引言利用流体和固体的直接接触,进行相互的热交换,以此过程实现热量的转移,称为对流换热。在此过程中,热量转移和介质本身的转移不可分割地相结合在一起。因此,对流换热具有换热效率高,换热能力大,控制性能好等特点。它在传热工程技术领域中得到了广泛的研究和应用。随着工业技术的发展,各类换热器的热负荷急骤加大,控制精度的要 Introduction The use of direct contact with the fluid and solid heat exchange with each other, as the process of heat transfer, known as the convection heat transfer. In this process, the heat transfer and the transfer of the medium itself are inextricably linked. Therefore, convection heat transfer with high efficiency, heat transfer capacity, control performance and so on. It has been extensively researched and applied in the field of heat transfer engineering. With the development of industrial technology, the heat load of all kinds of heat exchangers increases sharply, and the control accuracy