Evaporator TD and refrigeration effect

[nambiandy]

Hi

few question ran accross while understanding the relation of TD Vs Evaporator capacity .
with increase in TD the Refrigeration effect also increase , For eample an evaporator with TD 10degF delivers 12000btu/hr , with 15degF it delivers 14000 btu/hr approx and increases so on as the TD increases.( As i understand the Selection of TD will be based on the application /produced to be stored, humidity requirement etc). My question/doubt here is

1. How can we increase the TD in evaporator ? it with expansion valve

2. if it is with expansion valve , will their be any effect on superheat setting

3. The running cost/compressor running hrs of refrigeration system in case evaporator with high TD less compared to evaporator with low TD.

kindly suggest/help

Regards

[BritCit_Juve]

The td in question is between the evaporating temp and air on temp and is primarily a function of the evaporator/compressor/condenser match. The TEV will be selected based on the resulting evaporating temp.
The larger the compressor/condenser match in comparison to the evaporator the lower the evaporating temperature resulting in a greater duty due to the higer td. however this will also result in higher dehums, hihgher capital cost and shorter run times (with the added possibility of more dehum periods).
A lower td may result in a larger evaporator and longer run times but will dehum less so in theory require fewer dehums.
As to which has the lower run costs that is debatable but for fruit storage, storage of hygroscopic materials or wines then low td is king.
Brit
Brit

[nambiandy]

hi brit

I am checking the massage the forum after a gap.
Thanks for suggestion

namiandy