【作者】 刘涛；

【导师】 冯增朝；

【作者基本信息】 太原理工大学 ， 采矿工程， 2012， 硕士

【摘要】 油页岩作为常规能源的补充,其热解可得到类似原油的页岩油和可替代天然气的煤气,对改变我国能源结构,具有非常重要的战略意义。原位注热开采油页岩油气技术是未来油页岩安全高效开采的有效手段和技术途径,但是在热采过程尾端大量低温余热蒸汽因起不到油页岩热解作用而被浪费,因此对这部分热量进行回收发电不仅可以节约能源,同时也可以提高原位注热开采油页岩油气技术的经济性。本文以回收原位注热开采油页油气低温余热为目的,开展了低温余热发电的研究。在对国内外相关领域的研究进行充分调研的基础上,结合原位注热开采油页岩油气实际工程状况,对现行的低温余热发电系统进行比较,选择了由蒸发器、冷凝器、工质泵、汽轮机等主要部件组成的有机朗肯循环(0RC)发电系统模型。本文从安全性和经济性等各方面考虑,选取了五种作为可选用的有机朗肯循环工质,针对有机朗肯循环各组成部分,以热力学理论为基础,进行了详细的热力分析,确立了系统热力方程,并且以系统的净输出电功和热效率作为性能的衡量标准,采用工程计算软件EES来考察循环参数对其的影响,以及不同工质之间的区别,从而确定最佳循环参数及最佳循环工质。通过同一工质循环参数对系统的影响分析来看,各参数对系统的影响程度不一,其中以蒸发温度对净输出电功的影响最大,在余热流体温度、汽轮机背压一定的情况下,对于系统存在一个“最佳蒸发温度”使得净输出电功达到最大,并且“最佳蒸发温度”随着余热流体温度、汽轮机背压的增加而增加。对于不同工质之间循环参数对比分析,分别分析了不同工质最佳蒸发温度所对应的各种参数,综合经济性和环保性的考虑,选取R11作为最适宜循环工质。以R11为循环工质,额定功率为5kw的单级背压式汽轮机为计算参考,对系统进行设备选型,搭建了系统实验平台,并进行了实验,对所得到的实验数据进行了分析以验证数值模拟结果。利用工程计算软件EES,对系统进行了及(?)效率、火用损失分析,分析了(?)损失的部位、类型和数量,得出预热器蒸发器、冷凝器(?)损失所占的比例最大的结论,并根据此结论,对系统进行了优化,增加了回热器,减少了冷凝器与预热器蒸发器的传热温差和(?)损失,降低了系统的不可逆性。此项研究的实验模型不仅可以对原位注热开采油页油气低温余热进行回收利用,而且对其他工程或项目低温余热利用均有参考价值。更多还原

【Abstract】 Oil shale is the conventional energy supplement. Its pyrolysis can receive shale oil similar to crude and substitute for natural gas. It has very important strategy sense to change the energy structure of our country.Oil shale in-situ hot exploitation is the safe and effective means for mining and the technical way in the future. But in the finality of the thermal process, a large number of low temperature and waste heat steam was wasted because of the unusefulness to oil shale pyrolysis effect. Recovering this part of heat to power generation can not only save energy, but also improve the economic factor in Oil shale in-situ hot exploitation. In this paper, the purpose is to recover the low temperature waste heat stream of Oil shale in-situ hot exploitation. On that basis, we carry out the study of using low temperature waste heat stream to power generation. On the basis of investigating the domestic and international research, the paper combined with the actual engineering situation of Oil shale in-situ hot exploitation, made comparisons with the current low temperature waste heat power generation system and finally chosen the organic Rankine cycle (ORC) generation system model consist of the evaporator, condenser, refrigerant pump, turbine and other main components.Considering the safety and environmental protection and other aspects, we selected five refrigerant for the ORC.Aiming at the components of ORC and basing on the thermodynamic theory, we has carried on the detailed thermal analysis and established the system thermodynamic equation. And then, we took the net output power and heat efficiency of the system as the performance measures and used the engineering calculation software--EES to study the influence to cycle parameters.We also analyzed the distinction between different working mediums and thereby determined the optimum cycle parameters and optimum circulating refrigerant. Through analyzing the influence to the system from the same refrigerant cycle parameters, we found that the influence of parameters to the system was different and the evaporation temperature on net output power had the greatest effect. When the waste heat fluid temperature and steam pressure was in a certain way, there exited a "best evaporating temperature" to make the net output power maximum and the "best evaporation temperature" increased with the increasing of the waste heat fluid temperature and steam pressure. Comparing with the cycle parameters between different refrigerant, we analyzed in the best evaporation temperature of different refrigerants corresponding to the parameters. Considering comprehensive economic and environmental, we finally selected R245fa as the most suitable cycle refrigerant.By using the engineering calculation software--EES, this paper carried on the exergy efficiency and exergy loss analysis to the system, and analyzed the position, type and quantity of the exergy loss. Then we found that the preheater evaporator and condenser exergy loss accounted for the largest proportion. Basing on this conclusion, we optimized the system, increased the heat regenerator, reduced the transfer temperature difference and the exergy loss of condenser and the preheater evaporator heat and reduced the system irreversibility.The study of experimental model can not only recovery on the Oil shale in-situ hot exploitation and gas low temperature waste heat recycling, but also be referenced by other engineering or projects to the low temperature waste heat.更多还原