【摘要】 变频螺杆式冷热水机组具有优良的制冷制热效果，并可满足广泛的部分负荷需求。本文研究了此类机组的系统原理、部件选型、控制策略、运行特性以及经济性，并给出了结论和建议。依据本研制机组，各部分负荷工况下，变频下的性能系数（COP）要大于定频下的COP，增大2%～15%，尤其是制冷工况下的COP_c，变频调节使得机组在低负荷率下的性能更优；在定频和变频运行下的制冷工况制冷综合部分负荷性能系数（IPLV_c）和制热工况制热综合部分负荷性能系数（IPLV_h），变频IPLV_c明显大于定频IPLV_c，增长6.95%，变频IPLV_h大于定频IPLV_h，增长3.55%，变频调节使得机组综合能效系数更高；机组变频运行时，可每年减少电能消耗，节省运行费用，减少二氧化碳排放。更多还原

【Abstract】 Variable frequency screw chiller type cold and hot water unit has excellent cooling and heating effect,and can meet a wide range of partial load requirements. In this paper, the system principle, component selection,control strategy, operation characteristics and economy of such units are studied, conclusions and suggestions are given. According to the developed unit, coefficient of performance(COP) under variable frequency is larger than COP under constant frequency under various partial load conditions, and increases by 2%-15%, especially COPC under refrigeration conditions. Variable frequency control makes the unit performance better under low load rate. In variable frequency and constant frequency operation, for Integrated Part Load Value(cold)-IPLVc of refrigeration condition and Integrated Part Load Value(heat)-IPLVh of heating condition, variable frequency IPLVc is significantly higher than constant frequency IPLVc, with an increase of 6.95%, variable frequency IPLVh is higher than constant frequency IPLVh, with an increase of 3.55%. Variable frequency control makes the comprehensive energy efficiency coefficient of the unit higher. When the unit runs with variable frequency, it can reduce electric energy consumption, save operation cost and reduce carbon dioxide emission every year.更多还原