某購(gòu)物廣場(chǎng)中央空調(diào)水系統(tǒng)的設(shè)計(jì)計(jì)算過程案例目錄TOC\o"1-3"\h\u70861.1冷凍水系統(tǒng)的設(shè)計(jì)計(jì)算 1109631.1.1空調(diào)管路系統(tǒng)的設(shè)計(jì)原則 152621.1.2冷凍水系統(tǒng)形式的確定 1322051.1.3開式、閉式選擇 2191801.2冷凍水系統(tǒng)水平管的水力計(jì)算 252261.2.1一層冷凍水系統(tǒng)水平管的水力計(jì)算 27821.2.2二，三層冷凍水系統(tǒng)水平管的水力計(jì)算 8319321.2.3四層冷凍水系統(tǒng)水平管的水力計(jì)算 1025821.3冷凍水系統(tǒng)立管的水力計(jì)算 12208091.4冷凝水系統(tǒng)的設(shè)計(jì)及管徑確定 13211481.6水系統(tǒng)的泄水與排氣 161.1冷凍水系統(tǒng)的設(shè)計(jì)計(jì)算1.1.1空調(diào)管路系統(tǒng)的設(shè)計(jì)原則a.空調(diào)管路系統(tǒng)應(yīng)該具備足夠的輸送能力。比如，在空調(diào)系統(tǒng)中通過水系統(tǒng)來(lái)保證每臺(tái)新風(fēng)機(jī)組和風(fēng)機(jī)盤管的循環(huán)水量達(dá)到設(shè)計(jì)流量，以確保機(jī)組能夠正常運(yùn)行。b.合理地布置管道。管道的布置要盡可能地選擇同程式系統(tǒng)，雖然初投資有所增加，但易于保持環(huán)路

的水力穩(wěn)定；若采用異程式系統(tǒng)，設(shè)計(jì)中應(yīng)注意各支管間的壓力平衡問題。

c.在設(shè)計(jì)中，必須進(jìn)行嚴(yán)格的水力計(jì)算才能確保各個(gè)環(huán)路之間符合水力平衡要求，使空調(diào)水系統(tǒng)在實(shí)際運(yùn)行中有良好的水力和熱力工況。

d.空調(diào)管路系統(tǒng)應(yīng)滿足空調(diào)部分負(fù)荷運(yùn)行時(shí)的調(diào)節(jié)要求

。e.空調(diào)管路系統(tǒng)設(shè)計(jì)中要盡可能多采用節(jié)能技術(shù)措施。f.

空調(diào)管路系統(tǒng)選用的管材、配件要符合有關(guān)的規(guī)范要求。

g.空調(diào)管路系統(tǒng)設(shè)計(jì)中要注意便于維修管理，操作、調(diào)節(jié)方便。1.1.2冷凍水系統(tǒng)形式的確定冷凍水系統(tǒng)形式可分為以下幾種：a.按介質(zhì)是否與空氣接觸劃分，可分為開式系統(tǒng)和閉式系統(tǒng)。閉式系統(tǒng)的優(yōu)點(diǎn)是對(duì)管路和設(shè)備的腐蝕性小，水容量比開式系統(tǒng)小，水泵只需要克服系統(tǒng)的流動(dòng)阻力，系統(tǒng)簡(jiǎn)單；缺點(diǎn)是系統(tǒng)的蓄冷能力差。開式系統(tǒng)的優(yōu)點(diǎn)是有較大的水容量，所以溫度較為穩(wěn)定，蓄冷能力強(qiáng)；缺點(diǎn)是容易腐蝕，要克服系統(tǒng)的流動(dòng)阻力，能耗大。b.按系統(tǒng)中的各并聯(lián)環(huán)路中水的流程劃分，可分為同程式系統(tǒng)和異程式系統(tǒng)。同程式系統(tǒng)的優(yōu)點(diǎn)是各并聯(lián)管路的管長(zhǎng)相等，阻力大致相同，系統(tǒng)的水力穩(wěn)定性好，流量分配均勻；缺點(diǎn)是管道布置復(fù)雜，管路長(zhǎng)，初投資較大。異程式系統(tǒng)的優(yōu)點(diǎn)是管路配置簡(jiǎn)單，節(jié)省管材，初投資少；缺點(diǎn)是由于各并聯(lián)環(huán)路管長(zhǎng)不等，阻力不平衡，流量分配不均勻。c.按系統(tǒng)循環(huán)水量的特性劃分，可分為定流量系統(tǒng)和變流量系統(tǒng)。d.按系統(tǒng)中的循環(huán)水泵設(shè)置情況劃分，可分為單級(jí)泵系統(tǒng)和雙級(jí)泵系統(tǒng)。e.按冷熱水管道的設(shè)置方式劃分，可分為雙管制、三管制和四管制系統(tǒng)。本設(shè)計(jì)考慮到管道內(nèi)潔凈和腐蝕性問題，采用閉式系統(tǒng)。根據(jù)本建筑物的建筑特點(diǎn)，只設(shè)一個(gè)水系統(tǒng)，冷凍水都在同側(cè)回供；由于整個(gè)建筑物并不太高，在豎向不會(huì)造成太大的阻力不平衡，因此采用水平同程、豎向異程。該建筑物空調(diào)房間不會(huì)出現(xiàn)同時(shí)供冷、供熱，故采用雙管制系統(tǒng)。另外，考慮到初投資問題和各房間負(fù)荷分布不均勻等方面，采用單級(jí)泵變流量系統(tǒng)。1.1.3開式、閉式選擇除設(shè)蓄冷、蓄熱水池等直接供冷、供熱的蓄能系統(tǒng)及用噴水室處理空氣的開式系統(tǒng)外，空調(diào)水系統(tǒng)，宜采用以膨脹水箱或其他設(shè)各定壓的閉式循環(huán)系統(tǒng)。表7-1開式閉式的比較形式開式閉式特點(diǎn)水泵要克服從水池吸入點(diǎn)到系統(tǒng)最高點(diǎn)的水柱壓力。此外還要克服水路的管件、管路、冷水機(jī)組以及末端設(shè)備的阻力水泵運(yùn)行時(shí)不需要克服水柱的勢(shì)能，只要克服系統(tǒng)水路的管件、管路、冷水機(jī)組以及末端設(shè)備的阻力。優(yōu)點(diǎn)與水蓄冷系統(tǒng)的連接相對(duì)簡(jiǎn)單氧腐蝕幾率小，水泵揚(yáng)程低，輸送能耗小。缺點(diǎn)系統(tǒng)中的溶解氧過多，管網(wǎng)和設(shè)備易腐蝕；需要增加克服靜水壓力的額外能耗；輸送能耗高。與水蓄冷系統(tǒng)的連接相對(duì)復(fù)雜1.2冷凍水系統(tǒng)水平管的水力計(jì)算1.2.1一層冷凍水系統(tǒng)水平管的水力計(jì)算冷凍水系統(tǒng)管路設(shè)計(jì)的合理與否將會(huì)直接影響到空調(diào)系統(tǒng)是否能夠正常運(yùn)行與經(jīng)濟(jì)運(yùn)行問題，因此在設(shè)計(jì)時(shí)要符合實(shí)際情況，在計(jì)算時(shí)要加倍仔細(xì)，避免出現(xiàn)錯(cuò)誤。水管管徑的確定和風(fēng)管管徑的確定相似，所以同樣采用假定流速法來(lái)進(jìn)行水力計(jì)算。以第一層冷凍水系統(tǒng)為例，水力計(jì)算步驟如下：a.對(duì)管段進(jìn)行編號(hào)如下圖，由于該層水系統(tǒng)布置為同程式，所以最不利環(huán)路可任意取一末端作為供回節(jié)點(diǎn)，如下圖取最后一個(gè)機(jī)組管為節(jié)點(diǎn)，則確定最不利環(huán)路為Ⅰ-2-9-22-25。圖7-1第一層冷凍水布置圖b.根據(jù)各管段的冷負(fù)荷，計(jì)算各管段的流量，計(jì)算公式如下：（7-1）式中：——管段流量，m3/h；——各管段冷負(fù)荷，kW；——水的比熱，為4.18kJ/kg·℃； ——水的密度，為1000kg/m3——冷凍水回水溫度，查閱《實(shí)用供熱空調(diào)設(shè)計(jì)手冊(cè)》，取12℃；——冷凍水供水溫度，查閱《實(shí)用供熱空調(diào)設(shè)計(jì)手冊(cè)》，取7℃。以管段0-1為例c.用假定流速法確定管段管徑。查閱《民用建筑空調(diào)設(shè)計(jì)》，流速的取值范圍如下：表7-1水管流速推薦表（）管徑(mm)20253240506580100125150閉式系統(tǒng)0.5-0.60.6-0.70.7-0.90.8-10.9-1.21.1-1.41.2-1.61.3-1.81.5-2.01.6-2.2開式系統(tǒng)0.4-0.50.5-0.60.6-0.80.7-0.90.8-1.00.9-1.21.1-1.41.2-1.61.4-1.81.5-2.0根據(jù)假定的流速和計(jì)算出的流量確定管徑，計(jì)算公式如下：（7-2）式中：——管段流量，m3/h；——假定的水流速度，m/s。以管段0-1為例在空調(diào)水系統(tǒng)中常用的是鍍鋅鋼管和不鍍鋅的無(wú)縫鋼管，其規(guī)格以公稱直徑（DN）表示。在本設(shè)計(jì)中采用鍍鋅鋼管，根據(jù)國(guó)家標(biāo)準(zhǔn)的公稱直徑選取管徑，按照比所算管徑值大的原則，選取公稱直徑為80mm的鍍鋅鋼管。校核：將所選的公稱直徑為80mm鍍鋅鋼管代入公式7-2，則該管段的實(shí)際流速為，符合要求。d.計(jì)算出管段的比摩阻從而求出沿程阻力。沿程阻力計(jì)算公式（7-3）式中：——單位長(zhǎng)度管段的摩擦阻力（稱比摩阻），Pa/m；——管段長(zhǎng)度，。單位長(zhǎng)度管段的摩擦阻力計(jì)算公式（7-4）式中：——摩擦阻力系數(shù)，無(wú)因次量；——水的密度，1000kg/m3；——水流速度，m/s。摩擦阻力系數(shù)可由下式確定（7-5）式中——管內(nèi)表面的當(dāng)量絕對(duì)粗糙度，；查閱《簡(jiǎn)明空調(diào)設(shè)計(jì)手冊(cè)》，閉式水系統(tǒng)=0.2mm?！字Z數(shù)。其中雷諾數(shù)計(jì)算公式（7-6）式中：——實(shí)際流速，m/s；——運(yùn)動(dòng)黏滯系數(shù)，水在7℃時(shí)的運(yùn)動(dòng)黏滯系數(shù)為m2/s。管0-1的雷諾數(shù)管段0-1的比摩阻管段0-1的管長(zhǎng)為10.2m，則沿程阻力為e.用局部阻力系數(shù)法求出管段的局部阻力，計(jì)算公式如下：（7-7）式中：——管段中總的局部阻力系數(shù)；——水的密度，1000kg/m3；——水流速度，m/s。管段Ⅰ-1中有兩個(gè)三通，其局部阻力系數(shù)為1.6，則該管段的局部阻力為f.計(jì)算管段的總阻力。管段的總阻力即為沿程阻力和局部阻力相加，則管段7-8的總阻力為表7-2第一層供水管水力計(jì)算表管段管長(zhǎng)m管段負(fù)荷KW送水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpaβ-00.81206.9635.651001.26311.07256.821193.491450.320-110.20129.1522.25801.23438.854476.231210.205686.441-26.80122.8821.17801.17399.222714.671711.914426.582-33.40111.9320.31801.12369.181255.22946.052201.273-43.40112.9819.46801.08340.281156.94868.292025.234-53.40108.0318.61801.03312.511062.52793.861856.385-63.40103.0811.76800.98285.87971.96722.771694.736-73.4098.1316.90800.93260.38885.28655.011540.297-83.4093.6916.14800.89238.51810.95591.151408.108-92.9090.2915.55800.86222.37644.87554.591199.459-1020.0386.7014.93651.25645.5612930.491955.5714886.0710-118.8281.4514.03651.17572.885052.801035.446088.2411-123.8376.1813.12651.10504.241931.26905.862831.1212-133.6370.4012.13651.02433.751574.52773.552348.0813-143.6364.6111.13650.93368.391331.24651.681988.9314-153.6358.8310.13650.85308.171118.66540.251658.9115-163.6353.059.14650.77253.14918.89439.261358.1516-173.6341.278.14650.68203.32738.04348.711086.7617-183.6341.481.15501.01671.652459.85761.163221.0118-193.6335.706.15500.87508.391845.46568.182413.6419-203.6329.925.15500.73362.711316.64399.011715.6520-213.6324.134.16400.92836.013034.72633.953668.6721-223.6318.353.16400.70494.251794.12366.542160.6522-236.9212.572.16300.851205.878344.621086.749431.3623-2415.635.720.99250.56742.1711600.11233.4311833.5424-256.993.020.52200.46770.275384.21371.765755.97表7-3第一層回水管水力計(jì)算表管段管長(zhǎng)m回水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpaa-b19.4713.40651.12525.1410224.501008.2611232.76b-c5.6514.48651.21608.843439.921839.315279.23c-d3.4015.34651.28679.182309.201231.363546.56d-e3.4016.19800.90239.93815.75600.881416.63e-f3.4011.04800.94264.46899.18665.851565.03f-g3.4011.89800.99290.14986.49734.151720.65g-h3.4018.75801.04316.961071.68805.791883.47h-i3.4019.51801.08341.951162.64872.782035.42i-j2.9020.10801.11361.731049.03925.981975.01j-k20.0320.72801.15383.207675.471639.779315.24k-l8.8221.62801.20415.683666.281071.714731.99l-m3.8322.53801.25449.501721.601163.532885.13m-n3.6323.52801.30488.111771.851268.703040.55n-o3.6324.52801.36528.251911.551378.423295.97o-p3.6325.52801.41569.912068.781492.693561.47p-q3.6326.511000.94181.00651.01660.081311.09q-r3.6321.511000.97194.06704.45710.611415.06r-s3.6328.501001.01201.56753.46763.001516.46s-t3.6329.501001.04221.50804.04811.261621.31t-u3.6330.501001.08235.87856.20873.391729.59u-v3.6331.491001.11250.67909.92931.371841.30v-w3.6332.491001.15265.90965.21991.231956.43w-x6.9233.481001.18281.561948.372105.884054.25x-y15.6334.661001.23300.654699.211128.435821.63y-z6.9935.131001.24308.342155.272704.014859.28z-σ68.2535.651001.26311.0721639.783182.6524822.42最不利環(huán)路α-1-2-9-10-22-23-25-風(fēng)機(jī)盤管-回水管段z-σ的總阻力為120.76K1.2.2二，三層冷凍水系統(tǒng)水平管的水力計(jì)算圖7-2第二層冷凍水布置圖表7-3第二層送水管水力計(jì)算表管段管長(zhǎng)m管段負(fù)荷KW送水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpaα-β4.9152.5326.27801.45602.642952.913165.406118.31β-2611.3895.3616.43800.91246.634286.401443.395729.7826-279.1481.1415.01800.83201.901900.17516.562416.7327-289.1479.5413.70651.15541.525004.29981.475991.7628-299.1471.9312.39651.04451.994131.17801.704938.8729-3024.2464.3411.08650.93365.468858.851501.9310366.7830-31A11.3655.479.55650.80275.533130.04480.253610.2931A-31B6.1249.588.54650.72222.631362.47383.701746.1731B-32A6.1243.691.53650.63175.141071.85291.951369.8032A-32B6.1231.806.51500.92561.143470.90636.994101.8932B-3330.6931.905.49500.78409.9912582.74756.1013338.8433-3433.6920.993.62400.80639.4621543.541438.5922982.1334-3510.1013.132.26320.78910.759198.55458.109656.6535-361.351.861.35320.47339.882498.15273.602771.75表7-4第二層回水管水力計(jì)算表管段管長(zhǎng)m回水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpaa-b11.389.85650.82291.855072.401020.436092.83b-c9.1411.26650.94376.873444.60661.454112.06c-d9.1412.57651.05464.794248.15831.705079.85d-e9.1413.88651.16561.545132.511013.996146.51e-f24.2415.19800.84212.655154.71881.746036.45f-g11.3616.72800.92255.062891.44640.913538.34g-h6.1211.73800.98285.221745.53721.022466.55h-i6.1218.75801.04311.001940.04805.882745.92i-j6.1219.76801.09350.392144.39895.463039.86j-k30.6920.78801.15385.4511829.351649.8813479.23k-l33.6922.66801.25454.4915311.713531.2518842.96l-m10.1024.01801.33501.615126.861321.956448.81m-n1.3524.92801.38544.814004.331423.795428.13n-o68.5126.27801.45602.6441286.553692.9744979.52最不利環(huán)路α-β-26-30-33-36-風(fēng)機(jī)盤管-回水管段n-o的總阻力為140.12K第三層送回水與第二層完全相同機(jī)總阻力為140.12K1.2.3四層冷凍水系統(tǒng)水平管的水力計(jì)算圖7-3第四層冷凍水布置圖表7-5第四層回水管水力計(jì)算表管段管長(zhǎng)m管段負(fù)荷KW送水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpaα-β4.9166.0628.601001.01208.941023.791536.682560.48β-4811.38108.0918.62801.03312.865431.462384.407821.8548-499.1498.8311.02800.94263.912412.18664.393076.5749-509.1490.1815.53800.86221.842021.59553.192580.7750-519.1481.5314.04651.18573.985246.171031.526283.6951-52A24.2473.0112.58651.05464.9811271.121386.7712651.8952A-52B3.9668.0511.72650.98406.601610.13722.822332.9652B-53A8.9863.0910.87650.91352.013161.05621.293782.3553A-53B3.9656.509.73650.82285.361130.01498.281628.2953B-54A8.9849.918.60650.72225.452024.52388.822413.3454A-54B3.9643.331.46501.06736.642911.10831.003754.1054B-55A31.8736.746.33500.90531.1017111.341002.9418120.2855A-55B5.2430.595.27500.75378.441983.05411.172400.2155B-5629.5824.434.21500.60246.497291.25798.218089.4656-575.4218.443.18400.70498.842703.71370.093073.8057-583.7615.372.65400.59352.031323.63251.121580.7558-593.7612.302.12320.73803.153019.83402.013421.8459-603.769.221.59320.55461.551735.44225.891961.3260-613.766.151.06250.60853.363208.65269.793478.4461-623.763.070.53250.30224.38843.68112.05955.72表7-6第四層回水管水力計(jì)算表管段管長(zhǎng)m回水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpaa-b11.389.98650.84299.615201.241398.636605.87b-c9.1411.58650.97391.333631.60705.544331.14c-d9.1413.07651.09500.474574.29898.755473.04d-e9.1414.56651.22615.025621.311115.326736.63e-f24.2416.03800.89235.415706.32981.596681.91f-g3.9616.88800.93259.781028.74653.431682.17g-h8.9811.74800.98285.302561.99721.243283.23h-i3.9618.87801.04320.971271.05816.522081.57i-j8.9820.01801.11358.663220.73911.704138.43j-k3.9621.14801.17398.281571.211024.622601.83k-l31.8722.28801.23439.9714021.811896.0215911.83l-m5.2423.33801.29480.672518.701248.393761.08m-o29.5824.40801.35523.1715475.234093.5019568.73續(xù)表7-6管段管長(zhǎng)m回水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpao-p5.4225.43801.41566.153068.541482.364550.90p-q3.7625.961000.92173.89653.84632.691286.54q-r3.7626.481000.94180.65679.24658.731331.97r-s3.7621.021000.96181.55705.18685.391390.57s-t3.7621.541000.97194.55731.50712.481443.98t-u1.5628.071000.99201.691524.801233.662758.45u-w6.9728.601001.01208.941456.29512.231968.52最不利環(huán)路α-β-48-51-52A-54B-55B-62-風(fēng)機(jī)盤管-回水管段u-w的總阻力為93.92KPa1.3冷凍水系統(tǒng)立管的水力計(jì)算為了將冷凍水安全快速的輸送到末端設(shè)備，冷凍水系統(tǒng)立管的合理布置有著重要作用。合理布置的立管不僅可以減少水平管的管材，也可以避免管路出現(xiàn)較大的阻力。冷凍水系統(tǒng)立管的水力計(jì)算步驟與水平管相同，其布置圖如下：圖7-4冷凍水立管布置圖表7-7送水立管水力計(jì)算表管段管長(zhǎng)m回水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpaα-Ⅰ4.8035.651001.26311.071521.922386.983908.90Ⅰ-Ⅱ4.8061.921251.40268.771290.103441.584731.68Ⅱ-Ⅲ4.5088.201501.39196.36883.643366.924250.56Ⅲ-Ⅳ4.50116.801501.84333.881502.455904.947401.39表7-8回水立管水力計(jì)算表管段管長(zhǎng)m回水量m3/h管徑Dmm實(shí)際流速Vm/s比摩阻Rpa/m沿程阻力HfPa局部阻力HdPa總阻力ΔPpa0-14.80116.801501.84333.881602.625061.386663.991-24.8088.201501.39196.36942.553366.924309.472-34.5061.921251.40268.771209.473441.584651.053-44.5035.651001.26311.071426.802784.824211.61在1.1.4節(jié)中已計(jì)算出各層水平干管最不利環(huán)路的阻力，由此可算出冷凍水最不利環(huán)路水管為供水立管a-第一層水平干管-回水立管a總阻力為160.89KPa。不平率校核：取整層樓的最不利和離立管最近的一個(gè)管路進(jìn)行對(duì)比理論上是需要加設(shè)閥門進(jìn)行調(diào)節(jié)水量，各層的不平衡率經(jīng)計(jì)算，均滿足不平衡率范圍，詳細(xì)閥門標(biāo)注，可見水管系統(tǒng)圖。1.4冷凝水系統(tǒng)的設(shè)計(jì)及管徑確定當(dāng)空氣被冷卻處理時(shí)，由于空氣冷卻器的表面溫度等于或低于處理空氣的露點(diǎn)溫度，空氣中的水氣就會(huì)在冷卻器表面冷凝。各種空調(diào)設(shè)備（如風(fēng)機(jī)盤管、新風(fēng)機(jī)組等）在運(yùn)行過程中產(chǎn)生的凝結(jié)水必須及時(shí)的排走，那么必須設(shè)置冷凝水排放管路。在設(shè)計(jì)冷凝水排水系統(tǒng)時(shí)，應(yīng)注意以下幾點(diǎn)：a.風(fēng)機(jī)盤管的凝結(jié)水盤的泄水支管坡度，不宜小于1/100；其余水平支干管沿水流方向應(yīng)該保持不小于2/1000的坡度，并且不能有積水部位；若受到條件的限制，而用無(wú)坡敷設(shè)時(shí)，管內(nèi)流速不能小于0.25。b.當(dāng)冷凝水盤位于風(fēng)機(jī)盤管的負(fù)壓段時(shí)，在凝結(jié)水盤的出水口處就必須設(shè)置水封，水封的高度應(yīng)比凝結(jié)水盤處的負(fù)壓（相當(dāng)于水柱高度）大50%左右，以防止凝結(jié)水的回流。水封的出口，應(yīng)該與大氣相通；一般可通過排水漏斗與排水系統(tǒng)連接；通氣口長(zhǎng)約50mm，存水彎前應(yīng)有50mm高度的短管。c.冷凝水管宜采用聚氯乙烯塑料管或者鍍鋅鋼管，不宜采用焊接鋼管。d.冷凝水立管的直徑應(yīng)該與水平干管的直徑保持相同。e.冷凝水管的頂部應(yīng)該設(shè)置通向大氣的透氣管。f.設(shè)計(jì)冷凝系統(tǒng)時(shí)應(yīng)該考慮到系統(tǒng)定期進(jìn)行沖洗的可能性；運(yùn)行中要定期清洗水盤，防止凝結(jié)水管的堵塞和溢流。g.冷凝水管的公稱直徑DN（mm），應(yīng)根據(jù)凝水量和敷設(shè)坡度計(jì)算確定，一般情況下，每千瓦的冷負(fù)荷每小時(shí)產(chǎn)生0.4左右的冷凝水，在潛熱負(fù)荷較高的場(chǎng)合，每千瓦的冷負(fù)荷每小時(shí)產(chǎn)生0.8左右的冷凝水。查閱《實(shí)用供熱空調(diào)設(shè)計(jì)手冊(cè)》，通常可以根據(jù)各管段的冷負(fù)荷按下表近似的選擇冷凝水管的公稱直徑。表7-9冷凝水管的管徑選擇表冷負(fù)荷（）公稱直徑（）冷負(fù)荷（）公稱直徑（）冷負(fù)荷（）公稱直徑（）20101~176401056~15121001.1~11.625177~598501513~246212511.7~10032599~10558012462150由于本建筑物的第一、二兩層沒有衛(wèi)生間，所以綜合考慮之下，整棟樓的凝結(jié)水統(tǒng)一用一根立管就近排放到城市下水道。凝結(jié)水系統(tǒng)管道布置樣式和冷凍水供水系統(tǒng)一致，所以凝結(jié)水系統(tǒng)管段編號(hào)和冷凍水供水一致，可見1.2節(jié)中冷凍水供水管段的編號(hào)。表7-10一層冷凝水管徑選擇管段管段負(fù)荷KW管徑mmβ-0206.96500-1129.15401-2122.88402-3111.93403-4112.98404-5108.03405-6103.08406-798.13327-893.69328-990.29329-1086.703210-1181.453211-1276.183212-1370.403213-1464.613214-1558.833215-1653.053216-1741.273217-1841.483218-1935.7032續(xù)表7-10管段管段負(fù)荷KW管徑mm19-2029.923220-2124.133221-2218.353222-2312.572523-245.722024-253.0220表7-11二，三層冷凝水管徑選擇管段管段負(fù)荷KW管徑mmα-β152.5340β