Refrigeration leak detection

Abstract

To provide an HVAC (Heating Ventilation and Air Conditioning) system that uses an A2L refrigerant ensuring proper operation while providing occupants of a building with the maximum amount of comfort.SOLUTION: A refrigeration system of a building comprises: a compressor module configured to, in response to a determination that the amount of a refrigerant of the refrigeration system that is present outside of the refrigeration system within the building is greater than a first predetermined amount, maintain a compressor off continuously for a predetermined period of time; and a fan module configured to, in response to the determination, maintain a fan on continuously for at least the predetermined period of time. The compressor module is further configured to, without receiving an input indicative of a reset of the refrigeration system, after the compressor is off for the predetermined period of time and the amount of refrigerant that is present outside of the refrigeration system within the building becomes less than a second predetermined amount, selectively turn the compressor on.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 16 / 988,269, filed August 7, 2020, the entire disclosure of which is incorporated herein by reference.

[0002] Field FIELD OF THE DISCLOSURE This disclosure relates to heating ventilation and air conditioning (HVAC) and other types of refrigeration systems, and more particularly to refrigeration leak detection and mitigation systems and methods for HVAC or refrigeration systems. [Background technology]

[0003] background This section provides background information related to the present disclosure that is not necessarily prior art.

[0004] Refrigeration and air conditioning applications are under increasing regulatory pressure to reduce the global warming potential of the refrigerants they use. In order to use refrigerants with lower global warming potential, the flammability of the refrigerants may increase.

[0005] Several refrigerants have been developed that are considered low global warming potential options and are listed by ASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers) as A2L. It has a Refrigerating and Air-Conditioning Engineers (EPA) classification and is mildly flammable. This means that the product complies with the UL (Underwriters Laboratory) 60335-2-40 standard and Similar standards specify a certain (M1) level for A2L refrigerants and indicate that A2L refrigerant fill levels below the certain level do not require leak detection and mitigation. Summary of the Invention [Means for solving the problem]

[0006] overview This section provides an overview of the disclosure and is not an exhaustive disclosure of its entire scope or any of its features.

[0007] HVAC systems that use A2L refrigerants may be required to have leak detection and mitigation capabilities. Control systems may be used to ensure proper operation of the HVAC system and avoid nuisance problems while providing the maximum amount of comfort to the building occupants.

[0008] A2L (mildly flammable) refrigerants may be used as refrigerants for refrigeration and HVAC systems. Due to their flammability, systems using A2L refrigerants may be required to mitigate any possible leaks. This may be done by operating indoor fans in the air handler to disperse the leaked refrigerant and reduce its concentration within the building. The system may automatically reset after a mitigation event.

[0009] The present application allows for the system to be manually reset (eg, by the building owner) to put the system into a reduced capacity mode where some cooling is available, but at less than full capacity.

[0010] The present disclosure relates to a refrigerant sensor or detection system for detecting leaking refrigerant (e.g., A2L). The present invention relates to a resettable algorithm for the system. A control module controls the system and a switch is used to manually reset the system. The system also automatically resets after the A2L leakage is mitigated, allowing the system to return to normal operation.

[0011] If more than three (or some other predetermined number) leak events occur, the control module may lock out the compressor (keep the compressor on) and request that a contractor be contacted, or the building owner may be requested to contact a contractor.

[0012] The system may be reset manually or automatically if the refrigerant leakage level exceeds a predetermined level (e.g., 25% or another suitable level) of the lower flammability limit (LFL) of the refrigerant being used in the system. If the compressor is locked out due to a refrigerant leakage event, the control module may maintain the compressor lockout until a contractor arrives at the premises to service the system. The system may also allow the sensor / control module to retain data for a predetermined period of time (e.g., the last seven days or other period of time) and allow the contractor to use this information for diagnostic purposes.

[0013] Thus, the present application provides controlled relief while ensuring operation, providing the maximum amount of comfort to the homeowner and avoiding annoying issues.

[0014] The vapor compression system includes a refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator. A refrigerant leakage sensor is located adjacent to a component of the refrigeration cycle. A fan is associated with the vapor compression system. A control module controls operation of the compressor and the fan and receives a signal from the refrigeration leakage sensor, and upon detection of a leak, the control module automatically resets operation of the vapor compression system after the refrigerant leakage is mitigated by the fan, allowing the system to return to normal operation.

[0015] In one feature, a building refrigeration system includes a compressor module configured to continuously keep a compressor of the refrigeration system off for at least a predetermined period of time in response to determining that an amount of refrigerant present outside the refrigeration system in the building is greater than a first predetermined amount, and a fan module configured to continuously keep a fan on for at least a predetermined period of time in response to determining that the amount of refrigerant present outside the refrigeration system in the building is greater than the first predetermined amount, the fan moving air across an evaporator of the refrigeration system when the fan is on, and the compressor module is further configured to selectively turn on the compressor after the compressor has been off for the predetermined period of time and the amount of refrigerant present outside the refrigeration system in the building is less than a second predetermined amount, without receiving an input indicating a reset of the refrigeration system.

[0016] In a further feature, a sensor is configured to measure an amount of refrigerant present outside the refrigeration system in the building.

[0017] In a further feature, the sensor is disposed adjacent to the evaporator. In further features, the second predetermined amount is less than the first predetermined amount.

[0018] In a further feature, the refrigerant has an American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) classification of A2L.

[0019] In a further feature, the compressor module is configured to maintain the compressor off when a number of events in which an amount of refrigerant present outside the building refrigeration system is greater than a first predetermined amount is greater than a predetermined number of events until an input indicating a reset of the refrigeration system is received.

[0020] In a further feature, the predetermined number of events is an integer greater than one. In a further feature, the compressor module is configured to maintain the compressor off when an amount of refrigerant present outside the refrigeration system in the building exceeds a third predetermined amount until an input indicating a reset of the refrigeration system is received.

[0021] In further features, the third predetermined amount is greater than the second predetermined amount. In further features, the third predetermined amount is at least 20 percent of a lower flammable limit (LFL) of the refrigerant.

[0022] In a further feature, the lockout module is configured to prevent the one or more ignition devices from igniting for at least a predetermined period of time in response to determining that an amount of refrigerant present outside the refrigeration system in the building is greater than a first predetermined amount.

[0023] In one feature, a method includes, in response to determining that an amount of refrigerant present outside the refrigeration system in a building is greater than a first predetermined amount, maintaining a compressor of the refrigeration system continuously off for at least a predetermined period of time, and in response to determining that an amount of refrigerant present outside the refrigeration system in the building is greater than the first predetermined amount, maintaining a fan continuously on for at least a predetermined period of time, the fan moving air across an evaporator of the refrigeration system when the fan is on, and the method further includes, without receiving an input indicating a reset of the refrigeration system, selectively turning on the compressor after the compressor has been off for the predetermined period of time and the amount of refrigerant present outside the refrigeration system in the building is less than a second predetermined amount.

[0024] In a further feature, the method further includes measuring an amount of refrigerant present outside the refrigeration system in the building using a sensor.

[0025] In a further feature, the sensor is disposed adjacent to the evaporator. In further features, the second predetermined amount is less than the first predetermined amount.

[0026] In a further feature, maintaining the compressor off includes maintaining the compressor off when a number of events in which the amount of refrigerant present outside the refrigeration system in the building is greater than a first predetermined amount is greater than a predetermined number of events until an input indicating a reset of the refrigeration system is received.

[0027] In a further feature, maintaining the compressor off includes maintaining the compressor off when an amount of refrigerant present outside the refrigeration system in the building exceeds a third predetermined amount until an input indicating a reset of the refrigeration system is received.

[0028] In further features, the third predetermined amount is greater than the second predetermined amount. In further features, the third predetermined amount is at least 20 percent of a lower flammable limit (LFL) of the refrigerant.

[0029] In a further feature, the method further includes preventing the one or more ignition devices from igniting for at least a predetermined period of time in response to determining that an amount of refrigerant present outside the refrigeration system in the building is greater than a first predetermined amount.

[0030] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0031] drawing The drawings described herein are only for purposes of illustrating selected embodiments rather than all possible implementations and are not intended to limit the scope of the present disclosure. [Brief description of the drawings]

[0032] [Figure 1] 1 is a schematic diagram of an exemplary refrigeration system including a leak sensor. [Diagram 2]4 is a flow chart illustrating an exemplary method for automatically resetting operation of a refrigeration system after a refrigerant leak is mitigated and allowing the system to return to normal operation as long as a predetermined number of leaks are not detected. [Diagram 3] 1 is a flow chart illustrating an exemplary method for automatically resetting operation of a refrigeration system after a refrigerant leak has been mitigated, allowing the system to return to normal operation as long as the A2L refrigerant level leak does not exceed a predetermined level. [Figure 4] FIG. 2 is a functional block diagram of an exemplary control system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. Detailed Description Example embodiments will now be described more fully with reference to the accompanying drawings.

[0034] The exemplary embodiments are provided so that the disclosure is comprehensive and fully conveys the scope of the present disclosure to those skilled in the art. In order to fully understand the embodiments of the present disclosure, numerous specific details are described, such as examples of specific components, devices, and methods. It will be apparent to those skilled in the art that the specific details need not be used, and that the exemplary embodiments may be embodied in many different forms and should not be construed as limiting the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0035] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. ", "an" and "the" include the plural forms unless the context clearly dictates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and thus specify the presence of stated features, integers, steps, operations, elements, and / or components. However, it does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as necessarily requiring their execution in the particular order discussed or illustrated, unless specifically identified as an order of execution. It should also be understood that additional or alternative steps may be employed.

[0036] Referring to FIG. 1, a schematic diagram of an exemplary refrigeration (e.g., air conditioning) system 10 is shown including a compressor 12 and a condenser 14, which may be located outside (i.e., outdoors) of a building, and an expansion valve 16 and an evaporator 18, which may be located inside (i.e., indoors) of a building.

[0037] The fan 24 is disposed adjacent to the evaporator 18 and blows air across the evaporator 18. A control module 26 controls the operation (e.g., on, off, speed) of the fan 24. The fan 24 may be a whole house blower (e.g., configured to blow air through a duct of the refrigeration system 10 across the evaporator 18) or may alternatively be a ventilation system fan or an air exchange system fan. The control module 26 may also control the operation (e.g., on, off, speed, capacity) of the compressor 12.

[0038] A refrigerant leak sensor 30 or other leak detection system is provided to detect leaked refrigerant. The leak sensor 30 may be, for example, an infrared leak sensor, an optical leak sensor, a chemical leak sensor, a thermal conductivity leak sensor, an acoustic leak sensor, an ultrasonic leak sensor, or another suitable type of leak sensor. Alternatively, the leak detection module may measure the amount of refrigerant in the refrigerant system and detect a leak when the amount of refrigerant decreases by a predetermined amount. The leak detection module may calculate the amount of refrigerant based on one or more measurements, such as, for example, one or more refrigerant pressures, one or more refrigerant temperatures, etc.

[0039] In various implementations, the control module 26 may receive a signal from the leak sensor 30 and communicate with a second control module if a leak is detected.

[0040] The leak sensor 30 and / or the control module 26 may include (e.g., non-volatile) memory in case of loss of power. Loss of power may be due to a grid power interruption, cycling of power to the refrigeration system, etc. If the refrigeration system is locked out due to an A2L refrigerant leak event, the control module 26 may maintain the lockout until a contractor resets the refrigeration system.

[0041] The leak sensor 30 and / or control module 26 may store and retain data for a period of time (e.g., data from the last seven days or another suitable period of time) for use by the contractor for diagnostic purposes. The leak sensor 30 may be located near or within the evaporator 18, such as near or at a midpoint of the evaporator 18.

[0042] The control module 26 communicates with the compressor 12, the fan 24, and the leakage sensor 30. The control module 26 may communicate wirelessly or via wires, directly or indirectly via another device or control module.

[0043] Control module 26 may include a single module or multiple control modules and may be implemented as part of a control board, furnace control board, thermostat, air handler board, contactor, or diagnostic system. Control module 26 may include power conditioning circuitry to power the electronics using 24 volts (V) alternating current (AC), 120V-240V AC, 5V direct current (DC), or another suitable power source.

[0044] The control module 26 may include a bidirectional communication port, which may be wired, wireless, or both. The port may be used, for example, for system debug, programming, updates, monitoring, parameter value / status transfer, etc.

[0045] Refrigeration system 10 may be used in a home or another type of residential, commercial, or industrial building.

[0046] If a leak is detected by control module 26, control module 26 may turn on fan 24 and / or one or more other mitigation devices to dissipate the leaked refrigerant. Additionally, control module 26 may disable / lock out the operation of any ignition sources.

[0047] In accordance with the present disclosure, the control module 26 automatically resets the refrigeration system 10 after the refrigeration leak is mitigated, allowing the refrigeration system 10 to return to normal operation. The control module 26 may output an alert to the building owner or operator when a leak is detected. The alert may be, for example, a visual alert, an audible alert, both, or another suitable type of alert.

[0048] After at least a predetermined number of refrigerant leak events (e.g., three or another suitable number), the control module 26 may disable the refrigeration system 10 until the refrigeration system 10 is manually reset, such as via receiving a reset input from a building owner or operator or a contractor. In various implementations, the control module 26 may require a manual reset only if the refrigerant leak level (e.g., the amount of refrigerant leaked) exceeds a predetermined value (e.g., 25% of the lower flammable limit (LFL)) for the refrigerant being used. If the refrigeration system is locked out due to a refrigerant leak event, the control module 26 may maintain the lockout until, for example, a contractor resets the refrigeration system 10. The control module 26 may receive a manual reset, for example, from a reset actuator in response to a user input to a reset actuator, from an external device (e.g., via a port), from a thermostat in response to a user input to the thermostat, or in another suitable manner.

[0049] Control module 26 may store at least a predetermined amount of measurements from sensors 30 (e.g., for the last seven days or another suitable period), as well as other data, to allow a contractor to use this stored information, for example, for diagnostic purposes. The other data may include system run-time dates, time / date of leak events, how high gas concentration levels became during each leak event, how long it took to mitigate each leak event, and other suitable data.

[0050] 2 is a flow chart illustrating an exemplary method for automatically resetting a refrigeration system after a refrigerant leak has been mitigated and allowing the refrigeration system to return to normal operation. Control begins in S100 and proceeds to S102. In S102, control module 26 measures or determines the amount of refrigerant in the refrigeration system (A2L refrigerant level).

[0051] In S104, control module 26 determines whether a mitigating event has occurred. If a mitigating event has occurred, control continues to S106. If a mitigating event has not occurred, control continues to S118, which is further described below.

[0052] In S106, control module 26 determines whether the A2L refrigerant level (measurement from sensor 30, such as concentration) is below a predetermined de-mitigation level. The predetermined de-mitigation level may be a predetermined level (amount) that may cause mitigation of the leak to cease and may be calibrated. By way of example only, the predetermined de-mitigation level may be 1% of the LFL of the refrigerant or another suitable value. If S106 is true, control continues to S108. If S106 is false, control returns to S100.

[0053] In S108, the control module 26 turns on all house blowers (e.g., fan 24) for the building and begins incrementing a fan operation timer. The fan operation timer thus tracks the period of time that the all house blowers have been on. In S110, the control module 26 determines whether the all house blowers have been on for a predetermined period of time (e.g., whether the fan operation timer is greater than a predetermined value). By way of example only, the predetermined period of time may be about 5 minutes or another suitable period of time. If S110 is true, control continues to S112. If S110 is false, control returns to S100.

[0054] In S112, the control module 26 increments the Mitigation ON Counter. The Mitigation ON Counter thus tracks the number of mitigation events that are performed to mitigate the refrigerant leak. The control module 26 may also turn off all house blowers in S112.

[0055] At S114, control module 26 determines whether the mitigation ON counter is greater than or equal to a predetermined value. By way of example only, the predetermined value may be three or another suitable integer greater than zero. If S114 is true, the control module 26 may keep the compressor 12 disabled and maintain the lockout of the refrigeration system 10 until a manual reset is received in S116, such as from a contractor or building owner or operator. If S114 is false, the control module 26 may automatically reset the refrigeration system 10 in S117 and allow the compressor 12 to turn on again (e.g., as required by the thermostat). Control returns to S100.

[0056] Returning to S118, (when S104 is false - a mitigation event has not occurred) control module 26 determines whether the A2L refrigerant level (as measured by sensor 30) is greater than a predetermined mitigation start level. The predetermined mitigation start level may be a predetermined level (e.g., concentration) at which mitigation of the leak should begin, and may be calibrated. By way of example only, the predetermined mitigation start level may be greater than or equal to a predetermined mitigation stop level (e.g., greater than or equal to 1% of the LFL of the refrigerant) or another suitable value.

[0057] If S118 is true, control continues to S120. If S118 is false, control continues to S124. In S120, the control module 26 locks out the compressor 12, thereby preventing the compressor 12 from being turned on (e.g., despite a request from a thermostat). In S122, the control module 26 turns on the entire house blower (e.g., fan 24). In S124, the control module 26 allows the refrigeration system 10 to operate in a normal operating mode (e.g., turning the compressor on and off based on a request from a thermostat, etc.).

[0058] FIG. 3 is a flow chart illustrating an exemplary method for automatically resetting the refrigeration system after a refrigerant leak has been mitigated and allowing the refrigeration system 10 to return to normal operation as long as the A2L refrigerant level (measurement from sensor 30) does not exceed a predetermined lockout level (e.g., 25% of the refrigerant LFL).

[0059] Control begins in S200 and proceeds to S202. In S202, control module 26 determines the A2L refrigerant level (e.g., a measurement from sensor 30). The A2L refrigerant level may reflect the amount (e.g., concentration) of A2L refrigerant at sensor 30.

[0060] In S204, control module 26 determines whether a mitigating event has occurred. If a mitigating event has occurred, control continues to S206. If a mitigating event has not occurred, control proceeds to S216, which is further described below.

[0061] In S206, control module 26 determines whether the A2L refrigerant level (as measured by sensor 30) is below a predetermined de-rate shutoff level. If S206 is false, control may return to S200. If S206 is true, control may continue to S208.

[0062] In S208, the control module 26 turns on the whole house blower (e.g., fan 24) and begins incrementing a fan operation timer. In S210, the control module 26 determines whether the whole house blower has been on for a predetermined period of time (e.g., whether the fan operation timer is equal to or greater than a predetermined value). The predetermined period of time may be, for example, about five minutes or another suitable period of time. If S210 is false, the control module 26 leaves the whole house blower on and control returns to S200. If S210 is true, control continues to S212.

[0063] In S212, control module 26 determines whether the A2L refrigerant level is greater than (or equal to) a predetermined lockout level. The predetermined lockout level may be calibrated and may be, for example, 25% of the LFL of the refrigerant or another suitable value. .

[0064] If S212 is true, control continues to S213 where the control module 26 disables the compressor and maintains the lockout of the refrigeration system 10 until a manual reset is received, such as from a contractor or building owner or operator. If S212 is false, the control module 26 automatically resets the refrigeration system 10 in S224, allowing the compressor 12 to turn on again (e.g., as required by the thermostat). Control returns to S200.

[0065] Returning to S216, (when S204 is false and an abatement event has not occurred) control module 26 determines whether the A2L refrigerant level measured by sensor 30 is greater than a predetermined abatement start level. If S216 is true, control continues to S218 where the compressor is locked out from operating. If S216 is false, control passes to S222.

[0066] At S218, the control module 26 locks out the compressor 12, thereby preventing the compressor 12 from being turned on (e.g., despite a request from a thermostat). At S220, the control module 26 turns on the entire house blower (e.g., fan 24). At S222, the control module 26 allows the refrigeration system 10 to operate in a normal operating mode (e.g., turning the compressor on and off based on requests from a thermostat, etc.).

[0067] 4 is a functional block diagram of an exemplary control system. A fan module 404 controls the operation (e.g., on, off, speed) of the fan 24 as described above. A compressor module 408 controls the operation (e.g., on, off, speed, capacity, etc.) of the compressor 12 as described above. A lockout module 412 controls the operation of a lockout device as described above. The lockout module 412 may also control the lockout of the compressor 12 as described above.

[0068] The leak module 436 determines whether there is a leak (i.e., refrigerant is leaking from the refrigeration system in the building) based on the A2L refrigerant level (e.g., measured by the leak sensor 30). Alternatively, the A2L refrigerant level may be determined based on one or more other measured parameters. For example, the leak module 436 may determine that there is a leak when the A2L refrigerant level is greater than a predetermined de-mitigation level. The leak module 436 may determine that the leak is mitigated (no leak) when the A2L refrigerant level is less than a predetermined de-mitigation level.

[0069] The leakage module 436 generates a signal indicative of whether there is leakage based on the For example, the leakage module 436 may set the signal to a first state when there is leakage and set the signal to a second state when there is no leakage.

[0070] If there is a leak, one or more corrective actions may be taken. For example, the fan module 404 may turn on the fan 24 when there is a leak, as described above. Additionally, the compressor module 408 may turn off the compressor 12 and keep it off until the leak is remedied, as described above. However, the compressor module 408 may keep the compressor 12 off when the mitigation on counter is equal to or greater than a predetermined value or the A2L refrigerant level is equal to or greater than a predetermined lockout level. Additionally, the lockout module 412 may activate the lockout device 32 to prevent ignition by one or more ignition devices in the building. The lockout module 412 may maintain the state of the lockout device 32 for a predetermined period of time, such as to allow the refrigerant leak to dissipate.

[0071] Additionally, the alarm module 440 may generate one or more indicators when there is a leak. For example, the alarm module 440 may send an indicator to one or more external devices 444, generate one or more visual indicators 448 (e.g., turning on one or more lights, displaying information on one or more displays, etc.), and / or generate one or more audible indicators, such as via one or more speakers 452.

[0072] The foregoing description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure may be embodied in various forms. Thus, while the disclosure includes certain examples, the true scope of the disclosure should not be so limited, since other modifications will become apparent upon study of the drawings, specification, and claims. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without altering the principles of the disclosure. Furthermore, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure may be realized in other embodiments and / or combined with any feature of the other embodiments, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitution of one or more embodiments with each other remains within the scope of the disclosure.

[0073] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using a variety of terms, including "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Unless expressly described as "direct," when a relationship between a first element and a second element is described in the disclosure above, the relationship may be a direct relationship where there are no other intervening elements between the first element and the second element, but it may also be an indirect relationship where there are one or more intervening elements (either spatially or functionally) between the first element and the second element. As used herein, the phrase at least one of A, B, and C should be interpreted to mean logical (A or B or C) using a non-exclusive logical OR, and not to mean "at least one of A, at least one of B, and at least one of C."

[0074] In the figures, the direction of the arrow, indicated by the arrowhead, generally indicates the flow of information (such as data or instructions) that is of interest to the illustration. For example, an arrow may point from element A to element B if element A and element B exchange various information, but the information sent from element A to element B is relevant to the illustration. This unidirectional arrow does not imply that there is no other information sent from element B to element A. Furthermore, for information sent from element A to element B, element B may send element A a request for that information or an acknowledgment of receipt of that information.

[0075] In this application, the term "module" or "control module" may be substituted for the term "circuitry", including the following definitions: The term "module" may refer to, be a part of, or include an application specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinatorial logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system on a chip.

[0076] A module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that connect to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules that are connected via interface circuits. For example, multiple modules may enable load balancing. In a further example, a server (also known as remote or cloud) module may accomplish some functionality on behalf of a client module.

[0077] The term code as used above may include software, firmware, and / or microcode and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple modules. The term group processor circuit encompasses a processor circuit that executes some or all code from one or more modules in combination with additional processor circuits. References to multiple processor circuits encompass multiple processor circuits on separate dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or combinations of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple modules. The term group memory circuit encompasses a memory circuit that stores some or all code from one or more modules in combination with additional memory.

[0078] The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not encompass a transitory electric or electromagnetic signal propagating through a medium (such as on a carrier wave), and therefore the term computer-readable medium may be considered to be tangible and non-transient. Non-limiting examples of non-transient tangible computer-readable media are non-volatile memory circuits (e.g., flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (e.g., static random access memory circuits or dynamic random access memory circuits), magnetic storage media (e.g., analog or digital magnetic tape or hard disk drives), and optical storage media (e.g., CDs, DVDs, Blu-ray disks, etc.).

[0079] The apparatus and methods described herein may be implemented in part or in whole by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The functional blocks, flow chart components, and other elements described above serve as software specifications, which may be converted into a computer program by the routine work of a skilled technician or programmer.

[0080] A computer program includes processor-executable instructions stored on at least one non-transitory tangible computer-readable medium. A computer program may also include or rely on stored data. A computer program may encompass a basic input / output system (BIOS) that interacts with the hardware of a special-purpose computer, device drivers that interact with specific devices of a special-purpose computer, one or more operating systems, user applications, background services, background applications, and the like.

[0081] The computer program is (i) HTML (HyperText Markup Language); The source code may include descriptive text to be parsed, such as XML (Extensible Markup Language) or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. By way of example only, the source code may include C, C++, C#, Objective C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language Fifth Revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB®, SIMULINK®, and the like. ), and may be written using syntax from languages ​​including Python®. .

Claims

1. 1. A building refrigeration system comprising: a compressor module configured to continuously maintain a compressor of the refrigeration system off for at least a predetermined period of time in response to determining that an amount of refrigerant of the refrigeration system present outside the building refrigeration system is greater than a first predetermined amount; a fan module configured to, in response to determining that the amount of the refrigerant present outside the refrigeration system in the building is greater than the first predetermined amount, keep a fan on continuously for at least the predetermined period of time; the fan moves air across an evaporator of the refrigeration system when the fan is on; the compressor module is further configured to selectively turn on the compressor after the compressor has been off for the predetermined period of time without receiving an input indicating a reset of the refrigeration system and an amount of refrigerant present outside the refrigeration system in the building is less than a second predetermined amount.

2. The refrigeration system of claim 1 , further comprising a sensor configured to measure the amount of the refrigerant present outside the refrigeration system within the building.

3. The refrigeration system of claim 2 , wherein the sensor is disposed adjacent to the evaporator.

4. 2. The refrigeration system of claim 1, wherein the second predetermined amount is less than the first predetermined amount.

5. 2. The refrigeration system of claim 1, wherein the refrigerant has an ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) classification of A2L.

6. 2. The refrigeration system of claim 1, wherein the compressor module is configured to maintain the compressor off when a number of events in which the amount of the refrigerant present outside the refrigeration system in the building is greater than the first predetermined amount is greater than a predetermined number of events until the input indicating the reset of the refrigeration system is received.

7. The refrigeration system of claim 6 , wherein the predetermined number of events is an integer greater than one.

8. 2. The refrigeration system of claim 1, wherein the compressor module is configured to keep the compressor off when the amount of the refrigerant present outside the refrigeration system in the building exceeds a third predetermined amount until the input indicating the reset of the refrigeration system is received.

9. 9. The refrigeration system of claim 8, wherein the third predetermined amount is greater than the second predetermined amount.

10. 9. The refrigeration system of claim 8, wherein the third predetermined amount is at least 20 percent of a lower flammable limit (LFL) of the refrigerant.

11. 10. The refrigeration system of claim 1, further comprising a lockout module configured to prevent one or more ignition devices from igniting for at least the predetermined period of time in response to determining that the amount of refrigerant present outside the refrigeration system in the building is greater than the first predetermined amount.

12. 1. A method comprising: The amount of refrigerant in the refrigeration system present outside the refrigeration system in the building is greater than a first predetermined amount. continuously maintaining a compressor of the refrigeration system off for at least a predetermined period of time in response to determining that the temperature is greater than the predetermined temperature. and in response to determining that the amount of the refrigerant present outside the refrigeration system in the building is greater than the first predetermined amount, maintaining a fan on continuously for at least the predetermined period of time; The fan moves air across an evaporator of the refrigeration system when the fan is on, and the method further comprises: selectively turning on the compressor after the compressor has been off for the predetermined period of time without receiving an input indicating a reset of the refrigeration system and an amount of refrigerant present outside the refrigeration system in the building is less than a second predetermined amount.

13. The method of claim 12 , further comprising using a sensor to measure the amount of the refrigerant present outside the refrigeration system in the building.

14. The method of claim 13 , wherein the sensor is disposed adjacent to the evaporator.

15. The method of claim 12 , wherein the second predetermined amount is less than the first predetermined amount.

16. 13. The method of claim 12, wherein maintaining the compressor off includes maintaining the compressor off when a number of events in which the amount of the refrigerant present outside the refrigeration system in the building is greater than the first predetermined amount is greater than a predetermined number of events until the input indicating the reset of the refrigeration system is received.

17. 13. The method of claim 12, wherein maintaining the compressor off includes maintaining the compressor off when the amount of the refrigerant present outside the refrigeration system in the building exceeds a third predetermined amount until the input indicating the reset of the refrigeration system is received.

18. The method of claim 17 , wherein the third predetermined amount is greater than the second predetermined amount.

19. 20. The method of claim 17, wherein the third predetermined amount is at least 20 percent of a lower flammable limit (LFL) of the refrigerant.

20. 13. The method of claim 12, further comprising, in response to determining that the amount of the refrigerant present outside the refrigeration system in the building is greater than the first predetermined amount, preventing one or more ignition devices from igniting for at least the predetermined period of time.

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