【作者】 吴小舟；

【导师】 赵加宁；

【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， 2013， 博士

【摘要】 在能源、健康与环境问题日益严重的当今世界，使办公人员在健康、舒适及低能耗的室内热环境中保持最大的工作效率将成为办公建筑暖通空调系统设计及运行控制的目标。低温供暖与新风复合系统作为能够营造健康、舒适及低能耗室内热环境的暖通空调系统之一，非常具有潜力和应用价值，将成为今后暖通空调系统发展的一个趋势。本课题以低温供暖与供新风办公房间为研究对象，围绕着室内热环境与人体工作效率及房间热负荷三者之间的关系，对基于人体工效的低温供暖与新风复合系统设计理论及应用相关问题展开深入研究。基于热力学第二定律和Gagge的人体热平衡模型，建立了人体平衡模型，并导出了人体损计算式。以实验数据为依据，分析了冬季典型办公房间中室内操作温度及人体热感觉对人体损和人体工效的影响。结果表明：当室内操作温度变化范围为17~28℃或室内人体热感觉变化范围为-1.0~1.4时，人体损变化曲线和人体工效变化曲线变化趋势正好相反并呈x‘形状，并当室内操作温度等于19℃或人体热感觉等于-0.56时，人体损达到最小，人体工效达到最大。实验研究了低温辐射地板供暖系统分别与混合通风系统和置换通风系统复合时办公房间室内热环境及新风系统的通风效率。结果表明：当辐射地板表面温度变化范围为25~29℃、送风温度变化范围为15~19℃及新风量等于224l/s时，低温辐射地板供暖与混合通风房间室内垂直温差较小，不超过1℃，新风系统的通风效率大约为1.0，而低温辐射地板供暖与置换通风房间室内垂直温差较大，最大能达到4℃，新风系统的通风效率为1.1左右。基于室内空气流动特性分别建立了合理的低温供暖与混合通风房间室内温度预测模型和低温供暖与置换通风房间室内温度预测模型，指出了房间室内计算温度计算式与用于评价室内热环境的室内操作温度计算式之间存在差别，并以人体工效最大时的室内操作温度为基准点对房间室内计算温度进行了修正，发现当外围护结构热负荷在20~50W/m~2之间变化时，低温供暖与混合通风房间室内计算温度修正值大约为0.4~1.0℃，而低温供暖与置换通风房间室内计算温度修正值大约为0.6~1.2℃。建立了以多次交叉翅片管作为散热核心部件的低温强制对流散热器传热模型，导出了逆流和顺流两种流体流动趋势时多次交叉翅片管换热器传热单元数（NTU）计算式。以低温供暖常用的二次交叉翅片管低温强制对流散热器为例，发现当供水温度变化范围为45～60℃及热水流量变化范围为50～110kg/h时，由本课题推导的计算式（ε-NTU法）和前人推导的计算式（LMTD法）计算的散热器传热系数相差不超过5%。对低温强制对流散热器传热系数影响因素进行了分析，发现当散热器结构参数不变时热水流量的变化对散热器传热系数的影响较大，而平均传热温差的变化对散热器传热系数的影响较小。建立了基于形状因子的低温辐射地板散热量计算等效热阻模型，与基于HEAT2软件的数值模拟计算结果进行了对比。结果表明：当热水管上端填充层厚度变化范围为25~65mm、管间距变化范围为50~300mm及热水平均温度变化范围为25~45℃时，本课题提出的基于形状因子的等效热阻模型散热量计算结果与数值模拟计算结果的相对误差均小于5%。对低温辐射地板散热量影响因素进行了分析，发现热水管上端填充层厚度的变化对低温辐射地板散热量的影响较小，而管间距和热水平均温度的变化对低温辐射地板散热量的影响较大。提出了形式简单的低温供暖与新风复合系统运行控制策略，并导出了低温强制对流供暖系统和低温辐射地板供暖系统供水温度调节关系式。以某一典型办公建筑中低温供暖与混合通风复合系统为研究对象，基于TRNSYS软件数值模拟研究了室温设定值的变化对哥本哈根地区、北京地区及哈尔滨地区三个典型气候区房间室内人体热感觉、室内人体工效及系统能耗的影响。结果表明：仅考虑室内人体工效时，低温强制对流供暖与混合通风房间在哥本哈根地区、北京地区及哈尔滨地区最佳室温设定值分别为19℃、17℃及19℃，低温辐射地板供暖与混合通风房间在哥本哈根地区、北京地区及哈尔滨地区最佳室温设定值分别为18℃、17℃及18℃。通过本课题的研究，为营造健康、舒适、低能耗及高效的办公建筑室内热环境提供理论依据，为新建或改建办公建筑中低温供暖与新风复合系统的设计及运行控制提供理论方法。更多还原

【Abstract】 Nowadays, the problems with regard to energy, health and environment aregrowing rapidly in the world. The design goal of HVAC system is to make peoplework efficiently and productively in comfortable, healthy, and energy efficientenvironments. The low temperature heating systems (LTHS) combined withdedicated outdoor air supply systems (DOAS), which can create a healthy,comfortable, energy efficient and productive indoor thermal environment, hasgreat potential and application value to be the future of the HVAC systems. Thisstudy focus on the design theory and application of LTHS combined with DOASbased on productivity, involving relation between indoor thermal environment andproductivity and building heat load when an office room with LTHS and DOASwas regard as the research object.Human exergy balance model was established according to the second law ofthermodynamics and based on Gagge‘s human balance model. Human body exergyconsumption formula was derived based on the human body exergy balancemodel. Effect of indoor operative temperature and human thermal sensation on thehuman body exergy consumption and productivity in typical office building werestudied by analyzing the data obtained in simulated office environments in winterusing the human body exergy consumption formula. The results show that humanbody exergy consumption and productivity are inversely as operative temperaturechanges from17to28℃or human thermal sensation changes from-1.0to+1.4,and that human body exergy consumption reach its minimum and productivityreach its maximum when indoor operative temperature equals19℃or thermalsensation equals-0.56, and the change of human body exergy consumption resultsin the change of productivity in slight cool and slight warm indoor thermalenvironment.Experimental studies of indoor thermal environment and ventilationeffectiveness in a room with low temperature radiant floor heating systemcombined with mixing ventilation system and displacement ventilation system asradiant floor surface temperature ranges from25to29℃, supply air temperatureranges from15to19℃and supply air flow rate equals224l/s. The results showthat the distribution of indoor thermal environmental parameters are relativelyuniform, the indoor vertical air temperature differences are less than1℃andventilation effectiveness is approximately1.0when low temperature radiant floorheating system is integrated with mixing ventilation system. The distribution ofindoor thermal environmental parameters are relatively non-uniform, the indoor vertical air temperature differences are large and up to4℃and ventilationeffectiveness is approximately1.1when low temperature radiant floor heatingsystem is integrated with displacement ventilation system.Indoor temperature prediction models in a room with LTHS combined withmixing ventilation system or displacement ventilation system were establishedbased on the characteristics of indoor air flow. Compared with the experimentalresults, the data predicted by these models agree well with the experimental data.The difference between indoor design temperature for calculating building heatload and indoor operative temperature for evaluating the indoor thermalenvironment is pointed out according to the formula. Correcting on the indoordesign temperature based on the indoor operative temperature for maximumproductivity were performed The results show that correction of indoor designtemperature is0.4~1.0℃in a room with LTHS combined with mixing ventilationsystem and0.6~1.2℃in a room with LTHS combined with displacementventilation system when external envelope heat loss ranges from20to50W/m2.Heat transfer model of low temperature forced convector with multi-pass fintube heat exchanger as core compartment was established. The numbers of heattransfer unit (NTU) formulas of multi-pass fin tube heat exchanger were derivedbased on the heat transfer model. Subsequently, a two-pass fin tube heat exchangerwas selected as test case to validate these NTU formulas. The results show that theheat transfer coefficients of the heat exchanger calculated by these NTU formulas(ε-NTU method) agree very well with that calculated by logarithm meantemperature difference formulas (LMTD method), under the condition of inletwater temperature from45to60°C and water flow rate from50to170kg/h.Factor analysis of effect on the heat transfer coefficients of fin tube heatexchanger were performed using these NTU formulas. The result shows that theheat transfer coefficients of fin tube heat exchanger are related to the water flowrate but not the mean temperature difference.The equivalent thermal resistance model for calculating heat dissipation oflow temperature radiant floor based on shape factor was established. The resultscalculated by the equivalent thermal resistance model based on shape factor werecompared with numerical simulation. The results show that the relative errorsbetween heat dissipation calculated by the equivalent thermal resistance modelbased on shape factor and calculated by the simulation software are less than5%as the tube space ranges from50to300mm, the distance above pipe ranges from25to65mm and average hot water temperature ranges from25to45℃. Then theequivalent thermal resistance model based on shape factor was used to analyze theimpact of factors on the heat dissipation of low temperature radiant floor. The results shows that the distance above pipe has no significant effect on the heatdissipation of low temperature radiant floor, and the average water temperatureand tube space have a big effect on the heat dissipation of low temperature radiantfloor.The supply water temperature adjustment relationship of low temperatureforced convector heating system and low temperature radiant floor were derived.Low temperature forced convector heating system and low temperature radiantfloor heating system in a mixing ventilation room in a typical office building wereselected as research objective, and effect of indoor temperature set-up values onthe indoor human thermal sensation distribution, productivity distribution andsystem energy consumption were studied. The results show that the optimal indoortemperature set-up values for a room with low temperature forced convectionheating system and mixing ventilation are19℃,17℃and19℃in Copenhagen,Beijing and Harin, and the optimal indoor temperature set-up values for a roomwith low temperature radiant floor heating system and mixing ventilation are18℃,17℃and18℃in Copenhagen, Beijing and Harin.Based on the research of the design theory and application of low temperatureheating systems combined with outdoor air supply systems based on productivity,it is expected that this study could help to develop a universal approach to create ahealthy, comfortable, energy efficient and productive indoor thermal environmentand guide the design and operation and control of low temperature heating systemscombined with outdoor air supply systems in the new or used office buildings.更多还原