Dynamic Analysis of Cross Flow Heat Exchangers in Data Centers Using Transient Effectiveness Method
Dynamic Analysis of Cross Flow Heat Exchangers in Data Centers Using Transient Effectiveness Method
复制标题
使用瞬态有效性方法对数据中心错流换热器进行动态分析
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
R. Schmidt
中科院分区：
文献类型：
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作者：
Tianyi Gao;B. Sammakia;J. Geer;A. Ortega;R. Schmidt
热交换器是数据中心冷却系统中的重要设备。热交换器的有效性对冷却系统的热性能有很大的影响。后门热交换器、排式冷却器、顶置冷却器和全封闭机柜是数据中心中使用的液体和混合冷却系统的一些示例。液对液热交换器是冷却剂分配装置的重要组成部分，它向上述热交换器提供冷冻水。计算机房空气处理装置通常也是液体到空气的交叉流热交换器。表征这些热交换器的动态行为对于数据中心的热管理，改进控制策略的设计和能源效率是非常重要的。研究了具有有限壁容的二维非混合-非混合交叉流换热器的瞬态响应。采用瞬态效率的概念建立数学模型，用于求解和分析涉及交叉流换热器的瞬态问题。数值研究了最小容量速率流体入口温度阶跃、斜坡和指数变化的几种瞬态情况，以及热流体和冷流体流量的阶跃和斜坡变化。在参数研究中测试了瞬态有效性特性。结果表明，瞬态效率是分析和预测交叉流换热器动态性能的有效方法。
Heat exchangers are important facilities used in data center cooling systems. The effectiveness of heat exchangers strongly influences the thermal performance of cooling systems. Rear door heat exchangers, in-row, overhead coolers, and fully contained cabinets are some examples of executing liquid and hybrid cooling systems used in data centers. A liquid to liquid heat exchanger is an important component of the coolant distribution unit, which supplies chilled water to the aforementioned heat exchangers. Computer room air handler units are also typically liquid to air cross flow heat exchangers. It is important to characterize the dynamic behavior of these heat exchangers for the thermal management of data centers, to improve the design of control strategies, and energy efficiency. The transient response of a 2-D unmixed-unmixed cross flow heat exchanger, with a finite wall capacitance, is investigated. The transient effectiveness concept is used to build the mathematical models that will be used to solve and analyze the transient problems involving cross flow heat exchangers. Several transient cases are investigated numerically for step, ramp, and exponential variations in the inlet temperature of the minimum capacity rate fluid, as well as step and ramp changes in the flow rate of hot and cold fluids. The transient effectiveness characteristics are tested in parametric studies. The results obtained show that transient effectiveness is a useful method of analyzing and predicting the dynamic performance of cross flow heat exchangers.