| 摘要 |
The invention relates to a thermostatic valve assembly for refrigeration systems. The valve assembly is between the condenser and the evaporator and includes two valve units in series. The two valve units are shown integrated in one casing but could be provided with individual casings. The second valve unit has the conventional thermostatic function while the first valve unit functions to isolate the second valve unit from the effects of varying condenser pressures which go from high in the winter to low in the summer. In a pressure chamber between the two valve units a mean pressure is maintained which is between the condenser and evaporator pressures. The first valve unit is controlled by a balancing between opening forces created by evaporator pressure and a differential spring and a closing force created by the mean pressure in the mean pressure chamber. In this way the mean pressure is constantly maintained larger than the evaporator pressure by a predetermined difference and the effects of a varying condenser pressure are substantially minimized. |
