流热交换试验自动控制系统的实现及研究

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摘要

课题来源于一个现实的工程项目，即内燃机机油冷却器多股流热交换试验自

动控制系统。该全自动测试系统主要用来测试冷却器的传热性能。由于系统测点

较多，试验工况复杂，要求系统结构和测点布置合理，并对温度控制的稳定性，

精度和控制速度都有较高的要求。

根据国家试验标准和用户要求，提出了控制系统的设计方案。对实现自动控

制试验台的构建细节，从试验设备确定、测点布置、控制线路安排等方面进行详

细的考虑。在软件设计阶段，从需求分析出发，确定用户需求。为提高系统的可

重用性，采用面向对象的方法进行控制软件的设计，并讨论了软件编制中一些关

键技术，如实时曲线处理，端口操作等的实现。根据 JB/T 5095-91 内燃机机油冷

却器传热性能试验方法的国家标准，要求在试验过程中，温度控制在目标温度的

±1℃范围之内，并且在稳定状态下温度的变化每分钟不大于 0.1℃。对于这么高

的控制精度要求，常规控制算法的效果很不理想。从控制的角度出发，讨论了被

控对象的数学模型，并对各种控制算法进行分析、比较，从而最后得出一种适合

于该自动控制系统的模糊逻辑、专家系统及神经网络集成的控制算法，称之为模

糊神经网络控制（FNNC）。通过对系统状态的分析，确定专家规则，得出具体的

算法实现。通过仿真进行比较，证明模糊神经网络控制算法比常规算法响应更快，

稳定性更好。在系统调试阶段，按照单通道测试到回路测试，再到系统联锁调试

分步进行。对系统调试中所遇到的问题进行分析，并给出解决方案。在完成整个

系统的调试以后，对一种类型的冷却器进行了现场测试。测试结果表明，整个自

动控制系统的控制逻辑正确，且试验数据表明系统控制精度已基本达到试验要求。

最后，展望当前控制系统发展方向，分析传统控制系统的特点，对控制系统的总

线结构方面进行了探讨。并提出使用现场总线技术，来解决传统控制的信息集成

差，可靠性差，可维护性差等缺点。结合 PROFIBUS 总线技术的特点，给出了系

统改善方案。

关键字:自动控制系统模糊神经网络控制现场总线 PROFIBUS 机油冷却器

传热性能试验

Abstract

The subject is based on a reality project . It is named the automatic control system

of multi-stream heat transfer performance test for internal-combustion engine radiator.

The automatic control system is mainly used to test the performance of the radiator. The

system structure and the reasonable testing point distributing is needed because of lost

of testing points and the complicated work conditions. It also require stabilization,

rapidly and high precision for temperature controlled.

According the user’s demand and National standard, a control system scheme was

brought forward. Consider conscientiously in testing equipment choosing, testing point

distributing and wiring for the automatic control system. At design phase of software, the

author analyses the user’s demand and decided what user want. In The paper the author

apply the Object Oriented method to improve the Reusable of the code. Some key

technology of software realization are listed, such as The real-time curve and The port

operating. According the National standard JB/T 5095-91，the testing temperature is ask

to be within the range of ±1℃around aim temperature and not allowed to change ±

0.1 ℃in one minute. The request in control temperature is so strict that the classic

control algorithm can not do good at it. According study a lot of control algorithm, a

integration of fuzzy, expert system and neural networks algorithm is put forward. It is

named fuzzy neural networks control (FNNC)algorithm. The expert rules was decided

by system state. The code realization is also given. The FNNC algorithm is better than

classic control algorithm in response and stability by emulation. During the course of

the system debugging three step was applied. They were I/O port debugging, single

circuit debugging and Jointly debugging. Analyze the problem during debugging and

give a solution. After debugging , a three medium radiator was tested by the automatic

control system. The system is proved to meet the user’s demands basically. Lastly, the

field bus control system was studied . In order to solve the shortcoming of the

traditional control system, such as poor in Information integration, the dependability

and The maintainability are bad and PROFIBUS was adopted to be a system improving

scheme.

Keywords: Automatic Control System, Fuzzy Neural Networks Control,

Fieldbus, PROFIBUS, Internal-Combustion Engine Radiator, Heat Transfer

Performance Test

III

第一章引言························································································1

1.1 机油冷却器传热性能试验现状····························································1

1.2 实现机油冷却器传热性能试验自动控制系统的意义································ 1

第二章多股流热交换试验自动控制系统设计············································· 3

2.1 概述······························································································3

2.2 系统设计要求··················································································3

2.3 现场试验台的设计··········································································· 3

2.4 控制系统的确定 ············································································· 7

2.5 自动控制系统硬件设计····································································10

2.6 综述···························································································· 15

第三章控制系统软件设计····································································16

3.1 概述···························································································· 16

3.2 冷却器换热性能试验控制软件的需求分析············································16

3.3 面向对象的分析(OOA)和面向对象的设计(OOD)··································· 17

3.4 程序关键代码实现 ········································································ 18

3.5 控制界面及操作步骤介绍·································································23

3.6 综述···························································································· 26

第四章试验控制算法比较和实现···························································27

4.1 试验对控制的要求·········································································· 27

4.2 冷却器换热性能的确定····································································27

4.3 控制对象数学模型的确定·································································29

4.4 算法比较······················································································ 31

4.5 模糊逻辑、专家系统及神经网络在控制系统中的集成···························· 37

4.6 控制算法实现················································································ 40

第五章系统现场调试·········································································· 42

5.1 概述···························································································· 42

5.2 系统调试中遇到的主要问题及解决·····················································43

5.3 系统现场测试················································································ 45

第六章控制系统总线的研究与改进························································47

6.1 控制系统发展现状·········································································· 47

6.2 现现场总线的必要性······································································· 47

6.3 总线改进方案研究与展望·································································48

6.4 综述···························································································· 50

结束语······························································································51

参考文献···························································································52

第一章引言

1.1 机油冷却器传热性能试验现状

内燃机机油冷却器新产品鉴定、等级评定和产品出厂必须经过传热性能试验。

当前，国内对于机油冷却器的换热性能试验大部分采用的是人工操作进行的。即

温度控制、流量控制、开关量的开启和闭合、测量数据的读取以及数据记录和计

算都通过人力操作来完成。人工测试系统主要有如下缺点：(1)耗费大量人力。当

要测量的工况点多的时候，往往需要好几天的连续试验。对工况点的监测也需要

一定的人员配置。(2)对试验人员的要求较高。在试验中需要试验人员注意力集中，

时刻观察被控对象的数据，而且需要一定的试验经验，来使系统尽快达到控制目

标。(3)对系统设计的要求高。人工试验不可能同时对多个数据进行采样记录，这

就要求系统的稳定性好，能够保持在要求的状态之下。不过由于系统处于动态的

稳定状态，波动不可避免，带来由于测量时间不同而产生的数据误差。(4)人为误

差在所难免。不论在数据读取还是数据统计中，这种错误都有可能发生。此外，

由于试验对时间和精度的要求较高。厂方要求在十分钟之内达到设定温度，且根

据国标 JB/T 5095-91 规定温差不超过±1℃。这都给人工控制试验带来了很大的难

度。

上述可知人工试验可谓缺点众多，可是为何大多数厂家还是采用人工方法来

进行性能测试。究其原因如下：(1)采用自动控制系统的一次性投入大。例如采用

成本较低的工业 PC 机控制系统，其投入也需要几十万，尽管这些投资从长远看来

还是合算的，但一些不经常做冷却器性能试验的小型企业，肯定不会采用。(2)当

前人工试验系统已经能够满足要求。由于多年一直采用人工试验，已经有一批有

经验的试验人员，和一个成熟的试验台系统，完全能够满足厂方的当前要求。(3)

自动控制系统的试验效果尚有待评估。由于多年以来，对冷却器换热性能试验很

少采用自动控制系统，在这方面的自控系统屈指可数。针对该试验的自动控制系

统设计经验还不丰富，难免带来设计的不合理，不成熟。这就可能使得自动控制

系统的试验效果不理想。这些原因导致一些厂家对冷却器性能试验采用自动控制

系统处于观望状态。但实现工业自动化是以后工业企业生存和发展的必由之路。

因此，要求对冷却器性能试验实现自动控制也是必然的。

1.2 实现机油冷却器传热性能试验自动控制系统的意义

随着工业自动化水平的发展，原来主要由人力来完成的冷却器传热性能试验

的已经跟不上工业发展的步伐，其耗费人力多、控制精度低，控制难度大等缺点

是显而易见的。在机油冷却器换热性能试验中采用自动控制系统能极大的提高测

试效率；减少大量的人力劳动；减少人为失误；提高控制精度从而提高试验的准

确性和可靠性。从长远看来，能够使企业通过降低试验费用，从而到达降低成本

的目的。而且由于当前这种冷却器换热性能试验控制系统很少，基本上属于空白

领域，如果能够实现，并达到良好的试验效果，不仅能够彻底改变厂家对冷却器

试验人工操作的落后状态而且能够为以后此类系统的设计积累足够的经验，以及

为其他同类厂家实现自动化控制起了示范作用，为整个行业的工业自动化进程迈

多股流热交换试验自动控制系统的实现及研究

出有力一步。

第二章多股流热交换试验自动控制系统设计

2.1 概述

试验测试对象为板翅式机油冷却器，测试对象中包括三介质冷却器和两介质

冷却器，要求通过换热试验，来完成机油冷却器传热性能的测定，以此为指标来

评定该种机油冷却器产品的传热性能，从而进行进一步的改进性能或者进行批量

生产。

内燃机机油冷却器的传热性能试验系统设计必须按照中华人民共和国机械行

业标准来进行。机械行业标准编号为：JB/T 5095－91，题目为：《内燃机机油冷

却器传热性能试验方法》，在遵照标准的同时，根据客户的需求可以进行适当的调

整，以符合现实需要。

2.2 系统设计要求

根据机械行业内燃机机油冷却器传热性能试验标准的规定，试验热介质为 11

号或 14 号CD 级中增压柴油机油，冷介质为清水。试验台在运行情况下，冷却器

试件的进油温度 to1＝95±1℃，进水温度 tw1＝85±1℃或根据委托单位的要求，

但温度必须稳定在给定的范围内，且温度的变化每分钟不大于 0.1℃。水流量在

流速为 0.1~1.2m/s 范围内，油流量在流速为 0.1~1.2m/s 范围内根据委托单位要求

分别选取不同流量的若干档。设 Qo为油的放热量，Qw为水的吸热量，当在设定

的工况下热平衡误差

%5%100 





时采集的数据为有效。

系统中为使试验达到标准所要求的工况，在油箱和水箱中安装加热器，将用

于热交换的流体温度加热到设定温度。再用泵将流体送到冷却器中进行热交换。

由于油为放热，水为吸热，为保持水的试验温度必须在水回路中增加散热装置，

这里采用通过冷却塔散热。这样就形成一个闭环控制系统。根据试验标准换热试

验台系统布置图如下：

图2－1两股流换热试验台系统布置图

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摘要：

I摘要课题来源于一个现实的工程项目，即内燃机机油冷却器多股流热交换试验自动控制系统。该全自动测试系统主要用来测试冷却器的传热性能。由于系统测点较多，试验工况复杂，要求系统结构和测点布置合理，并对温度控制的稳定性，精度和控制速度都有较高的要求。根据国家试验标准和用户要求，提出了控制系统的设计方案。对实现自动控制试验台的构建细节，从试验设备确定、测点布置、控制线路安排等方面进行详细的考虑。在软件设计阶段，从需求分析出发，确定用户需求。为提高系统的可重用性，采用面向对象的方法进行控制软件的设计，并讨论了软件编制中一些关键技术，如实时曲线处理，端口操作等的实现。根据JB/T5095-91内燃机机油冷却...

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