Refrigeration system and a thermostatic expansion valve best suited for the same

A thermostatic expansion valve, comprising:

• a thermo-tube means for containing a working fluid and for detecting a superheated vapor temperature of a refrigerant at an outlet of an evaporator in a refrigeration system, said fluid changing its pressure in accordance with the detected superheated vapor temperature;
• a valve body being movable between an open position and a closed position and also being adapted to be driven, by means of the pressure of the working fluid contained in the thermo-tube means, toward the closed position;
• means for urging the valve body towards said open position;
• a valve body housing coupled to the thermo-tube means so as be adjacent thereto and integral therewith;
• a temperature sensitivity adjusting solid material contained within the thermo-tube means, said material being made of a ceramic having a property which can either adsorb or absorb the working fluid contained in the thermo-tube means so as to adjust a temperature-sensitive speed of the thermo-tube means;
• an integral joint block means for containing the thermostatic expansion valve, said block means having a refrigerant intake passage means and a refrigerant discharge passage means for communicating with a refrigerant inlet and a refrigerant outlet, respectively, of the evaporator;
• said thermostatic expansion valve being housing in the integral joint block means in a manner such that the thermo-tube means and the valve body housing are exposed to the refrigerant discharge passage means and the refrigerant intake passage means, respectively;
• said working fluid in the thermo-tube means being constituted by a first working fluid having a saturated vapor pressure lower than a superheated vapor pressure of the refrigerant at the outlet of the evaporator, and also being constituted by a second working fluid incapable of being liquefied within a range of an evaporating temperature of the refrigerant;
• said working fluid in the thermo-tube means also driving the valve body so that a resultant force caused by a sum of the superheated vapor pressure of the refrigerant at the outlet of the evaporator and the force of the valve body urging means is resisted;
• and
• said pressure of the working fluid in the thermo-tube means further becoming greater than the resultant force to be resisted, thereby moving the valve body to the open position when the evaporating temperature of the refrigerant is lowered under a predetermined level and a difference between the detected superheated vapor temperature and the evaporating temperature, that is a super heat of the refrigerant, is lowered under zero degrees Kelvin.