Estimation of Thermal and Hydraulic Characteristics of Compact Brazed Plate Heat Exchangers
Estimation of Thermal and Hydraulic Characteristics of Compact Brazed Plate Heat Exchangers
复制标题
紧凑型钎焊板式换热器的热和水力特性估算
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
V. Gullapalli
中科院分区：
文献类型：
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作者：
V. Gullapalli
本论文提出了紧凑型钎焊板的各种性能评估方法
单相运行的热交换器 (BPHE)、冷凝器、蒸发器、级联和
跨临界应用。这些方法在换热器的发展中发挥着至关重要的作用
选择软件以及新产品开发中的几何参数估计
过程。
采用商业计算流体力学 (CFD) 代码的适用性
研究了估计单相热力和水力性能。参数研究
对单相流体截面的几何形状进行分离和量化
各个几何参数的影响。网格特性、选择的影响
边界条件和湍流建模对热和温度精度的影响
提出了水力预测。模拟整个通道中流体流动的优点
还提出了不同几何图案的渠道流量特征。
一种计算量轻、通用、鲁棒且连续的评级计算方法是
开发用于在 BPHE 选择软件中实施。基于压力-热函的
方法为各种类型的应用程序提供了通用的评级核心，并提供了广泛的
传热过程的后处理信息。一般单相热电偶
水力经验相关性被开发为板几何参数的函数。
为了促进所开发的计算方法与其他制冷更好的集成
系统仿真软件，子程序中保持一阶或高阶连续性
用于计算局部传热系数和制冷剂特性。一个新的有限
网格插值法是为了快速准确地检索制冷剂特性而开发的。
所开发的方法目前在SSPG7（BPHE选型软件）中实现
SWEP International AB) 用于支持跨临界 CO2 计算和级联热量
交换器计算。
此外，还开发了单相和两相测试数据评估方法
还提出了基于元启发式优化例程。应用及结果
总结了使用开发的评级模型进行各种类型的计算。其他
诸如可变流体特性对 BPHE 额定值计算的影响、
简要介绍了集总 BPHE 额定值计算中的多程流量布置。
This thesis work presents various performance estimation methods of compact brazed plate
heat exchangers (BPHE) operating in single phase, condenser, evaporator, cascaded and
transcritical applications. Such methods play a vital role in development of heat exchanger
selection software and during geometry parameter estimation in the new product development
process.
The suitability of employing commercial computational fluid dynamics (CFD) codes for
estimating single phase thermal and hydraulic performance is investigated. Parametric studies
are conducted on geometries of single phase fluid sections to isolate and quantify the
influence of individual geometric parameters. The influence of mesh characteristics, choice of
boundary conditions and turbulent flow modeling on the accuracy of the thermal and
hydraulic predictions is presented. Benefits of simulation of fluid flow in entire channels and
characteristics of channel flow for different geometric patterns are also presented.
A computationally light, general, robust and continuous rating calculation method is
developed for implementation in BPHE selection software. The pressure-enthalpy based
method provides a generic rating core for various types of applications and provides extensive
post processing information of the heat transfer process. General single phase thermal and
hydraulic empirical correlations are developed as functions of plate geometric parameters.
For facilitating better integration of the developed calculation method with other refrigeration
system simulation software, first or higher order continuity is maintained in the sub-routines
used for calculating local heat transfer coefficients and refrigerant properties. A new finite
grid interpolation method is developed for fast and accurate retrieval of refrigerant properties.
The developed method is currently implemented in SSPG7 (BPHE selection software of
SWEP International AB) for supporting transcritical CO2 calculations and cascaded heat
exchanger calculations.
Additionally, the methods developed for single phase and two phase test data evaluation
based on meta-heuristic optimization routines is also presented. The application and results of
using the developed rating models for various types of calculations is summarized. Other
topics such as influence of variable fluid properties on BPHE rating calculations, influence of
multi-pass flow arrangement on lumped BPHE rating calculations are briefly presented.