Experimental Investigation And Numerical Simulation Of Shell Side Heat Exchanger Of Gas Phase Rotary Shell And Tube Heat Exchanger

When we dry the grain in North of China,the heat exchangers used in conjunction with the grain dryer have low heat exchange efficiency,small heat transfer and uneven distribution of flue gas in low temperature environment,which seriously restricts the following grain drying production efficiency.Rotating shell-and-ltube heat exchanger is a new type of energy saving and environment-friendly heat exchanger,which can solve the problem of uneven distribution of flue gas in the process of heat exchange.Taking the rotating shell-and-tube heat exchanger as the research object,cold and hot air as the medium,studied the heat transfer performance of the shell side of the heat exchanger by test and numerical analysis.Firstly,the rotate shell-and-tube heat exchanger as the test object,set up a test bed,have some tests on rotating shell-and-tube heat exchanger.Have a study on the heat transfer performance of the shell with the method of multifactor univariate single argument.The results show that the Reynolds number have a significant influence on the Nusselt number and ?P of the shell of heat exchanger;the rotating speed of heat exchanger have a significant influence on the Nusselt number,but don't have a significant influence on ?P.According to the experimental data,the shell path Nu equation is established,the best heat transfer condition of heat exchanger is determined when rotating speed is 25r/min,fitting the Nu Association at this speed.Secondly,set up the rotating tube shell heat exchanger numerical model,the results shows that shell side ?P experiment values of relative error between experimental and simulation results is1.4% ~ 8.9%,and the relative error of Nu is 1.15% ~ 3.06%.The reliability of the numerical calculation and the result is verified.With the method of numerical simulation,simulating on speed of 25r/min and static state condition,analyzed on flow field,temperature field and pressure field on the shell side heat transfer performance of the two.The results showed that 25r/min rotating tube shell heat exchangers producing turbulent flow under the action of rotating shell,have full contact with heat exchanger tube in the direction of the flow of the fluid,the turbulent degree of the boundary of the shell side is enhanced;compared with static state,the heat exchanger Delta region has improved,solving the problem of leakage current which caused by triangular area generated by a spiral blade under the static state.Finally,on the situation of the shell temperature is 100?,flow rate at 2 ~ 10m/s,have a comparison about the Nu and ?P between 25r/min and static state condition,and the comprehensive performance PEC is introduced to evaluate the performance.The results showed that the 25r/min heat exchanger Nu was increased by 10% compared with static state,and ?P has no significant changes;the comprehensive performance of the shell side is between 1.031 and1.267,which are over 1.It is shown that the shell side heat transfer performance of the gas phase rotary shell and tube heat exchanger at 25r/min is better than that the heat exchanger at rest.