中小型空调水系统备用泵的优化设计探讨

分析目前空调水系统设计中常用的多台相同型号的水泵并联运行的弊端,从备用泵的选配设计入手,提出更节能、实用性更强的大小泵匹配的方案,并将其与常规水泵选配方案进行对比分析。     

空调系统水泵变频运行特性分析

本文通过分析空调系统水泵变频运行时,冷水泵和冷却水泵的能耗变化及冷水、冷却水量的变化对冷水机组运行能耗的影响,综合评价空调系统水泵变频运行的节能效果。     

空气源热泵空调水系统中循环水泵选型探讨

基于一级泵系统(冷源侧定流量末端变流量),对不同热负荷、冷负荷比例下空气源热泵空调水系统中循环水泵的选型进行了探讨,并对具体工程实例中循环水泵的选型进行了计算。结果表明,空气源热泵空调水系统,需根据制冷、制热工况下系统的水流量决定循环水泵采用一套定速水泵、采用一套变频调速水泵还是分设冷热水循环水泵。     

空调水泵优化选型的探讨

空调系统中出现部分负荷情况下,为了节省能耗,既需要对水泵流量进行调节,同时又要求保证水泵的高效运行。本文通过对水泵联合运行几种工作方式的比较,探讨水泵优化选型的方法。     

定冷水泵叶轮切割的改进设计

本文介绍了某发电公司1×600MW机组发电机定冷水泵存在设计、选型时流量、扬程富裕量大的问题,造成定子冷却水系统运行可靠性下降,增加了厂用电率。通过分析、计算,使定冷水泵的流量、扬程满足定子冷却水系统运行要求的前提下,对定冷水泵叶轮进行有效、适当切削。既保障了发电机定子冷却水系统安全、可靠运行,又起到节能降耗作用。     

空调水系统并联水泵的选择配置与分析

分析了空调水系统中水泵选择时应注意的方面,并通过泵的性能曲线(两台水泵为例)与水管道特性曲线对定频泵并联、定频泵,变频泵并联、变频泵并联三种组合方式下水泵的运行状况进行了分析,通过对比得出三种组合方式中变频泵并联方式最为节能,定频泵、变频泵并联次之,定频泵并联节能较差.     

空调变流量系统的分析与探讨

通过分析一次泵，二次泵空调水系统存在的问题以及水泵变频运行特性，提出了在一次泵基础上实现变流量运行的可能性。同时探讨了变流量系统对主机，空调末端及水系统平衡的影响。     

集中空调水系统并联水泵选型与流量调节特性

针对空调水系统,基于水泵性能曲线和管网特性曲线,分析了水泵选型是否需要考虑扬程和总流量的富裕量以及并联水泵选型是否要对额定流量进行附加;讨论了确定管网增加并联水泵运行台数导致总流量衰减和减少并联水泵运行台数有可能导致超载;阐述了水泵变速调节,系统流量的影响因素及变化规律。     

汽油机水泵性能试验方法的研究

近年来,汽油机水泵作为一种重要的农林排灌机械,具有体积小、移动灵活、使用方便等特点,在我国广大农村地区应用越来越广泛。目前,汽油机水泵质量参差不齐,特别是流量和扬程等性能参数合格率低,一定程度影响了农业生产率的提高。泵的水力性能试验方法标准GB／T3216是直接引用ISO 9906国际标准,它是关于回转动力泵水力性能的通用试验方法,主要是针对回转动力泵作为独立试验对象,并未考虑到水泵及其配套动力作为一个整体的情况,该文围绕汽油机水泵的特点对性能试验方法进行研究。     

空调冷水泵变频调速特性试验研究

对流量、扬程、能耗、转速、频率等参数进行的现场测试表明,采用定压差控制的变频冷水泵的流量、能耗等参数已不能简单地按相似定律来计算,转速改变越大,测试结果与相似定律计算结果的差别也越大,尤其是流量与转速的关系与相似定律有着显著的差异,且当转速低于一定值时,管内冷水的流态会发生转变;当采用手动变频且不改变管路特性时,测试结果则与相似定律的结果相吻合,管内冷水的流态也能在很大范围内维持为充分发展的紊流.测试与分析表明,空调冷水泵变频调速特性与冷水管路系统的特性密切相关.     

Solar absorption system for air conditioning

This Paper presents a new continous operating solar desiccant absorption system in which CaCl₂-H₂O is used as the absorbent. The flat-plate solar collector is utilized as the desorber where water from the solution is evaporated to ambient air in passing over the collector above the solution film. The plant is equipped with a latent heat accumulation system which is extremely compact in size and very efficient. The coefficient of performance—solar collector efficiency product, indicating the grade of solar energy utilized, is estimated as being the highest of all presently known systems.     

小型蓄冷空调系统动态性能研究

阐述小型空调系统的工作原理和循环特性,分析了该蓄冷空调系统在不同工况下的性能,讨论了不同工况下的过冷度对该系统性能的影响.     

A generalized coefficient of performance for conditioning moist air

The psychrometric chart is a useful tool for calculating the energy change between any two states and visually identifying the contribution of ‘sensible’ and ‘latent’ effects. However, the amount of work needed to move from one state to another is not read directly from the chart. In this paper, temperature and vapor pressure changes are cast into terms of minimum work relative to a dead state, and work contours are plotted on the psychrometric chart. These contours show the minimum work needed to move the state of the air further from the ambient conditions or the maximum work produced by letting a state approach the ambient conditions. A dividing line between heat pump and refrigeration operation is set on the basis total energy of the conditioned space relative to the ambient. Finally, an example is used to illustrate the implementation of the analysis.     

组合式空调数字化设计与选型平台开发

为了更快速高效率地进行组合式空调机组的设计,建立了以稳态仿真为基础的组合式空调机组数字化设计与分析系统。该平台通过使用Visual Basic编程语言,实现机组段体的选择,进行进风口、过滤器、风机、电加热器等的选型以及表冷器、加湿器和蒸汽加热器的设计和仿真。建立空调箱表冷器集总参数模型,选取适用于模型计算的空气侧和水侧换热关联式,实验验证结果表明,该模型计算冷量和水流量精度很高,适用于仿真计算。     

A new procedure for performance prediction of air conditioning coils

A new numerical model has been developed for the simulation of pate-fin-tube type of cooling and dehumidifying coils widely used in the air conditioning industry. The model discretizes the coil into nodes along the coolant path and carries out repetitive marches from the coolant inlet to its outlet while simultaneously updating the values of the air stream properties for obtaining quick convergence. Unlike previous models, this model is capable of analyzing complicated circuiting arrangements and can take into account the variation in heat transfer coefficient along the coil. Since the heat transfer and pressure drop through each circuit are calculated separately, the model can be helpful in pointing out any maldistribution of coolant in various circuits of the coil.     

车辆空气质量及空调系统探讨

新冠肺炎病毒疫情下车辆用户及汽车产业链都对空气质量进行热议,从使用和开发及生产角度提出了不同的要求和看法,健康汽车概念成为关注的焦点。空气质量作为车辆空调系统舒适性指标的一个维度,也需要从用户需求、法规标准、现有技术及技术应用成本几个方面进行考量,通过法规标准和市场推广两个轮子驱动,在整车厂和车辆空调厂家的合作和共同努力下,才能做好车辆空气质量的技术路径选择、产品开发和品质提升。     

Thermal performance of cold storage in thermal battery for air conditioning

This article studies, experimentally and theoretically, the thermal performance of cold storage in thermal battery for air conditioning. Thermal battery utilizes the superior heat transfer characteristics of heat pipe and eliminates drawbacks found in the conventional thermal storage tank. Experimental investigations are first conducted to study the cold storage thermal performance in two experimental systems: the ratio of distance between heat pipes to outer diameter of heat pipe W/D=6 and 2. Different heat transfer mechanisms including nucleate boiling, geyser boiling and natural convection are identified in different experimental systems with various liquid fills. A theoretical model to determine the thermal characteristics of the thermal battery has also been developed. Comparisons of this theory with experimental data show good agreements in the nucleate boiling stage of cold storage process.     

Experimental study on cooling performance of air conditioning system with dual independent evaporative condenser

Evaporative condenser is an energy efficient and environmentally friendly air conditioning equipment. This paper proposed an air conditioning system using dual independent evaporative condenser and investigated the cooling performance. Many factors, such as evaporator water inlet temperature, compressor frequency, air dry-bulb temperature, air velocity and water spray rate, which influenced the cooling performances of air conditioning system with evaporative condenser have been investigated. The results indicated that cooling capacity and coefficient of performance (COP) increased significantly with the increasing of evaporator water inlet temperature (12–25 °C), the air velocity (2.05–3.97 m s⁻¹) and the water spray rate (0.03–0.05 kg m⁻¹ s). However, COP decreased with the increasing ambient air dry-bulb temperature (31.2–35.1 °C) and the compressor frequency (50–90 Hz). Furthermore, the heat transfer coefficient (K₀) was 232–409 W m⁻² K⁻¹ in different air velocity and water spray rate.     

标准动车组空调系统智能化优化设计

为进一步提升中国标准动车组空调系统的安全性、舒适性,本文介绍了一系列在既有CR400系列中国标准动车组定频空调机组基础上实施技术创新的设计、研究成果,包括在空调机组上应用智能变频技术,降低列车空调能耗,提高车内的控温精度;增加空气净化和病毒灭活装置,解决车内异味问题,满足车辆的绿色环保使用要求;增加PHM故障诊断预警功能,提高列车在途故障应急处理效率,降低运营安监事故率,降低列车运营成本;增加车内压力监测装置,进行减振降噪优化设计,提高乘车舒适性。提升了标准动车组空调系统智能化水平,进一步提高乘客乘坐体验。     

Analysis of an air cycle refrigerator driving air conditioning system integrated desiccant system

This study presents theoretical investigation on the performance of air cycle refrigerator driving air conditioning system integrated desiccant system. Total system performance is evaluated and the system feasibility is examined. The system has such characteristics that (1) safe material of air and water are used as a refrigerant, (2) waste heat from air cycle refrigerator performs the regeneration of desiccant material for energy saving. It has been clarifying that (1) controlling the evaporative cooling process in air washer, the system can operate for a wide range of cooling loads, (2) the total coefficient of performance on air conditioning system is better than the conventional vapor compression system with reheating coil, and (3) the system performance highly depends on the ratio of the amount of outdoor intake air to the supply air.