Method and apparatus for pressure equalization in rotary compressors

Patent metadata

Field	Value
Publication number	US-2018306196-A1
Application number	US-201715495061-A
Country	US
Kind code	A1
Filing date	Apr 24, 2017
Priority date	Apr 24, 2017
Publication date	Oct 25, 2018
Grant date	—

Abstract

A rotary compressor system includes a compressor housing that includes a compressor motor that draws in fluid from a suction side. The fluid is compressed within a compression chamber and discharged through a discharge side. The compression chamber is disposed between the suction side and the discharge side. An overload-protection switch is electrically coupled in series with the compressor motor and is adapted to cut power to the compressor motor responsive to an overload event. A solenoid valve is fluidly coupled between the compression chamber and a location upstream of the suction side and is electrically coupled in series with the overload-protection switch. An interruption of electrical current to the compressor motor also interrupts electrical current to the solenoid valve, which opens the solenoid valve to equalize pressure between the suction side and the discharge side.

First claim

What is claimed is:

1 . A rotary compressor system comprising:
a compressor housing comprising:
a compressor motor;
a suction side;
a discharge side;
a compression chamber disposed between the suction side and the discharge side; and
an overload-protection switch electrically coupled in series with the compressor motor and adapted to cut power to the compressor motor responsive to an overload event;
a solenoid valve comprising a valve fluidly coupled between the compression chamber and a location upstream of the suction side and a drive coil electrically coupled in series with the overload-protection switch; and wherein interruption of electrical current to the compressor motor interrupts electrical current to the drive coil thereby opening the valve to equalize pressure between the suction side and the discharge side.

2 . The rotary compressor system of claim 1 , further comprising:
a capacitor electrically coupled between a power source and a terminal of the compressor motor; and wherein the drive coil is wired in parallel with the capacitor.

3 . The rotary compressor system of claim 1 , further comprising a resistor wired in series with the drive coil to tune a voltage drop across the resistor and the solenoid valve.

4 . The rotary compressor system of claim 1 , further comprising:
an accumulator coupled to the suction side; and wherein the valve is fluidly coupled to the accumulator via a pressure-equalization tube.

5 . The rotary compressor system of claim 1 , further comprising:
an outdoor unit comprising:
the compressor housing; and
a condenser coil fluidly coupled to the discharge side of the compressor housing; and
an indoor unit comprising:
an evaporator coil fluidly coupled to the condenser coil; and
a circulation fan adapted to blow air from an enclosed space over the evaporator coil.

6 . A rotary compressor system comprising:
a compressor housing comprising:
a compressor motor;
a suction side;
a discharge side; a compression chamber; and
an overload-protection switch electrically coupled to the compressor motor and adapted to cut power to the compressor motor responsive to an overload event;
a solenoid valve comprising a valve fluidly coupled between the compression chamber and a location upstream of the suction side and a drive coil adapted to be electrically coupled to a power source; a current detector electrically coupled in series between the power source and a combination of the drive coil and the overload-protection switch; and wherein the current detector cuts power to the drive coil in response to the compressor motor losing power to open the valve so that pressure between the suction side and the discharge side can equalize.

7 . The rotary compressor system of claim 6 , further comprising:
a switch electrically coupled in series with the drive coil; and wherein the current detector controls operation of the switch to facilitate pressure equalization of the compressor housing.

8 . The rotary compressor system of claim 6 , further comprising:
an accumulator coupled to the suction side; and wherein the valve is fluidly coupled to the accumulator via a pressure-equalization tube.

9 . The rotary compressor system of claim 6 , further comprising:
an outdoor unit comprising:
the compressor housing; and
a condenser coil fluidly coupled to the discharge side of the compressor housing; and
an indoor unit comprising:
an evaporator coil fluidly coupled to the condenser coil; and
a circulation fan adapted to blow air from an enclosed space over the evaporator coil.

10 . A method of equalizing pressure in a rotary compressor system, the method comprising:
fluidly coupling a valve of a solenoid valve between a compression chamber of a compressor housing and a location upstream of a suction side of the compressor housing; electrically coupling a drive coil of the solenoid valve in series with an overload-protection switch; wherein, when the overload-protection switch is tripped, the drive coil receives no power and the valve is in an open position to permit equalization of pressure between the suction side of the compressor housing and a discharge side of the compressor housing; and wherein, when the overload-protection switch is in a closed position, the drive coil receives power and the valve is in a closed position to permit a compressed refrigerant to exit the compressor housing via the discharge side.

11 . The method of claim 10 , wherein the drive coil is electrically coupled in parallel with a capacitor.

12 . The method of claim 11 , wherein a voltage drop across the drive coil is configured to be approximately equal to a voltage drop across the capacitor.

13 . The method of claim 12 , wherein the voltage drop across the drive coil is adjusted by wiring a resistor in series with the drive coil.

14 . The method of claim 10 , wherein, responsive to the valve opening, fluid flows from a compression chamber within the compressor housing to the location upstream of the suction side.

15 . A method of equalizing pressure in a rotary compressor system, the method comprising:
fluidly coupling a valve of a solenoid valve between a compression chamber of a compressor housing and a suction side of the compressor housing; and electrically coupling a drive coil of the solenoid valve in parallel with a compressor motor; electrically coupling a current detector in series with a combination of the drive coil and the compressor motor so that the current detector measures a current drawn by the drive coil and the compressor motor; electrically coupling a switch to the drive coil such that when the switch is open the drive coil is depowered to open the valve; wherein, responsive to the current detector detecting a first current level indicating that the compressor motor is operating, the current detector sends a signal to the switch to close the switch; and wherein, responsive to the current detector detecting a second current level indicating that the compressor motor is not operating, the current detector sends a signal to the switch to open the switch.

16 . The method of claim 15 , wherein the compressor stops operating responsive to an overload-protection switch tripping.

17 . The method of claim 15 , wherein, responsive to the valve opening, fluid flows from a compression chamber within the compressor housing to a location upstream of the suction side.

Assignees

• Lennox Ind Inc

Inventors

• Ullrich Brandon
• Wang Wei

Classifications

• F04C28/24

  characterised by using valves controlling pressure or flow rate, e.g. discharge valves {or unloading valves}(F04C28/10 takes precedence) · CPC title

• F04C28/28

  Safety arrangements; Monitoring · CPC title

• F04C29/0085

  Prime movers · CPC title

• F25B2700/151

  of the compressor motor · CPC title

• F04C2240/40

  Electric motor · CPC title