【作者】 叶凌；

【导师】 姚杨；

【作者基本信息】 哈尔滨工业大学 ， 供热、供燃气、通风及空调工程， 2011， 博士

【摘要】 开发利用地下空间是医治―城市综合症‖和解决城市人口、资源、环境三大难题的有效途径,同时也是践行科学发展观和建设两型社会的重要方面。通风空调系统作为营造保障地下空间人工环境、进而实现其可持续发展的一个主要手段,应在保证室内空气品质的前提下尽可能地实现节能环保。针对常规系统在资(能)源和环境两大方面存在的问题,本文遵循能和热的梯级合理利用原则,提出了统筹考虑多种用热、以热泵为主要设备的热能综合利用系统新理念。而且,还统筹考虑城市地下空间密集区域内的各类建筑,进一步得到了一种以水环路为主要特点的系统应用形式,实现了热能在空间上的转移和回用。此外,还提出了一种置于排风井内的水-空气-制冷剂三流体复合换热器,以之作为系统排热和补热设备。依此理念,对热能综合利用系统所涉及的通风空调系统、卫生热水系统、复合换热器及空气源热泵机组和系统整体进行了数学建模,以研究系统水环路及与之相连的主要设备的热力特性。其中,空调机组空气处理过程主要基于-NTU法;冷水机组制冷过程按照压缩机理论循环耗功计算和基于测试数据的热损失拟合两部分叠加考虑;卫生热水蓄热水箱基于考虑了热水分层效应的多节点模型;复合换热器中的空气直接冷却仍采用-NTU法,间接蒸发冷却则基于各传热阶段的热平衡;对于热能综合利用系统整体,对其立体环网的各个管段采用质点法,重点考虑其热量平衡和质量平衡。运用所得数学模型,将一个基于现实区域的系统应用案例分别置于哈尔滨、北京、西安、上海、重庆和广州的典型年气候条件下进行了基于逐时热平衡的准动态模拟。通过从终端效果、热能需求、热源消耗、水环路性能和主要设备运行等方面对模拟结果的不同季节典型日逐时值、各自然月度平均值和年度统计值进行考察,认为系统能够在不同地区不同气候条件下实现正常运转,但其电耗整体呈现出南方高于北方、夏季高于冬季的总趋势;同时,也发现复合换热器虽能完成排热任务,但其水侧进出口温差小,致使系统水环路水温震荡、水泵功耗过高,工作效能还有待改善。为评价前述案例模拟所得运行数据,建立了包括效能评价和节能评价两大方面的热能综合利用系统能量性能评价指标体系。在效能评价方面,从系统整体的能量总输出/输入比、室内余热的有效利用量与总发生量之比、有效回收热量与热回收设备电耗之比、水环路承载热量与水泵电耗之比等角度分别提出了综合能效比、热能综合利用率、热回收效能、水环路效能等指标,还结合了通风空调系统能效比、单位温差能耗、单位人均新风量能耗及卫生热水系统能效比等。在节能评价方面,则从热能综合利用系统能耗相对于常规系统能耗的当量热量、等效电量、等价发电煤耗等不同方面的节能率/量指标来进行评价。此外,还基于案例评价内容,分析了热能综合利用系统的地区适用性。最后,还提出了针对热能综合利用系统整体和通风空调系统自身的多类优化策略,并以前述案例印证了优化效果。本文也探讨了以能源管理模式对热能综合利用系统进行运作。更多还原

【Abstract】 Underground space development is an effective approach to solve the City Syndrome and problems on population, resources and environment, and it’s also an important way to implement the concept of scientific development and to construct the society with resource conservation and environment friendness. As a major mean to create and maintain built environment and consequently to ensure sustainable development of underground space, HVAC system should be energy-saving and environmentally benign on the premise of indoor air quality. Aiming at resource and environment disadvantages of conventional system, and following the principle of step utilization on thermal energy, the thesis brought up a new concept of thermal comprehensive utilization system (TCUS), using kinds of heat pump as major equipments and considering multiple thermal usage. Furthermore, it gives out an application form of the TCUS using water loop as major characteristics, which takes different building types in concentrated area of underground space into consideration, and hence achieves thermal energy shift and utilization in spatial dimension. To remove heat surplus and fill heat gap of TCUS, it also brought up a water-to-air-to-refrigerant triple-fluid heat exchanger installed in exhaust air shaft.According to the concept of TCUS, mathematics models of involved HVAC system, sanitary hot-water (SHW) system, triple-fluid heat exchanger and air-source heat pump (ASHP), and the whole system were created, in order to study energy performance of water loop and major equipments in the system. The models include (a) air handling process in AHU using -NTU method; (b) refrigeration circulation in chiller, consisting of compressor energy consumption in refrigeration theory circulation and fitted heat loss based on test data; (c) thermal storage water tank based on multinode considering thermal stratification; (d) triple-fluid heat exchanger, both directly air cooling using -NTU method and indirectly evaporation cooling based on thermal balance; and (e) each pipe in TCUS’s ridimensional ring network using particle method, focusing on heat balance and mess balance.Using those models, quasi dynamic simulation based on hourly heat balance state for an application case in real area was accomplished, under the data of typical meteorological year of Harbin, Beijing, Xi’an, Shanghai, Chongqing and Guangzhou, respectively. By examining hourly parameter in typical day of each season, average value of each month and statistic data of the whole year of simulation results, from aspects of terminal performance, thermal quantity requirement, energy consumption, water loop performance and main equipment operation, respectively, it’s concluded that TCUS can be used in different cities and climate, and the general trend of electricity consumption is Southern higher than Northern and summer higher than winter. Although triple-fluid heat exchanger achieves to remove heat surplus, small temperature difference between inlet and outlet water results in strong temperature fluctuation in water loop and high energy consumption of water pump, and indicates requirement on efficiency improvement.For operation data simulated in case study, evaluation index system on energy performance of TCUS was established, including energy efficiency evaluation and energy saving evaluation. On energy efficiency evaluation, comprehensive EER, thermal comprehensive utilization rate, thermal recovery efficiency and water loop efficiency, was presented from angles of overall energy output/input ratio, usage/generation ratio of indoor remaining heat, the ratio of recovered heat to used energy of recovery equipments and the ratio of carried heat of water loop to consumed energy of its water pump, respectively, together with indices of EER, energy consumption per temperature difference and energy consumption per fresh air volume per person of HVAC system, and EER of SHW system. On energy saving evaluation, saving quantity and/or rate of TCUS compared to conventional system was assessed, in terms of equivalent heat, equivalent electricity and equivalent power coal consumption, respectively. In addition to evaluation on studied case, it’s followed by area applicability analysis of TCUS.At last, optimization strategies on the whole TCUS and HVAC system were given out, and their effect were corroborated by former studied case. Introduction of energy management mode into TCUS operation was also put forward.更多还原