在这项研究中，这个模拟分析考虑的电路加载顺序和可变冷凝温度控制的操作方案。五操作方案（CS1 CS5）的影响。方案1的操作方案，加载优先考虑引线电路当机组负荷低于额定制冷能力的一半，使容量电路1和2相等时的总制冷负荷超过一半的额定制冷能力，这是传统电路的时序控制和服务作为基线。首先启动的电路是引线电路。方案CS2平衡电路加载控制系统保持电路1和2是相等的在任何时间当冷水机组的操作能力。方案是加载了CS3的铅铅电路电路直至完全加载的优先级，然后其他电路满足负载平衡时的总冷负荷超过一半的额定制冷能力。一个最佳方案CS4华彩，在机组负荷是由两个制冷回路优化共享。

Operating schemes CS1 to CS4 were under HPC。 As CTC could further improve the chiller performance, therefore, the chiller performance for the twin-circuit chiller under CTC was investigated。 Scheme CS5 is the operating scheme CS1 under CTC。 For all the operating schemes, the two compressors in one refrigeration circuit operated with even load when the cooling load of the circuit was more than 25% of the rated chiller capacity, or one compressor operated in this refrigeration circuit, which was the common control scheme。 

操作方案CS1 CS4在HPC。作为CTC可以进一步提高冷水机组的性能，因此，在CTC下的双回路冷水机组的冷水机组性能进行了研究。方案的CS5是操作方案CS1在CTC。对于所有的操作方案，在一个制冷电路中的两个压缩机的操作时，即使负载的电路的冷却负荷超过25%的额定制冷量，或一个压缩机操作在这个制冷电路，这是共同的控制方案。

4。2。 COP improvements due to circuit loading sequence 文献综述

4。2。cop由于电路加载顺序的改进

As the use of different CLS brought about changes in the steady-state behavior of chiller COP, it was worth analyzing how this control strategy helped improve the chiller COP under various operating conditions。 Fig。 3 shows COP curves of the studied chiller under various part load ratio (PLR) for scheme CS1, and the outdoor dry bulb temperature (DBT) was from 15 to 35 °C at an interval of 5 °C。 The chiller COP varied following the operating sequence of the two refrigerant circuits and the sequence of compressors in one refrigeration circuit of the chiller。 This clearly revealed that the chiller COP dropped substantially when an additional compressor or refrigerant circuit was staged to cope with a rising load, because compressor efficiency dramatically decreased at low part load conditions under HPC。 

由于不同CLS的使用带来了变化的稳态行为的冷水机组COP，它是值得分析如何控制策略，有助于改善冷水机组COP在各种操作条件下。图3显示了不同部分负荷率下的COP曲线研究（PLR）方案CS1，和室外干球温度（DBT）是从15到35°C 5°C。冷水机组COP随这两个制冷剂回路的操作顺序和冷水机组的制冷电路之一压缩机的序列间隔。这清楚地表明，冷水机COP大幅下降时，一个额外的压缩机或制冷剂电路上演，以应付不断上升的负载，因为压缩机效率显着降低，在低负荷条件下HPC。

。 Variation of COP with PLR of scheme CS1 

Fig。4 shows the percentage change of chiller COP related to scheme CS1 under different circuit loading sequences。 For the scheme CS2 as shown in Fig。4 (a), the chiller COP dropped significantly when the PLR was less than 0。25, and it could drop up to 54。3%。 When PLR ranged from 0。25 to 0。5, COP could be improved up to 12。9%。 When PLR was greater than 0。5, the operating schemes of CS1 and CS2 were identical, therefore, the chiller COP were the same。 

图4显示冷水机组COP不同电路加载顺序下方案CS1相关变化率。对这一计划的CS2为如图所示（一），冷水机组COP下降明显时，PLR小于0。25，并可下降到54。3%。当PLR的范围从0。25到0。5，COP可提高12。9%。当丢包率大于0。5，CS1和CS2的操作方案是相同的，因此，冷水机组COP是相同的。