Design Considerations For Shell & Tube Heat Exchangers

Heat Exchanger is an industrial equipment used to transfer thermal energy between two or more fluids from one medium to another. The fluids can be in the form of liquids, vapors, or gases of different temperatures.

And, you might be aware that knowingly or unknowingly, heat exchangers are around us all the time. We use it in our homes, workplaces, and our vehicles. Heat exchangers are used in air conditioning systems, refrigerators, central heating radiators, geothermal, and other similar solar thermal energy systems.

How does it work?

Heat exchangers consist of the mass of metal shell and tubes which transfers heat from one fluid to another. The heat source, such as a burner, boiler, or similar heating devices, is used to absorb heat for the primary thermal fluids. It then circulates the thermal fluid through the heat exchanger, where the temperature is removed from the liquid and is transferred to a secondary fluid. Heat exchangers are extensively used in manufacturing units, refineries, chemical plants, power plants, process industries as well as other large scale plants for several applications.

There are various types of heat exchangers available in the market based on their size, shape, and kind. But Shell & Tube Heat Exchangers and Plate Heat Exchangers are the most dominant in today’s global industrial engineering world.

Thermal Design Requirements For Shell & Tube Heat Exchangers

• Thermal designing for shell and tube heat exchangers requires numerous iterations. It is usually performed using the proprietary software or other available programs developed by regulatory bodies.
• The first step is to finalize the operating temperature and pressure of the heat exchanger.
• An engineer must acknowledge and understand the thermal design logic used behind the calculations.
• Inlet/Outlet temperatures for hot and cold fluid should be finalized.
• It is essential to determine the heat transfer coefficient on the shell and tube side of the heat exchanger.
• It is vital to determine thermal parameter like pressure drop on the tube side.
• Design parameters of elements such as shell diameter, tube length, and baffle pitch are required to be selected.
• It is necessary to calculate the heat transfer coefficient and wall resistance.

Mechanical Design Parameters

• Mechanical strength is of utmost necessary for the shell and tube heat exchanger to withstand temperature and pressure carefully.
• It determines the thickness of the shell and flange used in the heat exchanger.
• The design of shell and tube type heat exchangers is governed by standards provided by TEMA (Tubular Exchanger Manufacturers Association)
• The standard pressure vessel code, like ASME Boiler & Pressure Vessel Code (BPVC) and British Master Pressure Vessel Standard, BS 5500, is widely used to determine the design of heat exchangers.
• The most applicable code for heat exchangers is Section VIII (Confined Pressure Vessels).

To conclude, industrial equipment design is a critical aspect to maintain the efficiency and safety of large scale plants. It also ensures to produce high-quality products. Are you looking for the design and analysis of pressure vessels, boilers, heat exchangers, and storage tanks for your next project? Then, it would help if you consider outsourcing equipment engineering services delivering excellent performance and having an acute knowledge of international codes and standards.