连续螺旋折流板换热器壳程流动与传热数值模拟

建立了连续螺旋折流板换热器三维模型并划分网格,采用分离式求解器、SIMPLE压力速度耦合方式与Realizable k-ε湍流模型,利用FLUENT软件对连续螺旋折流板换热器壳程流体流动与传热进行了模拟计算,得到壳程流体速度、压力与温度分布图,并与传统弓形折流板换热器作比较。螺旋折流板节距与弓形折流板间距相等时,螺旋折流板换热器壳程传热系数增加了25%左右,而压力降减小了18%左右。通过对不同螺旋角度的螺旋折流板换热器进行模拟分析,发现随螺旋角增大壳程传热系数和压力降都呈减小趋势,且壳程流体进口平均速度越大,作用越明显,故在实际工程中,盲目追求高的传热系数或低的压降都是不可取的。本数值模拟可为螺旋折流板换热器进一步的工程研究提供可靠的理论参考依据。

Numerical Simulation of the Flow and Heat Transfer in Shell Side of Continuous Helical Baffled Heat Exchangers

The three-dimensional model of spiral baffled heat interchanger was built and meshed.The fluid flow dynamics and heat transfer of shell side in the helical baffled heat exchanger was simulated and calculated,using CFD software FLUENT with segregated solver,SIMPLE pressure-velocity coupling and realizable k-ε viscous model.The velocity,pressure and temperature distributions achieved were compared with conventional segmental baffled heat exchanger.With the same baffle distance,the shell side heat transfer coefficient of helical baffled exchanger was about 25 % higher,while the pressure drop was 18 % lower,than those of segmental baffled heat exchanger.With the analyzing of the flow and heat transfer in heat exchanger with different helical angle baffles,it can be found that both shell side heat transfer coefficient and pressure drop will decrease while the helical angle increases.Numerical simulation provided reliable theoretical reference for further engineering research of heat exchanger with helical baffles.