Numerical Study Of Natural Gas Water Bath Heater

The water bath heater is a kind of equipment which is usually used for heating the crude oil and natural gas,it comprises a boiler barrel,heat exchanger pipes,furnace and smoke pipes etc.there are about 20000 water bath heaters in service.So the research of flow and heat transfer in water bath heater makes sense for heat transfer enhancement.In this paper,the physical model of the heat exchanger pipe was established.The convective heat transfer coefficient of the inner and outer wall surfaces of the heat exchanger pipe is calculated.The structure parameter of heat exchanger pipe was obtained.A physical model of furnace and smoke tube was established and combustion which in different diameter of furnace was numerically simulated.Through the analysis,actual cylinder diameter was obtained,and the distribution law of the temperature,velocity and component concentration in the tube was obtained.The results showed that: temperature of the gas which is at tail of the pipe is high,Numerical model of the smoke tube inserted into sixteen types different twisted tapes were established based on the physical model of smoke tube.The flow and thermal characteristics including averaged Nusselt,friction factor and thermal performace ratio were investigated numerically.The results show that the average Nu number is increased by 30%~50%,the friction factor f is increased by 107%~197% and the comprehensive heat transfer performance is better than before.Compared with the traditional arrangement form,the heat absorption of the coil increased by 49.4%.the way coils are evenly arranged around the furnace and the smoke tube is in favour of the heat transfer between intermediate medium fluid and the coil,compared with the traditional arrangement,The heat absorption of the coil in this kind of arrangement increased by 24.87%;the ribbed furnace and smoke tube arranged in the same way have the best heat transfer performance,and the heat absorption of the coil is increased by 86.6%.