Study of the Temperature Distribution Model and Designing Method for Efficient Shell-and-Tube Heat Exchangers
|School||East China University of Science and Technology|
|Course||Chemical Process Equipment|
|Keywords||Shell and tube heat exchanger No phase transition Condensation Temperature Distribution Model Effective average temperature difference|
The heat exchanger, the temperature of the fluid in the process industry longitudinally along the heat exchanger changes, its physical properties often varies with temperature . Condensation process , the temperature of the fluid , the composition of the gas and liquid phase and vapor phase fraction will change greatly , the possible formation of imports to exports between several different flow -type state . Design and check the heat exchanger , it is critical to accurately predict the heat exchanger flow and temperature fields and static simulation . This paper studies the multi- tube process , different flow pattern layout case heat exchanger no phase transition and the temperature of the condensation heat transfer distribution . No phase transition temperature distribution model is based on the differential method, Nb and tube number n according to the number of baffles , the heat exchanger is divided into a (Nb 1) unit , the ( Nb 1 ) n sub-unit , the tube side fluid cis The views flowing through the sub-unit is parallel to the shell-side fluid flow through the large unit . Condensing temperature distribution model is assumed condensed curve diagrammatically derivation of the temperature distribution of the coolant-side , by the proportional relationship of the temperature and heat load . Based on the above temperature model , by calculating the local temperature of the heat exchanger and the overall effective average temperature difference , explore calculate the amount of surplus heat exchanger design . Further , on the basis of the design method , were used in this model and Cell model to calculate floating head and the U-tube type heat exchanger temperature distribution , no phase change heat transfer temperature distribution calculation model verified by comparison with the calculation result of HTRI accuracy. Condensation model used , the temperature distribution of the condenser will HTRI calculation results compared to verify the feasibility of the model is described by calculating a condenser .