Tips on Heat Exchanger Sizing
Heat exchanger sizing is very important in order for the device to function effectively.
Factors that people need to consider when it comes to the size of this device are: the type of heat exchanger, the characteristics of the heat transfer fluid (specific heat, viscosity, and density), flow rate, and inlet and outlet temperatures for each fluid.
In buying this type of device, you will usually find that manufacturers give supply heat transfer ratings in the form of Btu/hour for different fluid temperatures and flow rates.
In determining size, you will also need to take into consideration the surface area of the device as this can also affect the speed and efficiency of the device.
Usually a large surface area can transfer heat faster and more efficiently.
Calculation of heat exchanger sizing can be done using the HYSYS or the UniSim.
This system can provide you with a plot of temperature for both streams versus the amount of heat transferred.
But, with this system, it usually gives a heat transfer area of 60.
32 meters squared for all heat exchangers irregardless of what is specified because of its weighted or end point engineering design.
For economic evaluation, you will have to estimate the utility requirements and the area for your entire device, including the condensers and reboilers with the distillation columns.
You also need to use built-in heat exchangers to estimate size and utilities requirements.
In calculating heat exchanger sizing using the HYSYS, there are several things that you have to keep in mind.
One, the utilities must be above one atm pressure, both entering and leaving the device.
Two, when steam is used for heating, the entering steam should be specified as all vapors with vapor fraction of one, and either Pressure or Temperature unless it's a superheated device.
The exiting water should be specified as all liquid with vapor fraction of 0 at a pressure only slightly lower than the entering pressure.
Flow rate need not be specified.
And when a process steam is cooled by water going to steam, then the entering water should be specified as all liquid with vapor fraction of 0 at a specified pressure or temperature or both.
And, the exiting steam should be specified as all vapors at a slightly lower pressure.
And, when a process stream is cooled by a refrigerant, then the entering refrigerant should be specified as all liquid at a high pressure and the exiting refrigerant as all vapors at a much lower pressure.
And, when cooling water is used, then specifies temperature and pressure but not vapor fraction.
You should keep this in mind when calculating using the HYSYS or UniSim because different values will give you an inaccurate result.
You can also try searching online as there are websites, which will calculate heat exchanger sizing for you.
Factors that people need to consider when it comes to the size of this device are: the type of heat exchanger, the characteristics of the heat transfer fluid (specific heat, viscosity, and density), flow rate, and inlet and outlet temperatures for each fluid.
In buying this type of device, you will usually find that manufacturers give supply heat transfer ratings in the form of Btu/hour for different fluid temperatures and flow rates.
In determining size, you will also need to take into consideration the surface area of the device as this can also affect the speed and efficiency of the device.
Usually a large surface area can transfer heat faster and more efficiently.
Calculation of heat exchanger sizing can be done using the HYSYS or the UniSim.
This system can provide you with a plot of temperature for both streams versus the amount of heat transferred.
But, with this system, it usually gives a heat transfer area of 60.
32 meters squared for all heat exchangers irregardless of what is specified because of its weighted or end point engineering design.
For economic evaluation, you will have to estimate the utility requirements and the area for your entire device, including the condensers and reboilers with the distillation columns.
You also need to use built-in heat exchangers to estimate size and utilities requirements.
In calculating heat exchanger sizing using the HYSYS, there are several things that you have to keep in mind.
One, the utilities must be above one atm pressure, both entering and leaving the device.
Two, when steam is used for heating, the entering steam should be specified as all vapors with vapor fraction of one, and either Pressure or Temperature unless it's a superheated device.
The exiting water should be specified as all liquid with vapor fraction of 0 at a pressure only slightly lower than the entering pressure.
Flow rate need not be specified.
And when a process steam is cooled by water going to steam, then the entering water should be specified as all liquid with vapor fraction of 0 at a specified pressure or temperature or both.
And, the exiting steam should be specified as all vapors at a slightly lower pressure.
And, when a process stream is cooled by a refrigerant, then the entering refrigerant should be specified as all liquid at a high pressure and the exiting refrigerant as all vapors at a much lower pressure.
And, when cooling water is used, then specifies temperature and pressure but not vapor fraction.
You should keep this in mind when calculating using the HYSYS or UniSim because different values will give you an inaccurate result.
You can also try searching online as there are websites, which will calculate heat exchanger sizing for you.
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