燃气热水器为热源的地板辐射供暖系统

介绍了壁挂式燃气热水器的结构及特点,对以壁挂式燃气热水器为热源的地板辐射供暖系统的结构、特点、经济性进行了分析。与燃油锅炉单体建筑物供暖系统、天然气锅炉单体建筑物供暖系统、电供暖系统相比,以壁挂式燃气热水器为热源的地板辐射供暖系统的工程造价最高、年运行费用最低。     

宾馆建筑太阳能热水系统中辅助热源研究

太阳能热水系统由于太阳能资源的不稳定性特点,需要配置辅助能源.常用的辅助热源形式有电直接加热、燃气加热、空气源热泵加热以及燃油加热.本文利用RETScreen分析工具,以宾馆建筑为例建立太阳能热水系统基准模型,选取太阳能资源分区的四个典型城市,对寿命期内能效状况、减排效果、经济性等方面进行分析,确定太阳能热水系统最佳太阳能保证率和辅助热源的地域适用性,进而为太阳能热水系统的设计和选型提供参考.     

A novel water heater using injected hydrogen combustion exhaust

With the aim of mitigating the necessity of water storage when using electric heaters and the losses and pollutant emissions produced by natural gas heaters, this article proposes a water heater based on a gas turbine system, fed with hydrogen and oxygen obtained by electrolysis within the same unit.By applying a thermodynamic analysis to the whole process, a global energy efficiency of 100% can be obtained. This high efficiency makes sense because the electrolysis losses occur in the form of heat losses, which can be used by the cold water. Because the potential of the electrolysis increases, the heat generation due to the electrolysis heat losses increases and, although the electrolysis efficiency is reduced, the global energy efficiency of the water heater remains at 100%. However, the increase in the electrolysis potential also reduces the response speed of the heater, because of the switch in both convection and conduction heat transfer. Convection heat transfer takes place when the combustion exhaust is injected directly in the cold water flow, downstream of the turbine, avoiding the losses associated with a heat exchanger and a high-temperature exhaust. The electrolysis heat losses are transferred to the water by conduction through the electrolyser walls.     

燃气机热泵在夏热冬冷地区应用的经济性分析

以上海地区某独立的两层结构别墅为对象,考虑了燃气机热泵、电驱动空气源热泵与电热水器及燃气热水器组合3种方案,比较了三者在夏季制冷、冬季供暖、制备生活热水时的全年能耗及运行费用。在生活热水产量相同的情况下,燃气机热泵的能耗和运行费用均低于电驱动空气源热泵与电热水器及燃气热水器组合方案,经济性显著。     

一种高温相变蓄热电暖器的研制及其热性能测试

本文介绍了一种新型的高温相变蓄热电暖器的研制。对该蓄热电暖器热性能进行了测试,结果表明该电暖器蓄热效率高,相变材料在相变阶段温度恒定且散热功率基本不变,热舒适性好;此种电暖器热性能与显热式蓄热电暖器比较具有明显的优势。因此,高温相变蓄热电暖器是一种理想的电采暖设备,可以实现对电网负荷削峰填谷、降低电采暖费用的目的。     

低碳经济与城市天然气销售

天然气具有用途广、燃烧效率高、碳排放少等优点,因此在低碳经济社会,努力提高天然气在一次能源中的占有率,能够有效的降低二氧化碳排放,促进经济、社会的可持续发展。文章从上海的实际情况出发,结合天然气的资源优势,着重阐述在低碳经济下,上海燃气市北销售有限公司（以下简称市北公司）如何拓展城市天然气消费市场。     

LCNG加气站冷热电三联供系统的应用研究

简述了国内外对LCNG冷能利用的研究及应用现状,设计了一种LCNG加气站冷热电三联供系统,该系统包括LCNG气化站系统和冷热电三联供系统。LCNG气化站系统包括LNG储罐、抽风机、LNG-冷媒换热器以及CNG压缩机;冷热电三联供系统包括冷媒-制冷剂换热器、冷媒储罐、发电机、废热回收装置、充电桩。LNG通过管道依次连接抽风机、LNG-冷媒换热器、冷媒储罐、冷媒-制冷剂换热器,再通过制冷循环将冷量传递到室内。本系统的有益效果是:LCNG气化站系统耦合冷热电三联供系统,实现能量梯级利用;天然气用于发电,产生的电能供充电桩使用,利用废热回收装置收集发电产生的热量,用于预热燃烧室入口端的天然气,提高发电效率;利用废热回收装置收集的热量加热LNG,使之转变为天然气,替代水浴式加热器的使用,起到节能的效果;本系统可以与传统的石化加油站结合,实现"油气电非"的综合使用。     

电热水器运行方式与能耗的理论分析

运用总传热系数法,建立电热水器的物理模型及相应耗热量的数学模型。通过对电热水器不同运行方式能耗的理论计算,指出电热水器连续运行更加节能,为电热水器的节能提供了新的方向。     

Comparison of natural gas driven heat pumps and electrically driven heat pumps with conventional systems for building heating purposes

Electrically driven heat pumps achieve good efficiencies for space heating. If heat pumps are driven directly by a combustion engine instead of an electric motor, losses attributed to the production and transport of electricity are eliminated. Additionally, the use of the combustion engine's heat leads to a reduced temperature difference across the heat pump. This article presents annual efficiencies of these systems and compares internal combustion engine and electrically driven heat pumps in terms of primary energy consumption and CO₂ emissions. Because heat pump performance depends strongly on the heating circuit's flow temperature level, the comparison is performed for air-to-water and geothermal heat pump systems in two cases of maximum flow temperatures (40 °C and 60 °C). These temperature levels represent typical modern buildings with large heating surfaces and older buildings with high-temperature radiators, respectively. In addition to the different heat pump setups, conventional space heating systems are included in the comparison. The calculations show that natural gas-driven heat pumps achieve about the same efficiency and CO₂ emissions as electrically driven heat pumps powered with electricity from the most modern natural gas-fired combined cycle power plants. The efficiency of such systems is about twice that of conventional boiler technologies.     

热电联供系统复合除湿空调系统动态仿真

将燃气内燃机热电联供系统(CHP)与热湿独立处理空调系统(采用固体除湿转轮)组成复合空调系统.供冷期,利用燃气内燃机余热再生除湿转轮.供暖期,利用燃气内燃机余热加热新风与供暖.针对上海某超市建筑,使用动态仿真方法对常规分供系统(采用热湿联合处理,配置电制冷机、燃气锅炉)、复合空调系统的一次能源利用率、静态投资回收期、二...     

冷凝式燃气快速热水器排烟温度的探讨

根据冷凝式天然气快速热水器排烟温度与其热效率关系的理论分析,并通过试验得出冷凝式天然气快速热水器效率与其排烟温度的关系。试验结果表明冷凝式燃气快速热水器有很好的实用价值。     

冷凝式燃气热水器技术与经济分析

论述了冷凝式燃气热水器的理论热效率,国内外冷凝式燃气热水器的发展概况,冷凝式燃气热水器的3种换热方式的结构原理,酸性冷凝水的产生和排放,换热器表面的防腐措施,冷凝式燃气热水器的经济性。与普通燃气热水器相比,冷凝式燃气热水器对于消费者价格偏高。     

太阳能与燃气结合的热水系统的能耗评价

文章从太阳能热利用的角度出发,以太阳能集热器加快速式燃气热水器的组合为系统基本配置,在不同的用水定额指标情况和上海的特定气象资料下,采用MATLAB软件进行了动态负荷计算与分析,得出逐时集热温度,并以此为基础计算燃气耗量,分析了改变集热器面积,蓄热水箱体积,系统所需要的燃气量以及相应的费用变化,从而评价出最佳配置方案。     

Performance assessment of fuel cell micro-cogeneration systems for residential buildings

The reduction of greenhouse gas emissions in the building sector to a sustainable level will require tremendous efforts to increase both energy efficiency and the share of renewable energies. Apart from the lowering of energy demand through better insulation and fenestration, small combined heat and power (micro-cogeneration) systems may help improve the situation on the supply side by cutting both the non-renewable energy demand for residential buildings and peak loads in the electric grid. Though still on the brink of market entry, fuel cells are the focus of interest as the prime technology for such systems. In this study, a methodology for assessing the performance of such systems in terms of primary energy demand and the CO₂ emissions by transient computer simulations is established, and demonstrated for a natural gas driven solid oxide fuel cell (SOFC) and, to a lesser extend, a polymer electrolyte fuel cell (PEFC) home fuel cell cogeneration system. The systems were evaluated for different grid electricity generation mix types and compared to traditional gas boiler systems. The interaction with hot water storage and solar thermal collectors, and the impact of storage size and predictive control was analyzed. Typical heat and electricity demand load profiles for different types of residential buildings and occupancy were considered, and the sizing of the fuel cell system in relation to the heat demand of the building was analyzed. Primary energy savings decline for cases with lower heat demand and for cases with solar thermal systems, and peak for fuel cell systems sized in accordance with the heat demand of the building. Future assessments of fuel cell systems will need a refined methodology, and depend on realistic performance characteristics and models that accurately consider dynamic conditions.     

集中供热、燃气锅炉及电热供暖系统的经济分析

对采用集中供热，燃气锅炉及电热供暖系统分别进行了经济比较，其结果表明集中供热系统运行费用最低，电热供暖系统运行费用最高；电暖器供暖系统初投资最低，除集中供热地板供暖系统之外顶棚电热膜供暖系统初投资最高。     

冷凝式天然气快速热水器的应用探讨

根据对冷凝式燃气快速热水器节能效果的理论分析，产通过试验得出冷凝式天然气快速热水器热效率与其排烟温度的关系，试验结果表明冷凝式天然气快速热水器有很好的实用价值。     

冷凝式热水器热效率的分析

本文对冷凝式燃气快速热水器的节能效果和天然气冷凝式热水器的热效率进行了理论分析，并列出试验数据证明天然气冷凝式热水器的热效率比普通型水器高１４％左右。     

夏热冬暖地区太阳能溶液除湿空调的应用分析

本文介绍了太阳能溶液除湿空调系统的形式及其工作原理,并将该系统运用到广州某一小型办公楼上,利用DesT软件,进行了逐时模拟计算。计算结果表明：在不考虑传统空调的再热量,忽略其他传热损失下,溶液除湿空调系统用电量仅为传统空调系统的40％;由于通过溶液的蓄能来充分利用太阳能,使得燃气加热器的供热量仅为再生热负荷的13．4％;在广州地区的电、燃气价格下,太阳能溶液除湿空调系统的运行费用仅为传统空调系统的49．03％。     

高校学生宿舍热水系统建设模式选择

学生生活热水是校园耗能的重要部分之一,合理选择生活热水系统的热源是节能校园建设的一个关键因素。空气能热水器被称为"第四代热水器",与之前"燃气热水器"、"电热水器"、"太阳能热水器"相比,在各方面均有非常明显的优势。目前高校采用较多的太阳能+空气能热水系统是一种最安全的系统,其建设模式多采用BOT投资模式。     

如何合理确定电蓄热供暖蓄热水箱的容积

就如何合理确定电蓄热供暖用蓄热水箱的有效体积给出了计算公式;并确定了公式中各项取值,提出蓄热水箱最高设计温度和最低设计温度确定的条件;对采暖和锅炉加热形式循环系统中防止水泵汽蚀的条件给出了计算公式;最后还给出蓄热水箱的建筑面积估算指标范围。