首页 > 学术发表知识库 > 中央空调节能能毕业论文

中央空调节能能毕业论文

发布时间:

中央空调节能能毕业论文

随着经济的迅速发展,能源和环境问题日益尖锐。在特别炎热的夏天,我们都切身地体会到了电力的紧张。可以预见,这种状况在今后还会出现,并且会日趋严重。一、暖通空调领域节能的重要性和可行性随着社会的发展,建筑能耗在总能耗中所占的比例越来越大,在发达国家已达到40%,据统计在湖南省也达到27.8%。在城市远高于这个比例。而在建筑能耗里,用于暖通空调的能耗又占建筑能耗的30%-50%,且在逐年上升。随着人均建筑面积的不断增大,暖通空调系统的广泛应用,用于暖通空调系统的能耗将进一步增大。这势必会使能源供求矛盾的进一步激化。另一方面,现有的暖通空调系统所使用的能源基本上是高品位的不可再生能源,其中电能占了绝对比例。对这些能源的大量使用,使得地球资源日益匮乏,同时也带来严重的环境问题,如在我国的一些地区酸雨、飘尘问题呈日益严重之势,对生态环境和可持续发展带来了很大影响。以湖南长沙地区为例,2003年夏季电力系统最大负荷大约为160万千瓦,据有关部门推算,其中空调系统的负荷就占了约60万千瓦。在最热的夏天,如果对暖通空调系统采取节能措施,不仅可以大大缓解电力紧张状况,同时对于降低不可再生能源的消耗、保护生态环境、维持可持续发展、振兴湖南经济等都有着重要的意义。根据暖通空调行业的研究成果,现有空调系统的能耗是惊人的,如果采用节能技术,现有空调系统节能20%-50%完全可能。显然,如果对长沙地区的空调系统和建筑系统采用节能措施,那么即使遇到今夏那样的炎热天气,长沙也不会超过现有电力系统峰值而停电了。二、暖通空调领域节能的途径与方法科学技术的不断进步,使暖通空调领域新的技术不断出现,我们可以通过多种方法实现暖通空调系统的节能。1、精心设计暖通空调系统,使其在高效经济的状况下运行暖通空调系统特别是中央空调系统是一个庞大复杂的系统,系统设计的优劣直接影响到系统的使用性能。例如系统往往都是按最大负荷设计的,而实际运行基本上是在部分负荷下运行,如果系统各部分的设计不能满足部分负荷运行的要求,那系统的能耗是很大的。又如新风系统的设计,系统应该能随着室外气象参数的变化改变新风量,以最大限度地缩短主机的开启时间。可以说空调系统的设计对系统的节能起着重要的作用。2、改善建筑维护结构的保温性能,减少冷热损失我们知道对于暖通空调系统而言,通过维护结构的空调负荷占有很大比例,而维护结构的保温性能决定维护结构综合传热系数的大小,亦即决定通过维护结构的空调负荷的大小。所以在国家出台的建筑节能设计规范和标准中,首先要求的就是提高维护结构的保温隔热性能。3、提高系统控制水平,调整室内热湿环境参数,尽可能降低空调系统能耗空调系统特别是舒适性空调系统对人体的作用是通过空气温度、湿度、风速、环境平均辐射温度进行的,人体对环境的冷热感觉是这些环境因素综合作用的结果。以往的空调控制方式仅仅是测控空气的温度湿度,甚至仅空气温度。显然是不全面的,势必带来许多问题,如空调系统对人体的作用不直接、当环境变化时对环境的调控不迅速、人体感到不舒适、空调系统的这种调控方式不节能。热湿环境研究成果的应用,为我们采用新的控制方式方法提供了理论基础。如果采用舒适性评价指标即体感指标作为空调系统的调控参数,如采用PMV或SET*指标对空调系统进行调控,不仅可以解决传统控制方法存在的弊病,而且可以实现大幅度的节能,据我们的初步研究表明,采用这种控制方法可使空调系统在人体舒适的条件下节能30%左右。4、采用新型节能舒适健康的空调方式如上所述,影响人体热舒适性的环境参数众多,不同的环境参数组合可以得到相同的热舒适性效果,但不同的热湿环境参数组合空调系统的能耗是不相同 的。例如在冬季,如果我们采用传统的空调方式,把整个室内的空气加热,通过空气实现人体与环境的热湿交换,就需要较高的空气温度,此时通过维护结构的热损失和加热新风的热损失都比较大。如果我们根据热湿环境的研究成果,改变传统的空调方式,增加辐射热(如低温地板辐射采暖),此时所需要的空气温度降显著下降,一般可达到12~14度,而传统方式一般在18~20度,显然后者比前者具有显著的节能效果。在夏季也有类似的结果。5、推广应用使用可再生能源或低品位能源的空调系统随着空调系统的广泛应用,空调对不可再生能源的消耗将大幅度上升,同时对生态环境的破坏也在日趋加剧。如何利用可再生能源及低品位能源已经成了该领域重要的研究课题。地源热泵空调系统就是在这种形势下发展起来的,它利源地下恒温层土壤热显著提高空调系统的COP值,使得同等制热(或制冷)量下的系统能耗大幅度下降。另外,利用太阳能供热或制冷技术也在开发研究着。6、开展冷热回收利用的研究运用工作,实现能源的最大限度利用目前许多空调系统冷热回收利用研究也在蓬勃开展,如空调系统排风的全热回收器,夏季利用冷凝热的卫生热水供应等,都是对系统冷热的回收利用,显著提高了空调系统能源利用率。三、存在的问题与对策要实现空调系统的节能降耗,已经具备了许多成熟的条件,但同时也存在许多问题有待于解决:1、暖通空调系统的设计管理问题如前所述,空调系统的设计对空调系统的节能性有着重要的影响。然而在实际中往往得不到一些设计部门和设计人员的足够重视,使得设计建造的系统不仅初投资大,运行能耗也相当惊人,大大超过了国家标准。据实测,有的公共建筑的空调能耗占建筑总能耗的60%。为此, 我们有必要建议政府有关职能部门加强对暖通空调设计项目的管理,可以委托相关技术部门如学会等对设计图纸文件进行严格审查,对未达到国家有关节能标准的设计严禁施工建造。2、暖通空调系统的运行管理问题除设计外,我们发现运行管理也起着重要的作用。有些单位的空调系统,一年四季只有开机关机和冬夏季转换操作,显然系统达不到相应的节能效果。为此 要求运行管理人员不仅要有强烈的责任心,上岗前还必须要进行系统的培训和考核,对没有达到要求的,应重新培训,考核合格后才能上岗。在调查中我们发现,同样一套系统,管理人员不同,系统的能耗大不相同,有的甚至相差50%以上。3、新型空调方式、控制方法及新的节能技术的开发应用问题如前所述,采用新型空调方式、新的控制方法,不仅能显著提高热舒适性而且可以使系统大幅度节能。在我省对新型空调方式和控制方法的研究可以说在全国都是比较早的,并且已经取得了一些可喜的成果,只要政府部门略加扶持这些成果将很快能得到适用,并形成产业化,对这些项目的实施,将对我省的能源、环境和经济都将起到巨大的推动作用。4、公众对空调系统作用的理解观念问题对于舒适性空调系统,从本专业的角度来讲就是使人体有好的热舒适性。而在社会上我们常常发现一种这样的观念:认为空调在夏季是越冷冬季越热效果越好。这显然与舒适性空调的出发点相违背的。事实上,这样不仅大大增大了空调系统的能耗,同时由于室内外温差的增大,也使人体对不同环境的适应性下降,身体免疫力降低。这些可以通过宣传改变人们的观念。5、使用可再生能源空调系统的开发推广应用问题利用可再生能源的暖通空调系统,如地源热泵空调系统、太阳能制冷、供热系统,不仅有着显著的环境和社会效益,有的还有着显著的经济效益(如地源热泵空调系统),应大力开发推广。当然,和其他任何新技术一样,这些技术也存在着一些问题(如地源热泵系统的地源热提取问题等),也需要进一步研究完善,也需要政府部门的重视和支持。综上所述,暖通空调系统在建筑节能中占据重要的位置,起着重要的作用,节能技术的研究开发和运用是暖通空调系统、建筑系统节能的基础,政府职能部门的重视和支持,则是实现大幅度节能、产生显著的环境和社会效益、推动经济发展的保证。

空调节能论文文献

中达咨询通过对深圳市某办公楼的空调系统运行状况的调查测试及模拟,对该工程节能改造及运行方法进行了分析。总结了整个办公楼空调系统节能改造方案及经济性,为今后工程改造提供了依据。一、 引言 在能源总消耗中,建筑能耗占有着很大比例,其中照明和空调,特别是空调,占据了建筑能耗的绝大部分,所以,进行空调节能潜力的分析具有非常重要的意义。我们可以根据分析结果,通过对空调系统设计或对已有的空调系统进行改造,达到降低能耗的目的。对于供冷期较长的地区,空调能耗高,因此节能工作尤为重要,并具有代表意义。本文以深圳市某办公楼为对象进行研究和讨论,该办公楼由地下两层及地上二十层组成,总建筑面积39200平方米,空调面积30000平方米。空调用制冷系统选用3台制冷量为1336KW的离心式冷水机组,但实际只运行2台即可满足要求。冷冻水与冷却水系统均为定流量运行。该办公楼的室内设计参数是:干球温度为24℃-26℃,相对湿度为50%-60%。通过实测调查得知,该办公楼空调系统全年供冷,运行时数为2530小时,当冬季室外空气温度降低而不需供冷时,停开冷水机组。 二、 空调负荷 对建筑物进行能耗分析和运行模拟,都要以空调负荷计算为基础。空调系统的设计与运行能耗都与空调动态负荷有关,本文使用美国能源部大型能耗分析软件DOE-2对该办公楼的空调动态负荷进行模拟,结果见图1。模拟得到的逐时峰值负荷为2415KW,图中所示为月平均负荷,其峰值为1600KW。由计算结果可知,该办公楼全年均需要供冷。图1 办公楼动态负荷 获得空调动态负荷后,为使用负荷频率法对冷水机组的能耗进行分析,现按文献[1]提出的一种用于制冷设备运行分析及容量选择的全年空调负荷统计方法,将空调动态负荷转换成负荷率与时间频数之间的关系,该办公楼空调系统全年运行时数平均为2530小时,平均的空调冷负荷时间频数如表1所示。空调冷负荷时间频数 表1负荷率(%) 10 20 30 40 50 60 70 80 90 100 时间频数(%) 27.9 8.7 8.2 11.6 9.9 10.2 11.6 6.4 4.2 1.3三、 冷水机组的节能分析 在一年之中,由于空调系统在部分负荷下运行的时间较多,因此,全年耗能量与制冷机部分负荷下的工作特性有关。离心式冷水机组部分负荷性能见表2[2]。由2可以看出,与负荷率为100%的情况相比,部分负荷下的运行效率有增有减。离心式冷水机组部分负荷性能参数 表2机组负荷率(%)100908070605040302010机组功率百分数(%)10087.076.065.056.048.040.033.025.021.0根据表2,采用线性回归的方法得出典型的离心式冷水机特性曲线方程,从而采用负荷频率法计算出不同制冷量时,输出功率的变化。 该制冷系统的实际运行方案是:先开启一台冷水机组,使其冷量由小至大调节满足实际负荷变化,直至出力不够时,再开启另一台。并且第一台冷水机组始终保持满负荷,而第二台随负荷变化进行调节。本文又根据模拟优化计算得到了冷水机组的最优运行方案(即全年机组运行的平均输出功率最小)。由于离心式制冷机在设计负荷的10~15%以下时出现喘振,本文模拟冷水机组实际运行时,让冷机最低调节范围不得低于15%,否则停机。两种运行方案的计算结果见表3。冷水机组运行耗功率 表3负荷率(%)102030405060708090100年平 均值时间频数(%)27.98.78.211.69.910.211.66.44.21.3实 际 运 行 方 案运行台数1111122222-制冷量 (%)1台18.136.254.272.390.493.41001001001002台0000015.026.544.662.780.8平均功率 (kW)19.248.8411.5221.6423.7732.0041.1425.0217.976.29207.43最 优 运 行 方 案运行台数1111122222-制冷量 (%)1台18.136.254.272.390.454.263.372.381.390.42台0000054.263.372.381.390.4平均功率 (kW)19.248.8411.5221.6423.7728.6637.7523.8717.826.24199.37由表3中结果可知,最优运行方案是:先开启一台冷水机组,使其冷量由小至大调节满足实际负荷变化,直至出力不够时,再开启一台。当开启两台制冷机时,平均分配负荷,每台冷水机组的制冷量按上表由小至大满足负荷变化的要求。此时,总运行能耗为最小。 四、 水系统的节能分析 一些调查表明,空调水系统的工作普遍存在着大流量小温差的问题。夏季供冷水系统的供回水温差:较好的为3℃左右,差的只有1~1.5℃。而循环水量一般为设计水量的1.5倍数。高层建筑供冷系统一般规模较大,能耗很大,但节能潜力也很大,一个节能的制冷系统,不仅要求选择的设备性能和台数能与空调系统负荷的变化相适应,而且要求在运行中整个系统在各种负荷下能够保持能耗最小。 空调水系统在应用变频调速成装置进行变流量运行时,可以在不改变管路特性,而靠移动水泵工作点使之沿管路特性曲线移动,保持水泵在最高效率点运行,达到最大节能效果。对于闭式系统来说,当流量减少时,其实耗功率相应按三次方的比例降低。这对于目前空调水系统的设计水量与实际水量差别很大的情况来说,具有非常明显的节能意义。 由于本文的研究重点是能耗,也就是总结出实时的运行调节对空调系统能有多大的节能潜力,从而指导实际运行。本文模拟了两台并联水泵采用变频装置,根据负荷变化进行流量调节时,不同流量下的最优调速比及相应的耗功率。调速水泵全年运行平均功率计算在模拟水泵运行能耗时,同样存在着各运行水泵间负荷的最优分配问题。我们的目的是在尽量满足流量和扬程前提下,达到耗能最小,即水泵总耗功率最小。本文在考虑流量变化满足部分负荷要求时,只对冷冻水泵变流量时二者的能耗进行计算,而冷却水侧的变流量分析将不做研究。计算运行能耗时,假定最小临界水量(负荷)为总水量的50%,该工程每台机组冷冻水的循环流量为230m3/h,所以最小临界水量为115m3/h。模拟时校核水泵流量,如果低于该值,水泵的调速比就保持不变。本文对多种调速方案进行了计算。 该冷冻水系统的实际运行方案是:50%以下负荷时,一台泵运行;50%-100%负荷时, 开启两台泵。本文又根据多种调速方案模拟优化计算得到了冷水机组的最优运行方案(即冷冻水泵运行的平均输出功率最小):当50%负荷以下时,开一台水泵;50%-100%负荷时, 开启两台水泵。并且水泵分阶段调速运行满足负荷率变化。两种运行方案的计算结果见表4。冷冻水系统运行耗功率 表4负荷率(%)102030405060708090100年平均值时间频数(%)27.98.78.211.69.910.211.66.44.21.3实际运行方案运行台数1111122222-速比 (%)1台11111111112台0000011111平均功率 (Kw)12.583.903.705.214.469.2110.425.763.741.1760.15最优运行方案运行台数1111122222-速比 (%)1台0.350.350.350.470.590.350.410.470.530.592台000000.350.410.470.530.59平均功率 (Kw)0.550.170.160.540.910.410.730.600.560.244.87经校核,两台水泵都变速运行时,每台机组的水量始终在最小临界水量以上。从以上2个方案中可以看出,在部分负荷时变频调速水泵与恒速泵比较,其节能效果非常显著。 五、 室内空气参数与建筑能耗 影响空调系统能耗因素很多,针对本文所研究的办公楼,根据现有实际条件及能力,本工程从设计标准选取的角度进行建筑能耗分析。 在空调设计中,首先要确定室内设计参数,这关系到舒适标准与卫生要求。合理的室内设计温度与湿度应该是在满足热舒适要求的前提下力求减少能耗。干球温度22~27℃,相对湿度30%~70%被普遍认为是舒适区,根据该办公楼的室内设计参数,通过组合(6个设计点)计算,可以得到相应的人对热环境的反应状况与耗电量,见表5。不同室内参数下空调系统耗电量 表5设计点干球温度(℃)相对湿度(%)舒适度耗电量(kWh)12450%稍冰864 70022550%舒适824 90032650%舒适784 60042460%舒适855 90052560%舒适815 90062660%舒适775 900由表5可以看出,温度的升高和相对湿度的增加,都会使能耗有所降低。上述设计点基本都在舒适区范围内,但耗电量有所不同。可见,通过改变室内设计标准所具有的节能潜力是很大的。所以在满足舒适度要求的前提下,可选择提高室内温度和相对湿度来减少空调系统能耗。 六、 节能综合效果分析 针对该办公楼的实际情况,通过研究,本文提出了该办公楼空调系统的若干节能措施并进行了分析,如果仅考虑对前三项改造所带来的节能效果和经济效益,其综合效果见表6。 空调系统节能潜力分析一览表 表6改造项目增加投入(元)耗电量(kWh)节能率 (%)节省运行费① (元/年)回收年限改前改后冷水机组的最优运行方案-524 798504 4063.920 392 冷冻水泵定水量改为变水量运行变频器及辅助设备 80 000152 18012 32191.9139 8591年总和80 000676 978516 72723.7159 8511年①深圳市电价为1元/(kWh) 从表6中的数据可知,对现有的空调系统人工冷源进行以上的改造,做较少的投资,就可以获得可观的节能效果和节省大量的运行费用。由于有些节能措施对已经施工运行的系统难以操作,如果在设计阶段就能充分考虑系统的节能问题,则效果会更好。 七、 结语 通过对深圳市某办公楼的空调系统进行节能潜力分析可以看到,现有的空调系统具有很大的节能潜力。仅从制冷系统的优化运行和冷冻水系统角度去进行调整,其运行节能潜力已非常之大,节能率可达23.7%,如果能在系统设计时就充分考虑系统的节能问题,则可以得到更好的节能性和经济性。 参考文献 1 章雅锐,单寄平.从节能运行出发对制冷机容量匹配的初步探讨.暖通空调,1990,20(1):14~17 2 曹琦,张华.计算部分负荷性能参数正确选择冷水机组.暖通空调,1996,26(6):58~60更多关于工程/服务/采购类的标书代写制作,提升中标率,您可以点击底部官网客服免费咨询:

随着改革开放逐步深化、国民经济的快速发展、人民对生活品质要求的提高,空调在现代建设中被广泛的应用。下面是我为大家精心推荐的空调节能技术论文,希望能够对您有所帮助。

空调节能技术浅谈

摘要:随着近年来社会经济的不断发展,人们生活品质的逐步提高,对于物质生活和环境舒适性的需求也更加苛刻,空调系统显然已经成为现代建筑行业中一个不可忽视的部分。但是,近年来能源危机突出和环境破坏对人类的影响逐步加深,已经让人类清晰的认识环境保护和能源节约的重要,国家也制定了一系列的法律法规和行业标准。因此,能源的有效节约、提高能源有效利用的方法和技术的研究成为了当今一项重要课题。本研究从影响空调系统的能耗的关键因素出发,提出了几项空调节能的可行性方案,最后探讨了空调节能的未来发展趋势。

关键词:空调系统;节能技术;措施建议

中图分类号:TU831.3+5文献标识码: A

前言:

随着人们经济水平的不断提高,生活品质的提升,无论是生活环境还是工作环境,空调系统在现代建筑中的应用也越来越广泛。根据统计表明,在我国空调耗能占建筑物总能源消耗的60%~70%,因此,采取有效的节能措施,解决高层建筑节能问题符合我国经济的可持续发展的要求,对节能减排和建设环境友好型社会有着至关重要的意义。

空调能耗的现状以及节能的重要性

随着改革开放逐步深化、国民经济的快速发展、人民对生活品质要求的提高,空调在现代建设中被广泛的应用。而在建筑能耗里,空调能耗已经占到建筑能耗的60%~70%左右,而且比重还在逐年上升。因此空调节能技术的发展对提高能源利用率、环境可持续发展有重要影响。

在我国现阶段中央空调系统的应用中,通常认为空调系统的温湿度控制以及空气品质的控制是最为重要的,进而忽略了空调系统的能源消耗情况。在我国,影响中央空调系统能源不能得到有效利用的主要因素有三方面,首先,在设计过程中重视投资成本,而忽略了能耗指标计算,在整个系统方案中,缺乏节能引导中央空调系统的经济性分析。导致在工程建筑方案的运行过程中,使用投资低、耗能大、运行费用高的空调系统。其次,对于中央空调而言,整个的系统工程相对复杂,所以对于中央空调能源有效利用的评价,要从整个系统全面来看,而不能单纯地停留在对机器设备本身的评价上,真正意义上的节能是与各个系统设计理念、施工优劣情况以及运行管理水平和建筑物热特性等因素息息相关,而不是只看重设备本身。最后,还有一个主要的因素,就是缺乏高素质运行管理人员和节能监控,致使空调系统在运行和管理的过程中没有得到很好地控制和监管,合格的管理人才可以大大改善运行不合理的地方,有利于节能。

建筑节能技术

空调系统的节能技术首先可以从建筑物本身入手,结合建筑、结构等相关知识,使建筑物在形状、色彩、方位及材料等方面为空调节能创造最基础的条件。对于空调位置的安排要进行合理布局,合理设计相关比例与系数,选择保温隔热性能良好的材料作为墙体和屋面,并提高改善建筑围护结构的性能等,都是建筑节能的可行性措施。

2.1选择合理的室内设计参数

在整个建筑物中,主要的热损失来自于围护结构和门窗缝隙空气渗透。因此, 在建筑物进行建筑节能中,注重室内设计中加强围护结构,使用环保、节能型建筑材料, 可有效地减少通过围护结构的传热这一主要的空调负荷, 从而各主要设备的容量达到显著的节能效果。通过这种方法进行保温隔热,同时加强门窗的气密性。另外,在夏季空调供冷时,室内外侧玻璃受阳光照射,是空调冷负荷的主要部分,应采取必要的遮阳措施。而在冬季空调供热时,则要求改善窗户的保温效果,可以采用光热性能好的玻璃;为了减少窗的冷(热)桥传热,可以采用钢塑窗代替铝合金窗;同时还可以采用双层玻璃窗提高窗的保温性。在窗户的设计位置上要减小窗洞口与墙的面积比值减少空调房间两侧温差大的外墙面积及其薄弱环节窗的面积,利于空调建筑节能。

2.2合理设计建筑结构

合理的设计建筑结构也是进行空调节能的一个有效途径之一。可以通过改善建筑的保温隔热性能,使房间内冷热量的损失通过房间的墙壁和门窗传递出去,这样可以有效地减少建筑物的冷热负荷。建筑物的朝向对空调冷负荷有很大的影响,根据我国的地理位置来分析确定良好的建筑朝向,一般建筑物为南朝向是我国建筑节能的必要条件,可以通过保持合理的建筑间距以及建筑群的错落布局,使建筑物接受适当的太阳辐射,同时有利于获得自然通风气流。

空调设计方面节能

在面积较大的空调房内,在空调房内区的负荷与周边区的相比较差距较大,如果两个区域选择使用一个空调系统进行制冷,两个空调房区域的房间的将会产生较大的温差,尤其是在冬季及过渡季节,所以同时处于两个不同区域的工作人员对环境空间的温度反映冷热温差较大,,根据我国在2001年版的《采暖通风与空气调节设计规范》新增5.3.2条之规定,建筑物内负荷特性相差较大的内区与周边区,以及同一时间内必须分别进行加热与冷却的房间,宜分别设置空气调节系统.。内区系统主要处理室内负荷,与外区负荷相比,内区负荷则相对稳定,内区往往需要全年供冷,去除室内余热。外区系统主要处理外部得热,外区负荷波动大,外区新风来源一般是内区空调系统,与外区回风混合经风机盘管处理后达到送风点,外区冬季供暖,夏季供冷,从而满足舒适性要求。

空调系统中的节能技术

空调系统如何适应在低负荷下高效节能运行及在系统设计中对设备进行节能选配就成为空调节能的关键。

4. 1 加强中央空调的运行管理和控制设备的调节控制

提高空调能源的有效利用,需提高操控人员的职业素质,避免由于管理不善而引起的空调耗能。操控人员要做好设备运行记录,分析机组各种压力表、温度计、流量计的读数是否正常准确,并根据空调负荷的变化调节机组,确保机组运行在节能状态,而且定期保养检查,及时更换磨损的零件。

4. 2 设备及管道的保温及水质处理

要实现降低能量的过多耗费这一目标,就要做好设备及管道的保温。保温的目的是为了阻绝内外温度传递,如果室外的温度小于空调排水的温度加保温是为了防止空调水管结冰冻裂水管,如果环境温度大于空调排水温度加保温是为了防止有冷凝水造成漏水。空调设备和管道的保温,对于节省能量消耗、降低运行费用也是相当重要的。空调能耗高还有一个重要的原因,就是空调系统中水管中水质的污染。

5、建筑空调系统设备的节能运行技术

设备的节能运行技术在建筑空调系统综合节能技术中, 其也至关重要。主要技术包括: 蓄能空调技术、热回收技术、变频技术等。

5.1蓄能空调技术

蓄能系统就是储蓄在不需要的冷/热量或需要的冷/热量减少的时间的过程中,制冷/热设备将蓄冷/热介质中所移出的热量,并在空调处于用冷/热或工艺性的用能高峰时,启动此能量。这样既减少了能源的流失,又可以有效地利用能源,既有经济效益又有社会效益, 是一项双赢的节能举措。

5.2 热回收技术

热回收技术包括排风余热回收和制冷机组的冷凝热回收。排风余热回收充分利用排风的能量, 对其进行回收,从而对新风进行预冷或预热,减小新风负荷是暖通空调节能的重要途径。制冷机组的冷凝热回收系统既可以避免冷凝热排放到大气中造成热污染, 又可以节省为提供热水而设的锅炉及其附属设备, 避免了由于燃料的燃烧向大气排放的有害物, 应该说是一种效果明显, 又有环保作用的节能技术。

5.3变频技术

随着电力电子技术和计算机控制技术的不断发展,在空调控制系统中变频器也得到了广泛的应用,它的应用主要是针对空调控制系统的特点而进行控制。不同类型的冷水机组都有较完善的自动控制调节装置, 能随负荷变化自动调节运行状况, 保持高效率运行,从而实现了一种既能达到控制要求又能节约能源的方法。

5.4太阳能空调技术

太阳能是绿色能源中最重要的能源, 太阳能的热利用是目前建筑中利用太阳能的主要利用形式。它包括被动式和主动式两种形式。被动式太阳能房的结构相对简单、造价低、不需要任何辅助能源, 通过建筑方位合理布置和建筑构件的恰当处理, 以自然热交换方式来利用太阳能。主动式太阳房结构较为复杂,造价较高,需要用电作为辅助能源。采暖降温系统由太阳集热器、风机、泵、散热器及储热器等组成。在建筑外围护结构中还可采用太阳能集热墙, 利用太阳能采暖。

6、结束语

能源问题是我国实现经济发展的重点问题之一,建筑空调节能技术是节约能源、改善环境、促进经济可持续发展的有效措施。空调系统在高负荷下高效节能运行以及在系统设计中选配节能设备是建筑空调节能的关键因素, 这对于节约能源、降低运行费用、促进国民经济发展具有十分重要的意义。在未来的建筑物中,在空调系统设计方面,要在节约能源以及有效利用能源这两方面引起高度重视。只要各方共同努力,空调系统的节能降耗问题的解决指日可待。

参考文献:

[1] 农孙仁. 中央空调系统节能改造探析[J]. 企业科技与发展. 2012(18)

[2] 叶宁. 中央空调系统的节能运行[J]. 科技资讯. 2012(03)

[3] 李令言. 中央空调节能控制系统的研究与开发[D]. 中国科学技术大学 2011

点击下页还有更多>>>空调节能技术论文

中央空调毕业论文

1、论文题目:要求准确、简练、醒目、新颖。2、目录:目录是论文中主要段落的简表。(短篇论文不必列目录)3、提要:是文章主要内容的摘录,要求短、精、完整。字数少可几十字,多不超过三百字为宜。4、关键词或主题词:关键词是从论文的题名、提要和正文中选取出来的,是对表述论文的中心内容有实质意义的词汇。关键词是用作机系统标引论文内容特征的词语,便于信息系统汇集,以供读者检索。 每篇论文一般选取3-8个词汇作为关键词,另起一行,排在“提要”的左下方。主题词是经过规范化的词,在确定主题词时,要对论文进行主题,依照标引和组配规则转换成主题词表中的规范词语。5、论文正文:(1)引言:引言又称前言、序言和导言,用在论文的开头。 引言一般要概括地写出作者意图,说明选题的目的和意义, 并指出论文写作的范围。引言要短小精悍、紧扣主题。〈2)论文正文:正文是论文的主体,正文应包括论点、论据、 论证过程和结论。主体部分包括以下内容:a.提出-论点;b.分析问题-论据和论证;c.解决问题-论证与步骤;d.结论。6、一篇论文的参考文献是将论文在和写作中可参考或引证的主要文献资料,列于论文的末尾。参考文献应另起一页,标注方式按《GB7714-87文后参考文献著录规则》进行。中文:标题--作者--出版物信息(版地、版者、版期):作者--标题--出版物信息所列参考文献的要求是:(1)所列参考文献应是正式出版物,以便读者考证。(2)所列举的参考文献要标明序号、著作或文章的标题、作者、出版物信息。

你这问题难度太大因为中央空调的维护是一个系统工程涉及到很多工序

我有小车的论文

基于单片机的中央空调模糊控制器设计摘 要:传统空调对温度的调节是一种断续变化过程,不能根据环境温度变化及时调整空调器工作状态,因此不能实现完全自动控制,耗电量大。本文介绍了一种基于单片机的中央空调模糊控制器,采用模糊控制技术实现对房间温度的自动控制,并阐述了它的组成、硬件、软件以及模糊算法的设计。 关键词:中央空调控制器 单片机;模糊控制 相关资料已经发送到你百度信息,希望对你有所帮助

暖通空调节能毕业论文英文

毕业论文”的英文:Graduation Dissertation

Dissertation 读法 英 [,dɪsə'teɪʃ(ə)n]  美 ['dɪsɚ'teʃən]

n. 论文,专题;学术演讲

短语:

1、academic dissertation 学位论文 ; 学术论文

2、Graduation Dissertation 毕业论文

3、Doctorate dissertation 博士论文

4、Dissertation Committee 论文委员会

5、dissertation topics 毕业论文题目

词义辨析:

article, paper,dissertation, essay, prose, thesis这组词都有“文章”的意思,其区别是:

1、article 多指在报刊、杂志上发表的非文艺性的文章,包括新闻报导、学术论文等。

2、paper 正式用词,多指在学术刊物上发表或在学术会议上宣读的专题论文,也指高等学校的学期论文,或学校里的作文练习。

3、dissertation 书面语用词,指独立研究后所写的较为详细的专题文章;也可指学位论文。

4、essay 指任何一种非小说性的,篇幅不长、结构简练的文章,如论说文、报道、评论、讽刺性杂文等。

5、prose 专指散文。

6、thesis 既可指毕业论文、学位论文,又可指一般的为阐述学术观点而写的论文。

例句:

1、Exploring "Trinity Working Mode" of Integrating Graduation Field Work, Graduation Dissertation and Employment on Graduation.

毕业实习、毕业论文与学生就业三位一体工作模式探索。

2、On Problems in Writing Graduation Dissertation

关于撰写毕业论文应该注意的问题。

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 units.Keywords: 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 immediately.Concerns 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 refrigeration.Thermo 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 turbochargers.2. 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 Eqs.The 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 COP.The 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 plant.The 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 intercooler.shows 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 loss.The 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 ratios.Since 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 expansion.Lower 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/s.By 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 cycle.3. 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 controller.From 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 efficiency.A 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 clutch.4. 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 performance.Most 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 used.The 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 silencer.The 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 plant.Several 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 speed.7. 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 standards.The 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 testing.8. 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

毕业论文是Graduation thesis 若要在论文里指论文就可以直接说thesis或者paper

暖通空调就很好了

新能源汽车空调节能论文题目

提供一些关于汽车的毕业论文的题目,供参考。1 发动机排放技术的应用分析2 微型车怠速不良原因与控制措施3 柴油机电子控制系统的发展4 我国汽车尾气排放控制现状与对策5 发动机自动熄火的诊断分析6 汽车发动机的维护与保养7 柴油机微粒排放的净化技术发展趋势8 汽车污染途径及控制措施9 现代发动机自诊断系统探讨10 关于奔驰300SEL型不能着车的故障分析11 奔驰Sprinter动力不足的检测与维修12 上海通用别克发动机电控系统故障的诊断与检修13 现代伊兰特发动机电控系统故障的诊断与检修14 广本雅阁发动机电控系统故障的诊断与检修15 电子燃油喷射系统的诊断与维修16 帕萨特1.8T排放控制系统的结构控制原理与检修17 广本雅阁排放控制系统的结构控制原理与检修18 汽车发动机怠速成抖动现象的原因及排查方法探讨19 汽车排放控制系统的检修20 上海帕萨特B5电子燃油喷射系统的诊断与维修21 论汽车检测技术的发展22 奥迪A6排放控制系统的结构控制原理与检修23 丰田凌志400发动机电控系统故障的诊断与检修24 奥迪A6B5电子燃油喷射系统的诊断与维修25 标致307电子燃油喷射系统的诊断与维修26 捷达轿车发动机常见故障分析与检修27 汽车转向盘摆振故障分析28 防抱死系统在常用轿车上的使用特点分析29 汽车底盘的故障诊断分30 汽车的常用转向系统的性能分析31 汽车变速箱故障故障诊断32 安全气囊的发展与应用33 汽车制动系统故障诊断34 分析国产几种汽车行走系统特点35 分析国产几种汽车制动系统特点36 分析国产几种汽车转向系统特点37 机电液一体化技术在汽车中的应用38 丰田系列ABS故障诊断方法的探讨39 通用系列ABS故障诊断探讨40 奔驰560SEL车型ABS系统故障案例分析41 AL4自动变速器的结构控制原理与检修42 汽车制动系43 汽车四轮定位的探讨44 4T65E自动变速器的结构控制原理与检修45 上海通用别克转向系统故障的诊断与检修46 上海通用别克制动系统故障的诊断与检修47 现代伊兰特转向系统故障的诊断与检修48 现代伊兰特制动系统故障的诊断与检修49 SONATA制动系统的结构控制原理与检修50 电控悬架系统的结构控制原理与检修51 上海帕萨特B5自动变速器的结构控制原理与检修52 丰田佳美制动系统的结构控制原理与检修53 丰田凌志400悬架系统的结构控制原理与检修54 标致307制动系统故障的诊断与检修55 标致307手动变速器的结构控制原理与检修56 上海通用别克悬架与车桥故障分析与检修57 电控液动式自动变速器的结构控制原理与维修58 分析轮胎性能对汽车行走行使的影响59 捷达轿车底盘常见故障分析与检修60 汽车转向系课件设计61 汽车ABS综述62 车用防抱死制动系统设计63 汽车蓄电池的维护与故障控制64 信息技术在汽车中的应用65 现代汽车渗漏故障与控制技术66 汽车点火系统故障诊断67 丰田凌志400空调控制系统分析68 桑塔纳故障诊断方法的研究69 汽车空调技术浅析70 蒙迪欧的空调系统分析71 氧传感器故障检测72 传统诊断在轿车维修中的应用73 广本雅阁的空调系统故障的诊断与检修74 电子点火系统的诊断与维修75 上海帕萨特B5的空调系统故障的诊断与检修76 论车身计算机系统的结构控制原理与检修77 上海通用别克空调控制系统故障分析与检修78 广本雅阁电气设备及附件系统常见故障分析与检修79 汽车常用防盗系统综述80 汽车防撞技术综术81 现代汽车音响防干扰设计82 汽车电控技术分析83 奥迪A6电气设备及附件系统常见故障分析与检修84 上海通用别克电气设备及附件系统常见故障分析与检修85 标致307电气设备及附件系统常见故障分析与检修

这个你要问的是格式还是内容,这个偶区别的你怎么探讨

找中国论文榜,说清楚论文要求就好了

(一)论文名称论文名称就是课题的名字第一,名称要准确、规范。准确就是论文的名称要把论文研究的问题是什么,研究的对象是什么交待清楚,论文的名称一定要和研究的内容相一致,不能太大,也不能太小,要准确地把你研究的对象、问题概括出来。第二,名称要简洁,不能太长。不管是论文或者课题,名称都不能太长,能不要的字就尽量不要,一般不要超过20个字。(二)论文研究的目的、意义研究的目的、意义也就是为什么要研究、研究它有什么价值。这一般可以先从现实需要方面去论述,指出现实当中存在这个问题,需要去研究,去解决,本论文的研究有什么实际作用,然后,再写论文的理论和学术价值。这些都要写得具体一点,有针对性一点,不能漫无边际地空喊口号。主要内容包括:⑴研究的有关背景(课题的提出):即根据什么、受什么启发而搞这项研究。⑵通过分析本地(校)的教育教学实际,指出为什么要研究该课题,研究的价值,要解决的问题。(三)本论文国内外研究的历史和现状(文献综述)规范些应该有,如果是小课题可以省略。一般包括:掌握其研究的广度、深度、已取得的成果;寻找有待进一步研究的问题,从而确定本课题研究的平台(起点)、研究的特色或突破点。(四)论文研究的指导思想指导思想就是在宏观上应坚持什么方向,符合什么要求等,这个方向或要求可以是哲学、政治理论,也可以是政府的教育发展规划,也可以是有关研究问题的指导性意见等。(五)论文写作的目标论文写作的目标也就是课题最后要达到的具体目的,要解决哪些具体问题,也就是本论文研究要达到的预定目标:即本论文写作的目标定位,确定目标时要紧扣课题,用词要准确、精练、明了。常见存在问题是:不写研究目标;目标扣题不紧;目标用词不准确;目标定得过高, 对预定的目标没有进行研究或无法进行研究。

  • 索引序列
  • 中央空调节能能毕业论文
  • 空调节能论文文献
  • 中央空调毕业论文
  • 暖通空调节能毕业论文英文
  • 新能源汽车空调节能论文题目
  • 返回顶部