某证券大厦空调系统配电改造

Power Distribution Transformation of Air Conditioning System in a Securities Building

对已有建筑进行配电改造的要点在于是否有足够的配电容量,当建筑内有不同供电等级的负荷存在时,应满足其各等级负荷的供电需求。当建筑内设有数据中心时,确保其正常运行的空调负荷通常供电等级较高,对空调系统进行改造时,要满足其负荷等级的供电要求。对于供电路径长的配电回路,除了满足电缆载流量要大于负载电流外,还应该校验线路电压降,满足最大压降小于5%;校验线路保护的灵敏度,确保保护电器能够在线路出现故障时安全跳闸,必要时需增加短延时保护功能。以笔者工作中参与的实际空调系统升级改造项目为例,介绍了原始配电情况、负荷分级、改造方案、供配电设计、结果校验等几个方面,并着重对长距离线路的保护整定值进行了计算和分析,最后为空调系统改造类的工程设计提供合理化建议。

The key point of the power distribution transformation of existing buildings is whether there is sufficient power distribution capacity. When there are loads of different power levels in the building, the power supply demand of each level of load should be satisfied. When there is a data center in the building, the air-conditioning load to ensure its normal operation usually has a higher level. When the air-conditioning system is modified, the power supply requirements of its load level must be met. Power distribution circuits with long lines, in addition to ensuring that the cable current carrying capacity is greater than the load current, the line voltage drop should also be checked to ensure that the maximum voltage drop is less than 5%;the sensitivity of the line protection should be verified to ensure that the protective equipment can trip safely in case of failure, and short delay protection function should be added when necessary. Based on the actual work involved in air conditioning system upgrade and transformation project, this paper introduces the original distribution situation, load classification, retrofit scheme, design of power supply, result verification, etc., and focuses on long lines of protection setting values for the calculation and analysis, and finally provides reasonable suggestions for engineering design.