Optimum Energy Management of the Central Air-Conditioning System in Intelligent Buildings

An optimum energy saving scheduling strategy of the central air conditioning system in an intelligent building (IB) was proposed. Based on the system analysis a set of models of the central air conditioning system was established. The periodically autoregressive models (PARM) based on genetic algorithms (GA) were used to predict the next day’s cold load. The improved genetic algorithms (IGA) with stochastic real number coding were used to finish the optimum energy saving scheduling of the system. The simulation results for the building of the Liangmahe Plaza show that the proposed strategy can save energy up to about 24 5%.

An Energy-Saving Control Strategy on Central Air-Conditioning System

An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature control systems, and then parameters in the cold load model and in the central air-conditioning system model are estimated. Generalized predictive control (GPC) is used to establish an optimization model to minimize the consumption of energy and the control error of temperature. The simulated annealing (SA) algorithm, combined with quadratic programming, is adopted to solve the optimal problem. Contrasted with the simulation of traditional PID control, the results prove the effectiveness of this proposed strategy.

Application of Dual Throttling Air-Conditioning System to Explosion-Proof Frequency Converter

An explosion-proof dual throttling air-conditioning system was put forward to solve the heat dissipation and internal dewing problems of explosion-proof frequency converter in the underground coal mine. This study investigated the feasibility and benefits of explosion-proof dual throttling cooling and dehumidification air-conditioning system applied to the explosion-proof frequency converter. The physical model of dual throttling air-conditioning system was established and its performance parameter was described by mathematical method. The design calculation of the system has also been done. The experimental result showed that the system reached the steady state at the refrigeration mode after running 45 min, and the maximum internal temperature of the flame-proof cavity was 31.0 ℃. The system reached the steady state at the dehumidification mode after running 37 min. The maximum internal relative humidity and temperature of the flame-proof cavity were 33.4% and 36.3 ℃, respectively. Therefore, the proposed system had excellent ability of heat dissipation and avoided internal dewing. Compared with water cooling system, it was more energy-saving and economical. The airflow field of dual throttling air-conditioning system was also studied by CFD simulation. It was found that the result of CFD numerical simulation was highly consistent with the experimental data.

Analysis and Modeling of the Central Air-Conditioning System in Intelligent Buildings

The central air conditioning system in an intelligent building (IB) was analyzed and modeled in order to perform the optimization scheduling strategy of the central air conditioning system. A set of models proposed and a type of periodically autoregressive model (PAR) based on the improved genetic algorithms (IGA) were used to perform the optimum energy saving scheduling. The example of the Liangmahe Plaza was taken to show the effectiveness of the methods.

Design of Fuzzy Controller for Central Air Conditioner

A structure of central air conditioning system in building and its running pattern are proposed in order to perform optimum energy saving strategy. The design of room temperature controller is taken as an example to discuss the design of fuzzy controller using common microprogrammed control unit (MCU) in detail. Based on fuzzy theory the query control tables fixed in read only memory (ROM) of MCU are established to realize the energy saving in the room temperature controller and the reasoning procedure is analyzed. The diagram of hardware design and the flow chart of software of room temperature controller are presented. The results show that the proposed method is practical and effective to achieve the energy saving goal.

Effectiveness of PMV-Based Controls for Commercial Buildings in the USA

Using an accurate energy model,this paper simulated existing commercial buildings to compare PMV-based comfort control with conventional thermostatic control and conduct a sensitivity analysis using the Design of Experiments method with monitored energy consumption data.This analysis was applied considering the impact of building envelope characteristics including thermal insulation level of exterior walls and air leakage rate on the ability of both control options to maintain indoor thermal comfort while minimizing cooling energy consumption.The analysis findings indicated that PMV-based comfort control is viable for striking a middle ground between thermal comfort and heating energy consumption with a PPD(predicted percentage of dissatisfied)level at 8%for any combination of walls’R-value and air infiltration rate while temperature-based controls result in an unacceptable indoor thermal comfort performance especially for low R-values regardless of the air infiltration rate with PPD level reaching over 76%.Also,the results show that in a comfort-controlled space,the average radioactive temperature and occupant-related features like metabolic rate and clothing level have a far bigger effect on energy use than other parameters like relative humidity.

地铁站空调水系统节能控制研究

为了降低空调水系统的能耗,研究广州某地铁站的空调水系统节能控制策略。使用设备厂商提供的样本数据进行参数拟合,建立较为准确的设备模型,利用Trnsys软件搭建地铁站空调水系统模型。针对“大流量、小温差”现象,提出定温差控制策略,以降低水系统的能源消耗。结果显示:与定流量水系统相比,定温差控制策略下地铁站空调水系统节能率达到25.86%;在整个供冷季,相对于常规7℃的供水温度定温差控制策略,变冷冻水供水温度定温差控制策略的空调水系统节能约3.40%。

电动车废热辅助空调系统的研究

针对目前电动车空调存在的节能性和低温适应性等问题,提出了一种电动车废热辅助热泵空调系统。该系统将多变频器协调控制技术、双级压缩循环技术、废热辅助热泵技术有机融合,通过仿真分析研究系统在不同运行状态下的系统性能。仿真结果表明:协调调节低压级压缩机和风扇电机的频率,可实现系统制冷/制热量和能效比的优化控制;合理设置单双级压缩的温度切换点,能提升制热性能、保证系统在低温工况下的可靠运行;利用废热辅助空气源热泵技术,能实现系统的节能。研究结果为减小空调系统对电动车续航里程的影响、推动电动车的普及提供了参考。

纺织空调绿色生产技术途径

探讨纺织空调实现绿色生产的途径和方法。针对纺织空调运行能耗高、耗水量大的问题,以创建绿色工厂为目标,从提高设备能效、优化空调热湿处理方法、加强运行调试与能源管理等方面提出具体要求和措施,并提出了细纱车间热分流、热回收、送回风系统低能耗运行的方法。认为:做好纺织空调节能降耗工作有助于实现纺织车间绿色生产。

某调度通信楼空调系统节能减碳改造设计实践

重点介绍了某调度通信楼空调系统的节能减碳改造设计,通过综合运用余热回收、可再生能源、固体蓄热、高效制冷机房等多项技术,构建了安全可靠、绿色低碳、高效节能的空调系统。采用HDY-SMAD空调负荷计算及分析软件模拟了建筑物全年的空调能耗,并对优化前后空调系统的运行能耗和碳排放进行了测算。结果显示,优化方案空调系统全年节约电量100万kW·h,全年碳减排573 t,节能减碳效果显著。

微小型压缩空气储能系统用涡旋压缩机流动特性研究

以空气为工质,基于计算流体动力学方法,对无油空气涡旋压缩机在变工况运行条件下进行了三维非稳态数值模拟。研究发现:动静涡旋齿之间存在的径向间隙,会使得压缩机工作腔内温度、流速和压力的分布不规律;增大转速,不但可以增加涡旋压缩机的质量流量,而且还可以减小切向泄漏量,进而提高压缩机的工作效率;排气压力过大,会降低涡旋压缩机的基本输出性能;在低转速下,过高的排气压力会使得压缩机排气口出现“净回流”现象。

北京某大型商场空调系统节能改造方案分析

大型商场人流量大、散热设备多、空调系统运行时间长,有较大节能潜力。调研了北京某大型商场空调系统的能耗情况,针对其运行过程存在的问题,提出了一套基于空调系统节能控制技术的综合节能改造方案。研究表明,该空调系统节能改造后,年节电量为140.56万k Wh,每年节省电费160.24万元;节热量为601.82GJ,每年节省供热费用5.95万元,节能效果与经济效益较好,可为北京地区类似公建节能改造提供借鉴和参考。

基于航班信息确定旅客数模型联动空调节能技术研究

针对机场航站楼内空调系统能耗高且节能潜力巨大的特点,提出一种基于航班信息动态预测分时段分区旅客数,进而联动优化空调节能控制的新方法。新方法研究重点在于航站楼空调调控分区的划分、航班信息有效数据的提取、分时段分区旅客数模型的构建、节能档位控制的实现策略与步骤。结合华南地区某支线机场航站楼冷源及空调末端控制的实际测试数据进行模拟分析,结果表明,在保障旅客舒适度的基础上,通过分区旅客数精准调控空调系统运行模式,实现了能耗较大幅度的降低,节能成效显著,为航站楼空调节能技术提供了新的思路,为同类型其他机场提供了参考。

中央空调系统制冷机组节能优化

空调系统是公共建筑中重要的基础配套设施,其能源消耗占据较大比重,在节能降耗方面存在巨大潜力。为实现在满足冷负荷需求的条件下达到中央空调系统总运行能耗最小的目标,建立了中央空调系统制冷机组能耗模型,并将室外湿球温度和实时的冷负荷值作为空调系统能耗模型的输入条件,分别利用粒子群算法和改进粒子群算法获得在不同负荷需求时空调系统对应的最佳工作点,实现中央空调系统运行优化节能的效果。

基于最优动态功率补偿的先进绝热压缩空气储能一次调频控制策略

随着大规模新能源接入电网,新型电力系统“低惯量、弱支撑”特征凸显,电网频率调节资源日益稀缺,系统频率稳定问题愈发严峻。先进绝热压缩空气储能(advanced adiabatic compressed air energy storage,AA-CAES)具有容量大、寿命长等优势而受到广泛关注,但由于其储能和释能过程涉及气-热动态耦合过程,调频特性较为复杂,调频潜力还有待挖掘。因此,首先建立AA-CAES系统全工况动态仿真模型,进而基于期望频率动态曲线设计AA-CAES系统调频传递函数,优化目标传递函数关键参数,实现AA-CAES最小动态功率补偿下满足系统频率调节需求。最后通过仿真实验,验证了所提控制策略可优化AA-CAES调频容量的同时减小系统的稳态频率偏差与频率超调量,显著改善频率响应特性,为建设电网友好型AA-CAES电站提供技术支撑。

溶液调湿空调在医药厂房工程应用的碳减排潜力分析

众多医药生产车间要求低湿环境,需要送风含湿在7 g/kg甚至5 g/kg以下,常规7℃冷冻水驱动的冷冻除湿方式难以完成上述除湿任务,因而医药厂房通常采用转轮除湿系统对空气进行湿处理以满足环境热湿控制需求。然而,转轮系统所需再生温度较高,通常使用高温蒸汽或电加热器作为再生热源,限制了系统的低碳化运行。溶液空调系统具有利用低品位冷热源的优势,但现有研究对于溶液空调技术在医药建筑中应用可行性研究尚不充分,无法揭示其在医药建筑应用的节能减排潜力。因此,现场测试了溶液空调系统在某试点医药厂房的实际应用效果,对比了其与常规转轮系统的性能差异并阐明差异原因。示范工程应用结果表明,一次回风系统送风含湿量在6 g/kg左右时,溶液系统可以将再生热源温度从100℃以上降至50℃以下,相较于常规转轮系统的节能比率为15%~45%,典型工况下的碳减排率为20.7%。以期为医药建筑低碳化发展提供经验参考与数据支撑。

数据中心间接蒸发冷却复合空调系统的节能运行分析

结合上海地区的气候条件,采用TRNSYS软件,通过设定数据中心机房条件模拟出全年所需冷负荷随时间的变化规律,确定设备选型,并基于间接蒸发冷却复合空调系统主要设备的数学模型搭建了仿真平台。通过对空调系统运行模式的切换,模拟得到3种运行模式下的送风状态图及运行特性。结果表明,冬季应采用能耗更低的干模式,过渡季采用湿模式,夏季采用混合模式。对比常规机械制冷系统,复合空调系统的全年耗电量为352.6万kW·h,节能率高达34.8%。

夏热冬暖地区办公建筑空调系统节能优化研究

随着社会经济的高速发展,办公建筑的数量及能耗日趋增加,为了缓解能源紧缺现状,对既有办公建筑的节能改造成为节约能耗、降低碳排放的重要手段之一。对于夏热冬暖地区,其办公建筑能耗主要为空调系统制冷,本文基于深圳市某办公建筑的原始空调系统,提出两种基于空调系统主要设备的节能优化方案,即磁悬浮机组+变频冷冻水系统、变流量机组+变频变流量系统。通过Trnsys软件对提出的2种优化方案进行对比分析。结果表明,对冷水机组进行设备改换和采用变频技术能在一定程度上降低空调系统能耗,系统的COP有较大的提升。

基于群体热感觉和区域占用率的多区域变风量空调系统优化控制方法

为优化多区域变风量空调系统的控制性能,同时使室内环境满足人员的热舒适需求,提出了一种基于群体热感觉和区域占用率的多区域变风量空调系统优化控制方法。根据室内人员的群体热感觉和各区域内的人员数量,采用调控算法调整室温设定值,进而调整各控制区域的末端送风量。搭建了仿真平台,对该控制方法与传统控制方法从控制效果、人员热舒适性、空调系统能耗等方面进行了对比分析。研究结果表明:加入群体热感觉后,该控制方法相较于传统控制方法空调系统节能率为7.5%以上;若同时考虑群体热感觉和区域占用率,该控制方法的节能率高于8.5%。

基于人工智能的通信基站智能新风及空调节能系统应用

文章探讨如何利用人工智能技术实现新风系统和空调系统的联动节能。首先,介绍新风系统和空调系统的工作原理和节能重要性;其次,详细探讨人工智能技术在联动节能方面的应用,如数据分析、模型预测和智能控制等;最后,提出一种基于人工智能技术的控制策略,通过实时监测和分析室内环境参数,自动调节新风系统和空调系统的运行状态,实现节能目的。该研究对提高建筑能源利用效率、减少能源消耗和环境污染具有重要意义。