Energy Saving And Design Optimization Of Secondary Water Supply System In High-rise Office Building

For now,11.4%of the world’s total energy consumption is public buildingenergy consumption, and office buildings account for about1/5of the public buildingenergy consumption. Office building energy saving measures mainly include the useof water-saving appliances, the promotion of solar hot water technology as well as thecontrol of water supply pressure based on the building water supply and drainage.Reasonable water supply way and correct evaluation of energy consumption play abig role in the reduction of water consumption and power consumption of high-riseoffice building. In this paper, taking the energy-saving design of secondary watersupply system for a more in-depth discussion based on the frequency conversionwater supply system, which is most widely used in practical engineering.First of all, in this paper, the typical secondary water supply system of high-riseoffice building, in real-time, is monitored. Constant pressure variable frequency andvariable voltage variable frequency of single pump’s energy efficiency curve is fittedbased on the established pumps, and the best way of multi-pump in parallel to run arediscussed by combining graphic analysis method. The same type pumps in parallel,when Q≤QR, using frequency conversion water supply, and when Q≥QR, usingtwo-frequency conversion water supply; the different type pumps in parallel, when Q≤QSR, using the small pump frequency conversion operation, when QSR≤Q≤QLR,adopting the large pump frequency conversion operation, and when Q≥QLR, adoptingthe large pump frequency conversion operation and the small pump under ratedoperating condition.Secondly, combined with the end pressure change rule of domestic watersupply system, the best pressure control scheme of the single pump and multi-pumprunning is proposed. Pressure control schemes of single pump operation includemulti-time variable pressure control system, the pipeline characteristic curve ofvariable pressure control system, the linear variable pressure control system and thebroken line pressure control system. The derived optimal control scheme ofmulti-pump in parallel to run, give priority to the broken line variable-voltage control,and the two endpoints of variable line should be accorded to the static head, the sizeof the rated conditions and the design pressure value of the pumps.In the end, respectively from two aspects of energy consumption and efficiency, the reclaimed water and domestic water supply systems’ optimization control schemeof this high-rise office building are quantitative evaluated. Compared with theconstant pressure control of the high area reclaimed water supply system, both thebroken line pressure control system and the linear variable pressure control system arehigher efficiency and lower energy, energy saving25.0%、30.2%respectively;compared with the constant pressure control of the high area water supply system, allthese programs include the multi-time variable pressure control system, the linearvariable pressure and the pipeline characteristic curve of variable pressure controlsystem are higher efficiency and lower energy, energy saving9.2%、12.1%、15.1%respectively.