冷熱銅管水力計(jì)算探討

1、冷熱水銅管水力計(jì)算探討摘要： 冷熱水銅管水力計(jì)算探討我國(guó)目前尚無(wú)冷熱水銅管水力計(jì)算公式和圖表可供從事建筑給排水設(shè)計(jì)、教學(xué)和科研的人員參考，仍沿用冷熱水鍍鋅鋼管的計(jì)算公式和圖表，其結(jié)果與實(shí)際情況不符。為盡快填補(bǔ)這個(gè)空缺，筆者分析了英國(guó)銅管適用于65熱水的列線圖1資料(見圖1)，對(duì)照我國(guó)現(xiàn)行手冊(cè)熱水鍍鋅鋼管計(jì)算公式和圖表水力參數(shù)，認(rèn)為可引進(jìn)英國(guó)列線圖的成果，按我國(guó)冷熱水鍍鋅鋼管計(jì)算公式乘以修正系數(shù)，解決銅管水力計(jì)算上的難題。圖11現(xiàn)行計(jì)算方法與英國(guó)列線圖計(jì)算結(jié)果的對(duì)比由電子和靜電除垢殺菌器和紫銅冷熱水管的匹配作用2一文中公式（5）（6）（7）可列出暫按采用我國(guó)計(jì)算公式的英國(guó)Y系列紫銅熱水管水力參數(shù)

2、表(見表1)。表1英國(guó)Y系列紫銅熱水管的水力參數(shù)外徑mm壁厚mmdmm比阻A0流速系數(shù)KcQ0.44*/L/s比阻5330.058169101811647944.9730.0885626221.219.616353.3140.1331919281.225.6397.11.9420.227465.9351.532121.71.2430.354142.8421.53942.650.8370.52650.055425011.430.5090.86413.4176.1272.11.6430.2451.7971.9271082.51030.2480.1203.6670.291*

3、：Q0.44為流速0.44m/s時(shí)的流量。 利用表1和列線圖即可建立中英兩國(guó)采用不同計(jì)算方法得出的英國(guó)紫銅熱水管水力參數(shù)對(duì)比表(見表2)。從表2可知總平均R1/R20.379，說明英國(guó)采用的銅管粗糙系數(shù)n值比我國(guó)小很多。一般說來(lái)，不同材質(zhì)管道在計(jì)算內(nèi)徑、流量和水溫均相同的條件下，其單位長(zhǎng)度的水頭損失i(冷水)或R(熱水)值與它的粗糙系數(shù)n的平方成正比。令英國(guó)和我國(guó)的銅管粗糙系數(shù)分別為n1和n2，即表2兩種方法計(jì)算英國(guó)Y系列銅管水力參數(shù)對(duì)比Vms外徑mmQLs英國(guó)列線圖R1我國(guó)R2mmH2OmR1R2PammH2Om1.0150.13390091.82980.3081.0180.20171572

4、.92280.3201.0220.30255556.61750.3231.0280.50740040.81200.3401.0350.80530030.692.40.3311.0421.19524525.071.50.3501.0541.96418018.451.70.3561.076.14.08312012.232.10.3801.01088.33375.57.7020.20.381平均0.3430.4150.05318518.948.40.3900.4180.08014514.837.00.4000.4220.12111511.728.40.4120.4280.20678.07.9620.

5、10.3960.4350.32260.06.1215.00.4080.4420.47845.54.6411.60.4000.4540.78634.53.528.410.4190.476.11.63322.52.305.220.4410.41083.33315.01.533.280.466平均0.415目前我國(guó)熱水管水力計(jì)算沿用鍍鋅鋼管的參數(shù)，從n20.013，可算出n10.615 6×0.0130.008。與UPVC給排水管的n值取0.009相比，比較接近，基本上符合實(shí)際情況。2紫銅冷熱水管的簡(jiǎn)化計(jì)算按參考文獻(xiàn)2公式(2)(4)(6)(7)右邊同乘以0.379的修正系數(shù)后可列新式如下

6、：紫銅冷水管V1.2ms，iAQ2A6.579×10-10d5.3（2a）V<1.2ms，i(10.867KcQ)0.3A0Q2A05.609×10-10d5.3（4a）紫銅熱水管V0.44ms，R(10.318 7KcQ)0.3A0Q2A05.511×107d5.3（6a）V0.44ms，RAQ2A6.466×107d5.3（7a）以上各式中i以mH2Om計(jì)，R以mmH2Om計(jì)，Q以Ls計(jì)。由VKcQ，可推導(dǎo)出Kc0.001 273d2。筆者曾和提供英國(guó)列線圖原始資料的馮及先生討論過，認(rèn)為建筑生活冷熱水供應(yīng)系統(tǒng)使用英國(guó)X系列紫銅管比較經(jīng)濟(jì)合理，它

7、比英國(guó)Y系列紫銅管的管壁更薄，但引用的列線圖僅有英國(guó)Y系列的原始資料，故據(jù)此才建立用于生活冷熱水系統(tǒng)的國(guó)產(chǎn)和英國(guó)X系列冷熱水銅管水力參數(shù)表(表3和表4)供讀者參考選用。表3推薦冷水銅管水力參數(shù)DNmm外徑mm壁厚mmdmm比阻A0流速系數(shù)KcQ1.2L/s比阻A15161.0143.7536.4950.1854.40220221.5190.7443.5260.3400.87325281.5250.1742.0370.5890.20432351.5320.0471.2430.9650.05540442.0400.0140.7961.5080.01750552.0513.970×1030

8、.4892.4524.656×10365702.5651.098×1030.3013.9831.287×10380852.5803.652×1040.1996.0334.283×1041001052.51001.119×1040.1279.4271.313×1041251332.51283.025×1050.07815.443.548×1051501593.01531.175×1050.05422.071.378×105英國(guó)X系列150.713.64.3776.8830.1745.13

9、3180.816.41.6234.7330.2541.903220.920.20.5383.1200.3210.631280.926.20.1361.8540.6470.159351.232.60.0431.1981.0020.050421.239.60.0150.8121.4780.018541.251.63.731×1030.4782.5104.376×103671.264.61.134×1030.3053.9341.330×10376.11.573.15.890×1040.2385.0386.909×1041081.51058.

10、641×1050.11610.391.014×1051331.51302.786×1050.07515.933.268×1051592.01551.097×1050.05322.651.286×105表4推薦熱水銅管水力參數(shù)DN/mm外徑mm壁厚mmdmm比阻A0流速系數(shù)KcQ0.44/L/s比阻A15161.01436886.4950.068432720221.519730.93.5260.125857.525281.525170.72.0370.216200.232351.53246.121.2430.35454.1240442.

11、04014.140.7960.55316.5950552.0513.9000.4890.8994.57665702.5651.0780.3011.4601.26580852.5800.3590.1992.2120.4211001052.51000.1100.1273.4560.1291251332.51280.0290.0785.6630.0351501593.01530.0120.0548.0910.014英國(guó)XT >系列150.713.643006.8830.0645045180.816.415944.7330.0931871220.920.2528.33.1200.141619.8280.926.2133.11.8540.237156.2351.232.641.801.1980.36749.04421.239.614.910.8120.54217.49541.251.63.6660.4780.9204.301671.264.61.1140.3051.4431.30776.11.573.10.5790.2381.8470.6791081.51050.0850.1163.8100.0991331.51300.0270.0755.8410.0321592.01550.0110.0538.3030.013作者單位：530011廣西