溴化锂吸收式热泵回收循环水余热的模拟研究

Using lithium bromide absorption heat pump to recycle circulating water heat:a simulation

循环水的余热造成环境热污染,同时也损失了大量的热能。对此,利用吸收式热泵对其进行回收利用。以某200 MW抽凝机组及其供热系统为例,采用Aspen Plus软件建立单、双效溴化锂吸收式热泵模型,并进行变工况模拟对比分析。研究结果表明:当热泵出口热网水温度升高或热泵驱动汽源汽量增加时,单、双效循环热泵热力系数均降低;在相同热泵出口热网水温度下,双效循环比单效循环节省蒸汽率约30%;当采用多效循环且热泵出口热网水温度高于90℃时,可采用热泵先将热网回水加热到90℃左右,然后采用尖峰加热器加热热网水到需要的温度,以保证系统稳定运行。

Waste heat of circulating water emitted to the environment causes huge thermal pollution and los-ses lots of thermal energy.Thus,absorption heat pump is applied to recycle the heat.Taking a certain 200 MW extraction condensing unit and its heating system as the example,the Aspen Plus software was employed to establish the single/double effect lithium bromide absorption heat pump model.Moreover, comparative analysis for the system under variable conditions was performed.The results indicate that, with an increase in the heat pump outlet heating network water temperature or the heat pump driven steam source,the coefficient of performance （COP）of both the single and double effect cycle heat pump declined. For the same heating temperature,the double-effect cycle can save steam by about 30% more than the sin-gle-effect cycle.When the temperature of heat pump outlet heating network water exceeded 90 ℃,the heat-ing network return water can be heated to about 90 ℃ by heat pump first,and then to the required temper-ature by spike heater,thus to ensure the stable operation of system.