Condition responsive liquid line valve for refrigeration appliance

In a refrigeration system having a refrigerant fluid compressor having a suction inlet and a high pressure fluid outlet, a condenser connected to said compressor outlet for receiving compressed refrigerant therefrom, and an evaporator connected to said compressor suction inlet, a fluid flow control means connected between said condenser and evaporator comprising:

• a fixed restrictor;
• a valve for controlling refrigerant fluid flow through the restrictor;
• and
• means for controlling said valve to permit fluid flow therethrough whenever the compressor is running, and when the compressor is not running only in the event a sensed temperature condition corresponding to a preselected undesirable pressure at the outlet of the compressor is above a preselected temperature corresponding to said preselected pressure, thereby to effect reduction of said pressure to below said preselected pressure to permit subsequent starting of the compressor.

In a refrigeration system having a rotary compressor having a suction inlet and a high pressure fluid outlet, a condenser connected to said compressor outlet for receiving compressed refrigerant therefrom, and an evaporator connected to said compressor suction inlet, fluid flow control means connected between said condenser and evaporator comprising:

• a fixed restrictor;
• a normally open valve for controlling refrigerant fluid flow through the restrictor;
• and
• means for closing said valve only in the event the compressor is not running and the pressure at the outlet of the compressor is below a preselected pressure, thereby to assure that said outlet pressure is below said preselected pressure upon attempted subsequent starting of the compressor.

In a refrigerant system having a rotary refrigerant fluid compressor having a suction inlet and a high pressure fluid outlet which cannot be started when the outlet pressure is above a preselected value, a condenser connected to said compressor outlet for receiving compressed refrigerant therefrom, and an evaporator connected to said compressor suction inlet, a fluid flow control means connected between said condenser and evaporator comprising:

• a fixed restrictor;
• a valve having electric operating means for controlling refrigerant fluid flow through the restrictor;
• and
• a control circuit for controlling said valve operating means to permit fluid flow therethrough whenever the compressor is running, and when the compressor is not running only in the event a sensed temperature condition related to the pressure at the outlet of the compressor is above a preselected temperature corresponding to said preselected pressure, said control circuit including temperature responsive switch means for sensing the temperature of the compressed refrigerant fluid upstream of the valve, and a switch, said switch being electrically associated with said valve electrical operating means for causing selective open and closed conditions of said valve as a function of the operation of said compressor and said sensed temperature.

In a refrigeration system having a source of AC power, a rotary compressor having a suction inlet and an outlet, a condenser connected to said compressor outlet for receiving compressed refrigerant therefrom, an evaporator coupled to said compressor inlet, and a capillary tube restrictor for supplying refrigerant to said evaporator from said condenser, an improved refrigerant flow control means comprising:

• a temperature responsive switch arranged to sense a temperature indicative of the refrigerant pressure at said compressor outlet, said switch being normally closed at sensed temperatures below a predetermined temperature corresponding to an undesirably high refrigerant pressure condition at said outlet;
• a normally open electrically operated valve connected between said condenser and said capillary tube for controlling the refrigerant flow to said capillary tube, said valve and said temperature responsive switch and said compressor being electrically connected in series across said AC power source;
• a defrost switch having a contact normally closed during operation of the refrigeration system and open during defrosting operations;
• and
• a thermostat switch for controlling energization of said refrigeration system, said thermostat switch being electrically connected in series with said defrost switch and said compressor across said AC power source, said series connected thermostat switch and defrost switch being electrically connected in parallel with said series connected temperature responsive switch and electrically operated valve.