共查询到19条相似文献,搜索用时 171 毫秒
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《青岛理工大学学报》2015,(5)
运用CFD数值模拟软件对某高层建筑空调室外机的风环境进行模拟,研究室外机放置于风井中时室外机散热对上层设备的影响.模拟室外机未加导风罩情况下的温度场,发现下层室外机的排风导致上层室外机回风温度升高显著.室外机增加导风罩后,室外机的回风温度平均降低了10℃左右,优化了室外机的风环境,提高了空调的制冷性能. 相似文献
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《建筑热能通风空调》2017,(5)
为了保证建筑物外立面的美观性,VRF空调室外机的放置平台常被各种百叶窗遮挡起来,百叶窗叶片的倾斜角度、方向和开口率直接影响室外机的散热效果,从而影响空调的运行效果。本文通过数值模拟对室外机周围的气流环境进行了计算分析,研究了百叶窗参数对室外机散热器进风温度的影响。计算结果表明:叶片倾斜角度越大,室外机散热效果越差;开口率越小,室外机散热效果越差。为了满足室外机的正常运行,空调机位外立面处的百叶窗倾斜角度和开口率必须满足设计要求。 相似文献
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本文以分体式空调的室外机为对象,采用CFD方法,使用FLUENT软件模拟了不同的环境风速条件下,不同热释放率的室外机周围的速度场、温度场,分析室外机释放的冷凝热对建筑周围热环境的影响。还模拟了室外机置于建筑迎风面、背风面和无室外机散热影响情况下某大开口单体建筑的自然通风情况,分析通风过程中的速度、温度以及压力分布情况,研究冷凝热释放对自然通风的影响。室外机组的尺寸为900mm×900mm×300mm,距建筑外墙的距离为0.2m,距地面0.5m。由模拟结果可以看出由于热浮力的作用,热气流有明显的上升趋势,并逐渐向外墙面贴附,且影响范围很大。热空气的上升运动不仅与室外机的热释放率有关,而且与室外环境的风速也有关系。本文首次采用热污染边界层的概念来定义室外机冷凝热释放的影响范围,并对室外机的安装布置提出合理化建议。 相似文献
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本文分析了VRV空调系统室外机的散热问题,并通过工程实例,探讨了如何对VRV空调系统室外机进行散热校核. 相似文献
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风机盘管是一种最为常见的空调末端设备,作为供热末端设备使用时,其优点与散热器相比,属于机械对流散热设备,散热能力强。目前对于风机盘管变工况散热特性的研究结果都是基于进水温度、水流量为基础的数据拟合公式,与常规暖通设计时设定系统供、回水温度的设计方法并不匹配。本文借鉴散热器散热量计算公式,进行了基于过余温度△TM的散热量研究,给出了风机盘管在不同进、出水温度下散热量公式,最大误差仅为7.01%,满足工程设计使用要求。 相似文献
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蔡亚桥 《建筑热能通风空调》2014,(2):90-92
依据地铁车站空调系统的运行特点,结合地铁车站新、排风井的设置原则,指出地铁车站的冷却塔、蒸发式冷水机组、蒸发式冷却塔、多联机室外机等空调系统的散热设备放在地下是可行的,该方法对于地铁车站地面冷却塔等散热设备长期以来与地面占地征用协调困难、与城市景观不协调、噪音扰民等矛盾的解决具有一定的借鉴意义。 相似文献
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Current paper numerically investigated the effect of three main surrounding structures (exhaust grille, deflecting-ring, and heat exchanger) on airflow characteristics passing through the outdoor unit of split-type air conditioner. Characteristic curves of the fan were obtained, and then simulation results were successfully validated compared to experimental data. Three types of grilles (a circular grille, a rectangular grille, and a proposed novel grille) were evaluated and comprised with two parameters of non-dimensional aero-dynamic and air throw distances. Results indicated the superiority of proposed grille and circular grille, respectively in two mentioned parameters. Increment of the deflecting-ring’s width increased the non-dimensional aero-dynamic performance, the efficiency, and the turbulence intensity and vice versa. Decrement of deflecting ring’s width led to decreasing in these parameters except turbulence intensity. Besides, condenser blockage made a decrease in the non-dimensional aero-dynamic performance and increase in the total pressure coefficient. 相似文献
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基于对我国家用空调器产品现状的分析,探讨了执行新能效标准后空调换热器采用新型强化传热技术的潜在需求。制冷剂在微细管内凝结和沸腾传热的已有研究成果显示,家用空调器采用微细尺度强化传热技术,可以使换热器趋于紧凑、高效,从而使空调器满足新能效标准的要求。 相似文献
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当室外气温较高时,风冷热泵系统冷凝器存在换热效果下降的问题,而蒸发式冷凝器可以改善此问题,蒸发式冷凝器因此逐步得到广泛重视。为研究采用蒸发式冷凝器制冷系统的能耗情况,通过正交实验的方法,对比研究了蒸发式冷凝器与风冷式冷凝器在相同工况下压缩机能耗情况,并对影响其性能的因素进行了分析。研究表明,各因素对压缩机耗功量的影响能力依次为:冷凝器进口空气温度、速度及冷凝器喷水量。压缩机耗功量随进口空气温度的升高、进风空气速度降低而增大,随喷水量增加存在先减小后保持不变的现象。 相似文献
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Salama M. Abdel-Hady Soubhi A. Hassanein Waleed A. Abdel-Fadeel Hesham S. Abdel-Mohsen 《Energy and Buildings》2011,43(11):3053-3058
This study presents a proposed idea about making use of the thermal energy rejected by the condenser in a water-cooled split-air-conditioning systems to decrease the relative humidity of the cold air supplied by such air conditioners. Most of split air-conditioner systems cool air without controlling its humidity. An amount of heat is rejected from the air conditioner, through the condenser, into the surrounding in order to allow the refrigerant to cool down and condense, thus, part of the lost energy can be exploited to decrease the relative humidity of the sub-cooled air that leaves the evaporator as saturated humid air. Four variables, viz. the coil type (single or double), the amount of flowing water, water, temperature, and the cooled air velocity were studied to find out the optimum conditions required for this purpose. The requisite amount of heat that may adjust the relative humidity of the conditioned air was also determined. The experimental results suggest an optimum design of a heat exchanger for performing the use of the heat rejected from the condenser to achieve the aim. As a result, the proposed heat recovery concept can be worthily adopted to achieve economic results in large-scale systems. 相似文献
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空调内区余热问题解决方法探讨 总被引:5,自引:2,他引:3
建筑物内区余热已成为空调设计中不容忽视的问题。提出了内区分路设置冷冻机、内区分路设置板式换热器利用冷却塔供冷、利用新风机组送冷风以及利用设双风机的全空气系统解决内区余热问题的几种方法。 相似文献
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Recent anecdotal information suggests that “cool” roofs might produce significant energy savings by reducing the temperature of air entering rooftop air-conditioner (RTU) condensers. Unfortunately, measurements to support this claim are not well documented. To overcome this problem, we carried out a set of six rigorous field experiments to determine the effects of roof reflectance on the heating of condenser inlet air by the roof, and to assess the effects of condenser fan operation on the potential recirculation of hot discharge air from the condenser. The experiments involved combinations of two roof conditions (a “hot” roof and then the same roof with a “cool” coating) and three RTU operation modes (condenser fan and compressor both operating, condenser fan operating without the compressor, and condenser fan and compressor both not operating). For each case, we continuously measured outdoor air temperature at 26 locations near and far from the RTU, as well as roof surface temperatures at 2 locations (1 near and 1 far from the RTU), wind speed and direction, and solar radiation. 相似文献