Shandong heat exchanger maintenance 51. Design scheme introduction: the tube and shell heat exchanger is a widely used heat exchange equipment in chemical industry. It has simple and strong structure, high pressure resistance, high reliability, strong adaptability and wide range of manufacturing materials; The unit volume has a large heat transfer area and good heat transfer effect; And the variety, model is complete, the manufacturing process is relatively mature. Therefore, this design is to select and design the tube heat exchanger, the equipment used in the heat transfer process. The structure of the tube type heat exchanger can be divided into three types: fixed tube plate, floating head type and U-shaped tube type. When selecting, suitable heat exchanger can be designed according to different application conditions and their advantages and disadvantages. To design a more perfect heat exchanger, in addition to meeting the requirements of heat transfer, it also strives to achieve high heat transfer efficiency, small volume, light weight, Shandong heat exchanger maintenance, less materials consumption, low manufacturing cost, convenient cleaning and maintenance and operation * *. Therefore, the design of the tubular heat exchanger is to determine the heat transfer area of the heat exchanger according to the requirements of chemical process conditions. At the same time, the pipe diameter and pipe length are selected to determine the number of pipes, the number of pipe passes and the number of shell passes, and then the mechanical selection design is carried out. The selection and design process of the tube heat exchanger has been mature, and the specific steps are as follows: (1) according to the physical properties and the requirements of the process conditions, the space for the flow in is determined（ 2) Determine the temperature of the fluid at both ends of the heat exchanger and select the type of the tube heat exchanger（ 3) Calculate the qualitative temperature of the fluid and determine the physical properties of the fluid（ 4) Calculate the heat load according to the heat transfer task（ 5) According to the convection heat transfer coefficient A2 and A1, the maintenance resistance of the Shandong heat exchanger is determined. Then calculate the total heat transfer coefficient K meter. According to the empirical range of total heat transfer coefficient or according to the actual situation, the total heat transfer coefficient K is selected（ 6) By chemical process calculation, the total heat transfer rate equation q = KS Δ Brief introduction: the tube and shell heat exchanger is a widely used heat exchange equipment in chemical industry. It has simple and strong structure, high pressure resistance, high reliability, strong adaptability and wide range of manufacturing materials; The unit volume has a large heat transfer area and good heat transfer effect; And the variety, model is complete, the manufacturing process is relatively mature. Therefore, this design is to select and design the tube heat exchanger, the equipment used in the heat transfer process. The structure of the tube type heat exchanger can be divided into three types: fixed tube plate, floating head type and U-shaped tube type. The suitable heat exchanger can be designed according to the different maintenance and application conditions of Shandong heat exchanger and their advantages and disadvantages. To design a more perfect heat exchanger, in addition to meeting the requirements of heat transfer, it also strives to achieve high heat transfer efficiency, small volume, light weight, less materials consumption, low manufacturing cost, convenient cleaning and maintenance and operation * *. Therefore, the design of the tubular heat exchanger is to determine the heat transfer area of the heat exchanger according to the requirements of chemical process conditions. At the same time, the pipe diameter and pipe length are selected to determine the number of pipes, the number of pipe passes and the number of shell passes, and then the mechanical selection design is carried out. The selection and design process of the tube heat exchanger has been mature, and the specific steps are as follows: (1) according to the physical properties and the requirements of the process conditions, the space for the flow in is determined（ 2) Determine the temperature of the fluid at both ends of the heat exchanger and select the type of the tube heat exchanger（ 3) Calculate the qualitative temperature of the fluid and determine the physical properties of the fluid（ 4) Calculate the heat load according to the heat transfer task（ 5) According to the convection heat transfer coefficient A2 and A1, the fouling resistance RS2 and RSL are determined for the maintenance of Shandong heat exchanger. Then calculate the total heat transfer coefficient K meter. According to the empirical range of total heat transfer coefficient or according to the actual situation, the total heat transfer coefficient K is selected.