微型离心式冷水机组性能分析

以桌公司开发的微型离心式冷水机组为研究对象,阐述了离心式压缩机微型化和冷水机组性能高效化的主要技术途径.根据机组在不同运行工况下的性能测试数据建立了能耗模型,分析了微型离心式冷水机组用于参考建筑供冷时的SEER特性.与名义制冷量、COP相近的单螺杆机组的计算结果进行比较表明,其全供冷季运行性能已达到或优于同等容量常规单螺杆机组的性能.     

暖通空调设计中的常见问题分析

分析了风机盘管选型、新风竖井设置、风冷冷水机组选型、冷却水箱设置、散流器布置等设计中应注意的问题。     

Design and performance of solar powered absorption cooling systems in office buildings

The paper contributes to the system design of solar thermal absorption chillers. A full simulation model was developed for absorption cooling systems, combined with a stratified storage tank, steady-state or dynamic collector model and hourly resolved building loads. The model was validated with experimental data from various solar cooling plants.As the absorption chillers can be operated at reduced generator temperatures under partial load conditions, the control strategy has a strong influence on the solar thermal system design and performance. It could be shown that buildings with the same maximum cooling load, but very different load time series, require collector areas varying by more than a factor 2 to achieve the same solar fraction. Depending on control strategy, recooling temperature levels, location and cooling load time series, between 1.7 and 3.6 m² vacuum tube collectors per kW cooling load are required to cover 80% of the cooling load.The cost analysis shows that Southern European locations with higher cooling energy demand lead to significantly lower costs. For long operation hours, cooling costs are around 200 € MWh⁻¹ and about 280 € MWh⁻¹ for buildings with lower internal gains and shorter cooling periods. For a Southern German climate, the costs are more than double.     

A novel approach for optimal chiller loading using particle swarm optimization

This study employs two new methods to solve optimal chiller loading (OCL) problem. These methods are continuous genetic algorithm (GA) and particle swarm optimization (PSO). Because of continuous nature of variables in OCL problem, continuous GA and PSO easily overcome deficiencies in other conventional optimization methods. Partial load ratio (PLR) of the chiller is chosen as the variable to be optimized and consumption power of the chiller is considered as fitness function. Both of these methods find the optimal solution while the equality constraint is exactly satisfied. Some of the major advantages of proposed approaches over other conventional methods can be mentioned as fast convergence, escaping from getting into local optima, simple implementation as well as independency of the solution from the problem. Abilities of proposed methods are examined with reference to an example system. To demonstrate these abilities, results are compared with binary genetic algorithm method. The proposed approaches can be perfectly applied to air-conditioning systems.     

西北地区使用干空气能的蒸发冷却辐射供冷系统应用分析

介绍了蒸发冷却技术和辐射供冷的特点,根据西北地区独特的干热气候条件,提出使用干空气能的蒸发冷却辐射供冷系统,并对该复合系统的特点、应用前景及存在问题进行了分析。     

双效溴化锂吸收式制冷机动态特性研究

应用模块化建模和集总参数法并参考实例建立双效溴化锂吸收式制冷机动态仿真模型,并在不同范围内进行了变工况仿真实验,结果和理论分析能较好地吻合,对楼宇冷热电联供系统的优化设计及节能节材目标的实现具有一定的指导意义.     

变风量对中大型风冷热泵结霜工况性能的影响

采用试验方法研究了风量变化对中大型风冷热泵机组结霜工况性能的影响。研究发现,迎面风量的变化对V型换热器最早结霜位置几乎没有影响,最早结霜位置总在换热器弯头连接段附近,风量的变化只是影响管壁温度的高低,与直管段相比,弯管段制冷剂压损较大,管壁温度较低,利于霜晶形成;迎面风量降低导致系统蒸发温度降低,致使结霜速度加快,直接造成机组稳定工作时间缩短;适当提高风机转速具有抑制结霜,减少除霜次数,有效提高机组运行性能的作用;消除V型换热器较高位置和较低位置支路出口带液是解决振荡的根本办法。     

微燃机冷热电联供系统性能的模拟研究

介绍了冷热电联供(CCHP)系统,以上海某示范性微燃机冷热电联供系统为研究对象,通过建立系统主要设备的数学模型,模拟分析了系统在不同环境温度下的性能和系统全年的运行工况。结果表明:微燃机冷热电联供系统的性能受环境温度的影响,系统过渡季节不运行时年平均能源综合利用率可达到70%以上。     

冷水机组的回油技术研究

主要从取油位置、取油技巧和回油方法3个方面对冷水机组的回油问题进行论述,并对冷水机组回油的3种方式——重力回油、引射器回油和直接回油进行详细分析。     

离心式制冷压缩机的发展及思考

回顾我国离心式制冷压缩机的发展历程,介绍该领域国内外目前关注的难点、热点课题,并就今后我国离心式制冷压缩机产业的持续发展谈几点个人的看法。