【作者】 陈强；

【导师】 金红光； 韩巍；

【作者基本信息】 中国科学院研究生院（工程热物理研究所） ， 工程热物理， 2014， 博士

【摘要】 分布式燃气轮机冷热电联供系统是以能的综合梯级利用和冷热电联供为特色的分布式能源,具有良好的节能特性、可靠性、经济性以及环保特性,受到世界各国广泛关注。由于直接面向用户,它总是处于变工况状态,运行节能特性与设计情况相悖问题成为发展应用的瓶颈。本学位论文依托国家重点基础研究发展计划(973计划)和国家自然科学基金等重要项目,以典型分布式燃气轮机冷热电联供系统为研究对象,从用户负荷变化和系统全工况特性关联层面探讨系统内部能量转换与梯级利用机理,深入系统地研究联供系统的全工况特性和相应主动控制方法,旨在为破解发展难题提供一类思路、途径与方法。本文主要研究内容和成果如下：(1)分布式联供系统全工况模拟。概述了分布式冷热电联供系统全工况特性模拟核心问题,阐述分布式联供系统全工况概念,提出相应的模拟方法和评价准则。构建了基于模块全工况特性的分布式联供系统模拟程序,包括率先构建高精度通用性的全径流微小型燃气轮机全工况模型,还包括建筑用户全年逐小时冷热电负荷模块、烟气型双效溴化锂吸收式制冷机、烟气热水换热器以及追踪冷热电负荷控制模块等全工况模型。全工况模拟软件不仅考虑用户负荷变化对系统性能的影响,也考虑单元模块变工况特性对系统性能的影响,为研究分布式冷热电联供系统全工况性能和主动调控方法奠定了基础。(2)分布式联供系统全工况特性。研究了典型分布式燃气轮机冷热电联供系统的全工况特性与变工况运行性能下降机理。分析了用户日负荷变工况、全年制冷期逐小时运行特性和典型分布式燃气轮机冷热电联供系统配置及全工况特性规律。探索了冷热电联供系统性能的变化规律和与组成模块之间的关联关系,以及系统输出与用户负荷之间的匹配变化规律,凝练了冷热电联供系统高效变工况运行的调控要求。运用(?)与能量品位分析法剖析燃气轮机联供系统全工况能量平衡与能量品位的变化以及(?)损失特性规律,探讨造成冷热电系统变工况运行性能下降的本质原因和提升的潜力,从科学用能高度揭示分布式联供系统全工况能量转换与梯级利用机制。(3)分布式联供系统主动调控方法与运行优化。全面论述燃气轮机联供系统主动调控概念、机制与方法。针对传统调控方式下变工况运行时燃气轮机透平入口温度下降而导致联供系统性能大幅度恶化的问题,提出组合式主动调控思路与方法。尝试两种改善系统变工况性能的主动调控新思路：一是压气机入口空气调控,另是燃气轮机排气回注调控。通过全工况模拟,探讨了主动调控方法对分布式联供系统能量转换过程的影响和对联供系统变工况特性强化机理。理论研究表明,与传统调控方法相比,主动调控方法能显著改善冷热电联供系统变工况运行的节能性能,其中压气机入口空气调控将平均系统相对节能率由9.63%提高到17.75%。(4)典型分布式联供系统概念性设计研究。基于全工况特性概念和主动调控方法,研究提出两类新型燃气轮机冷热电联供系统,分析探讨了联供系统中动力循环与吸收式制冷循环之间的能量品位匹配问题,开展典型联供系统概念性设计。第一类新型系统为应用正逆耦合循环概念的分布式冷热电联供系统；第二类新型系统为太阳能化石能源互补的分布式冷热电联供系统。对两类新型系统进行联供系统流程设计和系统模拟以及联供系统节能机理分析等,研究表明,在分布式冷热电联供系统中应用正拟耦合循环概念,可以提升联供系统热力性能,相对节能率从23.1%提高到30.89%；应用太阳能化石能源品位互补机理,新型系统不仅提高了燃气轮机烟气余热的梯级利用程度,而且降低了太阳能系统的运行温度。更多还原

【Abstract】 Combined Cooling, Heating and Power (CCHP) system based on small-scale gas turbine is featured by the cascade utilization of energy and the simultaneous generation of cooling, heating and power. It has attracted worldwide growing attention due to its characteristics of energy saving, reliability and environmental protection. CCHP system operates in off-design conditions in most cases, which goes against its energy saving features. Therefore, this dissertation made a deep investigation of the gas turbine CCHP system in the view of the connection between the typical users’load variation and the system performance, with the purpose of providing some useful methods to this problem. In this dissertation, the system energy conversion and cascade utilization mechanism of energy were discussed, and the system all-operation region performance features and the corresponding active control methods were investigated.This study mainly includes the following contents:(1) Model of the CCHP system in all-operation region was developed. The key problems of the CCHP system running in all-operation region were summarized, and the simulation method and evaluation criteria were proposed. The performance simulation model for the gas turbine CCHP system under all-operation region was developed, which includes small-scale gas turbine, flue gas-double effect Lithium Bromide (LiBr) absorption chiller, domestic hot water exchanger and the control module tracing the user’s load. The effects of the fluctuation of the user’s load and the off-design performance of the equipment unit on the system performance were taken into consideration in this model. This model laid a solid foundation for the research of the all-operation region performance of the CCHP system and the corresponding active control methods.(2) The all-operation region performance and the performance deterioration mechanism of the CCHP system were investigated. This study was carried out by considering an hour-by-hour CCHP simulation for a typical day and a whole cooling period. In addition, the off-design performance of the CCHP system itself was simulated and analyzed. The requirements for a high performance control method of the CCHP system under off-design condition were obtained from the all-operation region simulation results, the effect of the off-design characteristics of equipment on each other, the relationships between the CCHP output and the user’s load. The mechanism of the performance deterioration of the CCHP system was explored through the exergy analysis and energy level analysis of the main equipment of the CCHP system under off-design condition. The main factors leading to the CCHP system performance deterioration were revealed and the potential for improving the system performance were illustrated.(3) The active control methods and the optimizing operation modes were proposed. The mechanism and method of the active control of the gas turbine CCHP system were illustrated comprehensively. On the basis of the analysis of the decrease of the turbine inlet temperature in the conventional control method, two types of active control methods were proposed to enhancing the system performance. The first is the control of the compressor inlet air pressure, and the second is the recirculation of the turbine exhaust gas. The effects of these active control methods on the energy conversion processes and the mechanism of the CCHP system under off-design condition were investigated through the all-operation region simulation. The results demonstrated that both the two active control methods can enhance the off-design performance of the CCHP system effectively. The average PES is enhanced from9.63%to17.75%by active control method of the control of the compressor inlet air pressure.(4) The concept design research of novel CCHP system was carried out. Based on the all-operation region performance characteristic and the active control methods, two types of new gas turbine CCHP systems were proposed to utilize the energy level between the Bryaton cycle and the absorption cycle. The first type system integrated with Ammonia Water Rankine Cycle (AMRC), and the second type system integrated with direct steam generating system (DSG). The thermodynamic analysis and the effects of the key parameters on the system performance are carried out. Performance analysis results show that the PES of the fist type system is improved from23.1%to30.89%. The energy level analysis results show that the cascade utilization of the energy in the two novel CCHP systems are both improved.更多还原