七氟丙烷壓力計(jì)算

1)計(jì)算管道平均設(shè)計(jì)流量主干管：式中——主干管平均設(shè)計(jì)流量(kg/s)；——滅火劑設(shè)計(jì)噴放時(shí)間(s)。支管1：=/2=14.24(kg/s)支管2：=/2=7.12(kg/s)儲(chǔ)存容器出流管：2)計(jì)算充裝率系統(tǒng)儲(chǔ)存量：管網(wǎng)剩余量：=0儲(chǔ)存容器剩余量：=×2=7×2=14(kg)充裝率：3)計(jì)算管網(wǎng)管道容積先按管道徑求出單位長(zhǎng)度的容積，然后依據(jù)管網(wǎng)計(jì)算圖上管段長(zhǎng)度求算：=18×3.42+2.8×1.96+13.6×1.25=0.0841(m3)12)選用額定增壓壓力依據(jù)本《規(guī)》中規(guī)定，選用=4.3Mpa(絕對(duì)壓力)。4)計(jì)算全部?jī)?chǔ)存容器氣相總?cè)莘e依據(jù)本《規(guī)》公式=7×0.07(1-642.9/1407)=0.266(m3)14)計(jì)算“過(guò)程中點(diǎn)”儲(chǔ)存容器壓力依據(jù)本《規(guī)》公式=(4.3×0.266)/[0.266+284.75/(2×1407)+0.0841]=2.535(MPa，絕對(duì)壓力)式中——過(guò)程中點(diǎn)時(shí)儲(chǔ)存容器壓力(MPa，絕對(duì)壓力)；——滅火劑儲(chǔ)存容器增壓壓力(MPa，絕對(duì)壓力)；——噴放前，全部?jī)?chǔ)存容器的氣相總?cè)莘e(m3)；——七氟丙烷液體密度(kg/m3)，20℃時(shí)為1407kg/m3；——管網(wǎng)管道的容積(m3)；——儲(chǔ)存容器的數(shù)量(個(gè))；——儲(chǔ)存容器的容量(m3)；——充裝量(kg/m3)。5)計(jì)算管路損失(1)a-b段以=4.07kg/s及Dn=40mm，計(jì)算得：(ΔP/L)ab=0.0020MPa/m計(jì)算長(zhǎng)度Lab=7.6(m)ΔPab=(ΔP/L)ab×Lab=0.0020×7.6=0.0152(MPa)(2)b-b’段以0.55=15.66kg/s及DN=65mm，計(jì)算得：(ΔP/L)bb’=0.0023MPa/m計(jì)算長(zhǎng)度Lbb’=2.5(m)ΔPbb’=(ΔP/L)bb’×Lbb’=0.0023×2.5=0.00575(MPa)(3)b’-c段以=28.48/kg/s及DN=65mm，計(jì)算得：(ΔP/L)b’c=0.0077MPa/m計(jì)算長(zhǎng)度Lb’c=2+2.4+10.6+7.5(選擇閥)+4.02(兩個(gè)彎頭)=26.52(m)ΔPb’c=(ΔP/L)b’c×Lb’c=0.0077×26.52=0.2042(MPa)(4)c-d段以=14.24kg/s及DN=50mm，計(jì)算得：(ΔP/L)cd=0.0077MPa/m計(jì)算長(zhǎng)度Lcd=1.4+0.67+2.1=4.17(m)ΔPcd=(ΔP/L)cd×Lcd=0.0077×4.17=0.0321(MPa)(5)d-e段以=7.12kg/s及DN=40mm，計(jì)算得：(ΔP/L)de=0.0062MPa/m計(jì)算長(zhǎng)度Lcd=3.2+1.65+1.31=6.16(m)ΔPcd=(ΔP/L)cd×Lcd=0.0062×6.16=0.0382(MPa)(5)求得管路總損失：=ΔPab+ΔPbb’+ΔPb’c+ΔPcd+ΔPde=0.2823(MPa)6)計(jì)算高程壓頭依據(jù)本《規(guī)》中公式，其中，H=3.7m(“過(guò)程中點(diǎn)”時(shí)，噴頭高度相對(duì)儲(chǔ)存容器液面的位差)∴=10-6×1407×3.7×9.81=0.051(MPa)7)計(jì)算噴頭工作壓力依據(jù)本《規(guī)》中公式，=2.535-0.2823-0.051=2.2(MPa，絕對(duì)壓力)8)驗(yàn)算設(shè)計(jì)計(jì)算結(jié)果依據(jù)本《規(guī)》的規(guī)定，應(yīng)滿足下列條件：(1)≥0.7(MPa，絕對(duì)壓力)；(2)≥=2.535/2=1.2675(MPa，絕對(duì)壓力)。皆滿足，合格。9)計(jì)算噴頭等效孔口面積及確定噴頭規(guī)格以=2.2MPa從本《規(guī)》附錄C表C-2中查得，噴頭等效孔口單位面積噴射率：=4.55[(kg/s)/cm2]又，噴頭平均設(shè)計(jì)流量：=/4=7.12kg/s由本《規(guī)》中公式求得噴頭等效孔口面積：=7.12/4.55=1.565(cm2)由此，即可依據(jù)求得的值，性能跟設(shè)計(jì)一致的噴頭為18。管道附件當(dāng)量長(zhǎng)度(mm)管道徑選擇閥彎頭(m)三通直通(m)三通側(cè)通(m)1520.520.31.04202.50.670.270.852530.850.341.073241.130.461.44051.310.521.655061.680.672.1657.52.010.822.58092.51.013.1110010.51.71.44.1125122.11.765.115013.52.472.016.16螺紋接口縮徑接頭局部損失當(dāng)量長(zhǎng)度規(guī)格(mm)規(guī)格(mm)25X200.2法蘭32X250.2100X800.632X200.4100X650.940X320.3125X1000.840X250.4125X801.150X400.350X320.565X500.465X400.680X650.580X500.7附錄C七氟丙烷滅火系統(tǒng)噴頭等效孔口單位面積噴射率充壓壓力為2.5MPa(表壓)時(shí)的七氟丙烷系統(tǒng)的等效孔口單位面積噴射率表C-1噴頭入口壓力MPa(絕對(duì)壓力)噴射率kg/(s·cm2)噴頭入口壓力MPa(絕對(duì)壓力)噴射率kg/(s·cm2)2.14.671.32.862.04.481.22.581.94.281.12.281.84.071.01.981.73.850.91.661.63.620.81.321.53.380.70.971.43.130.60.62注：等效孔口流量系數(shù)為0.98充壓壓力為4.2MPa(表壓)時(shí)的七氟丙烷系統(tǒng)的等效孔口單位面積噴射率表C-2噴頭入口壓力MPa(絕對(duì)壓力)噴射率kg/(s·cm2)噴頭入口壓力MPa(絕對(duì)壓力)噴射率kg/(s·cm2)3.46.041.63.503.25.831.43.053.05.611.32.802.85.371.22.502.65.121.12.202.44.851.01.932.24.550.91.622.04.250.81.271.83.900.70.90注：等效孔口流量系數(shù)為0.98附錄D噴頭規(guī)格和等效孔口面積噴頭規(guī)格和等效孔口面積表D噴頭規(guī)格代號(hào)等效孔口面積