Thermal expansion valve for a residential refrigeration application

Abstract

The present invention is directed at a thermal expansion valve for a residential refrigeration application, including a valve body with a high pressure inlet, a low pressure outlet, a first suction gas port and a second suction gas port. The valve further includes a superheat defining mechanism with a diaphragm, a pushpin and a charge.

What is claimed is: 
     
         1 . A thermal expansion valve for a residential refrigeration application, comprising a valve body with a high pressure inlet, a low pressure outlet, a first suction gas port and a second suction gas port, the valve further comprising a superheat defining mechanism with a diaphragm, a pushpin and a charge, wherein the amount of charge is selected such that a part of the charge is in a liquid state at typical operation conditions of the refrigeration application. 
     
     
         2 . The thermal expansion valve according to  claim 1 , wherein the charge comprises ballast material and/or that the charge comprises a refrigerant other than CO2 and/or that the time constant of the valve is a function of at least the dimensions and materials of the superheat defining mechanism, wherein the superheat defining mechanism is designed for providing a time constant of greater than 30 seconds, in particular greater than 60 seconds, and wherein the charge is designed such that it determines the value of the time constant for the most part and/or that the superheat defining mechanism comprises a superheat setting screw. 
     
     
         3 . The thermal expansion valve according to  claim 2 , wherein a protection member is provided between the diaphragm and the ballast material of the charge or that the ballast material of the charge is in direct contact with the diaphragm and/or that the charge density is 30 to 350 mg/cm 3 , preferably 60 mg/cm 3  to 100 mg/cm 3  if ballast material is provided and 50-400 mg/cm 3  if no ballast material is provided. 
     
     
         4 . The thermal expansion valve according to  claim 1 , wherein the superheat defining mechanism comprises a diaphragm top, a diaphragm bottom and/or a diaphragm support, wherein the diaphragm support comprises a perforated plate and/or a ring and/or a non-rotational-symmetric plate. 
     
     
         5 . The thermal expansion valve according to  claim 1 , wherein a connection element is provided for connecting the superheat defining mechanism to the valve body. 
     
     
         6 . The thermal expansion valve according to  claim 1 , wherein the diaphragm top is shaped at least partially cylindrically. 
     
     
         7 . The thermal expansion valve according to  claim 1 , wherein ballast material of the charge comprises diatomite, a molecular sieve and/or marinite and/or is provided in cylindrical, cubic, conical, spherical and/or toroidal form. 
     
     
         8 . The thermal expansion valve according to  claim 1 , wherein the charge is pressurized with an inert gas such as nitrogen. 
     
     
         9 . The thermal expansion valve according to  claim 1 , wherein the high pressure inlet is provided between the low pressure outlet on the one side and the first suction gas port and/or second suction gas port on the other side with respect to an axial direction of the valve body. 
     
     
         10 . The thermal expansion valve according to  claim 1 , wherein the connection between the diaphragm and the valve body comprises a knife edge seal and/or an O-ring and/or a weld. 
     
     
         11 . The thermal expansion valve according to  claim 1 , wherein it comprises a check valve.