热管空气预热器计算

热管空气预热器计算书,,,,,,,,,,

序号,名称,符号,单位,计算公式及来源,结果,备注,,,,

一,已知条件,,,,,,,,,

1,烟气入口温度,ty1,℃,已知,337,,,,,

2,烟气出口温度,ty2,℃,已知,140,,,,,

3,烟气流量,My,Kg/h,已知,145764,,,,,

4,空气进口温度,tk1,℃,已知,4.4,,,,,

5,空气出口温度,tk2,℃,tk1+Qy*3600/Mk*Ck,269,,,,,

6,空气流量,Mk,Kg/h,已知,114264,,,200,300,238.5

二,热平衡的计算,,,,,,ρk,0.748,0.617,0.697565

1,烟气平均温度,typj,℃,,238.5,,λk,0.0401,0.0484,0.0432955

2,烟气平均定压比热,Cy,KJ/(Kg℃),查表,1.106,,μk,0.0000245,0.0000282,2.59245E-05

3,烟气散热损失系数,Ysr,,选定,0.04,,Prk,0.67,0.65,0.6623

4,烟气放出热量,Qy,KW,(1-Ysr)*My*Cy*(ty1-ty2)/3600,8469,,,,,

5,空气平均温度,tkpj,℃,,136.5,,,100,120,136.5

6,空气平均定压比热,Ck,KJ/(Kg℃),"假定空气平均温度,估算查表",1.01,,ρk,0.946,0.898,0.858415145

7,空气温升,△tK,℃,tK2-tK1,264,,λk,0.0321,0.0334,0.03447209

三,基本选择,,,,,,μk,0.0000219,0.0000228,2.35422E-05

1,工质的选择,,,(ty1+tk2)/2,303,水做工质合适,Prk,0.688,0.686,0.684350631

2,管材选择,,,,,20#钢,,270,280,278

,外径,d0,mm,选定,38,,ρlh,769.9,750.7,754.54

,壁厚,δg,mm,选定,3,,ρvh,28.1,33.19,32.172

,内径,di,mm,d0-2*δg,32,20,rh,1604.8,1543.7,1555.92

,翅片厚度,δcp,mm,选定,1.3,,σh,0.02148,0.01913,0.0196

,翅片间距,b,mm,选定,5,,,,,

,翅片间隙,Y,mm,选定,3.7,,,,,

,翅片高度,H,mm,选定,18,,,,,

,翅片外径,df,mm,d0+2*H,74,,,,,

,每米翅片管的翅片数目,S,,1000/b,200,,,,,

,每米翅片管的翅片面积,Af,m2,Sπ((df2-d02)/4*2+dfδcp),1.3265,,,,,

,每米翅片管的裸管面积,Ab,m2,πd0YS,0.0883,,,,,

,每米翅片管的光管面积,A0,m2,πd0,0.1193,,,,,

,翅化比,β,,,11.9,,,,,

3,结构的选取,,,,,,,,,

3.1,入口质量流速的初步选择,,,,,,,,,

,烟气侧迎风面质量流速,Gy,Kg/(m2.S),选定,3,,,,,

,空气侧迎风面质量流速,Gk,Kg/(m2.S),Gy(Mk/My)1.538,2.06,,,,,

3.2,经济长度比,,,,,,,,,

,烟气段和空气段的经济长度比,Ljj,,(My/Mk)-0.538,0.877,,,,,

,选用的长度比,Lxy,,选定,1.000,,,,,

3.3,进口截面尺寸,,,,,,,,,

,烟气侧迎风面积,Ayy,m2,My/Gy/3600,13.50,,,,,

,空气侧迎风面积,Aky,m2,Mk/Gk/3600,15.39,,,,,

,烟气侧热管长度,Ly,mm,选定,3500,,,,,

,空气侧热管长度,Lk,mm,选定,3000,,,,,

,烟气侧管束的计算宽度,Byjs,mm,Ayy/Ly,3856,,,,,

,空气侧管束的计算宽度,Bkjs,mm,Akk/Lk,5129,,,,,

,管束的宽度富裕系数,fb,,选定,0.10,,,,,

,管束的计算宽度,Bjs,mm,"(1+fb)*MIN(Byjs,Bkjs)",4242,,,,,

,管束的宽度,B,mm,选定,3000,,,,,

,实际烟气侧迎风面质量流速,Gysj,Kg/(m2.S),My/Ly/B,3.86,,,,,

,实际空气侧迎风面质量流速,Gksj,Kg/(m2.S),MK/LK/B,3.53,,,,,

,迎风面横向管间距,S1,mm,选定,90,,,,,

,迎风面每排管根数,np,根,B/S1,33.3,,,,,

,烟气侧每根热管光管外表面积,A0yd,m2,πd0Ly,0.418,,,,,

,烟气侧每排热管光管外表面积,A0yp,m2,np*A0yd,13.921,,,,,

,空气侧每根热管光管外表面积,A0kd,m2,πd0Lk,0.358,,,,,

,空气侧每排热管光管外表面积,A0kp,m2,np*A0kd,11.932,,,,,

,烟气侧最窄流通面积比,xAyz,m2,(S1*Ly-2d0-2Ly/b*δcp)/(S1*Ly),0.572,,,,,

,空气侧最窄流通面积比,xAkz,m2,(S1*Lk-2d0-2Lk/b*δcp)/(S1*Lk),0.572,,,,,

,烟气侧最窄流通面实际质量流速,Gymax,Kg/(m2.S),Gysj/xAyz,6.74,,,,,

,空气侧最窄流通面面实际质量流速,Gkmax,Kg/(m2.S),Gksj/xAkz,6.17,,,,,

4,传热计算,μ,Kg/(m.s),,,,,,,

4.1,烟气侧传热系数计算,,,,,,,,,

,烟气的平均温度,typj,℃,(ty1+ty2)/2,238.5,,,,,

,烟气的密度,ρy,Kg/m3,查表,0.70,,,,,

,烟气的导热系数,λy,W/(m.℃),查表,0.0429,,,,,

,烟气的动力粘度系数,μy,Kg/(m.s),查表,0.000026,,,,,

,烟气的普朗特数,Pry,,查表,0.66,,,,,

,翅径比,X,,df/d0,1.95,,,,,

,烟气侧以翅片管外表面积为基准放热系数,αy',W/(m2.℃),0.1378(λy/d0)(d0Gymax/μy)0.718(Pry)1/3(Y/H)0.296,63.04,"X=1.7-2.4,d0=12-41",,,,

,,,,0.1057(λy/d0)(d0Gymax/μy)0.667(Pry)1/3(Y/H)0.164(Y/δcp)0.075,,"X=1.2-1.7,d0=13.5-16",,,,

,m,,,,46.42,,,,,

,m.H,,,,0.84,,,,,

,烟气侧翅片管翅片效率,ηy,,查图,0.85,,,,,

,烟气侧以光管外表面积为基准放热系数,αy,W/(m2.℃),η*β*αy',635.3,,,,,

,烟气侧以光管外表面热阻,Ry,m2℃/W,1/αy,0.001574,,,,,

4.2,空气侧传热系数计算,,,,,,,,,

,空气的平均温度,tkpj,℃,(tk1+tk2)/2,136.5,,,,,

,空气的密度,ρk,Kg/m3,查表,0.887,,,,,

,空气的导热系数,λk,W/(m.℃),查表,0.0337,,,,,

,空气的动力粘度系数,μk,Kg/(m.s),查表,0.0000230,,,,,

,空气的普朗特数,Prk,,,0.686,,,,,

,空气侧以翅片管外表面积为基准放热系数,αk',W/(m2.℃),0.1378(λk/d0)(d0Gkmax/μk)0.718(Prk)1/3(Y/H)0.296,50.90,"X=1.7-2.4,d0=12-41",,,,

,,,,0.1057(λk/d0)(d0Gkmax/μk)0.667(Prk)1/3(Y/H)0.164(Y/δcp)0.075,,"X=1.2-1.7,d0=13.5-16",,,,

,空气侧翅片管翅片效率,ηk,,查图,0.85,,,,,

,空气侧以光管外表面积为基准放热系数,αk,W/(m2.℃),η*βk*αk',512.9,,,,,

,空气侧以光管外表面热阻,Rk,m2℃/W,1/αk,0.001950,,,,,

4.3,管壁热阻的计算,,,,,,,,,

,钢管的导热系数,λw,W/(m.℃),选定,45.0,,,,,

,钢管的管壁热阻,Rg,m2℃/W,d0/(2λw)*Ln(d0/di),0.000073,,,,,

4.4,烟气侧污垢热阻,Rw,m2℃/W,选定,0.001,,,,,

4.5,热管的传热系数计算,,,,,,,,,

,热管的总热阻,Rz,m2℃/W,Ry+Rk*(Ly/Lk)+Rg*(1+Ly/Lk)+Rw,0.00501,,,,,

,热管的传热系数,K0,W/(m.℃),1/Rz,199.8,,,,,

4.6,传热温差计算,,,,,,,,,

,最大温差,△tmax,℃,ty2-tK1,135.6,,,,,

,最小温差,△tmin,℃,ty1-tk2,68.4,,,,,

,对数平均温差,△T,℃,(△tmax-△tmin)/(ln(△tmax/△tmin)),98.2,,,,,

4.7,传热面积计算,,,,,,,,,

,传热面积,A0,m2,Qy/(K0△T),431.68,,,,,

,所需管子根数,n1,根,A0/(πd0Ly),1033.7,,,,,

,所需管子根数取整,n1',根,INT(n1)+1,1034,,,,,

,富裕系数,fx,,选定,0.1,,,,,

,选取管子根数,n2,根,n1'(1+fx),1086,,,,,

,叉排多管层数,N1,排,选定,19,,,,,

,叉排少管层数,N2,排,选定,18,,,,,

,叉排管总层数,N,排,N1+N2,37,,,,,

,实际选取管子根数,n,根,N1*np+N2(np-1),1215,,,,,

,每根管的平均传热量,Qpdj,KW,Qy/N,6.97,,,,,

四,阻力的计算,,,,,,,,,

1,烟气侧阻力的计算,,,,,,,,,

,烟气侧摩擦系数,fy,,18.93(d0Gymax/μy)-0.316(S1/d0)-0.927(S1/S2)-0.515,0.5001,,,,,

,烟气侧总阻力,△Pyz,Pa,fy*N*Gymax2/ρy,1195.37,,,,,

,烟气侧每排管阻力,△Pyd,Pa,△Pyz/△Pyd,32.31,,,,,

2,空气侧阻力的计算,,,,,,,,,

,空气侧摩擦系数,fk,,18.93(d0Gkmax/μk)-0.316(S1/d0)-0.927(S1/S2)-0.515,0.4963,,,,,

,空气侧总阻力,△Pkz,Pa,fk*N*Gkmax2/ρk,786.54,,,,,

,空气侧每排管阻力,△Pkd,Pa,△Pkz/△Pkd,21.26,,,,,

五,烟气侧最低管壁温度计算,,,,,,,,,

,烟气侧最低管壁温度,tw,℃,ty2-Qpdj/(A0yd*αy),113.7,,,,,

六,热管最大传热能力的计算,,,,,,,,,

6.1,热管最高工作温度,Tvmax,℃,,303,,,,,

,最高工作温度水的密度,ρlh,Kg/m3,查表,754.5,,,,,

,最高工作温度水蒸汽的密度,ρvh,Kg/m3,查表,32.172,,,,,

,最高工作温度水蒸汽的汽化潜热,rh,KJ/Kg,查表,1555.9,,,,,

,最高工作温度水的表面张力,σh,N/m,查表,0.01960,,,,,

,最高工作温度邦德数,B0h,,di(g(ρlh-ρvh)/σh)0.5,19.232,,,,,

,最高工作温度Ck值,Ckh,,3.20.5tanh(0.5B0h0.25),1.396,,,,,

,最高工作温度携带极限功率,Qenth,KW,Ckh2rh(π/4di2)(ρlh-0.25-ρvh-0.25)-2*(gσh(ρlh-ρvh))0.25,22.447,,,,,

6.2,热管最低工作温度,Tvmin,℃,,72.20,,,,,

,最低工作温度水的密度,ρll,Kg/m3,查表,971.8,,,,,

,最低工作温度水蒸汽的密度,ρvl,Kg/m3,查表,0.293,,,,,

,最低工作温度水蒸汽的汽化潜热,rl,KJ/Kg,查表,2309.0,,,,,

,最低工作温度水的表面张力,σl,N/m,查表,0.06259,,,,,

,最低工作温度邦德数,B0l,,di(g(ρll-ρvl)/σl)0.5,12.481,,,,,

,最低工作温度Ck值,Ckl,,3.20.5tanh(0.5B0l0.25),1.315,,,,,

,最低工作温度携带极限功率,Qentl,KW,Ckl2rl(π/4di2)(ρll-0.25-ρvl