Ajay:
If your condenser is “fully fouled”, then it is probably the reason you can’t condense the ammonia at a design pressure. As I’ve stated before, you must try to keep the condensed ammonia as cool as you possibly can. You certainly can’t do that if your condenser is fouled. You either clean it out or replace it.
Please refer to the attached workbook Rev2 in the ammonia saturated Properties Tab to see the thermodynamic properties of the refrigerant in various locations within your cycle. Note that the suction of the Booster Compressor is always going to be in the partial vacuum range if it is to maintain its evaporator at -45 oC. Also note the quality of my sketch as compared with the P&ID you submitted. You can clearly read and understand my sketch because of its layout and the clarity of the symbols and values. That is the quality of sketch that I expected from you since you are the one soliciting the help.
Use my sketch to indicate what you mean by “surge drum” and place the values of the temperatures and pressures in “call-outs” that are readily available in Excel.
Your local atmospheric conditions show that you should have no trouble in obtaining good cooling from your ammonia condenser – and consequently good efficiency from your system.
What do you mean by “-10” and “-40” plant? Please be concise and clear in your descriptions. As I stated, simply show your pressure and temperature inputs on my PFD in the workbook – and title the workbook with the next Rev number.
Your Booster compressor should be having a suction pressure of approximately 0.5 kg/cm2A and that is what you report, so your unit is supposedly working as designed. I don’t know how you are making your efficiency calculations or where you get your information. Now that you have a legible and simple PFD to work with, you should be able to communicate the various process values with ease and accuracy. I will await your information. This thread has already surpassed 15 posts and that is excessive writing. This is all due to your lack of communicating with the proper, legible, clear, and concise information on a decent PFD.
I await your response.
Ajays Ammonia Chiller System Rev2.xlsx 1.14MB
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