In the specific form of the heat exchanger, the following will explain the relevant knowledge for the shell-and-tube heat exchanger, so that everyone can learn how this is a kind of heat exchanger and then know how to To correctly use and rationally use it, and play its due role and effect. And this is a very good learning opportunity for all of us, so don't miss it!
1. Definition and application of shell-and-tube heat exchanger
Shell and tube heat exchangers, which in turn can be called shell and tube heat exchangers, from the current point of view, this kind of heat exchanger has a wide range of applications. If used to heat steam, it can be called shell-tube steam-water heat exchanger. When used to heat high-temperature water, it can be called shell-tube water-water heat exchanger. Its application is mainly in hot water heating systems, as well as low temperature water conditioning and some production activities that require continuous use of hot water.
2. Selection of process conditions for shell-and-tube heat exchanger
Shell and tube heat exchanger process conditions 1: temperature
In the cooling water outlet temperature, there is a certain requirement, is that its outlet temperature can not be higher than 60 °C, so as to avoid scaling problems in the heat exchanger.
The temperature difference at the high temperature end should not be less than 20°C, and the temperature difference at the low temperature end should not be less than 5°C. In addition, if the heat is transferred between the two process fluids, the difference in temperature at the low temperature side cannot be less than 20°C.
If the heat exchanger is a single-shell and multi-tube heat exchanger and water is used as a coolant, then the coolant exit temperature must not be higher than the exit temperature of the process stream.
Shell and tube heat exchanger process conditions 2: pressure drop
The main requirement is that the pressure drop of the heat exchanger is within a certain range. Too large or too small is not good, because the pressure drop is too large, it will increase the power consumption of the heat exchanger, and at the same time, increase the operating load of the shell and tube heat exchanger. However, the pressure drop is too small, it will affect the heat exchanger heat transfer effect.
3. Structure of shell-and-tube heat exchanger
Shell and tube heat exchangers, which mainly include the shell, tube sheets, tube bundles, baffles and boxes and other parts. The heat exchange tube of the heat exchanger is an important part and can use light tubes, threaded tubes or spiral grooved tubes. And the number of its management, there are eight kinds of 1 to 8, of which 1, 2 and 4 are more common.
In the shell-and-tube heat exchanger shell side, in the form of baffle, there are three kinds of round shape, disk shape, and hole shape. In addition, there is a type of baffle, or a baffle. Its role is to change the flow direction of the shell side fluid, and can appropriately increase the fluid flow rate, thereby increasing the degree of turbulence of the fluid flow, so that the heat exchanger can obtain good heat exchange effect.