【作者】 张强；

【导师】 杨昭；

【作者基本信息】 天津大学 ， 制冷及低温工程， 2019， 博士

【摘要】 我国建筑能耗占全社会总能耗的35%以上,空调采暖能耗占建筑总能耗的比重逐年增加。现有各类建筑用冷热源系统用能形式单一、系统运行效率易受天气因素影响。燃气机热泵(GEHP)系统是利用天然气作为能源,回收燃气机的烟气余热,高效供冷、供热及供热水的联供系统,其运行效率受天气影响较小。此外,燃气机热泵的推广使用可以有效缓解燃气与电力供应的失衡问题,起到削峰填谷的作用。在一次化石能源储量以及价格(逐年上涨)不可控的前提下,研究GEHP系统能够改善建筑用能结构、降低建筑能源消耗、有效控制建筑排放具有极大的现实意义。然而,GEHP系统输出负荷与建筑实时负荷需求之间存在供需不匹配的问题。针对此问题,本文提出一种新的蓄能型燃气机热泵系统(ESGEHP)研究方法,研究ESGEHP系统与建筑实时负荷的最优匹配关系,探索ESGEHP系统对不同建筑供能的最佳供能模式。在此基础上,提出一种新型的太阳能PV/T系统辅助ESGEHP的联合建筑供能系统(SESGEHP),对SESGEHP系统的运行特性进行了实验研究。本文主要研究内容如下:(1)建立ESGEHP系统变容量调节、各部件间耦合以及建筑实时负荷需求计算模型,以燃气机转速、自备电量、蓄能水箱体积以及系统COP为决策变量,结合典型天的冷、热及生活热水负荷需求计算模型,基于粒子群算(APSO)优化算法探究得到ESGEHP系统与建筑实时负荷需求之间的匹配机理,制定四种新的ESGEHP系统建筑供能模式,分别为低负荷模式(Mode L)、部分负荷模式(Mode P)、全负荷模式(Mode F)以及超负荷模式(Mode O),能够在建筑负荷发生突变时,快速调节系统输出容量。实现ESGEHP系统在供冷、供热过程中对能量进行高效蓄放。采用GEHP系统输出容量联合蓄能系统为建筑供能的方式,在出现极端天气或是供热需求增大(比如会议室改成办公室)时,ESGEHP系统只需增加较小的制热量,联合余热回收量,满足增大的建筑负荷需求。仿真结果与实验数据吻合较好,采暖、制冷及过渡季一次能源利用率平均相对误差分别为8.9%、9.63%和21.7%。(2)为了提高ESGEHP系统对不同类型建筑供暖和制冷时的适用性和运行效率,探究典型天条件下ESGEHP系统供能特点和建筑冷、热负荷变化规律,采用Design Builder软件建立天津市住宅、宾馆、办公、高校四类建筑的物理模型,得到四类建筑实时冷热负荷需求特性。选取夏季典型天(17/07/2016)和冬季典型天(07/01/2017)的建筑实时冷、热负荷特征作为研究对象,结合ESGEHP系统决策变量的最优值,得到ESGEHP系统在典型天对四类使用功能建筑供冷、供热时的具体供能模式,结果表明,ESGEHP系统一次能源利用率(PER)比传统GEHP系统分别高出21.4%(住宅类建筑),35.2%(酒店类建筑),23%(办公类建筑),26.6%(高校类建筑)。同时,以高校类建筑为例进行了实验验证:除建筑热负荷需求相对误差为35.6%以外,高校类建筑冷负荷、ESGEHP系统制冷、制热量、一次能源消耗量和PER仿真值与实验值之间的相对误差均小于12%。(3)为了提高ESGEHP系统对既有建筑供能时的运行效率,选用太阳能光伏光热系统(PV/T)作为低温热源,提出一种新型双向蓄能的太阳能PV/T辅助ESGEHP联合建筑供能系统(SESGEHP)。对SESGEHP系统运行特性、太阳能PV/T系统性能、建筑实时热负荷需求和环境参数进行了仿真和实验研究。研究结果表明,SESGEHP系统的平均COP和PER分别比ESGEHP系统高24.5%和20.4%。SESGEHP系统的一次能源消耗率和平均压缩机功率分别比ESGEHP系统低7.5%和24.0%。最后,利用广义回归神经网络(GRNN)对实验数据进行处理,得到了单因素变量(太阳辐射、室外干球温度、风速)对因变量(建筑实时热负荷需求、SESGEHP系统制热量、PV/T系统得热量和发电量)的影响。更多还原

【Abstract】 China’s building energy consumption accounts for more than 35% of the total energy consumption of the whole society.The proportion of air conditioning and heating energy consumption in the total energy consumption of buildings is increasing year by year.Gas-engine driven heat pump(GEHP)system is an efficient air conditioning system,which can not only use natural gas as energy source,but also recover waste heat from the flue gas of gas engine.The main contents of this paper are as follows:Firstly,the calculation models of the variable capacity regulation of ESGEHP system,coupling among components and real-time load demand of the buildings are established.Taking gas engine speed,self-contained electricity,storage tank volume and COP as decision variables,combined with the calculation model of the real-time cooling,heating and hot water load of the typical days,based on particle swarm optimization(APSO)algorithm,the matching relationship of the ESGEHP system and the real-time load of the buildings is obtained.A new operation mode of ESGEHP system is developed,which is low load mode(Mode L),partial load mode(Mode P),full load mode(Mode F)and overload mode(Mode O),to realize efficient energy storage and release of ESGEHP system in the process of cooling and heating.In the case of extreme weather or increasing demand for heating(such as changing conference rooms into offices),the ESGEHP system only needs to increase small heat generation and combined waste heat recovery to meet the increasing demand for building load,for the combination of the energy storage system to the GEHP system.The simulation results were well agreed with experimental data,the average difference is 8.9%,9.63% and 21.7% for the annual primary energy ratio of heating,cooling,transitional season,respectively.Secondly,in order to improve the applicability and operational efficiency of ESGEHP system when supply heating and cooling to different types of buildings,the energy supply characteristics of ESGEHP system and the variation of the building cold and heat load under typical weather conditions were explored.Based on the operation strategy of ESGEHP system,the real-time cooling and heating load characteristics of buildings on typical summer days(17/07/2016)and winter days(07/01/2017)are selected as the research objects.The specific operation mode of ESGEHP system for cooling and heating of four functional buildings in the typical days were obtained,combing the optimal value of decision variables of ESGEHP system.The results show that the primary energy utilization of ESGEHP system is feasible,and the primary energy ratio of the gas engine driven heat pump with energy storage system is about 21.4%(residential building),35.2%(hotel building),23%(office building)and 26.6%(university building)higher than traditional GEHP.The simulation and experiments were carried out to study the performance of the system,including the performance of the PV/T system,the real-time heat load demand of the building and the environment parameters.The research results showed that the average COP and PER of the SESGEHPs were nearly 24.5% and 20.4% higher than the ESGEHPs,respectively.The fuel-consumption and the average compressor power consumption of SESGEHP system were nearly 7.5% and 24.0% lower than the ESGEHP system,respectively.Finally,the experimental data are processed using the generalized regression neural network(GRNN)to get the relationship between the independent variable(solar radiation,outdoor dry bulb temperature and wind speed)and dependent variable(the building heating load,heating capacity of the SESGEHPs,heat-obtained quantity and power generation of the PV/T system).更多还原