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熔盐功率计算熔盐融化功率(Q2)融化潜热(kj/kg)质量流量(kg/h)融化时间(h)3.392857143180190028熔盐功率(Q1)熔盐比热容(kj/kg·℃)质量流量(kg/h)温差(℃)12.063492061.61900400熔盐总功率(Q1+Q2)17.86904762例:容积1m3,密度1900kg/m3,加热温度0~550,升温速度15℃/h,最终达到550℃计算可得融化时间h=550/15≈36分配36h,融化8h,液化28h(见右侧表格)温度550℃,融化150℃,液化400℃(见右侧表格)蒸汽功率计算(焓值单位:kj/kg)饱和状态的焓值过热状态的焓值蒸汽流量(kg/h)蒸汽功率267638141200455.2例:流量1.2t蒸汽,0.1Mpa压力,进口100℃,出口650℃查询0.5MPa下20℃时的焓值h'(84.33kj/kg),查询0.5MPa下的焓值h"(2748kj/kg)熔盐炉初热时间表熔盐体积(m3)<11~55~10>10液化时间(h)初热时间(h)8~1212~2424~3030~4028融化潜热(kj/kg)范围:80~180kj/kg熔盐密度:1900~2000kg/m3熔盐比热容(kj/kg·℃):1.6~1.8kj/kg·℃例:容积1m3,密度1900kg/m3,加热温度0~550,升温速度15℃/h,最终达到550℃固态(℃)0~1500~8融化温度视具体情况而定蒸发一吨的水需720KWh'为水状态h"为汽状态以常压下为例,查询0.1MPa下20℃时的焓值h'(83.96kj/kg),查询0.1MPa下的焓值h"(2675kj/kg)(2675-83.96)*1000/3600≈720KW例:流量1.2t蒸汽,0.1Mpa压力,进口100℃,出口650℃查询0.5MPa下20℃时的焓值h'(84.33kj/kg),查询0.5MPa下的焓值h"(2748kj/kg)融化(℃)液态(℃)150150~5508h28hh'为水状态h"为汽状态以常压下为例,查询0.1MPa下20℃时的焓值h'(83.96kj/kg),查询0.1MPa下的焓值h"(2675kj/kg)查询0.5MPa下20℃时的焓值h'(84.33kj/kg),查询0.5MPa下的焓值h"(2748kj/kg)计算电热管支数Q/B=表面功率*πd*L(B:电热管个数d:电热管直径L:电热管长度)加热器功率(W)表面功率(W/cm2)π电热管直径(cm)120001.73.141.2计算电热管长度Q/B=表面功率*πd*L(B:电热管个数d:电热管直径L:电热管长度)加热器功率(W)表面功率(W/cm2)πU型电热管Φ(cm)2000001.53.141.21000002.33.141.21000002.33.141.6加热器功率(W)表面功率(W/cm2)π直型电热管Φ(cm)4001.53.141.64002.663.1424002.663.143计算进出口管径A=Q/V(Q体积流量:m3/hV流速:m/s)流速选取:气体流速:10—30m/s液体:<2m/s进出口管径mm体积流量m3/s流速m/s385.51259061.16666666710计算电热管功率Q/B=表面功率*πd*L(B:电热管个数d:电热管直径L:电热管长度)加热器功率(W)表面功率(W/cm2)π电热管直径(cm)61041.62.53.141.2电加热器功率(KW)Q=(C*M*△T)*1.2C:介质比热(kcal/kg℃)1kCal/s=4186J/s=4186W=4.186kW最终功率*1.2系数介质比热质量流量温差2.53169280.240.021100介质比热(kcal/kg℃=4.186*KJ(kg.K))风道加热器:1、电热管根数与管道电热器选取方式一样(根数整除以6)2、接线仓地板厚度:12-15mm3、法兰厚度15-20mm4、电热管重量12的管子0.6kg/m5、风道加热器最高温度做到300度水扬程10米:0.1MPa根据折流板间距计算流速,流量越大的情况下,流速放小(一般指液体流速)流动性差的相对大一些例:体积流量100-300m3/h,流速放小,最好在1.5m/s以内压缩空气功率计算例:1m3/min6MPa压力下温升20-120℃第一个60为时间,第二个60为6MPa压力(0.1MPa的60倍)若是标况下1Nm3/min流量,则不需要乘以60若是标况下1Nm3/min流量,则需要除以60,60为6MPa压力(0.1MPa的60倍)导热油炉:设计压力等于工作压力加0.3设计温度等于工作温度加30度房间供暖:一个平方100瓦1吨的水(锅炉)蒸发需要720KW电热管分组(确定接线仓接线口数量):先分几组,余数需整除3例:72支电热管分6组余数除以372/6=99/3=3380V△型接法220VY型接法低温空气(0~100℃)表面负荷:2~3w/cm2高温空气(400℃以上)表面负荷:2.5w/cm2以内导热油表面负荷:2.3~3w/cm2以内重油表面负荷:1~1.5w/cm2以内静止导热油表面负荷:2w/cm2以内熔盐表面负荷:2.3~3w/cm2以内注:导热油最高温度380℃,380℃以上需用熔盐0.1Mpa下的气体体积流量计算功率需乘以20.1Mpa压力下气体与标况下气体体积相差2倍在容器状态下循环加热水,容器内为饱和水蒸汽状态,如果是静止状态,随着时间推移,会由饱和水蒸汽变成过热蒸汽水进容器前的状态为未饱和水相关技术参数需查询未饱和水及饱和水与饱和水蒸汽热力性质表水加热不能直接变成过热蒸汽,高温高压下水可以加热变成饱和蒸汽,若要变成过热蒸汽,需要另备加热器进行二次加热电热管长度(cm)电热管支数B排管数(中心)管总数8011.708505068.5205633660电热管长度(cm)电热管支数B配电电源(A=Q*1.52)Q单位KW294.880868160电源A152240.392012124功率Q100144.235207230电热管长度(cm)电热管支数B53.07855626123.94521335115.963475571流速选取:气体流速:10—30m/s液体:<2m/sQ体积流量(m3/h)=质量流量(kg/h)/密度(kg/m3)体积流量m3/s质量流量(kg/h)密度(kg/m3)1.16666666754181.29电热管长度(cm)电热管支数B12027C:介质比热(kcal/kg℃)1kCal/s=4186J/s=4186W=4.186kWM:质量流量(kg/s)△T:温差1KW=1KJ/sg/cm3kg/m30.001291.29g/skg/h110396l/minm3/h55033barMpa10.1根据折流板间距计算流速,流量越大的情况下,流速放小(一般指液体流速)例:体积流量100-300m3/h,流速放小,最好在1.5m/s以内单位换算在容器状态下循环加热水,容器内为饱和水蒸汽状态,如果是静止状态,随着时间推移,会由饱和水蒸汽变成过热蒸汽水加热不能直接变成过热蒸汽,高温高压下水可以加热变成饱和蒸汽,若要变成过热蒸汽,需要另备加热器进行二次加热Q体积流量(m3/h)=质量流量(kg/h)/密度(kg/m3)电热丝电阻(R=U2/P)电阻R(Ω)电压U2单相功率P(W)1.9364840025000电压U:220电热丝长度(L=R/A)Φ5.5阻值0.0518Φ76孔24个电热丝长度L(m)电阻R(Ω)每米电阻值(查表Ω/m)管径瓷盘孔数电热丝外径mm1.3884107861.9360.0581245电热丝表面功率(按电热管算法)表面功率w/cm2单相功率P(W)电热丝长度cm电热丝外径mmπ4.7787150625000138.841078653.14例1:300KW电加热器6支Φ76电热管分两组(每组三支,每组三相,分相为3的倍数)单相150KW单支50KW例2:850KW12支Φ76电热管24孔,分4组,1组3相,1相1支单支功率:70.8KW单支电热管内部并联,12孔一组,如下图所示:(并联电路,电压不变)单组电热管功率:70.8/2=35.4KW电热丝材质电热丝总长(m)Cr20Ni8033.32185886管径瓷盘孔数24例1:300KW电加热器6支Φ76电热管分两组(每组三支,每组三相,分相为3的倍数)单相150KW单支50KW电热丝外径电热丝材质0.05815Cr20Ni80公称直径Cr20Ni80Cr30Ni70Cr15Ni60Cr20Ni301Cr13Al40Cr20Al30.023471375735663312398039170.031542166915841741176817400.04867.4939891.3827.6994.7978.80.05555.1601570.4529.7636.6636.40.06385.5417.3396.1367.8442.14350.07283.2306.6291270.2324.8319.60.08216.8234.8222.8206.9248.7244.70.09171.3185.5176.1163.5196.5193.30.1138.8150.2142.6132.4159.2156.60.11114.7124.2117.9109.4131.5129.40.1296.38104.399.0391.96110.5108.80.1382.1288.984.3878.3594.1792.670.1470.8176.6572.7667.5681.279.90.1561.6866.7763.3858.8570.7469.60.1654.2158.6955.751.7362.1761.180.1748.0251.9949.3445.8255.0754.190.1842.8346.3744.0140.8749.1248.340.1938.4441.6239.536.6844.0943.380.234.737.5635.6533.139.7939.150.2228.6731.0429.4627.3632.8832.360.2522.2124.0422.8221.1925.4625.060.2817.719.1618.1916.8920.319.980.315.4216.6915.8414.7117.6817.40.3213.5514.6713.9312.9315.5415.290.3511.3312.2611.6410.8112.9912.780.389.61110.49.8769.1711.0210.850.48.6749.398.9138.2769.9479.7880.427.8688.5178.0847.59.0028.8780.456.5837.4197.0426.5397.867.7340.486.0246.5216.1895.7476.9086.7970.55.5516.015.7045.2976.3666.3640.554.7565.0514.844.3785.2615.1770.63.9974.2444.0673.6784.4214.350.653.4053.6163.4663.1343.7673.7070.72.9363.1182.9882.7033.2483.1960.752.5582.7162.6032.3552.8292.7840.82.2482.3872.2882.0692.4872.4470.851.9912.1152.0271.8332.2032.1680.91.7761.8861.8081.6351.9651.9330.951.5941.6931.6221.4671.7631.73511.4391.5281.4641.3241.5921.5661.50.63940.67910.65080.58850.70740.696120.35970.3820.36610.3310.3979
本文标题:电加热器设计
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