Method of and system for reducing refrigerant pressure in HVAC systems

Patent metadata

Field	Value
Publication number	US-10921032-B2
Application number	US-201916421611-A
Country	US
Kind code	B2
Filing date	May 24, 2019
Priority date	May 15, 2014
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

A method that determines whether at least one condition indicating a likelihood of one or more high refrigerant pressures within a heating, ventilation, and air-conditioning (HVAC) system is present. The method includes generating a first control signal configured to switch a first valve from an open to a closed position in response to determining that at least one condition indicating a likelihood of one or more high refrigerant pressures within the HVAC system is present and upon expiration of a defined first period of time. The method further includes generating a second control signal configured to switch the first valve from a closed to an open position following generation of the first control signal and upon expiration of a defined second period of time.

First claim

The invention claimed is:

1. A heating, ventilation, and air-conditioning (HVAC) system, comprising:
a receptacle;
a first tube comprising a first end and a second end, the first tube coupled to a manifold at the first end and coupled to the receptacle at the second end, the manifold coupled to a condenser of the HVAC system and configured to receive refrigerant from at least one outlet of a first pass of tubing for routing refrigerant through the condenser,
wherein the receptacle is in fluid communication with the at least one outlet of the first pass of tubing through the condenser via the first tube, the first tube configured to form a conduit for refrigerant migration into the receptacle in response to, at least, one or more high refrigerant pressures within the HVAC system, and the first tube configured to form a conduit for refrigerant draining from the receptacle in response to, at least, one or more low refrigerant pressures within the HVAC system;
a first valve coupled to the first tube, the first valve configured to permit refrigerant to migrate into or drain from the receptacle when open, the first valve further configured to prevent refrigerant to migrate into or drain from the receptacle when closed; and
a controller operable to:
determine whether at least one condition indicating a likelihood of one or more high refrigerant pressures within the HVAC system is present;
generate a first control signal configured to, at least, switch the first valve from an open to a closed position in response to determining that at least one condition indicating a likelihood of one or more high refrigerant pressures within the HVAC system is present and upon expiration of a defined first period of time; and
generate a second control signal configured to, at least, switch the first valve from a closed to an open position following generation of the first control signal and upon expiration of a defined second period of time.

2. The system of claim 1 , wherein the second end of the first tube is disposed at a position vertically higher than the first end of the first tube; and wherein refrigerant within the receptacle drains from the receptacle via the first tube in response to, at least, the force of gravity.

3. The system of claim 1 , wherein the refrigerant within the manifold comprises both liquid phase and gas phase refrigerant, and wherein first tube is configured to allow migration of liquid phase refrigerant into the receptacle in response to at least, one or more high refrigerant pressures within the HVAC system.

4. The system of claim 3 , wherein the first tube is coupled to the manifold at a location vertically below a saturation height of refrigerant within the manifold, and wherein the second end of the first tube is disposed at a location vertically above the saturation height of refrigerant within the manifold.

5. The system of claim 1 , further comprising:
a second tube comprising a first end and a second end, the second tube coupled to the receptacle at the first end and coupled to the manifold at the second end, the second tube configured to form a conduit for refrigerant migration between the receptacle and the manifold allowing for one or more pressure differences between refrigerant within the receptacle and refrigerant within the manifold may dissipate through the second tube; and
a second valve coupled to the second tube, the second valve configured to permit refrigerant migration between the receptacle and the manifold when open, the second valve further configured to prevent refrigerant flow between the receptacle and the manifold when closed;
the controller further operable to:
generate the first control signal configured to, at least, switch both the first and second valves from open to closed positions in response to determining that at least one condition indicating a likelihood of one or more high refrigerant pressures within the HVAC system is present and upon expiration of a defined first period of time; and
generate the second control signal configured to, at least, switch the first and second valves from closed to open positions following generation of the first control signal and upon expiration of a defined second period of time.

6. The system of claim 5 , wherein the first and second valves are solenoid valves.

7. The system of claim 5 , wherein the refrigerant within the manifold comprises both liquid phase and gas phase refrigerant, and wherein second tube is configured to allow migration of gaseous phase refrigerant between the receptacle in response to at least, one or more refrigerant pressure differences between refrigerant within the receptacle and refrigerant within the manifold.

8. The system of claim 7 , wherein the second tube is coupled to the manifold at a location vertically above a saturation height of refrigerant within the manifold, and wherein the first end of the second tube is disposed at a location vertically above the saturation height of refrigerant within the manifold.

9. The system of claim 1 , further comprising:
a first compressor and a second compressor, the first and second compressors configured for operation as tandem compressors and in fluid communication with the condenser; and
wherein the condenser is a microchannel heat exchanger.

10. The system of claim 1 , wherein the receptacle is disposed downstream of the condenser.

11. A method comprising:
determining, using a controller, whether at least one condition indicating a likelihood of one or more high refrigerant pressures within a heating, ventilation, and air-conditioning (HVAC) system is present;
generating, using the controller, a first control signal configured to, at least, switch a first valve from an open to a closed position in response to determining that at least one condition indicating a likelihood of one or more high refrigerant pressures within the HVAC system is present and upon expiration of a defined first period of time;
wherein the first valve is coupled to a first tube, the first valve configured to permit refrigerant to flow through the first tube when open and configured to prevent refrigerant to flow through the first tube when closed, the first tube coupled to a manifold of a condenser, the manifold configured to receive refrigerant from at least one outlet of a first pass of tubing of the condenser; wherein the first tube is coupled to a first receptacle, the first receptacle configured to be in fluid communication with the first pass of tubing through a condenser via the first tube and the manifold for receiving refrigerant exiting the first pass of the condenser at times when one or more high refrigerant pressures are present within the HVAC system;
generating, using the controller, a second control signal configured to, at least, switch the first valve from a closed to an open position following generation of the first control signal and upon expiration of a defined second period of time.

12. The method of claim 11 , further comprising:
generating, using the controller, the second control signal for, at least, switching the first valve from a closed to an open position upon the controller determining that the at least one condition indicating a likelihood of one or more high refrigerant pressures within the HVAC system is no longer present.

13. The method of claim 11 , further comprising:
generating, using the controller, the second control signal for, at least, switching the first valve from a closed to an open position upon the controller determining that no conditions indicating a likelihood of one or more high refrigerant pressures within the HVAC system are present.

14. Th

Assignees

• Lennox Ind Inc

Inventors

• Goel Rakesh

Classifications

• F16L55/02 Primary

  Energy absorbers; Noise absorbers · CPC title

• F25B45/00 Primary

  Arrangements for charging or discharging refrigerant · CPC title

• F25B41/39

  Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator · CPC title

• F25B41/40

  Fluid line arrangements · CPC title

• F25B41/20

  Disposition of valves, e.g. of on-off valves or flow control valves (expansion valves F25B41/31) · CPC title