US 6,615,599 B1Granted

Thermostatic expansion valve and air conditioning system for low refrigerant charge

AssigneeDelphi Technologies, Inc.

InventorsEdward Douglas Pettitt, John Paul Telesz, Jing Zheng

Life of this patent

Estimating the term…

Loading patent…

Abstract

A thermostatic expansion valve controls a flow of refrigerant. The valve includes a body defining a fluid chamber. A refrigerant inlet is defined within the body. The inlet communicates with the chamber such that the refrigerant can flow through the inlet and into the chamber. First and second outlets are defined within the body. The first outlet communicates with the chamber such that the refrigerant can flow from the chamber to an evaporator during normal and low refrigerant charge. The second outlet communicates with the chamber such that the refrigerant can flow from the chamber to a compressor during low charge. A moveable needle controls the flow of the refrigerant into and out of the body. A notch is defined within the needle such that, during low charge, the refrigerant that flows into the chamber can flow to the second outlet and to the compressor without flowing through the evaporator.

Claims35

Dependent claims

A thermostatic expansion valve for use in an air conditioning system that includes a refrigerant compressor, a condenser in fluid communication with an outlet of the compressor, a receiver in fluid communication with an outlet of the condenser, and an evaporator in fluid communication with an outlet of the receiver and with an inlet of the compressor, wherein said thermostatic expansion valve is adapted to control a flow of refrigerant to the evaporator under conditions of normal refrigerant charge, and is adapted to control the flow of refrigerant to the evaporator and to the compressor under conditions of low refrigerant charge, said thermostatic expansion valve comprising:

a valve body comprising a first end, a second end, and an interior wall defining a fluid chamber between said ends;
a liquid refrigerant inlet defined within said valve body in fluid communication with said fluid chamber such that the refrigerant can flow from the receiver through said liquid refrigerant inlet and into said fluid chamber;
a first liquid refrigerant outlet defined within said valve body in fluid communication with said fluid chamber such that the refrigerant can flow from said fluid chamber through said first liquid refrigerant outlet and to the evaporator during the conditions of normal and low refrigerant charge;
a second liquid refrigerant outlet defined within said valve body in fluid communication with said fluid chamber such that the refrigerant can flow from said fluid chamber through said second liquid refrigerant outlet and to the compressor during the conditions of low refrigerant charge;
a needle disposed in said fluid chamber and being moveable therein to control the flow of the refrigerant into and out of said valve body during the conditions of normal and low refrigerant charge;
and
a notch defined within said needle extending between said liquid refrigerant inlet and said second liquid refrigerant outlet such that, during the conditions of low refrigerant charge, an amount of the refrigerant that flows into said fluid chamber, from the receiver can flow through said fluid chamber to said second liquid refrigerant outlet and to the compressor without flowing through the evaporator.

4 more elements

An air conditioning system for controlling a flow of refrigerant under conditions of normal and low refrigerant charge, said air conditioning system comprising:

a refrigerant compressor;
a condenser in fluid communication with an outlet of said compressor;
a receiver in fluid communication with an outlet of said condenser;
an evaporator in fluid communication with an outlet of said receiver and with an inlet of said compressor;
a valve body disposed between said receiver and said evaporator and between said evaporator and said compressor, said valve body comprising a first end, a second end, and an interior wall defining a fluid chamber between said ends;
a liquid refrigerant inlet defined within said valve body in fluid communication with said receiver and said fluid chamber such that the refrigerant can flow from said receiver through said liquid refrigerant inlet and into said fluid chamber;
a first liquid refrigerant outlet defined within said valve body in fluid communication with said fluid chamber and said evaporator such that the refrigerant can flow from said fluid chamber through said first liquid refrigerant outlet and to said evaporator during the conditions of normal and low refrigerant charge;
a second liquid refrigerant outlet defined within said valve body in fluid communication with said fluid chamber and said compressor such that the refrigerant can flow from said fluid chamber through said second liquid refrigerant outlet and to said compressor during the conditions of low refrigerant charge;
a needle disposed in said fluid chamber and being moveable therein to control the flow of the refrigerant into and out of said valve body during the conditions of normal and low refrigerant charge;
and
a notch defined within said needle extending between said liquid refrigerant inlet and said second liquid refrigerant outlet such that, during the conditions of low refrigerant charge, an amount of the refrigerant that flows into said fluid chamber from said receiver can flow through said fluid chamber to said second liquid refrigerant outlet and to said compressor without flowing through said evaporator.

8 more elements

An air conditioning system for controlling a flow of refrigerant under conditions of normal and low refrigerant charge, said air conditioning system comprising:

a refrigerant compressor;
a condenser in fluid communication with an outlet of said compressor;
an evaporator in fluid communication with an outlet of said condenser and with an inlet of said compressor;
a valve body disposed between said condenser and said evaporator and between said evaporator and said compressor, said valve body comprising a first end, a second end, and an interior wall defining a fluid chamber between said ends;
a liquid refrigerant inlet defined within said valve body in fluid communication with said condenser and said fluid chamber such that the refrigerant can flow from said condenser through said liquid refrigerant inlet and into said fluid chamber;
a first liquid refrigerant outlet defined within said valve body in fluid communication with said fluid chamber and said evaporator such that the refrigerant can flow from said fluid chamber through said first liquid refrigerant outlet and to said evaporator during the conditions of normal and low refrigerant charge;
a second liquid refrigerant outlet defined within said valve body in fluid communication with said fluid chamber and said compressor such that the refrigerant can flow from said fluid chamber through said second liquid refrigerant outlet and to said compressor during the conditions of low refrigerant charge;
a needle disposed in said fluid chamber and being moveable therein to control the flow of the refrigerant into and out of said valve body during the conditions of normal and low refrigerant charge;
and
a notch defined within said needle extending between said liquid refrigerant inlet and said second liquid refrigerant outlet such that, during the conditions of low refrigerant charge, an amount of the refrigerant that flows into said fluid chamber from said condenser can flow through said fluid chamber to said second liquid refrigerant outlet and to said compressor without flowing through said evaporator.

7 more elements

Dependencies are inferred from the claim text.