空调负荷计算表(简化逐时法)
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时间0.250.290.330.380.420.460.5032.8032.6032.3032.1031.8031.0031.40-1.60-1.60-1.60-1.60-1.60-1.60-1.600.970.970.970.970.970.970.970.940.940.940.940.940.940.9428.4528.2727.9927.8127.5426.8127.1725.0025.0025.0025.0025.0025.0025.003.45 3.27 2.99 2.81 2.54 1.81 2.170.650.650.650.650.650.650.6541.7641.7641.7641.7641.7641.7641.7693.6088.6581.2276.2768.8549.0558.95时间0.250.290.330.380.420.460.5033.6038.2037.8037.3036.8036.3035.90-1.90-1.90-1.90-1.90-1.90-1.90-1.900.970.970.970.970.970.970.970.940.940.940.940.940.940.9428.9033.1032.7332.2831.8231.3731.0025.0025.0025.0025.0025.0025.0025.003.908.107.737.28 6.82 6.37 6.000.650.650.650.650.650.650.6524.4224.4224.4224.4224.4224.4224.4261.97128.54122.76115.52108.28101.0595.26时间0.250.290.330.380.420.460.5036.9036.4036.0035.5035.2035.0035.00-1.90-1.90-1.90-1.90-1.90-1.90-1.900.970.970.970.970.970.970.970.940.940.940.940.940.940.9431.9131.4631.0930.6430.3630.1830.1825.0025.0025.0025.0025.0025.0025.006.91 6.46 6.09 5.64 5.36 5.18 5.180.650.650.650.650.650.650.6515.3315.3315.3315.3315.3315.3315.3368.8864.3460.7156.1653.4451.6251.62时间0.250.290.330.380.420.460.5035.3035.0034.6034.2033.9033.5033.20-1.40-1.40-1.40-1.40-1.40-1.40-1.400.970.970.970.970.970.970.970.940.940.940.940.940.940.9430.9130.6430.2729.9129.6329.2729.0025.0025.0025.0025.0025.0025.0025.005.91 5.64 5.27 4.91 4.63 4.27 4.000.650.650.650.650.650.650.6563.3063.3063.3063.3063.3063.3063.30243.17231.91216.91201.90190.65175.64164.38 467.62513.45481.59449.86421.21377.35370.21时间0.250.290.330.380.420.460.5037.1035.5034.1033.1032.7033.0034.00-2.70-2.70-2.70-2.70-2.70-2.70-2.700.970.970.970.970.970.970.970.940.940.940.940.940.940.9431.3729.9128.6327.7227.3527.6328.5425.0025.0025.0025.0025.0025.0025.006.37 4.91 3.63 2.72 2.35 2.63 3.541.95 1.95 1.95 1.95 1.95 1.95 1.95228.00228.00228.00228.00228.00228.00228.002830.292181.671614.131208.741046.591168.201573.59时间0.250.290.330.380.420.460.5025.4026.0026.9027.9029.0029.9030.80-1.00-1.00-1.00-1.00-1.00-1.00-1.0024.4025.0025.9026.9028.0028.9029.8025.0025.0025.0025.0025.0025.0025.00-0.600.000.90 1.90 3.00 3.90 4.803.61 3.61 3.61 3.61 3.61 3.61 3.61162.03162.03162.03162.03162.03162.03162.03-421.380.00632.071334.382106.912738.983371.05时间0.250.290.330.380.420.460.500.470.680.820.790.590.380.24599.00599.00599.00599.00599.00599.00599.000.520.520.520.520.520.520.5215.7515.7515.7515.7515.7515.7515.751716.002482.722993.862884.332154.121387.40876.25时间0.250.290.330.380.420.460.500.080.110.140.170.180.190.20599.00599.00599.00599.00599.00599.00599.000.520.520.520.520.520.520.520.000.000.000.000.000.000.00时间0.250.290.330.380.420.460.500.110.180.260.400.580.720.84302.00302.00302.00302.00302.00302.00302.000.520.520.520.520.520.520.52142.50142.50142.50142.50142.50142.50142.501832.002997.824330.186661.829659.6411991.2713989.82时间0.250.290.330.380.420.460.500.590.540.540.650.750.810.83114.00114.00114.00114.00114.00114.00114.000.520.520.520.520.520.520.523.78 3.78 3.78 3.78 3.78 3.78 3.7898.3990.0590.05108.40125.07135.08138.423646.395570.597414.109654.5511938.8313513.7515004.49时间0.250.290.330.380.420.460.500.070.060.530.620.690.740.7765.1365.1365.1365.1365.1365.1365.130.930.930.930.930.930.930.930.000.000.000.000.000.000.0068.6168.6168.6168.6168.6168.6168.610.000.000.000.000.000.000.00合计0.000.000.000.000.000.000.00时间0.250.290.330.380.420.460.500.130.110.580.660.720.770.8063.9763.9763.9763.9763.9763.9763.97322.00322.00322.00322.00322.00322.00322.000.890.890.890.890.890.890.892383.232016.5810632.8612099.4613199.4214116.0414666.02117.46117.46117.46117.46117.46117.46117.464376.023702.7919523.7822216.7124236.4125919.5026929.35合计675957193015734316374364003641595时间0.250.290.330.380.420.460.500.120.110.370.670.710.740.761.20 1.20 1.20 1.20 1.20 1.20 1.200.600.600.600.600.600.600.60807.28807.28807.28807.28807.28807.28807.28 557.99511.491720.483115.453301.453440.953533.95时间0.250.290.330.380.420.460.50屋顶负荷外墙负荷窗传热负1574 28302182161412091047 4685134824504213773701168-42106321334210727393371荷窗日射负荷人员负荷灯光负荷设备负荷总计14995155464873657530642276967074159时间6:007:008:009:0010:0011:0012:000.110.100.640.710.760.800.8310494.6410494.6410494.6410494.6410494.6410494.6410494.6413.0013.0013.0013.0013.0013.0013.00807.28807.28807.28807.28807.28807.28807.281154.411049.466716.577451.197975.938395.718710.551500436465571741496551193967595719301573431637436400364159513514558511172031153301344135348396871111541049671774517976北外墙冷负荷0.540.580.630.670.710.750.790.830.88 31.3031.2031.2031.3031.4031.6031.8032.1032.40 -1.60-1.60-1.60-1.60-1.60-1.60-1.60-1.60-1.60 0.970.970.970.970.970.970.970.970.97 0.940.940.940.940.940.940.940.940.94 27.0826.9926.9927.0827.1727.3527.5427.8128.08 25.0025.0025.0025.0025.0025.0025.0025.0025.00 2.08 1.99 1.99 2.08 2.17 2.35 2.54 2.81 3.08 0.650.650.650.650.650.650.650.650.65 41.7641.7641.7641.7641.7641.7641.7641.7641.76 56.4754.0054.0056.4758.9563.9068.8576.2783.70西外墙冷负荷0.540.580.630.670.710.750.790.830.88 35.5035.2034.9034.8034.8034.9035.3035.8036.50 -1.90-1.90-1.90-1.90-1.90-1.90-1.90-1.90-1.90 0.970.970.970.970.970.970.970.970.97 0.940.940.940.940.940.940.940.940.94 30.6430.3630.0930.0030.0030.0930.4530.9131.55 25.0025.0025.0025.0025.0025.0025.0025.0025.00 5.64 5.36 5.09 5.00 5.00 5.09 5.45 5.91 6.55 0.650.650.650.650.650.650.650.650.65 24.4224.4224.4224.4224.4224.4224.4224.4224.42 89.4785.1380.7879.3479.3480.7886.5793.81103.94东外墙冷负荷0.540.580.630.670.710.750.790.830.88 35.2035.6036.1036.6037.1037.5037.9038.2038.40 -1.90-1.90-1.90-1.90-1.90-1.90-1.90-1.90-1.90 0.970.970.970.970.970.970.970.970.97 0.940.940.940.940.940.940.940.940.94 30.3630.7331.1831.6432.1032.4632.8233.1033.28 25.0025.0025.0025.0025.0025.0025.0025.0025.00 5.36 5.73 6.18 6.647.107.467.828.108.28 0.650.650.650.650.650.650.650.650.65 15.3315.3315.3315.3315.3315.3315.3315.3315.33 53.4457.0761.6266.1670.7074.3477.9780.7082.51南外墙冷负荷0.540.580.630.670.710.750.790.830.88 32.9032.8032.9033.1033.4033.9034.4034.9035.30 -1.40-1.40-1.40-1.40-1.40-1.40-1.40-1.40-1.40 0.970.970.970.970.970.970.970.970.97 0.940.940.940.940.940.940.940.940.94 28.7228.6328.7228.9029.1829.6330.0930.5530.91 25.0025.0025.0025.0025.0025.0025.0025.0025.00 3.72 3.63 3.72 3.90 4.18 4.63 5.09 5.55 5.91 0.650.650.650.650.650.650.650.650.6563.3063.3063.3063.3063.3063.3063.3063.3063.30 153.13149.38153.13160.63171.89190.65209.40228.16243.17 352.51345.57349.53362.60380.87409.66442.79478.94513.32屋顶冷负荷0.540.580.630.670.710.750.790.830.88 35.8038.1040.7043.5046.1048.3049.9050.8050.90-2.70-2.70-2.70-2.70-2.70-2.70-2.70-2.70-2.700.970.970.970.970.970.970.970.970.970.940.940.940.940.940.940.940.940.94 30.1832.2834.6537.2039.5741.5843.0443.8643.95 25.0025.0025.0025.0025.0025.0025.0025.0025.00 5.187.289.6512.2014.5716.5818.0418.8618.95 1.95 1.95 1.95 1.95 1.95 1.95 1.95 1.95 1.95 228.00228.00228.00228.00228.00228.00228.00228.00228.00 2303.293235.674289.685424.766478.767370.618019.238384.088424.62瞬时传热冷负荷0.540.580.630.670.710.750.790.830.88 31.5031.9032.2032.0032.0031.6030.8029.9029.10-1.00-1.00-1.00-1.00-1.00-1.00-1.00-1.00-1.00 30.5030.9031.2031.0031.0030.6029.8028.9028.10 25.0025.0025.0025.0025.0025.0025.0025.0025.00 5.50 5.90 6.20 6.00 6.00 5.60 4.80 3.90 3.103.61 3.61 3.61 3.61 3.61 3.61 3.61 3.61 3.61 162.03162.03162.03162.03162.03162.03162.03162.03162.03 3862.674143.594354.284213.824213.823932.903371.052738.982177.14东外窗入射得热引起的冷负荷0.540.580.630.670.710.750.790.830.880.240.230.210.180.150.110.080.070.07 599.00599.00599.00599.00599.00599.00599.00599.00599.00 0.520.520.520.520.520.520.520.520.52 15.7515.7515.7515.7515.7515.7515.7515.7515.75 876.25839.74766.72657.19547.66401.62292.08255.57255.57西外窗入射得热引起的冷负荷0.540.580.630.670.710.750.790.830.880.340.560.720.830.770.530.110.100.09 599.00599.00599.00599.00599.00599.00599.00599.00599.00 0.520.520.520.520.520.520.520.520.520.000.000.000.000.000.000.000.000.00南外窗入射得热引起的冷负荷0.540.580.630.670.710.750.790.830.880.800.620.450.320.240.160.100.090.09 302.00302.00302.00302.00302.00302.00302.00302.00302.00 0.520.520.520.520.520.520.520.520.52 142.50142.50142.50142.50142.50142.50142.50142.50142.5013323.6410325.827494.555329.453997.092664.731665.451498.911498.910.540.580.630.670.710.750.790.830.880.830.790.710.600.610.680.170.160.15114.00114.00114.00114.00114.00114.00114.00114.00114.000.520.520.520.520.520.520.520.520.523.78 3.78 3.78 3.78 3.78 3.78 3.78 3.78 3.78138.42131.75118.40100.06101.73113.4028.3526.6825.0114338.3011297.318379.676086.704646.483179.741985.891781.171779.500.540.580.630.670.710.750.790.830.880.800.830.850.870.890.420.340.280.2365.1365.1365.1365.1365.1365.1365.1365.1365.130.930.930.930.930.930.930.930.930.930.000.000.000.000.000.000.000.000.0068.6168.6168.6168.6168.6168.6168.6168.6168.610.000.000.000.000.000.000.000.000.000.000.000.000.000.000.000.000.000.000.540.580.630.670.710.750.790.830.880.830.850.870.890.900.910.920.930.9463.9763.9763.9763.9763.9763.9763.9763.9763.97322.00322.00322.00322.00322.00322.00322.00322.00322.000.890.890.890.890.890.890.890.890.8915215.9915582.6415949.2916315.9516499.2716682.6016865.9217049.2517232.57117.46117.46117.46117.46117.46117.46117.46117.46117.4627939.2028612.4329285.6729958.9030295.5230632.1330968.7531305.3731641.994315544195452354627546795473154783548355488750.540.580.630.670.710.750.790.830.880.790.810.830.840.860.870.890.900.921.20 1.20 1.20 1.20 1.20 1.20 1.20 1.20 1.200.600.600.600.600.600.600.600.600.60807.28807.28807.28807.28807.28807.28807.28807.28807.283673.453766.453859.443905.943998.944045.444138.444184.944277.940.540.580.630.670.710.750.790.830.88办公人员散热引起的冷负荷照明散热引起的冷负荷商场人员散热引起的冷负荷各分项逐时冷负荷汇总表北外窗入射得热引起的冷负荷23033236429051384253533463503633815425647973718019838427392177386341444354421442143933337141044347976606761147580875714761697601375552757887601713:0014:0015:0016:0017:0018:0019:0020:0021:000.850.870.890.900.920.930.930.940.9510494.6410494.6410494.6410494.6410494.6410494.6410494.6410494.6410494.6413.0013.0013.0013.0013.0013.0013.0013.0013.00807.28807.28807.28807.28807.28807.28807.28807.28807.288920.449130.349340.239445.189655.079760.029760.029864.969969.91设备散热引起的冷负荷143381129783804887517794315544195452354627546795608746463180198617814185427836733766385939063999404541384731547835483558920913093409970944596559760976098650.920.96 1.00 32.6032.9033.10 -1.60-1.60-1.60 0.970.970.97 0.940.940.94 28.2728.5428.72 25.0025.0025.00 3.27 3.54 3.72 0.650.650.65 41.7641.7641.76 88.6596.07101.020.920.96 1.00 37.3038.0038.50 -1.90-1.90-1.90 0.970.970.97 0.940.940.94 32.2832.9233.37 25.0025.0025.00 7.287.928.37 0.650.650.65 24.4224.4224.42 115.52125.65132.890.920.96 1.00 38.5038.6038.50 -1.90-1.90-1.90 0.970.970.97 0.940.940.94 33.3733.4633.37 25.0025.0025.00 8.378.468.37 0.650.650.65 15.3315.3315.33 83.4284.3383.420.920.96 1.00 35.7036.0036.10 -1.40-1.40-1.40 0.970.970.97 0.940.940.94 31.2731.5531.64 25.0025.0025.00 6.27 6.55 6.64 0.650.650.6563.3063.3063.30 258.17269.43273.18 545.76575.48590.510.920.96 1.00 50.3049.2047.70-2.70-2.70-2.700.970.970.970.940.940.94 43.4042.4041.03 25.0025.0025.00 18.4017.4016.03 1.95 1.95 1.95 228.00228.00228.00 8181.397735.467127.380.920.96 1.000.060.060.06 599.00599.00599.00 0.520.520.52 15.7515.7515.75 219.06219.06219.060.920.96 1.000.090.080.08 599.00599.00599.00 0.520.520.520.000.000.000.920.96 1.000.080.080.07 302.00302.00302.00 0.520.520.52 142.50142.50142.501332.361332.361165.820.920.96 1.000.140.130.12 114.00114.00114.00 0.520.520.523.78 3.78 3.78 23.3521.6820.01 1574.771573.111404.890.920.96 1.000.200.170.15 65.1365.1365.130.930.930.930.000.000.00 68.6168.6168.610.000.000.000.000.000.000.920.96 1.000.470.380.31 63.9763.9763.97 322.00322.00322.00 0.890.890.89 8616.296966.365683.08 117.46117.46117.46 15820.9912791.4410435.12 2443719758161180.920.96 1.000.290.260.231.20 1.20 1.200.600.600.60807.28807.28807.28 1348.481208.981069.480.920.96 1.00 818177357127546575591 1686126484341971354732998722:0023:0024:00:000.400.320.2710494.6410494.6410494.6413.0013.0013.00807.28807.28807.284197.863358.282833.55244371575157314051348120910691975816118419833582834。
空调房间冷热负荷计算1 电算表格编制说明1.1 冬季围护结构热负荷计算1、 按空调房间为正压考虑,不计算空气渗透热负荷;当需要计算时,应采用《采暖房间热负荷计算》电算表。
2、 按不考虑房间发热量的最不利情况,计算围护结构热负荷作为空调房间热负荷;需要考虑发热量时另行计算。
3、 围护结构传热系数K 值和房间冬季围护结构热负荷采用公式同《采暖房间热负荷计算》电算表。
1.2 空调房间逐时冷负荷计算采用冷负荷系数法,并进行了如下简化和假设。
当实际情况与之不符时,应对计算进行修改。
1、 忽略冬夏季外围护结构外表面换热系数的不同,均按冬季不利情况考虑。
2、 忽略窗的内遮阳和有效面积修正。
3、 假设无外遮阳设施。
4、 按空调房间为正压考虑,不计算空气渗透冷负荷。
5、 灯光、人体、设备和其他负荷按稳定传热考虑。
1.3 空调房间各项冷负荷采用以下公式计算:1、 外墙和屋面传热引起的逐时冷负荷0CL (W ))'(0000n l t t K F CL −=ραC C t t t dl l l ·)('00+=式中:0K ——外墙和屋面的传热系数(W/(m 2·℃));0F ——外墙和屋面的面积(m 2);n t ——室内计算温度(℃);0'l t ——外墙和屋面的综合冷负荷计算温度的逐时值(℃);0l t ——外墙和屋面的冷负荷计算温度的逐时值(℃);dl t ——围护结构的地点修正值(℃);αC ——外表面放热系数修正值,为简化计算,表中取1;ρC ——吸热系数修正值,为安全和简化计算,表中统一取1。
2、 玻璃窗瞬变传热引起的冷负荷1·ch CL (W )]t )t [(t C C K F CL n d lc K K ch ch ch −+2211·=式中:ch F ——窗口面积(m 2);ch K ——玻璃窗的传热系数(W/(m 2·℃));1K C ——不同类型窗框的玻璃窗传热系数修正值,安全起见,本表中取最大值1.2;2K C ——有内遮阳设施玻璃窗的传热系数修正值,安全起见,本表中取最大值1.0,即无内遮阳设施;n t ——室内设计温度(℃);lc t ——玻璃窗的逐时冷负荷计算温度(℃);2d t ——玻璃窗的地点修正值(℃);3、 由于太阳辐射透过玻璃窗进入室内的热量引起的逐时冷负荷2⋅ch CL (W )])112N ch (CL zd sh ch ch CL zd ch a n S ch C )J F (F C J [F C C C CL ⋅⋅⋅⋅⋅−+=式中:S C ——窗玻璃的遮挡系数;n C ——窗内遮阳设施的遮阳系数,安全起见,本表中取值1.0,即无内遮阳设施;a C ——窗的有效面积系数,安全起见,本表中取1.0;zd ch J ⋅——透过标准窗玻璃的太阳总辐射照度(直接辐射和散射辐射之和)(W/m 2); zd sh J ⋅——透过标准窗玻璃的太阳散射辐射照度(W/m 2);ch F ——窗口面积(m 2);1F ——窗上受太阳直接照射的面积(m 2),为安全和简化计算取1F =ch F ;N ch (CL ch CL C C )⋅⋅,——冷负荷系数(N ch (CL C )⋅系北向冷负荷系数)。
空调冷负荷计算一、屋顶冷负荷表1:屋顶冷负荷由附录8差得屋顶冷负荷计算温度逐时值t wl,即可以按照CL=KF(t'w1-t Nx)和式t'w1=(t wl+t d)kаkρ。
算出屋顶逐时值冷负荷,计算结果如下:时间8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 t38.1 37.0 36.1 35.6 35.6 36.0 37.0 38.4 40.1 41.9 43.7 45.4 46.7wlt0.1dK0.97aK1.0pt'37.05 35.99 35.11 34.63 34.63 35.02 35.99 37.35 38.99 40.74 42.49 44.14 45.40wlt26NxK 0.48F 24000*15000=360CL 1909.44 1726.27 1574.21 1491.26 1491.26 1558.66 1726.27 1961.28 2244.67 2547.07 2849.47 3134.59 3352.321二、东外墙冷负荷表2:东外墙冷负荷由附录7查得东外墙冷负荷计算温度逐时值t wl,即可以按照CL=KF(t'w1-t Nx)和式t'w1=(t wl+td)kаkρ。
算出屋顶逐时值冷负荷,计算结果如下:时间8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 t36.0 35.5 35.2 35.0 35.0 35.2 35.6 36.1 36.6 37.1 37.5 37.9 38.2wlt0.5dK0.97aK1.0pt'35.41 34.92 34.63 34.44 34.44 34.63 35.02 35.50 35.99 36.47 36.86 37.25 37.54wlt26Nx△t 9.41 8.92 8.63 8.44 8.44 8.63 9.02 9.50 9.99 10.47 10.86 11.25 11.54 K 1.5F 15000*6000-2000*2000*2=82CL 1157.43 1097.16 1061.49 1038.12 1038.12 1061.49 1109.46 1168.50 1228.77 1287.81 1335.78 1383.75 1419.422三、南外墙冷负荷表3:南外墙冷负荷由附录7查得南外墙冷负荷计算温度逐时值t wl,即可以按照CL=KF(t'w1-t Nx)和式t'w1=(t wl+td)kаkρ。
1、t cl实际=(t cl+t d)K a Kρ(9-5); CL q=KF(t cl实际-t N) (9-6)2、t cl——屋顶的冷负荷逐时计算温度(℃),由附录9-8和9-9查取;应用公式(9-5)计算,应注意外墙和屋顶的逐时冷负荷计算温度值tcl 是以北京地区气象参数数据为依据计算出来的。
所何用的外表面放热系数为18.6W/(m2.K);内表面放热系数为8.7W/(m2.K)。
所采用的外墙和屋面的吸收系数为ρ=0.90。
房间传递系数V0=0.681,W1=-0.87。
3、t d——地点修正值(℃),见附录9-104、K a——外表放热系数修正值,见表9-75、Kρ——外表面吸收系数修正值,考虑到城市大气污染和中浅颜色的耐久性差,建议吸收系数均采用Kρ=0.9,但确有把握经久保持建筑围护结构表 面的中、浅色时,风可采用表9-8的修正值。
6、t N——室内计算温度(℃)7、K——屋顶的传热系数[W/(m2.K)],参见附录9-8和9-98、F——屋顶的计算面积(m2)南 外 墙 冷 负 荷说明:1、t cl实际=(t cl+t d)K a Kρ(9-5); CL q=KF(t cl实际-t N) (9-6)2、t cl——外墙的冷负荷逐时计算温度(℃),由附录9-8和9-9查取;应用公式(9-5)计算,应注意外墙和屋顶的逐时冷负荷计算温度值tcl 是以北京地区气象参数数据为依据计算出来的。
所何用的外表面放热系数为18.6W/(m2.K);内表面放热系数为8.7W/(m2.K)。
所采用的外墙和屋面的吸收系数为ρ=0.90。
房间传递系数V0=0.681,W1=-0.87。
3、t d——地点修正值(℃),见附录9-104、K a——外表放热系数修正值,见表9-75、Kρ——外表面吸收系数修正值,考虑到城市大气污染和中浅颜色的耐久性差,建议吸收系数均采用Kρ=0.9,但确有把握经久保持建筑围护结构表 面的中、浅色时,风可采用表9-8的修正值。
空调冷热负荷计算1、冷负荷计算(一)外墙的冷负荷计算通过墙体、天棚的得热量形成的冷负荷,可按下式计算:CLQτ=KF⊿tτ-ε W式中K——围护结构传热系数,W/m2•K;F——墙体的面积,m2;β——衰减系数;ν——围护结构外侧综合温度的波幅与内表面温度波幅的比值为该墙体的传热衰减度;τ——计算时间,h;ε——围护结构表面受到周期为24小时谐性温度波作用,温度波传到内表面的时间延迟,h;τ-ε——温度波的作用时间,即温度波作用于围护结构内表面的时间,h;⊿tε-τ——作用时刻下,围护结构的冷负荷计算温差,简称负荷温差。
(二)窗户的冷负荷计算通过窗户进入室内的得热量有瞬变传热得热和日射得热量两部分,日射得热量又分成两部分:直接透射到室内的太阳辐射热qt和被玻璃吸收的太阳辐射热传向室内的热量qα。
(a)窗户瞬变传热得形成的冷负荷本次工程窗户为一个框二层3.0mm厚玻璃,主要计算参数K=3.5 W/m2•K。
工程中用下式计算:CLQτ=KF⊿tτ W式中K——窗户传热系数,W/m2•K;F——窗户的面积,m2;⊿tτ——计算时刻的负荷温差,℃。
(b)窗户日射得热形成的冷负荷日射得热取决于很多因素,从太阳辐射方面来说,辐射强度、入射角均依纬度、月份、日期、时间的不同而不同。
从窗户本身来说,它随玻璃的光学性能,是否有遮阳装置以及窗户结构(钢、木窗,单、双层玻璃)而异。
此外,还与内外放热系数有关。
工程中用下式计算:CLQj•τ= xg xd Cs Cn Jj•τ W式中xg——窗户的有效面积系数;xd——地点修正系数;Jj•τ——计算时刻时,透过单位窗口面积的太阳总辐射热形成的冷负荷,简称负荷,W/m2;Cs——窗玻璃的遮挡系数;Cn——窗内遮阳设施的遮阳系数。
(三)外门的冷负荷计算当房间送风两大于回风量而保持相当的正压时,如形成正压的风量大于无正压时渗入室内的空气量,则可不计算由于门、窗缝隙渗入空气的热、湿量。