水蓄冷系统在既有厂房的应用分析

以珠海某厂房为例,通过对该厂房既有制冷机房进行改造设计,充分提高制冷效率,使工厂实现能源利用效率最大化,达到节能降耗的目的。在改造设计方案中,采用水蓄冷及变频控制双重节能技术,保证制冷效率的提升效果。     

空冷凝汽系统尖峰冷却装置应用现状

介绍目前国内空冷系统运行中存在的问题,提出提高空冷系统运行效率的技术方案。分析国内外火力发电厂空冷凝汽系统发展历程以及运行中存在问题的调研情况,通过对空冷系统采用的尖峰冷却系统工程及其应用效果分析,对比目前所采用的尖峰冷却形式的系统原理及应用方式,并在此基础上提出改进后的新型尖峰冷却装置的原理,以充实尖峰冷却装置在空冷系统中应用的范围。展望该尖峰冷却装置的应用前景,为相关技术人员提高空冷凝汽系统运行效率提供参考改造思路。     

获能式制冷及其在工业冷却中的应用

在制冷装置中,利用简易的汽轮发电机取代其冷却系统,制冷中吸收的热能和剩余动能用于发电反馈回电网,从而将制冷由耗能变为获能。采用获能式的制冷装置对工业生产中余热进行冷却,从而获取热能用于发电以提高设备效率。     

浅谈水环真空泵工作液温度对真空度的影响及对策

本文主要针对重庆市涪陵区三峰环保发电有限公司夏季真空度低进行分析,对厂内抽真空系统进行技术分析和改造加装冷却装置,从而提高汽轮发电机组的效率,达到节能降耗、挖潜增效的目的。     

火力发电机组水环式真空泵深度冷却改造试验研究与分析

凝汽器抽真空系统的节能改造是近年来电厂技术改造的重要项目。通过加装深度冷却装置降低水环真空泵组工作液温度来提升真空泵组抽吸量为其改造方向之一。以某安装了真空泵工作液深度冷却装置的机组为例,通过现场试验的方法确定了凝汽器真空严密性和真空泵组抽吸量对凝汽器内凝结换热系数的影响。详细计算了水环式真空泵工作液深度冷却改造项目的节能量,为今后凝汽器抽真空系统节能改造提供了重要试验数据支持。     

悬摆喷淋快速制冷方式的节能应用

文章通过对快速制冷的理论和工程应用分析．讨论在实际工程应用中如何利用快速制冷的技术达到高效、经济、节能的目的，同时，提出了一种利用喷淋制冷方式的工程实用方案，可在3～5分钟内快速冷却所需储品，具有即插即用、高效节能、快速冷却的效果。     

CO_2制冷技术的研究发展

二氧化碳作为一种高效、节能、环保的制冷剂,具有广泛的应用前景和可观的经济价值。但由于其采用跨临界循环,工作压力远远高于常规制冷剂,对设备的承压能力提出了较高要求。这一特点限制了二氧化碳制冷系统的推广和应用,所以为了在提高系统运行安全性、稳定性的同时,达到更高的效率,需要探索新型二氧化碳制冷装置。而这一装置需充分利用二氧化碳性质及其循环特点。文中简要介绍了二氧化碳制冷剂的发展史、性质、跨临界制冷循环技术的完善过程及其应用情况。     

分压式供水在冷却循环水系统节能改造中的应用

介绍冷却循环水系统采用分压式供水的原理和应用案例,这是循环水系统节能改造的一种新方法。案例表明,通过对循环水系统不同高度的换热装置进行分压供水,可以达到可观的节能效果。     

蒸发冷却技术

文章介绍了蒸发冷却技术的原理和分类，详细介绍了直接蒸发冷却和间接蒸发冷却的实际应用情况，指出该技术是节能环保的，是可持续发展的制冷技术，具有应用前景。     

制冷空调系统的冷却水节能运行研究

计算了典型两级压缩制冷系统循环中压缩机功耗与冷凝温度的关系。根据对两个工业制冷装置的实地测试和分析 ,提出了制冷空调装置在部分负荷时冷却水系统的节能调节原则。该原则可指导现行制冷空调装置的节能调节和新制冷空调装置的优化设计。     

An experimental and theoretical investigation of refrigerant charge on a secondary loop air‐conditioning heat pump system in electric vehicles

Automotive air‐conditioning heat pump systems are particular interest worldwide in energy conservation and emission reduction for electric vehicles, hybrid electric vehicles, and fuel cell electric vehicles. Refrigerant charge amount is a key factor for the air‐conditioning heat pump system optimization affecting the condensing pressure and subcooling in both heating and cooling modes. In this paper, the influence of the refrigerant charge on system performances was investigated using the experiment method on a secondary loop air‐conditioning heat pump system. The typical heat transfer and flow parameters were recorded, and both cooling and heating performances of the system were investigated and illustrated by pressure‐enthalpy diagrams. The critical refrigerant charges were determined in both heating and cooling modes. Three typical void fraction correlation models were also applied for the refrigerant charge determination modeling as a system off‐design method. Results show that the Hughmark void fraction correlation method has the best prediction of the critical refrigerant charge in both cooling and heating modes.     

Investigation on the Influence of Refrigerant Charge Amount on the Cooling Performance of Air Conditioning Heat Pump System for Electric Vehicles

The application of air conditioning heat pump(ACHP) in electric vehicles could lead to significant electrical power saving effect. As for an air conditioning heat pump system for electric vehicles, the influence of refrigerant charge amount should be investigated during the design phase. In this study, experimental method was employed to investigate the influence of the refrigerant charge amount on the performance of the ACHP system. The results showed that the refrigerant charge amount had different influence on the refrigerant properties at various locations within the system. The coefficient of performance and pressure-enthalpy diagram were calculated, and showed a close relationship with refrigerant charge amount under different compressor speeds. The degree of subcooling and the degree of superheating were recorded and the critical charge amount was determined by a typical practical test method. In addition, the critical refrigerant charge amount determined by the experimental method was also compared with two typical void fraction correlation models, and the model with consideration of two phase stream reaction of the refrigerant showed a good estimation accuracy on the critical charge amount.     

分液热泵空调系统的制热性能研究

随着热泵空调的普及,热泵空调的能耗占比不断增大,其节能问题成为了关注焦点。换热器对系统性能有着重要的影响,如何通过改进换热器来提升系统性能则成为了研究的热点。其中分液冷凝器作为一种新型的换热设备,能对系统制冷性能产生积极影响。但热泵空调系统在制热工况下,分液冷凝器变成气液分离式蒸发器,其系统制热性能尚未可知。通过实验研究,调整毛细管长度和制冷剂充注量,发现在国家标准工况下分液热泵空调系统的最大制热量比原系统高4.50%,C OP比原系统高7.93%,所对应的毛细管长度为700 mm,制冷剂充注量为700 g。且制冷剂过充注的情况下,分液热泵空调系统的制热性能比较稳定。     

Technical development of rotary desiccant dehumidification and air conditioning: A review

Rotary desiccant air conditioning system, which combines the technologies of desiccant dehumidification and evaporative cooling, is advantageous in being free from CFCs, using low grade thermal energy and controlling humidity and temperature separately. Compared with conventional vapor compression air conditioning system, it preserves the merits of environment-friendly, energy saving, healthy, comfortable, etc. Ongoing research and development works suggest that new desiccant materials and novel system configurations have significant potential for improving the performance and reliability and reducing the cost and size of rotary desiccant dehumidification and air conditioning system, thereby increasing its market competitiveness and breaking out the current fairly small niche market. For the purpose of providing an overview of recent efforts on these issues and showing how rotary desiccant air conditioning systems can be designed and coupled to available thermal energy, this paper presents and analyzes the status of rotary desiccant dehumidification and air conditioning in the following three aspects: the development of advanced desiccant materials, the optimization of system configuration and the utilization of solar energy and other low grade heat sources, such as solar energy, district heating, waste heat and bioenergy. Some key problems to further push forward the research and development of this technology are also summarized.     

Performance of a single‐duct portable propane air conditioning system under different refrigerant charge levels

The effects of the refrigerant charge on the performance of a portable propane air conditioning system have been evaluated and compared to nonportable systems in which the surrounding temperatures of the evaporator and condenser are not equal. This study aims to determine the similarities and differences in the performance of the two types of propane air conditioners under different charge levels, and to serve as a source of reference for future designs of portable air conditioners. The refrigerant charge was changed from ?12.3% to +30% of its normal charge at several room temperatures ranging from 20 °C to 35 °C. The performance parameters include the refrigerant temperature, mass flow rate, maximum velocity of refrigerant, maximum pressure, cooling capacity, compressor work, specific cooling capacity, and coefficient of performance of the system. It has been found that an increase in charge level was found to increase the cooling capacity, coefficient of performance, and maximum velocity of refrigerant in the system while decreasing specific cooling capacity. The increase in the charge caused a relatively insignificant rise in the maximum pressure of the system and useful work of the compressor.     

饭店空调系统的直接数字控制技术与实例

为了实现节能运行，空调系统必须设置相应的自动控制系统。通过介绍直接数字控制(DDC)系统的基本构成，并结合饭店空调系统特点，介绍某些典型的控制实例，指出饭店空调设备采用DDC系统进行控制管理，可有效改善系统的运行品质，节省运行能耗。     

Thermal storage in an air conditioning system with dual energy storage unit

在自行搭建的双蓄能实验平台上进行了制冷兼蓄热实验研究,对比了制冷兼蓄热模式和一般制冷模式,探讨了不同冷冻水流量和不同风机盘管风量对机组性能的影响.实验结果表明:蓄热对机组制冷端的影响很小,但是由于回收了大量的冷凝热,使得机组的综合能效比得到大幅提高,因此蓄热对空调节能具有较大作用.此外,在制冷兼蓄热模式下,冷冻水流量或风机盘管风量越大,机组的综合能效比越大,当风量为1033 m³/h,冷冻水流量为972 L/h时,机组综合能效比高达7.06.     

数码涡旋空调系统节能分析

目前变制冷剂流量空调系统越来越受到广泛的关注，而数码涡旋空调系统是变制冷剂流量空调系统中的一种新兴技术。介绍了数码涡旋压缩机技术，分析了数码涡旋空调系统的特点和节能因素，并将其与VAV(Variable Air Volume)空调系统进行对比，指出了数码涡旋空调系统是目前中央空调尤其是小型的中央空调系统的一个发展方向。     

基于毛细管型辐射供暖与供冷系统影响因素的研究

随着建筑节能的推广和人们对室内生活舒适性要求的提高,采用一种更先进、更节能的室内空气调节系统就显得日趋重要。毛细管型辐射供暖与供冷系统因具有舒适度高、节能效果显著、节省建筑空间等的优点逐渐被广泛采用。对以毛细管为末端的毛细管型辐射供暖与供冷系统布置形式作了介绍,分析了该系统的组成及优点。以辐射供冷为例,探讨了辐射冷系统的末端一毛细管席供冷量的影响因素。