dichloropropylene; and a catalyst Fe / ZSM‑5 is added during the rectification treatment. The treatment method of the present invention is simple to operate, does not need to react under conditions such as high temperature or high pressure, realizes the resource treatment of the trans-dichloropropylene deteriorated product, greatly reduces the treatment cost of organic waste liquid, and has good economic and environmental benefits.

This invention provides a method for preparing 1,1,2,3-tetrachloropropene using a microchannel reaction. The method includes the following steps: (1) dichloropropene feedstock undergoes a first chlorination reaction in a microchannel reactor to obtain a first material containing tetrachloropropane; (2) the first material undergoes a first purification to obtain tetrachloropropane, and the tetrachloropropane undergoes a first dehydrochlorination reaction to obtain a second material containing trichloropropene; (3) the second material undergoes a second chlorination reaction in a microchannel reactor to obtain a third material containing pentachloropropane; (4) the third material undergoes a second dehydrochlorination reaction to obtain a fourth material containing tetrachloropropene; (5) the fourth material undergoes a photocatalytic isomerization reaction in a microchannel reactor to obtain 1,1,2,3-tetrachloropropene. The method provided by this invention can shorten the reaction time, significantly improve the reaction yield, and has good economic benefits and industrial application potential.

The invention discloses a synthetic method of dichloropropenylamine. The invention relates to the technical field of dichloroallylamine, which comprises the following steps: step 1, slowly dropwise adding liquid caustic soda with the mass fraction of 30-35% into 86-90g of cyanamide under the condition of normal temperature, controlling the system temperature to be not higher than 30 DEG C in the dropwise adding process, keeping the temperature for 30-40 minutes after dropwise adding, then adding 228-236g of allyl chloride and a composite solvent, reacting for 2-2.5 hours at the stirring speed of 250-300r / min, and after the reaction is finished, cooling to room temperature to obtain a reaction liquid; and distilling to recover the solvent, extracting and distilling under reduced pressure to obtain the diallyl cyanamide. According to the synthetic method of dichloropropenylamine and the preparation stage of diallyl cyanamide, a composite solvent is adopted, so that the solubility of raw materials is improved, the mass transfer efficiency is enhanced, gradient heating solvent recovery is combined, the solvent recovery rate is effectively improved, and meanwhile, the yield of diallyl cyanamide is stabilized at 93-95%; the 5% sodium chloride aqueous solution is added as a layering aid to destroy an emulsion layer, so that the layering time is shortened, and the efficiency is remarkably improved.

The invention relates to the technical field of synthesis of 1-isothiocyanic acid-2-chloro-2-propylene, and provides a preparation method of the 1-isothiocyanic acid-2-chloro-2-propylene. The invention relates to a preparation method of 1-isothiocyanate-2-chloro-2-propylene, which comprises the following steps: S1, blending a thiocyanate aqueous solution and 2, 3-dichloropropene in a primary reactor, and carrying out primary reaction and separation to obtain an oil phase and a salt water phase; s2, carrying out secondary reaction on the oil phase in a secondary reactor to obtain a reaction solution; s3, carrying out refining treatment on the reaction liquid, so as to obtain 1-isothiocyanate-2-chloro-2-propylene; during the primary reaction, the temperature is 80-90 DEG C, and the reaction time is 10-20 minutes; and during the secondary reaction, the temperature is 100-105 DEG C, and the reaction time is 1.5-4 hours. According to the technical scheme, the problems of low yield, low purity and low production efficiency during production of the 1-isothiocyanate-2-chloro-2-propylene in the prior art are solved.

The present application relates to a method for producing 1,1,2,3-tetrachloropropane from a mixture of 1,3-dichloropropene and 3-chloropropene. The method comprises the following steps: a) subjecting a raw material comprising a mixture of 1,3-dichloropropene and 3-chloropropene, and Cl2 to a first chlorine addition reaction at a temperature T1, so as to obtain a first product; b) subjecting the first product to a first chlorine substitution reaction under UV at a temperature T2, so as to obtain a second product; and c) subjecting the second product to a second chlorine addition reaction at a temperature T3, so as to obtain a third product, which comprises 1,1,2,3-tetrachloropropane. A second aspect of the present application relates to a method for producing 1,1,2,3-tetrachloropropene from a mixture of 1,3-dichloropropene and 3-chloropropene. The present application further relates to a 1,1,2,3-tetrachloropropane product and a 1,1,2,3-tetrachloropropene product produced by using the methods described in the first and second aspects.

This disclosure relates to the technical field of waste heat recovery. One embodiment of this disclosure provides a waste heat recovery device for dichloropropylene production, comprising: a base plate, a foundation, and a shell. The foundation is vertically fixed to the base plate, and the shell is disposed on the foundation. A fixing assembly is disposed between the shell and the foundation. Flow chambers are all opened within the side surface of the foundation and are distributed in multiple rows. Heat exchange components are disposed on the foundation and the shell, and the heat exchange components include a main inlet pipe and a main outlet pipe, which are respectively disposed at the top and bottom of the foundation. Both the main inlet pipe and the main outlet pipe are connected to the flow chambers, and several solenoid valves are installed on both the main inlet pipe and the main outlet pipe. This technical solution solves the technical problem of inconvenient disassembly and maintenance of existing heat exchangers in practical applications.