Small and medium air separation unit configuration

Temperature difference is the power of heat transfer. As long as there is temperature difference between two materials, they will carry out the heat or cold transfer spontaneously. The heat is always transferred from the fluid with higher temperature to the lower temperature fluid. Although the heat transfer process of various heat exchangers is not identical, the heat transfer law is basically the same. The following is an example of the most widely used dividing wall heat exchanger: heat is transferred from hot fluid to cold fluid through the wall and flows in the opposite direction. The whole heat transfer process is divided into three stages. In the first stage, convection heat transfer: the heat flow body transmits heat to the wall surface. This process not only has heat transfer caused by the relative displacement of each part of the fluid, but also has heat conduction in the fluid, which is the comprehensive function of convection and heat conduction. In the second

In order to reduce the air temperature in the low temperature air separation unit, various heat exchange equipment are needed for cold and heat exchange in various air separation systems, such as nitrogen water precooler, switching heat exchanger, main heat exchanger, condensing evaporator, subcooler, liquefier, vaporizer, electric heater, etc. These heat exchange equipments are installed in each system of the air separation unit, which are necessary for air liquefaction and gas separation. According to the principle of heat transfer, the heat exchanger of air separation unit can be divided into three types: 1. Dividing wall type: the cold and hot fluid is separated by the heat transfer wall, the medium does not directly contact in the heat transfer process, and the hot fluid transfers heat to the cold fluid through the heat transfer wall. For example, tube heat exchanger and plate heat exchanger. 2. Heat storage type: the cold and hot fluid alternately flows through the solid