曾志伟

摘要：在传统过程控制教学实训系统中，由于采用冷水和热进行温度控制实验，导致所需的时间长，不能在规定课时内完成实验;如果实验失败，不能马上重新开始实验，必须要等到水降温后才可以进行下一次实验;如果温度一旦控制不好水可能会汽化，存在极大的安全隐患等问题。针对以上问题，本文开发设计一种基于气液两相介质的换热工艺流程，以进行温度控制教学内容的改进。该系统设计工艺流程时，先将空气通过热风机加热至较高温度，然后在板式换热器内与水进行换热，由于空气比热小，整个温度控制过程时间大大缩短。同时冷却水换热之后吸收的热量，通过空冷器与液位水罐进行散热，能够实现整个系统的热量平衡，实现系统自循环。

关键词：温度控制实验改进;空气与水换热

Abstract：In the traditional process control teaching and training system，due to the use of cold water and heat for temperature control experiments，it takes a long time to complete the experiment within the prescribed time;if the experiment fails，the experiment cannot be restarted immediately，and it must be waited until The next experiment can only be carried out after the water is cooled down;if the temperature is not well controlled，the water may vaporize，posing great safety hazards and other problems. In view of the above problems，this paper develops and designs a heat exchange process based on gas-liquid two-phase medium to improve the teaching content of temperature control. When designing the process flow of the system，the air is first heated to a higher temperature by a hot air blower，and then the heat is exchanged with water in the plate heat exchanger. Because the specific heat of the air is small，the entire temperature control process time is greatly shortened. At the same time，the heat absorbed by the cooling water after heat exchange is dissipated by the air cooler and the liquid level tank，which can achieve the heat balance of the entire system and realize the self-circulation of the system.

Keywords：temperature control experiment improvement;heat exchange between air and water;

過程控制系统是自动化专业非常重要的一门综合性应用学科，课程内容包括控制理论、生产工艺、计算机控制技术和仪器仪表知识[1-2]。在实际教学过程中，常以水箱液位系统开展过程控制系统实践教学。水箱液位系统具有生产工艺简单、直观，涵盖温度、流量、液位、压力等典型过程变量的检测与变送实训、泵和调节阀等典型执行机构的操作实训、控制系统设计与实施实训等内容。由于过程控制系统需要理论与应用结合紧密且实践性较强，造成学生在学习的过程中遇到很多的实际困难[3]。其中温度控制的实践学习一直是难点之一。……