Virtual sensing method for leakage fault of heat exchanger

doi:10.11949/0438-1157.20221687

Abstract

Abstract:

The nuclear power industry is becoming more complex in terms of process. However, the safety monitoring of the shell and tube heat exchanger equipment in the power station still remains in the direct monitoring and indirect characterization of the performance parameters, and it is difficult to achieve accurate fault diagnosis and early warning. In this paper, a virtual sensing method for leakage fault of shell and tube heat exchanger is proposed. Firstly, by analyzing the leakage mechanism of shell and tube heat exchanger and the influence of leakage on performance indexes and monitoring parameters, a virtual sensing reasoning model for two working conditions of heat exchanger leakage and flange leakage is constructed. The model can not only judge the leakage state and leakage category, but also realize direct characterization of performance parameters. In order to verify the proposed model, a leakage fault test rig of shell and tube heat exchanger is built. The results show that the model can diagnose the leakage with a leakage rate of 1.8%, and its diagnosis error is no more than 11.32% for different working conditions, with high accuracy and reliability.

Key words: heat exchanger, leakage, virtual sensing, condition monitoring, fault diagnosis

摘要：

核电行业工艺复杂程度与日俱增，而电站热交换器设备的安全监测仍停留在对性能参数的直接监测和间接表征，难以实现故障的准确诊断与预警。提出了一种热交换器泄漏故障虚拟感知方法，首先通过分析热交换器的泄漏机理及泄漏对性能指标和监测参数的影响规律，构建了针对换热管泄漏和法兰泄漏两种工况的虚拟传感推理模型，不仅能对泄漏状态、泄漏类型进行判断，还能实现对泄漏量的虚拟感知和对性能参数的直接表征。为了验证所提模型，搭建了热交换器泄漏故障实验装置，结果表明，该模型能够诊断出泄漏率1.80%的小泄漏量，对于不同的工况，其诊断误差不超过11.32%，具有较高的准确性和可靠性。

关键词: 热交换器, 泄漏, 虚拟传感, 状态监测, 故障诊断

CLC Number:

TK 172

Qian MING, Yi GAO, Jian HU, Shengjie LI, Jinjiang WANG. Virtual sensing method for leakage fault of heat exchanger[J]. CIESC Journal, 2023, 74(4): 1836-1846.

明迁, 高逸, 胡剑, 李盛杰, 王金江. 热交换器泄漏故障虚拟感知方法研究[J]. 化工学报, 2023, 74(4): 1836-1846.

Figures/Tables 14

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参数	仪表	误差
流量	罗茨流量计	0.01~0.5 m³/s:±2.0%FS（FS，Full-scale，仪表量程）
		0.5~0.1 m³/s:±1.5%FS
		0.1~10 m³/s:±2.5%FS
温度	铂电阻温度计	±0.5℃
压差	CYG5000压力变送器	±0.25%FS

参数	仪表	误差
流量	罗茨流量计	0.01~0.5 m³/s:±2.0%FS（FS，Full-scale，仪表量程）
		0.5~0.1 m³/s:±1.5%FS
		0.1~10 m³/s:±2.5%FS
温度	铂电阻温度计	±0.5℃
压差	CYG5000压力变送器	±0.25%FS

序号	实验内容	实验对象	工况条件	说明
1	热交换器运行状态监测模块的测试验证	热交换器	不同温度、压力、流量工况条件	模拟正常运行工况，考察模型能否根据测得的温度、压力、流量等运行参数获得设备实时换热性能
2	热交换器性能监测模块对泄漏过程监测的实验验证数据	热交换器	不同压力、流量和泄漏率工况条件	模拟热交换器发生不同程度泄漏时的工况，考察模型的敏感程度，验证模型中泄漏程度与进出口压力、温度等参数的变化关系，评价模型对泄漏感知的灵敏度以及对泄漏量计算的准确度

序号	实验内容	实验对象	工况条件	说明
1	热交换器运行状态监测模块的测试验证	热交换器	不同温度、压力、流量工况条件	模拟正常运行工况，考察模型能否根据测得的温度、压力、流量等运行参数获得设备实时换热性能
2	热交换器性能监测模块对泄漏过程监测的实验验证数据	热交换器	不同压力、流量和泄漏率工况条件	模拟热交换器发生不同程度泄漏时的工况，考察模型的敏感程度，验证模型中泄漏程度与进出口压力、温度等参数的变化关系，评价模型对泄漏感知的灵敏度以及对泄漏量计算的准确度

工况	热侧进口温度/℃	冷侧进口温度/℃	热侧进口压力/MPa	冷侧进口压力/MPa	热侧流量/(m³/h)	冷侧流量/(m³/h)	管程介质	壳程介质	介质内泄泄漏量/%	法兰密封面泄漏量/%
工况1	55	35	1.0	0.1	30	20	水	水	2.93	3.02
工况2	55	35	1.5	0.1	30	20	水	水	3.04	3.44
工况3	55	35	2.0	0.1	30	20	水	水	2.16	2.11
工况4	55	35	2.0	0.1	35	20	水	水	1.80	1.83
工况5	55	35	2.0	0.1	25	20	水	水	3.16	3.37