Self-generated Heat To Enhance The Heating Of Liquid Carbon Dioxide

The newly proposed 14 th Five-Year Plan proposes that carbon emissions will stabilize and decline after reaching the peak,and will peak in 2030,which means that carbon dioxide needs to be used more rationally.Carbon dioxide phase change blasting technology is a good application direction,which mainly uses the energy of liquid carbon dioxide phase change to complete a series of engineering operations,and this technology is also listed in the development plan of the blasting industry.In this paper,a new heating medium is proposed,which adopts the reaction of salt solution to provide the heat of the phase transition of liquid carbon dioxide.The main research contents are as follows:(1)The effects of reaction temperature,reactant concentration,catalyst concentration,catalyst type,and stirring rate on the pressure increase rate and temperature distribution were investigated,and the results showed that reaction temperature,reactant concentration,and catalyst concentration had positive effects on the reaction rate;Strong acid is not suitable for catalyzing this reaction.The catalytic effect of oxalic acid in weak acid is better than that of phosphoric acid;the presence of stirring can better break the equilibrium relationship between the undissolved reactants and the liquid phase,promote the dissolution of substances,make the reaction more complete,and increase the The stirring rate can also increase the reaction rate while making the temperature distribution more uniform.(2)The possibility of the autogenous reaction causing the phase transition of liquid carbon dioxide by heating was investigated.The results show that when the reactant is0.9 mol,the initial reaction temperature is 25 °C,the pressure of the system after the reaction exceeds 65 MPa,and the temperature in the system exceeds phase transformation temperature points.Under the theoretical conditions,thermodynamic calculations were carried out to obtain the pressure in the ideal state,and the TNT blasting equivalent was calculated.(3)The corrosiveness of the reaction solution and the catalyst solution to different steels was investigated,characterized by metallographic microscope,AFM microscope,and scanning electron microscope,and the corrosion rate was calculated.Non-corrosive,ammonium chloride is corrosive to a certain extent,and oxalic acid is the most corrosive.Long-term corrosion results show that 301 stainless steel has good corrosion resistance,and the corrosion of ordinary steel is more serious,which provides suggestions for the storage of reactive substances and the selection and manufacture of equipment.