北方农村中小学供暖方案选择

分析农村中小学供暖现状,提出几种适用于北方农村中小学的太阳能与辅助热源一体化供暖系统形式.以济南农村某小学为例,对太阳能与碳晶电热板复合供暖系统、太阳能与空气源热泵复合供暖系统、太阳能与地源热泵复合供暖系统及太阳能与沼气燃气锅炉复合供暖系统4种供暖方案的能耗、系统造价和系统运行费用进行研究.研究结果表明:对于该小学来说,太阳能与空气源热泵复合供暖系统长期运行较经济.     

太阳能联合城市燃气锅炉供暖系统的节能设计优化

研究太阳能联合城市燃气锅炉供暖系统的节能设计优化方案。设计集太阳能集热器、蓄热水箱、换热器、水泵、燃气锅炉等重要设备于一体的联合供暖系统，分析串联供暖与并联供暖组合方式，以及适用于联合供暖组合的太阳能单独供暖、同时供暖、燃气锅炉单独供暖三种供暖模式，采用TRNSYS构建串联供暖系统与并联供暖系统模型，对串联供暖系统与并联供暖系统节能设计进行比选，并从运行经济性角度出发优化联合供暖系统容量匹配节能设计。串联供暖系统节能设计比并联供暖系统节能设计的太阳能保证率高、系统性能好、系统能耗低。     

严寒地区多源互补清洁供热系统研究现状及展望

为了解决严寒地区供热结构单一及远离城市集中供热的建筑供暖问题,实现热泵及太阳能清洁能源的推广应用,对近年来严寒地区清洁供热系统的研究与应用进行总结,分析目前存在的主要问题。在研究总结空气源热泵、土壤源热泵、太阳能集热器及多热源联合运行方案及节能效益的基础上,探讨严寒地区多源互补供热系统的构建基本思想,为今后该地区热泵与太阳能供热系统设计和应用提供参考。     

严寒地区太阳能_土壤源热泵运行经济性分析

针对北方严寒地区光照特性和冬天室外温度偏低的特点,提出利用太阳能—土壤源热泵进行供暖的方案,并以哈尔滨市为背景,对太阳能—土壤源热泵、土壤源热泵、燃油锅炉、燃气锅炉和电锅炉5种供暖方式的一次能源利用率和燃料价格变化对运行能耗费用等因素的影响进行了比较分析,得出太阳能—土壤源热泵是5种供暖方式中能源消耗费用最低、一次能源利用率最高的结论.     

基于相变储能的太阳能空气源热泵系统的研究

针对由天气变化导致太阳能利用不稳定和寒冷地区热泵性能低的问题,文章介绍了一种基于相变储能的太阳能空气源热泵系统,该系统能够根据气象情况灵活切换4种供暖模式,大大减少了系统耗电量。文章通过独特设计的储能冷凝器,不仅可以调节太阳能空气源热泵系统能量分配,改善太阳能空气源热泵系统制热量和建筑热负荷之间不平衡的供需关系、提高太阳能利用率,还可以提高空气源热泵低温性能,快速恢复供暖,从而实现提高太阳能空气源热泵系统整体性能的目的。文章以石家庄农村某户为研究对象进行研究,研究结果表明,太阳能空气源热泵系统供暖效果较好,太阳能空气源热泵系统COP最大值为5.19,节能环保效益十分明显。     

空气源热泵与燃气锅炉供暖能耗对比分析

随着清洁能源供热应用的推广,能耗成本将成为选择热源方式的重要依据之一.以河北省霸州市A小区实际供暖项目为例,对安装空气源热泵前后2个采暖季的能耗成本进行比较分析,再结合理论,对空气源热泵系统和燃气锅炉2种供暖方式的运行成本进行了详细分析.总结出在霸州地区以及燃气价格相近的北方寒冷区域,空气源热泵的优势比燃气锅炉的优势更...     

燃气锅炉与空气源热泵高效耦合供暖系统的设计

燃气锅炉与空气源热泵耦合供暖系统是现阶段实现“双碳”目标的可行和可靠技术路径之一。通过分析耦合供暖系统在节能、节碳、舒适等方面的表现,探讨实现高效供热耦合供暖系统的选型策略、耦合方式、控制逻辑。结果显示空气源热泵能耗方面有优势,但投资强度大,其运行费用、碳排放量在不同条件下相比燃气锅炉各有优劣,故耦合系统的选型应在全生命周期成本测算后,选择经济合理的配置方案;耦合系统的设计应充分考虑系统与两个热源的流量要求,推荐采用二级泵形式耦合供暖;耦合系统的运行逻辑应选择费用、能耗、碳排放量表现更好的热源优先运行,并保证供暖的舒适度及稳定性。在实际项目应用中,上述三个方面的设计要点可帮助实现耦合供暖系统的高效供热。     

太阳能-空气源双能源复合供暖在严寒地区农村住宅中的应用研究

针对空气源热泵热风机在室外低温环境下供暖性能衰减，导致室内冬季供暖效果变差等问题，为充分发挥资源优势，提出了一种太阳能-空气源双能源复合高效集成装置，实现了太阳能集热器与低温空气源热泵热风机联合供暖。介绍了该集成装置的技术原理和控制策略，通过TRNSYS软件对该集成装置在哈尔滨地区农村住宅的供暖效果进行了研究，并对该集成装置供暖和低温空气源热泵热风机单独供暖的效果进行了对比分析。研究结果表明：太阳能-空气源双能源复合高效集成装置实现了太阳能与空气源两种能源更为合理的供暖时段匹配。在整个供暖季，与低温空气源热泵热风机单独供暖相比，该集成装置的供暖效果更好且能耗更低，其系统总能耗降低了2034.8 kWh，制热能效比提升了35.06%。     

寒冷地区户用大平板太阳能集热器-空气源热泵系统性能研究

针对太阳能难以单独稳定供暖和空气源热泵供暖成本高的问题，提出空气源热泵辅助太阳能稳定供暖构想，在甘肃省兰州市七里河区魏岭乡绿化村研发搭建大平板太阳能集热器-空气源热泵系统，对比研究晴天、多云和阴天3种典型工况下大平板太阳能集热器的集热效率、太阳能热泵和空气源热泵COP、太阳能保证率、系统总供热量和系统能效比等性能参数。结果表明：晴天、多云和阴天系统集热效率分别为44.9%、38.7%和20.6%,3种工况下太阳能热泵COP均为4.0，空气源热泵COP分别为3.5、3.3和3.1，太阳能保证率分别为38.1%、32.3%和12.9%，系统全天供热量分别为142.52、135.22和120.96 kWh，系统能效比分别为3.5、3.4和2.7。研究结果证明大平板太阳能集热器-空气源热泵系统用于寒冷地区单体建筑供暖的可行性，可为寒冷地区农村单体建筑的供暖提供一种新途径。     

太阳能与复叠式高温空气源热泵联合供热系统应用

设计一套太阳能与空气源热泵联合供热系统，出水温度为80～90℃。通过对太阳能集热器和空气源热泵产品性能进行比较，选择集热效率高的中温型太阳能集热器和双级压缩复叠式空气源热泵，并对两种热源并联的供热系统进行详细的控制逻辑设计。以泰国CPC太阳能热水项目为例，对供热系统的稳定运行情况和节能效果进行验证。项目地辐照资源好，联合供热系统运行稳定、效果良好。     

Relativistic moving heat source

The relativistic heat conduction (RHCE) model is particularly important in the analysis of processes involving moving heat sources (MHS) at speeds or frequencies comparable with those of heat propagation in the medium. This paper establishes a unified framework for solving heat conduction problems using the RHCE model. It offers “Fundamental Solutions” in one, two, and three spatial dimensions, for the transient response due to an instantaneous point MHS. Moreover, it presents the transient response due to a continuous point MHS, the quasi-steady response due a periodic point MHS, as well as guidelines for solving the RHCE equation under various loading and boundary conditions.     

地下水水源热泵的水源问题研究

地下水是应用地下水水源热泵的前提。文章简单阐述了地下水温度、流量和水质对水源热泵运行效率的影响。介绍了水处理技术和回灌技术，探讨了工程中应注意“热短路”问题。     

太阳能蒸发面板为辅助热源的空气源热泵系统的分析

在传统太阳能热泵基础上,提出中间安装有制冷剂蒸发管的太阳能为辅助热源的空气源热泵,能够解决夏季制冷、冬季采暖和全年热水供应问题,同时在寒冷高湿地区也可以除霜。节能经济性可观。     

Potential of ground heat source systems

This paper presents a historical background of ground source heat pump technology, followed by a review of its current shortcomings. Based on these observations the author assesses the R&D needs and recommendations for future research.     

Working fluids for low-temperature heat source

The performance of different working fluids to recover low-temperature heat source is studied. A simple Rankine cycle with subcritical configuration is considered. This work is to screen working fluids based on power production capability and component (heat exchanger and turbine) size requirements. Working fluids considered are R134a, R123, R227ea, R245fa, R290, and n-pentane. Energy balance is carried out to predict operating conditions of the process. Outputs of energy balance are used as input for exergy analysis and components (heat exchanger and turbine) design. The heat exchanger is divided into small intervals so that logarithmic mean temperature difference (LMTD) method is applicable. R227ea gives highest power for heat source temperature range of 80–160 °C and R245fa produces the highest in the range of 160–200 °C. There is optimal pressure where the heat exchanger surface area is minimum. This optimal pressure changes with heat source temperature and working fluid used. The least heat exchanger area required at constant power rating is found when the working fluid is n-pentane. At lower heat source temperature (80 °C), the maximum power output and minimum heat exchanger surface area for different working fluids is comparable.     

Internal heat generation in a discrete heat source: Conjugate heat transfer analysis

In the present work, we conduct an asymptotic and numerical analysis for the cooling process of a discrete heat source, which is placed in a rectangular-channel laminar cooling flow. In our physical model, the heated strip is embedded in a substrate, generating continuously a uniform volumetric heat rate. We assume that this heat-generation mechanism is due to an electrical current in the heat source. Hence, heat losses to the cooling fluid and to the substrate material during this process are presented. The governing equations of the cooling flow and the participating solid are reduced to an integro-differential equation that predicts the temperature variations of the heat source. We show that the conjugate heat transfer process is controlled by a conjugate nondimensional parameter, here denoted by α, which determines the basic heat transfer regimes between the cooling flow and the discrete heat source.     

U型波纹埋管对于增强土壤源热泵换热性能的研究

为了增强土壤源热泵系统地下埋管换热器的换热性能,通过CFD方法,探讨改用波纹管对地下换热所产生的影响,首次提出采用波纹管代替光管作为强化地下埋管换热器换热效率。     

地源热泵的套管式地下换热器传热研究

地源热泵是一种节能、对环境无害的绿色空调设备,可成为下个世纪冷暖技术的核心,采用能量平衡,建立了地下浅埋套管式换热器传热平衡式,进行求解,并分析了影响传热的各关联因子,提出了需研究的强化地下换热的措施,根据求解结果,给出了相应的函数关系图。对实验设计和工程实践有一定的指导作用。     

Performance of a solar air composite heat source heat pump system

For the shortcoming of air source heat pump in heating condition, a composite heat exchanger was designed which integrates fin tube and tube heat exchanger, and it can achieve synchronous and composite heat exchange in one heat exchanger between working fluids, gaseous and liquid heat source. With the above composite heat exchanger as the core component, the Solar Air Composite Heat Source Heat Pump System (SACHP) was developed which has three working modes, including single solar heat source mode, single air heat source mode and solar air dual heat sources mode. A SACHP experiment table was established and conducted a comprehensive experimental study of three working modes of this system in the standard enthalpy difference laboratory. The results show that when the ambient temperature was −15 °C, compared to the single air heat source mode, the dual heat source mode increased 62% in heat capacity and 59% in COP; when the temperature difference of combined heat transfer was 5 °C, compared to the single air heat source mode, the dual heat source mode increased 51% in heat capacity and 49% in COP. Experimental results demonstrate that the application of the solar air composite heat pump technology can accelerate the application process of the solar heat pump in air conditioners for buildings.     

地源热泵换热器可靠性设计方法研究

介绍地源热泵换热器传热模型和设计方法的研究现状,分析地源热泵换热器传热影响因素的随机特征,提出地源热泵换热器的可靠度分析方法,讨论采暖热能指标及设计值的变异性。结合工程实例提出基于可靠性理论的地源热泵换热器设计与分析方法。