一种基于低温烟气余热深度应用的热电冷联产系统研究

A Study of the CCHP System Based on the Deep Utilization of Low Temperature Flue Gas

为深度利用热电冷联产(combined cooling heating and power,CCHP)系统低温烟气余热;并缓解因夏季建筑冷负荷波动所导致的CCHP系统变工况效率低下问题,提出一种低温烟气热回收与蓄冷一体化装置与CCHP系统相集成的新型CCHP一体化系统。为了进一步阐释新型CCHP一体化系统性能,运用Aspen plus流程模拟软件和理论分析,对一案例系统进行了数值模拟计算。结果表明,该集成方式可将系统排烟温降至50.5℃,系统总能利用效率增加8.1%;并实现夏季系统单位时间最大蓄冷量900 k W。根据新型一体化CCHP系统集成特征,对低温烟气热回收与蓄冷一体化装置进行了研究,分析了该装置设计长度与管内流动工质(烟气、生活热水、载冷介质)流速的变化对系统热力性能及系统蓄/释冷能力的影响特性。新型一体化CCHP系统的集成方式可为进一步提高能源利用效率与实现新一代的建筑能源供应系统提供了思路。

To deeply utilize the low-temperature waste heat of combined cooling,heating and power( CCHP)system and solve the inefficiency of the CCHP system running in varying condition duo to the fluctuating cooling load of buildings,an integrated system was proposed: the traditional CCHP system coupled with a low-temperature flue gas heat recovery and storage integrated device. To further illustrate the performance of this new CCHP system,a case system is calculated numerically and simulated by a process simulation software,Aspen plus. The results show that the system can drop the exhaust temperature to 50. 5 ℃,increase the energy efficiency by 8. 1%,and realize maximum storage capacity of 900 k W. According to the feature of this new CCHP system,the paper also studies the low-temperature flue gas heat recovery and storage integrated device,and analyses how the length of the device and the flow rate of working fluids( gas,domestic hot water,refrigerant) have influence on system performance. And this study also shows a promising way for further advanced distributed energy systems integration.