VRV空调系统的节能性研究与应用

介绍VRV空调系统的特点及发展状况,特别从传热介质、设计理念创新等不同角度分析了该系统的运行节能因素,并且对变频控制热泵式VRV空调系统的节能性能和冬、夏季的运行特性作了一系列实验研究,从而分析了影响室内机制冷量、制热量以及室外机组功率的因素。通过具体的实例分析,对VRV空调系统与常规的空调系统在节能性能方面进行了比较,最后提出了该系统有待解决的一些问题,并对这种系统产品的应用与前景进行了简单的阐述。     

蓄能型液体除湿蒸发冷却系统中除湿性能的实验研究

提出了一种新型空调系统——液体除湿冷却空调系统的设计方案并搭建一功率为3kW的实验台，考虑到除湿过程和再生过程是该系统性能优良的决定性环节，设计加工了水冷型波纹板降膜式结构的除湿器和以丝网填料作为内部填料的再生器。在此实验装置上对系统的除湿过程以及其蓄能能力特性进行了实验研究，得出影响该系统除湿能力、蓄能能力等方面的主要因素，为系统的优化设计和运行提供依据。     

废热驱动的高效除湿空调系统实验研究

文章构建了由固体废弃物气化炉废热驱动的高效除湿空调系统,该空调系统利用除湿换热器承担湿负荷。此外,该空调系统内还设有回热装置,利用该回热装置能够显著降低实际能耗。文章在有、无回热子系统的情况下,分析了高效除湿空调系统的热湿传递特性,并得到了带有回热子系统的高效除湿空调系统的最优工况参数。分析结果表明:当驱动热源温度为70℃时,若高效除湿空调系统存在回热子系统,则该空调系统的平均除湿量达到了9.01 g/kg;在有、无回热子系统的条件下,高效除湿空调系统的COP分别为0.7,1.34;当预再生时间为180 s时,高效除湿空调系统的运行性能最佳。     

毛细管网辐射空调末端换热性能实验研究

为了研究毛细管网空调末端的换热性能,对郑州中南科莱空调设备有限公司会议厅毛细管网空调辐射系统空调末端进行了设计计算,并在该系统上进行了冬季供暖实验研究,通过分析实验数据,计算得到毛细管网辐射末端的平均换热量和综合传热系数,分别为38.95 W/m2和4.14 W/（m2·K）,与已有经验数据基本吻合,但是由于实验条件的局限性,该结果有待进一步校核。     

基于Kuli的某商用车空调系统性能仿真及优化分析

本文利用流体分析软件Kuli建立了基于几何参数和实验数据的空调系统计算模型,对某商用车的空调系统进行了仿真分析,并用实验证实了仿真的可行性。分别建立了此空调系统的国内和国外某炎热地区的计算模型,结果表明此空调系统在国内工况可满足设计要求,而不满足国外某炎热地区的降温需求,在此基础上对空调系统提出了优化方案,优化后的空调系统可满足国外工况的设计要求。     

内燃机车司机室吸附式空调器的实验与性能分析

机车司机室吸附式空调器是一种以内燃机排气的余热驱动的空调系统。该系统利用固体吸附式制冷原理，分子筛—水作为工质对，采用单吸附器结构，通过蓄冷器实现向内燃机车司机室连续、稳定地供冷。该文阐述了该空调器的实验方法，并对实验结果及性能影响因素进行了分析。实验表明：机车司机室吸附式空调器是一种实用、可行的新型空调系统。实验结果对原型样机及其运行控制方法的设计有重要的参考价值。     

VRV空调系统的节能性研究与应用

介绍VRV空调系统的特点及发展状况，特别从传热介质、设计理念创新等不同的角度分析该系统的运行节能因素，并且对变频控制热泵式VRV空调系统的节能性能和冬季、夏季的运行特性作了一系列实验研究，从而分析影响室内机制冷量、制热量以及室外机组功率的因素。通过具体的实例分析，对VRV空调系统与常规的空调系统在节能性能方面进行比较，最后提出该系统有待解决的一些问题，并对这种系统产品的应用与前景进行简单的阐述。     

小型固体吸附式太阳能空调装置的实验研究

根据小型太阳能空调装置的要求和特点,对固体吸附式太阳能空调系统进行了实验研究。通过对装置运行工况的具体分析,选择硅胶水作为吸附剂与制冷工质,介绍了集热／再生器、空冷冷凝器和蒸发器的结构设计。在此基础上,建立了小型固体吸附式太阳能空调实验装置,并对整个系统的运行性能进行了一系列的实验研究。结果表明,采用硅胶水工质的小型吸附式太阳能空调装置进行间歇式空调,在技术上是可行的,为进一步研究性能的优化提供了依据。     

土壤冷源直接供冷空调系统供冷特性的实验研究

提出一个以土壤作为冷源直接供冷空调的新构想,并在哈尔滨地区建立了相应的实验系统.根据该系统运行一个空调季所得实验数据,除获得一些重要参数(如季节供冷系数、平均供冷率)外,着重对它在运行期间的供冷特性进行了研究,得到一些重要分析结论.实验结果还表明,所提出的土壤直接供冷系统在一定地域范围内具有巨大节能潜力.     

温湿度独立控制空调系统的现状及发展

综述温湿度独立控制空调系统的国内外研究现状,比较该空调系统与常规空调系统的优势。通过分析该系统的优缺点,论述该系统存在的主要问题,并对今后温湿度独立控制系统的发展提出了展望。     

A new solar and geothermal based integrated ammonia fuel cell system for multigeneration

In this study, a new solar and geothermal based integrated system is developed for multigeneration of electricity, fresh water, hydrogen and cooling. The system also entails a solar integrated ammonia fuel cell subsystem. Furthermore, a reverse osmosis desalination system is used for fresh water production and a proton exchange membrane based hydrogen production system is employed. Moreover, an absorption cooling system is utilized for district cooling via available system waste heat. The system designed is assessed thermodynamically through approaches of energy and exergy analyses. The overall energy efficiency is determined to be 42.3%. Also, the overall exergy efficiency is assessed, and it is found to be 21.3%. The exergy destruction rates in system components are also analysed and the absorption cooling system generator as well as geothermal flash chamber are found to have comparatively higher exergy destruction rates of 2370.2 kW and 643.3 kW, respectively. In addition, the effects of varying system parameters on the system performance are studied through a parametric analyses of the overall system and associated subsystems.     

模块化分布式热电联供技术与实践

本文介绍了分布式热电联供系统,分析了分布式热电联供系统当前的发展形势。同时,也指出了国内冷热电联供推广过程中的一些制约因素。在此基础之上,提出了模块化分布式热电联供系统的概念,并且从几个方面阐述了模块化分布式热电联供系统的优势。最后,以实例说明了模块化的分布式热电联供系统的合理性。模块化冷热电联供必将成为热电联供系统设计和运行管理的有效模式。     

Analysis and assessment of an advanced hydrogen liquefaction system

In the present work, an advanced hydrogen liquefaction system with catalyst infused heat exchangers is proposed, analyzed and assessed energetically and exergetically. The analysis starts with exergetic considerations on hydrogen liquefaction using different alternatives of pre-cooling including the conversion from normal to parahydrogen. It further explains the fundamentals of a proposed liquefaction process. The goal is then to assess the proposed system, make modifications and improve the system. The present system covers all of these portions of a hydrogen liquefaction system with an ultimate goal of achieving a sustainable and environmentally harmless system. The proposed hydrogen liquefaction system is simulated in the Aspen Plus and the performance of the system is measured through energy and exergy efficiencies. The resulting energy efficiency of the system is calculated to be 15.4%, and the exergy efficiency of the system is found to be 11.5%.     

Thermodynamic analysis of a novel energy storage system with carbon dioxide as working fluid

Recently, energy storage system (ESS) with carbon dioxide (CO₂) as working fluid has been proposed as a new method to deal with the application restrictions of Compressed Air Energy Storage (CAES) technology, such as dependence on geological formations and low energy storage density. A novel ESS named as Compressed CO₂ Energy Storage (CCES) based on transcritical CO₂ Brayton cycle is presented in this paper. The working principle of CCES system is introduced and thermodynamic model is established to assess the system performance. Parametric analysis is carried out to study the effect of some key parameters on system performance. Results show that the increase of turbine efficiency is more favorable for system optimization and the effect of minimum pressures on system performance is more significant compared with maximum pressures. A simple comparison of CCES system, liquid CO₂ system and Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) system is conducted. It is shown that the system efficiency of CCES is lower than that of AA-CAES system but 4.05% higher than that of liquid CO₂ system, while the energy density of CCES system is 2.8 times the value of AA-CAES system, which makes CCES a novel ESS with potential application.     

Thermodynamic modeling and exergy analysis of proton exchange membrane fuel cell power system

The proton exchange membrane (PEM) fuel cell (PEMFC) is equipped with a series of auxiliary components which consume considerable amount of energy. It is necessary to investigate the design and operation of the PEMFC power system for better system performance. In this study, a typical PEMFC power system is developed, and a thermodynamic model of the system is established. Simulation is carried out, and the power distribution of each auxiliary component in the system, the net power and power efficiency of the system are obtained. This power system uses cooling water for preheating inlet gases, and its energy-saving effect is also verified by the simulation. On this basis, the exergy analysis is applied on the system, and the indexes of the system exergy loss, exergy efficiency and ecological function are proposed to evaluate the system performance. The results show that fuel cell stack and heat exchanger are the two components that cause the most exergy loss. Furthermore, the system performance under various stack inlet temperatures and current densities is also analyzed. It is found that the net power, energy efficiency and exergy efficiency of the system reach the maximum when the stack inlet temperature is about 348.15 K. The ecological function is maintained at a high level when the stack inlet temperature is around 338.15 K. Lower current density increases the system ecological function and the power and exergy efficiencies, and also helps decrease the system exergy loss, but it decreases the system net power.     

Modeling and control of a wind fuel cell hybrid energy system

This paper describes a hybrid energy system consisting of a 5 kW wind turbine and a fuel cell system. Such a system is expected to be a more efficient, zero emission alternative to wind diesel system. Dynamic modeling of various components of this isolated system is presented. Selection of control strategies and design of controllers for the system is described. Simnon is used for the simulation of this highly nonlinear system. Transient responses of the system for a step change in the electrical load and wind speed are presented. System simulation results for a pre-recorded wind speed data indicates the transients expected in such a system. Design, modeling, control and limitations of a wind fuel cell hybrid energy system are discussed.     

电站凝汽器运行状态监测智能决策系统研究

凝汽器系统是电站凝汽式汽轮机的重要辅助设备,其运行状态的优劣对汽轮机组的安全性与经济性都有很大影响。针对某火力发电厂凝汽器系统,设计了将故障诊断和性能优化融合在一起的状态监测智能决策系统软件。该软件具有两大特色：一是性能优化与故障诊断的结合;二是故障诊断采用模糊神经网络与专家推理串行连接的模式。主要介绍了系统的组成、接口及其特点。该软件已在运行中得到了成功应用。     

Dynamic modeling of a proton exchange membrane fuel cell system with a shell-and-tube gas-to-gas membrane humidifier

The proton exchange membrane fuel cell (PEMFC) system with a shell-and-tube gas-to-gas membrane humidifier is considered to be a promising PEMFC system because of its energy-efficient operation. However, because the relative humidity of the dry air flowing into the stack depends on the stack exhaust air, this system can be unstable during transients. To investigate the dynamic behavior of the PEMFC system, a system model composed of a lumped dynamic model of an air blower, a two-dimensional dynamic model of a shell-and-tube gas-to-gas membrane humidifier, and a one-dimensional dynamic model of a PEMFC system is developed. Because the water management during transient of the PEMFC system is one of the key challenges, the system model is simulated at the step change of current. The variations in the PEMFC system characteristics are captured. To confirm the superiority of the system model, it is compared with the PEMFC component model during transients.     

汽轮发电机组转子—轮盘—叶片系统耦合扭转振动研究

在传统的汽轮发电机转子系统强度及振动计算中，转子，叶片是分开考虑的，忽略了相互间的耦合作用，随着大扭曲长叶片的普遍采用，进行精胡的转子－轮盘－叶片耦合拓动分析对防止叶片，轮盘，转子事故已很有必要，本文提出了一种转子，轮系耦合扭转振动的分析方法，将耦合系统分为主部件转子和分支部件轮盘－叶片系统，分支部件的各阶模态可简化为等效的质量－弹簧系统，这样可以将原来大规模耦合振动系统降阶为低阶等效的小规模耦保系统，进而求出其频率和振型。     

电厂管系水击分析

对电厂管系水击激发的管道振动进行了研究,利用有限元方法,对研究的管系进行了有限元建模,把水击基本方程得出的水击力作为加载力,计算出了水击激发的位移、转角响应幅值和激发出的管系模态系数,从计算结果看出水击对管系的动力特性有重要影响,在管道设计时必须加以考虑,最后提出了消除水击影响的措施。