Research On Scale Inhibition And Corrosion Inhibition Performance Of Heavy-duty Engine Cooling Systems

The engine cooling system is an important part of heavy-duty vehicles and the key to safe driving of vehicles.Usually,the medium of heavy-duty vehicle cooling system uses antifreeze.However,some car users choose not to obtain or to use the antifreeze in the cooling system.The source of more convenient and cheap tap water is used as a medium instead of antifreeze to achieve the purpose of cooling the engine.In summer,this phenomenon is more common,and some kinds of antifreeze in the process of preparation,soft water instead of pure water as the base liquid.,which causes scaling and corrosion on the inner wall of the cooling system tank and its components.In order to solve the problem of scaling and corrosion of the engine cooling system,this study used as a monomer,such as sodium acrylate,sodium methacrylate,hydroxyethyl methacrylate and 2-acrylamide-2-methylpropanesulfonic acid.The optimal synthesis conditions were obtained by aqueous solution free radical polymerization using orthogonal test method: n(MAH): n(HEMA):n(AMPS): n(ALS)is 10:6.25:3.5:2.5,the water bath temperature is 80 °C,the reaction time is 5.5h,the initiator ammonium persulfate and the molecular regulator t-butanol content each account for the overall mass of the monomer.10%,under this condition,a tetrapolymer-PMAAH having a fouling ratio of 96.95% and a conversion rate of92.1% was synthesized.From the gel chromatogram,it is known that PMAAH is a transition zone molecular weight polymer,and under the optimal synthesis conditions,the tetrapolymer has a dispersion index of approximately 1,which is a polymer having a narrow molecular weight distribution.It can be seen from the infrared spectrum that PMAAH contains various functional groups such as carboxylic acid group,hydroxyl group,ester group and sulfonic acid group.In the image analysis by scanning electron microscopy,it indicates that the scale inhibitor can change the crystal form of calcium carbonate and calcium sulfate.When the copolymer scale inhibitor is added,the morphology of the inorganic salt crystal is regular;after adding the copolymer scale inhibitor,the growth rate and morphology of the crystal are changed,and a large number of crystallites are not formed and appear in a powder form,effectivelypreventing the scale.Aggregate deposition.Through the static scale inhibition test,in the performance measurement of calcium carbonate,calcium sulfate and calcium phosphate,it can be seen that PMAAH has better calcium barrier properties than the traditional scale inhibitor,and the water bath temperature is 80 ° C,the Ca 2+ concentration is 300 mg / L,When the constant temperature time is 10 h and the dosage is 4.0mg/L,the scale rate of PMAAH to calcium carbonate can reach about 96%,and the scale inhibition rate is also high for calcium sulfate and calcium phosphate.At the same time,in the compounding study with antifreeze,it was found that the optimal ratio of PMAAH to antifreeze was3:1.Under this condition,the onion of the inion was up to 96%,and the temperature in the water bath was 90 °C.The running time is 72 h,the rotation speed is 75r/min,and the dosage is measured.It has a high corrosion inhibition rate.It is known from the experimental results that PMAAH and antifreeze can produce a good compounding effect,which can further optimize the antifreeze solution.Scale inhibition and corrosion inhibition performance.In the biodegradability test of the copolymer,the results showed that the biodegradation rate of the copolymer reached 75% on the 30 th day,indicating that the synthesized PMAAH has excellent biodegradability,and in the test of dispersing iron oxide,the experimental results It shows that when the amount of PMAAH is 6mg/L,the light transmittance can reach 44%,so PMAAH has good performance of dispersing iron oxide.Through the analysis of experimental application,the fouling rate,corrosion rate and cost performance of the pipe are discussed.The compounding agent can maximize the service time of the engine system and the economic benefit is remarkable.This paper has a total of 29 pictures,9 charts and 109 references.