Thermal Decomposition Mechanism Of R410A,HFO-1234yf/R32,HFO-1336mzz(Z)/R32

Organic Rankine Cycle(ORC)is an important way of waste heat utilization technology.In the actual circulation process,over-temperature phenomenon may occur,causing decomposition of organic working fluid.Therefore,research on thermal decomposition of organic working fluid is very important.In this paper,ReaxFF reaction molecular dynamics(RMD)and density functional(DFT)methods are used to study the pyrolysis reaction mechanism of R410 A,HFO-1234 yf / R32,and HFO-1336mzz(Z)/ R32.The main research contents are as follows:(1)Pure working fluids R125,R32,HFO-1234 yf and HFO1336mzz(Z)pyrolysis initial reaction are reported.Temperature has a great influence on the pyrolysis process and reaction products.(2)The effects of different number of R32 on the pyrolysis of R125,HFO-1234 yf,HFO-1336mzz(Z)are studied in three binary mixtures,R32 / R125,R32 / HFO-1234 yf,R32 / HFO-1336mzz(Z).It is found that under different conditions,there are inhibition and promotion effects,and the influence methods are different.After observing each pyrolysis process,the reaction pathway was analyzed by using the method of quantum chemistry.Comparing the pure working fluid with the corresponding mixed working fluid system,the main influencing factors are obtained.(3)HF is the main pyrolysis product of all systems.Temperature has a great influence on the generation of HF,and the rate of HF generation increases with increasing temperature.Comparing the production of HF in pure working fluid and the corresponding mixed working fluid,the main factors affecting the generation of HF were analyzed.(4)Through kinetic analysis,use Arrhenius equation to make a graph of the relationship between the fitted rate constant and the reverse temperature.Analyze the curves in pure working fluid and the corresponding mixed working fluid,and calculate the activation energy and pre-finger factor.