refrigerant charge 1

[MrReds]

hallo to everybody and thanks to who has answered to my previous posts!
Please,I'm looking for some clarifications concerning this issue:
- what happens to the cycle when I add some refrigerant charge ?
What happens to condensing and evaporating pressures ?
and to condenser subcooling and evaporator superheating ?
Are there some differences between a capillary system and a thermostatic expansion valve system?
Could you suggest me some literature - or any web-site - about this issue ?
Thanks in advance, and Season Greetings to everybody !!

 

[imok2]

This is petty good>

http://www.cibse.org/pdfs/GPG280.pdf

 

[KiwiMace]

try out this excellent online (free) heat pump/air-con model from Oak Ridge National Labs in US: The default is a 2ton heat pump, but it will run in air con only mode and discount the accumulator. You can change all your parameters around ad infinitum.

http://www.ornl.gov/~wlj/hpdm/doehpdm.shtml

Note the solver method before you get too carried away - default solves for a fixed subcool i think. Not easy to determine the effect on subcool if it is the base of your solution.

 

[WhoDey09]

Depends what refrigerant, but assuming it is R22,condensing and evaporating pressures will increase.
Subcooling temperatures will rise and superheat will fall.
Capillary tube is a very small diameter line to meter the refrigerant. With a TXV you have a valve with a remote bulb that is mounted to the suction line.That bulb may be filled with the same refrigerant as the system or with a different type(cross charge), depending on the application.
The bulbs internal pressure is changed according to temperature change on the suction line. This pressure pushes against a diaphram, which cause the push rods to open the valve. Some valves are internally equalized or externally. The latter means that an external line will also feed to the valve and that coupled with the spring pressure act to close the valve.Bulb pressure,Evaporator pressure, and spring pressure are the 3 pressures that act to open and close the valve.whew!

Who dey