关于教育局冷热源配套系统变更
Changes for cold and heat source supporting system of Education Bureau
变更原因:Reasons for Change
1、依据初设方案,教育局大楼将新增的热源塔安装位于地面一层室外地坪上,临近办公楼西北外墙。武汉市教育局反映若能源塔设备安装在一层室外地坪上,不仅挡住了教育局大楼的消防通道,不符合建筑设计消防规范,且设备产生的噪音恐会对相邻办公室正常办公造成影响。因此武汉市教育局建议根据大楼的建筑结构条件,在不增加大楼承重的情况下,拆除楼顶旧塔,并将新的能源塔摆放置楼顶原旧塔位置。
1. According to the original scheme, the newly increased heat -source tower of the Education Bureau′s building will be located in outdoor terrace of ground first floor, close to northwest outer wall of office building. Wuhan Municipal Education Bureau reflects that if the equipment of energy tower is installed in outdoor terrace of the first floor, it will block the fire fighting access of Education Bureau′s building at variance with building design fire protection rules, and the noise caused by the equipment could affect normal work of neighboring office. Therefore, Wuhan Municipal Education Bureau suggests that according to architectural structure condition of the building, without adding load-bearing of the building, remove the old energy tower on the roof, and place the new energy tower in the location of the old tower.
2、初设方案热源塔热泵系统采用人工检测盐溶液溶度,依据检测值人工加投料(抗冻剂)调整盐溶液溶度在允许值范围内,使热源塔热泵系统稳定运行在高能效比状态。采用这种模式,如人工检测和加投料出现偏差,轻则降低热源塔热泵系统能效比(COP),降低节能率,延长投资回收期;重则因盐溶液溶度过低导致冰点上升,可能导致溶液在低温下凝固,导致热源塔热泵机组蒸发器管道损坏,机组停机。
2. In the original scheme, the heat pump system of the heat-source tower adopts the methods of detecting the solubility of salt solution by hand, according to the detection value, adjusts the solubility of salt solution with hand feeding (antifreeze agent) within the scope of the allowable value, and makes the heat pump system of hear-source tower operate stably in the conditions of high energy efficiency ration. Using this model, if manual detection and feeding appears deviation, at best, the COP of heat pump system in the heat-source tower will be reduced, the fractional energy savings will be lowered and the pay back period will be extended; at worst, the rising freezing point resulted from low solubility of salt solution may cause the solution to freeze under the low temperature, and lead to damage to the evaporator pipelines of the heat pump units in heat-source tower, the units will shut down.
热源塔在夏季制冷时以清水为载体,在冬季制热时以盐溶液(清水+抗冻剂)为载体,初设方案未考虑热源塔热泵机组正常运行时抗冻剂的损耗量,也未考虑盐溶液的回收循环使用。每年抗冻剂消耗费用42,300.00元。
The heat-source tower uses the water as the carrier when refrigerating in summer, and uses salt solution (water +antifreeze agent )as the carrier when heating in winter, in original scheme , the wastage of antifreeze agent producing during the normal operation of the heat pump units of heat-source tower and the recycling use of salt solution are not taken into account. The annual consumption expense of antifreeze agent is 42,300.00 RMB.
初设和能源审计报告中,节约率44.21%和回收期7.96年的算法均未考虑到每年的抗冻剂费用。如考虑此费用,实际节约率为38.71%,实际回收期为9.11年。
In the original scheme and energy audit report, the calculation method as 44.21% ratio of saving and 7.96-year payback period neither considered the annual consumption expense of antifreeze agent. If consider this expense, the actual ratio of saving should be 38.71%, and the actual payback period should be 9.11 years.
现增加溶度检测、自动加投料和盐溶液回收装置,工程造价198,300.00元,但因新增装置,每年减少抗冻剂使用费17,415.00元,节约率上升至40.97%,回收期下降至8.77年。节约率和回收期均优于初设方案。
Now adding an equipment for solubility testing, self-feeding and saline solution payback, the project cost of which is 198,300.00 RMB. But because of the additional equipment, the annual consumption expense of antifreeze agent will reduce 17,415.00 RMB, ratio of saving will rise to 40.97%, and payback period reduce to 8.77 years. Both of the ratio of saving and payback period are superior to the original scheme.
变更过程:Processes for change
热源塔安装位置调整和溶度检测、自动加投料、盐溶液回收装置两项变更,工程总造价376,118.99元,超发改委核定概算。但热源塔位置必须调整,增加溶度检测、自动加投料和盐溶液回收装置能确保热源塔热泵机组稳定运行,提升节约率缩短回收期,两项变更均需实施。我司通过对合同内各项节能措施深入分析,并结合教育局实地踏勘情况决定调减建筑外窗改造(9.3万元)、风机盘管控制系统改造(7.2万元)、冷却水泵改造(2.4万元)、电动调节阀和变频控制柜内变频器调减(4万元)工作及合同暂定金来完成上述两项变更工作。因建筑外窗和风机盘管控制系统两项改造措施损失的节约率与上述两项变更提高的节约率相抵消,教育局节能改造合同价款未调整,所以节约率和回收期为持不变,节约率38.71%,回收期9.11年。
The project cost produced by the changes of the adjustment of heat-source tower location and the equipment for solubility testing, self-feeding and saline solution payback reaches 376,118.99 RMB, which exceeds NDRC approved estimates. However, the location of heat-source tower must be adjusted, while the equipment for solubility testing, self-feeding and saline solution payback can ensure the heat-source tower pump assembly running stably. In order to improve the ratio of saving and shorten the payback period, both the 2 changes should be implemented. By deeply analyzing all the energy-saving measures in contract, combining the education bureau′s site investigation, my company decides to reduce the reconstruction of building external windows(93,000RMB), the reconstruction of fan-coil units system(72,000RMB), the reconstruction of cooling-water pump(24,000RMB), electric control valves and reduce the work of frequency converters in transducer control cabin(40,000RMB) and complete above-mentioned 2 changes with contract tentative amount. Because the loss of ratio of saving by the reconstruction of building external windows and fan-coil units system is offset by the improvement of ratio of saving by the above-mentioned 2 changes, as well as the contract price of education bureau energy-saving reconstruction is unadjusted, the ratio of saving and payback period remain unchanged, as 38.7% ratio of saving and 9.11-year payback period.
2000年3月24日市建筑节能办按照《法开署项目工程变更管理办法》主持召开了武汉市教育局大楼能源塔安装位置及冷热源配套系统优化技术论证会,经充分讨论后,同意能源塔安装位置由地面移至楼顶,完善相应的冷却水系统设计;同意冷热源配套系统优化设计;同意调减外窗改造方案,以每层增加手动控制阀门的方案替代原风机盘管控制系统改造方案,2台冷却水泵改为利用原来冷却水泵,原4台变频器改为2台变频器。
On March 24,2000, according to “Project Engineering Change Management Method ”, Wuhan Municipal Building Energy Efficiency Office hosted technology discussion meeting about installation position adjustment of energy tower and supporting system optimization of cold and heat source of the building of Wuhan Municipal Education Bureau, after full discussion, the meeting agreed to move the installation position of energy tower form the ground to the roof, improve corresponding cooling water system design; agreed with supporting system optimization design of cold and heat source; agreed to simply outer window reconstruction scheme , use the scheme of adding manual control valves in each layer to replace the modification scheme of original fan coil control system , use the original cooling pump instead of two cooling water pumps, and use two frequency converters instead of original four frequency converters .
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