Ultraviolet (UV) light-based refrigerant leak detection system and method
A leak detection system of a heating, ventilating, and air conditioning (HVAC) system includes a sensor configured to detect a UV tracer in a monitored gas volume of the HVAC system. The leak detection system also includes a controller communicatively coupled to the sensor. The controller is configured to modify operation of the HVAC system in response to the sensor detecting the UV tracer in the monitored gas volume.
1. A leak detection system of a heating, ventilating, and air conditioning (HVAC) system, comprising:
a sensor configured to measure a concentration of an ultraviolet (UV) tracer in a monitored gas volume of the HVAC system; and
a controller communicatively coupled to the sensor, wherein the controller is configured to:
determine a concentration of leaked refrigerant in the monitored gas volume based on the measured concentration of the UV tracer within the monitored gas volume; and
modify operation of the HVAC system when the concentration of the leaked refrigerant in the monitored gas volume is greater than a predetermined threshold value.
2. The system of claim 1 , comprising a sample preparation unit configured to collect a gas sample from the monitored gas volume and to prepare the gas sample for UV analysis, wherein the gas sample comprises the leaked refrigerant and the UV tracer.
3. The system of claim 2 , comprising a valve communicatively coupled to the controller, wherein the valve is configured to actuate to collect the gas sample from the monitored gas volume in response to control signals from the controller.
4. The system of claim 2 , wherein the sample preparation unit comprises a compressor configured to compress the gas sample to prepare the gas sample for the UV analysis.
5. The system of claim 1 , wherein the sensor comprises a UV tracer detection unit configured to detect a concentration of the UV tracer in a sample collected from the monitored gas volume.
6. The system of claim 5 , wherein the UV tracer detection unit comprises:
a light source configured to irradiate the gas sample with emitted light; and
a light detector configured to detect modified light from the gas sample, wherein the emitted light interacts with the sample to generate the modified light.
7. The system of claim 6 , wherein the sensor is configured to use a difference between an intensity of the emitted light and an intensity of the modified light to detect the concentration of the UV tracer in the sample.
8. The system of claim 6 , wherein a frequency of the emitted light is different than a frequency of the modified light, and wherein the sensor is configured to correlate an intensity of the modified light with the concentration of the UV tracer in the sample.
9. The system of claim 6 , wherein the controller is configured to correlate the UV tracers being present in the sample with the concentration of leaked refrigerant in the monitored gas volume using a predetermined ratio associated with a refrigerant of the HVAC system and the UV tracer.
10. The system of claim 6 , wherein the UV tracer detection unit comprises a reflective surface configured to direct the emitted light to the sample.
11. The system of claim 6 , wherein the UV tracer detection unit comprises a reflective surface configured to direct modified light to the light detector.
12. The system of claim 6 , wherein the UV tracer detection unit comprises a plurality of reflective surfaces, wherein the plurality of reflective surfaces is configured to cooperate to direct the emitted light to the gas sample, to direct the modified light to the light detector, or a combination thereof.
13. The system of claim 10 , wherein the reflective surface is a surface of a duct of the HVAC system.
14. The system of claim 6 , wherein the light detector comprises a camera configured to detect the modified light from the gas sample.
15. The system of claim 6 , wherein the light detector comprises a photovoltaic device that is configured to detect the modified light from the gas sample.
16. The system of claim 1 , wherein the sensor is disposed within a duct of the HVAC system, and wherein the monitored gas volume comprises conditioned air within the HVAC system.
17. The system of claim 1 , wherein the sensor is disposed within a casing of an interior HVAC unit of the HVAC system, and wherein the monitored gas volume is within the casing of the interior HVAC unit.
18. The system of claim 17 , wherein the HVAC system comprises an evaporator disposed within the casing of the interior HVAC unit, and wherein the sensor is disposed near the evaporator.
19. The system of claim 1 , wherein the sensor is disposed within a casing of an exterior HVAC unit of the HVAC system, and wherein the monitored gas volume is within the casing of the exterior HVAC unit.
20. The system of claim 19 , wherein the HVAC system comprises a condenser disposed within the casing of the exterior HVAC unit, and wherein the sensor is disposed near the condenser.
21. A leak detection system of a heating, ventilating, and air conditioning (HVAC) system, comprising:
a vapor compression system configured to circulate a refrigerant that includes an ultraviolet (UV) tracer;
a UV tracer sensor comprising a UV tracer detection unit having a light source and a light detector, wherein the light source is configured to irradiate a gas sample with emitted light, wherein the gas sample is in a monitored gas volume near the vapor compression system of the HVAC system, and wherein the light detector is configured to detect modified light from the gas sample;
a controller configured to:
output a control signal causing the light source to emit the emitted light;
receive, from the light detector, a concentration of the UV tracer based on detection of the modified light;
determine a concentration of refrigerant in the monitored gas volume based on the concentration of the UV tracer; and
modify operation of the HVAC system when the concentration of refrigerant in the monitored gas volume is greater than a predetermined threshold value wherein modifying comprises at least preventing a compressor of the HVAC system from activating.
22. The system of claim 21 , wherein the UV tracer sensor comprises a sample preparation unit fluidly coupled to the UV tracer detection unit, wherein the sample preparation unit is configured to collect the gas sample from the monitored gas volume; and
wherein the controller is configured to:
determine whether the compressor associated with the HVAC system is idle; and
provide a second control signal to the sample preparation unit causing the sample preparation unit to collect the gas sample from the monitored gas volume in response to determining that compressor is idle.
23. The system of claim 21 , wherein the vapor compression system comprises an evaporator, and wherein the sensor is disposed near the evaporator.
24. The system of claim 22 , wherein the sample preparation unit comprises a compressor configured to compress the gas sample before the UV tracer detection unit measures the concentration of the UV tracer in the gas sample.
25. The system of claim 21 , wherein the UV tracer detection unit comprises a plurality of reflective materials configured to cooperate to direct the emitted light to the gas sample, to direct the modified light to the light detector, or a combination thereof.
26. The system of claim 25 , wherein the reflective materials are disposed along an inner surface of a casing of an indoor HVAC unit or outdoor HVAC unit of the HVAC system.
27. The system of claim 21 , wherein the light detector comprises a camera configured to detect the modified light from the gas sample.
28. The system of claim 21 , wherein the UV tracer sensor is disposed within a duct of the HVAC system, and wherein the monitored gas volume comprises conditioned air within the HVAC system.
29. A method of operating a sensor to detect a refrigerant in a monitored gas volume associated with a heating, ventilation, and air conditioning (HVAC) system, the method comprising:
collecting a sample from the monitored gas volume;
measuring an amount of ultraviolet (UV) tracer in the sample;
determining an amount of refrigerant present in the monitored gas volume based at least in part on the measured amount of UV tracer in the sample; and
modifying operation of the HVAC system in response to determining that the amount of refrigerant present in the monitored gas volume is greater than a predetermined threshold value, wherein modifying the operation comprises at least preventing the compressor system from activating.
30. The method of claim 29 , comprising disabling the compressor before collecting the sample.
31. The method of claim 29 , comprising preparing the sensor before collecting the sample.
32. The method of claim 29 , wherein modifying operation comprises activating one or more fans associated with ductwork of the HVAC system.
33. The system of claim 2 , wherein the controller is configured to:
output a first control signal causing a compressor of the HVAC system to disable operation; and
output a second control signal to the sample preparation unit causing the sample preparation unit to collect the gas sample from the monitored gas volume after outputting the first control signal.
34. The system of claim 29 , where in the sample comprises the refrigerant and the UV tracer.
35. The system of claim 21 , where in the controller is configured to:
provide a control signal that causes the compressor to disable operation before determining the concentration of the refrigerant in the monitored gas volume.
36. The system of claim 21 , wherein modifying operation comprises activating one or more fans associated with a ductwork of the HVAC system.
37. The system of claim 21 , wherein modifying operation comprises deactivating one or more fans associated with a condenser, an evaporator, or both, of the HVAC system.