Method of introducing an in situant into a vapor compression system, especially useful for leak detection, as well as an apparatus for leak detection and a composition useful for leak detection

• US 6,327,897 B1
• Filed: 06/11/1998
• Issued: 12/11/2001
• Est. Priority Date: 01/24/1997
• Status: Expired due to Term

• Current Assignee: Mainstream Engineering Coporation
• Original Assignee: Mainstream Engineering Coporation
• Inventors: Meyer, John A., Grzyll, Lawrence R., Back, Dwight D., Mayer, Joseph, Scaringe, Robert Peter
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): CYGAN, MICHAEL T
• Application Number:
  US09/095,513
• Time in Patent Office: 1,279 Days
• Field of Search: 73/40, 73/405.R, 73/407, 73/492, 73/493, 250/301, 250/302, 252/301.19, 252/301.16, 252/301.33, 503/583
• US Class Current: 73/40.7
• CPC Class Codes: F25B 2500/222 Detecting refrigerant leaks
• CPC Class Codes: G01M 3/20 using special tracer materials, e.g. dye, fluorescent material, radioactive material
• CPC Class Codes: G01M 3/228 for radiators
• CPC Class Codes: G01M 3/38 by using light G01M3/02 takes precedence

Abstract

Leaks are detected in a vapor compression system using fluorescent and daylight visible in situants which are introduced to a system by way of a carrier and dissolved into the systems oil or lubricant. This invention teaches the use of POE oil as a universal carrier fluid, alone or in combination with an alcohol, and combined with one or more “in situants”. The in situants are compounds which are the same or substantially similar to compounds already present in oils or lubricants. An on-off UV light source, such as a xenon light, can the be used to visually detect the leak from the vapor compression system components.

Claims

1. A method of introducing at least one in situant into an oil or lubricant of a vapor compression system for the purpose of detecting leaks in the vapor compression system components, comprising the steps of:

dissolving the at least one in situant in a carrier fluid of pure polyol ester oil or a polyol ester oil and alcohol solution,

delivering the at least one in situant and the carrier fluid into a vapor compression system fluid,

leaving the at least one in situant dissolved in the combined carrier/system fluid solution, and

removing any immiscible or slightly miscible components of the carrier fluid from the system fluid, thereby leaving the miscible carrier fluid components and at least one in situant dissolved in the system fluid,

wherein the at least one in situant is an oil or lubricant additive selected from the group consisting of anti-oxidation, anti-wear, anti-friction, dispersion improvement, viscosity index improvement additives.

2. The method of claim 1, further comprising the step of delivering an amount of the at least one in situant into the system in concentrations of up to the solubility limit of the at least one in situant in the system fluid.

3. The method of claim 1, wherein the at least one in situant comprises at least one compound which is soluble in the system fluid and the carrier fluid and has fluorescent properties.

4. The method of claim 1, wherein the at least one in situant comprises at least one organic compound that emits color in the visible spectrum.

5. The method of claim 1, wherein the at least one in situant comprises at least one fluorescent compound and at least one organic compound which emits color in the visible spectrum.

6. The method of claim 1, wherein the system oil or lubricant comprises at least one of polyalkylene glycol, polyol ester, mineral oil and alkylbenzene.

7. The method of claim 1, wherein one or more coumarin compounds are used with the at least one in situant.

8. The method of claim 1, wherein the carrier fluid comprises at least one of ethanol, methanol, and 2-propanol in solution with polyol ester oil.

9. The method of claim 1, wherein the at least one in situant comprises a heterocyclic molecule comprising at least one cyclic group comprising C, H, halogens, S, N, and O.

10. The method of claim 1, wherein the at least one in situant comprises a molecule comprising at least one cyclic group comprising C, H, halogens, S, N, and O.

11. The method of claim 1, wherein the at least one in situant comprises an organo-metallic compound.

12. The method of claim 1, wherein the at least one in situant is used in combination with one or more compounds selected from the group consisting of coumarin and derivatives thereof shown by the following structure,

wherein G represents groups comprising C, H, halogens N, and j is greater than or equal to 0.

13. The method of claim 1, wherein the at least one in situant is selected from the group consisting of phenylnaphthylamines shown by the following structure,

wherein R₁, R₂, and R₃ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures.

14. The method of claim 1, wherein the at least one in situant is selected from the group consisting of diphenylamines shown by the following structure,

wherein R₄ and R⁵ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures.

15. The method of claim 1, wherein the at least one in situant is selected from the group consisting of benzothiazolines shown by the following structure,

wherein R₆, R₇, R₈ and R₉ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures.

16. The method of claim 1, wherein the at least one in situant is selected from the group consisting of benzothiazoles, shown by the following structure,

wherein R₁₀ and R₁₁ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures.

17. The method of claim 1, wherein the at least one in situant is selected from the group of polyhydroxy-anthraquinone compounds where k is greater than or equal to one with the structure:

18. A leak detection method, comprising the steps of:

dissolving an organo-metallic in situant compound comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures in a carrier fluid comprising an alcohol in solution with polyol ester oil;

delivering the compound and the carrier fluid into a refrigeration system comprising a fluid system; and

causing the compound to fluoresce at any point in the system where there is a leak.

19. The method of claim 18, wherein the step of introducing the in situant compound into the system is effected in concentration up to the solubility limit of the compound in the system fluid.

20. The method of claim 18, wherein the system oil or lubricant comprises at least one of polyalkylene glycol, polyol ester, mineral oil and alkylbenzene.

21. The method of claim 18, wherein the carrier fluid comprises at least one of ethanol, methanol and 2-propanol in solution with polyol ester oil.

22. A leak detection method comprising the steps of:

dissolving an in situant capable of fluorescing into a carrier fluid comprising a polyol ester oil and alcohol solution;

introducing the carrier fluid and in situant into a refrigeration system comprising a system fluid comprising at least one of polyalkylene glycol, polyol ester, mineral oil and alkylbenzene; and

causing the compound to fluoresce at any point in the system where there is a leak, wherein the compound is soluble in the system fluid and comprises at least one of phenylnaphthylamines;

where R₁, R₂, and R₃ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures;

dialkyldiphenylamines;

where R₄ and R₅ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures;

organometallic compounds comprising molecular groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures in combination with at least one metal;

benzothiazolines;

where R₆, R₇, R₈ and R₉ are groups comprising at least one of C, H, halogens, N, S, and O in cyclic or acyclic structures;

benzothiazoles;

where R₁₀, and R₁₁ are groups comprising at least one C, H, halogens, N, S, and O in cyclic or acyclic structures; and

a group of compounds derived from the polyhydroxy-anthraquinone structure with k greater than or equal to 1;

23. The method of claim 22, wherein the step of introducing the in situant compound into the system is effected in concentrations of up to the solubility limit of the compound in the system fluid.

24. The method of claim 22, wherein one or more coumarin compounds are used in combination with an in situant compound.

25. The method of claim 22, further comprising removing immiscible components of the carrier fluid from the system fluid.

26. The method of claim 22, wherein the carrier fluid comprises at least one of ethanol, methanol and 2-propanol in solution with polyol ester oil.

27. A method of detecting leaks in a refrigeration system comprising a fluid system, comprising the steps of:

dissolving a fluorescing in situant compound into a carrier fluid comprising polyol ester oil and an alcohol;

delivering the in situant compound and the carrier fluid into the fluid system; and

detecting the leak with a UV lamp.

28. The method of claim 27, wherein the UV lamp is a xenon flash tube.

29. The method of claim 28, wherein the xenon flash tube comprises a quartz glass.

30. The method of claim 28, wherein the xenon flash tube is filled with a xenon gas mixture at a pressure of less than about 4 atmospheres.

31. The method of claim 28, wherein the xenon flash tube comprises a trigger circuitry means for obtaining an adjustable or a preset flash rate.

32. The method of claim 31, wherein the means produces a flash rate from about 4 flashes per second to about 1 flash every four seconds.

33. The method of claim 28, wherein the xenon flash tube comprises a filter glass with a high degree of internal transmittance in the 180 to 390 nm ultraviolet wavelength range.

34. The method of claim 28, wherein the xenon flash tube comprises an ultraviolet flash pulse circuit.

35. A method of introducing N-phenyl-1-naphthylamine into an oil or lubricant of a vapor compression system for the purpose of detecting leaks in the vapor compression system components, comprising the steps of:

dissolving the N-phenyl-1-naphthylamine in a carrier fluid of pure polyol ester oil or a polyol ester oil and alcohol solution,

delivering the N-phenyl-1-naphthylamine and the carrier fluid into the vapor compression system fluid,

leaving the N-phenyl-1-naphthylamine dissolved in the combined carrier/system fluid solution, and

removing any immiscible or slightly miscible components of the carrier fluid from the system fluid, thereby leaving the miscible carrier fluid components and N-phenyl-1-naphthylamine dissolved in the system fluid.

36. The method of claim 35, wherein said dissolving further comprises dissolving one or more coumarin compounds or one or more additional in situants in the carrier fluid.