暖通空调期刊以往文章

暖通空调期刊以往文章

testing of an air-cycle refrigeration system for road transportAbstractThe environmental attractions of air-cycle refrigeration are considerable. Following a thermodynamic design analysis, an air-cycle demonstrator plant was constructed within the restricted physical envelope of an existing Thermo King SL200 trailer refrigeration unit. This unique plant operated satisfactorily, delivering sustainable cooling for refrigerated trailers using a completely natural and safe working fluid. The full load capacity of the air-cycle unit at −20 °C was 7,8 kW, 8% greater than the equivalent vapour-cycle unit, but the fuel consumption of the air-cycle plant was excessively high. However, at part load operation the disparity in fuel consumption dropped from approximately 200% to around 80%. The components used in the air-cycle demonstrator were not optimised and considerable potential exists for efficiency improvements, possibly to the point where the air-cycle system could rival the efficiency of the standard vapour-cycle system at part-load operation, which represents the biggest proportion of operating time for most : Air conditioner; Refrigerated transport; Thermodynamic cycle; Air; Centrifuge compressor; Turbine expander COP, NomenclaturePRCompressor or turbine pressure ratioTAHeat exchanger side A temperature (K)TBHeat exchanger side B temperature (K)TinletInlet temperature (K)ToutletOutlet temperature (K)ηcompCompressor isentropic efficiencyηturbTurbine isentropic efficiencyηheat exchangerHeat exchanger effectiveness1. IntroductionThe current legislative pressure on conventional refrigerants is well known. The reason why vapour-cycle refrigeration is preferred over air-cycle refrigeration is simply that in the great majority of cases vapour-cycle is the most energy efficient option. Consequently, as soon as alternative systems, such as non-HFC refrigerants or air-cycle systems are considered, the issue of increased energy consumption arises over legislation affecting HFC refrigerants and the desire to improve long-term system reliability led to the examination of the feasibility of an air-cycle system for refrigerated transport. With the support of Enterprise Ireland and Thermo King (Ireland), the authors undertook the design and construction of an air-cycle refrigeration demonstrator plant at LYIT and QUB. This was not the first time in recent years that air-cycle systems had been employed in transport. NormalAir Garrett developed and commercialised an air-cycle air conditioning pack that was fitted to high speed trains in Germany in the 90s. As part of an European funded programme, a range of applications for air-cycle refrigeration were investigated and several demonstrator plants were constructed. However, the authors are unaware of any other case where a self-contained air-cycle unit has been developed for the challenging application of trailer King decided that the demonstrator should be a trailer refrigeration unit, since those were the units with the largest refrigeration capacity but presented the greatest challenges with regard to physical packaging. Consequently, the main objective was to demonstrate that an air-cycle system could fit within the existing physical envelop and develop an equivalent level of cooling power to the existing vapour-cycle unit, but using only air as the working fluid. The salient performance specifications for the existing Thermo King SL200 vapour-cycle trailer refrigeration unit are listed .It was not the objective of the exercise to complete the design and development of a new refrigeration product that would be ready for manufacture. To limit the level of resources necessary, existing hardware was to be used where possible with the recognition that the efficiencies achieved would not be optimal. In practical terms, this meant using the chassis and panels for an existing SL200 unit along with the standard diesel engine and circulation fans. The turbomachinery used for compression and expansion was adapted from commercial . Thermodynamic modelling and design of the demonstrator plantThe thermodynamics of the air-cycle (or the reverse ‘Joule cycle’) are adequately presented in most thermodynamic textbooks and will not be repeated here. For anything other than the smallest flow rates, the most efficient machines available for the necessary compression and expansion processes are turbomachines. Considerations for the selection of turbomachinery for air-cycle refrigeration systems have been presented and discussed by Spence et al. [3]. a typical configuration of an air-cycle system, which is sometimes called the ‘boot-strap’ configuration. For mechanical convenience the compression process is divided into two stages, meaning that the turbine is not constrained to operate at the same speed as the primary compressor. Instead, the work recovered by the turbine during expansion is utilised in the secondary compressor. The two-stage compression also permits intercooling, which enhances the overall efficiency of the compression process. An ‘open system’ where the cold air is ejected directly into the cold space, removing the need for a heat exchanger in the cold space. In the interests of efficiency, the return air from the cold space is used to pre-cool the compressed air entering the turbine by means of a heat exchanger known as the ‘regenerator’ or the ‘recuperato ’. To support the design of the air-cycle demonstrator plant, and the selection of suitable components, a simple thermodynamic model of the air-cycle configuration shown in was developed. The compression and expansion processes were modelled using appropriate values of isentropic efficiency, as defined in heat exchange processes were modelled using values of heat exchanger effectiveness as defined in The model also made allowance for heat exchanger pressure drop. The system COP was determined from the ratio of the cooling power delivered to the power input to the primary compressor, as defined in illustrate air-cycle performance characteristics as determined from the thermodynamic model:illustrates the variation in air-cycle COP and expander outlet temperature over a range of cycle pressure ratios for a plant operating between −20 °C and +30 °C. The cycle pressure ratio is defined as the ratio of the maximum cycle pressure at secondary compressor outlet to the pressure at turbine outlet. For the ideal air-cycle, with no losses, the cycle COP increases with decreasing cycle pressure ratio and tends to infinity as the pressure ratio approaches unity. However, the introduction of real component efficiencies means that there is a definite peak value of COP that occurs at a certain pressure ratio for a particular cycle. However,illustrates, there is a broad range of pressure ratio and duty over which the system can be operated with only moderate variation of class of turbomachinery suitable for the demonstrator plant required speeds of around 50 000 rev/min. To simplify the mechanical arrangement and avoid the need for a high-speed electric motor, the two-stage compression system shown was adopted. The existing Thermo King SL200 chassis incorporated a substantial system of belts and pulleys to power circulation fans, which severely restricted the useful space available for mounting heat exchangers. A simple thermodynamic model was used to assess the influence of heat exchanger performance on the efficiency of the plant so that the best compromise could be developed show the impact of intercooler and aftercooler effectiveness and pressure loss on the COP of the proposed two-stage system in incorporated an intercooler between the two compression stages. By dispensing with the intercooler and its associated duct work a larger aftercooler could be accommodated with improved effectiveness and reduced pressure loss. Analysis suggested that the improved performance from a larger aftercooler could compensate for the loss of the the impact of the recuperator effectiveness on the COP of the plant, which is clearly more significant than that of the other heat exchangers. As well as boosting cycle efficiency, increased recuperator effectiveness also moves the peak COP to a lower overall system pressure ratio. The impact of pressure loss in the recuperator is the same as for the intercooler and aftercooler shown in. The model did not distinguish between pressure losses in different locations; it was only the sum of the pressure losses that was significant. Any pressure loss in connecting duct work and headers was also lumped together with the heat exchanger pressure loss and analysed as a block pressure specific cooling capacity of the air-cycle increases with system pressure ratio. Consequently, if a higher system pressure ratio was used the required cooling duty could be achieved with a smaller flow rate of air. shows the mass flow rate of air required to deliver 7,5 kW of cooling power for varying system pressure the demonstrator system was to be based on commercially available turbomachinery, it became important to choose a pressure ratio and flow rate that could be accommodated efficiently by some existing compressor and turbine rotors. and were based on efficiencies of 81 and 85% for compression and expansion, respectively. While such efficiencies are attainable with optimised designs, they would not be realised using compromised turbocharger components. For the design of the demonstrator plant efficiencies of 78 and 80% were assumed to be realistically attainable for compression and turbomachinery efficiencies corresponded to higher cycle pressure ratios and flow rates in order to achieve the target cooling duty. The cycle design point was also compromised to help heat exchanger performance. The pressure losses in duct work and heat exchangers increased in proportion with the square of flow velocity. Selecting a higher cycle pressure ratio corresponded to a lower mass flow rate and also increased density at inlet to the aftercooler heat exchanger. The combined effect was a decrease in the mean velocity in the heat exchanger, a decrease in the expected pressure losses in the heat exchanger and duct work, and an increase in the effectiveness of the heat exchanger. Consequently, a system pressure ratio higher than the value corresponding to peak COP was chosen in order to achieve acceptable heat exchanger performance within the available physical space. The below optimum performance of turbomachinery and heat exchanger components, coupled with excessive bearing losses, meant that the predicted COP of the overall system dropped to around 0,41. The system pressure ratio at the design point was 2,14 and the corresponding mass flow rate of air was 0,278 kg/ moving the design point beyond the pressure ratio for peak COP, it was anticipated that the demonstrator plant would yield good part-load performance since the COP would not fall as the pressure ratio was reduced. Also, operating at part-load corresponded to lower flow velocities and anticipated improvements in heat exchanger performance. Part-load operation was achieved by reducing the speed of the primary compressor, resulting in a decrease in both pressure and mass flow rate throughout the . Prime mover and primary compressorThe existing diesel engine was judged adequate to power the demonstrator plant. The standard engine was a four cylinder, water cooled diesel engine fitted with a centrifugal clutch and all necessary ancillaries and was controlled by a microprocessor the thermodynamic model, the pressure ratio for the primary compressor was 1,70. The centrifugal compressor required a shaft speed of around 55 000 rev/min. Other alternatives were evaluated for primary compression with the aim of obtaining a suitable device that operated at a lower speed. Other commercially available devices such as Roots blowers and rotary piston blowers were all excluded on the basis of poor one-off gearbox was designed and manufactured as part of the project to step-up the engine shaft speed to around 55 000 rev/min. The gearbox was a two stage, three shaft unit which mounted directly on the end of the diesel engine and was driven through the existing centrifugal . Cold air unitThe secondary compressor and the expansion turbine were mounted on the same shaft in a free rotating unit. The combination of the secondary compressor and the turbine was designated as the ‘Cold Air Unit’ (CAU). While the CAU was mechanically equivalent to a turbocharger, a standard turbocharger would not satisfy the aerodynamic requirements efficiently since the pressure ratios and inlet densities for both the compressor and the turbine were significantly different from any turbocharger installation. Consequently, both the secondary compressor and the turbine stage were specially chosen and developed to deliver suitable turbochargers use plain oil fed journal bearings, which are low-cost, reliable and provide effective damping of shaft vibrations. However, plain bearings dissipate a substantial amount of shaft power through viscous losses in the oil films. A plain bearing arrangement for the CAU was expected to absorb 2–3 kW of mechanical power, which represented around 25% of the anticipated turbine power. Also, the clearances in plain bearings require larger blade tip clearances for both the compressor and the turbine with a consequential efficiency penalty. Given the pressurised inlet to the secondary compressor, the limited thrust capacity of the plain bearing arrangement was also a concern. A CAU utilising high-speed ball bearings, or air bearings, was identified as a preferable arrangement to plain bearings. Benefits would include greatly reduced bearing power losses, reduced turbomachinery tip clearance losses and increased thrust load capacity. However, adequate resources were not available to design a special one-off high speed ball bearing system. Consequently, a standard turbocharger plain bearing system was secondary compressor stage was a standard turbocharger compressor selected for a pressure ratio of 1,264. Secondary compressor and turbine selection were linked because of the requirement to balance power and match the speed. Since most commercial turbines are sized for high temperature (and consequently low density) air at inlet, a special turbine stage was developed for the application. Cost considerations precluded the manufacture of a custom turbine rotor, so a commercially available rotor was used. The standard turbine rotor blade profile was substantially modified and vaned nozzles for turbine inlet were designed to match the modified rotor, in line with previous turbine investigations at QUB (Spence and Artt,). An exhaust diffuser was also incorporated into the turbine stage in order to improve turbine efficiency and to moderate the exhaust noise levels through reduced air velocity. The exhaust diffuser exited into a specially designed exhaust performance of the turbine stage was measured before the unit was incorporated into the complete demonstrator plant. The peak efficiency of the turbine was established at 81%.5. Heat exchangersDue to packaging constraints, the heat exchangers had to be specially designed with careful consideration being given to heat exchanger position and header geometry in an attempt to achieve the best performance from the heat exchangers. Tube and fin aluminium heat exchangers, similar to those used in automotive intercooler applications, were chosen primarily because they could be produced on a ‘one-off’ basis at a reasonable cost. There were other heat exchanger technologies available that would have yielded better performance from the available volume, but high one-off production costs precluded their use in the demonstrator different tube and fin heat exchangers were tested and used to validate a computational model. Once validated, the model was used to assess a wide range of possible heat exchanger configurations that could fit within the Thermo King SL200 chassis. Fitting the proposed heat exchangers within the existing chassis and around the mechanical drive system for the circulation fans, but while still achieving the necessary heat exchanger performance was very challenging. It was clear that potential heat exchanger performance was being sacrificed through the choice of tube and fin construction and by the constraints of the layout of the existing SL200 chassis. The final selection comprised two separate aftercooler units, while the single recuperator was a large, triple pass unit. Based on laboratory tests and the heat exchanger model, the anticipated effectiveness of both the recuperator and aftercooler units was 80%.6. InstrumentationA range of conventional pressure and temperature instrumentation was installed on the air-cycle demonstrator plant. Air temperature and pressure was logged at inlet and outlet from each heat exchanger, compressor and the turbine. The speed of the primary compressor was determined from the speed measurement on the diesel engine control unit, while the cold air unit was equipped with a magnetic speed counter. No air flow measurement was included on the demonstrator plant. Instead, the air flow rate was deduced from the previously obtained turbine performance map using the measurements of turbine pressure ratio and rotational . System testingDuring some preliminary tests a heat load was applied and the functionality of the demonstrator plant was established. Having assessed that it was capable of delivering approximately the required performance, the plant was transported to a Thermo King calorimeter test facility specifically for measuring the performance of transport refrigeration units. The calorimeter was ideally suited for accurately measuring the refrigeration capacity of the air-cycle demonstrator plant. The calorimeter was operated according to standard ARI 1100-2001; the absolute accuracy was better than 200W and all auxiliary instrumentation was calibrated against appropriate performance capacity of transport refrigeration units is generally rated at two operating conditions; 0 and −20 °C, and both at an ambient temperature of +30 °C. Along with the specified operating conditions of 0 and −20 °C, a further part-load condition at −20 °C was assessed. Considering that the air-cycle plant was only intended to demonstrate a concept and that there were concerns about the reliability of the gearbox and the cold air unit thrust bearing, it was decided to operate the plant only as long as was necessary to obtain stabilised measurements at each operating point. The demonstrator plant operated satisfactorily, allowing sufficient measurements to be obtained at each of the three operating conditions. The recorded performance is summarised .In total, the unit operated for approximately 3 h during the course of the various tests. While the demonstrator plant operated adequately to allow measurements, some smoke from the oil system breather suggested that the thrust bearing of the CAU was heavily overloaded and would fail, as had been anticipated at the design stage. Testing was concluded in case the bearing failed completely causing the destruction of the entire CAU. There was no evidence of any gearbox deterioration during . Discussion of measured performanceFrom the calorimeter performance measurements, the primary objective of the project had been achieved. A unique air-cycle refrigeration system had been developed within the same physical envelope as the existing Thermo King SL200 refrigeration unit, w

暖通空调 就是一个杂志啊或者其他自然学科的杂志

暖通专业的核心期刊有——《暖通空调》《太阳能学报》《建筑科学》《流体机械》《制冷学报》《土木建筑与环境工程》等等；其他一般的期刊就比较多了像《制冷与空调》（北京的，四川的）《建筑热能通风空调》《建筑节能》《节能技术》《供热与制冷》《山西建筑》等等；还有一类就是一些名校的学报（不在列举），也是值得参考的！！

暖通专业的论文，最好是发国家级或者核心期刊了，不过审核也相当严的，

暖通空调期刊增刊

登陆他们的网站，点击个性化订阅。以下是联系方式《暖通空调》编辑部 地址： 北京市西城区德胜门外大街36号A楼4层 邮编： 100120电话： 010－88361727（主编） 010－88383814（杨爱丽） 010－68316357（刘学民） 010－57368821（于松波）010－68335394（李丽萍） 010－68330305（胡竹萍） 010－57368823（龚雪） 010－88362746（查询） 010－68363186（广告） 010－68362755（邮购）

要给你个电话么 我们单位定着呢

暖通专业的论文，最好是发国家级或者核心期刊了，不过审核也相当严的，

暖通空调 就是一个杂志啊或者其他自然学科的杂志

暖通空调外文期刊

暖通专业的论文，最好是发国家级或者核心期刊了，不过审核也相当严的，

暖通专业的核心期刊有——《暖通空调》《太阳能学报》《建筑科学》《流体机械》《制冷学报》《土木建筑与环境工程》等等；其他一般的期刊就比较多了像《制冷与空调》（北京的，四川的）《建筑热能通风空调》《建筑节能》《节能技术》《供热与制冷》《山西建筑》等等；还有一类就是一些名校的学报（不在列举），也是值得参考的！！

暖通空调就很好了

暖通空调 就是一个杂志啊或者其他自然学科的杂志

暖通空调核心期刊

分类: 教育/科学 >> 科学技术 问题描述: 我需要一些世界著名的自然科学杂志的名称，像《自然》，《科学》一类的。请高手们再给我提供一些这方面的资讯好吗？感激不尽！！！ 解析: 网站请见参考资料 科技文献 《Science》杂志[英文] 美国自然科学权威杂志。 《Nature Asia》 Gateway to Nature's world of science。 中华医学网 中国生物医学资讯的门户网站。 《金卡工程》 具有权威、全面、真实等特点，可浏览过往杂志内容。 《Proceedings of the National Academy of Sciences》 [英文] 介绍美国国家科学院的科技进展。 Science Daily[英文] 科学技术在线杂志. 中国期刊网CERNET网站 中国知识基础设施工程之一。 复杂性研究文摘（中英文） 圣菲研究所“复杂性研究文摘”，全世界分美、德、中三处发布。 电镀与涂饰 （双月刊）1982年创刊 Academic press electronic journal library [英文] 学术出版社电子期刊图书馆 软件学报 报道国家自然科学基金等资助的研究项目，代表我国软件研究水平。 《暖通空调》 中国建筑科学类核心期刊。 西安交通大学学报 报道一般工程技术和数学、物理、化学等方面的科研成果 《natureasia/门》[英文] 全球网际网路杂志 提供电子商务，法规政策及网路世界探索等资讯。 《Journal of Theoretics》 [英文] 理论期刊。 消防技术与产品信息 杂志。 中国信息年鉴网 介绍反映我国信息化建设全貌的专业年刊-《中国信息年鉴》的基本情况。 中国科学 中国科学院主办、中国科学杂志社出版的自然科学专业性学术刊物。 深圳特区科技杂志社 深圳特区科技杂志社的网站，包括每期的最新资讯，热辣新闻等。 《管理信息系统》杂志社 现代化工 中国化工信息中心主办的公开发行的大型综合性化工科技刊物。 《Prometheus》[英文] 《Annual Reviews/年度评论》[英文] 《流体工程学》[英文] Journal of Fluides Engineering，美国著名的工科院校Virginia Tech主办。 大众科技报 大众科技报网络版。 中国期刊网汕头镜像站 提供近7000种学术期刊（全文或文摘），经济、商务、法律、科技。 工业计量杂志 网站设有全年刊物内容，广告服务，投稿须知，征订启示等内容。 Isis[英文] 科学基金杂志部 4种学术期刊和其他业务活动情况. 中国科学院科院刊 《Journal of Young Investigators》 [英文] 青年科学家期刊。 中国地质文摘 中文地学文献检索刊物。中国地质图书馆主办。 橡胶工业 以橡胶加工技术为主的综合性全国专业期刊。 北极科学考察（人民日报） 科技新潮网 Library of Congress Science Tracer Bullets[英文] 科技新闻大观 提供科技产业新闻，美国硅谷和台湾新竹高科技业厂商的信息。 《ChemPort》[英文] 华夏星火 《华夏星火》月刊由国家科技部主管，被誉为中国星火计划第一刊。 水利水电市场 介绍水利水电市场需求与政策法规。 中外产业科技杂志社 广东省办事处 专家理论指导，让科技界、产业界发展更快更健康，大型企业成功经验。 《科学月刊 》[繁体] 科学网际月刊，由台湾天下文化书坊维护。 《金卡工程》杂志社 中国卡业界获得国家科技部和新闻出版总署批准的国家科技核心期刊。 量测资讯双月刊[繁体] 发现者[繁体] 能源、资源与环境季刊[繁体] 砂石产业的现况与未来，海砂开采的经济效益分析等等。 新电子[繁体] 新电子杂志的站点。 3C领域介绍与成果季刊[繁体] 由工研院资讯服务中心制作。内有本杂志各期全文档。 ITRIToday[繁体] 工研院发行的线上英文学术季刊。 工业技术与资讯月刊[繁体] 内有产业研发系列报导，机械通讯产业透析等单元。 《技术评论》[英文] 该杂志注重于应用科学，强调解决问题的技巧和方法。

这位学长，我只知道国内最好的核心期刊是《暖通空调》，国外的就不清楚了，呵呵。要是太阳能相关的，可以发到《太阳能学报》。

暖通专业的核心期刊有——《暖通空调》《太阳能学报》《建筑科学》《流体机械》《制冷学报》《土木建筑与环境工程》等等；其他一般的期刊就比较多了像《制冷与空调》（北京的，四川的）《建筑热能通风空调》《建筑节能》《节能技术》《供热与制冷》《山西建筑》等等；还有一类就是一些名校的学报（不在列举），也是值得参考的！！

暖通空调设计期刊

暖通空调就很好啊，他的增刊很好，制冷与空调也行，得看自己侧重的行业

暖通方面的论文在品学论文网很多的哦，你可以参考下，如果还有不清楚的地方，可以咨询下他们的在线辅导老师，我之前也是求助他们帮忙的，很快就给我了，当时还是品学论文的王老师帮忙的，态度不错，呵呵，相对于一些小机构和个人要靠谱的多

暖通专业的核心期刊有——《暖通空调》《太阳能学报》《建筑科学》《流体机械》《制冷学报》《土木建筑与环境工程》等等；其他一般的期刊就比较多了像《制冷与空调》（北京的，四川的）《建筑热能通风空调》《建筑节能》《节能技术》《供热与制冷》《山西建筑》等等；还有一类就是一些名校的学报（不在列举），也是值得参考的！！

暖通空调 [1002-8501] 本刊收录在：中国科技期刊引证报告(2007年版) 提示: 《引证报告》2007年版影响因子: 本刊收录在：中国科技期刊引证报告(2008年版) 提示: 《引证报告》2008年版影响因子: 本刊收录在：中文核心期刊要目总览(2004年版) 提示: 排序：建筑科学 - 第20位 本刊收录在：中文核心期刊要目总览(2008年版) 提示: 排序：建筑科学 - 第20位 主题分类： Engineering: General and Others Engineering: Energy Engineering 土木建筑工程类: 土木建筑工程类 建筑科学: 建筑科学 A类期刊凡被SSCI、A&HCI收录及中国社会科学期刊，学校认定为A类一级按CSSCI的学科分类（以国标分类为基础）即：管理学、马克思主义、哲学、宗教学、语言学、中国文学、外国文学、艺术学、历史学、考古学、经济学、政治学（含国际问题、台港澳问题）、法学、社会学、民族学、新闻与传播学、图书、情报与档案学、教育学、体育学、统计学、心理学、综合性社科、高校综合性社科学报、人文、经济地理、环境科学、港台澳地区及海外等26个文科学科，并根据学校现有学科设置，拟选定所属一级学科的全国性、权威性综合性期刊23种，认定为A类二级当然，不同学校有不同规定但sci ei 一定是A类 暖通空调为sci附网址一个：