Moderate-to-low global warming potential value refrigerant leak detection

Patent metadata

Field	Value
Publication number	US-2021108819-A1
Application number	US-201816496091-A
Country	US
Kind code	A1
Filing date	Apr 4, 2018
Priority date	Apr 6, 2017
Publication date	Apr 15, 2021
Grant date	—

Abstract

An air conditioning system is provided and includes a unit receptive of refrigerant having a moderate-to-low global warming potential (GWP) value for thermal interaction with a fluid, an enclosure, a fan disposed and configured for urging a flow of the fluid through the unit, a refrigerant detection sensor and a controller. The refrigerant detection sensor is disposed in the enclosure to be operable in a first mode in which a baseline response is established and a second mode in which refrigerant leak detection is executed based on the baseline response. The refrigerant detection sensor is further configured to generate a binary output of leak and non-leak signals in accordance with a result of the refrigerant leak detection. The controller is configured to control operations of the fan and the vent based on the binary output.

First claim

What is claimed is:

1 . An air conditioning system, comprising:
a unit receptive of a refrigerant having a moderate-to-low global warming potential (GWP) value for thermal interaction with a fluid; an enclosure comprising a main section surrounding the unit and having a vent, an outlet and an inlet, an exhaust duct leading from the outlet to the vent and a return-air duct extending from the exhaust duct to the inlet; a fan disposed and configured for urging a flow of the fluid through the unit; a refrigerant detection sensor disposed in the enclosure to be operable in a first mode in which a baseline response is established and a second mode in which refrigerant leak detection is executed based on the baseline response; the refrigerant detection sensor being further configured to generate a binary output of leak and non-leak signals in accordance with a result of the refrigerant leak detection; and a control device and firmware configured to communicate to the main controller of the air conditioning system for operations of the fan and the optional vent based on the output.

2 . The air conditioning system according to claim 1 , wherein the refrigerant detection sensor is disposed proximate to a pooling region of the enclosure.

3 . The air conditioning system according to claim 1 , wherein the refrigerant detection sensor comprises:
a detection assembly; and an actuation assembly receptive of a signal from the detection assembly and configured for generation of the binary output based on the signal and for issuance of the binary output to the controller.

4 . The air conditioning system according to claim 3 , wherein the detection assembly comprises:
an emitter; a detector; an optical element to reflect radiation emitted by the emitter toward the detector such that the radiation passes through an elongate section of the enclosure; and a band pass filter disposed along a radiation pathway between the emitter and the detector.

5 . The air conditioning system according to claim 4 , wherein the detection assembly is configured to detect multiple types of the refrigerant.

6 . The air conditioning system according to claim 4 , wherein the detection assembly further comprises a flow driving element.

7 . The air conditioning system according to claim 3 , wherein the actuation assembly comprises an analog-to-binary output conversion circuit.

8 . The air conditioning system according to claim 1 , wherein the intermittent baseline calibration comprises establishing a baseline response of the refrigerant detection sensor to an execution of leak detection.

9 . The air conditioning system according to claim 1 , wherein the refrigerant detection sensor recalibrates at certain times and/or at predefined intervals.

10 . The air conditioning system according to claim 9 , wherein the refrigerant detection sensor executes diagnostics at the certain times and/or the predefined intervals.

11 . The air conditioning sensor according to claim 1 , wherein the leak detection comprises:
an iterative determination that a concentration of the refrigerant in a sample drawn from the enclosure exceeds first or second thresholds defined in accordance with the most recent recalibration; a setting of the output to correspond to the leak signal in an event the concentration exceeds either of the first or second thresholds; and a setting of the output to correspond to the non-leak signal in an event the concentration does not exceed either of the first or second thresholds.

12 . The air conditioning sensor according to claim 11 , wherein the system controller activates the fan for extended or abbreviated periods of time and opens the vent based on the discrete output corresponding to the leak signal and in the event the concentration exceeds either of the first or second thresholds, respectively, and deactivates the fan and closes the vent based on the binary output corresponding to the non-leak signal.

13 . The air conditioning sensor according to claim 1 , wherein the system controller comprises a relay electrically interposed between the refrigerant detection sensor and the fan and the optional vent.

14 . A controllable moderate-to-low global warming potential (GWP) value refrigerant leak detector, comprising:
a detection assembly comprising an emitter, a detector, an optical element to reflect radiation emitted by the emitter toward the detector such that the radiation passes through an elongate section of an enclosure and a band pass filter disposed along a radiation pathway between the emitter and the detector, wherein: the band pass filter is tuned for detection of the moderate-to-low GWP value refrigerant, and the detector is receptive of a portion of the radiation passing through the band pass filter; and an actuation assembly receptive of a signal, which is reflective of a magnitude of the portion of the radiation, from the detector and configured for generation of a binary output based on the signal and for issuance of the binary output to a fan/vent controller.

15 . A method of operating an air conditioning system comprising a refrigerant detection sensor configured to execute leak detection with respect to leakage of refrigerant having a moderate-to-low global warming potential (GWP) value into an enclosure, the method comprising:
recalibrating the refrigerant detection sensor; setting the refrigerant detection sensor to a detection mode; iteratively determining, at the refrigerant detection sensor, that a concentration of the refrigerant in a sample drawn from the enclosure exceeds a threshold defined in accordance with a most recent recalibration; setting a binary output of the refrigerant detection sensor to correspond to leak or non-leak signals in an event the concentration exceeds or does not exceed the threshold, respectively; and mitigating the leakage of the refrigerant based on the binary output corresponding to the leak signal.

16 . The method according to claim 15 , wherein the refrigerant detection sensor comprises:
a detection assembly; and an actuation assembly receptive of a signal from the detection assembly and configured for generation of the binary output based on the signal and for issuance of the binary output to the controller.

17 . The method according to claim 15 , wherein the detection assembly comprises:
an emitter; a detector; an optical element to reflect radiation emitted by the emitter toward the detector such that the radiation passes through an elongate section of the enclosure; and a band pass filter disposed along a radiation pathway between the emitter and the detector.

18 . The method according to claim 17 , wherein the detection assembly is configured to detect multiple types of the refrigerant.

19 . The method according to claim 15 , further comprising executing diagnostics at the predefined intervals.

20 . The method according to claim 15 , wherein the mitigating comprises:
activating a fan and opening a vent based on the binary output corresponding to the leak signal, and deactivating the fan and closing the vent based on the binary output corresponding to the non-leak signal.

Assignees

• Carrier Corp

Inventors

• Chen Lei
• Lord Richard G

Classifications

• F24F11/30

  for purposes related to the operation of the system, e.g. for safety or monitoring · CPC title

• F25B2400/12

  Inflammable refrigerants · CPC title

• G01N21/3504

  for analysing gases, e.g. multi-gas analysis · CPC title

• F24F11/89

  Arrangement or mounting of control or safety devices · CPC title

• F24F11/77

  by controlling the speed of ventilators · CPC title