塑料换热技术在溴化锂吸收式制冷机上的应用展望

溴化锂吸收式制冷机在工业中有着广泛的应用,但换热装置腐蚀及其引起的冷量衰减一直以来是人们难以解决的问题.根据现有的溴化锂吸收式制冷机组的性能,结合塑料换热装置的一些特点,提出了采用塑料换热装置代替金属换热装置来解决溴化锂吸收式制冷机的这个难题;并以研制一台制冷量为3.49×104W的溴化锂吸收式制冷机组为例,对塑料换热装置的溴化锂吸收式制冷机组与传统金属溴化锂吸收式制冷机组相关部件的参数进行比较.通过对溴化锂吸收式制冷机组的传热面积、管道阻力的计算和安全强度的校核,发现塑料换热装置应用在溴化锂吸收式制冷机上是可行的,塑料换热技术在溴化锂吸收式制冷机上有着较好的应用前景.     

冷水机组的防冻技术研究

分别从水侧和制冷剂侧分析了冷水机组的防冻方法和原理,水侧防冻主要是从水流量和水温方面进行控制,制冷剂侧防冻主要是控制蒸发器内的制冷剂压力,从安装、维护和成本进行比较,冷水机组的防冻更倾向于从水侧防冻。从水侧进行防冻时,不同的蒸发器根据其特点采用不同的方法,干式蒸发器可仅从水温进行防冻;满液式和板式蒸发器需从水流量和水温两方面进行防冻保护,同时,板式蒸发器还需在进水管增加水过滤器;多个蒸发器并联时,可在每个蒸发器增加水流量和水温检测,也可在最不利环路采用流量开关和温度控制器并在总出水管增加流量开关的方法进行防冻。     

Decentralised cooling in district heating network: Monitoring results and calibration of simulation model

This article presents the monitoring results of a thermally driven chiller (TDC) driven by district heat from a network supplied by a centralised combined heat and power (CHP) fired with municipal waste. The main objective of this article is to analyse the monitoring results obtained from the demonstration and calibrate a system model that is later used for parametric studies in order to find improved system design and control. The calibration of the system model was made in three stages and all the energy performance figures were within 4% of the measured values. Results show that the TDC system is capable of providing maximum thermal and electrical COP's of 0.50 and 4.6 respectively during the hottest period. For the complete monitoring period during the summer of 2008, the figures were 0.41 and 2.1. The lower figures were due to continuous pump operation inside the TDC even during periods of no cold production and a period when no cold was produced. However the internal pumps inside the TDC have been removed in the new version TDC to increase the electrical COP. System simulation and parametric studies will be employed to further determine how the electrical COP can be improved.     

采用系统法选择高效离心式冷水机组

离心式冷水机组能效越高，价格越高，主张选用高能效制冷机，但也反对盲目追求高能效，介绍了一种结合中国当前经济发展水平，。采用系统法选用高效离心式制冷机的方法与实例，供广大空调设计者与业主参考。     

Thermodynamic-behaviour model for air-cooled screw chillers with a variable set-point condensing temperature

This paper presents a thermodynamic model to evaluate the coefficient of performance (COP) of an air-cooled screw chiller under various operating conditions. The model accounts for the real process phenomena, including the capacity control of screw compressors and variations in the heat-transfer coefficients of an evaporator and a condenser at part load. It also contains an algorithm to determine how the condenser fans are staged in response to a set-point condensing temperature. The model parameters are identified, based on the performance data of chiller specifications. The chiller model is validated using a wide range of operating data of an air-cooled screw chiller. The difference between the measured and modelled COPs is within ±10% for 86% of the data points. The chiller’s COP can increase by up to 115% when the set-point condensing temperature is adjusted, based on any given outdoor temperature. Having identified the variation in the chiller’s COP, a suitable strategy is proposed for air-cooled screw chillers to operate at maximum efficiency as much as possible when they have to satisfy a building’s cooling-load.     

An integrated model for the design of air-cooled chiller plants for commercial buildings

Cooling load calculation is the first step in designing the air-conditioning system of a building. The calculated cooling capacity with appropriate buffer is then used to select the number and size of chillers in the system. N + 1 is a common formula used by designers to size the chiller plants in Hong Kong buildings, where N is the actual number of chillers required and 1 is a redundant chiller provided to ensure reliability. This paper reviews the problem of excess capacity and discusses the risk exposure of chiller systems without redundant chillers. The cooling load profiles of the chiller plants of four medium-sized commercial buildings in Hong Kong are reviewed. The risk exposure of chiller systems without redundant chillers can be minimized by applying risk-based preventive maintenance. The just-in-demand design reduces capital cost of the building and frees up funds for continuous energy measurement and improving the energy efficiency of chiller plant systems. This paper presents a model for designing chiller plants that improves the energy efficiency of the plant in a cost effective and thoughtful manner. It is designed with consideration of the life cycle of the plant and real-time continuous commissioning, monitoring, measurement, comparison and execution for better energy management.     

工业建筑空调节能改造方案设计

借鉴当前的研究成果,将模拟技术应用到工业建筑空调节能改造方案的设计中,设计了基于模拟技术的工业建筑空调节能改造方案,并对设计方案进行测试与验证。基于模拟技术构建工业建筑空调模型,首先获取工业建筑空调的特征,根据其特征构建一种模拟稳态模型。通过构建模型,发现当前工业建筑空调冷机存在换热器脏堵、负荷率低等问题。基于此设计了冷机的节能改造方案。为使能够更加高效、安全地运行,以及使其整体不平衡率更低,对水系统实施节能改造。对于空调与通风系统,制定了一系列空调机组、通风系统、风量分配和气流组织、末端与室内温湿度调节的相关节能改造方案。分别在实施该方案前后对实验工业建筑空调进行能效测试,对比前后测试结果,发现设计方案能够明显提升工业建筑空调的运行能效,大幅降低了工业建筑空调的耗能量,说明设计方案能够起到显著作用。     

冰蓄冷系统中的两种运行模式

介绍了冰蓄冷空调系统中冷水机组优先和冰优先的两种运行模式及其两种运行模式制冷机组的选择方法和储水量的计算方法,以及冰蓄冷系统的配置。     

大型冷水机组在地源／污水源／海（江、河）水热泵系统中的应用

介绍大型冷水机组在地源／污水源／海（江、河）水热泵系统中应用的特点、供冷与供热运行模式转换,以及冷水机组串联逆向流系统设计特点,通过3个工程实例,说明其在节省系统运行费用和初投资方面的优势。     

溴化锂吸收式制冷技术在余热回收中的研究

本文对溴化锂吸收式制冷技术在燃汽轮机电站空气冷却和柴油机排气的余热利用等节能方面的应用进行了研究。