System and method for recovering refrigerant

Patent metadata

Field	Value
Publication number	US-10429110-B2
Application number	US-201514757633-A
Country	US
Kind code	B2
Filing date	Dec 23, 2015
Priority date	Dec 30, 2014
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

An air conditioning service system includes a plurality of conduits and voids defining a total refrigerant receiving volume of the air conditioning service system, a pressure transducer configured to sense a pressure at a first location in the plurality of conduits and voids, a compressor operably connected to the plurality of conduits and voids, and a controller. The controller determines a quantity of refrigerant recovered from a refrigeration system by obtaining a first pressure signal from the pressure transducer corresponding to a first pressure at the first location, operating the compressor to recover the refrigerant from the refrigeration system after the first pressure is sensed, obtaining a second pressure signal from the pressure transducer corresponding to a second pressure at the first location after operating the compressor, and determining an amount of refrigerant recovered from the refrigeration system based on the first pressure signal an the second pressure signal.

First claim

The invention claimed is:

1. An air conditioning service system comprising:
a plurality of conduits and chambers defining a total refrigerant receiving volume of the air conditioning service system;
a pressure transducer configured to sense a pressure at a first location in the plurality of conduits and chambers;
a compressor operably connected to the plurality of conduits and chambers; and
a controller operably connected to the pressure transducer and the compressor, the controller including a processor configured to execute program instructions stored in a memory to determine a quantity of refrigerant recovered from a refrigeration system by:
obtaining a first pressure signal from the pressure transducer corresponding to a first pressure at the first location,
operating the compressor to recover the refrigerant from the refrigeration system after the first pressure is sensed,
obtaining a second pressure signal from the pressure transducer corresponding to a second pressure at the first location after operating the compressor, and
determining an amount of refrigerant recovered from the refrigeration system based on the first pressure signal and the second pressure signal.

2. The system of claim 1 , wherein the controller is configured to execute the program instructions to determine the quantity of refrigerant recovered by
determining a change in mass of refrigerant in the conduits and chambers from before operating the compressor to after operating the compressor based on the first and second pressure signals, and
determining the amount of refrigerant recovered from the refrigeration system based on the determined change in mass.

3. The system of claim 2 , wherein the controller is configured to execute the program instructions to determine the change in mass of refrigerant based upon the following equation:

Δ
⁢

⁢
m

=

MV
R

⁢

(

P
2

T
2

-

P
1

T
1

)

wherein:
Δm is the change in mass of refrigerant,
M is a molar mass of the refrigerant,
V is a volume fluidly connected to the first location,
R is the universal gas constant,
P 2 is the second pressure,
T 2 is a second temperature associated with the second pressure,
P 1 is the first pressure, and
T 1 is a first temperature associated with the first pressure.

4. The system of claim 3 , further comprising:
a refrigerant storage vessel; and
a scale configured to sense a weight of the refrigerant storage vessel,
wherein the controller is operably connected to the scale and is further configured to execute the program instructions to determine the quantity of refrigerant recovered by:
obtaining a first weight signal from the scale corresponding to a first weight of the refrigerant storage vessel prior to operating the compressor,
obtaining a second weight signal from the scale corresponding to a second weight of the refrigerant storage vessel after operating the compressor, and
wherein the determining of the amount of refrigerant recovered from the refrigeration system is based on the first weight signal, the second weight signal, the first pressure signal, and the second pressure signal.

5. The system of claim 4 , wherein the controller is configured to execute the program instructions to determine the amount of refrigerant recovered from the refrigeration system based upon the following equation:

W
rec

=

W

2
,
isv

-

W

1
,
isv

-

gMV
R

⁢

(

P
2

T
2

-

P
1

T
1

)

wherein:
W rec is the amount of refrigerant recovered from the refrigeration system expressed as a weight,
W 2,isv is the second weight of the refrigerant storage vessel,
W 1,isv is the first weight of the refrigerant storage vessel, and
g is the gravitational constant.

6. The system of claim 3 , further comprising:
a temperature sensor configured to sense a temperature of the air conditioning service system,
wherein the controller is operably connected to the temperature sensor and is configured to execute the program instructions to determine the quantity of refrigerant recovered by:
obtaining a first temperature signal from the temperature sensor corresponding to the first temperature, and
obtaining a second temperature signal from the temperature sensor corresponding to the second temperature.

7. The system of claim 1 , wherein:
the plurality of conduits and chambers includes a first portion connected to a high pressure side of the compressor and a second portion connected to a low pressure side of the compressor,
the air conditioning system further comprises a valve configured to control a connection between the first portion and the second portion,
the pressure transducer is configured to sense a pressure in the second portion, and
the controller is operably connected to the valve and is configured to execute the program instructions to determine the quantity of refrigerant recovered by:
operating the valve to an open position to equalize pressure between the first portion and the second portion prior to obtaining the first pressure signal, and
operating the valve to an open position to equalize pressure between the first portion and the second portion after operating the compressor and prior to obtaining the second pressure signal.

8. The system of claim 1 , wherein:
the plurality of conduits and chambers includes a first portion connected to a high pressure side of the compressor and a second portion connected to a low pre

Assignees

• Bosch Automotive Service Solutions Inc
• Bosch Gmbh Robert

Inventors

• Brown William C
• Lundberg Dylan M
• Mcmasters Mark W
• Hanson Jacob

Classifications

• F25B45/00 Primary

  Arrangements for charging or discharging refrigerant · 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

• F25B2345/006

  characterised by charging or discharging valves · CPC title

• F25B2345/0052

  having wheels · CPC title