太阳能驱动的有机朗肯-蒸汽压缩空调

以太阳能驱动的有机朗肯-蒸汽压缩空调为研究对象,通过热力学模拟手段对工质类型、系统设计以及影响因素进行研究。结果表明:工质发生温度和冷凝温度对系统性能有重要影响,单位面积集热器的制冷功率和系统总效率随工质发生温度先增后减,随冷凝温度的增加而降低。通过性能对比发现,R123工质是较适宜的工质。在工质发生温度、冷凝温度和蒸发温度分别为120、45和5℃时,太阳能空调对应的单位面积集热器的制冷功率和系统总效率分别为136.01 W/m2和44.12%,论证了太阳能驱动的有机朗肯-蒸汽压缩空调系统的可行性。     

太阳能氨水吸收式制冷空调的研究

本文报道了40m~2平板型自动跟踪连续式太阳能制冷空调系统的设计与研制情况。 系统以氨水溶液为工质,考虑了利用工业余热制冷,进行了氨直接蒸发和间接蒸发试验。并在一个纺织厂的计量车间内作了太阳能空调的初步试验。     

太阳能空调技术发展述评

国际上用于民用空调所耗电能约占民用总电耗的５０% ,发达国家空调已步入千家万户。随着我国居民生活水平的不断提高 ,近几年空调用户大幅度增长 ,空调热有增无减 ,电耗大和工质污染问题越来越严重 ,研制开发节电型绿色空调成为一项十分迫切的重要课题。近年来常规空调替代工质的开发 ,节电压缩制冷、磁制冷、空气制冷、金属氢化物热泵以及太阳能空调等技术的开发 ,已取得不同程度的成果。特别是太阳能空调 ,既节电又不污染环境 ,更加备受各国太阳能工作者的重视 ,目前已有多种型式太阳能空调系统在各地示范运行。本文在综合比较不同型式太…     

利用低位余热的喷射式制冷机性能研究

研究了使用氟利昂作为工质的喷射式制冷机的性能,编制了计算机仿真程序,分析了状态参数对制冷循环性能的影响。计算结果表明这一装置可以用低位余热驱动,适合于空调系统。     

低品位热驱动的混合工质喷射制冷循环研究

提出一种低品位热驱动的混合工质喷射制冷循环,将沸点相差较大的非共沸混合工质引入喷射制冷循环,采用两级分凝分离降低该新循环压比,实现在喷射制冷循环中获得较低的制冷温度和较高制冷效率。建立组成循环各部件热力学数学模型,在系统稳定运行的条件下,分析喷射器压比、冷凝温度和混合工质组分配比对新循环工作性能的影响。研究表明:采用混合工质R600/R290的喷射制冷循环可获得低于-20℃的制冷温度。     

太阳能驱动喷射复合压缩式制冷空调系统设计

为北京市某综合楼设计了一种喷射复合压缩式制冷空调系统,阐述其运行原理、负荷计算、R245fa为工质的喷射式制冷设计计算、空调系统设计计算及选型等,通过对比新复合式空调系统和传统压缩制冷系统的能耗,得出新复合式空调系统可节电23.18%,系统性能提升超过30%,认为其具有一定的发展前景。     

欧洲准备"禁氟"

为彻底落实京都议定书,欧洲议会正在讨论全面"禁氟"事宜并制定相关法规."禁氟"是指在2011年后全面禁用目前广泛用于制冷工质、电气绝缘和日常生活的含氟化学气体,简称为氟气体(F-gases),其中对制冷空调工业影响特别大的是以R134a为代表的HFCs类工质.介绍了这项进展的背景和未来走向,建议中国制冷空调工业要未雨绸缪,大力开发自然工质,避免再走20世纪80年代CFCs替代时的旧路.     

吸附式制冷机及空调/热泵的运行实验和性能改进

研制了一台采用螺旋板式吸附器的连续回热型吸附式制冷机和一台采用板翅式吸附器的空调／热泵,给出了实验数据。吸附式制冷系统采用活性炭－甲醇吸附工质对,以９０－１００℃絷不作为热源,实验得到单位质量活性炭的制冷能量密度为：制冰机每ｋｇ吸附剂日制冰２．６ｋｇ,空调／热泵组在空调工况下每ｋｇ吸附剂制冷功率为１５０Ｗ。     

制冷工质CFCs、HCFC的限制使用及其对策

大气臭氧层的破坏和全球气候变化 ,是当前世界所面临的主要环境问题。制冷空调行业广泛以CFCs与HCFC类物质作为制冷工质 ,它对臭氧层的破坏及其产生温室效应日趋显著 ,使这一行业面临严重的挑战。本文讨论了保护臭氧层和防止全球气候变化对制冷空调行业所使用的制冷剂提出的要求与国际社会所采取的相应对策 ,综述了 2 1世纪国内外绿色环保制冷剂发展趋势     

一种使用发动机余热的新型客车采暖系统

介绍了一种新型的利用发动机余热的客车采暖系统,利用两级热回收技术,同时对发动机缸套冷却水热量和发动机尾气热量进行回收,可满足客车在冬季的取暖要求。由于该系统回收热量的能力比常规的非独立采暖系统大大提高,也可考虑将其作为吸收式制冷的热源,作为车辆夏季空调使用。     

Adaptation of an adsorptive solar refrigerator to Moroccan climates

In this paper, we introduce a model taking account of the real operation of an adsorptive solar refrigerator using activated carbon-methanol pairs, as a function of the climatic conditions: ambient temperature and insolation. The model is used to simulate the operation of the refrigerator in two Moroccan climates: Rabat, temperate and humid, and Marrakech, dry and hot. The numerical simulation shows that the behaviour of the refrigerator is different from one climate to the other. In Rabat, which has a Mediterranean climate, the cold room temperature can be maintained at a value practically always less than 5°C; whereas in Marrakech, which has a pre-Saharan climate, an overheating problem can arise in the summer season and temperatures in the cold room can reach 17°C. Results also show that in both climates we are confronted with the problem of freezing because the cold room temperatures can be less than 0°C and reach − 15°C in the winter.     

Thermal design of parabolic solar concentrator adsorption refrigeration system

This study presents a thermal design of solar-powered adsorption refrigeration with the type of activated carbon-methanol pair. The designed module consists of an evacuated glass tube equipped with a parabolic solar concentrator as generator, sorption bed, evaporator, and condenser units. A thermodynamic design procedure and a mathematical model of a steady state system with activated carbon refrigerator have been developed. The adsorber is heated by solar energy collected by a parabolic solar concentrator. The temperature of the working pair in the adsorber, the amount of methanol leaving and reabsorb bed, and the refrigerated box was estimated. An optimize design of the system to achieve higher cycle COP was presented. Maximum cycle COP = 0.576 and COP_net = 0.375 with T _max reached 157.8°C, T _B = 57.5°C, M _ac = 0.907 kg, and the concentration of methanoldesorped equal to 0.206 kg/kg _ac .     

吸附制冷中回质过程的新模型及循环性能的研究

吸附式制冷在余热回收方面具有很好的前景，设计了用于大客车发动机余热回收的吸附式制冷系统，进行了分布参数的模拟计算，结果显示吸附床设计是比较合理的。同时建立了一种新的回质计算模型，提出了新的回质操作方法。模拟计算显示，回质是改善吸附循环性能的重要手段，回质过程提高了循环SCP和COP达一倍以上，回质过程非常迅速，5s即已完成，可以有效地缩短循环时间，提高循环性能。     

Should existing pressure vessel regulations apply to gas filledelectrical equipment-an electrical engineer's viewpoint

Electrical equipment which uses an inert gas, sulfur hexafluoride, has been in commercial use for several decades and is today the most dominant design technology for high-voltage substation equipment. Sulfur hexafluoride gas possesses excellent electrical-insulation and arc-quenching properties. making it suitable for the design of circuit breakers, instrument transformers, bus ducts, and total gas-insulated metal-clad substations (GIS). The gas properties require that only modest equipment design pressures of 400 to 700 kPa (60 to 102 psig) be used. However. these pressures are sufficient to classify the equipment as a pressure vessel under many local boiler and pressure-vessel safety laws. New CENELEC standards, written specifically for this gas-filled equipment, should provide a logical basis for the future electrical industry regulation of this specialized equipment     

Experimental results on operating parameters influence for an adsorption refrigerator

A continuous heat recovery adsorption refrigerator using activated carbon-methanol has been developed. In this system, the heat source to drive the adsorption system can be controlled at a temperature from 60 °C to 110 °C, and the evaporating temperature can also be controlled at any requested value from 0 °C to 15 °C. To realize the operation performance of the system, many sensors of temperature, pressure and flow rate are installed in the adsorbers, the condenser and the evaporator. A lot of experiments have been completed in different operation conditions. Thus, by means of the experimental data, influences of the operating parameters, such as heat source temperature, evaporating temperature, cooling water temperature, cycle time and flow rate of throttling valve and so on, on p-t-x diagram of the cycle, specific cooling power (SCP) and coefficient of performance (COP) have been asserted. And causes of the influence are also analyzed. A series of conclusions are obtained.     

活性炭烟气脱硫工艺中影响脱硫效率因素的分析

在工业实测数据的基础上,分析了洗涤水温度、气液逆流、蓄积在活性炭孔隙中的硫酸对活性炭烟气脱硫工艺脱硫效率的影响,对脱硫塔高效运行及该技术的进一步推广应用具有指导意义.     

活性炭烟气脱硫效率影响因素的实验研究

参考燃煤电厂烟气参数，在自制的固定床活性炭烟气脱硫实验装置中，重点研究了氧量、水蒸气含量、活性炭床层温度及烟气在活性炭床层内的停留时间对脱硫效率的影响关系。     

基于LabVIEW的船用燃气轮机数字控制器软件设计

船用燃气轮机控制系统正处在由机械液压式控制系统向数字控制系统转变的过渡阶段,分布式控制系统取代集中式控制系统是燃气轮机控制系统的发展趋势。数字控制器是燃气轮机分布式控制系统的核心部分,设计采用工控机和CAN适配器组成数字控制器硬件,在此基础上制定CAN总线下的通信协议,并在LabVIEW环境下开发数字控制器软件,完成燃气轮机监测数据的采集与执行机构的控制,开展了包括多个传感器和执行机构在内的半实物实验,验证数字控制器的各项性能。     

Performance characteristics of mobile heat pump for a large passenger electric vehicle

In this study, the performance of a mobile heat pump for an electric bus, which uses the wasted heat of electric devices for a heating and air source for a cooling, was evaluated. Both cooling and heating performances of the mobile heat pump were tested under various experimental conditions, and then optimized by varying the refrigerant charge and the compressor frequency. The cooling capacity at all compressor frequencies was over 23.0 kW, which is sufficient for the cooling loads of an electric bus. The heating COP decreased but the heating capacity increased with the rise of outdoor temperature and the compressor frequency. The heating COP was 2.4 at an outdoor temperature of 10.0 °C. The observed heating and cooling performance characteristics of the mobile heat pump means it could be used for cabin heating and air conditioning of an electric vehicle with a short driving range.     

燃气-蒸汽联合循环系统的能量分析及火用分析

燃气-蒸汽联合循环系统是利用燃气侧高温吸热和蒸汽侧低温放热来扩大循环平均吸放热温差,促进能源的梯级利用,以提高循环效率。简述了余热锅炉型燃气-蒸汽联合循环的工作原理,采用能量平衡分析联合循环机组的热效率及其影响因素,采用火用分析方法和具体算例分析联合循环机组各部位火用损失及大小。通过分析计算,寻求燃气-蒸汽联合循环发电系统能量利用的薄弱环节,并为联合循环的节能指明方向。