Pressure Decay Leak Check Method and Apparatus

• US 20120291457A1
• Filed: 03/29/2012
• Published: 11/22/2012
• Est. Priority Date: 05/17/2011
• Status: Abandoned Application

• Current Assignee: Service Solutions US LLC
• Original Assignee: Service Solutions US LLC
• Inventors: Brown, William, McMasters, Mark, Murray, Gary
• Application Number:
  US13/434,120
• Publication Number:
  US 20120291457A1
• Time in Patent Office: Days
• US Class Current: 62/77
• CPC Class Codes: B60H 1/00585 Means for monitoring, testing or servicing the air-conditioning
• CPC Class Codes: F25B 2500/222 Detecting refrigerant leaks
• CPC Class Codes: F25B 45/00 Arrangements for charging or discharging refrigerant
• CPC Class Codes: G01M 3/26 by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
• CPC Class Codes: G01M 3/3227 for radiators

Abstract

Refrigerant recovery unit is provided that includes steps to test for refrigerant leaks. The steps include providing a close loop with the hoses that connect to a refrigerant system, measuring the ambient temperature, calculating the vapor pressure with the ambient temperature, calculating the test pressure as a percentage of the vapor pressure, filling the unit with the refrigerant, and performing a pressure leak test.

Claims

1. A method of performing a pressure leak test on a refrigerant recovery unit, comprising the steps of:

measuring an ambient temperature with a temperature sensor controlled by a controller of the refrigerant recovery unit;

determining a saturated vapor pressure with the measured ambient temperature using the controller;

determining a test pressure as a percentage of the determined saturated vapor pressure using the controller;

measuring a first pressure in the refrigerant recovery unit with a pressure sensor controlled by the controller; and

determining if the refrigerant recovery unit has passed the pressure leak test with the controller.

2. The method of claim 1 further comprising the steps of:

determining if the measured first pressure of the refrigerant recovery unit is above the determined test pressure using the controller;

determining a pressure leak test time based on the determined test pressure; and

running the pressure leak test based on the determined pressure leak test time.

3. The method of claim 2 further comprising the steps of:

performing a recovery function if the measured first pressure of the refrigerant recovery unit is above the determined test pressure; and

cycling refrigerant in the refrigerant recovery unit until the refrigerant recovery unit reaches the determined test pressure.

4. The method of claim 1 further comprising the steps of:

determining if the measured ambient temperature is below 10°

C.; and

alerting a user that the ambient temperature is too low to run the pressure leak test when the measured ambient temperature is below 10°

C.

5. The method of claim 1 further comprising the steps of:

determining if a measured tank pressure is above the determined saturated vapor pressure; and

alerting a user that the measured tank pressure is too high to run the pressure leak test when the measured tank is above the calculated saturated pressure.

6. The method of claim 2 further comprising the steps of:

allowing the refrigerant recovery unit to stabilize;

measuring a second pressure of the refrigerant recovering unit with the pressure sensor; and

saving the second pressure of the refrigerant recovery unit into a memory, wherein the refrigerant recovery unit passes the pressure leak test if a third measured pressure of the refrigerant recovery unit does not decrease beyond a predetermined amount from the saved the second measured pressure of the refrigerant recovery unit.

7. The method of claim 6, wherein the predetermined amount is about 0.20 bar.

8. The method of claim 2 further comprising the steps of:

allowing the refrigerant recovery unit to stabilize;

measuring a second pressure of the refrigerant recovering unit with the pressure sensor;

saving the measured second pressure of the refrigerant recovery unit into a memory, wherein the refrigerant recovery unit fails the pressure leak test if a third measured pressure of the refrigerant recovery unit decreases beyond a predetermined amount from the saved second measured pressure of the refrigerant recovery unit.

9. The method of claim 8, wherein the predetermined amount is about 0.20 bar.

10. A method of performing a pressure leak test on a refrigerant recovery unit, comprising the steps of:

measuring an ambient temperature with a temperature sensor controlled by a controller of the refrigerant recovery unit;

determining a saturated vapor pressure with the measured ambient temperature using the controller;

determining a test pressure as a percentage of the determined saturated vapor pressure; and

determining if the refrigerant recovery unit has passed the pressure leak test with the controller.

11. The method of claim 10 further comprising the steps of:

determining a pressure leak test time based on the determined test pressure; and

running the pressure leak test based on the determined pressure leak test time.

12. The method of claim 11 further comprising the steps of:

measuring a first pressure in the refrigerant recovery unit with a pressure sensor controlled by the controller;

determining if the measured first pressure of the refrigerant recovery unit is above the determined test pressure using the controller; and

reducing the measured first pressure of the refrigerant recovery unit if the measured first pressure is above the determined test pressure.

13. The method of claim 10 further comprising the step of:

cycling refrigerant in the refrigerant recovery unit until the refrigerant recovery unit reaches the determined test pressure.

14. The method of claim 10 further comprising the steps of:

determining if the measured ambient temperature is below 10°

C.; and

alerting a user that the ambient temperature is too low to run the pressure leak test when the measured ambient temperature is below 10°

C.

15. The method of claim 10 further comprising the steps of:

determining if a measured tank pressure is above the determined saturated pressure; and

alerting a user that the measured tank pressure is too high to run the pressure leak test when the measured tank pressure is above the determined saturated vapor pressure.

16. The method of claim 11 further comprising the steps of:

allowing the refrigerant recovery unit to stabilize;

measuring a second pressure of the refrigerant recovering unit with the pressure sensor; and

saving the second pressure of the refrigerant recovery unit into a memory, wherein the refrigerant recovery unit passes the pressure leak test if a third measured pressure of the refrigerant recovery unit pressure does not decrease beyond a predetermined amount from the saved second measured pressure of the refrigerant recovery unit.

17. The method of claim 16, wherein the predetermined amount is about 0.20 bar.

18. The method of claim 11 further comprising the steps of:

allowing the refrigerant recovery unit to stabilize;

measuring a second pressure of the refrigerant recovering unit with the pressure sensor;

saving the second pressure of the refrigerant recovery unit into a memory, wherein the refrigerant recovery unit fails the pressure leak test if a third measured pressure of the refrigerant recovery unit pressure decreases beyond a predetermined amount from the saved second measured pressure of the refrigerant recovery unit.

19. The method of claim 18, wherein the predetermined amount is about 0.20 bar.

20. A refrigerant recovery unit having a pressure leak test, comprising:

a recovery circuit configured to recover a refrigerant from a refrigerant system;

a charging circuit configured to charge the refrigerant into the refrigerant system;

a recycling circuit configured to recycle refrigerant recovered from the refrigerant system;

a refrigerant storage tank in fluid communication with the recovery, charging and recycling circuits; and

a controller that controls the recovery, charging and recycling circuits, wherein the controller performs the following steps;

measuring an ambient temperature with a temperature sensor;

determining a saturated vapor pressure with the measured ambient temperature;

determining a test pressure as a percentage of the determined saturated vapor pressure;

measuring a first pressure in the refrigerant recovery unit with a first pressure sensor;

determining if the measured first pressure of the refrigerant recovery unit is above the determined test pressure; and

determining if the refrigerant recovery unit has passed the pressure leak test.

21. The refrigerant recovery unit of claim 20, wherein the controller further perform the following steps:

determining a pressure leak test time based on the determined test pressure; and

running the pressure leak test based on the determined pressure leak test time.

22. The refrigerant recovery unit of claim 20, wherein the refrigerant storage tank is coupled to a second pressure sensor, wherein the second pressure sensor communicates with the controller.

23. The refrigerant recovery unit of claim 20 further comprising of hoses configured to couple to hose couplers to form a closed loop with the refrigerant recovery unit.