机构地区:[1]Tianjin University,Tianjin
出 处:《Chinese Journal of Chemical Engineering》1990年第2期160-173,共14页中国化学工程学报(英文版)
摘 要:Two heat transfer parameters in the fixed bed,radial effective conductiviw k<sub>er</sub>,and wall heat transfer coefficient h<sub>w</sub>are estimated by using the method of orthogonal collocation and non-linear least square.The temperatures at forty collo-cation points distributed along the radial direction are measured simultaneously by means of multiehannel data logger.Theeffects of bed height,Re<sub>p</sub>,d<sub>t</sub>/d<sub>p</sub>,gas inlet temperature and wall temperature on k<sub>er</sub>and h<sub>w</sub> are studied.The results indicatethat the effect of gas inlet temperature and wall temperature is negligible.Bed height will only influence the parameter es-timations in shallow bed and at low Re<sub>p</sub>.Both k<sub>er</sub>and h<sub>w</sub> tend to reach a limit with increasing bed height.The asymptoticbed height which is independent of d<sub>p</sub> is about 0.5 m,while the asymptotic values of k<sub>er</sub>and h<sub>w</sub> increase with d<sub>p</sub>.The pa-rameters obtained with the wall being heated are about 10% lower than those with the wall being cooled.k<sub>er</sub>,h<sub>w</sub> and stag-nant contribution terms k<sub>er</sub>and h<sub>w</sub> are all related to dp·k<sub>er</sub>and h<sub>w</sub> estimated at the asymptotic bed height are correlated bythe following equations:k<sub>er</sub>=0.199+0.015 d<sub>t</sub>/d<sub>p</sub>+0.0020/(1+14.15(d<sub>p</sub>/d<sub>t</sub>)<sup>2</sup>)Re<sub>p</sub>h<sub>w</sub>=33.4+4.23d<sub>t</sub>/d<sub>p</sub>+0.333/(1+8.54(d<sub>p</sub>/d<sub>t</sub>)<sup>2</sup>)Re<sub>p</sub>(5.5【d<sub>t</sub>/d<sub>p</sub>【13)(100【Re<sub>p</sub>【500)Two heat transfer parameters in the fixed bed,radial effective conductiviw k_(er),and wall heat transfer coefficient h_w are estimated by using the method of orthogonal collocation and non-linear least square.The temperatures at forty collo- cation points distributed along the radial direction are measured simultaneously by means of multiehannel data logger.The effects of bed height,Re_p,d_t/d_p,gas inlet temperature and wall temperature on k_(er)and h_w are studied.The results indicate that the effect of gas inlet temperature and wall temperature is negligible.Bed height will only influence the parameter es- timations in shallow bed and at low Re_p.Both k_(er)and h_w tend to reach a limit with increasing bed height.The asymptotic bed height which is independent of d_p is about 0.5 m,while the asymptotic values of k_(er)and h_w increase with d_p.The pa- rameters obtained with the wall being heated are about 10% lower than those with the wall being cooled.k_(er),h_w and stag- nant contribution terms k_(er)and h_w are all related to dp·k_(er)and h_w estimated at the asymptotic bed height are correlated by the following equations: k_(er)=0.199+0.015 d_t/d_p+0.0020/(1+14.15(d_p/d_t)~2)Re_p h_w=33.4+4.23d_t/d_p+0.333/(1+8.54(d_p/d_t)~2)Re_p (5.5<d_t/d_p<13)(100<Re_p<500)
关 键 词:INLET negligible ASYMPTOTIC COLLOCATION logger radial SHALLOW cooled OUTLET HEATED
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...