Heated gas detector

Abstract

A gas detector system for a refrigerated interior volume of a transport refrigeration unit (TRU) is disclosed, the system comprising: a gas detector defining an enclosure, the enclosure defining a chamber therein, the cover including a chamber opening and an infrared (IR) sensor located within the chamber; and a heater adjacent to or within the enclosure, the heater configured to reduce moisture within the chamber and / or prevent moisture from accumulating within the chamber during a refrigeration cycle.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Application No. 62 / 902,112, filed on September 18, 2019, which is incorporated herein by reference in its entirety. Technical Field

[0003] The following description relates to a gas detector, and more specifically to a heated nondispersive infrared (NDIR) gas detector for flammable low global warming potential (GWP) refrigerants. Background Technology

[0004] A typical refrigerated cargo compartment (such as those used for transporting goods by sea, rail, or road) is modified to include a refrigeration unit located at one end of the compartment. The refrigeration unit includes a compressor, condenser, expansion valve, and evaporator. A volume of refrigerant circulates throughout the refrigeration unit, and one or more evaporator fans in the refrigeration unit blow supply air across the evaporator, thereby cooling the supply air and compressing it into the cargo compartment.

[0005] In cases where the refrigeration unit uses a refrigeration cycle to cool the supply air, a portion of that volume of refrigerant may leak into the conditioned space. Since the refrigerant may be a moderately or highly flammable low-GWP refrigerant, such a leak, for example, into the conditioned space could pose a danger to refrigerated goods and personnel handling refrigerated cargo compartments.

[0006] Therefore, gas detectors are often installed in refrigerated cargo compartments or refrigeration units to sense gases present due to leaks. Such gas detectors can incorporate non-dispersive infrared (NDIR) technology and be used to determine the concentration of a specific gas in a given atmosphere. Summary of the Invention

[0007] A gas detector system for a transport refrigerated unit (TRU) with a cooled internal volume is disclosed. The system includes: a gas detector defining an encapsulation therein defining a chamber, the encapsulation including a chamber opening and an infrared (IR) sensor located within the chamber; and a heater adjacent to or within the encapsulation, the heater being configured to maintain a temperature required to reduce the relative moisture content within the chamber and / or prevent moisture condensation within the chamber.

[0008] In addition to or as an alternative to one or more of the aspects disclosed above, the heater includes a plurality of heating elements spaced apart from each other on or within one or more of the sidewalls of the encapsulation.

[0009] In addition to one or more of the features disclosed above, or as an alternative, the system includes a packaging temperature sensor disposed inside or near the packaging, wherein, during a cooling cycle: when the temperature inside or near the packaging is lower than the ambient temperature, the heater is activated; and when the temperature inside or near the packaging is higher than the ambient temperature, the heater is deactivated.

[0010] In addition to one or more of the features disclosed above, or as an alternative, the system includes a humidity sensor operatively connected to the heater and disposed inside or near the encapsulation, wherein, during a refrigeration cycle: the heater is activated when the humidity level inside or near the encapsulation is greater than a humidity threshold; and the heater is deactivated when the humidity level inside or near the encapsulation is less than the humidity threshold.

[0011] In addition to one or more of the features disclosed above, or as an alternative, the system includes an encapsulation temperature sensor operatively connected to the heater, the encapsulation temperature sensor being disposed inside or near the encapsulation, wherein: the heater is activated when the refrigeration cycle is started, and the heater is deactivated when a temperature threshold is reached at the encapsulation.

[0012] In addition to one or more of the features disclosed above, or as an alternative, the system includes periodically enabling and disabling the heater during the refrigeration cycle.

[0013] A transport refrigeration unit (TRU) is further disclosed, comprising a compressor, a condenser, an evaporator, a refrigerated internal volume, and a controller operatively connected to the compressor, the condenser, and the evaporator. The refrigerated internal volume includes a system having one or more of the aspects disclosed above, wherein a heater is operatively connected to the controller.

[0014] In addition to or as an alternative to one or more of the features disclosed above, the controller is configured to delay or pause the cooling cycle while the heater heats the encapsulation, and is selected to maintain a low relative humidity level indoors until the temperature inside or near the encapsulation is greater than or equal to a given temperature threshold. It will be appreciated that when a humidity sensor is used instead of a temperature sensor or in addition to a temperature sensor, the threshold can be implemented to maintain a relative humidity level below or equal to a given threshold. That is, the thresholds may vary and be correlated with each other.

[0015] In addition to or as an alternative to one or more of the features disclosed above, the method includes a TRU, the TRU including a compressor, a condenser, an evaporator, a refrigerated internal volume, and a controller operatively connected to the compressor, the condenser, and the evaporator, the refrigerated internal volume including a system having one or more of the aspects disclosed above, wherein a heater is operatively connected to the controller.

[0016] In addition to one or more of the aspects disclosed above, or as an alternative, the controller is configured to delay or pause the cooling cycle while the heater heats the encapsulation, until the humidity level inside or near the encapsulation is below a humidity threshold.

[0017] A further TRU is disclosed, comprising a compressor, a condenser, an evaporator, a refrigerated internal volume, and a controller operatively connected to the compressor, the condenser, and the evaporator. The refrigerated internal volume includes a system having one or more of the aspects disclosed above, wherein a heater is operatively connected to the controller.

[0018] In addition to one or more of the features disclosed above, or as an alternative, when the refrigeration cycle is started, the controller is configured to delay or pause the refrigeration cycle while the heater heats the encapsulation, until the temperature inside or near the encapsulation has reached a temperature threshold or the relative humidity is below a humidity threshold.

[0019] A method for operating a gas detector system for a transport refrigeration unit (TRU) with a refrigerated internal volume is further disclosed, the method comprising: heating a package of the gas detector during a refrigeration cycle to reduce moisture within the package and / or prevent moisture buildup within the package, wherein the package defines a chamber therein, a cover includes a chamber opening, and an infrared (IR) sensor is disposed within the chamber, and wherein a heater configured for heating the package is adjacent to or located within the package.

[0020] In addition to one or more of the features disclosed above, or as an alternative, the method includes heating the encapsulation only during a refrigeration cycle when the temperature inside or near the encapsulation is below ambient temperature, wherein an encapsulation temperature sensor is operatively connected to the heater, and the encapsulation temperature sensor is located inside or near the encapsulation.

[0021] In addition to one or more of the features disclosed above, or as an alternative, the method includes delaying or pausing the refrigeration cycle while heating the encapsulation, until the temperature inside or near the encapsulation is above or equal to the ambient temperature.

[0022] In addition to one or more of the features disclosed above, or as an alternative, the method includes heating the encapsulation only during a refrigeration cycle when the humidity level inside or near the encapsulation is greater than a humidity threshold, wherein a humidity sensor is operatively connected to the heater and is located inside or near the encapsulation.

[0023] In addition to one or more of the features disclosed above, or as an alternative, the method includes delaying or pausing the refrigeration cycle while heating the encapsulation, and until the humidity level inside or near the encapsulation is below a humidity threshold.

[0024] In addition to one or more of the features disclosed above, or as an alternative, the method includes heating the encapsulation upon initiation of the refrigeration cycle until a temperature threshold is reached, wherein an encapsulation temperature sensor is operatively connected to the heater and is disposed inside or near the encapsulation.

[0025] In addition to one or more of the features disclosed above, or as an alternative, the method includes periodically pulsating the heat during the refrigeration cycle after the temperature threshold is reached.

[0026] In addition to one or more of the features disclosed above, or as an alternative, the method includes delaying or pausing the start-up of the refrigeration cycle while heating the encapsulation, and continuing until the temperature inside or near the encapsulation has reached a temperature threshold. Attached Figure Description

[0027] The subject matter considered to be part of this disclosure is specifically pointed out and clearly claimed at the end of the specification. The foregoing features and advantages of this disclosure, as well as other features and advantages, will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0028] Figure 1 It is a perspective view of a transport vehicle that can utilize one or more aspects of the disclosed embodiments;

[0029] Figure 2 yes Figure 1 A schematic diagram of the refrigeration system of a transportation vehicle;

[0030] Figure 3 It is a side view of a gas detector that can utilize one or more aspects of the disclosed embodiments;

[0031] Figure 4 It is a gas detector system according to a disclosed embodiment;

[0032] Figure 5It is a gas detector system according to another disclosed embodiment;

[0033] Figure 6 This is a heated gas detector system according to another disclosed embodiment; and

[0034] Figure 7 This is a flowchart illustrating the operation of a heated gas detector system according to an embodiment.

[0035] These advantages and features, as well as other advantages and features, become more apparent from the following description taken in conjunction with the accompanying drawings. Detailed Implementation

[0036] refer to Figure 1 The figure shows a transportation system 101, which includes a tractor or vehicle 102, an adjustable space 103 pulled by the vehicle 102, and a refrigeration system 104 for adjusting the air in the adjustable space 103.

[0037] Although the transport system 101 is described herein as an adjustable space 103 pulled by a vehicle 102, it will be understood that there are embodiments in which the adjustable space 103 is transported by rail, sea or air or may be located in any suitable cargo compartment of the vehicle 102, such as a truck, train, ship, airplane, helicopter, etc.

[0038] Vehicle 102 may include an operator's compartment or cab 105 and a vehicle motor 106. Vehicle 102 may be driven by a driver located in the cab, remotely driven by a driver, autonomously driven, semi-autonomously driven, or any combination thereof. Vehicle motor 106 may be a combustion engine or an electric motor powered by combustible fuel. Vehicle motor 106 may also be part of the power system or drive system of a trailer system, and thus vehicle motor 106 is configured to propel the wheels of vehicle 102 and / or the wheels via adjustable space 103. Vehicle motor 106 may be mechanically connected to the wheels of vehicle 102 and / or the wheels via adjustable space 103.

[0039] The adjustable space 103 can be connected to the vehicle 102 and thus pulled or propelled to a desired destination. The adjustable space 103 may include a top wall 110, a bottom wall 111 opposite and spaced apart from the top wall 110, two side walls 112 spaced apart and opposite to each other, and opposite front and rear walls 113 and 114, wherein the front wall 113 is closest to the vehicle 102. The adjustable space 103 may further include a door (not shown) located at the rear wall 114 or any other wall. The top wall 110, bottom wall 111, side walls 112, front wall 113, and rear wall 114 together define the boundary of the cooled internal volume 115. The cooling system 104 is configured to adjust the cooled internal volume 115.

[0040] refer to Figure 2 The refrigerated space 103 can be provided as the interior of a refrigerated trailer, refrigerated truck, refrigerated compartment, or refrigerated cargo box with a refrigeration system 104 suitable for operation using refrigerants such as low-GWP refrigerants (e.g., A1, A2, A2L, A3, etc.). In some cases, refrigerant may leak into the refrigerated interior volume 115, and if the concentration of leaked refrigerant in the refrigerated interior volume 115 exceeds a threshold level, the refrigerant may pose a hazard. The threshold level needs to be a lower flammability limit of the refrigerant.

[0041] The portion of the evaporator 230, the portion of the refrigerant line 253 near the evaporator outlet 232, and the portion of the refrigerant line 250 near the evaporator inlet 231 may be located within the refrigerated internal volume 115 of the regulated space 103, and thus may be a potential source of refrigerant leakage.

[0042] The refrigeration system 104 may be a transport refrigeration system, such as a transport refrigeration unit (TRU). The refrigeration system 104 includes a compressor 210, a condenser 220, an evaporator 230, and a leak detection system 240, which includes a leak sensor 242 communicating with a controller 241. The leak detection system 240 is arranged to detect and mitigate the presence of refrigerant within the refrigerated internal volume 115.

[0043] Compressor 210 is powered or driven by power source 211. Compressor 210 receives refrigerant from evaporator 230 via compressor inlet 212 through receiver 221 and discharges refrigerant to condenser 220 via compressor outlet 213. Condenser 220 receives a refrigerant fluid flow from compressor 210 via condenser inlet 222 and discharges a refrigerant fluid flow to receiver 221 via condenser outlet 223. Condenser inlet 222 is fluidly connected to compressor outlet 213 via refrigerant line 2201. A fan (such as condenser fan 224) may be associated with and positioned close to condenser 220.

[0044] Evaporator 230 is arranged to receive a refrigerant fluid flow from condenser 220 through evaporator inlet 231 and to discharge a refrigerant fluid flow to compressor 210 through evaporator outlet 232. Evaporator inlet 231 is fluidly connected to condenser outlet 223 via refrigerant line 250 through a first valve 251 and / or a second valve 252 located on the side of receiver 221 opposite to the first valve 251. Evaporator outlet 232 is fluidly connected to compressor inlet 212 via refrigerant line 253. A fan (such as evaporator fan 233) may be associated with evaporator 230 and arranged close to evaporator 230.

[0045] The first valve 251 may be an expansion valve, such as an electronic expansion valve, a movable valve, or a thermal expansion valve. The first valve 251 is movable between an open position and a closed position to selectively inhibit and facilitate refrigerant flow between the evaporator 230 and at least one of the condenser 220 and receiver 221. The open position facilitates refrigerant flow through receiver 221 between the evaporator inlet 231 and the condenser outlet 223. The closed position inhibits refrigerant flow through receiver 221 between the evaporator inlet 231 and the condenser outlet 223, and also inhibits refrigerant flow between receiver 221 and the evaporator inlet 231.

[0046] Receiver 221 is fluidly connected to condenser 220 and evaporator 230 and is arranged to receive and store refrigerant based on the position of at least one of first valve 251 and / or second valve 252. Receiver 221 is arranged to receive refrigerant from condenser outlet 223 via refrigerant line 250 through first receiver inlet 2211. In at least one embodiment, second valve 252 is arranged to selectively facilitate fluid flow between condenser outlet 223 and first receiver inlet 2211. Second valve 252 may be a movable valve, solenoid valve, liquid access valve, thermal expansion valve, or electronic expansion valve, and is movable between an open position and a closed position to facilitate or impede refrigerant flow between condenser outlet 223 and first receiver inlet 2211. Receiver 221 is arranged to discharge or supply refrigerant fluid through receiver outlet 2212 to evaporator inlet 231 via refrigerant line 250 through first valve 251.

[0047] The third valve 254 can be arranged to selectively facilitate fluid flow between the compressor outlet 213 and the condenser inlet 222. The third valve 254 can be a movable valve, a check valve, a liquid service valve, a thermal expansion valve, or an electronic expansion valve, and can move between an open position and a closed position to facilitate or impede the fluid flow of refrigerant between the compressor outlet 213 and the condenser inlet 222.

[0048] The fourth valve 255 can be arranged to selectively facilitate fluid flow between the evaporator outlet 232 and the compressor inlet 212. The fourth valve 255 can be a movable valve, a check valve, a liquid service valve, a thermal expansion valve, or an electronic expansion valve, and can move between an open position and a closed position to facilitate or impede the fluid flow of refrigerant between the evaporator outlet 232 and the compressor inlet 212.

[0049] The leak detection system 240 includes a leak sensor 242 that communicates with the controller 241. The leak sensor 242 can be set and configured to detect a selected concentration of refrigerant and thus detect refrigerant leaks within the cooled internal volume 115 of the regulated space 103.

[0050] The controller 241 is provided with an input communication channel arranged to receive information, data, or signals from, for example, a compressor 210, a power source 211, a condenser fan 224, a first valve 251, an evaporator fan 233, a second valve 252, a pressure sensor 243, a compressor discharge pressure sensor 244, and a leakage sensor 242. The controller 241 is also provided with an output communication channel arranged to provide commands, signals, or data to, for example, the compressor 210, the power source 211, the condenser fan 224, the first valve 251, the evaporator fan 233, and the second valve 252.

[0051] The controller 241 may include at least one processor that is programmed to perform various operations, including but not limited to leak detection and / or leak mitigation strategies, based on information, data or signals provided via an input communication channel and to output commands via an output communication channel.

[0052] Leakage sensor 242 is arranged to provide a signal to controller 241 indicating the concentration, amount, or presence of refrigerant within the refrigerated internal volume 115 of the regulated space 103. Leakage sensor 242 may be positioned near evaporator 230 and / or near refrigerant line 250 or any other refrigerant line or component that may allow refrigerant to leak into the regulated space 103. Leakage sensor 242 may also be located near a likely location where refrigerant may be collected, such as near bottom wall 111.

[0053] Although the refrigeration system 104 has been described herein according to embodiments, it will be understood that other embodiments of the refrigeration system 104 and other regulating systems exist, and the following description relates to each of these various embodiments and systems.

[0054] refer to Figure 3 The gas detector (detector) 301 can be used as Figure 2 The leak sensor 242 is provided. The detector 301 includes: a gas sensing element 310; gas detector electronics 320 configured to control the operation of the gas detector element 310 and communicate with the controller 241; a printed circuit board (PCB) 330 on which the gas detector element 310 and gas detector electronics 320 are disposable; and an encapsulation 340. The encapsulation 340 is configured to expose the gas sensing element 310 to the outside (i.e., to the cooled internal volume 115, any gas or fluid therein, and particularly to any leaked refrigerant therein). The encapsulation 340 is further configured to cooperate with the PCB 330 to form an electronics housing that serves as a gas detection chamber 350. The gas detector electronics 320 is disposable within the gas detection chamber 350, thereby isolating the gas detector electronics 320 from the outside.

[0055] like Figure 3 As shown, the PCB 330 may include a solid, monolithic body 331 configured to impede the flow of fluid from the outside through the encapsulation 340 and into the gas detection chamber 350. The encapsulation 340 may include the body 341 and a cover 342. The PCB 330 may be attachable to the body 341, and the cover 342 may be attachable to the body 341 on top of the PCB 330. According to this configuration, the PCB 330 is substantially surrounded by the body 341 and the cover 342. One side of the PCB 330 faces the cover 342, and another second side of the PCB 330 faces the body 341. The cover 342 may be formed to define an aperture 343 through which the gas detector element 310 is exposed to the outside, and the aperture 343 may have ribs extending across the open space or may not. The body 341 may be formed to cooperate with the PCB 330 to define the gas detection chamber 350, in which the gas detector electronics 320 is disposable.

[0056] The main body 341 may include: a rear plane 3410 facing the PCB 330; and a sidewall 3411 connected to the PCB 330, positioning the rear plane 3410 at a distance D from the PCB 330. Thus, the gas detection chamber 350 may be defined by the rear plane 3410, the sidewall 3411, and the PCB 330. The distance D may be sufficient to at least tightly accommodate the gas detector electronics 320. The cover 342 may include a cover portion 3421 and a spacer portion 3422, which may be separate components or integrally disposed together in a single component and are located between the PCB 330 and the cover portion 3421. The spacer portion 3422 may include a seal 3424.

[0057] Detector 301 can be an infrared (IR) detector because it can detect gas by monitoring the absorption or attenuation of the infrared wavelength used in the IR sensor embodied in sensing element 301. The operational capability of sensing element 301 can be determined by the humidity level in the air, and the value sensed by sensing element 301 can change if the temperature around or inside sensing element 301 differs from the temperature of the air entering sensing element 301. This can cause erroneous readings due to calibration errors, resulting in false triggering of gas detection or allowing moisture to condense or even freeze in the cold environment within gas detection chamber 350. This could damage gas detector electronics 320.

[0058] In view of the concerns mentioned above, Figure 4-6 A sensor system (system) 400 is disclosed. System 400 includes a gas detector (detector) 410, which may be the same as detector 301. For example, detector 410 includes an encapsulation 420 having a cover 440, a rear plane 450, and a plurality of sidewalls 430. Encapsulation 420 defines a gas detection chamber (chamber) 460, and the cover includes a chamber opening 470. Gas detector electronics, which may include an IR sensor 480, are located within chamber 460. Detector 410 may be configured as a non-dispersive infrared (NDIR) detector. Detector 410 may operatively communicate with controller 241.

[0059] According to the disclosed embodiments, system 400 may include a heater 500 operatively connected to controller 241. Heater 500 may include a first set of heating elements 510. Figure 4In the embodiment illustrated, the heater 500 includes multiple sets of heating elements 520, including a first set of heating elements 510 and a second set of heating elements 530. The multiple sets of heating elements 520 are located outside the encapsulation 420. The first set of heating elements 510 is adjacent to one or more of the multiple sidewalls 430. More specifically, the first set of heating elements 510 is adjacent to a first sidewall 535 of the multiple sidewalls 430. The second set of heating elements 530 is adjacent to a second sidewall 540 of the multiple sidewalls 430.

[0060] exist Figure 5 In the embodiment illustrated, the heater 500 includes a first set of heating elements 510. The first set of heating elements 510 is located outside the encapsulation 420. The first set of heating elements 510 is adjacent to the rear plane 450. Figure 6 In the embodiment illustrated, heater 500 includes a first set of heating elements 510. The first set of heating elements 510 is disposed in chamber 460. The first set of heating elements 510 abuts against rear plane 450. Multiple sets of heating elements 520 are each illustrated as having multiple heating elements and more specifically three heating elements. However, the number of heating elements is not intended to be limiting.

[0061] exist Figure 4-6 In each of the embodiments illustrated, the encapsulation temperature sensor 600 may be disposed within or near the encapsulation 420. The controller 241 may use temperature readings from the encapsulation temperature sensor 600 to control the heater 500. The controller 241 may use such temperature readings independently or by comparison with temperature readings from an ambient temperature sensor 610 that reads, for example, the ambient temperature in or around the TRU. The humidity sensor 620 may be disposed within or near the encapsulation 420. The controller 241 may use humidity level readings from the humidity sensor 620 to control the heater 500. Methods for controlling the heater 500 using temperature and / or humidity readings are disclosed below and in [the following text is incomplete and requires further context]. Figure 7 The diagram in the middle is shown.

[0062] Now for reference Figure 4-7 ,flow chart( Figure 7The diagram illustrates a method of the operating system 400. As illustrated in block 900, the method includes heating the encapsulation 420 of the detector 410 during a cooling cycle to reduce moisture within the encapsulation 420 and / or prevent moisture buildup within the encapsulation 420. As indicated, the encapsulation 420 includes a cover 440, a rear plane 450, and a plurality of sidewalls 430 to define a chamber 460 within the encapsulation 420. The cover 440 includes a chamber opening 470. An infrared sensor (IR sensor) 480 is disposed within the chamber 460. A heater 500 for heating the encapsulation 420 is adjacent to or located within the encapsulation 420. The heater 500 is operatively connected to a controller 241. Figure 4 ).

[0063] As illustrated in block 910, depending on the configuration of system 400, system 400 can operate according to one of several modes. As illustrated in block 920, in a first operating mode (mode 1 at block 910), during a refrigeration cycle, the encapsulation 420 is heated when the temperature inside or near the encapsulation 420 is lower than the ambient temperature. For operation in this mode, an encapsulation temperature sensor 600 can be operatively connected to the heater 500. The encapsulation temperature sensor 600 is located inside or near the encapsulation 420. Figure 4-6 In the diagram, the encapsulation temperature sensor 600 is schematically shown located inside the encapsulation 420. The ambient temperature sensor 610 can read the ambient temperature. The ambient temperature sensor 610, or TRU, can be located outside the cooled internal volume (see [reference]). Figure 2 As illustrated in box 930, in this operating mode, the method may include delaying or pausing the cooling cycle while heating the encapsulation 420 until the temperature inside or near the encapsulation 420 is above or equal to the ambient temperature.

[0064] As illustrated in block 940, in the second operating mode (mode 2 at block 910), the method includes heating the encapsulation 420 during a refrigeration cycle when the humidity level inside or near the encapsulation 420 is greater than a humidity threshold. For this operating mode, a humidity sensor 620 is operatively connected to the heater 500. The humidity sensor 620 is located inside or near the encapsulation 420. Figure 4-6 In the diagram, humidity sensor 620 is schematically shown located inside encapsulation 420. In this operating mode, as shown in block 950, the method includes delaying or pausing the cooling cycle while heating encapsulation 420 until the humidity level inside or near encapsulation 420 is below a humidity threshold.

[0065] As shown in block 960, in the third operating mode (mode 3 at block 910), the method includes heating the encapsulation 420 upon initiation of the refrigeration cycle until a temperature threshold is reached. In this operating mode, as in the first operating mode, the encapsulation temperature sensor 600 is operatively connected to the heater 500. The encapsulation temperature sensor 600 is disposed inside or near the encapsulation. In this operating mode, as shown in block 970, the method includes periodically pulsating the heat during the refrigeration cycle after the temperature threshold is reached. As shown in block 980, the method further includes delaying or pausing the initiation of the refrigeration cycle while the heater heats the encapsulation 420 until the temperature inside or near the encapsulation 420 has reached the temperature threshold.

[0066] In one embodiment, a combination of the modes mentioned above is used to reduce moisture within the encapsulation and / or prevent moisture buildup within the encapsulation. Additionally, the thresholds mentioned herein can be varied based on an understanding relevant to humidity measurement, thereby ensuring that the sensor operates at temperature and humidity levels where calibration can be performed and readings are more accurate.

[0067] According to the embodiments disclosed above, a heating system (system) 400 is provided to melt and vaporize frozen moisture inside the gas detection chamber 350 and to increase the temperature inside the gas detection chamber 350 to promote the elimination of moisture inside the gas detection chamber 350. The heating system 400 also actively prevents moisture from re-entering the gas detection chamber 350. The system 400 can utilize an encapsulation temperature sensor 600, an ambient temperature sensor 610, and / or a humidity sensor 620 disposed around the gas detector electronics 320 to determine when the detector 301 can correctly identify the presence of a detectable gas in the atmosphere. The disclosed embodiments can enhance the utilization of gas detectors that use IR technology to achieve accuracy and robustness. The disclosed embodiments also provide control logic that can save power consumption when using a limited power source.

[0068] As described above, embodiments can take the form of processes implemented by a processor and means (such as a processor) for performing those processes. Embodiments can also take the form of computer program code containing instructions embodied in a tangible medium (such as a network cloud storage device, SD card, flash drive, floppy disk, CD ROM, hard disk drive, or any other computer-readable storage medium), wherein when the computer program code is loaded into and executed by the computer, the computer becomes a means for performing the embodiments. Embodiments can also take the form of computer program code (e.g., whether stored in a storage medium, loaded into and / or executed by a computer, or transmitted via a transmission medium, such as via electrical wiring or cabling, via optical fiber, or via electromagnetic radiation), wherein when the computer program code is loaded into and executed by the computer, the computer becomes a means for performing the embodiments. When implemented on a general-purpose microprocessor, computer program code segments configure the microprocessor to create specific logic circuitry.

[0069] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well. It will be further understood that, when used in this specification, the terms “comprises and / or comprising” specify the presence of the illustrated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups of the above items.

[0070] Those skilled in the art will recognize that various exemplary embodiments have been shown and described herein, each having certain features of a particular embodiment, but this disclosure is not thereby limited. Rather, this disclosure can be modified to incorporate any number of variations, alterations, substitutions, combinations, sub-combinations, or equivalent arrangements not described to date, but these are proportionate to the scope of this disclosure. Furthermore, while various embodiments of this disclosure have been described, it will be understood that aspects of this disclosure may include only some of the described embodiments. Therefore, this disclosure should not be considered limited to the foregoing description, but only to the scope of the appended claims.

Claims

1. A gas detector system for transporting the cooled internal volume of a refrigeration unit, the system comprising: A gas detector that defines an encapsulation therein defining a chamber, the encapsulation including a cover including a chamber opening and an infrared sensing element located within the chamber; A heater, which is adjacent to or located within the encapsulation, is configured to reduce moisture in the room and / or prevent moisture buildup in the room during a refrigeration cycle; as well as An encapsulation temperature sensor disposed inside or near the encapsulation, wherein during the refrigeration cycle: The heater is activated when the temperature inside or near the encapsulation is lower than the ambient temperature; and... The heater is deactivated when the temperature inside or near the encapsulation is higher than the ambient temperature.

2. A gas detector system for transporting the cooled internal volume of a refrigeration unit, the system comprising: A gas detector that defines an encapsulation therein defining a chamber, the encapsulation including a cover including a chamber opening and an infrared sensing element located within the chamber; A heater, which is adjacent to or located within the encapsulation, is configured to reduce moisture in the room and / or prevent moisture buildup in the room during a refrigeration cycle; as well as A humidity sensor, operatively connected to the heater and located inside or near the encapsulation, wherein during the refrigeration cycle: The heater is activated when the relative humidity level inside or near the encapsulation exceeds a humidity threshold; and, The heater is deactivated when the relative humidity level inside or near the encapsulation is less than the humidity threshold.

3. The system of claim 2, further comprising an encapsulation temperature sensor operatively connected to the heater, the encapsulation temperature sensor being disposed inside the encapsulation or close to the encapsulation, wherein: The heater is activated when the refrigeration cycle is started, and is deactivated when a temperature threshold is reached at the encapsulation.

4. The system according to claim 3, wherein, The temperature and humidity thresholds change and are correlated with each other.

5. A gas detector system for transporting the cooled internal volume of a refrigeration unit, the system comprising: A gas detector that defines an encapsulation therein defining a chamber, the encapsulation including a cover including a chamber opening and an infrared sensing element located within the chamber; A heater, adjacent to or located within the encapsulation, configured to reduce moisture in the room and / or prevent moisture buildup in the room during a refrigeration cycle, wherein the heater includes a plurality of heating elements spaced apart from each other adjacent to one or more of the plurality of sidewalls of the encapsulation or spaced apart from each other within the room; and An encapsulation temperature sensor is operatively connected to the heater, the encapsulation temperature sensor being disposed inside the encapsulation or close to the encapsulation, wherein: The heater is activated when the refrigeration cycle is started, and is deactivated when a temperature threshold is reached at the encapsulation.

6. A transport refrigeration unit comprising a compressor, a condenser, an evaporator, a refrigerated internal volume, and a controller operatively connected to the compressor, the condenser, and the evaporator, wherein the refrigerated internal volume comprises the system according to claim 1, wherein... The heater is operatively connected to the controller.

7. The transport refrigeration unit according to claim 6, wherein, The controller is configured to delay or pause the cooling cycle while the heater heats the encapsulation until the temperature inside or near the encapsulation is higher than or equal to the ambient temperature.

8. A transport refrigeration unit comprising a compressor, a condenser, an evaporator, a refrigerated internal volume, and a controller operatively connected to the compressor, the condenser, and the evaporator, wherein the refrigerated internal volume comprises the system according to claim 2, wherein... The heater is operatively connected to the controller.

9. The transport refrigeration unit according to claim 8, wherein, The controller is configured to delay or pause the refrigeration cycle while the heater heats the encapsulation until the humidity level inside or near the encapsulation is less than the humidity threshold.

10. A transport refrigeration unit comprising a compressor, a condenser, an evaporator, a refrigerated internal volume, and a controller operatively connected to the compressor, the condenser, and the evaporator, wherein the refrigerated internal volume comprises the system according to claim 5, wherein... The heater is operatively connected to the controller.

11. The transport refrigeration unit according to claim 10, wherein, When the refrigeration cycle is started, the controller is configured to delay or pause the refrigeration cycle while the heater heats the encapsulation until the temperature inside or near the encapsulation has reached the temperature threshold.

12. A method of operating a gas detector system for transporting a refrigerated unit with a cooled internal volume, the method comprising: During the refrigeration cycle, the encapsulation of the gas detector is heated to reduce moisture within the encapsulation and / or prevent moisture buildup within the encapsulation, wherein the encapsulation defines a chamber, the encapsulation includes a cover having a chamber opening, and an infrared sensor is disposed within the chamber, wherein a heater configured for heating the encapsulation is adjacent to or located within the encapsulation. The method further includes heating the encapsulation during the refrigeration cycle when the temperature inside or near the encapsulation is lower than the ambient temperature, wherein an encapsulation temperature sensor is operatively connected to the heater and is disposed inside or near the encapsulation.

13. The method of claim 12, further comprising delaying or pausing the refrigeration cycle while heating the encapsulation, until the temperature inside or near the encapsulation is higher than or equal to the ambient temperature.

14. A method of operating a gas detector system for transporting a cooled internal volume of a refrigeration unit, the method comprising: During the refrigeration cycle, the encapsulation of the gas detector is heated to reduce moisture within the encapsulation and / or prevent moisture buildup within the encapsulation, wherein the encapsulation defines a chamber, the encapsulation includes a cover having a chamber opening, and an infrared sensor is disposed within the chamber, wherein a heater configured for heating the encapsulation is adjacent to or located within the encapsulation. The method further includes heating the encapsulation during the refrigeration cycle when the humidity level inside or near the encapsulation is greater than a humidity threshold, wherein a humidity sensor is operatively connected to the heater and is disposed inside or near the encapsulation.

15. The method of claim 14, further comprising delaying or pausing the refrigeration cycle while heating the encapsulation, until the humidity level inside or near the encapsulation is less than the humidity threshold.

16. A method of operating a gas detector system for transporting a cooled internal volume of a refrigeration unit, the method comprising: During the refrigeration cycle, the encapsulation of the gas detector is heated to reduce moisture within the encapsulation and / or prevent moisture buildup within the encapsulation, wherein the encapsulation defines a chamber, the encapsulation includes a cover having a chamber opening, and an infrared sensor is disposed within the chamber, wherein a heater configured for heating the encapsulation is adjacent to or located within the encapsulation. The method further includes heating the encapsulation when the refrigeration cycle is started, until a temperature threshold is reached, wherein an encapsulation temperature sensor is operatively connected to the heater and is disposed inside or near the encapsulation.

17. The method of claim 16, further comprising periodically pulsating the heat during the refrigeration cycle after the temperature threshold is reached.

18. The method of claim 17, further comprising delaying or pausing the start-up of the refrigeration cycle while heating the encapsulation, and until the temperature inside or near the encapsulation has reached the temperature threshold.

Images