Energy performance of a cooling plant system using the inverter chiller for industrial building

The purpose of this paper is to clarify energy performance of the cooling plant system in the industrial building using actual measured operating data and numerical simulation analysis. One aspect of industrial buildings is that they have large energy consumption for manufacturing and air-conditioning compared with office and commercial buildings. Some examples of high-efficiency technologies installed in this particular cooling plant system are inverter chillers, integrated cooling towers and a free-cooling system. The inverter chiller which has been put on the market recently is state-of-the-art technology. The maximum COP of the inverter chiller reaches about 18 under certain conditions and integrated cooling towers make lower temperature cooling water as the whole capacity is large. Actual operating data indicates satisfied values for chiller and system COP during the running period and the simulation results show that the cooling plant system can cut down annual electric power consumption by about 48% compared with conventional cooling system.     

Effects of utilizing seawater as a cooling source system in a commercial complex

This paper treats energy and cost performance of a cooling source system with indirect seawater utilization for air conditioning in a commercial complex. Seawater utilization has merits as a cooling source, because seawater temperature is lower than outdoor air in summer and it is cost effective because there is no water monetary cost. Actual operating data has been measured for about 2 years and the chiller and system co-efficient of performance (COP) have indicated about 4.77 and 2.93, respectively, even in summer season and the mean efficiency of the thermal storage system was about 89.9% taking into account heat loss of pumps. In addition, we have constructed simulation models for cooling tower systems, air cooling chiller systems and direct seawater utilization systems then compared them to this system. The electric power consumption of the indirect seawater utilization system was almost the same as the other systems except the air cooling chiller system, because using lower seawater temperature made the chiller efficiency higher. In conclusion, our results showed the indirect seawater utilization system was able to improve the system COP compared to air cooling chiller system, and cancel water consumption compared with the cooling tower system, and cut down an initial and maintenance costs compared with the direct seawater utilization system.     

Analysis on energy saving potential of integrated supermarket HVAC and refrigeration systems using multiple subcoolers

The paper presents a model-based analysis on the energy saving potential of supermarket HVAC (heating, ventilating, and air-conditioning) and refrigeration systems using multiple subcoolers among the high-temperature HVAC system, the medium-temperature refrigeration system, and the low-temperature refrigeration system. The principle of energy reduction is to have the higher COP (coefficient of performance) system generate more cooling capacity to increase the cooling capacity or reduce the power consumption of the lower COP system. The subcooler could be placed between the medium-temperature and low-temperature systems, between the high-temperature and medium-temperature systems, and between the high-temperature and low-temperature systems. All integration scenarios of adding one, two and three subcoolers have been investigated. The energy saving potential varies with the load ratio between high-, medium- and low-temperature systems, COP of three systems, and the “on-off” duty time of HVAC system. The optimal sequence of adding subcoolers is also proposed.     

我国建筑耗能状况及有效的节能途径

简要分析了我国建筑能源消耗状况,从用能特点出发,对建筑物和建筑用能途径进行了新的分类,给出各类的现状、问题和节能潜力。在此基础上列出为实现建筑节能所需要的主要技术与产品研究领域和政策研究与保障机制。文中列出的关键技术研究为：基于模拟分析的建筑节能优化设计;新型建筑围护结构材料与部品;通风装置与排风热回收装置;热泵技术;降低输配系统能源消耗的技术;集中空调的温度湿度独立控制技术;建筑自动化系统的节能优化控制;楼宇式燃气驱动的热电冷三联供技术;燃煤燃气联合供热和末端调峰技术;节能灯、节能灯具与控制。有关政策与保障机制的研究问题为：建筑能耗数据的统计系统;住宅能耗标识方法与保障机制;大型公共建筑能耗评估与用能配额制;各种建筑用能装置的能耗标识标准与方法。     

某卷烟厂冷水机组运行的性能研究

对某卷烟厂冷水机组运行时进行实验研究,结果表明分别在60%、90%负荷运行时,实际COP值为3.83、4.60,小于该机组的名义工况下5.53的COP值。建议在原空调系统上增加温差控制器和变频器,以控制冷却水泵和冷冻水泵的工作状态,保证该冷水机组的COP在最优化的节能运行状态,从而降低系统的能耗。     

Study on a novel thermally driven air conditioning system with desiccant dehumidification and regenerative evaporative cooling

Existing desiccant cooling systems reduce the temperature of process air either by adopting evaporative coolers or incorporating vapor compression systems. While the former is restricted by inaccurate control, the latter still consumes certain quantity of electric power. To solve this problem, a thermally driven air conditioning system, which combines the technologies of rotary desiccant dehumidification and regenerative evaporative cooling, has been proposed and investigated. In addition to dehumidification, the system is capable of producing chilled water, thereby realizing separate temperature and humidity control without increasing electrical load. To find out the characteristics of produced chilled water and evaluate the feasibility and energy saving potential of this novel system, a mathematical model has been developed. Case studies have been conducted under Air conditioning and Refrigeration Institute (ARI) summer, ARI humid and Shanghai summer conditions. It is found that the system can achieve a thermal COP higher than 1.0 and an electric COP about 8.0. The temperature of chilled water produced by the system is around 14–20 °C. This chilled water can be used with capillary tube mats for radiant cooling. It is suggested that the system can also be designed as a standalone chilled water plant. As a desiccant dehumidification-based chilled water producing technology, this would expand desiccant cooling to a boarder niche application. The effects of chilled water flow rate, air distribution ratio, inlet air conditions and regeneration temperature have been analyzed in detail. Reachable handling regions, which will be helpful to system design and optimization, have been obtained.     

北京某商业建筑温湿度独立控制空调系统的全年能耗分析

以北京某一商业建筑为模拟对象,对其空调冷负荷进行模拟,并在此基础上计算普通空调系统和温湿度独立控制空调系统的能耗.经过对能耗的比较和分析表明,温湿度独立控制空调系统的能耗比普通空调系统的能耗降低了16.4%,冷水机组全年平均性能系数提高了13%.结果表明温湿度独立控制空调系统具有很好的应用前景.     

化纤厂空冷站和空压站的运行管理节能

介绍了化纤厂空冷站和空压站的运行管理节能的一些经验，提出了两套节能方案，并在实际的应用中取得了良好的效果，节约了大量的能耗，同时还解决了生产中的一些相关问题。     

某大型空调系统能耗分析

能源问题是决定我国能否可持续发展的关键因素之一。对某大型空调系统能耗进行了测试和分析，表明冷机实际COP低于其额定COP，并且空调箱能耗占到30％-50％；另外，对系统的负荷分析表明，造成系统的供需比下降的主要原因是该系统设计本身所造成。因此，对空调系统优化运行是节能改造必不可少的一个环节；同时，如何优化空调系统各级的设定参数以及系统的划分，将会从根本上提高系统冷负荷的供需比，从而大大减少系统能耗，可为大型空调系统的运行人员、设计人员提供参考。     

新型节能墙体传热研究

建筑墙体负荷计算是建筑能源系统设计的基本依据，也是建筑能耗分析和能源管理的基础。根据反应系数法编程计算，得到适合工程技术应用的新型节能墙体冷负荷温度计算用表和动态传热特性基础数据，从而将节能建筑墙体改革成果应用于空调冷负荷计算，并为建筑新型节能墙体热工性能的深入研究和综合性能评价提供参考依据。     

冬季冷却塔供冷系统在长沙卷烟厂的节能应用

本文通过对长沙卷烟厂生产车间冬季和过渡季节的供冷需求和长沙室外气象条件的分析,提出在冬季和过渡季节,采用冷却塔对产热量较大的卷烟生产车间进行供冷,可实现冷冻站节能运行的目的。本文结合长沙卷烟厂的运行实践,对冬季或过渡季节冷却塔供冷的系统设计、热工性能、全年运行时间、节能效果以及投资回收期进行了计算和分析。     

集中空调冷却水变流量问题辨析

指出集中空调冷却水系统为开式系统,一般不适用功率三次方定律,静压头应为冷却塔塔体扬程,并提出了冷却水泵变速时轴功率的计算公式;明确变流量的节能效果与控制方式密切相关,即使机组处于满负荷状态,但只要是在非设计工况,采用冷凝温度控制法,也可能实现变流量节能;指出制定多台冷水机组部分负荷性能指标的意义。     

夏季湿热地区置换通风和冷却顶板复合系统节能潜力研究

根据上海一办公楼置换通风和冷却顶板复合系统的设计及运行特点,应用EnergyPlus软件模拟了采用转轮除湿方式的复合系统的供冷季能耗,并分别模拟了采用冷却除湿方式的复合系统、带热回收装置的混合通风系统和置换通风系统的供冷季能耗以进行对比。结果表明,在湿热地区采用转轮除湿方式可比冷却除湿方式节约制冷机冷量,空调季总能源费用比混合通风系统节约30%左右。     

Performance analysis of liquid desiccant based air-conditioning system under variable fresh air ratios

In conventional air-conditioning system, fresh air volume is always restricted to save energy, which sacrifices indoor air quality (IAQ) to some extent. However, removing the latent load of air by liquid desiccant rather than by cooling is an alternative way of reducing energy consumption. Therefore, IAQ can be improved by increasing the volume of fresh air introduced into an air-conditioning system. In this paper, a liquid desiccant based air-conditioning system is studied, with the system performance under various fresh air ratios analyzed using simulation tests. In addition, the proposed system and a conventional system are compared. In the proposed system, with the increase in fresh air ratio, the heating load for solution regeneration rises, the dehumidification efficiency increases and the regeneration efficiency drops. The coefficient of performance (COP) of the liquid desiccant based system decreases sharply when the fresh air ratio exceeds 60%. The results also show that the proposed system can save power notably. The maximum power saving ratio is 58.9% when the fresh air ratio is 20%; however, the ratio drops when the fresh air ratio increases. These findings will be beneficial in the selection of fresh air ventilation strategies for liquid desiccant based air-conditioning systems.     

冷却塔风机运行节能之模式与策略的分析

冷却塔风机是整个冷却水系统的核心设备,其运行状况直接关系到系统性能与能耗状况.本文针对国内某办公建筑的冷却塔风机运行状况进行实测,从风机与变频器电耗、冷却塔效率、冷机COP,设备寿命与运行策略的可行性4个方面分析评价了风机运行模式和策略对能耗的影响.     

中国被动房外围护系统研究——以寒冷、严寒气候区被动房项目为例

德国的被动房是目前世界公认的具有超低能耗、超低碳排放量、超高室内舒适度等特点的建筑技术体系。德国的气候特征与中国华北地区的气候特征具有相似性,因此,研究并建造被动房对于我国建筑节能工作的发展具有重大的意义。外围护系统作为被动房设计的重点要素,对建筑的节能效率有重大的影响。以寒冷、严寒气候区的被动房项目为例,对被动房外围护系统进行分析与阐述,并以秦皇岛"在水一方"被动式住宅示范项目为例,进行能耗模拟与对比分析。提出适合我国寒冷、严寒气候区气候特点的被动式超低能耗建筑外围护系统的设计策略。     

企业自备热电厂的节能性分析

以余姚市某化纤企业自备热电厂热电联产系统为研究对象,对其热、电负荷做了计算,同时用标准煤耗量和总热效率2个指标对系统进行节能性分析。分析结果表明:热电联产系统节能性要优于分产系统,实施热电联产后全厂总热效率提高27.3%,在企业年生产总量不变的条件下,年节约标准煤18125.55t,极大地节约运行成本。文章最后还指出该系统在夏季运行时热负荷减少导致发电量减少,并提出将系统改进为热电冷联产系统的建议。实行热电冷联产后,系统总热效率较原来夏季热电联产系统总热效率提高24.7%,系统节能性进一步提高。     

多台不同冷量冷水机组并联节能运行及控制

针对多台不同制冷量冷水机组并联运行的情况,分析了影响系统能耗的各因素,结合实例对比了不同运行方案的能耗,提出了制定节能运行方案的方法。对冷水机组群控的逻辑判据进行分析,从兼顾节能效果和设备使用寿命的角度,提出了将节能运行方案与负荷变化趋势预测相结合的群控策略。     

热电冷联产系统节能效益分析

分别以热电冷联产系统的燃料节约量、当量热力系数及热电冷联产系统的供电煤耗作为评价标准,对热电冷联产系统的节能效益进行了分析与研究,并提出了临界供电煤耗概念,作为判断在热电冷联产系统中节能的条件。     

海南某数据中心空调系统设计

结合项目当地具体气候条件,综合对比多种空调系统方案,从节能效果、初投资、运行费用等各方面计算分析,找到适合本项目的 空调系统节能设计.空调设计从系统架构特点出发,利用备用机组的制冷能力,结合磁悬浮机组部分负荷效率高的优点,实际运行时冷水机组全部运行,主机负载率为70％～80％,磁悬浮主机的COP可达15以上,配合冷却塔...