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Performance of Heat Transfer Coils
Introduction
Given the tube geometry and coil dimensions ,the program predicts the thermal performance of various types of convective heat transfer surfaces with bare or finned tubes in inline or staggered arrangement and in parallel or counter flow configuration. By convective surfaces is meant is that external radiation from a furnace or flame is not considered,though non-luminous heat transfer coefficient is evaluated. Hence the program is suitable for predicting the performance of: 
1.water tube boiler evaporators /HRSG evaporators 
2.superheaters
3.economizers
4.tubular air heaters(single, multiple pass) 
5.steam-air heaters /air-cooled condensers 
6.coils heating industrial heat transfer fluids such as therminol/glycol
Note:This is NOT a heat exchanger program. The fluid outside the tubes should be either air or flue gas and not a liquid. Fluid inside can be steam, air or flue gas, water, steam-water mixture or heat transfer fluid whose thermal, transport properties are known.
The program may be used to arrive at the geometry for a given duty or may be used to predict the performance of an existing coil. By playing with variables such as tube size,spacing,fin geometry,lengths,one can arrive at the optimum size for a new application which matches the duty and gas pressure drops desired.This is called the design mode. In the performance mode,one checks the thermal performance for a given coil,whose geometry and dimensions are known. For example the plant engineer may use it to see how the superheater in the HRSG behaves under different conditions of steam flow, steam pressure, gas flow or gas analysis. One can study if the economizer will “steam” under new or different operating modes or compare the actual performance with predicted and see if there is a possibility of fouling.Hence this program may be used for a variety of purposes.
The cooling or heating gas/air flows outside the bare or finned tubes while the fluid, such as steam/water/liquid/gas/air flows inside the tubes. All the tubes of the coil should have the same tube/fin configuration. If there are different configurations within the coil such as two different fin geometries or tube sizes, then the program may be run as many times as required, taking the results from each run and inputting them as data for the next run. 
The program computes several useful data for the coil as can be seen from the DEMO. In addition to the duty and exit fluid temperatures for a wide variety of bare/finned tube configurations, one can evaluate gas side pressure drop, tube wall and fin tip temperatures at inlet and exit of the coil,fluid velocities and heat transfer coefficients. With an economizer for example, the tube wall temperature at both inlet and exit of the coil are computed so that concerns about acid dew point corrosion may be addressed. Steaming if present is also computed. A wide variety of coils used in waste heat boilers, heat recovery equipment and boiler plants can be evaluated with this program,though it is designed for a single coil. 
The program runs on both British and Metric units. It runs on any Windows platform such as Windows 95,98, NT or later versions with as little as 16 MB RAM memory and on any processor. Hard disk space required is less than a MB.
Download the FREE coil program Demo!
Create a directory called VG and save the file;doubleclick it from windows explorer to expand the files.Run using command "C:\vg\coild"
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