蒸发式风冷冷水机组年运行节能潜力研究

介绍了蒸发式风冷冷水机组的能耗模型,通过选取具有代表性城市的全年气象参数,分析了蒸发式风冷冷水机组在不同气候条件、不同直接蒸发冷却器填料厚度、不同运行风速下的年运行节能潜力,获得了一些具有参考价值的分析数据,为蒸发式风冷冷水机组的节能设计和推广使用提供了参考数据。     

磁悬浮冷水机组优化运行调节策略节能运行工程案例研究

以某科研楼磁悬浮冷水机组供冷系统实际工程为例,对磁悬浮冷水机组的应用特点,特别是通过优化运行调节策略实现高效节能运行的方法进行研究。通过分析运行过程中存在的问题,研究节能优化运行策略,进行运行调适优化。经连续监测发现,与原运行模式相比,调适优化后系统4月至11月中旬运行节约电量13.0万kW·h,预计全年运行节约电量23.7万kW·h。如能进一步给冷却塔安装变频器和更新优化控制策略,则全年运行还存在节能潜力。     

风冷螺杆冷水机组的发展现状

从可靠性、节能性、环保性和耐候性等四个方面，介绍当前风冷螺杆冷水机产品的技术特点。     

冷水机组的优化运行

针对冷水温度、冷却水温度及机组启停控制等影响冷水机组运行的主要因素进行了分析，指出适当提高冷水出口温度和(或)降低冷却水出口温度，采用智能调节策略对多台制冷机和水泵的启动顺序进行合理调配，采用BP网络预测最小预热(冷)期和最长提前停机时间对压缩机进行最优启停控制等，都可以降低系统能耗。     

多台冷水机组的优化配置与节能运行研究

本文针对公共建筑中的空调能耗,尤其是冷水机组能耗过大的问题,建立了多台冷水机组配置模型及优化目标.以某办公建筑为例,分析了不同运行策略下多台冷水机组运行时的能耗,同时对不同策略和配置情况下的运行情况进行了经济性比较.分析可知,当选用多台机组时,平均分配负荷的运行策略比较节能,节能效果视组合方式的不同而不同,其中容量相同的组合方式采用该运行策略优势最为明显.     

基于遗传算法的冷水机组运行优化策略研究

本文通过采用回归方法获得冷水机组性能系数(COP)与部分负荷率(PLR)的关系,并建立各台冷水机组能耗方程,利用遗传算法求解其最小值,从而获得各冷水机组所承担的最优负荷比率,同时根据某一实际建筑计算了其全年的冷负荷率时间分布情况,在此基础对系统冷水机组全年的运行情况进行了优化,从而达到5.7%的节能效果。     

模块式和离心式冷水机组匹配运行的节能分析

空调设备运行方式的优化也是降低能耗的重要途径之一。经冷水机组性能分析,模块式冷水机组会根据所需负荷的变化关闭或开启部分压缩机,保持高效率的运行。     

冷水机组联合运行策略仿真与分析

在空调系统的能耗中,冷水机组运行产生的能耗占很大的比例。多台冷水机组联合运行时,存在多种运行策略。当根据负荷控制冷水机组的运行时,负荷控制点大小的确定及不同的运行策略会对总能耗造成影响。探讨了冷水机组性能系数和综合部分负荷性能系数分析在冷水机组联合运行策略中的不足,对某建筑空调冷冻水系统冷水机组提出不同运行策略,并采用TRNSYS仿真软件进行仿真,对仿真结果进行了对比分析,得出冷水机组全年优化运行策略,以降低运行能耗。     

冷水机组的优化群控节能分析

本文对中央空调系统的冷水机组的优化群控节能做了概要性介绍,特别对容量冗余的精细设计、提高控制精度实施节能的内容以及大群控和小群控的结合方面做了较为深入的分析.通过冷水机组的优化群控,可以实现较好的节能效果.     

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。     

风冷冷水机组在工程中的应用及应注意的问题

简要介绍了风冷冷水机组在某工程中的应用，结合设计经验分析了风冷冷水机组噪声，等。     

Part load performance of air-cooled centrifugal chillers with variable speed condenser fan control

Air-cooled centrifugal chillers are commonly used in commercial buildings but their performance analysis is lacking. This paper investigates the part load performance of the chillers via a thermodynamic model. The model was validated using a wide range of operating data from an existing chiller with specific settings of outdoor temperature and condensing pressure in controlling the condensing temperature. The validated model was developed specifically to ascertain the maximum coefficient of performance of chiller (COP) together with the strategy for optimizing the condensing temperature under various operating conditions. It is found that the highest COP occurs at a part load ratio (PLR) of 0.71–0.84, depending on the outdoor temperature and the control of condensing temperature, rather than at full load. Yet the chillers operating at such part load conditions will cause extra energy used for the early staging of chilled water pumps. To minimize the overall chiller plant energy consumption, it is still preferable to implement chiller sequencing based on the full load condition than on the aforementioned PLRs. The results of this paper present criteria for implementing low-energy strategies for operating air-cooled chillers satisfying a given building cooling load profile.     

三效溴化锂吸收式制冷机研制及变工况分析

介绍了几种三效溴化锂吸收式制冷循环，并利用计算机对其模拟优化、认为双冷凝器耦合的串联和并联（ＤＣＣＳＡ、ＤＣＣＰ）循环比较适合我国国情；研制了三效机样机，分析了机组变工况运行数据，较为详细地阐述了ＤＣＣＳＡ和ＤＣＣＰ循环特性，指出它们与双效机在设计、运行、控制方面的差异。     

Life cycle analysis of enhanced condenser features for air-cooled chillers serving air-conditioned buildings

Air-cooled chillers are commonly used to provide cooling energy for air-conditioned buildings at the expense of considerable electricity. This paper examines the life cycle electricity cost of these chillers with the improved condenser features of condensing temperature control (CTC), evaporative pre-coolers (EC) and variable speed condenser fans (VSF). A validated model for an air-cooled screw chiller was used to ascertain how the individual and mixed features influence the annual electricity consumption of chillers in various operating conditions. It is estimated that the life cycle electricity cost savings range from HK$ 2,099,742 with EC to HK$ 6,399,564 with all the three features, with regard to a chiller plant serving an office building for 15 yr. The life cycle analysis reported here provides important insights into how to reap the benefits of energy efficient technologies for air-cooled chillers.     

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.     

联合运行冷水机组负荷优化分配及仿真研究

根据冷水机组的性能系数与其部分负荷率相关的特性,提出一种基于最小能耗的联合运行冷水机组负荷优化分配方法,从而获得最佳的机组负荷分配率和性能系数。对该负荷优化分配方法进行了MATLAB仿真。仿真结果表明,该控制策略能够优化机组的运行,减少系统能耗。     

空冷配电间降温通风设备选型优化

简要介绍了空冷配电间的特点。结合工程实例,利用CFD技术对采用蒸发冷却降温机组时空冷配电间的室内环境进行了模拟分析,认为其完全满足室内运行要求。通过与常规方案进行技术经济比较,认为在今后空冷配电间设计中,应依据具体工程实际采用适合的蒸发冷却降温机组,以达到节能、经济的目的。     

变频冷水机组部分负荷下冷却水定变流量性能研究

冷水机组大部分时间是在部分负荷下运行,而变频技术的发展使得变频压缩机和变频水泵越来越多地应用到制冷空调当中。本文针对制冷循环各部件建立了稳态模型,并在模型中引入RKS方程精确计算制冷剂的热物性。模拟结果表明:变频冷水机组在部分负荷下运行,定、变冷却水流量对机组蒸发温度影响不大,但冷凝温度有不同程度的降低。同时,考察定、变冷却水流量是否节能应着重考虑冷却水系统能耗在机组总能耗中所占的比例,冷却水系统能耗比例越大,变流量节能效果越明显。     

水平荷载作用下复合地基的设计参数优化

用有限元方法建立了复合地基刚性桩在水平荷载作用下的三维有限元模型，以桩的最大拉应变为目标函数，采用零阶优化法，定量地分析了各种因素影响下单桩复合地基的最优设计。