| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an expansion valve using a refrigerant least influencing global warming as working fluid of a power element, and achieving desired temperature and pressure characteristics. <P>SOLUTION: The working fluid prepared by mixing an artificial refrigerant having a global warming potential (GWP) of 150 or less and a natural refrigerant is sealed in a temperature sensitive chamber 20a of the power element 20 of the expansion valve. The artificial refrigerant is selected from HFC-152a, HFC-41 and trifluoromethane iodide, and the natural refrigerant is selected from butane (R600), isobutane (R600a), propane (R290), carbon dioxide (R744) and ammonia (R717). Further an inert gas is mixed in the working fluid with a prescribed mixing ratio, thus the desired temperature and pressure characteristics are easily achieved. The bad influence on the environment is reduced even when the working fluid in the power element can not be recovered at disposal of the expansion valve. <P>COPYRIGHT: (C)2011,JPO&INPIT |
