水管水力计算

1、6.2.2水系统水力计算对半集中系统空调水系统平面图，绘制水管平面布置图并进行水力计算，确 定管径。冷冻水水力计算用假定流速法：1）根据轴侧图选择配水最不利点，确定计算管路。若在轴侧图中难以判定 配水最不利点，则应同时选择几条计算管路，分别计算各管路所需压力，其最大 值方为水系统所需要的压力；2）以流量变化为节点，从配水最不利点开始，进行管段编号，将计算管路 划分成计算管段，并标出管段的长度；3）根据各室内的冷负荷，计算出各室内所需要的冷冻水量，再计算出各管 段的流量；4）进行各管段水力计算；5）确定非计算管路各管段的管径。6）计算结果见表6.4。表6.4水管水力计算表最不利环路阻 力（Pa）

2、91028最有利环路阻 力41080不平衡率54.90%编号Q(W)G(kg/h)L(m)D(mm)U (m/s)R(Pa/m)E& Py(Pa) Pj(Pa) P(Pa)VG42721950.0133891250.98179170432977339E263820657.044.52200.53287.43312993041731716FG3387601506.720.27250.68316.98387693780FG29164402827.682.57320.82334.974.385914332293FG28182203133.841.54400.66181.281279217497FG2

3、72000034401.46400.72216.431316262578FG26217803746.161.54400.79254.651392311703FG25235604052.321.46400.85295.941432364796FG24280604826.320.38500.61111.24143185228FG233300056761.16500.71151.371175255430FG20347805982.161.46500.75167.321244284528FG19365606288.321.54500.79184.051283314597F48

4、1.46500.83201.571294345639F641.54500.87219.881339378716F81.46500.91238.971349412761F961.54500.95258.851399448846FG12454607819.120.54500.98279.511150485635FG11504008668.83.33501.09340.96111375961732FG10553409518.485.63501.2408.47122987183016FG86522011217.840.365

5、0.86155.74147368415FG77016012067.521.66650.92179.171298426724FG67510012917.26.11650.99204.21112494881737FG58004013766.884.14651.05230.87395716642620FG49510016357.21.71651.25322.154.355233663919FG310243017617.963.72800.95151.3215634511014FG210737018467.643.26801165.6815394961035FG111119019124.684.858

6、01.03177.2208600860FH2887601506.720.32250.68316.983100693793FH25191803298.962.67400.69199.861.3533313846FH24209603605.120.94400.76236.671222288510FH23227403911.282.06400.82276.541570339908FH22245204217.440.94400.89319.471300394694FH21263004523.62.06400.95365.4617534531206FH20308005297.60.19500.67132

7、.75126223248FH19357406147.280.75500.77176.251132300431F442.06500.81193.41398330729F60.94500.85211.351199362561FH16410807065.762.06500.89230.081474396870F920.94500.93249.591235431666F082.06500.97269.8915564671023F240.94501.01290.9812745

8、05779FH12482008290.40.95501.04312.851296545841FH11531409140.083.53501.15377.66113316621994FH10580809989.765.33650.76124.751664292956FH96302010839.440.3650.83145.83144344388FH77290012538.81.55650.96192.861300460760FH67784013388.486.11651.02218.8113385241862FH58278014238.164.55651.09246.36311211780290

9、1FH49784016828.481.37800.91138.561.3189535724FH310517018089.244.13800.98159.2116574761132FH211011018938.923.04801.02173.9215295211050FH111393019595.965.39801.06185.7401002010027.2.2循环水泵的选型水泵的流量按下式计算：Q邛 1Qmax(7-1)式中Q管网的最大流量，ms/h ；d：一流量储备系数，对单台水泵工作时，P】值取1.1;两台水泵及以 上并联工作时P值取1.2。Q邛 Q =1.2 X 224=268ms/h。

10、(2)水泵的扬程按下式计算：H= d 2Hmax(7-2 )式中一管网最大计算总阻力，kPa ； d一扬程(压头)储备系数，d 2=1.1-1.2。蒸发器的压降为66KPa，一楼管路加末端盘管的总阻力为175KPa,。H= 8 2Hm =1.2 X（ 66+175 ） =241KPa，扬程为 24.1m。（3）根据水泵的扬程和流量选择水泵，并将主要参数列于表4.6中。冷冻 水泵一共3台，两用一备。分析：水泵采用并联的方式，其并联运行时的工况如图7.3:表4.6裙楼冷冻水泵的主要参数水泵型号KQL125-160A流量（m3/h）150效率（）76扬程（m）28转速（r/min）2900电动机功率（KW）18.5重量（kg）230图7.3相同两台水泵并联运行工况从图中可以看出，Q1值也就是并联时较单台水泵运行多出的流量。可以得 出两台水泵并联运行时，其总管路的实际总流量是小于两台水泵的名牌标出流量 的两倍。经验算