换热器试验过程温度控制系统应用研究

发布时间：2018-04-04 05:03

本文选题：换热器　切入点：性能试验　出处：《兰州理工大学》2015年硕士论文

【摘要】：换热器是使热量从热流体传递给冷流体的一种热量交换设备,广泛应用于化工、石油、暖通、电子等工业部门,其产品质量对能源利用率起着重要的作用。因此,为保证换热器的产品质量,需要专业机构对换热器的性能进行监督检验。本文以甘肃蓝科石化高新装备股份有限公司的上海蓝滨炼化设备实验室测控系统为背景,在了解换热器性能试验原理的基础上,研究换热器性能试验测控系统。系统以PLC为核心,采用工业控制计算机对试验过程进行监控。PLC实现对现场信号的采集、执行机构的控制以及不同试验工况的切换控制。工控机与PLC通过PROFIBUS实现通讯,实现换热器试验过程的实时监控、参数设置以及数据处理等功能。换热器性能试验的重点在于建立满足一定温度和流量条件的检测工况。试验时,设定换热器试件冷热侧进口介质流量,控制试件冷热侧进口温度快速稳定到检测工况设定值,按照换热器检验标准,采集相应数据并存储;然后改变换热器试件冷热侧进口介质流量,在温度重新稳定到设定值时,继续检测数据。最后根据试验数据分析计算总传热系数和流动阻力,评价换热器的总体性能。整个试验过程中,控制换热器试件冷热侧进口温度快速稳定是研究的关键。换热器试件的冷热侧进口温度控制系统是大时滞、时变、多变量的非线性系统,传统的PID控制算法调节时间长、控制精度低,很难实现冷热侧进口温度的快速稳定控制。文章建立了换热器试验过程的温度控制模型,分析了PID控制算法的优缺点,研究了模糊控制算法,并结合模糊控制算法与PID控制算法,研究了模糊-PID控制算法,实现了换热器试验过程冷热侧进口温度的快速稳定控制。通过MATLAB/Simulink建模、仿真,说明了模糊-PID控制算法具有抑制超调、响应速度快、调节时间短、控制精度高等优点,可以满足换热器试验过程对冷热侧进口温度的控制要求。
[Abstract]:Heat exchanger is a kind of heat exchange equipment which can transfer heat from hot fluid to cold fluid. It is widely used in chemical, petroleum, HVAC, electronics and other industries. The product quality plays an important role in energy utilization.Therefore, in order to ensure the quality of heat exchangers, professional organizations are required to supervise the performance of heat exchangers.Based on the laboratory measurement and control system of Shanghai Lanbin Refinery equipment Co., Ltd., Gansu Lanke Petrochemical Co., Ltd., the performance test and control system of heat exchanger is studied on the basis of understanding the principle of heat exchanger performance test.The system takes PLC as the core and uses the industrial control computer to monitor and control the test process. The system realizes the collection of the field signal, the control of the executing mechanism and the switching control of different test conditions.The communication between IPC and PLC is realized through PROFIBUS, and the functions of real-time monitoring, parameter setting and data processing during heat exchanger test are realized.The key point of the performance test of heat exchanger is to establish the test condition satisfying certain temperature and flow rate.During the test, the inlet medium flow rate of the cold and hot side of the heat exchanger is set, the inlet temperature of the hot and cold side of the heat exchanger is controlled quickly to the set value of the testing condition, and the corresponding data are collected and stored according to the test standard of the heat exchanger;Then the flow rate of the inlet medium on the cold and hot side of the heat exchanger specimen is changed, and the detection data are continued when the temperature is stabilized to the set value.Finally, the total heat transfer coefficient and flow resistance are calculated according to the experimental data, and the overall performance of the heat exchanger is evaluated.During the whole test process, the key to the research is to control the inlet temperature of the heat exchanger.The inlet temperature control system of hot and cold side of heat exchanger is a nonlinear system with large time delay, time varying and multivariable. The traditional PID control algorithm has long adjusting time and low control precision, so it is difficult to realize fast and stable control of inlet temperature of cold and hot side.In this paper, the temperature control model of heat exchanger test process is established, the advantages and disadvantages of PID control algorithm are analyzed, the fuzzy control algorithm is studied, and the fuzzy pid control algorithm is studied by combining fuzzy control algorithm with PID control algorithm.The fast and stable control of inlet temperature of cold and hot side during heat exchanger test is realized.Through MATLAB/Simulink modeling and simulation, it is proved that the fuzzy pid control algorithm has the advantages of restraining overshoot, fast response speed, short adjusting time and high control precision. It can meet the control requirements of the inlet temperature of the cold and hot side during the heat exchanger test.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK172;TP273

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