Study of the efficiency of plate-type and tubular-type heat exchangers with intensifiers taking into account the flow patterns

Experiments are conducted on liquid (water) heating by hot vapor in a plate-type heat exchanger. The coolant agent temperature and flow rates are measured; the heat balance and heat transfer equations are applied for calculating the heat flux and the heat transfer coefficient as a function of flow rate for heated water. The mathematical models are developed for the thermal number of transfer units and for liquid displacement in a smooth duct. A cell model for coolant flow patterns using the surface-type heat transfer enhancers (wire inserts) and volumetric enhancers (chaotic packing) is developed. The calcuations and experimental data are in satisfactory agreement with each other. Experimental and modeling methods demonstrated that the use of surface-type enhancers in a problem of high-viscosity liquid heating (e.g., industrial oil) increases the heat transfer coefficient by 2.75 – 6 times and the gain in thermal efficiency is about 2.4 – 3.2 times. The gains from using the volumetric-type enhancers are 15 – 20 times and 2 – 3 times, respectively, for heating with hot water. The developed mathematical model with accounting for flow patterns can be applied in design or modernization of heat transfer apparatuses in various industries.