共查询到19条相似文献,搜索用时 109 毫秒
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新风负荷约占空调能耗的30%,减少新风处理能耗对降低空调能耗有重要作用.本文提出了一种将太阳能空气集热器与间接蒸发冷却器相结合的新型新风处理机组,夏季采用间接蒸发冷却器对新风预冷,喷淋水以循环水为主,利用冷凝水作为其补充水,降低了喷淋水的水温,并利用室内排风作为间接蒸发冷却器的二次空气,提高了换热效率;冬季采用太阳能空气集热器对新风预热,并利用间接蒸发冷却器作为一次空气与二次空气的显热换热器来承担部分冬季新风负荷,从而大大减少了新风处理机组的能耗.能耗计算分析结果表明,与传统新风处理机组相比,新型新风处理机组夏季节能36.9%,冬季节能64.0%,静态投资回收期为3.7年,动态投资回收期为4.7年. 相似文献
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《节能》2020,(2):62-65
传统空调系统存在如吹风感、冷表面滋生霉菌、能效比较低等一系列弊端。为了解决这些问题,提出一种基于金属毛细管网的辐射式热泵系统,利用敷设于建筑物围护结构内的金属毛细管作为室内侧换热器,由热泵系统控制室内温度。然而,热泵系统无法保证新风供应、存在室内结露等问题,因此提出在该系统基础上复合运行太阳能溶液除湿新风系统,利用太阳能集热板收集的热量对除湿溶液进行加热再生,室外新风经浓溶液除湿并经制冷剂冷却后,送入室内控制室内相对湿度。夏季供冷时,热泵系统和除湿系统共用1套制冷剂,达到同时实现室内供冷、除湿溶液再生和新风冷却的效果,保证室内舒适度及空气品质,避免室内结露。这种基于太阳能溶液除湿和金属毛细管网的新型辐射空调系统可实现室内温湿度独立控制,降低能源消耗,促进绿色建筑可持续发展。 相似文献
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针对湖北某棉纺织厂车间的空调系统能耗大和温湿度控制精度低的情况,对系统中的管道、喷淋室、热泵机组、新风机组等设备进行了节能改造。经过分析计算表明,该方案可节约用电量442.24万k Wh/a,间接减少标准煤用量1474t/a,取得了良好的经济效益和社会环境效益。 相似文献
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在风机盘管加新风空调系统中,风机盘管干工况时只承担少部分室内瞬变负荷,由于干工况下新风机组需处理的新风焓差大,存在着干工况应用困难的问题.采用空气-空气能量回收装置(AAERE)预处理新风,可以解决风机盘管干工况运行中的困难.结果表明:采用AAERE回收部分余热预处理新风,可以降低新风机组需处理的焓差值,使用热回收后新风处理焓差值降低为33.6 kJ/kg,供冷量节约16.2%,使空调系统经济运行得到保障. 相似文献
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提出了两种新型的热泵回收冷凝热供热系统——汽水双热源供热量可调集中供热系统和电热泵回收冷凝热供热系统,并与现有的热泵回收冷凝热供热系统比较,分析比较各自的节能经济性。结果表明,汽水双热源供热量可调集中供热系统和电热泵回收冷凝热供热系统的经济效益比常见的吸收式热泵回收冷凝热供热系统分别高出33%和117.9%。对于296MW供热机组,汽水双热源可调集中供热系统和电热泵回收冷凝热供热系统每年可分别减排二氧化碳10万t和11.5万t。电热泵回收冷凝热供热系统节约的冷却水量要远高于其他两个系统,这对北方缺水地区意义重大。 相似文献
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哈密某电厂在其空冷岛中使用了一种新型消能导流装置来抵抗侧风影响、稳定机组背压。然而,该电厂冬季空冷单元散热管束冻结的情况依然存在。为了探究该装置对空冷岛冬季防冻的影响,利用Fluent软件对该电厂冬季大风时空冷岛的流动传热特性及各空冷单元的冻结风险进行了模拟研究。研究表明:空冷岛“消能导流装置”整体上对空冷单元的防冻起负面作用;在冬季大风条件下该装置迎风侧空冷单元的散热量平均超出警戒值27%以上,最高达到50%;消能导流装置主要通过提升轴流风机空气流速来增加对应空冷单元的换热量,该装置迎风侧空冷单元轴流风机的轴向空气流速甚至能达到与环境侧风相同的水平,这导致对应空冷单元换热量激增,更容易出现冻结事故;大风条件下该装置在空冷岛下方形成的高压区域分布并不均匀,临近主厂房与相邻空冷岛一侧的高压区域压力更高、面积更大,这些区域空冷单元的冻结风险更高。 相似文献
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基于流态冰的冰源热泵可以利用近冰点淡水或海水相变潜热作为热源,具有采暖能效高、适用性广的特点。为研究新型冰源热泵在采暖期的能效及经济性,选取我国典型供暖区域的5个城市作为研究对象,结合近5年采暖期各城市的气象参数,分别模拟计算空气源热泵、冰源热泵、地源热泵的系统能效。通过计算各热泵机组的初投资及采暖期运行费用,确定了不同类型热泵系统的静态投资回收期。结果表明,本文提出的新型冰源热泵在采暖期的系统能效较高,为2.8 ~ 3.2。相较于空气源热泵和地源热泵,哈尔滨地区冰源热泵系统的初投资及运行费用最低,不存在静态投资回收期。在北京、郑州、武汉、南京地区的静态投资回收期分别为3.0年、5.1年、2.3年、2.6年。基于流态冰的冰源热泵在冬季供暖方面有很好的应用前景。 相似文献
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《Applied Thermal Engineering》2014,62(2):823-829
The world is facing a challenge to reduce energy use to meet the environmental goals set for the future. One factor that has a great impact on the energy performance of buildings is the ventilation losses. To handle these losses, heat recovery systems with rotating heat exchanger are often implemented. These systems have been shown to recover about 60–70% of the energy in the exhaust air on an annual basis.After a heat recovery system is installed it is hard to improve the efficiency of the installed recovery system with an acceptable economic payback period. In the present paper one way to improve the energy performance of a building with this type of heat recovery system by the use of a heat pump is investigated by simulations in TrnSys.The heat pump system is arranged so that the evaporator is connected to a heat exchanger mounted in the exhaust airstream after the energy wheel, and the condenser of the heat pump is mounted so that the temperature of return water from the heating coil is increased.The simulations show that there is a possibility to increase the heat recovery rate of the air handling unit in a significant way by retrofitting a heat pump to the system. 相似文献
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《International Journal of Hydrogen Energy》2019,44(56):29692-29699
Proton exchange membrane fuel cell (PEMFC) receives increasing attention as an alternative in small-scale residential distributed generation (DG) application, especially for remote cold region where the utility electricity is not accessible. The open-cathode PEMFC is featured with the integrated fabrication of air supply and coolant flow cathode. Although simple, the waste heat of the exhaust air is difficult to reuse by heat exchangers, because of the low exhaust temperature. To this end, this paper investigates a hybrid structure consisting of open-cathode PEMFC and heat pump. It is revealed in this paper that the oxygen excess ratio of open-cathode PEMFC is usually as big as 100, which makes it doable and safe to directly exporting the exhaust air into the indoor environment. The temperature of the mixed air is thereby lifted. The thermal load of the heat pump is consequently alleviated and the power consumption is reduced. A comprehensive quantitative model is developed by considering the fuel cell electrochemical characteristic, cathode thermodynamics and heat pump coefficient. A case study is carried out by comparing the coefficient of performance (COP) of the system with and without the cogeneration design, showing a 7.6% improvement of the proposed hybrid structure. The results of the paper depict a promising prospect in accelerating the commercialization of open-cathode PEMFC in the field of domestic cogeneration filed. 相似文献
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以西安地区的某个房间为研究对象,采用TRNSYS软件针对该房间分别应用太阳能集热系统、空气源热泵系统及太阳能与空气源热泵复合式供暖系统进行供暖时的情况进行了分析。首先,建立了太阳能与空气源热泵复合式供暖系统的仿真模型,并对其正确性进行了实验验证;其次,对比分析了在3种运行模式下各个系统的运行特性;最后,以系统能耗及能效比(COP)等参数为指标,对太阳能与空气源热泵复合式供暖系统的性能进行了评价。结果表明:在整个供暖期内,太阳能与空气源热泵复合式供暖系统的总能耗为284.61kWh,其中,空气源热泵消耗的电能为264.10kWh;该复合式供暖系统的太阳能保证率为30.71%,平均COPc-sys为3.04,比单独采用空气源热泵系统进行供暖时的平均COPhp-sys提高了0.33,这表明太阳能与空气源热泵复合式供暖系统在西安地区具有较好的节能优势。这一研究结果为太阳能与空气源热泵复合式供暖系统在西安地区的应用及优化奠定了理论基础,对其推广应用具有重要意义。 相似文献
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A heat pump process is proposed for the recovery of the latent heat of water vapour in waste heat gases. The process includes a humidifier where the moist waste gas is additionally humidified. The moist gas leaving the humidifier is pressurized in a turbocompressor. The dew point temperature of the gas is increased by the humidification and the compression. This is utilized by indirect heat exchange for the production of low pressure steam and for the required heat of vaporization in the humidifier. It should be possible to use the process for waste heat recovery from moist flue gases and from process gases such as dryer exhaust air. Performance data have been calculated for production of low pressure steam at 1.2 bar from moist air at atmospheric pressure, dry temperature 100°C and the absolute humidity 0.19 kg water vapour per kg dry air. With these data a coefficient of performance for the heat pump process has been calculated to be 2.8. 85% (m/m) of the waste heat has been recovered from the moisture content. For these calculations the pressurization in the compressor has been set to 4.0 bar. The process should be further investigated to find performance data under optimal operating conditions. 相似文献
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以某石化公司为例,对加氢裂化装置应用高压绕管式换热器和往复式压缩机气量无级调节系统(HydroCOM),并对高压空冷器进行改造,实现装置节能进行总结.高压绕管式换热器具有占地面积小,换热效率高,换热面积大,制造成本低等特点,相应节省燃料消耗,降低设备制造费用.装置设计能耗为45.39kg标油/t,实际标定能耗为36.77kg标油/t,仅为设计值的81%.按照同比例折算后,每年节约燃料费用1569.9万元.气量无级调节系统投用后,往复式压缩机的轴功率随加工负荷的降低而降低,低负荷运行时,功率消耗明显下降,且100%满负荷运行时,相比投用HydroCOM系统前,电流下降约30A,每小时节电约300kW.h,也能起到节能作用.针对该加氢裂化装置夏季高压空冷器冷后温度偏高问题进行改造:采用升力系数大、升阻比高的新一代HY高效叶片;将摩擦传动改为同步传动.改造后冷后温度下降3~4C,循环氢压缩机汽耗下降0.5t/h,且投资回收期只需4个月. 相似文献