磁悬浮离心式冷水机组和国家标准北大核心

磁悬浮离心式冷水机组已在国内外诸多空调工程中应用,因其性能系数高,大大降低了冷水机组的全年能耗。分析了该类型冷水机组在国内的应用现状,指出作为一种冷水机组产品,应执行现有的相关国家标准,同时应参考国外标准;建议深入理解国内外标准中名义工况下的COP、综合部分负荷性能系数IPLV和非标准工况下综合部分负荷性能系数NPLV,正确评价磁悬浮离心式冷水机组的性能。工程实例计算结果表明,磁悬浮离心式冷水机组与普通离心式冷水机组相比,全年可减少能耗40%左右,其名义工况下的COP达到国家冷水机组1级能效等级,其IPLV超过8.7。认为其独有的特性将改变部分空调系统的传统设计方法,值得深入研究,磁悬浮离心式冷水机组是一种值得大力推广的高效节能产品。     

磁悬浮变频冷水机组在中央空调系统中的节能分析

简要介绍了磁悬浮冷水机组的工作原理;分析了在不同工况下,不同形式冷水机组的节能效果。通过分析比较,磁悬浮离心式冷水机组具有无油路系统、噪声低、启动电流低、部分负荷时有着较高的综合部分负荷性能系数(IPLV)以及节能环保等特点。通过工程实例对其进行了经济性分析,计算结果表明,磁悬浮变频离心式冷水机组与定频离心式冷水机组相比,全年可降低能耗32%左右,大大降低了中央空调系统的全年运行费用,在建筑节能减排方面有着显著的效果。     

冷水机组季节性能评价新指标SPLV和IPLV的比较

基于"性能指标应等于季节总制冷量与总耗电量之比"的物理意义提出了季节部分负荷性能系数SPLV新指标。就SPLV和IPLV的公式形式、指标大小以及在典型性能曲线中的应用三个方面对二者的区别与联系进行分析,得出结论:SPLV与IPLV采用相同的构成要素,但二者的公式形式和量纲不同;对同一机组而言,IPLV≥SPLV,且各部分负荷工况点的性能系数COPc差别越大,其IPLV相对SPLV偏差也越大。     

一种冷水机组季节性能评价新指标与多台机组联合运行性能评价

综合部分负荷性能系数IPLV是评价冷水机组季节运行性能的重要指标,但在对其合理性的评价上存在诸多争议。从季节性能评价指标的物理本质出发,构建了描述单台冷水机组性能的季节部分负荷性能系数SPLV指标;基于SPLV的评价思想,提出了描述多台冷水机组联合运行时的季节部分负荷性能系数SPLV(N)的计算方法和测试工况,并应用SPLV(N)对不同类型冷水机组进行了性能评价。结果表明,所构建的SPLV指标可以更为真实地反映冷水机组的季节运行性能;SPLV(N)的大小与冷水机组的性能曲线形状有很大关系,不同类型的机组各有其适宜的应用形式。     

北方地区多联式空调机组IPLV(C)试验研究

以一拖四多联式空调系统为例,通过空调系统焓差试验性能测试,将空调系统末端各负荷比例分别调整为100%、(75±10)%、(50±10)%和(25±10)%四种情况,控制机组室外机的变频压缩机及定频压缩机启停,调节变频压缩机的工作频率、风扇电机的转动速度,测定分析多联式空调系统最佳的EER值,获得理想的制冷性能系数IPLV(C)值为4.160 3,为后续的变更程序设计思想和参数设定提供了试验依据。试验过程中,尽管有个别数据偏差较大,但从数据变化曲线上看,基本上可以反映出系统的运行规律。     

关于冷水机组综合部分负荷系数的研究

讨论了IPLV所适用的场合,通过阅读大量文献,作者认为IPLV更适合单台机组运行状况的评估。探讨了IPLV是否能够估算冷水机组全年的能耗。以北京某医院2013年的全年耗电量为依据,验证了现有通用公式的权重系数,发现比实际数据大34.5%。查看相关文献,以寒冷地区气候数据作为气象参数,本项目冷水机组数据作为建筑负荷数,重新计算公式的权重系数,得到的最后结果比原结果更加接近实际数据,提高约10%左右。     

冷水机组节能驱动与控制系统的选择与计算（三）

本文提出一种在工程设计中能快速列表计算、具有几种不同节能驱动与控制系统的冷水机组的综合部分负荷性能系数LPLV的方法。这些部基于LPLV的标准公式和它们的特性曲线族图表。比较它们的IPLV的计算结果的大小,即能选择高效驱动节能控制系统。关键词冷水机组ARI标准国家标准综合部分负荷性能系数性能系数能效比能耗比驱动特性曲线族图表变频驱动恒速驱动节能驱动与控制系统     

地板供暖用空气源热泵产品标准关键问题研究

以空气源热泵为热源设备、辐射地板为末端的供暖系统广泛应用于我国大部分气候区的农村与城镇住宅、办公等建筑中,而用于该类供暖系统的空气源热泵机组尚无统一的产品标准。针对不同气候区的供暖需求,通过分析,给出了典型地区典型建筑的负荷模型、不同负荷率下空气源热泵使用侧的供水温度和制热运行时的室外工况条件;根据空气源热泵实测数据,建立了性能模型,分析所提出的该类空气源热泵机组的名义工况、季节性能评价工况,以及名义工况性能系数COPh与综合部分负荷性能系数IPLV(H)限定值,可为产品标准制定提供参考。     

现行国标中冷水机组IPLV定义式的错误剖析

在分析GB/T18430.11-2007、GB50189-2005以及相关研究文献的基础上,指出我国关于冷水机组综合部分负荷性能系数IPLV的定义无论是表达形式还是其4个权重系数都是错误的。以现有文献资料数据为案例,给出了正确构建IPLV表达式的方法。     

基于k-means聚类的地源热泵机组运行策略优化研究

以上海某地源热泵为研究对象,基于长期实测数据对全年工况性能特性进行了研究。通过k-means对全年工况的日逐时负荷进行聚类分析,获得采暖、制冷和过渡季节等不同季节最佳族数及对应族下典型日负荷曲线特性。构建地源机组的性能仿真模型,通过实测数据获得模型相关参数值。分别以最优制热制冷性能系数为目标,建立了运行负荷配比优化模型,并将模型应用于上述不同季节典型工况,对各典型工况下的运行策略进行优化,获得各工况下最优运行策略。通过与实测数据的对比,运行策略优化有效提高了热泵系统的能效。     

冷水机组综合部分负荷性能指标与能耗计算

探讨了ARI标准550／590-2003中综合部分负荷性能系数的含义及其与季节能效比的关系,认为季节能效比能更全面地反映冷水机组的季节或全年平均能源利用效率。给出了一个简单实用的全年能耗计算公式和一个基于全年能耗的部分负荷性能指标。     

Thermodynamic perfectibility based analysis of energy-efficiency standards for air conditioning products in China

There are presently different types of air conditioning products in China such as room air conditioners, variable speed room air conditioners, unity air conditioners, multi-connected air-condition (heat pump) unit, chilled water air conditioning systems. For these air conditioning products, evaluation indexes have been created, respectively including energy efficiency ratio (EER), coefficient of performance (COP), seasonal energy efficiency ratio (SEER) and integrated part load value (IPLV), and their energy efficiency standards have been established. Based on thermodynamic perfectibility, this paper makes the compatible analysis of the energy efficiency and thermodynamic perfectibility gradient of energy efficiency standards for different air conditioning products. According to testing conditions of evaluation indexes, these air conditioning products are classified into two groups, the standard rating conditions group (EER, COP) and the variable working condition group (SEER, IPLV). The results show the thermodynamic perfectibility of different air conditioning products grade as the same level for energy efficiency standards in each group differ from one another. Besides, the average thermodynamic perfectibility gradient of energy efficiency levels for air conditioning product in the standard rating conditions group is basically the same, and that of variable speed room air conditioners and multi-connected air-condition (heat pump) unit are the highest and lowest, respectively.     

An alternative approach for the performance rating of air-cooled chillers used in air-conditioned buildings

Air-cooled chillers are widely used to provide cooling energy for air-conditioned buildings at the expense of considerable electricity. The (Air-Conditioning & Refrigeration Institute) ARI standard 550/590 sets out a rating condition to specify the coefficient of performance (COP) of the chillers under part-load conditions. This condition was found to be insufficient to deal with diverse operating conditions under the multiple chiller arrangement. This paper proposes an alternative approach to specifying more precisely the chiller COP under part-load conditions. It is desirable to establish a set of part-load performance curves showing how the chiller COP varies with the condensing temperature at various combinations of chiller loads and outdoor temperatures. The results of this paper will give engineers and researchers a better idea about how to specify the upper limit of condensing temperature for more energy efficient chillers and how chiller COP curves help compare air-cooled chillers for buildings in any climate zone and to estimate the annual electricity consumption of chillers satisfying any given building cooling load profile.     

Effects of hydrocarbon fuel extracted from waste transformer oil on a DI diesel engine

In this study, hydrocarbon fuel (HCF) was derived from waste transformer oil through a traditional base-catalysed trans-esterification process. The experimental investigations using its blends of 25%, 50%, 75%, 100% and diesel fuel were carried out separately. The HCF obtained from waste transformer oil is used in a direct injection (DI) diesel engine without any engine modification to evaluate its performance, emission and combustion characteristics. The results indicate that the engine operating on test fuel blends shows a marginal increase in brake thermal efficiency (BTE) with a significant reduction in smoke. Nitrous oxides (NO_x) emission was slightly higher for test fuel blends than for diesel. The results show that at maximum load conditions, 25% HCF reduces carbon monoxide, smoke and hydrocarbon emission by 50%, 31% and 10%, respectively, whereas 50% HCF shows a greater BTE than other blends and is 12% higher than that of the diesel fuel. The combustion characteristics of fuel blends closely followed those of standard diesel.     

Experimental investigations on the influence of properties of Calophyllum inophyllum biodiesel on performance,combustion, and emission characteristics of a DI diesel engine

The current state of future energy and environmental crises has revitalised the need to find alternative sources of energy due to escalating oil prices and depleting oil reserves. To meet increasing energy requirements, there has been a growing interest in alternative fuels like biodiesel that can become a suitable diesel fuel substitute for compression ignition engine. Biodiesel offers a very promising alternative to diesel fuel, since they are renewable and have similar properties. Calophyllum inophyllum seed oil collected from different restaurants in the Nagapattinam region of South India was converted into methyl esters (biodiesel) by transesterification. Biodiesel produced from C. inophyllum oil was blended with diesel by different volume proportions (25%, 50%, and 75%). Biodiesel and its blends were tested on a direct injection (DI) diesel engine at a constant speed by varying loads from 0% to 100% in steps of 20% to analyse its performance, emission, and combustion characteristics. The results obtained were compared with that of diesel fuel. B25 (27.5%) showed better performance than diesel fuel (26.28%) at full load and B50 showed performances similar to diesel fuel. Smoke density of B25 was slightly (2.6%) higher than that of diesel at full load conditions. At full load, measured carbon monoxide emissions for B25 and B50 were 4% lower than that of diesel. Hydrocarbon emissions for B25 and B100 were 5.37% and 25.8% higher than that of diesel, respectively. Nitrogen oxides (NO_x) emission was lower for all biodiesel blends. NO_x emissions of B100 and B75 were lower than that of diesel by 22.16% and 13.29% at full load, respectively. Combustion profile was smoother, and no knocking problem was observed while operating with biodiesel blends. B75 produced peak cylinder pressure.     

热泵驱动的双级溶液调湿新风机组原理及性能测试

介绍了一种新型热泵驱动的双级溶液调湿新风机组的工作原理和全年运行方式,重点介绍和分析了该机组主要部件的实测性能数据.测试结果表明,双级溶液全热回收单元的全热回收效率和潜热回收效率分别为55%左右,而新风机组在满负荷工况下整机COP为5.0,部分负荷下可超过5.9,其中的热泵制冷系统在满负荷工况下COP为4.01,部分负荷下可超过5.72,溶液热回收板式换热器的显热回收效率在80%以上.测试分析了机组进行新风处理的整体性能,指出了在再生单元补水的重要性.     

用IPLV/NPLV值评估冷水机组全年能耗的局限性

提出用IPLV/NPLV值评估冷水机组全年能耗在工程应用中存在4方面局限,即IPLV/NPLV计算法则未考虑机组负荷百分比的权重对单台机组全年能耗的影响,不适用于多台冷水机组系统,不能反映多机头机组的真实能效特性,因各地区气象条件不同而不能直接应用于实际项目。认为在工程中应正确理解和应用IPLV/NPLV指标。     

A study on the energy performance of a cooling plant system: Air-conditioning in a semiconductor factory

This paper will focus on the energy performance evaluation of a cooling plant system in a semiconductor factory. Several energy saving technologies namely: integrated cooling towers, free cooling systems, control of the chilled water quantity, etc., have been adopted to improve efficiency of the cooling plant system. We have collected actual operating data for 2 years and evaluated the performance of chillers’ COP and the whole cooling plant system's COP and they showed satisfactory results even if the thermal load of the factory was about half compared with design phase assumption.

We also have verified each effect of the energy saving technologies through model-based simulation analysis. The annual electric power consumption dropped about 35% compared to conventional cooling plant systems in case of design phase thermal load. And the faulty status operation of the chiller's number control miss occurred while we monitored. Electric power consumption increased about 17% compared to normal status operation at the same period.     

冷水机组节能驱动与控制系统的选择与计算（二）

本文提出一种在工程设计中能快速列表计算、具有几种不同节能驱动与控制系统的冷水机组的综合部分负荷性能系数LPLV的方法。这些部基于LPLV的标准公式和它们的特性曲线族图表。比较它们的IPLV的计算结果的大小,即能选择高效驱动节能控制系统。