System and Method for Venting Refrigerant from an Air Conditioning System

Patent metadata

Field	Value
Publication number	US-2016123641-A1
Application number	US-201514925271-A
Country	US
Kind code	A1
Filing date	Oct 28, 2015
Priority date	Oct 31, 2014
Publication date	May 5, 2016
Grant date	—

Abstract

An air conditioning service system includes an inlet port configured to connect to an air conditioning system to receive refrigerant, a discharge circuit, a pressure transducer, and a controller. The discharge circuit includes a plurality of discharge lines arranged in parallel with one another, each of the plurality of discharge lines fluidly connecting the inlet port to the atmosphere through an associated orifice to vent the refrigerant to atmosphere, and a plurality of discharge valves, each of which is configured to open and close an associated one of the plurality of discharge lines. The controller is configured to obtain the pressure at the inlet port and determine a theoretical mass flow rate through each of the plurality of discharge lines based upon the pressure and the cross-sectional area of the associated orifice, and to operate selected ones of the discharge valves based upon the determined theoretical mass flow rates.

First claim

1 . An air conditioning service system comprising:
an inlet port configured to connect to an air conditioning system to receive refrigerant; a discharge circuit including a plurality of discharge lines arranged in parallel with one another, each of the plurality of discharge lines fluidly connecting the inlet port to the atmosphere through an associated orifice having a cross-sectional area to vent the refrigerant to atmosphere, and a plurality of discharge valves, each of which is associated with one of the plurality of discharge lines and is configured to open and close the associated one of the plurality of discharge lines; a pressure transducer configured to sense a pressure at the inlet port; and a controller operably connected to the pressure transducer and to each of the plurality of discharge valves, the controller including a memory and a processor configured to execute program instructions stored in the memory to obtain the sensed pressure at the inlet port and determine a theoretical mass flow rate through each of the plurality of discharge lines based upon the sensed pressure and the cross-sectional area of the associated orifice, and to operate selected ones of the plurality of discharge valves based upon the determined theoretical mass flow rates.

2 . The air conditioning service system of claim 1 , wherein the controller is configured to determine a first set of the plurality of discharge valves having a combined theoretical flow rate that is less than a predetermined maximum flow rate, and to operate the first set of the plurality of discharge valves to open.

3 . The air conditioning service system of claim 2 , wherein the controller is configured to determine the first set of the plurality of discharge valves such that the total theoretical flow rate of the valves of the first set is a maximum possible combined theoretical flow rate that is less than the predetermined maximum flow rate.

4 . The air conditioning service system of claim 2 , wherein the controller is further configured to determine a first mass flow through the first set of the plurality of discharge valves during a first time period, and to store the mass flow in the memory.

5 . The air conditioning service system of claim 4 , wherein the controller is further configured to determine a total mass by summing a plurality of mass flows determined during a venting operation.

6 . A method comprising:
sensing a pressure of a refrigerant at an inlet port of an air conditioning service system that is connected to an air conditioning system to receive refrigerant therefrom; determining a theoretical mass flow rate through each discharge line of a plurality of discharge lines based upon the sensed pressure and a cross-sectional area of an associated orifice arranged in the discharge line, the plurality of discharge lines being arranged in parallel with one another in a discharge circuit and each of the plurality of discharge lines connecting the inlet port to the atmosphere through the associated orifice; and operating a plurality of discharge valves, each of the plurality of discharge valves being configured to open and close an associated one of the plurality of discharge lines, based upon the determined theoretical mass flow rates; and discharging refrigerant to atmosphere through selected ones of the plurality of discharge valves that are open.

7 . The method of claim 6 , further comprising:
determining a first set of the plurality of discharge valves having a combined theoretical flow rate that is less than a predetermined maximum flow rate, and wherein operating the plurality of discharge valves includes operating the first set of the plurality of discharge valves to open.

8 . The method of claim 7 , wherein the determining of the first set of the plurality of discharge valves includes determining the first set having a maximum possible total combined theoretical flow rate that is less than the predetermined maximum flow rate.

9 . The method of claim 7 , further comprising:
determining a first mass flow through the first set of valves during a first time period; and storing the mass flow in a memory.

10 . The method of claim 9 , further comprising:
determining a total mass by summing a plurality of mass flows determined during a venting operation; and storing the total mass in the memory.

11 . An air conditioning service system comprising:
an inlet port configured connect to an air conditioning system; a discharge circuit including a first discharge line fluidly connecting the inlet port to the atmosphere and a first discharge valve configured to open and close the first discharge line, the first discharge line including a first orifice having a first flow area; a pressure transducer configured to sense a pressure at the inlet port; and a controller operably connected to the pressure transducer and configured to obtain the sensed pressure at the inlet port and determine a first theoretical mass flow rate through the first orifice based upon the sensed pressure and the first cross-sectional area and to operate the first discharge valve based upon the first theoretical mass flow rate.

12 . The air conditioning service system of claim 11 , wherein:
the discharge circuit further comprises a second discharge line fluidly connecting the inlet port to the atmosphere and a second discharge valve configured to open and close the second discharge line, the second discharge line including a second orifice having a second flow area, and the controller is further configured to determine a second theoretical mass flow rate through the second orifice based upon the sensed pressure and the second cross-sectional area, and to operate the first and second discharge valves based upon the first and second theoretical mass flow rates.

13 . The air conditioning service system of claim 12 , wherein the first cross-sectional area is different from the second cross-sectional area.

Assignees

• Bosch Automotive Service Solutions Llc
• Bosch Gmbh Robert

Inventors

• Mcmasters Mark W
• Lundberg Dylan M

Classifications

• F25B2345/007

  characterised by the weighing of refrigerant or oil · CPC title

• F25B2345/006

  characterised by charging or discharging valves · CPC title

• F25B2345/0052

  having wheels · CPC title

• F25B2345/003

  Control issues for charging or collecting refrigerant to or from a cycle · CPC title

• F25B2345/002

  Collecting refrigerant from a cycle · CPC title