吸收升温Kalina发电循环的模拟及实验研究

发布时间：2018-03-18 12:57

  本文选题：Kalina　切入点：吸收　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：Kalina地热发电厂的尾水排放温度较高,针对此问题,文中对Kalina发电循环进行优化改进,结合第二类吸收式热泵提出了吸收升温Kalina循环。该循环以经过一次换热之后温度较高的地热尾水作为吸收式热泵的驱动热源,通过换热的方式,将稀氨水溶液与氨气在吸收器中完成吸收过程时所放出的热量传递给温度较低的氨水基本溶液,成功的提高了发生器入口工质的温度,进而增加了进入汽轮机做功的氨蒸汽的流量。文中建立了数学计算模型并采用engineering equation solver(EES)工程计算软件编写热力学计算程序,分析其在理论上的可行性,并对影响循环性能的主要参数进行了影响分析,同时采用化工流程模拟软件ASPEN Plus建立系统模型加以验证。模拟结果表明,在相同的工况条件下吸收升温Kalina循环的净发电量相比于Kalina循环,从2098.7 kW上升到2241.24 kW,提高6.8%左右。吸收升温Kalina循环的净发电量随着热源温度的升高而逐渐升高,但是其效率存在一个最佳值,对应的最佳热源温度为110℃左右。冷源温度与乏汽压力以及工质浓度存在一定关系,计算结果表明,当工质浓度上升,其可以匹配的冷源温度范围越宽广。计算还发现随着冷源温度的升高,系统净发电量会有所降低,但是随着汽轮机入口压力的升高,系统净发电量会增加。当汽轮机入口压力增加到一定程度时将导致工质泵耗功急剧增加,造成系统净发电量的降低。此外,系统净发电量随着氨水基本溶液浓度的升高而升高,但浓度超过最佳值就会造成净发电量的下降,不同的汽轮机入口压力对应着不同的最佳工质浓度。为了进一步研究该循环提高工质温度的效果,在理论分析的基础上,根据实验条件,搭建了吸收升温子系统实验台,对影响其升温性能的主要因素进行了实验研究。实验结果表明,热源温度以及氨水基本溶液浓度的升高有助于提高实验台的升温性能,但是冷源温度的升高则对实验台的升温性能具有抑制作用。保证吸收器管内流体处于湍流阶段有助于提高实验台的升温性能,同时流量比(稀溶液泵流量与液氨泵流量的比值)的升高在一定程度上也有助于提高实验台的升温性能,但是超过最佳流量比则对实验台升温性能的提高没有帮助。实验系统中加入纳米颗粒在一定程度上有利于实验台升温性能的提高,并且存在着最佳的添加比例。但是当纳米颗粒的浓度达到一定程度(0.3%左右)时,继续添加纳米颗粒对提高实验台的升温性能没有帮助。
[Abstract]:The tail water discharge temperature of Kalina geothermal power plant is high. In order to solve this problem, the Kalina generation cycle is optimized and improved in this paper. Combined with the second kind of absorption heat pump, the absorption heating Kalina cycle is proposed. The geothermal tailings with higher temperature after primary heat transfer are used as the driving heat source of the absorption heat pump. The heat released from dilute ammonia solution and ammonia gas in the absorber was transferred to the basic solution of ammonia water with lower temperature, which successfully raised the temperature of the working fluid at the inlet of the generator. Furthermore, the flow rate of ammonia steam entering the work of steam turbine is increased. In this paper, the mathematical calculation model is established and the thermodynamic calculation program is compiled by engineering equation solver EES, and its feasibility in theory is analyzed. At the same time, the main parameters affecting the cycle performance are analyzed, and the system model is established by the chemical process simulation software ASPEN Plus. The simulation results show that, Compared with the Kalina cycle, the net power generation of the absorption heating Kalina cycle under the same operating conditions increased by about 6.8%, from 2098.7 kW to 2241.24 kW. The net generating capacity of the absorption heating Kalina cycle gradually increased with the increase of the heat source temperature. However, there is an optimum value of its efficiency, and the corresponding optimum heat source temperature is about 110 鈩，

本文编号：1629675