1、降低工程造价。 据有关部门测算，双管制供热管道，一般情况下可以降低工程造价的25%（采用玻璃钢做保护层）和10%（采用高密度聚乙烯做保护层）左右。
1. Reduce project cost. According to the calculation of relevant departments, the double pipe heating pipeline can reduce the project cost by about 25% (using FRP as the protective layer) and 10% (using HDPE as the protective layer) in general.
2 热损耗低，节约能源。
2. Low heat loss and energy saving.
预制聚氨酯直埋保温管其导热系数为：λ=0．013—0．03kcal/m·h·oC，比其他过去常用的管道保温材料低得多，保温效果提高4~9倍。再有其吸水率很低，约为0．2kg/m2。吸水率低的原因是由于聚氨酯泡沫的闭孔率高达92%左右。低导热系数和低吸水率，加上保温层和外面防水性能好的高密度聚乙烯或玻璃钢保护壳，改变了传统地沟敷设供热管道“穿湿棉袄”的状况，大大减少了供热管道的整体热损耗，热网热损失为2%，小于10%的标准要求。
The thermal conductivity of prefabricated polyurethane direct buried insulation pipe is λ = 0.013-0.03kcal/m · h · OC, which is much lower than other commonly used pipeline insulation materials in the past, and the insulation effect is increased by 4-9 times. Moreover, its water absorption is very low, about 0.2kg/m2. The reason for low water absorption is that the polyurethane foam has a closed porosity of about 92%. Low thermal conductivity and low water absorption, together with thermal insulation layer and high-density polyethylene or fiberglass protective shell with good waterproof performance, have changed the situation of "wet padded jacket" of traditional heat supply pipeline laid in trench, greatly reducing the overall heat loss of heat supply pipeline. The heat loss of heat supply network is 2%, which is less than the international 10% standard requirements.
3、防腐，绝缘性能好，使用寿命长。
3. Anticorrosion, good insulation and long service life.
预制聚氨酯直埋保温管由于聚氨酯硬质泡沫保温层紧密地粘结在钢管外皮，隔绝了空气和水的渗入，能起到良好的防腐作用。同时它的发泡孔都是闭合的，吸水性很小。高密度聚乙烯外壳、玻璃钢外壳均具有良好的防腐、绝缘和机械性能。因此，工作钢管外皮很难受到外界空气和水的侵蚀。只要管道内部水质处理好，据国外资料介绍，预制聚氨酯直埋保温管的使用寿命可达50年以上，比传统的地沟敷设、架空敷设使用寿命高3~4倍。
The rigid polyurethane foam insulation layer is tightly bonded to the outer surface of the steel pipe, and the air and water infiltration can be isolated from the prefabricated polyurethane insulation pipe. At the same time, its foam pores are closed and its water absorption is very small. HDPE shell and FRP shell have good anticorrosion, insulation and mechanical properties. Therefore, the outer skin of the working steel pipe is hard to be eroded by the outside air and water. As long as the internal water quality of the pipeline is well treated, according to foreign data, the service life of the prefabricated polyurethane direct buried insulation pipe can be more than 50 years, 3-4 times longer than that of the traditional trench laying and overhead laying.
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