高校建筑空调方案设计探讨

高校建筑选择合理空调方案能够有效降低能耗,实现低碳减排,节约运行费用,建设绿色校园。通过对高校建筑单体供冷、供热需求特点和空调方案能耗分析,总结了空调方案设计方法。     

水源热泵在空调系统中应用的经济性分析

本文对水源热泵的能耗进行了分析,表明水源热泵机组的性能系数与水源的温度直接相关,讨论了水源热泵在嵊州市空调系统集中供冷供热的可行性,对集中冷热水供水系统夏季空调工况与冬季热泵工况的经济性进行了计算与分析,结果表明,嵊州市利用水源热泵建立集中冷热水供水系统的社会经济效益显著,具有重要的节能与环保意义。     

毛细管辐射供冷性能实验研究

以与温湿度独立空调系统相结合的毛细管辐射空调为研究对象,通过实验研究的方法研究了毛细管辐射空调采用高温水系统工况时,不同安装方式、水系统参数、空气设定参数等条件对毛细管空调供冷性能的影响。实验结果表明:裸露安装方式的毛细管辐射供冷能力约为表面与金属板结合的2倍;采用室内空气温度28℃条件比26℃条件下的供冷能力高20%～30%;通过调节流量降低泵耗的方式会使毛细管辐射空调供冷量能力降低。     

能耗模拟软件在空调方案设计中的应用实践

采用能耗模拟软件对设计项目进行空调方案比选,精确计算多联机空调系统相比于风机盘管系统的节能效果,并通过经济回报分析确定适合项目的空调方案,为业主做出正确决策提供依据。通过能耗模拟软件与实际项目的结合,提出应在辅助空调设计阶段应用能耗模拟软件,而非后期的节能计算评估阶段。     

地源热泵空调机组连续运行过程仿真与经济性分析

对1台额定供冷量为5 kW的地源热泵空调机组进行数学建模,并将其用于地源热泵空调机组夏季连续稳定制冷运行过程的仿真研究,以揭示地下埋管传热特性对地源热泵空调机组运行经济性的影响。研究结果表明,地源热泵空调机组的能耗和COP始终处于变化之中,大致分为急变、过渡和趋稳3个阶段,各个阶段的能耗和COP差别显著,但仍总是优于空气源热泵空调机组。对于该工况下运行的地源热泵空调机组,应以趋稳阶段的能耗和COP作为选型的依据。     

辐射供冷系统末端形式对比及发展研究

介绍几种辐射供冷空调的末端形式,比较冷吊顶、楼板辐射供冷、毛细管席的供冷能力、热舒适性、能耗及投资等方面的不同,并建议完善辐射供冷系统试验研究方法,着重进行拥有自主产权产品的制造工艺的研究。     

变水量系统在空调系统节能中的应用

通过对空调能耗的组成分析,指出空调系统辅助设备(风机、水泵)的能耗在空调节能中占有重要地位,以变水量空调水系统为分析对象,说明变水量技术的成功应用来源于节能的需求与技术的发展,分析了空调水系统采用变频技术后对水系统的水力工况、系统能耗、设备降温除湿能力的影响,最后就作者在工程中碰到的一些典型案例作简单分析,指出变水量系统的设计与改造原则应该立足于建筑空调负荷的全年变化特征,必须结合水泵特征和水系统阻力特征进行具体分析,避免节能技术应用中的鱼目混珠现象。     

地板辐射供冷技术的应用分析

为了推广地板辐射供冷这一新型节能技术,本文论述了国内外地板辐射供冷技术的发展状况,对地板辐射供冷的实际应用特点、供冷能力、供冷能耗、设计要点进行了分析.辐射供冷要比常规空调系统节能28%～40%且舒适性强.由于可以冷暖联供,在我国南方和北方都有巨大的发展空间.     

能源站供冷系统冷源优化配置分析研究

对能源站供冷系统蒸汽溴化锂机组和电制冷机组的冷源优化配置进行分析研究。基于DeST软件建立某区域内若干典型建筑物的能耗模拟模型,通过模拟计算得到能源站供冷系统总的全年逐时负荷。综合考虑初投资及年运行费用,采用全寿命周期成本评价指标法,分析研究能源站供冷系统中的蒸汽型双效溴化锂与电制冷冷水机组容量的优化分配,通过计算得到典型工况下得到全寿命周期成本最低的溴化锂制最优供冷比例为61.8%。在此基础上,进而分别探讨电制冷主机COP及蒸汽价格变量因子对能源站供冷系统的制冷主机容量配比的影响规律,得出溴化锂机组最优配比随电制冷主机COP值升高而下降,随蒸汽价格升高而下降的基本规律。研究成果可为能源站供冷系冷源的配置选型提供参考。     

基于建筑动态负荷优化风冷热泵机组配置

为得到中央空调系统中风冷热泵机组的最优化配置方案,本文建立了风冷热泵机组变工况能耗计算模型,根据建筑典型负荷工况、多台机组运行策略、以及机组变工况性能等参数,对风冷热泵机组的技术性、经济性进行了分析。研究结果表明：制热工况下采用多台机组配置方案比制冷工况下采用多台机组配置方案节能效果明显,较常规空调系统配置和方案,全年节约电耗3．4％。     

不同地区住宅能耗与太阳能吸收式空调系统匹配性分析与模拟研究

为了满足农村住宅清洁用能的需求,多种形式的能源系统逐渐开始应用于广大的农村地区。随着太阳能集热器集热效率的提高,热驱动机组各项性能不断改善,这样有利于太阳能吸收式空调系统在农村地区的应用。为了研究太阳能吸收式空调系统与农村住宅全年能耗的匹配问题,文章首先建立了DeST住宅模型,然后利用TRNSYS软件建立了太阳能吸收式空调系统模型,最后根据模拟结果对国内不同气候区内农村住宅供热季、供冷季的平均热负荷值,以及全年的能耗进行分析。此外,文章还分析了典型日太阳能吸收式空调系统的运行策略与效果。分析结果表明:在无辅助热源的条件下,太阳能集热器的集热温度会大于80℃,满足空调机组的热驱动温度,因此可以作为太阳能吸收式空调系统的的热源;当启动温度为85℃时,空调机组的制冷量可以达到8 kW,性能系数COP为0.733。     

Fuel processor-battery-fuel cell hybrid drivetrain for extended range operation of passenger vehicles

Power required to run auxiliary systems on a passenger car, such as those for air conditioning and advanced vehicle control, reduces the driving range of a vehicle equipped with a hybrid drive train. Under practical driving conditions, a significant amount of additional energy is required at low power levels compared to the rated power of the drive unit. In the present study, we consider a fuel cell-battery drive train augmented by an on-board fuel (ethanol) processor to provide the motoring power requirements of a car. Using systematic driving cycle simulations that take account of power-to-weight, energy-to-weight and power-to-efficiency factors of on-board power sources under simulated load conditions, we show that a combination of steadily-operated compact ethanol reformer, a low-power battery continuously charged by excess reformer capacity and a high-power fuel cell powered by conservatively-used hydrogen from cylinder can increase the range of hybrid fuel cell drivetrains to about 750 km. Although the overall energy consumption of the three-way hybrid is more than that of fuel cell-battery hybrid, lesser use of stored hydrogen improves the fuel economy of the hybrid drivetrain. While the system complexity is increased, long-range distressed mode operation becomes feasible with the added fuel processor.     

风冷式太阳能吸收式制冷机性能模拟研究

在环境温度和太阳辐射动态变化的情况下,对制冷量为5 kW的风冷式太阳能吸收式制冷机的性能进行了模拟,得出了集热器出口水温和热水储槽温度随时间变化的规律曲线以及在此规律的影响下吸收式制冷机的性能曲线.模拟结果表明风冷式太阳能吸收式制冷机在理论上是切实可行的,但是环境温度的变化以及风冷系统的散热能力对系统性能有较大的影响,环境温度的升高会使需要风冷降温的冷凝器、吸收器温度升高,从而提高了发生温度的要求,这不利于太阳能的利用和系统的制冷.为此需要强化冷凝器和吸收器的散热效果,来降低境温度对系统的不利影响.     

Analysis of air conditioning system impact on a fuel cell vehicle performance based on a realistic model under actual urban conditions

In this study, a practical fuel cell vehicle considering the Heating, Ventilation, and Air conditioning system is considered to analyze hydrogen consumption under different working conditions. As a prevalent hydrogen-fueled vehicle, Toyota Mirai has been meticulously modeled in Simecenter Amesim software. The simulated model covers all of the vehicle's components with a concentration on Heating, Ventilation, and Air conditioning system. Since the air temperature and ‘weather conditions can significantly impact the vehicle's overall performance, various environmental conditions, including temperature variations, humidity, and varied solar fluxes, are taken into account. Furthermore, New York City is chosen as a densely populated megacity to simulate the dynamic behavior of the fuel cell vehicle under actual driving circumstances. The results illustrate that the Heating, Ventilation, and Air conditioning system can notably alter hydrogen consumption under real driving conditions. In this regard, turning on the Heating, Ventilation, and Air Conditioning system results in a 19% increase in fuel consumption. Moreover, the degradation phenomenon, which is a typical result of using fuel cell vehicles under urban driving conditions, impacts the vehicle's mileage and hydrogen consumption. The simulation results indicate that a fresh fuel cell stack consumes 80 g of hydrogen, while for 2500 and 5500 working hours fuel cells, the stack consumes 89.6 and 107 g of hydrogen, respectively. Based on the obtained results, a 33.75% increase in fuel consumption occurs by implementing a degraded fuel cell stack under real driving conditions.     

基于溶液除湿的风冷热泵系统性能分析

为了克服利用冷却除湿的风冷热泵空调系统机器露点过低、需要再冷和过热、难以适应显热潜热比例的变化、不能蓄能等缺点,提出基于集热再生器溶液除湿的热泵空调系统。通过济南某工程实例研究表明,与冷却除湿空调系统相比较耗电量减少12.3%,利用太阳能加热溶液除湿具有降低空调除湿能耗、利用可再生能源、减少高品位能源消耗等优势。证明太阳能溶液除湿在空调系统中是处理潜热负荷的理想选择,具有较好的节能性。     

基于新能源发电的电解水制氢直流电源研究

利用新能源发电进行电解水制氢是实现新能源就地消纳和氢能利用的重要途径,以匹配电解水制氢工作特性的制氢电源为研究对象,通过分析质子交换膜电解槽电解电流、温度与电解槽端口电压、能量效率、制氢速度之间的关系,得出制氢电源需具备输出低电流纹波、输出大电流、宽范围电压输出的特性。为满足新能源电解制氢系统需求,提出一种基于Y型三相交错并联LLC拓扑结构的制氢电源方案,该方案谐振腔三相交错并联输出,满足电解槽大电流低纹波工作特性,并采用脉冲频率控制实现谐振软开关,提高变换效率。最后,搭建仿真模型和6 kW模块化实验样机,验证所提出方案的合理性与可行性。     

Contribution to the Study of the Reduction of Energy Consumption through the Exchanger Coupled Conventional Air‐Ground‐Air Conditioner. Application to the Building

In this study, a new method of using the earth‐air heat exchangers to reduce energy consumption in buildings is discussed. The idea is to couple the EAHE with the condenser of a residential air conditioning system to enhance the effectiveness of the latter. Under the climatic conditions of high temperature in summer (south‐eastern region of Algeria), which can sometimes exceed 50 °C, what makes the heat exchange between the air conditioner and the external environment very difficult in addition to the problem of thermal comfort and the cost of energy consumption. Conducting a simulation by the TRNSYS software that allows to couple the model of the EAHE with the condenser of a residential air conditioner and connect the system with a building. The results show a clear reduction in the energy consumed by this system in connection with the direct use of the air conditioner and increase air conditioning efficiency, coefficient of performance, and energy efficiency rating. In this paper the Hollmuller model was ameliorated and the obtained results are in concord with it. The system is capable of resolving the problem of mal cooling of buildings by air conditioners under critical climate conditions, in addition to lowering the heat output of the condenser, and reducing its effect on the environment.     

基于分区建模的大空间分层空调负荷随分层高度变化的研究

以某坡屋顶大空间建筑为研究对象,利用eQUEST软件,提出了空调区和非空调区分区的建模方法,依据所建模型分析全室空调和不同分层高度时夏季分层空调峰值冷负荷特性.模拟结果表明,分层空调形式的负荷比全室空调的减少30%以上,夏季空调峰值负荷随分层高度增加近似线性增加.比较模拟负荷与常规分层空调负荷计算结果发现,两者相对误差小于3%,说明基于动态能耗模拟软件分区模拟大空间分层空调负荷的方法合理.     

水上和水下提取次表层海水冷量的对比和分析

夏季的酷热迫使人们耗费大量能源以维持狭窄的温度环境,城市空调负荷节节攀升;近在身边的海中,表层以下巨大的水团静静地安卧,闲置着天然的冷量.冷媒水与海水在海中进行换热,是实现水下直接提取海洋冷量的构想.与陆上提取冷量方案的对比,可以证明其技术优势和节能效果.水下取冷方案甚至可应用于高盐度海区,并提高海水与冷媒水的换热温差,以提升海水冷量利用率;采用自来水作为冷媒水,不需要对海水进行处理,也不会出现管道堵塞的故障;作为空调系统回水的自来水,又可用作其它工业或生活用途.该方案在提供相同冷媒水流量的条件下,输水耗功减少幅度达到90%.     

Experimental investigation on mini‐channel cooling–based thermal management for Li‐ion battery module under different cooling schemes

The performance of Li‐ion battery depends on the temperature. Active liquid cooling system can keep the battery temperature within an optimal range, but the system itself consumes energy. This paper reported the experimental work on the thermal performance of liquid cooling system for the battery module under different cooling schemes. It was hoped that energy consumption could be reduced as much as possible. Meanwhile, liquid cooling system could provide effective cooling for the battery module. Two identical real battery modules including 18 cylindrical cells (with and without cooling system) were manufactured for the validity of comparison. The 2 battery modules discharged at the discharge rates of 1C and 1.5C. Charge and discharge cycle test was also carried out. The results indicated that a simple hysteresis control cooling scheme could reduce the energy consumption effectively. The energy consumption was saved by 83.2% and 49% at the discharge rates of 1C and 1.5C, respectively. Meanwhile, the temperature of battery module was still kept within the optimal range. The maximum temperature appeared on different cells in the battery module during the process of charge and discharge. Thus, the temperature dynamic comparison mechanism was very necessary.