Simulation research on a variable-lift absorption cycle and its application in waste heat recovery of combined heat and power system
Simulation research on a variable-lift absorption cycle and its application in waste heat recovery of combined heat and power system
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DOI：
10.1016/j.energy.2017.09.002
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发表时间：
2017-12
期刊：
影响因子：
9
通讯作者：
T. Hu;Xiaoyun Xie;Yi Jiang
中科院分区：
文献类型：
--
作者：
T. Hu;Xiaoyun Xie;Yi Jiang
为解决吸收式热泵应用于低品位热能利用时温度提升能力与性能系数（COP）之间的矛盾，介绍了一种变扬程吸收式循环及其改进型吸收式循环。变升程吸收循环具有相对简单的系统，并且包含足够数量的吸收器和冷凝器以产生大量逐渐升高的温度水平以匹配加热过程。在给定供热需求和余热温度水平的情况下，变扬程吸收式循环在热电联产系统余热回收中的应用结果表明，当一次热网回水温度在30 °C ~ 50 °C范围内变化时，变扬程吸收式循环始终能够有效地工作。变升程循环所需的热源温度总是比单效循环低12 °C以上。PHN的回水温度越高，改进循环的优势越明显。当PHN回水温度为50 °C时，变升程-2C循环和变升程-3C循环比单效循环可分别降低8.5%和15%的等效采暖能耗。从T-Q图的传热分析进一步阐明了变升程循环的本质。
To solve the dilemma between temperature lift capability and coefficient of performance (COP) when absorption heat pump is applied in low grade heat utilization, a variable-lift absorption cycle and an improved one based on it are introduced here. The variable-lift absorption cycles have relatively simple systems and contains enough number of absorbers and condensers to develop plenty of gradually increasing temperature levels to match heating process. For a given heating demand and waste heat temperature level, the results of application of variable-lift absorption cycles in waste heat recovery of combined heat and power(CHP) system show that, the variable-lift cycles can always work efficiently when return water temperature of primary heating network (PHN) varies from 30 °C to 50 °C. The needed heat source temperatures of variable-lift cycles are always over 12 °C lower than single effect cycle. The higher return water temperature of PHN yields more obvious advantage of the improved cycle. When the return water temperature of PHN is 50 °C, variable lift-2C cycle and variable lift-3C cycle can reduce the equivalent power consumption for space heating by 8.5% and 15% respectively when comparing to single effect cycle. The essence of the variable-lift cycles is further clarified from the heat transfer analysis in T-Q diagram.