Working Fluid Selection and Electrical Performance Optimisation of a Domestic Solar-ORC Combined Heat and Power System for Year-Round Operation in the UK
Working Fluid Selection and Electrical Performance Optimisation of a Domestic Solar-ORC Combined Heat and Power System for Year-Round Operation in the UK
复制标题
DOI：
10.1016/j.apenergy.2016.04.041
复制
发表时间：
2017-01
期刊：
影响因子：
11.2
通讯作者：
James Freeman;K. Hellgardt;C. Markides
中科院分区：
文献类型：
--
作者：
James Freeman;K. Hellgardt;C. Markides
在本文中，我们研究了国内规模的太阳能热电联产（S-CHP）系统的发电潜力，该系统采用有机朗肯循环（ORC）发动机和15-m2非集中式太阳能集热器阵列。该系统采用一系列有机工质进行模拟，其性能针对英国气候进行了优化。研究结果适用于类似的地理位置，具有显着的云层覆盖，低太阳能资源和有限的安装区域。该系统设计的一个关键特征是在操作期间实现固定的流体流速，以避免在部分负载下部件的性能受到影响。通过蒸发器出口处的工作流体缓冲容器提供在变化的太阳辐射条件下的稳定操作，该缓冲容器保持在ORC的蒸发温度和压力下。通过采用两级太阳能集热器/蒸发器配置，在最佳蒸发饱和温度为126 °C（对应于16.2巴的蒸发压力）的情况下，以HFC-245 ca为工作流体，报告的最大净年发电量为1070 kW h yr-1（连续平均功率为122 W），太阳能发电效率为6.3%。这相当于典型/平均英国家庭电力需求的1.32%，并且代表了相同作者基于早期S-CHP系统配置和HFC-245 fa作为工作流体[1]的最新努力的50%以上的改进，从而突出了使用最佳系统配置和流体时可能的收益，并表明可能有进一步的显著改进。性能和简单的成本比较与独立的，并排的光伏和太阳能热加热系统。
In this paper, we examine the electrical power-generation potential of a domestic-scale solar combined heating and power (S-CHP) system featuring an organic Rankine cycle (ORC) engine and a 15-m2non-concentrated solar-thermal collector array. The system is simulated with a range of organic working fluids and its performance is optimised for operation in the UK climate. The findings are applicable to similar geographical locations with significant cloud coverage, a low solar resource and limited installation areas. A key feature of the system’s design is the implementation of fixed fluid flow-rates during operation in order to avoid penalties in the performance of components suffered at part-load. Steady operation under varying solar irradiance conditions is provided by way of a working-fluid buffer vessel at the evaporator outlet, which is maintained at the evaporation temperature and pressure of the ORC. By incorporating a two-stage solar collector/evaporator configuration, a maximum net annual electrical work output of 1070 kW h yr−1(continuous average power of 122 W) and a solar-to-electrical efficiency of 6.3% is reported with HFC-245ca as the working fluid at an optimal evaporation saturation temperature of 126 °C (corresponding to an evaporation pressure of 16.2 bar). This is equivalent to ∼32% of the electricity demand of a typical/average UK home, and represents an improvement of more than 50% over a recent effort by the same authors based on an earlier S-CHP system configuration and HFC-245fa as the working fluid [1], thus highlighting the gains possible when using optimal system configurations and fluids and suggesting that significant further improvements may be possible. A performance and simple cost comparison with stand-alone, side-by-side PV and solar-thermal heating systems is presented.